Single Marker and Haplotype-Based Association Analysis of Semolina and Pasta Colour in Elite Durum Wheat Breeding Lines Using a High-Density Consensus Map.

PubMed

N'Diaye, Amidou; Haile, Jemanesh K; Cory, Aron T; Clarke, Fran R; Clarke, John M; Knox, Ron E; Pozniak, Curtis J

2017-01-01

Association mapping is usually performed by testing the correlation between a single marker and phenotypes. However, because patterns of variation within genomes are inherited as blocks, clustering markers into haplotypes for genome-wide scans could be a worthwhile approach to improve statistical power to detect associations. The availability of high-density molecular data allows the possibility to assess the potential of both approaches to identify marker-trait associations in durum wheat. In the present study, we used single marker- and haplotype-based approaches to identify loci associated with semolina and pasta colour in durum wheat, the main objective being to evaluate the potential benefits of haplotype-based analysis for identifying quantitative trait loci. One hundred sixty-nine durum lines were genotyped using the Illumina 90K Infinium iSelect assay, and 12,234 polymorphic single nucleotide polymorphism (SNP) markers were generated and used to assess the population structure and the linkage disequilibrium (LD) patterns. A total of 8,581 SNPs previously localized to a high-density consensus map were clustered into 406 haplotype blocks based on the average LD distance of 5.3 cM. Combining multiple SNPs into haplotype blocks increased the average polymorphism information content (PIC) from 0.27 per SNP to 0.50 per haplotype. The haplotype-based analysis identified 12 loci associated with grain pigment colour traits, including the five loci identified by the single marker-based analysis. Furthermore, the haplotype-based analysis resulted in an increase of the phenotypic variance explained (50.4% on average) and the allelic effect (33.7% on average) when compared to single marker analysis. The presence of multiple allelic combinations within each haplotype locus offers potential for screening the most favorable haplotype series and may facilitate marker-assisted selection of grain pigment colour in durum wheat. These results suggest a benefit of haplotype-based analysis over single marker analysis to detect loci associated with colour traits in durum wheat.

Selection for population-specific adaptation shaped patterns of variation in the photoperiod pathway genes in Arabidopsis lyrata during post-glacial colonization.

PubMed

Mattila, Tiina M; Aalto, Esa A; Toivainen, Tuomas; Niittyvuopio, Anne; Piltonen, Susanna; Kuittinen, Helmi; Savolainen, Outi

2016-01-01

Spatially varying selection can lead to population-specific adaptation, which is often recognized at the phenotypic level; however, the genetic evidence is weaker in many groups of organisms. In plants, environmental shifts that occur due to colonization of a novel environment may require adaptive changes in the timing of growth and flowering, which are often governed by location-specific environmental cues such as day length. We studied locally varying selection in 19 flowering time loci in nine populations of the perennial herb Arabidopsis lyrata, which has a wide but patchy distribution in temperate and boreal regions of the northern hemisphere. The populations differ in their recent population demographic and colonization histories and current environmental conditions, especially in the growing season length. We searched for population-specific molecular signatures of directional selection by comparing a set of candidate flowering time loci with a genomic reference set within each population using multiple approaches and contrasted the patterns of different populations. The candidate loci possessed approximately 20% of the diversity of the reference loci. On average the flowering time loci had more rare alleles (a smaller Tajima's D) and an excess of highly differentiated sites relative to the reference, suggesting positive selection. The strongest signal of selection was detected in photoperiodic pathway loci in the colonizing populations of Northwestern Europe, whereas no evidence of positive selection was detected in the Central European populations. These findings emphasized the population-specific nature of selection and suggested that photoperiodic adaptation was important during postglacial colonization of the species. © 2015 John Wiley & Sons Ltd.

[Molecular-genetic characteristics of Mycobacterium tuberculosis strains isolated from patients with tuberculous spondylitis].

PubMed

Viazovaia, A A; Solov'eva, N S; Zhuravlev, V Iu; Mokrousov, I V; Manicheva, O A; Vishnevskiĭ, B I; Narvskaia, O V

2013-01-01

Molecular-genetic characteristic of M. tuberculosis strains isolated from operation material of patients with tuberculous spondylitis. 107 strains of M. tuberculosis isolated in 2007 - 2011 from patients with spine tuberculosis were studied by methods of spoligotyping and MIRU-VNTR by 12 and 24 loci. Strains of genetic family Beijing dominated (n = 80), 78% of those had multiple drug resistance (MDR). Strains of genetic families T, H3 (Ural), LAM, Manu, H4 and S were also detected. Differentiating of 80 strains of Beijing genotype by MIRU-VNTR method by 24 loci revealed 24 variants (HGI = 0.83) including 7 clusters, the largest of those (100-32) included 23 strains (87% MDR). The leading role of Beijing genotype M. tuberculosis strains in development of tuberculous spondylitis with multiple drug resistance of the causative agent is shown.

Characterization and Mapping of Leaf Rust and Stripe Rust Resistance Loci in Hexaploid Wheat Lines UC1110 and PI610750 under Mexican Environments.

PubMed

Lan, Caixia; Hale, Iago L; Herrera-Foessel, Sybil A; Basnet, Bhoja R; Randhawa, Mandeep S; Huerta-Espino, Julio; Dubcovsky, Jorge; Singh, Ravi P

2017-01-01

Growing resistant wheat varieties is a key method of minimizing the extent of yield losses caused by the globally important wheat leaf rust (LR) and stripe rust (YR) diseases. In this study, a population of 186 F 8 recombinant inbred lines (RILs) derived from a cross between a synthetic wheat derivative (PI610750) and an adapted common wheat line (cv. "UC1110") were phenotyped for LR and YR response at both seedling and adult plant stages over multiple seasons. Using a genetic linkage map consisting of single sequence repeats and diversity arrays technology markers, in combination with inclusive composite interval mapping analysis, we detected a new LR adult plant resistance (APR) locus, QLr.cim-2DS , contributed by UC1110. One co-located resistance locus to both rusts, QLr.cim-3DC/QYr.cim-3DC , and the known seedling resistance gene Lr26 were also mapped. QLr.cim-2DS and QLr.cim-3DC showed a marginally significant interaction for LR resistance in the adult plant stage. In addition, two previously reported YR APR loci, QYr.ucw-3BS and Yr48 , were found to exhibit stable performances in rust environments in both Mexico and the United States and showed a highly significant interaction in the field. Yr48 was also observed to confer intermediate seedling resistance against Mexican YR races, thus suggesting it should be re-classified as an all-stage resistance gene. We also identified 5 and 2 RILs that possessed all detected YR and LR resistance loci, respectively. With the closely linked molecular markers reported here, these RILs could be used as donors for multiple resistance loci to both rusts in wheat breeding programs.

Background controlled QTL mapping in pure-line genetic populations derived from four-way crosses

PubMed Central

Zhang, S; Meng, L; Wang, J; Zhang, L

2017-01-01

Pure lines derived from multiple parents are becoming more important because of the increased genetic diversity, the possibility to conduct replicated phenotyping trials in multiple environments and potentially high mapping resolution of quantitative trait loci (QTL). In this study, we proposed a new mapping method for QTL detection in pure-line populations derived from four-way crosses, which is able to control the background genetic variation through a two-stage mapping strategy. First, orthogonal variables were created for each marker and used in an inclusive linear model, so as to completely absorb the genetic variation in the mapping population. Second, inclusive composite interval mapping approach was implemented for one-dimensional scanning, during which the inclusive linear model was employed to control the background variation. Simulation studies using different genetic models demonstrated that the new method is efficient when considering high detection power, low false discovery rate and high accuracy in estimating quantitative trait loci locations and effects. For illustration, the proposed method was applied in a reported wheat four-way recombinant inbred line population. PMID:28722705

Background controlled QTL mapping in pure-line genetic populations derived from four-way crosses.

PubMed

Zhang, S; Meng, L; Wang, J; Zhang, L

2017-10-01

Pure lines derived from multiple parents are becoming more important because of the increased genetic diversity, the possibility to conduct replicated phenotyping trials in multiple environments and potentially high mapping resolution of quantitative trait loci (QTL). In this study, we proposed a new mapping method for QTL detection in pure-line populations derived from four-way crosses, which is able to control the background genetic variation through a two-stage mapping strategy. First, orthogonal variables were created for each marker and used in an inclusive linear model, so as to completely absorb the genetic variation in the mapping population. Second, inclusive composite interval mapping approach was implemented for one-dimensional scanning, during which the inclusive linear model was employed to control the background variation. Simulation studies using different genetic models demonstrated that the new method is efficient when considering high detection power, low false discovery rate and high accuracy in estimating quantitative trait loci locations and effects. For illustration, the proposed method was applied in a reported wheat four-way recombinant inbred line population.

SCOPA and META-SCOPA: software for the analysis and aggregation of genome-wide association studies of multiple correlated phenotypes.

PubMed

Mägi, Reedik; Suleimanov, Yury V; Clarke, Geraldine M; Kaakinen, Marika; Fischer, Krista; Prokopenko, Inga; Morris, Andrew P

2017-01-11

Genome-wide association studies (GWAS) of single nucleotide polymorphisms (SNPs) have been successful in identifying loci contributing genetic effects to a wide range of complex human diseases and quantitative traits. The traditional approach to GWAS analysis is to consider each phenotype separately, despite the fact that many diseases and quantitative traits are correlated with each other, and often measured in the same sample of individuals. Multivariate analyses of correlated phenotypes have been demonstrated, by simulation, to increase power to detect association with SNPs, and thus may enable improved detection of novel loci contributing to diseases and quantitative traits. We have developed the SCOPA software to enable GWAS analysis of multiple correlated phenotypes. The software implements "reverse regression" methodology, which treats the genotype of an individual at a SNP as the outcome and the phenotypes as predictors in a general linear model. SCOPA can be applied to quantitative traits and categorical phenotypes, and can accommodate imputed genotypes under a dosage model. The accompanying META-SCOPA software enables meta-analysis of association summary statistics from SCOPA across GWAS. Application of SCOPA to two GWAS of high-and low-density lipoprotein cholesterol, triglycerides and body mass index, and subsequent meta-analysis with META-SCOPA, highlighted stronger association signals than univariate phenotype analysis at established lipid and obesity loci. The META-SCOPA meta-analysis also revealed a novel signal of association at genome-wide significance for triglycerides mapping to GPC5 (lead SNP rs71427535, p = 1.1x10 -8 ), which has not been reported in previous large-scale GWAS of lipid traits. The SCOPA and META-SCOPA software enable discovery and dissection of multiple phenotype association signals through implementation of a powerful reverse regression approach.

Understanding genetic control of root system architecture in soybean: Insights into the genetic basis of lateral root number.

PubMed

Prince, Silvas J; Valliyodan, Babu; Ye, Heng; Yang, Ming; Tai, Shuaishuai; Hu, Wushu; Murphy, Mackensie; Durnell, Lorellin A; Song, Li; Joshi, Trupti; Liu, Yang; Van de Velde, Jan; Vandepoele, Klaas; Grover Shannon, J; Nguyen, Henry T

2018-05-10

Developing crops with better root systems is a promising strategy to ensure productivity in both optimum and stress environments. Root system architectural (RSA) traits in 397 soybean accessions were characterized and a high-density single nucleotide polymorphisms (SNP) based genome-wide association study was performed to identify the underlying genes associated with root structure. SNPs associated with root architectural traits specific to landraces and elite germplasm pools were detected. Four loci were detected in landraces for lateral root number (LRN) and distribution of root thickness in diameter class I with a major locus on chromosome 16. This major loci was detected in the coding region of unknown protein, and subsequent analyses demonstrated that root traits are affected with mutated haplotypes of the gene. In elite germplasm pool, three significant SNPs in alanine-glyoxalate aminotransferase, Leucine-Rich Repeat receptor/No apical meristem and unknown functional genes were found to govern multiple traits including root surface area and volume. However, no major loci were detected for LRN in elite germplasm. Nucleotide diversity analysis found evidence of selective sweeps around the landraces LRN gene. Soybean accessions with minor and mutated allelic variants of LRN gene were found to perform better in both water-limited and optimal field conditions. This article is protected by copyright. All rights reserved.

Use of qualitative environmental and phenotypic variables in the context of allele distribution models: detecting signatures of selection in the genome of Lake Victoria cichlids.

PubMed

Joost, Stéphane; Kalbermatten, Michael; Bezault, Etienne; Seehausen, Ole

2012-01-01

When searching for loci possibly under selection in the genome, an alternative to population genetics theoretical models is to establish allele distribution models (ADM) for each locus to directly correlate allelic frequencies and environmental variables such as precipitation, temperature, or sun radiation. Such an approach implementing multiple logistic regression models in parallel was implemented within a computing program named MATSAM: . Recently, this application was improved in order to support qualitative environmental predictors as well as to permit the identification of associations between genomic variation and individual phenotypes, allowing the detection of loci involved in the genetic architecture of polymorphic characters. Here, we present the corresponding methodological developments and compare the results produced by software implementing population genetics theoretical models (DFDIST: and BAYESCAN: ) and ADM (MATSAM: ) in an empirical context to detect signatures of genomic divergence associated with speciation in Lake Victoria cichlid fishes.

Population genetic data of the AmpFℓSTR® Identifiler® Plus and PowerPlex® 16 HS STR loci in four Canadian populations.

PubMed

Laurin, Nancy; Milot, Emmanuel

2014-03-01

Allele frequencies and forensically relevant population statistics were estimated for the short tandem repeat (STR) loci of the AmpFℓSTR® Identifiler® Plus and PowerPlex® 16 HS amplification kits, including D2S1338, D19S433, Penta D, and Penta E, for three First Nations Aboriginal populations and for Caucasians in Canada. The cumulative power of discrimination was ≥ 0.999999999999984 and the cumulative power of exclusion was ≥ 0.999929363 for both amplification systems in all populations. No significant departure from Hardy-Weinberg equilibrium was detected for D2S1338, D19S433, Penta D, and Penta E or the 13 Combined DNA Index System core STR loci after correction for multiple testing. Significant genetic diversity was observed between these four populations. Comparison with published frequency data for other populations is also presented.

Dynamic of mutational events in variable number tandem repeats of Escherichia coli O157:H7.

PubMed

Bustamante, A V; Sanso, A M; Segura, D O; Parma, A E; Lucchesi, P M A

2013-01-01

VNTRs regions have been successfully used for bacterial subtyping; however, the hypervariability in VNTR loci is problematic when trying to predict the relationships among isolates. Since few studies have examined the mutation rate of these markers, our aim was to estimate mutation rates of VNTRs specific for verotoxigenic E. coli O157:H7. The knowledge of VNTR mutational rates and the factors affecting them would make MLVA more effective for epidemiological or microbial forensic investigations. For this purpose, we analyzed nine loci performing parallel, serial passage experiments (PSPEs) on 9 O157:H7 strains. The combined 9 PSPE population rates for the 8 mutating loci ranged from 4.4 × 10(-05) to 1.8 × 10(-03) mutations/generation, and the combined 8-loci mutation rate was of 2.5 × 10(-03) mutations/generation. Mutations involved complete repeat units, with only one point mutation detected. A similar proportion between single and multiple repeat changes was detected. Of the 56 repeat mutations, 59% were insertions and 41% were deletions, and 72% of the mutation events corresponded to O157-10 locus. For alleles with up to 13 UR, a constant and low mutation rate was observed; meanwhile longer alleles were associated with higher and variable mutation rates. Our results are useful to interpret data from microevolution and population epidemiology studies and particularly point out that the inclusion or not of O157-10 locus or, alternatively, a differential weighting data according to the mutation rates of loci must be evaluated in relation with the objectives of the proposed study.

Identification of quantitative trait loci influencing wood specific gravity in an outbred pedigree of loblolly pine

Treesearch

A. Groover; M. Devey; T. Fiddler; J. Lee; R. Megraw; T. Mitchel-Olds; B. Sherman; S. Vujcic; C. Williams; D. Neale

1994-01-01

We report the identification of quantitative trait loci (QTL) influencing wood specific gravity (WSG) in an outbred pedigree of loblolly pine (Pinus taeda L.) . QTL mapping in an outcrossing species is complicated by the presence of multiple alleles (>2) at QTL and marker loci. Multiple alleles at QTL allow the examination of interaction among...

Single Marker and Haplotype-Based Association Analysis of Semolina and Pasta Colour in Elite Durum Wheat Breeding Lines Using a High-Density Consensus Map

PubMed Central

Haile, Jemanesh K.; Cory, Aron T.; Clarke, Fran R.; Clarke, John M.; Knox, Ron E.; Pozniak, Curtis J.

2017-01-01

Association mapping is usually performed by testing the correlation between a single marker and phenotypes. However, because patterns of variation within genomes are inherited as blocks, clustering markers into haplotypes for genome-wide scans could be a worthwhile approach to improve statistical power to detect associations. The availability of high-density molecular data allows the possibility to assess the potential of both approaches to identify marker-trait associations in durum wheat. In the present study, we used single marker- and haplotype-based approaches to identify loci associated with semolina and pasta colour in durum wheat, the main objective being to evaluate the potential benefits of haplotype-based analysis for identifying quantitative trait loci. One hundred sixty-nine durum lines were genotyped using the Illumina 90K Infinium iSelect assay, and 12,234 polymorphic single nucleotide polymorphism (SNP) markers were generated and used to assess the population structure and the linkage disequilibrium (LD) patterns. A total of 8,581 SNPs previously localized to a high-density consensus map were clustered into 406 haplotype blocks based on the average LD distance of 5.3 cM. Combining multiple SNPs into haplotype blocks increased the average polymorphism information content (PIC) from 0.27 per SNP to 0.50 per haplotype. The haplotype-based analysis identified 12 loci associated with grain pigment colour traits, including the five loci identified by the single marker-based analysis. Furthermore, the haplotype-based analysis resulted in an increase of the phenotypic variance explained (50.4% on average) and the allelic effect (33.7% on average) when compared to single marker analysis. The presence of multiple allelic combinations within each haplotype locus offers potential for screening the most favorable haplotype series and may facilitate marker-assisted selection of grain pigment colour in durum wheat. These results suggest a benefit of haplotype-based analysis over single marker analysis to detect loci associated with colour traits in durum wheat. PMID:28135299

Meta-analysis of correlated traits via summary statistics from GWASs with an application in hypertension.

PubMed

Zhu, Xiaofeng; Feng, Tao; Tayo, Bamidele O; Liang, Jingjing; Young, J Hunter; Franceschini, Nora; Smith, Jennifer A; Yanek, Lisa R; Sun, Yan V; Edwards, Todd L; Chen, Wei; Nalls, Mike; Fox, Ervin; Sale, Michele; Bottinger, Erwin; Rotimi, Charles; Liu, Yongmei; McKnight, Barbara; Liu, Kiang; Arnett, Donna K; Chakravati, Aravinda; Cooper, Richard S; Redline, Susan

2015-01-08

Genome-wide association studies (GWASs) have identified many genetic variants underlying complex traits. Many detected genetic loci harbor variants that associate with multiple-even distinct-traits. Most current analysis approaches focus on single traits, even though the final results from multiple traits are evaluated together. Such approaches miss the opportunity to systemically integrate the phenome-wide data available for genetic association analysis. In this study, we propose a general approach that can integrate association evidence from summary statistics of multiple traits, either correlated, independent, continuous, or binary traits, which might come from the same or different studies. We allow for trait heterogeneity effects. Population structure and cryptic relatedness can also be controlled. Our simulations suggest that the proposed method has improved statistical power over single-trait analysis in most of the cases we studied. We applied our method to the Continental Origins and Genetic Epidemiology Network (COGENT) African ancestry samples for three blood pressure traits and identified four loci (CHIC2, HOXA-EVX1, IGFBP1/IGFBP3, and CDH17; p < 5.0 × 10(-8)) associated with hypertension-related traits that were missed by a single-trait analysis in the original report. Six additional loci with suggestive association evidence (p < 5.0 × 10(-7)) were also observed, including CACNA1D and WNT3. Our study strongly suggests that analyzing multiple phenotypes can improve statistical power and that such analysis can be executed with the summary statistics from GWASs. Our method also provides a way to study a cross phenotype (CP) association by using summary statistics from GWASs of multiple phenotypes. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Genetic Analysis of the Pathogenic Molecular Sub-phenotype Interferon Alpha Identifies Multiple Novel Loci Involved in Systemic Lupus Erythematosus

PubMed Central

Kariuki, Silvia N.; Ghodke-Puranik, Yogita; Dorschner, Jessica M.; Chrabot, Beverly S.; Kelly, Jennifer A.; Tsao, Betty P.; Kimberly, Robert P.; Alarcón-Riquelme, Marta E.; Jacob, Chaim O.; Criswell, Lindsey A.; Sivils, Kathy L.; Langefeld, Carl D.; Harley, John B.; Skol, Andrew D.; Niewold, Timothy B.

2014-01-01

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disorder characterized by inflammation of multiple organ systems and dysregulated interferon responses. SLE is both genetically and phenotypically heterogeneous, greatly reducing the power of case-control studies in SLE. Elevated circulating interferon alpha (IFN-α) is a stable, heritable trait in SLE, which has been implicated in primary disease pathogenesis. 40–50% of patients have high IFN-α, and high levels correspond with clinical differences. To study genetic heterogeneity in SLE, we performed a case-case study comparing patients with high vs. low IFN-α in over 1550 SLE cases, including GWAS and replication cohorts. In meta-analysis, the top associations in European ancestry were PRKG1 rs7897633 (PMeta=2.75 × 10−8) and PNP rs1049564 (PMeta=1.24 × 10−7). We also found evidence for cross-ancestral background associations with the ANKRD44 and PLEKHF2 loci. These loci have not been previously identified in case-control SLE genetic studies. Bioinformatic analyses implicated these loci functionally in dendritic cells and natural killer cells, both of which are involved in IFN-α production in SLE. As case-control studies of heterogeneous diseases reach a limit of feasibility with respect to subject number and detectable effect size, the study of informative pathogenic subphenotypes becomes an attractive strategy for genetic discovery in complex disease. PMID:25338677

Digital detection of multiple minority mutants in stool DNA for noninvasive colorectal cancer diagnosis.

PubMed

Deng, Lili; Qi, Zongtai; Zou, Binjie; Wu, Haiping; Huang, Huan; Kajiyama, Tomoharu; Kambara, Hideki; Zhou, Guohua

2012-07-03

Somatic mutations in stool DNA are quite specific to colorectal cancer (CRC), but a method being able to detect the extraordinarily low amounts of mutants is challengeable in sensitivity. We proposed a hydrogel bead-array to digitally count CRC-specific mutants in stool at a low cost. At first, multiplex amplification of targets containing multiple mutation loci of interest is carried out by a target enriched multiplex PCR (Tem-PCR), yielding the templates qualified for emulsion PCR (emPCR). Then, after immobilizing the beads from emPCR on a glass surface, the incorporation of Cy3-dUTP into the mutant-specific probes, which are specifically hybridized with the amplified beads from emPCR, is used to color the beads coated with mutants. As all amplified beads are hybridized with the Cy5-labeled universal probe, a mutation rate is readily obtained by digitally counting the beads with different colors (yellow and red). A high specificity of the method is achieved by removing the mismatched probes in a bead-array with electrophoresis. The approach has been used to simultaneously detect 8 mutation loci within the APC, TP53, and KRAS genes in stools from eight CRC patients, and 50% of CRC patients were positively diagnosed; therefore, our method can be a potential tool for the noninvasive diagnosis of CRC.

Genetic analysis of autoimmune sialadenitis in nonobese diabetic mice: a major susceptibility region on chromosome 1.

PubMed

Boulard, Olivier; Fluteau, Guy; Eloy, Laure; Damotte, Diane; Bedossa, Pierre; Garchon, Henri-Jean

2002-04-15

The nonobese diabetic (NOD) mouse strain provides a good study model for Sjögren's syndrome (SS). The genetic control of SS was investigated in this model using different matings, including a (NOD x C57BL/6 (B6))F(2) cross, a (NOD x NZW)F(2) cross, and ((NOD x B6) x NOD) backcross. Multiple and different loci were detected depending on parent strain combination and sex. Despite significant complexity, two main features were prominent. First, the middle region of chromosome 1 (chr.1) was detected in all crosses. Its effect was most visible in the (NOD x B6)F(2) cross and dominated over that of other loci, including those mapping on chr.8, 9, 10, and 16; the effect of these minor loci was observed only in the absence of the NOD haplotype on chr.1. Most critically, the chr.1 region was sufficient to trigger an SS-like inflammatory infiltrate of salivary glands as shown by the study of a new C57BL/6 congenic strain carrying a restricted segment derived from NOD chr.1. Second, several chromosomal regions were previously associated with NOD autoimmune phenotypes, including Iddm (chr.1, 2, 3, 9, and 17, corresponding to Idd5, Idd13, Idd3, Idd2, and Idd1, respectively), accounting for the strong linkage previously reported between insulitis and sialitis, and autoantibody production (chr.10 and 16, corresponding to Bana2 and Bah2, respectively). Interestingly, only two loci were detected in the (NOD x NZW)F(2) cross, on chr.1 in females and on chr.7 in males, probably because of the latent autoimmune predisposition of the NZW strain. Altogether these findings reflect the complexity and heterogeneity of human SS.

APOE Modulates the Correlation Between Triglycerides, Cholesterol, and CHD Through Pleiotropy, and Gene-by-Gene Interactions

PubMed Central

Maxwell, Taylor J.; Ballantyne, Christie M.; Cheverud, James M.; Guild, Cameron S.; Ndumele, Chiadi E.; Boerwinkle, Eric

2013-01-01

Relationship loci (rQTL) exist when the correlation between multiple traits varies by genotype. rQTL often occur due to gene-by-gene (G × G) or gene-by-environmental interactions, making them a powerful tool for detecting G × G. Here we present an empirical analysis of apolipoprotein E (APOE) with respect to lipid traits and incident CHD leading to the discovery of loci that interact with APOE to affect these traits. We found that the relationship between total cholesterol (TC) and triglycerides (ln TG) varies by APOE isoform genotype in African-American (AA) and European-American (EA) populations. The e2 allele is associated with strong correlation between ln TG and TC while the e4 allele leads to little or no correlation. This led to a priori hypotheses that APOE genotypes affect the relationship of TC and/or ln TG with incident CHD. We found that APOE*TC was significant (P = 0.016) for AA but not EA while APOE*ln TG was significant for EA (P = 0.027) but not AA. In both cases, e2e2 and e2e3 had strong relationships between TC and ln TG with CHD while e2e4 and e4e4 results in little or no relationship between TC and ln TG with CHD. Using ARIC GWAS data, scans for loci that significantly interact with APOE produced four loci for African Americans (one CHD, one TC, and two HDL). These interactions contribute to the rQTL pattern. rQTL are a powerful tool to identify loci that modify the relationship between risk factors and disease and substantially increase statistical power for detecting G × G. PMID:24097412

Dynamic of Mutational Events in Variable Number Tandem Repeats of Escherichia coli O157:H7

PubMed Central

Bustamante, A. V.; Sanso, A. M.; Segura, D. O.; Parma, A. E.; Lucchesi, P. M. A.

2013-01-01

VNTRs regions have been successfully used for bacterial subtyping; however, the hypervariability in VNTR loci is problematic when trying to predict the relationships among isolates. Since few studies have examined the mutation rate of these markers, our aim was to estimate mutation rates of VNTRs specific for verotoxigenic E. coli O157:H7. The knowledge of VNTR mutational rates and the factors affecting them would make MLVA more effective for epidemiological or microbial forensic investigations. For this purpose, we analyzed nine loci performing parallel, serial passage experiments (PSPEs) on 9 O157:H7 strains. The combined 9 PSPE population rates for the 8 mutating loci ranged from 4.4 × 10−05 to 1.8 × 10−03 mutations/generation, and the combined 8-loci mutation rate was of 2.5 × 10−03 mutations/generation. Mutations involved complete repeat units, with only one point mutation detected. A similar proportion between single and multiple repeat changes was detected. Of the 56 repeat mutations, 59% were insertions and 41% were deletions, and 72% of the mutation events corresponded to O157-10 locus. For alleles with up to 13 UR, a constant and low mutation rate was observed; meanwhile longer alleles were associated with higher and variable mutation rates. Our results are useful to interpret data from microevolution and population epidemiology studies and particularly point out that the inclusion or not of O157-10 locus or, alternatively, a differential weighting data according to the mutation rates of loci must be evaluated in relation with the objectives of the proposed study. PMID:24093095

Cryptosporidium in fish: alternative sequencing approaches and analyses at multiple loci to resolve mixed infections.

PubMed

Paparini, Andrea; Yang, Rongchang; Chen, Linda; Tong, Kaising; Gibson-Kueh, Susan; Lymbery, Alan; Ryan, Una M

2017-11-01

Currently, the systematics, biology and epidemiology of piscine Cryptosporidium species are poorly understood. Here, we compared Sanger ‒ and next-generation ‒ sequencing (NGS), of piscine Cryptosporidium, at the 18S rRNA and actin genes. The hosts comprised 11 ornamental fish species, spanning four orders and eight families. The objectives were: to (i) confirm the rich genetic diversity of the parasite and the high frequency of mixed infections; and (ii) explore the potential of NGS in the presence of complex genetic mixtures. By Sanger sequencing, four main genotypes were obtained at the actin locus, while for the 18S locus, seven genotypes were identified. At both loci, NGS revealed frequent mixed infections, consisting of one highly dominant variant plus substantially rarer genotypes. Both sequencing methods detected novel Cryptosporidium genotypes at both loci, including a novel and highly abundant actin genotype that was identified by both Sanger sequencing and NGS. Importantly, this genotype accounted for 68·9% of all NGS reads from all samples (249 585/362 372). The present study confirms that aquarium fish can harbour a large and unexplored Cryptosporidium genetic diversity. Although commonly used in molecular parasitology studies, nested PCR prevents quantitative comparisons and thwarts the advantages of NGS, when this latter approach is used to investigate multiple infections.

Adaptive population divergence and directional gene flow across steep elevational gradients in a climate‐sensitive mammal

USGS Publications Warehouse

Waterhouse, Matthew D.; Erb, Liesl P.; Beever, Erik; Russello, Michael A.

2018-01-01

The American pika is a thermally sensitive, alpine lagomorph species. Recent climate-associated population extirpations and genetic signatures of reduced population sizes range-wide indicate the viability of this species is sensitive to climate change. To test for potential adaptive responses to climate stress, we sampled pikas along two elevational gradients (each ~470 to 1640 m) and employed three outlier detection methods, BAYESCAN, LFMM, and BAYPASS, to scan for genotype-environment associations in samples genotyped at 30,763 SNP loci. We resolved 173 loci with robust evidence of natural selection detected by either two independent analyses or replicated in both transects. A BLASTN search of these outlier loci revealed several genes associated with metabolic function and oxygen transport, indicating natural selection from thermal stress and hypoxia. We also found evidence of directional gene flow primarily downslope from large high-elevation populations and reduced gene flow at outlier loci, a pattern suggesting potential impediments to the upward elevational movement of adaptive alleles in response to contemporary climate change. Finally, we documented evidence of reduced genetic diversity associated the south-facing transect and an increase in corticosterone stress levels associated with inbreeding. This study suggests the American pika is already undergoing climate-associated natural selection at multiple genomic regions. Further analysis is needed to determine if the rate of climate adaptation in the American pika and other thermally sensitive species will be able to keep pace with rapidly changing climate conditions.

Multiple loci on 8q24 associated with prostate cancer susceptibility.

PubMed

Al Olama, Ali Amin; Kote-Jarai, Zsofia; Giles, Graham G; Guy, Michelle; Morrison, Jonathan; Severi, Gianluca; Leongamornlert, Daniel A; Tymrakiewicz, Malgorzata; Jhavar, Sameer; Saunders, Ed; Hopper, John L; Southey, Melissa C; Muir, Kenneth R; English, Dallas R; Dearnaley, David P; Ardern-Jones, Audrey T; Hall, Amanda L; O'Brien, Lynne T; Wilkinson, Rosemary A; Sawyer, Emma; Lophatananon, Artitaya; Horwich, Alan; Huddart, Robert A; Khoo, Vincent S; Parker, Christopher C; Woodhouse, Christopher J; Thompson, Alan; Christmas, Tim; Ogden, Chris; Cooper, Colin; Donovan, Jenny L; Hamdy, Freddie C; Neal, David E; Eeles, Rosalind A; Easton, Douglas F

2009-10-01

Previous studies have identified multiple loci on 8q24 associated with prostate cancer risk. We performed a comprehensive analysis of SNP associations across 8q24 by genotyping tag SNPs in 5,504 prostate cancer cases and 5,834 controls. We confirmed associations at three previously reported loci and identified additional loci in two other linkage disequilibrium blocks (rs1006908: per-allele OR = 0.87, P = 7.9 x 10(-8); rs620861: OR = 0.90, P = 4.8 x 10(-8)). Eight SNPs in five linkage disequilibrium blocks were independently associated with prostate cancer susceptibility.

Efficient Generation of Somatic Cell Nuclear Transfer-Competent Porcine Cells with Mutated Alleles at Multiple Target Loci by Using CRISPR/Cas9 Combined with Targeted Toxin-Based Selection System.

PubMed

Sato, Masahiro; Miyoshi, Kazuchika; Nakamura, Shingo; Ohtsuka, Masato; Sakurai, Takayuki; Watanabe, Satoshi; Kawaguchi, Hiroaki; Tanimoto, Akihide

2017-12-04

The recent advancement in genome editing such a CRISPR/Cas9 system has enabled isolation of cells with knocked multiple alleles through a one-step transfection. Somatic cell nuclear transfer (SCNT) has been frequently employed as one of the efficient tools for the production of genetically modified (GM) animals. To use GM cells as SCNT donor, efficient isolation of transfectants with mutations at multiple target loci is often required. The methods for the isolation of such GM cells largely rely on the use of drug selection-based approach using selectable genes; however, it is often difficult to isolate cells with mutations at multiple target loci. In this study, we used a novel approach for the efficient isolation of porcine cells with at least two target loci mutations by one-step introduction of CRISPR/Cas9-related components. A single guide (sg) RNA targeted to GGTA1 gene, involved in the synthesis of cell-surface α-Gal epitope (known as xenogenic antigen), is always a prerequisite. When the transfected cells were reacted with toxin-labeled BS-I-B₄ isolectin for 2 h at 37 C to eliminate α-Gal epitope-expressing cells, the surviving clones lacked α-Gal epitope expression and were highly expected to exhibit induced mutations at another target loci. Analysis of these α-Gal epitope-negative surviving cells demonstrated a 100% occurrence of genome editing at target loci. SCNT using these cells as donors resulted in the production of cloned blastocysts with the genotype similar to that of the donor cells used. Thus, this novel system will be useful for SCNT-mediated acquisition of GM cloned piglets, in which multiple target loci may be mutated.

Development of eighteen microsatellite loci in walleye (Sander vitreus)

USGS Publications Warehouse

Coykendall, D. Katharine; Morrison, Cheryl L.; Stott, Wendylee; Springmann, Marcus J.

2014-01-01

A suite of tri- and tetra-nucleotide microsatellite loci were developed for walleye (Sander vitreus) from 454 pyrosequencing data. Eighteen of the 50 primer sets tested amplified consistently in 35 walleye from two lakes on Isle Royale, Lake Superior: Chickenbone Lake and Whittlesey Lake. The loci displayed moderate levels of allelic diversity (average 5.5 alleles/locus) and heterozygosity (average 35.8 %). Levels of genetic diversity were sufficient to produce unique multi-locus genotypes and detect phylogeographic structuring as individuals assigned back to their population of origin. Cross-species amplification within S. canadensis(sauger) was successful for 15 loci, and 11 loci were diagnostic to species. The loci characterized here will be useful for detecting fine-scale spatial structuring, resolving the taxonomic status of Sander species and sub-species, and detecting walleye/sauger hybrids.

Mapping quantitative trait loci for yield, yield components and morphological traits in an advanced backcross population between Oryza rufipogon and the Oryza sativa cultivar Jefferson.

PubMed

Thomson, M J; Tai, T H; McClung, A M; Lai, X-H; Hinga, M E; Lobos, K B; Xu, Y; Martinez, C P; McCouch, S R

2003-08-01

An advanced backcross population between an accession of Oryza rufipogon (IRGC 105491) and the U.S. cultivar Jefferson (Oryza sativa ssp. japonica) was developed to identify quantitative trait loci (QTLs) for yield, yield components and morphological traits. The genetic linkage map generated for this population consisted of 153 SSR and RFLP markers with an average interval size of 10.3 cM. Thirteen traits were examined, nine of which were measured in multiple environments. Seventy-six QTLs above an experiment-wise significance threshold of P<0.01 (corresponding to an interval mapping LOD>3.6 or a composite interval mapping LOD>3.9) were identified. For the traits measured in multiple environments, 47% of the QTLs were detected in at least two environments. The O. rufipogon allele was favorable for 53% of the yield and yield component QTLs, including loci for yield, grains per panicle, panicle length, and grain weight. Morphological traits related to the domestication process and/or weedy characteristics, including plant height, shattering, tiller type and awns, were found clustered on chromosomes 1 and 4. Comparisons to previous studies involving wild x cultivated crosses revealed O. rufipogon alleles with stable effects in multiple genetic backgrounds and environments, several of which have not been detected in studies between Oryza sativa cultivars, indicating potentially novel alleles from O. rufipogon. Some O. rufipogon-derived QTLs, however, were in similar regions as previously reported QTLs from Oryza sativa cultivars, providing evidence for conservation of these QTLs across the Oryza genus. In addition, several QTLs for grain weight, plant height, and flowering time were localized to putative homeologous regions in maize where QTLs for these traits have been previously reported, supporting the hypothesis of functional conservation of QTLs across the grasses.

Global analysis of genes involved in freshwater adaptation in threespine sticklebacks (Gasterosteus aculeatus).

PubMed

DeFaveri, Jacquelin; Shikano, Takahito; Shimada, Yukinori; Goto, Akira; Merilä, Juha

2011-06-01

Examples of parallel evolution of phenotypic traits have been repeatedly demonstrated in threespine sticklebacks (Gasterosteus aculeatus) across their global distribution. Using these as a model, we performed a targeted genome scan--focusing on physiologically important genes potentially related to freshwater adaptation--to identify genetic signatures of parallel physiological evolution on a global scale. To this end, 50 microsatellite loci, including 26 loci within or close to (<6 kb) physiologically important genes, were screened in paired marine and freshwater populations from six locations across the Northern Hemisphere. Signatures of directional selection were detected in 24 loci, including 17 physiologically important genes, in at least one location. Although no loci showed consistent signatures of selection in all divergent population pairs, several outliers were common in multiple locations. In particular, seven physiologically important genes, as well as reference ectodysplasin gene (EDA), showed signatures of selection in three or more locations. Hence, although these results give some evidence for consistent parallel molecular evolution in response to freshwater colonization, they suggest that different evolutionary pathways may underlie physiological adaptation to freshwater habitats within the global distribution of the threespine stickleback. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

CASFISH: CRISPR/Cas9-mediated in situ labeling of genomic loci in fixed cells.

PubMed

Deng, Wulan; Shi, Xinghua; Tjian, Robert; Lionnet, Timothée; Singer, Robert H

2015-09-22

Direct visualization of genomic loci in the 3D nucleus is important for understanding the spatial organization of the genome and its association with gene expression. Various DNA FISH methods have been developed in the past decades, all involving denaturing dsDNA and hybridizing fluorescent nucleic acid probes. Here we report a novel approach that uses in vitro constituted nuclease-deficient clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated caspase 9 (Cas9) complexes as probes to label sequence-specific genomic loci fluorescently without global DNA denaturation (Cas9-mediated fluorescence in situ hybridization, CASFISH). Using fluorescently labeled nuclease-deficient Cas9 (dCas9) protein assembled with various single-guide RNA (sgRNA), we demonstrated rapid and robust labeling of repetitive DNA elements in pericentromere, centromere, G-rich telomere, and coding gene loci. Assembling dCas9 with an array of sgRNAs tiling arbitrary target loci, we were able to visualize nonrepetitive genomic sequences. The dCas9/sgRNA binary complex is stable and binds its target DNA with high affinity, allowing sequential or simultaneous probing of multiple targets. CASFISH assays using differently colored dCas9/sgRNA complexes allow multicolor labeling of target loci in cells. In addition, the CASFISH assay is remarkably rapid under optimal conditions and is applicable for detection in primary tissue sections. This rapid, robust, less disruptive, and cost-effective technology adds a valuable tool for basic research and genetic diagnosis.

[Application of multiple polymorphism genetic markers in determination of half sibling sharing a same mother].

PubMed

Que, Ting-zhi; Zhao, Shu-min; Li, Cheng-tao

2010-08-01

Determination strategies for half sibling sharing a same mother were investigated through the detection of autosomal and X-chromosomal STR (X-STR) loci and polymorphisms on hypervariable (HV) region of mitochondrial DNA (mtDNA). Genomic DNA were extracted from blood stain samples of the 3 full siblings and one dubious half sibling sharing the same mother with them. Fifteen autosomal STR loci were genotyped by Sinofiler kit, and 19 X-STR loci were genotyped by Mentype Argus X-8 kit and 16 plex in-house system. Polymorphisms of mtDNA HV-I and HV-II were also detected with sequencing technology. Full sibling relationship between the dubious half sibling and each of the 3 full siblings were excluded based on the results of autosomal STR genotyping and calculation of full sibling index (FSI) and half sibling index (HIS). Results of sequencing for mtDNA HV-I and HV-II showed that all of the 4 samples came from a same maternal line. X-STR genotyping results determined that the dubious half sibling shared a same mother with the 3 full siblings. It is reliable to combine three different genotyping technologies including autosomal STR, X-STR and sequencing of mtDNA HV-I and HV-II for determination of half sibling sharing a same mother.

Changes in Malaria Parasite Drug Resistance in an Endemic Population Over a 25-Year Period With Resulting Genomic Evidence of Selection

PubMed Central

Nwakanma, Davis C.; Duffy, Craig W.; Amambua-Ngwa, Alfred; Oriero, Eniyou C.; Bojang, Kalifa A.; Pinder, Margaret; Drakeley, Chris J.; Sutherland, Colin J.; Milligan, Paul J.; MacInnis, Bronwyn; Kwiatkowski, Dominic P.; Clark, Taane G.; Greenwood, Brian M.; Conway, David J.

2014-01-01

Background. Analysis of genome-wide polymorphism in many organisms has potential to identify genes under recent selection. However, data on historical allele frequency changes are rarely available for direct confirmation. Methods. We genotyped single nucleotide polymorphisms (SNPs) in 4 Plasmodium falciparum drug resistance genes in 668 archived parasite-positive blood samples of a Gambian population between 1984 and 2008. This covered a period before antimalarial resistance was detected locally, through subsequent failure of multiple drugs until introduction of artemisinin combination therapy. We separately performed genome-wide sequence analysis of 52 clinical isolates from 2008 to prospect for loci under recent directional selection. Results. Resistance alleles increased from very low frequencies, peaking in 2000 for chloroquine resistance-associated crt and mdr1 genes and at the end of the survey period for dhfr and dhps genes respectively associated with pyrimethamine and sulfadoxine resistance. Temporal changes fit a model incorporating likely selection coefficients over the period. Three of the drug resistance loci were in the top 4 regions under strong selection implicated by the genome-wide analysis. Conclusions. Genome-wide polymorphism analysis of an endemic population sample robustly identifies loci with detailed documentation of recent selection, demonstrating power to prospectively detect emerging drug resistance genes. PMID:24265439

An evolutionary reduction principle for mutation rates at multiple Loci.

PubMed

Altenberg, Lee

2011-06-01

A model of mutation rate evolution for multiple loci under arbitrary selection is analyzed. Results are obtained using techniques from Karlin (Evolutionary Biology, vol. 14, pp. 61-204, 1982) that overcome the weak selection constraints needed for tractability in prior studies of multilocus event models.A multivariate form of the reduction principle is found: reduction results at individual loci combine topologically to produce a surface of mutation rate alterations that are neutral for a new modifier allele. New mutation rates survive if and only if they fall below this surface-a generalization of the hyperplane found by Zhivotovsky et al. (Proc. Natl. Acad. Sci. USA 91, 1079-1083, 1994) for a multilocus recombination modifier. Increases in mutation rates at some loci may evolve if compensated for by decreases at other loci. The strength of selection on the modifier scales in proportion to the number of germline cell divisions, and increases with the number of loci affected. Loci that do not make a difference to marginal fitnesses at equilibrium are not subject to the reduction principle, and under fine tuning of mutation rates would be expected to have higher mutation rates than loci in mutation-selection balance.Other results include the nonexistence of 'viability analogous, Hardy-Weinberg' modifier polymorphisms under multiplicative mutation, and the sufficiency of average transmission rates to encapsulate the effect of modifier polymorphisms on the transmission of loci under selection. A conjecture is offered regarding situations, like recombination in the presence of mutation, that exhibit departures from the reduction principle. Constraints for tractability are: tight linkage of all loci, initial fixation at the modifier locus, and mutation distributions comprising transition probabilities of reversible Markov chains.

Multiple Genetic Associations with Irish Wolfhound Dilated Cardiomyopathy.

PubMed

Simpson, Siobhan; Dunning, Mark D; Brownlie, Serena; Patel, Janika; Godden, Megan; Cobb, Malcolm; Mongan, Nigel P; Rutland, Catrin S

2016-01-01

Cardiac disease is a leading cause of morbidity and mortality in dogs and humans, with dilated cardiomyopathy being a large contributor to this. The Irish Wolfhound (IWH) is one of the most commonly affected breeds and one of the few breeds with genetic loci associated with the disease. Mutations in more than 50 genes are associated with human dilated cardiomyopathy (DCM), yet very few are also associated with canine DCM. Furthermore, none of the identified canine loci explain many cases of the disease and previous work has indicated that genotypes at multiple loci may act together to influence disease development. In this study, loci previously associated with DCM in IWH were tested for associations in a new cohort both individually and in combination. We have identified loci significantly associated with the disease individually, but no genotypes individually or in pairs conferred a significantly greater risk of developing DCM than the population risk. However combining three loci together did result in the identification of a genotype which conferred a greater risk of disease than the overall population risk. This study suggests multiple rather than individual genetic factors, cooperating to influence DCM risk in IWH.

Multiple Genetic Associations with Irish Wolfhound Dilated Cardiomyopathy

PubMed Central

Dunning, Mark D.; Brownlie, Serena

2016-01-01

Cardiac disease is a leading cause of morbidity and mortality in dogs and humans, with dilated cardiomyopathy being a large contributor to this. The Irish Wolfhound (IWH) is one of the most commonly affected breeds and one of the few breeds with genetic loci associated with the disease. Mutations in more than 50 genes are associated with human dilated cardiomyopathy (DCM), yet very few are also associated with canine DCM. Furthermore, none of the identified canine loci explain many cases of the disease and previous work has indicated that genotypes at multiple loci may act together to influence disease development. In this study, loci previously associated with DCM in IWH were tested for associations in a new cohort both individually and in combination. We have identified loci significantly associated with the disease individually, but no genotypes individually or in pairs conferred a significantly greater risk of developing DCM than the population risk. However combining three loci together did result in the identification of a genotype which conferred a greater risk of disease than the overall population risk. This study suggests multiple rather than individual genetic factors, cooperating to influence DCM risk in IWH. PMID:28070514

Isolation and genotyping of Toxoplasma gondii from Ugandan chickens reveals frequent multiple infections.

PubMed

Lindström, I; Sundar, N; Lindh, J; Kironde, F; Kabasa, J D; Kwok, O C H; Dubey, J P; Smith, J E

2008-01-01

The genetic make-up of an infecting Toxoplasma gondii strain may be important for the outcome of infection and the risk of reactivation of chronic disease. In order to survey the distribution of different genotypes within an area, free-range chickens act as a good model species. In this study 85 chickens were used to investigate the prevalence, genotype and mouse virulence of T. gondii in Kampala, Uganda. Antibodies were detected in 40 chickens, of which 20 had MAT-titres of 1:20 or higher and were also positive by PCR. Genotyping of 5 loci (SAG1, SAG2, SAG3, BTUB and GRA6) showed that 6 strains belonged to genotype I, 8 to Type II and 1 to Type III. Five chickens had multiple infections; 3 individuals with Type I plus Type II and a further 2 harbouring Types I, II and III. Isolates were obtained from 9 chickens via bioassay in mice, 6 were Type II strains and 3 were from animals with mixed infection. This is the first set of African T. gondii strains to be genotyped at multiple loci and in addition to the 3 predominant lineages we found a small number of new polymorphisms and a high frequency of multiple infections.

Inferring genome-wide interplay landscape between DNA methylation and transcriptional regulation.

PubMed

Tang, Binhua; Wang, Xin

2015-01-01

DNA methylation and transcriptional regulation play important roles in cancer cell development and differentiation processes. Based on the currently available cell line profiling information from the ENCODE Consortium, we propose a Bayesian inference model to infer and construct genome-wide interaction landscape between DNA methylation and transcriptional regulation, which sheds light on the underlying complex functional mechanisms important within the human cancer and disease context. For the first time, we select all the currently available cell lines (>=20) and transcription factors (>=80) profiling information from the ENCODE Consortium portal. Through the integration of those genome-wide profiling sources, our genome-wide analysis detects multiple functional loci of interest, and indicates that DNA methylation is cell- and region-specific, due to the interplay mechanisms with transcription regulatory activities. We validate our analysis results with the corresponding RNA-sequencing technique for those detected genomic loci. Our results provide novel and meaningful insights for the interplay mechanisms of transcriptional regulation and gene expression for the human cancer and disease studies.

Effectively Identifying eQTLs from Multiple Tissues by Combining Mixed Model and Meta-analytic Approaches

PubMed Central

Choi, Ted; Eskin, Eleazar

2013-01-01

Gene expression data, in conjunction with information on genetic variants, have enabled studies to identify expression quantitative trait loci (eQTLs) or polymorphic locations in the genome that are associated with expression levels. Moreover, recent technological developments and cost decreases have further enabled studies to collect expression data in multiple tissues. One advantage of multiple tissue datasets is that studies can combine results from different tissues to identify eQTLs more accurately than examining each tissue separately. The idea of aggregating results of multiple tissues is closely related to the idea of meta-analysis which aggregates results of multiple genome-wide association studies to improve the power to detect associations. In principle, meta-analysis methods can be used to combine results from multiple tissues. However, eQTLs may have effects in only a single tissue, in all tissues, or in a subset of tissues with possibly different effect sizes. This heterogeneity in terms of effects across multiple tissues presents a key challenge to detect eQTLs. In this paper, we develop a framework that leverages two popular meta-analysis methods that address effect size heterogeneity to detect eQTLs across multiple tissues. We show by using simulations and multiple tissue data from mouse that our approach detects many eQTLs undetected by traditional eQTL methods. Additionally, our method provides an interpretation framework that accurately predicts whether an eQTL has an effect in a particular tissue. PMID:23785294

Multilocus lod scores in large pedigrees: combination of exact and approximate calculations.

PubMed

Tong, Liping; Thompson, Elizabeth

2008-01-01

To detect the positions of disease loci, lod scores are calculated at multiple chromosomal positions given trait and marker data on members of pedigrees. Exact lod score calculations are often impossible when the size of the pedigree and the number of markers are both large. In this case, a Markov Chain Monte Carlo (MCMC) approach provides an approximation. However, to provide accurate results, mixing performance is always a key issue in these MCMC methods. In this paper, we propose two methods to improve MCMC sampling and hence obtain more accurate lod score estimates in shorter computation time. The first improvement generalizes the block-Gibbs meiosis (M) sampler to multiple meiosis (MM) sampler in which multiple meioses are updated jointly, across all loci. The second one divides the computations on a large pedigree into several parts by conditioning on the haplotypes of some 'key' individuals. We perform exact calculations for the descendant parts where more data are often available, and combine this information with sampling of the hidden variables in the ancestral parts. Our approaches are expected to be most useful for data on a large pedigree with a lot of missing data. (c) 2007 S. Karger AG, Basel

Multilocus Lod Scores in Large Pedigrees: Combination of Exact and Approximate Calculations

PubMed Central

Tong, Liping; Thompson, Elizabeth

2007-01-01

To detect the positions of disease loci, lod scores are calculated at multiple chromosomal positions given trait and marker data on members of pedigrees. Exact lod score calculations are often impossible when the size of the pedigree and the number of markers are both large. In this case, a Markov Chain Monte Carlo (MCMC) approach provides an approximation. However, to provide accurate results, mixing performance is always a key issue in these MCMC methods. In this paper, we propose two methods to improve MCMC sampling and hence obtain more accurate lod score estimates in shorter computation time. The first improvement generalizes the block-Gibbs meiosis (M) sampler to multiple meiosis (MM) sampler in which multiple meioses are updated jointly, across all loci. The second one divides the computations on a large pedigree into several parts by conditioning on the haplotypes of some ‘key’ individuals. We perform exact calculations for the descendant parts where more data are often available, and combine this information with sampling of the hidden variables in the ancestral parts. Our approaches are expected to be most useful for data on a large pedigree with a lot of missing data. PMID:17934317

Genome wide analysis of flowering time trait in multiple environments via high-throughput genotyping technique in Brassica napus L.

PubMed

Li, Lun; Long, Yan; Zhang, Libin; Dalton-Morgan, Jessica; Batley, Jacqueline; Yu, Longjiang; Meng, Jinling; Li, Maoteng

2015-01-01

The prediction of the flowering time (FT) trait in Brassica napus based on genome-wide markers and the detection of underlying genetic factors is important not only for oilseed producers around the world but also for the other crop industry in the rotation system in China. In previous studies the low density and mixture of biomarkers used obstructed genomic selection in B. napus and comprehensive mapping of FT related loci. In this study, a high-density genome-wide SNP set was genotyped from a double-haploid population of B. napus. We first performed genomic prediction of FT traits in B. napus using SNPs across the genome under ten environments of three geographic regions via eight existing genomic predictive models. The results showed that all the models achieved comparably high accuracies, verifying the feasibility of genomic prediction in B. napus. Next, we performed a large-scale mapping of FT related loci among three regions, and found 437 associated SNPs, some of which represented known FT genes, such as AP1 and PHYE. The genes tagged by the associated SNPs were enriched in biological processes involved in the formation of flowers. Epistasis analysis showed that significant interactions were found between detected loci, even among some known FT related genes. All the results showed that our large scale and high-density genotype data are of great practical and scientific values for B. napus. To our best knowledge, this is the first evaluation of genomic selection models in B. napus based on a high-density SNP dataset and large-scale mapping of FT loci.

Identification of five novel modifier loci of ApcMin harbored in the BXH14 recombinant inbred strain

PubMed Central

Siracusa, Linda D.

2012-01-01

Every year thousands of people in the USA are diagnosed with small intestine and colorectal cancers (CRC). Although environmental factors affect disease etiology, uncovering underlying genetic factors is imperative for risk assessment and developing preventative therapies. Familial adenomatous polyposis is a heritable genetic disorder in which individuals carry germ-line mutations in the adenomatous polyposis coli (APC) gene that predisposes them to CRC. The Apc Min mouse model carries a point mutation in the Apc gene and develops polyps along the intestinal tract. Inbred strain background influences polyp phenotypes in Apc Min mice. Several Modifier of Min (Mom) loci that alter tumor phenotypes associated with the Apc Min mutation have been identified to date. We screened BXH recombinant inbred (RI) strains by crossing BXH RI females with C57BL/6J (B6) Apc Min males and quantitating tumor phenotypes in backcross progeny. We found that the BXH14 RI strain harbors five modifier loci that decrease polyp multiplicity. Furthermore, we show that resistance is determined by varying combinations of these modifier loci. Gene interaction network analysis shows that there are multiple networks with proven gene–gene interactions, which contain genes from all five modifier loci. We discuss the implications of this result for studies that define susceptibility loci, namely that multiple networks may be acting concurrently to alter tumor phenotypes. Thus, the significance of this work resides not only with the modifier loci we identified but also with the combinations of loci needed to get maximal protection against polyposis and the impact of this finding on human disease studies. Abbreviations:APCadenomatous polyposis coliGWASgenome-wide association studiesQTLquantitative trait lociSNPsingle-nucleotide polymorphism. PMID:22637734

Laboratory and wild-derived mice with multiple loci for production of xenotropic murine leukemia virus.

PubMed

Kozak, C A; Hartley, J W; Morse, H C

1984-07-01

Mendelian segregation analysis was used to define genetic loci for the induction of infectious xenotropic murine leukemia virus in several laboratory and wild-derived mice. MA/My mice contain two loci for xenotropic virus inducibility, one of which, Bxv -1, is the only induction locus carried by five other inbred strains. The second, novel MA/My locus, designated Mxv -1, is unlinked to Bxv -1 and shows a lower efficiency of virus induction. The NZB mouse carries two induction loci; both are distinct from Bxv -1 since neither is linked to the Pep-3 locus on chromosome 1. Finally, one partially inbred strain derived from the wild Japanese mouse, Mus musculus molossinus, carries multiple (at least three) unlinked loci for induction of xenotropic virus. Although it is probable that inbred strains inherited xenotropic virus inducibility from Japanese mice, our data suggest that none of the induction loci carried by this particular M. m. molossinus strain are allelic with Bxv -1.

Laboratory and wild-derived mice with multiple loci for production of xenotropic murine leukemia virus.

PubMed Central

Kozak, C A; Hartley, J W; Morse, H C

1984-01-01

Mendelian segregation analysis was used to define genetic loci for the induction of infectious xenotropic murine leukemia virus in several laboratory and wild-derived mice. MA/My mice contain two loci for xenotropic virus inducibility, one of which, Bxv -1, is the only induction locus carried by five other inbred strains. The second, novel MA/My locus, designated Mxv -1, is unlinked to Bxv -1 and shows a lower efficiency of virus induction. The NZB mouse carries two induction loci; both are distinct from Bxv -1 since neither is linked to the Pep-3 locus on chromosome 1. Finally, one partially inbred strain derived from the wild Japanese mouse, Mus musculus molossinus, carries multiple (at least three) unlinked loci for induction of xenotropic virus. Although it is probable that inbred strains inherited xenotropic virus inducibility from Japanese mice, our data suggest that none of the induction loci carried by this particular M. m. molossinus strain are allelic with Bxv -1. PMID:6328046

Meta-analysis identifies gene-by-environment interactions as demonstrated in a study of 4,965 mice.

PubMed

Kang, Eun Yong; Han, Buhm; Furlotte, Nicholas; Joo, Jong Wha J; Shih, Diana; Davis, Richard C; Lusis, Aldons J; Eskin, Eleazar

2014-01-01

Identifying environmentally-specific genetic effects is a key challenge in understanding the structure of complex traits. Model organisms play a crucial role in the identification of such gene-by-environment interactions, as a result of the unique ability to observe genetically similar individuals across multiple distinct environments. Many model organism studies examine the same traits but under varying environmental conditions. For example, knock-out or diet-controlled studies are often used to examine cholesterol in mice. These studies, when examined in aggregate, provide an opportunity to identify genomic loci exhibiting environmentally-dependent effects. However, the straightforward application of traditional methodologies to aggregate separate studies suffers from several problems. First, environmental conditions are often variable and do not fit the standard univariate model for interactions. Additionally, applying a multivariate model results in increased degrees of freedom and low statistical power. In this paper, we jointly analyze multiple studies with varying environmental conditions using a meta-analytic approach based on a random effects model to identify loci involved in gene-by-environment interactions. Our approach is motivated by the observation that methods for discovering gene-by-environment interactions are closely related to random effects models for meta-analysis. We show that interactions can be interpreted as heterogeneity and can be detected without utilizing the traditional uni- or multi-variate approaches for discovery of gene-by-environment interactions. We apply our new method to combine 17 mouse studies containing in aggregate 4,965 distinct animals. We identify 26 significant loci involved in High-density lipoprotein (HDL) cholesterol, many of which are consistent with previous findings. Several of these loci show significant evidence of involvement in gene-by-environment interactions. An additional advantage of our meta-analysis approach is that our combined study has significantly higher power and improved resolution compared to any single study thus explaining the large number of loci discovered in the combined study.

Meta-Analysis Identifies Gene-by-Environment Interactions as Demonstrated in a Study of 4,965 Mice

PubMed Central

Joo, Jong Wha J.; Shih, Diana; Davis, Richard C.; Lusis, Aldons J.; Eskin, Eleazar

2014-01-01

Identifying environmentally-specific genetic effects is a key challenge in understanding the structure of complex traits. Model organisms play a crucial role in the identification of such gene-by-environment interactions, as a result of the unique ability to observe genetically similar individuals across multiple distinct environments. Many model organism studies examine the same traits but under varying environmental conditions. For example, knock-out or diet-controlled studies are often used to examine cholesterol in mice. These studies, when examined in aggregate, provide an opportunity to identify genomic loci exhibiting environmentally-dependent effects. However, the straightforward application of traditional methodologies to aggregate separate studies suffers from several problems. First, environmental conditions are often variable and do not fit the standard univariate model for interactions. Additionally, applying a multivariate model results in increased degrees of freedom and low statistical power. In this paper, we jointly analyze multiple studies with varying environmental conditions using a meta-analytic approach based on a random effects model to identify loci involved in gene-by-environment interactions. Our approach is motivated by the observation that methods for discovering gene-by-environment interactions are closely related to random effects models for meta-analysis. We show that interactions can be interpreted as heterogeneity and can be detected without utilizing the traditional uni- or multi-variate approaches for discovery of gene-by-environment interactions. We apply our new method to combine 17 mouse studies containing in aggregate 4,965 distinct animals. We identify 26 significant loci involved in High-density lipoprotein (HDL) cholesterol, many of which are consistent with previous findings. Several of these loci show significant evidence of involvement in gene-by-environment interactions. An additional advantage of our meta-analysis approach is that our combined study has significantly higher power and improved resolution compared to any single study thus explaining the large number of loci discovered in the combined study. PMID:24415945

Tandem repeat regions within the Burkholderia pseudomallei genome and their application for high resolution genotyping.

PubMed

U'Ren, Jana M; Schupp, James M; Pearson, Talima; Hornstra, Heidie; Friedman, Christine L Clark; Smith, Kimothy L; Daugherty, Rebecca R Leadem; Rhoton, Shane D; Leadem, Ben; Georgia, Shalamar; Cardon, Michelle; Huynh, Lynn Y; DeShazer, David; Harvey, Steven P; Robison, Richard; Gal, Daniel; Mayo, Mark J; Wagner, David; Currie, Bart J; Keim, Paul

2007-03-30

The facultative, intracellular bacterium Burkholderia pseudomallei is the causative agent of melioidosis, a serious infectious disease of humans and animals. We identified and categorized tandem repeat arrays and their distribution throughout the genome of B. pseudomallei strain K96243 in order to develop a genetic typing method for B. pseudomallei. We then screened 104 of the potentially polymorphic loci across a diverse panel of 31 isolates including B. pseudomallei, B. mallei and B. thailandensis in order to identify loci with varying degrees of polymorphism. A subset of these tandem repeat arrays were subsequently developed into a multiple-locus VNTR analysis to examine 66 B. pseudomallei and 21 B. mallei isolates from around the world, as well as 95 lineages from a serial transfer experiment encompassing ~18,000 generations. B. pseudomallei contains a preponderance of tandem repeat loci throughout its genome, many of which are duplicated elsewhere in the genome. The majority of these loci are composed of repeat motif lengths of 6 to 9 bp with 4 to 10 repeat units and are predominately located in intergenic regions of the genome. Across geographically diverse B. pseudomallei and B.mallei isolates, the 32 VNTR loci displayed between 7 and 28 alleles, with Nei's diversity values ranging from 0.47 and 0.94. Mutation rates for these loci are comparable (>10-5 per locus per generation) to that of the most diverse tandemly repeated regions found in other less diverse bacteria. The frequency, location and duplicate nature of tandemly repeated regions within the B. pseudomallei genome indicate that these tandem repeat regions may play a role in generating and maintaining adaptive genomic variation. Multiple-locus VNTR analysis revealed extensive diversity within the global isolate set containing B. pseudomallei and B. mallei, and it detected genotypic differences within clonal lineages of both species that were identical using previous typing methods. Given the health threat to humans and livestock and the potential for B. pseudomallei to be released intentionally, MLVA could prove to be an important tool for fine-scale epidemiological or forensic tracking of this increasingly important environmental pathogen.

Retrospective genomic analysis of sorghum adaptation to temperate-zone grain production.

PubMed

Thurber, Carrie S; Ma, Justin M; Higgins, Race H; Brown, Patrick J

2013-06-26

Sorghum is a tropical C4 cereal that recently adapted to temperate latitudes and mechanized grain harvest through selection for dwarfism and photoperiod-insensitivity. Quantitative trait loci for these traits have been introgressed from a dwarf temperate donor into hundreds of diverse sorghum landraces to yield the Sorghum Conversion lines. Here, we report the first comprehensive genomic analysis of the molecular changes underlying this adaptation. We apply genotyping-by-sequencing to 1,160 Sorghum Conversion lines and their exotic progenitors, and map donor introgressions in each Sorghum Conversion line. Many Sorghum Conversion lines carry unexpected haplotypes not found in either presumed parent. Genome-wide mapping of introgression frequencies reveals three genomic regions necessary for temperate adaptation across all Sorghum Conversion lines, containing the Dw1, Dw2, and Dw3 loci on chromosomes 9, 6, and 7 respectively. Association mapping of plant height and flowering time in Sorghum Conversion lines detects significant associations in the Dw1 but not the Dw2 or Dw3 regions. Subpopulation-specific introgression mapping suggests that chromosome 6 contains at least four loci required for temperate adaptation in different sorghum genetic backgrounds. The Dw1 region fractionates into separate quantitative trait loci for plant height and flowering time. Generating Sorghum Conversion lines has been accompanied by substantial unintended gene flow. Sorghum adaptation to temperate-zone grain production involves a small number of genomic regions, each containing multiple linked loci for plant height and flowering time. Further characterization of these loci will accelerate the adaptation of sorghum and related grasses to new production systems for food and fuel.

Genome-wide methylation analysis in Silver-Russell syndrome patients

PubMed Central

Böhm, S; Frost, JM; Puszyk, W; Abu-Amero, S; Stanier, P; Schulz, R; Moore, GE; Oakey, RJ

2015-01-01

Silver-Russell Syndrome (SRS) is a clinically heterogeneous disorder characterised by severe in utero growth restriction and poor postnatal growth, body asymmetry, irregular craniofacial features and several additional minor malformations. The aetiology of SRS is complex and current evidence strongly implicates imprinted genes. Approximately half of all patients exhibit DNA hypomethylation at the H19/IGF2 imprinted domain, and around 10% have maternal uniparental disomy of chromosome 7. We measured DNA methylation in 18 SRS patients at >485,000 CpG sites using DNA methylation microarrays. Using a novel bioinformatics methodology specifically designed to identify subsets of patients with a shared epimutation, we analysed methylation changes genome-wide as well as at known imprinted regions to identify SRS-associated epimutations. Our analysis identifies epimutations at the previously characterised domains of H19/IGF2 and at imprinted regions on chromosome 7, providing proof of principle that our methodology can detect DNA methylation changes at imprinted loci. In addition we discovered two novel epimutations associated with SRS and located at imprinted loci previously linked to relevant mouse and human phenotypes. We identify RB1 as an additional imprinted locus associated with SRS, with a region near the RB1 DMR hypermethylated in 13/18 (~70 %) patients. We also report 6/18 (~33 %) patients were hypermethylated at a CpG island near the ANKRD11 gene. We do not observe consistent cooccurrence of epimutations at multiple imprinted loci in single SRS individuals. SRS is clinically heterogeneous and the absence of multiple imprinted loci epimutations reflects the heterogeneity at the molecular level. Further stratification of SRS patients by molecular phenotypes might aid the identification of disease causes. PMID:25563730

Immunochip Analysis Identifies Multiple Susceptibility Loci for Systemic Sclerosis

PubMed Central

Mayes, Maureen D.; Bossini-Castillo, Lara; Gorlova, Olga; Martin, José Ezequiel; Zhou, Xiaodong; Chen, Wei V.; Assassi, Shervin; Ying, Jun; Tan, Filemon K.; Arnett, Frank C.; Reveille, John D.; Guerra, Sandra; Teruel, María; Carmona, Francisco David; Gregersen, Peter K.; Lee, Annette T.; López-Isac, Elena; Ochoa, Eguzkine; Carreira, Patricia; Simeón, Carmen Pilar; Castellví, Iván; González-Gay, Miguel Ángel; Ortego-Centeno, Norberto; Ríos, Raquel; Callejas, José Luis; Navarrete, Nuria; García Portales, Rosa; Camps, María Teresa; Fernández-Nebro, Antonio; González-Escribano, María F.; Sánchez-Román, Julio; García-Hernández, Francisco José; Castillo, María Jesús; Aguirre, María Ángeles; Gómez-Gracia, Inmaculada; Fernández-Gutiérrez, Benjamín; Rodríguez-Rodríguez, Luis; Vicente, Esther; Andreu, José Luis; Fernández de Castro, Mónica; García de la Peña, Paloma; López-Longo, Francisco Javier; Martínez, Lina; Fonollosa, Vicente; Espinosa, Gerard; Tolosa, Carlos; Pros, Anna; Rodríguez Carballeira, Mónica; Narváez, Francisco Javier; Rubio Rivas, Manel; Ortiz Santamaría, Vera; Díaz, Bernardino; Trapiella, Luis; Freire, María del Carmen; Sousa, Adrián; Egurbide, María Victoria; Fanlo Mateo, Patricia; Sáez-Comet, Luis; Díaz, Federico; Hernández, Vanesa; Beltrán, Emma; Román-Ivorra, José Andrés; Grau, Elena; Alegre Sancho, Juan José; Blanco García, Francisco J.; Oreiro, Natividad; Fernández Sueiro, Luis; Zhernakova, Alexandra; Padyukov, Leonid; Alarcón-Riquelme, Marta; Wijmenga, Cisca; Brown, Matthew; Beretta, Lorenzo; Riemekasten, Gabriela; Witte, Torsten; Hunzelmann, Nicolas; Kreuter, Alexander; Distler, Jörg H.W.; Voskuyl, Alexandre E.; Schuerwegh, Annemie J.; Hesselstrand, Roger; Nordin, Annika; Airó, Paolo; Lunardi, Claudio; Shiels, Paul; van Laar, Jacob M.; Herrick, Ariane; Worthington, Jane; Denton, Christopher; Wigley, Fredrick M.; Hummers, Laura K.; Varga, John; Hinchcliff, Monique E.; Baron, Murray; Hudson, Marie; Pope, Janet E.; Furst, Daniel E.; Khanna, Dinesh; Phillips, Kristin; Schiopu, Elena; Segal, Barbara M.; Molitor, Jerry A.; Silver, Richard M.; Steen, Virginia D.; Simms, Robert W.; Lafyatis, Robert A.; Fessler, Barri J.; Frech, Tracy M.; AlKassab, Firas; Docherty, Peter; Kaminska, Elzbieta; Khalidi, Nader; Jones, Henry Niall; Markland, Janet; Robinson, David; Broen, Jasper; Radstake, Timothy R.D.J.; Fonseca, Carmen; Koeleman, Bobby P.; Martin, Javier

2014-01-01

In this study, 1,833 systemic sclerosis (SSc) cases and 3,466 controls were genotyped with the Immunochip array. Classical alleles, amino acid residues, and SNPs across the human leukocyte antigen (HLA) region were imputed and tested. These analyses resulted in a model composed of six polymorphic amino acid positions and seven SNPs that explained the observed significant associations in the region. In addition, a replication step comprising 4,017 SSc cases and 5,935 controls was carried out for several selected non-HLA variants, reaching a total of 5,850 cases and 9,401 controls of European ancestry. Following this strategy, we identified and validated three SSc risk loci, including DNASE1L3 at 3p14, the SCHIP1-IL12A locus at 3q25, and ATG5 at 6q21, as well as a suggested association of the TREH-DDX6 locus at 11q23. The associations of several previously reported SSc risk loci were validated and further refined, and the observed peak of association in PXK was related to DNASE1L3. Our study has increased the number of known genetic associations with SSc, provided further insight into the pleiotropic effects of shared autoimmune risk factors, and highlighted the power of dense mapping for detecting previously overlooked susceptibility loci. PMID:24387989

Temporal and multiple quantitative trait loci analyses of resistance to bacterial wilt in tomato permit the resolution of linked loci.

PubMed

Mangin, B; Thoquet, P; Olivier, J; Grimsley, N H

1999-03-01

Ralstonia solanacearum is a soil-borne bacterium that causes the serious disease known as bacterial wilt in many plant species. In tomato, several QTL controlling resistance have been found, but in different studies, markers spanning a large region of chromosome 6 showed strong association with the resistance. By using two different approaches to analyze the data from a field test F3 population, we show that at least two separate loci approximately 30 cM apart on this chromosome are most likely involved in the resistance. First, a temporal analysis of the progression of symptoms reveals a distal locus early in the development of the disease. As the disease progresses, the maximum LOD peak observed shifts toward the proximal end of the chromosome, obscuring the distal locus. Second, although classical interval mapping could only detect the presence of one locus, a statistical "two-QTL model" test, specifically adapted for the resolution of linked QTL, strongly supported the hypothesis for the presence of two loci. These results are discussed in the context of current molecular knowledge about disease resistance genes on chromosome 6 and observations made by tomato breeders during the production of bacterial wilt-resistant varieties.

Temporal and multiple quantitative trait loci analyses of resistance to bacterial wilt in tomato permit the resolution of linked loci.

PubMed Central

Mangin, B; Thoquet, P; Olivier, J; Grimsley, N H

1999-01-01

Ralstonia solanacearum is a soil-borne bacterium that causes the serious disease known as bacterial wilt in many plant species. In tomato, several QTL controlling resistance have been found, but in different studies, markers spanning a large region of chromosome 6 showed strong association with the resistance. By using two different approaches to analyze the data from a field test F3 population, we show that at least two separate loci approximately 30 cM apart on this chromosome are most likely involved in the resistance. First, a temporal analysis of the progression of symptoms reveals a distal locus early in the development of the disease. As the disease progresses, the maximum LOD peak observed shifts toward the proximal end of the chromosome, obscuring the distal locus. Second, although classical interval mapping could only detect the presence of one locus, a statistical "two-QTL model" test, specifically adapted for the resolution of linked QTL, strongly supported the hypothesis for the presence of two loci. These results are discussed in the context of current molecular knowledge about disease resistance genes on chromosome 6 and observations made by tomato breeders during the production of bacterial wilt-resistant varieties. PMID:10049932

Global transcriptional analysis of psoriatic skin and blood confirms known disease-associated pathways and highlights novel genomic "hot spots" for differentially expressed genes.

PubMed

Coda, Alvin B; Icen, Murat; Smith, Jason R; Sinha, Animesh A

2012-07-01

There are major gaps in our knowledge regarding the exact mechanisms and genetic basis of psoriasis. To investigate the pathogenesis of psoriasis, gene expression in 10 skin (5 lesional, 5 nonlesional) and 11 blood (6 psoriatic, 5 nonpsoriatic) samples were examined using Affymetrix HG-U95A microarrays. We detected 535 (425 upregulated, 110 downregulated) DEGs in lesional skin at 1% false discovery rate (FDR). Combining nine microarray studies comparing lesional and nonlesional psoriatic skin, 34.5% of dysregulated genes were overlapped in multiple studies. We further identified 20 skin and 2 blood associated transcriptional "hot spots" at specified genomic locations. At 5% FDR, 11.8% skin and 10.4% blood DEGs in our study mapped to one of the 12 PSORS loci. DEGs that overlap with PSORS loci may offer prioritized targets for downstream genetic fine mapping studies. Novel DEG "hot spots" may provide new targets for defining susceptibility loci in future studies. Copyright © 2012 Elsevier Inc. All rights reserved.

Systematic cloning of human minisatellites from ordered array charomid libraries.

PubMed

Armour, J A; Povey, S; Jeremiah, S; Jeffreys, A J

1990-11-01

We present a rapid and efficient method for the isolation of minisatellite loci from human DNA. The method combines cloning a size-selected fraction of human MboI DNA fragments in a charomid vector with hybridization screening of the library in ordered array. Size-selection of large MboI fragments enriches for the longer, more variable minisatellites and reduces the size of the library required. The library was screened with a series of multi-locus probes known to detect a large number of hypervariable loci in human DNA. The gridded library allowed both the rapid processing of positive clones and the comparative evaluation of the different multi-locus probes used, in terms of both the relative success in detecting hypervariable loci and the degree of overlap between the sets of loci detected. We report 23 new human minisatellite loci isolated by this method, which map to 14 autosomes and the sex chromosomes.

Association analyses of East Asian individuals and trans-ancestry analyses with European individuals reveal new loci associated with cholesterol and triglyceride levels.

PubMed

Spracklen, Cassandra N; Chen, Peng; Kim, Young Jin; Wang, Xu; Cai, Hui; Li, Shengxu; Long, Jirong; Wu, Ying; Wang, Ya Xing; Takeuchi, Fumihiko; Wu, Jer-Yuarn; Jung, Keum-Ji; Hu, Cheng; Akiyama, Koichi; Zhang, Yonghong; Moon, Sanghoon; Johnson, Todd A; Li, Huaixing; Dorajoo, Rajkumar; He, Meian; Cannon, Maren E; Roman, Tamara S; Salfati, Elias; Lin, Keng-Hung; Guo, Xiuqing; Sheu, Wayne H H; Absher, Devin; Adair, Linda S; Assimes, Themistocles L; Aung, Tin; Cai, Qiuyin; Chang, Li-Ching; Chen, Chien-Hsiun; Chien, Li-Hsin; Chuang, Lee-Ming; Chuang, Shu-Chun; Du, Shufa; Fan, Qiao; Fann, Cathy S J; Feranil, Alan B; Friedlander, Yechiel; Gordon-Larsen, Penny; Gu, Dongfeng; Gui, Lixuan; Guo, Zhirong; Heng, Chew-Kiat; Hixson, James; Hou, Xuhong; Hsiung, Chao Agnes; Hu, Yao; Hwang, Mi Yeong; Hwu, Chii-Min; Isono, Masato; Juang, Jyh-Ming Jimmy; Khor, Chiea-Chuen; Kim, Yun Kyoung; Koh, Woon-Puay; Kubo, Michiaki; Lee, I-Te; Lee, Sun-Ju; Lee, Wen-Jane; Liang, Kae-Woei; Lim, Blanche; Lim, Sing-Hui; Liu, Jianjun; Nabika, Toru; Pan, Wen-Harn; Peng, Hao; Quertermous, Thomas; Sabanayagam, Charumathi; Sandow, Kevin; Shi, Jinxiu; Sun, Liang; Tan, Pok Chien; Tan, Shu-Pei; Taylor, Kent D; Teo, Yik-Ying; Toh, Sue-Anne; Tsunoda, Tatsuhiko; van Dam, Rob M; Wang, Aili; Wang, Feijie; Wang, Jie; Wei, Wen Bin; Xiang, Yong-Bing; Yao, Jie; Yuan, Jian-Min; Zhang, Rong; Zhao, Wanting; Chen, Yii-Der Ida; Rich, Stephen S; Rotter, Jerome I; Wang, Tzung-Dau; Wu, Tangchun; Lin, Xu; Han, Bok-Ghee; Tanaka, Toshihiro; Cho, Yoon Shin; Katsuya, Tomohiro; Jia, Weiping; Jee, Sun-Ha; Chen, Yuan-Tsong; Kato, Norihiro; Jonas, Jost B; Cheng, Ching-Yu; Shu, Xiao-Ou; He, Jiang; Zheng, Wei; Wong, Tien-Yin; Huang, Wei; Kim, Bong-Jo; Tai, E-Shyong; Mohlke, Karen L; Sim, Xueling

2017-05-01

Large-scale meta-analyses of genome-wide association studies (GWAS) have identified >175 loci associated with fasting cholesterol levels, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). With differences in linkage disequilibrium (LD) structure and allele frequencies between ancestry groups, studies in additional large samples may detect new associations. We conducted staged GWAS meta-analyses in up to 69,414 East Asian individuals from 24 studies with participants from Japan, the Philippines, Korea, China, Singapore, and Taiwan. These meta-analyses identified (P < 5 × 10-8) three novel loci associated with HDL-C near CD163-APOBEC1 (P = 7.4 × 10-9), NCOA2 (P = 1.6 × 10-8), and NID2-PTGDR (P = 4.2 × 10-8), and one novel locus associated with TG near WDR11-FGFR2 (P = 2.7 × 10-10). Conditional analyses identified a second signal near CD163-APOBEC1. We then combined results from the East Asian meta-analysis with association results from up to 187,365 European individuals from the Global Lipids Genetics Consortium in a trans-ancestry meta-analysis. This analysis identified (log10Bayes Factor ≥6.1) eight additional novel lipid loci. Among the twelve total loci identified, the index variants at eight loci have demonstrated at least nominal significance with other metabolic traits in prior studies, and two loci exhibited coincident eQTLs (P < 1 × 10-5) in subcutaneous adipose tissue for BPTF and PDGFC. Taken together, these analyses identified multiple novel lipid loci, providing new potential therapeutic targets. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Multilocus genotyping of Giardia duodenalis and Enterocytozoon bieneusi in dairy and native beef (Qinchuan) calves in Shaanxi province, northwestern China.

PubMed

Wang, X T; Wang, R J; Ren, G J; Yu, Z Q; Zhang, L X; Zhang, S Y; Lu, H; Peng, X Q; Zhao, G H

2016-03-01

Giardia duodenalis and Enterocytozoon bieneusi are two common protozoa that parasitize the intestinal epithelium of animals and humans. Calves have been identified as important reservoirs of these two pathogens, but limited data is available for these two pathogens in calves in China. In the present study, the prevalence and assemblages/genotypes of both parasites in calves of dairy and native beef (Qinchuan) cattle in Shaanxi province, northwestern China, were analyzed using multilocus genotyping (MLST). Of 371 fecal samples collected from calves (including 198 dairy calves and 173 Qinchuan calves), the respective overall prevalence of G. duodenalis and E. bieneusi was 18.87 (70 of 371) and 19.68 % (73 of 371). Both the zoonotic G. duodenalis assemblage A and animal adapted assemblage E were found in dairy and Qinchuan calves. Seventeen, eight, five, and two G. duodenalis subtypes were detected at the triose phosphate isomerase (tpi), β-giardin (bg), glutamate dehydrogenase (gdh), and small subunit ribosomal RNA (SSU-rRNA) loci, with five and two novel subtypes detected at the tpi and bg loci, forming 25 multiple genotypes (MLGs) (15 and 11 in dairy and Qinchuan calves, respectively). Of 73 samples that were positive for E. bieneusi at the ribosomal RNA internal transcribed spacer (ITS) locus, five ITS genotypes were found, including three known zoonotic genotypes (I, J, CHN1) and two novel genotypes (CSX1 and CSX2). MLST analysis of three microsatellite loci (MS1, MS3, MS7) and one minisatellite locus (MS4) detected six, two, two, and two genotypes at the MS1, MS3, MS4, and MS7 loci, respectively, forming ten MLGs (seven and four in dairy and Qinchuan calves, respectively). These results indicate complex population structures of G. duodenalis and E. bieneusi in calves in Shaanxi province and the zoonotic potential of these two pathogens in calves in this province.

Negligible impact of rare autoimmune-locus coding-region variants on missing heritability.

PubMed

Hunt, Karen A; Mistry, Vanisha; Bockett, Nicholas A; Ahmad, Tariq; Ban, Maria; Barker, Jonathan N; Barrett, Jeffrey C; Blackburn, Hannah; Brand, Oliver; Burren, Oliver; Capon, Francesca; Compston, Alastair; Gough, Stephen C L; Jostins, Luke; Kong, Yong; Lee, James C; Lek, Monkol; MacArthur, Daniel G; Mansfield, John C; Mathew, Christopher G; Mein, Charles A; Mirza, Muddassar; Nutland, Sarah; Onengut-Gumuscu, Suna; Papouli, Efterpi; Parkes, Miles; Rich, Stephen S; Sawcer, Steven; Satsangi, Jack; Simmonds, Matthew J; Trembath, Richard C; Walker, Neil M; Wozniak, Eva; Todd, John A; Simpson, Michael A; Plagnol, Vincent; van Heel, David A

2013-06-13

Genome-wide association studies (GWAS) have identified common variants of modest-effect size at hundreds of loci for common autoimmune diseases; however, a substantial fraction of heritability remains unexplained, to which rare variants may contribute. To discover rare variants and test them for association with a phenotype, most studies re-sequence a small initial sample size and then genotype the discovered variants in a larger sample set. This approach fails to analyse a large fraction of the rare variants present in the entire sample set. Here we perform simultaneous amplicon-sequencing-based variant discovery and genotyping for coding exons of 25 GWAS risk genes in 41,911 UK residents of white European origin, comprising 24,892 subjects with six autoimmune disease phenotypes and 17,019 controls, and show that rare coding-region variants at known loci have a negligible role in common autoimmune disease susceptibility. These results do not support the rare-variant synthetic genome-wide-association hypothesis (in which unobserved rare causal variants lead to association detected at common tag variants). Many known autoimmune disease risk loci contain multiple, independently associated, common and low-frequency variants, and so genes at these loci are a priori stronger candidates for harbouring rare coding-region variants than other genes. Our data indicate that the missing heritability for common autoimmune diseases may not be attributable to the rare coding-region variant portion of the allelic spectrum, but perhaps, as others have proposed, may be a result of many common-variant loci of weak effect.

Analysis of MHC class I genes across horse MHC haplotypes

PubMed Central

Tallmadge, Rebecca L.; Campbell, Julie A.; Miller, Donald C.; Antczak, Douglas F.

2010-01-01

The genomic sequences of 15 horse Major Histocompatibility Complex (MHC) class I genes and a collection of MHC class I homozygous horses of five different haplotypes were used to investigate the genomic structure and polymorphism of the equine MHC. A combination of conserved and locus-specific primers was used to amplify horse MHC class I genes with classical and non-classical characteristics. Multiple clones from each haplotype identified three to five classical sequences per homozygous animal, and two to three non-classical sequences. Phylogenetic analysis was applied to these sequences and groups were identified which appear to be allelic series, but some sequences were left ungrouped. Sequences determined from MHC class I heterozygous horses and previously described MHC class I sequences were then added, representing a total of ten horse MHC haplotypes. These results were consistent with those obtained from the MHC homozygous horses alone, and 30 classical sequences were assigned to four previously confirmed loci and three new provisional loci. The non-classical genes had few alleles and the classical genes had higher levels of allelic polymorphism. Alleles for two classical loci with the expected pattern of polymorphism were found in the majority of haplotypes tested, but alleles at two other commonly detected loci had more variation outside of the hypervariable region than within. Our data indicate that the equine Major Histocompatibility Complex is characterized by variation in the complement of class I genes expressed in different haplotypes in addition to the expected allelic polymorphism within loci. PMID:20099063

Markov Logic Networks in the Analysis of Genetic Data

PubMed Central

Sakhanenko, Nikita A.

2010-01-01

Abstract Complex, non-additive genetic interactions are common and can be critical in determining phenotypes. Genome-wide association studies (GWAS) and similar statistical studies of linkage data, however, assume additive models of gene interactions in looking for genotype-phenotype associations. These statistical methods view the compound effects of multiple genes on a phenotype as a sum of influences of each gene and often miss a substantial part of the heritable effect. Such methods do not use any biological knowledge about underlying mechanisms. Modeling approaches from the artificial intelligence (AI) field that incorporate deterministic knowledge into models to perform statistical analysis can be applied to include prior knowledge in genetic analysis. We chose to use the most general such approach, Markov Logic Networks (MLNs), for combining deterministic knowledge with statistical analysis. Using simple, logistic regression-type MLNs we can replicate the results of traditional statistical methods, but we also show that we are able to go beyond finding independent markers linked to a phenotype by using joint inference without an independence assumption. The method is applied to genetic data on yeast sporulation, a complex phenotype with gene interactions. In addition to detecting all of the previously identified loci associated with sporulation, our method identifies four loci with smaller effects. Since their effect on sporulation is small, these four loci were not detected with methods that do not account for dependence between markers due to gene interactions. We show how gene interactions can be detected using more complex models, which can be used as a general framework for incorporating systems biology with genetics. PMID:20958249

Phage-Induced Expression of CRISPR-Associated Proteins is Revealed by Shotgun Proteomics in Streptococcus thermophilus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Jacque C; Dill, Brian; Pan, Chongle

The CRISPR/Cas system, comprised of clustered regularly interspaced short palindromic repeats along with their associated (Cas) proteins, protects bacteria and archaea from viral predation and invading nucleic acids. While the mechanism of action for this acquired immunity is currently under investigation, the response of Cas protein expression to phage infection has yet to be elucidated. In this study, we employed shotgun proteomics to measure the global proteome expression in a model system for studying the CRISPR/Cas response: infection of S. thermophilus DGCC7710 with phage 2972. Host and viral proteins were simultaneously measured following inoculation at two different multiplicities of infectionmore » and across various time points using two-dimensional liquid chromatography tandem mass spectroscopy. Thirty-seven out of forty predicted viral proteins were detected, including all proteins of the structural virome and viral effector proteins. In total, 1,013 of 2,079 predicted S. thermophilus proteins were detected, facilitating the monitoring of host protein synthesis changes in response to virus infection. Importantly, Cas proteins from all four CRISPR loci in the S. thermophilus DGCC7710 genome were detected, including loci previously thought to be inactive. Many Cas proteins were found to be constitutively expressed, but several demonstrated increased abundance during peak infection, including the Cas9 proteins from the CRISPR1 and CRISPR3 loci, which are key players in the interference phase of the CRISPR/Cas response. Altogether, these results provide novel insights into the proteomic response of S. thermophilus, specifically CRISPR-associated proteins, upon phage 2972 infection.« less

Identification of novel loci for the generation of reporter mice

PubMed Central

Rebecchi, Monica; Levandis, Giovanna

2017-01-01

Abstract Deciphering the etiology of complex pathologies at molecular level requires longitudinal studies encompassing multiple biochemical pathways (apoptosis, proliferation, inflammation, oxidative stress). In vivo imaging of current reporter animals enabled the spatio-temporal analysis of specific molecular events, however, the lack of a multiplicity of loci for the generalized and regulated expression of the integrated transgenes hampers the creation of systems for the simultaneous analysis of more than a biochemical pathways at the time. We here developed and tested an in vivo-based methodology for the identification of multiple insertional loci suitable for the generation of reliable reporter mice. The validity of the methodology was tested with the generation of novel mice useful to report on inflammation and oxidative stress. PMID:27899606

Characterization of molecular diversity and genome-wide mapping of loci associated with resistance to stripe rust and stem rust in Ethiopian bread wheat accessions.

PubMed

Muleta, Kebede T; Rouse, Matthew N; Rynearson, Sheri; Chen, Xianming; Buta, Bedada G; Pumphrey, Michael O

2017-08-04

The narrow genetic basis of resistance in modern wheat cultivars and the strong selection response of pathogen populations have been responsible for periodic and devastating epidemics of the wheat rust diseases. Characterizing new sources of resistance and incorporating multiple genes into elite cultivars is the most widely accepted current mechanism to achieve durable varietal performance against changes in pathogen virulence. Here, we report a high-density molecular characterization and genome-wide association study (GWAS) of stripe rust and stem rust resistance in 190 Ethiopian bread wheat lines based on phenotypic data from multi-environment field trials and seedling resistance screening experiments. A total of 24,281 single nucleotide polymorphism (SNP) markers filtered from the wheat 90 K iSelect genotyping assay was used to survey Ethiopian germplasm for population structure, genetic diversity and marker-trait associations. Upon screening for field resistance to stripe rust in the Pacific Northwest of the United States and Ethiopia over multiple growing seasons, and against multiple races of stripe rust and stem rust at seedling stage, eight accessions displayed resistance to all tested races of stem rust and field resistance to stripe rust in all environments. Our GWAS results show 15 loci were significantly associated with seedling and adult plant resistance to stripe rust at false discovery rate (FDR)-adjusted probability (P) <0.10. GWAS also detected 9 additional genomic regions significantly associated (FDR-adjusted P < 0.10) with seedling resistance to stem rust in the Ethiopian wheat accessions. Many of the identified resistance loci were mapped close to previously identified rust resistance genes; however, three loci on the short arms of chromosomes 5A and 7B for stripe rust resistance and two on chromosomes 3B and 7B for stem rust resistance may be novel. Our results demonstrate that considerable genetic variation resides within the landrace accessions that can be utilized to broaden the genetic base of rust resistance in wheat breeding germplasm. The molecular markers identified in this study should be useful in efficiently targeting the associated resistance loci in marker-assisted breeding for rust resistance in Ethiopia and other countries.

Evidence for gene-gene epistatic interactions among susceptibility loci for systemic lupus erythematosus.

PubMed

Hughes, Travis; Adler, Adam; Kelly, Jennifer A; Kaufman, Kenneth M; Williams, Adrienne H; Langefeld, Carl D; Brown, Elizabeth E; Alarcón, Graciela S; Kimberly, Robert P; Edberg, Jeffrey C; Ramsey-Goldman, Rosalind; Petri, Michelle; Boackle, Susan A; Stevens, Anne M; Reveille, John D; Sanchez, Elena; Martín, Javier; Niewold, Timothy B; Vilá, Luis M; Scofield, R Hal; Gilkeson, Gary S; Gaffney, Patrick M; Criswell, Lindsey A; Moser, Kathy L; Merrill, Joan T; Jacob, Chaim O; Tsao, Betty P; James, Judith A; Vyse, Timothy J; Alarcón-Riquelme, Marta E; Harley, John B; Richardson, Bruce C; Sawalha, Amr H

2012-02-01

Several confirmed genetic susceptibility loci for lupus have been described. To date, no clear evidence for genetic epistasis in lupus has been established. The aim of this study was to test for gene-gene interactions in a number of known lupus susceptibility loci. Eighteen single-nucleotide polymorphisms tagging independent and confirmed lupus susceptibility loci were genotyped in a set of 4,248 patients with lupus and 3,818 normal healthy control subjects of European descent. Epistasis was tested by a 2-step approach using both parametric and nonparametric methods. The false discovery rate (FDR) method was used to correct for multiple testing. We detected and confirmed gene-gene interactions between the HLA region and CTLA4, IRF5, and ITGAM and between PDCD1 and IL21 in patients with lupus. The most significant interaction detected by parametric analysis was between rs3131379 in the HLA region and rs231775 in CTLA4 (interaction odds ratio 1.19, Z = 3.95, P = 7.8 × 10(-5) [FDR ≤0.05], P for multifactor dimensionality reduction = 5.9 × 10(-45)). Importantly, our data suggest that in patients with lupus, the presence of the HLA lupus risk alleles in rs1270942 and rs3131379 increases the odds of also carrying the lupus risk allele in IRF5 (rs2070197) by 17% and 16%, respectively (P = 0.0028 and P = 0.0047, respectively). We provide evidence for gene-gene epistasis in systemic lupus erythematosus. These findings support a role for genetic interaction contributing to the complexity of lupus heritability. Copyright © 2012 by the American College of Rheumatology.

Replication of association of DENND1A and THADA variants with polycystic ovary syndrome in European cohorts.

PubMed

Goodarzi, Mark O; Jones, Michelle R; Li, Xiaohui; Chua, Angela K; Garcia, Obed A; Chen, Yii-Der I; Krauss, Ronald M; Rotter, Jerome I; Ankener, Wendy; Legro, Richard S; Azziz, Ricardo; Strauss, Jerome F; Dunaif, Andrea; Urbanek, Margrit

2012-02-01

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder with a strong familial component. PCOS is characterised by hyperandrogenaemia and irregular menses. A recent genome-wide association study (GWAS) of PCOS in a Chinese cohort identified three reproducible PCOS susceptibility loci mapping to 2p16.3 (luteinising hormone/choriogonadotropin receptor; LHCGR), 2p21 (thyroid associated protein; THADA), and 9q33.3 (DENN/MADD domain containing 1A; DENNDIA). The impact of these loci in non-Chinese PCOS cohorts remains to be determined. The study tested association with PCOS of seven single nucleotide polymorphisms mapping to the three Chinese PCOS loci in two European derived PCOS cohorts (cohort A = 939 cases and 957 controls; cohort B = 535 cases and 845 controls). Cases fulfilled the National Institute of Child Health & Human Development criteria for PCOS. Variation in DENND1A was strongly associated with PCOS in the study cohort (p(combined cohorts)=10(-8)); multiple variants in THADA were also associated with PCOS, while there was no significant evidence for association of LHCGR variation with PCOS. The present study had >80% power to detect an effect of similar size as was observed by Chen et al for DENND1A and THADA, but reduced power (at <40%) for LHCGR at p=0.0001. The study had sufficient power (57-88%) for LHCGR at p=0.01. At least two of the PCOS susceptibility loci identified in the Chinese PCOS GWAS (DENND1A and THADA) are also associated with PCOS in European derived populations, and are therefore likely to be important in the aetiology of PCOS regardless of ethnicity. The analysis of the LHCGR gene was not sufficiently powered to detect modest effects.

Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans.

PubMed

Amin Al Olama, Ali; Dadaev, Tokhir; Hazelett, Dennis J; Li, Qiuyan; Leongamornlert, Daniel; Saunders, Edward J; Stephens, Sarah; Cieza-Borrella, Clara; Whitmore, Ian; Benlloch Garcia, Sara; Giles, Graham G; Southey, Melissa C; Fitzgerald, Liesel; Gronberg, Henrik; Wiklund, Fredrik; Aly, Markus; Henderson, Brian E; Schumacher, Fredrick; Haiman, Christopher A; Schleutker, Johanna; Wahlfors, Tiina; Tammela, Teuvo L; Nordestgaard, Børge G; Key, Tim J; Travis, Ruth C; Neal, David E; Donovan, Jenny L; Hamdy, Freddie C; Pharoah, Paul; Pashayan, Nora; Khaw, Kay-Tee; Stanford, Janet L; Thibodeau, Stephen N; Mcdonnell, Shannon K; Schaid, Daniel J; Maier, Christiane; Vogel, Walther; Luedeke, Manuel; Herkommer, Kathleen; Kibel, Adam S; Cybulski, Cezary; Wokołorczyk, Dominika; Kluzniak, Wojciech; Cannon-Albright, Lisa; Brenner, Hermann; Butterbach, Katja; Arndt, Volker; Park, Jong Y; Sellers, Thomas; Lin, Hui-Yi; Slavov, Chavdar; Kaneva, Radka; Mitev, Vanio; Batra, Jyotsna; Clements, Judith A; Spurdle, Amanda; Teixeira, Manuel R; Paulo, Paula; Maia, Sofia; Pandha, Hardev; Michael, Agnieszka; Kierzek, Andrzej; Govindasami, Koveela; Guy, Michelle; Lophatonanon, Artitaya; Muir, Kenneth; Viñuela, Ana; Brown, Andrew A; Freedman, Mathew; Conti, David V; Easton, Douglas; Coetzee, Gerhard A; Eeles, Rosalind A; Kote-Jarai, Zsofia

2015-10-01

Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same region. © The Author 2015. Published by Oxford University Press.

Mapping Quantitative Trait Loci in Crosses between Outbred Lines Using Least Squares

PubMed Central

Haley, C. S.; Knott, S. A.; Elsen, J. M.

1994-01-01

The use of genetic maps based upon molecular markers has allowed the dissection of some of the factors underlying quantitative variation in crosses between inbred lines. For many species crossing inbred lines is not a practical proposition, although crosses between genetically very different outbred lines are possible. Here we develop a least squares method for the analysis of crosses between outbred lines which simultaneously uses information from multiple linked markers. The method is suitable for crosses where the lines may be segregating at marker loci but can be assumed to be fixed for alternative alleles at the major quantitative trait loci (QTLs) affecting the traits under analysis (e.g., crosses between divergent selection lines or breeds with different selection histories). The simultaneous use of multiple markers from a linkage group increases the sensitivity of the test statistic, and thus the power for the detection of QTLs, compared to the use of single markers or markers flanking an interval. The gain is greater for more closely spaced markers and for markers of lower information content. Use of multiple markers can also remove the bias in the estimated position and effect of a QTL which may result when different markers in a linkage group vary in their heterozygosity in the F(1) (and thus in their information content) and are considered only singly or a pair at a time. The method is relatively simple to apply so that more complex models can be fitted than is currently possible by maximum likelihood. Thus fixed effects and effects of background genotype can be fitted simultaneously with the exploration of a single linkage group which will increase the power to detect QTLs by reducing the residual variance. More complex models with several QTLs in the same linkage group and two-locus interactions between QTLs can similarly be examined. Thus least squares provides a powerful tool to extend the range of crosses from which QTLs can be dissected whilst at the same time allowing flexible and realistic models to be explored. PMID:8005424

Patient-Specific Bacteroides Genome Variants in Pouchitis

DOE PAGES

Vineis, Joseph H.; Ringus, Daina L.; Morrison, Hilary G.; ...

2016-11-15

Here, a 2-year longitudinal microbiome study of 22 patients who underwent colectomy with an ileal pouch anal anastomosis detected significant increases in distinct populations of Bacteroides during 9 of 11 patient visits that coincided with inflammation (pouchitis). Oligotyping and metagenomic short-read annotation identified Bacteroides populations that occurred in early samples, bloomed during inflammation, and reappeared after antibiotic treatment. Targeted cultivation of Bacteroides isolates from the same individual at multiple time points and from several patients detected subtle genomic changes, including the identification of rapidly evolving genomic elements that differentiate isogenic strains of Bacteroides fragilis from the mucosa versus lumen. Eachmore » patient harbored Bacteroides spp. that are closely related to commonly occurring clinical isolates, including Bacteroides ovatus, B. thetaiotaomicron, B. vulgatus, and B. fragilis, which contained unique loci in different patients for synthesis of capsular polysaccharides. The presence of unique Bacteroides capsular polysaccharide loci within different hosts and between the lumen and mucosa may represent adaptations to stimulate, suppress, and evade host-specific immune responses at different microsites of the ileal pouch.« less

Patient-Specific Bacteroides Genome Variants in Pouchitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vineis, Joseph H.; Ringus, Daina L.; Morrison, Hilary G.

Here, a 2-year longitudinal microbiome study of 22 patients who underwent colectomy with an ileal pouch anal anastomosis detected significant increases in distinct populations of Bacteroides during 9 of 11 patient visits that coincided with inflammation (pouchitis). Oligotyping and metagenomic short-read annotation identified Bacteroides populations that occurred in early samples, bloomed during inflammation, and reappeared after antibiotic treatment. Targeted cultivation of Bacteroides isolates from the same individual at multiple time points and from several patients detected subtle genomic changes, including the identification of rapidly evolving genomic elements that differentiate isogenic strains of Bacteroides fragilis from the mucosa versus lumen. Eachmore » patient harbored Bacteroides spp. that are closely related to commonly occurring clinical isolates, including Bacteroides ovatus, B. thetaiotaomicron, B. vulgatus, and B. fragilis, which contained unique loci in different patients for synthesis of capsular polysaccharides. The presence of unique Bacteroides capsular polysaccharide loci within different hosts and between the lumen and mucosa may represent adaptations to stimulate, suppress, and evade host-specific immune responses at different microsites of the ileal pouch.« less

Predicting nuclear gene coalescence from mitochondrial data: the three-times rule.

PubMed

Palumbi, S R; Cipriano, F; Hare, M P

2001-05-01

Coalescence theory predicts when genetic drift at nuclear loci will result in fixation of sequence differences to produce monophyletic gene trees. However, the theory is difficult to apply to particular taxa because it hinges on genetically effective population size, which is generally unknown. Neutral theory also predicts that evolution of monophyly will be four times slower in nuclear than in mitochondrial genes primarily because genetic drift is slower at nuclear loci. Variation in mitochondrial DNA (mtDNA) within and between species has been studied extensively, but can these mtDNA data be used to predict coalescence in nuclear loci? Comparison of neutral theories of coalescence of mitochondrial and nuclear loci suggests a simple rule of thumb. The "three-times rule" states that, on average, most nuclear loci will be monophyletic when the branch length leading to the mtDNA sequences of a species is three times longer than the average mtDNA sequence diversity observed within that species. A test using mitochondrial and nuclear intron data from seven species of whales and dolphins suggests general agreement with predictions of the three-times rule. We define the coalescence ratio as the mitochondrial branch length for a species divided by intraspecific mtDNA diversity. We show that species with high coalescence ratios show nuclear monophyly, whereas species with low ratios have polyphyletic nuclear gene trees. As expected, species with intermediate coalescence ratios show a variety of patterns. Especially at very high or low coalescence ratios, the three-times rule predicts nuclear gene patterns that can help detect the action of selection. The three-times rule may be useful as an empirical benchmark for evaluating evolutionary processes occurring at multiple loci.

Genome-wide association study for Crohn's disease in the Quebec Founder Population identifies multiple validated disease loci.

PubMed

Raelson, John V; Little, Randall D; Ruether, Andreas; Fournier, Hélène; Paquin, Bruno; Van Eerdewegh, Paul; Bradley, W E C; Croteau, Pascal; Nguyen-Huu, Quynh; Segal, Jonathan; Debrus, Sophie; Allard, René; Rosenstiel, Philip; Franke, Andre; Jacobs, Gunnar; Nikolaus, Susanna; Vidal, Jean-Michel; Szego, Peter; Laplante, Nathalie; Clark, Hilary F; Paulussen, René J; Hooper, John W; Keith, Tim P; Belouchi, Abdelmajid; Schreiber, Stefan

2007-09-11

Genome-wide association (GWA) studies offer a powerful unbiased method for the identification of multiple susceptibility genes for complex diseases. Here we report the results of a GWA study for Crohn's disease (CD) using family trios from the Quebec Founder Population (QFP). Haplotype-based association analyses identified multiple regions associated with the disease that met the criteria for genome-wide significance, with many containing a gene whose function appears relevant to CD. A proportion of these were replicated in two independent German Caucasian samples, including the established CD loci NOD2 and IBD5. The recently described IL23R locus was also identified and replicated. For this region, multiple individuals with all major haplotypes in the QFP were sequenced and extensive fine mapping performed to identify risk and protective alleles. Several additional loci, including a region on 3p21 containing several plausible candidate genes, a region near JAKMIP1 on 4p16.1, and two larger regions on chromosome 17 were replicated. Together with previously published loci, the spectrum of CD genes identified to date involves biochemical networks that affect epithelial defense mechanisms, innate and adaptive immune response, and the repair or remodeling of tissue.

Egg Case Silk Gene Sequences from Argiope Spiders: Evidence for Multiple Loci and a Loss of Function Between Paralogs

PubMed Central

Chaw, R. Crystal; Collin, Matthew; Wimmer, Marjorie; Helmrick, Kara-Leigh; Hayashi, Cheryl Y.

2017-01-01

Spiders swath their eggs with silk to protect developing embryos and hatchlings. Egg case silks, like other fibrous spider silks, are primarily composed of proteins called spidroins (spidroin = spider-fibroin). Silks, and thus spidroins, are important throughout the lives of spiders, yet the evolution of spidroin genes has been relatively understudied. Spidroin genes are notoriously difficult to sequence because they are typically very long (≥ 10 kb of coding sequence) and highly repetitive. Here, we investigate the evolution of spider silk genes through long-read sequencing of Bacterial Artificial Chromosome (BAC) clones. We demonstrate that the silver garden spider Argiope argentata has multiple egg case spidroin loci with a loss of function at one locus. We also use degenerate PCR primers to search the genomic DNA of congeneric species and find evidence for multiple egg case spidroin loci in other Argiope spiders. Comparative analyses show that these multiple loci are more similar at the nucleotide level within a species than between species. This pattern is consistent with concerted evolution homogenizing gene copies within a genome. More complicated explanations include convergent evolution or recent independent gene duplications within each species. PMID:29127108

Multiple-Locus Variable-Number Tandem-Repeat Analysis in Genotyping Yersinia enterocolitica Strains from Human and Porcine Origins

PubMed Central

Laukkanen-Ninios, R.; Ortiz Martínez, P.; Siitonen, A.; Fredriksson-Ahomaa, M.; Korkeala, H.

2013-01-01

Sporadic and epidemiologically linked Yersinia enterocolitica strains (n = 379) isolated from fecal samples from human patients, tonsil or fecal samples from pigs collected at slaughterhouses, and pork samples collected at meat stores were genotyped using multiple-locus variable-number tandem-repeat analysis (MLVA) with six loci, i.e., V2A, V4, V5, V6, V7, and V9. In total, 312 different MLVA types were found. Similar types were detected (i) in fecal samples collected from human patients over 2 to 3 consecutive years, (ii) in samples from humans and pigs, and (iii) in samples from pigs that originated from the same farms. Among porcine strains, we found farm-specific MLVA profiles. Variations in the numbers of tandem repeats from one to four for variable-number tandem-repeat (VNTR) loci V2A, V5, V6, and V7 were observed within a farm. MLVA was applicable for serotypes O:3, O:5,27, and O:9 and appeared to be a highly discriminating tool for distinguishing sporadic and outbreak-related strains. With long-term use, interpretation of the results became more challenging due to variations in more-discriminating loci, as was observed for strains originating from pig farms. Additionally, we encountered unexpectedly short V2A VNTR fragments and sequenced them. According to the sequencing results, updated guidelines for interpreting V2A VNTR results were prepared. PMID:23637293

Discovery of rare, diagnostic AluYb8/9 elements in diverse human populations.

PubMed

Feusier, Julie; Witherspoon, David J; Scott Watkins, W; Goubert, Clément; Sasani, Thomas A; Jorde, Lynn B

2017-01-01

Polymorphic human Alu elements are excellent tools for assessing population structure, and new retrotransposition events can contribute to disease. Next-generation sequencing has greatly increased the potential to discover Alu elements in human populations, and various sequencing and bioinformatics methods have been designed to tackle the problem of detecting these highly repetitive elements. However, current techniques for Alu discovery may miss rare, polymorphic Alu elements. Combining multiple discovery approaches may provide a better profile of the polymorphic Alu mobilome. Alu Yb8/9 elements have been a focus of our recent studies as they are young subfamilies (~2.3 million years old) that contribute ~30% of recent polymorphic Alu retrotransposition events. Here, we update our ME-Scan methods for detecting Alu elements and apply these methods to discover new insertions in a large set of individuals with diverse ancestral backgrounds. We identified 5,288 putative Alu insertion events, including several hundred novel Alu Yb8/9 elements from 213 individuals from 18 diverse human populations. Hundreds of these loci were specific to continental populations, and 23 non-reference population-specific loci were validated by PCR. We provide high-quality sequence information for 68 rare Alu Yb8/9 elements, of which 11 have hallmarks of an active source element. Our subfamily distribution of rare Alu Yb8/9 elements is consistent with previous datasets, and may be representative of rare loci. We also find that while ME-Scan and low-coverage, whole-genome sequencing (WGS) detect different Alu elements in 41 1000 Genomes individuals, the two methods yield similar population structure results. Current in-silico methods for Alu discovery may miss rare, polymorphic Alu elements. Therefore, using multiple techniques can provide a more accurate profile of Alu elements in individuals and populations. We improved our false-negative rate as an indicator of sample quality for future ME-Scan experiments. In conclusion, we demonstrate that ME-Scan is a good supplement for next-generation sequencing methods and is well-suited for population-level analyses.

A MAD-Bayes Algorithm for State-Space Inference and Clustering with Application to Querying Large Collections of ChIP-Seq Data Sets.

PubMed

Zuo, Chandler; Chen, Kailei; Keleş, Sündüz

2017-06-01

Current analytic approaches for querying large collections of chromatin immunoprecipitation followed by sequencing (ChIP-seq) data from multiple cell types rely on individual analysis of each data set (i.e., peak calling) independently. This approach discards the fact that functional elements are frequently shared among related cell types and leads to overestimation of the extent of divergence between different ChIP-seq samples. Methods geared toward multisample investigations have limited applicability in settings that aim to integrate 100s to 1000s of ChIP-seq data sets for query loci (e.g., thousands of genomic loci with a specific binding site). Recently, Zuo et al. developed a hierarchical framework for state-space matrix inference and clustering, named MBASIC, to enable joint analysis of user-specified loci across multiple ChIP-seq data sets. Although this versatile framework estimates both the underlying state-space (e.g., bound vs. unbound) and also groups loci with similar patterns together, its Expectation-Maximization-based estimation structure hinders its applicability with large number of loci and samples. We address this limitation by developing MAP-based asymptotic derivations from Bayes (MAD-Bayes) framework for MBASIC. This results in a K-means-like optimization algorithm that converges rapidly and hence enables exploring multiple initialization schemes and flexibility in tuning. Comparison with MBASIC indicates that this speed comes at a relatively insignificant loss in estimation accuracy. Although MAD-Bayes MBASIC is specifically designed for the analysis of user-specified loci, it is able to capture overall patterns of histone marks from multiple ChIP-seq data sets similar to those identified by genome-wide segmentation methods such as ChromHMM and Spectacle.

Identifying Loci Under Selection Against Gene Flow in Isolation-with-Migration Models

PubMed Central

Sousa, Vitor C.; Carneiro, Miguel; Ferrand, Nuno; Hey, Jody

2013-01-01

When divergence occurs in the presence of gene flow, there can arise an interesting dynamic in which selection against gene flow, at sites associated with population-specific adaptations or genetic incompatibilities, can cause net gene flow to vary across the genome. Loci linked to sites under selection may experience reduced gene flow and may experience genetic bottlenecks by the action of nearby selective sweeps. Data from histories such as these may be poorly fitted by conventional neutral model approaches to demographic inference, which treat all loci as equally subject to forces of genetic drift and gene flow. To allow for demographic inference in the face of such histories, as well as the identification of loci affected by selection, we developed an isolation-with-migration model that explicitly provides for variation among genomic regions in migration rates and/or rates of genetic drift. The method allows for loci to fall into any of multiple groups, each characterized by a different set of parameters, thus relaxing the assumption that all loci share the same demography. By grouping loci, the method can be applied to data with multiple loci and still have tractable dimensionality and statistical power. We studied the performance of the method using simulated data, and we applied the method to study the divergence of two subspecies of European rabbits (Oryctolagus cuniculus). PMID:23457232

Localizing multiple X chromosome-linked retinitis pigmentosa loci using multilocus homogeneity tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ott, J.; Terwilliger, J.D.; Bhattacharya, S.

1990-01-01

Multilocus linkage analysis of 62 family pedigrees with X chromosome-linked retinitis pigmentosa (XLRP) was undertaken to determine the presence of possible multiple disease loci and to reliability estimate their map location. Multilocus homogeneity tests furnish convincing evidence for the presence of two XLRP loci, the likelihood ratio being 6.4 {times} 10{sup 9}:1 in a favor of two versus a single XLRP locus and gave accurate estimates for their map location. In 60-75% of the families, location of an XLRP gene was estimated at 1 centimorgan distal to OTC, and in 25-40% of the families, an XLRP locus was located halfwaymore » between DXS14 (p58-1) and DXZ1 (Xcen), with an estimated recombination fraction of 25% between the two XLRP loci. There is also good evidence for third XLRP locus, midway between DXS28 (C7) and DXS164 (pERT87), supported by a likelihood ratio of 293:1 for three versus two XLRP loci.« less

Accuracy of Perceptual and Acoustic Methods for the Detection of Inspiratory Loci in Spontaneous Speech

PubMed Central

Wang, Yu-Tsai; Nip, Ignatius S. B.; Green, Jordan R.; Kent, Ray D.; Kent, Jane Finley; Ullman, Cara

2012-01-01

The current study investigates the accuracy of perceptually and acoustically determined inspiratory loci in spontaneous speech for the purpose of identifying breath groups. Sixteen participants were asked to talk about simple topics in daily life at a comfortable speaking rate and loudness while connected to a pneumotach and audio microphone. The locations of inspiratory loci were determined based on the aerodynamic signal, which served as a reference for loci identified perceptually and acoustically. Signal detection theory was used to evaluate the accuracy of the methods. The results showed that the greatest accuracy in pause detection was achieved (1) perceptually based on the agreement between at least 2 of the 3 judges; (2) acoustically using a pause duration threshold of 300 ms. In general, the perceptually-based method was more accurate than was the acoustically-based method. Inconsistencies among perceptually-determined, acoustically-determined, and aerodynamically-determined inspiratory loci for spontaneous speech should be weighed in selecting a method of breath-group determination. PMID:22362007

Identifying Causal Variants at Loci with Multiple Signals of Association

PubMed Central

Hormozdiari, Farhad; Kostem, Emrah; Kang, Eun Yong; Pasaniuc, Bogdan; Eskin, Eleazar

2014-01-01

Although genome-wide association studies have successfully identified thousands of risk loci for complex traits, only a handful of the biologically causal variants, responsible for association at these loci, have been successfully identified. Current statistical methods for identifying causal variants at risk loci either use the strength of the association signal in an iterative conditioning framework or estimate probabilities for variants to be causal. A main drawback of existing methods is that they rely on the simplifying assumption of a single causal variant at each risk locus, which is typically invalid at many risk loci. In this work, we propose a new statistical framework that allows for the possibility of an arbitrary number of causal variants when estimating the posterior probability of a variant being causal. A direct benefit of our approach is that we predict a set of variants for each locus that under reasonable assumptions will contain all of the true causal variants with a high confidence level (e.g., 95%) even when the locus contains multiple causal variants. We use simulations to show that our approach provides 20–50% improvement in our ability to identify the causal variants compared to the existing methods at loci harboring multiple causal variants. We validate our approach using empirical data from an expression QTL study of CHI3L2 to identify new causal variants that affect gene expression at this locus. CAVIAR is publicly available online at http://genetics.cs.ucla.edu/caviar/. PMID:25104515

Identifying causal variants at loci with multiple signals of association.

PubMed

Hormozdiari, Farhad; Kostem, Emrah; Kang, Eun Yong; Pasaniuc, Bogdan; Eskin, Eleazar

2014-10-01

Although genome-wide association studies have successfully identified thousands of risk loci for complex traits, only a handful of the biologically causal variants, responsible for association at these loci, have been successfully identified. Current statistical methods for identifying causal variants at risk loci either use the strength of the association signal in an iterative conditioning framework or estimate probabilities for variants to be causal. A main drawback of existing methods is that they rely on the simplifying assumption of a single causal variant at each risk locus, which is typically invalid at many risk loci. In this work, we propose a new statistical framework that allows for the possibility of an arbitrary number of causal variants when estimating the posterior probability of a variant being causal. A direct benefit of our approach is that we predict a set of variants for each locus that under reasonable assumptions will contain all of the true causal variants with a high confidence level (e.g., 95%) even when the locus contains multiple causal variants. We use simulations to show that our approach provides 20-50% improvement in our ability to identify the causal variants compared to the existing methods at loci harboring multiple causal variants. We validate our approach using empirical data from an expression QTL study of CHI3L2 to identify new causal variants that affect gene expression at this locus. CAVIAR is publicly available online at http://genetics.cs.ucla.edu/caviar/. Copyright © 2014 by the Genetics Society of America.

Genome-Wide Association Analysis Reveals Different Genetic Control in Panicle Architecture Between and Rice.

PubMed

Bai, Xufeng; Zhao, Hu; Huang, Yong; Xie, Weibo; Han, Zhongmin; Zhang, Bo; Guo, Zilong; Yang, Lin; Dong, Haijiao; Xue, Weiya; Li, Guangwei; Hu, Gang; Hu, Yong; Xing, Yongzhong

2016-07-01

Panicle architecture determines the number of spikelets per panicle (SPP) and is highly associated with grain yield in rice ( L.). Understanding the genetic basis of panicle architecture is important for improving the yield of rice grain. In this study, we dissected panicle architecture traits into eight components, which were phenotyped from a germplasm collection of 529 cultivars. Multiple regression analysis revealed that the number of secondary branch (NSB) was the major factor that contributed to SPP. Genome-wide association analysis was performed independently for the eight particle architecture traits observed in the and rice subpopulations compared with the whole rice population. In total, 30 loci were associated with these traits. Of these, 13 loci were closely linked to known panicle architecture genes, and 17 novel loci were repeatedly identified in different environments. An association signal cluster was identified for NSB and number of spikelets per secondary branch (NSSB) in the region of 31.6 to 31.7 Mb on chromosome 4. In addition to the common associations detected in both and subpopulations, many associated loci were unique to one subpopulation. For example, and were specifically associated with panicle length (PL) in and rice, respectively. Moreover, the -mediated flowering genes and were associated with the formation of panicle architecture in rice. These results suggest that different gene networks regulate panicle architecture in and rice. Copyright © 2016 Crop Science Society of America.

A novel high-resolution multilocus sequence typing of Giardia intestinalis Assemblage A isolates reveals zoonotic transmission, clonal outbreaks and recombination.

PubMed

Ankarklev, Johan; Lebbad, Marianne; Einarsson, Elin; Franzén, Oscar; Ahola, Harri; Troell, Karin; Svärd, Staffan G

2018-06-01

Molecular epidemiology and genotyping studies of the parasitic protozoan Giardia intestinalis have proven difficult due to multiple factors, such as low discriminatory power in the commonly used genotyping loci, which has hampered molecular analyses of outbreak sources, zoonotic transmission and virulence types. Here we have focused on assemblage A Giardia and developed a high-resolution assemblage-specific multilocus sequence typing (MLST) method. Analyses of sequenced G. intestinalis assemblage A genomes from different sub-assemblages identified a set of six genetic loci with high genetic variability. DNA samples from both humans (n = 44) and animals (n = 18) that harbored Giardia assemblage A infections, were PCR amplified (557-700 bp products) and sequenced at the six novel genetic loci. Bioinformatic analyses showed five to ten-fold higher levels of polymorphic sites than what was previously found among assemblage A samples using the classic genotyping loci. Phylogenetically, a division of two major clusters in assemblage A became apparent, separating samples of human and animal origin. A subset of human samples (n = 9) from a documented Giardia outbreak in a Swedish day-care center, showed full complementarity at nine genetic loci (the six new and the standard BG, TPI and GDH loci), strongly suggesting one source of infection. Furthermore, three samples of human origin displayed MLST profiles that were phylogenetically more closely related to MLST profiles from animal derived samples, suggesting zoonotic transmission. These new genotyping loci enabled us to detect events of recombination between different assemblage A isolates but also between assemblage A and E isolates. In summary, we present a novel and expanded MLST strategy with significantly improved sensitivity for molecular analyses of virulence types, zoonotic potential and source tracking for assemblage A Giardia. Copyright © 2018. Published by Elsevier B.V.

Proteins Encoded in Genomic Regions Associated with Immune-Mediated Disease Physically Interact and Suggest Underlying Biology

PubMed Central

Rossin, Elizabeth J.; Lage, Kasper; Raychaudhuri, Soumya; Xavier, Ramnik J.; Tatar, Diana; Benita, Yair

2011-01-01

Genome-wide association studies (GWAS) have defined over 150 genomic regions unequivocally containing variation predisposing to immune-mediated disease. Inferring disease biology from these observations, however, hinges on our ability to discover the molecular processes being perturbed by these risk variants. It has previously been observed that different genes harboring causal mutations for the same Mendelian disease often physically interact. We sought to evaluate the degree to which this is true of genes within strongly associated loci in complex disease. Using sets of loci defined in rheumatoid arthritis (RA) and Crohn's disease (CD) GWAS, we build protein–protein interaction (PPI) networks for genes within associated loci and find abundant physical interactions between protein products of associated genes. We apply multiple permutation approaches to show that these networks are more densely connected than chance expectation. To confirm biological relevance, we show that the components of the networks tend to be expressed in similar tissues relevant to the phenotypes in question, suggesting the network indicates common underlying processes perturbed by risk loci. Furthermore, we show that the RA and CD networks have predictive power by demonstrating that proteins in these networks, not encoded in the confirmed list of disease associated loci, are significantly enriched for association to the phenotypes in question in extended GWAS analysis. Finally, we test our method in 3 non-immune traits to assess its applicability to complex traits in general. We find that genes in loci associated to height and lipid levels assemble into significantly connected networks but did not detect excess connectivity among Type 2 Diabetes (T2D) loci beyond chance. Taken together, our results constitute evidence that, for many of the complex diseases studied here, common genetic associations implicate regions encoding proteins that physically interact in a preferential manner, in line with observations in Mendelian disease. PMID:21249183

A Genome-Wide Association Analysis Reveals Epistatic Cancellation of Additive Genetic Variance for Root Length in Arabidopsis thaliana.

PubMed

Lachowiec, Jennifer; Shen, Xia; Queitsch, Christine; Carlborg, Örjan

2015-01-01

Efforts to identify loci underlying complex traits generally assume that most genetic variance is additive. Here, we examined the genetics of Arabidopsis thaliana root length and found that the genomic narrow-sense heritability for this trait in the examined population was statistically zero. The low amount of additive genetic variance that could be captured by the genome-wide genotypes likely explains why no associations to root length could be found using standard additive-model-based genome-wide association (GWA) approaches. However, as the broad-sense heritability for root length was significantly larger, and primarily due to epistasis, we also performed an epistatic GWA analysis to map loci contributing to the epistatic genetic variance. Four interacting pairs of loci were revealed, involving seven chromosomal loci that passed a standard multiple-testing corrected significance threshold. The genotype-phenotype maps for these pairs revealed epistasis that cancelled out the additive genetic variance, explaining why these loci were not detected in the additive GWA analysis. Small population sizes, such as in our experiment, increase the risk of identifying false epistatic interactions due to testing for associations with very large numbers of multi-marker genotypes in few phenotyped individuals. Therefore, we estimated the false-positive risk using a new statistical approach that suggested half of the associated pairs to be true positive associations. Our experimental evaluation of candidate genes within the seven associated loci suggests that this estimate is conservative; we identified functional candidate genes that affected root development in four loci that were part of three of the pairs. The statistical epistatic analyses were thus indispensable for confirming known, and identifying new, candidate genes for root length in this population of wild-collected A. thaliana accessions. We also illustrate how epistatic cancellation of the additive genetic variance explains the insignificant narrow-sense and significant broad-sense heritability by using a combination of careful statistical epistatic analyses and functional genetic experiments.

Innate immune activity conditions the effect of regulatory variants upon monocyte gene expression.

PubMed

Fairfax, Benjamin P; Humburg, Peter; Makino, Seiko; Naranbhai, Vivek; Wong, Daniel; Lau, Evelyn; Jostins, Luke; Plant, Katharine; Andrews, Robert; McGee, Chris; Knight, Julian C

2014-03-07

To systematically investigate the impact of immune stimulation upon regulatory variant activity, we exposed primary monocytes from 432 healthy Europeans to interferon-γ (IFN-γ) or differing durations of lipopolysaccharide and mapped expression quantitative trait loci (eQTLs). More than half of cis-eQTLs identified, involving hundreds of genes and associated pathways, are detected specifically in stimulated monocytes. Induced innate immune activity reveals multiple master regulatory trans-eQTLs including the major histocompatibility complex (MHC), coding variants altering enzyme and receptor function, an IFN-β cytokine network showing temporal specificity, and an interferon regulatory factor 2 (IRF2) transcription factor-modulated network. Induced eQTL are significantly enriched for genome-wide association study loci, identifying context-specific associations to putative causal genes including CARD9, ATM, and IRF8. Thus, applying pathophysiologically relevant immune stimuli assists resolution of functional genetic variants.

Recognition of Y Fragment Deletion by Genotyping Graphs after Amplified by PowerPlex® 21 Detection Kit.

PubMed

Wang, S C; Ding, M M; Wei, X L; Zhang, T; Yao, F

2016-06-01

To recognize the possibility of Y fragment deletion of Amelogenin gene intuitively and simply according to the genotyping graphs. By calculating the ratio of total peak height of genotyping graphs, the statistics of equilibrium distribution between Amelogenin and D3S1358 loci, Amelogenin X-gene and Amelogenin Y-gene, and different alleles of D3S1358 loci from 1 968 individuals was analyzed after amplified by PowerPlex ® 21 detection kit. Sum of peak height of Amelogenin X allele was not less than 60% that of D3S1358 loci alleles in 90.8% female samples, and sum of peak height of Amelogenin X allele was not higher than 70% that of D3S1358 loci alleles in 94.9% male samples. The result of genotyping after amplified by PowerPlex ® 21 detection kit shows that the possibility of Y fragment deletion should be considered when only Amelogenin X-gene of Amelogenin is detected and the peak height of Amelogenin X-gene is not higher than 70% of the total peak height of D3S1358 loci. Copyright© by the Editorial Department of Journal of Forensic Medicine

Variation in heading date conceals quantitative trait loci for other traits of importance in breeding selection of rice

PubMed Central

Hori, Kiyosumi; Kataoka, Tomomori; Miura, Kiyoyuki; Yamaguchi, Masayuki; Saka, Norikuni; Nakahara, Takahiro; Sunohara, Yoshihiro; Ebana, Kaworu; Yano, Masahiro

2012-01-01

To identify quantitative trait loci (QTLs) associated with the primary target traits for selection in practical rice breeding programs, backcross inbred lines (BILs) derived from crosses between temperate japonica rice cultivars Nipponbare and Koshihikari were evaluated for 50 agronomic traits at six experimental fields located throughout Japan. Thirty-three of the 50 traits were significantly correlated with heading date. Using a linkage map including 647 single-nucleotide polymorphisms (SNPs), a total of 122 QTLs for 38 traits were mapped on all rice chromosomes except chromosomes 5 and 9. Fifty-eight of the 122 QTLs were detected near the heading date QTLs Hd16 and Hd17 and the remaining 64 QTLs were found in other chromosome regions. QTL analysis of 51 BILs having homozygous for the Koshihikari chromosome segments around Hd16 and Hd17 allowed us to detect 40 QTLs associated with 27 traits; 23 of these QTLs had not been detected in the original analysis. Among the 97 QTLs for the 30 traits measured in multiple environments, the genotype-by-environment interaction was significant for 44 QTLs and not significant for 53 QTLs. These results led us to propose a new selection strategy to improve agronomic performance in temperate japonica rice cultivars. PMID:23226082

Chromosomal Distribution of Endogenous Jaagsiekte Sheep Retrovirus Proviral Sequences in the Sheep Genome

PubMed Central

Carlson, Jonathan; Lyon, Monique; Bishop, Jeanette; Vaiman, Anne; Cribiu, Edmond; Mornex, Jean-François; Brown, Susan; Knudson, Dennis; DeMartini, James; Leroux, Caroline

2003-01-01

A family of endogenous retroviruses (enJSRV) closely related to Jaagsiekte sheep retrovirus (JSRV) is ubiquitous in domestic and wild sheep and goats. Southern blot hybridization studies indicate that there is little active replication or movement of the enJSRV proviruses in these species. Two approaches were used to investigate the distribution of proviral loci in the sheep genome. Fluorescence in situ hybridization (FISH) to metaphase chromosome spreads using viral DNA probes was used to detect loci on chromosomes. Hybridization signals were reproducibly detected on seven sheep chromosomes and eight goat chromosomes in seven cell lines. In addition, a panel of 30 sheep-hamster hybrid cell lines, each of which carries one or more sheep chromosomes and which collectively contain the whole sheep genome, was examined for enJSRV sequences. DNA from each of the lines was used as a template for PCR with JSRV gag-specific primers. A PCR product was amplified from 27 of the hybrid lines, indicating that JSRV gag sequences are found on at least 15 of the 28 sheep chromosomes, including those identified by FISH. Thus, enJSRV proviruses are essentially randomly distributed among the chromosomes of sheep and goats. FISH and/or Southern blot hybridization on DNA from several of the sheep-hamster hybrid cell lines suggests that loci containing multiple copies of enJSRV are present on chromosomes 6 and 9. The origin and functional significance of these arrays is not known. PMID:12915578

Multilocus variable-number tandem repeat analysis distinguishes outbreak and sporadic Escherichia coli O157:H7 isolates.

PubMed

Noller, Anna C; McEllistrem, M Catherine; Pacheco, Antonio G F; Boxrud, David J; Harrison, Lee H

2003-12-01

Escherichia coli O157:H7 is a major cause of food-borne illness in the United States. Outbreak detection involves traditional epidemiological methods and routine molecular subtyping by pulsed-field gel electrophoresis (PFGE). PFGE is labor-intensive, and the results are difficult to analyze and not easily transferable between laboratories. Multilocus variable-number tandem repeat (VNTR) analysis (MLVA) is a fast, portable method that analyzes multiple VNTR loci, which are areas of the bacterial genome that evolve quickly. Eighty isolates, including 21 isolates from five epidemiologically well-characterized outbreaks from Pennsylvania and Minnesota, were analyzed by PFGE and MLVA. Strains in PFGE clusters were defined as strains that differed by less than or equal to one band by using XbaI and the confirmatory enzyme SpeI. MLVA was performed by comparing the number of tandem repeats at seven loci. From 6 to 30 alleles were found at the seven loci, resulting in 64 MLVA types among the 80 isolates. MLVA correctly identified the isolates from all five outbreaks if only a single-locus variant was allowed. MLVA differentiated strains with unique PFGE types. Additionally, MLVA discriminated strains within PFGE-defined clusters that were not known to be part of an outbreak. In addition to being a simple and validated method for E. coli O157:H7 outbreak detection, MLVA appears to have a sensitivity equal to that of PFGE and a specificity superior to that of PFGE.

Evolutionary relationships among Pinus (Pinaceae) subsections inferred from multiple low-copy nuclear loci.

Treesearch

John Syring; Ann Willyard; Richard Cronn; Aaron Liston

2005-01-01

Sequence data from nrITS and cpDNA have failed to fully resolve phylogenetic relationships among Pinus species. Four low-copy nuclear genes, developed from the screening of 73 mapped conifer anchor loci, were sequenced from 12 species representing all subsections. Individual loci do not uniformly support either the nrITS or cpDNA hypotheses and in...

Tracking genes of ecological relevance using a genome scan in two independent regional population samples of Arabis alpina.

PubMed

Poncet, Bénédicte N; Herrmann, Doris; Gugerli, Felix; Taberlet, Pierre; Holderegger, Rolf; Gielly, Ludovic; Rioux, Delphine; Thuiller, Wilfried; Aubert, Serge; Manel, Stéphanie

2010-07-01

Understanding the genetic basis of adaptation in response to environmental variation is fundamental as adaptation plays a key role in the extension of ecological niches to marginal habitats and in ecological speciation. Based on the assumption that some genomic markers are correlated to environmental variables, we aimed to detect loci of ecological relevance in the alpine plant Arabis alpina L. sampled in two regions, the French (99 locations) and the Swiss (109 locations) Alps. We used an unusually large genome scan [825 amplified fragment length polymorphism loci (AFLPs)] and four environmental variables related to temperature, precipitation and topography. We detected linkage disequilibrium among only 3.5% of the considered AFLP loci. A population structure analysis identified no admixture in the study regions, and the French and Swiss Alps were differentiated and therefore could be considered as two independent regions. We applied generalized estimating equations (GEE) to detect ecologically relevant loci separately in the French and Swiss Alps. We identified 78 loci of ecological relevance (9%), which were mainly related to mean annual minimum temperature. Only four of these loci were common across the French and Swiss Alps. Finally, we discuss that the genomic characterization of these ecologically relevant loci, as identified in this study, opens up new perspectives for studying functional ecology in A. alpina, its relatives and other alpine plant species.

Evaluation of six candidate DNA barcode loci for identification of five important invasive grasses in eastern Australia

PubMed Central

Wang, Aisuo; Gopurenko, David; Wu, Hanwen; Lepschi, Brendan

2017-01-01

Invasive grass weeds reduce farm productivity, threaten biodiversity, and increase weed control costs. Identification of invasive grasses from native grasses has generally relied on the morphological examination of grass floral material. DNA barcoding may provide an alternative means to identify co-occurring native and invasive grasses, particularly during early growth stages when floral characters are unavailable for analysis. However, there are no universal loci available for grass barcoding. We herein evaluated the utility of six candidate loci (atpF intron, matK, ndhK-ndhC, psbE—petL, ETS and ITS) for barcode identification of several economically important invasive grass species frequently found among native grasses in eastern Australia. We evaluated these loci in 66 specimens representing five invasive grass species (Chloris gayana, Eragrostis curvula, Hyparrhenia hirta, Nassella neesiana, Nassella trichotoma) and seven native grass species. Our results indicated that, while no single locus can be universally used as a DNA barcode for distinguishing the grass species examined in this study, two plastid loci (atpF and matK) showed good distinguishing power to separate most of the taxa examined, and could be used as a dual locus to distinguish several of the invasive from the native species. Low PCR success rates were evidenced among two nuclear loci (ETS and ITS), and few species were amplified at these loci, however ETS was able to genetically distinguish the two important invasive Nassella species. Multiple loci analyses also suggested that ETS played a crucial role in allowing identification of the two Nassella species in the multiple loci combinations. PMID:28399170

Evaluation of six candidate DNA barcode loci for identification of five important invasive grasses in eastern Australia.

PubMed

Wang, Aisuo; Gopurenko, David; Wu, Hanwen; Lepschi, Brendan

2017-01-01

Invasive grass weeds reduce farm productivity, threaten biodiversity, and increase weed control costs. Identification of invasive grasses from native grasses has generally relied on the morphological examination of grass floral material. DNA barcoding may provide an alternative means to identify co-occurring native and invasive grasses, particularly during early growth stages when floral characters are unavailable for analysis. However, there are no universal loci available for grass barcoding. We herein evaluated the utility of six candidate loci (atpF intron, matK, ndhK-ndhC, psbE-petL, ETS and ITS) for barcode identification of several economically important invasive grass species frequently found among native grasses in eastern Australia. We evaluated these loci in 66 specimens representing five invasive grass species (Chloris gayana, Eragrostis curvula, Hyparrhenia hirta, Nassella neesiana, Nassella trichotoma) and seven native grass species. Our results indicated that, while no single locus can be universally used as a DNA barcode for distinguishing the grass species examined in this study, two plastid loci (atpF and matK) showed good distinguishing power to separate most of the taxa examined, and could be used as a dual locus to distinguish several of the invasive from the native species. Low PCR success rates were evidenced among two nuclear loci (ETS and ITS), and few species were amplified at these loci, however ETS was able to genetically distinguish the two important invasive Nassella species. Multiple loci analyses also suggested that ETS played a crucial role in allowing identification of the two Nassella species in the multiple loci combinations.

Evaluating mixed samples as a source of error in non-invasive genetic studies using microsatellites

USGS Publications Warehouse

Roon, David A.; Thomas, M.E.; Kendall, K.C.; Waits, L.P.

2005-01-01

The use of noninvasive genetic sampling (NGS) for surveying wild populations is increasing rapidly. Currently, only a limited number of studies have evaluated potential biases associated with NGS. This paper evaluates the potential errors associated with analysing mixed samples drawn from multiple animals. Most NGS studies assume that mixed samples will be identified and removed during the genotyping process. We evaluated this assumption by creating 128 mixed samples of extracted DNA from brown bear (Ursus arctos) hair samples. These mixed samples were genotyped and screened for errors at six microsatellite loci according to protocols consistent with those used in other NGS studies. Five mixed samples produced acceptable genotypes after the first screening. However, all mixed samples produced multiple alleles at one or more loci, amplified as only one of the source samples, or yielded inconsistent electropherograms by the final stage of the error-checking process. These processes could potentially reduce the number of individuals observed in NGS studies, but errors should be conservative within demographic estimates. Researchers should be aware of the potential for mixed samples and carefully design gel analysis criteria and error checking protocols to detect mixed samples.

Rapid and high resolution genotyping of all Escherichia coli serotypes using 10 genomic repeat-containing loci.

PubMed

Løbersli, Inger; Haugum, Kjersti; Lindstedt, Bjørn-Arne

2012-01-01

Our laboratory has previously published two multiple-locus variable-number tandem-repeats analysis (MLVA) methods for rapid genotyping of Escherichia coli (E. coli), which are now in routine use for surveillance and outbreak detection. The first assay developed was specific for E. coli O157:H7; however this assay was not suitable for genotyping other E. coli serotypes. A new generic MLVA-assay was then developed with the capability of genotyping all E. coli serotypes. This generic E. coli MLVA (GECM7) was based on polymorphism in seven variable number of tandem repeats (VNTR) loci. GECM7 worked well with the majority of E. coli serotypes; however we wanted to increase the resolution for this method based in part of comparison with PFGE typing of E. coli O26:H11, where PFGE appeared to display higher resolution. The GECM7 method was improved by adding three new repeat-loci to a total of ten (GECM10), and a considerable increase in resolution was observed (from 296 to 507 genotypes on the same set of strains). Copyright © 2011 Elsevier B.V. All rights reserved.

Multiple loci and epistases control genetic variation for seed dormancy in weedy rice (Oryza sativa).

PubMed Central

Gu, Xing-You; Kianian, Shahryar F; Foley, Michael E

2004-01-01

Weedy rice has much stronger seed dormancy than cultivated rice. A wild-like weedy strain SS18-2 was selected to investigate the genetic architecture underlying seed dormancy, a critical adaptive trait in plants. A framework genetic map covering the rice genome was constructed on the basis of 156 BC(1) [EM93-1 (nondormant breeding line)//EM93-1/SS18-2] individuals. The mapping population was replicated using a split-tiller technique to control and better estimate the environmental variation. Dormancy was determined by germination of seeds after 1, 11, and 21 days of after-ripening (DAR). Six dormancy QTL, designated as qSD(S)-4, -6, -7-1, -7-2, -8, and -12, were identified. The locus qSD(S)-7-1 was tightly linked to the red pericarp color gene Rc. A QTL x DAR interaction was detected for qSD(S)-12, the locus with the largest main effect at 1, 11, and 21 DAR (R(2) = 0.14, 0.24, and 0.20, respectively). Two, three, and four orders of epistases were detected with four, six, and six QTL, respectively. The higher-order epistases strongly suggest the presence of genetically complex networks in the regulation of variation for seed dormancy in natural populations and make it critical to select for a favorable combination of alleles at multiple loci in positional cloning of a target dormancy gene. PMID:15082564

High variation in clonal vs. sexual reproduction in populations of the wild strawberry, Fragaria virginiana (Rosaceae)

PubMed Central

Wilk, John A.; Kramer, Andrea T.; Ashley, Mary V.

2009-01-01

Background and Aims Many plants reproduce both clonally and sexually, and the balance between the two modes of reproduction will vary among populations. Clonal reproduction was characterized in three populations of the wild strawberry, Fragaria virginiana, to determine the extent that reproductive mode varied locally between sites. The study sites were fragmented woodlands in Cook County, Illinois, USA. Methods A total of 95 strawberry ramets were sampled from the three sites via transects. Ramets were mapped and genotyped at five variable microsatellite loci. The variability at these five loci was sufficient to assign plants to clones with high confidence, and the spatial pattern of genets was mapped at each site. Key Results A total of 27 distinct multilocus genotypes were identified. Of these, 18 genotypes were detected only once, with the remaining nine detected in multiple ramets. The largest clone was identified in 16 ramets. No genets were shared between sites, and each site exhibited markedly different clonal and sexual recruitment patterns, ranging from two non-overlapping and widespread genets to 19 distinct genets. Only one flowering genet was female; the remainder were hermaphrodites. Conclusions Local population history or fine-scale ecological differences can result in dramatically different reproductive patterns at small spatial scales. This finding may be fairly widespread among clonal plant species, and studies that aim to characterize reproductive modes in species capable of asexual reproduction need to evaluate reproductive modes in multiple populations and sites. PMID:19797422

Defining the proximal border of the Huntington disease candidate region by multipoint recombination analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skraastad, M.I.; De Rooij, K.E.; De Koning Gans, P.A.M.

1993-06-01

The candidate region for the Huntington disease (HD) gene has been narrowed down to a 2.2-Mb region between D4S10 and D4S98 on the short arm of chromosome 4. To map the HD gene within this candidate region 65 Dutch HD families were studied. In total 338 informative meioses were analyzed and 11 multiple informative crossovers were detected. Assuming a minimum number of recombinations and no double recombinations, the multiple informative crossovers are consistent with one specific genetic order for 12 loci: D4S10-(D4S81,D4S126)-D4S125-(D4S127,D4S95)-D4S43-(D4S115, D4S96, D4S111, D4S90, D4S141).This is in agreement with the known data derived from similar and other methods. Themore » loci between brackets could not be mapped relative to each other. In the family material, two informative three-point marker recombination events were detected in the proximal HD candidate region, which are also informative for HD. Both recombination events map the HD gene distal to D4S81 and most likely distal to D4S125, narrowing down the HD candidate region to a 1.7-Mb region between D4S125 and D4S98. 39 refs., 3 figs., 2 tabs.« less

Fractional populations in multiple gene inheritance.

PubMed

Chung, Myung-Hoon; Kim, Chul Koo; Nahm, Kyun

2003-01-22

With complete knowledge of the human genome sequence, one of the most interesting tasks remaining is to understand the functions of individual genes and how they communicate. Using the information about genes (locus, allele, mutation rate, fitness, etc.), we attempt to explain population demographic data. This population evolution study could complement and enhance biologists' understanding about genes. We present a general approach to study population genetics in complex situations. In the present approach, multiple allele inheritance, multiple loci inheritance, natural selection and mutations are allowed simultaneously in order to consider a more realistic situation. A simulation program is presented so that readers can readily carry out studies with their own parameters. It is shown that the multiplicity of the loci greatly affects the demographic results of fractional population ratios. Furthermore, the study indicates that some high infant mortality rates due to congenital anomalies can be attributed to multiple loci inheritance. The simulation program can be downloaded from http://won.hongik.ac.kr/~mhchung/index_files/yapop.htm. In order to run this program, one needs Visual Studio.NET platform, which can be downloaded from http://msdn.microsoft.com/netframework/downloads/default.asp.

Genome-wide association study identifies novel loci associated with circulating phospho- and sphingolipid concentrations.

PubMed

Demirkan, Ayşe; van Duijn, Cornelia M; Ugocsai, Peter; Isaacs, Aaron; Pramstaller, Peter P; Liebisch, Gerhard; Wilson, James F; Johansson, Åsa; Rudan, Igor; Aulchenko, Yurii S; Kirichenko, Anatoly V; Janssens, A Cecile J W; Jansen, Ritsert C; Gnewuch, Carsten; Domingues, Francisco S; Pattaro, Cristian; Wild, Sarah H; Jonasson, Inger; Polasek, Ozren; Zorkoltseva, Irina V; Hofman, Albert; Karssen, Lennart C; Struchalin, Maksim; Floyd, James; Igl, Wilmar; Biloglav, Zrinka; Broer, Linda; Pfeufer, Arne; Pichler, Irene; Campbell, Susan; Zaboli, Ghazal; Kolcic, Ivana; Rivadeneira, Fernando; Huffman, Jennifer; Hastie, Nicholas D; Uitterlinden, Andre; Franke, Lude; Franklin, Christopher S; Vitart, Veronique; Nelson, Christopher P; Preuss, Michael; Bis, Joshua C; O'Donnell, Christopher J; Franceschini, Nora; Witteman, Jacqueline C M; Axenovich, Tatiana; Oostra, Ben A; Meitinger, Thomas; Hicks, Andrew A; Hayward, Caroline; Wright, Alan F; Gyllensten, Ulf; Campbell, Harry; Schmitz, Gerd

2012-01-01

Phospho- and sphingolipids are crucial cellular and intracellular compounds. These lipids are required for active transport, a number of enzymatic processes, membrane formation, and cell signalling. Disruption of their metabolism leads to several diseases, with diverse neurological, psychiatric, and metabolic consequences. A large number of phospholipid and sphingolipid species can be detected and measured in human plasma. We conducted a meta-analysis of five European family-based genome-wide association studies (N = 4034) on plasma levels of 24 sphingomyelins (SPM), 9 ceramides (CER), 57 phosphatidylcholines (PC), 20 lysophosphatidylcholines (LPC), 27 phosphatidylethanolamines (PE), and 16 PE-based plasmalogens (PLPE), as well as their proportions in each major class. This effort yielded 25 genome-wide significant loci for phospholipids (smallest P-value = 9.88×10(-204)) and 10 loci for sphingolipids (smallest P-value = 3.10×10(-57)). After a correction for multiple comparisons (P-value<2.2×10(-9)), we observed four novel loci significantly associated with phospholipids (PAQR9, AGPAT1, PKD2L1, PDXDC1) and two with sphingolipids (PLD2 and APOE) explaining up to 3.1% of the variance. Further analysis of the top findings with respect to within class molar proportions uncovered three additional loci for phospholipids (PNLIPRP2, PCDH20, and ABDH3) suggesting their involvement in either fatty acid elongation/saturation processes or fatty acid specific turnover mechanisms. Among those, 14 loci (KCNH7, AGPAT1, PNLIPRP2, SYT9, FADS1-2-3, DLG2, APOA1, ELOVL2, CDK17, LIPC, PDXDC1, PLD2, LASS4, and APOE) mapped into the glycerophospholipid and 12 loci (ILKAP, ITGA9, AGPAT1, FADS1-2-3, APOA1, PCDH20, LIPC, PDXDC1, SGPP1, APOE, LASS4, and PLD2) to the sphingolipid pathways. In large meta-analyses, associations between FADS1-2-3 and carotid intima media thickness, AGPAT1 and type 2 diabetes, and APOA1 and coronary artery disease were observed. In conclusion, our study identified nine novel phospho- and sphingolipid loci, substantially increasing our knowledge of the genetic basis for these traits.

A subset of skin tumor modifier loci determines survival time of tumor-bearing mice

PubMed Central

Nagase, Hiroki; Mao, Jian-Hua; Balmain, Allan

1999-01-01

Studies of mouse models of human cancer have established the existence of multiple tumor modifiers that influence parameters of cancer susceptibility such as tumor multiplicity, tumor size, or the probability of malignant progression. We have carried out an analysis of skin tumor susceptibility in interspecific Mus musculus/Mus spretus hybrid mice and have identified another seven loci showing either significant (six loci) or suggestive (one locus) linkage to tumor susceptibility or resistance. A specific search was carried out for skin tumor modifier loci associated with time of survival after development of a malignant tumor. A combination of resistance alleles at three markers [D6Mit15 (Skts12), D7Mit12 (Skts2), and D17Mit7 (Skts10)], all of which are close to or the same as loci associated with carcinoma incidence and/or papilloma multiplicity, is significantly associated with increased survival of mice with carcinomas, whereas the reverse combination of susceptibility alleles is significantly linked to early mortality caused by rapid carcinoma growth (χ2 = 25.22; P = 5.1 × 10−8). These data indicate that host genetic factors may be used to predict carcinoma growth rate and/or survival of individual backcross mice exposed to the same carcinogenic stimulus and suggest that mouse models may provide an approach to the identification of genetic modifiers of cancer survival in humans. PMID:10611333

Ascertainment correction for Markov chain Monte Carlo segregation and linkage analysis of a quantitative trait.

PubMed

Ma, Jianzhong; Amos, Christopher I; Warwick Daw, E

2007-09-01

Although extended pedigrees are often sampled through probands with extreme levels of a quantitative trait, Markov chain Monte Carlo (MCMC) methods for segregation and linkage analysis have not been able to perform ascertainment corrections. Further, the extent to which ascertainment of pedigrees leads to biases in the estimation of segregation and linkage parameters has not been previously studied for MCMC procedures. In this paper, we studied these issues with a Bayesian MCMC approach for joint segregation and linkage analysis, as implemented in the package Loki. We first simulated pedigrees ascertained through individuals with extreme values of a quantitative trait in spirit of the sequential sampling theory of Cannings and Thompson [Cannings and Thompson [1977] Clin. Genet. 12:208-212]. Using our simulated data, we detected no bias in estimates of the trait locus location. However, in addition to allele frequencies, when the ascertainment threshold was higher than or close to the true value of the highest genotypic mean, bias was also found in the estimation of this parameter. When there were multiple trait loci, this bias destroyed the additivity of the effects of the trait loci, and caused biases in the estimation all genotypic means when a purely additive model was used for analyzing the data. To account for pedigree ascertainment with sequential sampling, we developed a Bayesian ascertainment approach and implemented Metropolis-Hastings updates in the MCMC samplers used in Loki. Ascertainment correction greatly reduced biases in parameter estimates. Our method is designed for multiple, but a fixed number of trait loci. Copyright (c) 2007 Wiley-Liss, Inc.

Genome-wide association mapping reveals a rich genetic architecture of stripe rust resistance loci in emmer wheat (Triticum turgidum ssp. dicoccum).

PubMed

Liu, Weizhen; Maccaferri, Marco; Chen, Xianming; Laghetti, Gaetano; Pignone, Domenico; Pumphrey, Michael; Tuberosa, Roberto

2017-11-01

SNP-based genome scanning in worldwide domesticated emmer germplasm showed high genetic diversity, rapid linkage disequilibrium decay and 51 loci for stripe rust resistance, a large proportion of which were novel. Cultivated emmer wheat (Triticum turgidum ssp. dicoccum), one of the oldest domesticated crops in the world, is a potentially rich reservoir of variation for improvement of resistance/tolerance to biotic and abiotic stresses in wheat. Resistance to stripe rust (Puccinia striiformis f. sp. tritici) in emmer wheat has been under-investigated. Here, we employed genome-wide association (GWAS) mapping with a mixed linear model to dissect effective stripe rust resistance loci in a worldwide collection of 176 cultivated emmer wheat accessions. Adult plants were tested in six environments and seedlings were evaluated with five races from the United States and one from Italy under greenhouse conditions. Five accessions were resistant across all experiments. The panel was genotyped with the wheat 90,000 Illumina iSelect single nucleotide polymorphism (SNP) array and 5106 polymorphic SNP markers with mapped positions were obtained. A high level of genetic diversity and fast linkage disequilibrium decay were observed. In total, we identified 14 loci associated with field resistance in multiple environments. Thirty-seven loci were significantly associated with all-stage (seedling) resistance and six of them were effective against multiple races. Of the 51 total loci, 29 were mapped distantly from previously reported stripe rust resistance genes or quantitative trait loci and represent newly discovered resistance loci. Our results suggest that GWAS is an effective method for characterizing genes in cultivated emmer wheat and confirm that emmer wheat is a rich source of stripe rust resistance loci that can be used for wheat improvement.

A Conformal, Fully-Conservative Approach for Predicting Blast Effects on Ground Vehicles

DTIC Science & Technology

2014-04-01

time integration  Approximate Riemann Fluxes (HLLE, HLLC) ◦ Robust mixture model for multi-material flows  Multiple Equations of State ◦ Perfect Gas...Loci/CHEM: Chemically reacting compressible flow solver . ◦ Currently in production use by NASA for the simulation of rocket motors, plumes, and...vehicles  Loci/DROPLET: Eulerian and Lagrangian multiphase solvers  Loci/STREAM: pressure-based solver ◦ Developed by Streamline Numerics and

Finding missing heritability in less significant Loci and allelic heterogeneity: genetic variation in human height.

PubMed

Zhang, Ge; Karns, Rebekah; Sun, Guangyun; Indugula, Subba Rao; Cheng, Hong; Havas-Augustin, Dubravka; Novokmet, Natalija; Durakovic, Zijad; Missoni, Sasa; Chakraborty, Ranajit; Rudan, Pavao; Deka, Ranjan

2012-01-01

Genome-wide association studies (GWAS) have identified many common variants associated with complex traits in human populations. Thus far, most reported variants have relatively small effects and explain only a small proportion of phenotypic variance, leading to the issues of 'missing' heritability and its explanation. Using height as an example, we examined two possible sources of missing heritability: first, variants with smaller effects whose associations with height failed to reach genome-wide significance and second, allelic heterogeneity due to the effects of multiple variants at a single locus. Using a novel analytical approach we examined allelic heterogeneity of height-associated loci selected from SNPs of different significance levels based on the summary data of the GIANT (stage 1) studies. In a sample of 1,304 individuals collected from an island population of the Adriatic coast of Croatia, we assessed the extent of height variance explained by incorporating the effects of less significant height loci and multiple effective SNPs at the same loci. Our results indicate that approximately half of the 118 loci that achieved stringent genome-wide significance (p-value<5×10(-8)) showed evidence of allelic heterogeneity. Additionally, including less significant loci (i.e., p-value<5×10(-4)) and accounting for effects of allelic heterogeneity substantially improved the variance explained in height.

Detection of the testis determining factor in an XX man.

PubMed

Fukutani, K; Kajiwara, T; Nagafuchi, S; Nakahori, Y; Nakagome, Y

1993-01-01

An XX male patient was examined for the presence of 25 loci on the Y chromosome. Only 2 loci, the proximal border of the pseudoautosomal region Y and the sex determining region Y, were detected in this patient. The other 23 loci, including the zinc finger protein Y, were absent. We presume that a crossing over between the X and Y chromosomes occurred at the region proximal to the sex determining region Y but distal to the zinc finger protein Y during meiosis of the father.

Identifying the most likely contributors to a Y-STR mixture using the discrete Laplace method.

PubMed

Andersen, Mikkel Meyer; Eriksen, Poul Svante; Mogensen, Helle Smidt; Morling, Niels

2015-03-01

In some crime cases, the male part of the DNA in a stain can only be analysed using Y chromosomal markers, e.g. Y-STRs. This may be the case in e.g. rape cases, where the male components can only be detected as Y-STR profiles, because the fraction of male DNA is much smaller than that of female DNA, which can mask the male results when autosomal STRs are investigated. Sometimes, mixtures of Y-STRs are observed, e.g. in rape cases with multiple offenders. In such cases, Y-STR mixture analysis is required, e.g. by mixture deconvolution, to deduce the most likely DNA profiles from the contributors. We demonstrate how the discrete Laplace method can be used to separate a two person Y-STR mixture, where the Y-STR profiles of the true contributors are not present in the reference dataset, which is often the case for Y-STR profiles in real case work. We also briefly discuss how to calculate the weight of the evidence using the likelihood ratio principle when a suspect's Y-STR profile fits into a two person mixture. We used three datasets with between 7 and 21 Y-STR loci: Denmark (n=181), Somalia (n=201) and Germany (n=3443). The Danish dataset with 21 loci was truncated to 15 and 10 loci to examine the effect of the number of loci. For each of these datasets, an out of sample simulation study was performed: A total of 550 mixtures were composed by randomly sampling two haplotypes, h1 and h2, from the dataset. We then used the discrete Laplace method on the remaining data (excluding h1 and h2) to rank the contributor pairs by the product of the contributors' estimated haplotype frequencies. Successful separation of mixtures (defined by the observation that the true contributor pair was among the 10 most likely contributor pairs) was found in 42-52% of the cases for 21 loci, 69-75% for 15 loci and 92-99% for 10 loci or less depending on the dataset and how the discrete Laplace model was chosen. Y-STR mixtures with many loci are difficult to separate, but even haplotypes with 21 Y-STR loci can be separated. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Phylogeography of the endangered Cathaya argyrophylla (Pinaceae) inferred from sequence variation of mitochondrial and nuclear DNA.

PubMed

Wang, Hong-Wei; Ge, Song

2006-11-01

Cathaya argyrophylla is an endangered conifer restricted to subtropical mountains of China. To study phylogeographical pattern and demographic history of C. argyrophylla, species-wide genetic variation was investigated using sequences of maternally inherited mtDNA and biparentally inherited nuclear DNA. Of 15 populations sampled from all four distinct regions, only three mitotypes were detected at two loci, without single region having a mixed composition (G(ST) = 1). Average nucleotide diversity (theta(ws) = 0.0024; pi(s) = 0.0029) across eight nuclear loci is significantly lower than those found for other conifers (theta(ws) = 0.003 approximately 0.015; pi(s) = 0.002 approximately 0.012) based on estimates of multiple loci. Because of its highest diversity among the eight nuclear loci and evolving neutrally, one locus (2009) was further used for phylogeographical studies and eight haplotypes resulting from 12 polymorphic sites were obtained from 98 individuals. All the four distinct regions had at least four haplotypes, with the Dalou region (DL) having the highest diversity and the Bamian region (BM) the lowest, paralleling the result of the eight nuclear loci. An AMOVA revealed significant proportion of diversity attributable to differences among regions (13.4%) and among populations within regions (8.9%). F(ST) analysis also indicated significantly high differentiation among populations (F(ST) = 0.22) and between regions (F(ST) = 0.12-0.38). Non-overlapping distribution of mitotypes and high genetic differentiation among the distinct geographical groups suggest the existence of at least four separate glacial refugia. Based on network and mismatch distribution analyses, we do not find evidence of long distance dispersal and population expansion in C. argyrophylla. Ex situ conservation and artificial crossing are recommended for the management of this endangered species.

Discovery and Fine-Mapping of Glycaemic and Obesity-Related Trait Loci Using High-Density Imputation.

PubMed

Horikoshi, Momoko; Mӓgi, Reedik; van de Bunt, Martijn; Surakka, Ida; Sarin, Antti-Pekka; Mahajan, Anubha; Marullo, Letizia; Thorleifsson, Gudmar; Hӓgg, Sara; Hottenga, Jouke-Jan; Ladenvall, Claes; Ried, Janina S; Winkler, Thomas W; Willems, Sara M; Pervjakova, Natalia; Esko, Tõnu; Beekman, Marian; Nelson, Christopher P; Willenborg, Christina; Wiltshire, Steven; Ferreira, Teresa; Fernandez, Juan; Gaulton, Kyle J; Steinthorsdottir, Valgerdur; Hamsten, Anders; Magnusson, Patrik K E; Willemsen, Gonneke; Milaneschi, Yuri; Robertson, Neil R; Groves, Christopher J; Bennett, Amanda J; Lehtimӓki, Terho; Viikari, Jorma S; Rung, Johan; Lyssenko, Valeriya; Perola, Markus; Heid, Iris M; Herder, Christian; Grallert, Harald; Müller-Nurasyid, Martina; Roden, Michael; Hypponen, Elina; Isaacs, Aaron; van Leeuwen, Elisabeth M; Karssen, Lennart C; Mihailov, Evelin; Houwing-Duistermaat, Jeanine J; de Craen, Anton J M; Deelen, Joris; Havulinna, Aki S; Blades, Matthew; Hengstenberg, Christian; Erdmann, Jeanette; Schunkert, Heribert; Kaprio, Jaakko; Tobin, Martin D; Samani, Nilesh J; Lind, Lars; Salomaa, Veikko; Lindgren, Cecilia M; Slagboom, P Eline; Metspalu, Andres; van Duijn, Cornelia M; Eriksson, Johan G; Peters, Annette; Gieger, Christian; Jula, Antti; Groop, Leif; Raitakari, Olli T; Power, Chris; Penninx, Brenda W J H; de Geus, Eco; Smit, Johannes H; Boomsma, Dorret I; Pedersen, Nancy L; Ingelsson, Erik; Thorsteinsdottir, Unnur; Stefansson, Kari; Ripatti, Samuli; Prokopenko, Inga; McCarthy, Mark I; Morris, Andrew P

2015-07-01

Reference panels from the 1000 Genomes (1000G) Project Consortium provide near complete coverage of common and low-frequency genetic variation with minor allele frequency ≥0.5% across European ancestry populations. Within the European Network for Genetic and Genomic Epidemiology (ENGAGE) Consortium, we have undertaken the first large-scale meta-analysis of genome-wide association studies (GWAS), supplemented by 1000G imputation, for four quantitative glycaemic and obesity-related traits, in up to 87,048 individuals of European ancestry. We identified two loci for body mass index (BMI) at genome-wide significance, and two for fasting glucose (FG), none of which has been previously reported in larger meta-analysis efforts to combine GWAS of European ancestry. Through conditional analysis, we also detected multiple distinct signals of association mapping to established loci for waist-hip ratio adjusted for BMI (RSPO3) and FG (GCK and G6PC2). The index variant for one association signal at the G6PC2 locus is a low-frequency coding allele, H177Y, which has recently been demonstrated to have a functional role in glucose regulation. Fine-mapping analyses revealed that the non-coding variants most likely to drive association signals at established and novel loci were enriched for overlap with enhancer elements, which for FG mapped to promoter and transcription factor binding sites in pancreatic islets, in particular. Our study demonstrates that 1000G imputation and genetic fine-mapping of common and low-frequency variant association signals at GWAS loci, integrated with genomic annotation in relevant tissues, can provide insight into the functional and regulatory mechanisms through which their effects on glycaemic and obesity-related traits are mediated.

Discovery and Fine-Mapping of Glycaemic and Obesity-Related Trait Loci Using High-Density Imputation

PubMed Central

van de Bunt, Martijn; Surakka, Ida; Sarin, Antti-Pekka; Mahajan, Anubha; Marullo, Letizia; Thorleifsson, Gudmar; Hӓgg, Sara; Hottenga, Jouke-Jan; Ladenvall, Claes; Ried, Janina S.; Winkler, Thomas W.; Willems, Sara M.; Pervjakova, Natalia; Esko, Tõnu; Beekman, Marian; Nelson, Christopher P.; Willenborg, Christina; Ferreira, Teresa; Fernandez, Juan; Gaulton, Kyle J.; Steinthorsdottir, Valgerdur; Hamsten, Anders; Magnusson, Patrik K. E.; Willemsen, Gonneke; Milaneschi, Yuri; Robertson, Neil R.; Groves, Christopher J.; Bennett, Amanda J.; Lehtimӓki, Terho; Viikari, Jorma S.; Rung, Johan; Lyssenko, Valeriya; Perola, Markus; Heid, Iris M.; Herder, Christian; Grallert, Harald; Müller-Nurasyid, Martina; Roden, Michael; Hypponen, Elina; Isaacs, Aaron; van Leeuwen, Elisabeth M.; Karssen, Lennart C.; Mihailov, Evelin; Houwing-Duistermaat, Jeanine J.; de Craen, Anton J. M.; Deelen, Joris; Havulinna, Aki S.; Blades, Matthew; Hengstenberg, Christian; Erdmann, Jeanette; Schunkert, Heribert; Kaprio, Jaakko; Tobin, Martin D.; Samani, Nilesh J.; Lind, Lars; Salomaa, Veikko; Lindgren, Cecilia M.; Slagboom, P. Eline; Metspalu, Andres; van Duijn, Cornelia M.; Eriksson, Johan G.; Peters, Annette; Gieger, Christian; Jula, Antti; Groop, Leif; Raitakari, Olli T.; Power, Chris; Penninx, Brenda W. J. H.; de Geus, Eco; Smit, Johannes H.; Boomsma, Dorret I.; Pedersen, Nancy L.; Ingelsson, Erik; Thorsteinsdottir, Unnur; Stefansson, Kari; Ripatti, Samuli; Prokopenko, Inga; McCarthy, Mark I.; Morris, Andrew P.

2015-01-01

Reference panels from the 1000 Genomes (1000G) Project Consortium provide near complete coverage of common and low-frequency genetic variation with minor allele frequency ≥0.5% across European ancestry populations. Within the European Network for Genetic and Genomic Epidemiology (ENGAGE) Consortium, we have undertaken the first large-scale meta-analysis of genome-wide association studies (GWAS), supplemented by 1000G imputation, for four quantitative glycaemic and obesity-related traits, in up to 87,048 individuals of European ancestry. We identified two loci for body mass index (BMI) at genome-wide significance, and two for fasting glucose (FG), none of which has been previously reported in larger meta-analysis efforts to combine GWAS of European ancestry. Through conditional analysis, we also detected multiple distinct signals of association mapping to established loci for waist-hip ratio adjusted for BMI (RSPO3) and FG (GCK and G6PC2). The index variant for one association signal at the G6PC2 locus is a low-frequency coding allele, H177Y, which has recently been demonstrated to have a functional role in glucose regulation. Fine-mapping analyses revealed that the non-coding variants most likely to drive association signals at established and novel loci were enriched for overlap with enhancer elements, which for FG mapped to promoter and transcription factor binding sites in pancreatic islets, in particular. Our study demonstrates that 1000G imputation and genetic fine-mapping of common and low-frequency variant association signals at GWAS loci, integrated with genomic annotation in relevant tissues, can provide insight into the functional and regulatory mechanisms through which their effects on glycaemic and obesity-related traits are mediated. PMID:26132169

Complementary epistasis involving Sr12 explains adult plant resistance to stem rust in Thatcher wheat (Triticum aestivum L.).

PubMed

Rouse, Matthew N; Talbert, Luther E; Singh, Davinder; Sherman, Jamie D

2014-07-01

Quantitative trait loci conferring adult plant resistance to Ug99 stem rust in Thatcher wheat display complementary gene action suggesting multiple quantitative trait loci are needed for effective resistance. Adult plant resistance (APR) in wheat (Triticum aestivum L.) to stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is desirable because this resistance can be Pgt race non-specific. Resistance derived from cultivar Thatcher can confer high levels of APR to the virulent Pgt race TTKSK (Ug99) when combined with stem rust resistance gene Sr57 (Lr34). To identify the loci conferring APR in Thatcher, we evaluated 160 RILs derived from Thatcher crossed to susceptible cultivar McNeal for field stem rust reaction in Kenya for two seasons and in St. Paul for one season. All RILs and parents were susceptible as seedlings to race TTKSK. However, adult plant stem rust severities in Kenya varied from 5 to 80 %. Composite interval mapping identified four quantitative trait loci (QTL). Three QTL were inherited from Thatcher and one, Sr57, was inherited from McNeal. The markers closest to the QTL peaks were used in an ANOVA to determine the additive and epistatic effects. A QTL on 3BS was detected in all three environments and explained 27-35 % of the variation. The peak of this QTL was at the same location as the Sr12 seedling resistance gene effective to race SCCSC. Epistatic interactions were significant between Sr12 and QTL on chromosome arms 1AL and 2BS. Though Sr12 cosegregated with the largest effect QTL, lines with Sr12 were not always resistant. The data suggest that Sr12 or a linked gene, though not effective to race TTKSK alone, confers APR when combined with other resistance loci.

Loci on chromosomes 1A and 2A affect resistance to tan (yellow) spot in wheat populations not segregating for tsn1.

PubMed

Shankar, Manisha; Jorgensen, Dorthe; Taylor, Julian; Chalmers, Ken J; Fox, Rebecca; Hollaway, Grant J; Neate, Stephen M; McLean, Mark S; Vassos, Elysia; Golzar, Hossein; Loughman, Robert; Mather, Diane E

2017-12-01

QTL for tan spot resistance were mapped on wheat chromosomes 1A and 2A. Lines were developed with resistance alleles at these loci and at the tsn1 locus on chromosome 5B. These lines expressed significantly higher resistance than the parent with tsn1 only. Tan spot (syn. yellow spot and yellow leaf spot) caused by Pyrenophora tritici-repentis is an important foliar disease of wheat in Australia. Few resistance genes have been mapped in Australian germplasm and only one, known as tsn1 located on chromosome 5B, is known in Australian breeding programs. This gene confers insensitivity to the fungal effector ToxA. The main aim of this study was to map novel resistance loci in two populations: Calingiri/Wyalkatchem, which is fixed for the ToxA-insensitivity allele tsn1, and IGW2574/Annuello, which is fixed for the ToxA-sensitivity allele Tsn1. A second aim was to combine new loci with tsn1 to develop lines with improved resistance. Tan spot severity was evaluated at various growth stages and in multiple environments. Symptom severity traits exhibited quantitative variation. The most significant quantitative trait loci (QTL) were detected on chromosomes 2A and 1A. The QTL on 2A explained up to 29.2% of the genotypic variation in the Calingiri/Wyalkatchem population with the resistance allele contributed by Wyalkatchem. The QTL on 1A explained up to 28.1% of the genotypic variation in the IGW2574/Annuello population with the resistance allele contributed by Annuello. The resistance alleles at both QTL were successfully combined with tsn1 to develop lines that express significantly better resistance at both seedling and adult plant stages than Calingiri which has tsn1 only.

[Full Sibling Identification by IBS Scoring Method and Establishment of the Query Table of Its Critical Value].

PubMed

Li, R; Li, C T; Zhao, S M; Li, H X; Li, L; Wu, R G; Zhang, C C; Sun, H Y

2017-04-01

To establish a query table of IBS critical value and identification power for the detection systems with different numbers of STR loci under different false judgment standards. Samples of 267 pairs of full siblings and 360 pairs of unrelated individuals were collected and 19 autosomal STR loci were genotyped by Golden e ye™ 20A system. The full siblings were determined using IBS scoring method according to the 'Regulation for biological full sibling testing'. The critical values and identification power for the detection systems with different numbers of STR loci under different false judgment standards were calculated by theoretical methods. According to the formal IBS scoring criteria, the identification power of full siblings and unrelated individuals was 0.764 0 and the rate of false judgment was 0. The results of theoretical calculation were consistent with that of sample observation. The query table of IBS critical value for identification of full sibling detection systems with different numbers of STR loci was successfully established. The IBS scoring method defined by the regulation has high detection efficiency and low false judgment rate, which provides a relatively conservative result. The query table of IBS critical value for identification of full sibling detection systems with different numbers of STR loci provides an important reference data for the result judgment of full sibling testing and owns a considerable practical value. Copyright© by the Editorial Department of Journal of Forensic Medicine

GWAS of clinically defined gout and subtypes identifies multiple susceptibility loci that include urate transporter genes

PubMed Central

Nakayama, Akiyoshi; Nakaoka, Hirofumi; Yamamoto, Ken; Sakiyama, Masayuki; Shaukat, Amara; Toyoda, Yu; Okada, Yukinori; Kamatani, Yoichiro; Nakamura, Takahiro; Takada, Tappei; Inoue, Katsuhisa; Yasujima, Tomoya; Yuasa, Hiroaki; Shirahama, Yuko; Nakashima, Hiroshi; Shimizu, Seiko; Higashino, Toshihide; Kawamura, Yusuke; Ogata, Hiraku; Kawaguchi, Makoto; Ohkawa, Yasuyuki; Danjoh, Inaho; Tokumasu, Atsumi; Ooyama, Keiko; Ito, Toshimitsu; Kondo, Takaaki; Wakai, Kenji; Stiburkova, Blanka; Pavelka, Karel; Stamp, Lisa K; Dalbeth, Nicola; Sakurai, Yutaka; Suzuki, Hiroshi; Hosoyamada, Makoto; Fujimori, Shin; Yokoo, Takashi; Hosoya, Tatsuo; Inoue, Ituro; Takahashi, Atsushi; Kubo, Michiaki; Ooyama, Hiroshi; Shimizu, Toru; Ichida, Kimiyoshi; Shinomiya, Nariyoshi; Merriman, Tony R; Matsuo, Hirotaka

2017-01-01

Objective A genome-wide association study (GWAS) of gout and its subtypes was performed to identify novel gout loci, including those that are subtype-specific. Methods Putative causal association signals from a GWAS of 945 clinically defined gout cases and 1213 controls from Japanese males were replicated with 1396 cases and 1268 controls using a custom chip of 1961 single nucleotide polymorphisms (SNPs). We also first conducted GWASs of gout subtypes. Replication with Caucasian and New Zealand Polynesian samples was done to further validate the loci identified in this study. Results In addition to the five loci we reported previously, further susceptibility loci were identified at a genome-wide significance level (p<5.0×10−8): urate transporter genes (SLC22A12 and SLC17A1) and HIST1H2BF-HIST1H4E for all gout cases, and NIPAL1 and FAM35A for the renal underexcretion gout subtype. While NIPAL1 encodes a magnesium transporter, functional analysis did not detect urate transport via NIPAL1, suggesting an indirect association with urate handling. Localisation analysis in the human kidney revealed expression of NIPAL1 and FAM35A mainly in the distal tubules, which suggests the involvement of the distal nephron in urate handling in humans. Clinically ascertained male patients with gout and controls of Caucasian and Polynesian ancestries were also genotyped, and FAM35A was associated with gout in all cases. A meta-analysis of the three populations revealed FAM35A to be associated with gout at a genome-wide level of significance (pmeta=3.58×10−8). Conclusions Our findings including novel gout risk loci provide further understanding of the molecular pathogenesis of gout and lead to a novel concept for the therapeutic target of gout/hyperuricaemia. PMID:27899376

Investigation of major genetic alterations in neuroblastoma.

PubMed

Costa, Régis Afonso; Seuánez, Héctor N

2018-06-01

Neuroblastoma (NB) is the most common extracranial solid tumor in childhood. This malignancy shows a wide spectrum of clinical outcome and its prognosis is conditioned by manifold biological and genetic factors. We investigated the tumor genetic profile and clinical data of 29 patients with NB by multiplex ligation-dependent probe amplification (MLPA) to assess therapeutic risk. In 18 of these tumors, MYCN status was assessed by fluorescence in situ hybridization (FISH). Copy number variation was also determined for confirming MLPA findings in two 6p loci. We found 2p, 7q and 17q gains, and 1p and 11q losses as the most frequent chromosome alterations in this cohort. FISH confirmed all cases of MYCN amplification detected by MLPA. In view of unexpected 6p imbalance, copy number variation of two 6p loci was assessed for validating MLPA findings. Based on clinical data and genetic profiles, patients were stratified in pretreatment risk groups according to international consensus. MLPA proved to be effective for detecting multiple genetic alterations in all chromosome regions as requested by the International Neuroblastoma Risk Group (INRG) for therapeutic stratification. Moreover, this technique proved to be cost effective, reliable, only requiring standard PCR equipment, and attractive for routine analysis. However, the observed 6p imbalances made PKHD1 and DCDC2 inadequate for control loci. This must be considered when designing commercial MLPA kits for NB. Finally, four patients showed a normal MLPA profile, suggesting that NB might have a more complex genetic pattern than the one assessed by presently available MLPA kits.

Detection of epistatic effects with logic regression and a classical linear regression model.

PubMed

Malina, Magdalena; Ickstadt, Katja; Schwender, Holger; Posch, Martin; Bogdan, Małgorzata

2014-02-01

To locate multiple interacting quantitative trait loci (QTL) influencing a trait of interest within experimental populations, usually methods as the Cockerham's model are applied. Within this framework, interactions are understood as the part of the joined effect of several genes which cannot be explained as the sum of their additive effects. However, if a change in the phenotype (as disease) is caused by Boolean combinations of genotypes of several QTLs, this Cockerham's approach is often not capable to identify them properly. To detect such interactions more efficiently, we propose a logic regression framework. Even though with the logic regression approach a larger number of models has to be considered (requiring more stringent multiple testing correction) the efficient representation of higher order logic interactions in logic regression models leads to a significant increase of power to detect such interactions as compared to a Cockerham's approach. The increase in power is demonstrated analytically for a simple two-way interaction model and illustrated in more complex settings with simulation study and real data analysis.

Mapping of four distinct BCR-related loci to chromosome region 22q11: order of BCR loci relative to chronic myelogenous leukemia and acute lymphoblastic leukemia breakpoints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croce, C.M.; Huebner, K.; Isobe, M.

1987-10-01

A probe derived from the 3' region of the BCR gene (breakpoint cluster region gene) detects four distinct loci in the human genome. One of the loci corresponds to the complete BCR gene, whereas the other contain a 3' segment of the gene. After HindIII cleavage of human DNA, these four loci are detected as 23-, 19-, 13-, and 9-kikobase-pair fragments, designated BCR4, BCR3, BCR2, and BCR1, respectively, with BCR1 deriving from the original complete BCR gene. All four BCR loci segregate 100% concordantly with human chromosome 22 in a rodent-human somatic cell hybrid panel and are located at chromosomemore » region 22q11.2 by chromosomal in situ hybridization. The BCR2 and BCR4 loci are amplified in leukemia cell line K562 cells, indicating that they fall within the amplification unit that includes immunoglobulin lambda light chain locus (IGL) and ABL locus on the K562 Philadelphia chromosome (Ph/sup 1/). Similarly, in mouse-human hybrids retaining a Ph/sup 1/ chromosome derived from an acute lymphoblastic leukemia-in the absence of the 9q/sup +/ and 22, only BCR2 and BCR4 loci are retained. Thus, the order of loci on chromosome 22 is centromere ..-->.. BCR2, BCR4, and IGL ..-->.. BCR1 ..-->.. BCR3 ..-->.. SIS, possibly eliminating BCR2 and BCR4 loci as candidate targets for juxtaposition to the ABL gene in the acute lymphoblastic leukemia Ph/sup 1/ chromosome.« less

Polymorphic microsatellite loci identified through development and cross-species amplification within shorebirds

USGS Publications Warehouse

Williams, I.; Guzzetti, B.M.; Gust, Judy R.; Sage, G.K.; Gill, Robert E.; Tibbitts, T.L.; Sonsthagen, S.A.; Talbot, S.L.

2012-01-01

We developed microsatellite loci for demographic assessments of shorebirds, a group with limited markers. First, we isolated five dinucleotide repeat microsatellite loci from the Black Oystercatcher (Haematopodidae: Haematopus bachmani), and three from the Bristle-thighed Curlew (Scolopacidae: Numenius tahitiensis); both species are of conservation concern. All eight loci were polymorphic in their respective target species. Hbaμ loci were characterized by two to three alleles with observed heterozygosity ranging from 0.07 to 0.33, and two to nine alleles were detected for Nut loci with observed heterozygosity ranging from 0.08 to 0.72. No linkage disequilibrium or departures from Hardy–Weinberg equilibrium were observed. The eight loci were also tested for cross-species amplification in 12 other species within Charadriidae and Scolopacidae, and the results demonstrated transferability across several genera. We further tested all 14 species at 12 additional microsatellite markers developed for other shorebirds: Dunlin (Calidris alpina; four loci) and Ruff (Philomachus pugnax; eight loci). Two markers (Hbaμ4 and Ruff6) were polymorphic in 13 species, while two (Calp6 and Ruff9) were monomorphic. The remaining eight markers revealed polymorphism in one to nine species each. Our results provide further evidence that locus Ruff10 is sex-linked, contrary to the initial description. These markers can be used to enhance our understanding of shorebird biology by, for example, helping to determine migratory connectivity among breeding and wintering populations and detecting relatedness among individuals.

Multiancestry genome-wide association study of 520,000 subjects identifies 32 loci associated with stroke and stroke subtypes.

PubMed

Malik, Rainer; Chauhan, Ganesh; Traylor, Matthew; Sargurupremraj, Muralidharan; Okada, Yukinori; Mishra, Aniket; Rutten-Jacobs, Loes; Giese, Anne-Katrin; van der Laan, Sander W; Gretarsdottir, Solveig; Anderson, Christopher D; Chong, Michael; Adams, Hieab H H; Ago, Tetsuro; Almgren, Peter; Amouyel, Philippe; Ay, Hakan; Bartz, Traci M; Benavente, Oscar R; Bevan, Steve; Boncoraglio, Giorgio B; Brown, Robert D; Butterworth, Adam S; Carrera, Caty; Carty, Cara L; Chasman, Daniel I; Chen, Wei-Min; Cole, John W; Correa, Adolfo; Cotlarciuc, Ioana; Cruchaga, Carlos; Danesh, John; de Bakker, Paul I W; DeStefano, Anita L; den Hoed, Marcel; Duan, Qing; Engelter, Stefan T; Falcone, Guido J; Gottesman, Rebecca F; Grewal, Raji P; Gudnason, Vilmundur; Gustafsson, Stefan; Haessler, Jeffrey; Harris, Tamara B; Hassan, Ahamad; Havulinna, Aki S; Heckbert, Susan R; Holliday, Elizabeth G; Howard, George; Hsu, Fang-Chi; Hyacinth, Hyacinth I; Ikram, M Arfan; Ingelsson, Erik; Irvin, Marguerite R; Jian, Xueqiu; Jiménez-Conde, Jordi; Johnson, Julie A; Jukema, J Wouter; Kanai, Masahiro; Keene, Keith L; Kissela, Brett M; Kleindorfer, Dawn O; Kooperberg, Charles; Kubo, Michiaki; Lange, Leslie A; Langefeld, Carl D; Langenberg, Claudia; Launer, Lenore J; Lee, Jin-Moo; Lemmens, Robin; Leys, Didier; Lewis, Cathryn M; Lin, Wei-Yu; Lindgren, Arne G; Lorentzen, Erik; Magnusson, Patrik K; Maguire, Jane; Manichaikul, Ani; McArdle, Patrick F; Meschia, James F; Mitchell, Braxton D; Mosley, Thomas H; Nalls, Michael A; Ninomiya, Toshiharu; O'Donnell, Martin J; Psaty, Bruce M; Pulit, Sara L; Rannikmäe, Kristiina; Reiner, Alexander P; Rexrode, Kathryn M; Rice, Kenneth; Rich, Stephen S; Ridker, Paul M; Rost, Natalia S; Rothwell, Peter M; Rotter, Jerome I; Rundek, Tatjana; Sacco, Ralph L; Sakaue, Saori; Sale, Michele M; Salomaa, Veikko; Sapkota, Bishwa R; Schmidt, Reinhold; Schmidt, Carsten O; Schminke, Ulf; Sharma, Pankaj; Slowik, Agnieszka; Sudlow, Cathie L M; Tanislav, Christian; Tatlisumak, Turgut; Taylor, Kent D; Thijs, Vincent N S; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Tiedt, Steffen; Trompet, Stella; Tzourio, Christophe; van Duijn, Cornelia M; Walters, Matthew; Wareham, Nicholas J; Wassertheil-Smoller, Sylvia; Wilson, James G; Wiggins, Kerri L; Yang, Qiong; Yusuf, Salim; Bis, Joshua C; Pastinen, Tomi; Ruusalepp, Arno; Schadt, Eric E; Koplev, Simon; Björkegren, Johan L M; Codoni, Veronica; Civelek, Mete; Smith, Nicholas L; Trégouët, David A; Christophersen, Ingrid E; Roselli, Carolina; Lubitz, Steven A; Ellinor, Patrick T; Tai, E Shyong; Kooner, Jaspal S; Kato, Norihiro; He, Jiang; van der Harst, Pim; Elliott, Paul; Chambers, John C; Takeuchi, Fumihiko; Johnson, Andrew D; Sanghera, Dharambir K; Melander, Olle; Jern, Christina; Strbian, Daniel; Fernandez-Cadenas, Israel; Longstreth, W T; Rolfs, Arndt; Hata, Jun; Woo, Daniel; Rosand, Jonathan; Pare, Guillaume; Hopewell, Jemma C; Saleheen, Danish; Stefansson, Kari; Worrall, Bradford B; Kittner, Steven J; Seshadri, Sudha; Fornage, Myriam; Markus, Hugh S; Howson, Joanna M M; Kamatani, Yoichiro; Debette, Stephanie; Dichgans, Martin; Malik, Rainer; Chauhan, Ganesh; Traylor, Matthew; Sargurupremraj, Muralidharan; Okada, Yukinori; Mishra, Aniket; Rutten-Jacobs, Loes; Giese, Anne-Katrin; van der Laan, Sander W; Gretarsdottir, Solveig; Anderson, Christopher D; Chong, Michael; Adams, Hieab H H; Ago, Tetsuro; Almgren, Peter; Amouyel, Philippe; Ay, Hakan; Bartz, Traci M; Benavente, Oscar R; Bevan, Steve; Boncoraglio, Giorgio B; Brown, Robert D; Butterworth, Adam S; Carrera, Caty; Carty, Cara L; Chasman, Daniel I; Chen, Wei-Min; Cole, John W; Correa, Adolfo; Cotlarciuc, Ioana; Cruchaga, Carlos; Danesh, John; de Bakker, Paul I W; DeStefano, Anita L; Hoed, Marcel den; Duan, Qing; Engelter, Stefan T; Falcone, Guido J; Gottesman, Rebecca F; Grewal, Raji P; Gudnason, Vilmundur; Gustafsson, Stefan; Haessler, Jeffrey; Harris, Tamara B; Hassan, Ahamad; Havulinna, Aki S; Heckbert, Susan R; Holliday, Elizabeth G; Howard, George; Hsu, Fang-Chi; Hyacinth, Hyacinth I; Ikram, M Arfan; Ingelsson, Erik; Irvin, Marguerite R; Jian, Xueqiu; Jiménez-Conde, Jordi; Johnson, Julie A; Jukema, J Wouter; Kanai, Masahiro; Keene, Keith L; Kissela, Brett M; Kleindorfer, Dawn O; Kooperberg, Charles; Kubo, Michiaki; Lange, Leslie A; Langefeld, Carl D; Langenberg, Claudia; Launer, Lenore J; Lee, Jin-Moo; Lemmens, Robin; Leys, Didier; Lewis, Cathryn M; Lin, Wei-Yu; Lindgren, Arne G; Lorentzen, Erik; Magnusson, Patrik K; Maguire, Jane; Manichaikul, Ani; McArdle, Patrick F; Meschia, James F; Mitchell, Braxton D; Mosley, Thomas H; Nalls, Michael A; Ninomiya, Toshiharu; O'Donnell, Martin J; Psaty, Bruce M; Pulit, Sara L; Rannikmäe, Kristiina; Reiner, Alexander P; Rexrode, Kathryn M; Rice, Kenneth; Rich, Stephen S; Ridker, Paul M; Rost, Natalia S; Rothwell, Peter M; Rotter, Jerome I; Rundek, Tatjana; Sacco, Ralph L; Sakaue, Saori; Sale, Michele M; Salomaa, Veikko; Sapkota, Bishwa R; Schmidt, Reinhold; Schmidt, Carsten O; Schminke, Ulf; Sharma, Pankaj; Slowik, Agnieszka; Sudlow, Cathie L M; Tanislav, Christian; Tatlisumak, Turgut; Taylor, Kent D; Thijs, Vincent N S; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Tiedt, Steffen; Trompet, Stella; Tzourio, Christophe; van Duijn, Cornelia M; Walters, Matthew; Wareham, Nicholas J; Wassertheil-Smoller, Sylvia; Wilson, James G; Wiggins, Kerri L; Yang, Qiong; Yusuf, Salim; Amin, Najaf; Aparicio, Hugo S; Arnett, Donna K; Attia, John; Beiser, Alexa S; Berr, Claudine; Buring, Julie E; Bustamante, Mariana; Caso, Valeria; Cheng, Yu-Ching; Choi, Seung Hoan; Chowhan, Ayesha; Cullell, Natalia; Dartigues, Jean-François; Delavaran, Hossein; Delgado, Pilar; Dörr, Marcus; Engström, Gunnar; Ford, Ian; Gurpreet, Wander S; Hamsten, Anders; Heitsch, Laura; Hozawa, Atsushi; Ibanez, Laura; Ilinca, Andreea; Ingelsson, Martin; Iwasaki, Motoki; Jackson, Rebecca D; Jood, Katarina; Jousilahti, Pekka; Kaffashian, Sara; Kalra, Lalit; Kamouchi, Masahiro; Kitazono, Takanari; Kjartansson, Olafur; Kloss, Manja; Koudstaal, Peter J; Krupinski, Jerzy; Labovitz, Daniel L; Laurie, Cathy C; Levi, Christopher R; Li, Linxin; Lind, Lars; Lindgren, Cecilia M; Lioutas, Vasileios; Liu, Yong Mei; Lopez, Oscar L; Makoto, Hirata; Martinez-Majander, Nicolas; Matsuda, Koichi; Minegishi, Naoko; Montaner, Joan; Morris, Andrew P; Muiño, Elena; Müller-Nurasyid, Martina; Norrving, Bo; Ogishima, Soichi; Parati, Eugenio A; Peddareddygari, Leema Reddy; Pedersen, Nancy L; Pera, Joanna; Perola, Markus; Pezzini, Alessandro; Pileggi, Silvana; Rabionet, Raquel; Riba-Llena, Iolanda; Ribasés, Marta; Romero, Jose R; Roquer, Jaume; Rudd, Anthony G; Sarin, Antti-Pekka; Sarju, Ralhan; Sarnowski, Chloe; Sasaki, Makoto; Satizabal, Claudia L; Satoh, Mamoru; Sattar, Naveed; Sawada, Norie; Sibolt, Gerli; Sigurdsson, Ásgeir; Smith, Albert; Sobue, Kenji; Soriano-Tárraga, Carolina; Stanne, Tara; Stine, O Colin; Stott, David J; Strauch, Konstantin; Takai, Takako; Tanaka, Hideo; Tanno, Kozo; Teumer, Alexander; Tomppo, Liisa; Torres-Aguila, Nuria P; Touze, Emmanuel; Tsugane, Shoichiro; Uitterlinden, Andre G; Valdimarsson, Einar M; van der Lee, Sven J; Völzke, Henry; Wakai, Kenji; Weir, David; Williams, Stephen R; Wolfe, Charles D A; Wong, Quenna; Xu, Huichun; Yamaji, Taiki; Sanghera, Dharambir K; Melander, Olle; Jern, Christina; Strbian, Daniel; Fernandez-Cadenas, Israel; Longstreth, W T; Rolfs, Arndt; Hata, Jun; Woo, Daniel; Rosand, Jonathan; Pare, Guillaume; Hopewell, Jemma C; Saleheen, Danish; Stefansson, Kari; Worrall, Bradford B; Kittner, Steven J; Seshadri, Sudha; Fornage, Myriam; Markus, Hugh S; Howson, Joanna M M; Kamatani, Yoichiro; Debette, Stephanie; Dichgans, Martin

2018-04-01

Stroke has multiple etiologies, but the underlying genes and pathways are largely unknown. We conducted a multiancestry genome-wide-association meta-analysis in 521,612 individuals (67,162 cases and 454,450 controls) and discovered 22 new stroke risk loci, bringing the total to 32. We further found shared genetic variation with related vascular traits, including blood pressure, cardiac traits, and venous thromboembolism, at individual loci (n = 18), and using genetic risk scores and linkage-disequilibrium-score regression. Several loci exhibited distinct association and pleiotropy patterns for etiological stroke subtypes. Eleven new susceptibility loci indicate mechanisms not previously implicated in stroke pathophysiology, with prioritization of risk variants and genes accomplished through bioinformatics analyses using extensive functional datasets. Stroke risk loci were significantly enriched in drug targets for antithrombotic therapy.

Multiancestry genome-wide association study of 520,000 subjects identifies 32 loci associated with stroke and stroke subtypes

PubMed Central

Malik, Rainer; Chauhan, Ganesh; Traylor, Matthew; Sargurupremraj, Muralidharan; Okada, Yukinori; Mishra, Aniket; Rutten-Jacobs, Loes; Giese, Anne-Katrin; van der Laan, Sander W.; Gretarsdottir, Solveig; Anderson, Christopher D.; Chong, Michael; Adams, Hieab H. H.; Ago, Tetsuro; Almgren, Peter; Amouyel, Philippe; Ay, Hakan; Bartz, Traci M.; Benavente, Oscar R.; Bevan, Steve; Boncoraglio, Giorgio B.; Brown, Robert D.; Butterworth, Adam S.; Carrera, Caty; Carty, Cara L.; Chasman, Daniel I.; Chen, Wei-Min; Cole, John W.; Correa, Adolfo; Cotlarciuc, Ioana; Cruchaga, Carlos; Danesh, John; de Bakker, Paul I. W.; DeStefano, Anita L.; den Hoed, Marcel; Duan, Qing; Engelter, Stefan T.; Falcone, Guido J.; Gottesman, Rebecca F.; Grewal, Raji P.; Gudnason, Vilmundur; Gustafsson, Stefan; Haessler, Jeffrey; Harris, Tamara B.; Hassan, Ahamad; Havulinna, Aki S.; Heckbert, Susan R.; Holliday, Elizabeth G.; Howard, George; Hsu, Fang-Chi; Hyacinth, Hyacinth I.; Ikram, M. Arfan; ingelsson, Erik; Irvin, Marguerite R.; Jian, Xueqiu; Jimenez-Conde, Jordi; Johnson, Julie A.; Jukema, J. Wouter; Kanai, Masahiro; Keene, Keith L.; Kissela, Brett M.; Kleindorfer, Dawn O.; Kooperberg, Charles; Kubo, Michiaki; Lange, Leslie A.; Langefeld, Carl D.; Langenberg, Claudia; Launer, Lenore J.; Lee, Jin-Moo; Lemmens, Robin; Leys, Didier; Lewis, Cathryn M.; Lin, Wei-Yu; Lindgren, Arne G.; Lorentzen, Erik; Magnusson, Patrik K.; Maguire, Jane; Manichaikul, Ani; McArdle, Patrick F.; Meschia, James F.; Mitchell, Braxton D.; Mosley, Thomas H.; Nalls, Michael A.; Ninomiya, Toshiharu; O’Donnell, Martin J.; Psaty, Bruce M.; Pulit, Sara L.; Rannikmäe, Kristiina; Reiner, Alexander P.; Rexrode, Kathryn M.; Rice, Kenneth; Rich, Stephen S.; Ridker, Paul M.; Rost, Natalia S.; Rothwell, Peter M.; Rotter, Jerome I.; Rundek, Tatjana; Sacco, Ralph L.; Sakaue, Saori; Sale, Michele M.; Salomaa, Veikko; Sapkota, Bishwa R.; Schmidt, Reinhold; Schmidt, Carsten O.; Schminke, Ulf; Sharma, Pankaj; Slowik, Agnieszka; Sudlow, Cathie L. M.; Tanislav, Christian; Tatlisumak, Turgut; Taylor, Kent D.; Thijs, Vincent N. S.; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Tiedt, Steffen; Trompet, Stella; Tzourio, Christophe; van Duijn, Cornelia M.; Walters, Matthew; Wareham, Nicholas J.; Wassertheil-Smoller, Sylvia; Wilson, James G.; Wiggins, Kerri L.; Yang, Qiong; Yusuf, Salim; Bis, Joshua C.; Pastinen, Tomi; Ruusalepp, Arno; Schadt, Eric E.; Koplev, Simon; Björkegren, Johan L. M.; Codoni, Veronica; Civelek, Mete; Smith, Nicholas L.; Tregouet, David A.; Christophersen, Ingrid E.; Roselli, Carolina; Lubitz, Steven A.; Ellinor, Patrick T.; Tai, E. Shyong; Kooner, Jaspal S.; Kato, Norihiro; He, Jiang; van der Harst, Pim; Elliott, Paul; Chambers, John C.; Takeuchi, Fumihiko; Johnson, Andrew D.; Sanghera, Dharambir K.; Melander, Olle; Jern, Christina; Strbian, Daniel; Fernandez-Cadenas, Israel; Longstreth, W. T.; Rolfs, Arndt; Hata, Jun; Woo, Daniel; Rosand, Jonathan; Pare, Guillaume; Hopewell, Jemma C.; Saleheen, Danish; Stefansson, Kari; Worrall, Bradford B.; Kittner, Steven J.; Seshadri, Sudha; Fornage, Myriam; Markus, Hugh S.; Howson, Joanna M. M.; Kamatani, Yoichiro; Debette, Stephanie; Dichgans, Martin

2018-01-01

Stroke has multiple etiologies, but the underlying genes and pathways are largely unknown. We conducted a multiancestry genome-wide-association meta-analysis in 521,612 individuals (67,162 cases and 454,450 controls) and discovered 22 new stroke risk loci, bringing the total to 32. We further found shared genetic variation with related vascular traits, including blood pressure, cardiac traits, and venous thromboembolism, at individual loci (n = 18), and using genetic risk scores and linkage-disequilibrium-score regression. Several loci exhibited distinct association and pleiotropy patterns for etiological stroke subtypes. Eleven new susceptibility loci indicate mechanisms not previously implicated in stroke pathophysiology, with prioritization of risk variants and genes accomplished through bioinformatics analyses using extensive functional datasets. Stroke risk loci were significantly enriched in drug targets for antithrombotic therapy. PMID:29531354

Comparative analysis of methods for detecting interacting loci

PubMed Central

2011-01-01

Background Interactions among genetic loci are believed to play an important role in disease risk. While many methods have been proposed for detecting such interactions, their relative performance remains largely unclear, mainly because different data sources, detection performance criteria, and experimental protocols were used in the papers introducing these methods and in subsequent studies. Moreover, there have been very few studies strictly focused on comparison of existing methods. Given the importance of detecting gene-gene and gene-environment interactions, a rigorous, comprehensive comparison of performance and limitations of available interaction detection methods is warranted. Results We report a comparison of eight representative methods, of which seven were specifically designed to detect interactions among single nucleotide polymorphisms (SNPs), with the last a popular main-effect testing method used as a baseline for performance evaluation. The selected methods, multifactor dimensionality reduction (MDR), full interaction model (FIM), information gain (IG), Bayesian epistasis association mapping (BEAM), SNP harvester (SH), maximum entropy conditional probability modeling (MECPM), logistic regression with an interaction term (LRIT), and logistic regression (LR) were compared on a large number of simulated data sets, each, consistent with complex disease models, embedding multiple sets of interacting SNPs, under different interaction models. The assessment criteria included several relevant detection power measures, family-wise type I error rate, and computational complexity. There are several important results from this study. First, while some SNPs in interactions with strong effects are successfully detected, most of the methods miss many interacting SNPs at an acceptable rate of false positives. In this study, the best-performing method was MECPM. Second, the statistical significance assessment criteria, used by some of the methods to control the type I error rate, are quite conservative, thereby limiting their power and making it difficult to fairly compare them. Third, as expected, power varies for different models and as a function of penetrance, minor allele frequency, linkage disequilibrium and marginal effects. Fourth, the analytical relationships between power and these factors are derived, aiding in the interpretation of the study results. Fifth, for these methods the magnitude of the main effect influences the power of the tests. Sixth, most methods can detect some ground-truth SNPs but have modest power to detect the whole set of interacting SNPs. Conclusion This comparison study provides new insights into the strengths and limitations of current methods for detecting interacting loci. This study, along with freely available simulation tools we provide, should help support development of improved methods. The simulation tools are available at: http://code.google.com/p/simulation-tool-bmc-ms9169818735220977/downloads/list. PMID:21729295

Comparative analysis of methods for detecting interacting loci.

PubMed

Chen, Li; Yu, Guoqiang; Langefeld, Carl D; Miller, David J; Guy, Richard T; Raghuram, Jayaram; Yuan, Xiguo; Herrington, David M; Wang, Yue

2011-07-05

Interactions among genetic loci are believed to play an important role in disease risk. While many methods have been proposed for detecting such interactions, their relative performance remains largely unclear, mainly because different data sources, detection performance criteria, and experimental protocols were used in the papers introducing these methods and in subsequent studies. Moreover, there have been very few studies strictly focused on comparison of existing methods. Given the importance of detecting gene-gene and gene-environment interactions, a rigorous, comprehensive comparison of performance and limitations of available interaction detection methods is warranted. We report a comparison of eight representative methods, of which seven were specifically designed to detect interactions among single nucleotide polymorphisms (SNPs), with the last a popular main-effect testing method used as a baseline for performance evaluation. The selected methods, multifactor dimensionality reduction (MDR), full interaction model (FIM), information gain (IG), Bayesian epistasis association mapping (BEAM), SNP harvester (SH), maximum entropy conditional probability modeling (MECPM), logistic regression with an interaction term (LRIT), and logistic regression (LR) were compared on a large number of simulated data sets, each, consistent with complex disease models, embedding multiple sets of interacting SNPs, under different interaction models. The assessment criteria included several relevant detection power measures, family-wise type I error rate, and computational complexity. There are several important results from this study. First, while some SNPs in interactions with strong effects are successfully detected, most of the methods miss many interacting SNPs at an acceptable rate of false positives. In this study, the best-performing method was MECPM. Second, the statistical significance assessment criteria, used by some of the methods to control the type I error rate, are quite conservative, thereby limiting their power and making it difficult to fairly compare them. Third, as expected, power varies for different models and as a function of penetrance, minor allele frequency, linkage disequilibrium and marginal effects. Fourth, the analytical relationships between power and these factors are derived, aiding in the interpretation of the study results. Fifth, for these methods the magnitude of the main effect influences the power of the tests. Sixth, most methods can detect some ground-truth SNPs but have modest power to detect the whole set of interacting SNPs. This comparison study provides new insights into the strengths and limitations of current methods for detecting interacting loci. This study, along with freely available simulation tools we provide, should help support development of improved methods. The simulation tools are available at: http://code.google.com/p/simulation-tool-bmc-ms9169818735220977/downloads/list.

Genome-wide co-localization of Polycomb orthologs and their effects on gene expression in human fibroblasts

PubMed Central

2014-01-01

Background Polycomb group proteins form multicomponent complexes that are important for establishing lineage-specific patterns of gene expression. Mammalian cells encode multiple permutations of the prototypic Polycomb repressive complex 1 (PRC1) with little evidence for functional specialization. An aim of this study is to determine whether the multiple orthologs that are co-expressed in human fibroblasts act on different target genes and whether their genomic location changes during cellular senescence. Results Deep sequencing of chromatin immunoprecipitated with antibodies against CBX6, CBX7, CBX8, RING1 and RING2 reveals that the orthologs co-localize at multiple sites. PCR-based validation at representative loci suggests that a further six PRC1 proteins have similar binding patterns. Importantly, sequential chromatin immunoprecipitation with antibodies against different orthologs implies that multiple variants of PRC1 associate with the same DNA. At many loci, the binding profiles have a distinctive architecture that is preserved in two different types of fibroblast. Conversely, there are several hundred loci at which PRC1 binding is cell type-specific and, contrary to expectations, the presence of PRC1 does not necessarily equate with transcriptional silencing. Interestingly, the PRC1 binding profiles are preserved in senescent cells despite changes in gene expression. Conclusions The multiple permutations of PRC1 in human fibroblasts congregate at common rather than specific sites in the genome and with overlapping but distinctive binding profiles in different fibroblasts. The data imply that the effects of PRC1 complexes on gene expression are more subtle than simply repressing the loci at which they bind. PMID:24485159

[Analysis of allele dropout at TH01 locus in paternity testing].

PubMed

Lai, Li; Shen, Xiao-li; Xue, Shi-jie; Hu, Jie

2013-10-01

To analyze allele dropout at TH01 locus in paternity testing in order to determine the accurate genotype. To use a two STR loci genotyping system to verify an abnormal genotype for the TH01 locus with PCR using specific primers, cloning and DNA sequencing. A rare allele at TH01 locus named 5.2, which was undetectable with PowerPlex 21 system, was detected with an Identifiler system. Genetic variations may result in rare alleles and loci loss. To avoid misjudgment, laboratories should have a variety of methods for detecting loci loss.

Another procedure for the preliminary ordering of loci based on two point lod scores.

PubMed

Curtis, D

1994-01-01

Because of the difficulty of performing full likelihood analysis over multiple loci and the large numbers of possible orders, a number of methods have been proposed for quickly evaluating orders and, to a lesser extent, for generating good orders. A new method is proposed which uses a function which is moderately laborious to compute, the sum of lod scores between all pairs of loci. This function can be smoothly minimized by initially allowing the loci to be placed anywhere in space, and only subsequently constraining them to lie along a one-dimensional map. Application of this approach to sample data suggests that it has promise and might usefully be combined with other methods when loci need to be ordered.

Dominant Epistasis Between Two Quantitative Trait Loci Governing Sporulation Efficiency in Yeast Saccharomyces cerevisiae

PubMed Central

Bergman, Juraj; Mitrikeski, Petar T.

2015-01-01

Summary Sporulation efficiency in the yeast Saccharomyces cerevisiae is a well-established model for studying quantitative traits. A variety of genes and nucleotides causing different sporulation efficiencies in laboratory, as well as in wild strains, has already been extensively characterised (mainly by reciprocal hemizygosity analysis and nucleotide exchange methods). We applied a different strategy in order to analyze the variation in sporulation efficiency of laboratory yeast strains. Coupling classical quantitative genetic analysis with simulations of phenotypic distributions (a method we call phenotype modelling) enabled us to obtain a detailed picture of the quantitative trait loci (QTLs) relationships underlying the phenotypic variation of this trait. Using this approach, we were able to uncover a dominant epistatic inheritance of loci governing the phenotype. Moreover, a molecular analysis of known causative quantitative trait genes and nucleotides allowed for the detection of novel alleles, potentially responsible for the observed phenotypic variation. Based on the molecular data, we hypothesise that the observed dominant epistatic relationship could be caused by the interaction of multiple quantitative trait nucleotides distributed across a 60--kb QTL region located on chromosome XIV and the RME1 locus on chromosome VII. Furthermore, we propose a model of molecular pathways which possibly underlie the phenotypic variation of this trait. PMID:27904371

Temporal genetic population structure and interannual variation in migration behavior of Pacific Lamprey Entosphenus tridentatus

USGS Publications Warehouse

Clemens, Benjamin J.; Wyss, Lance A.; McCoun, Rebecca; Courter, Ian; Schwabe, Lawrence; Peery, Christopher; Schreck, Carl B.; Spice, Erin K.; Docker, Margaret F.

2017-01-01

Studies using neutral loci suggest that Pacific lamprey, Entosphenus tridentatus, lack strong spatial genetic population structure. However, it is unknown whether temporal genetic population structure exists. We tested whether adult Pacific lamprey: (1) show temporal genetic population structure; and (2) migrate different distances between years. We non-lethally sampled lamprey for DNA in 2009 and 2010 and used eight microsatellite loci to test for genetic population structure. We used telemetry to record the migration behaviors of these fish. Lamprey were assignable to three moderately differentiated genetic clusters (FST = 0.16–0.24 for all pairwise comparisons): one cluster was composed of individuals from 2009, and the other two contained individuals from 2010. The FST value between years was 0.13 and between genetic clusters within 2010 was 0.20. A total of 372 (72.5%) fish were detected multiple times during their migrations. Most fish (69.9%) remained in the mainstem Willamette River; the remaining 30.1% migrated into tributaries. Eighty-two lamprey exhibited multiple back-and-forth movements among tributaries and the mainstem, which may indicate searching behaviors. All migration distances were significantly greater in 2010, when the amplitude of river discharge was greater. Our data suggest genetic structuring between and within years that may reflect different cohorts.

Noninvasive individual and species identification of jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) in Belize, Central America using cross-species microsatellites and faecal DNA.

PubMed

Wultsch, Claudia; Waits, Lisette P; Kelly, Marcella J

2014-11-01

There is a great need to develop efficient, noninvasive genetic sampling methods to study wild populations of multiple, co-occurring, threatened felids. This is especially important for molecular scatology studies occurring in challenging tropical environments where DNA degrades quickly and the quality of faecal samples varies greatly. We optimized 14 polymorphic microsatellite loci for jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) and assessed their utility for cross-species amplification. Additionally, we tested their reliability for species and individual identification using DNA from faeces of wild felids detected by a scat detector dog across Belize in Central America. All microsatellite loci were successfully amplified in the three target species, were polymorphic with average expected heterozygosities of HE = 0.60 ± 0.18 (SD) for jaguars, HE = 0.65 ± 0.21 (SD) for pumas and HE = 0.70 ± 0.13 (SD) for ocelots and had an overall PCR amplification success of 61%. We used this nuclear DNA primer set to successfully identify species and individuals from 49% of 1053 field-collected scat samples. This set of optimized microsatellite multiplexes represents a powerful tool for future efforts to conduct noninvasive studies on multiple, wild Neotropical felids. © 2014 John Wiley & Sons Ltd.

High-Density Genomewide Linkage Analysis of Exceptional Human Longevity Identifies Multiple Novel Loci

PubMed Central

Boyden, Steven E.; Kunkel, Louis M.

2010-01-01

Background Human lifespan is approximately 25% heritable, and genetic factors may be particularly important for achieving exceptional longevity. Accordingly, siblings of centenarians have a dramatically higher probability of reaching extreme old age than the general population. Methodology/Principal Findings To map the loci conferring a survival advantage, we performed the second genomewide linkage scan on human longevity and the first using a high-density marker panel of single nucleotide polymorphisms. By systematically testing a range of minimum age cutoffs in 279 families with multiple long-lived siblings, we identified a locus on chromosome 3p24-22 with a genomewide significant allele-sharing LOD score of 4.02 (empirical P = 0.037) and a locus on chromosome 9q31-34 with a highly suggestive LOD score of 3.89 (empirical P = 0.054). The empirical P value for the combined result was 0.002. A third novel locus with a LOD score of 4.05 on chromosome 12q24 was detected in a subset of the data, and we also obtained modest evidence for a previously reported interval on chromosome 4q22-25. Conclusions/Significance Our linkage data should facilitate the discovery of both common and rare variants that determine genetic variability in lifespan. PMID:20824210

Development of Multiple-Locus Variable-Number Tandem-Repeat Analysis for Molecular Subtyping of Campylobacter jejuni by Using Capillary Electrophoresis

PubMed Central

Techaruvichit, Punnida; Vesaratchavest, Mongkol; Keeratipibul, Suwimon; Kuda, Takashi; Kimura, Bon

2015-01-01

Campylobacter jejuni is a common cause of the frequently reported food-borne diseases in developed and developing nations. This study describes the development of multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) using capillary electrophoresis as a novel typing method for microbial source tracking and epidemiological investigation of C. jejuni. Among 36 tandem repeat loci detected by the Tandem Repeat Finder program, 7 VNTR loci were selected and used for characterizing 60 isolates recovered from chicken meat samples from retail shops, samples from chicken meat processing factory, and stool samples. The discrimination ability of MLVA was compared with that of multilocus sequence typing (MLST). MLVA (diversity index of 0.97 with 31 MLVA types) provided slightly higher discrimination than MLST (diversity index of 0.95 with 25 MLST types). The overall concordance between MLVA and MLST was estimated at 63% by adjusted Rand coefficient. MLVA predicted MLST type better than MLST predicted MLVA type, as reflected by Wallace coefficient (Wallace coefficient for MLVA to MLST versus MLST to MLVA, 86% versus 51%). MLVA is a useful tool and can be used for effective monitoring of C. jejuni and investigation of epidemics caused by C. jejuni. PMID:26025899

A LDR-PCR approach for multiplex polymorphisms genotyping of severely degraded DNA with fragment sizes <100 bp.

PubMed

Zhang, Zhen; Wang, Bao-Jie; Guan, Hong-Yu; Pang, Hao; Xuan, Jin-Feng

2009-11-01

Reducing amplicon sizes has become a major strategy for analyzing degraded DNA typical of forensic samples. However, amplicon sizes in current mini-short tandem repeat-polymerase chain reaction (PCR) and mini-sequencing assays are still not suitable for analysis of severely degraded DNA. In this study, we present a multiplex typing method that couples ligase detection reaction with PCR that can be used to identify single nucleotide polymorphisms and small-scale insertion/deletions in a sample of severely fragmented DNA. This method adopts thermostable ligation for allele discrimination and subsequent PCR for signal enhancement. In this study, four polymorphic loci were used to assess the ability of this technique to discriminate alleles in an artificially degraded sample of DNA with fragment sizes <100 bp. Our results showed clear allelic discrimination of single or multiple loci, suggesting that this method might aid in the analysis of extremely degraded samples in which allelic drop out of larger fragments is observed.

Biological Insights From 108 Schizophrenia-Associated Genetic Loci

PubMed Central

Ripke, Stephan; Neale, Benjamin M; Corvin, Aiden; Walters, James TR; Farh, Kai-How; Holmans, Peter A; Lee, Phil; Bulik-Sullivan, Brendan; Collier, David A; Huang, Hailiang; Pers, Tune H; Agartz, Ingrid; Agerbo, Esben; Albus, Margot; Alexander, Madeline; Amin, Farooq; Bacanu, Silviu A; Begemann, Martin; Belliveau, Richard A; Bene, Judit; Bergen, Sarah E; Bevilacqua, Elizabeth; Bigdeli, Tim B; Black, Donald W; Bruggeman, Richard; Buccola, Nancy G; Buckner, Randy L; Byerley, William; Cahn, Wiepke; Cai, Guiqing; Campion, Dominique; Cantor, Rita M; Carr, Vaughan J; Carrera, Noa; Catts, Stanley V; Chambert, Kimberley D; Chan, Raymond CK; Chan, Ronald YL; Chen, Eric YH; Cheng, Wei; Cheung, Eric FC; Chong, Siow Ann; Cloninger, C Robert; Cohen, David; Cohen, Nadine; Cormican, Paul; Craddock, Nick; Crowley, James J; Curtis, David; Davidson, Michael; Davis, Kenneth L; Degenhardt, Franziska; Del Favero, Jurgen; Demontis, Ditte; Dikeos, Dimitris; Dinan, Timothy; Djurovic, Srdjan; Donohoe, Gary; Drapeau, Elodie; Duan, Jubao; Dudbridge, Frank; Durmishi, Naser; Eichhammer, Peter; Eriksson, Johan; Escott-Price, Valentina; Essioux, Laurent; Fanous, Ayman H; Farrell, Martilias S; Frank, Josef; Franke, Lude; Freedman, Robert; Freimer, Nelson B; Friedl, Marion; Friedman, Joseph I; Fromer, Menachem; Genovese, Giulio; Georgieva, Lyudmila; Giegling, Ina; Giusti-Rodríguez, Paola; Godard, Stephanie; Goldstein, Jacqueline I; Golimbet, Vera; Gopal, Srihari; Gratten, Jacob; de Haan, Lieuwe; Hammer, Christian; Hamshere, Marian L; Hansen, Mark; Hansen, Thomas; Haroutunian, Vahram; Hartmann, Annette M; Henskens, Frans A; Herms, Stefan; Hirschhorn, Joel N; Hoffmann, Per; Hofman, Andrea; Hollegaard, Mads V; Hougaard, David M; Ikeda, Masashi; Joa, Inge; Julià, Antonio; Kahn, René S; Kalaydjieva, Luba; Karachanak-Yankova, Sena; Karjalainen, Juha; Kavanagh, David; Keller, Matthew C; Kennedy, James L; Khrunin, Andrey; Kim, Yunjung; Klovins, Janis; Knowles, James A; Konte, Bettina; Kucinskas, Vaidutis; Kucinskiene, Zita Ausrele; Kuzelova-Ptackova, Hana; Kähler, Anna K; Laurent, Claudine; Lee, Jimmy; Lee, S Hong; Legge, Sophie E; Lerer, Bernard; Li, Miaoxin; Li, Tao; Liang, Kung-Yee; Lieberman, Jeffrey; Limborska, Svetlana; Loughland, Carmel M; Lubinski, Jan; Lönnqvist, Jouko; Macek, Milan; Magnusson, Patrik KE; Maher, Brion S; Maier, Wolfgang; Mallet, Jacques; Marsal, Sara; Mattheisen, Manuel; Mattingsdal, Morten; McCarley, Robert W; McDonald, Colm; McIntosh, Andrew M; Meier, Sandra; Meijer, Carin J; Melegh, Bela; Melle, Ingrid; Mesholam-Gately, Raquelle I; Metspalu, Andres; Michie, Patricia T; Milani, Lili; Milanova, Vihra; Mokrab, Younes; Morris, Derek W; Mors, Ole; Murphy, Kieran C; Murray, Robin M; Myin-Germeys, Inez; Müller-Myhsok, Bertram; Nelis, Mari; Nenadic, Igor; Nertney, Deborah A; Nestadt, Gerald; Nicodemus, Kristin K; Nikitina-Zake, Liene; Nisenbaum, Laura; Nordin, Annelie; O’Callaghan, Eadbhard; O’Dushlaine, Colm; O’Neill, F Anthony; Oh, Sang-Yun; Olincy, Ann; Olsen, Line; Van Os, Jim; Pantelis, Christos; Papadimitriou, George N; Papiol, Sergi; Parkhomenko, Elena; Pato, Michele T; Paunio, Tiina; Pejovic-Milovancevic, Milica; Perkins, Diana O; Pietiläinen, Olli; Pimm, Jonathan; Pocklington, Andrew J; Powell, John; Price, Alkes; Pulver, Ann E; Purcell, Shaun M; Quested, Digby; Rasmussen, Henrik B; Reichenberg, Abraham; Reimers, Mark A; Richards, Alexander L; Roffman, Joshua L; Roussos, Panos; Ruderfer, Douglas M; Salomaa, Veikko; Sanders, Alan R; Schall, Ulrich; Schubert, Christian R; Schulze, Thomas G; Schwab, Sibylle G; Scolnick, Edward M; Scott, Rodney J; Seidman, Larry J; Shi, Jianxin; Sigurdsson, Engilbert; Silagadze, Teimuraz; Silverman, Jeremy M; Sim, Kang; Slominsky, Petr; Smoller, Jordan W; So, Hon-Cheong; Spencer, Chris C A; Stahl, Eli A; Stefansson, Hreinn; Steinberg, Stacy; Stogmann, Elisabeth; Straub, Richard E; Strengman, Eric; Strohmaier, Jana; Stroup, T Scott; Subramaniam, Mythily; Suvisaari, Jaana; Svrakic, Dragan M; Szatkiewicz, Jin P; Söderman, Erik; Thirumalai, Srinivas; Toncheva, Draga; Tosato, Sarah; Veijola, Juha; Waddington, John; Walsh, Dermot; Wang, Dai; Wang, Qiang; Webb, Bradley T; Weiser, Mark; Wildenauer, Dieter B; Williams, Nigel M; Williams, Stephanie; Witt, Stephanie H; Wolen, Aaron R; Wong, Emily HM; Wormley, Brandon K; Xi, Hualin Simon; Zai, Clement C; Zheng, Xuebin; Zimprich, Fritz; Wray, Naomi R; Stefansson, Kari; Visscher, Peter M; Adolfsson, Rolf; Andreassen, Ole A; Blackwood, Douglas HR; Bramon, Elvira; Buxbaum, Joseph D; Børglum, Anders D; Cichon, Sven; Darvasi, Ariel; Domenici, Enrico; Ehrenreich, Hannelore; Esko, Tõnu; Gejman, Pablo V; Gill, Michael; Gurling, Hugh; Hultman, Christina M; Iwata, Nakao; Jablensky, Assen V; Jönsson, Erik G; Kendler, Kenneth S; Kirov, George; Knight, Jo; Lencz, Todd; Levinson, Douglas F; Li, Qingqin S; Liu, Jianjun; Malhotra, Anil K; McCarroll, Steven A; McQuillin, Andrew; Moran, Jennifer L; Mortensen, Preben B; Mowry, Bryan J; Nöthen, Markus M; Ophoff, Roel A; Owen, Michael J; Palotie, Aarno; Pato, Carlos N; Petryshen, Tracey L; Posthuma, Danielle; Rietschel, Marcella; Riley, Brien P; Rujescu, Dan; Sham, Pak C; Sklar, Pamela; St Clair, David; Weinberger, Daniel R; Wendland, Jens R; Werge, Thomas; Daly, Mark J; Sullivan, Patrick F; O’Donovan, Michael C

2014-01-01

Summary Schizophrenia is a highly heritable disorder. Genetic risk is conferred by a large number of alleles, including common alleles of small effect that might be detected by genome-wide association studies. Here, we report a multi-stage schizophrenia genome-wide association study of up to 36,989 cases and 113,075 controls. We identify 128 independent associations spanning 108 conservatively defined loci that meet genome-wide significance, 83 of which have not been previously reported. Associations were enriched among genes expressed in brain providing biological plausibility for the findings. Many findings have the potential to provide entirely novel insights into aetiology, but associations at DRD2 and multiple genes involved in glutamatergic neurotransmission highlight molecules of known and potential therapeutic relevance to schizophrenia, and are consistent with leading pathophysiological hypotheses. Independent of genes expressed in brain, associations were enriched among genes expressed in tissues that play important roles in immunity, providing support for the hypothesized link between the immune system and schizophrenia. PMID:25056061

High prevalence of Mycobacterium tuberculosis mixed infection in the capital of moderate tuberculosis incidence country.

PubMed

Hajimiri, Elahe Sadat; Masoomi, Morteza; Ebrahimzadeh, Nayereh; Fateh, Abolfazl; Hadizadeh Tasbiti, Alireza; Rahimi Jamnani, Fatemeh; Bahrmand, Ahmad Reza; Mirsaeidi, Mehdi; Vaziri, Farzam; Siadat, Seyed Davar

2016-04-01

Recent studies using molecular epidemiological techniques have demonstrated mixed infection with multiple strains of Mycobacterium tuberculosis especially in countries with high tuberculosis (TB) burden. We aimed to determine the prevalence of mixed infection among patients with TB in the capital of Iran as a country with moderate incidence rate. Samples were collected randomly from January 2011 to December 2013 in Tehran, capital of Iran. A total of 75 M. tuberculosis isolates were genotyped by 24 loci mycobacterial interspersed repetitive unit-variable number tandem repeat typing (MIRU-VNTR) for screening the mixed infection. Twenty patients (20/75) were identified with mixed infection, and the estimated rate of mixed infection was 26.6%. Thirteen out of the 24 loci were able to detect the mixed infection in our study. Mixed infections occur at high prevalence among studied Iranian TB patients. Further research is inevitable to evaluate the association of mixed infection and disease progression and treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Functional mapping of yeast genomes by saturated transposition

PubMed Central

Michel, Agnès H; Hatakeyama, Riko; Kimmig, Philipp; Arter, Meret; Peter, Matthias; Matos, Joao; De Virgilio, Claudio; Kornmann, Benoît

2017-01-01

Yeast is a powerful model for systems genetics. We present a versatile, time- and labor-efficient method to functionally explore the Saccharomyces cerevisiae genome using saturated transposon mutagenesis coupled to high-throughput sequencing. SAturated Transposon Analysis in Yeast (SATAY) allows one-step mapping of all genetic loci in which transposons can insert without disrupting essential functions. SATAY is particularly suited to discover loci important for growth under various conditions. SATAY (1) reveals positive and negative genetic interactions in single and multiple mutant strains, (2) can identify drug targets, (3) detects not only essential genes, but also essential protein domains, (4) generates both null and other informative alleles. In a SATAY screen for rapamycin-resistant mutants, we identify Pib2 (PhosphoInositide-Binding 2) as a master regulator of TORC1. We describe two antagonistic TORC1-activating and -inhibiting activities located on opposite ends of Pib2. Thus, SATAY allows to easily explore the yeast genome at unprecedented resolution and throughput. DOI: http://dx.doi.org/10.7554/eLife.23570.001 PMID:28481201

Large-scale gene-centric meta-analysis across 32 studies identifies multiple lipid loci

USDA-ARS?s Scientific Manuscript database

Genome-wide association studies (GWASs) have identified many SNPs underlying variations in plasma-lipid levels. We explore whether additional loci associated with plasma-lipid phenotypes, such as high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholest...

Multiple recent horizontal transfers of a large genomic region in cheese making fungi.

PubMed

Cheeseman, Kevin; Ropars, Jeanne; Renault, Pierre; Dupont, Joëlle; Gouzy, Jérôme; Branca, Antoine; Abraham, Anne-Laure; Ceppi, Maurizio; Conseiller, Emmanuel; Debuchy, Robert; Malagnac, Fabienne; Goarin, Anne; Silar, Philippe; Lacoste, Sandrine; Sallet, Erika; Bensimon, Aaron; Giraud, Tatiana; Brygoo, Yves

2014-01-01

While the extent and impact of horizontal transfers in prokaryotes are widely acknowledged, their importance to the eukaryotic kingdom is unclear and thought by many to be anecdotal. Here we report multiple recent transfers of a huge genomic island between Penicillium spp. found in the food environment. Sequencing of the two leading filamentous fungi used in cheese making, P. roqueforti and P. camemberti, and comparison with the penicillin producer P. rubens reveals a 575 kb long genomic island in P. roqueforti--called Wallaby--present as identical fragments at non-homologous loci in P. camemberti and P. rubens. Wallaby is detected in Penicillium collections exclusively in strains from food environments. Wallaby encompasses about 250 predicted genes, some of which are probably involved in competition with microorganisms. The occurrence of multiple recent eukaryotic transfers in the food environment provides strong evidence for the importance of this understudied and probably underestimated phenomenon in eukaryotes.

Multiple recent horizontal transfers of a large genomic region in cheese making fungi

PubMed Central

Cheeseman, Kevin; Ropars, Jeanne; Renault, Pierre; Dupont, Joëlle; Gouzy, Jérôme; Branca, Antoine; Abraham, Anne-Laure; Ceppi, Maurizio; Conseiller, Emmanuel; Debuchy, Robert; Malagnac, Fabienne; Goarin, Anne; Silar, Philippe; Lacoste, Sandrine; Sallet, Erika; Bensimon, Aaron; Giraud, Tatiana; Brygoo, Yves

2014-01-01

While the extent and impact of horizontal transfers in prokaryotes are widely acknowledged, their importance to the eukaryotic kingdom is unclear and thought by many to be anecdotal. Here we report multiple recent transfers of a huge genomic island between Penicillium spp. found in the food environment. Sequencing of the two leading filamentous fungi used in cheese making, P. roqueforti and P. camemberti, and comparison with the penicillin producer P. rubens reveals a 575 kb long genomic island in P. roqueforti—called Wallaby—present as identical fragments at non-homologous loci in P. camemberti and P. rubens. Wallaby is detected in Penicillium collections exclusively in strains from food environments. Wallaby encompasses about 250 predicted genes, some of which are probably involved in competition with microorganisms. The occurrence of multiple recent eukaryotic transfers in the food environment provides strong evidence for the importance of this understudied and probably underestimated phenomenon in eukaryotes. PMID:24407037

A powerful approach reveals numerous expression quantitative trait haplotypes in multiple tissues.

PubMed

Ying, Dingge; Li, Mulin Jun; Sham, Pak Chung; Li, Miaoxin

2018-04-26

Recently many studies showed single nucleotide polymorphisms (SNPs) affect gene expression and contribute to development of complex traits/diseases in a tissue context-dependent manner. However, little is known about haplotype's influence on gene expression and complex traits, which reflects the interaction effect between SNPs. In the present study, we firstly proposed a regulatory region guided eQTL haplotype association analysis approach, and then systematically investigate the expression quantitative trait loci (eQTL) haplotypes in 20 different tissues by the approach. The approach has a powerful design of reducing computational burden by the utilization of regulatory predictions for candidate SNP selection and multiple testing corrections on non-independent haplotypes. The application results in multiple tissues showed that haplotype-based eQTLs not only increased the number of eQTL genes in a tissue specific manner, but were also enriched in loci that associated with complex traits in a tissue-matched manner. In addition, we found that tag SNPs of eQTL haplotypes from whole blood were selectively enriched in certain combination of regulatory elements (e.g. promoters and enhancers) according to predicted chromatin states. In summary, this eQTL haplotype detection approach, together with the application results, shed insights into synergistic effect of sequence variants on gene expression and their susceptibility to complex diseases. The executable application "eHaplo" is implemented in Java and is publicly available at http://grass.cgs.hku.hk/limx/ehaplo/. jonsonfox@gmail.com, limiaoxin@mail.sysu.edu.cn. Supplementary data are available at Bioinformatics online.

Mapping of quantitative trait loci controlling adaptive traits in coastal Douglas-fir.II. Spring and fall cold-hardiness

Treesearch

K.D. Jermstad; D.L. Bassoni; N.C. Wheeler; T.S. Anekonda; S.N. Aitken; W.T. Adams; D.B. Neale

2001-01-01

Abstract Quantitative trait loci (QTLs) affecting fall and spring cold-hardiness were identified in a three-generation outbred pedigree of coastal Douglas-fir [Pseudotsuga meniziesii (Mirb.) Franco var. menziesii]. Eleven QTLs controlling fall cold-hardiness were detected on four linkage groups, and 15 QTLs controlling spring cold-hardiness were detected on four...

Differential detection of genetic Loci underlying stem and root lignin content in Populus.

PubMed

Yin, Tongming; Zhang, Xinye; Gunter, Lee; Priya, Ranjan; Sykes, Robert; Davis, Mark; Wullschleger, Stan D; Tuskan, Gerald A

2010-11-22

In this study, we established a comprehensive genetic map with a large number of progeny from a three-generation hybrid Populus intercross, and phenotyped the lignin content, S/G ratio and 28 cell wall subcomponents both in stems and roots for the mapping individuals. Phenotypic analysis revealed that lignin content and syringyl-to-guaiacyl (S/G) ratio using pyrolysis molecular beam mass spectroscopy (pyMBMS) varied among mapping individuals. Phenotypic analysis revealed that stem lignin content is significantly higher than that in root and the quantified traits can be classified into four distinct groups, with strong correlations observed among components within organs. Altogether, 179 coordinating QTLs were detected, and they were co-localized into 49 genetic loci, 27 of which appear to be pleiotropic. Many of the detected genetic loci were detected differentially in stem and root. This is the first report of separate genetic loci controlling cell wall phenotypes above and below ground. These results suggest that it may be possible to modify lignin content and composition via breed and/or engineer as a means of simultaneously improving Populus for cellulosic ethanol production and carbon sequestration.

Genetic analysis of children of atomic bomb survivors.

PubMed Central

Satoh, C; Takahashi, N; Asakawa, J; Kodaira, M; Kuick, R; Hanash, S M; Neel, J V

1996-01-01

Studies are under way for the detection of potential genetic effects of atomic bomb radiation at the DNA level in the children of survivors. In a pilot study, we have examined six minisatellites and five microsatellites in DNA derived from 100 families including 124 children. We detected a total of 28 mutations in three minisatellite loci. The mean mutation rates per locus per gamete in the six minisatellite loci were 1.5% for 65 exposed gametes for which mean parental gonadal dose was 1.9 Sv and 2.0% for 183 unexposed gametes. We detected four mutations in two tetranucleotide repeat sequences but no mutations in three trinucleotide repeat sequences. The mean mutation rate per locus per gamete was o% for the exposed gametes and 0.5% for the unexposed gametes in the five microsatellite loci. No significant differences in the mutation rates between the exposed and the unexposed gametes were detected in these repetitive sequences. Additional loci are being analyzed to increase the power of our study to observe a significant difference in the mutation rates at the 0.05 level of significance. Images Figure 1. Figure 2. Figure 2. Figure 2. Figure 2. Figure 2. Figure 2. PMID:8781374

Genetic analyses of captive Alala (Corvus hawaiiensis) using AFLP analyses

USGS Publications Warehouse

Jarvi, Susan I.; Bianchi, Kiara R.

2006-01-01

Population level studies of genetic diversity can provide information about population structure, individual genetic distinctiveness and former population size. They are especially important for rare and threatened species like the Alala, where they can be used to assess extinction risks and evolutionary potential. In an ideal situation multiple methods should be used to detect variation, and these methods should be comparable across studies. In this report, we discuss AFLP (Amplified Fragment Length Polymorphism) as a genetic approach for detecting variation in the Alala , describe our findings, and discuss these in relation to mtDNA and microsatellite data reported elsewhere in this same population. AFLP is a technique for DNA fingerprinting that has wide applications. Because little or no prior knowledge of the particular species is required to carry out this method of analysis, AFLP can be used universally across varied taxonomic groups. Within individuals, estimates of diversity or heterozygosity across genomes may be complex because levels of diversity differ between and among genes. One of the more traditional methods of estimating diversity employs the use of codominant markers such as microsatellites. Codominant markers detect each allele at a locus independently. Hence, one can readily distinguish heterozygotes from homozygotes, directly assess allele frequencies and calculate other population level statistics. Dominant markers (for example, AFLP) are scored as either present or absent (null) so heterozygotes cannot be directly distinguished from homozygotes. However, the presence or absence data can be converted to expected heterozygosity estimates which are comparable to those determined by codominant markers. High allelic diversity and heterozygosity inherent in microsatellites make them excellent tools for studies of wild populations and they have been used extensively. One limitation to the use of microsatellites is that heterozygosity estimates are affected by the mutation rate at microsatellite loci, thus introducing a bias. Also, the number of loci that can be studied is frequently limited to fewer than 10. This theoretically represents a maximum of one marker for each of 10 chromosomes. Dominant markers like AFLP allow a larger fraction of the genome to be screened. Large numbers of loci can be screened by AFLP to resolve very small individual differences that can be used for identification of individuals, estimates of pairwise relatedness and, in some cases, for parentage analyses. Since AFLP is a dominant marker (can not distinguish between +/+ homozygote versus +/- heterozygote), it has limitations for parentage analyses. Only when both parents are homozygous for the absence of alleles (-/-) and offspring show a presence (+/+ or +/-) can the parents be excluded. In this case, microsatellites become preferable as they have the potential to exclude individual parents when the other parent is unknown. Another limitation of AFLP is that the loci are generally less polymorphic (only two alleles/locus) than microsatellite loci (often >10 alleles/locus). While generally fewer than 10 highly polymorphic microsatellite loci are enough to exclude and assign parentage, it might require up to 100 or more AFLP loci. While there are pros and cons to different methodologies, the total number of loci evaluated by AFLP generally offsets the limitations imposed due to the dominant nature of this approach and end results between methods are generally comparable. Overall objectives of this study were to evaluate the level of genetic diversity in the captive population of Alala, to compare genetic data with currently available pedigree information, and to determine the extent of relatedness of mating pairs and among founding individuals.

Allozyme variation of Port-Orford-Cedar (Chamaecyparis lawsoniana): implications for genetic conservation

Treesearch

Constance I. Millar; Kimberly A. Marshall

1991-01-01

Variation at 32 allozyme loci in nine disjunct populations of Part-Orford-cedar (POC) from the California floristic region was measured to estimate the amount and pattern of genetic variability in natural stands. Variation in electrophoretically detectable loci was moderately high, with mean number of alleles per locus = 1.9, 64.9% polymorphic loci, and observed...

[Genetic polymorphism and forensic application of 30 InDel loci of Han population in Beijing].

PubMed

Bai, Ru-Feng; Jiang, Li-Zhe; Zhang, Zhong; Shi, Mei-Sen

2013-12-01

To study the genetic diversities of 30 insertion-deletion (InDel) polymorphisms loci of Han population in Beijing, and to evaluate their forensic application, 210 unrelated healthy individuals of Han population in Beijing were investigated to determine the distributions of allele frequencies by using Investigator DIP system. The PCR products were detected with ABI 3130 XL Genetic Analyzer. Forensic parameters were calculated with relevant statistical analysis software. As a result, after the Bonferroni correction at a 95% significance level, there were no significant departures from Hardy-Weinberg equilibrium or significant linkage disequilibrium between the loci. The power of discrimination (DP) varies between 0.2690 (HLD118) and 0.6330 (HLD45), and the combined discrimination power (TDP) for the 30 InDel loci is 0.999999999985. The combined power of exclusion was 0.98771049 in trio cases (CPE(trio)) and 0.94579456 in duo cases (CPE(duo)). The parentage testing of 32 cases revealed no mutations happened to 30 InDel loci. Multiplex detection of the 30 InDel loci revealed a highly polymorphic genetic distribution in Beijing Han population, which represents a complementary tool in human identification studies, especially in challenging DNA cases.

Association Mapping of Main Tomato Fruit Sugars and Organic Acids

PubMed Central

Zhao, Jiantao; Xu, Yao; Ding, Qin; Huang, Xinli; Zhang, Yating; Zou, Zhirong; Li, Mingjun; Cui, Lu; Zhang, Jing

2016-01-01

Association mapping has been widely used to map the significant associated loci responsible for natural variation in complex traits and are valuable for crop improvement. Sugars and organic acids are the most important metabolites in tomato fruits. We used a collection of 174 tomato accessions composed of Solanum lycopersicum (123 accessions) and S. lycopersicum var cerasiforme (51 accessions) to detect significantly associated loci controlling the variation of main sugars and organic acids. The accessions were genotyped with 182 SSRs spreading over the tomato genome. Association mapping was conducted on the main sugars and organic acids detected by gas chromatography-mass spectrometer (GC-MS) over 2 years using the mixed linear model (MLM). We detected a total of 58 significantly associated loci (P < 0.001) for the 17 sugars and organic acids, including fructose, glucose, sucrose, citric acid, malic acid. These results not only co-localized with several reported QTLs, including fru9.1/PV, suc9.1/PV, ca2.1/HS, ca3.1/PV, ca4.1/PV, and ca8.1/PV, but also provided a list of candidate significantly associated loci to be functionally validated. These significantly associated loci could be used for deciphering the genetic architecture of tomato fruit sugars and organic acids and for tomato quality breeding. PMID:27617019

Association Mapping of Main Tomato Fruit Sugars and Organic Acids.

PubMed

Zhao, Jiantao; Xu, Yao; Ding, Qin; Huang, Xinli; Zhang, Yating; Zou, Zhirong; Li, Mingjun; Cui, Lu; Zhang, Jing

2016-01-01

Association mapping has been widely used to map the significant associated loci responsible for natural variation in complex traits and are valuable for crop improvement. Sugars and organic acids are the most important metabolites in tomato fruits. We used a collection of 174 tomato accessions composed of Solanum lycopersicum (123 accessions) and S. lycopersicum var cerasiforme (51 accessions) to detect significantly associated loci controlling the variation of main sugars and organic acids. The accessions were genotyped with 182 SSRs spreading over the tomato genome. Association mapping was conducted on the main sugars and organic acids detected by gas chromatography-mass spectrometer (GC-MS) over 2 years using the mixed linear model (MLM). We detected a total of 58 significantly associated loci (P < 0.001) for the 17 sugars and organic acids, including fructose, glucose, sucrose, citric acid, malic acid. These results not only co-localized with several reported QTLs, including fru9.1/PV, suc9.1/PV, ca2.1/HS, ca3.1/PV, ca4.1/PV, and ca8.1/PV, but also provided a list of candidate significantly associated loci to be functionally validated. These significantly associated loci could be used for deciphering the genetic architecture of tomato fruit sugars and organic acids and for tomato quality breeding.

Current sequencing technology makes microhaplotypes a powerful new type of genetic marker for forensics.

PubMed

Kidd, Kenneth K; Pakstis, Andrew J; Speed, William C; Lagacé, Robert; Chang, Joseph; Wootton, Sharon; Haigh, Eva; Kidd, Judith R

2014-09-01

SNPs that are molecularly very close (<10kb) will generally have extremely low recombination rates, much less than 10(-4). Multiple haplotypes will often exist because of the history of the origins of the variants at the different sites, rare recombinants, and the vagaries of random genetic drift and/or selection. Such multiallelic haplotype loci are potentially important in forensic work for individual identification, for defining ancestry, and for identifying familial relationships. The new DNA sequencing capabilities currently available make possible continuous runs of a few hundred base pairs so that we can now determine the allelic combination of multiple SNPs on each chromosome of an individual, i.e., the phase, for multiple SNPs within a small segment of DNA. Therefore, we have begun to identify regions, encompassing two to four SNPs with an extent of <200bp that define multiallelic haplotype loci. We have identified candidate regions and have collected pilot data on many candidate microhaplotype loci. Here we present 31 microhaplotype loci that have at least three alleles, have high heterozygosity, are globally informative, and are statistically independent at the population level. This study of microhaplotype loci (microhaps) provides proof of principle that such markers exist and validates their usefulness for ancestry inference, lineage-clan-family inference, and individual identification. The true value of microhaplotypes will come with sequencing methods that can establish alleles unambiguously, including disentangling of mixtures, because a single sequencing run on a single strand of DNA will encompass all of the SNPs. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Next generation sequencing to dissect the genetic architecture of KNG1 and F11 loci using factor XI levels as an intermediate phenotype of thrombosis.

PubMed

Martin-Fernandez, Laura; Gavidia-Bovadilla, Giovana; Corrales, Irene; Brunel, Helena; Ramírez, Lorena; López, Sonia; Souto, Juan Carlos; Vidal, Francisco; Soria, José Manuel

2017-01-01

Venous thromboembolism is a complex disease with a high heritability. There are significant associations among Factor XI (FXI) levels and SNPs in the KNG1 and F11 loci. Our aim was to identify the genetic variation of KNG1 and F11 that might account for the variability of FXI levels. The KNG1 and F11 loci were sequenced completely in 110 unrelated individuals from the GAIT-2 (Genetic Analysis of Idiopathic Thrombophilia 2) Project using Next Generation Sequencing on an Illumina MiSeq. The GAIT-2 Project is a study of 935 individuals in 35 extended Spanish families selected through a proband with idiopathic thrombophilia. Among the 110 individuals, a subset of 40 individuals was chosen as a discovery sample for identifying variants. A total of 762 genetic variants were detected. Several significant associations were established among common variants and low-frequency variants sets in KNG1 and F11 with FXI levels using the PLINK and SKAT packages. Among these associations, those of rs710446 and five low-frequency variant sets in KNG1 with FXI level variation were significant after multiple testing correction and permutation. Also, two putative pathogenic mutations related to high and low FXI levels were identified by data filtering and in silico predictions. This study of KNG1 and F11 loci should help to understand the connection between genotypic variation and variation in FXI levels. The functional genetic variants should be useful as markers of thromboembolic risk.

Genetic structure and signatures of selection in grey reef sharks (Carcharhinus amblyrhynchos).

PubMed

Momigliano, P; Harcourt, R; Robbins, W D; Jaiteh, V; Mahardika, G N; Sembiring, A; Stow, A

2017-09-01

With overfishing reducing the abundance of marine predators in multiple marine ecosystems, knowledge of genetic structure and local adaptation may provide valuable information to assist sustainable management. Despite recent technological advances, most studies on sharks have used small sets of neutral markers to describe their genetic structure. We used 5517 nuclear single-nucleotide polymorphisms (SNPs) and a mitochondrial DNA (mtDNA) gene to characterize patterns of genetic structure and detect signatures of selection in grey reef sharks (Carcharhinus amblyrhynchos). Using samples from Australia, Indonesia and oceanic reefs in the Indian Ocean, we established that large oceanic distances represent barriers to gene flow, whereas genetic differentiation on continental shelves follows an isolation by distance model. In Australia and Indonesia differentiation at nuclear SNPs was weak, with coral reefs acting as stepping stones maintaining connectivity across large distances. Differentiation of mtDNA was stronger, and more pronounced in females, suggesting sex-biased dispersal. Four independent tests identified a set of loci putatively under selection, indicating that grey reef sharks in eastern Australia are likely under different selective pressures to those in western Australia and Indonesia. Genetic distances averaged across all loci were uncorrelated with genetic distances calculated from outlier loci, supporting the conclusion that different processes underpin genetic divergence in these two data sets. This pattern of heterogeneous genomic differentiation, suggestive of local adaptation, has implications for the conservation of grey reef sharks; furthermore, it highlights that marine species showing little genetic differentiation at neutral loci may exhibit patterns of cryptic genetic structure driven by local selection.

Three Approaches to Modeling Gene-Environment Interactions in Longitudinal Family Data: Gene-Smoking Interactions in Blood Pressure.

PubMed

Basson, Jacob; Sung, Yun Ju; de Las Fuentes, Lisa; Schwander, Karen L; Vazquez, Ana; Rao, Dabeeru C

2016-01-01

Blood pressure (BP) has been shown to be substantially heritable, yet identified genetic variants explain only a small fraction of the heritability. Gene-smoking interactions have detected novel BP loci in cross-sectional family data. Longitudinal family data are available and have additional promise to identify BP loci. However, this type of data presents unique analysis challenges. Although several methods for analyzing longitudinal family data are available, which method is the most appropriate and under what conditions has not been fully studied. Using data from three clinic visits from the Framingham Heart Study, we performed association analysis accounting for gene-smoking interactions in BP at 31,203 markers on chromosome 22. We evaluated three different modeling frameworks: generalized estimating equations (GEE), hierarchical linear modeling, and pedigree-based mixed modeling. The three models performed somewhat comparably, with multiple overlaps in the most strongly associated loci from each model. Loci with the greatest significance were more strongly supported in the longitudinal analyses than in any of the component single-visit analyses. The pedigree-based mixed model was more conservative, with less inflation in the variant main effect and greater deflation in the gene-smoking interactions. The GEE, but not the other two models, resulted in substantial inflation in the tail of the distribution when variants with minor allele frequency <1% were included in the analysis. The choice of analysis method should depend on the model and the structure and complexity of the familial and longitudinal data. © 2015 WILEY PERIODICALS, INC.

Two-locus maximum lod score analysis of a multifactorial trait: joint consideration of IDDM2 and IDDM4 with IDDM1 in type 1 diabetes.

PubMed

Cordell, H J; Todd, J A; Bennett, S T; Kawaguchi, Y; Farrall, M

1995-10-01

To investigate the genetic component of multifactorial diseases such as type 1 (insulin-dependent) diabetes mellitus (IDDM), models involving the joint action of several disease loci are important. These models can give increased power to detect an effect and a greater understanding of etiological mechanisms. Here, we present an extension of the maximum lod score method of N. Risch, which allows the simultaneous detection and modeling of two unlinked disease loci. Genetic constraints on the identical-by-descent sharing probabilities, analogous to the "triangle" restrictions in the single-locus method, are derived, and the size and power of the test statistics are investigated. The method is applied to affected-sib-pair data, and the joint effects of IDDM1 (HLA) and IDDM2 (the INS VNTR) and of IDDM1 and IDDM4 (FGF3-linked) are assessed with relation to the development of IDDM. In the presence of genetic heterogeneity, there is seen to be a significant advantage in analyzing more than one locus simultaneously. Analysis of these families indicates that the effects at IDDM1 and IDDM2 are well described by a multiplicative genetic model, while those at IDDM1 and IDDM4 follow a heterogeneity model.

Two-locus maximum lod score analysis of a multifactorial trait: joint consideration of IDDM2 and IDDM4 with IDDM1 in type 1 diabetes.

PubMed Central

Cordell, H J; Todd, J A; Bennett, S T; Kawaguchi, Y; Farrall, M

1995-01-01

To investigate the genetic component of multifactorial diseases such as type 1 (insulin-dependent) diabetes mellitus (IDDM), models involving the joint action of several disease loci are important. These models can give increased power to detect an effect and a greater understanding of etiological mechanisms. Here, we present an extension of the maximum lod score method of N. Risch, which allows the simultaneous detection and modeling of two unlinked disease loci. Genetic constraints on the identical-by-descent sharing probabilities, analogous to the "triangle" restrictions in the single-locus method, are derived, and the size and power of the test statistics are investigated. The method is applied to affected-sib-pair data, and the joint effects of IDDM1 (HLA) and IDDM2 (the INS VNTR) and of IDDM1 and IDDM4 (FGF3-linked) are assessed with relation to the development of IDDM. In the presence of genetic heterogeneity, there is seen to be a significant advantage in analyzing more than one locus simultaneously. Analysis of these families indicates that the effects at IDDM1 and IDDM2 are well described by a multiplicative genetic model, while those at IDDM1 and IDDM4 follow a heterogeneity model. PMID:7573054

Comparison of taxon-specific versus general locus sets for targeted sequence capture in plant phylogenomics.

PubMed

Chau, John H; Rahfeldt, Wolfgang A; Olmstead, Richard G

2018-03-01

Targeted sequence capture can be used to efficiently gather sequence data for large numbers of loci, such as single-copy nuclear loci. Most published studies in plants have used taxon-specific locus sets developed individually for a clade using multiple genomic and transcriptomic resources. General locus sets can also be developed from loci that have been identified as single-copy and have orthologs in large clades of plants. We identify and compare a taxon-specific locus set and three general locus sets (conserved ortholog set [COSII], shared single-copy nuclear [APVO SSC] genes, and pentatricopeptide repeat [PPR] genes) for targeted sequence capture in Buddleja (Scrophulariaceae) and outgroups. We evaluate their performance in terms of assembly success, sequence variability, and resolution and support of inferred phylogenetic trees. The taxon-specific locus set had the most target loci. Assembly success was high for all locus sets in Buddleja samples. For outgroups, general locus sets had greater assembly success. Taxon-specific and PPR loci had the highest average variability. The taxon-specific data set produced the best-supported tree, but all data sets showed improved resolution over previous non-sequence capture data sets. General locus sets can be a useful source of sequence capture targets, especially if multiple genomic resources are not available for a taxon.

Deficiency mapping of quantitative trait loci affecting longevity in Drosophila melanogaster.

PubMed Central

Pasyukova, E G; Vieira, C; Mackay, T F

2000-01-01

In a previous study, sex-specific quantitative trait loci (QTL) affecting adult longevity were mapped by linkage to polymorphic roo transposable element markers, in a population of recombinant inbred lines derived from the Oregon and 2b strains of Drosophila melanogaster. Two life span QTL were each located on chromosomes 2 and 3, within sections 33E-46C and 65D-85F on the cytological map, respectively. We used quantitative deficiency complementation mapping to further resolve the locations of life span QTL within these regions. The Oregon and 2b strains were each crossed to 47 deficiencies spanning cytological regions 32F-44E and 64C-76B, and quantitative failure of the QTL alleles to complement the deficiencies was assessed. We initially detected a minimum of five and four QTL in the chromosome 2 and 3 regions, respectively, illustrating that multiple linked factors contribute to each QTL detected by recombination mapping. The QTL locations inferred from deficiency mapping did not generally correspond to those of candidate genes affecting oxidative and thermal stress or glucose metabolism. The chromosome 2 QTL in the 35B-E region was further resolved to a minimum of three tightly linked QTL, containing six genetically defined loci, 24 genes, and predicted genes that are positional candidates corresponding to life span QTL. This region was also associated with quantitative variation in life span in a sample of 10 genotypes collected from nature. Quantitative deficiency complementation is an efficient method for fine-scale QTL mapping in Drosophila and can be further improved by controlling the background genotype of the strains to be tested. PMID:11063689

Concordance of nuclear and mitochondrial DNA markers in detecting a founder event in Lake Clark sockeye salmon

USGS Publications Warehouse

Ramstad, Kristina M.; Woody, Carol Ann; Habicht, Chris; Sage, G. Kevin; Seeb, James E.; Allendorf, Fred W.

2007-01-01

Genetic bottleneck effects can reduce genetic variation, persistence probability, and evolutionary potential of populations. Previous microsatellite analysis suggested a bottleneck associated with a common founding of sock-eye salmon Oncorhynchus nerka populations of Lake Clark, Alaska, about 100 to 400 generations ago. The common foundingevent occurred after the last glacial recession and resulted in reduced allelic diversity and strong divergence of Lake Clarksockeye salmon relative to neighboring Six Mile Lake and LakeIliamna populations. Here we used two additional genetic marker types (allozymes and mtDNA) to examine these patterns further. Allozyme and mtDNA results were congruent with the microsatellite data in suggesting a common founder event in LakeClark sockeye salmon and confirmed the divergence of Lake Clarkpopulations from neighboring Six Mile Lake and Lake Iliamna populations. The use of multiple marker types provided better understanding of the bottleneck in Lake Clark. For example, the Sucker Bay Lake population had an exceptionally severe reduction in allelic diversity at microsatellite loci, but not at mtDNA. This suggests that the reduced microsatellite variation in Sucker Bay Lake fish is due to consistently smaller effective population size than other Lake Clark populations, rather than a more acute or additional bottleneck since founding. Caution is urged in using reduced heterozygosity as a measure of genetic bottleneck effects because stochastic variance among loci resulted in an overall increase in allozyme heterozygosity within bottlenecked Lake Clark populations. However, heterozygosity excess, which assesses heterozygosity relative to allelic variation, detected genetic bottleneck effects in both allozyme and microsatellite loci. 

Genetics and the conservation of natural populations: allozymes to genomes.

PubMed

Allendorf, Fred W

2017-01-01

I consider how the study of genetic variation has influenced efforts to conserve natural populations over the last 50 years. Studies with allozymes in the 1970s provided the first estimates of the amount of genetic variation within and between natural populations at multiple loci. These early studies played an important role in developing plans to conserve species. The description of genetic variation in mitochondrial DNA in the early 1980s laid the foundation for the field of phylogeography, which provided a deeper look in time of the relationships and connectivity among populations. The development of microsatellites in the 1990s provided much more powerful means to describe genetic variation at nuclear loci, including the ability to detect past bottlenecks and estimate current effective population size with a single temporal sample. In the 2000s, single nucleotide polymorphisms presented a cornucopia of loci that has greatly improved power to estimate genetic and population demographic parameters important for conservation. Today, population genomics presents the ability to detect regions of the genome that are affected by natural selection (e.g. local adaptation or inbreeding depression). In addition, the ability to genotype historical samples has provided power to understand how climate change and other anthropogenic phenomena have affected populations. Modern molecular techniques provide unprecedented power to understand genetic variation in natural populations. Nevertheless, application of this information requires sound understanding of population genetics theory. I believe that current training in conservation genetics focuses too much on the latest techniques and too little on understanding the conceptual basis which is needed to interpret these data and ask good questions. © 2016 John Wiley & Sons Ltd.

SNR analysis: molecular investigation of an anthrax epidemic

PubMed Central

2010-01-01

Background In Italy, anthrax is endemic but occurs sporadically. During the summer of 2004, in the Pollino National Park, Basilicata, Southern Italy, an anthrax epidemic consisting of 41 outbreaks occurred; it claimed the lives of 124 animals belonging to different mammal species. This study is a retrospective molecular epidemiological investigation carried out on 53 isolates collected during the epidemic. A 25-loci Multiple Locus VNTR Analysis (MLVA) MLVA was initially performed to define genetic relationships, followed by an investigation of genetic diversity between epidemic strains through Single Nucleotide Repeat (SNR) analysis. Results 53 Bacillus anthracis strains were isolated. The 25-loci MLVA analysis identified all of them as belonging to a single genotype, while the SNR analysis was able to detect the existence of five subgenotypes (SGTs), allowing a detailed epidemic investigation. SGT-1 was the most frequent (46/53); SGTs 2 (4/53), 3 (1/53) 4 (1/53) and 5 (1/53) were detected in the remaining seven isolates. Conclusions The analysis revealed the prevalent spread, during this epidemic, of a single anthrax clone. SGT-1 - widely distributed across the epidemic area and present throughout the period in question - may, thus, be the ancestral form. SGTs 2, 3 and 4 differed from SGT-1 at only one locus, suggesting that they could have evolved directly from the latter during the course of this epidemic. SGT-5 differed from the other SGTs at 2-3 loci. This isolate, thus, appears to be more distantly related to SGT-1 and may not be a direct descendant of the lineage responsible for the majority of cases in this epidemic. These data confirm the importance of molecular typing and subtyping methods for in-depth epidemiological analyses of anthrax epidemics. PMID:20187980

Genome-wide Association Study Identifies New Loci for Resistance to Leptosphaeria maculans in Canola

PubMed Central

Raman, Harsh; Raman, Rosy; Coombes, Neil; Song, Jie; Diffey, Simon; Kilian, Andrzej; Lindbeck, Kurt; Barbulescu, Denise M.; Batley, Jacqueline; Edwards, David; Salisbury, Phil A.; Marcroft, Steve

2016-01-01

Key message “We identified both quantitative and quantitative resistance loci to Leptosphaeria maculans, a fungal pathogen, causing blackleg disease in canola. Several genome-wide significant associations were detected at known and new loci for blackleg resistance. We further validated statistically significant associations in four genetic mapping populations, demonstrating that GWAS marker loci are indeed associated with resistance to L. maculans. One of the novel loci identified for the first time, Rlm12, conveys adult plant resistance in canola.” Blackleg, caused by Leptosphaeria maculans, is a significant disease which affects the sustainable production of canola (Brassica napus). This study reports a genome-wide association study based on 18,804 polymorphic SNPs to identify loci associated with qualitative and quantitative resistance to L. maculans. Genomic regions delimited with 694 significant SNP markers, that are associated with resistance evaluated using 12 single spore isolates and pathotypes from four canola stubble were identified. Several significant associations were detected at known disease resistance loci including in the vicinity of recently cloned Rlm2/LepR3 genes, and at new loci on chromosomes A01/C01, A02/C02, A03/C03, A05/C05, A06, A08, and A09. In addition, we validated statistically significant associations on A01, A07, and A10 in four genetic mapping populations, demonstrating that GWAS marker loci are indeed associated with resistance to L. maculans. One of the novel loci identified for the first time, Rlm12, conveys adult plant resistance and mapped within 13.2 kb from Arabidopsis R gene of TIR-NBS class. We showed that resistance loci are located in the vicinity of R genes of Arabidopsis thaliana and Brassica napus on the sequenced genome of B. napus cv. Darmor-bzh. Significantly associated SNP markers provide a valuable tool to enrich germplasm for favorable alleles in order to improve the level of resistance to L. maculans in canola. PMID:27822217

Isolation and characterization of microsatellite loci in Greater Sage-Grouse (Centlocerus urophasianus)

USGS Publications Warehouse

Taylor, S.E.; Oyler-McCance, S.J.; Quinn, T.W.

2003-01-01

Primers for five polymorphic microsatellite loci were developed for Greater Sage-Grouse (Centrocercus urophasianus) using an enrichment/detection protocol. The high level of polymorphism (nine to 33 alleles) suggests that these loci will be applicable for investigating mating systems and paternity analysis as well as population genetics. Cross-species amplification was successful for each locus in at least two other galliform species.

CBCL Pediatric Bipolar Disorder Profile and ADHD: Comorbidity and Quantitative Trait Loci Analysis

ERIC Educational Resources Information Center

McGough, James J.; Loo, Sandra K.; McCracken, James T.; Dang, Jeffery; Clark, Shaunna; Nelson, Stanley F.; Smalley, Susan L.

2008-01-01

The pediatric bipolar disorder profile of the Child Behavior checklist is used to differentiate patterns of comorbidity and to search for quantitative trait loci in multiple affected ADHD sibling pairs. The CBCL-PBD profiling identified 8 percent of individuals with severe psychopathology and increased rates of oppositional defiant, conduct and…

Development of ten microsatellite loci in the invasive giant African land snail, Achatina (=Lissachatina) fulica Bowdich, 1822

USGS Publications Warehouse

Morrison, Cheryl L.; Springmann, Marcus J.; Iwanowicz, Deborah D.; Wade, Christopher M.

2015-01-01

A suite of tetra-nucleotide microsatellite loci were developed for the invasive giant African land snail, Achatina (=Lissachatina) fulica Bowdich, 1822, from Ion Torrent next-generation sequencing data. Ten of the 96 primer sets tested amplified consistently in 30 snails from Miami, Florida, plus 12 individuals representative of their native East Africa, Indian and Pacific Ocean regions. The loci displayed moderate levels of allelic diversity (average 5.6 alleles/locus) and heterozygosity (average 42 %). Levels of genetic diversity were sufficient to produce unique multi-locus genotypes and detect phylogeographic structuring among regional samples. The invasive A. fulica can cause extensive damage to important food crops and natural resources, including native flora and fauna. The loci characterized here will be useful for determining the origins and tracking the spread of invasions, detecting fine-scale spatial structuring and estimating demographic parameters.

Evaluating the performance of selection scans to detect selective sweeps in domestic dogs

PubMed Central

Schlamp, Florencia; van der Made, Julian; Stambler, Rebecca; Chesebrough, Lewis; Boyko, Adam R.; Messer, Philipp W.

2015-01-01

Selective breeding of dogs has resulted in repeated artificial selection on breed-specific morphological phenotypes. A number of quantitative trait loci associated with these phenotypes have been identified in genetic mapping studies. We analyzed the population genomic signatures observed around the causal mutations for 12 of these loci in 25 dog breeds, for which we genotyped 25 individuals in each breed. By measuring the population frequencies of the causal mutations in each breed, we identified those breeds in which specific mutations most likely experienced positive selection. These instances were then used as positive controls for assessing the performance of popular statistics to detect selection from population genomic data. We found that artificial selection during dog domestication has left characteristic signatures in the haplotype and nucleotide polymorphism patterns around selected loci that can be detected in the genotype data from a single population sample. However, the sensitivity and accuracy at which such signatures were detected varied widely between loci, the particular statistic used, and the choice of analysis parameters. We observed examples of both hard and soft selective sweeps and detected strong selective events that removed genetic diversity almost entirely over regions >10 Mbp. Our study demonstrates the power and limitations of selection scans in populations with high levels of linkage disequilibrium due to severe founder effects and recent population bottlenecks. PMID:26589239

Evaluating the performance of selection scans to detect selective sweeps in domestic dogs.

PubMed

Schlamp, Florencia; van der Made, Julian; Stambler, Rebecca; Chesebrough, Lewis; Boyko, Adam R; Messer, Philipp W

2016-01-01

Selective breeding of dogs has resulted in repeated artificial selection on breed-specific morphological phenotypes. A number of quantitative trait loci associated with these phenotypes have been identified in genetic mapping studies. We analysed the population genomic signatures observed around the causal mutations for 12 of these loci in 25 dog breeds, for which we genotyped 25 individuals in each breed. By measuring the population frequencies of the causal mutations in each breed, we identified those breeds in which specific mutations most likely experienced positive selection. These instances were then used as positive controls for assessing the performance of popular statistics to detect selection from population genomic data. We found that artificial selection during dog domestication has left characteristic signatures in the haplotype and nucleotide polymorphism patterns around selected loci that can be detected in the genotype data from a single population sample. However, the sensitivity and accuracy at which such signatures were detected varied widely between loci, the particular statistic used and the choice of analysis parameters. We observed examples of both hard and soft selective sweeps and detected strong selective events that removed genetic diversity almost entirely over regions >10 Mbp. Our study demonstrates the power and limitations of selection scans in populations with high levels of linkage disequilibrium due to severe founder effects and recent population bottlenecks. © 2015 John Wiley & Sons Ltd.

Knock-in/Knock-out (KIKO) vectors for rapid integration of large DNA sequences, including whole metabolic pathways, onto the Escherichia coli chromosome at well-characterised loci.

PubMed

Sabri, Suriana; Steen, Jennifer A; Bongers, Mareike; Nielsen, Lars K; Vickers, Claudia E

2013-06-24

Metabolic engineering projects often require integration of multiple genes in order to control the desired phenotype. However, this often requires iterative rounds of engineering because many current insertion approaches are limited by the size of the DNA that can be transferred onto the chromosome. Consequently, construction of highly engineered strains is very time-consuming. A lack of well-characterised insertion loci is also problematic. A series of knock-in/knock-out (KIKO) vectors was constructed for integration of large DNA sequences onto the E. coli chromosome at well-defined loci. The KIKO plasmids target three nonessential genes/operons as insertion sites: arsB (an arsenite transporter); lacZ (β-galactosidase); and rbsA-rbsR (a ribose metabolism operon). Two homologous 'arms' target each insertion locus; insertion is mediated by λ Red recombinase through these arms. Between the arms is a multiple cloning site for the introduction of exogenous sequences and an antibiotic resistance marker (either chloramphenicol or kanamycin) for selection of positive recombinants. The resistance marker can subsequently be removed by flippase-mediated recombination. The insertion cassette is flanked by hairpin loops to isolate it from the effects of external transcription at the integration locus. To characterize each target locus, a xylanase reporter gene (xynA) was integrated onto the chromosomes of E. coli strains W and K-12 using the KIKO vectors. Expression levels varied between loci, with the arsB locus consistently showing the highest level of expression. To demonstrate the simultaneous use of all three loci in one strain, xynA, green fluorescent protein (gfp) and a sucrose catabolic operon (cscAKB) were introduced into lacZ, arsB and rbsAR respectively, and shown to be functional. The KIKO plasmids are a useful tool for efficient integration of large DNA fragments (including multiple genes and pathways) into E. coli. Chromosomal insertion provides stable expression without the need for continuous antibiotic selection. Three non-essential loci have been characterised as insertion loci; combinatorial insertion at all three loci can be performed in one strain. The largest insertion at a single site described here was 5.4 kb; we have used this method in other studies to insert a total of 7.3 kb at one locus and 11.3 kb across two loci. These vectors are particularly useful for integration of multigene cassettes for metabolic engineering applications.

Comprehensive Analysis of Human Endogenous Retrovirus Group HERV-W Locus Transcription in Multiple Sclerosis Brain Lesions by High-Throughput Amplicon Sequencing

PubMed Central

Schmitt, Katja; Richter, Christin; Backes, Christina; Meese, Eckart; Ruprecht, Klemens

2013-01-01

Human endogenous retroviruses (HERVs) of the HERV-W group comprise hundreds of loci in the human genome. Deregulated HERV-W expression and HERV-W locus ERVWE1-encoded Syncytin-1 protein have been implicated in the pathogenesis of multiple sclerosis (MS). However, the actual transcription of HERV-W loci in the MS context has not been comprehensively analyzed. We investigated transcription of HERV-W in MS brain lesions and white matter brain tissue from healthy controls by employing next-generation amplicon sequencing of HERV-W env-specific reverse transcriptase (RT) PCR products, thus revealing transcribed HERV-W loci and the relative transcript levels of those loci. We identified more than 100 HERV-W loci that were transcribed in the human brain, with a limited number of loci being predominantly transcribed. Importantly, relative transcript levels of HERV-W loci were very similar between MS and healthy brain tissue samples, refuting deregulated transcription of HERV-W env in MS brain lesions, including the high-level-transcribed ERVWE1 locus encoding Syncytin-1. Quantitative RT-PCR likewise did not reveal differences in MS regarding HERV-W env general transcript or ERVWE1- and ERVWE2-specific transcript levels. However, we obtained evidence for interindividual differences in HERV-W transcript levels. Reporter gene assays indicated promoter activity of many HERV-W long terminal repeats (LTRs), including structurally incomplete LTRs. Our comprehensive analysis of HERV-W transcription in the human brain thus provides important information on the biology of HERV-W in MS lesions and normal human brain, implications for study design, and mechanisms by which HERV-W may (or may not) be involved in MS. PMID:24109235

Genome-wide association study identifies multiple susceptibility loci for multiple myeloma

PubMed Central

Mitchell, Jonathan S.; Li, Ni; Weinhold, Niels; Försti, Asta; Ali, Mina; van Duin, Mark; Thorleifsson, Gudmar; Johnson, David C.; Chen, Bowang; Halvarsson, Britt-Marie; Gudbjartsson, Daniel F.; Kuiper, Rowan; Stephens, Owen W.; Bertsch, Uta; Broderick, Peter; Campo, Chiara; Einsele, Hermann; Gregory, Walter A.; Gullberg, Urban; Henrion, Marc; Hillengass, Jens; Hoffmann, Per; Jackson, Graham H.; Johnsson, Ellinor; Jöud, Magnus; Kristinsson, Sigurður Y.; Lenhoff, Stig; Lenive, Oleg; Mellqvist, Ulf-Henrik; Migliorini, Gabriele; Nahi, Hareth; Nelander, Sven; Nickel, Jolanta; Nöthen, Markus M.; Rafnar, Thorunn; Ross, Fiona M.; da Silva Filho, Miguel Inacio; Swaminathan, Bhairavi; Thomsen, Hauke; Turesson, Ingemar; Vangsted, Annette; Vogel, Ulla; Waage, Anders; Walker, Brian A.; Wihlborg, Anna-Karin; Broyl, Annemiek; Davies, Faith E.; Thorsteinsdottir, Unnur; Langer, Christian; Hansson, Markus; Kaiser, Martin; Sonneveld, Pieter; Stefansson, Kari; Morgan, Gareth J.; Goldschmidt, Hartmut; Hemminki, Kari; Nilsson, Björn; Houlston, Richard S.

2016-01-01

Multiple myeloma (MM) is a plasma cell malignancy with a significant heritable basis. Genome-wide association studies have transformed our understanding of MM predisposition, but individual studies have had limited power to discover risk loci. Here we perform a meta-analysis of these GWAS, add a new GWAS and perform replication analyses resulting in 9,866 cases and 239,188 controls. We confirm all nine known risk loci and discover eight new loci at 6p22.3 (rs34229995, P=1.31 × 10−8), 6q21 (rs9372120, P=9.09 × 10−15), 7q36.1 (rs7781265, P=9.71 × 10−9), 8q24.21 (rs1948915, P=4.20 × 10−11), 9p21.3 (rs2811710, P=1.72 × 10−13), 10p12.1 (rs2790457, P=1.77 × 10−8), 16q23.1 (rs7193541, P=5.00 × 10−12) and 20q13.13 (rs6066835, P=1.36 × 10−13), which localize in or near to JARID2, ATG5, SMARCD3, CCAT1, CDKN2A, WAC, RFWD3 and PREX1. These findings provide additional support for a polygenic model of MM and insight into the biological basis of tumour development. PMID:27363682

Detecting Selection on Temporal and Spatial Scales: A Genomic Time-Series Assessment of Selective Responses to Devil Facial Tumor Disease

PubMed Central

Brüniche-Olsen, Anna; Austin, Jeremy J.; Jones, Menna E.; Holland, Barbara R.; Burridge, Christopher P.

2016-01-01

Detecting loci under selection is an important task in evolutionary biology. In conservation genetics detecting selection is key to investigating adaptation to the spread of infectious disease. Loci under selection can be detected on a spatial scale, accounting for differences in demographic history among populations, or on a temporal scale, tracing changes in allele frequencies over time. Here we use these two approaches to investigate selective responses to the spread of an infectious cancer—devil facial tumor disease (DFTD)—that since 1996 has ravaged the Tasmanian devil (Sarcophilus harrisii). Using time-series ‘restriction site associated DNA’ (RAD) markers from populations pre- and post DFTD arrival, and DFTD free populations, we infer loci under selection due to DFTD and investigate signatures of selection that are incongruent among methods, populations, and times. The lack of congruence among populations influenced by DFTD with respect to inferred loci under selection, and the direction of that selection, fail to implicate a consistent selective role for DFTD. Instead genetic drift is more likely driving the observed allele frequency changes over time. Our study illustrates the importance of applying methods with different performance optima e.g. accounting for population structure and background selection, and assessing congruence of the results. PMID:26930198

Identification and characterization of microsatellite markers from the tropical sea cucumber, Stichopus horrens (Selenka).

PubMed

Shangguan, J B; Li, Z B; Yuan, Y; Huang, Y S

2015-10-28

Tropical commercial sea cucumber Stichopus horrens is extensively distributed throughout the tropical Indo-Pacific region, and wild stocks have been severely depleted over the past decade. In this study, we used the microsatellite enrichment library of S. horrens to identify and characterize 13 microsatellite loci, including 11 polymorphic loci and 2 monomorphic loci. Among the 11 polymorphic loci, the number of alleles was 3-8. The observed and expected heterozygosity varied from 0.1364 to 0.8966 and from 0.1653 to 0.7551, respectively. Additionally, all 11 polymorphic loci showed moderate and high polymorphism with the polymorphism information content (0.271-0.7311). A total of 9 polymorphic loci were in Hardy-Weinberg equilibrium, except for 2 loci (adjusted P = 0.004545). Linkage disequilibrium was not detected in any pairs of polymorphic loci. The present study will be useful for studying genetic structure, population conservation, and breeding of wild S. horrens; moreover, our results contribute to the phylogeny and evolutionary research of Holothuroidea.

Evaluation of forensic genetic parameters of 12 STR loci in the Korean population using the InvestigatorⓇ HDplex kit.

PubMed

Jung, Ju Yeon; Kim, Eun Hye; Oh, Yu-Li; Park, Hyun-Chul; Hwang, Jung Ho; Lim, Si-Keun

2017-09-01

We genotyped and calculated the forensic parameters of 10 non-CODIS loci and 2 CODIS loci of 990 Korean individuals using the Investigator Ⓡ HDplex kit. No significant deviations from Hardy-Weinberg equilibrium (after Bonferroni correction for multiple testing) or genetic linkage disequilibrium were observed. The calculated matching probability and power of discrimination ranged from 0.0080 to 0.2014, and 0.7986 to 0.9920, respectively. We conclude that the markers of the kit are highly informative corroborative tools for forensic DNA analysis.

Genetic variation of loci potentially under selection confounds species-genetic diversity correlations in a fragmented habitat.

PubMed

Bertin, Angeline; Gouin, Nicolas; Baumel, Alex; Gianoli, Ernesto; Serratosa, Juan; Osorio, Rodomiro; Manel, Stephanie

2017-01-01

Positive species-genetic diversity correlations (SGDCs) are often thought to result from the parallel influence of neutral processes on genetic and species diversity. Yet, confounding effects of non-neutral mechanisms have not been explored. Here, we investigate the impact of non-neutral genetic diversity on SGDCs in high Andean wetlands. We compare correlations between plant species diversity and genetic diversity (GD) calculated with and without loci potentially under selection (outlier loci). The study system includes 2188 specimens from five species (three common aquatic macroinvertebrate and two dominant plant species) that were genotyped for 396 amplified fragment length polymorphism loci. We also appraise the importance of neutral processes on SGDCs by investigating the influence of habitat fragmentation features. Significant positive SGDCs were detected for all five species (mean SGDC = 0.52 ± 0.05). While only a few outlier loci were detected in each species, they resulted in significant decreases in GD and in SGDCs. This supports the hypothesis that neutral processes drive species-genetic diversity relationships in high Andean wetlands. Unexpectedly, the effects on genetic diversity GD of the habitat fragmentation characteristics in this study increased with the presence of outlier loci in two species. Overall, our results reveal pitfalls in using habitat features to infer processes driving SGDCs and show that a few loci potentially under selection are enough to cause a significant downward bias in SGDC. Investigating confounding effects of outlier loci thus represents a useful approach to evidence the contribution of neutral processes on species-genetic diversity relationships. © 2016 John Wiley & Sons Ltd.

Haplotype data for 23 Y-chromosome markers in a reference sample from Bosnia and Herzegovina.

PubMed

Kovačević, Lejla; Fatur-Cerić, Vera; Hadzic, Negra; Čakar, Jasmina; Primorac, Dragan; Marjanović, Damir

2013-06-01

To detect polymorphisms of 23 Y-chromosomal short tandem repeat (STR) loci, including 6 new loci, in a reference database of male population of Bosnia and Herzegovina, as well as to assess the importance of increasing the number of Y-STR loci utilized in forensic DNA analysis. The reference sample consisted of 100 healthy, unrelated men originating from Bosnia and Herzegovina. Sample collection using buccal swabs was performed in all geographical regions of Bosnia and Herzegovina in the period from 2010 to 2011. DNA samples were typed for 23 Y STR loci, including 6 new loci: DYS576, DYS481, DYS549, DYS533, DYS570, and DYS643, which are included in the new PowerPlex® Y 23 amplification kit. The absolute frequency of generated haplotypes was calculated and results showed that 98 samples had unique Y 23 haplotypes, and that only two samples shared the same haplotype. The most polymorphic locus was DYS418, with 14 detected alleles and the least polymorphic loci were DYS389I, DYS391, DYS437, and DYS393. This study showed that by increasing the number of highly polymorphic Y STR markers, to include those tested in our analysis, leads to a reduction of repeating haplotypes, which is very important in the application of forensic DNA analysis.

New quantitative trait loci in wheat for flag leaf resistance to Stagonospora nodorum blotch.

PubMed

Francki, M G; Shankar, M; Walker, E; Loughman, R; Golzar, H; Ohm, H

2011-11-01

Stagonospora nodorum blotch (SNB) is a significant disease in some wheat-growing regions of the world. Resistance in wheat to Stagonospora nodorum is complex, whereby genes for seedling, flag leaf, and glume resistance are independent. The aims of this study were to identify alternative genes for flag leaf resistance, to compare and contrast with known quantitative trait loci (QTL) for SNB resistance, and to determine the potential role of host-specific toxins for SNB QTL. Novel QTL for flag leaf resistance were identified on chromosome 2AS inherited from winter wheat parent 'P92201D5' and chromosome 1BS from spring wheat parent 'EGA Blanco'. The chromosomal map position of markers associated with QTL on 1BS and 2AS indicated that they were unlikely to be associated with known host-toxin insensitivity loci. A QTL on chromosome 5BL inherited from EGA Blanco had highly significant association with markers fcp001 and fcp620 based on disease evaluation in 2007 and, therefore, is likely to be associated with Tsn1-ToxA insensitivity for flag leaf resistance. However, fcp001 and fcp620 were not associated with a QTL detected based on disease evaluation in 2008, indicating two linked QTL for flag leaf resistance with multiple genes residing on 5BL. This study identified novel QTL and their effects in controlling flag leaf SNB resistance.

Selection on overdominant genes maintains heterozygosity along multiple chromosomes in a clonal lineage of honey bee.

PubMed

Goudie, Frances; Allsopp, Michael H; Oldroyd, Benjamin P

2014-01-01

Correlations between fitness and genome-wide heterozygosity (heterozygosity-fitness correlations, HFCs) have been reported across a wide range of taxa. The genetic basis of these correlations is controversial: do they arise from genome-wide inbreeding ("general effects") or the "local effects" of overdominant loci acting in linkage disequilibrium with neutral loci? In an asexual thelytokous lineage of the Cape honey bee (Apis mellifera capensis), the effects of inbreeding have been homogenized across the population, making this an ideal system in which to detect overdominant loci, and to make inferences about the importance of overdominance on HFCs in general. Here we investigate the pattern of zygosity along two chromosomes in 42 workers from the clonal Cape honey bee population. On chromosome III (which contains the sex-locus, a gene that is homozygous-lethal) and chromosome IV we show that the pattern of zygosity is characterized by loss of heterozygosity in short regions followed by the telomeric restoration of heterozygosity. We infer that at least four selectively overdominant genes maintain heterozygosity on chromosome III and three on chromosome IV via local effects acting on neutral markers in linkage disequilibrium. We conclude that heterozygote advantage and local effects may be more common and evolutionarily significant than is generally appreciated. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

A complete genetic linkage map and QTL analyses for bast fibre quality traits, yield and yield components in jute (Corchorus olitorius L.).

PubMed

Topdar, N; Kundu, A; Sinha, M K; Sarkar, D; Das, M; Banerjee, S; Kar, C S; Satya, P; Balyan, H S; Mahapatra, B S; Gupta, P K

2013-01-01

We report the first complete microsatellite genetic map of jute (Corchorus olitorius L.; 2n = 2x = 14) using an F6 recombinant inbred population. Of the 403 microsatellite markers screened, 82 were mapped on the seven linkage groups (LGs) that covered a total genetic distance of 799.9 cM, with an average marker interval of 10.7 cM. LG5 had the longest and LG7 the shortest genetic lengths, whereas LG1 had the maximum and LG7 the minimum number of markers. Segregation distortion of microsatellite loci was high (61%), with the majority of them (76%) skewed towards the female parent. Genomewide non-parametric single-marker analysis in combination with multiple quantitative trait loci (QTL)-models (MQM) mapping detected 26 definitive QTLs for bast fibre quality, yield and yield-related traits. These were unevenly distributed on six LGs, as colocalized clusters, at genomic sectors marked by 15 microsatellite loci. LG1 was the QTL-richest map sector, with the densest colocalized clusters of QTLs governing fibre yield, yield-related traits and tensile strength. Expectedly, favorable QTLs were derived from the desirable parents, except for nearly all of those of fibre fineness, which might be due to the creation of new gene combinations. Our results will be a good starting point for further genome analyses in jute.

Identification of Mom12 and Mom13, two novel modifier loci of Apc (Min) -mediated intestinal tumorigenesis.

PubMed

Crist, Richard C; Roth, Jacquelyn J; Lisanti, Michael P; Siracusa, Linda D; Buchberg, Arthur M

2011-04-01

Colorectal cancer is a heterogeneous disease resulting from a combination of genetic and environmental factors. The C57BL/6J (B6) Apc (Min/+) mouse develops polyps throughout the gastrointestinal tract and has been a valuable model for understanding the genetic basis of intestinal tumorigenesis. Apc (Min/+) mice have been used to study known oncogenes and tumor suppressor genes on a controlled genetic background. These studies often utilize congenic knockout alleles, which can carry an unknown amount of residual donor DNA. The Apc (Min) model has also been used to identify modifer loci, known as Modifier of Min (Mom) loci, which alter Apc (Min) -mediated intestinal tumorigenesis. B6 mice carrying a knockout allele generated in WW6 embryonic stem cells were crossed to B6 Apc (Min/+) mice to determine the effect on polyp multiplicity. The newly generated colony developed significantly more intestinal polyps than Apc (Min/+) controls. Polyp multiplicity did not correlate with inheritance of the knockout allele, suggesting the presence of one or more modifier loci segregating in the colony. Genotyping of simple sequence length polymorphism (SSLP) markers revealed residual 129X1/SvJ genomic DNA within the congenic region of the parental knockout line. An analysis of polyp multiplicity data and SSLP genotyping indicated the presence of two Mom loci in the colony: 1) Mom12, a dominant modifier linked to the congenic region on chromosome 6, and 2) Mom13, which is unlinked to the congenic region and whose effect is masked by Mom12. The identification of Mom12 and Mom13 demonstrates the potential problems resulting from residual heterozygosity present in congenic lines.

Parapatric speciation in three islands: dynamics of geographical configuration of allele sharing

PubMed Central

Iwasa, Yoh

2017-01-01

We studied the time to speciation by geographical isolation for a species living on three islands connected by rare migration. We assumed that incompatibility was controlled by a number of quantitative loci and that individuals differing in loci by more than a threshold did not mix genetically with each other. For each locus, we defined the geographical configuration (GC), which specifies islands with common alleles, and traced the stochastic transitions between different GCs. From these results, we calculated the changes in genetic distances. As a single migration event provides an opportunity for transitions in multiple loci, the GCs of different loci are correlated, which can be evaluated by constructing the stochastic differential equations of the number of loci with different GCs. Our model showed that the low number of incompatibility loci facilitates parapatric speciation and that migrants arriving as a group shorten the waiting time to speciation compared with the same number of migrants arriving individually. We also discuss how speciation rate changes with geographical structure. PMID:28386439

GWAS of clinically defined gout and subtypes identifies multiple susceptibility loci that include urate transporter genes.

PubMed

Nakayama, Akiyoshi; Nakaoka, Hirofumi; Yamamoto, Ken; Sakiyama, Masayuki; Shaukat, Amara; Toyoda, Yu; Okada, Yukinori; Kamatani, Yoichiro; Nakamura, Takahiro; Takada, Tappei; Inoue, Katsuhisa; Yasujima, Tomoya; Yuasa, Hiroaki; Shirahama, Yuko; Nakashima, Hiroshi; Shimizu, Seiko; Higashino, Toshihide; Kawamura, Yusuke; Ogata, Hiraku; Kawaguchi, Makoto; Ohkawa, Yasuyuki; Danjoh, Inaho; Tokumasu, Atsumi; Ooyama, Keiko; Ito, Toshimitsu; Kondo, Takaaki; Wakai, Kenji; Stiburkova, Blanka; Pavelka, Karel; Stamp, Lisa K; Dalbeth, Nicola; Sakurai, Yutaka; Suzuki, Hiroshi; Hosoyamada, Makoto; Fujimori, Shin; Yokoo, Takashi; Hosoya, Tatsuo; Inoue, Ituro; Takahashi, Atsushi; Kubo, Michiaki; Ooyama, Hiroshi; Shimizu, Toru; Ichida, Kimiyoshi; Shinomiya, Nariyoshi; Merriman, Tony R; Matsuo, Hirotaka

2017-05-01

A genome-wide association study (GWAS) of gout and its subtypes was performed to identify novel gout loci, including those that are subtype-specific. Putative causal association signals from a GWAS of 945 clinically defined gout cases and 1213 controls from Japanese males were replicated with 1396 cases and 1268 controls using a custom chip of 1961 single nucleotide polymorphisms (SNPs). We also first conducted GWASs of gout subtypes. Replication with Caucasian and New Zealand Polynesian samples was done to further validate the loci identified in this study. In addition to the five loci we reported previously, further susceptibility loci were identified at a genome-wide significance level (p<5.0×10 -8 ): urate transporter genes ( SLC22A12 and SLC17A1 ) and HIST1H2BF-HIST1H4E for all gout cases, and NIPAL1 and FAM35A for the renal underexcretion gout subtype. While NIPAL1 encodes a magnesium transporter, functional analysis did not detect urate transport via NIPAL1, suggesting an indirect association with urate handling. Localisation analysis in the human kidney revealed expression of NIPAL1 and FAM35A mainly in the distal tubules, which suggests the involvement of the distal nephron in urate handling in humans. Clinically ascertained male patients with gout and controls of Caucasian and Polynesian ancestries were also genotyped, and FAM35A was associated with gout in all cases. A meta-analysis of the three populations revealed FAM35A to be associated with gout at a genome-wide level of significance (p meta =3.58×10 -8 ). Our findings including novel gout risk loci provide further understanding of the molecular pathogenesis of gout and lead to a novel concept for the therapeutic target of gout/hyperuricaemia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Generalization of Associations of Kidney-Related Genetic Loci to American Indians

PubMed Central

Haack, Karin; Almasy, Laura; Laston, Sandra; Lee, Elisa T.; Best, Lyle G.; Fabsitz, Richard R.; MacCluer, Jean W.; Howard, Barbara V.; Umans, Jason G.; Cole, Shelley A.

2014-01-01

Summary Background and objectives CKD disproportionally affects American Indians, who similar to other populations, show genetic susceptibility to kidney outcomes. Recent studies have identified several loci associated with kidney traits, but their relevance in American Indians is unknown. Design, setting, participants, & measurements This study used data from a large, family-based genetic study of American Indians (the Strong Heart Family Study), which includes 94 multigenerational families enrolled from communities located in Oklahoma, the Dakotas, and Arizona. Individuals were recruited from the Strong Heart Study, a population-based study of cardiovascular disease in American Indians. This study selected 25 single nucleotide polymorphisms in 23 loci identified from recently published kidney-related genome-wide association studies in individuals of European ancestry to evaluate their associations with kidney function (estimated GFR; individuals 18 years or older, up to 3282 individuals) and albuminuria (urinary albumin to creatinine ratio; n=3552) in the Strong Heart Family Study. This study also examined the association of single nucleotide polymorphisms in the APOL1 region with estimated GFR in 1121 Strong Heart Family Study participants. GFR was estimated using the abbreviated Modification of Diet in Renal Disease Equation. Additive genetic models adjusted for age and sex were used. Results This study identified significant associations of single nucleotide polymorphisms with estimated GFR in or nearby PRKAG2, SLC6A13, UBE2Q2, PIP5K1B, and WDR72 (P<2.1 × 10-3 to account for multiple testing). Single nucleotide polymorphisms in these loci explained 2.2% of the estimated GFR total variance and 2.9% of its heritability. An intronic variant of BCAS3 was significantly associated with urinary albumin to creatinine ratio. APOL1 single nucleotide polymorphisms were not associated with estimated GFR in a single variant test or haplotype analyses, and the at-risk variants identified in individuals with African ancestry were not detected in DNA sequencing of American Indians. Conclusion This study extends the genetic associations of loci affecting kidney function to American Indians, a population at high risk of kidney disease, and provides additional support for a potential biologic relevance of these loci across ancestries. PMID:24311711

My-Forensic-Loci-queries (MyFLq) framework for analysis of forensic STR data generated by massive parallel sequencing.

PubMed

Van Neste, Christophe; Vandewoestyne, Mado; Van Criekinge, Wim; Deforce, Dieter; Van Nieuwerburgh, Filip

2014-03-01

Forensic scientists are currently investigating how to transition from capillary electrophoresis (CE) to massive parallel sequencing (MPS) for analysis of forensic DNA profiles. MPS offers several advantages over CE such as virtually unlimited multiplexy of loci, combining both short tandem repeat (STR) and single nucleotide polymorphism (SNP) loci, small amplicons without constraints of size separation, more discrimination power, deep mixture resolution and sample multiplexing. We present our bioinformatic framework My-Forensic-Loci-queries (MyFLq) for analysis of MPS forensic data. For allele calling, the framework uses a MySQL reference allele database with automatically determined regions of interest (ROIs) by a generic maximal flanking algorithm which makes it possible to use any STR or SNP forensic locus. Python scripts were designed to automatically make allele calls starting from raw MPS data. We also present a method to assess the usefulness and overall performance of a forensic locus with respect to MPS, as well as methods to estimate whether an unknown allele, which sequence is not present in the MySQL database, is in fact a new allele or a sequencing error. The MyFLq framework was applied to an Illumina MiSeq dataset of a forensic Illumina amplicon library, generated from multilocus STR polymerase chain reaction (PCR) on both single contributor samples and multiple person DNA mixtures. Although the multilocus PCR was not yet optimized for MPS in terms of amplicon length or locus selection, the results show excellent results for most loci. The results show a high signal-to-noise ratio, correct allele calls, and a low limit of detection for minor DNA contributors in mixed DNA samples. Technically, forensic MPS affords great promise for routine implementation in forensic genomics. The method is also applicable to adjacent disciplines such as molecular autopsy in legal medicine and in mitochondrial DNA research. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

An update on the genetic architecture of hyperuricemia and gout.

PubMed

Merriman, Tony R

2015-04-10

Genome-wide association studies that scan the genome for common genetic variants associated with phenotype have greatly advanced medical knowledge. Hyperuricemia is no exception, with 28 loci identified. However, genetic control of pathways determining gout in the presence of hyperuricemia is still poorly understood. Two important pathways determining hyperuricemia have been confirmed (renal and gut excretion of uric acid with glycolysis now firmly implicated). Major urate loci are SLC2A9 and ABCG2. Recent studies show that SLC2A9 is involved in renal and gut excretion of uric acid and is implicated in antioxidant defense. Although etiological variants at SLC2A9 are yet to be identified, it is clear that considerable genetic complexity exists at the SLC2A9 locus, with multiple statistically independent genetic variants and local epistatic interactions. The positions of implicated genetic variants within or near chromatin regions involved in transcriptional control suggest that this mechanism (rather than structural changes in SLC2A9) is important in regulating the activity of SLC2A9. ABCG2 is involved primarily in extra-renal uric acid under-excretion with the etiological variant influencing expression. At the other 26 loci, probable causal genes can be identified at three (PDZK1, SLC22A11, and INHBB) with strong candidates at a further 10 loci. Confirmation of the causal gene will require a combination of re-sequencing, trans-ancestral mapping, and correlation of genetic association data with expression data. As expected, the urate loci associate with gout, although inconsistent effect sizes for gout require investigation. Finally, there has been no genome-wide association study using clinically ascertained cases to investigate the causes of gout in the presence of hyperuricemia. In such a study, use of asymptomatic hyperurcemic controls would be expected to increase the ability to detect genetic associations with gout.

Directed evolution of multiple genomic loci allows the prediction of antibiotic resistance.

PubMed

Nyerges, Ákos; Csörgő, Bálint; Draskovits, Gábor; Kintses, Bálint; Szili, Petra; Ferenc, Györgyi; Révész, Tamás; Ari, Eszter; Nagy, István; Bálint, Balázs; Vásárhelyi, Bálint Márk; Bihari, Péter; Számel, Mónika; Balogh, Dávid; Papp, Henrietta; Kalapis, Dorottya; Papp, Balázs; Pál, Csaba

2018-06-19

Antibiotic development is frequently plagued by the rapid emergence of drug resistance. However, assessing the risk of resistance development in the preclinical stage is difficult. Standard laboratory evolution approaches explore only a small fraction of the sequence space and fail to identify exceedingly rare resistance mutations and combinations thereof. Therefore, new rapid and exhaustive methods are needed to accurately assess the potential of resistance evolution and uncover the underlying mutational mechanisms. Here, we introduce directed evolution with random genomic mutations (DIvERGE), a method that allows an up to million-fold increase in mutation rate along the full lengths of multiple predefined loci in a range of bacterial species. In a single day, DIvERGE generated specific mutation combinations, yielding clinically significant resistance against trimethoprim and ciprofloxacin. Many of these mutations have remained previously undetected or provide resistance in a species-specific manner. These results indicate pathogen-specific resistance mechanisms and the necessity of future narrow-spectrum antibacterial treatments. In contrast to prior claims, we detected the rapid emergence of resistance against gepotidacin, a novel antibiotic currently in clinical trials. Based on these properties, DIvERGE could be applicable to identify less resistance-prone antibiotics at an early stage of drug development. Finally, we discuss potential future applications of DIvERGE in synthetic and evolutionary biology. Copyright © 2018 the Author(s). Published by PNAS.

GEOGRAPHIC DISTRIBUTION OF MOLECULAR VARIANCE WITHIN THE BLUE MARLIN (MAKAIRA NIGRICANS): A HIERARCHICAL ANALYSIS OF ALLOZYME, SINGLE-COPY NUCLEAR DNA, AND MITOCHONDRIAL DNA MARKERS.

PubMed

Buonaccorsi, Vincent P; Reece, Kimberly S; Morgan, Lee W; Graves, John E

1999-04-01

This study presents a comparative hierarchical analysis of variance applied to three classes of molecular markers within the blue marlin (Makaira nigricans). Results are reported from analyses of four polymorphic allozyme loci, four polymorphic anonymously chosen single-copy nuclear DNA (scnDNA) loci, and previously reported restriction fragment length polymorphisms (RFLPs) of mitochondrial DNA (mtDNA). Samples were collected within and among the Atlantic and Pacific Oceans over a period of several years. Although moderate levels of genetic variation were detected at both polymorphic allozyme (H = 0.30) and scnDNA loci (H = 0.37), mtDNA markers were much more diverse (h = 0.85). Allele frequencies were significantly different between Atlantic and Pacific Ocean samples at three of four allozyme loci and three of four scnDNA loci. Estimates of allozyme genetic differentiation (θ O ) ranged from 0.00 to 0.15, with a mean of 0.08. The θ O values for scnDNA loci were similar to those of allozymes, ranging from 0.00 to 0.12 with a mean of 0.09. MtDNA RFLP divergence between oceans (θ O = 0.39) was significantly greater than divergence detected at nuclear loci (95% nuclear confidence interval = 0.04-0.11). The fourfold smaller effective population size of mtDNA and male-mediated gene flow may account for the difference observed between nuclear and mitochondrial divergence estimates. © 1999 The Society for the Study of Evolution.

Isolation and Characterization of Polymorphic Microsatellite Loci from Metapenaeopsis barbata Using PCR-Based Isolation of Microsatellite Arrays (PIMA)

PubMed Central

Chiang, Tzen-Yuh; Tzeng, Tzong-Der; Lin, Hung-Du; Cho, Ching-Ju; Lin, Feng-Jiau

2012-01-01

The red-spot prawn, Metapenaeopsis barbata, is a commercially important, widely distributed demersal species in the Indo-West Pacific Ocean. Overfishing has made its populations decline in the past decade. To study conservation genetics, eight polymorphic microsatellite loci were isolated. Genetic characteristics of the SSR (simple sequence repeat) fingerprints were estimated in 61 individuals from adjacent seas of Taiwan and China. The number of alleles, ranging from 2 to 4, as well as observed and expected heterozygosities in populations, ranging from 0.048 to 0.538, and 0.048 and 0.654, respectively, were detected. No deviation from Hardy–Weinberg expectations was detected at either locus. No significant linkage disequilibrium was detected in locus pairs. The polymorphic microsatellite loci will be useful for investigations of the genetic variation, population structure, and conservation genetics of this species. PMID:22489123

Twenty-seven nonoverlapping zinc finger cDNAs from human T cells map to nine different chromosomes with apparent clustering.

PubMed Central

Huebner, K; Druck, T; Croce, C M; Thiesen, H J

1991-01-01

cDNA clones encoding zinc finger structures were isolated by screening Molt4 and Jurkat cDNA libraries with zinc finger consensus sequences. Candidate clones were partially sequenced to verify the presence of zinc finger-encoding regions; nonoverlapping cDNA clones were chosen on the basis of sequences and genomic hybridization pattern. Zinc finger structure-encoding clones, which were designated by the term "Kox" and a number from 1 to 32 and which were apparently unique (i.e., distinct from each other and distinct from those isolated by other laboratories), were chosen for mapping in the human genome. DNAs from rodent-human somatic cell hybrids retaining defined complements of human chromosomes were analyzed for the presence of each of the Kox genes. Correlation between the presence of specific human chromosome regions and specific Kox genes established the chromosomal locations. Multiple Kox loci were mapped to 7q (Kox 18 and 25 and a locus detected by both Kox 8 cDNA and Kox 27 cDNA), 8q24 5' to the myc locus (Kox 9 and 32), 10cen----q24 (Kox 2, 15, 19, 21, 30, and 31), 12q13-qter (Kox 1 and 20), 17p13 (Kox 11 and 26), and 19q (Kox 5, 6, 10, 22, 24, and 28). Single Kox loci were mapped to 7p22 (Kox 3), 18q12 (Kox 17), 19p (Kox 13), 22q11 between IG lambda and BCR-1 (locus detected by both Kox 8 cDNA and Kox 27 cDNA), and Xp (Kox 14). Several of the Kox loci map to regions in which other zinc finger structure-encoding loci have already been localized, indicating possible zinc finger gene clusters. In addition, Kox genes at 8q24, 17p13, and 22q11--and perhaps other Kox genes--are located near recurrent chromosomal translocation breakpoints. Others, such as those on 7p and 7q, may be near regions specifically active in T cells. Images Figure 4 Figure 5 Figure 2 Figure 3 PMID:2014798

Candidate loci involved in domestication and improvement detected by a published 90K wheat SNP array

PubMed Central

Gao, Lifeng; Zhao, Guangyao; Huang, Dawei; Jia, Jizeng

2017-01-01

Selection is one of the most important forces in crop evolution. Common wheat is a major world food crop and a typical allopolyploid with a huge and complex genome. We applied four approaches to detect loci selected in wheat during domestication and improvement. A total of 7,984 candidate loci were detected, accounting for 23.3% of all 34,317 SNPs analysed, a much higher proportion than estimated in previous reports. We constructed a first generation wheat selection map which revealed the following new insights on genome-wide selection: (1) diversifying selection acted by increasing, decreasing or not affecting gene frequencies; (2) the number of loci under selection during domestication was much higher than that during improvement; (3) the contribution to wheat improvement by the D sub-genome was relatively small due to the bottleneck of hexaploidisation and diversity can be expanded by using synthetic wheat and introgression lines; and (4) clustered selection regions occur throughout the wheat genome, including the centromere regions. This study will not only help future wheat breeding and evolutionary studies, but will also accelerate study of other crops, especially polyploids. PMID:28327671

Extent of height variability explained by known height-associated genetic variants in an isolated population of the Adriatic coast of Croatia.

PubMed

Zhang, Ge; Karns, Rebekah; Sun, Guangyun; Indugula, Subba Rao; Cheng, Hong; Havas-Augustin, Dubravka; Novokmet, Natalija; Rudan, Dusko; Durakovic, Zijad; Missoni, Sasa; Chakraborty, Ranajit; Rudan, Pavao; Deka, Ranjan

2011-01-01

Human height is a classical example of a polygenic quantitative trait. Recent large-scale genome-wide association studies (GWAS) have identified more than 200 height-associated loci, though these variants explain only 2∼10% of overall variability of normal height. The objective of this study was to investigate the variance explained by these loci in a relatively isolated population of European descent with limited admixture and homogeneous genetic background from the Adriatic coast of Croatia. In a sample of 1304 individuals from the island population of Hvar, Croatia, we performed genome-wide SNP typing and assessed the variance explained by genetic scores constructed from different panels of height-associated SNPs extracted from five published studies. The combined information of the 180 SNPs reported by Lango Allen el al. explained 7.94% of phenotypic variation in our sample. Genetic scores based on 20~50 SNPs reported by the remaining individual GWA studies explained 3~5% of height variance. These percentages of variance explained were within ranges comparable to the original studies and heterogeneity tests did not detect significant differences in effect size estimates between our study and the original reports, if the estimates were obtained from populations of European descent. We have evaluated the portability of height-associated loci and the overall fitting of estimated effect sizes reported in large cohorts to an isolated population. We found proportions of explained height variability were comparable to multiple reference GWAS in cohorts of European descent. These results indicate similar genetic architecture and comparable effect sizes of height loci among populations of European descent. © 2011 Zhang et al.

Divergence of Mammalian Higher Order Chromatin Structure Is Associated with Developmental Loci

PubMed Central

Chambers, Emily V.; Bickmore, Wendy A.; Semple, Colin A.

2013-01-01

Several recent studies have examined different aspects of mammalian higher order chromatin structure – replication timing, lamina association and Hi-C inter-locus interactions — and have suggested that most of these features of genome organisation are conserved over evolution. However, the extent of evolutionary divergence in higher order structure has not been rigorously measured across the mammalian genome, and until now little has been known about the characteristics of any divergent loci present. Here, we generate a dataset combining multiple measurements of chromatin structure and organisation over many embryonic cell types for both human and mouse that, for the first time, allows a comprehensive assessment of the extent of structural divergence between mammalian genomes. Comparison of orthologous regions confirms that all measurable facets of higher order structure are conserved between human and mouse, across the vast majority of the detectably orthologous genome. This broad similarity is observed in spite of many loci possessing cell type specific structures. However, we also identify hundreds of regions (from 100 Kb to 2.7 Mb in size) showing consistent evidence of divergence between these species, constituting at least 10% of the orthologous mammalian genome and encompassing many hundreds of human and mouse genes. These regions show unusual shifts in human GC content, are unevenly distributed across both genomes, and are enriched in human subtelomeric regions. Divergent regions are also relatively enriched for genes showing divergent expression patterns between human and mouse ES cells, implying these regions cause divergent regulation. Particular divergent loci are strikingly enriched in genes implicated in vertebrate development, suggesting important roles for structural divergence in the evolution of mammalian developmental programmes. These data suggest that, though relatively rare in the mammalian genome, divergence in higher order chromatin structure has played important roles during evolution. PMID:23592965

Selection on domestication traits and quantitative trait loci in crop-wild sunflower hybrids.

PubMed

Baack, Eric J; Sapir, Yuval; Chapman, Mark A; Burke, John M; Rieseberg, Loren H

2008-01-01

The strength and extent of gene flow from crops into wild populations depends, in part, on the fitness of the crop alleles, as well as that of alleles at linked loci. Interest in crop-wild gene flow has increased with the advent of transgenic plants, but nontransgenic crop-wild hybrids can provide case studies to understand the factors influencing introgression, provided that the genetic architecture and the fitness effects of loci are known. This study used recombinant inbred lines (RILs) generated from a cross between crop and wild sunflowers to assess selection on domestication traits and quantitative trait loci (QTL) in two contrasting environments, in Indiana and Nebraska, USA. Only a small fraction of plants (9%) produced seed in Nebraska, due to adverse weather conditions, while the majority of plants (79%) in Indiana reproduced. Phenotypic selection analysis found that a mixture of crop and wild traits were favoured in Indiana (i.e. had significant selection gradients), including larger leaves, increased floral longevity, larger disk diameter, reduced ray flower size and smaller achene (seed) mass. Selection favouring early flowering was detected in Nebraska. QTLs for fitness were found at the end of linkage groups six (LG6) and nine (LG9) in both field sites, each explaining 11-12% of the total variation. Crop alleles were favoured on LG9, but wild alleles were favoured on LG6. QTLs for numerous domestication traits overlapped with the fitness QTLs, including flowering date, achene mass, head number, and disk diameter. It remains to be seen if these QTL clusters are the product of multiple linked genes, or individual genes with pleiotropic effects. These results indicate that crop trait values and alleles may sometimes be favoured in a noncrop environment and across broad geographical regions.

CoLIde: a bioinformatics tool for CO-expression-based small RNA Loci Identification using high-throughput sequencing data.

PubMed

Mohorianu, Irina; Stocks, Matthew Benedict; Wood, John; Dalmay, Tamas; Moulton, Vincent

2013-07-01

Small RNAs (sRNAs) are 20-25 nt non-coding RNAs that act as guides for the highly sequence-specific regulatory mechanism known as RNA silencing. Due to the recent increase in sequencing depth, a highly complex and diverse population of sRNAs in both plants and animals has been revealed. However, the exponential increase in sequencing data has also made the identification of individual sRNA transcripts corresponding to biological units (sRNA loci) more challenging when based exclusively on the genomic location of the constituent sRNAs, hindering existing approaches to identify sRNA loci. To infer the location of significant biological units, we propose an approach for sRNA loci detection called CoLIde (Co-expression based sRNA Loci Identification) that combines genomic location with the analysis of other information such as variation in expression levels (expression pattern) and size class distribution. For CoLIde, we define a locus as a union of regions sharing the same pattern and located in close proximity on the genome. Biological relevance, detected through the analysis of size class distribution, is also calculated for each locus. CoLIde can be applied on ordered (e.g., time-dependent) or un-ordered (e.g., organ, mutant) series of samples both with or without biological/technical replicates. The method reliably identifies known types of loci and shows improved performance on sequencing data from both plants (e.g., A. thaliana, S. lycopersicum) and animals (e.g., D. melanogaster) when compared with existing locus detection techniques. CoLIde is available for use within the UEA Small RNA Workbench which can be downloaded from: http://srna-workbench.cmp.uea.ac.uk.

Gene-centric meta-analyses for central adiposity traits in up to 57 412 individuals of European descent confirm known loci and reveal several novel associations

USDA-ARS?s Scientific Manuscript database

Waist circumference (WC) and waist-to-hip ratio (WHR) are surrogate measures of central adiposity that are associated with adverse cardiovascular events, type 2 diabetes and cancer independent of body mass index (BMI). WC and WHR are highly heritable with multiple susceptibility loci identified to d...

An ImmunoChip study of multiple sclerosis risk in African Americans

PubMed Central

Isobe, Noriko; Madireddy, Lohith; Khankhanian, Pouya; Matsushita, Takuya; Caillier, Stacy J.; Moré, Jayaji M.; Gourraud, Pierre-Antoine; McCauley, Jacob L.; Beecham, Ashley H.; Piccio, Laura; Herbert, Joseph; Khan, Omar; Cohen, Jeffrey; Stone, Lael; Santaniello, Adam; Cree, Bruce A. C.; Onengut-Gumuscu, Suna; Rich, Stephen S.; Hauser, Stephen L.; Sawcer, Stephen

2015-01-01

The aims of this study were: (i) to determine to what degree multiple sclerosis-associated loci discovered in European populations also influence susceptibility in African Americans; (ii) to assess the extent to which the unique linkage disequilibrium patterns in African Americans can contribute to localizing the functionally relevant regions or genes; and (iii) to search for novel African American multiple sclerosis-associated loci. Using the ImmunoChip custom array we genotyped 803 African American cases with multiple sclerosis and 1516 African American control subjects at 130 135 autosomal single nucleotide polymorphisms. We conducted association analysis with rigorous adjustments for population stratification and admixture. Of the 110 non-major histocompatibility complex multiple sclerosis-associated variants identified in Europeans, 96 passed stringent quality control in our African American data set and of these, >70% (69) showed over-representation of the same allele amongst cases, including 21 with nominally significant evidence for association (one-tailed test P < 0.05). At a further eight loci we found nominally significant association with an alternate correlated risk-tagging single nucleotide polymorphism from the same region. Outside the regions known to be associated in Europeans, we found seven potentially associated novel candidate multiple sclerosis variants (P < 10−4), one of which (rs2702180) also showed nominally significant evidence for association (one-tailed test P = 0.034) in an independent second cohort of 620 African American cases and 1565 control subjects. However, none of these novel associations reached genome-wide significance (combined P = 6.3 × 10−5). Our data demonstrate substantial overlap between African American and European multiple sclerosis variants, indicating common genetic contributions to multiple sclerosis risk. PMID:25818868

An ImmunoChip study of multiple sclerosis risk in African Americans.

PubMed

Isobe, Noriko; Madireddy, Lohith; Khankhanian, Pouya; Matsushita, Takuya; Caillier, Stacy J; Moré, Jayaji M; Gourraud, Pierre-Antoine; McCauley, Jacob L; Beecham, Ashley H; Piccio, Laura; Herbert, Joseph; Khan, Omar; Cohen, Jeffrey; Stone, Lael; Santaniello, Adam; Cree, Bruce A C; Onengut-Gumuscu, Suna; Rich, Stephen S; Hauser, Stephen L; Sawcer, Stephen; Oksenberg, Jorge R

2015-06-01

The aims of this study were: (i) to determine to what degree multiple sclerosis-associated loci discovered in European populations also influence susceptibility in African Americans; (ii) to assess the extent to which the unique linkage disequilibrium patterns in African Americans can contribute to localizing the functionally relevant regions or genes; and (iii) to search for novel African American multiple sclerosis-associated loci. Using the ImmunoChip custom array we genotyped 803 African American cases with multiple sclerosis and 1516 African American control subjects at 130 135 autosomal single nucleotide polymorphisms. We conducted association analysis with rigorous adjustments for population stratification and admixture. Of the 110 non-major histocompatibility complex multiple sclerosis-associated variants identified in Europeans, 96 passed stringent quality control in our African American data set and of these, >70% (69) showed over-representation of the same allele amongst cases, including 21 with nominally significant evidence for association (one-tailed test P < 0.05). At a further eight loci we found nominally significant association with an alternate correlated risk-tagging single nucleotide polymorphism from the same region. Outside the regions known to be associated in Europeans, we found seven potentially associated novel candidate multiple sclerosis variants (P < 10(-4)), one of which (rs2702180) also showed nominally significant evidence for association (one-tailed test P = 0.034) in an independent second cohort of 620 African American cases and 1565 control subjects. However, none of these novel associations reached genome-wide significance (combined P = 6.3 × 10(-5)). Our data demonstrate substantial overlap between African American and European multiple sclerosis variants, indicating common genetic contributions to multiple sclerosis risk. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genomic approaches for the elucidation of genes and gene networks underlying cardiovascular traits.

PubMed

Adriaens, M E; Bezzina, C R

2018-06-22

Genome-wide association studies have shed light on the association between natural genetic variation and cardiovascular traits. However, linking a cardiovascular trait associated locus to a candidate gene or set of candidate genes for prioritization for follow-up mechanistic studies is all but straightforward. Genomic technologies based on next-generation sequencing technology nowadays offer multiple opportunities to dissect gene regulatory networks underlying genetic cardiovascular trait associations, thereby aiding in the identification of candidate genes at unprecedented scale. RNA sequencing in particular becomes a powerful tool when combined with genotyping to identify loci that modulate transcript abundance, known as expression quantitative trait loci (eQTL), or loci modulating transcript splicing known as splicing quantitative trait loci (sQTL). Additionally, the allele-specific resolution of RNA-sequencing technology enables estimation of allelic imbalance, a state where the two alleles of a gene are expressed at a ratio differing from the expected 1:1 ratio. When multiple high-throughput approaches are combined with deep phenotyping in a single study, a comprehensive elucidation of the relationship between genotype and phenotype comes into view, an approach known as systems genetics. In this review, we cover key applications of systems genetics in the broad cardiovascular field.

Isogenic mice exhibit sexually-dimorphic DNA methylation patterns across multiple tissues.

PubMed

McCormick, Helen; Young, Paul E; Hur, Suzy S J; Booher, Keith; Chung, Hunter; Cropley, Jennifer E; Giannoulatou, Eleni; Suter, Catherine M

2017-12-13

Cytosine methylation is a stable epigenetic modification of DNA that plays an important role in both normal physiology and disease. Most diseases exhibit some degree of sexual dimorphism, but the extent to which epigenetic states are influenced by sex is understudied and poorly understood. To address this deficit we studied DNA methylation patterns across multiple reduced representation bisulphite sequencing datasets (from liver, heart, brain, muscle and spleen) derived from isogenic male and female mice. DNA methylation patterns varied significantly from tissue to tissue, as expected, but they also varied between the sexes, with thousands of sexually dimorphic loci identified. The loci affected were largely autonomous to each tissue, even within tissues derived from the same germ layer. At most loci, differences between genders were driven by females exhibiting hypermethylation relative to males; a proportion of these differences were independent of the presence of testosterone in males. Loci harbouring gender differences were clustered in ontologies related to tissue function. Our findings suggest that gender is underwritten in the epigenome in a tissue-specific and potentially sex hormone-independent manner. Gender-specific epigenetic states are likely to have important implications for understanding sexually dimorphic phenotypes in health and disease.

Asymmetric Introgression in the Horticultural Living Fossil Cycas Sect. Asiorientales Using a Genome-Wide Scanning Approach

PubMed Central

Chiang, Yu-Chung; Huang, Bing-Hong; Chang, Chun-Wen; Wan, Yu-Ting; Lai, Shih-Jie; Huang, Shong; Liao, Pei-Chun

2013-01-01

The Asian cycads are mostly allopatric, distributed in small population sizes. Hybridization between allopatric species provides clues in determining the mechanism of species divergence. Horticultural introduction provides the chance of interspecific gene flow between allopatric species. Two allopatrically eastern Asian Cycas sect. Asiorientales species, C. revoluta and C. taitungensis, which are widely distributed in Ryukyus and Fujian Province and endemic to Taiwan, respectively, were planted in eastern Taiwan for horticultural reason. Higher degrees of genetic admixture in cultivated samples than wild populations in both cycad species were detected based on multilocus scans by neutral AFLP markers. Furthermore, bidirectional but asymmetric introgression by horticultural introduction of C. revoluta is evidenced by the reanalyses of species associated loci, which are assumed to be diverged after species divergence. Partial loci introgressed from native cycad to the invaders were also detected at the loci of strong species association. Consistent results tested by all neutral loci, and the species-associated loci, specify the recent introgression from the paradox of sharing of ancestral polymorphisms. Phenomenon of introgression of cultivated cycads implies niche conservation among two geographic-isolated cycads, even though the habitats of the extant wild populations of two species are distinct. PMID:23591840

Discovery and validation of sub-threshold genome-wide association study loci using epigenomic signatures

PubMed Central

Wang, Xinchen; Tucker, Nathan R; Rizki, Gizem; Mills, Robert; Krijger, Peter HL; de Wit, Elzo; Subramanian, Vidya; Bartell, Eric; Nguyen, Xinh-Xinh; Ye, Jiangchuan; Leyton-Mange, Jordan; Dolmatova, Elena V; van der Harst, Pim; de Laat, Wouter; Ellinor, Patrick T; Newton-Cheh, Christopher; Milan, David J; Kellis, Manolis; Boyer, Laurie A

2016-01-01

Genetic variants identified by genome-wide association studies explain only a modest proportion of heritability, suggesting that meaningful associations lie 'hidden' below current thresholds. Here, we integrate information from association studies with epigenomic maps to demonstrate that enhancers significantly overlap known loci associated with the cardiac QT interval and QRS duration. We apply functional criteria to identify loci associated with QT interval that do not meet genome-wide significance and are missed by existing studies. We demonstrate that these 'sub-threshold' signals represent novel loci, and that epigenomic maps are effective at discriminating true biological signals from noise. We experimentally validate the molecular, gene-regulatory, cellular and organismal phenotypes of these sub-threshold loci, demonstrating that most sub-threshold loci have regulatory consequences and that genetic perturbation of nearby genes causes cardiac phenotypes in mouse. Our work provides a general approach for improving the detection of novel loci associated with complex human traits. DOI: http://dx.doi.org/10.7554/eLife.10557.001 PMID:27162171

A Versatile Omnibus Test for Detecting Mean and Variance Heterogeneity

PubMed Central

Bailey, Matthew; Kauwe, John S. K.; Maxwell, Taylor J.

2014-01-01

Recent research has revealed loci that display variance heterogeneity through various means such as biological disruption, linkage disequilibrium (LD), gene-by-gene (GxG), or gene-by-environment (GxE) interaction. We propose a versatile likelihood ratio test that allows joint testing for mean and variance heterogeneity (LRTMV) or either effect alone (LRTM or LRTV) in the presence of covariates. Using extensive simulations for our method and others we found that all parametric tests were sensitive to non-normality regardless of any trait transformations. Coupling our test with the parametric bootstrap solves this issue. Using simulations and empirical data from a known mean-only functional variant we demonstrate how linkage disequilibrium (LD) can produce variance-heterogeneity loci (vQTL) in a predictable fashion based on differential allele frequencies, high D’ and relatively low r2 values. We propose that a joint test for mean and variance heterogeneity is more powerful than a variance only test for detecting vQTL. This takes advantage of loci that also have mean effects without sacrificing much power to detect variance only effects. We discuss using vQTL as an approach to detect gene-by-gene interactions and also how vQTL are related to relationship loci (rQTL) and how both can create prior hypothesis for each other and reveal the relationships between traits and possibly between components of a composite trait. PMID:24482837

Identification of Genetic Loci Jointly Influencing Schizophrenia Risk and the Cognitive Traits of Verbal-Numerical Reasoning, Reaction Time, and General Cognitive Function.

PubMed

Smeland, Olav B; Frei, Oleksandr; Kauppi, Karolina; Hill, W David; Li, Wen; Wang, Yunpeng; Krull, Florian; Bettella, Francesco; Eriksen, Jon A; Witoelar, Aree; Davies, Gail; Fan, Chun C; Thompson, Wesley K; Lam, Max; Lencz, Todd; Chen, Chi-Hua; Ueland, Torill; Jönsson, Erik G; Djurovic, Srdjan; Deary, Ian J; Dale, Anders M; Andreassen, Ole A

2017-10-01

Schizophrenia is associated with widespread cognitive impairments. Although cognitive deficits are one of the factors most strongly associated with functional outcome in schizophrenia, current treatment strategies largely fail to ameliorate these impairments. To develop more efficient treatment strategies in patients with schizophrenia, a better understanding of the pathogenesis of these cognitive deficits is needed. Accumulating evidence indicates that genetic risk of schizophrenia may contribute to cognitive dysfunction. To identify genomic regions jointly influencing schizophrenia and the cognitive domains of reaction time and verbal-numerical reasoning, as well as general cognitive function, a phenotype that captures the shared variation in performance across cognitive domains. Combining data from genome-wide association studies from multiple phenotypes using conditional false discovery rate analysis provides increased power to discover genetic variants and could elucidate shared molecular genetic mechanisms. Data from the following genome-wide association studies, published from July 24, 2014, to January 17, 2017, were combined: schizophrenia in the Psychiatric Genomics Consortium cohort (n = 79 757 [cases, 34 486; controls, 45 271]); verbal-numerical reasoning (n = 36 035) and reaction time (n = 111 483) in the UK Biobank cohort; and general cognitive function in CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) (n = 53 949) and COGENT (Cognitive Genomics Consortium) (n = 27 888). Genetic loci identified by conditional false discovery rate analysis. Brain messenger RNA expression and brain expression quantitative trait locus functionality were determined. Among the participants in the genome-wide association studies, 21 loci jointly influencing schizophrenia and cognitive traits were identified: 2 loci shared between schizophrenia and verbal-numerical reasoning, 6 loci shared between schizophrenia and reaction time, and 14 loci shared between schizophrenia and general cognitive function. One locus was shared between schizophrenia and 2 cognitive traits and represented the strongest shared signal detected (nearest gene TCF20; chromosome 22q13.2), and was shared between schizophrenia (z score, 5.01; P = 5.53 × 10-7), general cognitive function (z score, -4.43; P = 9.42 × 10-6), and verbal-numerical reasoning (z score, -5.43; P = 5.64 × 10-8). For 18 loci, schizophrenia risk alleles were associated with poorer cognitive performance. The implicated genes are expressed in the developmental and adult human brain. Replicable expression quantitative trait locus functionality was identified for 4 loci in the adult human brain. The discovered loci improve the understanding of the common genetic basis underlying schizophrenia and cognitive function, suggesting novel molecular genetic mechanisms.

Haplotype data for 23 Y-chromosome markers in a reference sample from Bosnia and Herzegovina

PubMed Central

Kovačević, Lejla; Fatur-Cerić, Vera; Hadžić, Negra; Čakar, Jasmina; Primorac, Dragan; Marjanović, Damir

2013-01-01

Aim To detect polymorphisms of 23 Y-chromosomal short tandem repeat (STR) loci, including 6 new loci, in a reference database of male population of Bosnia and Herzegovina, as well as to assess the importance of increasing the number of Y-STR loci utilized in forensic DNA analysis. Methods The reference sample consisted of 100 healthy, unrelated men originating from Bosnia and Herzegovina. Sample collection using buccal swabs was performed in all geographical regions of Bosnia and Herzegovina in the period from 2010 to 2011. DNA samples were typed for 23 Y STR loci, including 6 new loci: DYS576, DYS481, DYS549, DYS533, DYS570, and DYS643, which are included in the new PowerPlex® Y 23 amplification kit. Results The absolute frequency of generated haplotypes was calculated and results showed that 98 samples had unique Y 23 haplotypes, and that only two samples shared the same haplotype. The most polymorphic locus was DYS418, with 14 detected alleles and the least polymorphic loci were DYS389I, DYS391, DYS437, and DYS393. Conclusion This study showed that by increasing the number of highly polymorphic Y STR markers, to include those tested in our analysis, leads to a reduction of repeating haplotypes, which is very important in the application of forensic DNA analysis. PMID:23771760

Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture

PubMed Central

Berndt, Sonja I.; Gustafsson, Stefan; Mägi, Reedik; Ganna, Andrea; Wheeler, Eleanor; Feitosa, Mary F.; Justice, Anne E.; Monda, Keri L.; Croteau-Chonka, Damien C.; Day, Felix R.; Esko, Tõnu; Fall, Tove; Ferreira, Teresa; Gentilini, Davide; Jackson, Anne U.; Luan, Jian’an; Randall, Joshua C.; Vedantam, Sailaja; Willer, Cristen J.; Winkler, Thomas W.; Wood, Andrew R.; Workalemahu, Tsegaselassie; Hu, Yi-Juan; Lee, Sang Hong; Liang, Liming; Lin, Dan-Yu; Min, Josine L.; Neale, Benjamin M.; Thorleifsson, Gudmar; Yang, Jian; Albrecht, Eva; Amin, Najaf; Bragg-Gresham, Jennifer L.; Cadby, Gemma; den Heijer, Martin; Eklund, Niina; Fischer, Krista; Goel, Anuj; Hottenga, Jouke-Jan; Huffman, Jennifer E.; Jarick, Ivonne; Johansson, Åsa; Johnson, Toby; Kanoni, Stavroula; Kleber, Marcus E.; König, Inke R.; Kristiansson, Kati; Kutalik, Zoltán; Lamina, Claudia; Lecoeur, Cecile; Li, Guo; Mangino, Massimo; McArdle, Wendy L.; Medina-Gomez, Carolina; Müller-Nurasyid, Martina; Ngwa, Julius S.; Nolte, Ilja M.; Paternoster, Lavinia; Pechlivanis, Sonali; Perola, Markus; Peters, Marjolein J.; Preuss, Michael; Rose, Lynda M.; Shi, Jianxin; Shungin, Dmitry; Smith, Albert Vernon; Strawbridge, Rona J.; Surakka, Ida; Teumer, Alexander; Trip, Mieke D.; Tyrer, Jonathan; Van Vliet-Ostaptchouk, Jana V.; Vandenput, Liesbeth; Waite, Lindsay L.; Zhao, Jing Hua; Absher, Devin; Asselbergs, Folkert W.; Atalay, Mustafa; Attwood, Antony P.; Balmforth, Anthony J.; Basart, Hanneke; Beilby, John; Bonnycastle, Lori L.; Brambilla, Paolo; Bruinenberg, Marcel; Campbell, Harry; Chasman, Daniel I.; Chines, Peter S.; Collins, Francis S.; Connell, John M.; Cookson, William; de Faire, Ulf; de Vegt, Femmie; Dei, Mariano; Dimitriou, Maria; Edkins, Sarah; Estrada, Karol; Evans, David M.; Farrall, Martin; Ferrario, Marco M.; Ferrières, Jean; Franke, Lude; Frau, Francesca; Gejman, Pablo V.; Grallert, Harald; Grönberg, Henrik; Gudnason, Vilmundur; Hall, Alistair S.; Hall, Per; Hartikainen, Anna-Liisa; Hayward, Caroline; Heard-Costa, Nancy L.; Heath, Andrew C.; Hebebrand, Johannes; Homuth, Georg; Hu, Frank B.; Hunt, Sarah E.; Hyppönen, Elina; Iribarren, Carlos; Jacobs, Kevin B.; Jansson, John-Olov; Jula, Antti; Kähönen, Mika; Kathiresan, Sekar; Kee, Frank; Khaw, Kay-Tee; Kivimaki, Mika; Koenig, Wolfgang; Kraja, Aldi T.; Kumari, Meena; Kuulasmaa, Kari; Kuusisto, Johanna; Laitinen, Jaana H.; Lakka, Timo A.; Langenberg, Claudia; Launer, Lenore J.; Lind, Lars; Lindström, Jaana; Liu, Jianjun; Liuzzi, Antonio; Lokki, Marja-Liisa; Lorentzon, Mattias; Madden, Pamela A.; Magnusson, Patrik K.; Manunta, Paolo; Marek, Diana; März, Winfried; Mateo Leach, Irene; McKnight, Barbara; Medland, Sarah E.; Mihailov, Evelin; Milani, Lili; Montgomery, Grant W.; Mooser, Vincent; Mühleisen, Thomas W.; Munroe, Patricia B.; Musk, Arthur W.; Narisu, Narisu; Navis, Gerjan; Nicholson, George; Nohr, Ellen A.; Ong, Ken K.; Oostra, Ben A.; Palmer, Colin N.A.; Palotie, Aarno; Peden, John F.; Pedersen, Nancy; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P.; Prokopenko, Inga; Pütter, Carolin; Radhakrishnan, Aparna; Raitakari, Olli; Rendon, Augusto; Rivadeneira, Fernando; Rudan, Igor; Saaristo, Timo E.; Sambrook, Jennifer G.; Sanders, Alan R.; Sanna, Serena; Saramies, Jouko; Schipf, Sabine; Schreiber, Stefan; Schunkert, Heribert; Shin, So-Youn; Signorini, Stefano; Sinisalo, Juha; Skrobek, Boris; Soranzo, Nicole; Stančáková, Alena; Stark, Klaus; Stephens, Jonathan C.; Stirrups, Kathleen; Stolk, Ronald P.; Stumvoll, Michael; Swift, Amy J.; Theodoraki, Eirini V.; Thorand, Barbara; Tregouet, David-Alexandre; Tremoli, Elena; Van der Klauw, Melanie M.; van Meurs, Joyce B.J.; Vermeulen, Sita H.; Viikari, Jorma; Virtamo, Jarmo; Vitart, Veronique; Waeber, Gérard; Wang, Zhaoming; Widén, Elisabeth; Wild, Sarah H.; Willemsen, Gonneke; Winkelmann, Bernhard R.; Witteman, Jacqueline C.M.; Wolffenbuttel, Bruce H.R.; Wong, Andrew; Wright, Alan F.; Zillikens, M. Carola; Amouyel, Philippe; Boehm, Bernhard O.; Boerwinkle, Eric; Boomsma, Dorret I.; Caulfield, Mark J.; Chanock, Stephen J.; Cupples, L. Adrienne; Cusi, Daniele; Dedoussis, George V.; Erdmann, Jeanette; Eriksson, Johan G.; Franks, Paul W.; Froguel, Philippe; Gieger, Christian; Gyllensten, Ulf; Hamsten, Anders; Harris, Tamara B.; Hengstenberg, Christian; Hicks, Andrew A.; Hingorani, Aroon; Hinney, Anke; Hofman, Albert; Hovingh, Kees G.; Hveem, Kristian; Illig, Thomas; Jarvelin, Marjo-Riitta; Jöckel, Karl-Heinz; Keinanen-Kiukaanniemi, Sirkka M.; Kiemeney, Lambertus A.; Kuh, Diana; Laakso, Markku; Lehtimäki, Terho; Levinson, Douglas F.; Martin, Nicholas G.; Metspalu, Andres; Morris, Andrew D.; Nieminen, Markku S.; Njølstad, Inger; Ohlsson, Claes; Oldehinkel, Albertine J.; Ouwehand, Willem H.; Palmer, Lyle J.; Penninx, Brenda; Power, Chris; Province, Michael A.; Psaty, Bruce M.; Qi, Lu; Rauramaa, Rainer; Ridker, Paul M.; Ripatti, Samuli; Salomaa, Veikko; Samani, Nilesh J.; Snieder, Harold; Sørensen, Thorkild I.A.; Spector, Timothy D.; Stefansson, Kari; Tönjes, Anke; Tuomilehto, Jaakko; Uitterlinden, André G.; Uusitupa, Matti; van der Harst, Pim; Vollenweider, Peter; Wallaschofski, Henri; Wareham, Nicholas J.; Watkins, Hugh; Wichmann, H.-Erich; Wilson, James F.; Abecasis, Goncalo R.; Assimes, Themistocles L.; Barroso, Inês; Boehnke, Michael; Borecki, Ingrid B.; Deloukas, Panos; Fox, Caroline S.; Frayling, Timothy; Groop, Leif C.; Haritunian, Talin; Heid, Iris M.; Hunter, David; Kaplan, Robert C.; Karpe, Fredrik; Moffatt, Miriam; Mohlke, Karen L.; O’Connell, Jeffrey R.; Pawitan, Yudi; Schadt, Eric E.; Schlessinger, David; Steinthorsdottir, Valgerdur; Strachan, David P.; Thorsteinsdottir, Unnur; van Duijn, Cornelia M.; Visscher, Peter M.; Di Blasio, Anna Maria; Hirschhorn, Joel N.; Lindgren, Cecilia M.; Morris, Andrew P.; Meyre, David; Scherag, André; McCarthy, Mark I.; Speliotes, Elizabeth K.; North, Kari E.; Loos, Ruth J.F.; Ingelsson, Erik

2014-01-01

Approaches exploiting extremes of the trait distribution may reveal novel loci for common traits, but it is unknown whether such loci are generalizable to the general population. In a genome-wide search for loci associated with upper vs. lower 5th percentiles of body mass index, height and waist-hip ratio, as well as clinical classes of obesity including up to 263,407 European individuals, we identified four new loci (IGFBP4, H6PD, RSRC1, PPP2R2A) influencing height detected in the tails and seven new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3, ZZZ3) for clinical classes of obesity. Further, we show that there is large overlap in terms of genetic structure and distribution of variants between traits based on extremes and the general population and little etiologic heterogeneity between obesity subgroups. PMID:23563607

Detection and analysis of CRISPRs of Shigella.

PubMed

Guo, Xiangjiao; Wang, Yingfang; Duan, Guangcai; Xue, Zerun; Wang, Linlin; Wang, Pengfei; Qiu, Shaofu; Xi, Yuanlin; Yang, Haiyan

2015-01-01

The recently discovered CRISPRs (Clustered regularly interspaced short palindromic repeats) and Cas (CRISPR-associated) proteins are a novel genetic barrier that limits horizontal gene transfer in prokaryotes and the CRISPR loci provide a historical view of the exposure of prokaryotes to a variety of foreign genetic elements. The aim of study was to investigate the occurrence and distribution of the CRISPRs in Shigella. A collection of 61 strains of Shigella were screened for the existence of CRISPRs. Three CRISPR loci were identified among 61 shigella strains. CRISPR1/cas loci are detected in 49 strains of shigella. Yet, IS elements were detected in cas gene in some strains. In the remaining 12 Shigella flexneri strains, the CRISPR1/cas locus is deleted and only a cas3' pseudo gene and a repeat sequence are present. The presence of CRISPR2 is frequently accompanied by the emergence of CRISPR1. CRISPR3 loci were present in almost all strains (52/61). The length of CRISPR arrays varied from 1 to 9 spacers. Sequence analysis of the CRISPR arrays revealed that few spacers had matches in the GenBank databases. However, one spacer in CRISPR3 loci matches the cognate cas3 genes and no cas gene was present around CRISPR3 region. Analysis of CRISPR sequences show that CRISPR have little change which makes CRISPR poor genotyping markers. The present study is the first attempt to determine and analyze CRISPRs of shigella isolated from clinical patients.

[Detection of the introgression of genome elements of Aegilops cylindrica Host. into Triticum aestivum L. genome with ISSR-analysis].

PubMed

Galaev, A V; Babaiants, L T; Sivolap, Iu M

2003-01-01

Comparative analysis of introgressive and parental forms of wheat was carried out to reveal the sites of donor genome with new loci of resistance to fungal diseases. By ISSR-method 124 ISSR-loci were detected in the genomes of 18 individual plants of introgressive line 5/20-91; 17 of them have been related to introgressive fragments of Ae. cylindrica genome in T. aestivum. It was shown that ISSR-method is effective for detection of the variability caused by introgression of alien genetic material to T. aestivum genome.

Novel Sources of Stripe Rust Resistance Identified by Genome-Wide Association Mapping in Ethiopian Durum Wheat (Triticum turgidum ssp. durum)

PubMed Central

Liu, Weizhen; Maccaferri, Marco; Rynearson, Sheri; Letta, Tesfaye; Zegeye, Habtemariam; Tuberosa, Roberto; Chen, Xianming; Pumphrey, Michael

2017-01-01

Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst), is a global concern for wheat production, and has been increasingly destructive in Ethiopia, as well as in the United States and in many other countries. As Ethiopia has a long history of stripe rust epidemics, its native wheat germplasm harbors potentially valuable resistance loci. Moreover, the Ethiopian germplasm has been historically underutilized in breeding of modern wheat worldwide and thus the resistance alleles from the Ethiopian germplasm represent potentially novel sources. The objective of this study was to identify loci conferring resistance to predominant Pst races in Ethiopia and the United States. Using a high-density 90 K wheat single nucleotide polymorphism array, a genome-wide association analysis (GWAS) was conducted on 182 durum wheat landrace accessions and contemporary varieties originating from Ethiopia. Landraces were detected to be more resistant at the seedling stage while cultivars were more resistant at the adult-plant stages. GWAS identified 68 loci associated with seedling resistance to one or more races. Six loci on chromosome arms 1AS, 1BS, 3AS, 4BL, and 5BL were associated with resistance against at least two races at the seedling stage, and five loci were previously undocumented. GWAS analysis of field resistance reactions identified 12 loci associated with resistance on chromosomes 1A, 1B, 2BS, 3BL, 4AL, 4B and 5AL, which were detected in at least two of six field screening nurseries at the adult-plant stage. Comparison with previously mapped resistance loci indicates that six of the 12 resistance loci are newly documented. This study reports effective sources of resistance to contemporary races in Ethiopia and the United States and reveals that Ethiopian durum wheat landraces are abundant in novel Pst resistance loci that may be transferred into adapted cultivars to provide resistance against Pst. PMID:28553306

Quantitative trait loci associated with the tocochromanol (vitamin E) pathway in barley

USDA-ARS?s Scientific Manuscript database

In this study, the Genome-Wide Association Studies approach was used to detect Quantitative Trait Loci associated with tocochromanol concentrations using a panel of 1,466 barley accessions. All major tocochromanol types- alpha-, beta-, delta-, gamma-tocopherol and tocotrienol- were assayed. We found...

Proactive control of proactive interference using the method of loci.

PubMed

Bass, Willa S; Oswald, Karl M

2014-01-01

Proactive interferencebuilds up with exposure to multiple lists of similar items with a resulting reduction in recall. This study examined the effectiveness of using a proactive strategy of the method of loci to reduce proactive interference in a list recall paradigm of categorically similar words. While all participants reported using some form of strategy to recall list words, this study demonstrated that young adults were able to proactively use the method of loci after 25 min of instruction to reduce proactive interference as compared with other personal spontaneous strategies. The implications of this study are that top-down proactive strategies such as the method of loci can significantly reduce proactive interference, and that the use of image and sequence or location are especially useful in this regard.

Proactive control of proactive interference using the method of loci

PubMed Central

Bass, Willa S.; Oswald, Karl M.

2014-01-01

Proactive interferencebuilds up with exposure to multiple lists of similar items with a resulting reduction in recall. This study examined the effectiveness of using a proactive strategy of the method of loci to reduce proactive interference in a list recall paradigm of categorically similar words. While all participants reported using some form of strategy to recall list words, this study demonstrated that young adults were able to proactively use the method of loci after 25 min of instruction to reduce proactive interference as compared with other personal spontaneous strategies. The implications of this study are that top-down proactive strategies such as the method of loci can significantly reduce proactive interference, and that the use of image and sequence or location are especially useful in this regard. PMID:25157300

Analysis of immune-related loci identifies 48 new susceptibility variants for multiple sclerosis

PubMed Central

Beecham, Ashley H; Patsopoulos, Nikolaos A; Xifara, Dionysia K; Davis, Mary F; Kemppinen, Anu; Cotsapas, Chris; Shahi, Tejas S; Spencer, Chris; Booth, David; Goris, An; Oturai, Annette; Saarela, Janna; Fontaine, Bertrand; Hemmer, Bernhard; Martin, Claes; Zipp, Frauke; D’alfonso, Sandra; Martinelli-Boneschi, Filippo; Taylor, Bruce; Harbo, Hanne F; Kockum, Ingrid; Hillert, Jan; Olsson, Tomas; Ban, Maria; Oksenberg, Jorge R; Hintzen, Rogier; Barcellos, Lisa F; Agliardi, Cristina; Alfredsson, Lars; Alizadeh, Mehdi; Anderson, Carl; Andrews, Robert; Søndergaard, Helle Bach; Baker, Amie; Band, Gavin; Baranzini, Sergio E; Barizzone, Nadia; Barrett, Jeffrey; Bellenguez, Céline; Bergamaschi, Laura; Bernardinelli, Luisa; Berthele, Achim; Biberacher, Viola; Binder, Thomas M C; Blackburn, Hannah; Bomfim, Izaura L; Brambilla, Paola; Broadley, Simon; Brochet, Bruno; Brundin, Lou; Buck, Dorothea; Butzkueven, Helmut; Caillier, Stacy J; Camu, William; Carpentier, Wassila; Cavalla, Paola; Celius, Elisabeth G; Coman, Irène; Comi, Giancarlo; Corrado, Lucia; Cosemans, Leentje; Cournu-Rebeix, Isabelle; Cree, Bruce A C; Cusi, Daniele; Damotte, Vincent; Defer, Gilles; Delgado, Silvia R; Deloukas, Panos; di Sapio, Alessia; Dilthey, Alexander T; Donnelly, Peter; Dubois, Bénédicte; Duddy, Martin; Edkins, Sarah; Elovaara, Irina; Esposito, Federica; Evangelou, Nikos; Fiddes, Barnaby; Field, Judith; Franke, Andre; Freeman, Colin; Frohlich, Irene Y; Galimberti, Daniela; Gieger, Christian; Gourraud, Pierre-Antoine; Graetz, Christiane; Graham, Andrew; Grummel, Verena; Guaschino, Clara; Hadjixenofontos, Athena; Hakonarson, Hakon; Halfpenny, Christopher; Hall, Gillian; Hall, Per; Hamsten, Anders; Harley, James; Harrower, Timothy; Hawkins, Clive; Hellenthal, Garrett; Hillier, Charles; Hobart, Jeremy; Hoshi, Muni; Hunt, Sarah E; Jagodic, Maja; Jelčić, Ilijas; Jochim, Angela; Kendall, Brian; Kermode, Allan; Kilpatrick, Trevor; Koivisto, Keijo; Konidari, Ioanna; Korn, Thomas; Kronsbein, Helena; Langford, Cordelia; Larsson, Malin; Lathrop, Mark; Lebrun-Frenay, Christine; Lechner-Scott, Jeannette; Lee, Michelle H; Leone, Maurizio A; Leppä, Virpi; Liberatore, Giuseppe; Lie, Benedicte A; Lill, Christina M; Lindén, Magdalena; Link, Jenny; Luessi, Felix; Lycke, Jan; Macciardi, Fabio; Männistö, Satu; Manrique, Clara P; Martin, Roland; Martinelli, Vittorio; Mason, Deborah; Mazibrada, Gordon; McCabe, Cristin; Mero, Inger-Lise; Mescheriakova, Julia; Moutsianas, Loukas; Myhr, Kjell-Morten; Nagels, Guy; Nicholas, Richard; Nilsson, Petra; Piehl, Fredrik; Pirinen, Matti; Price, Siân E; Quach, Hong; Reunanen, Mauri; Robberecht, Wim; Robertson, Neil P; Rodegher, Mariaemma; Rog, David; Salvetti, Marco; Schnetz-Boutaud, Nathalie C; Sellebjerg, Finn; Selter, Rebecca C; Schaefer, Catherine; Shaunak, Sandip; Shen, Ling; Shields, Simon; Siffrin, Volker; Slee, Mark; Sorensen, Per Soelberg; Sorosina, Melissa; Sospedra, Mireia; Spurkland, Anne; Strange, Amy; Sundqvist, Emilie; Thijs, Vincent; Thorpe, John; Ticca, Anna; Tienari, Pentti; van Duijn, Cornelia; Visser, Elizabeth M; Vucic, Steve; Westerlind, Helga; Wiley, James S; Wilkins, Alastair; Wilson, James F; Winkelmann, Juliane; Zajicek, John; Zindler, Eva; Haines, Jonathan L; Pericak-Vance, Margaret A; Ivinson, Adrian J; Stewart, Graeme; Hafler, David; Hauser, Stephen L; Compston, Alastair; McVean, Gil; De Jager, Philip; Sawcer, Stephen; McCauley, Jacob L

2013-01-01

Using the ImmunoChip custom genotyping array, we analysed 14,498 multiple sclerosis subjects and 24,091 healthy controls for 161,311 autosomal variants and identified 135 potentially associated regions (p-value < 1.0 × 10-4). In a replication phase, we combined these data with previous genome-wide association study (GWAS) data from an independent 14,802 multiple sclerosis subjects and 26,703 healthy controls. In these 80,094 individuals of European ancestry we identified 48 new susceptibility variants (p-value < 5.0 × 10-8); three found after conditioning on previously identified variants. Thus, there are now 110 established multiple sclerosis risk variants in 103 discrete loci outside of the Major Histocompatibility Complex. With high resolution Bayesian fine-mapping, we identified five regions where one variant accounted for more than 50% of the posterior probability of association. This study enhances the catalogue of multiple sclerosis risk variants and illustrates the value of fine-mapping in the resolution of GWAS signals. PMID:24076602

Meta-analysis of 32 genome-wide linkage studies of schizophrenia

PubMed Central

Ng, MYM; Levinson, DF; Faraone, SV; Suarez, BK; DeLisi, LE; Arinami, T; Riley, B; Paunio, T; Pulver, AE; Irmansyah; Holmans, PA; Escamilla, M; Wildenauer, DB; Williams, NM; Laurent, C; Mowry, BJ; Brzustowicz, LM; Maziade, M; Sklar, P; Garver, DL; Abecasis, GR; Lerer, B; Fallin, MD; Gurling, HMD; Gejman, PV; Lindholm, E; Moises, HW; Byerley, W; Wijsman, EM; Forabosco, P; Tsuang, MT; Hwu, H-G; Okazaki, Y; Kendler, KS; Wormley, B; Fanous, A; Walsh, D; O’Neill, FA; Peltonen, L; Nestadt, G; Lasseter, VK; Liang, KY; Papadimitriou, GM; Dikeos, DG; Schwab, SG; Owen, MJ; O’Donovan, MC; Norton, N; Hare, E; Raventos, H; Nicolini, H; Albus, M; Maier, W; Nimgaonkar, VL; Terenius, L; Mallet, J; Jay, M; Godard, S; Nertney, D; Alexander, M; Crowe, RR; Silverman, JM; Bassett, AS; Roy, M-A; Mérette, C; Pato, CN; Pato, MT; Roos, J Louw; Kohn, Y; Amann-Zalcenstein, D; Kalsi, G; McQuillin, A; Curtis, D; Brynjolfson, J; Sigmundsson, T; Petursson, H; Sanders, AR; Duan, J; Jazin, E; Myles-Worsley, M; Karayiorgou, M; Lewis, CM

2009-01-01

A genome scan meta-analysis (GSMA) was carried out on 32 independent genome-wide linkage scan analyses that included 3255 pedigrees with 7413 genotyped cases affected with schizophrenia (SCZ) or related disorders. The primary GSMA divided the autosomes into 120 bins, rank-ordered the bins within each study according to the most positive linkage result in each bin, summed these ranks (weighted for study size) for each bin across studies and determined the empirical probability of a given summed rank (PSR) by simulation. Suggestive evidence for linkage was observed in two single bins, on chromosomes 5q (142-168 Mb) and 2q (103-134 Mb). Genome-wide evidence for linkage was detected on chromosome 2q (119-152 Mb) when bin boundaries were shifted to the middle of the previous bins. The primary analysis met empirical criteria for ‘aggregate’ genome-wide significance, indicating that some or all of 10 bins are likely to contain loci linked to SCZ, including regions of chromosomes 1, 2q, 3q, 4q, 5q, 8p and 10q. In a secondary analysis of 22 studies of European-ancestry samples, suggestive evidence for linkage was observed on chromosome 8p (16-33 Mb). Although the newer genome-wide association methodology has greater power to detect weak associations to single common DNA sequence variants, linkage analysis can detect diverse genetic effects that segregate in families, including multiple rare variants within one locus or several weakly associated loci in the same region. Therefore, the regions supported by this meta-analysis deserve close attention in future studies. PMID:19349958

Applicability of major histocompatibility complex DRB1 alleles as markers to detect vertebrate hybridization: a case study from Iberian ibex × domestic goat in southern Spain

PubMed Central

2012-01-01

Background Hybridization between closely related wild and domestic species is of great concern because it can alter the evolutionary integrity of the affected populations. The high allelic variability of Major Histocompatibility Complex (MHC) loci usually excludes them from being used in studies to detect hybridization events. However, if a) the parental species don’t share alleles, and b) one of the parental species possesses an exceptionally low number of alleles (to facilitate analysis), then even MHC loci have the potential to detect hybrids. Results By genotyping the exon2 of the MHC class II DRB1 locus, we were able to detect hybridization between domestic goats (Capra hircus) and free-ranging Iberian ibex (Capra pyrenaica hispanica) by molecular means. Conclusions This is the first documentation of a Capra pyrenaica × Capra hircus hybridization, which presented us the opportunity to test the applicability of MHC loci as new, simple, cost-effective, and time-saving approach to detect hybridization between wild species and their domesticated relatives, thus adding value to MHC genes role in animal conservation and management. PMID:23006678

Genetic diversity analysis in the section Caulorrhizae (genus Arachis) using microsatellite markers.

PubMed

Palmieri, Darío A; Bechara, Marcelo D; Curi, Rogério A; Monteiro, Jomar P; Valente, Sérgio E S; Gimenes, Marcos A; Lopes, Catalina R

2010-01-01

Diversity in 26 microsatellite loci from section Caulorrhizae germplasm was evaluated by using 33 accessions of A. pintoi Krapov. & W.C. Gregory and ten accessions of Arachis repens Handro. Twenty loci proved to be polymorphic and a total of 196 alleles were detected with an average of 9.8 alleles per locus. The variability found in those loci was greater than the variability found using morphological characters, seed storage proteins and RAPD markers previously used in this germplasm. The high potential of these markers to detect species-specific alleles and discriminate among accessions was demonstrated. The set of microsatellite primer pairs developed by our group for A. pintoi are useful molecular tools for evaluating Section Caulorrhizae germplasm, as well as that of species belonging to other Arachis sections.

Genetic diversity analysis in the section Caulorrhizae (genus Arachis) using microsatellite markers

PubMed Central

2010-01-01

Diversity in 26 microsatellite loci from section Caulorrhizae germplasm was evaluated by using 33 accessions of A. pintoi Krapov. & W.C. Gregory and ten accessions of Arachis repens Handro. Twenty loci proved to be polymorphic and a total of 196 alleles were detected with an average of 9.8 alleles per locus. The variability found in those loci was greater than the variability found using morphological characters, seed storage proteins and RAPD markers previously used in this germplasm. The high potential of these markers to detect species-specific alleles and discriminate among accessions was demonstrated. The set of microsatellite primer pairs developed by our group for A. pintoi are useful molecular tools for evaluating Section Caulorrhizae germplasm, as well as that of species belonging to other Arachis sections. PMID:21637613

Linkage of loci associated with two pigment mutations on mouse chromosome 13.

PubMed

Holcombe, R F; Stephenson, D A; Zweidler, A; Stewart, R M; Chapman, V M; Seidman, J G

1991-08-01

Progeny from one intra- and two inter-specific backcrosses between divergent strains of mice were typed to map multiple markers in relation to two pigment mutations on mouse chromosome 13, beige (bg) and pearl (pe). Both recessive mutants on a C57BL/6J background were crossed separately with laboratory strain PAC (M. domesticus) and the partially inbred M. musculus stock PWK. The intra- and inter-specific F1 hybrids were backcrossed to the C57BL/6J parental strain and DNA was prepared from progeny. Restriction fragment length polymorphisms were used to follow the segregation of alleles in the backcross offspring at loci identified with molecular probes. The linkage analysis defines the association between the bg and pe loci and the loci for the T-cell receptor gamma-chain gene (Tcrg), the spermatocyte specific histone gene (Hist1), the prolactin gene (Prl), the Friend murine leukaemia virus integration site 1 (Fim-1), the murine Hanukuh Factor gene (Muhf/Ctla-3) and the dihydrofolate reductase gene (Dhfr). This data confirms results of prior chromosomal mapping studies utilizing bg as an anchor locus, and provides previously unreported information defining the localization of the prolactin gene on mouse chromosome 13. The relationship of multiple loci in relation to pe is similarly defined. These results may help facilitate localization of the genes responsible for two human syndromes homologous with bg and pe, Chediak-Higashi syndrome and Hermansky-Pudlak syndrome.

[Role of CRISPR/Cas systems in drugresistance and virulence and the effect of IS600 on the expression of cse2 in Shigella].

PubMed

Hong, Lijuan; Zhang, Bing; Duan, Guangcai; Liang, Wenjuan; Wang, Yingfang; Chen, Shuaiyin; Yang, Haiyan; Xi, Yuanlin

2016-12-04

To analyze the relationship between CRISPR/Cas system and drug-resistance, virulence. To investigate the effect of IS600 on the expression of CRISPR associated gene cse2 in Shigella. CRISPR loci, CRISPR associated gene cse2, drug-resistant genes and virulent genes were detected by PCR in 33 Shigella strains; Trypan Blue counting test was used to detect bacterial virulence; Real-time PCR was used to detect relative mRNA expression of cse2; susceptibilities of Shigella strains were tested by agar diffusion method. Furthermore, we analyzed the relationship between CRISPR loci and drug-resistant genes, virulent genes. The effect of the IS600 on the expression of CRISPR associated gene cse2 was investigated. The mortality of Hela cells infected by Shigella with CRISPR1 loci was significantly lower (P<0.05) than those infected by Shigella without CRISPR1. The mRNA expression level of cse2 in group with IS600 was significantly (P<0.05) lower than that in group without IS600. CRISPR loci were widely present in Shigella. Shigella without CRISPR1 has a higher pathogenicity. Due to the insertion of IS600, the mRNA expression level of cse2 was decreased in Shigella.

Allelic-based gene-gene interaction associated with quantitative traits.

PubMed

Jung, Jeesun; Sun, Bin; Kwon, Deukwoo; Koller, Daniel L; Foroud, Tatiana M

2009-05-01

Recent studies have shown that quantitative phenotypes may be influenced not only by multiple single nucleotide polymorphisms (SNPs) within a gene but also by the interaction between SNPs at unlinked genes. We propose a new statistical approach that can detect gene-gene interactions at the allelic level which contribute to the phenotypic variation in a quantitative trait. By testing for the association of allelic combinations at multiple unlinked loci with a quantitative trait, we can detect the SNP allelic interaction whether or not it can be detected as a main effect. Our proposed method assigns a score to unrelated subjects according to their allelic combination inferred from observed genotypes at two or more unlinked SNPs, and then tests for the association of the allelic score with a quantitative trait. To investigate the statistical properties of the proposed method, we performed a simulation study to estimate type I error rates and power and demonstrated that this allelic approach achieves greater power than the more commonly used genotypic approach to test for gene-gene interaction. As an example, the proposed method was applied to data obtained as part of a candidate gene study of sodium retention by the kidney. We found that this method detects an interaction between the calcium-sensing receptor gene (CaSR), the chloride channel gene (CLCNKB) and the Na, K, 2Cl cotransporter gene (CLC12A1) that contributes to variation in diastolic blood pressure.

Microsphere-Based Multiplex Analysis of DNA Methylation in Acute Myeloid Leukemia

PubMed Central

Wertheim, Gerald B.W.; Smith, Catherine; Figueroa, Maria E.; Kalos, Michael; Bagg, Adam; Carroll, Martin; Master, Stephen R.

2015-01-01

Aberrant regulation of DNA methylation is characteristic of cancer cells and clearly influences phenotypes of various malignancies. Despite clear correlations between DNA methylation and patient outcome, tests that directly measure multiple-locus DNA methylation are typically expensive and technically challenging. Previous studies have demonstrated that the prognosis of patients with acute myeloid leukemia can be predicted by the DNA methylation pattern of 18 loci. We have developed a novel strategy, termed microsphere HpaII tiny fragment enrichment by ligation-mediated PCR (MELP), to simultaneously analyze the DNA methylation pattern at these loci using methylation-specific DNA digestion, fluorescently labeled microspheres, and branched DNA hybridization. The method uses techniques that are inexpensive and easily performed in a molecular laboratory. MELP accurately reflects the methylation levels at each locus analyzed and segregates patients with acute myeloid leukemia into prognostic subgroups. Our results demonstrate the usefulness of MELP as a platform for simultaneous evaluation of DNA methylation of multiple loci. PMID:24373919

High-fidelity simulations of blast loadings in urban environments using an overset meshing strategy

NASA Astrophysics Data System (ADS)

Wang, X.; Remotigue, M.; Arnoldus, Q.; Janus, M.; Luke, E.; Thompson, D.; Weed, R.; Bessette, G.

2017-05-01

Detailed blast propagation and evolution through multiple structures representing an urban environment were simulated using the code Loci/BLAST, which employs an overset meshing strategy. The use of overset meshes simplifies mesh generation by allowing meshes for individual component geometries to be generated independently. Detailed blast propagation and evolution through multiple structures, wave reflection and interaction between structures, and blast loadings on structures were simulated and analyzed. Predicted results showed good agreement with experimental data generated by the US Army Engineer Research and Development Center. Loci/BLAST results were also found to compare favorably to simulations obtained using the Second-Order Hydrodynamic Automatic Mesh Refinement Code (SHAMRC). The results obtained demonstrated that blast reflections in an urban setting significantly increased the blast loads on adjacent buildings. Correlations of computational results with experimental data yielded valuable insights into the physics of blast propagation, reflection, and interaction under an urban setting and verified the use of Loci/BLAST as a viable tool for urban blast analysis.

Detection of genomic loci associated with environmental variables using generalized linear mixed models.

PubMed

Lobréaux, Stéphane; Melodelima, Christelle

2015-02-01

We tested the use of Generalized Linear Mixed Models to detect associations between genetic loci and environmental variables, taking into account the population structure of sampled individuals. We used a simulation approach to generate datasets under demographically and selectively explicit models. These datasets were used to analyze and optimize GLMM capacity to detect the association between markers and selective coefficients as environmental data in terms of false and true positive rates. Different sampling strategies were tested, maximizing the number of populations sampled, sites sampled per population, or individuals sampled per site, and the effect of different selective intensities on the efficiency of the method was determined. Finally, we apply these models to an Arabidopsis thaliana SNP dataset from different accessions, looking for loci associated with spring minimal temperature. We identified 25 regions that exhibit unusual correlations with the climatic variable and contain genes with functions related to temperature stress. Copyright © 2014 Elsevier Inc. All rights reserved.

Genomic Changes Associated with Reproductive and Migratory Ecotypes in Sockeye Salmon (Oncorhynchus nerka)

PubMed Central

Veale, Andrew J.

2017-01-01

Mechanisms underlying adaptive evolution can best be explored using paired populations displaying similar phenotypic divergence, illuminating the genomic changes associated with specific life history traits. Here, we used paired migratory [anadromous vs. resident (kokanee)] and reproductive [shore- vs. stream-spawning] ecotypes of sockeye salmon (Oncorhynchus nerka) sampled from seven lakes and two rivers spanning three catchments (Columbia, Fraser, and Skeena) in British Columbia, Canada to investigate the patterns and processes underlying their divergence. Restriction-site associated DNA sequencing was used to genotype this sampling at 7,347 single nucleotide polymorphisms, 334 of which were identified as outlier loci and candidates for divergent selection within at least one ecotype comparison. Sixty-eight of these outliers were present in two or more comparisons, with 33 detected across multiple catchments. Of particular note, one locus was detected as the most significant outlier between shore and stream-spawning ecotypes in multiple comparisons and across catchments (Columbia, Fraser, and Snake). We also detected several genomic islands of divergence, some shared among comparisons, potentially showing linked signals of differential selection. The single nucleotide polymorphisms and genomic regions identified in our study offer a range of mechanistic hypotheses associated with the genetic basis of O. nerka life history variation and provide novel tools for informing fisheries management. PMID:29045601

Standing Genetic Variation in Contingency Loci Drives the Rapid Adaptation of Campylobacter jejuni to a Novel Host

PubMed Central

Jerome, John P.; Bell, Julia A.; Plovanich-Jones, Anne E.; Barrick, Jeffrey E.; Brown, C. Titus; Mansfield, Linda S.

2011-01-01

The genome of the food-borne pathogen Campylobacter jejuni contains multiple highly mutable sites, or contingency loci. It has been suggested that standing variation at these loci is a mechanism for rapid adaptation to a novel environment, but this phenomenon has not been shown experimentally. In previous work we showed that the virulence of C. jejuni NCTC11168 increased after serial passage through a C57BL/6 IL-10-/- mouse model of campylobacteriosis. Here we sought to determine the genetic basis of this adaptation during passage. Re-sequencing of the 1.64Mb genome to 200-500X coverage allowed us to define variation in 23 contingency loci to an unprecedented depth both before and after in vivo adaptation. Mutations in the mouse-adapted C. jejuni were largely restricted to the homopolymeric tracts of thirteen contingency loci. These changes cause significant alterations in open reading frames of genes in surface structure biosynthesis loci and in genes with only putative functions. Several loci with open reading frame changes also had altered transcript abundance. The increase in specific phases of contingency loci during in vivo passage of C. jejuni, coupled with the observed virulence increase and the lack of other types of genetic changes, is the first experimental evidence that these variable regions play a significant role in C. jejuni adaptation and virulence in a novel host. PMID:21283682

Navigating the Interface Between Landscape Genetics and Landscape Genomics.

PubMed

Storfer, Andrew; Patton, Austin; Fraik, Alexandra K

2018-01-01

As next-generation sequencing data become increasingly available for non-model organisms, a shift has occurred in the focus of studies of the geographic distribution of genetic variation. Whereas landscape genetics studies primarily focus on testing the effects of landscape variables on gene flow and genetic population structure, landscape genomics studies focus on detecting candidate genes under selection that indicate possible local adaptation. Navigating the transition between landscape genomics and landscape genetics can be challenging. The number of molecular markers analyzed has shifted from what used to be a few dozen loci to thousands of loci and even full genomes. Although genome scale data can be separated into sets of neutral loci for analyses of gene flow and population structure and putative loci under selection for inference of local adaptation, there are inherent differences in the questions that are addressed in the two study frameworks. We discuss these differences and their implications for study design, marker choice and downstream analysis methods. Similar to the rapid proliferation of analysis methods in the early development of landscape genetics, new analytical methods for detection of selection in landscape genomics studies are burgeoning. We focus on genome scan methods for detection of selection, and in particular, outlier differentiation methods and genetic-environment association tests because they are the most widely used. Use of genome scan methods requires an understanding of the potential mismatches between the biology of a species and assumptions inherent in analytical methods used, which can lead to high false positive rates of detected loci under selection. Key to choosing appropriate genome scan methods is an understanding of the underlying demographic structure of study populations, and such data can be obtained using neutral loci from the generated genome-wide data or prior knowledge of a species' phylogeographic history. To this end, we summarize recent simulation studies that test the power and accuracy of genome scan methods under a variety of demographic scenarios and sampling designs. We conclude with a discussion of additional considerations for future method development, and a summary of methods that show promise for landscape genomics studies but are not yet widely used.

Navigating the Interface Between Landscape Genetics and Landscape Genomics

PubMed Central

Storfer, Andrew; Patton, Austin; Fraik, Alexandra K.

2018-01-01

As next-generation sequencing data become increasingly available for non-model organisms, a shift has occurred in the focus of studies of the geographic distribution of genetic variation. Whereas landscape genetics studies primarily focus on testing the effects of landscape variables on gene flow and genetic population structure, landscape genomics studies focus on detecting candidate genes under selection that indicate possible local adaptation. Navigating the transition between landscape genomics and landscape genetics can be challenging. The number of molecular markers analyzed has shifted from what used to be a few dozen loci to thousands of loci and even full genomes. Although genome scale data can be separated into sets of neutral loci for analyses of gene flow and population structure and putative loci under selection for inference of local adaptation, there are inherent differences in the questions that are addressed in the two study frameworks. We discuss these differences and their implications for study design, marker choice and downstream analysis methods. Similar to the rapid proliferation of analysis methods in the early development of landscape genetics, new analytical methods for detection of selection in landscape genomics studies are burgeoning. We focus on genome scan methods for detection of selection, and in particular, outlier differentiation methods and genetic-environment association tests because they are the most widely used. Use of genome scan methods requires an understanding of the potential mismatches between the biology of a species and assumptions inherent in analytical methods used, which can lead to high false positive rates of detected loci under selection. Key to choosing appropriate genome scan methods is an understanding of the underlying demographic structure of study populations, and such data can be obtained using neutral loci from the generated genome-wide data or prior knowledge of a species' phylogeographic history. To this end, we summarize recent simulation studies that test the power and accuracy of genome scan methods under a variety of demographic scenarios and sampling designs. We conclude with a discussion of additional considerations for future method development, and a summary of methods that show promise for landscape genomics studies but are not yet widely used. PMID:29593776

DNA variation in a conifer, Cryptomeria japonica (Cupressaceae sensu lato).

PubMed Central

Kado, Tomoyuki; Yoshimaru, Hiroshi; Tsumura, Yoshihiko; Tachida, Hidenori

2003-01-01

We investigated the nucleotide variation of a conifer, Cryptomeria japonica, and the divergence between this species and its closest relative, Taxodium distichum, at seven nuclear loci (Acl5, Chi1, Ferr, GapC, HemA, Lcyb, and Pat). Samples of C. japonica were collected from three areas, Kantou-Toukai, Hokuriku, and Iwate. No apparent geographic differentiation was found among these samples. However, the frequency spectrum of the nucleotide polymorphism revealed excesses of intermediate-frequency variants, which suggests that the population was not panmictic and a constant size in the past. The average nucleotide diversity, pi, for silent sites was 0.00383. However, values of pi for silent sites vary among loci. Comparisons of polymorphism to divergence among loci (the HKA test) showed that the polymorphism at the Acl5 locus was significantly lower. We also observed a nearly significant excess of replacement polymorphisms at the Lcyb locus. These results suggested possibilities of natural selection acting at some of the loci. Intragenic recombination was detected only once at the Chi1 locus and was not detected at the other loci. The low level of population recombination rate, 4Nr, seemed to be due to both low level of recombination, r, and small population size, N. PMID:12930759

Case of successful IVF treatment of an oligospermic male with 46,XX/46,XY chimerism.

PubMed

Laursen, R J; Alsbjerg, B; Vogel, I; Gravholt, C H; Elbaek, H; Lildballe, D L; Humaidan, P; Vestergaard, E M

2018-04-30

We present a case of an infertile male with 46,XX/46,XYchimerism fathering a child after ICSI procedure. Conventional cytogenetic analysis on chromosomes, derived from lymphocytes, using standard Q-banding procedures with a 450-550-band resolution and short-tandem-repeat analysis of 14 loci. Analysis of 20 metaphases from lymphocytes indicated that the proband was a karyotypic mosaic with an almost equal distribution between male and female cell lines. In total, 12 of 20 (60%) metaphases exhibited a normal female karyotype 46,XX, while 8 of 20 (40%) metaphases demonstrated a normal male karyotype 46,XY. No structural chromosomal abnormalities were present. Out of 14 STR loci, two loci (D18S51 and D21S11) showed four different alleles in peripheral blood, buccal mucosal cells, conjunctival mucosal cells, and seminal fluid. In three loci (D2S1338, D7S820, and vWA), three alleles were detected with quantitative differences that indicated presence of four alleles. In DNA extracted from washed semen, four alleles were detected in one locus, and three alleles were detected in three loci. This pattern is consistent with tetragametic chimerism. There were no quantitative significant differences in peak heights between maternal and paternal alleles. STR-analysis on DNA from the son confirmed paternity. We report a unique case with 46,XX/46,XY chimerism confirmed to be tetragametic, demonstrated in several tissues, with male phenotype and no genital ambiguity with oligospermia fathering a healthy child after IVF with ICSI procedure.

Construction of a high-density linkage map and mapping quantitative trait loci for somatic embryogenesis using leaf petioles as explants in upland cotton (Gossypium hirsutum L.).

PubMed

Xu, Zhenzhen; Zhang, Chaojun; Ge, Xiaoyang; Wang, Ni; Zhou, Kehai; Yang, Xiaojie; Wu, Zhixia; Zhang, Xueyan; Liu, Chuanliang; Yang, Zuoren; Li, Changfeng; Liu, Kun; Yang, Zhaoen; Qian, Yuyuan; Li, Fuguang

2015-07-01

The first high-density linkage map was constructed to identify quantitative trait loci (QTLs) for somatic embryogenesis (SE) in cotton ( Gossypium hirsutum L.) using leaf petioles as explants. Cotton transformation is highly limited by only a few regenerable genotypes and the lack of understanding of the genetic and molecular basis of somatic embryogenesis (SE) in cotton (Gossypium hirsutum L.). To construct a more saturated linkage map and further identify quantitative trait loci (QTLs) for SE using leaf petioles as explants, a high embryogenesis frequency line (W10) from the commercial Chinese cotton cultivar CRI24 was crossed with TM-1, a genetic standard upland cotton with no embryogenesis frequency. The genetic map spanned 2300.41 cM in genetic distance and contained 411 polymorphic simple sequence repeat (SSR) loci. Of the 411 mapped loci, 25 were developed from unigenes identified for SE in our previous study. Six QTLs for SE were detected by composite interval mapping method, each explaining 6.88-37.07% of the phenotypic variance. Single marker analysis was also performed to verify the reliability of QTLs detection, and the SSR markers NAU3325 and DPL0209 were detected by the two methods. Further studies on the relatively stable and anchoring QTLs/markers for SE in an advanced population of W10 × TM-1 and other cross combinations with different SE abilities may shed light on the genetic and molecular mechanism of SE in cotton.

In silico mapping of quantitative trait loci in maize.

PubMed

Parisseaux, B; Bernardo, R

2004-08-01

Quantitative trait loci (QTL) are most often detected through designed mapping experiments. An alternative approach is in silico mapping, whereby genes are detected using existing phenotypic and genomic databases. We explored the usefulness of in silico mapping via a mixed-model approach in maize (Zea mays L.). Specifically, our objective was to determine if the procedure gave results that were repeatable across populations. Multilocation data were obtained from the 1995-2002 hybrid testing program of Limagrain Genetics in Europe. Nine heterotic patterns comprised 22,774 single crosses. These single crosses were made from 1,266 inbreds that had data for 96 simple sequence repeat (SSR) markers. By a mixed-model approach, we estimated the general combining ability effects associated with marker alleles in each heterotic pattern. The numbers of marker loci with significant effects--37 for plant height, 24 for smut [Ustilago maydis (DC.) Cda.] resistance, and 44 for grain moisture--were consistent with previous results from designed mapping experiments. Each trait had many loci with small effects and few loci with large effects. For smut resistance, a marker in bin 8.05 on chromosome 8 had a significant effect in seven (out of a maximum of 18) instances. For this major QTL, the maximum effect of an allele substitution ranged from 5.4% to 41.9%, with an average of 22.0%. We conclude that in silico mapping via a mixed-model approach can detect associations that are repeatable across different populations. We speculate that in silico mapping will be more useful for gene discovery than for selection in plant breeding programs. Copyright 2004 Springer-Verlag

Isolation and characterization of microsatellite markers of sea cucumber Stichopus horrens.

PubMed

Li, Z B; Dai, G; Shangguan, J B; Ning, Y F; Li, Y Y; Chen, R B; Yuan, Y; Huang, Y S

2015-07-28

Curry fish (Stichopus horrens) is a tropical holothurian species and is widely distributed in the India-West Pacific. In the present study, 9 polymorphic microsatellite loci were isolated and characterized for S. horrens. These loci were tested in 30 individuals from Hainan Island in China. The number of alleles ranged from 2 to 5. The polymorphism information content ranged from 0.348-0.584. The levels of observed and expected heterozygosities varied from 0.1500-0.8000 and from 0.2014-0.5000, respectively. Most loci were in Hardy-Weinberg equilibrium, except HCS1-27 and HCS2-7, after sequential Bonferroni's correction, and no significant linkage disequilibrium was detected for any pairwise combination of loci. These polymorphic microsatellite loci will be useful for studying population structure and conservation strategy design for S. horrens.

Analysis of mating system parameters and population structure in Douglas-fir using single-locus and multilocus methods

Treesearch

D. V. Shaw; R. W. Allard

1981-01-01

Two methods of estimating the proportion of self-fertilization as opposed to outcrossing in plant populations are described. The first method makes use of marker loci one at a time; the second method makes use of multiple marker loci simultaneously. Comparisons of the estimates of proportions of selfing and outcrossing obtained using the two methods are shown to yield...

DNA methylome signature in rheumatoid arthritis.

PubMed

Nakano, Kazuhisa; Whitaker, John W; Boyle, David L; Wang, Wei; Firestein, Gary S

2013-01-01

Epigenetics can influence disease susceptibility and severity. While DNA methylation of individual genes has been explored in autoimmunity, no unbiased systematic analyses have been reported. Therefore, a genome-wide evaluation of DNA methylation loci in fibroblast-like synoviocytes (FLS) isolated from the site of disease in rheumatoid arthritis (RA) was performed. Genomic DNA was isolated from six RA and five osteoarthritis (OA) FLS lines and evaluated using the Illumina HumanMethylation450 chip. Cluster analysis of data was performed and corrected using Benjamini-Hochberg adjustment for multiple comparisons. Methylation was confirmed by pyrosequencing and gene expression was determined by qPCR. Pathway analysis was performed using the Kyoto Encyclopedia of Genes and Genomes. RA and control FLS segregated based on DNA methylation, with 1859 differentially methylated loci. Hypomethylated loci were identified in key genes relevant to RA, such as CHI3L1, CASP1, STAT3, MAP3K5, MEFV and WISP3. Hypermethylation was also observed, including TGFBR2 and FOXO1. Hypomethylation of individual genes was associated with increased gene expression. Grouped analysis identified 207 hypermethylated or hypomethylated genes with multiple differentially methylated loci, including COL1A1, MEFV and TNF. Hypomethylation was increased in multiple pathways related to cell migration, including focal adhesion, cell adhesion, transendothelial migration and extracellular matrix interactions. Confirmatory studies with OA and normal FLS also demonstrated segregation of RA from control FLS based on methylation pattern. Differentially methylated genes could alter FLS gene expression and contribute to the pathogenesis of RA. DNA methylation of critical genes suggests that RA FLS are imprinted and implicate epigenetic contributions to inflammatory arthritis.

Multiple Novel Prostate Cancer Predisposition Loci Confirmed by an International Study: The PRACTICAL Consortium

PubMed Central

Kote-Jarai, Zsofia; Easton, Douglas F.; Stanford, Janet L.; Ostrander, Elaine A.; Schleutker, Johanna; Ingles, Sue A.; Schaid, Daniel; Thibodeau, Stephen; Dörk, Thilo; Neal, David; Cox, Angela; Maier, Christiane; Vogel, Walter; Guy, Michelle; Muir, Kenneth; Lophatananon, Artitaya; Kedda, Mary-Anne; Spurdle, Amanda; Steginga, Suzanne; John, Esther M.; Giles, Graham; Hopper, John; Chappuis, Pierre O.; Hutter, Pierre; Foulkes, William D.; Hamel, Nancy; Salinas, Claudia A.; Koopmeiners, Joseph S.; Karyadi, Danielle M.; Johanneson, Bo; Wahlfors, Tiina; Tammela, Teuvo L.; Stern, Mariana C.; Corral, Roman; McDonnell, Shannon K.; Schürmann, Peter; Meyer, Andreas; Kuefer, Rainer; Leongamornlert, Daniel A.; Tymrakiewicz, Malgorzata; Liu, Jo-fen; O'Mara, Tracy; Gardiner, R.A. (Frank); Aitken, Joanne; Joshi, Amit D.; Severi, Gianluca; English, Dallas R.; Southey, Melissa; Edwards, Stephen M.; Amin Al Olama, Ali; Eeles, Rosalind A.

2009-01-01

A recent genome-wide association study found that genetic variants on chromosomes 3, 6, 7, 10, 11, 19 and X were associated with prostate cancer risk. We evaluated the most significant single-nucleotide polymorphisms (SNP) in these loci using a worldwide consortium of 13 groups (PRACTICAL). Blood DNA from 7,370 prostate cancer cases and 5,742 male controls was analyzed by genotyping assays. Odds ratios (OR) associated with each genotype were estimated using unconditional logistic regression. Six of the seven SNPs showed clear evidence of association with prostate cancer (P = 0.0007-P = 10−17). For each of these six SNPs, the estimated per-allele OR was similar to those previously reported and ranged from 1.12 to 1.29. One SNP on 3p12 (rs2660753) showed a weaker association than previously reported [per-allele OR, 1.08 (95% confidence interval, 1.00-1.16; P = 0.06) versus 1.18 (95% confidence interval, 1.06-1.31)]. The combined risks associated with each pair of SNPs were consistent with a multiplicative risk model. Under this model, and in combination with previously reported SNPs on 8q and 17q, these loci explain 16% of the familial risk of the disease, and men in the top 10% of the risk distribution have a 2.1-fold increased risk relative to general population rates. This study provides strong confirmation of these susceptibility loci in multiple populations and shows that they make an important contribution to prostate cancer risk prediction. PMID:18708398

Genome-wide mapping in a house mouse hybrid zone reveals hybrid sterility loci and Dobzhansky-Muller interactions.

PubMed

Turner, Leslie M; Harr, Bettina

2014-12-09

Mapping hybrid defects in contact zones between incipient species can identify genomic regions contributing to reproductive isolation and reveal genetic mechanisms of speciation. The house mouse features a rare combination of sophisticated genetic tools and natural hybrid zones between subspecies. Male hybrids often show reduced fertility, a common reproductive barrier between incipient species. Laboratory crosses have identified sterility loci, but each encompasses hundreds of genes. We map genetic determinants of testis weight and testis gene expression using offspring of mice captured in a hybrid zone between M. musculus musculus and M. m. domesticus. Many generations of admixture enables high-resolution mapping of loci contributing to these sterility-related phenotypes. We identify complex interactions among sterility loci, suggesting multiple, non-independent genetic incompatibilities contribute to barriers to gene flow in the hybrid zone.

Genetic characterization of the UCS and Kex1 loci of Pneumocystis jirovecii.

PubMed

Esteves, F; Tavares, A; Costa, M C; Gaspar, J; Antunes, F; Matos, O

2009-02-01

Nucleotide variation in the Pneumocystis jirovecii upstream conserved sequence (UCS) and kexin-like serine protease (Kex1) loci was studied in pulmonary specimens from Portuguese HIV-positive patients. DNA was extracted and used for specific molecular sequence analysis. The number of UCS tandem repeats detected in 13 successfully sequenced isolates ranged from three (9 isolates, 69%) to four (4 isolates, 31%). A novel tandem repeat pattern and two novel polymorphisms were detected in the UCS region. For the Kex1 gene, the wild-type (24 isolates, 86%) was the most frequent sequence detected among the 28 sequenced isolates. Nevertheless, a nonsynonymous (1 isolate, 3%) and three synonymous (3 isolates, 11%) polymorphisms were detected and are described here for the first time.

Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture.

PubMed

Berndt, Sonja I; Gustafsson, Stefan; Mägi, Reedik; Ganna, Andrea; Wheeler, Eleanor; Feitosa, Mary F; Justice, Anne E; Monda, Keri L; Croteau-Chonka, Damien C; Day, Felix R; Esko, Tõnu; Fall, Tove; Ferreira, Teresa; Gentilini, Davide; Jackson, Anne U; Luan, Jian'an; Randall, Joshua C; Vedantam, Sailaja; Willer, Cristen J; Winkler, Thomas W; Wood, Andrew R; Workalemahu, Tsegaselassie; Hu, Yi-Juan; Lee, Sang Hong; Liang, Liming; Lin, Dan-Yu; Min, Josine L; Neale, Benjamin M; Thorleifsson, Gudmar; Yang, Jian; Albrecht, Eva; Amin, Najaf; Bragg-Gresham, Jennifer L; Cadby, Gemma; den Heijer, Martin; Eklund, Niina; Fischer, Krista; Goel, Anuj; Hottenga, Jouke-Jan; Huffman, Jennifer E; Jarick, Ivonne; Johansson, Åsa; Johnson, Toby; Kanoni, Stavroula; Kleber, Marcus E; König, Inke R; Kristiansson, Kati; Kutalik, Zoltán; Lamina, Claudia; Lecoeur, Cecile; Li, Guo; Mangino, Massimo; McArdle, Wendy L; Medina-Gomez, Carolina; Müller-Nurasyid, Martina; Ngwa, Julius S; Nolte, Ilja M; Paternoster, Lavinia; Pechlivanis, Sonali; Perola, Markus; Peters, Marjolein J; Preuss, Michael; Rose, Lynda M; Shi, Jianxin; Shungin, Dmitry; Smith, Albert Vernon; Strawbridge, Rona J; Surakka, Ida; Teumer, Alexander; Trip, Mieke D; Tyrer, Jonathan; Van Vliet-Ostaptchouk, Jana V; Vandenput, Liesbeth; Waite, Lindsay L; Zhao, Jing Hua; Absher, Devin; Asselbergs, Folkert W; Atalay, Mustafa; Attwood, Antony P; Balmforth, Anthony J; Basart, Hanneke; Beilby, John; Bonnycastle, Lori L; Brambilla, Paolo; Bruinenberg, Marcel; Campbell, Harry; Chasman, Daniel I; Chines, Peter S; Collins, Francis S; Connell, John M; Cookson, William O; de Faire, Ulf; de Vegt, Femmie; Dei, Mariano; Dimitriou, Maria; Edkins, Sarah; Estrada, Karol; Evans, David M; Farrall, Martin; Ferrario, Marco M; Ferrières, Jean; Franke, Lude; Frau, Francesca; Gejman, Pablo V; Grallert, Harald; Grönberg, Henrik; Gudnason, Vilmundur; Hall, Alistair S; Hall, Per; Hartikainen, Anna-Liisa; Hayward, Caroline; Heard-Costa, Nancy L; Heath, Andrew C; Hebebrand, Johannes; Homuth, Georg; Hu, Frank B; Hunt, Sarah E; Hyppönen, Elina; Iribarren, Carlos; Jacobs, Kevin B; Jansson, John-Olov; Jula, Antti; Kähönen, Mika; Kathiresan, Sekar; Kee, Frank; Khaw, Kay-Tee; Kivimäki, Mika; Koenig, Wolfgang; Kraja, Aldi T; Kumari, Meena; Kuulasmaa, Kari; Kuusisto, Johanna; Laitinen, Jaana H; Lakka, Timo A; Langenberg, Claudia; Launer, Lenore J; Lind, Lars; Lindström, Jaana; Liu, Jianjun; Liuzzi, Antonio; Lokki, Marja-Liisa; Lorentzon, Mattias; Madden, Pamela A; Magnusson, Patrik K; Manunta, Paolo; Marek, Diana; März, Winfried; Mateo Leach, Irene; McKnight, Barbara; Medland, Sarah E; Mihailov, Evelin; Milani, Lili; Montgomery, Grant W; Mooser, Vincent; Mühleisen, Thomas W; Munroe, Patricia B; Musk, Arthur W; Narisu, Narisu; Navis, Gerjan; Nicholson, George; Nohr, Ellen A; Ong, Ken K; Oostra, Ben A; Palmer, Colin N A; Palotie, Aarno; Peden, John F; Pedersen, Nancy; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Prokopenko, Inga; Pütter, Carolin; Radhakrishnan, Aparna; Raitakari, Olli; Rendon, Augusto; Rivadeneira, Fernando; Rudan, Igor; Saaristo, Timo E; Sambrook, Jennifer G; Sanders, Alan R; Sanna, Serena; Saramies, Jouko; Schipf, Sabine; Schreiber, Stefan; Schunkert, Heribert; Shin, So-Youn; Signorini, Stefano; Sinisalo, Juha; Skrobek, Boris; Soranzo, Nicole; Stančáková, Alena; Stark, Klaus; Stephens, Jonathan C; Stirrups, Kathleen; Stolk, Ronald P; Stumvoll, Michael; Swift, Amy J; Theodoraki, Eirini V; Thorand, Barbara; Tregouet, David-Alexandre; Tremoli, Elena; Van der Klauw, Melanie M; van Meurs, Joyce B J; Vermeulen, Sita H; Viikari, Jorma; Virtamo, Jarmo; Vitart, Veronique; Waeber, Gérard; Wang, Zhaoming; Widén, Elisabeth; Wild, Sarah H; Willemsen, Gonneke; Winkelmann, Bernhard R; Witteman, Jacqueline C M; Wolffenbuttel, Bruce H R; Wong, Andrew; Wright, Alan F; Zillikens, M Carola; Amouyel, Philippe; Boehm, Bernhard O; Boerwinkle, Eric; Boomsma, Dorret I; Caulfield, Mark J; Chanock, Stephen J; Cupples, L Adrienne; Cusi, Daniele; Dedoussis, George V; Erdmann, Jeanette; Eriksson, Johan G; Franks, Paul W; Froguel, Philippe; Gieger, Christian; Gyllensten, Ulf; Hamsten, Anders; Harris, Tamara B; Hengstenberg, Christian; Hicks, Andrew A; Hingorani, Aroon; Hinney, Anke; Hofman, Albert; Hovingh, Kees G; Hveem, Kristian; Illig, Thomas; Jarvelin, Marjo-Riitta; Jöckel, Karl-Heinz; Keinanen-Kiukaanniemi, Sirkka M; Kiemeney, Lambertus A; Kuh, Diana; Laakso, Markku; Lehtimäki, Terho; Levinson, Douglas F; Martin, Nicholas G; Metspalu, Andres; Morris, Andrew D; Nieminen, Markku S; Njølstad, Inger; Ohlsson, Claes; Oldehinkel, Albertine J; Ouwehand, Willem H; Palmer, Lyle J; Penninx, Brenda; Power, Chris; Province, Michael A; Psaty, Bruce M; Qi, Lu; Rauramaa, Rainer; Ridker, Paul M; Ripatti, Samuli; Salomaa, Veikko; Samani, Nilesh J; Snieder, Harold; Sørensen, Thorkild I A; Spector, Timothy D; Stefansson, Kari; Tönjes, Anke; Tuomilehto, Jaakko; Uitterlinden, André G; Uusitupa, Matti; van der Harst, Pim; Vollenweider, Peter; Wallaschofski, Henri; Wareham, Nicholas J; Watkins, Hugh; Wichmann, H-Erich; Wilson, James F; Abecasis, Goncalo R; Assimes, Themistocles L; Barroso, Inês; Boehnke, Michael; Borecki, Ingrid B; Deloukas, Panos; Fox, Caroline S; Frayling, Timothy; Groop, Leif C; Haritunian, Talin; Heid, Iris M; Hunter, David; Kaplan, Robert C; Karpe, Fredrik; Moffatt, Miriam F; Mohlke, Karen L; O'Connell, Jeffrey R; Pawitan, Yudi; Schadt, Eric E; Schlessinger, David; Steinthorsdottir, Valgerdur; Strachan, David P; Thorsteinsdottir, Unnur; van Duijn, Cornelia M; Visscher, Peter M; Di Blasio, Anna Maria; Hirschhorn, Joel N; Lindgren, Cecilia M; Morris, Andrew P; Meyre, David; Scherag, André; McCarthy, Mark I; Speliotes, Elizabeth K; North, Kari E; Loos, Ruth J F; Ingelsson, Erik

2013-05-01

Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.

Tools to exploit sequence data to find new markers and disease loci in dairy cattle

USDA-ARS?s Scientific Manuscript database

The decrease in cost of Next-Generation Sequencing has brought the technology into the realm of practical applications in livestock genomics. Recently, the 1000 Bulls Project has heralded the possibility of using full sequence data to improve imputation and detect disease loci within select founder ...

Microsatellite genotyping and genome-wide single nucleotide polymorphism-based indices of Plasmodium falciparum diversity within clinical infections.

PubMed

Murray, Lee; Mobegi, Victor A; Duffy, Craig W; Assefa, Samuel A; Kwiatkowski, Dominic P; Laman, Eugene; Loua, Kovana M; Conway, David J

2016-05-12

In regions where malaria is endemic, individuals are often infected with multiple distinct parasite genotypes, a situation that may impact on evolution of parasite virulence and drug resistance. Most approaches to studying genotypic diversity have involved analysis of a modest number of polymorphic loci, although whole genome sequencing enables a broader characterisation of samples. PCR-based microsatellite typing of a panel of ten loci was performed on Plasmodium falciparum in 95 clinical isolates from a highly endemic area in the Republic of Guinea, to characterize within-isolate genetic diversity. Separately, single nucleotide polymorphism (SNP) data from genome-wide short-read sequences of the same samples were used to derive within-isolate fixation indices (F ws), an inverse measure of diversity within each isolate compared to overall local genetic diversity. The latter indices were compared with the microsatellite results, and also with indices derived by randomly sampling modest numbers of SNPs. As expected, the number of microsatellite loci with more than one allele in each isolate was highly significantly inversely correlated with the genome-wide F ws fixation index (r = -0.88, P < 0.001). However, the microsatellite analysis revealed that most isolates contained mixed genotypes, even those that had no detectable genome sequence heterogeneity. Random sampling of different numbers of SNPs showed that an F ws index derived from ten or more SNPs with minor allele frequencies of >10 % had high correlation (r > 0.90) with the index derived using all SNPs. Different types of data give highly correlated indices of within-infection diversity, although PCR-based analysis detects low-level minority genotypes not apparent in bulk sequence analysis. When whole-genome data are not obtainable, quantitative assay of ten or more SNPs can yield a reasonably accurate estimate of the within-infection fixation index (F ws).

Multiple Genetic Backgrounds of the Amplified Plasmodium falciparum Multidrug Resistance (pfmdr1) Gene and Selective Sweep of 184F Mutation in Cambodia

PubMed Central

Vinayak, Sumiti; Alam, Md Tauqeer; Sem, Rithy; Shah, Naman K.; Susanti, Augustina I.; Lim, Pharath; Muth, Sinuon; Maguire, Jason D.; Rogers, William O.; Fandeur, Thierry; Barnwell, John W.; Escalante, Ananias A.; Wongsrichanalai, Chansuda; Ariey, Frederick; Meshnick, Steven R.; Udhayakumar, Venkatachalam

2011-01-01

Background The emergence of artesunate-mefloquine (AS+MQ)–resistant Plasmodium falciparum in the Thailand-Cambodia region is a major concern for malaria control. Studies indicate that copy number increase and key alleles in the pfmdr1 gene are associated with AS+MQ resistance. In the present study, we investigated evidence for a selective sweep around pfmdr1 because of the spread of adaptive mutation and/or multiple copies of this gene in the P. falciparum population in Cambodia. Methods We characterized 13 microsatellite loci flanking (± 99 kb) pfmdr1 in 93 single-clone P. falciparum infections, of which 31 had multiple copies and 62 had a single copy of the pfmdr1 gene. Results Genetic analysis revealed no difference in the mean (± standard deviation) expected heterozygosity (He) at loci around single (0.75 ± 0.03) and multiple (0.76 ± 0.04) copies of pfmdr1. Evidence of genetic hitchhiking with the selective sweep of certain haplotypes was seen around mutant (184F) pfmdr1 allele, irrespective of the copy number. There was an overall reduction of 28% in mean He (± SD) around mutant allele (0.56 ± 0.05), compared with wild-type allele (0.84 ± 0.02). Significant linkage disequilibrium was also observed between the loci flanking mutant pfmdr1 allele. Conclusion The 184F mutant allele is under selection, whereas amplification of pfmdr1 gene in this population occurs on multiple genetic backgrounds. PMID:20367478

Multiple New Loci Associated with Kidney Function and Chronic Kidney Disease: The CKDGen consortium

PubMed Central

Köttgen, Anna; Pattaro, Cristian; Böger, Carsten A.; Fuchsberger, Christian; Olden, Matthias; Glazer, Nicole L.; Parsa, Afshin; Gao, Xiaoyi; Yang, Qiong; Smith, Albert V.; O’Connell, Jeffrey R.; Li, Man; Schmidt, Helena; Tanaka, Toshiko; Isaacs, Aaron; Ketkar, Shamika; Hwang, Shih-Jen; Johnson, Andrew D.; Dehghan, Abbas; Teumer, Alexander; Paré, Guillaume; Atkinson, Elizabeth J.; Zeller, Tanja; Lohman, Kurt; Cornelis, Marilyn C.; Probst-Hensch, Nicole M.; Kronenberg, Florian; Tönjes, Anke; Hayward, Caroline; Aspelund, Thor; Eiriksdottir, Gudny; Launer, Lenore; Harris, Tamara B.; Rapmersaud, Evadnie; Mitchell, Braxton D.; Boerwinkle, Eric; Struchalin, Maksim; Cavalieri, Margherita; Singleton, Andrew; Giallauria, Francesco; Metter, Jeffery; de Boer, Ian; Haritunians, Talin; Lumley, Thomas; Siscovick, David; Psaty, Bruce M.; Zillikens, M. Carola; Oostra, Ben A.; Feitosa, Mary; Province, Michael; Levy, Daniel; de Andrade, Mariza; Turner, Stephen T.; Schillert, Arne; Ziegler, Andreas; Wild, Philipp S.; Schnabel, Renate B.; Wilde, Sandra; Muenzel, Thomas F.; Leak, Tennille S; Illig, Thomas; Klopp, Norman; Meisinger, Christa; Wichmann, H.-Erich; Koenig, Wolfgang; Zgaga, Lina; Zemunik, Tatijana; Kolcic, Ivana; Minelli, Cosetta; Hu, Frank B.; Johansson, Åsa; Igl, Wilmar; Zaboli, Ghazal; Wild, Sarah H; Wright, Alan F; Campbell, Harry; Ellinghaus, David; Schreiber, Stefan; Aulchenko, Yurii S; Rivadeneira, Fernando; Uitterlinden, Andre G; Hofman, Albert; Imboden, Medea; Nitsch, Dorothea; Brandstätter, Anita; Kollerits, Barbara; Kedenko, Lyudmyla; Mägi, Reedik; Stumvoll, Michael; Kovacs, Peter; Boban, Mladen; Campbell, Susan; Endlich, Karlhans; Völzke, Henry; Kroemer, Heyo K.; Nauck, Matthias; Völker, Uwe; Polasek, Ozren; Vitart, Veronique; Badola, Sunita; Parker, Alexander N.; Ridker, Paul M.; Kardia, Sharon L. R.; Blankenberg, Stefan; Liu, Yongmei; Curhan, Gary C.; Franke, Andre; Rochat, Thierry; Paulweber, Bernhard; Prokopenko, Inga; Wang, Wei; Gudnason, Vilmundur; Shuldiner, Alan R.; Coresh, Josef; Schmidt, Reinhold; Ferrucci, Luigi; Shlipak, Michael G.; van Duijn, Cornelia M.; Borecki, Ingrid; Krämer, Bernhard K.; Rudan, Igor; Gyllensten, Ulf; Wilson, James F.; Witteman, Jacqueline C.; Pramstaller, Peter P.; Rettig, Rainer; Hastie, Nick; Chasman, Daniel I.; Kao, W. H.; Heid, Iris M.; Fox, Caroline S.

2010-01-01

Chronic kidney disease (CKD) is a significant public health problem, and recent genetic studies have identified common CKD susceptibility variants. The CKDGen consortium performed a meta-analysis of genome-wide association data in 67,093 Caucasian individuals from 20 population-based studies to identify new susceptibility loci for reduced renal function, estimated by serum creatinine (eGFRcrea), cystatin C (eGFRcys), and CKD (eGFRcrea <60 ml/min/1.73m2; n = 5,807 CKD cases). Follow-up of the 23 genome-wide significant loci (p<5×10−8) in 22,982 replication samples identified 13 novel loci for renal function and CKD (in or near LASS2, GCKR, ALMS1, TFDP2, DAB2, SLC34A1, VEGFA, PRKAG2, PIP5K1B, ATXN2, DACH1, UBE2Q2, and SLC7A9) and 7 creatinine production and secretion loci (CPS1, SLC22A2, TMEM60, WDR37, SLC6A13, WDR72, BCAS3). These results further our understanding of biologic mechanisms of kidney function by identifying loci potentially influencing nephrogenesis, podocyte function, angiogenesis, solute transport, and metabolic functions of the kidney. PMID:20383146

Meta-analysis identifies common variants associated with body mass index in East Asians

PubMed Central

Wen, Wanqing; Cho, Yoon Shin; Zheng, Wei; Dorajoo, Rajkumar; Kato, Norihiro; Qi, Lu; Chen, Chien-Hsiun; Delahanty, Ryan J.; Okada, Yukinori; Tabara, Yasuharu; Gu, Dongfeng; Zhu, Dingliang; Haiman, Christopher A.; Mo, Zengnan; Gao, Yu-Tang; Saw, Seang Mei; Go, Min Jin; Takeuchi, Fumihiko; Chang, Li-Ching; Kokubo, Yoshihiro; Liang, Jun; Hao, Mei; Marchand, Loic Le; Zhang, Yi; Hu, Yanling; Wong, Tien Yin; Long, Jirong; Han, Bok-Ghee; Kubo, Michiaki; Yamamoto, Ken; Su, Mei-Hsin; Miki, Tetsuro; Henderson, Brian E.; Song, Huaidong; Tan, Aihua; He, Jiang; Ng, Daniel P.-K.; Cai, Qiuyin; Tsunoda, Tatsuhiko; Tsai, Fuu-Jen; Iwai, Naoharu; Chen, Gary K.; Shi, Jiajun; Xu, Jianfeng; Sim, Xueling; Xiang, Yong-Bing; Maeda, Shiro; Ong, Rick T.H.; Li, Chun; Nakamura, Yusuke; Aung, Tin; Kamatani, Naoyuki; Liu, Jian Jun; Lu, Wei; Yokota, Mitsuhiro; Seielstad, Mark; Fann, Cathy S.J.; Wu, Jer-Yuarn; Lee, Jong-Young; Hu, Frank B.; Tanaka, Toshihiro; Tai, E. Shyong; Shu, Xiao Ou

2012-01-01

Multiple genetic loci associated with obesity or body mass index (BMI) have been identified through genome-wide association studies conducted predominantly in populations of European ancestry. We conducted a meta-analysis of associations between BMI and approximately 2.4 million SNPs in 27,715 East Asians, followed by in silico and de novo replication in 37,691 and 17,642 additional East Asians, respectively. We identified ten BMI-associated loci at the genome-wide significance level (P<5.0×10−8), including seven previously identified loci (FTO, SEC16B, MC4R, GIPR/QPCTL, ADCY3/RBJ, BDNF, and MAP2K5) and three novel loci in or near the CDKAL1,PCSK1, and GP2 genes. Three additional loci nearly reached the genome-wide significance threshold, including two previously identified loci in the GNPDA2 and TFAP2B genes and a new locus near PAX6, which all had P<5.0×10−7. Findings from this study may shed light on new pathways involved in obesity and demonstrate the value of conducting genetic studies in non-European populations. PMID:22344219

Toxin-antitoxin systems and regulatory mechanisms in Mycobacterium tuberculosis.

PubMed

Slayden, Richard A; Dawson, Clinton C; Cummings, Jason E

2018-06-01

There has been a significant reduction in annual tuberculosis incidence since the World Health Organization declared tuberculosis a global health threat. However, treatment of M. tuberculosis infections requires lengthy multidrug therapeutic regimens to achieve a durable cure. The development of new drugs that are active against resistant strains and phenotypically diverse organisms continues to present the greatest challenge in the future. Numerous phylogenomic analyses have revealed that the Mtb genome encodes a significantly expanded repertoire of toxin-antitoxin (TA) loci that makes up the Mtb TA system. A TA loci is a two-gene operon encoding a 'toxin' protein that inhibits bacterial growth and an interacting 'antitoxin' partner that neutralizes the inhibitory activity of the toxin. The presence of multiple chromosomally encoded TA loci in Mtb raises important questions in regard to expansion, regulation and function. Thus, the functional roles of TA loci in Mtb pathogenesis have received considerable attention over the last decade. The cumulative results indicate that they are involved in regulating adaptive responses to stresses associated with the host environment and drug treatment. Here we review the TA families encoded in Mtb, discuss the duplication of TA loci in Mtb, regulatory mechanism of TA loci, and phenotypic heterogeneity and pathogenesis.

Russian Doll Genes and Complex Chromosome Rearrangements in Oxytricha trifallax

PubMed Central

Braun, Jasper; Nabergall, Lukas; Neme, Rafik; Landweber, Laura F.; Saito, Masahico; Jonoska, Nataša

2018-01-01

Ciliates have two different types of nuclei per cell, with one acting as a somatic, transcriptionally active nucleus (macronucleus; abbr. MAC) and another serving as a germline nucleus (micronucleus; abbr. MIC). Furthermore, Oxytricha trifallax undergoes extensive genome rearrangements during sexual conjugation and post-zygotic development of daughter cells. These rearrangements are necessary because the precursor MIC loci are often both fragmented and scrambled, with respect to the corresponding MAC loci. Such genome architectures are remarkably tolerant of encrypted MIC loci, because RNA-guided processes during MAC development reorganize the gene fragments in the correct order to resemble the parental MAC sequence. Here, we describe the germline organization of several nested and highly scrambled genes in Oxytricha trifallax. These include cases with multiple layers of nesting, plus highly interleaved or tangled precursor loci that appear to deviate from previously described patterns. We present mathematical methods to measure the degree of nesting between precursor MIC loci, and revisit a method for a mathematical description of scrambling. After applying these methods to the chromosome rearrangement maps of O. trifallax we describe cases of nested arrangements with up to five layers of embedded genes, as well as the most scrambled loci in O. trifallax. PMID:29545465

Human minisatellite alleles detectable only after PCR amplification.

PubMed

Armour, J A; Crosier, M; Jeffreys, A J

1992-01-01

We present evidence that a proportion of alleles at two human minisatellite loci is undetected by standard Southern blot hybridization. In each case the missing allele(s) can be identified after PCR amplification and correspond to tandem arrays too short to detect by hybridization. At one locus, there is only one undetected allele (population frequency 0.3), which contains just three repeat units. At the second locus, there are at least five undetected alleles (total population frequency 0.9) containing 60-120 repeats; they are not detected because these tandem repeats give very poor signals when used as a probe in standard Southern blot hybridization, and also cross-hybridize with other sequences in the genome. Under these circumstances only signals from the longest tandemly repeated alleles are detectable above the nonspecific background. The structures of these loci have been compared in human and primate DNA, and at one locus the short human allele containing three repeat units is shown to be an intermediate state in the expansion of a monomeric precursor allele in primates to high copy number in the longer human arrays. We discuss the implications of such loci for studies of human populations, minisatellite isolation by cloning, and the evolution of highly variable tandem arrays.

Single-trait and multi-trait genome-wide association analyses identify novel loci for blood pressure in African-ancestry populations

PubMed Central

Liang, Jingjing; Le, Thu H.; Edwards, Digna R. Velez; Tayo, Bamidele O.; Gaulton, Kyle J.; Lu, Yingchang; Jensen, Richard A.; Chen, Guanjie; Schwander, Karen; McKenzie, Colin A.; Fox, Ervin; Nalls, Michael A.; Young, J. Hunter; Lane, Jacqueline M.; Zhou, Jie; Tang, Hua; Fornage, Myriam; Musani, Solomon K.; Wang, Heming; Forrester, Terrence; Chu, Pei-Lun; Evans, Michele K.; Morrison, Alanna C.; Martin, Lisa W.; Wiggins, Kerri L.; Hui, Qin; Zhao, Wei; Jackson, Rebecca D.; Faul, Jessica D.; Reiner, Alex P.; Bray, Michael; Denny, Joshua C.; Mosley, Thomas H.; Palmas, Walter; Guo, Xiuqing; Polak, Joseph F.; Taylor, Ken D.; Boerwinkle, Eric; Bottinger, Erwin P.; Liu, Kiang; Risch, Neil; Hunt, Steven C.; Kooperberg, Charles; Zonderman, Alan B.; Becker, Diane M.; Cai, Jianwen; Loos, Ruth J. F.; Psaty, Bruce M.; Weir, David R.; Kardia, Sharon L. R.; Arnett, Donna K.; Won, Sungho; Edwards, Todd L.; Redline, Susan; Cooper, Richard S.; Rao, D. C.; Rotimi, Charles; Levy, Daniel; Chakravarti, Aravinda

2017-01-01

Hypertension is a leading cause of global disease, mortality, and disability. While individuals of African descent suffer a disproportionate burden of hypertension and its complications, they have been underrepresented in genetic studies. To identify novel susceptibility loci for blood pressure and hypertension in people of African ancestry, we performed both single and multiple-trait genome-wide association analyses. We analyzed 21 genome-wide association studies comprised of 31,968 individuals of African ancestry, and validated our results with additional 54,395 individuals from multi-ethnic studies. These analyses identified nine loci with eleven independent variants which reached genome-wide significance (P < 1.25×10−8) for either systolic and diastolic blood pressure, hypertension, or for combined traits. Single-trait analyses identified two loci (TARID/TCF21 and LLPH/TMBIM4) and multiple-trait analyses identified one novel locus (FRMD3) for blood pressure. At these three loci, as well as at GRP20/CDH17, associated variants had alleles common only in African-ancestry populations. Functional annotation showed enrichment for genes expressed in immune and kidney cells, as well as in heart and vascular cells/tissues. Experiments driven by these findings and using angiotensin-II induced hypertension in mice showed altered kidney mRNA expression of six genes, suggesting their potential role in hypertension. Our study provides new evidence for genes related to hypertension susceptibility, and the need to study African-ancestry populations in order to identify biologic factors contributing to hypertension. PMID:28498854

From genome-wide to candidate gene: an investigation of variation at the major histocompatibility complex in common bottlenose dolphins exposed to harmful algal blooms.

PubMed

Cammen, Kristina M; Wilcox, Lynsey A; Rosel, Patricia E; Wells, Randall S; Read, Andrew J

2015-02-01

The role the major histocompatibility complex (MHC) plays in response to exposure to environmental toxins is relatively poorly understood, particularly in comparison to its well-described role in pathogen immunity. We investigated associations between MHC diversity and resistance to brevetoxins in common bottlenose dolphins (Tursiops truncatus). A previous genome-wide association study investigating an apparent difference in harmful algal bloom (HAB) resistance among dolphin populations in the Gulf of Mexico identified genetic variation associated with survival in close genomic proximity to multiple MHC class II loci. Here, we characterized genetic variation at DQA, DQB, DRA, and DRB loci in dolphins from central-west Florida and the Florida Panhandle, including dolphins that died during HABs and dolphins presumed to have survived HAB exposure. We found that DRB and DQB exhibited patterns of genetic differentiation among geographic regions that differed from neutral microsatellite loci. In addition, genetic differentiation at DRB across multiple pairwise comparisons of live and dead dolphins was greater than differentiation observed at neutral loci. Our findings at these MHC loci did not approach the strength of association with survival previously described for a nearby genetic variant. However, the results provide evidence that selective pressures at the MHC vary among dolphin populations that differ in the frequency of HAB exposure and that the overall composition of DRB variants differs between dolphin survivors and non-survivors of HABs. These results may suggest a potential role of MHC diversity in variable survival of bottlenose dolphins exposed to HABs.

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

PubMed Central

Milano, Elizabeth R.; Lowry, David B.; Juenger, Thomas E.

2016-01-01

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mapping population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes. PMID:27613751

Genome-wide association studies for multiple diseases of the German Shepherd Dog

PubMed Central

Tsai, Kate L.; Noorai, Rooksana E.; Starr-Moss, Alison N.; Quignon, Pascale; Rinz, Caitlin J.; Ostrander, Elaine A.; Steiner, Jörg M.; Murphy, Keith E.

2012-01-01

The German Shepherd Dog (GSD) is a popular working and companion breed for which over 50 hereditary diseases have been documented. Herein, SNP profiles for 197 GSDs were generated using the Affymetrix v2 canine SNP array for a genome-wide association study to identify loci associated with four diseases: pituitary dwarfism, degenerative myelopathy (DM), congenital megaesophagus (ME), and pancreatic acinar atrophy (PAA). A locus on Chr 9 is strongly associated with pituitary dwarfism and is proximal to a plausible candidate gene, LHX3. Results for DM confirm a major locus encompassing SOD1, in which an associated point mutation was previously identified, but do not suggest modifier loci. Several SNPs on Chr 12 are associated with ME and a 4.7 Mb haplotype block is present in affected dogs. Analysis of additional ME cases for a SNP within the haplotype provides further support for this association. Results for PAA indicate more complex genetic underpinnings. Several regions on multiple chromosomes reach genome-wide significance. However, no major locus is apparent and only two associated haplotype blocks, on Chrs 7 and 12 are observed. These data suggest that PAA may be governed by multiple loci with small effects, or it may be a heterogeneous disorder. PMID:22105877

Identification of rRNA gene loci in the wild mouse (Mus musculus molossinus) captured at Hachioji, Tokyo.

PubMed

Ito, Tsuyoshi; Osawa, Susumu; Shibata, Hideshi; Kanda, Naotoshi

2007-12-01

Mus musculus (M. m.) molossinus has been considered an independent subspecies of Mus musculus. To elucidate the evolutional origin of this subspecies, we carried out double-color FISH using 18s-28s ribosomal DNA and mouse chromosome paint probes. Among eleven rDNA loci detected, five loci on chromosomes 12, 15, 16, 18 and 19 were common to both Mus musculus (M. m.) musculus and M. m. molossinus and the other six loci, on chromosomes 1, 5, 10, 11, 13 and 17, were characteristic in M. m. molossinus. As M. m. molossinus is thought to originate from a hybrid between ancestral colonies of M. m. musculus and Mus musculus castaneus, we supposed that these six rDNA loci might have evolved after geographical isolation of the ancestral hybrid animals from M. m. musculus and M. m. castaneus.

Three sympatric clusters of the malaria vector Anopheles culicifacies E (Diptera: Culicidae) detected in Sri Lanka.

PubMed

Harischandra, Iresha Nilmini; Dassanayake, Ranil Samantha; De Silva, Bambaranda Gammacharige Don Nissanka Kolitha

2016-01-04

The disease re-emergence threat from the major malaria vector in Sri Lanka, Anopheles culicifacies, is currently increasing. To predict malaria vector dynamics, knowledge of population genetics and gene flow is required, but this information is unavailable for Sri Lanka. This study was carried out to determine the population structure of An. culicifacies E in Sri Lanka. Eight microsatellite markers were used to examine An. culicifacies E collected from six sites in Sri Lanka during 2010-2012. Standard population genetic tests and analyses, genetic differentiation, Hardy-Weinberg equilibrium, linkage disequilibrium, Bayesian cluster analysis, AMOVA, SAMOVA and isolation-by-distance were conducted using five polymorphic loci. Five microsatellite loci were highly polymorphic with high allelic richness. Hardy-Weinberg Equilibrium (HWE) was significantly rejected for four loci with positive F(IS) values in the pooled population (p < 0.0100). Three loci showed high deviations in all sites except Kataragama, which was in agreement with HWE for all loci except one locus (p < 0.0016). Observed heterozygosity was less than the expected values for all sites except Kataragama, where reported negative F(IS) values indicated a heterozygosity excess. Genetic differentiation was observed for all sampling site pairs and was not supported by the isolation by distance model. Bayesian clustering analysis identified the presence of three sympatric clusters (gene pools) in the studied population. Significant genetic differentiation was detected in cluster pairs with low gene flow and isolation by distance was not detected between clusters. Furthermore, the results suggested the presence of a barrier to gene flow that divided the populations into two parts with the central hill region of Sri Lanka as the dividing line. Three sympatric clusters were detected among An. culicifacies E specimens isolated in Sri Lanka. There was no effect of geographic distance on genetic differentiation and the central mountain ranges in Sri Lanka appeared to be a barrier to gene flow.

Genome-wide association analysis in primary sclerosing cholangitis and ulcerative colitis identifies risk loci at GPR35 and TCF4.

PubMed

Ellinghaus, David; Folseraas, Trine; Holm, Kristian; Ellinghaus, Eva; Melum, Espen; Balschun, Tobias; Laerdahl, Jon K; Shiryaev, Alexey; Gotthardt, Daniel N; Weismüller, Tobias J; Schramm, Christoph; Wittig, Michael; Bergquist, Annika; Björnsson, Einar; Marschall, Hanns-Ulrich; Vatn, Morten; Teufel, Andreas; Rust, Christian; Gieger, Christian; Wichmann, H-Erich; Runz, Heiko; Sterneck, Martina; Rupp, Christian; Braun, Felix; Weersma, Rinse K; Wijmenga, Cisca; Ponsioen, Cyriel Y; Mathew, Christopher G; Rutgeerts, Paul; Vermeire, Séverine; Schrumpf, Erik; Hov, Johannes R; Manns, Michael P; Boberg, Kirsten M; Schreiber, Stefan; Franke, Andre; Karlsen, Tom H

2013-09-01

Approximately 60%-80% of patients with primary sclerosing cholangitis (PSC) have concurrent ulcerative colitis (UC). Previous genome-wide association studies (GWAS) in PSC have detected a number of susceptibility loci that also show associations in UC and other immune-mediated diseases. We aimed to systematically compare genetic associations in PSC with genotype data in UC patients with the aim of detecting new susceptibility loci for PSC. We performed combined analyses of GWAS for PSC and UC comprising 392 PSC cases, 987 UC cases, and 2,977 controls and followed up top association signals in an additional 1,012 PSC cases, 4,444 UC cases, and 11,659 controls. We discovered novel genome-wide significant associations with PSC at 2q37 [rs3749171 at G-protein-coupled receptor 35 (GPR35); P = 3.0 × 10(-9) in the overall study population, combined odds ratio [OR] and 95% confidence interval [CI] of 1.39 (1.24-1.55)] and at 18q21 [rs1452787 at transcription factor 4 (TCF4); P = 2.61 × 10(-8) , OR (95% CI) = 0.75 (0.68-0.83)]. In addition, several suggestive PSC associations were detected. The GPR35 rs3749171 is a missense single nucleotide polymorphism resulting in a shift from threonine to methionine. Structural modeling showed that rs3749171 is located in the third transmembrane helix of GPR35 and could possibly alter efficiency of signaling through the GPR35 receptor. By refining the analysis of a PSC GWAS by parallel assessments in a UC GWAS, we were able to detect two novel risk loci at genome-wide significance levels. GPR35 shows associations in both UC and PSC, whereas TCF4 represents a PSC risk locus not associated with UC. Both loci may represent previously unexplored aspects of PSC pathogenesis. Copyright © 2012 American Association for the Study of Liver Diseases.

SUSCEPTIBILITY LOCI FOR UMBILICAL HERNIA IN SWINE DETECTED BY GENOME-WIDE ASSOCIATION.

PubMed

Liao, X J; Lia, L; Zhang, Z Y; Long, Y; Yang, B; Ruan, G R; Su, Y; Ai, H S; Zhang, W C; Deng, W Y; Xiao, S J; Ren, J; Ding, N S; Huang, L S

2015-10-01

Umbilical hernia (UH) is a complex disorder caused by both genetic and environmental factors. UH brings animal welfare problems and severe economic loss to the pig industry. Until now, the genetic basis of UH is poorly understood. The high-density 60K porcine SNP array enables the rapid application of genome-wide association study (GWAS) to identify genetic loci for phenotypic traits at genome wide scale in pigs. The objective of this research was to identify susceptibility loci for swine umbilical hernia using the GWAS approach. We genotyped 478 piglets from 142 families representing three Western commercial breeds with the Illumina PorcineSNP60 BeadChip. Then significant SNPs were detected by GWAS using ROADTRIPS (Robust Association-Detection Test for Related Individuals with Population Substructure) software base on a Bonferroni corrected threshold (P = 1.67E-06) or suggestive threshold (P = 3.34E-05) and false discovery rate (FDR = 0.05). After quality control, 29,924 qualified SNPs and 472 piglets were used for GWAS. Two suggestive loci predisposing to pig UH were identified at 44.25MB on SSC2 (rs81358018, P = 3.34E-06, FDR = 0.049933) and at 45.90MB on SSC17 (rs81479278, P = 3.30E-06, FDR = 0.049933) in Duroc population, respectively. And no SNP was detected to be associated with pig UH at significant level in neither Landrace nor Large White population. Furthermore, we carried out a meta-analysis in the combined pure-breed population containing all the 472 piglets. rs81479278 (P = 1.16E-06, FDR = 0.022475) was identified to associate with pig UH at genome-wide significant level. SRC was characterized as plausible candidate gene for susceptibility to pig UH according to its genomic position and biological functions. To our knowledge, this study gives the first description of GWAS identifying susceptibility loci for umbilical hernia in pigs. Our findings provide deeper insights to the genetic architecture of umbilical hernia in pigs.

Accurate and fast multiple-testing correction in eQTL studies.

PubMed

Sul, Jae Hoon; Raj, Towfique; de Jong, Simone; de Bakker, Paul I W; Raychaudhuri, Soumya; Ophoff, Roel A; Stranger, Barbara E; Eskin, Eleazar; Han, Buhm

2015-06-04

In studies of expression quantitative trait loci (eQTLs), it is of increasing interest to identify eGenes, the genes whose expression levels are associated with variation at a particular genetic variant. Detecting eGenes is important for follow-up analyses and prioritization because genes are the main entities in biological processes. To detect eGenes, one typically focuses on the genetic variant with the minimum p value among all variants in cis with a gene and corrects for multiple testing to obtain a gene-level p value. For performing multiple-testing correction, a permutation test is widely used. Because of growing sample sizes of eQTL studies, however, the permutation test has become a computational bottleneck in eQTL studies. In this paper, we propose an efficient approach for correcting for multiple testing and assess eGene p values by utilizing a multivariate normal distribution. Our approach properly takes into account the linkage-disequilibrium structure among variants, and its time complexity is independent of sample size. By applying our small-sample correction techniques, our method achieves high accuracy in both small and large studies. We have shown that our method consistently produces extremely accurate p values (accuracy > 98%) for three human eQTL datasets with different sample sizes and SNP densities: the Genotype-Tissue Expression pilot dataset, the multi-region brain dataset, and the HapMap 3 dataset. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

The association between HLA DQ genetic polymorphism and type 1 diabetes in a case-parent study conducted in an admixed population.

PubMed

Mimbacas, Adriana; Pérez-Bravo, Fernando; Santos, Jose Luis; Pisciottano, Carmen; Grignola, Rosario; Javiel, Gerardo; Jorge, Ana Maria; Cardoso, Horacio

2004-01-01

Susceptibility to the type 1 diabetes is genetically controlled and there is an increased risk associated with the presence of some specific alleles of the human leukocyte antigens class II loci (DQA1 and DQB1 genes). The purpose of this study is to evaluate the association between type 1 diabetes and HLA DQ alleles using case-parents trios in the admixed population of Uruguay composed by a mixture of Caucasian, Amerindian and Negroid populations. DQA1 and DQB1 genotyping was performed by polimerase chain reaction followed by oligospecific probes hybridization in 51 case-parents trios. The transmission disequilibrium test was used for detecting differential transmission in the HLA DQ loci. DQB1*0302 was the only allele for which preferential transmission is suggested (probability of transmission = 67.56%; exact p-value TDT = 0.047 uncorrected for multiple comparisons). DQA1*0301 allele showed a trend for preferential transmission without achieving statistical significance. This result would confirm the hypothesis previously advanced in a case-control study. Therefore, DQB1*0302 allele could be considered as the most important susceptibility allele for developing type 1 diabetes in Uruguay population.

Genomic signatures of positive selection in humans and the limits of outlier approaches.

PubMed

Kelley, Joanna L; Madeoy, Jennifer; Calhoun, John C; Swanson, Willie; Akey, Joshua M

2006-08-01

Identifying regions of the human genome that have been targets of positive selection will provide important insights into recent human evolutionary history and may facilitate the search for complex disease genes. However, the confounding effects of population demographic history and selection on patterns of genetic variation complicate inferences of selection when a small number of loci are studied. To this end, identifying outlier loci from empirical genome-wide distributions of genetic variation is a promising strategy to detect targets of selection. Here, we evaluate the power and efficiency of a simple outlier approach and describe a genome-wide scan for positive selection using a dense catalog of 1.58 million SNPs that were genotyped in three human populations. In total, we analyzed 14,589 genes, 385 of which possess patterns of genetic variation consistent with the hypothesis of positive selection. Furthermore, several extended genomic regions were found, spanning >500 kb, that contained multiple contiguous candidate selection genes. More generally, these data provide important practical insights into the limits of outlier approaches in genome-wide scans for selection, provide strong candidate selection genes to study in greater detail, and may have important implications for disease related research.

Pooled genome wide association detects association upstream of FCRL3 with Graves' disease.

PubMed

Khong, Jwu Jin; Burdon, Kathryn P; Lu, Yi; Laurie, Kate; Leonardos, Lefta; Baird, Paul N; Sahebjada, Srujana; Walsh, John P; Gajdatsy, Adam; Ebeling, Peter R; Hamblin, Peter Shane; Wong, Rosemary; Forehan, Simon P; Fourlanos, Spiros; Roberts, Anthony P; Doogue, Matthew; Selva, Dinesh; Montgomery, Grant W; Macgregor, Stuart; Craig, Jamie E

2016-11-18

Graves' disease is an autoimmune thyroid disease of complex inheritance. Multiple genetic susceptibility loci are thought to be involved in Graves' disease and it is therefore likely that these can be identified by genome wide association studies. This study aimed to determine if a genome wide association study, using a pooling methodology, could detect genomic loci associated with Graves' disease. Nineteen of the top ranking single nucleotide polymorphisms including HLA-DQA1 and C6orf10, were clustered within the Major Histo-compatibility Complex region on chromosome 6p21, with rs1613056 reaching genome wide significance (p = 5 × 10 -8 ). Technical validation of top ranking non-Major Histo-compatablity complex single nucleotide polymorphisms with individual genotyping in the discovery cohort revealed four single nucleotide polymorphisms with p ≤ 10 -4 . Rs17676303 on chromosome 1q23.1, located upstream of FCRL3, showed evidence of association with Graves' disease across the discovery, replication and combined cohorts. A second single nucleotide polymorphism rs9644119 downstream of DPYSL2 showed some evidence of association supported by finding in the replication cohort that warrants further study. Pooled genome wide association study identified a genetic variant upstream of FCRL3 as a susceptibility locus for Graves' disease in addition to those identified in the Major Histo-compatibility Complex. A second locus downstream of DPYSL2 is potentially a novel genetic variant in Graves' disease that requires further confirmation.

A genome-wide scan for signatures of directional selection in domesticated pigs.

PubMed

Moon, Sunjin; Kim, Tae-Hun; Lee, Kyung-Tai; Kwak, Woori; Lee, Taeheon; Lee, Si-Woo; Kim, Myung-Jick; Cho, Kyuho; Kim, Namshin; Chung, Won-Hyong; Sung, Samsun; Park, Taesung; Cho, Seoae; Groenen, Martien Am; Nielsen, Rasmus; Kim, Yuseob; Kim, Heebal

2015-02-25

Animal domestication involved drastic phenotypic changes driven by strong artificial selection and also resulted in new populations of breeds, established by humans. This study aims to identify genes that show evidence of recent artificial selection during pig domestication. Whole-genome resequencing of 30 individual pigs from domesticated breeds, Landrace and Yorkshire, and 10 Asian wild boars at ~16-fold coverage was performed resulting in over 4.3 million SNPs for 19,990 genes. We constructed a comprehensive genome map of directional selection by detecting selective sweeps using an F ST-based approach that detects directional selection in lineages leading to the domesticated breeds and using a haplotype-based test that detects ongoing selective sweeps within the breeds. We show that candidate genes under selection are significantly enriched for loci implicated in quantitative traits important to pig reproduction and production. The candidate gene with the strongest signals of directional selection belongs to group III of the metabolomics glutamate receptors, known to affect brain functions associated with eating behavior, suggesting that loci under strong selection include loci involved in behaviorial traits in domesticated pigs including tameness. We show that a significant proportion of selection signatures coincide with loci that were previously inferred to affect phenotypic variation in pigs. We further identify functional enrichment related to behavior, such as signal transduction and neuronal activities, for those targets of selection during domestication in pigs.

Genome-wide mapping in a house mouse hybrid zone reveals hybrid sterility loci and Dobzhansky-Muller interactions

PubMed Central

Turner, Leslie M; Harr, Bettina

2014-01-01

Mapping hybrid defects in contact zones between incipient species can identify genomic regions contributing to reproductive isolation and reveal genetic mechanisms of speciation. The house mouse features a rare combination of sophisticated genetic tools and natural hybrid zones between subspecies. Male hybrids often show reduced fertility, a common reproductive barrier between incipient species. Laboratory crosses have identified sterility loci, but each encompasses hundreds of genes. We map genetic determinants of testis weight and testis gene expression using offspring of mice captured in a hybrid zone between M. musculus musculus and M. m. domesticus. Many generations of admixture enables high-resolution mapping of loci contributing to these sterility-related phenotypes. We identify complex interactions among sterility loci, suggesting multiple, non-independent genetic incompatibilities contribute to barriers to gene flow in the hybrid zone. DOI: http://dx.doi.org/10.7554/eLife.02504.001 PMID:25487987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farahani, Poupak; Chiu, Sally; Bowlus, Christopher L.

Obesity is a complex disease. To date, over 100 chromosomal loci for body weight, body fat, regional white adipose tissue weight, and other obesity-related traits have been identified in humans and in animal models. For most loci, the underlying genes are not yet identified; some of these chromosomal loci will be alleles of known obesity genes, whereas many will represent alleles of unknown genes. Microarray analysis allows simultaneous multiple gene and pathway discovery. cDNA and oligonucleotide arrays are commonly used to identify differentially expressed genes by surveys of large numbers of known and unnamed genes. Two papers previously identified genesmore » differentially expressed in adipose tissue of mouse models of obesity and diabetes by analysis of hybridization to Affymetrix oligonucleotide chips.« less

Population-scale whole genome sequencing identifies 271 highly polymorphic short tandem repeats from Japanese population.

PubMed

Hirata, Satoshi; Kojima, Kaname; Misawa, Kazuharu; Gervais, Olivier; Kawai, Yosuke; Nagasaki, Masao

2018-05-01

Forensic DNA typing is widely used to identify missing persons and plays a central role in forensic profiling. DNA typing usually uses capillary electrophoresis fragment analysis of PCR amplification products to detect the length of short tandem repeat (STR) markers. Here, we analyzed whole genome data from 1,070 Japanese individuals generated using massively parallel short-read sequencing of 162 paired-end bases. We have analyzed 843,473 STR loci with two to six basepair repeat units and cataloged highly polymorphic STR loci in the Japanese population. To evaluate the performance of the cataloged STR loci, we compared 23 STR loci, widely used in forensic DNA typing, with capillary electrophoresis based STR genotyping results in the Japanese population. Seventeen loci had high correlations and high call rates. The other six loci had low call rates or low correlations due to either the limitations of short-read sequencing technology, the bioinformatics tool used, or the complexity of repeat patterns. With these analyses, we have also purified the suitable 218 STR loci with four basepair repeat units and 53 loci with five basepair repeat units both for short read sequencing and PCR based technologies, which would be candidates to the actual forensic DNA typing in Japanese population.

Identification and validation of quantitative trait loci for seed yield, oil and protein contents in two recombinant inbred line populations of soybean.

PubMed

Wang, Xianzhi; Jiang, Guo-Liang; Green, Marci; Scott, Roy A; Song, Qijian; Hyten, David L; Cregan, Perry B

2014-10-01

Soybean seeds contain high levels of oil and protein, and are the important sources of vegetable oil and plant protein for human consumption and livestock feed. Increased seed yield, oil and protein contents are the main objectives of soybean breeding. The objectives of this study were to identify and validate quantitative trait loci (QTLs) associated with seed yield, oil and protein contents in two recombinant inbred line populations, and to evaluate the consistency of QTLs across different environments, studies and genetic backgrounds. Both the mapping population (SD02-4-59 × A02-381100) and validation population (SD02-911 × SD00-1501) were phenotyped for the three traits in multiple environments. Genetic analysis indicated that oil and protein contents showed high heritabilities while yield exhibited a lower heritability in both populations. Based on a linkage map constructed previously with the mapping population and using composite interval mapping and/or interval mapping analysis, 12 QTLs for seed yield, 16 QTLs for oil content and 11 QTLs for protein content were consistently detected in multiple environments and/or the average data over all environments. Of the QTLs detected in the mapping population, five QTLs for seed yield, eight QTLs for oil content and five QTLs for protein content were confirmed in the validation population by single marker analysis in at least one environment and the average data and by ANOVA over all environments. Eight of these validated QTLs were newly identified. Compared with the other studies, seven QTLs for seed yield, eight QTLs for oil content and nine QTLs for protein content further verified the previously reported QTLs. These QTLs will be useful for breeding higher yield and better quality cultivars, and help effectively and efficiently improve yield potential and nutritional quality in soybean.

Young inversion with multiple linked QTLs under selection in a hybrid zone.

PubMed

Lee, Cheng-Ruei; Wang, Baosheng; Mojica, Julius P; Mandáková, Terezie; Prasad, Kasavajhala V S K; Goicoechea, Jose Luis; Perera, Nadeesha; Hellsten, Uffe; Hundley, Hope N; Johnson, Jenifer; Grimwood, Jane; Barry, Kerrie; Fairclough, Stephen; Jenkins, Jerry W; Yu, Yeisoo; Kudrna, Dave; Zhang, Jianwei; Talag, Jayson; Golser, Wolfgang; Ghattas, Kathryn; Schranz, M Eric; Wing, Rod; Lysak, Martin A; Schmutz, Jeremy; Rokhsar, Daniel S; Mitchell-Olds, Thomas

2017-04-03

Fixed chromosomal inversions can reduce gene flow and promote speciation in two ways: by suppressing recombination and by carrying locally favoured alleles at multiple loci. However, it is unknown whether favoured mutations slowly accumulate on older inversions or if young inversions spread because they capture pre-existing adaptive quantitative trait loci (QTLs). By genetic mapping, chromosome painting and genome sequencing, we have identified a major inversion controlling ecologically important traits in Boechera stricta. The inversion arose since the last glaciation and subsequently reached local high frequency in a hybrid speciation zone. Furthermore, the inversion shows signs of positive directional selection. To test whether the inversion could have captured existing, linked QTLs, we crossed standard, collinear haplotypes from the hybrid zone and found multiple linked phenology QTLs within the inversion region. These findings provide the first direct evidence that linked, locally adapted QTLs may be captured by young inversions during incipient speciation.

Golden Gate Assembly of CRISPR gRNA expression array for simultaneously targeting multiple genes.

PubMed

Vad-Nielsen, Johan; Lin, Lin; Bolund, Lars; Nielsen, Anders Lade; Luo, Yonglun

2016-11-01

The engineered CRISPR/Cas9 technology has developed as the most efficient and broadly used genome editing tool. However, simultaneously targeting multiple genes (or genomic loci) in the same individual cells using CRISPR/Cas9 remain one technical challenge. In this article, we have developed a Golden Gate Assembly method for the generation of CRISPR gRNA expression arrays, thus enabling simultaneous gene targeting. Using this method, the generation of CRISPR gRNA expression array can be accomplished in 2 weeks, and contains up to 30 gRNA expression cassettes. We demonstrated in the study that simultaneously targeting 10 genomic loci or simultaneously inhibition of multiple endogenous genes could be achieved using the multiplexed gRNA expression array vector in human cells. The complete set of plasmids is available through the non-profit plasmid repository Addgene.

Young inversion with multiple linked QTLs under selection in a hybrid zone

PubMed Central

Lee, Cheng-Ruei; Wang, Baosheng; Mojica, Julius; Mandáková, Terezie; Prasad, Kasavajhala V. S. K.; Goicoechea, Jose Luis; Perera, Nadeesha; Hellsten, Uffe; Hundley, Hope N.; Johnson, Jenifer; Grimwood, Jane; Barry, Kerrie; Fairclough, Stephen; Jenkins, Jerry W.; Yu, Yeisoo; Kudrna, Dave; Zhang, Jianwei; Talag, Jayson; Golser, Wolfgang; Ghattas, Katherine; Schranz, M. Eric; Wing, Rod; Lysak, Martin A.; Schmutz, Jeremy; Rokhsar, Daniel S.; Mitchell-Olds, Thomas

2017-01-01

Fixed chromosomal inversions can reduce gene flow and promote speciation in two ways: by suppressing recombination and by carrying locally favored alleles at multiple loci. However, it is unknown whether favored mutations slowly accumulate on older inversions or if young inversions spread because they capture preexisting adaptive Quantitative Trait Loci (QTLs). By genetic mapping, chromosome painting and genome sequencing we have identified a major inversion controlling ecologically important traits in Boechera stricta. The inversion arose since the last glaciation and subsequently reached local high frequency in a hybrid speciation zone. Furthermore, the inversion shows signs of positive directional selection. To test whether the inversion could have captured existing, linked QTLs, we crossed standard, collinear haplotypes from the hybrid zone and found multiple linked phenology QTLs within the inversion region. These findings provide the first direct evidence that linked, locally adapted QTLs may be captured by young inversions during incipient speciation. PMID:28812690

CoLIde

PubMed Central

Mohorianu, Irina; Stocks, Matthew Benedict; Wood, John; Dalmay, Tamas; Moulton, Vincent

2013-01-01

Small RNAs (sRNAs) are 20–25 nt non-coding RNAs that act as guides for the highly sequence-specific regulatory mechanism known as RNA silencing. Due to the recent increase in sequencing depth, a highly complex and diverse population of sRNAs in both plants and animals has been revealed. However, the exponential increase in sequencing data has also made the identification of individual sRNA transcripts corresponding to biological units (sRNA loci) more challenging when based exclusively on the genomic location of the constituent sRNAs, hindering existing approaches to identify sRNA loci.   To infer the location of significant biological units, we propose an approach for sRNA loci detection called CoLIde (Co-expression based sRNA Loci Identification) that combines genomic location with the analysis of other information such as variation in expression levels (expression pattern) and size class distribution. For CoLIde, we define a locus as a union of regions sharing the same pattern and located in close proximity on the genome. Biological relevance, detected through the analysis of size class distribution, is also calculated for each locus. CoLIde can be applied on ordered (e.g., time-dependent) or un-ordered (e.g., organ, mutant) series of samples both with or without biological/technical replicates. The method reliably identifies known types of loci and shows improved performance on sequencing data from both plants (e.g., A. thaliana, S. lycopersicum) and animals (e.g., D. melanogaster) when compared with existing locus detection techniques. CoLIde is available for use within the UEA Small RNA Workbench which can be downloaded from: http://srna-workbench.cmp.uea.ac.uk. PMID:23851377

Hereditary Melanoma: Update on Syndromes and Management - Genetics of familial atypical multiple mole melanoma syndrome

PubMed Central

Soura, E.; Eliades, P.; Shannon, K.; Stratigos, A.; Tsao, H.

2015-01-01

Malignant melanoma is considered the most lethal skin cancer if not detected and treated at its early stages. About 10% of melanoma patients report a family history of melanoma; however, individuals with features of true hereditary melanoma (i.e. unilateral lineage, multi-generational, multiple primary lesions, and early onset of disease) are in fact quite rare. Although many new loci have been implicated in hereditary melanoma, CDKN2A mutations remain the most common. Familial melanoma in the presence of multiple atypical nevi should raise suspicion for a germline CDKN2A mutation. Such patients have a high risk of developing multiple primary melanomas and internal organ malignancies especially pancreatic cancer; thus, a multidisciplinary approach is necessary in many cases. The value of dermoscopy examination and total body photography performed at regular intervals has been suggested by a number of studies, and should therefore be considered for these patients and their first degree relatives. In addition, genetic counseling with the possibility of testing can be a valuable adjunct for familial melanoma patients. But, this must be performed with care and only by qualified individuals trained in cancer risk analysis. PMID:26892650

Epigenetics of drought-induced trans-generational plasticity: consequences for range limit development

PubMed Central

Alsdurf, Jacob; Anderson, Cynthia; Siemens, David H.

2016-01-01

Genetic variation gives plants the potential to adapt to stressful environments that often exist beyond their geographic range limits. However, various genetic, physiological or developmental constraints might prevent the process of adaptation. Alternatively, environmentally induced epigenetic changes might sustain populations for several generations in stressful areas across range boundaries, but previous work on Boechera stricta, an upland mustard closely related to Arabidopsis, documented a drought-induced trans-generational plastic trade-off that could contribute to range limit development. Offspring of parents who were drought treated had higher drought tolerance, but lower levels of glucosinolate toxins. Both drought tolerance and defence are thought to be needed to expand the range to lower elevations. Here, we used methylation-sensitive amplified fragment length polymorphisms to determine whether environmentally induced DNA methylation and thus epigenetics could be a mechanism involved in the observed trans-generational plastic trade-off. We compared 110 offspring from the same self-fertilizing lineages whose parents were exposed to experimental drought stress treatments in the laboratory. Using three primer combinations, 643 polymorphic epi-loci were detected. Discriminant function analysis (DFA) on the amount of methylation detected resulted in significant combinations of epi-loci that distinguished the parent drought treatments in the offspring. Principal component (PC) and univariate association analyses also detected the significant differences, even after controlling for lineage, planting flat, developmental differences and multiple testing. Univariate tests also indicated significant associations between the amount of methylation and drought tolerance or glucosinolate toxin concentration. One epi-locus that was implicated in DFA, PC and univariate association analysis may be directly involved in the trade-off because increased methylation at this site on the genome decreased drought tolerance, but increased glucosinolate concentration. PMID:26685218

A Pooled Sequencing Approach Identifies a Candidate Meiotic Driver in Drosophila

PubMed Central

Wei, Kevin H.-C.; Reddy, Hemakumar M.; Rathnam, Chandramouli; Lee, Jimin; Lin, Deanna; Ji, Shuqing; Mason, James M.; Clark, Andrew G.; Barbash, Daniel A.

2017-01-01

Meiotic drive occurs when a selfish element increases its transmission frequency above the Mendelian ratio by hijacking the asymmetric divisions of female meiosis. Meiotic drive causes genomic conflict and potentially has a major impact on genome evolution, but only a few drive loci of large effect have been described. New methods to reliably detect meiotic drive are therefore needed, particularly for discovering moderate-strength drivers that are likely to be more prevalent in natural populations than strong drivers. Here, we report an efficient method that uses sequencing of large pools of backcross (BC1) progeny to test for deviations from Mendelian segregation genome-wide with single-nucleotide polymorphisms (SNPs) that distinguish the parental strains. We show that meiotic drive can be detected by a characteristic pattern of decay in distortion of SNP frequencies, caused by recombination unlinking the driver from distal loci. We further show that control crosses allow allele-frequency distortion caused by meiotic drive to be distinguished from distortion resulting from developmental effects. We used this approach to test whether chromosomes with extreme telomere-length differences segregate at Mendelian ratios, as telomeric regions are a potential hotspot for meiotic drive due to their roles in meiotic segregation and multiple observations of high rates of telomere sequence evolution. Using four different pairings of long and short telomere strains, we find no evidence that extreme telomere-length variation causes meiotic drive in Drosophila. However, we identify one candidate meiotic driver in a centromere-linked region that shows an ∼8% increase in transmission frequency, corresponding to a ∼54:46 segregation ratio. Our results show that candidate meiotic drivers of moderate strength can be readily detected and localized in pools of BC1 progeny. PMID:28258181

Revealing the selection history of adaptive loci using genome-wide scans for selection: an example from domestic sheep.

PubMed

Rochus, Christina Marie; Tortereau, Flavie; Plisson-Petit, Florence; Restoux, Gwendal; Moreno-Romieux, Carole; Tosser-Klopp, Gwenola; Servin, Bertrand

2018-01-23

One of the approaches to detect genetics variants affecting fitness traits is to identify their surrounding genomic signatures of past selection. With established methods for detecting selection signatures and the current and future availability of large datasets, such studies should have the power to not only detect these signatures but also to infer their selective histories. Domesticated animals offer a powerful model for these approaches as they adapted rapidly to environmental and human-mediated constraints in a relatively short time. We investigated this question by studying a large dataset of 542 individuals from 27 domestic sheep populations raised in France, genotyped for more than 500,000 SNPs. Population structure analysis revealed that this set of populations harbour a large part of European sheep diversity in a small geographical area, offering a powerful model for the study of adaptation. Identification of extreme SNP and haplotype frequency differences between populations listed 126 genomic regions likely affected by selection. These signatures revealed selection at loci commonly identified as selection targets in many species ("selection hotspots") including ABCG2, LCORL/NCAPG, MSTN, and coat colour genes such as ASIP, MC1R, MITF, and TYRP1. For one of these regions (ABCG2, LCORL/NCAPG), we could propose a historical scenario leading to the introgression of an adaptive allele into a new genetic background. Among selection signatures, we found clear evidence for parallel selection events in different genetic backgrounds, most likely for different mutations. We confirmed this allelic heterogeneity in one case by resequencing the MC1R gene in three black-faced breeds. Our study illustrates how dense genetic data in multiple populations allows the deciphering of evolutionary history of populations and of their adaptive mutations.

Inheritance and Variation of Genomic DNA Methylation in Diploid and Triploid Pacific Oyster (Crassostrea gigas).

PubMed

Jiang, Qun; Li, Qi; Yu, Hong; Kong, Lingfeng

2016-02-01

DNA methylation is an important epigenetic mechanism that could be responsive to environmental changes indicating a potential role in natural selection and adaption. In order to evaluate an evolutionary role of DNA methylation, it is essential to first gain a better insight into inheritability. To address this question, this study investigated DNA methylation variation from parents to offspring in the Pacific oyster Crassostrea gigas using fluorescent-labeled methylation-sensitive amplified polymorphism (F-MSAP) analysis. Most of parental methylated loci were stably transmitted to offspring segregating following Medelian expectation. However, methylated loci deviated more often than non-methylated loci and offspring showed a few de novo methylated loci indicating DNA methylation changes from parents to offspring. Interestingly, some male-specific methylated loci were found in this study which might help to explore sex determination in oyster. Despite environmental stimuli, genomic stresses such as polyploidization also can induce methylation changes. This study also compared global DNA methylation level and individual methylated loci between diploid and triploid oysters. Results showed no difference in global methylation state but a few ploidy-specific loci were detected. DNA methylation variation during polyploidization was less than autonomous methylation variation from parents to offspring.

Expansion of 50 CAG/CTG repeats excluded in schizophrenia by application of a highly efficient approach using repeat expansion detection and a PCR screening set

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowen, T.; Guy, C.; Speight, G.

Studies of the transmission of schizophrenia in families with affected members in several generations have suggested that an expanded trinucleotide repeat mechanism may contribute to the genetic inheritance of this disorder. Using repeat expansion detection (RED), we and others have previously found that the distribution of CAG/CTG repeat size is larger in patients with schizophrenia than in controls. In an attempt to identify the specific expanded CAG/CTG locus or loci associated with schizophrenia, we have now used an approach based on a CAG/CTG PCR screening set combined with RED data. This has allowed us to minimize genotyping while excluding 43more » polymorphic autosomal loci and 7 X-chromosomal loci from the screening set as candidates for expansion in schizophrenia with a very high degree of confidence. 18 refs., 1 tab.« less

Detection of a variable number of ribosomal DNA loci by fluorescent in situ hybridization in Populus species.

PubMed

Prado, E A; Faivre-Rampant, P; Schneider, C; Darmency, M A

1996-10-01

Fluorescent in situ hybridization (FISH) was applied to related Populus species (2n = 19) in order to detect rDNA loci. An interspecific variability in the number of hybridization sites was revealed using as probe an homologous 25S clone from Populus deltoides. The application of image analysis methods to measure fluorescence intensity of the hybridization signals has enabled us to characterize major and minor loci in the 18S-5.8S-25S rDNA. We identified one pair of such rDNA clusters in Populus alba; two pairs, one major and one minor, in both Populus nigra and P. deltoides; and three pairs in Populus balsamifera, (two major and one minor) and Populus euroamericana (one major and two minor). FISH results are in agreement with those based on RFLP analysis. The pBG13 probe containing 5S sequence from flax detected two separate clusters corresponding to the two size classes of units that coexist within 5S rDNA of most Populus species. Key words : Populus spp., fluorescent in situ hybridization, FISH, rDNA variability, image analysis.

A principal component meta-analysis on multiple anthropometric traits identifies novel loci for body shape

PubMed Central

Ried, Janina S.; Jeff M., Janina; Chu, Audrey Y.; Bragg-Gresham, Jennifer L.; van Dongen, Jenny; Huffman, Jennifer E.; Ahluwalia, Tarunveer S.; Cadby, Gemma; Eklund, Niina; Eriksson, Joel; Esko, Tõnu; Feitosa, Mary F.; Goel, Anuj; Gorski, Mathias; Hayward, Caroline; Heard-Costa, Nancy L.; Jackson, Anne U.; Jokinen, Eero; Kanoni, Stavroula; Kristiansson, Kati; Kutalik, Zoltán; Lahti, Jari; Luan, Jian'an; Mägi, Reedik; Mahajan, Anubha; Mangino, Massimo; Medina-Gomez, Carolina; Monda, Keri L.; Nolte, Ilja M.; Pérusse, Louis; Prokopenko, Inga; Qi, Lu; Rose, Lynda M.; Salvi, Erika; Smith, Megan T.; Snieder, Harold; Stančáková, Alena; Ju Sung, Yun; Tachmazidou, Ioanna; Teumer, Alexander; Thorleifsson, Gudmar; van der Harst, Pim; Walker, Ryan W.; Wang, Sophie R.; Wild, Sarah H.; Willems, Sara M.; Wong, Andrew; Zhang, Weihua; Albrecht, Eva; Couto Alves, Alexessander; Bakker, Stephan J. L.; Barlassina, Cristina; Bartz, Traci M.; Beilby, John; Bellis, Claire; Bergman, Richard N.; Bergmann, Sven; Blangero, John; Blüher, Matthias; Boerwinkle, Eric; Bonnycastle, Lori L.; Bornstein, Stefan R.; Bruinenberg, Marcel; Campbell, Harry; Chen, Yii-Der Ida; Chiang, Charleston W. K.; Chines, Peter S.; Collins, Francis S; Cucca, Fracensco; Cupples, L Adrienne; D'Avila, Francesca; de Geus, Eco J .C.; Dedoussis, George; Dimitriou, Maria; Döring, Angela; Eriksson, Johan G.; Farmaki, Aliki-Eleni; Farrall, Martin; Ferreira, Teresa; Fischer, Krista; Forouhi, Nita G.; Friedrich, Nele; Gjesing, Anette Prior; Glorioso, Nicola; Graff, Mariaelisa; Grallert, Harald; Grarup, Niels; Gräßler, Jürgen; Grewal, Jagvir; Hamsten, Anders; Harder, Marie Neergaard; Hartman, Catharina A.; Hassinen, Maija; Hastie, Nicholas; Hattersley, Andrew Tym; Havulinna, Aki S.; Heliövaara, Markku; Hillege, Hans; Hofman, Albert; Holmen, Oddgeir; Homuth, Georg; Hottenga, Jouke-Jan; Hui, Jennie; Husemoen, Lise Lotte; Hysi, Pirro G.; Isaacs, Aaron; Ittermann, Till; Jalilzadeh, Shapour; James, Alan L.; Jørgensen, Torben; Jousilahti, Pekka; Jula, Antti; Marie Justesen, Johanne; Justice, Anne E.; Kähönen, Mika; Karaleftheri, Maria; Tee Khaw, Kay; Keinanen-Kiukaanniemi, Sirkka M.; Kinnunen, Leena; Knekt, Paul B.; Koistinen, Heikki A.; Kolcic, Ivana; Kooner, Ishminder K.; Koskinen, Seppo; Kovacs, Peter; Kyriakou, Theodosios; Laitinen, Tomi; Langenberg, Claudia; Lewin, Alexandra M.; Lichtner, Peter; Lindgren, Cecilia M.; Lindström, Jaana; Linneberg, Allan; Lorbeer, Roberto; Lorentzon, Mattias; Luben, Robert; Lyssenko, Valeriya; Männistö, Satu; Manunta, Paolo; Leach, Irene Mateo; McArdle, Wendy L.; Mcknight, Barbara; Mohlke, Karen L.; Mihailov, Evelin; Milani, Lili; Mills, Rebecca; Montasser, May E.; Morris, Andrew P.; Müller, Gabriele; Musk, Arthur W.; Narisu, Narisu; Ong, Ken K.; Oostra, Ben A.; Osmond, Clive; Palotie, Aarno; Pankow, James S.; Paternoster, Lavinia; Penninx, Brenda W.; Pichler, Irene; Pilia, Maria G.; Polašek, Ozren; Pramstaller, Peter P.; Raitakari, Olli T; Rankinen, Tuomo; Rao, D. C.; Rayner, Nigel W.; Ribel-Madsen, Rasmus; Rice, Treva K.; Richards, Marcus; Ridker, Paul M.; Rivadeneira, Fernando; Ryan, Kathy A.; Sanna, Serena; Sarzynski, Mark A.; Scholtens, Salome; Scott, Robert A.; Sebert, Sylvain; Southam, Lorraine; Sparsø, Thomas Hempel; Steinthorsdottir, Valgerdur; Stirrups, Kathleen; Stolk, Ronald P.; Strauch, Konstantin; Stringham, Heather M.; Swertz, Morris A.; Swift, Amy J.; Tönjes, Anke; Tsafantakis, Emmanouil; van der Most, Peter J.; Van Vliet-Ostaptchouk, Jana V.; Vandenput, Liesbeth; Vartiainen, Erkki; Venturini, Cristina; Verweij, Niek; Viikari, Jorma S.; Vitart, Veronique; Vohl, Marie-Claude; Vonk, Judith M.; Waeber, Gérard; Widén, Elisabeth; Willemsen, Gonneke; Wilsgaard, Tom; Winkler, Thomas W.; Wright, Alan F.; Yerges-Armstrong, Laura M.; Hua Zhao, Jing; Carola Zillikens, M.; Boomsma, Dorret I.; Bouchard, Claude; Chambers, John C.; Chasman, Daniel I.; Cusi, Daniele; Gansevoort, Ron T.; Gieger, Christian; Hansen, Torben; Hicks, Andrew A.; Hu, Frank; Hveem, Kristian; Jarvelin, Marjo-Riitta; Kajantie, Eero; Kooner, Jaspal S.; Kuh, Diana; Kuusisto, Johanna; Laakso, Markku; Lakka, Timo A.; Lehtimäki, Terho; Metspalu, Andres; Njølstad, Inger; Ohlsson, Claes; Oldehinkel, Albertine J.; Palmer, Lyle J.; Pedersen, Oluf; Perola, Markus; Peters, Annette; Psaty, Bruce M.; Puolijoki, Hannu; Rauramaa, Rainer; Rudan, Igor; Salomaa, Veikko; Schwarz, Peter E. H.; Shudiner, Alan R.; Smit, Jan H.; Sørensen, Thorkild I. A.; Spector, Timothy D.; Stefansson, Kari; Stumvoll, Michael; Tremblay, Angelo; Tuomilehto, Jaakko; Uitterlinden, André G.; Uusitupa, Matti; Völker, Uwe; Vollenweider, Peter; Wareham, Nicholas J.; Watkins, Hugh; Wilson, James F.; Zeggini, Eleftheria; Abecasis, Goncalo R.; Boehnke, Michael; Borecki, Ingrid B.; Deloukas, Panos; van Duijn, Cornelia M.; Fox, Caroline; Groop, Leif C.; Heid, Iris M.; Hunter, David J.; Kaplan, Robert C.; McCarthy, Mark I.; North, Kari E.; O'Connell, Jeffrey R.; Schlessinger, David; Thorsteinsdottir, Unnur; Strachan, David P.; Frayling, Timothy; Hirschhorn, Joel N.; Müller-Nurasyid, Martina; Loos, Ruth J. F.

2016-01-01

Large consortia have revealed hundreds of genetic loci associated with anthropometric traits, one trait at a time. We examined whether genetic variants affect body shape as a composite phenotype that is represented by a combination of anthropometric traits. We developed an approach that calculates averaged PCs (AvPCs) representing body shape derived from six anthropometric traits (body mass index, height, weight, waist and hip circumference, waist-to-hip ratio). The first four AvPCs explain >99% of the variability, are heritable, and associate with cardiometabolic outcomes. We performed genome-wide association analyses for each body shape composite phenotype across 65 studies and meta-analysed summary statistics. We identify six novel loci: LEMD2 and CD47 for AvPC1, RPS6KA5/C14orf159 and GANAB for AvPC3, and ARL15 and ANP32 for AvPC4. Our findings highlight the value of using multiple traits to define complex phenotypes for discovery, which are not captured by single-trait analyses, and may shed light onto new pathways. PMID:27876822

The impact of the rate prior on Bayesian estimation of divergence times with multiple Loci.

PubMed

Dos Reis, Mario; Zhu, Tianqi; Yang, Ziheng

2014-07-01

Bayesian methods provide a powerful way to estimate species divergence times by combining information from molecular sequences with information from the fossil record. With the explosive increase of genomic data, divergence time estimation increasingly uses data of multiple loci (genes or site partitions). Widely used computer programs to estimate divergence times use independent and identically distributed (i.i.d.) priors on the substitution rates for different loci. The i.i.d. prior is problematic. As the number of loci (L) increases, the prior variance of the average rate across all loci goes to zero at the rate 1/L. As a consequence, the rate prior dominates posterior time estimates when many loci are analyzed, and if the rate prior is misspecified, the estimated divergence times will converge to wrong values with very narrow credibility intervals. Here we develop a new prior on the locus rates based on the Dirichlet distribution that corrects the problematic behavior of the i.i.d. prior. We use computer simulation and real data analysis to highlight the differences between the old and new priors. For a dataset for six primate species, we show that with the old i.i.d. prior, if the prior rate is too high (or too low), the estimated divergence times are too young (or too old), outside the bounds imposed by the fossil calibrations. In contrast, with the new Dirichlet prior, posterior time estimates are insensitive to the rate prior and are compatible with the fossil calibrations. We re-analyzed a phylogenomic data set of 36 mammal species and show that using many fossil calibrations can alleviate the adverse impact of a misspecified rate prior to some extent. We recommend the use of the new Dirichlet prior in Bayesian divergence time estimation. [Bayesian inference, divergence time, relaxed clock, rate prior, partition analysis.]. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

Linkage Disequilibrium Under Recurrent Bottlenecks

PubMed Central

Schaper, E.; Eriksson, A.; Rafajlovic, M.; Sagitov, S.; Mehlig, B.

2012-01-01

To model deviations from selectively neutral genetic variation caused by different forms of selection, it is necessary to first understand patterns of neutral variation. Best understood is neutral genetic variation at a single locus. But, as is well known, additional insights can be gained by investigating multiple loci. The resulting patterns reflect the degree of association (linkage) between loci and provide information about the underlying multilocus gene genealogies. The statistical properties of two-locus gene genealogies have been intensively studied for populations of constant size, as well as for simple demographic histories such as exponential population growth and single bottlenecks. By contrast, the combined effect of recombination and sustained demographic fluctuations is poorly understood. Addressing this issue, we study a two-locus Wright–Fisher model of a population subject to recurrent bottlenecks. We derive coalescent approximations for the covariance of the times to the most recent common ancestor at two loci in samples of two chromosomes. This covariance reflects the degree of association and thus linkage disequilibrium between these loci. We find, first, that an effective population-size approximation describes the numerically observed association between two loci provided that recombination occurs either much faster or much more slowly than the population-size fluctuations. Second, when recombination occurs frequently between but rarely within bottlenecks, we observe that the association of gene histories becomes independent of physical distance over a certain range of distances. Third, we show that in this case, a commonly used measure of linkage disequilibrium, σd2 (closely related to r^2), fails to capture the long-range association between two loci. The reason is that constituent terms, each reflecting the long-range association, cancel. Fourth, we analyze a limiting case in which the long-range association can be described in terms of a Xi coalescent allowing for simultaneous multiple mergers of ancestral lines. PMID:22048021

Mapping Quantitative Trait Loci Associated with Toot Traits Using Sequencing-Based Genotyping Chromosome Segment Substitution Lines Derived from 9311 and Nipponbare in Rice (Oryza sativa L.).

PubMed

Zhou, Yong; Dong, Guichun; Tao, Yajun; Chen, Chen; Yang, Bin; Wu, Yue; Yang, Zefeng; Liang, Guohua; Wang, Baohe; Wang, Yulong

2016-01-01

Identification of quantitative trait loci (QTLs) associated with rice root morphology provides useful information for avoiding drought stress and maintaining yield production under the irrigation condition. In this study, a set of chromosome segment substitution lines derived from 9311 as the recipient and Nipponbare as donor, were used to analysis root morphology. By combining the resequencing-based bin-map with a multiple linear regression analysis, QTL identification was conducted on root number (RN), total root length (TRL), root dry weight (RDW), maximum root length (MRL), root thickness (RTH), total absorption area (TAA) and root vitality (RV), using the CSSL population grown under hydroponic conditions. A total of thirty-eight QTLs were identified: six for TRL, six for RDW, eight for the MRL, four for RTH, seven for RN, two for TAA, and five for RV. Phenotypic effect variance explained by these QTLs ranged from 2.23% to 37.08%, and four single QTLs had more than 10% phenotypic explanations on three root traits. We also detected the correlations between grain yield (GY) and root traits, and found that TRL, RTH and MRL had significantly positive correlations with GY. However, TRL, RDW and MRL had significantly positive correlations with biomass yield (BY). Several QTLs identified in our population were co-localized with some loci for grain yield or biomass. This information may be immediately exploited for improving rice water and fertilizer use efficiency for molecular breeding of root system architectures.

Sherlock: Detecting Gene-Disease Associations by Matching Patterns of Expression QTL and GWAS

PubMed Central

He, Xin; Fuller, Chris K.; Song, Yi; Meng, Qingying; Zhang, Bin; Yang, Xia; Li, Hao

2013-01-01

Genetic mapping of complex diseases to date depends on variations inside or close to the genes that perturb their activities. A strong body of evidence suggests that changes in gene expression play a key role in complex diseases and that numerous loci perturb gene expression in trans. The information in trans variants, however, has largely been ignored in the current analysis paradigm. Here we present a statistical framework for genetic mapping by utilizing collective information in both cis and trans variants. We reason that for a disease-associated gene, any genetic variation that perturbs its expression is also likely to influence the disease risk. Thus, the expression quantitative trait loci (eQTL) of the gene, which constitute a unique “genetic signature,” should overlap significantly with the set of loci associated with the disease. We translate this idea into a computational algorithm (named Sherlock) to search for gene-disease associations from GWASs, taking advantage of independent eQTL data. Application of this strategy to Crohn disease and type 2 diabetes predicts a number of genes with possible disease roles, including several predictions supported by solid experimental evidence. Importantly, predicted genes are often implicated by multiple trans eQTL with moderate associations. These genes are far from any GWAS association signals and thus cannot be identified from the GWAS alone. Our approach allows analysis of association data from a new perspective and is applicable to any complex phenotype. It is readily generalizable to molecular traits other than gene expression, such as metabolites, noncoding RNAs, and epigenetic modifications. PMID:23643380

Characterization and transferability of microsatellite markers of the cultivated peanut (Arachis hypogaea)

PubMed Central

Gimenes, Marcos A; Hoshino, Andrea A; Barbosa, Andrea VG; Palmieri, Dario A; Lopes, Catalina R

2007-01-01

Background The genus Arachis includes Arachis hypogaea (cultivated peanut) and wild species that are used in peanut breeding or as forage. Molecular markers have been employed in several studies of this genus, but microsatellite markers have only been used in few investigations. Microsatellites are very informative and are useful to assess genetic variability, analyze mating systems and in genetic mapping. The objectives of this study were to develop A. hypogaea microsatellite loci and to evaluate the transferability of these markers to other Arachis species. Results Thirteen loci were isolated and characterized using 16 accessions of A. hypogaea. The level of variation found in A. hypogaea using microsatellites was higher than with other markers. Cross-transferability of the markers was also high. Sequencing of the fragments amplified using the primer pair Ah11 from 17 wild Arachis species showed that almost all wild species had similar repeated sequence to the one observed in A. hypogaea. Sequence data suggested that there is no correlation between taxonomic relationship of a wild species to A. hypogaea and the number of repeats found in its microsatellite loci. Conclusion These results show that microsatellite primer pairs from A. hypogaea have multiple uses. A higher level of variation among A. hypogaea accessions can be detected using microsatellite markers in comparison to other markers, such as RFLP, RAPD and AFLP. The microsatellite primers of A. hypogaea showed a very high rate of transferability to other species of the genus. These primer pairs provide important tools to evaluate the genetic variability and to assess the mating system in Arachis species. PMID:17326826

A genomic scan for selection reveals candidates for genes involved in the evolution of cultivated sunflower (Helianthus annuus).

PubMed

Chapman, Mark A; Pashley, Catherine H; Wenzler, Jessica; Hvala, John; Tang, Shunxue; Knapp, Steven J; Burke, John M

2008-11-01

Genomic scans for selection are a useful tool for identifying genes underlying phenotypic transitions. In this article, we describe the results of a genome scan designed to identify candidates for genes targeted by selection during the evolution of cultivated sunflower. This work involved screening 492 loci derived from ESTs on a large panel of wild, primitive (i.e., landrace), and improved sunflower (Helianthus annuus) lines. This sampling strategy allowed us to identify candidates for selectively important genes and investigate the likely timing of selection. Thirty-six genes showed evidence of selection during either domestication or improvement based on multiple criteria, and a sequence-based test of selection on a subset of these loci confirmed this result. In view of what is known about the structure of linkage disequilibrium across the sunflower genome, these genes are themselves likely to have been targeted by selection, rather than being merely linked to the actual targets. While the selection candidates showed a broad range of putative functions, they were enriched for genes involved in amino acid synthesis and protein catabolism. Given that a similar pattern has been detected in maize (Zea mays), this finding suggests that selection on amino acid composition may be a general feature of the evolution of crop plants. In terms of genomic locations, the selection candidates were significantly clustered near quantitative trait loci (QTL) that contribute to phenotypic differences between wild and cultivated sunflower, and specific instances of QTL colocalization provide some clues as to the roles that these genes may have played during sunflower evolution.

Immunogenetic aspects of a canine breeding colony.

PubMed

Ladiges, W C; Deeg, H J; Raff, R F; Storb, R

1985-02-01

A colony of dogs was expanded by selective breeding to study the immunogenetic determinants coded for by the major histocompatibility complex (DLA). Polymorphic determinants were identified by alloantisera specific for DLA-A and B loci antigens and by the mixed lymphocyte culture (MLC) which defined alleles at the D locus. Thirteen families totaling 58 offspring were produced and typed for allelic determinants coded for by each of the three gene loci. Allelic segregation in a codominant manner occurred as expected and a recombinant between the A and B loci was detected. A number of animals were homozygous at one or more loci, thus providing genetically standardized animals as a source of typing cells, antigens, and sera to further study the immunogenetic details of DLA and for in vivo studies in transplantation biology.

A Large-Scale Multi-ancestry Genome-wide Study Accounting for Smoking Behavior Identifies Multiple Significant Loci for Blood Pressure.

PubMed

Sung, Yun J; Winkler, Thomas W; de Las Fuentes, Lisa; Bentley, Amy R; Brown, Michael R; Kraja, Aldi T; Schwander, Karen; Ntalla, Ioanna; Guo, Xiuqing; Franceschini, Nora; Lu, Yingchang; Cheng, Ching-Yu; Sim, Xueling; Vojinovic, Dina; Marten, Jonathan; Musani, Solomon K; Li, Changwei; Feitosa, Mary F; Kilpeläinen, Tuomas O; Richard, Melissa A; Noordam, Raymond; Aslibekyan, Stella; Aschard, Hugues; Bartz, Traci M; Dorajoo, Rajkumar; Liu, Yongmei; Manning, Alisa K; Rankinen, Tuomo; Smith, Albert Vernon; Tajuddin, Salman M; Tayo, Bamidele O; Warren, Helen R; Zhao, Wei; Zhou, Yanhua; Matoba, Nana; Sofer, Tamar; Alver, Maris; Amini, Marzyeh; Boissel, Mathilde; Chai, Jin Fang; Chen, Xu; Divers, Jasmin; Gandin, Ilaria; Gao, Chuan; Giulianini, Franco; Goel, Anuj; Harris, Sarah E; Hartwig, Fernando Pires; Horimoto, Andrea R V R; Hsu, Fang-Chi; Jackson, Anne U; Kähönen, Mika; Kasturiratne, Anuradhani; Kühnel, Brigitte; Leander, Karin; Lee, Wen-Jane; Lin, Keng-Hung; 'an Luan, Jian; McKenzie, Colin A; Meian, He; Nelson, Christopher P; Rauramaa, Rainer; Schupf, Nicole; Scott, Robert A; Sheu, Wayne H H; Stančáková, Alena; Takeuchi, Fumihiko; van der Most, Peter J; Varga, Tibor V; Wang, Heming; Wang, Yajuan; Ware, Erin B; Weiss, Stefan; Wen, Wanqing; Yanek, Lisa R; Zhang, Weihua; Zhao, Jing Hua; Afaq, Saima; Alfred, Tamuno; Amin, Najaf; Arking, Dan; Aung, Tin; Barr, R Graham; Bielak, Lawrence F; Boerwinkle, Eric; Bottinger, Erwin P; Braund, Peter S; Brody, Jennifer A; Broeckel, Ulrich; Cabrera, Claudia P; Cade, Brian; Caizheng, Yu; Campbell, Archie; Canouil, Mickaël; Chakravarti, Aravinda; Chauhan, Ganesh; Christensen, Kaare; Cocca, Massimiliano; Collins, Francis S; Connell, John M; de Mutsert, Renée; de Silva, H Janaka; Debette, Stephanie; Dörr, Marcus; Duan, Qing; Eaton, Charles B; Ehret, Georg; Evangelou, Evangelos; Faul, Jessica D; Fisher, Virginia A; Forouhi, Nita G; Franco, Oscar H; Friedlander, Yechiel; Gao, He; Gigante, Bruna; Graff, Misa; Gu, C Charles; Gu, Dongfeng; Gupta, Preeti; Hagenaars, Saskia P; Harris, Tamara B; He, Jiang; Heikkinen, Sami; Heng, Chew-Kiat; Hirata, Makoto; Hofman, Albert; Howard, Barbara V; Hunt, Steven; Irvin, Marguerite R; Jia, Yucheng; Joehanes, Roby; Justice, Anne E; Katsuya, Tomohiro; Kaufman, Joel; Kerrison, Nicola D; Khor, Chiea Chuen; Koh, Woon-Puay; Koistinen, Heikki A; Komulainen, Pirjo; Kooperberg, Charles; Krieger, Jose E; Kubo, Michiaki; Kuusisto, Johanna; Langefeld, Carl D; Langenberg, Claudia; Launer, Lenore J; Lehne, Benjamin; Lewis, Cora E; Li, Yize; Lim, Sing Hui; Lin, Shiow; Liu, Ching-Ti; Liu, Jianjun; Liu, Jingmin; Liu, Kiang; Liu, Yeheng; Loh, Marie; Lohman, Kurt K; Long, Jirong; Louie, Tin; Mägi, Reedik; Mahajan, Anubha; Meitinger, Thomas; Metspalu, Andres; Milani, Lili; Momozawa, Yukihide; Morris, Andrew P; Mosley, Thomas H; Munson, Peter; Murray, Alison D; Nalls, Mike A; Nasri, Ubaydah; Norris, Jill M; North, Kari; Ogunniyi, Adesola; Padmanabhan, Sandosh; Palmas, Walter R; Palmer, Nicholette D; Pankow, James S; Pedersen, Nancy L; Peters, Annette; Peyser, Patricia A; Polasek, Ozren; Raitakari, Olli T; Renström, Frida; Rice, Treva K; Ridker, Paul M; Robino, Antonietta; Robinson, Jennifer G; Rose, Lynda M; Rudan, Igor; Sabanayagam, Charumathi; Salako, Babatunde L; Sandow, Kevin; Schmidt, Carsten O; Schreiner, Pamela J; Scott, William R; Seshadri, Sudha; Sever, Peter; Sitlani, Colleen M; Smith, Jennifer A; Snieder, Harold; Starr, John M; Strauch, Konstantin; Tang, Hua; Taylor, Kent D; Teo, Yik Ying; Tham, Yih Chung; Uitterlinden, André G; Waldenberger, Melanie; Wang, Lihua; Wang, Ya X; Wei, Wen Bin; Williams, Christine; Wilson, Gregory; Wojczynski, Mary K; Yao, Jie; Yuan, Jian-Min; Zonderman, Alan B; Becker, Diane M; Boehnke, Michael; Bowden, Donald W; Chambers, John C; Chen, Yii-Der Ida; de Faire, Ulf; Deary, Ian J; Esko, Tõnu; Farrall, Martin; Forrester, Terrence; Franks, Paul W; Freedman, Barry I; Froguel, Philippe; Gasparini, Paolo; Gieger, Christian; Horta, Bernardo Lessa; Hung, Yi-Jen; Jonas, Jost B; Kato, Norihiro; Kooner, Jaspal S; Laakso, Markku; Lehtimäki, Terho; Liang, Kae-Woei; Magnusson, Patrik K E; Newman, Anne B; Oldehinkel, Albertine J; Pereira, Alexandre C; Redline, Susan; Rettig, Rainer; Samani, Nilesh J; Scott, James; Shu, Xiao-Ou; van der Harst, Pim; Wagenknecht, Lynne E; Wareham, Nicholas J; Watkins, Hugh; Weir, David R; Wickremasinghe, Ananda R; Wu, Tangchun; Zheng, Wei; Kamatani, Yoichiro; Laurie, Cathy C; Bouchard, Claude; Cooper, Richard S; Evans, Michele K; Gudnason, Vilmundur; Kardia, Sharon L R; Kritchevsky, Stephen B; Levy, Daniel; O'Connell, Jeff R; Psaty, Bruce M; van Dam, Rob M; Sims, Mario; Arnett, Donna K; Mook-Kanamori, Dennis O; Kelly, Tanika N; Fox, Ervin R; Hayward, Caroline; Fornage, Myriam; Rotimi, Charles N; Province, Michael A; van Duijn, Cornelia M; Tai, E Shyong; Wong, Tien Yin; Loos, Ruth J F; Reiner, Alex P; Rotter, Jerome I; Zhu, Xiaofeng; Bierut, Laura J; Gauderman, W James; Caulfield, Mark J; Elliott, Paul; Rice, Kenneth; Munroe, Patricia B; Morrison, Alanna C; Cupples, L Adrienne; Rao, Dabeeru C; Chasman, Daniel I

2018-03-01

Genome-wide association analysis advanced understanding of blood pressure (BP), a major risk factor for vascular conditions such as coronary heart disease and stroke. Accounting for smoking behavior may help identify BP loci and extend our knowledge of its genetic architecture. We performed genome-wide association meta-analyses of systolic and diastolic BP incorporating gene-smoking interactions in 610,091 individuals. Stage 1 analysis examined ∼18.8 million SNPs and small insertion/deletion variants in 129,913 individuals from four ancestries (European, African, Asian, and Hispanic) with follow-up analysis of promising variants in 480,178 additional individuals from five ancestries. We identified 15 loci that were genome-wide significant (p < 5 × 10 -8 ) in stage 1 and formally replicated in stage 2. A combined stage 1 and 2 meta-analysis identified 66 additional genome-wide significant loci (13, 35, and 18 loci in European, African, and trans-ancestry, respectively). A total of 56 known BP loci were also identified by our results (p < 5 × 10 -8 ). Of the newly identified loci, ten showed significant interaction with smoking status, but none of them were replicated in stage 2. Several loci were identified in African ancestry, highlighting the importance of genetic studies in diverse populations. The identified loci show strong evidence for regulatory features and support shared pathophysiology with cardiometabolic and addiction traits. They also highlight a role in BP regulation for biological candidates such as modulators of vascular structure and function (CDKN1B, BCAR1-CFDP1, PXDN, EEA1), ciliopathies (SDCCAG8, RPGRIP1L), telomere maintenance (TNKS, PINX1, AKTIP), and central dopaminergic signaling (MSRA, EBF2). Copyright © 2018 American Society of Human Genetics. All rights reserved.

Genome wide association mapping for grain shape traits in indica rice.

PubMed

Feng, Yue; Lu, Qing; Zhai, Rongrong; Zhang, Mengchen; Xu, Qun; Yang, Yaolong; Wang, Shan; Yuan, Xiaoping; Yu, Hanyong; Wang, Yiping; Wei, Xinghua

2016-10-01

Using genome-wide association mapping, 47 SNPs within 27 significant loci were identified for four grain shape traits, and 424 candidate genes were predicted from public database. Grain shape is a key determinant of grain yield and quality in rice (Oryza sativa L.). However, our knowledge of genes controlling rice grain shape remains limited. Genome-wide association mapping based on linkage disequilibrium (LD) has recently emerged as an effective approach for identifying genes or quantitative trait loci (QTL) underlying complex traits in plants. In this study, association mapping based on 5291 single nucleotide polymorphisms (SNPs) was conducted to identify significant loci associated with grain shape traits in a global collection of 469 diverse rice accessions. A total of 47 SNPs were located in 27 significant loci for four grain traits, and explained ~44.93-65.90 % of the phenotypic variation for each trait. In total, 424 candidate genes within a 200 kb extension region (±100 kb of each locus) of these loci were predicted. Of them, the cloned genes GS3 and qSW5 showed very strong effects on grain length and grain width in our study. Comparing with previously reported QTLs for grain shape traits, we found 11 novel loci, including 3, 3, 2 and 3 loci for grain length, grain width, grain length-width ratio and thousand grain weight, respectively. Validation of these new loci would be performed in the future studies. These results revealed that besides GS3 and qSW5, multiple novel loci and mechanisms were involved in determining rice grain shape. These findings provided valuable information for understanding of the genetic control of grain shape and molecular marker assistant selection (MAS) breeding in rice.

Genomic Changes Associated with Reproductive and Migratory Ecotypes in Sockeye Salmon (Oncorhynchus nerka).

PubMed

Veale, Andrew J; Russello, Michael A

2017-10-01

Mechanisms underlying adaptive evolution can best be explored using paired populations displaying similar phenotypic divergence, illuminating the genomic changes associated with specific life history traits. Here, we used paired migratory [anadromous vs. resident (kokanee)] and reproductive [shore- vs. stream-spawning] ecotypes of sockeye salmon (Oncorhynchus nerka) sampled from seven lakes and two rivers spanning three catchments (Columbia, Fraser, and Skeena) in British Columbia, Canada to investigate the patterns and processes underlying their divergence. Restriction-site associated DNA sequencing was used to genotype this sampling at 7,347 single nucleotide polymorphisms, 334 of which were identified as outlier loci and candidates for divergent selection within at least one ecotype comparison. Sixty-eight of these outliers were present in two or more comparisons, with 33 detected across multiple catchments. Of particular note, one locus was detected as the most significant outlier between shore and stream-spawning ecotypes in multiple comparisons and across catchments (Columbia, Fraser, and Snake). We also detected several genomic islands of divergence, some shared among comparisons, potentially showing linked signals of differential selection. The single nucleotide polymorphisms and genomic regions identified in our study offer a range of mechanistic hypotheses associated with the genetic basis of O. nerka life history variation and provide novel tools for informing fisheries management. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

A case of false mother included with 46 autosomal STR markers.

PubMed

Li, Li; Lin, Yuan; Liu, Yan; Zhu, Ruxin; Zhao, Zhenmin; Que, Tingzhi

2015-01-01

For solving a maternity case, 19 autosomal short tandem repeats (STRs) were amplified using the AmpFℓSTR(®) Sinofiler(TM) kit and PowerPlex(®) 16 System. Additional 27 autosomal STR loci were analyzed using two domestic kits AGCU 21+1 and STRtyper-10G. The combined maternity index (CMI) was calculated to be 3.3 × 10(13), but the putative mother denied that she had given birth to the child. In order to reach an accurate conclusion, further testing of 20 X-chromosomal short tandem repeats (X-STRs), 40 single nucleotide polymorphism (SNP) loci, and mitochondrial DNA (mtDNA) was carried out. The putative mother and the boy shared at least one allele at all 46 tested autosomal STR loci. But, according to the profile data of 20 X-STR and 40 SNP markers, different genotypes at 13 X-STR loci and five SNP loci excluded maternity. Mitochondrial profiles also clearly excluded the mother as a parent of the son because they have multiple differences. It was finally found that the putative mother is the sister of the biological father. Different kinds of genetic markers needfully supplement the use of autosomal STR loci in case where the putative parent is suspected to be related to the true parent.

Genome-wide methylation analysis identifies differentially methylated CpG loci associated with severe obesity in childhood.

PubMed

Huang, R C; Garratt, E S; Pan, H; Wu, Y; Davis, E A; Barton, S J; Burdge, G C; Godfrey, K M; Holbrook, J D; Lillycrop, K A

2015-01-01

Childhood obesity is a major public health issue. Here we investigated whether differential DNA methylation was associated with childhood obesity. We studied DNA methylation profiles in whole blood from 78 obese children (mean BMI Z-score: 2.6) and 71 age- and sex-matched controls (mean BMI Z-score: 0.1). DNA samples from obese and control groups were pooled and analyzed using the Infinium HumanMethylation450 BeadChip array. Comparison of the methylation profiles between obese and control subjects revealed 129 differentially methylated CpG (DMCpG) loci associated with 80 unique genes that had a greater than 10% difference in methylation (P-value < 0.05). The top pathways enriched among the DMCpGs included developmental processes, immune system regulation, regulation of cell signaling, and small GTPase-mediated signal transduction. The associations between the methylation of selected DMCpGs with childhood obesity were validated using sodium bisulfite pyrosequencing across loci within the FYN, PIWIL4, and TAOK3 genes in individual subjects. Three CpG loci within FYN were hypermethylated in obese individuals (all P < 0.01), while obesity was associated with lower methylation of CpG loci within PIWIL4 (P = 0.003) and TAOK3 (P = 0.001). After building logistic regression models, we determined that a 1% increase in methylation in TAOK3, multiplicatively decreased the odds of being obese by 0.91 (95% CI: 0.86 - 0.97), and an increase of 1% methylation in FYN CpG3, multiplicatively increased the odds of being obese by 1.03 (95% CI: 0.99 - 1.07). In conclusion, these findings provide evidence that childhood obesity is associated with specific DNA methylation changes in whole blood, which may have utility as biomarkers of obesity risk.

Genetic susceptibility for Alzheimer disease neuritic plaque pathology.

PubMed

Shulman, Joshua M; Chen, Kewei; Keenan, Brendan T; Chibnik, Lori B; Fleisher, Adam; Thiyyagura, Pradeep; Roontiva, Auttawut; McCabe, Cristin; Patsopoulos, Nikolaos A; Corneveaux, Jason J; Yu, Lei; Huentelman, Matthew J; Evans, Denis A; Schneider, Julie A; Reiman, Eric M; De Jager, Philip L; Bennett, David A

2013-09-01

While numerous genetic susceptibility loci have been identified for clinical Alzheimer disease (AD), it is important to establish whether these variants are risk factors for the underlying disease pathology, including neuritic plaques. To investigate whether AD susceptibility loci from genome-wide association studies affect neuritic plaque pathology and to additionally identify novel risk loci for this trait. Candidate analysis of single-nucleotide polymorphisms and genome-wide association study in a joint clinicopathologic cohort, including 725 deceased subjects from the Religious Orders Study and the Rush Memory and Aging Project (2 prospective, community-based studies), followed by targeted validation in an independent neuroimaging cohort, including 114 subjects from multiple clinical and research centers. A quantitative measure of neuritic plaque pathologic burden, based on assessments of silver-stained tissue averaged from multiple brain regions. Validation based on β-amyloid load by immunocytochemistry, and replication with fibrillar β-amyloid positron emission tomographic imaging with Pittsburgh Compound B or florbetapir. Besides the previously reported APOE and CR1 loci, we found that the ABCA7 (rs3764650; P = .02) and CD2AP (rs9349407; P = .03) AD susceptibility loci are associated with neuritic plaque burden. In addition, among the top results of our genome-wide association study, we discovered a novel variant near the amyloid precursor protein gene (APP, rs2829887) that is associated with neuritic plaques (P = 3.3 × 10-6). This polymorphism was associated with postmortem β-amyloid load as well as fibrillar β-amyloid in 2 independent cohorts of adults with normal cognition. These findings enhance understanding of AD risk factors by relating validated susceptibility alleles to increased neuritic plaque pathology and implicate common genetic variation at the APP locus in the earliest, presymptomatic stages of AD.

Directional genetic selection by pulp mill effluent on multiple natural populations of three-spined stickleback (Gasterosteus aculeatus).

PubMed

Lind, Emma E; Grahn, Mats

2011-05-01

Contamination can cause a rapid environmental change which may require populations to respond with evolutionary changes. To evaluate the effects of pulp mill effluents on population genetics, we sampled three-spined sticklebacks (Gasterosteus aculeatus) near four pulp mills and four adjacent reference sites and analyzed Amplified Fragment Length Polymorphism (AFLP) to compare genetic variability. A fine scale genetic structure was detected and samples from polluted sites separated from reference sites in multidimensional scaling plots (P<0.005, 1000 permutations) and locus-by-locus Analysis of Molecular Variance (AMOVA) further confirmed that habitats are significantly separated (F(ST)=0.021, P<0.01, 1023 permutations). The amount of genetic variation between populations did not differ between habitats, and populations from both habitats had similar levels of heterozygosity (polluted sites Nei's Hs=0.11, reference sites Nei's Hs=0.11). Still, pairwise F(ST): s between three, out of four, pairs of polluted-reference sites were significant. A F(ST)-outlier analysis showed that 21 (8.4%) loci were statistically different from a neutral distribution at the P<0.05 level and therefore indicated to be under divergent selection. When removing 13 F(ST)-outlier loci, significant at the P<0.01 level, differentiation between habitats disappeared in a multidimensional scaling plot. In conclusion, pulp mill effluence has acted as a selective agent on natural populations of G. aculeatus, causing a convergence in genotype composition change at multiple sites in an open environment. © The Author(s) 2011. This article is published with open access at Springerlink.com

Migration and Gene Flow Among Domestic Populations of the Chagas Insect Vector Triatoma dimidiata (Hemiptera: Reduviidae) Detected by Microsatellite Loci

PubMed Central

Stevens, Lori; Monroy, M. Carlota; Rodas, Antonieta Guadalupe; Hicks, Robin M.; Lucero, David E.; Lyons, Leslie A.; Dorn, Patricia L.

2015-01-01

Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the parasite Trypanosoma cruzi in Central America, and particularly in Guatemala. Tr. cruzi is the causative agent of Chagas disease, and successful disease control requires understanding the geographic distribution and degree of migration of vectors such as T. dimidiata that frequently re-infest houses within months following insecticide application. The population genetic structure of T. dimidiata collected from six villages in southern Guatemala was studied to gain insight into the migration patterns of the insects in this region where populations are largely domestic. This study provided insight into the likelihood of eliminating T. dimidiata by pesticide application as has been observed in some areas for other domestic triatomines such as Triatoma infestans. Genotypes of microsatellite loci for 178 insects from six villages were found to represent five genetic clusters using a Bayesian Markov Chain Monte Carlo method. Individual clusters were found in multiple villages, with multiple clusters in the same house. Although migration occurred, there was statistically significant genetic differentiation among villages (FRT = 0.05) and high genetic differentiation among houses within villages (FSR = 0.11). Relatedness of insects within houses varied from 0 to 0.25, i.e., from unrelated to half-sibs. The results suggest that T. dimidiata in southern Guatemala moves between houses and villages often enough that recolonization is likely, implying the use of insecticides alone is not sufficient for effective control of Chagas disease in this region and more sustainable solutions are required. PMID:26334816

Evaluation of MLVA for epidemiological typing and outbreak detection of ESBL-producing Escherichia coli in Sweden.

PubMed

Helldal, Lisa; Karami, Nahid; Welinder-Olsson, Christina; Moore, Edward R B; Åhren, Christina

2017-01-06

To identify the spread of nosocomial infections and halt outbreak development caused by Escherichia coli that carry multiple antibiotic resistance factors, such as extended-spectrum beta-lactamases (ESBLs) and carbapenemases, is becoming demanding challenges due to the rapid global increase and constant and increasing influx of these bacteria from the community to the hospital setting. Our aim was to assess a reliable and rapid typing protocol for ESBL-E. coli, with the primary focus to screen for possible clonal relatedness between isolates. All clinical ESBL-E. coli isolates, collected from hospitals (n = 63) and the community (n = 41), within a single geographical region over a 6 months period, were included, as well as clinical isolates from a polyclonal outbreak (ST131, n = 9, and ST1444, n = 3). The sporadic cases represented 36 STs, of which eight STs dominated i.e. ST131 (n = 33 isolates), ST648 (n = 10), ST38 (n = 9), ST12 and 69 (each n = 4), ST 167, 405 and 372 (each n = 3). The efficacy of multiple-locus variable number tandem repeat analysis (MLVA) was evaluated using three, seven or ten loci, in comparison with that of pulsed-field gel electrophoresis (PFGE) and multi locus sequence typing (MLST). MLVA detected 39, 55 and 60 distinct types, respectively, using three (GECM-3), seven (GECM-7) or ten (GECM-10) loci. For GECM-7 and -10, 26 STs included one type and eleven STs each included several types, the corresponding numbers for GECM-3 were 29 and 8. The highest numbers were seen for ST131 (7,7 and 8 types, respectively), ST38 (5,5,8) and ST648 (4,5,5). Good concordance was observed with PFGE and GECM-7 and -10, despite fewer types being identified with MLVA; 78 as compared to 55 and 60 types. The lower discriminatory power of MLVA was primarily seen within the O25b-ST131 lineage (n = 34) and its H30-Rx subclone (n = 21). Epidemiologically unrelated O25b-ST131 isolates were clustered with O25b-ST131 outbreak isolates by MLVA, whereas the ST1444 outbreak isolates were accurately distinguished from unrelated isolates. MLVA, even when using only three loci, represents an easy initial typing tool for epidemiological screening of ESBL-E. coli. For the ST131-O25b linage, complementary methods may be needed to obtain sufficient resolution.

Genetic variation and population structure in Jamunapari goats using microsatellites, mitochondrial DNA, and milk protein genes.

PubMed

Rout, P K; Thangraj, K; Mandal, A; Roy, R

2012-01-01

Jamunapari, a dairy goat breed of India, has been gradually declining in numbers in its home tract over the years. We have analysed genetic variation and population history in Jamunapari goats based on 17 microsatellite loci, 2 milk protein loci, mitochondrial hypervariable region I (HVRI) sequencing, and three Y-chromosomal gene sequencing. We used the mitochondrial DNA (mtDNA) mismatch distribution, microsatellite data, and bottleneck tests to infer the population history and demography. The mean number of alleles per locus was 9.0 indicating that the allelic variation was high in all the loci and the mean heterozygosity was 0.769 at nuclear loci. Although the population size is smaller than 8,000 individuals, the amount of variability both in terms of allelic richness and gene diversity was high in all the microsatellite loci except ILST 005. The gene diversity and effective number of alleles at milk protein loci were higher than the 10 other Indian goat breeds that they were compared to. Mismatch analysis was carried out and the analysis revealed that the population curve was unimodal indicating the expansion of population. The genetic diversity of Y-chromosome genes was low in the present study. The observed mean M ratio in the population was above the critical significance value (Mc) and close to one indicating that it has maintained a slowly changing population size. The mode-shift test did not detect any distortion of allele frequency and the heterozygosity excess method showed that there was no significant departure from mutation-drift equilibrium detected in the population. However, the effects of genetic bottlenecks were observed in some loci due to decreased heterozygosity and lower level of M ratio. There were two observed genetic subdivisions in the population supporting the observations of farmers in different areas. This base line information on genetic diversity, bottleneck analysis, and mismatch analysis was obtained to assist the conservation decision and management of the breed.

Genetic Variation and Population Structure in Jamunapari Goats Using Microsatellites, Mitochondrial DNA, and Milk Protein Genes

PubMed Central

Rout, P. K.; Thangraj, K.; Mandal, A.; Roy, R.

2012-01-01

Jamunapari, a dairy goat breed of India, has been gradually declining in numbers in its home tract over the years. We have analysed genetic variation and population history in Jamunapari goats based on 17 microsatellite loci, 2 milk protein loci, mitochondrial hypervariable region I (HVRI) sequencing, and three Y-chromosomal gene sequencing. We used the mitochondrial DNA (mtDNA) mismatch distribution, microsatellite data, and bottleneck tests to infer the population history and demography. The mean number of alleles per locus was 9.0 indicating that the allelic variation was high in all the loci and the mean heterozygosity was 0.769 at nuclear loci. Although the population size is smaller than 8,000 individuals, the amount of variability both in terms of allelic richness and gene diversity was high in all the microsatellite loci except ILST 005. The gene diversity and effective number of alleles at milk protein loci were higher than the 10 other Indian goat breeds that they were compared to. Mismatch analysis was carried out and the analysis revealed that the population curve was unimodal indicating the expansion of population. The genetic diversity of Y-chromosome genes was low in the present study. The observed mean M ratio in the population was above the critical significance value (Mc) and close to one indicating that it has maintained a slowly changing population size. The mode-shift test did not detect any distortion of allele frequency and the heterozygosity excess method showed that there was no significant departure from mutation-drift equilibrium detected in the population. However, the effects of genetic bottlenecks were observed in some loci due to decreased heterozygosity and lower level of M ratio. There were two observed genetic subdivisions in the population supporting the observations of farmers in different areas. This base line information on genetic diversity, bottleneck analysis, and mismatch analysis was obtained to assist the conservation decision and management of the breed. PMID:22606053

Characterization of the uncertainty of divergence time estimation under relaxed molecular clock models using multiple loci.

PubMed

Zhu, Tianqi; Dos Reis, Mario; Yang, Ziheng

2015-03-01

Genetic sequence data provide information about the distances between species or branch lengths in a phylogeny, but not about the absolute divergence times or the evolutionary rates directly. Bayesian methods for dating species divergences estimate times and rates by assigning priors on them. In particular, the prior on times (node ages on the phylogeny) incorporates information in the fossil record to calibrate the molecular tree. Because times and rates are confounded, our posterior time estimates will not approach point values even if an infinite amount of sequence data are used in the analysis. In a previous study we developed a finite-sites theory to characterize the uncertainty in Bayesian divergence time estimation in analysis of large but finite sequence data sets under a strict molecular clock. As most modern clock dating analyses use more than one locus and are conducted under relaxed clock models, here we extend the theory to the case of relaxed clock analysis of data from multiple loci (site partitions). Uncertainty in posterior time estimates is partitioned into three sources: Sampling errors in the estimates of branch lengths in the tree for each locus due to limited sequence length, variation of substitution rates among lineages and among loci, and uncertainty in fossil calibrations. Using a simple but analogous estimation problem involving the multivariate normal distribution, we predict that as the number of loci ([Formula: see text]) goes to infinity, the variance in posterior time estimates decreases and approaches the infinite-data limit at the rate of 1/[Formula: see text], and the limit is independent of the number of sites in the sequence alignment. We then confirmed the predictions by using computer simulation on phylogenies of two or three species, and by analyzing a real genomic data set for six primate species. Our results suggest that with the fossil calibrations fixed, analyzing multiple loci or site partitions is the most effective way for improving the precision of posterior time estimation. However, even if a huge amount of sequence data is analyzed, considerable uncertainty will persist in time estimates. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society of Systematic Biologists.

Genetic heterogeneity in Finnish hereditary prostate cancer using ordered subset analysis

PubMed Central

Simpson, Claire L; Cropp, Cheryl D; Wahlfors, Tiina; George, Asha; Jones, MaryPat S; Harper, Ursula; Ponciano-Jackson, Damaris; Tammela, Teuvo; Schleutker, Johanna; Bailey-Wilson, Joan E

2013-01-01

Prostate cancer (PrCa) is the most common male cancer in developed countries and the second most common cause of cancer death after lung cancer. We recently reported a genome-wide linkage scan in 69 Finnish hereditary PrCa (HPC) families, which replicated the HPC9 locus on 17q21-q22 and identified a locus on 2q37. The aim of this study was to identify and to detect other loci linked to HPC. Here we used ordered subset analysis (OSA), conditioned on nonparametric linkage to these loci to detect other loci linked to HPC in subsets of families, but not the overall sample. We analyzed the families based on their evidence for linkage to chromosome 2, chromosome 17 and a maximum score using the strongest evidence of linkage from either of the two loci. Significant linkage to a 5-cM linkage interval with a peak OSA nonparametric allele-sharing LOD score of 4.876 on Xq26.3-q27 (ΔLOD=3.193, empirical P=0.009) was observed in a subset of 41 families weakly linked to 2q37, overlapping the HPCX1 locus. Two peaks that were novel to the analysis combining linkage evidence from both primary loci were identified; 18q12.1-q12.2 (OSA LOD=2.541, ΔLOD=1.651, P=0.03) and 22q11.1-q11.21 (OSA LOD=2.395, ΔLOD=2.36, P=0.006), which is close to HPC6. Using OSA allows us to find additional loci linked to HPC in subsets of families, and underlines the complex genetic heterogeneity of HPC even in highly aggregated families. PMID:22948022

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

DOE PAGES

Milano, E. R.; Lowry, D. B.; Juenger, T. E.

2016-09-09

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mappingmore » population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes.« less

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milano, E. R.; Lowry, D. B.; Juenger, T. E.

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mappingmore » population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes.« less

Short Communication Mendelian inheritance, linkage, and genotypic disequilibrium in microsatellite loci of Hymenaea stigonocarpa Mart. ex Hayne (Fabaceae-Caesalpinioideae).

PubMed

Moraes, M A; Kubota, T Y K; Silva, E C B; Silva, A M; Cambuim, J; Moraes, M L T; Furlani Junior, E; Sebbenn, A M

2016-07-29

Hymenaea stigonocarpa is a deciduous and monoecious Neotropical tree species pollinated by bats. Due to overexploitation and habitat destruction, the population size has drastically diminished in nature. No previous study has investigated Mendelian inheritance, linkage, and genotypic disequilibrium in the available microsatellite markers in this species. So, our aim was to estimate these parameters using six microsatellite loci in a sample of 470 adults and 219 juveniles from two populations of H. stigonocarpa. In addition, 30 seeds per tree from 35 seed-trees were collected. Each seed was kept record of the seed-trees and fruit origin. Based on the six microsatellite loci, we found that only 10.6% of the cases showed significant deviations from Mendelian segregation and 15.3% showed linkage. We detected no evidence of genotypic disequilibrium between the loci in the adult trees or juveniles. Thus, our results suggest that these loci can be used with great accuracy in future genetic analyses of H. stigonocarpa populations.

Multiple-locus variable-number tandem repeat analysis of Salmonella Enteritidis isolates from human and non-human sources using a single multiplex PCR

PubMed Central

Cho, Seongbeom; Boxrud, David J; Bartkus, Joanne M; Whittam, Thomas S; Saeed, Mahdi

2007-01-01

Simplified multiple-locus variable-number tandem repeat analysis (MLVA) was developed using one-shot multiplex PCR for seven variable-number tandem repeats (VNTR) markers with high diversity capacity. MLVA, phage typing, and PFGE methods were applied on 34 diverse Salmonella Enteritidis isolates from human and non-human sources. MLVA detected allelic variations that helped to classify the S. Enteritidis isolates into more evenly distributed subtypes than other methods. MLVA-based S. Enteritidis clonal groups were largely associated with sources of the isolates. Nei's diversity indices for polymorphism ranged from 0.25 to 0.70 for seven VNTR loci markers. Based on Simpson's and Shannon's diversity indices, MLVA had a higher discriminatory power than pulsed field gel electrophoresis (PFGE), phage typing, or multilocus enzyme electrophoresis. Therefore, MLVA may be used along with PFGE to enhance the effectiveness of the molecular epidemiologic investigation of S. Enteritidis infections. PMID:17692097

A PQL (protein quantity loci) analysis of mature pea seed proteins identifies loci determining seed protein composition.

PubMed

Bourgeois, Michael; Jacquin, Françoise; Cassecuelle, Florence; Savois, Vincent; Belghazi, Maya; Aubert, Grégoire; Quillien, Laurence; Huart, Myriam; Marget, Pascal; Burstin, Judith

2011-05-01

Legume seeds are a major source of dietary proteins for humans and animals. Deciphering the genetic control of their accumulation is thus of primary significance towards their improvement. At first, we analysed the genetic variability of the pea seed proteome of three genotypes over 3 years of cultivation. This revealed that seed protein composition variability was under predominant genetic control, with as much as 60% of the spots varying quantitatively among the three genotypes. Then, by combining proteomic and quantitative trait loci (QTL) mapping approaches, we uncovered the genetic architecture of seed proteome variability. Protein quantity loci (PQL) were searched for 525 spots detected on 2-D gels obtained for 157 recombinant inbred lines. Most protein quantity loci mapped in clusters, suggesting that the accumulation of the major storage protein families was under the control of a limited number of loci. While convicilin accumulation was mainly under the control of cis-regulatory regions, vicilins and legumins were controlled by both cis- and trans-regulatory regions. Some loci controlled both seed protein composition and protein content and a locus on LGIIa appears to be a major regulator of protein composition and of protein in vitro digestibility. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ontogenetic change in relative performance of allozyme genotypes influences detection of heterosis in the earthworm Eisenia andrei.

PubMed

McElroy, T C; Diehl, W J

2005-02-01

The effect of ontogeny on relationships between allozyme genotypes and fresh weight was measured weekly throughout the life history of the earthworm Eisenia andrei to test the hypothesis that there is an ontogenetic component to variation in such relationships. Two of six allozyme loci showed a significant increase in apparent heterosis with ontogeny, while one locus showed a significant decrease in apparent heterosis. Three loci showed a significant decrease in the performance of common homozygotes with ontogeny. Patterns of relative genotypic performance varied among loci, but the cumulative effect was an increase in apparent allozyme heterosis later in ontogeny coinciding with a series of positive relationships between multilocus heterozygosity and fresh weight. The results could not be used to determine whether these patterns were caused by selection acting on the loci directly or on loci tightly linked to allozyme loci. However, because the same individuals were used throughout this study and thus allele frequencies and heterozygote deficiency were constant, the presence of both ontogenetic effects and differences in such patterns among loci is not compatible with a general inbreeding effect. Examining relative genotypic performance repetitively using the same individuals through ontogeny or in different environments is a very powerful experimental design for testing the effects of inbreeding or other populational factors.

Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

PubMed

Sawcer, Stephen; Hellenthal, Garrett; Pirinen, Matti; Spencer, Chris C A; Patsopoulos, Nikolaos A; Moutsianas, Loukas; Dilthey, Alexander; Su, Zhan; Freeman, Colin; Hunt, Sarah E; Edkins, Sarah; Gray, Emma; Booth, David R; Potter, Simon C; Goris, An; Band, Gavin; Oturai, Annette Bang; Strange, Amy; Saarela, Janna; Bellenguez, Céline; Fontaine, Bertrand; Gillman, Matthew; Hemmer, Bernhard; Gwilliam, Rhian; Zipp, Frauke; Jayakumar, Alagurevathi; Martin, Roland; Leslie, Stephen; Hawkins, Stanley; Giannoulatou, Eleni; D'alfonso, Sandra; Blackburn, Hannah; Martinelli Boneschi, Filippo; Liddle, Jennifer; Harbo, Hanne F; Perez, Marc L; Spurkland, Anne; Waller, Matthew J; Mycko, Marcin P; Ricketts, Michelle; Comabella, Manuel; Hammond, Naomi; Kockum, Ingrid; McCann, Owen T; Ban, Maria; Whittaker, Pamela; Kemppinen, Anu; Weston, Paul; Hawkins, Clive; Widaa, Sara; Zajicek, John; Dronov, Serge; Robertson, Neil; Bumpstead, Suzannah J; Barcellos, Lisa F; Ravindrarajah, Rathi; Abraham, Roby; Alfredsson, Lars; Ardlie, Kristin; Aubin, Cristin; Baker, Amie; Baker, Katharine; Baranzini, Sergio E; Bergamaschi, Laura; Bergamaschi, Roberto; Bernstein, Allan; Berthele, Achim; Boggild, Mike; Bradfield, Jonathan P; Brassat, David; Broadley, Simon A; Buck, Dorothea; Butzkueven, Helmut; Capra, Ruggero; Carroll, William M; Cavalla, Paola; Celius, Elisabeth G; Cepok, Sabine; Chiavacci, Rosetta; Clerget-Darpoux, Françoise; Clysters, Katleen; Comi, Giancarlo; Cossburn, Mark; Cournu-Rebeix, Isabelle; Cox, Mathew B; Cozen, Wendy; Cree, Bruce A C; Cross, Anne H; Cusi, Daniele; Daly, Mark J; Davis, Emma; de Bakker, Paul I W; Debouverie, Marc; D'hooghe, Marie Beatrice; Dixon, Katherine; Dobosi, Rita; Dubois, Bénédicte; Ellinghaus, David; Elovaara, Irina; Esposito, Federica; Fontenille, Claire; Foote, Simon; Franke, Andre; Galimberti, Daniela; Ghezzi, Angelo; Glessner, Joseph; Gomez, Refujia; Gout, Olivier; Graham, Colin; Grant, Struan F A; Guerini, Franca Rosa; Hakonarson, Hakon; Hall, Per; Hamsten, Anders; Hartung, Hans-Peter; Heard, Rob N; Heath, Simon; Hobart, Jeremy; Hoshi, Muna; Infante-Duarte, Carmen; Ingram, Gillian; Ingram, Wendy; Islam, Talat; Jagodic, Maja; Kabesch, Michael; Kermode, Allan G; Kilpatrick, Trevor J; Kim, Cecilia; Klopp, Norman; Koivisto, Keijo; Larsson, Malin; Lathrop, Mark; Lechner-Scott, Jeannette S; Leone, Maurizio A; Leppä, Virpi; Liljedahl, Ulrika; Bomfim, Izaura Lima; Lincoln, Robin R; Link, Jenny; Liu, Jianjun; Lorentzen, Aslaug R; Lupoli, Sara; Macciardi, Fabio; Mack, Thomas; Marriott, Mark; Martinelli, Vittorio; Mason, Deborah; McCauley, Jacob L; Mentch, Frank; Mero, Inger-Lise; Mihalova, Tania; Montalban, Xavier; Mottershead, John; Myhr, Kjell-Morten; Naldi, Paola; Ollier, William; Page, Alison; Palotie, Aarno; Pelletier, Jean; Piccio, Laura; Pickersgill, Trevor; Piehl, Fredrik; Pobywajlo, Susan; Quach, Hong L; Ramsay, Patricia P; Reunanen, Mauri; Reynolds, Richard; Rioux, John D; Rodegher, Mariaemma; Roesner, Sabine; Rubio, Justin P; Rückert, Ina-Maria; Salvetti, Marco; Salvi, Erika; Santaniello, Adam; Schaefer, Catherine A; Schreiber, Stefan; Schulze, Christian; Scott, Rodney J; Sellebjerg, Finn; Selmaj, Krzysztof W; Sexton, David; Shen, Ling; Simms-Acuna, Brigid; Skidmore, Sheila; Sleiman, Patrick M A; Smestad, Cathrine; Sørensen, Per Soelberg; Søndergaard, Helle Bach; Stankovich, Jim; Strange, Richard C; Sulonen, Anna-Maija; Sundqvist, Emilie; Syvänen, Ann-Christine; Taddeo, Francesca; Taylor, Bruce; Blackwell, Jenefer M; Tienari, Pentti; Bramon, Elvira; Tourbah, Ayman; Brown, Matthew A; Tronczynska, Ewa; Casas, Juan P; Tubridy, Niall; Corvin, Aiden; Vickery, Jane; Jankowski, Janusz; Villoslada, Pablo; Markus, Hugh S; Wang, Kai; Mathew, Christopher G; Wason, James; Palmer, Colin N A; Wichmann, H-Erich; Plomin, Robert; Willoughby, Ernest; Rautanen, Anna; Winkelmann, Juliane; Wittig, Michael; Trembath, Richard C; Yaouanq, Jacqueline; Viswanathan, Ananth C; Zhang, Haitao; Wood, Nicholas W; Zuvich, Rebecca; Deloukas, Panos; Langford, Cordelia; Duncanson, Audrey; Oksenberg, Jorge R; Pericak-Vance, Margaret A; Haines, Jonathan L; Olsson, Tomas; Hillert, Jan; Ivinson, Adrian J; De Jager, Philip L; Peltonen, Leena; Stewart, Graeme J; Hafler, David A; Hauser, Stephen L; McVean, Gil; Donnelly, Peter; Compston, Alastair

2011-08-10

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.

Allele frequency distribution for 21 autosomal STR loci in Nepal.

PubMed

Kraaijenbrink, T; van Driem, G L; Opgenort, J R M L; Tuladhar, N M; de Knijff, P

2007-05-24

The allele frequency distributions of 21 autosomal loci contained in the AmpFlSTR Identifiler, the Powerplex 16 and the FFFL multiplex PCR kits, was studied in 953 unrelated individuals from Nepal. Several new alleles (i.e. not yet reported in the NIST Short Tandem Repeat DNA Internet DataBase [http://www.cstl.nist.gov/biotech/strbase/]) have been detected in the process.

Isolation and characterization of 16 microsatellite loci in the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae)

Treesearch

C. S. Davis; K. E. Mock; B. J. Bentz; S. M. Bromilow; N. V. Bartell; B. W. Murray; A. D. Roe; J. E. K. Cooke

2009-01-01

We isolated 16 polymorphic microsatellite loci in the mountain pine beetle (Dendroctonus ponderosae Hopkins) and developed conditions for amplifying these markers in four multiplex reactions. Three to 14 alleles were detected per locus across two sampled populations. Observed and expected heterozygosities ranged from 0.000 to 0.902 and from 0.100 to 0.830, respectively...

Genetic loci associated with coronary artery disease harbor evidence of selection and antagonistic pleiotropy.

PubMed

Byars, Sean G; Huang, Qin Qin; Gray, Lesley-Ann; Bakshi, Andrew; Ripatti, Samuli; Abraham, Gad; Stearns, Stephen C; Inouye, Michael

2017-06-01

Traditional genome-wide scans for positive selection have mainly uncovered selective sweeps associated with monogenic traits. While selection on quantitative traits is much more common, very few signals have been detected because of their polygenic nature. We searched for positive selection signals underlying coronary artery disease (CAD) in worldwide populations, using novel approaches to quantify relationships between polygenic selection signals and CAD genetic risk. We identified new candidate adaptive loci that appear to have been directly modified by disease pressures given their significant associations with CAD genetic risk. These candidates were all uniquely and consistently associated with many different male and female reproductive traits suggesting selection may have also targeted these because of their direct effects on fitness. We found that CAD loci are significantly enriched for lifetime reproductive success relative to the rest of the human genome, with evidence that the relationship between CAD and lifetime reproductive success is antagonistic. This supports the presence of antagonistic-pleiotropic tradeoffs on CAD loci and provides a novel explanation for the maintenance and high prevalence of CAD in modern humans. Lastly, we found that positive selection more often targeted CAD gene regulatory variants using HapMap3 lymphoblastoid cell lines, which further highlights the unique biological significance of candidate adaptive loci underlying CAD. Our study provides a novel approach for detecting selection on polygenic traits and evidence that modern human genomes have evolved in response to CAD-induced selection pressures and other early-life traits sharing pleiotropic links with CAD.

QTLs for heading date and plant height under multiple environments in rice.

PubMed

Han, Zhongmin; Hu, Wei; Tan, Cong; Xing, Yongzhong

2017-02-01

Both heading date and plant height are important traits related to grain yield in rice. In this study, a recombinant inbred lines (RILs) population was used to map quantitative trait loci (QTLs) for both traits under 3 long-day (LD) environments and 1 short-day (SD) environment. A total of eight QTLs for heading date and three QTLs for plant height were detected by composite interval mapping under LD conditions. Additional one QTL for heading date and three QTLs for plant height were identified by Two-QTL model under LD conditions. Among them, major QTLs qHd7.1, qHd7.2 and qHd8 for heading date, and qPh1 and qPh7.1 for plant height were commonly detected. qHd7.1 and qHd7.2 were mapped to small regions of less than 1 cM. Genome position comparison of previously cloned genes with QTLs detected in this study revealed that qHd5 and qPh3.1 were two novel QTLs. The alleles of these QTLs increasing trait values were dispersed in both parents, which well explained the transgressive segregation observed in this population. In addition, the interaction between qHd7.1 and qHd8 was detected under all LD conditions. Multiple-QTL model analysis revealed that all QTLs and their interactions explained over 80% of heading date variation and 50% of plant height variation. Two heading date QTLs were detected under SD condition. Of them, qHd10 were commonly identified under LD condition. The difference in QTL detection between LD and SD conditions indicated most heading date QTLs are sensitive to photoperiod. These findings will benefit breeding design for heading date and plant height in rice.

A modified multiplex ligation-dependent probe amplification method for the detection of 22q11.2 copy number variations in patients with congenital heart disease.

PubMed

Zhang, Xiaoqing; Xu, Yuejuan; Liu, Deyuan; Geng, Juan; Chen, Sun; Jiang, Zhengwen; Fu, Qihua; Sun, Kun

2015-05-08

Copy number variations (CNVs) of chromosomal region 22q11.2 are associated with a subset of patients with congenital heart disease (CHD). Accurate and efficient detection of CNV is important for genetic analysis of CHD. The aim of the study was to introduce a novel approach named CNVplex®, a high-throughput analysis technique designed for efficient detection of chromosomal CNVs, and to explore the prevalence of sub-chromosomal imbalances in 22q11.2 loci in patients with CHD from a single institute. We developed a novel technique, CNVplex®, for high-throughput detection of sub-chromosomal copy number aberrations. Modified from the multiplex ligation-dependent probe amplification (MLPA) method, it introduced a lengthening ligation system and four universal primer sets, which simplified the synthesis of probes and significantly improved the flexibility of the experiment. We used 110 samples, which were extensively characterized with chromosomal microarray analysis and MLPA, to validate the performance of the newly developed method. Furthermore, CNVplex® was used to screen for sub-chromosomal imbalances in 22q11.2 loci in 818 CHD patients consecutively enrolled from Shanghai Children's Medical Center. In the methodology development phase, CNVplex® detected all copy number aberrations that were previously identified with both chromosomal microarray analysis and MLPA, demonstrating 100% sensitivity and specificity. In the validation phase, 22q11.2 deletion and 22q11.2 duplication were detected in 39 and 1 of 818 patients with CHD by CNVplex®, respectively. Our data demonstrated that the frequency of 22q11.2 deletion varied among sub-groups of CHD patients. Notably, 22q11.2 deletion was more commonly observed in cases with conotruncal defect (CTD) than in cases with non-CTD (P<0.001). With higher resolution and more probes against selected chromosomal loci, CNVplex® also identified several individuals with small CNVs and alterations in other chromosomes. CNVplex® is sensitive and specific in its detection of CNVs, and it is an alternative to MLPA for batch screening of pathogenetic CNVs in known genomic loci.

Hundreds of variants clustered in genomic loci and biological pathways affect human height

PubMed Central

Lango Allen, Hana; Estrada, Karol; Lettre, Guillaume; Berndt, Sonja I.; Weedon, Michael N.; Rivadeneira, Fernando; Willer, Cristen J.; Jackson, Anne U.; Vedantam, Sailaja; Raychaudhuri, Soumya; Ferreira, Teresa; Wood, Andrew R.; Weyant, Robert J.; Segrè, Ayellet V.; Speliotes, Elizabeth K.; Wheeler, Eleanor; Soranzo, Nicole; Park, Ju-Hyun; Yang, Jian; Gudbjartsson, Daniel; Heard-Costa, Nancy L.; Randall, Joshua C.; Qi, Lu; Smith, Albert Vernon; Mägi, Reedik; Pastinen, Tomi; Liang, Liming; Heid, Iris M.; Luan, Jian'an; Thorleifsson, Gudmar; Winkler, Thomas W.; Goddard, Michael E.; Lo, Ken Sin; Palmer, Cameron; Workalemahu, Tsegaselassie; Aulchenko, Yurii S.; Johansson, Åsa; Zillikens, M.Carola; Feitosa, Mary F.; Esko, Tõnu; Johnson, Toby; Ketkar, Shamika; Kraft, Peter; Mangino, Massimo; Prokopenko, Inga; Absher, Devin; Albrecht, Eva; Ernst, Florian; Glazer, Nicole L.; Hayward, Caroline; Hottenga, Jouke-Jan; Jacobs, Kevin B.; Knowles, Joshua W.; Kutalik, Zoltán; Monda, Keri L.; Polasek, Ozren; Preuss, Michael; Rayner, Nigel W.; Robertson, Neil R.; Steinthorsdottir, Valgerdur; Tyrer, Jonathan P.; Voight, Benjamin F.; Wiklund, Fredrik; Xu, Jianfeng; Zhao, Jing Hua; Nyholt, Dale R.; Pellikka, Niina; Perola, Markus; Perry, John R.B.; Surakka, Ida; Tammesoo, Mari-Liis; Altmaier, Elizabeth L.; Amin, Najaf; Aspelund, Thor; Bhangale, Tushar; Boucher, Gabrielle; Chasman, Daniel I.; Chen, Constance; Coin, Lachlan; Cooper, Matthew N.; Dixon, Anna L.; Gibson, Quince; Grundberg, Elin; Hao, Ke; Junttila, M. Juhani; Kaplan, Lee M.; Kettunen, Johannes; König, Inke R.; Kwan, Tony; Lawrence, Robert W.; Levinson, Douglas F.; Lorentzon, Mattias; McKnight, Barbara; Morris, Andrew P.; Müller, Martina; Ngwa, Julius Suh; Purcell, Shaun; Rafelt, Suzanne; Salem, Rany M.; Salvi, Erika; Sanna, Serena; Shi, Jianxin; Sovio, Ulla; Thompson, John R.; Turchin, Michael C.; Vandenput, Liesbeth; Verlaan, Dominique J.; Vitart, Veronique; White, Charles C.; Ziegler, Andreas; Almgren, Peter; Balmforth, Anthony J.; Campbell, Harry; Citterio, Lorena; De Grandi, Alessandro; Dominiczak, Anna; Duan, Jubao; Elliott, Paul; Elosua, Roberto; Eriksson, Johan G.; Freimer, Nelson B.; Geus, Eco J.C.; Glorioso, Nicola; Haiqing, Shen; Hartikainen, Anna-Liisa; Havulinna, Aki S.; Hicks, Andrew A.; Hui, Jennie; Igl, Wilmar; Illig, Thomas; Jula, Antti; Kajantie, Eero; Kilpeläinen, Tuomas O.; Koiranen, Markku; Kolcic, Ivana; Koskinen, Seppo; Kovacs, Peter; Laitinen, Jaana; Liu, Jianjun; Lokki, Marja-Liisa; Marusic, Ana; Maschio, Andrea; Meitinger, Thomas; Mulas, Antonella; Paré, Guillaume; Parker, Alex N.; Peden, John F.; Petersmann, Astrid; Pichler, Irene; Pietiläinen, Kirsi H.; Pouta, Anneli; Ridderstråle, Martin; Rotter, Jerome I.; Sambrook, Jennifer G.; Sanders, Alan R.; Schmidt, Carsten Oliver; Sinisalo, Juha; Smit, Jan H.; Stringham, Heather M.; Walters, G.Bragi; Widen, Elisabeth; Wild, Sarah H.; Willemsen, Gonneke; Zagato, Laura; Zgaga, Lina; Zitting, Paavo; Alavere, Helene; Farrall, Martin; McArdle, Wendy L.; Nelis, Mari; Peters, Marjolein J.; Ripatti, Samuli; van Meurs, Joyce B.J.; Aben, Katja K.; Ardlie, Kristin G; Beckmann, Jacques S.; Beilby, John P.; Bergman, Richard N.; Bergmann, Sven; Collins, Francis S.; Cusi, Daniele; den Heijer, Martin; Eiriksdottir, Gudny; Gejman, Pablo V.; Hall, Alistair S.; Hamsten, Anders; Huikuri, Heikki V.; Iribarren, Carlos; Kähönen, Mika; Kaprio, Jaakko; Kathiresan, Sekar; Kiemeney, Lambertus; Kocher, Thomas; Launer, Lenore J.; Lehtimäki, Terho; Melander, Olle; Mosley, Tom H.; Musk, Arthur W.; Nieminen, Markku S.; O'Donnell, Christopher J.; Ohlsson, Claes; Oostra, Ben; Palmer, Lyle J.; Raitakari, Olli; Ridker, Paul M.; Rioux, John D.; Rissanen, Aila; Rivolta, Carlo; Schunkert, Heribert; Shuldiner, Alan R.; Siscovick, David S.; Stumvoll, Michael; Tönjes, Anke; Tuomilehto, Jaakko; van Ommen, Gert-Jan; Viikari, Jorma; Heath, Andrew C.; Martin, Nicholas G.; Montgomery, Grant W.; Province, Michael A.; Kayser, Manfred; Arnold, Alice M.; Atwood, Larry D.; Boerwinkle, Eric; Chanock, Stephen J.; Deloukas, Panos; Gieger, Christian; Grönberg, Henrik; Hall, Per; Hattersley, Andrew T.; Hengstenberg, Christian; Hoffman, Wolfgang; Lathrop, G.Mark; Salomaa, Veikko; Schreiber, Stefan; Uda, Manuela; Waterworth, Dawn; Wright, Alan F.; Assimes, Themistocles L.; Barroso, Inês; Hofman, Albert; Mohlke, Karen L.; Boomsma, Dorret I.; Caulfield, Mark J.; Cupples, L.Adrienne; Erdmann, Jeanette; Fox, Caroline S.; Gudnason, Vilmundur; Gyllensten, Ulf; Harris, Tamara B.; Hayes, Richard B.; Jarvelin, Marjo-Riitta; Mooser, Vincent; Munroe, Patricia B.; Ouwehand, Willem H.; Penninx, Brenda W.; Pramstaller, Peter P.; Quertermous, Thomas; Rudan, Igor; Samani, Nilesh J.; Spector, Timothy D.; Völzke, Henry; Watkins, Hugh; Wilson, James F.; Groop, Leif C.; Haritunians, Talin; Hu, Frank B.; Kaplan, Robert C.; Metspalu, Andres; North, Kari E.; Schlessinger, David; Wareham, Nicholas J.; Hunter, David J.; O'Connell, Jeffrey R.; Strachan, David P.; Wichmann, H.-Erich; Borecki, Ingrid B.; van Duijn, Cornelia M.; Schadt, Eric E.; Thorsteinsdottir, Unnur; Peltonen, Leena; Uitterlinden, André; Visscher, Peter M.; Chatterjee, Nilanjan; Loos, Ruth J.F.; Boehnke, Michael; McCarthy, Mark I.; Ingelsson, Erik; Lindgren, Cecilia M.; Abecasis, Gonçalo R.; Stefansson, Kari; Frayling, Timothy M.; Hirschhorn, Joel N

2010-01-01

Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence phenotype. Genome-wide association (GWA) studies have identified >600 variants associated with human traits1, but these typically explain small fractions of phenotypic variation, raising questions about the utility of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait2,3. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P=0.016), and that underlie skeletal growth defects (P<0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants, and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented amongst variants that alter amino acid structure of proteins and expression levels of nearby genes. Our data explain ∼10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to ∼16% of phenotypic variation (∼20% of heritable variation). Although additional approaches are needed to fully dissect the genetic architecture of polygenic human traits, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways. PMID:20881960

Novel Genetic Loci Control Calcium Absorption and Femur Bone Mass as well as Their Response to Low Calcium Intake in Male BXD Recombinant Inbred Mice†

PubMed Central

Reyes Fernandez, Perla C.; Replogle, Rebecca A.; Wang, Libo; Zhang, Min; Fleet, James C.

2016-01-01

Low dietary calcium (Ca) intake during growth limits peak bone mass but physiological adaptation can prevent this adverse effect. To assess the genetic control on the physiologic response to dietary Ca restriction (RCR) we conducted a study in 51 BXD lines fed either 0.5% (basal) or 0.25% (low) Ca diets from 4–12 wks of age (n=8/line/diet). Ca absorption (CaAbs), femur bone mineral density (BMD), and bone mineral content (BMC) were examined. ANCOVA with body size as covariate was used to detect significant line and diet main effects, and line-by-diet interactions. Body size-corrected residuals were used for linkage mapping and to estimate heritability (h2). Loci controlling the phenotypes were identified using composite interval mapping on each diet and for the RCR. h2 of basal phenotypes (0.37– 0.43) and their RCR (0.32–0.38) was moderate. For each phenotype we identified multiple QTL on each diet and for the RCR. Several loci affected multiple traits: Chr 1 (88.3–90.6 cM, CaAbs, BMC), Chr 4 (45.8–49.2 cM, CaAbs, BMD, BMC), Chr 8 (28.6–31.6 cM, CaAbs, BMD RCR), and Chr 15 (13.6–24 cM, BMD, BMC), and (32.3–36 cM, CaAbs RCR, BMD). This suggests that gene clusters may regulate interdependent bone-related phenotypes. Using in silico expression QTL (eQTL) mapping and bioinformatic tools we identified novel candidates for the regulation of bone under Ca stress (Ext1, Deptor), and for the first time, we report genes modulating Ca absorption (Inadl, Sc4mol, Sh3rf1 and Dennd3), and both Ca and bone metabolism (Tceanc2, Tll1 and Aadat). Our data reveal gene-by-diet interactions and the existence of novel relationships between bone and Ca metabolism during growth. This article is protected by copyright. All rights reserved PMID:26636428

Polymorphic microsatellite loci for the sand pocket mouse Chaetodipus arenarius, an endemic from the Baja California Peninsula

USGS Publications Warehouse

Munguia-Vega, A.; Rodriguez-Estrella, R.; Nachman, M.; Culver, M.

2009-01-01

Fifteen polymorphic microsatellite loci were isolated from an enriched genomic library of the sand pocket mouse Chaetodipus arenarius. The mean number of alleles per locus was 11.53 (range five to 19) and the average observed heterozygosity was 0.764 (range 0.121 to 1.0). The markers will be used for detecting the impact of human-induced habitat fragmentation on patterns of gene flow, genetic structure, and extinction risk. In addition, these markers will be useful across the genus because most of the loci cross-amplified and were polymorphic in three other species of Chaetodipus. ?? 2008 The Authors.

mrsFAST-Ultra: a compact, SNP-aware mapper for high performance sequencing applications.

PubMed

Hach, Faraz; Sarrafi, Iman; Hormozdiari, Farhad; Alkan, Can; Eichler, Evan E; Sahinalp, S Cenk

2014-07-01

High throughput sequencing (HTS) platforms generate unprecedented amounts of data that introduce challenges for processing and downstream analysis. While tools that report the 'best' mapping location of each read provide a fast way to process HTS data, they are not suitable for many types of downstream analysis such as structural variation detection, where it is important to report multiple mapping loci for each read. For this purpose we introduce mrsFAST-Ultra, a fast, cache oblivious, SNP-aware aligner that can handle the multi-mapping of HTS reads very efficiently. mrsFAST-Ultra improves mrsFAST, our first cache oblivious read aligner capable of handling multi-mapping reads, through new and compact index structures that reduce not only the overall memory usage but also the number of CPU operations per alignment. In fact the size of the index generated by mrsFAST-Ultra is 10 times smaller than that of mrsFAST. As importantly, mrsFAST-Ultra introduces new features such as being able to (i) obtain the best mapping loci for each read, and (ii) return all reads that have at most n mapping loci (within an error threshold), together with these loci, for any user specified n. Furthermore, mrsFAST-Ultra is SNP-aware, i.e. it can map reads to reference genome while discounting the mismatches that occur at common SNP locations provided by db-SNP; this significantly increases the number of reads that can be mapped to the reference genome. Notice that all of the above features are implemented within the index structure and are not simple post-processing steps and thus are performed highly efficiently. Finally, mrsFAST-Ultra utilizes multiple available cores and processors and can be tuned for various memory settings. Our results show that mrsFAST-Ultra is roughly five times faster than its predecessor mrsFAST. In comparison to newly enhanced popular tools such as Bowtie2, it is more sensitive (it can report 10 times or more mappings per read) and much faster (six times or more) in the multi-mapping mode. Furthermore, mrsFAST-Ultra has an index size of 2GB for the entire human reference genome, which is roughly half of that of Bowtie2. mrsFAST-Ultra is open source and it can be accessed at http://mrsfast.sourceforge.net. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Genome-wide Association Study Identifies African-Specific Susceptibility Loci in African Americans with Inflammatory Bowel Disease

PubMed Central

Brant, Steven R.; Okou, David T.; Simpson, Claire L.; Cutler, David J.; Haritunians, Talin; Bradfield, Jonathan P.; Chopra, Pankaj; Prince, Jarod; Begum, Ferdouse; Kumar, Archana; Huang, Chengrui; Venkateswaran, Suresh; Datta, Lisa W.; Wei, Zhi; Thomas, Kelly; Herrinton, Lisa J.; Klapproth, Jan-Micheal A.; Quiros, Antonio J.; Seminerio, Jenifer; Liu, Zhenqiu; Alexander, Jonathan S.; Baldassano, Robert N.; Dudley-Brown, Sharon; Cross, Raymond K.; Dassopoulos, Themistocles; Denson, Lee A.; Dhere, Tanvi A.; Dryden, Gerald W.; Hanson, John S.; Hou, Jason K.; Hussain, Sunny Z.; Hyams, Jeffrey S.; Isaacs, Kim L.; Kader, Howard; Kappelman, Michael D.; Katz, Jeffry; Kellermayer, Richard; Kirschner, Barbara S.; Kuemmerle, John F.; Kwon, John H.; Lazarev, Mark; Li, Ellen; Mack, David; Mannon, Peter; Moulton, Dedrick E.; Newberry, Rodney D.; Osuntokun, Bankole O.; Patel, Ashish S.; Saeed, Shehzad A.; Targan, Stephan R.; Valentine, John F.; Wang, Ming-Hsi; Zonca, Martin; Rioux, John D.; Duerr, Richard H.; Silverberg, Mark S.; Cho, Judy H.; Hakonarson, Hakon; Zwick, Michael E.; McGovern, Dermot P.B.; Kugathasan, Subra

2016-01-01

Background & Aims The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. Methods We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified [IBD-U]) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P<5.0×10−8 in meta-analysis with a nominal evidence (P<.05) in each scan were considered to have genome-wide significance. Results We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance associations for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P<1.6×10−6): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B, PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles. Conclusions We performed a genome-wide association study of African Americans with IBD and identified loci associated with CD and UC in only this population; we also replicated loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry. PMID:27693347

Determination of Yield in Inconel 718 for Axial-Torsional Loading at Temperatures up to 649 C

NASA Technical Reports Server (NTRS)

Gil, Christopher M.; Lissenden, Cliff J.; Lerch, Bradley A.

1998-01-01

An experimental program has been implemented to determine small offset yield loci under axial-torsional loading at elevated temperatures. The nickel-base superalloy Inconel 718 (IN718) was chosen for study due to its common use in aeropropulsion applications. Initial and subsequent yield loci were determined for solutioned IN718 at 23, 371, and 454 C and for aged (precipitation hardened) IN718 at 23 and 649 C. The shape of the initial yield loci for solutioned and aged IN718 agreed well with the von Mises prediction. However, in general, the centers of initial yield loci were eccentric to the origin due to a strength-differential (S-D) effect that increased with temperature. Subsequent yield loci exhibited anisotropic hardening in the form of translation and distortion of the locus. This work shows that it is possible to determine yield surfaces for metallic materials at temperatures up to at least 649 C using multiple probes of a single specimen. The experimental data is first-of-its-kind for a superalloy at these very high temperatures and will facilitate a better understanding of multiaxial material response, eventually leading to improved design tools for engine designers.

Genetic dissection of hybrid incompatibilities between Drosophila simulans and D. mauritiana. II. Mapping hybrid male sterility loci on the third chromosome.

PubMed

Tao, Yun; Zeng, Zhao-Bang; Li, Jian; Hartl, Daniel L; Laurie, Cathy C

2003-08-01

Hybrid male sterility (HMS) is a rapidly evolving mechanism of reproductive isolation in Drosophila. Here we report a genetic analysis of HMS in third-chromosome segments of Drosophila mauritiana that were introgressed into a D. simulans background. Qualitative genetic mapping was used to localize 10 loci on 3R and a quantitative trait locus (QTL) procedure (multiple-interval mapping) was used to identify 19 loci on the entire chromosome. These genetic incompatibilities often show dominance and complex patterns of epistasis. Most of the HMS loci have relatively small effects and generally at least two or three of them are required to produce complete sterility. Only one small region of the third chromosome of D. mauritiana by itself causes a high level of infertility when introgressed into D. simulans. By comparison with previous studies of the X chromosome, we infer that HMS loci are only approximately 40% as dense on this autosome as they are on the X chromosome. These results are consistent with the gradual evolution of hybrid incompatibilities as a by-product of genetic divergence in allopatric populations.

Genetic dissection of hybrid incompatibilities between Drosophila simulans and D. mauritiana. II. Mapping hybrid male sterility loci on the third chromosome.

PubMed Central

Tao, Yun; Zeng, Zhao-Bang; Li, Jian; Hartl, Daniel L; Laurie, Cathy C

2003-01-01

Hybrid male sterility (HMS) is a rapidly evolving mechanism of reproductive isolation in Drosophila. Here we report a genetic analysis of HMS in third-chromosome segments of Drosophila mauritiana that were introgressed into a D. simulans background. Qualitative genetic mapping was used to localize 10 loci on 3R and a quantitative trait locus (QTL) procedure (multiple-interval mapping) was used to identify 19 loci on the entire chromosome. These genetic incompatibilities often show dominance and complex patterns of epistasis. Most of the HMS loci have relatively small effects and generally at least two or three of them are required to produce complete sterility. Only one small region of the third chromosome of D. mauritiana by itself causes a high level of infertility when introgressed into D. simulans. By comparison with previous studies of the X chromosome, we infer that HMS loci are only approximately 40% as dense on this autosome as they are on the X chromosome. These results are consistent with the gradual evolution of hybrid incompatibilities as a by-product of genetic divergence in allopatric populations. PMID:12930748

Microsatellites loci reveal heterozygosis and population structure in vampire bats (Desmodus rotundus) (Chiroptera: Phyllostomidae) of Mexico.

PubMed

Romero-Nava, Claudia; León-Paniagua, Livia; Ortega, Jorge

2014-06-01

A limited number of studies have focused on the population genetic structure of vampire bats (Desmous rotundus) in America. This medium-sized bat is distributed in tropical areas of the continent with high prevalence in forested livestock areas. The aim of this work was to characterize the vampire population structure and their genetic differentiation. For this, we followed standard methods by which live vampires (caught by mist-netting) and preserved material from scientific collections, were obtained for a total of 15 different locations, ranging from Chihuahua (North) to Quintana Roo (Southeast). Tissue samples were obtained from both live and collected animals, and the genetic differentiation, within and among localities, was assessed by the use of seven microsatellite loci. Our results showed that all loci were polymorphic and no private alleles were detected. High levels of heterozygosis were detected when the proportion of alleles in each locus were compared. Pairwise (ST) and R(ST) detected significant genetic differentiation among individuals from different localities. Our population structure results indicate the presence of eleven clusters, with a high percentage of assigned individuals to some specific collecting site.

The Psychological Impact of Prenatal Diagnosis and Disclosure of Susceptibility Loci: First Impressions of Parents' Experiences.

PubMed

van der Steen, S L; Riedijk, S R; Verhagen-Visser, J; Govaerts, L C P; Srebniak, M I; Van Opstal, D; Joosten, M; Knapen, M F C M; Tibben, A; Diderich, K E M; Galjaard, R J H

2016-12-01

Genomic microarray may detect susceptibility loci (SL) for neurodevelopmental disorders such as autism and epilepsy, with a yet unquantifiable risk for the fetus. The prenatal disclosure of susceptibility loci is a topic of much debate. Many health care professionals fear that reporting susceptibility loci may put a psychological burden on pregnant couples. It is our policy to disclose prenatal susceptibility loci as we recognize them as actionable for prospective parents. The aim of this report was to evaluate the psychological impact of disclosing a prenatal diagnosis of susceptibility loci. The psychological impact of disclosing susceptibility loci was evaluated in the first patients who received such results. Eight out of 15 women who had a susceptibility locus disclosed and four of their partners consented to share their experiences through a telephonic evaluation (n = 12). Follow-up time ranged from 3 to 15 months after their prenatal test result. The reporting of susceptibility loci was initially 'shocking' for five parents while the other seven felt 'worried'. Ten out of 12 participants indicated they would like to be informed about the susceptibility locus again, two were unsure. Most had no enduring worries. Participants unanimously indicated that pregnant couples should have an individualized pre-test choice about susceptibility loci (non)disclosure. We observed no negative psychological impact with the prenatal diagnosis and disclosure of SL on participants. A key factor in mitigating parental anxiety with SL disclosure appears to be post-test genetic counseling. Our report confirms that pregnant women and their partners prefer an individualized choice regarding the scope of prenatal testing.

Genetic polymorphism analyses of a novel panel of 19 X-STR loci in the Chinese Uygur ethnic minority* #

PubMed Central

Guo, Yu-xin; Chen, Jian-gang; Wang, Yan; Yan, Jiang-wei; Chen, Jing; Yao, Tian-hua; Zhang, Li-ping; Yang, Guang; Meng, Hao-tian; Zhang, Yu-dang; Mei, Ting; Liu, Yao-shun; Dong, Qian; Zhu, Bo-feng

2016-01-01

The population genetic data and forensic parameters of 19 X-chromosome short tandem repeat (X-STR) loci in Chinese Uygur ethnic minority are presented. These loci were detected in a sample of 233 (94 males and 139 females) unrelated healthy individuals. We observed 238 alleles at the 19 X-STR loci, with the corresponding gene frequencies spanning the range from 0.0021 to 0.5644. After Bonferroni correction (P>0.0026), there were no significant deviations from Hardy-Weinberg equilibrium. The cumulative power of discrimination in females and males, and the probability of exclusion of the 19 X-STR loci were 0.999 999 999 999 999 999 998 091, 0.999 999 999 999 966, and 0.999 999 986 35, respectively. The cumulative mean exclusion chance was 0.999 999 992 849 in deficiency cases, 0.999 999 999 999 628 in normal trios, and 0.999 999 998 722 in duo cases. The high value of the forensic parameters mentioned above revealed that the novel panel of 19 loci had important values for forensic applications in the Uygur group. PMID:27143264

Examining Two Sets of Introgression Lines in Rice (Oryza sativa L.) Reveals Favorable Alleles that Improve Grain Zn and Fe Concentrations

PubMed Central

Hu, Xia; Cheng, Li-Rui; Xu, Jian-Long; Shi, Yu-Min; Li, Zhi-Kang

2015-01-01

In the modern world, the grain mineral concentration (GMC) in rice (Oryza sativa L.) not only includes important micronutrient elements such as iron (Fe) and zinc (Zn), but it also includes toxic heavy metal elements, especially cadmium (Cd) and lead (Pb). To date, the genetic mechanisms underlying the regulation of GMC, especially the genetic background and G × E effects of GMC, remain largely unknown. In this study, we adopted two sets of backcross introgression lines (BILs) derived from IR75862 (a Zn-dense rice variety) as the donor parent and two elite indica varieties, Ce258 and Zhongguangxiang1, as recurrent parents to detect QTL affecting GMC traits including Fe, Zn, Cd and Pb concentrations in two environments. We detected a total of 22 loci responsible for GMC traits, which are distributed on all 12 rice chromosomes except 5, 9 and 10. Six genetic overlap (GO) regions affecting multiple elements were found, in which most donor alleles had synergistic effects on GMC. Some toxic heavy metal-independent loci (such as qFe1, qFe2 and qZn12) and some regions that have opposite genetic effects on micronutrient (Fe and Zn) and heavy metal element (Pb) concentrations (such as GO-IV) may be useful for marker-assisted biofortification breeding in rice. We discuss three important points affecting biofortification breeding efforts in rice, including correlations between different GMC traits, the genetic background effect and the G × E effect. PMID:26161553

Variant-aware saturating mutagenesis using multiple Cas9 nucleases identifies regulatory elements at trait-associated loci.

PubMed

Canver, Matthew C; Lessard, Samuel; Pinello, Luca; Wu, Yuxuan; Ilboudo, Yann; Stern, Emily N; Needleman, Austen J; Galactéros, Frédéric; Brugnara, Carlo; Kutlar, Abdullah; McKenzie, Colin; Reid, Marvin; Chen, Diane D; Das, Partha Pratim; A Cole, Mitchel; Zeng, Jing; Kurita, Ryo; Nakamura, Yukio; Yuan, Guo-Cheng; Lettre, Guillaume; Bauer, Daniel E; Orkin, Stuart H

2017-04-01

Cas9-mediated, high-throughput, saturating in situ mutagenesis permits fine-mapping of function across genomic segments. Disease- and trait-associated variants identified in genome-wide association studies largely cluster at regulatory loci. Here we demonstrate the use of multiple designer nucleases and variant-aware library design to interrogate trait-associated regulatory DNA at high resolution. We developed a computational tool for the creation of saturating-mutagenesis libraries with single or multiple nucleases with incorporation of variants. We applied this methodology to the HBS1L-MYB intergenic region, which is associated with red-blood-cell traits, including fetal hemoglobin levels. This approach identified putative regulatory elements that control MYB expression. Analysis of genomic copy number highlighted potential false-positive regions, thus emphasizing the importance of off-target analysis in the design of saturating-mutagenesis experiments. Together, these data establish a widely applicable high-throughput and high-resolution methodology to identify minimal functional sequences within large disease- and trait-associated regions.

A Non-Degenerate Code of Deleterious Variants in Mendelian Loci Contributes to Complex Disease Risk

PubMed Central

Blair, David R.; Lyttle, Christopher S.; Mortensen, Jonathan M.; Bearden, Charles F.; Jensen, Anders Boeck; Khiabanian, Hossein; Melamed, Rachel; Rabadan, Raul; Bernstam, Elmer V.; Brunak, Søren; Jensen, Lars Juhl; Nicolae, Dan; Shah, Nigam H.; Grossman, Robert L.; Cox, Nancy J.; White, Kevin P.; Rzhetsky, Andrey

2013-01-01

Summary Whereas countless highly penetrant variants have been associated with Mendelian disorders, the genetic etiologies underlying complex diseases remain largely unresolved. Here, we examine the extent to which Mendelian variation contributes to complex disease risk by mining the medical records of over 110 million patients. We detect thousands of associations between Mendelian and complex diseases, revealing a non-degenerate, phenotypic code that links each complex disorder to a unique collection of Mendelian loci. Using genome-wide association results, we demonstrate that common variants associated with complex diseases are enriched in the genes indicated by this “Mendelian code.” Finally, we detect hundreds of comorbidity associations among Mendelian disorders, and we use probabilistic genetic modeling to demonstrate that Mendelian variants likely contribute non-additively to the risk for a subset of complex diseases. Overall, this study illustrates a complementary approach for mapping complex disease loci and provides unique predictions concerning the etiologies of specific diseases. PMID:24074861

Universal target-enrichment baits for anthozoan (Cnidaria) phylogenomics: New approaches to long-standing problems.

PubMed

Quattrini, Andrea M; Faircloth, Brant C; Dueñas, Luisa F; Bridge, Tom C L; Brugler, Mercer R; Calixto-Botía, Iván F; DeLeo, Danielle M; Forêt, Sylvain; Herrera, Santiago; Lee, Simon M Y; Miller, David J; Prada, Carlos; Rádis-Baptista, Gandhi; Ramírez-Portilla, Catalina; Sánchez, Juan A; Rodríguez, Estefanía; McFadden, Catherine S

2018-03-01

Anthozoans (e.g., corals, anemones) are an ecologically important and diverse group of marine metazoans that occur from shallow to deep waters worldwide. However, our understanding of the evolutionary relationships among the ~7,500 species within this class is hindered by the lack of phylogenetically informative markers that can be reliably sequenced across a diversity of taxa. We designed and tested 16,306 RNA baits to capture 720 ultraconserved element loci and 1,071 exon loci. Library preparation and target enrichment were performed on 33 taxa from all orders within the class Anthozoa. Following Illumina sequencing and Trinity assembly, we recovered 1,774 of 1,791 targeted loci. The mean number of loci recovered from each species was 638 ± 222, with more loci recovered from octocorals (783 ± 138 loci) than hexacorals (475 ± 187 loci). Parsimony informative sites ranged from 26 to 49% for alignments at differing hierarchical taxonomic levels (e.g., Anthozoa, Octocorallia, Hexacorallia). The per cent of variable sites within each of three genera (Acropora, Alcyonium, and Sinularia) for which multiple species were sequenced ranged from 4.7% to 30%. Maximum-likelihood analyses recovered highly resolved trees with topologies matching those supported by other studies, including the monophyly of the order Scleractinia. Our results demonstrate the utility of this target-enrichment approach to resolve phylogenetic relationships from relatively old to recent divergences. Redesigning the baits with improved affinities to capture loci within each subclass will provide a valuable toolset to address systematic questions, further our understanding of the timing of diversifications and help resolve long-standing controversial relationships in the class Anthozoa. © 2017 John Wiley & Sons Ltd.

Validation of prostate cancer risk-related loci identified from genome-wide association studies using family-based association analysis: evidence from the International Consortium for Prostate Cancer Genetics (ICPCG).

PubMed

Jin, Guangfu; Lu, Lingyi; Cooney, Kathleen A; Ray, Anna M; Zuhlke, Kimberly A; Lange, Ethan M; Cannon-Albright, Lisa A; Camp, Nicola J; Teerlink, Craig C; Fitzgerald, Liesel M; Stanford, Janet L; Wiley, Kathleen E; Isaacs, Sarah D; Walsh, Patrick C; Foulkes, William D; Giles, Graham G; Hopper, John L; Severi, Gianluca; Eeles, Ros; Easton, Doug; Kote-Jarai, Zsofia; Guy, Michelle; Rinckleb, Antje; Maier, Christiane; Vogel, Walther; Cancel-Tassin, Geraldine; Egrot, Christophe; Cussenot, Olivier; Thibodeau, Stephen N; McDonnell, Shannon K; Schaid, Daniel J; Wiklund, Fredrik; Grönberg, Henrik; Emanuelsson, Monica; Whittemore, Alice S; Oakley-Girvan, Ingrid; Hsieh, Chih-Lin; Wahlfors, Tiina; Tammela, Teuvo; Schleutker, Johanna; Catalona, William J; Zheng, S Lilly; Ostrander, Elaine A; Isaacs, William B; Xu, Jianfeng

2012-07-01

Multiple prostate cancer (PCa) risk-related loci have been discovered by genome-wide association studies (GWAS) based on case-control designs. However, GWAS findings may be confounded by population stratification if cases and controls are inadvertently drawn from different genetic backgrounds. In addition, since these loci were identified in cases with predominantly sporadic disease, little is known about their relationships with hereditary prostate cancer (HPC). The association between seventeen reported PCa susceptibility loci was evaluated with a family-based association test using 1,979 hereditary PCa families of European descent collected by members of the International Consortium for Prostate Cancer Genetics, with a total of 5,730 affected men. The risk alleles for 8 of the 17 loci were significantly over-transmitted from parents to affected offspring, including SNPs residing in 8q24 (regions 1, 2 and 3), 10q11, 11q13, 17q12 (region 1), 17q24 and Xp11. In subgroup analyses, three loci, at 8q24 (regions 1 and 2) plus 17q12, were significantly over-transmitted in hereditary PCa families with five or more affected members, while loci at 3p12, 8q24 (region 2), 11q13, 17q12 (region 1), 17q24 and Xp11 were significantly over-transmitted in HPC families with an average age of diagnosis at 65 years or less. Our results indicate that at least a subset of PCa risk-related loci identified by case-control GWAS are also associated with disease risk in HPC families.

Validation of prostate cancer risk-related loci identified from genome-wide association studies using family-based association analysis: evidence from the International Consortium for Prostate Cancer Genetics (ICPCG)

PubMed Central

Jin, Guangfu; Lu, Lingyi; Cooney, Kathleen A.; Ray, Anna M.; Zuhlke, Kimberly A.; Lange, Ethan M.; Cannon-Albright, Lisa A.; Camp, Nicola J.; Teerlink, Craig C.; FitzGerald, Liesel M.; Stanford, Janet L.; Wiley, Kathleen E.; Walsh, Patrick C.; Foulkes, William D.; Giles, Graham G.; Hopper, John L.; Severi, Gianluca; Eeles, Ros; Easton, Doug; Kote-Jarai, Zsofia; Guy, Michelle; Rinckleb, Antje; Maier, Christiane; Vogel, Walther; Cancel-Tassin, Geraldine; Egrot, Christophe; Cussenot, Olivier; Thibodeau, Stephen N.; McDonnell, Shannon K.; Schaid, Daniel J.; Wiklund, Fredrik; Grönberg, Henrik; Emanuelsson, Monica; Whittemore, Alice S.; Oakley-Girvan, Ingrid; Hsieh, Chih-Lin; Wahlfors, Tiina; Tammela, Teuvo; Schleutker, Johanna; Catalona, William J.; Zheng, S. Lilly; Isaacs, William B.

2012-01-01

Multiple prostate cancer (PCa) risk-related loci have been discovered by genome-wide association studies (GWAS) based on case–control designs. However, GWAS findings may be confounded by population stratification if cases and controls are inadvertently drawn from different genetic backgrounds. In addition, since these loci were identified in cases with predominantly sporadic disease, little is known about their relationships with hereditary prostate cancer (HPC). The association between seventeen reported PCa susceptibility loci was evaluated with a family-based association test using 1,979 hereditary PCa families of European descent collected by members of the International Consortium for Prostate Cancer Genetics, with a total of 5,730 affected men. The risk alleles for 8 of the 17 loci were significantly over-transmitted from parents to affected offspring, including SNPs residing in 8q24 (regions 1, 2 and 3), 10q11, 11q13, 17q12 (region 1), 17q24 and Xp11. In subgroup analyses, three loci, at 8q24 (regions 1 and 2) plus 17q12, were significantly over-transmitted in hereditary PCa families with five or more affected members, while loci at 3p12, 8q24 (region 2), 11q13, 17q12 (region 1), 17q24 and Xp11 were significantly over-transmitted in HPC families with an average age of diagnosis at 65 years or less. Our results indicate that at least a subset of PCa risk-related loci identified by case–control GWAS are also associated with disease risk in HPC families. PMID:22198737

Genome-wide association study meta-analysis identifies five new loci for systemic lupus erythematosus.

PubMed

Julià, Antonio; López-Longo, Francisco Javier; Pérez Venegas, José J; Bonàs-Guarch, Silvia; Olivé, Àlex; Andreu, José Luís; Aguirre-Zamorano, Mª Ángeles; Vela, Paloma; Nolla, Joan M; de la Fuente, José Luís Marenco; Zea, Antonio; Pego-Reigosa, José María; Freire, Mercedes; Díez, Elvira; Rodríguez-Almaraz, Esther; Carreira, Patricia; Blanco, Ricardo; Taboada, Víctor Martínez; López-Lasanta, María; Corbeto, Mireia López; Mercader, Josep M; Torrents, David; Absher, Devin; Marsal, Sara; Fernández-Nebro, Antonio

2018-05-30

Systemic lupus erythematosus (SLE) is a common systemic autoimmune disease with a complex genetic inheritance. Genome-wide association studies (GWAS) have significantly increased the number of significant loci associated with SLE risk. To date, however, established loci account for less than 30% of the disease heritability and additional risk variants have yet to be identified. Here we performed a GWAS followed by a meta-analysis to identify new genome-wide significant loci for SLE. We genotyped a cohort of 907 patients with SLE (cases) and 1524 healthy controls from Spain and performed imputation using the 1000 Genomes reference data. We tested for association using logistic regression with correction for the principal components of variation. Meta-analysis of the association results was subsequently performed on 7,110,321 variants using genetic data from a large cohort of 4036 patients with SLE and 6959 controls of Northern European ancestry. Genetic association was also tested at the pathway level after removing the effect of known risk loci using PASCAL software. We identified five new loci associated with SLE at the genome-wide level of significance (p < 5 × 10 - 8 ): GRB2, SMYD3, ST8SIA4, LAT2 and ARHGAP27. Pathway analysis revealed several biological processes significantly associated with SLE risk: B cell receptor signaling (p = 5.28 × 10 - 6 ), CTLA4 co-stimulation during T cell activation (p = 3.06 × 10 - 5 ), interleukin-4 signaling (p = 3.97 × 10 - 5 ) and cell surface interactions at the vascular wall (p = 4.63 × 10 - 5 ). Our results identify five novel loci for SLE susceptibility, and biologic pathways associated via multiple low-effect-size loci.

Loss of alleles from the distal short arm of chromosome 1 occurs late in melanoma tumor progression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dracopoli, N.C.; Harnett, P.; Bale, S.J.

The gene for familial malignant melanoma and its precursor lesion, the dysplastic nevus, has been assigned to a region of the distal short arm of chromosome 1, which is frequently involved in karyotypic abnormalities in melanoma cells. The authors have examined loci on chromosome 1p for loss-of-constitutional heterozygosity in 35 melanomas and 21 melanoma cell lines to analyze the role of these abnormalities in melanocyte transformation. Loss-of-heterozygosity at loci on chromosome 1p was identified in 15/35 (43%) melanomas and 11/21 (52%) melanoma cell lines. Analysis of multiple metastases derived from the same patient and of melanoma and lymphoblastoid samples frommore » a family with hereditary melanoma showed that the loss-of-heterozygosity at loci on distal 1p is a late event in tumor progression, rather than the second mutation that would occur if melanoma were due to a cellular recessive mechanism. Comparisons with neuroblastoma and multiple endocrine neoplasia (MEN2) suggest that the frequent 1p loss-of-heterozygosity in these malignancies is a common late event of neuroectodermal tumor progression.« less

Selection signatures in four lignin genes from switchgrass populations divergently selected for in vitro dry matter digestibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Shiyu; Kaeppler, Shawn M.; Vogel, Kenneth P.

Switchgrass is undergoing development as a dedicated cellulosic bioenergy crop. Fermentation of lignocellulosic biomass to ethanol in a bioenergy system or to volatile fatty acids in a livestock production system is strongly and negatively influenced by lignification of cell walls. This study detects specific loci that exhibit selection signatures across switchgrass breeding populations that differ in in vitro dry matter digestibility (IVDMD), ethanol yield, and lignin concentration. Allele frequency changes in candidate genes were used to detect loci under selection. Out of the 183 polymorphisms identified in the four candidate genes, twenty-five loci in the intron regions and four locimore » in coding regions were found to display a selection signature. All loci in the coding regions are synonymous substitutions. Selection in both directions were observed on polymorphisms that appeared to be under selection. Genetic diversity and linkage disequilibrium within the candidate genes were low. The recurrent divergent selection caused excessive moderate allele frequencies in the cycle 3 reduced lignin population as compared to the base population. As a result, this study provides valuable insight on genetic changes occurring in short-term selection in the polyploid populations, and discovered potential markers for breeding switchgrass with improved biomass quality.« less

Genetic dissection of adaptive form and function in rapidly speciating cichlid fishes.

PubMed

Henning, Frederico; Machado-Schiaffino, Gonzalo; Baumgarten, Lukas; Meyer, Axel

2017-05-01

Genes of major phenotypic effects and strong genetic correlations can facilitate adaptation, direct selective responses, and potentially lead to phenotypic convergence. However, the preponderance of this type of genetic architecture in repeatedly evolved adaptations remains unknown. Using hybrids between Haplochromis chilotes (thick-lipped) and Pundamilia nyererei (thin-lipped) we investigated the genetics underlying hypertrophied lips and elongated heads, traits that evolved repeatedly in cichlids. At least 25 loci of small-to-moderate and mainly additive effects were detected. Phenotypic variation in lip and head morphology was largely independent. Although several QTL overlapped for lip and head morphology traits, they were often of opposite effects. The distribution of effect signs suggests strong selection on lips. The fitness implications of several detected loci were demonstrated using a laboratory assay testing for the association between genotype and variation in foraging performance. The persistence of low fitness alleles in head morphology appears to be maintained through antagonistic pleiotropy/close linkage with positive-effect lip morphology alleles. Rather than being based on few major loci with strong positive genetic correlations, our results indicate that the evolution of the Lake Victoria thick-lipped ecomorph is the result of selection on numerous loci distributed throughout the genome. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Selection signatures in four lignin genes from switchgrass populations divergently selected for in vitro dry matter digestibility

DOE PAGES

Chen, Shiyu; Kaeppler, Shawn M.; Vogel, Kenneth P.; ...

2016-11-28

Switchgrass is undergoing development as a dedicated cellulosic bioenergy crop. Fermentation of lignocellulosic biomass to ethanol in a bioenergy system or to volatile fatty acids in a livestock production system is strongly and negatively influenced by lignification of cell walls. This study detects specific loci that exhibit selection signatures across switchgrass breeding populations that differ in in vitro dry matter digestibility (IVDMD), ethanol yield, and lignin concentration. Allele frequency changes in candidate genes were used to detect loci under selection. Out of the 183 polymorphisms identified in the four candidate genes, twenty-five loci in the intron regions and four locimore » in coding regions were found to display a selection signature. All loci in the coding regions are synonymous substitutions. Selection in both directions were observed on polymorphisms that appeared to be under selection. Genetic diversity and linkage disequilibrium within the candidate genes were low. The recurrent divergent selection caused excessive moderate allele frequencies in the cycle 3 reduced lignin population as compared to the base population. As a result, this study provides valuable insight on genetic changes occurring in short-term selection in the polyploid populations, and discovered potential markers for breeding switchgrass with improved biomass quality.« less

Genetic variation within and between strains of outbred Swiss mice.

PubMed

Cui, S; Chesson, C; Hope, R

1993-04-01

The aim of this survey was to measure levels of genetic variation within and between 5 different strains of outbred Swiss mice. Ten to 15 animals from each strain (NIH, Q(S), ARC, IMVS and STUD) were typed, using allozyme electrophoresis, at 10 gene loci: Mod-1, Idh-1, Gpi-I, Es-1, Es-3, Hbb, Pep-3, Gr-1, Got-2 and Pgm-1. Polymorphic variation in at least one of the 5 strains was detected at all 10 loci. The proportion of polymorphic loci ranged from 0.3 (NIH) to 0.8 (IMVS) with a mean of 0.52. Average expected heterozygosities ranged from 0.08 (NIH) to 0.37 (IMVS) with a mean of 0.21. The inbred strain SWR was, as expected, homozygous at all 10 loci. The amount of allelic substitution between pairs of strains was quantified using Nei's genetic distance, and a dendrogram based on these genetic distances showed a close overall similarity in its branching pattern to the known genealogy of the strains. This survey showed that a considerable degree of genetic variation persists in the 5 strains examined, a level of variation similar to that previously detected by Rice and O'Brien (1980) in 3 other outbred Swiss strains.

Patterns of gene flow and selection across multiple species of Acrocephalus warblers: footprints of parallel selection on the Z chromosome.

PubMed

Reifová, Radka; Majerová, Veronika; Reif, Jiří; Ahola, Markus; Lindholm, Antero; Procházka, Petr

2016-06-16

Understanding the mechanisms and selective forces leading to adaptive radiations and origin of biodiversity is a major goal of evolutionary biology. Acrocephalus warblers are small passerines that underwent an adaptive radiation in the last approximately 10 million years that gave rise to 37 extant species, many of which still hybridize in nature. Acrocephalus warblers have served as model organisms for a wide variety of ecological and behavioral studies, yet our knowledge of mechanisms and selective forces driving their radiation is limited. Here we studied patterns of interspecific gene flow and selection across three European Acrocephalus warblers to get a first insight into mechanisms of radiation of this avian group. We analyzed nucleotide variation at eight nuclear loci in three hybridizing Acrocephalus species with overlapping breeding ranges in Europe. Using an isolation-with-migration model for multiple populations, we found evidence for unidirectional gene flow from A. scirpaceus to A. palustris and from A. palustris to A. dumetorum. Gene flow was higher between genetically more closely related A. scirpaceus and A. palustris than between ecologically more similar A. palustris and A. dumetorum, suggesting that gradual accumulation of intrinsic barriers rather than divergent ecological selection are more efficient in restricting interspecific gene flow in Acrocephalus warblers. Although levels of genetic differentiation between different species pairs were in general not correlated, we found signatures of apparently independent instances of positive selection at the same two Z-linked loci in multiple species. Our study brings the first evidence that gene flow occurred during Acrocephalus radiation and not only between sister species. Interspecific gene flow could thus be an important source of genetic variation in individual Acrocephalus species and could have accelerated adaptive evolution and speciation rate in this avian group by creating novel genetic combinations and new phenotypes. Independent instances of positive selection at the same loci in multiple species indicate an interesting possibility that the same loci might have contributed to reproductive isolation in several speciation events.

Comparative genome-wide analysis reveals that Burkholderia contaminans MS14 possesses multiple antimicrobial biosynthesis genes but not major genetic loci required for pathogenesis.

PubMed

Deng, Peng; Wang, Xiaoqiang; Baird, Sonya M; Showmaker, Kurt C; Smith, Leif; Peterson, Daniel G; Lu, Shien

2016-06-01

Burkholderia contaminans MS14 shows significant antimicrobial activities against plant and animal pathogenic fungi and bacteria. The antifungal agent occidiofungin produced by MS14 has great potential for development of biopesticides and pharmaceutical drugs. However, the use of Burkholderia species as biocontrol agent in agriculture is restricted due to the difficulties in distinguishing between plant growth-promoting bacteria and the pathogenic bacteria. The complete MS14 genome was sequenced and analyzed to find what beneficial and virulence-related genes it harbors. The phylogenetic relatedness of B. contaminans MS14 and other 17 Burkholderia species was also analyzed. To research MS14's potential virulence, the gene regions related to the antibiotic production, antibiotic resistance, and virulence were compared between MS14 and other Burkholderia genomes. The genome of B. contaminans MS14 was sequenced and annotated. The genomic analyses reveal the presence of multiple gene sets for antimicrobial biosynthesis, which contribute to its antimicrobial activities. BLAST results indicate that the MS14 genome harbors a large number of unique regions. MS14 is closely related to another plant growth-promoting Burkholderia strain B. lata 383 according to the average nucleotide identity data. Moreover, according to the phylogenetic analysis, plant growth-promoting species isolated from soils and mammalian pathogenic species are clustered together, respectively. MS14 has multiple antimicrobial activity-related genes identified from the genome, but it lacks key virulence-related gene loci found in the pathogenic strains. Additionally, plant growth-promoting Burkholderia species have one or more antimicrobial biosynthesis genes in their genomes as compared with nonplant growth-promoting soil-isolated Burkholderia species. On the other hand, pathogenic species harbor multiple virulence-associated gene loci that are not present in nonpathogenic Burkholderia species. The MS14 genome as well as Burkholderia species genome show considerable diversity. Multiple antimicrobial agent biosynthesis genes were identified in the genome of plant growth-promoting species of Burkholderia. In addition, by comparing to nonpathogenic Burkholderia species, pathogenic Burkholderia species have more characterized homologs of the gene loci known to contribute to pathogenicity and virulence to plant and animals. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Detecting multiple DNA human profile from a mosquito blood meal.

PubMed

Rabêlo, K C N; Albuquerque, C M R; Tavares, V B; Santos, S M; Souza, C A; Oliveira, T C; Moura, R R; Brandão, L A C; Crovella, S

2016-08-26

Criminal traces commonly found at crime scenes may present mixtures from two or more individuals. The scene of the crime is important for the collection of various types of traces in order to find the perpetrator of the crime. Thus, we propose that hematophagous mosquitoes found at crime scenes can be used to perform genetic testing of human blood and aid in suspect investigation. The aim of the study was to obtain a single Aedes aegypti mosquito profile from a human DNA mixture containing genetic materials of four individuals. We also determined the effect of blood acquisition time by setting time intervals of 24, 48, and 72 h after the blood meal. STR loci and amelogenin were analyzed, and the results showed that human DNA profiles could be obtained from hematophagous mosquitos at 24 h following the blood meal. It is possible that hematophagous mosquitoes can be used as biological remains at the scene of the crime, and can be used to detect human DNA profiles of up to four individuals.

Pgltools: a genomic arithmetic tool suite for manipulation of Hi-C peak and other chromatin interaction data.

PubMed

Greenwald, William W; Li, He; Smith, Erin N; Benaglio, Paola; Nariai, Naoki; Frazer, Kelly A

2017-04-07

Genomic interaction studies use next-generation sequencing (NGS) to examine the interactions between two loci on the genome, with subsequent bioinformatics analyses typically including annotation, intersection, and merging of data from multiple experiments. While many file types and analysis tools exist for storing and manipulating single locus NGS data, there is currently no file standard or analysis tool suite for manipulating and storing paired-genomic-loci: the data type resulting from "genomic interaction" studies. As genomic interaction sequencing data are becoming prevalent, a standard file format and tools for working with these data conveniently and efficiently are needed. This article details a file standard and novel software tool suite for working with paired-genomic-loci data. We present the paired-genomic-loci (PGL) file standard for genomic-interactions data, and the accompanying analysis tool suite "pgltools": a cross platform, pypy compatible python package available both as an easy-to-use UNIX package, and as a python module, for integration into pipelines of paired-genomic-loci analyses. Pgltools is a freely available, open source tool suite for manipulating paired-genomic-loci data. Source code, an in-depth manual, and a tutorial are available publicly at www.github.com/billgreenwald/pgltools , and a python module of the operations can be installed from PyPI via the PyGLtools module.

Strong signatures of selection in the domestic pig genome.

PubMed

Rubin, Carl-Johan; Megens, Hendrik-Jan; Martinez Barrio, Alvaro; Maqbool, Khurram; Sayyab, Shumaila; Schwochow, Doreen; Wang, Chao; Carlborg, Örjan; Jern, Patric; Jørgensen, Claus B; Archibald, Alan L; Fredholm, Merete; Groenen, Martien A M; Andersson, Leif

2012-11-27

Domestication of wild boar (Sus scrofa) and subsequent selection have resulted in dramatic phenotypic changes in domestic pigs for a number of traits, including behavior, body composition, reproduction, and coat color. Here we have used whole-genome resequencing to reveal some of the loci that underlie phenotypic evolution in European domestic pigs. Selective sweep analyses revealed strong signatures of selection at three loci harboring quantitative trait loci that explain a considerable part of one of the most characteristic morphological changes in the domestic pig--the elongation of the back and an increased number of vertebrae. The three loci were associated with the NR6A1, PLAG1, and LCORL genes. The latter two have repeatedly been associated with loci controlling stature in other domestic animals and in humans. Most European domestic pigs are homozygous for the same haplotype at these three loci. We found an excess of derived nonsynonymous substitutions in domestic pigs, most likely reflecting both positive selection and relaxed purifying selection after domestication. Our analysis of structural variation revealed four duplications at the KIT locus that were exclusively present in white or white-spotted pigs, carrying the Dominant white, Patch, or Belt alleles. This discovery illustrates how structural changes have contributed to rapid phenotypic evolution in domestic animals and how alleles in domestic animals may evolve by the accumulation of multiple causative mutations as a response to strong directional selection.

Strong signatures of selection in the domestic pig genome

PubMed Central

Rubin, Carl-Johan; Megens, Hendrik-Jan; Barrio, Alvaro Martinez; Maqbool, Khurram; Sayyab, Shumaila; Schwochow, Doreen; Wang, Chao; Carlborg, Örjan; Jern, Patric; Jørgensen, Claus B.; Archibald, Alan L.; Fredholm, Merete; Groenen, Martien A. M.; Andersson, Leif

2012-01-01

Domestication of wild boar (Sus scrofa) and subsequent selection have resulted in dramatic phenotypic changes in domestic pigs for a number of traits, including behavior, body composition, reproduction, and coat color. Here we have used whole-genome resequencing to reveal some of the loci that underlie phenotypic evolution in European domestic pigs. Selective sweep analyses revealed strong signatures of selection at three loci harboring quantitative trait loci that explain a considerable part of one of the most characteristic morphological changes in the domestic pig—the elongation of the back and an increased number of vertebrae. The three loci were associated with the NR6A1, PLAG1, and LCORL genes. The latter two have repeatedly been associated with loci controlling stature in other domestic animals and in humans. Most European domestic pigs are homozygous for the same haplotype at these three loci. We found an excess of derived nonsynonymous substitutions in domestic pigs, most likely reflecting both positive selection and relaxed purifying selection after domestication. Our analysis of structural variation revealed four duplications at the KIT locus that were exclusively present in white or white-spotted pigs, carrying the Dominant white, Patch, or Belt alleles. This discovery illustrates how structural changes have contributed to rapid phenotypic evolution in domestic animals and how alleles in domestic animals may evolve by the accumulation of multiple causative mutations as a response to strong directional selection. PMID:23151514

Recapitulation of genome-wide association studies on body mass index in the Korean population.

PubMed

Hong, K W; Oh, B

2012-08-01

Obesity is a risk factor for multiple disorders such as diabetes and cardiovascular disease. Recently, a genome-wide association study for body mass index (BMI) was conducted in 249 796 individuals of European ancestry by the Genetic Investigation of Anthropometric Traits (GIANT) consortium. They identified 14 known obesity susceptibility loci and 18 new loci associated with BMI at the genome-wide significance level (P<5 × 10⁻⁸). Because the prevalence and severity of obesity vary among ethnic groups, it is worthy to investigate these results in another ethnic population. We examined the BMI association of 19 single-nucleotide polymorphisms (SNPs) out of the 32 in 8842 individuals from the Korean Association Resource data, and found 12 SNPs to be associated with BMI in the Korean population. Eight loci, rs10968576 (BDNF), rs3817334 (MTCH2), rs1558902 (FTO), rs571312 (MC4R), rs543874 (SEC16B), rs987237 (TFAP2B), rs2867125 (TMEM18) and rs7138803 (FAIM2), were previously known obesity susceptibility loci, and the remaining four loci, rs1514175 (TNNI3K), rs206936 (NUDT3), rs4771122 (MTIF3) and rs2241423 (MAP2K5), were newly identified as BMI loci by the GIANT study. Further, all 12 SNPs showed the same direction of effect on BMI between the two ethnic groups, suggesting a similar genetic architecture governing the obesity.

Genome-wide Meta-analyses of Breast, Ovarian and Prostate Cancer Association Studies Identify Multiple New Susceptibility Loci Shared by At Least Two Cancer Types

PubMed Central

Kar, Siddhartha P.; Beesley, Jonathan; Al Olama, Ali Amin; Michailidou, Kyriaki; Tyrer, Jonathan; Kote-Jarai, ZSofia; Lawrenson, Kate; Lindstrom, Sara; Ramus, Susan J.; Thompson, Deborah J.; Kibel, Adam S.; Dansonka-Mieszkowska, Agnieszka; Michael, Agnieszka; Dieffenbach, Aida K.; Gentry-Maharaj, Aleksandra; Whittemore, Alice S.; Wolk, Alicja; Monteiro, Alvaro; Peixoto, Ana; Kierzek, Andrzej; Cox, Angela; Rudolph, Anja; Gonzalez-Neira, Anna; Wu, Anna H.; Lindblom, Annika; Swerdlow, Anthony; Ziogas, Argyrios; Ekici, Arif B.; Burwinkel, Barbara; Karlan, Beth Y.; Nordestgaard, Børge G.; Blomqvist, Carl; Phelan, Catherine; McLean, Catriona; Pearce, Celeste Leigh; Vachon, Celine; Cybulski, Cezary; Slavov, Chavdar; Stegmaier, Christa; Maier, Christiane; Ambrosone, Christine B.; Høgdall, Claus K.; Teerlink, Craig C.; Kang, Daehee; Tessier, Daniel C.; Schaid, Daniel J.; Stram, Daniel O.; Cramer, Daniel W.; Neal, David E.; Eccles, Diana; Flesch-Janys, Dieter; Velez Edwards, Digna R.; Wokozorczyk, Dominika; Levine, Douglas A.; Yannoukakos, Drakoulis; Sawyer, Elinor J.; Bandera, Elisa V.; Poole, Elizabeth M.; Goode, Ellen L.; Khusnutdinova, Elza; Høgdall, Estrid; Song, Fengju; Bruinsma, Fiona; Heitz, Florian; Modugno, Francesmary; Hamdy, Freddie C.; Wiklund, Fredrik; Giles, Graham G.; Olsson, Håkan; Wildiers, Hans; Ulmer, Hans-Ulrich; Pandha, Hardev; Risch, Harvey A.; Darabi, Hatef; Salvesen, Helga B.; Nevanlinna, Heli; Gronberg, Henrik; Brenner, Hermann; Brauch, Hiltrud; Anton-Culver, Hoda; Song, Honglin; Lim, Hui-Yi; McNeish, Iain; Campbell, Ian; Vergote, Ignace; Gronwald, Jacek; Lubiński, Jan; Stanford, Janet L.; Benítez, Javier; Doherty, Jennifer A.; Permuth, Jennifer B.; Chang-Claude, Jenny; Donovan, Jenny L.; Dennis, Joe; Schildkraut, Joellen M.; Schleutker, Johanna; Hopper, John L.; Kupryjanczyk, Jolanta; Park, Jong Y.; Figueroa, Jonine; Clements, Judith A.; Knight, Julia A.; Peto, Julian; Cunningham, Julie M.; Pow-Sang, Julio; Batra, Jyotsna; Czene, Kamila; Lu, Karen H.; Herkommer, Kathleen; Khaw, Kay-Tee; Matsuo, Keitaro; Muir, Kenneth; Offitt, Kenneth; Chen, Kexin; Moysich, Kirsten B.; Aittomäki, Kristiina; Odunsi, Kunle; Kiemeney, Lambertus A.; Massuger, Leon F.A.G.; Fitzgerald, Liesel M.; Cook, Linda S.; Cannon-Albright, Lisa; Hooning, Maartje J.; Pike, Malcolm C.; Bolla, Manjeet K.; Luedeke, Manuel; Teixeira, Manuel R.; Goodman, Marc T.; Schmidt, Marjanka K.; Riggan, Marjorie; Aly, Markus; Rossing, Mary Anne; Beckmann, Matthias W.; Moisse, Matthieu; Sanderson, Maureen; Southey, Melissa C.; Jones, Michael; Lush, Michael; Hildebrandt, Michelle A. T.; Hou, Ming-Feng; Schoemaker, Minouk J.; Garcia-Closas, Montserrat; Bogdanova, Natalia; Rahman, Nazneen; Le, Nhu D.; Orr, Nick; Wentzensen, Nicolas; Pashayan, Nora; Peterlongo, Paolo; Guénel, Pascal; Brennan, Paul; Paulo, Paula; Webb, Penelope M.; Broberg, Per; Fasching, Peter A.; Devilee, Peter; Wang, Qin; Cai, Qiuyin; Li, Qiyuan; Kaneva, Radka; Butzow, Ralf; Kopperud, Reidun Kristin; Schmutzler, Rita K.; Stephenson, Robert A.; MacInnis, Robert J.; Hoover, Robert N.; Winqvist, Robert; Ness, Roberta; Milne, Roger L.; Travis, Ruth C.; Benlloch, Sara; Olson, Sara H.; McDonnell, Shannon K.; Tworoger, Shelley S.; Maia, Sofia; Berndt, Sonja; Lee, Soo Chin; Teo, Soo-Hwang; Thibodeau, Stephen N.; Bojesen, Stig E.; Gapstur, Susan M.; Kjær, Susanne Krüger; Pejovic, Tanja; Tammela, Teuvo L.J.; Dörk, Thilo; Brüning, Thomas; Wahlfors, Tiina; Key, Tim J.; Edwards, Todd L.; Menon, Usha; Hamann, Ute; Mitev, Vanio; Kosma, Veli-Matti; Setiawan, Veronica Wendy; Kristensen, Vessela; Arndt, Volker; Vogel, Walther; Zheng, Wei; Sieh, Weiva; Blot, William J.; Kluzniak, Wojciech; Shu, Xiao-Ou; Gao, Yu-Tang; Schumacher, Fredrick; Freedman, Matthew L.; Berchuck, Andrew; Dunning, Alison M.; Simard, Jacques; Haiman, Christopher A.; Spurdle, Amanda; Sellers, Thomas A.; Hunter, David J.; Henderson, Brian E.; Kraft, Peter; Chanock, Stephen J.; Couch, Fergus J.; Hall, Per; Gayther, Simon A.; Easton, Douglas F.; Chenevix-Trench, Georgia; Eeles, Rosalind; Pharoah, Paul D.P.; Lambrechts, Diether

2016-01-01

Breast, ovarian, and prostate cancers are hormone-related and may have a shared genetic basis but this has not been investigated systematically by genome-wide association (GWA) studies. Meta-analyses combining the largest GWA meta-analysis data sets for these cancers totaling 112,349 cases and 116,421 controls of European ancestry, all together and in pairs, identified at P < 10−8 seven new cross-cancer loci: three associated with susceptibility to all three cancers (rs17041869/2q13/BCL2L11; rs7937840/11q12/INCENP; rs1469713/19p13/GATAD2A), two breast and ovarian cancer risk loci (rs200182588/9q31/SMC2; rs8037137/15q26/RCCD1), and two breast and prostate cancer risk loci (rs5013329/1p34/NSUN4; rs9375701/6q23/L3MBTL3). Index variants in five additional regions previously associated with only one cancer also showed clear association with a second cancer type. Cell-type specific expression quantitative trait locus and enhancer-gene interaction annotations suggested target genes with potential cross-cancer roles at the new loci. Pathway analysis revealed significant enrichment of death receptor signaling genes near loci with P < 10−5 in the three-cancer meta-analysis. PMID:27432226

Integrating Genomic Analysis with the Genetic Basis of Gene Expression: Preliminary Evidence of the Identification of Causal Genes for Cardiovascular and Metabolic Traits Related to Nutrition in Mexicans123

PubMed Central

Bastarrachea, Raúl A.; Gallegos-Cabriales, Esther C.; Nava-González, Edna J.; Haack, Karin; Voruganti, V. Saroja; Charlesworth, Jac; Laviada-Molina, Hugo A.; Veloz-Garza, Rosa A.; Cardenas-Villarreal, Velia Margarita; Valdovinos-Chavez, Salvador B.; Gomez-Aguilar, Patricia; Meléndez, Guillermo; López-Alvarenga, Juan Carlos; Göring, Harald H. H.; Cole, Shelley A.; Blangero, John; Comuzzie, Anthony G.; Kent, Jack W.

2012-01-01

Whole-transcriptome expression profiling provides novel phenotypes for analysis of complex traits. Gene expression measurements reflect quantitative variation in transcript-specific messenger RNA levels and represent phenotypes lying close to the action of genes. Understanding the genetic basis of gene expression will provide insight into the processes that connect genotype to clinically significant traits representing a central tenet of system biology. Synchronous in vivo expression profiles of lymphocytes, muscle, and subcutaneous fat were obtained from healthy Mexican men. Most genes were expressed at detectable levels in multiple tissues, and RNA levels were correlated between tissue types. A subset of transcripts with high reliability of expression across tissues (estimated by intraclass correlation coefficients) was enriched for cis-regulated genes, suggesting that proximal sequence variants may influence expression similarly in different cellular environments. This integrative global gene expression profiling approach is proving extremely useful for identifying genes and pathways that contribute to complex clinical traits. Clearly, the coincidence of clinical trait quantitative trait loci and expression quantitative trait loci can help in the prioritization of positional candidate genes. Such data will be crucial for the formal integration of positional and transcriptomic information characterized as genetical genomics. PMID:22797999

A Robust Protocol for Using Multiplexed Droplet Digital PCR to Quantify Somatic Copy Number Alterations in Clinical Tissue Specimens.

PubMed

Hughesman, Curtis B; Lu, X J David; Liu, Kelly Y P; Zhu, Yuqi; Poh, Catherine F; Haynes, Charles

2016-01-01

The ability of droplet digital PCR (ddPCR) to accurately determine the concentrations of amplifiable targets makes it a promising platform for measuring copy number alterations (CNAs) in genomic biomarkers. However, its application to clinical samples, particularly formalin-fixed paraffin-embedded specimens, will require strategies to reliably determine CNAs in DNA of limited quantity and quality. When applied to cancerous tissue, those methods must also account for global genetic instability and the associated probability that the abundance(s) of one or more chosen reference loci do not represent the average ploidy of cells comprising the specimen. Here we present an experimental design strategy and associated data analysis tool that enables accurate determination of CNAs in a panel of biomarkers using multiplexed ddPCR. The method includes strategies to optimize primer and probes design to cleanly segregate droplets in the data output from reaction wells amplifying multiple independent templates, and to correct for bias from artifacts such as DNA fragmentation. We demonstrate how a panel of reference loci can be used to determine a stable CNA-neutral benchmark. These innovations, when taken together, provide a comprehensive strategy that can be used to reliably detect biomarker CNAs in DNA extracted from either frozen or FFPE tissue biopsies.

Using Next Generation Sequencing for Multiplexed Trait-Linked Markers in Wheat

PubMed Central

Bernardo, Amy; Wang, Shan; St. Amand, Paul; Bai, Guihua

2015-01-01

With the advent of next generation sequencing (NGS) technologies, single nucleotide polymorphisms (SNPs) have become the major type of marker for genotyping in many crops. However, the availability of SNP markers for important traits of bread wheat ( Triticum aestivum L.) that can be effectively used in marker-assisted selection (MAS) is still limited and SNP assays for MAS are usually uniplex. A shift from uniplex to multiplex assays will allow the simultaneous analysis of multiple markers and increase MAS efficiency. We designed 33 locus-specific markers from SNP or indel-based marker sequences that linked to 20 different quantitative trait loci (QTL) or genes of agronomic importance in wheat and analyzed the amplicon sequences using an Ion Torrent Proton Sequencer and a custom allele detection pipeline to determine the genotypes of 24 selected germplasm accessions. Among the 33 markers, 27 were successfully multiplexed and 23 had 100% SNP call rates. Results from analysis of "kompetitive allele-specific PCR" (KASP) and sequence tagged site (STS) markers developed from the same loci fully verified the genotype calls of 23 markers. The NGS-based multiplexed assay developed in this study is suitable for rapid and high-throughput screening of SNPs and some indel-based markers in wheat. PMID:26625271

Quantitative trait loci that control body weight in DDD/Sgn and C57BL/6J inbred mice.

PubMed

Suto, Jun-Ichi; Kojima, Misaki

2017-02-01

Inbred DDD/Sgn mice are heavier than inbred C57BL/6J mice. In the present study, we performed quantitative trait loci (QTL) mapping for body weight using R/qtl in reciprocal F 2 male populations between the two strains. We identified four significant QTL on Chrs 1, 2, 5, and 17 (proximal region). The DDD/Sgn allele was associated with increased body weight at QTL on Chrs 1 and 5, and the DDD/Sgn allele was associated with decreased body weight at QTL on Chrs 2 and 17. A multiple regression analysis indicated that the detected QTL explain 30.94 % of the body weight variation. Because DDD/Sgn male mice have extremely high levels of circulating testosterone relative to other inbred mouse strains, we performed QTL mapping for plasma testosterone level to examine the effect of testosterone levels on body weight. We identified one suggestive QTL on Chr 5, which overlapped with body weight QTL. The DDD/Sgn allele was associated with increased testosterone level. Thus, we confirmed that there was a genetic basis for the changes in body weight and testosterone levels in male mice. These findings provide insights into the genetic mechanism by which body weight is controlled in male mice.

An APOE-independent cis-eSNP on chromosome 19q13.32 influences tau levels and late-onset Alzheimer's disease risk.

PubMed

Rao, Shuquan; Ghani, Mahdi; Guo, Zhiyun; Deming, Yuetiva; Wang, Kesheng; Sims, Rebecca; Mao, Canquan; Yao, Yao; Cruchaga, Carlos; Stephan, Dietrich A; Rogaeva, Ekaterina

2018-06-01

Although multiple susceptibility loci for late-onset Alzheimer's disease (LOAD) have been identified, a large portion of the genetic risk for this disease remains unexplained. LOAD risk may be associated with single-nucleotide polymorphisms responsible for changes in gene expression (eSNPs). To detect eSNPs associated with LOAD, we integrated data from LOAD genome-wide association studies and expression quantitative trait loci using Sherlock (a Bayesian statistical method). We identified a cis-regulatory eSNP (rs2927438) located on chromosome 19q13.32, for which subsequent analyses confirmed the association with both LOAD risk and the expression level of several nearby genes. Importantly, rs2927438 may represent an APOE-independent LOAD eSNP according to the weak linkage disequilibrium of rs2927438 with the 2 polymorphisms (rs7412 and rs429358) defining the APOE-ε2, -ε3, and -ε4 alleles. Furthermore, rs2927438 does not influence chromatin interaction events at the APOE locus or cis-regulation of APOE expression. Further exploratory analysis revealed that rs2927438 is significantly associated with tau levels in the cerebrospinal fluid. Our findings suggest that rs2927438 may confer APOE-independent risk for LOAD. Copyright © 2017 Elsevier Inc. All rights reserved.

Quantitative Trait Loci for Resistance to Aspergillus Ear Rot: Analysis by Linkage Mapping, Characterization of Near-Isogenic Lines and Meta-Analysis

USDA-ARS?s Scientific Manuscript database

High levels of aflatoxin contamination of maize can be deadly for exposed human populations. Resistance to aflatoxin accumulation in maize has been reported in multiple studies and acts at multiple steps where there is fungal-plant interaction. In this study, we report the identification and mapping...

Historical biogeography and diversification of truffles in the Tuberaceae and their newly identified Southern hemisphere sister lineage

Treesearch

Gregory Bonito; Matthew E. Smith; Michael Nowak; Rosanne A. Healy; Gonzalo Guevara; Efren Cazares; Akihiko Kinoshita; Eduardo R. Nouhra; Laura S. Dominguez; Leho Tedersoo; Claude Murat; Yun Wang; Baldomero Arroyo Moreno; Donald H. Pfister; Kazuhide Nara; Alessandra Zambonelli; James M. Trappe; Rytas Vilgalys

2013-01-01

In this study we reassessed the biogeography and origin of the Tuberaceae and their relatives using multiple loci and a global sampling of taxa. Multiple independent transitions from an aboveground to a belowground truffie fruiting body form have occurred in the Tuberaceae and in its newly recognized sister lineage...

Genetic Susceptibility to Lipid Levels and Lipid Change Over Time and Risk of Incident Hyperlipidemia in Chinese Populations.

PubMed

Lu, Xiangfeng; Huang, Jianfeng; Mo, Zengnan; He, Jiang; Wang, Laiyuan; Yang, Xueli; Tan, Aihua; Chen, Shufeng; Chen, Jing; Gu, C Charles; Chen, Jichun; Li, Ying; Zhao, Liancheng; Li, Hongfan; Hao, Yongchen; Li, Jianxin; Hixson, James E; Li, Yunzhi; Cheng, Min; Liu, Xiaoli; Cao, Jie; Liu, Fangcao; Huang, Chen; Shen, Chong; Shen, Jinjin; Yu, Ling; Xu, Lihua; Mu, Jianjun; Wu, Xianping; Ji, Xu; Guo, Dongshuang; Zhou, Zhengyuan; Yang, Zili; Wang, Renping; Yang, Jun; Yan, Weili; Peng, Xiaozhong; Gu, Dongfeng

2016-02-01

Multiple genetic loci associated with lipid levels have been identified predominantly in Europeans, and the issue of to what extent these genetic loci can predict blood lipid levels increases over time and the incidence of future hyperlipidemia remains largely unknown. We conducted a meta-analysis of genome-wide association studies of lipid levels in 8344 subjects followed by replication studies including 14 739 additional individuals. We replicated 17 previously reported loci. We also newly identified 3 Chinese-specific variants in previous regions (HLA-C, LIPG, and LDLR) with genome-wide significance. Almost all the variants contributed to lipid levels change and incident hyperlipidemia >8.1-year follow-up among 6428 individuals of a prospective cohort study. The strongest associations for lipid levels change were detected at LPL, TRIB1, APOA1-C3-A4-A5, LIPC, CETP, and LDLR (P range from 4.84×10(-4) to 4.62×10(-18)), whereas LPL, TRIB1, ABCA1, APOA1-C3-A4-A5, CETP, and APOE displayed significant strongest associations for incident hyperlipidemia (P range from 1.20×10(-3) to 4.67×10(-16)). The 4 lipids genetic risk scores were independently associated with linear increases in their corresponding lipid levels and risk of incident hyperlipidemia. A C-statistics analysis showed significant improvement in the prediction of incident hyperlipidemia on top of traditional risk factors including the baseline lipid levels. These findings identified some evidence for allelic heterogeneity in Chinese when compared with Europeans in relation to lipid associations. The individual variants and those cumulative effects were independent risk factors for lipids increase and incident hyperlipidemia. © 2015 American Heart Association, Inc.

Combination of Eight Alleles at Four Quantitative Trait Loci Determines Grain Length in Rice

PubMed Central

Zeng, Yuxiang; Ji, Zhijuan; Wen, Zhihua; Liang, Yan; Yang, Changdeng

2016-01-01

Grain length is an important quantitative trait in rice (Oryza sativa L.) that influences both grain yield and exterior quality. Although many quantitative trait loci (QTLs) for grain length have been identified, it is still unclear how different alleles from different QTLs regulate grain length coordinately. To explore the mechanisms of QTL combination in the determination of grain length, five mapping populations, including two F2 populations, an F3 population, an F7 recombinant inbred line (RIL) population, and an F8 RIL population, were developed from the cross between the U.S. tropical japonica variety ‘Lemont’ and the Chinese indica variety ‘Yangdao 4’ and grown under different environmental conditions. Four QTLs (qGL-3-1, qGL-3-2, qGL-4, and qGL-7) for grain length were detected using both composite interval mapping and multiple interval mapping methods in the mapping populations. In each locus, there was an allele from one parent that increased grain length and another allele from another parent that decreased it. The eight alleles in the four QTLs were analyzed to determine whether these alleles act additively across loci, and lead to a linear relationship between the predicted breeding value of QTLs and phenotype. Linear regression analysis suggested that the combination of eight alleles determined grain length. Plants carrying more grain length-increasing alleles had longer grain length than those carrying more grain length-decreasing alleles. This trend was consistent in all five mapping populations and demonstrated the regulation of grain length by the four QTLs. Thus, these QTLs are ideal resources for modifying grain length in rice. PMID:26942914

Qualitative and quantitative trait loci conditioning resistance to Puccinia coronata pathotypes NQMG and LGCG in the oat (Avena sativa L.) cultivars Ogle and TAM O-301.

PubMed

Jackson, E W; Obert, D E; Menz, M; Hu, G; Bonman, J M

2008-02-01

Mapping disease resistance loci relies on the type and precision of phenotypic measurements. For crown rust of oat, disease severity is commonly assessed based on visual ratings of infection types (IT) and/or diseased leaf area (DLA) of infected plants in the greenhouse or field. These data can be affected by several variables including; (i) non-uniform disease development in the field; (ii) atypical symptom development in the greenhouse; (iii) the presence of multiple pathogenic races or pathotypes in the field, and (iv) rating bias. To overcome these limitations, we mapped crown rust resistance to single isolates in the Ogle/TAM O-301 (OT) recombinant inbred line (RIL) population using detailed measurements of IT, uredinia length (UL) and relative fungal DNA (FDNA) estimates determined by q-PCR. Measurements were taken on OT parents and recombinant inbred lines (RIL) inoculated with Puccinia coronata pathotypes NQMG and LGCG in separate greenhouse and field tests. Qualitative mapping identified an allele conferred by TAM O-301 on linkage group (LG) OT-11, which produced a bleached fleck phenotype to both NQMG and LGCG. Quantitative mapping identified two major quantitative trait loci (QTL) originating from TAM O-301 on LGs OT-11 and OT-32 which reduced UL and FDNA of both isolates in all experiments. Additionally, minor QTLs that reduced UL and FDNA were detected on LGs OT-15 and OT-8, originating from TAM O-301, and on LG OT-27, originating from Ogle. Detailed assessments of the OT population using two pathotypes in both the greenhouse and field provided comprehensive information to effectively map the genes responsible for crown rust resistance in Ogle and TAM O-301 to NQMG and LGCG.

Evaluation of copy-number variants as modifiers of breast and ovarian cancer risk for BRCA1 pathogenic variant carriers

PubMed Central

Walker, Logan C; Marquart, Louise; Pearson, John F; Wiggins, George A R; O'Mara, Tracy A; Parsons, Michael T; Barrowdale, Daniel; McGuffog, Lesley; Dennis, Joe; Benitez, Javier; Slavin, Thomas P; Radice, Paolo; Frost, Debra; Godwin, Andrew K; Meindl, Alfons; Schmutzler, Rita Katharina; Isaacs, Claudine; Peshkin, Beth N; Caldes, Trinidad; Hogervorst, Frans BL; Lazaro, Conxi; Jakubowska, Anna; Montagna, Marco; Chen, Xiaoqing; Offit, Kenneth; Hulick, Peter J; Andrulis, Irene L; Lindblom, Annika; Nussbaum, Robert L; Nathanson, Katherine L; Chenevix-Trench, Georgia; Antoniou, Antonis C; Couch, Fergus J; Spurdle, Amanda B

2017-01-01

Genome-wide studies of patients carrying pathogenic variants (mutations) in BRCA1 or BRCA2 have reported strong associations between single-nucleotide polymorphisms (SNPs) and cancer risk. To conduct the first genome-wide association analysis of copy-number variants (CNVs) with breast or ovarian cancer risk in a cohort of 2500 BRCA1 pathogenic variant carriers, CNV discovery was performed using multiple calling algorithms and Illumina 610k SNP array data from a previously published genome-wide association study. Our analysis, which focused on functionally disruptive genomic deletions overlapping gene regions, identified a number of loci associated with risk of breast or ovarian cancer for BRCA1 pathogenic variant carriers. Despite only including putative deletions called by at least two or more algorithms, detection of selected CNVs by ancillary molecular technologies only confirmed 40% of predicted common (>1% allele frequency) variants. These include four loci that were associated (unadjusted P<0.05) with breast cancer (GTF2H2, ZNF385B, NAALADL2 and PSG5), and two loci associated with ovarian cancer (CYP2A7 and OR2A1). An interesting finding from this study was an association of a validated CNV deletion at the CYP2A7 locus (19q13.2) with decreased ovarian cancer risk (relative risk=0.50, P=0.007). Genomic analysis found this deletion coincides with a region displaying strong regulatory potential in ovarian tissue, but not in breast epithelial cells. This study highlighted the need to verify CNVs in vitro, but also provides evidence that experimentally validated CNVs (with plausible biological consequences) can modify risk of breast or ovarian cancer in BRCA1 pathogenic variant carriers. PMID:28145423

Construction of a high-density genetic map and lint percentage and cottonseed nutrient trait QTL identification in upland cotton (Gossypium hirsutum L.).

PubMed

Liu, Dexin; Liu, Fang; Shan, Xiaoru; Zhang, Jian; Tang, Shiyi; Fang, Xiaomei; Liu, Xueying; Wang, Wenwen; Tan, Zhaoyun; Teng, Zhonghua; Zhang, Zhengsheng; Liu, Dajun

2015-10-01

Upland cotton plays a critical role not only in the textile industry, but also in the production of important secondary metabolites, such as oil and proteins. Construction of a high-density linkage map and identifying yield and seed trait quantitative trail loci (QTL) are prerequisites for molecular marker-assisted selective breeding projects. Here, we update a high-density upland cotton genetic map from recombinant inbred lines. A total of 25,313 SSR primer pairs were screened for polymorphism between Yumian 1 and T586, and 1712 SSR primer pairs were used to genotype the mapping population and construct a map. An additional 1166 loci have been added to our previously published map with 509 SSR markers. The updated genetic map spans a total recombinant length of 3338.2 cM and contains 1675 SSR loci and nine morphological markers, with an average interval of 1.98 cM between adjacent markers. Green lint (Lg) mapped on chromosome 15 in a previous report is mapped in an interval of 2.6 cM on chromosome 21. Based on the map and phenotypic data from multiple environments, 79 lint percentage and seed nutrient trait QTL are detected. These include 8 lint percentage, 13 crude protein, 15 crude oil, 8 linoleic, 10 oleic, 13 palmitic, and 12 stearic acid content QTL. They explain 3.5-62.7 % of the phenotypic variation observed. Four morphological markers identified have a major impact on lint percentage and cottonseed nutrients traits. In this study, our genetic map provides new sights into the tetraploid cotton genome. Furthermore, the stable QTL and morphological markers could be used for fine-mapping and map-based cloning.

Genetic approaches to addiction: genes and alcohol

PubMed Central

Ducci, Francesca; Goldman, David

2008-01-01

Aims Alcoholism is a chronic relapsing disorder with an enormous societal impact. Understanding the genetic basis of alcoholism is crucial to characterize individuals' risk and to develop efficacious prevention and treatment strategies. Methods We examined the available scientific literature to provide an overview of different approaches that are being integrated increasingly to advance our knowledge of the genetic bases of alcoholism. Examples of genes that have been shown to influence vulnerability to alcoholism and related phenotypes are also discussed. Results Genetic factors account for more than 50% of the variance in alcoholism liability. Susceptibility loci for alcoholism include both alcohol-specific genes acting either at the pharmacokinetic or pharmacodynamic levels, as well as loci moderating neuronal pathways such as reward, behavioral control and stress resiliency, that are involved in several psychiatric diseases. In recent years, major progress in gene identification has occurred using intermediate phenotypes such as task-related brain activation that confer the advantage of increased power and the opportunity of exploring the neuronal mechanisms through which genetic variation is translated into behavior. Fundamental to the detection of gene effects is also the understanding of the interplay between genes as well as genes/environment interactions. Whole Genome Association studies represent a unique opportunity to identify alcohol-related loci in hypothesis-free fashion. Finally, genome-wide analyses of transcripts and chromatin remodeling promise an increase in our understanding of the genome function and of the mechanisms through which gene and environment cause diseases. Conclusions Although the genetic bases of alcoholism remain largely unknown, there are reasons to think that more genes will be discovered in the future. Multiple and complementary approaches will be required to piece together the mosaic of causation. PMID:18422824

LOH at 16p13 is a novel chromosomal alteration detected in benign and malignant microdissected papillary neoplasms of the breast.

PubMed

Lininger, R A; Park, W S; Man, Y G; Pham, T; MacGrogan, G; Zhuang, Z; Tavassoli, F A

1998-10-01

Papillary carcinoma of the breast is a variant of predominantly intraductal carcinoma characterized by a papillary growth pattern with fibrovascular support. Loss of heterozygosity (LOH) was evaluated at multiple chromosomal loci (including loci reported to show frequent genetic alterations in breast cancer) to determine the frequency of genetic mutations in these tumors and their precursors. Thirty-three papillary lesions of the breast (6 papillary carcinomas, 12 carcinomas arising in a papilloma, and 15 intraductal papillomas with florid epithelial hyperplasia) were retrieved from the files of the Armed Forces Institute of Pathology (AFIP). Tumor cells and normal tissue were microdissected in each case and screened for LOH at INT-2 and p53 as well as several loci on chromosome 16p13 in the TSC2/PKD1 gene region (D16S423, D16S663, D16S665). LOH on chromosome 16p13 was present in 10 of 16 (63%) informative cases of either papillary carcinoma or carcinoma arising in a papilloma as well as in 6 of 10 (60%) informative cases of intraductal papilloma with florid epithelial hyperplasia (IDH). One case showed simultaneous LOH in both the florid IDH and carcinoma components of a papilloma. LOH was not observed at either INT-2 or p53 in any of the papillary carcinomas or papillomas with florid IDH. In conclusion, a high frequency of LOH at chromosome 16p13 (the TSC2/PKD1 gene region) is in both papillary carcinomas of the breast as well as in papillomas with florid IDH, including a case with LOH present simultaneously in both components. These findings suggest that chromosome 16p contains a tumor suppressor gene that frequently is mutated early in papillary neoplasia.

Integrating genome-wide genetic variations and monocyte expression data reveals trans-regulated gene modules in humans.

PubMed

Rotival, Maxime; Zeller, Tanja; Wild, Philipp S; Maouche, Seraya; Szymczak, Silke; Schillert, Arne; Castagné, Raphaele; Deiseroth, Arne; Proust, Carole; Brocheton, Jessy; Godefroy, Tiphaine; Perret, Claire; Germain, Marine; Eleftheriadis, Medea; Sinning, Christoph R; Schnabel, Renate B; Lubos, Edith; Lackner, Karl J; Rossmann, Heidi; Münzel, Thomas; Rendon, Augusto; Erdmann, Jeanette; Deloukas, Panos; Hengstenberg, Christian; Diemert, Patrick; Montalescot, Gilles; Ouwehand, Willem H; Samani, Nilesh J; Schunkert, Heribert; Tregouet, David-Alexandre; Ziegler, Andreas; Goodall, Alison H; Cambien, François; Tiret, Laurence; Blankenberg, Stefan

2011-12-01

One major expectation from the transcriptome in humans is to characterize the biological basis of associations identified by genome-wide association studies. So far, few cis expression quantitative trait loci (eQTLs) have been reliably related to disease susceptibility. Trans-regulating mechanisms may play a more prominent role in disease susceptibility. We analyzed 12,808 genes detected in at least 5% of circulating monocyte samples from a population-based sample of 1,490 European unrelated subjects. We applied a method of extraction of expression patterns-independent component analysis-to identify sets of co-regulated genes. These patterns were then related to 675,350 SNPs to identify major trans-acting regulators. We detected three genomic regions significantly associated with co-regulated gene modules. Association of these loci with multiple expression traits was replicated in Cardiogenics, an independent study in which expression profiles of monocytes were available in 758 subjects. The locus 12q13 (lead SNP rs11171739), previously identified as a type 1 diabetes locus, was associated with a pattern including two cis eQTLs, RPS26 and SUOX, and 5 trans eQTLs, one of which (MADCAM1) is a potential candidate for mediating T1D susceptibility. The locus 12q24 (lead SNP rs653178), which has demonstrated extensive disease pleiotropy, including type 1 diabetes, hypertension, and celiac disease, was associated to a pattern strongly correlating to blood pressure level. The strongest trans eQTL in this pattern was CRIP1, a known marker of cellular proliferation in cancer. The locus 12q15 (lead SNP rs11177644) was associated with a pattern driven by two cis eQTLs, LYZ and YEATS4, and including 34 trans eQTLs, several of them tumor-related genes. This study shows that a method exploiting the structure of co-expressions among genes can help identify genomic regions involved in trans regulation of sets of genes and can provide clues for understanding the mechanisms linking genome-wide association loci to disease.

Forensic Loci Allele Database (FLAD): Automatically generated, permanent identifiers for sequenced forensic alleles.

PubMed

Van Neste, Christophe; Van Criekinge, Wim; Deforce, Dieter; Van Nieuwerburgh, Filip

2016-01-01

It is difficult to predict if and when massively parallel sequencing of forensic STR loci will replace capillary electrophoresis as the new standard technology in forensic genetics. The main benefits of sequencing are increased multiplexing scales and SNP detection. There is not yet a consensus on how sequenced profiles should be reported. We present the Forensic Loci Allele Database (FLAD) service, made freely available on http://forensic.ugent.be/FLAD/. It offers permanent identifiers for sequenced forensic alleles (STR or SNP) and their microvariants for use in forensic allele nomenclature. Analogous to Genbank, its aim is to provide permanent identifiers for forensically relevant allele sequences. Researchers that are developing forensic sequencing kits or are performing population studies, can register on http://forensic.ugent.be/FLAD/ and add loci and allele sequences with a short and simple application interface (API). Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Multiple Loci are associated with dilated cardiomyopathy in Irish wolfhounds.

PubMed

Philipp, Ute; Vollmar, Andrea; Häggström, Jens; Thomas, Anne; Distl, Ottmar

2012-01-01

Dilated cardiomyopathy (DCM) is a highly prevalent and often lethal disease in Irish wolfhounds. Complex segregation analysis indicated different loci involved in pathogenesis. Linear fixed and mixed models were used for the genome-wide association study. Using 106 DCM cases and 84 controls we identified one SNP significantly associated with DCM on CFA37 and five SNPs suggestively associated with DCM on CFA1, 10, 15, 21 and 17. On CFA37 MOGAT1 and ACSL3 two enzymes of the lipid metabolism were located near the identified SNP.

Multiple Loci Are Associated with Dilated Cardiomyopathy in Irish Wolfhounds

PubMed Central

Philipp, Ute; Vollmar, Andrea; Häggström, Jens; Thomas, Anne; Distl, Ottmar

2012-01-01

Dilated cardiomyopathy (DCM) is a highly prevalent and often lethal disease in Irish wolfhounds. Complex segregation analysis indicated different loci involved in pathogenesis. Linear fixed and mixed models were used for the genome-wide association study. Using 106 DCM cases and 84 controls we identified one SNP significantly associated with DCM on CFA37 and five SNPs suggestively associated with DCM on CFA1, 10, 15, 21 and 17. On CFA37 MOGAT1 and ACSL3 two enzymes of the lipid metabolism were located near the identified SNP. PMID:22761652

The genome sequence of Bifidobacterium longum subsp. infantis reveals adaptations for milk utilization within the infant microbiome

PubMed Central

Sela, D. A.; Chapman, J.; Adeuya, A.; Kim, J. H.; Chen, F.; Whitehead, T. R.; Lapidus, A.; Rokhsar, D. S.; Lebrilla, C. B.; German, J. B.; Price, N. P.; Richardson, P. M.; Mills, D. A.

2008-01-01

Following birth, the breast-fed infant gastrointestinal tract is rapidly colonized by a microbial consortium often dominated by bifidobacteria. Accordingly, the complete genome sequence of Bifidobacterium longum subsp. infantis ATCC15697 reflects a competitive nutrient-utilization strategy targeting milk-borne molecules which lack a nutritive value to the neonate. Several chromosomal loci reflect potential adaptation to the infant host including a 43 kbp cluster encoding catabolic genes, extracellular solute binding proteins and permeases predicted to be active on milk oligosaccharides. An examination of in vivo metabolism has detected the hallmarks of milk oligosaccharide utilization via the central fermentative pathway using metabolomic and proteomic approaches. Finally, conservation of gene clusters in multiple isolates corroborates the genomic mechanism underlying milk utilization for this infant-associated phylotype. PMID:19033196

Alu expression in human cell lines and their retrotranspositional potential.

PubMed

Oler, Andrew J; Traina-Dorge, Stephen; Derbes, Rebecca S; Canella, Donatella; Cairns, Brad R; Roy-Engel, Astrid M

2012-06-20

The vast majority of the 1.1 million Alu elements are retrotranspositionally inactive, where only a few loci referred to as 'source elements' can generate new Alu insertions. The first step in identifying the active Alu sources is to determine the loci transcribed by RNA polymerase III (pol III). Previous genome-wide analyses from normal and transformed cell lines identified multiple Alu loci occupied by pol III factors, making them candidate source elements. Analysis of the data from these genome-wide studies determined that the majority of pol III-bound Alus belonged to the older subfamilies Alu S and Alu J, which varied between cell lines from 62.5% to 98.7% of the identified loci. The pol III-bound Alus were further scored for estimated retrotransposition potential (ERP) based on the absence or presence of selected sequence features associated with Alu retrotransposition capability. Our analyses indicate that most of the pol III-bound Alu loci candidates identified lack the sequence characteristics important for retrotransposition. These data suggest that Alu expression likely varies by cell type, growth conditions and transformation state. This variation could extend to where the same cell lines in different laboratories present different Alu expression patterns. The vast majority of Alu loci potentially transcribed by RNA pol III lack important sequence features for retrotransposition and the majority of potentially active Alu loci in the genome (scored high ERP) belong to young Alu subfamilies. Our observations suggest that in an in vivo scenario, the contribution of Alu activity on somatic genetic damage may significantly vary between individuals and tissues.

Association Analysis of the Extended MHC Region in Celiac Disease Implicates Multiple Independent Susceptibility Loci

PubMed Central

Ahn, Richard; Ding, Yuan Chun; Murray, Joseph; Fasano, Alessio; Green, Peter H. R.; Neuhausen, Susan L.; Garner, Chad

2012-01-01

Celiac disease is a common autoimmune disease caused by sensitivity to the dietary protein gluten. Forty loci have been implicated in the disease. All disease loci have been characterized as low-penetrance, with the exception of the high-risk genotypes in the HLA-DQA1 and HLA-DQB1 genes, which are necessary but not sufficient to cause the disease. The very strong effects from the known HLA loci and the genetically complex nature of the major histocompatibility complex (MHC) have precluded a thorough investigation of the region. The purpose of this study was to test the hypothesis that additional celiac disease loci exist within the extended MHC (xMHC). A set of 1898 SNPs was analyzed for association across the 7.6 Mb xMHC region in 1668 confirmed celiac disease cases and 517 unaffected controls. Conditional recursive partitioning was used to create an informative indicator of the known HLA-DQA1 and HLA-DQB1 high-risk genotypes that was included in the association analysis to account for their effects. A linkage disequilibrium-based grouping procedure was utilized to estimate the number of independent celiac disease loci present in the xMHC after accounting for the known effects. There was significant statistical evidence for four new independent celiac disease loci within the classic MHC region. This study is the first comprehensive association analysis of the xMHC in celiac disease that specifically accounts for the known HLA disease genotypes and the genetic complexity of the region. PMID:22615847

Genetic loci associated with coronary artery disease harbor evidence of selection and antagonistic pleiotropy

PubMed Central

Byars, Sean G.; Gray, Lesley-Ann; Ripatti, Samuli; Stearns, Stephen C.; Inouye, Michael

2017-01-01

Traditional genome-wide scans for positive selection have mainly uncovered selective sweeps associated with monogenic traits. While selection on quantitative traits is much more common, very few signals have been detected because of their polygenic nature. We searched for positive selection signals underlying coronary artery disease (CAD) in worldwide populations, using novel approaches to quantify relationships between polygenic selection signals and CAD genetic risk. We identified new candidate adaptive loci that appear to have been directly modified by disease pressures given their significant associations with CAD genetic risk. These candidates were all uniquely and consistently associated with many different male and female reproductive traits suggesting selection may have also targeted these because of their direct effects on fitness. We found that CAD loci are significantly enriched for lifetime reproductive success relative to the rest of the human genome, with evidence that the relationship between CAD and lifetime reproductive success is antagonistic. This supports the presence of antagonistic-pleiotropic tradeoffs on CAD loci and provides a novel explanation for the maintenance and high prevalence of CAD in modern humans. Lastly, we found that positive selection more often targeted CAD gene regulatory variants using HapMap3 lymphoblastoid cell lines, which further highlights the unique biological significance of candidate adaptive loci underlying CAD. Our study provides a novel approach for detecting selection on polygenic traits and evidence that modern human genomes have evolved in response to CAD-induced selection pressures and other early-life traits sharing pleiotropic links with CAD. PMID:28640878

A methodological study of genome-wide DNA methylation analyses using matched archival formalin-fixed paraffin embedded and fresh frozen breast tumors.

PubMed

Espinal, Allyson C; Wang, Dan; Yan, Li; Liu, Song; Tang, Li; Hu, Qiang; Morrison, Carl D; Ambrosone, Christine B; Higgins, Michael J; Sucheston-Campbell, Lara E

2017-02-28

DNA from archival formalin-fixed and paraffin embedded (FFPE) tissue is an invaluable resource for genome-wide methylation studies although concerns about poor quality may limit its use. In this study, we compared DNA methylation profiles of breast tumors using DNA from fresh-frozen (FF) tissues and three types of matched FFPE samples. For 9/10 patients, correlation and unsupervised clustering analysis revealed that the FF and FFPE samples were consistently correlated with each other and clustered into distinct subgroups. Greater than 84% of the top 100 loci previously shown to differentiate ER+ and ER- tumors in FF tissues were also FFPE DML. Weighted Correlation Gene Network Analyses (WCGNA) grouped the DML loci into 16 modules in FF tissue, with ~85% of the module membership preserved across tissue types. Restored FFPE and matched FF samples were profiled using the Illumina Infinium HumanMethylation450K platform. Methylation levels (β-values) across all loci and the top 100 loci previously shown to differentiate tumors by estrogen receptor status (ER+ or ER-) in a larger FF study, were compared between matched FF and FFPE samples using Pearson's correlation, hierarchical clustering and WCGNA. Positive predictive values and sensitivity levels for detecting differentially methylated loci (DML) in FF samples were calculated in an independent FFPE cohort. FFPE breast tumors samples show lower overall detection of DMLs versus FF, however FFPE and FF DMLs compare favorably. These results support the emerging consensus that the 450K platform can be employed to investigate epigenetics in large sets of archival FFPE tissues.

Cloud computing for detecting high-order genome-wide epistatic interaction via dynamic clustering.

PubMed

Guo, Xuan; Meng, Yu; Yu, Ning; Pan, Yi

2014-04-10

Taking the advantage of high-throughput single nucleotide polymorphism (SNP) genotyping technology, large genome-wide association studies (GWASs) have been considered to hold promise for unravelling complex relationships between genotype and phenotype. At present, traditional single-locus-based methods are insufficient to detect interactions consisting of multiple-locus, which are broadly existing in complex traits. In addition, statistic tests for high order epistatic interactions with more than 2 SNPs propose computational and analytical challenges because the computation increases exponentially as the cardinality of SNPs combinations gets larger. In this paper, we provide a simple, fast and powerful method using dynamic clustering and cloud computing to detect genome-wide multi-locus epistatic interactions. We have constructed systematic experiments to compare powers performance against some recently proposed algorithms, including TEAM, SNPRuler, EDCF and BOOST. Furthermore, we have applied our method on two real GWAS datasets, Age-related macular degeneration (AMD) and Rheumatoid arthritis (RA) datasets, where we find some novel potential disease-related genetic factors which are not shown up in detections of 2-loci epistatic interactions. Experimental results on simulated data demonstrate that our method is more powerful than some recently proposed methods on both two- and three-locus disease models. Our method has discovered many novel high-order associations that are significantly enriched in cases from two real GWAS datasets. Moreover, the running time of the cloud implementation for our method on AMD dataset and RA dataset are roughly 2 hours and 50 hours on a cluster with forty small virtual machines for detecting two-locus interactions, respectively. Therefore, we believe that our method is suitable and effective for the full-scale analysis of multiple-locus epistatic interactions in GWAS.

Cloud computing for detecting high-order genome-wide epistatic interaction via dynamic clustering

PubMed Central

2014-01-01

Backgroud Taking the advan tage of high-throughput single nucleotide polymorphism (SNP) genotyping technology, large genome-wide association studies (GWASs) have been considered to hold promise for unravelling complex relationships between genotype and phenotype. At present, traditional single-locus-based methods are insufficient to detect interactions consisting of multiple-locus, which are broadly existing in complex traits. In addition, statistic tests for high order epistatic interactions with more than 2 SNPs propose computational and analytical challenges because the computation increases exponentially as the cardinality of SNPs combinations gets larger. Results In this paper, we provide a simple, fast and powerful method using dynamic clustering and cloud computing to detect genome-wide multi-locus epistatic interactions. We have constructed systematic experiments to compare powers performance against some recently proposed algorithms, including TEAM, SNPRuler, EDCF and BOOST. Furthermore, we have applied our method on two real GWAS datasets, Age-related macular degeneration (AMD) and Rheumatoid arthritis (RA) datasets, where we find some novel potential disease-related genetic factors which are not shown up in detections of 2-loci epistatic interactions. Conclusions Experimental results on simulated data demonstrate that our method is more powerful than some recently proposed methods on both two- and three-locus disease models. Our method has discovered many novel high-order associations that are significantly enriched in cases from two real GWAS datasets. Moreover, the running time of the cloud implementation for our method on AMD dataset and RA dataset are roughly 2 hours and 50 hours on a cluster with forty small virtual machines for detecting two-locus interactions, respectively. Therefore, we believe that our method is suitable and effective for the full-scale analysis of multiple-locus epistatic interactions in GWAS. PMID:24717145

TECHNICAL ADVANCES: Effects of genotyping protocols on success and errors in identifying individual river otters (Lontra canadensis) from their faeces.

PubMed

Hansen, Heidi; Ben-David, Merav; McDonald, David B

2008-03-01

In noninvasive genetic sampling, when genotyping error rates are high and recapture rates are low, misidentification of individuals can lead to overestimation of population size. Thus, estimating genotyping errors is imperative. Nonetheless, conducting multiple polymerase chain reactions (PCRs) at multiple loci is time-consuming and costly. To address the controversy regarding the minimum number of PCRs required for obtaining a consensus genotype, we compared consumer-style the performance of two genotyping protocols (multiple-tubes and 'comparative method') in respect to genotyping success and error rates. Our results from 48 faecal samples of river otters (Lontra canadensis) collected in Wyoming in 2003, and from blood samples of five captive river otters amplified with four different primers, suggest that use of the comparative genotyping protocol can minimize the number of PCRs per locus. For all but five samples at one locus, the same consensus genotypes were reached with fewer PCRs and with reduced error rates with this protocol compared to the multiple-tubes method. This finding is reassuring because genotyping errors can occur at relatively high rates even in tissues such as blood and hair. In addition, we found that loci that amplify readily and yield consensus genotypes, may still exhibit high error rates (7-32%) and that amplification with different primers resulted in different types and rates of error. Thus, assigning a genotype based on a single PCR for several loci could result in misidentification of individuals. We recommend that programs designed to statistically assign consensus genotypes should be modified to allow the different treatment of heterozygotes and homozygotes intrinsic to the comparative method. © 2007 The Authors.

Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis

PubMed Central

Sawcer, Stephen; Hellenthal, Garrett; Pirinen, Matti; Spencer, Chris C.A.; Patsopoulos, Nikolaos A.; Moutsianas, Loukas; Dilthey, Alexander; Su, Zhan; Freeman, Colin; Hunt, Sarah E.; Edkins, Sarah; Gray, Emma; Booth, David R.; Potter, Simon C.; Goris, An; Band, Gavin; Oturai, Annette Bang; Strange, Amy; Saarela, Janna; Bellenguez, Céline; Fontaine, Bertrand; Gillman, Matthew; Hemmer, Bernhard; Gwilliam, Rhian; Zipp, Frauke; Jayakumar, Alagurevathi; Martin, Roland; Leslie, Stephen; Hawkins, Stanley; Giannoulatou, Eleni; D’alfonso, Sandra; Blackburn, Hannah; Boneschi, Filippo Martinelli; Liddle, Jennifer; Harbo, Hanne F.; Perez, Marc L.; Spurkland, Anne; Waller, Matthew J; Mycko, Marcin P.; Ricketts, Michelle; Comabella, Manuel; Hammond, Naomi; Kockum, Ingrid; McCann, Owen T.; Ban, Maria; Whittaker, Pamela; Kemppinen, Anu; Weston, Paul; Hawkins, Clive; Widaa, Sara; Zajicek, John; Dronov, Serge; Robertson, Neil; Bumpstead, Suzannah J.; Barcellos, Lisa F.; Ravindrarajah, Rathi; Abraham, Roby; Alfredsson, Lars; Ardlie, Kristin; Aubin, Cristin; Baker, Amie; Baker, Katharine; Baranzini, Sergio E.; Bergamaschi, Laura; Bergamaschi, Roberto; Bernstein, Allan; Berthele, Achim; Boggild, Mike; Bradfield, Jonathan P.; Brassat, David; Broadley, Simon A.; Buck, Dorothea; Butzkueven, Helmut; Capra, Ruggero; Carroll, William M.; Cavalla, Paola; Celius, Elisabeth G.; Cepok, Sabine; Chiavacci, Rosetta; Clerget-Darpoux, Françoise; Clysters, Katleen; Comi, Giancarlo; Cossburn, Mark; Cournu-Rebeix, Isabelle; Cox, Mathew B.; Cozen, Wendy; Cree, Bruce A.C.; Cross, Anne H.; Cusi, Daniele; Daly, Mark J.; Davis, Emma; de Bakker, Paul I.W.; Debouverie, Marc; D’hooghe, Marie Beatrice; Dixon, Katherine; Dobosi, Rita; Dubois, Bénédicte; Ellinghaus, David; Elovaara, Irina; Esposito, Federica; Fontenille, Claire; Foote, Simon; Franke, Andre; Galimberti, Daniela; Ghezzi, Angelo; Glessner, Joseph; Gomez, Refujia; Gout, Olivier; Graham, Colin; Grant, Struan F.A.; Guerini, Franca Rosa; Hakonarson, Hakon; Hall, Per; Hamsten, Anders; Hartung, Hans-Peter; Heard, Rob N.; Heath, Simon; Hobart, Jeremy; Hoshi, Muna; Infante-Duarte, Carmen; Ingram, Gillian; Ingram, Wendy; Islam, Talat; Jagodic, Maja; Kabesch, Michael; Kermode, Allan G.; Kilpatrick, Trevor J.; Kim, Cecilia; Klopp, Norman; Koivisto, Keijo; Larsson, Malin; Lathrop, Mark; Lechner-Scott, Jeannette S.; Leone, Maurizio A.; Leppä, Virpi; Liljedahl, Ulrika; Bomfim, Izaura Lima; Lincoln, Robin R.; Link, Jenny; Liu, Jianjun; Lorentzen, Åslaug R.; Lupoli, Sara; Macciardi, Fabio; Mack, Thomas; Marriott, Mark; Martinelli, Vittorio; Mason, Deborah; McCauley, Jacob L.; Mentch, Frank; Mero, Inger-Lise; Mihalova, Tania; Montalban, Xavier; Mottershead, John; Myhr, Kjell-Morten; Naldi, Paola; Ollier, William; Page, Alison; Palotie, Aarno; Pelletier, Jean; Piccio, Laura; Pickersgill, Trevor; Piehl, Fredrik; Pobywajlo, Susan; Quach, Hong L.; Ramsay, Patricia P.; Reunanen, Mauri; Reynolds, Richard; Rioux, John D.; Rodegher, Mariaemma; Roesner, Sabine; Rubio, Justin P.; Rückert, Ina-Maria; Salvetti, Marco; Salvi, Erika; Santaniello, Adam; Schaefer, Catherine A.; Schreiber, Stefan; Schulze, Christian; Scott, Rodney J.; Sellebjerg, Finn; Selmaj, Krzysztof W.; Sexton, David; Shen, Ling; Simms-Acuna, Brigid; Skidmore, Sheila; Sleiman, Patrick M.A.; Smestad, Cathrine; Sørensen, Per Soelberg; Søndergaard, Helle Bach; Stankovich, Jim; Strange, Richard C.; Sulonen, Anna-Maija; Sundqvist, Emilie; Syvänen, Ann-Christine; Taddeo, Francesca; Taylor, Bruce; Blackwell, Jenefer M.; Tienari, Pentti; Bramon, Elvira; Tourbah, Ayman; Brown, Matthew A.; Tronczynska, Ewa; Casas, Juan P.; Tubridy, Niall; Corvin, Aiden; Vickery, Jane; Jankowski, Janusz; Villoslada, Pablo; Markus, Hugh S.; Wang, Kai; Mathew, Christopher G.; Wason, James; Palmer, Colin N.A.; Wichmann, H-Erich; Plomin, Robert; Willoughby, Ernest; Rautanen, Anna; Winkelmann, Juliane; Wittig, Michael; Trembath, Richard C.; Yaouanq, Jacqueline; Viswanathan, Ananth C.; Zhang, Haitao; Wood, Nicholas W.; Zuvich, Rebecca; Deloukas, Panos; Langford, Cordelia; Duncanson, Audrey; Oksenberg, Jorge R.; Pericak-Vance, Margaret A.; Haines, Jonathan L.; Olsson, Tomas; Hillert, Jan; Ivinson, Adrian J.; De Jager, Philip L.; Peltonen, Leena; Stewart, Graeme J.; Hafler, David A.; Hauser, Stephen L.; McVean, Gil; Donnelly, Peter; Compston, Alastair

2011-01-01

Multiple sclerosis (OMIM 126200) is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability.1 Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals;2,3 and systematic attempts to identify linkage in multiplex families have confirmed that variation within the Major Histocompatibility Complex (MHC) exerts the greatest individual effect on risk.4 Modestly powered Genome-Wide Association Studies (GWAS)5-10 have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects play a key role in disease susceptibility.11 Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the Class I region. Immunologically relevant genes are significantly over-represented amongst those mapping close to the identified loci and particularly implicate T helper cell differentiation in the pathogenesis of multiple sclerosis. PMID:21833088

Characterization of 32 microsatellite loci for the Pacific red snapper, Lutjanus peru, through next generation sequencing.

PubMed

Paz-García, David A; Munguía-Vega, Adrián; Plomozo-Lugo, Tomas; Weaver, Amy Hudson

2017-04-01

We developed a set of hypervariable microsatellite markers for the Pacific red snapper (Lutjanus peru), an economically important marine fish for small-scale fisheries in the west coast of Mexico. We performed shotgun genome sequencing with the 454 XL titanium chemistry and used bioinformatic tools to search for perfect microsatellite loci. We selected 66 primer pairs that were synthesized and genotyped in an ABI PRISM 3730XL DNA sequencer in 32 individuals from the Gulf of California. We estimated levels of genetic diversity, deviations from linkage and Hardy-Weinberg equilibrium, estimated the frequency of null alleles and the probability of individual identity for the new markers. We reanalyzed 16 loci in 16 individuals to estimate genotyping error rates. Eighteen loci failed to amplify, 16 loci were discarded due to unspecific amplifications and 32 loci (14 tetranucleotide and 18 dinucleotide) were successfully scored. The average number of alleles per locus was 21 (±6.87, SD) and ranged from 8 to 34. The average observed and expected heterozygosities were 0.787 (±0.144 SD, range 0.250-0.935) and 0.909 (±0.122 SD, range 0.381-0.965), respectively. No significant linkage was detected. Eight loci showed deviations from Hardy-Weinberg equilibrium, and from these, four loci showed moderate null allele frequencies (0.104-0.220). The probability of individual identity for the new loci was 1.46 -62 . Genotyping error rates averaged 9.58%. The new markers will be useful to investigate patterns of larval dispersal, metapopulation dynamics, fine-scale genetic structure and diversity aimed to inform the implementation of spatially explicit fisheries management strategies in the Gulf of California.

Genetic structure of Pseudococcus microcirculus (Hemiptera: Pseudococcidae) populations on epiphytic orchids in south Florida.

PubMed

Zettler, J A; Adams, K; Frederick, B; Gutting, A; Ingebretsen, N; Ragsdale, A; Schrey, A

2017-03-01

In 2012, the orchid mealy bug Pseudococcus microcirculus was first detected in situ in North America's more diverse orchid region, the Big Cypress Basin (Collier Co FL). A follow-up survey showed that the mealy bug is more widespread and found on epiphytic orchids in two locations, in both the Fakahatchee Strand State Preserve (sites B and F) and the Florida Panther National Wildlife Refuge (sites M and C). There, we collected mealy bugs (n = 54) from 35 orchid individuals and screened allelic variation at seven microsatellite loci. We estimated genetic diversity and differentiation among all sites and compared the variation among individuals collected on the same plant. Genetic differentiation between sites M and C (F ST = 0.03, P < 0.01) and,Mand B (F ST = 0.04, P < 0.01) was detected.We also detected significantly lower mean pairwise relatedness among individuals from site B compared to all the other locations, and this population had the lowest inbreeding coefficient. Genetic diversity and mean pairwise relatedness were highly variable among plants with multiple individuals; however, plants from sites F and M tend to have collections of individuals with higher mean pairwise relatedness compared to sites B and C. Our results indicate that there is genetic diversity and differentiation among mealy bugs in these locations, and that collections of individuals on the same plant are genetically diverse. As such, the mealy bugs throughout these areas are likely to be genetically diverse and exist in multiple distinct populations.

ORMAN: optimal resolution of ambiguous RNA-Seq multimappings in the presence of novel isoforms.

PubMed

Dao, Phuong; Numanagić, Ibrahim; Lin, Yen-Yi; Hach, Faraz; Karakoc, Emre; Donmez, Nilgun; Collins, Colin; Eichler, Evan E; Sahinalp, S Cenk

2014-03-01

RNA-Seq technology is promising to uncover many novel alternative splicing events, gene fusions and other variations in RNA transcripts. For an accurate detection and quantification of transcripts, it is important to resolve the mapping ambiguity for those RNA-Seq reads that can be mapped to multiple loci: >17% of the reads from mouse RNA-Seq data and 50% of the reads from some plant RNA-Seq data have multiple mapping loci. In this study, we show how to resolve the mapping ambiguity in the presence of novel transcriptomic events such as exon skipping and novel indels towards accurate downstream analysis. We introduce ORMAN ( O ptimal R esolution of M ultimapping A mbiguity of R N A-Seq Reads), which aims to compute the minimum number of potential transcript products for each gene and to assign each multimapping read to one of these transcripts based on the estimated distribution of the region covering the read. ORMAN achieves this objective through a combinatorial optimization formulation, which is solved through well-known approximation algorithms, integer linear programs and heuristics. On a simulated RNA-Seq dataset including a random subset of transcripts from the UCSC database, the performance of several state-of-the-art methods for identifying and quantifying novel transcripts, such as Cufflinks, IsoLasso and CLIIQ, is significantly improved through the use of ORMAN. Furthermore, in an experiment using real RNA-Seq reads, we show that ORMAN is able to resolve multimapping to produce coverage values that are similar to the original distribution, even in genes with highly non-uniform coverage. ORMAN is available at http://orman.sf.net

Characterisation of ALS genes in the polyploid species Schoenoplectus mucronatus and implications for resistance management.

PubMed

Scarabel, Laura; Locascio, Antonella; Furini, Antonella; Sattin, Maurizio; Varotto, Serena

2010-03-01

The polyploid weed Schoenoplectus mucronatus (L.) Palla has evolved target-site resistance to ALS-inhibiting herbicides in Italian rice crops. Molecular and genetic characterisation of the resistance mechanism is relevant to the evolution and management of herbicide resistance. The authors aimed (a) to study the organisation of the target-site loci in two field-selected S. mucronatus populations with different cross-resistance patterns, (b) to identify the mutations endowing resistance to ALS inhibitors and determine the role of these mutations by using transgenesis and (c) to analyse the implications for the management of the S. mucronatus populations. Two complete ALS genes (ALS1 and ALS2) having an intron and a third partial intronless ALS gene (ALS3) were identified. The presence of multiple ALS genes was confirmed by Southern blot analyses, and ALS loci were characterised by examining cytosine methylation. In S. mucronatus leaves, the transcripts of ALS1, ALS2 and ALS3 were detected. Two mutations endowing resistance (Pro(197) to His and Trp(574) to Leu) were found in both resistant populations, but at different frequencies. Tobacco plants transformed with the two resistant alleles indicated that the Pro(197)-to-His substitution conferred resistance to SU and TP herbicides, while the allele with the Trp(574)-to-Leu substitution conferred cross-resistance to SU, TP, IMI and PTB herbicides. Schoenoplectus mucronatus has multiple ALS genes characterised by methylated sites that can influence the expression profile. The two mutated alleles proved to be responsible for ALS resistance. At population level, the resistance pattern depends on the frequency of various resistant genotypes, and this influences the efficacy of various ALS-inhibiting herbicides.

Application of mixsep software package: Performance verification of male-mixed DNA analysis

PubMed Central

HU, NA; CONG, BIN; GAO, TAO; CHEN, YU; SHEN, JUNYI; LI, SHUJIN; MA, CHUNLING

2015-01-01

An experimental model of male-mixed DNA (n=297) was constructed according to the mixed DNA construction principle. This comprised the use of the Applied Biosystems (ABI) 7500 quantitative polymerase chain reaction system, with scientific validation of mixture proportion (Mx; root-mean-square error ≤0.02). Statistical analysis was performed on locus separation accuracy using mixsep, a DNA mixture separation R-package, and the analytical performance of mixsep was assessed by examining the data distribution pattern of different mixed gradients, short tandem repeat (STR) loci and mixed DNA types. The results showed that locus separation accuracy had a negative linear correlation with the mixed gradient (R2=−0.7121). With increasing mixed gradient imbalance, locus separation accuracy first increased and then decreased, with the highest value detected at a gradient of 1:3 (≥90%). The mixed gradient, which is the theoretical Mx, was one of the primary factors that influenced the success of mixed DNA analysis. Among the 16 STR loci detected by Identifiler®, the separation accuracy was relatively high (>88%) for loci D5S818, D8S1179 and FGA, whereas the median separation accuracy value was lowest for the D7S820 locus. STR loci with relatively large numbers of allelic drop-out (ADO; >15) were all located in the yellow and red channels, including loci D18S51, D19S433, FGA, TPOX and vWA. These five loci featured low allele peak heights, which was consistent with the low sensitivity of the ABI 3130xl Genetic Analyzer to yellow and red fluorescence. The locus separation accuracy of the mixsep package was substantially different with and without the inclusion of ADO loci; inclusion of ADO significantly reduced the analytical performance of the mixsep package, which was consistent with the lack of an ADO functional module in this software. The present study demonstrated that the mixsep software had a number of advantages and was recommended for analysis of mixed DNA. This software was easy to operate and produced understandable results with a degree of controllability. PMID:25936428

A microsatellite study for determination of allelic variation of Kurdish population-Kurdistan region-Iraq

NASA Astrophysics Data System (ADS)

Murad, Media J.; Amin, Bushra K.

2017-09-01

The purpose of this study was detecting genetic variations for the Kurdish population in Kurdistan region-Iraq, using fifteen autosomal STR loci. Buccal swabs were collected and depositing on Nucleic Card (Copan, Italia Spa) from 302 healthy unrelated Iraqi Kurds in five provinces of Kurdistan region-Iraq. Fifteen autosomal STR loci are D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, FGA and Amelogenin included in the AmpFlSTR Identifiler® Direct PCR Amplification Kit (Applied Biosystems, Foster City, CA, USA). No significant departure from Hardy Weinberg Equilibrium (HWE) expectations were observed in 10 from 15 STR loci analyzed (a 5% significance level was taken). The exceptions were the CSF1PO, D3S1358, D13S317, D16S539 and D2S1338 loci. Statistical parameters of forensic efficiencies were estimated for the loci, based on allelic frequencies. The mean of observed heterozygosity, expected heterozygosity and PIC values across the 15 loci were 0.762, 0.797 and 0.768 respectively, indicating high gene diversity. The combined probability of exclusion, power of discrimination, probability of matching value for all the 15 STR loci were 0.9999968; 0.9999999 and 4.966×10-17, respectively. These parameters indicated the importance of the loci for forensic genetic purposes and paternity testing.

Population structure of Pneumocystis jirovecii isolated from immunodeficiency virus-positive patients.

PubMed

Esteves, Francisco; Gaspar, Jorge; Tavares, Adélcia; Moser, Inês; Antunes, Francisco; Mansinho, Kamal; Matos, Olga

2010-03-01

Pneumocystis jirovecii pneumonia (PcP) is an important opportunistic infection among immunocompromised patients. Genetic characterization of P. jirovecii isolated from HIV-positive patients, based on identification of multiple nucleotide sequences at eight distinct loci, was achieved by using PCR with DNA sequencing and RFLP. The present study showed that the mitochondrial large-subunit rRNA (mtLSU rRNA), the cytochrome b (CYB), the superoxide dismutase (SOD), the beta-tubulin (beta-tub), the dihydrofolate reductase (DHFR) and the dihydropteroate synthase (DHPS) loci sequences were more variable and therefore giving additional information than the thioredoxin reductase (Trr1) and the thymidylate synthase (TS) genes. Genotyping at those six most informative loci enabled the identification of 48 different P. jirovecii multilocus genotypes (MLGs). Significant statistical associations between infecting P. jirovecii genotypes and patients' age groups or PcP clinical status were found. Also, mtLSU rRNA sequences and specific genotypes from other three loci (CYB, SOD, and DHFR) were statistically associated. The results suggested large recombination between most P. jirovecii MLGs. However, one MLG occurred at a higher frequency than would be expected according to panmictic expectations, suggesting linkage disequilibrium and clonal propagation. The persistence of this specific MLG may be a consequence of clonal reproduction of this successful genotypic array in a P. jirovecii population with epidemic structure. The present study provided the description of multiple genomic regions of P. jirovecii, improving the understanding of genetic variability and frequency distribution of polymorphic genotypes, and exploring the criteria of clonality by testing over-representation of MLGs.

Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution.

PubMed

Heid, Iris M; Jackson, Anne U; Randall, Joshua C; Winkler, Thomas W; Qi, Lu; Steinthorsdottir, Valgerdur; Thorleifsson, Gudmar; Zillikens, M Carola; Speliotes, Elizabeth K; Mägi, Reedik; Workalemahu, Tsegaselassie; White, Charles C; Bouatia-Naji, Nabila; Harris, Tamara B; Berndt, Sonja I; Ingelsson, Erik; Willer, Cristen J; Weedon, Michael N; Luan, Jian'an; Vedantam, Sailaja; Esko, Tõnu; Kilpeläinen, Tuomas O; Kutalik, Zoltán; Li, Shengxu; Monda, Keri L; Dixon, Anna L; Holmes, Christopher C; Kaplan, Lee M; Liang, Liming; Min, Josine L; Moffatt, Miriam F; Molony, Cliona; Nicholson, George; Schadt, Eric E; Zondervan, Krina T; Feitosa, Mary F; Ferreira, Teresa; Lango Allen, Hana; Weyant, Robert J; Wheeler, Eleanor; Wood, Andrew R; Estrada, Karol; Goddard, Michael E; Lettre, Guillaume; Mangino, Massimo; Nyholt, Dale R; Purcell, Shaun; Smith, Albert Vernon; Visscher, Peter M; Yang, Jian; McCarroll, Steven A; Nemesh, James; Voight, Benjamin F; Absher, Devin; Amin, Najaf; Aspelund, Thor; Coin, Lachlan; Glazer, Nicole L; Hayward, Caroline; Heard-Costa, Nancy L; Hottenga, Jouke-Jan; Johansson, Asa; Johnson, Toby; Kaakinen, Marika; Kapur, Karen; Ketkar, Shamika; Knowles, Joshua W; Kraft, Peter; Kraja, Aldi T; Lamina, Claudia; Leitzmann, Michael F; McKnight, Barbara; Morris, Andrew P; Ong, Ken K; Perry, John R B; Peters, Marjolein J; Polasek, Ozren; Prokopenko, Inga; Rayner, Nigel W; Ripatti, Samuli; Rivadeneira, Fernando; Robertson, Neil R; Sanna, Serena; Sovio, Ulla; Surakka, Ida; Teumer, Alexander; van Wingerden, Sophie; Vitart, Veronique; Zhao, Jing Hua; Cavalcanti-Proença, Christine; Chines, Peter S; Fisher, Eva; Kulzer, Jennifer R; Lecoeur, Cecile; Narisu, Narisu; Sandholt, Camilla; Scott, Laura J; Silander, Kaisa; Stark, Klaus; Tammesoo, Mari-Liis; Teslovich, Tanya M; Timpson, Nicholas John; Watanabe, Richard M; Welch, Ryan; Chasman, Daniel I; Cooper, Matthew N; Jansson, John-Olov; Kettunen, Johannes; Lawrence, Robert W; Pellikka, Niina; Perola, Markus; Vandenput, Liesbeth; Alavere, Helene; Almgren, Peter; Atwood, Larry D; Bennett, Amanda J; Biffar, Reiner; Bonnycastle, Lori L; Bornstein, Stefan R; Buchanan, Thomas A; Campbell, Harry; Day, Ian N M; Dei, Mariano; Dörr, Marcus; Elliott, Paul; Erdos, Michael R; Eriksson, Johan G; Freimer, Nelson B; Fu, Mao; Gaget, Stefan; Geus, Eco J C; Gjesing, Anette P; Grallert, Harald; Grässler, Jürgen; Groves, Christopher J; Guiducci, Candace; Hartikainen, Anna-Liisa; Hassanali, Neelam; Havulinna, Aki S; Herzig, Karl-Heinz; Hicks, Andrew A; Hui, Jennie; Igl, Wilmar; Jousilahti, Pekka; Jula, Antti; Kajantie, Eero; Kinnunen, Leena; Kolcic, Ivana; Koskinen, Seppo; Kovacs, Peter; Kroemer, Heyo K; Krzelj, Vjekoslav; Kuusisto, Johanna; Kvaloy, Kirsti; Laitinen, Jaana; Lantieri, Olivier; Lathrop, G Mark; Lokki, Marja-Liisa; Luben, Robert N; Ludwig, Barbara; McArdle, Wendy L; McCarthy, Anne; Morken, Mario A; Nelis, Mari; Neville, Matt J; Paré, Guillaume; Parker, Alex N; Peden, John F; Pichler, Irene; Pietiläinen, Kirsi H; Platou, Carl G P; Pouta, Anneli; Ridderstråle, Martin; Samani, Nilesh J; Saramies, Jouko; Sinisalo, Juha; Smit, Jan H; Strawbridge, Rona J; Stringham, Heather M; Swift, Amy J; Teder-Laving, Maris; Thomson, Brian; Usala, Gianluca; van Meurs, Joyce B J; van Ommen, Gert-Jan; Vatin, Vincent; Volpato, Claudia B; Wallaschofski, Henri; Walters, G Bragi; Widen, Elisabeth; Wild, Sarah H; Willemsen, Gonneke; Witte, Daniel R; Zgaga, Lina; Zitting, Paavo; Beilby, John P; James, Alan L; Kähönen, Mika; Lehtimäki, Terho; Nieminen, Markku S; Ohlsson, Claes; Palmer, Lyle J; Raitakari, Olli; Ridker, Paul M; Stumvoll, Michael; Tönjes, Anke; Viikari, Jorma; Balkau, Beverley; Ben-Shlomo, Yoav; Bergman, Richard N; Boeing, Heiner; Smith, George Davey; Ebrahim, Shah; Froguel, Philippe; Hansen, Torben; Hengstenberg, Christian; Hveem, Kristian; Isomaa, Bo; Jørgensen, Torben; Karpe, Fredrik; Khaw, Kay-Tee; Laakso, Markku; Lawlor, Debbie A; Marre, Michel; Meitinger, Thomas; Metspalu, Andres; Midthjell, Kristian; Pedersen, Oluf; Salomaa, Veikko; Schwarz, Peter E H; Tuomi, Tiinamaija; Tuomilehto, Jaakko; Valle, Timo T; Wareham, Nicholas J; Arnold, Alice M; Beckmann, Jacques S; Bergmann, Sven; Boerwinkle, Eric; Boomsma, Dorret I; Caulfield, Mark J; Collins, Francis S; Eiriksdottir, Gudny; Gudnason, Vilmundur; Gyllensten, Ulf; Hamsten, Anders; Hattersley, Andrew T; Hofman, Albert; Hu, Frank B; Illig, Thomas; Iribarren, Carlos; Jarvelin, Marjo-Riitta; Kao, W H Linda; Kaprio, Jaakko; Launer, Lenore J; Munroe, Patricia B; Oostra, Ben; Penninx, Brenda W; Pramstaller, Peter P; Psaty, Bruce M; Quertermous, Thomas; Rissanen, Aila; Rudan, Igor; Shuldiner, Alan R; Soranzo, Nicole; Spector, Timothy D; Syvanen, Ann-Christine; Uda, Manuela; Uitterlinden, André; Völzke, Henry; Vollenweider, Peter; Wilson, James F; Witteman, Jacqueline C; Wright, Alan F; Abecasis, Gonçalo R; Boehnke, Michael; Borecki, Ingrid B; Deloukas, Panos; Frayling, Timothy M; Groop, Leif C; Haritunians, Talin; Hunter, David J; Kaplan, Robert C; North, Kari E; O'Connell, Jeffrey R; Peltonen, Leena; Schlessinger, David; Strachan, David P; Hirschhorn, Joel N; Assimes, Themistocles L; Wichmann, H-Erich; Thorsteinsdottir, Unnur; van Duijn, Cornelia M; Stefansson, Kari; Cupples, L Adrienne; Loos, Ruth J F; Barroso, Inês; McCarthy, Mark I; Fox, Caroline S; Mohlke, Karen L; Lindgren, Cecilia M

2010-11-01

Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻¹³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions.

Meta-analysis of genome-wide association studies of adult height in East Asians identifies 17 novel loci.

PubMed

He, Meian; Xu, Min; Zhang, Ben; Liang, Jun; Chen, Peng; Lee, Jong-Young; Johnson, Todd A; Li, Huaixing; Yang, Xiaobo; Dai, Juncheng; Liang, Liming; Gui, Lixuan; Qi, Qibin; Huang, Jinyan; Li, Yanping; Adair, Linda S; Aung, Tin; Cai, Qiuyin; Cheng, Ching-Yu; Cho, Myeong-Chan; Cho, Yoon Shin; Chu, Minjie; Cui, Bin; Gao, Yu-Tang; Go, Min Jin; Gu, Dongfeng; Gu, Weiqiong; Guo, Huan; Hao, Yongchen; Hong, Jie; Hu, Zhibin; Hu, Yanling; Huang, Jianfeng; Hwang, Joo-Yeon; Ikram, Mohammad Kamran; Jin, Guangfu; Kang, Dae-Hee; Khor, Chiea Chuen; Kim, Bong-Jo; Kim, Hung Tae; Kubo, Michiaki; Lee, Jeannette; Lee, Juyoung; Lee, Nanette R; Li, Ruoying; Li, Jun; Liu, JianJun; Longe, Jirong; Lu, Wei; Lu, Xiangfeng; Miao, Xiaoping; Okada, Yukinori; Ong, Rick Twee-Hee; Qiu, Gaokun; Seielstad, Mark; Sim, Xueling; Song, Huaidong; Takeuchi, Fumihiko; Tanaka, Toshihiro; Taylor, Phil R; Wang, Laiyuan; Wang, Weiqing; Wang, Yiqin; Wu, Chen; Wu, Ying; Xiang, Yong-Bing; Yamamoto, Ken; Yang, Handong; Liao, Ming; Yokota, Mitsuhiro; Young, Terri; Zhang, Xiaomin; Kato, Norihiro; Wang, Qing K; Zheng, Wei; Hu, Frank B; Lin, Dongxin; Shen, Hongbing; Teo, Yik Ying; Mo, Zengnan; Wong, Tien Yin; Lin, Xu; Mohlke, Karen L; Ning, Guang; Tsunoda, Tatsuhiko; Han, Bok-Ghee; Shu, Xiao-Ou; Tai, E Shyong; Wu, Tangchun; Qi, Lu

2015-03-15

Human height is associated with risk of multiple diseases and is profoundly determined by an individual's genetic makeup and shows a high degree of ethnic heterogeneity. Large-scale genome-wide association (GWA) analyses of adult height in Europeans have identified nearly 180 genetic loci. A recent study showed high replicability of results from Europeans-based GWA studies in Asians; however, population-specific loci may exist due to distinct linkage disequilibrium patterns. We carried out a GWA meta-analysis in 93 926 individuals from East Asia. We identified 98 loci, including 17 novel and 81 previously reported loci, associated with height at P < 5 × 10(-8), together explaining 8.89% of phenotypic variance. Among the newly identified variants, 10 are commonly distributed (minor allele frequency, MAF > 5%) in Europeans, with comparable frequencies with in Asians, and 7 single-nucleotide polymorphisms are with low frequency (MAF < 5%) in Europeans. In addition, our data suggest that novel biological pathway such as the protein tyrosine phosphatase family is involved in regulation of height. The findings from this study considerably expand our knowledge of the genetic architecture of human height in Asians. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genetic loci with parent-of-origin effects cause hybrid seed lethality in crosses between Mimulus species.

PubMed

Garner, Austin G; Kenney, Amanda M; Fishman, Lila; Sweigart, Andrea L

2016-07-01

In flowering plants, F1 hybrid seed lethality is a common outcome of crosses between closely related diploid species, but the genetic basis of this early-acting and potentially widespread form of postzygotic reproductive isolation is largely unknown. We intercrossed two closely related species of monkeyflower, Mimulus guttatus and Mimulus tilingii, to characterize the mechanisms and strength of postzygotic reproductive isolation. Then, using a reciprocal backcross design, we performed high-resolution genetic mapping to determine the genetic architecture of hybrid seed lethality and directly test for loci with parent-of-origin effects. We found that F1 hybrid seed lethality is an exceptionally strong isolating barrier between Mimulus species, with reciprocal crosses producing < 1% viable seeds. This form of postzygotic reproductive isolation appears to be highly polygenic, indicating that multiple incompatibility loci have accumulated rapidly between these closely related Mimulus species. It is also primarily caused by genetic loci with parent-of-origin effects, suggesting a possible role for imprinted genes in the evolution of Mimulus hybrid seed lethality. Our findings suggest that divergence in loci with parent-of-origin effects, which is probably driven by genomic coevolution within lineages, might be an important source of hybrid incompatibilities between flowering plant species. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution

PubMed Central

Heid, Iris M; Jackson, Anne U; Randall, Joshua C; Winkler, Thomas W; Qi, Lu; Steinthorsdottir, Valgerdur; Thorleifsson, Gudmar; Zillikens, M Carola; Speliotes, Elizabeth K; Mägi, Reedik; Workalemahu, Tsegaselassie; White, Charles C; Bouatia-Naji, Nabila; Harris, Tamara B; Berndt, Sonja I; Ingelsson, Erik; Willer, Cristen J; Weedon, Michael N; Luan, Jian’An; Vedantam, Sailaja; Esko, Tõnu; Kilpeläinen, Tuomas O; Kutalik, Zoltán; Li, Shengxu; Monda, Keri L; Dixon, Anna L; Holmes, Christopher C; Kaplan, Lee M; Liang, Liming; Min, Josine L; Moffatt, Miriam F; Molony, Cliona; Nicholson, George; Schadt, Eric E; Zondervan, Krina T; Feitosa, Mary F; Ferreira, Teresa; Allen, Hana Lango; Weyant, Robert J; Wheeler, Eleanor; Wood, Andrew R; Estrada, Karol; Goddard, Michael E; Lettre, Guillaume; Mangino, Massimo; Nyholt, Dale R; Purcell, Shaun; Smith, Albert Vernon; Visscher, Peter M; Yang, Jian; McCarroll, Steven A; Nemesh, James; Voight, Benjamin F; Absher, Devin; Amin, Najaf; Aspelund, Thor; Coin, Lachlan; Glazer, Nicole L; Hayward, Caroline; Heard-costa, Nancy L; Hottenga, Jouke-Jan; Johansson, Åsa; Johnson, Toby; Kaakinen, Marika; Kapur, Karen; Ketkar, Shamika; Knowles, Joshua W; Kraft, Peter; Kraja, Aldi T; Lamina, Claudia; Leitzmann, Michael F; McKnight, Barbara; Morris, Andrew P; Ong, Ken K; Perry, John R B; Peters, Marjolein J; Polasek, Ozren; Prokopenko, Inga; Rayner, Nigel W; Ripatti, Samuli; Rivadeneira, Fernando; Robertson, Neil R; Sanna, Serena; Sovio, Ulla; Surakka, Ida; Teumer, Alexander; van Wingerden, Sophie; Vitart, Veronique; Zhao, Jing Hua; Cavalcanti-Proença, Christine; Chines, Peter S; Fisher, Eva; Kulzer, Jennifer R; Lecoeur, Cecile; Narisu, Narisu; Sandholt, Camilla; Scott, Laura J; Silander, Kaisa; Stark, Klaus; Tammesoo, Mari-Liis; Teslovich, Tanya M; Timpson, Nicholas John; Watanabe, Richard M; Welch, Ryan; Chasman, Daniel I; Cooper, Matthew N; Jansson, John-Olov; Kettunen, Johannes; Lawrence, Robert W; Pellikka, Niina; Perola, Markus; Vandenput, Liesbeth; Alavere, Helene; Almgren, Peter; Atwood, Larry D; Bennett, Amanda J; Biffar, Reiner; Bonnycastle, Lori L; Bornstein, Stefan R; Buchanan, Thomas A; Campbell, Harry; Day, Ian N M; Dei, Mariano; Dörr, Marcus; Elliott, Paul; Erdos, Michael R; Eriksson, Johan G; Freimer, Nelson B; Fu, Mao; Gaget, Stefan; Geus, Eco J C; Gjesing, Anette P; Grallert, Harald; Gräßler, Jürgen; Groves, Christopher J; Guiducci, Candace; Hartikainen, Anna-Liisa; Hassanali, Neelam; Havulinna, Aki S; Herzig, Karl-Heinz; Hicks, Andrew A; Hui, Jennie; Igl, Wilmar; Jousilahti, Pekka; Jula, Antti; Kajantie, Eero; Kinnunen, Leena; Kolcic, Ivana; Koskinen, Seppo; Kovacs, Peter; Kroemer, Heyo K; Krzelj, Vjekoslav; Kuusisto, Johanna; Kvaloy, Kirsti; Laitinen, Jaana; Lantieri, Olivier; Lathrop, G Mark; Lokki, Marja-Liisa; Luben, Robert N; Ludwig, Barbara; McArdle, Wendy L; McCarthy, Anne; Morken, Mario A; Nelis, Mari; Neville, Matt J; Paré, Guillaume; Parker, Alex N; Peden, John F; Pichler, Irene; Pietiläinen, Kirsi H; Platou, Carl G P; Pouta, Anneli; Ridderstråle, Martin; Samani, Nilesh J; Saramies, Jouko; Sinisalo, Juha; Smit, Jan H; Strawbridge, Rona J; Stringham, Heather M; Swift, Amy J; Teder-Laving, Maris; Thomson, Brian; Usala, Gianluca; van Meurs, Joyce B J; van Ommen, Gert-Jan; Vatin, Vincent; Volpato, Claudia B; Wallaschofski, Henri; Walters, G Bragi; Widen, Elisabeth; Wild, Sarah H; Willemsen, Gonneke; Witte, Daniel R; Zgaga, Lina; Zitting, Paavo; Beilby, John P; James, Alan L; Kähönen, Mika; Lehtimäki, Terho; Nieminen, Markku S; Ohlsson, Claes; Palmer, Lyle J; Raitakari, Olli; Ridker, Paul M; Stumvoll, Michael; Tönjes, Anke; Viikari, Jorma; Balkau, Beverley; Ben-Shlomo, Yoav; Bergman, Richard N; Boeing, Heiner; Smith, George Davey; Ebrahim, Shah; Froguel, Philippe; Hansen, Torben; Hengstenberg, Christian; Hveem, Kristian; Isomaa, Bo; Jørgensen, Torben; Karpe, Fredrik; Khaw, Kay-Tee; Laakso, Markku; Lawlor, Debbie A; Marre, Michel; Meitinger, Thomas; Metspalu, Andres; Midthjell, Kristian; Pedersen, Oluf; Salomaa, Veikko; Schwarz, Peter E H; Tuomi, Tiinamaija; Tuomilehto, Jaakko; Valle, Timo T; Wareham, Nicholas J; Arnold, Alice M; Beckmann, Jacques S; Bergmann, Sven; Boerwinkle, Eric; Boomsma, Dorret I; Caulfield, Mark J; Collins, Francis S; Eiriksdottir, Gudny; Gudnason, Vilmundur; Gyllensten, Ulf; Hamsten, Anders; Hattersley, Andrew T; Hofman, Albert; Hu, Frank B; Illig, Thomas; Iribarren, Carlos; Jarvelin, Marjo-Riitta; Kao, W H Linda; Kaprio, Jaakko; Launer, Lenore J; Munroe, Patricia B; Oostra, Ben; Penninx, Brenda W; Pramstaller, Peter P; Psaty, Bruce M; Quertermous, Thomas; Rissanen, Aila; Rudan, Igor; Shuldiner, Alan R; Soranzo, Nicole; Spector, Timothy D; Syvanen, Ann-Christine; Uda, Manuela; Uitterlinden, André; Völzke, Henry; Vollenweider, Peter; Wilson, James F; Witteman, Jacqueline C; Wright, Alan F; Abecasis, Gonçalo R; Boehnke, Michael; Borecki, Ingrid B; Deloukas, Panos; Frayling, Timothy M; Groop, Leif C; Haritunians, Talin; Hunter, David J; Kaplan, Robert C; North, Kari E; O’connell, Jeffrey R; Peltonen, Leena; Schlessinger, David; Strachan, David P; Hirschhorn, Joel N; Assimes, Themistocles L; Wichmann, H-Erich; Thorsteinsdottir, Unnur; van Duijn, Cornelia M; Stefansson, Kari; Cupples, L Adrienne; Loos, Ruth J F; Barroso, Inês; McCarthy, Mark I; Fox, Caroline S; Mohlke, Karen L; Lindgren, Cecilia M

2011-01-01

Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10−9 to P = 1.8 × 10−40) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10−3 to P = 1.2 × 10−13). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions. PMID:20935629

Multilocus methods for estimating population sizes, migration rates and divergence time, with applications to the divergence of Drosophila pseudoobscura and D. persimilis.

PubMed Central

Hey, Jody; Nielsen, Rasmus

2004-01-01

The genetic study of diverging, closely related populations is required for basic questions on demography and speciation, as well as for biodiversity and conservation research. However, it is often unclear whether divergence is due simply to separation or whether populations have also experienced gene flow. These questions can be addressed with a full model of population separation with gene flow, by applying a Markov chain Monte Carlo method for estimating the posterior probability distribution of model parameters. We have generalized this method and made it applicable to data from multiple unlinked loci. These loci can vary in their modes of inheritance, and inheritance scalars can be implemented either as constants or as parameters to be estimated. By treating inheritance scalars as parameters it is also possible to address variation among loci in the impact via linkage of recurrent selective sweeps or background selection. These methods are applied to a large multilocus data set from Drosophila pseudoobscura and D. persimilis. The species are estimated to have diverged approximately 500,000 years ago. Several loci have nonzero estimates of gene flow since the initial separation of the species, with considerable variation in gene flow estimates among loci, in both directions between the species. PMID:15238526

A systemic sclerosis and systemic lupus erythematosus pan-meta-GWAS reveals new shared susceptibility loci

PubMed Central

Martin, Jose-Ezequiel; Assassi, Shervin; Diaz-Gallo, Lina-Marcela; Broen, Jasper C.; Simeon, Carmen P.; Castellvi, Ivan; Vicente-Rabaneda, Esther; Fonollosa, Vicente; Ortego-Centeno, Norberto; González-Gay, Miguel A.; Espinosa, Gerard; Carreira, Patricia; Camps, Mayte; Sabio, Jose M.; D'alfonso, Sandra; Vonk, Madelon C.; Voskuyl, Alexandre E.; Schuerwegh, Annemie J.; Kreuter, Alexander; Witte, Torsten; Riemekasten, Gabriella; Hunzelmann, Nicolas; Airo, Paolo; Beretta, Lorenzo; Scorza, Raffaella; Lunardi, Claudio; Van Laar, Jacob; Chee, Meng May; Worthington, Jane; Herrick, Arianne; Denton, Christopher; Fonseca, Carmen; Tan, Filemon K.; Arnett, Frank; Zhou, Xiaodong; Reveille, John D.; Gorlova, Olga; Koeleman, Bobby P.C.; Radstake, Timothy R.D.J.; Vyse, Timothy; Mayes, Maureen D.; Alarcón-Riquelme, Marta E.; Martin, Javier

2013-01-01

Systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are two archetypal systemic autoimmune diseases which have been shown to share multiple genetic susceptibility loci. In order to gain insight into the genetic basis of these diseases, we performed a pan-meta-analysis of two genome-wide association studies (GWASs) together with a replication stage including additional SSc and SLE cohorts. This increased the sample size to a total of 21 109 (6835 cases and 14 274 controls). We selected for replication 19 SNPs from the GWAS data. We were able to validate KIAA0319L (P = 3.31 × 10−11, OR = 1.49) as novel susceptibility loci for SSc and SLE. Furthermore, we also determined that the previously described SLE susceptibility loci PXK (P = 3.27 × 10−11, OR = 1.20) and JAZF1 (P = 1.11 × 10−8, OR = 1.13) are shared with SSc. Supporting these new discoveries, we observed that KIAA0319L was overexpressed in peripheral blood cells of SSc and SLE patients compared with healthy controls. With these, we add three (KIAA0319L, PXK and JAZF1) and one (KIAA0319L) new susceptibility loci for SSc and SLE, respectively, increasing significantly the knowledge of the genetic basis of autoimmunity. PMID:23740937

Meta-analysis of genome-wide association studies discovers multiple loci for chronic lymphocytic leukemia

PubMed Central

Berndt, Sonja I.; Camp, Nicola J.; Skibola, Christine F.; Vijai, Joseph; Wang, Zhaoming; Gu, Jian; Nieters, Alexandra; Kelly, Rachel S.; Smedby, Karin E.; Monnereau, Alain; Cozen, Wendy; Cox, Angela; Wang, Sophia S.; Lan, Qing; Teras, Lauren R.; Machado, Moara; Yeager, Meredith; Brooks-Wilson, Angela R.; Hartge, Patricia; Purdue, Mark P.; Birmann, Brenda M.; Vajdic, Claire M.; Cocco, Pierluigi; Zhang, Yawei; Giles, Graham G.; Zeleniuch-Jacquotte, Anne; Lawrence, Charles; Montalvan, Rebecca; Burdett, Laurie; Hutchinson, Amy; Ye, Yuanqing; Call, Timothy G.; Shanafelt, Tait D.; Novak, Anne J.; Kay, Neil E.; Liebow, Mark; Cunningham, Julie M.; Allmer, Cristine; Hjalgrim, Henrik; Adami, Hans-Olov; Melbye, Mads; Glimelius, Bengt; Chang, Ellen T.; Glenn, Martha; Curtin, Karen; Cannon-Albright, Lisa A.; Diver, W Ryan; Link, Brian K.; Weiner, George J.; Conde, Lucia; Bracci, Paige M.; Riby, Jacques; Arnett, Donna K.; Zhi, Degui; Leach, Justin M.; Holly, Elizabeth A.; Jackson, Rebecca D.; Tinker, Lesley F.; Benavente, Yolanda; Sala, Núria; Casabonne, Delphine; Becker, Nikolaus; Boffetta, Paolo; Brennan, Paul; Foretova, Lenka; Maynadie, Marc; McKay, James; Staines, Anthony; Chaffee, Kari G.; Achenbach, Sara J.; Vachon, Celine M.; Goldin, Lynn R.; Strom, Sara S.; Leis, Jose F.; Weinberg, J. Brice; Caporaso, Neil E.; Norman, Aaron D.; De Roos, Anneclaire J.; Morton, Lindsay M.; Severson, Richard K.; Riboli, Elio; Vineis, Paolo; Kaaks, Rudolph; Masala, Giovanna; Weiderpass, Elisabete; Chirlaque, María- Dolores; Vermeulen, Roel C. H.; Travis, Ruth C.; Southey, Melissa C.; Milne, Roger L.; Albanes, Demetrius; Virtamo, Jarmo; Weinstein, Stephanie; Clavel, Jacqueline; Zheng, Tongzhang; Holford, Theodore R.; Villano, Danylo J.; Maria, Ann; Spinelli, John J.; Gascoyne, Randy D.; Connors, Joseph M.; Bertrand, Kimberly A.; Giovannucci, Edward; Kraft, Peter; Kricker, Anne; Turner, Jenny; Ennas, Maria Grazia; Ferri, Giovanni M.; Miligi, Lucia; Liang, Liming; Ma, Baoshan; Huang, Jinyan; Crouch, Simon; Park, Ju-Hyun; Chatterjee, Nilanjan; North, Kari E.; Snowden, John A.; Wright, Josh; Fraumeni, Joseph F.; Offit, Kenneth; Wu, Xifeng; de Sanjose, Silvia; Cerhan, James R.; Chanock, Stephen J.; Rothman, Nathaniel; Slager, Susan L.

2016-01-01

Chronic lymphocytic leukemia (CLL) is a common lymphoid malignancy with strong heritability. To further understand the genetic susceptibility for CLL and identify common loci associated with risk, we conducted a meta-analysis of four genome-wide association studies (GWAS) composed of 3,100 cases and 7,667 controls with follow-up replication in 1,958 cases and 5,530 controls. Here we report three new loci at 3p24.1 (rs9880772, EOMES, P=2.55 × 10−11), 6p25.2 (rs73718779, SERPINB6, P=1.97 × 10−8) and 3q28 (rs9815073, LPP, P=3.62 × 10−8), as well as a new independent SNP at the known 2q13 locus (rs9308731, BCL2L11, P=1.00 × 10−11) in the combined analysis. We find suggestive evidence (P<5 × 10−7) for two additional new loci at 4q24 (rs10028805, BANK1, P=7.19 × 10−8) and 3p22.2 (rs1274963, CSRNP1, P=2.12 × 10−7). Pathway analyses of new and known CLL loci consistently show a strong role for apoptosis, providing further evidence for the importance of this biological pathway in CLL susceptibility. PMID:26956414

Homologous Chromosome Pairing in Drosophila melanogaster Proceeds through Multiple Independent Initiations

PubMed Central

Fung, Jennifer C.; Marshall, Wallace F.; Dernburg, Abby; Agard, David A.; Sedat, John W.

1998-01-01

The dynamics by which homologous chromosomes pair is currently unknown. Here, we use fluorescence in situ hybridization in combination with three-dimensional optical microscopy to show that homologous pairing of the somatic chromosome arm 2L in Drosophila occurs by independent initiation of pairing at discrete loci rather than by a processive zippering of sites along the length of chromosome. By evaluating the pairing frequencies of 11 loci on chromosome arm 2L over several timepoints during Drosophila embryonic development, we show that all 11 loci are paired very early in Drosophila development, within 13 h after egg deposition. To elucidate whether such pairing occurs by directed or undirected motion, we analyzed the pairing kinetics of histone loci during nuclear cycle 14. By measuring changes of nuclear length and correlating these changes with progression of time during cycle 14, we were able to express the pairing frequency and distance between homologous loci as a function of time. Comparing the experimentally determined dynamics of pairing to simulations based on previously proposed models of pairing motion, we show that the observed pairing kinetics are most consistent with a constrained random walk model and not consistent with a directed motion model. Thus, we conclude that simple random contacts through diffusion could suffice to allow pairing of homologous sites. PMID:9531544

Homologous chromosome pairing in Drosophila melanogaster proceeds through multiple independent initiations.

PubMed

Fung, J C; Marshall, W F; Dernburg, A; Agard, D A; Sedat, J W

1998-04-06

The dynamics by which homologous chromosomes pair is currently unknown. Here, we use fluorescence in situ hybridization in combination with three-dimensional optical microscopy to show that homologous pairing of the somatic chromosome arm 2L in Drosophila occurs by independent initiation of pairing at discrete loci rather than by a processive zippering of sites along the length of chromosome. By evaluating the pairing frequencies of 11 loci on chromosome arm 2L over several timepoints during Drosophila embryonic development, we show that all 11 loci are paired very early in Drosophila development, within 13 h after egg deposition. To elucidate whether such pairing occurs by directed or undirected motion, we analyzed the pairing kinetics of histone loci during nuclear cycle 14. By measuring changes of nuclear length and correlating these changes with progression of time during cycle 14, we were able to express the pairing frequency and distance between homologous loci as a function of time. Comparing the experimentally determined dynamics of pairing to simulations based on previously proposed models of pairing motion, we show that the observed pairing kinetics are most consistent with a constrained random walk model and not consistent with a directed motion model. Thus, we conclude that simple random contacts through diffusion could suffice to allow pairing of homologous sites.

A systemic sclerosis and systemic lupus erythematosus pan-meta-GWAS reveals new shared susceptibility loci.

PubMed

Martin, Jose-Ezequiel; Assassi, Shervin; Diaz-Gallo, Lina-Marcela; Broen, Jasper C; Simeon, Carmen P; Castellvi, Ivan; Vicente-Rabaneda, Esther; Fonollosa, Vicente; Ortego-Centeno, Norberto; González-Gay, Miguel A; Espinosa, Gerard; Carreira, Patricia; Camps, Mayte; Sabio, Jose M; D'alfonso, Sandra; Vonk, Madelon C; Voskuyl, Alexandre E; Schuerwegh, Annemie J; Kreuter, Alexander; Witte, Torsten; Riemekasten, Gabriella; Hunzelmann, Nicolas; Airo, Paolo; Beretta, Lorenzo; Scorza, Raffaella; Lunardi, Claudio; Van Laar, Jacob; Chee, Meng May; Worthington, Jane; Herrick, Arianne; Denton, Christopher; Fonseca, Carmen; Tan, Filemon K; Arnett, Frank; Zhou, Xiaodong; Reveille, John D; Gorlova, Olga; Koeleman, Bobby P C; Radstake, Timothy R D J; Vyse, Timothy; Mayes, Maureen D; Alarcón-Riquelme, Marta E; Martin, Javier

2013-10-01

Systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are two archetypal systemic autoimmune diseases which have been shown to share multiple genetic susceptibility loci. In order to gain insight into the genetic basis of these diseases, we performed a pan-meta-analysis of two genome-wide association studies (GWASs) together with a replication stage including additional SSc and SLE cohorts. This increased the sample size to a total of 21,109 (6835 cases and 14,274 controls). We selected for replication 19 SNPs from the GWAS data. We were able to validate KIAA0319L (P = 3.31 × 10(-11), OR = 1.49) as novel susceptibility loci for SSc and SLE. Furthermore, we also determined that the previously described SLE susceptibility loci PXK (P = 3.27 × 10(-11), OR = 1.20) and JAZF1 (P = 1.11 × 10(-8), OR = 1.13) are shared with SSc. Supporting these new discoveries, we observed that KIAA0319L was overexpressed in peripheral blood cells of SSc and SLE patients compared with healthy controls. With these, we add three (KIAA0319L, PXK and JAZF1) and one (KIAA0319L) new susceptibility loci for SSc and SLE, respectively, increasing significantly the knowledge of the genetic basis of autoimmunity.

Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels.

PubMed

Kilpeläinen, Tuomas O; Carli, Jayne F Martin; Skowronski, Alicja A; Sun, Qi; Kriebel, Jennifer; Feitosa, Mary F; Hedman, Åsa K; Drong, Alexander W; Hayes, James E; Zhao, Jinghua; Pers, Tune H; Schick, Ursula; Grarup, Niels; Kutalik, Zoltán; Trompet, Stella; Mangino, Massimo; Kristiansson, Kati; Beekman, Marian; Lyytikäinen, Leo-Pekka; Eriksson, Joel; Henneman, Peter; Lahti, Jari; Tanaka, Toshiko; Luan, Jian'an; Del Greco M, Fabiola; Pasko, Dorota; Renström, Frida; Willems, Sara M; Mahajan, Anubha; Rose, Lynda M; Guo, Xiuqing; Liu, Yongmei; Kleber, Marcus E; Pérusse, Louis; Gaunt, Tom; Ahluwalia, Tarunveer S; Ju Sung, Yun; Ramos, Yolande F; Amin, Najaf; Amuzu, Antoinette; Barroso, Inês; Bellis, Claire; Blangero, John; Buckley, Brendan M; Böhringer, Stefan; I Chen, Yii-Der; de Craen, Anton J N; Crosslin, David R; Dale, Caroline E; Dastani, Zari; Day, Felix R; Deelen, Joris; Delgado, Graciela E; Demirkan, Ayse; Finucane, Francis M; Ford, Ian; Garcia, Melissa E; Gieger, Christian; Gustafsson, Stefan; Hallmans, Göran; Hankinson, Susan E; Havulinna, Aki S; Herder, Christian; Hernandez, Dena; Hicks, Andrew A; Hunter, David J; Illig, Thomas; Ingelsson, Erik; Ioan-Facsinay, Andreea; Jansson, John-Olov; Jenny, Nancy S; Jørgensen, Marit E; Jørgensen, Torben; Karlsson, Magnus; Koenig, Wolfgang; Kraft, Peter; Kwekkeboom, Joanneke; Laatikainen, Tiina; Ladwig, Karl-Heinz; LeDuc, Charles A; Lowe, Gordon; Lu, Yingchang; Marques-Vidal, Pedro; Meisinger, Christa; Menni, Cristina; Morris, Andrew P; Myers, Richard H; Männistö, Satu; Nalls, Mike A; Paternoster, Lavinia; Peters, Annette; Pradhan, Aruna D; Rankinen, Tuomo; Rasmussen-Torvik, Laura J; Rathmann, Wolfgang; Rice, Treva K; Brent Richards, J; Ridker, Paul M; Sattar, Naveed; Savage, David B; Söderberg, Stefan; Timpson, Nicholas J; Vandenput, Liesbeth; van Heemst, Diana; Uh, Hae-Won; Vohl, Marie-Claude; Walker, Mark; Wichmann, Heinz-Erich; Widén, Elisabeth; Wood, Andrew R; Yao, Jie; Zeller, Tanja; Zhang, Yiying; Meulenbelt, Ingrid; Kloppenburg, Margreet; Astrup, Arne; Sørensen, Thorkild I A; Sarzynski, Mark A; Rao, D C; Jousilahti, Pekka; Vartiainen, Erkki; Hofman, Albert; Rivadeneira, Fernando; Uitterlinden, André G; Kajantie, Eero; Osmond, Clive; Palotie, Aarno; Eriksson, Johan G; Heliövaara, Markku; Knekt, Paul B; Koskinen, Seppo; Jula, Antti; Perola, Markus; Huupponen, Risto K; Viikari, Jorma S; Kähönen, Mika; Lehtimäki, Terho; Raitakari, Olli T; Mellström, Dan; Lorentzon, Mattias; Casas, Juan P; Bandinelli, Stefanie; März, Winfried; Isaacs, Aaron; van Dijk, Ko W; van Duijn, Cornelia M; Harris, Tamara B; Bouchard, Claude; Allison, Matthew A; Chasman, Daniel I; Ohlsson, Claes; Lind, Lars; Scott, Robert A; Langenberg, Claudia; Wareham, Nicholas J; Ferrucci, Luigi; Frayling, Timothy M; Pramstaller, Peter P; Borecki, Ingrid B; Waterworth, Dawn M; Bergmann, Sven; Waeber, Gérard; Vollenweider, Peter; Vestergaard, Henrik; Hansen, Torben; Pedersen, Oluf; Hu, Frank B; Eline Slagboom, P; Grallert, Harald; Spector, Tim D; Jukema, J W; Klein, Robert J; Schadt, Erik E; Franks, Paul W; Lindgren, Cecilia M; Leibel, Rudolph L; Loos, Ruth J F

2016-02-01

Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered. Therefore, we performed a genome-wide association study (GWAS) of circulating leptin levels from 32,161 individuals and followed up loci reaching P<10(-6) in 19,979 additional individuals. We identify five loci robustly associated (P<5 × 10(-8)) with leptin levels in/near LEP, SLC32A1, GCKR, CCNL1 and FTO. Although the association of the FTO obesity locus with leptin levels is abolished by adjustment for BMI, associations of the four other loci are independent of adiposity. The GCKR locus was found associated with multiple metabolic traits in previous GWAS and the CCNL1 locus with birth weight. Knockdown experiments in mouse adipose tissue explants show convincing evidence for adipogenin, a regulator of adipocyte differentiation, as the novel causal gene in the SLC32A1 locus influencing leptin levels. Our findings provide novel insights into the regulation of leptin production by adipose tissue and open new avenues for examining the influence of variation in leptin levels on adiposity and metabolic health.

Refining Susceptibility Loci of Chronic Obstructive Pulmonary Disease with Lung eqtls

PubMed Central

Lamontagne, Maxime; Couture, Christian; Postma, Dirkje S.; Timens, Wim; Sin, Don D.; Paré, Peter D.; Hogg, James C.; Nickle, David; Laviolette, Michel; Bossé, Yohan

2013-01-01

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of mortality worldwide. Recent genome-wide association studies (GWAS) have identified robust susceptibility loci associated with COPD. However, the mechanisms mediating the risk conferred by these loci remain to be found. The goal of this study was to identify causal genes/variants within susceptibility loci associated with COPD. In the discovery cohort, genome-wide gene expression profiles of 500 non-tumor lung specimens were obtained from patients undergoing lung surgery. Blood-DNA from the same patients were genotyped for 1,2 million SNPs. Following genotyping and gene expression quality control filters, 409 samples were analyzed. Lung expression quantitative trait loci (eQTLs) were identified and overlaid onto three COPD susceptibility loci derived from GWAS; 4q31 (HHIP), 4q22 (FAM13A), and 19q13 (RAB4B, EGLN2, MIA, CYP2A6). Significant eQTLs were replicated in two independent datasets (n = 363 and 339). SNPs previously associated with COPD and lung function on 4q31 (rs1828591, rs13118928) were associated with the mRNA expression of HHIP. An association between mRNA expression level of FAM13A and SNP rs2045517 was detected at 4q22, but did not reach statistical significance. At 19q13, significant eQTLs were detected with EGLN2. In summary, this study supports HHIP, FAM13A, and EGLN2 as the most likely causal COPD genes on 4q31, 4q22, and 19q13, respectively. Strong lung eQTL SNPs identified in this study will need to be tested for association with COPD in case-control studies. Further functional studies will also be needed to understand the role of genes regulated by disease-related variants in COPD. PMID:23936167

[Use of multiple locus variable number tandem repeats analysis for the Brucella systematization].

PubMed

Kulakov, Iu K; Kovalev, D A; Misetova, E N; Golovneva, S I; Liapustina, L V; Zheludkov, M M

2012-01-01

The methods of molecular-genetic differentiation to strain level acquire increasing significance in the current system of struggle with brucellosis. MLVA (multiple locus variable number tandem repeats analysis) was selected for molecular-genetic differentiation to strain level and simultaneous establishment of the genetic relationship of investigated Brucella strains. The goal of this work was MLVA typing of three pathogenic Brucella species strains with the analysis of stability of chosen loci, discrimination power and concordance to conventional phenotypic methods of the Brucella differentiation for use in systematization of brucellosis causing agents. Twenty six Brucella strains representing reference (n = 15), vaccine (n = 2) and field strains of three pathogenic Brucella species were tested: B. melitensis (n = 3), B. abortus (n = 2), B. suis (n = 2), and isolates (n = 2) with unidentified taxonomic position using MLVA with 9 pairs primers on known variable loci of Brucella genome. The analysis of the stability of chosen loci, discrimination power on Hunter-Gaston discrimination index (HGDI) and consistency to phenotypic methods of identification was performed. MLVA was confirmed for the results of phenotypic methods of identification, stability of the chosen loci in majority reference, and vaccine strains with a high index of variability HGDI 0.9969 for all loci. A dendrogram was plotted on the basis of MLVA data on distributed Brucella strains in related clusters according to its taxonomic species and biovar positions and construction of 25 genotypes. B. melitensis strains formed cluster related to the reference strain of B. melitensis 63/9 biovar 2. Australian isolates of Brucella 83-4 and Brucella 83-6 isolated from rodents formed a cluster distant from other strains of Brucella. MLVA is a promising method for differentiation of Brucella strains with known and unresolved taxonomic status for their systematization and creation of MLVA genotype catalogue that will promote qualitative improvement of brucellosis surveillance system in Russia.

Identification of heterotic loci associated with grain yield and its components using two CSSL test populations in maize

PubMed Central

Wang, Hongqiu; Zhang, Xiangge; Yang, Huili; Liu, Xiaoyang; Li, Huimin; Yuan, Liang; Li, Weihua; Fu, Zhiyuan; Tang, Jihua; Kang, Dingming

2016-01-01

Heterosis has widely been used to increase grain yield and quality. In this study, the genetic basis of heterosis on grain yield and its main components in maize were examined over 2 years in two locations in two test populations constructed from a set of 184 chromosome segment substitution lines (CSSLs) and two inbred lines (Zheng58 and Xun9058). Of the 169 heterotic loci (HL) associated with grain yield and its five components identified in CSSL × Zheng58 and CSSL × Xun9058 test populations, only 25 HL were detected in both populations. The comparison of quantitative trait loci (QTLs) detected in the CSSL population with HL detected in the two test populations revealed that only 15.46% and 17.35% of the HL in the given populations respectively, shared the same chromosomal regions as that of the corresponding QTLs and showed dominant effects as well as pleiotropism with additive and dominant effects. In addition, most of the HL (74.23% and 74.49%) had overdominant effects. These results suggest that overdominance is the main contributor to the effects of heterosis on grain yield and its components in maize, and different HL are associated with heterosis for different traits in different hybrids. PMID:27917917

CRISPR Detection From Short Reads Using Partial Overlap Graphs.

PubMed

Ben-Bassat, Ilan; Chor, Benny

2016-06-01

Clustered regularly interspaced short palindromic repeats (CRISPR) are structured regions in bacterial and archaeal genomes, which are part of an adaptive immune system against phages. CRISPRs are important for many microbial studies and are playing an essential role in current gene editing techniques. As such, they attract substantial research interest. The exponential growth in the amount of bacterial sequence data in recent years enables the exploration of CRISPR loci in more and more species. Most of the automated tools that detect CRISPR loci rely on fully assembled genomes. However, many assemblers do not handle repetitive regions successfully. The first tool to work directly on raw sequence data is Crass, which requires reads that are long enough to contain two copies of the same repeat. We present a method to identify CRISPR repeats from raw sequence data of short reads. The algorithm is based on an observation differentiating CRISPR repeats from other types of repeats, and it involves a series of partial constructions of the overlap graph. This enables us to avoid many of the difficulties that assemblers face, as we merely aim to identify the repeats that belong to CRISPR loci. A preliminary implementation of the algorithm shows good results and detects CRISPR repeats in cases where other existing tools fail to do so.

Neptune: a bioinformatics tool for rapid discovery of genomic variation in bacterial populations

PubMed Central

Marinier, Eric; Zaheer, Rahat; Berry, Chrystal; Weedmark, Kelly A.; Domaratzki, Michael; Mabon, Philip; Knox, Natalie C.; Reimer, Aleisha R.; Graham, Morag R.; Chui, Linda; Patterson-Fortin, Laura; Zhang, Jian; Pagotto, Franco; Farber, Jeff; Mahony, Jim; Seyer, Karine; Bekal, Sadjia; Tremblay, Cécile; Isaac-Renton, Judy; Prystajecky, Natalie; Chen, Jessica; Slade, Peter

2017-01-01

Abstract The ready availability of vast amounts of genomic sequence data has created the need to rethink comparative genomics algorithms using ‘big data’ approaches. Neptune is an efficient system for rapidly locating differentially abundant genomic content in bacterial populations using an exact k-mer matching strategy, while accommodating k-mer mismatches. Neptune’s loci discovery process identifies sequences that are sufficiently common to a group of target sequences and sufficiently absent from non-targets using probabilistic models. Neptune uses parallel computing to efficiently identify and extract these loci from draft genome assemblies without requiring multiple sequence alignments or other computationally expensive comparative sequence analyses. Tests on simulated and real datasets showed that Neptune rapidly identifies regions that are both sensitive and specific. We demonstrate that this system can identify trait-specific loci from different bacterial lineages. Neptune is broadly applicable for comparative bacterial analyses, yet will particularly benefit pathogenomic applications, owing to efficient and sensitive discovery of differentially abundant genomic loci. The software is available for download at: http://github.com/phac-nml/neptune. PMID:29048594

Multiple Novel Loci are Associated with Indices of Renal Function and Chronic Kidney Disease

PubMed Central

Köttgen, Anna; Glazer, Nicole L; Dehghan, Abbas; Hwang, Shih-Jen; Katz, Ronit; Li, Man; Yang, Qiong; Gudnason, Vilmundur; Launer, Lenore J; Harris, Tamara B; Smith, Albert V; Arking, Dan E; Astor, Brad C; Boerwinkle, Eric; Ehret, Georg B; Ruczinski, Ingo; Scharpf, Robert B; Chen, Yii-Der Ida; de Boer, Ian H; Haritunians, Talin; Lumley, Thomas; Sarnak, Mark; Siscovick, David; Benjamin, Emelia J; Levy, Daniel; Upadhyay, Ashish; Aulchenko, Yurii S; Hofman, Albert; Rivadeneira, Fernando; Uitterlinden, André G; van Duijn, Cornelia M; Chasman, Daniel I; Paré, Guillaume; Ridker, Paul M; Kao, WH Linda; Witteman, Jacqueline C; Coresh, Josef; Shlipak, Michael G; Fox, Caroline S

2011-01-01

Chronic kidney disease (CKD) has a heritable component and is an important global public health problem because of its high prevalence and morbidity.1 We conducted genome-wide association studies (GWAS) to identify susceptibility loci for glomerular filtration rate estimated by serum creatinine (eGFRcrea), cystatin C (eGFRcys), and CKD (eGFRcrea<60 ml/min/1.73m2) in European-ancestry participants of four populations-based cohorts (ARIC, CHS, FHS, RS; n=19,877, 2,388 CKD cases), and tested for external replication in 21,466 participants (1,932 CKD cases). Significant associations (p<5*10−8) were identified for SNPs with [1] CKD at the UMOD locus; [2] eGFRcrea at the UMOD, SHROOM3, and GATM/SPATA5L1 loci; [3] eGFRcys at the CST and STC1 loci. UMOD encodes the most common protein in human urine, Tamm-Horsfall protein,2 and rare mutations in UMOD cause Mendelian forms of kidney disease.3 Our findings provide new insights into CKD pathogenesis and underscore the importance of common genetic variants influencing renal function and disease. PMID:19430482

Genome-wide meta-analyses of multiancestry cohorts identify multiple new susceptibility loci for refractive error and myopia.

PubMed

Verhoeven, Virginie J M; Hysi, Pirro G; Wojciechowski, Robert; Fan, Qiao; Guggenheim, Jeremy A; Höhn, René; MacGregor, Stuart; Hewitt, Alex W; Nag, Abhishek; Cheng, Ching-Yu; Yonova-Doing, Ekaterina; Zhou, Xin; Ikram, M Kamran; Buitendijk, Gabriëlle H S; McMahon, George; Kemp, John P; Pourcain, Beate St; Simpson, Claire L; Mäkelä, Kari-Matti; Lehtimäki, Terho; Kähönen, Mika; Paterson, Andrew D; Hosseini, S Mohsen; Wong, Hoi Suen; Xu, Liang; Jonas, Jost B; Pärssinen, Olavi; Wedenoja, Juho; Yip, Shea Ping; Ho, Daniel W H; Pang, Chi Pui; Chen, Li Jia; Burdon, Kathryn P; Craig, Jamie E; Klein, Barbara E K; Klein, Ronald; Haller, Toomas; Metspalu, Andres; Khor, Chiea-Chuen; Tai, E-Shyong; Aung, Tin; Vithana, Eranga; Tay, Wan-Ting; Barathi, Veluchamy A; Chen, Peng; Li, Ruoying; Liao, Jiemin; Zheng, Yingfeng; Ong, Rick T; Döring, Angela; Evans, David M; Timpson, Nicholas J; Verkerk, Annemieke J M H; Meitinger, Thomas; Raitakari, Olli; Hawthorne, Felicia; Spector, Tim D; Karssen, Lennart C; Pirastu, Mario; Murgia, Federico; Ang, Wei; Mishra, Aniket; Montgomery, Grant W; Pennell, Craig E; Cumberland, Phillippa M; Cotlarciuc, Ioana; Mitchell, Paul; Wang, Jie Jin; Schache, Maria; Janmahasatian, Sarayut; Janmahasathian, Sarayut; Igo, Robert P; Lass, Jonathan H; Chew, Emily; Iyengar, Sudha K; Gorgels, Theo G M F; Rudan, Igor; Hayward, Caroline; Wright, Alan F; Polasek, Ozren; Vatavuk, Zoran; Wilson, James F; Fleck, Brian; Zeller, Tanja; Mirshahi, Alireza; Müller, Christian; Uitterlinden, André G; Rivadeneira, Fernando; Vingerling, Johannes R; Hofman, Albert; Oostra, Ben A; Amin, Najaf; Bergen, Arthur A B; Teo, Yik-Ying; Rahi, Jugnoo S; Vitart, Veronique; Williams, Cathy; Baird, Paul N; Wong, Tien-Yin; Oexle, Konrad; Pfeiffer, Norbert; Mackey, David A; Young, Terri L; van Duijn, Cornelia M; Saw, Seang-Mei; Bailey-Wilson, Joan E; Stambolian, Dwight; Klaver, Caroline C; Hammond, Christopher J

2013-03-01

Refractive error is the most common eye disorder worldwide and is a prominent cause of blindness. Myopia affects over 30% of Western populations and up to 80% of Asians. The CREAM consortium conducted genome-wide meta-analyses, including 37,382 individuals from 27 studies of European ancestry and 8,376 from 5 Asian cohorts. We identified 16 new loci for refractive error in individuals of European ancestry, of which 8 were shared with Asians. Combined analysis identified 8 additional associated loci. The new loci include candidate genes with functions in neurotransmission (GRIA4), ion transport (KCNQ5), retinoic acid metabolism (RDH5), extracellular matrix remodeling (LAMA2 and BMP2) and eye development (SIX6 and PRSS56). We also confirmed previously reported associations with GJD2 and RASGRF1. Risk score analysis using associated SNPs showed a tenfold increased risk of myopia for individuals carrying the highest genetic load. Our results, based on a large meta-analysis across independent multiancestry studies, considerably advance understanding of the mechanisms involved in refractive error and myopia.

Genome-wide association study reveals multiple loci associated with primary tooth development during infancy.

PubMed

Pillas, Demetris; Hoggart, Clive J; Evans, David M; O'Reilly, Paul F; Sipilä, Kirsi; Lähdesmäki, Raija; Millwood, Iona Y; Kaakinen, Marika; Netuveli, Gopalakrishnan; Blane, David; Charoen, Pimphen; Sovio, Ulla; Pouta, Anneli; Freimer, Nelson; Hartikainen, Anna-Liisa; Laitinen, Jaana; Vaara, Sarianna; Glaser, Beate; Crawford, Peter; Timpson, Nicholas J; Ring, Susan M; Deng, Guohong; Zhang, Weihua; McCarthy, Mark I; Deloukas, Panos; Peltonen, Leena; Elliott, Paul; Coin, Lachlan J M; Smith, George Davey; Jarvelin, Marjo-Riitta

2010-02-26

Tooth development is a highly heritable process which relates to other growth and developmental processes, and which interacts with the development of the entire craniofacial complex. Abnormalities of tooth development are common, with tooth agenesis being the most common developmental anomaly in humans. We performed a genome-wide association study of time to first tooth eruption and number of teeth at one year in 4,564 individuals from the 1966 Northern Finland Birth Cohort (NFBC1966) and 1,518 individuals from the Avon Longitudinal Study of Parents and Children (ALSPAC). We identified 5 loci at P<5x10(-8), and 5 with suggestive association (P<5x10(-6)). The loci included several genes with links to tooth and other organ development (KCNJ2, EDA, HOXB2, RAD51L1, IGF2BP1, HMGA2, MSRB3). Genes at four of the identified loci are implicated in the development of cancer. A variant within the HOXB gene cluster associated with occlusion defects requiring orthodontic treatment by age 31 years.

Genome-Wide Association Study Reveals Multiple Loci Associated with Primary Tooth Development during Infancy

PubMed Central

Sipilä, Kirsi; Lähdesmäki, Raija; Millwood, Iona Y.; Kaakinen, Marika; Netuveli, Gopalakrishnan; Blane, David; Charoen, Pimphen; Sovio, Ulla; Pouta, Anneli; Freimer, Nelson; Hartikainen, Anna-Liisa; Laitinen, Jaana; Vaara, Sarianna; Glaser, Beate; Crawford, Peter; Timpson, Nicholas J.; Ring, Susan M.; Deng, Guohong; Zhang, Weihua; McCarthy, Mark I.; Deloukas, Panos; Peltonen, Leena

2010-01-01

Tooth development is a highly heritable process which relates to other growth and developmental processes, and which interacts with the development of the entire craniofacial complex. Abnormalities of tooth development are common, with tooth agenesis being the most common developmental anomaly in humans. We performed a genome-wide association study of time to first tooth eruption and number of teeth at one year in 4,564 individuals from the 1966 Northern Finland Birth Cohort (NFBC1966) and 1,518 individuals from the Avon Longitudinal Study of Parents and Children (ALSPAC). We identified 5 loci at P<5×10−8, and 5 with suggestive association (P<5×10−6). The loci included several genes with links to tooth and other organ development (KCNJ2, EDA, HOXB2, RAD51L1, IGF2BP1, HMGA2, MSRB3). Genes at four of the identified loci are implicated in the development of cancer. A variant within the HOXB gene cluster associated with occlusion defects requiring orthodontic treatment by age 31 years. PMID:20195514

Sequencing chromosomal abnormalities reveals neurodevelopmental loci that confer risk across diagnostic boundaries

PubMed Central

Talkowski, Michael E.; Rosenfeld, Jill A.; Blumenthal, Ian; Pillalamarri, Vamsee; Chiang, Colby; Heilbut, Adrian; Ernst, Carl; Hanscom, Carrie; Rossin, Elizabeth; Lindgren, Amelia; Pereira, Shahrin; Ruderfer, Douglas; Kirby, Andrew; Ripke, Stephan; Harris, David; Lee, Ji-Hyun; Ha, Kyungsoo; Kim, Hyung-Goo; Solomon, Benjamin D.; Gropman, Andrea L.; Lucente, Diane; Sims, Katherine; Ohsumi, Toshiro K.; Borowsky, Mark L.; Loranger, Stephanie; Quade, Bradley; Lage, Kasper; Miles, Judith; Wu, Bai-Lin; Shen, Yiping; Neale, Benjamin; Shaffer, Lisa G.; Daly, Mark J.; Morton, Cynthia C.; Gusella, James F.

2012-01-01

SUMMARY Balanced chromosomal abnormalities (BCAs) represent a reservoir of single gene disruptions in neurodevelopmental disorders (NDD). We sequenced BCAs in autism and related NDDs, revealing disruption of 33 loci in four general categories: 1) genes associated with abnormal neurodevelopment (e.g., AUTS2, FOXP1, CDKL5), 2) single gene contributors to microdeletion syndromes (MBD5, SATB2, EHMT1, SNURF-SNRPN), 3) novel risk loci (e.g., CHD8, KIRREL3, ZNF507), and 4) genes associated with later onset psychiatric disorders (e.g., TCF4, ZNF804A, PDE10A, GRIN2B, ANK3). We also discovered profoundly increased burden of copy number variants among 19,556 neurodevelopmental cases compared to 13,991 controls (p = 2.07×10−47) and enrichment of polygenic risk alleles from autism and schizophrenia genome-wide association studies (p = 0.0018 and 0.0009, respectively). Our findings suggest a polygenic risk model of autism incorporating loci of strong effect and indicate that some neurodevelopmental genes are sensitive to perturbation by multiple mutational mechanisms, leading to variable phenotypic outcomes that manifest at different life stages. PMID:22521361

Quantitative Trait Loci (QTL)-Guided Metabolic Engineering of a Complex Trait.

PubMed

Maurer, Matthew J; Sutardja, Lawrence; Pinel, Dominic; Bauer, Stefan; Muehlbauer, Amanda L; Ames, Tyler D; Skerker, Jeffrey M; Arkin, Adam P

2017-03-17

Engineering complex phenotypes for industrial and synthetic biology applications is difficult and often confounds rational design. Bioethanol production from lignocellulosic feedstocks is a complex trait that requires multiple host systems to utilize, detoxify, and metabolize a mixture of sugars and inhibitors present in plant hydrolysates. Here, we demonstrate an integrated approach to discovering and optimizing host factors that impact fitness of Saccharomyces cerevisiae during fermentation of a Miscanthus x giganteus plant hydrolysate. We first used high-resolution Quantitative Trait Loci (QTL) mapping and systematic bulk Reciprocal Hemizygosity Analysis (bRHA) to discover 17 loci that differentiate hydrolysate tolerance between an industrially related (JAY291) and a laboratory (S288C) strain. We then used this data to identify a subset of favorable allelic loci that were most amenable for strain engineering. Guided by this "genetic blueprint", and using a dual-guide Cas9-based method to efficiently perform multikilobase locus replacements, we engineered an S288C-derived strain with superior hydrolysate tolerance than JAY291. Our methods should be generalizable to engineering any complex trait in S. cerevisiae, as well as other organisms.

The epidemiology of infections with Giardia species and genotypes in well cared for dogs and cats in Germany.

PubMed

Pallant, Louise; Barutzki, Dieter; Schaper, Roland; Thompson, R C Andrew

2015-01-06

Giardia is now considered the most common enteric parasite in well cared for dogs and cats in developed countries. The ecology, epidemiology and clinical impact of infections with this parasite in such animals is still not fully understood due to variable results across different studies. Faecal samples were collected between 2009 and 2012 from privately owned cats and dogs in Germany presented to local veterinarians for a variety of reasons. Giardia positive samples were identified by microscopy and coproantigen methods. Total faecal DNA was extracted from Giardia positive samples and multilocus genotyping methods (18S rDNA, β-giardin, GDH) were applied. Relationships between host age, sex, and breed, season of presentation and the different species of Giardia detected were assessed. A total of 60 cat and 130 dog samples were identified as Giardia positive. Potentially zoonotic Giardia was identified in both animal species. Cats had a similarly high rate of infection with the G. duodenalis and G. cati. Cats less than 1 year were more likely to have G. duodenalis than cats older than 1 year. Pure breed cats demonstrated a greater proportion of zoonotic species than mixed breed cats. In samples from dogs, G. canis (C and D genotypes) were identified most commonly. Male dogs were more likely to have G. canis (genotype D) than female dogs. The 18S rDNA PCR protocol was the most successful followed by the β-giardin and GDH (amplifying from 92%, 42% and 13% of samples respectively). The potentially zoonotic species G. duodenalis and G. enterica were found in cat and dog samples, with G. duodenalis found in greater numbers; however, this may be due to the detection techniques utilised. Cats appeared to show a relationship between G. duodenalis and G. cati with age and breed, which may be explained by different housing habitats for pure and mixed breed cats. The different success rates for the three loci utilised highlights the usefulness of the 18S locus as a screening tool, as well as the importance of using multiple loci for genotyping to fully determine the level of multiple infection of Giardia present.

Genetic Architecture of Atherosclerosis in Mice: A Systems Genetics Analysis of Common Inbred Strains

PubMed Central

Bennett, Brian J.; Davis, Richard C.; Civelek, Mete; Orozco, Luz; Wu, Judy; Qi, Hannah; Pan, Calvin; Packard, René R. Sevag; Eskin, Eleazar; Yan, Mujing; Kirchgessner, Todd; Wang, Zeneng; Li, Xinmin; Gregory, Jill C.; Hazen, Stanley L.; Gargalovic, Peter S.; Lusis, Aldons J.

2015-01-01

Common forms of atherosclerosis involve multiple genetic and environmental factors. While human genome-wide association studies have identified numerous loci contributing to coronary artery disease and its risk factors, these studies are unable to control environmental factors or examine detailed molecular traits in relevant tissues. We now report a study of natural variations contributing to atherosclerosis and related traits in over 100 inbred strains of mice from the Hybrid Mouse Diversity Panel (HMDP). The mice were made hyperlipidemic by transgenic expression of human apolipoprotein E-Leiden (APOE-Leiden) and human cholesteryl ester transfer protein (CETP). The mice were examined for lesion size and morphology as well as plasma lipid, insulin and glucose levels, and blood cell profiles. A subset of mice was studied for plasma levels of metabolites and cytokines. We also measured global transcript levels in aorta and liver. Finally, the uptake of acetylated LDL by macrophages from HMDP mice was quantitatively examined. Loci contributing to the traits were mapped using association analysis, and relationships among traits were examined using correlation and statistical modeling. A number of conclusions emerged. First, relationships among atherosclerosis and the risk factors in mice resemble those found in humans. Second, a number of trait-loci were identified, including some overlapping with previous human and mouse studies. Third, gene expression data enabled enrichment analysis of pathways contributing to atherosclerosis and prioritization of candidate genes at associated loci in both mice and humans. Fourth, the data provided a number of mechanistic inferences; for example, we detected no association between macrophage uptake of acetylated LDL and atherosclerosis. Fifth, broad sense heritability for atherosclerosis was much larger than narrow sense heritability, indicating an important role for gene-by-gene interactions. Sixth, stepwise linear regression showed that the combined variations in plasma metabolites, including LDL/VLDL-cholesterol, trimethylamine N-oxide (TMAO), arginine, glucose and insulin, account for approximately 30 to 40% of the variation in atherosclerotic lesion area. Overall, our data provide a rich resource for studies of complex interactions underlying atherosclerosis. PMID:26694027

Multicolor-based discrimination of 21 short tandem repeats and amelogenin using four fluorescent universal primers.

PubMed

Asari, Masaru; Okuda, Katsuhiro; Hoshina, Chisato; Omura, Tomohiro; Tasaki, Yoshikazu; Shiono, Hiroshi; Matsubara, Kazuo; Shimizu, Keiko

2016-02-01

The aim of this study was to develop a cost-effective genotyping method using high-quality DNA for human identification. A total of 21 short tandem repeats (STRs) and amelogenin were selected, and fluorescent fragments at 22 loci were simultaneously amplified in a single-tube reaction using locus-specific primers with 24-base universal tails and four fluorescent universal primers. Several nucleotide substitutions in universal tails and fluorescent universal primers enabled the detection of specific fluorescent fragments from the 22 loci. Multiplex polymerase chain reaction (PCR) produced intense FAM-, VIC-, NED-, and PET-labeled fragments ranging from 90 to 400 bp, and these fragments were discriminated using standard capillary electrophoretic analysis. The selected 22 loci were also analyzed using two commercial kits (the AmpFLSTR Identifiler Kit and the PowerPlex ESX 17 System), and results for two loci (D19S433 and D16S539) were discordant between these kits due to mutations at the primer binding sites. All genotypes from the 100 samples were determined using 2.5 ng of DNA by our method, and the expected alleles were completely recovered. Multiplex 22-locus genotyping using four fluorescent universal primers effectively reduces the costs to less than 20% of genotyping using commercial kits, and our method would be useful to detect silent alleles from commercial kit analysis. Copyright © 2015 Elsevier Inc. All rights reserved.

Quantification of DNA using the luminescent oxygen channeling assay.

PubMed

Patel, R; Pollner, R; de Keczer, S; Pease, J; Pirio, M; DeChene, N; Dafforn, A; Rose, S

2000-09-01

Simplified and cost-effective methods for the detection and quantification of nucleic acid targets are still a challenge in molecular diagnostics. Luminescent oxygen channeling assay (LOCI(TM)) latex particles can be conjugated to synthetic oligodeoxynucleotides and hybridized, via linking probes, to different DNA targets. These oligomer-conjugated LOCI particles survive thermocycling in a PCR reaction and allow quantified detection of DNA targets in both real-time and endpoint formats. The endpoint DNA quantification format utilized two sensitizer bead types that are sensitive to separate illumination wavelengths. These two bead types were uniquely annealed to target or control amplicons, and separate illuminations generated time-resolved chemiluminescence, which distinguished the two amplicon types. In the endpoint method, ratios of the two signals allowed determination of the target DNA concentration over a three-log range. The real-time format allowed quantification of the DNA target over a six-log range with a linear relationship between threshold cycle and log of the number of DNA targets. This is the first report of the use of an oligomer-labeled latex particle assay capable of producing DNA quantification and sequence-specific chemiluminescent signals in a homogeneous format. It is also the first report of the generation of two signals from a LOCI assay. The methods described here have been shown to be easily adaptable to new DNA targets because of the generic nature of the oligomer-labeled LOCI particles.

Allele frequencies of 15 STR loci in Bosnian and Herzegovinian population

PubMed Central

Pilav, Amela; Pojskić, Naris; Ahatović, Anesa; Džehverović, Mirela; Čakar, Jasmina; Marjanović, Damir

2017-01-01

Aim To determine newest the most accurate allele frequencies for 15 short tandem repeat (STR) loci in the Bosnian and Herzegovinian population, calculate statistical parameters, and compare them with the relevant data for seven neighboring populations. Methods Genomic DNA was obtained from buccal swabs of 1000 unrelated individuals from all regions of Bosnia and Herzegovina. Genotyping was performed using PowerPlex® 16 System to obtain allele frequencies for 15 polymorphic STR loci including D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX, and FGA. The calculated allele frequencies were also compared with the data from neighboring populations. Results The highest detected value of polymorphism information content (PIC) was detected at the PentaE locus, whereas the lowest value was detected at the TPOX locus. The power of discrimination (PD) values had similar distribution, with Penta E showing the highest PD of 0.9788. While D18S51 had the highest value of power of exclusion (PE), the lowest PE value was detected at the TPOX locus. Conclusion Upon comparison of Bosnian and Herzegovinian population data with those of seven neighboring populations, the highest allele frequency differentiation was noticed between Bosnian and Herzegovinian and Turkish population at 5 loci, the most informative of which was Penta E. The neighbor-joining dendrogram constructed on the basis of genetic distance showed grouping of Slovenian, Austrian, Hungarian, and Croatian populations. Bosnian and Herzegovinian population was between the mentioned cluster and Serbian population. To determine more accurate distribution of allelic frequencies and forensic parameters, our study included 1000 unrelated individuals from all regions of Bosnia and Herzegovina, and our findings demonstrated the applicability of these markers in both forensics and future population genetic studies. PMID:28613042

Allele frequencies of 15 STR loci in Bosnian and Herzegovinian population.

PubMed

Pilav, Amela; Pojskić, Naris; Ahatović, Anesa; Džehverović, Mirela; Čakar, Jasmina; Marjanović, Damir

2017-06-14

To determine newest the most accurate allele frequencies for 15 short tandem repeat (STR) loci in the Bosnian and Herzegovinian population, calculate statistical parameters, and compare them with the relevant data for seven neighboring populations. Genomic DNA was obtained from buccal swabs of 1000 unrelated individuals from all regions of Bosnia and Herzegovina. Genotyping was performed using PowerPlex® 16 System to obtain allele frequencies for 15 polymorphic STR loci including D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX, and FGA. The calculated allele frequencies were also compared with the data from neighboring populations. The highest detected value of polymorphism information content (PIC) was detected at the PentaE locus, whereas the lowest value was detected at the TPOX locus. The power of discrimination (PD) values had similar distribution, with Penta E showing the highest PD of 0.9788. While D18S51 had the highest value of power of exclusion (PE), the lowest PE value was detected at the TPOX locus. Upon comparison of Bosnian and Herzegovinian population data with those of seven neighboring populations, the highest allele frequency differentiation was noticed between Bosnian and Herzegovinian and Turkish population at 5 loci, the most informative of which was Penta E. The neighbor-joining dendrogram constructed on the basis of genetic distance showed grouping of Slovenian, Austrian, Hungarian, and Croatian populations. Bosnian and Herzegovinian population was between the mentioned cluster and Serbian population. To determine more accurate distribution of allelic frequencies and forensic parameters, our study included 1000 unrelated individuals from all regions of Bosnia and Herzegovina, and our findings demonstrated the applicability of these markers in both forensics and future population genetic studies.

The Negative Correlation between Fiber Color and Quality Traits Revealed by QTL Analysis.

PubMed

Feng, Hongjie; Guo, Lixue; Wang, Gaskin; Sun, Junling; Pan, Zhaoe; He, Shoupu; Zhu, Heqin; Sun, Jie; Du, Xiongming

2015-01-01

Naturally existing colored cotton was far from perfection due to having genetic factors for lower yield, poor fiber quality and monotonous color. These factors posed a challenge to colored cotton breeding and innovation. To identify novel quantitative trait loci (QTL) for fiber color along with understanding of correlation between fiber color and quality in colored cotton, a RIL and two F2 populations were generated from crosses among Zong128 (Brown fiber cotton) and two white fiber cotton lines which were then analyzed in four environments. Two stable and major QTLs (qLC-7-1, qFC-7-1) for fiber lint and fuzz color were detected accounting for 16.01%-59.85% of the phenotypic variation across multiple generations and environments. Meanwhile, some minor QTLs were also identified on chromosomes 5, 14, 21 and 24 providing low phenotypic variation (<5%) from only F2 populations, not from the RILs population. Especially, a multiple-effect locus for fiber color and quality has been detected between flanking markers NAU1043 and NAU3654 on chromosome 7 (A genome) over multiple environments. Of which, qLC-7-1, qFC-7-1 were responsible for positive effects and improved fiber color in offsprings. Meanwhile, the QTLs (qFL-7-1, qFU-7-1, qFF-7-1, qFE-7-1, and qFS-7-1) for fiber quality had negative effects and explained 2.19%-8.78% of the phenotypic variation. This multiple-effect locus for fiber color and quality may reveal the negative correlation between the two types of above traits, so paving the way towards cotton genetic improvement.

Identification and Validation of Loci Governing Seed Coat Color by Combining Association Mapping and Bulk Segregation Analysis in Soybean

PubMed Central

Ma, Yansong; Tian, Long; Li, Xinxiu; Li, Ying-Hui; Guan, Rongxia; Guo, Yong; Qiu, Li-Juan

2016-01-01

Soybean seed coat exists in a range of colors from yellow, green, brown, black, to bicolor. Classical genetic analysis suggested that soybean seed color was a moderately complex trait controlled by multi-loci. However, only a couple of loci could be detected using a single biparental segregating population. In this study, a combination of association mapping and bulk segregation analysis was employed to identify genes/loci governing this trait in soybean. A total of 14 loci, including nine novel and five previously reported ones, were identified using 176,065 coding SNPs selected from entire SNP dataset among 56 soybean accessions. Four of these loci were confirmed and further mapped using a biparental population developed from the cross between ZP95-5383 (yellow seed color) and NY279 (brown seed color), in which different seed coat colors were further dissected into simple trait pairs (green/yellow, green/black, green/brown, yellow/black, yellow/brown, and black/brown) by continuously developing residual heterozygous lines. By genotyping entire F2 population using flanking markers located in fine-mapping regions, the genetic basis of seed coat color was fully dissected and these four loci could explain all variations of seed colors in this population. These findings will be useful for map-based cloning of genes as well as marker-assisted breeding in soybean. This work also provides an alternative strategy for systematically isolating genes controlling relative complex trait by association analysis followed by biparental mapping. PMID:27404272

The distribution and impact of common copy-number variation in the genome of the domesticated apple, Malus x domestica Borkh.

PubMed

Boocock, James; Chagné, David; Merriman, Tony R; Black, Michael A

2015-10-23

Copy number variation (CNV) is a common feature of eukaryotic genomes, and a growing body of evidence suggests that genes affected by CNV are enriched in processes that are associated with environmental responses. Here we use next generation sequence (NGS) data to detect copy-number variable regions (CNVRs) within the Malus x domestica genome, as well as to examine their distribution and impact. CNVRs were detected using NGS data derived from 30 accessions of M. x domestica analyzed using the read-depth method, as implemented in the CNVrd2 software. To improve the reliability of our results, we developed a quality control and analysis procedure that involved checking for organelle DNA, not repeat masking, and the determination of CNVR identity using a permutation testing procedure. Overall, we identified 876 CNVRs, which spanned 3.5 % of the apple genome. To verify that detected CNVRs were not artifacts, we analyzed the B- allele-frequencies (BAF) within a single nucleotide polymorphism (SNP) array dataset derived from a screening of 185 individual apple accessions and found the CNVRs were enriched for SNPs having aberrant BAFs (P < 1e-13, Fisher's Exact test). Putative CNVRs overlapped 845 gene models and were enriched for resistance (R) gene models (P < 1e-22, Fisher's exact test). Of note was a cluster of resistance gene models on chromosome 2 near a region containing multiple major gene loci conferring resistance to apple scab. We present the first analysis and catalogue of CNVRs in the M. x domestica genome. The enrichment of the CNVRs with R gene models and their overlap with gene loci of agricultural significance draw attention to a form of unexplored genetic variation in apple. This research will underpin further investigation of the role that CNV plays within the apple genome.

Genetic Diversity of Giardia duodenalis: Multilocus Genotyping Reveals Zoonotic Potential between Clinical and Environmental Sources in a Metropolitan Region of Brazil

PubMed Central

Durigan, Mauricio; Abreu, Aluana Gonçalves; Zucchi, Maria Imaculada; Franco, Regina Maura Bueno; de Souza, Anete Pereira

2014-01-01

Background Giardia duodenalis is a flagellate protozoan that parasitizes humans and several other mammals. Protozoan contamination has been regularly documented at important environmental sites, although most of these studies were performed at the species level. There is a lack of studies that correlate environmental contamination and clinical infections in the same region. The aim of this study is to evaluate the genetic diversity of a set of clinical and environmental samples and to use the obtained data to characterize the genetic profile of the distribution of G. duodenalis and the potential for zoonotic transmission in a metropolitan region of Brazil. Methodology/Principal Findings The genetic assemblages and subtypes of G. duodenalis isolates obtained from hospitals, a veterinary clinic, a day-care center and important environmental sites were determined via multilocus sequence-based genotyping using three unlinked gene loci. Cysts of Giardia were detected at all of the environmental sites. Mixed assemblages were detected in 25% of the total samples, and an elevated number of haplotypes was identified. The main haplotypes were shared among the groups, and new subtypes were identified at all loci. Ten multilocus genotypes were identified: 7 for assemblage A and 3 for assemblage B. Conclusions/Significance There is persistent G. duodenalis contamination at important environmental sites in the city. The identified mixed assemblages likely represent mixed infections, suggesting high endemicity of Giardia in these hosts. Most Giardia isolates obtained in this study displayed zoonotic potential. The high degree of genetic diversity in the isolates obtained from both clinical and environmental samples suggests that multiple sources of infection are likely responsible for the detected contamination events. The finding that many multilocus genotypes (MLGs) and haplotypes are shared by different groups suggests that these sources of infection may be related and indicates that there is a notable risk of human infection caused by Giardia in this region. PMID:25536055

Trans-ethnic meta-regression of genome-wide association studies accounting for ancestry increases power for discovery and improves fine-mapping resolution

PubMed Central

Mägi, Reedik; Horikoshi, Momoko; Sofer, Tamar; Mahajan, Anubha; Kitajima, Hidetoshi; Franceschini, Nora; McCarthy, Mark I.; Morris, Andrew P.

2017-01-01

Abstract Trans-ethnic meta-analysis of genome-wide association studies (GWAS) across diverse populations can increase power to detect complex trait loci when the underlying causal variants are shared between ancestry groups. However, heterogeneity in allelic effects between GWAS at these loci can occur that is correlated with ancestry. Here, a novel approach is presented to detect SNP association and quantify the extent of heterogeneity in allelic effects that is correlated with ancestry. We employ trans-ethnic meta-regression to model allelic effects as a function of axes of genetic variation, derived from a matrix of mean pairwise allele frequency differences between GWAS, and implemented in the MR-MEGA software. Through detailed simulations, we demonstrate increased power to detect association for MR-MEGA over fixed- and random-effects meta-analysis across a range of scenarios of heterogeneity in allelic effects between ethnic groups. We also demonstrate improved fine-mapping resolution, in loci containing a single causal variant, compared to these meta-analysis approaches and PAINTOR, and equivalent performance to MANTRA at reduced computational cost. Application of MR-MEGA to trans-ethnic GWAS of kidney function in 71,461 individuals indicates stronger signals of association than fixed-effects meta-analysis when heterogeneity in allelic effects is correlated with ancestry. Application of MR-MEGA to fine-mapping four type 2 diabetes susceptibility loci in 22,086 cases and 42,539 controls highlights: (i) strong evidence for heterogeneity in allelic effects that is correlated with ancestry only at the index SNP for the association signal at the CDKAL1 locus; and (ii) 99% credible sets with six or fewer variants for five distinct association signals. PMID:28911207

Similar Genetic Architecture with Shared and Unique Quantitative Trait Loci for Bacterial Cold Water Disease Resistance in Two Rainbow Trout Breeding Populations

PubMed Central

Vallejo, Roger L.; Liu, Sixin; Gao, Guangtu; Fragomeni, Breno O.; Hernandez, Alvaro G.; Leeds, Timothy D.; Parsons, James E.; Martin, Kyle E.; Evenhuis, Jason P.; Welch, Timothy J.; Wiens, Gregory D.; Palti, Yniv

2017-01-01

Bacterial cold water disease (BCWD) causes significant mortality and economic losses in salmonid aquaculture. In previous studies, we identified moderate-large effect quantitative trait loci (QTL) for BCWD resistance in rainbow trout (Oncorhynchus mykiss). However, the recent availability of a 57 K SNP array and a reference genome assembly have enabled us to conduct genome-wide association studies (GWAS) that overcome several experimental limitations from our previous work. In the current study, we conducted GWAS for BCWD resistance in two rainbow trout breeding populations using two genotyping platforms, the 57 K Affymetrix SNP array and restriction-associated DNA (RAD) sequencing. Overall, we identified 14 moderate-large effect QTL that explained up to 60.8% of the genetic variance in one of the two populations and 27.7% in the other. Four of these QTL were found in both populations explaining a substantial proportion of the variance, although major differences were also detected between the two populations. Our results confirm that BCWD resistance is controlled by the oligogenic inheritance of few moderate-large effect loci and a large-unknown number of loci each having a small effect on BCWD resistance. We detected differences in QTL number and genome location between two GWAS models (weighted single-step GBLUP and Bayes B), which highlights the utility of using different models to uncover QTL. The RAD-SNPs detected a greater number of QTL than the 57 K SNP array in one population, suggesting that the RAD-SNPs may uncover polymorphisms that are more unique and informative for the specific population in which they were discovered. PMID:29109734

Similar Genetic Architecture with Shared and Unique Quantitative Trait Loci for Bacterial Cold Water Disease Resistance in Two Rainbow Trout Breeding Populations.

PubMed

Vallejo, Roger L; Liu, Sixin; Gao, Guangtu; Fragomeni, Breno O; Hernandez, Alvaro G; Leeds, Timothy D; Parsons, James E; Martin, Kyle E; Evenhuis, Jason P; Welch, Timothy J; Wiens, Gregory D; Palti, Yniv

2017-01-01

Bacterial cold water disease (BCWD) causes significant mortality and economic losses in salmonid aquaculture. In previous studies, we identified moderate-large effect quantitative trait loci (QTL) for BCWD resistance in rainbow trout ( Oncorhynchus mykiss ). However, the recent availability of a 57 K SNP array and a reference genome assembly have enabled us to conduct genome-wide association studies (GWAS) that overcome several experimental limitations from our previous work. In the current study, we conducted GWAS for BCWD resistance in two rainbow trout breeding populations using two genotyping platforms, the 57 K Affymetrix SNP array and restriction-associated DNA (RAD) sequencing. Overall, we identified 14 moderate-large effect QTL that explained up to 60.8% of the genetic variance in one of the two populations and 27.7% in the other. Four of these QTL were found in both populations explaining a substantial proportion of the variance, although major differences were also detected between the two populations. Our results confirm that BCWD resistance is controlled by the oligogenic inheritance of few moderate-large effect loci and a large-unknown number of loci each having a small effect on BCWD resistance. We detected differences in QTL number and genome location between two GWAS models (weighted single-step GBLUP and Bayes B), which highlights the utility of using different models to uncover QTL. The RAD-SNPs detected a greater number of QTL than the 57 K SNP array in one population, suggesting that the RAD-SNPs may uncover polymorphisms that are more unique and informative for the specific population in which they were discovered.

Genetic variation and population structure of the mixed-mating cactus, Melocactus curvispinus (Cactaceae).

PubMed

Nassar, J M; Hamrick, J L; Fleming, T H

2001-07-01

Genetic diversity was measured in the mixed-mating cactus, Melocactus curvispinus, in Venezuela. Allozyme diversity was surveyed in 19 putative loci over 18 populations. Compared to other plant taxa, this cactus is rich in polymorphic loci (Ps=89.5%), with high numbers of alleles per polymorphic locus (APs=3.82), but moderate levels of heterozygosity (Hes=0.145). Substantial levels of inbreeding were detected across loci and populations at macrogeographic (FIS=0.348) and regional levels (FIS=0.194-0.402). Moderate levels of genetic differentiation among populations were detected at macrogeographical (FST=0.193) and regional (FST=0.084-0.187) scales, suggesting that gene flow is relatively restricted, but increases within regions without topographic barriers. The population genetic structure observed for this cactus was attributed to, at least, three factors: short-distance pollination and seed dispersal, the mixed-mating condition of the species, and genetic drift. High genetic identities between populations (I=0.942) supported the conspecific nature of all populations surveyed. The levels and patterns of genetic structure observed for M. curvispinus were consistent with its mating system and gene dispersal mechanisms.

Effects of Yangtze River source water on genomic polymorphisms of male mice detected by RAPD.

PubMed

Zhang, Xiaolin; Zhang, Zongyao; Zhang, Xuxiang; Wu, Bing; Zhang, Yan; Yang, Liuyan; Cheng, Shupei

2010-02-01

In order to evaluate the environmental health risk of drinking water from Yangtze River source, randomly amplified polymorphic DNA (RAPD) markers were used to detect the effects of the source water on genomic polymorphisms of hepatic cell of male mice (Mus musculus, ICR). After the mice were fed with source water for 90 days, RAPD-polymerase chain reactions (PCRs) were performed on hepatic genomic DNA using 20 arbitrary primers. Totally, 189 loci were generated, including 151 polymorphic loci. On average, one PCR primer produced 5.3, 4.9 and 4.8 bands for each mouse in the control, the groups fed with source water and BaP solution, respectively. Compared with the control, feeding mice with Yangtze River source water caused 33 new loci to appear and 19 to disappear. Statistical analysis of RAPD printfingers revealed that Yangtze River source water exerted a significant influence on the hepatic genomic polymorphisms of male mice. This study suggests that RAPD is a reliable and sensitive method for the environmental health risk of Yangtze River source water.

Isolation and characterization of microsatellite DNA loci in the threatened flat-spired three-toothed land snail Triodopsis platysayoides

USGS Publications Warehouse

King, Timothy L.; Eackles, Michael S.; Garner, B. A.; van Tuinen, M.; Arbogast, B. S.

2015-01-01

The hermaphroditic flat-spired three-tooth land snail (Triodopsis platysayoides) is endemic to a 21-km stretch of the Cheat River Gorge of northeastern West Virginia, USA. We document isolation and characterization of ten microsatellite DNA markers in this at-risk species. The markers displayed a moderate level of allelic diversity (averaging 7.1 alleles/locus) and heterozygosity (averaging 58.6 %). Allelic diversity at seven loci was sufficient to produce unique multilocus genotypes; no indication of selfing was detected in this cosexual species. Minimal deviations from Hardy–Weinberg equilibrium and no linkage disequilibrium were observed within subpopulations. All loci deviated from Hardy–Weinberg expectations when individuals from subpopulations were pooled. Microsatellite markers developed for T. platysayoides yielded sufficient genetic diversity to (1) distinguish all individuals sampled and the level of selfing; (2) be appropriate for addressing fine-scale population structuring; (3) provide novel demographic insights for the species; and (4) cross-amplify and detect allelic diversity in the congeneric T. juxtidens.

Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease.

PubMed

Brant, Steven R; Okou, David T; Simpson, Claire L; Cutler, David J; Haritunians, Talin; Bradfield, Jonathan P; Chopra, Pankaj; Prince, Jarod; Begum, Ferdouse; Kumar, Archana; Huang, Chengrui; Venkateswaran, Suresh; Datta, Lisa W; Wei, Zhi; Thomas, Kelly; Herrinton, Lisa J; Klapproth, Jan-Micheal A; Quiros, Antonio J; Seminerio, Jenifer; Liu, Zhenqiu; Alexander, Jonathan S; Baldassano, Robert N; Dudley-Brown, Sharon; Cross, Raymond K; Dassopoulos, Themistocles; Denson, Lee A; Dhere, Tanvi A; Dryden, Gerald W; Hanson, John S; Hou, Jason K; Hussain, Sunny Z; Hyams, Jeffrey S; Isaacs, Kim L; Kader, Howard; Kappelman, Michael D; Katz, Jeffry; Kellermayer, Richard; Kirschner, Barbara S; Kuemmerle, John F; Kwon, John H; Lazarev, Mark; Li, Ellen; Mack, David; Mannon, Peter; Moulton, Dedrick E; Newberry, Rodney D; Osuntokun, Bankole O; Patel, Ashish S; Saeed, Shehzad A; Targan, Stephan R; Valentine, John F; Wang, Ming-Hsi; Zonca, Martin; Rioux, John D; Duerr, Richard H; Silverberg, Mark S; Cho, Judy H; Hakonarson, Hakon; Zwick, Michael E; McGovern, Dermot P B; Kugathasan, Subra

2017-01-01

The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10 -8 in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance. We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10 -6 ): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B,PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles. We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Loss of function of a rice TPR-domain RNA-binding protein confers broad-spectrum disease resistance.

PubMed

Zhou, Xiaogang; Liao, Haicheng; Chern, Mawsheng; Yin, Junjie; Chen, Yufei; Wang, Jianping; Zhu, Xiaobo; Chen, Zhixiong; Yuan, Can; Zhao, Wen; Wang, Jing; Li, Weitao; He, Min; Ma, Bingtian; Wang, Jichun; Qin, Peng; Chen, Weilan; Wang, Yuping; Liu, Jiali; Qian, Yangwen; Wang, Wenming; Wu, Xianjun; Li, Ping; Zhu, Lihuang; Li, Shigui; Ronald, Pamela C; Chen, Xuewei

2018-03-20

Crops carrying broad-spectrum resistance loci provide an effective strategy for controlling infectious disease because these loci typically confer resistance to diverse races of a pathogen or even multiple species of pathogens. Despite their importance, only a few crop broad-spectrum resistance loci have been reported. Here, we report the identification and characterization of the rice bsr-k1 (broad-spectrum resistance Kitaake-1) mutant, which confers broad-spectrum resistance against Magnaporthe oryzae and Xanthomonas oryzae pv oryzae with no major penalty on key agronomic traits. Map-based cloning reveals that Bsr-k1 encodes a tetratricopeptide repeats (TPRs)-containing protein, which binds to mRNAs of multiple OsPAL ( OsPAL1-7 ) genes and promotes their turnover. Loss of function of the Bsr-k1 gene leads to accumulation of OsPAL1-7 mRNAs in the bsr-k1 mutant. Furthermore, overexpression of OsPAL1 in wild-type rice TP309 confers resistance to M. oryzae , supporting the role of OsPAL1 Our discovery of the bsr-k1 allele constitutes a significant conceptual advancement and provides a valuable tool for breeding broad-spectrum resistant rice. Copyright © 2018 the Author(s). Published by PNAS.

Meta-Analysis of Genome-Wide Scans Provides Evidence for Sex- and Site-Specific Regulation of Bone Mass

PubMed Central

Sham, Pak C; Zintzaras, Elias; Lewis, Cathryn M; Deng, Hong-Wen; Econs, Michael J; Karasik, David; Devoto, Marcella; Kammerer, Candace M; Spector, Tim; Andrew, Toby; Cupples, L Adrienne; Duncan, Emma L; Foroud, Tatiana; Kiel, Douglas P; Koller, Daniel; Langdahl, Bente; Mitchell, Braxton D; Peacock, Munro; Recker, Robert; Shen, Hui; Sol-Church, Katia; Spotila, Loretta D; Uitterlinden, Andre G; Wilson, Scott G; Kung, Annie WC; Ralston, Stuart H

2014-01-01

Several genome-wide scans have been performed to detect loci that regulate BMD, but these have yielded inconsistent results, with limited replication of linkage peaks in different studies. In an effort to improve statistical power for detection of these loci, we performed a meta-analysis of genome-wide scans in which spine or hip BMD were studied. Evidence was gained to suggest that several chromosomal loci regulate BMD in a site-specific and sex-specific manner. Introduction BMD is a heritable trait and an important predictor of osteoporotic fracture risk. Several genome-wide scans have been performed in an attempt to detect loci that regulate BMD, but there has been limited replication of linkage peaks between studies. In an attempt to resolve these inconsistencies, we conducted a collaborative meta-analysis of genome-wide linkage scans in which femoral neck BMD (FN-BMD) or lumbar spine BMD (LS-BMD) had been studied. Materials and Methods Data were accumulated from nine genome-wide scans involving 11,842 subjects. Data were analyzed separately for LS-BMD and FN-BMD and by sex. For each study, genomic bins of 30 cM were defined and ranked according to the maximum LOD score they contained. While various densitometers were used in different studies, the ranking approach that we used means that the results are not confounded by the fact that different measurement devices were used. Significance for high average rank and heterogeneity was obtained through Monte Carlo testing. Results For LS-BMD, the quantitative trait locus (QTL) with greatest significance was on chromosome 1p13.3-q23.3 (p = 0.004), but this exhibited high heterogeneity and the effect was specific for women. Other significant LS-BMD QTLs were on chromosomes 12q24.31-qter, 3p25.3-p22.1, 11p12-q13.3, and 1q32-q42.3, including one on 18p11-q12.3 that had not been detected by individual studies. For FN-BMD, the strongest QTL was on chromosome 9q31.1-q33.3 (p = 0.002). Other significant QTLs were identified on chromosomes 17p12-q21.33, 14q13.1-q24.1, 9q21.32-q31.1, and 5q14.3-q23.2. There was no correlation in average ranks of bins between men and women and the loci that regulated BMD in men and women and at different sites were largely distinct. Conclusions This large-scale meta-analysis provided evidence for replication of several QTLs identified in previous studies and also identified a QTL on chromosome 18p11-q12.3, which had not been detected by individual studies. However, despite the large sample size, none of the individual loci identified reached genome-wide significance. PMID:17228994

Development of microsatellites from Fothergilla ×intermedia (Hamamelidaceae) and cross transfer to four other genera within Hamamelidaceae1

PubMed Central

Hatmaker, E. Anne; Wadl, Phillip A.; Mantooth, Kristie; Scheffler, Brian E.; Ownley, Bonnie H.; Trigiano, Robert N.

2015-01-01

Premise of the study: We developed microsatellites from Fothergilla ×intermedia to establish loci capable of distinguishing species and cultivars, and to assess genetic diversity for use by ornamental breeders and to transfer within Hamamelidaceae. Methods and Results: We sequenced a small insert genomic library enriched for microsatellites to develop 12 polymorphic microsatellite loci. The number of alleles detected ranged from four to 15 across five genera within Hamamelidaceae. Shannon’s information index ranged from 0.07 to 0.14. Conclusions: These microsatellite loci provide a set of markers to evaluate genetic diversity of natural and cultivated collections and assist ornamental plant breeders for genetic studies of five popular genera of woody ornamental plants. PMID:25909044

Effects of sample size, number of markers, and allelic richness on the detection of spatial genetic pattern

USGS Publications Warehouse

Landguth, Erin L.; Gedy, Bradley C.; Oyler-McCance, Sara J.; Garey, Andrew L.; Emel, Sarah L.; Mumma, Matthew; Wagner, Helene H.; Fortin, Marie-Josée; Cushman, Samuel A.

2012-01-01

The influence of study design on the ability to detect the effects of landscape pattern on gene flow is one of the most pressing methodological gaps in landscape genetic research. To investigate the effect of study design on landscape genetics inference, we used a spatially-explicit, individual-based program to simulate gene flow in a spatially continuous population inhabiting a landscape with gradual spatial changes in resistance to movement. We simulated a wide range of combinations of number of loci, number of alleles per locus and number of individuals sampled from the population. We assessed how these three aspects of study design influenced the statistical power to successfully identify the generating process among competing hypotheses of isolation-by-distance, isolation-by-barrier, and isolation-by-landscape resistance using a causal modelling approach with partial Mantel tests. We modelled the statistical power to identify the generating process as a response surface for equilibrium and non-equilibrium conditions after introduction of isolation-by-landscape resistance. All three variables (loci, alleles and sampled individuals) affect the power of causal modelling, but to different degrees. Stronger partial Mantel r correlations between landscape distances and genetic distances were found when more loci were used and when loci were more variable, which makes comparisons of effect size between studies difficult. Number of individuals did not affect the accuracy through mean equilibrium partial Mantel r, but larger samples decreased the uncertainty (increasing the precision) of equilibrium partial Mantel r estimates. We conclude that amplifying more (and more variable) loci is likely to increase the power of landscape genetic inferences more than increasing number of individuals.

Effects of sample size, number of markers, and allelic richness on the detection of spatial genetic pattern

USGS Publications Warehouse

Landguth, E.L.; Fedy, B.C.; Oyler-McCance, S.J.; Garey, A.L.; Emel, S.L.; Mumma, M.; Wagner, H.H.; Fortin, M.-J.; Cushman, S.A.

2012-01-01

The influence of study design on the ability to detect the effects of landscape pattern on gene flow is one of the most pressing methodological gaps in landscape genetic research. To investigate the effect of study design on landscape genetics inference, we used a spatially-explicit, individual-based program to simulate gene flow in a spatially continuous population inhabiting a landscape with gradual spatial changes in resistance to movement. We simulated a wide range of combinations of number of loci, number of alleles per locus and number of individuals sampled from the population. We assessed how these three aspects of study design influenced the statistical power to successfully identify the generating process among competing hypotheses of isolation-by-distance, isolation-by-barrier, and isolation-by-landscape resistance using a causal modelling approach with partial Mantel tests. We modelled the statistical power to identify the generating process as a response surface for equilibrium and non-equilibrium conditions after introduction of isolation-by-landscape resistance. All three variables (loci, alleles and sampled individuals) affect the power of causal modelling, but to different degrees. Stronger partial Mantel r correlations between landscape distances and genetic distances were found when more loci were used and when loci were more variable, which makes comparisons of effect size between studies difficult. Number of individuals did not affect the accuracy through mean equilibrium partial Mantel r, but larger samples decreased the uncertainty (increasing the precision) of equilibrium partial Mantel r estimates. We conclude that amplifying more (and more variable) loci is likely to increase the power of landscape genetic inferences more than increasing number of individuals. ?? 2011 Blackwell Publishing Ltd.

A methodological study of genome-wide DNA methylation analyses using matched archival formalin-fixed paraffin embedded and fresh frozen breast tumors

PubMed Central

Yan, Li; Liu, Song; Tang, Li; Hu, Qiang; Morrison, Carl D.; Ambrosone, Christine B.; Higgins, Michael J.; Sucheston-Campbell, Lara E.

2017-01-01

Background DNA from archival formalin-fixed and paraffin embedded (FFPE) tissue is an invaluable resource for genome-wide methylation studies although concerns about poor quality may limit its use. In this study, we compared DNA methylation profiles of breast tumors using DNA from fresh-frozen (FF) tissues and three types of matched FFPE samples. Results For 9/10 patients, correlation and unsupervised clustering analysis revealed that the FF and FFPE samples were consistently correlated with each other and clustered into distinct subgroups. Greater than 84% of the top 100 loci previously shown to differentiate ER+ and ER– tumors in FF tissues were also FFPE DML. Weighted Correlation Gene Network Analyses (WCGNA) grouped the DML loci into 16 modules in FF tissue, with ~85% of the module membership preserved across tissue types. Materials and Methods Restored FFPE and matched FF samples were profiled using the Illumina Infinium HumanMethylation450K platform. Methylation levels (β-values) across all loci and the top 100 loci previously shown to differentiate tumors by estrogen receptor status (ER+ or ER−) in a larger FF study, were compared between matched FF and FFPE samples using Pearson's correlation, hierarchical clustering and WCGNA. Positive predictive values and sensitivity levels for detecting differentially methylated loci (DML) in FF samples were calculated in an independent FFPE cohort. Conclusions FFPE breast tumors samples show lower overall detection of DMLs versus FF, however FFPE and FF DMLs compare favorably. These results support the emerging consensus that the 450K platform can be employed to investigate epigenetics in large sets of archival FFPE tissues. PMID:28118602

Epistasis analysis for quantitative traits by functional regression model.

PubMed

Zhang, Futao; Boerwinkle, Eric; Xiong, Momiao

2014-06-01

The critical barrier in interaction analysis for rare variants is that most traditional statistical methods for testing interactions were originally designed for testing the interaction between common variants and are difficult to apply to rare variants because of their prohibitive computational time and poor ability. The great challenges for successful detection of interactions with next-generation sequencing (NGS) data are (1) lack of methods for interaction analysis with rare variants, (2) severe multiple testing, and (3) time-consuming computations. To meet these challenges, we shift the paradigm of interaction analysis between two loci to interaction analysis between two sets of loci or genomic regions and collectively test interactions between all possible pairs of SNPs within two genomic regions. In other words, we take a genome region as a basic unit of interaction analysis and use high-dimensional data reduction and functional data analysis techniques to develop a novel functional regression model to collectively test interactions between all possible pairs of single nucleotide polymorphisms (SNPs) within two genome regions. By intensive simulations, we demonstrate that the functional regression models for interaction analysis of the quantitative trait have the correct type 1 error rates and a much better ability to detect interactions than the current pairwise interaction analysis. The proposed method was applied to exome sequence data from the NHLBI's Exome Sequencing Project (ESP) and CHARGE-S study. We discovered 27 pairs of genes showing significant interactions after applying the Bonferroni correction (P-values < 4.58 × 10(-10)) in the ESP, and 11 were replicated in the CHARGE-S study. © 2014 Zhang et al.; Published by Cold Spring Harbor Laboratory Press.

DNA commission of the International Society of Forensic Genetics: Recommendations on the evaluation of STR typing results that may include drop-out and/or drop-in using probabilistic methods

PubMed Central

Gill, P.; Gusmão, L.; Haned, H.; Mayr, W.R.; Morling, N.; Parson, W.; Prieto, L.; Prinz, M.; Schneider, H.; Schneider, P.M.; Weir, B.S.

2015-01-01

DNA profiling of biological material from scenes of crimes is often complicated because the amount of DNA is limited and the quality of the DNA may be compromised. Furthermore, the sensitivity of STR typing kits has been continuously improved to detect low level DNA traces. This may lead to (1) partial DNA profiles and (2) detection of additional alleles. There are two key phenomena to consider: allelic or locus ‘drop-out’, i.e. ‘missing’ alleles at one or more genetic loci, while ‘drop-in’ may explain alleles in the DNA profile that are additional to the assumed main contributor(s). The drop-in phenomenon is restricted to 1 or 2 alleles per profile. If multiple alleles are observed at more than two loci then these are considered as alleles from an extra contributor and analysis can proceed as a mixture of two or more contributors. Here, we give recommendations on how to estimate probabilities considering drop-out, Pr(D), and drop-in, Pr(C). For reasons of clarity, we have deliberately restricted the current recommendations considering drop-out and/or drop-in at only one locus. Furthermore, we offer recommendations on how to use Pr(D) and Pr(C) with the likelihood ratio principles that are generally recommended by the International Society of Forensic Genetics (ISFG) as measure of the weight of the evidence in forensic genetics. Examples of calculations are included. An Excel spreadsheet is provided so that scientists and laboratories may explore the models and input their own data. PMID:22864188

A versatile system for rapid multiplex genome-edited CAR T cell generation

PubMed Central

Ren, Jiangtao; Zhang, Xuhua; Liu, Xiaojun; Fang, Chongyun; Jiang, Shuguang; June, Carl H.; Zhao, Yangbing

2017-01-01

The therapeutic potential of CRISPR system has already been demonstrated in many instances and begun to overlap with the rapidly expanding field of cancer immunotherapy, especially on the production of genetically modified T cell receptor or chimeric antigen receptor (CAR) T cells. Efficient genomic disruption of multiple gene loci to generate universal donor cells, as well as potent effector T cells resistant to multiple inhibitory pathways such as PD-1 and CTLA4 is an attractive strategy for cell therapy. In this study, we accomplished rapid and efficient multiplex genomic editing, and re-directing T cells with antigen specific CAR via a one-shot CRISPR protocol by incorporation of multiple gRNAs in a CAR lentiviral vector. High efficient double knockout of endogenous TCR and HLA class I could be easily achieved to generate allogeneic universal CAR T cells. We also generated Fas-resistant universal CAR T cells by triple gene disruption. Simultaneous gene editing of four gene loci using the one-shot CRISPR protocol to generate allogeneic universal T cells deficient of both PD1 and CTLA-4 was also attempted. PMID:28199983

Genetic testing for patients with renal disease: procedures, pitfalls, and ethical considerations.

PubMed

Korf, B R

1999-07-01

The Human Genome Project is rapidly producing insights into the molecular basis of human genetic disorders. The most immediate clinical benefit is the advent of new diagnostic methods. Molecular diagnostic tools are available for several genetic renal disorders and are in development for many more. Two general approaches to molecular diagnosis are linkage-based testing and direct mutation detection. The former is used when the gene has not been cloned but has been mapped in relation to polymorphic loci. Linkage-based testing is also helpful when a large diversity of mutations makes direct detection difficult. Limitations include the need to study multiple family members, the need for informative polymorphisms, and genetic heterogeneity. Direct mutation detection is limited by genetic heterogeneity and the need to distinguish nonpathogenic allelic variants from pathogenic mutations. Molecular testing raises a number of complex ethical issues, including those associated with prenatal or presymptomatic diagnosis. In addition, there are concerns about informed consent, privacy, genetic discrimination, and technology transfer for newly developed tests. Health professionals need to be aware of the technical and ethical implications of these new methods of testing, as well as the complexities in test interpretation, as molecular approaches are increasingly integrated into medical practice.

Genome-Wide Meta-Analyses of Breast, Ovarian, and Prostate Cancer Association Studies Identify Multiple New Susceptibility Loci Shared by at Least Two Cancer Types.

PubMed

Kar, Siddhartha P; Beesley, Jonathan; Amin Al Olama, Ali; Michailidou, Kyriaki; Tyrer, Jonathan; Kote-Jarai, ZSofia; Lawrenson, Kate; Lindstrom, Sara; Ramus, Susan J; Thompson, Deborah J; Kibel, Adam S; Dansonka-Mieszkowska, Agnieszka; Michael, Agnieszka; Dieffenbach, Aida K; Gentry-Maharaj, Aleksandra; Whittemore, Alice S; Wolk, Alicja; Monteiro, Alvaro; Peixoto, Ana; Kierzek, Andrzej; Cox, Angela; Rudolph, Anja; Gonzalez-Neira, Anna; Wu, Anna H; Lindblom, Annika; Swerdlow, Anthony; Ziogas, Argyrios; Ekici, Arif B; Burwinkel, Barbara; Karlan, Beth Y; Nordestgaard, Børge G; Blomqvist, Carl; Phelan, Catherine; McLean, Catriona; Pearce, Celeste Leigh; Vachon, Celine; Cybulski, Cezary; Slavov, Chavdar; Stegmaier, Christa; Maier, Christiane; Ambrosone, Christine B; Høgdall, Claus K; Teerlink, Craig C; Kang, Daehee; Tessier, Daniel C; Schaid, Daniel J; Stram, Daniel O; Cramer, Daniel W; Neal, David E; Eccles, Diana; Flesch-Janys, Dieter; Edwards, Digna R Velez; Wokozorczyk, Dominika; Levine, Douglas A; Yannoukakos, Drakoulis; Sawyer, Elinor J; Bandera, Elisa V; Poole, Elizabeth M; Goode, Ellen L; Khusnutdinova, Elza; Høgdall, Estrid; Song, Fengju; Bruinsma, Fiona; Heitz, Florian; Modugno, Francesmary; Hamdy, Freddie C; Wiklund, Fredrik; Giles, Graham G; Olsson, Håkan; Wildiers, Hans; Ulmer, Hans-Ulrich; Pandha, Hardev; Risch, Harvey A; Darabi, Hatef; Salvesen, Helga B; Nevanlinna, Heli; Gronberg, Henrik; Brenner, Hermann; Brauch, Hiltrud; Anton-Culver, Hoda; Song, Honglin; Lim, Hui-Yi; McNeish, Iain; Campbell, Ian; Vergote, Ignace; Gronwald, Jacek; Lubiński, Jan; Stanford, Janet L; Benítez, Javier; Doherty, Jennifer A; Permuth, Jennifer B; Chang-Claude, Jenny; Donovan, Jenny L; Dennis, Joe; Schildkraut, Joellen M; Schleutker, Johanna; Hopper, John L; Kupryjanczyk, Jolanta; Park, Jong Y; Figueroa, Jonine; Clements, Judith A; Knight, Julia A; Peto, Julian; Cunningham, Julie M; Pow-Sang, Julio; Batra, Jyotsna; Czene, Kamila; Lu, Karen H; Herkommer, Kathleen; Khaw, Kay-Tee; Matsuo, Keitaro; Muir, Kenneth; Offitt, Kenneth; Chen, Kexin; Moysich, Kirsten B; Aittomäki, Kristiina; Odunsi, Kunle; Kiemeney, Lambertus A; Massuger, Leon F A G; Fitzgerald, Liesel M; Cook, Linda S; Cannon-Albright, Lisa; Hooning, Maartje J; Pike, Malcolm C; Bolla, Manjeet K; Luedeke, Manuel; Teixeira, Manuel R; Goodman, Marc T; Schmidt, Marjanka K; Riggan, Marjorie; Aly, Markus; Rossing, Mary Anne; Beckmann, Matthias W; Moisse, Matthieu; Sanderson, Maureen; Southey, Melissa C; Jones, Michael; Lush, Michael; Hildebrandt, Michelle A T; Hou, Ming-Feng; Schoemaker, Minouk J; Garcia-Closas, Montserrat; Bogdanova, Natalia; Rahman, Nazneen; Le, Nhu D; Orr, Nick; Wentzensen, Nicolas; Pashayan, Nora; Peterlongo, Paolo; Guénel, Pascal; Brennan, Paul; Paulo, Paula; Webb, Penelope M; Broberg, Per; Fasching, Peter A; Devilee, Peter; Wang, Qin; Cai, Qiuyin; Li, Qiyuan; Kaneva, Radka; Butzow, Ralf; Kopperud, Reidun Kristin; Schmutzler, Rita K; Stephenson, Robert A; MacInnis, Robert J; Hoover, Robert N; Winqvist, Robert; Ness, Roberta; Milne, Roger L; Travis, Ruth C; Benlloch, Sara; Olson, Sara H; McDonnell, Shannon K; Tworoger, Shelley S; Maia, Sofia; Berndt, Sonja; Lee, Soo Chin; Teo, Soo-Hwang; Thibodeau, Stephen N; Bojesen, Stig E; Gapstur, Susan M; Kjær, Susanne Krüger; Pejovic, Tanja; Tammela, Teuvo L J; Dörk, Thilo; Brüning, Thomas; Wahlfors, Tiina; Key, Tim J; Edwards, Todd L; Menon, Usha; Hamann, Ute; Mitev, Vanio; Kosma, Veli-Matti; Setiawan, Veronica Wendy; Kristensen, Vessela; Arndt, Volker; Vogel, Walther; Zheng, Wei; Sieh, Weiva; Blot, William J; Kluzniak, Wojciech; Shu, Xiao-Ou; Gao, Yu-Tang; Schumacher, Fredrick; Freedman, Matthew L; Berchuck, Andrew; Dunning, Alison M; Simard, Jacques; Haiman, Christopher A; Spurdle, Amanda; Sellers, Thomas A; Hunter, David J; Henderson, Brian E; Kraft, Peter; Chanock, Stephen J; Couch, Fergus J; Hall, Per; Gayther, Simon A; Easton, Douglas F; Chenevix-Trench, Georgia; Eeles, Rosalind; Pharoah, Paul D P; Lambrechts, Diether

2016-09-01

Breast, ovarian, and prostate cancers are hormone-related and may have a shared genetic basis, but this has not been investigated systematically by genome-wide association (GWA) studies. Meta-analyses combining the largest GWA meta-analysis data sets for these cancers totaling 112,349 cases and 116,421 controls of European ancestry, all together and in pairs, identified at P < 10(-8) seven new cross-cancer loci: three associated with susceptibility to all three cancers (rs17041869/2q13/BCL2L11; rs7937840/11q12/INCENP; rs1469713/19p13/GATAD2A), two breast and ovarian cancer risk loci (rs200182588/9q31/SMC2; rs8037137/15q26/RCCD1), and two breast and prostate cancer risk loci (rs5013329/1p34/NSUN4; rs9375701/6q23/L3MBTL3). Index variants in five additional regions previously associated with only one cancer also showed clear association with a second cancer type. Cell-type-specific expression quantitative trait locus and enhancer-gene interaction annotations suggested target genes with potential cross-cancer roles at the new loci. Pathway analysis revealed significant enrichment of death receptor signaling genes near loci with P < 10(-5) in the three-cancer meta-analysis. We demonstrate that combining large-scale GWA meta-analysis findings across cancer types can identify completely new risk loci common to breast, ovarian, and prostate cancers. We show that the identification of such cross-cancer risk loci has the potential to shed new light on the shared biology underlying these hormone-related cancers. Cancer Discov; 6(9); 1052-67. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 932. ©2016 American Association for Cancer Research.

Effects of multiple genetic loci on age at onset in late-onset Alzheimer disease: a genome-wide association study.

PubMed

Naj, Adam C; Jun, Gyungah; Reitz, Christiane; Kunkle, Brian W; Perry, William; Park, Yo Son; Beecham, Gary W; Rajbhandary, Ruchita A; Hamilton-Nelson, Kara L; Wang, Li-San; Kauwe, John S K; Huentelman, Matthew J; Myers, Amanda J; Bird, Thomas D; Boeve, Bradley F; Baldwin, Clinton T; Jarvik, Gail P; Crane, Paul K; Rogaeva, Ekaterina; Barmada, M Michael; Demirci, F Yesim; Cruchaga, Carlos; Kramer, Patricia L; Ertekin-Taner, Nilufer; Hardy, John; Graff-Radford, Neill R; Green, Robert C; Larson, Eric B; St George-Hyslop, Peter H; Buxbaum, Joseph D; Evans, Denis A; Schneider, Julie A; Lunetta, Kathryn L; Kamboh, M Ilyas; Saykin, Andrew J; Reiman, Eric M; De Jager, Philip L; Bennett, David A; Morris, John C; Montine, Thomas J; Goate, Alison M; Blacker, Deborah; Tsuang, Debby W; Hakonarson, Hakon; Kukull, Walter A; Foroud, Tatiana M; Martin, Eden R; Haines, Jonathan L; Mayeux, Richard P; Farrer, Lindsay A; Schellenberg, Gerard D; Pericak-Vance, Margaret A; Albert, Marilyn S; Albin, Roger L; Apostolova, Liana G; Arnold, Steven E; Barber, Robert; Barnes, Lisa L; Beach, Thomas G; Becker, James T; Beekly, Duane; Bigio, Eileen H; Bowen, James D; Boxer, Adam; Burke, James R; Cairns, Nigel J; Cantwell, Laura B; Cao, Chuanhai; Carlson, Chris S; Carney, Regina M; Carrasquillo, Minerva M; Carroll, Steven L; Chui, Helena C; Clark, David G; Corneveaux, Jason; Cribbs, David H; Crocco, Elizabeth A; DeCarli, Charles; DeKosky, Steven T; Dick, Malcolm; Dickson, Dennis W; Duara, Ranjan; Faber, Kelley M; Fallon, Kenneth B; Farlow, Martin R; Ferris, Steven; Frosch, Matthew P; Galasko, Douglas R; Ganguli, Mary; Gearing, Marla; Geschwind, Daniel H; Ghetti, Bernardino; Gilbert, John R; Glass, Jonathan D; Growdon, John H; Hamilton, Ronald L; Harrell, Lindy E; Head, Elizabeth; Honig, Lawrence S; Hulette, Christine M; Hyman, Bradley T; Jicha, Gregory A; Jin, Lee-Way; Karydas, Anna; Kaye, Jeffrey A; Kim, Ronald; Koo, Edward H; Kowall, Neil W; Kramer, Joel H; LaFerla, Frank M; Lah, James J; Leverenz, James B; Levey, Allan I; Li, Ge; Lieberman, Andrew P; Lin, Chiao-Feng; Lopez, Oscar L; Lyketsos, Constantine G; Mack, Wendy J; Martiniuk, Frank; Mash, Deborah C; Masliah, Eliezer; McCormick, Wayne C; McCurry, Susan M; McDavid, Andrew N; McKee, Ann C; Mesulam, Marsel; Miller, Bruce L; Miller, Carol A; Miller, Joshua W; Murrell, Jill R; Olichney, John M; Pankratz, Vernon S; Parisi, Joseph E; Paulson, Henry L; Peskind, Elaine; Petersen, Ronald C; Pierce, Aimee; Poon, Wayne W; Potter, Huntington; Quinn, Joseph F; Raj, Ashok; Raskind, Murray; Reisberg, Barry; Ringman, John M; Roberson, Erik D; Rosen, Howard J; Rosenberg, Roger N; Sano, Mary; Schneider, Lon S; Seeley, William W; Smith, Amanda G; Sonnen, Joshua A; Spina, Salvatore; Stern, Robert A; Tanzi, Rudolph E; Thornton-Wells, Tricia A; Trojanowski, John Q; Troncoso, Juan C; Valladares, Otto; Van Deerlin, Vivianna M; Van Eldik, Linda J; Vardarajan, Badri N; Vinters, Harry V; Vonsattel, Jean Paul; Weintraub, Sandra; Welsh-Bohmer, Kathleen A; Williamson, Jennifer; Wishnek, Sarah; Woltjer, Randall L; Wright, Clinton B; Younkin, Steven G; Yu, Chang-En; Yu, Lei

2014-11-01

Because APOE locus variants contribute to risk of late-onset Alzheimer disease (LOAD) and to differences in age at onset (AAO), it is important to know whether other established LOAD risk loci also affect AAO in affected participants. To investigate the effects of known Alzheimer disease risk loci in modifying AAO and to estimate their cumulative effect on AAO variation using data from genome-wide association studies in the Alzheimer Disease Genetics Consortium. The Alzheimer Disease Genetics Consortium comprises 14 case-control, prospective, and family-based data sets with data on 9162 participants of white race/ethnicity with Alzheimer disease occurring after age 60 years who also had complete AAO information, gathered between 1989 and 2011 at multiple sites by participating studies. Data on genotyped or imputed single-nucleotide polymorphisms most significantly associated with risk at 10 confirmed LOAD loci were examined in linear modeling of AAO, and individual data set results were combined using a random-effects, inverse variance-weighted meta-analysis approach to determine whether they contribute to variation in AAO. Aggregate effects of all risk loci on AAO were examined in a burden analysis using genotype scores weighted by risk effect sizes. Age at disease onset abstracted from medical records among participants with LOAD diagnosed per standard criteria. Analysis confirmed the association of APOE with earlier AAO (P = 3.3 × 10(-96)), with associations in CR1 (rs6701713, P = 7.2 × 10(-4)), BIN1 (rs7561528, P = 4.8 × 10(-4)), and PICALM (rs561655, P = 2.2 × 10(-3)) reaching statistical significance (P < .005). Risk alleles individually reduced AAO by 3 to 6 months. Burden analyses demonstrated that APOE contributes to 3.7% of the variation in AAO (R(2) = 0.256) over baseline (R(2) = 0.221), whereas the other 9 loci together contribute to 2.2% of the variation (R(2) = 0.242). We confirmed an association of APOE (OMIM 107741) variants with AAO among affected participants with LOAD and observed novel associations of CR1 (OMIM 120620), BIN1 (OMIM 601248), and PICALM (OMIM 603025) with AAO. In contrast to earlier hypothetical modeling, we show that the combined effects of Alzheimer disease risk variants on AAO are on the scale of, but do not exceed, the APOE effect. While the aggregate effects of risk loci on AAO may be significant, additional genetic contributions to AAO are individually likely to be small.

The OncoArray Consortium: A Network for Understanding the Genetic Architecture of Common Cancers.

PubMed

Amos, Christopher I; Dennis, Joe; Wang, Zhaoming; Byun, Jinyoung; Schumacher, Fredrick R; Gayther, Simon A; Casey, Graham; Hunter, David J; Sellers, Thomas A; Gruber, Stephen B; Dunning, Alison M; Michailidou, Kyriaki; Fachal, Laura; Doheny, Kimberly; Spurdle, Amanda B; Li, Yafang; Xiao, Xiangjun; Romm, Jane; Pugh, Elizabeth; Coetzee, Gerhard A; Hazelett, Dennis J; Bojesen, Stig E; Caga-Anan, Charlisse; Haiman, Christopher A; Kamal, Ahsan; Luccarini, Craig; Tessier, Daniel; Vincent, Daniel; Bacot, François; Van Den Berg, David J; Nelson, Stefanie; Demetriades, Stephen; Goldgar, David E; Couch, Fergus J; Forman, Judith L; Giles, Graham G; Conti, David V; Bickeböller, Heike; Risch, Angela; Waldenberger, Melanie; Brüske-Hohlfeld, Irene; Hicks, Belynda D; Ling, Hua; McGuffog, Lesley; Lee, Andrew; Kuchenbaecker, Karoline; Soucy, Penny; Manz, Judith; Cunningham, Julie M; Butterbach, Katja; Kote-Jarai, Zsofia; Kraft, Peter; FitzGerald, Liesel; Lindström, Sara; Adams, Marcia; McKay, James D; Phelan, Catherine M; Benlloch, Sara; Kelemen, Linda E; Brennan, Paul; Riggan, Marjorie; O'Mara, Tracy A; Shen, Hongbing; Shi, Yongyong; Thompson, Deborah J; Goodman, Marc T; Nielsen, Sune F; Berchuck, Andrew; Laboissiere, Sylvie; Schmit, Stephanie L; Shelford, Tameka; Edlund, Christopher K; Taylor, Jack A; Field, John K; Park, Sue K; Offit, Kenneth; Thomassen, Mads; Schmutzler, Rita; Ottini, Laura; Hung, Rayjean J; Marchini, Jonathan; Amin Al Olama, Ali; Peters, Ulrike; Eeles, Rosalind A; Seldin, Michael F; Gillanders, Elizabeth; Seminara, Daniela; Antoniou, Antonis C; Pharoah, Paul D P; Chenevix-Trench, Georgia; Chanock, Stephen J; Simard, Jacques; Easton, Douglas F

2017-01-01

Common cancers develop through a multistep process often including inherited susceptibility. Collaboration among multiple institutions, and funding from multiple sources, has allowed the development of an inexpensive genotyping microarray, the OncoArray. The array includes a genome-wide backbone, comprising 230,000 SNPs tagging most common genetic variants, together with dense mapping of known susceptibility regions, rare variants from sequencing experiments, pharmacogenetic markers, and cancer-related traits. The OncoArray can be genotyped using a novel technology developed by Illumina to facilitate efficient genotyping. The consortium developed standard approaches for selecting SNPs for study, for quality control of markers, and for ancestry analysis. The array was genotyped at selected sites and with prespecified replicate samples to permit evaluation of genotyping accuracy among centers and by ethnic background. The OncoArray consortium genotyped 447,705 samples. A total of 494,763 SNPs passed quality control steps with a sample success rate of 97% of the samples. Participating sites performed ancestry analysis using a common set of markers and a scoring algorithm based on principal components analysis. Results from these analyses will enable researchers to identify new susceptibility loci, perform fine-mapping of new or known loci associated with either single or multiple cancers, assess the degree of overlap in cancer causation and pleiotropic effects of loci that have been identified for disease-specific risk, and jointly model genetic, environmental, and lifestyle-related exposures. Ongoing analyses will shed light on etiology and risk assessment for many types of cancer. Cancer Epidemiol Biomarkers Prev; 26(1); 126-35. ©2016 AACR. ©2016 American Association for Cancer Research.

The OncoArray Consortium: a Network for Understanding the Genetic Architecture of Common Cancers

PubMed Central

Amos, Christopher I.; Dennis, Joe; Wang, Zhaoming; Byun, Jinyoung; Schumacher, Fredrick R.; Gayther, Simon A.; Casey, Graham; Hunter, David J.; Sellers, Thomas A.; Gruber, Stephen B.; Dunning, Alison M.; Michailidou, Kyriaki; Fachal, Laura; Doheny, Kimberly; Spurdle, Amanda B.; Li, Yafang; Xiao, Xiangjun; Romm, Jane; Pugh, Elizabeth; Coetzee, Gerhard A.; Hazelett, Dennis J.; Bojesen, Stig E.; Caga-Anan, Charlisse; Haiman, Christopher A.; Kamal, Ahsan; Luccarini, Craig; Tessier, Daniel; Vincent, Daniel; Bacot, François; Van Den Berg, David J.; Nelson, Stefanie; Demetriades, Stephen; Goldgar, David E.; Couch, Fergus J.; Forman, Judith L.; Giles, Graham G.; Conti, David V.; Bickeböller, Heike; Risch, Angela; Waldenberger, Melanie; Brüske, Irene; Hicks, Belynda D.; Ling, Hua; McGuffog, Lesley; Lee, Andrew; Kuchenbaecker, Karoline B.; Soucy, Penny; Manz, Judith; Cunningham, Julie M.; Butterbach, Katja; Kote-Jarai, Zsofia; Kraft, Peter; FitzGerald, Liesel M.; Lindström, Sara; Adams, Marcia; McKay, James D.; Phelan, Catherine M.; Benlloch, Sara; Kelemen, Linda E.; Brennan, Paul; Riggan, Marjorie; O’Mara, Tracy A.; Shen, Hongbin; Shi, Yongyong; Thompson, Deborah J.; Goodman, Marc T.; Nielsen, Sune F.; Berchuck, Andrew; Laboissiere, Sylvie; Schmit, Stephanie L.; Shelford, Tameka; Edlund, Christopher K.; Taylor, Jack A.; Field, John K.; Park, Sue K.; Offit, Kenneth; Thomassen, Mads; Schmutzler, Rita; Ottini, Laura; Hung, Rayjean J.; Marchini, Jonathan; Al Olama, Ali Amin; Peters, Ulrike; Eeles, Rosalind A.; Seldin, Michael F.; Gillanders, Elizabeth; Seminara, Daniela; Antoniou, Antonis C.; Pharoah, Paul D.; Chenevix-Trench, Georgia; Chanock, Stephen J.; Simard, Jacques; Easton, Douglas F.

2016-01-01

Background Common cancers develop through a multistep process often including inherited susceptibility. Collaboration among multiple institutions, and funding from multiple sources, has allowed the development of an inexpensive genotyping microarray, the OncoArray. The array includes a genome-wide backbone, comprising 230,000 SNPs tagging most common genetic variants, together with dense mapping of known susceptibility regions, rare variants from sequencing experiments, pharmacogenetic markers and cancer related traits. Methods The OncoArray can be genotyped using a novel technology developed by Illumina to facilitate efficient genotyping. The consortium developed standard approaches for selecting SNPs for study, for quality control of markers and for ancestry analysis. The array was genotyped at selected sites and with prespecified replicate samples to permit evaluation of genotyping accuracy among centers and by ethnic background. Results The OncoArray consortium genotyped 447,705 samples. A total of 494,763 SNPs passed quality control steps with a sample success rate of 97% of the samples. Participating sites performed ancestry analysis using a common set of markers and a scoring algorithm based on principal components analysis. Conclusions Results from these analyses will enable researchers to identify new susceptibility loci, perform fine mapping of new or known loci associated with either single or multiple cancers, assess the degree of overlap in cancer causation and pleiotropic effects of loci that have been identified for disease-specific risk, and jointly model genetic, environmental and lifestyle related exposures. Impact Ongoing analyses will shed light on etiology and risk assessment for many types of cancer. PMID:27697780

Genome-wide association study identifies multiple loci influencing human serum metabolite levels

PubMed Central

Kettunen, Johannes; Tukiainen, Taru; Sarin, Antti-Pekka; Ortega-Alonso, Alfredo; Tikkanen, Emmi; Lyytikäinen, Leo-Pekka; Kangas, Antti J; Soininen, Pasi; Würtz, Peter; Silander, Kaisa; Dick, Danielle M; Rose, Richard J; Savolainen, Markku J; Viikari, Jorma; Kähönen, Mika; Lehtimäki, Terho; Pietiläinen, Kirsi H; Inouye, Michael; McCarthy, Mark I; Jula, Antti; Eriksson, Johan; Raitakari, Olli T; Salomaa, Veikko; Kaprio, Jaakko; Järvelin, Marjo-Riitta; Peltonen, Leena; Perola, Markus; Freimer, Nelson B; Ala-Korpela, Mika; Palotie, Aarno; Ripatti, Samuli

2013-01-01

Nuclear magnetic resonance assays allow for measurement of a wide range of metabolic phenotypes. We report here the results of a GWAS on 8,330 Finnish individuals genotyped and imputed at 7.7 million SNPs for a range of 216 serum metabolic phenotypes assessed by NMR of serum samples. We identified significant associations (P < 2.31 × 10−10) at 31 loci, including 11 for which there have not been previous reports of associations to a metabolic trait or disorder. Analyses of Finnish twin pairs suggested that the metabolic measures reported here show higher heritability than comparable conventional metabolic phenotypes. In accordance with our expectations, SNPs at the 31 loci associated with individual metabolites account for a greater proportion of the genetic component of trait variance (up to 40%) than is typically observed for conventional serum metabolic phenotypes. The identification of such associations may provide substantial insight into cardiometabolic disorders. PMID:22286219

Multiple convergent supergene evolution events in mating-type chromosomes.

PubMed

Branco, Sara; Carpentier, Fantin; Rodríguez de la Vega, Ricardo C; Badouin, Hélène; Snirc, Alodie; Le Prieur, Stéphanie; Coelho, Marco A; de Vienne, Damien M; Hartmann, Fanny E; Begerow, Dominik; Hood, Michael E; Giraud, Tatiana

2018-05-21

Convergent adaptation provides unique insights into the predictability of evolution and ultimately into processes of biological diversification. Supergenes (beneficial gene linkage) are striking examples of adaptation, but little is known about their prevalence or evolution. A recent study on anther-smut fungi documented supergene formation by rearrangements linking two key mating-type loci, controlling pre- and post-mating compatibility. Here further high-quality genome assemblies reveal four additional independent cases of chromosomal rearrangements leading to regions of suppressed recombination linking these mating-type loci in closely related species. Such convergent transitions in genomic architecture of mating-type determination indicate strong selection favoring linkage of mating-type loci into cosegregating supergenes. We find independent evolutionary strata (stepwise recombination suppression) in several species, with extensive rearrangements, gene losses, and transposable element accumulation. We thus show remarkable convergence in mating-type chromosome evolution, recurrent supergene formation, and repeated evolution of similar phenotypes through different genomic changes.

Phylogenetic and microsatellite markers for Tulasnella (Tulasnellaceae) mycorrhizal fungi associated with Australian orchids.

PubMed

Ruibal, Monica P; Peakall, Rod; Smith, Leon M; Linde, Celeste C

2013-03-01

Phylogenetic and microsatellite markers were developed for Tulasnella mycorrhizal fungi to investigate fungal species identity and diversity. These markers will be useful in future studies investigating the phylogenetic relationship of the fungal symbionts, specificity of orchid-mycorrhizal associations, and the role of mycorrhizae in orchid speciation within several orchid genera. • We generated partial genome sequences of two Tulasnella symbionts originating from Chiloglottis and Drakaea orchid species with 454 genome sequencing. Cross-genus transferability across mycorrhizal symbionts associated with multiple genera of Australian orchids (Arthrochilus, Chiloglottis, Drakaea, and Paracaleana) was found for seven phylogenetic loci. Five loci showed cross-transferability to Tulasnella from other orchid genera, and two to Sebacina. Furthermore, 11 polymorphic microsatellite loci were developed for Tulasnella from Chiloglottis. • Highly informative markers were obtained, allowing investigation of mycorrhizal diversity of Tulasnellaceae associated with a wide variety of terrestrial orchids in Australia and potentially worldwide.

Attentional effects on gaze preference for salient loci in traffic scenes.

PubMed

Sakai, Hiroyuki; Shin, Duk; Kohama, Takeshi; Uchiyama, Yuji

2012-01-01

Alerting drivers for self-regulation of attention might decrease crash risks attributable to absent-minded driving. However, no reliable method exists for monitoring driver attention. Therefore, we examined attentional effects on gaze preference for salient loci (GPS) in traffic scenes. In an active viewing (AV) condition requiring endogenous attention for traffic scene comprehension, participants identified appropriate speeds for driving in presented traffic scene images. In a passive viewing (PV) condition requiring no endogenous attention, participants passively viewed traffic scene images. GPS was quantified by the mean saliency value averaged across fixation locations. Results show that GPS was less during AV than during PV. Additionally, gaze dwell time on signboards was shorter for AV than for PV. These results suggest that, in the absence of endogenous attention for traffic scene comprehension, gaze tends to concentrate on irrelevant salient loci in a traffic environment. Therefore, increased GPS can indicate absent-minded driving. The present study demonstrated that, without endogenous attention for traffic scene comprehension, gaze tends to concentrate on irrelevant salient loci in a traffic environment. This result suggests that increased gaze preference for salient loci indicates absent-minded driving, which is otherwise difficult to detect.

Differential principal component analysis of ChIP-seq.

PubMed

Ji, Hongkai; Li, Xia; Wang, Qian-fei; Ning, Yang

2013-04-23

We propose differential principal component analysis (dPCA) for analyzing multiple ChIP-sequencing datasets to identify differential protein-DNA interactions between two biological conditions. dPCA integrates unsupervised pattern discovery, dimension reduction, and statistical inference into a single framework. It uses a small number of principal components to summarize concisely the major multiprotein synergistic differential patterns between the two conditions. For each pattern, it detects and prioritizes differential genomic loci by comparing the between-condition differences with the within-condition variation among replicate samples. dPCA provides a unique tool for efficiently analyzing large amounts of ChIP-sequencing data to study dynamic changes of gene regulation across different biological conditions. We demonstrate this approach through analyses of differential chromatin patterns at transcription factor binding sites and promoters as well as allele-specific protein-DNA interactions.

Study of 300,486 individuals identifies 148 independent genetic loci influencing general cognitive function.

PubMed

Davies, Gail; Lam, Max; Harris, Sarah E; Trampush, Joey W; Luciano, Michelle; Hill, W David; Hagenaars, Saskia P; Ritchie, Stuart J; Marioni, Riccardo E; Fawns-Ritchie, Chloe; Liewald, David C M; Okely, Judith A; Ahola-Olli, Ari V; Barnes, Catriona L K; Bertram, Lars; Bis, Joshua C; Burdick, Katherine E; Christoforou, Andrea; DeRosse, Pamela; Djurovic, Srdjan; Espeseth, Thomas; Giakoumaki, Stella; Giddaluru, Sudheer; Gustavson, Daniel E; Hayward, Caroline; Hofer, Edith; Ikram, M Arfan; Karlsson, Robert; Knowles, Emma; Lahti, Jari; Leber, Markus; Li, Shuo; Mather, Karen A; Melle, Ingrid; Morris, Derek; Oldmeadow, Christopher; Palviainen, Teemu; Payton, Antony; Pazoki, Raha; Petrovic, Katja; Reynolds, Chandra A; Sargurupremraj, Muralidharan; Scholz, Markus; Smith, Jennifer A; Smith, Albert V; Terzikhan, Natalie; Thalamuthu, Anbupalam; Trompet, Stella; van der Lee, Sven J; Ware, Erin B; Windham, B Gwen; Wright, Margaret J; Yang, Jingyun; Yu, Jin; Ames, David; Amin, Najaf; Amouyel, Philippe; Andreassen, Ole A; Armstrong, Nicola J; Assareh, Amelia A; Attia, John R; Attix, Deborah; Avramopoulos, Dimitrios; Bennett, David A; Böhmer, Anne C; Boyle, Patricia A; Brodaty, Henry; Campbell, Harry; Cannon, Tyrone D; Cirulli, Elizabeth T; Congdon, Eliza; Conley, Emily Drabant; Corley, Janie; Cox, Simon R; Dale, Anders M; Dehghan, Abbas; Dick, Danielle; Dickinson, Dwight; Eriksson, Johan G; Evangelou, Evangelos; Faul, Jessica D; Ford, Ian; Freimer, Nelson A; Gao, He; Giegling, Ina; Gillespie, Nathan A; Gordon, Scott D; Gottesman, Rebecca F; Griswold, Michael E; Gudnason, Vilmundur; Harris, Tamara B; Hartmann, Annette M; Hatzimanolis, Alex; Heiss, Gerardo; Holliday, Elizabeth G; Joshi, Peter K; Kähönen, Mika; Kardia, Sharon L R; Karlsson, Ida; Kleineidam, Luca; Knopman, David S; Kochan, Nicole A; Konte, Bettina; Kwok, John B; Le Hellard, Stephanie; Lee, Teresa; Lehtimäki, Terho; Li, Shu-Chen; Liu, Tian; Koini, Marisa; London, Edythe; Longstreth, Will T; Lopez, Oscar L; Loukola, Anu; Luck, Tobias; Lundervold, Astri J; Lundquist, Anders; Lyytikäinen, Leo-Pekka; Martin, Nicholas G; Montgomery, Grant W; Murray, Alison D; Need, Anna C; Noordam, Raymond; Nyberg, Lars; Ollier, William; Papenberg, Goran; Pattie, Alison; Polasek, Ozren; Poldrack, Russell A; Psaty, Bruce M; Reppermund, Simone; Riedel-Heller, Steffi G; Rose, Richard J; Rotter, Jerome I; Roussos, Panos; Rovio, Suvi P; Saba, Yasaman; Sabb, Fred W; Sachdev, Perminder S; Satizabal, Claudia L; Schmid, Matthias; Scott, Rodney J; Scult, Matthew A; Simino, Jeannette; Slagboom, P Eline; Smyrnis, Nikolaos; Soumaré, Aïcha; Stefanis, Nikos C; Stott, David J; Straub, Richard E; Sundet, Kjetil; Taylor, Adele M; Taylor, Kent D; Tzoulaki, Ioanna; Tzourio, Christophe; Uitterlinden, André; Vitart, Veronique; Voineskos, Aristotle N; Kaprio, Jaakko; Wagner, Michael; Wagner, Holger; Weinhold, Leonie; Wen, K Hoyan; Widen, Elisabeth; Yang, Qiong; Zhao, Wei; Adams, Hieab H H; Arking, Dan E; Bilder, Robert M; Bitsios, Panos; Boerwinkle, Eric; Chiba-Falek, Ornit; Corvin, Aiden; De Jager, Philip L; Debette, Stéphanie; Donohoe, Gary; Elliott, Paul; Fitzpatrick, Annette L; Gill, Michael; Glahn, David C; Hägg, Sara; Hansell, Narelle K; Hariri, Ahmad R; Ikram, M Kamran; Jukema, J Wouter; Vuoksimaa, Eero; Keller, Matthew C; Kremen, William S; Launer, Lenore; Lindenberger, Ulman; Palotie, Aarno; Pedersen, Nancy L; Pendleton, Neil; Porteous, David J; Räikkönen, Katri; Raitakari, Olli T; Ramirez, Alfredo; Reinvang, Ivar; Rudan, Igor; Dan Rujescu; Schmidt, Reinhold; Schmidt, Helena; Schofield, Peter W; Schofield, Peter R; Starr, John M; Steen, Vidar M; Trollor, Julian N; Turner, Steven T; Van Duijn, Cornelia M; Villringer, Arno; Weinberger, Daniel R; Weir, David R; Wilson, James F; Malhotra, Anil; McIntosh, Andrew M; Gale, Catharine R; Seshadri, Sudha; Mosley, Thomas H; Bressler, Jan; Lencz, Todd; Deary, Ian J

2018-05-29

General cognitive function is a prominent and relatively stable human trait that is associated with many important life outcomes. We combine cognitive and genetic data from the CHARGE and COGENT consortia, and UK Biobank (total N = 300,486; age 16-102) and find 148 genome-wide significant independent loci (P < 5 × 10 -8 ) associated with general cognitive function. Within the novel genetic loci are variants associated with neurodegenerative and neurodevelopmental disorders, physical and psychiatric illnesses, and brain structure. Gene-based analyses find 709 genes associated with general cognitive function. Expression levels across the cortex are associated with general cognitive function. Using polygenic scores, up to 4.3% of variance in general cognitive function is predicted in independent samples. We detect significant genetic overlap between general cognitive function, reaction time, and many health variables including eyesight, hypertension, and longevity. In conclusion we identify novel genetic loci and pathways contributing to the heritability of general cognitive function.

[DNA analysis of chromosome Y in the area of the azoospermia factor (AZF) in infertile men].

PubMed

Kolárová, J; Santavá, A; Vrtĕl, R

2001-09-01

Establishment of investigation of sterile male DNA in AZF region--choice of loci and primers for investigation, optimization of PCR conditions (polymerase chain reaction). For practice. Department of Medical Genetics and Foetal Medicine, Faculty of Medicine, Palacky University and Faculty Hospital Olomouc. PCR amplification of DNA isolated from blood of sterile men and consequential electrophoresis of synthesized DNA fragments to appoint microdeletions in AZF. From January to June 2000 were detected the microdeletions in AZF of 3 out of 79 sterile men (3.80%) by means of the Experteam firm kit. From July to December 2000 were tested and optimized conditions of amplification of 10 AZF loci to substitute the kit and they were used for examination of the first 20 sterile men of our collection. In our laboratory was established routine examination male sterility related to microdeletions in AZF. With our collection of loci was substituted the original Experteam firm kit and was widened spectrum of observed loci.

Insights into population ecology and sexual selection in snakes through the application of DNA-based genetic markers.

PubMed

Gibbs, H L; Weatherhead, P J

2001-01-01

Hypervariable genetic markers have revolutionized studies of kinship, behavioral ecology, and population biology in vertebrate groups such as birds, but their use in snakes remains limited. To illustrate the value of such markers in snakes, we review studies that have used microsatellite DNA loci to analyze local population differentiation and parentage in snakes. Four ecologically distinct species of snakes all show evidence for differentiation at small spatial scales (2-15 km), but with substantial differences among species. This result highlights how genetic analysis can reveal hidden aspects of the natural history of difficult-to-observe taxa, and it raises important questions about the ecological factors that may contribute to restricted gene flow. A 3-year study of genetic parentage in marked populations of the northern water snake showed that (1) participation in mating aggregations was a poor predictor of genetic-based measures of reproductive success; (2) multiple paternity was high, yet there was no detectable fitness advantage to multiple mating by females; and (3) the opportunity for selection was far higher in males than in females due to a larger variance in male reproductive success, and yet this resulted in no detectable selection on morphological variation in males. Thus genetic markers have provided accurate measures of individual reproductive success in this species, an important step toward resolving the adaptive significance of key features including multiple paternity and reversed sexual size dimorphism. Overall these studies illustrate how genetic analyses of snakes provide previously unobtainable information of long-standing interest to behavioral ecologists.

Replication of long-bone length QTL in the F9-F10 LG,SM advanced intercross.

PubMed

Norgard, Elizabeth A; Jarvis, Joseph P; Roseman, Charles C; Maxwell, Taylor J; Kenney-Hunt, Jane P; Samocha, Kaitlin E; Pletscher, L Susan; Wang, Bing; Fawcett, Gloria L; Leatherwood, Christopher J; Wolf, Jason B; Cheverud, James M

2009-04-01

Quantitative trait locus (QTL) mapping techniques are frequently used to identify genomic regions associated with variation in phenotypes of interest. However, the F(2) intercross and congenic strain populations usually employed have limited genetic resolution resulting in relatively large confidence intervals that greatly inhibit functional confirmation of statistical results. Here we use the increased resolution of the combined F(9) and F(10) generations (n = 1455) of the LG,SM advanced intercross to fine-map previously identified QTL associated with the lengths of the humerus, ulna, femur, and tibia. We detected 81 QTL affecting long-bone lengths. Of these, 49 were previously identified in the combined F(2)-F(3) population of this intercross, while 32 represent novel contributors to trait variance. Pleiotropy analysis suggests that most QTL affect three to four long bones or serially homologous limb segments. We also identified 72 epistatic interactions involving 38 QTL and 88 novel regions. This analysis shows that using later generations of an advanced intercross greatly facilitates fine-mapping of confidence intervals, resolving three F(2)-F(3) QTL into multiple linked loci and narrowing confidence intervals of other loci, as well as allowing identification of additional QTL. Further characterization of the biological bases of these QTL will help provide a better understanding of the genetics of small variations in long-bone length.

Sod1 deficiency reduces incubation time in mouse models of prion disease.

PubMed

Akhtar, Shaheen; Grizenkova, Julia; Wenborn, Adam; Hummerich, Holger; Fernandez de Marco, Mar; Brandner, Sebastian; Collinge, John; Lloyd, Sarah E

2013-01-01

Prion infections, causing neurodegenerative conditions such as Creutzfeldt-Jakob disease and kuru in humans, scrapie in sheep and BSE in cattle are characterised by prolonged and variable incubation periods that are faithfully reproduced in mouse models. Incubation time is partly determined by genetic factors including polymorphisms in the prion protein gene. Quantitative trait loci studies in mice and human genome-wide association studies have confirmed that multiple genes are involved. Candidate gene approaches have also been used and identified App, Il1-r1 and Sod1 as affecting incubation times. In this study we looked for an association between App, Il1-r1 and Sod1 representative SNPs and prion disease incubation time in the Northport heterogeneous stock of mice inoculated with the Chandler/RML prion strain. No association was seen with App, however, significant associations were seen with Il1-r1 (P = 0.02) and Sod1 (P<0.0001) suggesting that polymorphisms at these loci contribute to the natural variation observed in incubation time. Furthermore, following challenge with Chandler/RML, ME7 and MRC2 prion strains, Sod1 deficient mice showed highly significant reductions in incubation time of 20, 13 and 24%, respectively. No differences were detected in Sod1 expression or activity. Our data confirm the protective role of endogenous Sod1 in prion disease.

Systematic quantification of HDR and NHEJ reveals effects of locus, nuclease, and cell type on genome-editing.

PubMed

Miyaoka, Yuichiro; Berman, Jennifer R; Cooper, Samantha B; Mayerl, Steven J; Chan, Amanda H; Zhang, Bin; Karlin-Neumann, George A; Conklin, Bruce R

2016-03-31

Precise genome-editing relies on the repair of sequence-specific nuclease-induced DNA nicking or double-strand breaks (DSBs) by homology-directed repair (HDR). However, nonhomologous end-joining (NHEJ), an error-prone repair, acts concurrently, reducing the rate of high-fidelity edits. The identification of genome-editing conditions that favor HDR over NHEJ has been hindered by the lack of a simple method to measure HDR and NHEJ directly and simultaneously at endogenous loci. To overcome this challenge, we developed a novel, rapid, digital PCR-based assay that can simultaneously detect one HDR or NHEJ event out of 1,000 copies of the genome. Using this assay, we systematically monitored genome-editing outcomes of CRISPR-associated protein 9 (Cas9), Cas9 nickases, catalytically dead Cas9 fused to FokI, and transcription activator-like effector nuclease at three disease-associated endogenous gene loci in HEK293T cells, HeLa cells, and human induced pluripotent stem cells. Although it is widely thought that NHEJ generally occurs more often than HDR, we found that more HDR than NHEJ was induced under multiple conditions. Surprisingly, the HDR/NHEJ ratios were highly dependent on gene locus, nuclease platform, and cell type. The new assay system, and our findings based on it, will enable mechanistic studies of genome-editing and help improve genome-editing technology.

Quantitative trait loci × environment interactions for plant morphology vary over ontogeny in Brassica rapa.

PubMed

Dechaine, Jennifer M; Brock, Marcus T; Iniguez-Luy, Federico L; Weinig, Cynthia

2014-01-01

Growth in plants occurs via the addition of repeating modules, suggesting that the genetic architecture of similar subunits may vary between earlier- and later-developing modules. These complex environment × ontogeny interactions are not well elucidated, as studies examining quantitative trait loci (QTLs) expression over ontogeny have not included multiple environments. Here, we characterized the genetic architecture of vegetative traits and onset of reproduction over ontogeny in recombinant inbred lines of Brassica rapa in the field and glasshouse. The magnitude of genetic variation in plasticity of seedling internodes was greater than in those produced later in ontogeny. We correspondingly detected that QTLs for seedling internode length were environment-specific, whereas later in ontogeny the majority of QTLs affected internode lengths in all treatments. The relationship between internode traits and onset of reproduction varied with environment and ontogenetic stage. This relationship was observed only in the glasshouse environment and was largely attributable to one environment-specific QTL. Our results provide the first evidence of a QTL × environment × ontogeny interaction, and provide QTL resolution for differences between early- and later-stage plasticity for stem elongation. These results also suggest potential constraints on morphological evolution in early vs later modules as a result of associations with reproductive timing. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

A high-density consensus map of barley linking DArT markers to SSR, RFLP and STS loci and agricultural traits

PubMed Central

Wenzl, Peter; Li, Haobing; Carling, Jason; Zhou, Meixue; Raman, Harsh; Paul, Edie; Hearnden, Phillippa; Maier, Christina; Xia, Ling; Caig, Vanessa; Ovesná, Jaroslava; Cakir, Mehmet; Poulsen, David; Wang, Junping; Raman, Rosy; Smith, Kevin P; Muehlbauer, Gary J; Chalmers, Ken J; Kleinhofs, Andris; Huttner, Eric; Kilian, Andrzej

2006-01-01

Background Molecular marker technologies are undergoing a transition from largely serial assays measuring DNA fragment sizes to hybridization-based technologies with high multiplexing levels. Diversity Arrays Technology (DArT) is a hybridization-based technology that is increasingly being adopted by barley researchers. There is a need to integrate the information generated by DArT with previous data produced with gel-based marker technologies. The goal of this study was to build a high-density consensus linkage map from the combined datasets of ten populations, most of which were simultaneously typed with DArT and Simple Sequence Repeat (SSR), Restriction Enzyme Fragment Polymorphism (RFLP) and/or Sequence Tagged Site (STS) markers. Results The consensus map, built using a combination of JoinMap 3.0 software and several purpose-built perl scripts, comprised 2,935 loci (2,085 DArT, 850 other loci) and spanned 1,161 cM. It contained a total of 1,629 'bins' (unique loci), with an average inter-bin distance of 0.7 ± 1.0 cM (median = 0.3 cM). More than 98% of the map could be covered with a single DArT assay. The arrangement of loci was very similar to, and almost as optimal as, the arrangement of loci in component maps built for individual populations. The locus order of a synthetic map derived from merging the component maps without considering the segregation data was only slightly inferior. The distribution of loci along chromosomes indicated centromeric suppression of recombination in all chromosomes except 5H. DArT markers appeared to have a moderate tendency toward hypomethylated, gene-rich regions in distal chromosome areas. On the average, 14 ± 9 DArT loci were identified within 5 cM on either side of SSR, RFLP or STS loci previously identified as linked to agricultural traits. Conclusion Our barley consensus map provides a framework for transferring genetic information between different marker systems and for deploying DArT markers in molecular breeding schemes. The study also highlights the need for improved software for building consensus maps from high-density segregation data of multiple populations. PMID:16904008

Genome-wide Association Studies for Female Fertility Traits in Chinese and Nordic Holsteins.

PubMed

Liu, Aoxing; Wang, Yachun; Sahana, Goutam; Zhang, Qin; Liu, Lin; Lund, Mogens Sandø; Su, Guosheng

2017-08-16

Reduced female fertility could cause considerable economic loss and has become a worldwide problem in the modern dairy industry. The objective of this study was to detect quantitative trait loci (QTL) for female fertility traits in Chinese and Nordic Holsteins using various strategies. First, single-trait association analyses were performed for female fertility traits in Chinese and Nordic Holsteins. Second, the SNPs with P-value < 0.005 discovered in Chinese Holsteins were validated in Nordic Holsteins. Third, the summary statistics from single-trait association analyses were combined into meta-analyses to: (1) identify common QTL for multiple fertility traits within each Holstein population; (2) detect SNPs which were associated with a female fertility trait across two Holstein populations. A large numbers of QTL were discovered or confirmed for female fertility traits. The QTL segregating at 31.4~34.1 Mb on BTA13, 48.3~51.9 Mb on BTA23 and 34.0~37.6 Mb on BTA28 shared between Chinese and Nordic Holsteins were further ascertained using a validation approach and meta-analyses. Furthermore, multiple novel variants identified in Chinese Holsteins were validated with Nordic data as well as meta-analyses. The genes IL6R, SLC39A12, CACNB2, ZEB1, ZMIZ1 and FAM213A were concluded to be strong candidate genes for female fertility in Holsteins.

Interactions of dietary whole-grain intake with fasting glucose- and insulin-related genetic loci in individuals of European descent: a meta-analysis of 14 cohort studies.

PubMed

Nettleton, Jennifer A; McKeown, Nicola M; Kanoni, Stavroula; Lemaitre, Rozenn N; Hivert, Marie-France; Ngwa, Julius; van Rooij, Frank J A; Sonestedt, Emily; Wojczynski, Mary K; Ye, Zheng; Tanaka, Tosh; Garcia, Melissa; Anderson, Jennifer S; Follis, Jack L; Djousse, Luc; Mukamal, Kenneth; Papoutsakis, Constantina; Mozaffarian, Dariush; Zillikens, M Carola; Bandinelli, Stefania; Bennett, Amanda J; Borecki, Ingrid B; Feitosa, Mary F; Ferrucci, Luigi; Forouhi, Nita G; Groves, Christopher J; Hallmans, Goran; Harris, Tamara; Hofman, Albert; Houston, Denise K; Hu, Frank B; Johansson, Ingegerd; Kritchevsky, Stephen B; Langenberg, Claudia; Launer, Lenore; Liu, Yongmei; Loos, Ruth J; Nalls, Michael; Orho-Melander, Marju; Renstrom, Frida; Rice, Kenneth; Riserus, Ulf; Rolandsson, Olov; Rotter, Jerome I; Saylor, Georgia; Sijbrands, Eric J G; Sjogren, Per; Smith, Albert; Steingrímsdóttir, Laufey; Uitterlinden, André G; Wareham, Nicholas J; Prokopenko, Inga; Pankow, James S; van Duijn, Cornelia M; Florez, Jose C; Witteman, Jacqueline C M; Dupuis, Josée; Dedoussis, George V; Ordovas, Jose M; Ingelsson, Erik; Cupples, L Adrienne; Siscovick, David S; Franks, Paul W; Meigs, James B

2010-12-01

Whole-grain foods are touted for multiple health benefits, including enhancing insulin sensitivity and reducing type 2 diabetes risk. Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with fasting glucose and insulin concentrations in individuals free of diabetes. We tested the hypothesis that whole-grain food intake and genetic variation interact to influence concentrations of fasting glucose and insulin. Via meta-analysis of data from 14 cohorts comprising ∼ 48,000 participants of European descent, we studied interactions of whole-grain intake with loci previously associated in GWAS with fasting glucose (16 loci) and/or insulin (2 loci) concentrations. For tests of interaction, we considered a P value <0.0028 (0.05 of 18 tests) as statistically significant. Greater whole-grain food intake was associated with lower fasting glucose and insulin concentrations independent of demographics, other dietary and lifestyle factors, and BMI (β [95% CI] per 1-serving-greater whole-grain intake: -0.009 mmol/l glucose [-0.013 to -0.005], P < 0.0001 and -0.011 pmol/l [ln] insulin [-0.015 to -0.007], P = 0.0003). No interactions met our multiple testing-adjusted statistical significance threshold. The strongest SNP interaction with whole-grain intake was rs780094 (GCKR) for fasting insulin (P = 0.006), where greater whole-grain intake was associated with a smaller reduction in fasting insulin concentrations in those with the insulin-raising allele. Our results support the favorable association of whole-grain intake with fasting glucose and insulin and suggest a potential interaction between variation in GCKR and whole-grain intake in influencing fasting insulin concentrations.

A radiation hybrid map of the proximal long arm of human chromosome 11 containing the multiple endocrine neoplasia type 1 (MEN-1) and bcl-1 disease loci.

PubMed Central

Richard, C W; Withers, D A; Meeker, T C; Maurer, S; Evans, G A; Myers, R M; Cox, D R

1991-01-01

We describe a high-resolution radiation hybrid map of the proximal long arm of human chromosome 11 containing the bcl-1 and multiple endocrine neoplasia type 1 (MEN-1) disease gene loci. We used X-ray irradiation and cell fusion to generate a panel of 102 hamster-human somatic cell hybrids containing fragments of human chromosome 11. Sixteen human loci in the 11q12-13 region were mapped by statistical analysis of the cosegregation of markers in these radiation hybrids. The most likely order for these loci is C1NH-OSBP-(CD5/CD20)-PGA-FTH1-COX8-PYGM -SEA-KRN1-(MTC/P11EH/HSTF1/INT2)-GST3- PPP1A. Our localization of the human protooncogene SEA between PYGM and INT2, two markers that flank MEN-1, suggests SEA as a potential candidate for the MEN-1 locus. We map two mitogenic fibroblast growth factor genes, HSTF1 and INT2, close to bcl-1, a mapping that is consistent with previously published data. Our map places the human leukocyte antigen genes CD5 and CD20 far from the bcl-1 locus, indicating that CD5 and CD20 expression is unlikely to be altered by bcl-1 rearrangements. PPP1A, which has been postulated as a MEN-1 candidate tumor suppressor gene, and GST3, a gene transcriptionally active in many human cancers, both map distal to the bcl-1 translocation cluster and the region containing MEN-1, and therefore are unlikely to be directly involved in bcl-1 or MEN-1. PMID:1684084

A radiation hybrid map of the proximal long arm of human chromosome 11 containing the multiple endocrine neoplasia type 1 (MEN-1) and bcl-1 disease loci.

PubMed

Richard, C W; Withers, D A; Meeker, T C; Maurer, S; Evans, G A; Myers, R M; Cox, D R

1991-12-01

We describe a high-resolution radiation hybrid map of the proximal long arm of human chromosome 11 containing the bcl-1 and multiple endocrine neoplasia type 1 (MEN-1) disease gene loci. We used X-ray irradiation and cell fusion to generate a panel of 102 hamster-human somatic cell hybrids containing fragments of human chromosome 11. Sixteen human loci in the 11q12-13 region were mapped by statistical analysis of the cosegregation of markers in these radiation hybrids. The most likely order for these loci is C1NH-OSBP-(CD5/CD20)-PGA-FTH1-COX8-PYGM -SEA-KRN1-(MTC/P11EH/HSTF1/INT2)-GST3- PPP1A. Our localization of the human protooncogene SEA between PYGM and INT2, two markers that flank MEN-1, suggests SEA as a potential candidate for the MEN-1 locus. We map two mitogenic fibroblast growth factor genes, HSTF1 and INT2, close to bcl-1, a mapping that is consistent with previously published data. Our map places the human leukocyte antigen genes CD5 and CD20 far from the bcl-1 locus, indicating that CD5 and CD20 expression is unlikely to be altered by bcl-1 rearrangements. PPP1A, which has been postulated as a MEN-1 candidate tumor suppressor gene, and GST3, a gene transcriptionally active in many human cancers, both map distal to the bcl-1 translocation cluster and the region containing MEN-1, and therefore are unlikely to be directly involved in bcl-1 or MEN-1.

Species-Level Phylogeny and Polyploid Relationships in Hordeum (Poaceae) Inferred by Next-Generation Sequencing and In Silico Cloning of Multiple Nuclear Loci.

PubMed

Brassac, Jonathan; Blattner, Frank R

2015-09-01

Polyploidization is an important speciation mechanism in the barley genus Hordeum. To analyze evolutionary changes after allopolyploidization, knowledge of parental relationships is essential. One chloroplast and 12 nuclear single-copy loci were amplified by polymerase chain reaction (PCR) in all Hordeum plus six out-group species. Amplicons from each of 96 individuals were pooled, sheared, labeled with individual-specific barcodes and sequenced in a single run on a 454 platform. Reference sequences were obtained by cloning and Sanger sequencing of all loci for nine supplementary individuals. The 454 reads were assembled into contigs representing the 13 loci and, for polyploids, also homoeologues. Phylogenetic analyses were conducted for all loci separately and for a concatenated data matrix of all loci. For diploid taxa, a Bayesian concordance analysis and a coalescent-based dated species tree was inferred from all gene trees. Chloroplast matK was used to determine the maternal parent in allopolyploid taxa. The relative performance of different multilocus analyses in the presence of incomplete lineage sorting and hybridization was also assessed. The resulting multilocus phylogeny reveals for the first time species phylogeny and progenitor-derivative relationships of all di- and polyploid Hordeum taxa within a single analysis. Our study proves that it is possible to obtain a multilocus species-level phylogeny for di- and polyploid taxa by combining PCR with next-generation sequencing, without cloning and without creating a heavy load of sequence data. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

Common and Rare Coding Genetic Variation Underlying the Electrocardiographic PR Interval.

PubMed

Lin, Honghuang; van Setten, Jessica; Smith, Albert V; Bihlmeyer, Nathan A; Warren, Helen R; Brody, Jennifer A; Radmanesh, Farid; Hall, Leanne; Grarup, Niels; Müller-Nurasyid, Martina; Boutin, Thibaud; Verweij, Niek; Lin, Henry J; Li-Gao, Ruifang; van den Berg, Marten E; Marten, Jonathan; Weiss, Stefan; Prins, Bram P; Haessler, Jeffrey; Lyytikäinen, Leo-Pekka; Mei, Hao; Harris, Tamara B; Launer, Lenore J; Li, Man; Alonso, Alvaro; Soliman, Elsayed Z; Connell, John M; Huang, Paul L; Weng, Lu-Chen; Jameson, Heather S; Hucker, William; Hanley, Alan; Tucker, Nathan R; Chen, Yii-Der Ida; Bis, Joshua C; Rice, Kenneth M; Sitlani, Colleen M; Kors, Jan A; Xie, Zhijun; Wen, Chengping; Magnani, Jared W; Nelson, Christopher P; Kanters, Jørgen K; Sinner, Moritz F; Strauch, Konstantin; Peters, Annette; Waldenberger, Melanie; Meitinger, Thomas; Bork-Jensen, Jette; Pedersen, Oluf; Linneberg, Allan; Rudan, Igor; de Boer, Rudolf A; van der Meer, Peter; Yao, Jie; Guo, Xiuqing; Taylor, Kent D; Sotoodehnia, Nona; Rotter, Jerome I; Mook-Kanamori, Dennis O; Trompet, Stella; Rivadeneira, Fernando; Uitterlinden, André; Eijgelsheim, Mark; Padmanabhan, Sandosh; Smith, Blair H; Völzke, Henry; Felix, Stephan B; Homuth, Georg; Völker, Uwe; Mangino, Massimo; Spector, Timothy D; Bots, Michiel L; Perez, Marco; Kähönen, Mika; Raitakari, Olli T; Gudnason, Vilmundur; Arking, Dan E; Munroe, Patricia B; Psaty, Bruce M; van Duijn, Cornelia M; Benjamin, Emelia J; Rosand, Jonathan; Samani, Nilesh J; Hansen, Torben; Kääb, Stefan; Polasek, Ozren; van der Harst, Pim; Heckbert, Susan R; Jukema, J Wouter; Stricker, Bruno H; Hayward, Caroline; Dörr, Marcus; Jamshidi, Yalda; Asselbergs, Folkert W; Kooperberg, Charles; Lehtimäki, Terho; Wilson, James G; Ellinor, Patrick T; Lubitz, Steven A; Isaacs, Aaron

2018-05-01

Electrical conduction from the cardiac sinoatrial node to the ventricles is critical for normal heart function. Genome-wide association studies have identified more than a dozen common genetic loci that are associated with PR interval. However, it is unclear whether rare and low-frequency variants also contribute to PR interval heritability. We performed large-scale meta-analyses of the PR interval that included 83 367 participants of European ancestry and 9436 of African ancestry. We examined both common and rare variants associated with the PR interval. We identified 31 genetic loci that were significantly associated with PR interval after Bonferroni correction ( P <1.2×10 -6 ), including 11 novel loci that have not been reported previously. Many of these loci are involved in heart morphogenesis. In gene-based analysis, we found that multiple rare variants at MYH6 ( P =5.9×10 -11 ) and SCN5A ( P =1.1×10 -7 ) were associated with PR interval. SCN5A locus also was implicated in the common variant analysis, whereas MYH6 was a novel locus. We identified common variants at 11 novel loci and rare variants within 2 gene regions that were significantly associated with PR interval. Our findings provide novel insights to the current understanding of atrioventricular conduction, which is critical for cardiac activity and an important determinant of health. © 2018 American Heart Association, Inc.

AFLP genome scan in the black rat (Rattus rattus) from Madagascar: detecting genetic markers undergoing plague-mediated selection.

PubMed

Tollenaere, C; Duplantier, J-M; Rahalison, L; Ranjalahy, M; Brouat, C

2011-03-01

The black rat (Rattus rattus) is the main reservoir of plague (Yersinia pestis infection) in Madagascar's rural zones. Black rats are highly resistant to plague within the plague focus (central highland), whereas they are susceptible where the disease is absent (low altitude zone). To better understand plague wildlife circulation and host evolution in response to a highly virulent pathogen, we attempted to determine genetic markers associated with plague resistance in this species. To this purpose, we combined a population genomics approach and an association study, both performed on 249 AFLP markers, in Malagasy R. rattus. Simulated distributions of genetic differentiation were compared to observed data in four independent pairs, each consisting of one population from the plague focus and one from the plague-free zone. We found 22 loci (9% of 249) with higher differentiation in at least two independent population pairs or with combining P-values over the four pairs significant. Among the 22 outlier loci, 16 presented significant association with plague zone (plague focus vs. plague-free zone). Population genetic structure inferred from outlier loci was structured by plague zone, whereas the neutral loci dataset revealed structure by geography (eastern vs. western populations). A phenotype association study revealed that two of the 22 loci were significantly associated with differentiation between dying and surviving rats following experimental plague challenge. The 22 outlier loci identified in this study may undergo plague selective pressure either directly or more probably indirectly due to hitchhiking with selected loci. © 2010 Blackwell Publishing Ltd.

Simultaneous Differentiation and Typing of Entamoeba histolytica and Entamoeba dispar

PubMed Central

Zaki, Mehreen; Meelu, Parool; Sun, Wei; Clark, C. Graham

2002-01-01

Sequences corresponding to some of the polymorphic loci previously reported from Entamoeba histolytica have been detected in Entamoeba dispar. Comparison of nucleotide sequences of two loci between E. dispar strain SAW760 and E. histolytica strain HM-1:IMSS revealed significant differences in both repeat and flanking regions. The tandem repeat units varied not only in sequence but also in number and arrangement between the two species at both the loci. Using the sequences obtained, primer pairs aimed at amplifying species-specific products were designed and tested on a variety of E. histolytica and E. dispar samples. Amplification results were in complete agreement with the original species classification in all cases, and the PCR products displayed discernible size and pattern variations among the isolates. PMID:11923344

Estimation of genetic parameters and detection of quantitative trait loci for metabolites in Danish Holstein milk.

PubMed

Buitenhuis, A J; Sundekilde, U K; Poulsen, N A; Bertram, H C; Larsen, L B; Sørensen, P

2013-05-01

Small components and metabolites in milk are significant for the utilization of milk, not only in dairy food production but also as disease predictors in dairy cattle. This study focused on estimation of genetic parameters and detection of quantitative trait loci for metabolites in bovine milk. For this purpose, milk samples were collected in mid lactation from 371 Danish Holstein cows in first to third parity. A total of 31 metabolites were detected and identified in bovine milk by using (1)H nuclear magnetic resonance (NMR) spectroscopy. Cows were genotyped using a bovine high-density single nucleotide polymorphism (SNP) chip. Based on the SNP data, a genomic relationship matrix was calculated and used as a random factor in a model together with 2 fixed factors (herd and lactation stage) to estimate the heritability and breeding value for individual metabolites in the milk. Heritability was in the range of 0 for lactic acid to >0.8 for orotic acid and β-hydroxybutyrate. A single SNP association analysis revealed 7 genome-wide significant quantitative trait loci [malonate: Bos taurus autosome (BTA)2 and BTA7; galactose-1-phosphate: BTA2; cis-aconitate: BTA11; urea: BTA12; carnitine: BTA25; and glycerophosphocholine: BTA25]. These results demonstrate that selection for metabolites in bovine milk may be possible. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Evidence for three genetic loci involved in both anorexia nervosa risk and variation of body mass index

PubMed Central

Hinney, Anke; Kesselmeier, Miriam; Jall, Sigrid; Volckmar, Anna-Lena; Föcker, Manuel; Antel, Jochen; Heid, Iris M.; Winkler, Thomas W.; Grant, Struan F. A.; Guo, Yiran; Bergen, Andrew W.; Kaye, Walter; Berrettini, Wade; Hakonarson, Hakon; Herpertz-Dahlmann, Beate; de Zwaan, Martina; Herzog, Wolfgang; Ehrlich, Stefan; Zipfel, Stephan; Egberts, Karin Maria; Adan, Roger; Brandys, Marek; van Elburg, Annemarie; Perica, Vesna Boraska; Franklin, Christopher S.; Tschöp, Matthias H.; Zeggini, Eleftheria; Bulik, Cynthia M.; Collier, David; Scherag, André; Müller, Timo D.; Hebebrand, Johannes

2016-01-01

The maintenance of normal body weight is disrupted in patients with anorexia nervosa (AN) for prolonged periods of time. Prior to the onset of AN, premorbid body mass index (BMI) spans the entire range from underweight to obese. After recovery, patients have reduced rates of overweight and obesity. As such, loci involved in body weight regulation may also be relevant for AN and vice versa. Our primary analysis comprised a cross-trait analysis of the 1000 single nucleotide polymorphisms (SNPs) with the lowest p-values in a genome-wide association meta-analysis (GWAMA) of AN (GCAN) for evidence of association in the largest published GWAMA for BMI (GIANT). Subsequently we performed sex-stratified analyses for these 1000 SNPs. Functional ex vivo studies on four genes ensued. Lastly, a look-up of GWAMA-derived BMI related loci was performed in the AN GWAMA. We detected significant associations (p-values < 5×10−5, Bonferroni corrected p < 0.05) for 9 SNP alleles at 3 independent loci. Interestingly, all AN susceptibility alleles were consistently associated with increased BMI. None of the genes (chr. 10: CTBP2, chr. 19: CCNE1, chr. 2: CARF and NBEAL1; the latter is a region with high linkage disequilibrium) nearest to these SNPs has previously been associated with AN or obesity. Sex-stratified analyses revealed that the strongest BMI signal originated predominantly from females (chr. 10 rs1561589; poverall: 2.47 × 10−06/pfemales: 3.45 × 10−07/pmales: 0.043). Functional ex vivo studies in mice revealed reduced hypothalamic expression of Ctbp2 and Nbeal1 after fasting. Hypothalamic expression of Ctbp2 was increased in diet induced obese (DIO) mice as compared to age-matched lean controls. We observed no evidence for associations for the look-up of BMI related loci in the AN GWAMA. A cross-trait analysis of AN and BMI loci revealed variants at three chromosomal loci with potential joint impact. The chromosome 10 locus is particularly promising given that the association with obesity was primarily driven by females. In addition, the detected altered hypothalamic expression patterns of Ctbp2 and Nbeal1 as a result of fasting and DIO implicate these genes in weight regulation. PMID:27184124

Evidence for three genetic loci involved in both anorexia nervosa risk and variation of body mass index.

PubMed

Hinney, A; Kesselmeier, M; Jall, S; Volckmar, A-L; Föcker, M; Antel, J; Heid, I M; Winkler, T W; Grant, S F A; Guo, Y; Bergen, A W; Kaye, W; Berrettini, W; Hakonarson, H; Herpertz-Dahlmann, B; de Zwaan, M; Herzog, W; Ehrlich, S; Zipfel, S; Egberts, K M; Adan, R; Brandys, M; van Elburg, A; Boraska Perica, V; Franklin, C S; Tschöp, M H; Zeggini, E; Bulik, C M; Collier, D; Scherag, A; Müller, T D; Hebebrand, J

2017-02-01

The maintenance of normal body weight is disrupted in patients with anorexia nervosa (AN) for prolonged periods of time. Prior to the onset of AN, premorbid body mass index (BMI) spans the entire range from underweight to obese. After recovery, patients have reduced rates of overweight and obesity. As such, loci involved in body weight regulation may also be relevant for AN and vice versa. Our primary analysis comprised a cross-trait analysis of the 1000 single-nucleotide polymorphisms (SNPs) with the lowest P-values in a genome-wide association meta-analysis (GWAMA) of AN (GCAN) for evidence of association in the largest published GWAMA for BMI (GIANT). Subsequently we performed sex-stratified analyses for these 1000 SNPs. Functional ex vivo studies on four genes ensued. Lastly, a look-up of GWAMA-derived BMI-related loci was performed in the AN GWAMA. We detected significant associations (P-values <5 × 10 -5 , Bonferroni-corrected P<0.05) for nine SNP alleles at three independent loci. Interestingly, all AN susceptibility alleles were consistently associated with increased BMI. None of the genes (chr. 10: CTBP2, chr. 19: CCNE1, chr. 2: CARF and NBEAL1; the latter is a region with high linkage disequilibrium) nearest to these SNPs has previously been associated with AN or obesity. Sex-stratified analyses revealed that the strongest BMI signal originated predominantly from females (chr. 10 rs1561589; P overall : 2.47 × 10 -06 /P females : 3.45 × 10 -07 /P males : 0.043). Functional ex vivo studies in mice revealed reduced hypothalamic expression of Ctbp2 and Nbeal1 after fasting. Hypothalamic expression of Ctbp2 was increased in diet-induced obese (DIO) mice as compared with age-matched lean controls. We observed no evidence for associations for the look-up of BMI-related loci in the AN GWAMA. A cross-trait analysis of AN and BMI loci revealed variants at three chromosomal loci with potential joint impact. The chromosome 10 locus is particularly promising given that the association with obesity was primarily driven by females. In addition, the detected altered hypothalamic expression patterns of Ctbp2 and Nbeal1 as a result of fasting and DIO implicate these genes in weight regulation.

Genotype Reconstruction of Paternity in European Lobsters (Homarus gammarus).

PubMed

Ellis, Charlie D; Hodgson, David J; André, Carl; Sørdalen, Tonje K; Knutsen, Halvor; Griffiths, Amber G F

2015-01-01

Decapod crustaceans exhibit considerable variation in fertilisation strategies, ranging from pervasive single paternity to the near-ubiquitous presence of multiple paternity, and such knowledge of mating systems and behaviour are required for the informed management of commercially-exploited marine fisheries. We used genetic markers to assess the paternity of individual broods in the European lobster, Homarus gammarus, a species for which paternity structure is unknown. Using 13 multiplexed microsatellite loci, three of which are newly described in this study, we genotyped 10 eggs from each of 34 females collected from an Atlantic peninsula in the south-western United Kingdom. Single reconstructed paternal genotypes explained all observed progeny genotypes in each of the 34 egg clutches, and each clutch was fertilised by a different male. Simulations indicated that the probability of detecting multiple paternity was in excess of 95% if secondary sires account for at least a quarter of the brood, and in excess of 99% where additional sire success was approximately equal. Our results show that multiple paternal fertilisations are either absent, unusual, or highly skewed in favour of a single male among H. gammarus in this area. Potential mechanisms upholding single paternal fertilisation are discussed, along with the prospective utility of parentage assignments in evaluations of hatchery stocking and other fishery conservation approaches in light of this finding.

Theory and methodology for utilizing genes as biomarkers to determine potential biological mixtures.

PubMed

Shrestha, Sadeep; Smith, Michael W; Beaty, Terri H; Strathdee, Steffanie A

2005-01-01

Genetically determined mixture information can be used as a surrogate for physical or behavioral characteristics in epidemiological studies examining research questions related to socially stigmatized behaviors and horizontally transmitted infections. A new measure, the probability of mixture discrimination (PMD), was developed to aid mixture analysis that estimates the ability to differentiate single from multiple genomes in biological mixtures. Four autosomal short tandem repeats (STRs) were identified, genotyped and evaluated in African American, European American, Hispanic, and Chinese individuals to estimate PMD. Theoretical PMD frameworks were also developed for autosomal and sex-linked (X and Y) STR markers in potential male/male, male/female and female/female mixtures. Autosomal STRs genetically determine the presence of multiple genomes in mixture samples of unknown genders with more power than the apparently simpler X and Y chromosome STRs. Evaluation of four autosomal STR loci enables the detection of mixtures of DNA from multiple sources with above 99% probability in all four racial/ethnic populations. The genetic-based approach has applications in epidemiology that provide viable alternatives to survey-based study designs. The analysis of genes as biomarkers can be used as a gold standard for validating measurements from self-reported behaviors that tend to be sensitive or socially stigmatizing, such as those involving sex and drugs.

Further localization of the gene for nevoid basal cell carcinoma syndrome (NBCCS) in 15 Australasian families: Linkage and loss of heterozygosity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chenevix-Trench, G.; Wicking, C.; Berkman, J.

Nevoid basal cell carcinoma syndrome (NBCCS; basal cell nevus syndrome or Gorlin syndrome) is a cancer-predisposition syndrome characterized by multiple basal cell carcinomas (BCCs) and diverse developmental defects. The gene for NBCCS has been mapped to 9q23.1-q31 in North Americal and European families. In addition, loss of heterozygosity (LOH) for genetic markers in this region has been detected in sporadic BCCs, indicating that the NBCCs gene is probably a tumor-suppressor gene. In this study the authors have determined that the NBCCS gene is also linked to this region in Australasian pedigrees and that there is no significant evidence of heterogeneity.more » They have defined the localization of the gene by multipoint and haplotype analysis of 15 families, using four microsatellite markers. LOH at these loci was detected in 50% of sporadic BCCs, a rate that is significantly higher than that in other skin lesions used as controls. 21 refs., 3 figs., 2 tabs.« less

Acute death associated with Citrobacter freundii infection in an African elephant (Loxodonta africana).

PubMed

Ortega, Joaquín; Corpa, Juan M; Orden, José A; Blanco, Jorge; Carbonell, María D; Gerique, Amalia C; Latimer, Erin; Hayward, Gary S; Roemmelt, Andreas; Kraemer, Thomas; Romey, Aurore; Kassimi, Labib B; Casares, Miguel

2015-09-01

A 21-year-old male African elephant (Loxodonta africana) died suddenly with no previous medical history. Grossly, there were severe multifocal epicardial and endocardial hemorrhages of the atria and ventricles, hydropericardium, multifocal pleural hemorrhages, and severe pulmonary congestion and edema. Histologically, there was fibrinoid vasculitis and thrombosis in the heart and lung and myocardial necrosis. Citrobacter freundii was isolated in abundance in pure culture from liver and heart samples. Low levels of multiples types of elephant endotheliotropic herpesvirus (EEHV-6, EEHV-2B, and EEHV-3A) were detected in spleen samples, but not in heart samples. The levels of EEHV DNA found were much lower than those usually associated with acute EEHV hemorrhagic disease, and many other genomic loci that would normally be found in such cases were evidently below the level of detection. Therefore, these findings are unlikely to indicate lethal EEHV disease. Polymerase chain reaction for encephalomyocarditis virus (EMCV) and toxicology for oleander (Nerium oleander) were negative. Stress, resulting from recent transport, and antimicrobial therapy may have contributed to the death of this animal. © 2015 The Author(s).

Population-based structural variation discovery with Hydra-Multi.

PubMed

Lindberg, Michael R; Hall, Ira M; Quinlan, Aaron R

2015-04-15

Current strategies for SNP and INDEL discovery incorporate sequence alignments from multiple individuals to maximize sensitivity and specificity. It is widely accepted that this approach also improves structural variant (SV) detection. However, multisample SV analysis has been stymied by the fundamental difficulties of SV calling, e.g. library insert size variability, SV alignment signal integration and detecting long-range genomic rearrangements involving disjoint loci. Extant tools suffer from poor scalability, which limits the number of genomes that can be co-analyzed and complicates analysis workflows. We have developed an approach that enables multisample SV analysis in hundreds to thousands of human genomes using commodity hardware. Here, we describe Hydra-Multi and measure its accuracy, speed and scalability using publicly available datasets provided by The 1000 Genomes Project and by The Cancer Genome Atlas (TCGA). Hydra-Multi is written in C++ and is freely available at https://github.com/arq5x/Hydra. aaronquinlan@gmail.com or ihall@genome.wustl.edu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press.

Transposition behavior of nonautonomous a hAT superfamily transposon nDart in rice (Oryza sativa L.).

PubMed

Fujino, Kenji; Sekiguchi, Hiroshi

2011-08-01

Transposable elements (TEs) have a significant impact on the evolution of gene function and genome structures. An endogenous nonautonomous transposable element nDart was discovered in an albino mutant that had an insertion in the Mg-protoporphyrin IX methyltransferase gene in rice. In this study, we elucidated the transposition behavior of nDart, the frequency of nDart transposition and characterized the footprint of nDart. Novel independent nDart insertions in backcrossed progenies were detected by DNA blotting analysis. In addition, germinal excision of nDart occurred at very low frequency compared with that of somatic excision, 0-13.3%, in the nDart1-4(3-2) and nDart1-A loci by a locus-specific PCR strategy. A total of 253 clones from somatic excision at five nDart loci in 10 varieties were determined. nDart rarely caused deletions beyond target site duplication (TSD). The footprint of nDart contained few transversions of nucleotides flanking to both sides of the TSD. The predominant footprint of nDart was an 8-bp addition. Precise excision of nDart was detected at a rate of only 2.2%, which occurred at two loci among the five loci examined. Furthermore, the results in this study revealed that a highly conserved mechanism of transposition is involved between maize Ac/Ds and rice Dart/nDart, which are two-component transposon systems of the hAT superfamily transposons in plant species.

The Genetics of Resistance to Morinda Fruit Toxin During the Postembryonic Stages in Drosophila sechellia

PubMed Central

Huang, Yan; Erezyilmaz, Deniz

2015-01-01

Although a great deal has been learned regarding the genetic changes that give rise to adaptation in bacteria and yeast, an understanding of how new complex traits arise in multicellular organisms is far less complete. Many phytophagous insect species are ecological specialists that have adapted to utilize a single host plant. Drosophila sechellia is a specialist that utilizes the ripe fruit of Morinda citrifolia, which is toxic to its sibling species, D. simulans. Here we apply multiplexed shotgun genotyping and QTL analysis to examine the genetic basis of resistance to M. citrifolia fruit toxin in interspecific hybrids. We identify a locus of large effect on the third chromosome (QTL-IIIsima) in the D. simulans backcross that was not detected in previous analyses. We also identify a highly significant QTL of large effect on the X chromosome, QTL-Xsim. Additional smaller-effect loci were also identified in the D. simulans and D. sechellia backcrosses. We did not detect significant epistasis between loci. Instead, our analysis reveals large and smaller-effect loci that contribute to M. citrifolia resistance additively. The additive effect of each locus suggests that partial resistance to lower levels of M. citrifolia toxin could be passed through introgression from D. sechellia to D. simulans in nature. The identification of the major effect loci, QTL-IIIsima and QTL-Xsim, is an important step toward identifying the molecular basis of adaptation in a multicellular organism. PMID:26224784

Comparative analysis of genetic architectures for nine developmental traits of rye.

PubMed

Masojć, Piotr; Milczarski, P; Kruszona, P

2017-08-01

Genetic architectures of plant height, stem thickness, spike length, awn length, heading date, thousand-kernel weight, kernel length, leaf area and chlorophyll content were aligned on the DArT-based high-density map of the 541 × Ot1-3 RILs population of rye using the genes interaction assorting by divergent selection (GIABDS) method. Complex sets of QTL for particular traits contained 1-5 loci of the epistatic D class and 10-28 loci of the hypostatic, mostly R and E classes controlling traits variation through D-E or D-R types of two-loci interactions. QTL were distributed on each of the seven rye chromosomes in unique positions or as a coinciding loci for 2-8 traits. Detection of considerable numbers of the reversed (D', E' and R') classes of QTL might be attributed to the transgression effects observed for most of the studied traits. First examples of E* and F QTL classes, defined in the model, are reported for awn length, leaf area, thousand-kernel weight and kernel length. The results of this study extend experimental data to 11 quantitative traits (together with pre-harvest sprouting and alpha-amylase activity) for which genetic architectures fit the model of mechanism underlying alleles distribution within tails of bi-parental populations. They are also a valuable starting point for map-based search of genes underlying detected QTL and for planning advanced marker-assisted multi-trait breeding strategies.

Locus-specific mutational events in a multilocus variable-number tandem repeat analysis of Escherichia coli O157:H7.

PubMed

Noller, Anna C; McEllistrem, M Catherine; Shutt, Kathleen A; Harrison, Lee H

2006-02-01

Multilocus variable-number tandem repeat analysis (MLVA) is a validated molecular subtyping method for detecting and evaluating Escherichia coli O157:H7 outbreaks. In a previous study, five outbreaks with a total of 21 isolates were examined by MLVA. Nearly 20% of the epidemiologically linked strains were single-locus variants (SLV) of their respective predominant outbreak clone. This result prompted an investigation into the mutation rates of the seven MLVA loci (TR1 to TR7). With an outbreak strain that was an SLV at the TR1 locus of the predominant clone, parallel and serial batch culture experiments were performed. In a parallel experiment, none (0/384) of the strains analyzed had mutations at the seven MLVA loci. In contrast, in the two 5-day serial experiments, 4.3% (41/960) of the strains analyzed had a significant variation in at least one of these loci (P < 0.001). The TR2 locus accounted for 85.3% (35/41) of the mutations, with an average mutation rate of 3.5 x 10(-3); the mutations rates for TR1 and TR5 were 10-fold lower. Single additions accounted for 77.1% (27/35) of the mutation events in TR2 and all (6/6) of the additions in TR1 and TR5. The remaining four loci had no slippage events detected. The mutation rates were locus specific and may impact the interpretation of MLVA data for epidemiologic investigations.

ABC transporters and the proteasome complex are implicated in susceptibility to Stevens-Johnson syndrome and toxic epidermal necrolysis across multiple drugs.

PubMed

Nicoletti, Paola; Bansal, Mukesh; Lefebvre, Celine; Guarnieri, Paolo; Shen, Yufeng; Pe'er, Itsik; Califano, Andrea; Floratos, Aris

2015-01-01

Stevens-Johnson syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) represent rare but serious adverse drug reactions (ADRs). Both are characterized by distinctive blistering lesions and significant mortality rates. While there is evidence for strong drug-specific genetic predisposition related to HLA alleles, recent genome wide association studies (GWAS) on European and Asian populations have failed to identify genetic susceptibility alleles that are common across multiple drugs. We hypothesize that this is a consequence of the low to moderate effect size of individual genetic risk factors. To test this hypothesis we developed Pointer, a new algorithm that assesses the aggregate effect of multiple low risk variants on a pathway using a gene set enrichment approach. A key advantage of our method is the capability to associate SNPs with genes by exploiting physical proximity as well as by using expression quantitative trait loci (eQTLs) that capture information about both cis- and trans-acting regulatory effects. We control for known bias-inducing aspects of enrichment based analyses, such as: 1) gene length, 2) gene set size, 3) presence of biologically related genes within the same linkage disequilibrium (LD) region, and, 4) genes shared among multiple gene sets. We applied this approach to publicly available SJS/TEN genome-wide genotype data and identified the ABC transporter and Proteasome pathways as potentially implicated in the genetic susceptibility of non-drug-specific SJS/TEN. We demonstrated that the innovative SNP-to-gene mapping phase of the method was essential in detecting the significant enrichment for those pathways. Analysis of an independent gene expression dataset provides supportive functional evidence for the involvement of Proteasome pathways in SJS/TEN cutaneous lesions. These results suggest that Pointer provides a useful framework for the integrative analysis of pharmacogenetic GWAS data, by increasing the power to detect aggregate effects of multiple low risk variants. The software is available for download at https://sourceforge.net/projects/pointergsa/.

Genome-wide association study identifies multiple loci associated with both mammographic density and breast cancer risk

PubMed Central

Lindström, Sara; Thompson, Deborah J.; Paterson, Andrew D.; Li, Jingmei; Gierach, Gretchen L.; Scott, Christopher; Stone, Jennifer; Douglas, Julie A.; dos-Santos-Silva, Isabel; Fernandez-Navarro, Pablo; Verghase, Jajini; Smith, Paula; Brown, Judith; Luben, Robert; Wareham, Nicholas J.; Loos, Ruth J.F.; Heit, John A.; Pankratz, V. Shane; Norman, Aaron; Goode, Ellen L.; Cunningham, Julie M.; deAndrade, Mariza; Vierkant, Robert A.; Czene, Kamila; Fasching, Peter A.; Baglietto, Laura; Southey, Melissa C.; Giles, Graham G.; Shah, Kaanan P.; Chan, Heang-Ping; Helvie, Mark A.; Beck, Andrew H.; Knoblauch, Nicholas W.; Hazra, Aditi; Hunter, David J.; Kraft, Peter; Pollan, Marina; Figueroa, Jonine D.; Couch, Fergus J.; Hopper, John L.; Hall, Per; Easton, Douglas F.; Boyd, Norman F.; Vachon, Celine M.; Tamimi, Rulla M.

2015-01-01

Mammographic density reflects the amount of stromal and epithelial tissues in relation to adipose tissue in the breast and is a strong risk factor for breast cancer. Here we report the results from meta-analysis of genome-wide association studies (GWAS) of three mammographic density phenotypes: dense area, non-dense area and percent density in up to 7,916 women in stage 1 and an additional 10,379 women in stage 2. We identify genome-wide significant (P<5×10−8) loci for dense area (AREG, ESR1, ZNF365, LSP1/TNNT3, IGF1, TMEM184B, SGSM3/MKL1), non-dense area (8p11.23) and percent density (PRDM6, 8p11.23, TMEM184B). Four of these regions are known breast cancer susceptibility loci, and four additional regions were found to be associated with breast cancer (P<0.05) in a large meta-analysis. These results provide further evidence of a shared genetic basis between mammographic density and breast cancer and illustrate the power of studying intermediate quantitative phenotypes to identify putative disease susceptibility loci. PMID:25342443

Efficient computation of the joint probability of multiple inherited risk alleles from pedigree data.

PubMed

Madsen, Thomas; Braun, Danielle; Peng, Gang; Parmigiani, Giovanni; Trippa, Lorenzo

2018-06-25

The Elston-Stewart peeling algorithm enables estimation of an individual's probability of harboring germline risk alleles based on pedigree data, and serves as the computational backbone of important genetic counseling tools. However, it remains limited to the analysis of risk alleles at a small number of genetic loci because its computing time grows exponentially with the number of loci considered. We propose a novel, approximate version of this algorithm, dubbed the peeling and paring algorithm, which scales polynomially in the number of loci. This allows extending peeling-based models to include many genetic loci. The algorithm creates a trade-off between accuracy and speed, and allows the user to control this trade-off. We provide exact bounds on the approximation error and evaluate it in realistic simulations. Results show that the loss of accuracy due to the approximation is negligible in important applications. This algorithm will improve genetic counseling tools by increasing the number of pathogenic risk alleles that can be addressed. To illustrate we create an extended five genes version of BRCAPRO, a widely used model for estimating the carrier probabilities of BRCA1 and BRCA2 risk alleles and assess its computational properties. © 2018 WILEY PERIODICALS, INC.

A genome-wide association meta-analysis identifies new childhood obesity loci

PubMed Central

Bradfield, Jonathan P.; Taal, H. Rob; Timpson, Nicholas J.; Scherag, André; Lecoeur, Cecile; Warrington, Nicole M.; Hypponen, Elina; Holst, Claus; Valcarcel, Beatriz; Thiering, Elisabeth; Salem, Rany M.; Schumacher, Fredrick R.; Cousminer, Diana L.; Sleiman, Patrick M.A.; Zhao, Jianhua; Berkowitz, Robert I.; Vimaleswaran, Karani S.; Jarick, Ivonne; Pennell, Craig E.; Evans, David M.; St. Pourcain, Beate; Berry, Diane J.; Mook-Kanamori, Dennis O; Hofman, Albert; Rivadeinera, Fernando; Uitterlinden, André G.; van Duijn, Cornelia M.; van der Valk, Ralf J.P.; de Jongste, Johan C.; Postma, Dirkje S.; Boomsma, Dorret I.; Gauderman, William J.; Hassanein, Mohamed T.; Lindgren, Cecilia M.; Mägi, Reedik; Boreham, Colin A.G.; Neville, Charlotte E.; Moreno, Luis A.; Elliott, Paul; Pouta, Anneli; Hartikainen, Anna-Liisa; Li, Mingyao; Raitakari, Olli; Lehtimäki, Terho; Eriksson, Johan G.; Palotie, Aarno; Dallongeville, Jean; Das, Shikta; Deloukas, Panos; McMahon, George; Ring, Susan M.; Kemp, John P.; Buxton, Jessica L.; Blakemore, Alexandra I.F.; Bustamante, Mariona; Guxens, Mònica; Hirschhorn, Joel N.; Gillman, Matthew W.; Kreiner-Møller, Eskil; Bisgaard, Hans; Gilliland, Frank D.; Heinrich, Joachim; Wheeler, Eleanor; Barroso, Inês; O'Rahilly, Stephen; Meirhaeghe, Aline; Sørensen, Thorkild I.A.; Power, Chris; Palmer, Lyle J.; Hinney, Anke; Widen, Elisabeth; Farooqi, I. Sadaf; McCarthy, Mark I.; Froguel, Philippe; Meyre, David; Hebebrand, Johannes; Jarvelin, Marjo-Riitta; Jaddoe, Vincent W.V.; Smith, George Davey; Hakonarson, Hakon; Grant, Struan F.A.

2012-01-01

Multiple genetic variants have been associated with adult obesity and a few with severe obesity in childhood; however, less progress has been made to establish genetic influences on common early-onset obesity. We performed a North American-Australian-European collaborative meta-analysis of fourteen studies consisting of 5,530 cases (≥95th percentile of body mass index (BMI)) and 8,318 controls (<50th percentile of BMI) of European ancestry. Taking forward the eight novel signals yielding association with P < 5×10−6 in to nine independent datasets (n = 2,818 cases and 4,083 controls) we observed two loci that yielded a genome wide significant combined P-value, namely near OLFM4 on 13q14 (rs9568856; P=1.82×10−9; OR=1.22) and within HOXB5 on 17q21 (rs9299; P=3.54×10−9; OR=1.14). Both loci continued to show association when including two extreme childhood obesity cohorts (n = 2,214 cases and 2,674 controls). Finally, these two loci yielded directionally consistent associations in the GIANT meta-analysis of adult BMI1. PMID:22484627

Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

PubMed Central

Drong, Alexander W; Abbott, James; Wahl, Simone; Tan, Sian-Tsung; Scott, William R; Campanella, Gianluca; Chadeau-Hyam, Marc; Afzal, Uzma; Ahluwalia, Tarunveer S; Bonder, Marc Jan; Chen, Peng; Dehghan, Abbas; Edwards, Todd L; Esko, Tõnu; Go, Min Jin; Harris, Sarah E; Hartiala, Jaana; Kasela, Silva; Kasturiratne, Anuradhani; Khor, Chiea-Chuen; Kleber, Marcus E; Li, Huaixing; Yu Mok, Zuan; Nakatochi, Masahiro; Sapari, Nur Sabrina; Saxena, Richa; Stewart, Alexandre F R; Stolk, Lisette; Tabara, Yasuharu; Teh, Ai Ling; Wu, Ying; Wu, Jer-Yuarn; Zhang, Yi; Aits, Imke; Da Silva Couto Alves, Alexessander; Das, Shikta; Dorajoo, Rajkumar; Hopewell, Jemma C; Kim, Yun Kyoung; Koivula, Robert W; Luan, Jian’an; Lyytikäinen, Leo-Pekka; Nguyen, Quang N; Pereira, Mark A; Postmus, Iris; Raitakari, Olli T; Bryan, Molly Scannell; Scott, Robert A; Sorice, Rossella; Tragante, Vinicius; Traglia, Michela; White, Jon; Yamamoto, Ken; Zhang, Yonghong; Adair, Linda S; Ahmed, Alauddin; Akiyama, Koichi; Asif, Rasheed; Aung, Tin; Barroso, Inês; Bjonnes, Andrew; Braun, Timothy R; Cai, Hui; Chang, Li-Ching; Chen, Chien-Hsiun; Cheng, Ching-Yu; Chong, Yap-Seng; Collins, Rory; Courtney, Regina; Davies, Gail; Delgado, Graciela; Do, Loi D; Doevendans, Pieter A; Gansevoort, Ron T; Gao, Yu-Tang; Grammer, Tanja B; Grarup, Niels; Grewal, Jagvir; Gu, Dongfeng; Wander, Gurpreet S; Hartikainen, Anna-Liisa; Hazen, Stanley L; He, Jing; Heng, Chew-Kiat; Hixson, James E; Hofman, Albert; Hsu, Chris; Huang, Wei; Husemoen, Lise L N; Hwang, Joo-Yeon; Ichihara, Sahoko; Igase, Michiya; Isono, Masato; Justesen, Johanne M; Katsuya, Tomohiro; Kibriya, Muhammad G; Kim, Young Jin; Kishimoto, Miyako; Koh, Woon-Puay; Kohara, Katsuhiko; Kumari, Meena; Kwek, Kenneth; Lee, Nanette R; Lee, Jeannette; Liao, Jiemin; Lieb, Wolfgang; Liewald, David C M; Matsubara, Tatsuaki; Matsushita, Yumi; Meitinger, Thomas; Mihailov, Evelin; Milani, Lili; Mills, Rebecca; Mononen, Nina; Müller-Nurasyid, Martina; Nabika, Toru; Nakashima, Eitaro; Ng, Hong Kiat; Nikus, Kjell; Nutile, Teresa; Ohkubo, Takayoshi; Ohnaka, Keizo; Parish, Sarah; Paternoster, Lavinia; Peng, Hao; Peters, Annette; Pham, Son T; Pinidiyapathirage, Mohitha J; Rahman, Mahfuzar; Rakugi, Hiromi; Rolandsson, Olov; Ann Rozario, Michelle; Ruggiero, Daniela; Sala, Cinzia F; Sarju, Ralhan; Shimokawa, Kazuro; Snieder, Harold; Sparsø, Thomas; Spiering, Wilko; Starr, John M; Stott, David J; Stram, Daniel O; Sugiyama, Takao; Szymczak, Silke; Tang, W H Wilson; Tong, Lin; Trompet, Stella; Turjanmaa, Väinö; Ueshima, Hirotsugu; Uitterlinden, André G; Umemura, Satoshi; Vaarasmaki, Marja; van Dam, Rob M; van Gilst, Wiek H; van Veldhuisen, Dirk J; Viikari, Jorma S; Waldenberger, Melanie; Wang, Yiqin; Wang, Aili; Wilson, Rory; Wong, Tien-Yin; Xiang, Yong-Bing; Yamaguchi, Shuhei; Ye, Xingwang; Young, Robin D; Young, Terri L; Yuan, Jian-Min; Zhou, Xueya; Asselbergs, Folkert W; Ciullo, Marina; Clarke, Robert; Deloukas, Panos; Franke, Andre; Franks, Paul W; Franks, Steve; Friedlander, Yechiel; Gross, Myron D; Guo, Zhirong; Hansen, Torben; Jarvelin, Marjo-Riitta; Jørgensen, Torben; Jukema, J Wouter; kähönen, Mika; Kajio, Hiroshi; Kivimaki, Mika; Lee, Jong-Young; Lehtimäki, Terho; Linneberg, Allan; Miki, Tetsuro; Pedersen, Oluf; Samani, Nilesh J; Sørensen, Thorkild I A; Takayanagi, Ryoichi; Toniolo, Daniela; Ahsan, Habibul; Allayee, Hooman; Chen, Yuan-Tsong; Danesh, John; Deary, Ian J; Franco, Oscar H; Franke, Lude; Heijman, Bastiaan T; Holbrook, Joanna D; Isaacs, Aaron; Kim, Bong-Jo; Lin, Xu; Liu, Jianjun; März, Winfried; Metspalu, Andres; Mohlke, Karen L; Sanghera, Dharambir K; Shu, Xiao-Ou; van Meurs, Joyce B J; Vithana, Eranga; Wickremasinghe, Ananda R; Wijmenga, Cisca; Wolffenbuttel, Bruce H W; Yokota, Mitsuhiro; Zheng, Wei; Zhu, Dingliang; Vineis, Paolo; Kyrtopoulos, Soterios A; Kleinjans, Jos C S; McCarthy, Mark I; Soong, Richie; Gieger, Christian; Scott, James

2016-01-01

We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10−11 to 5.0 × 10−21). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10−6). Our results provide new evidence for the role of DNA methylation in blood pressure regulation. PMID:26390057

Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation.

PubMed

Kato, Norihiro; Loh, Marie; Takeuchi, Fumihiko; Verweij, Niek; Wang, Xu; Zhang, Weihua; Kelly, Tanika N; Saleheen, Danish; Lehne, Benjamin; Leach, Irene Mateo; Drong, Alexander W; Abbott, James; Wahl, Simone; Tan, Sian-Tsung; Scott, William R; Campanella, Gianluca; Chadeau-Hyam, Marc; Afzal, Uzma; Ahluwalia, Tarunveer S; Bonder, Marc Jan; Chen, Peng; Dehghan, Abbas; Edwards, Todd L; Esko, Tõnu; Go, Min Jin; Harris, Sarah E; Hartiala, Jaana; Kasela, Silva; Kasturiratne, Anuradhani; Khor, Chiea-Chuen; Kleber, Marcus E; Li, Huaixing; Yu Mok, Zuan; Nakatochi, Masahiro; Sapari, Nur Sabrina; Saxena, Richa; Stewart, Alexandre F R; Stolk, Lisette; Tabara, Yasuharu; Teh, Ai Ling; Wu, Ying; Wu, Jer-Yuarn; Zhang, Yi; Aits, Imke; Da Silva Couto Alves, Alexessander; Das, Shikta; Dorajoo, Rajkumar; Hopewell, Jemma C; Kim, Yun Kyoung; Koivula, Robert W; Luan, Jian'an; Lyytikäinen, Leo-Pekka; Nguyen, Quang N; Pereira, Mark A; Postmus, Iris; Raitakari, Olli T; Bryan, Molly Scannell; Scott, Robert A; Sorice, Rossella; Tragante, Vinicius; Traglia, Michela; White, Jon; Yamamoto, Ken; Zhang, Yonghong; Adair, Linda S; Ahmed, Alauddin; Akiyama, Koichi; Asif, Rasheed; Aung, Tin; Barroso, Inês; Bjonnes, Andrew; Braun, Timothy R; Cai, Hui; Chang, Li-Ching; Chen, Chien-Hsiun; Cheng, Ching-Yu; Chong, Yap-Seng; Collins, Rory; Courtney, Regina; Davies, Gail; Delgado, Graciela; Do, Loi D; Doevendans, Pieter A; Gansevoort, Ron T; Gao, Yu-Tang; Grammer, Tanja B; Grarup, Niels; Grewal, Jagvir; Gu, Dongfeng; Wander, Gurpreet S; Hartikainen, Anna-Liisa; Hazen, Stanley L; He, Jing; Heng, Chew-Kiat; Hixson, James E; Hofman, Albert; Hsu, Chris; Huang, Wei; Husemoen, Lise L N; Hwang, Joo-Yeon; Ichihara, Sahoko; Igase, Michiya; Isono, Masato; Justesen, Johanne M; Katsuya, Tomohiro; Kibriya, Muhammad G; Kim, Young Jin; Kishimoto, Miyako; Koh, Woon-Puay; Kohara, Katsuhiko; Kumari, Meena; Kwek, Kenneth; Lee, Nanette R; Lee, Jeannette; Liao, Jiemin; Lieb, Wolfgang; Liewald, David C M; Matsubara, Tatsuaki; Matsushita, Yumi; Meitinger, Thomas; Mihailov, Evelin; Milani, Lili; Mills, Rebecca; Mononen, Nina; Müller-Nurasyid, Martina; Nabika, Toru; Nakashima, Eitaro; Ng, Hong Kiat; Nikus, Kjell; Nutile, Teresa; Ohkubo, Takayoshi; Ohnaka, Keizo; Parish, Sarah; Paternoster, Lavinia; Peng, Hao; Peters, Annette; Pham, Son T; Pinidiyapathirage, Mohitha J; Rahman, Mahfuzar; Rakugi, Hiromi; Rolandsson, Olov; Ann Rozario, Michelle; Ruggiero, Daniela; Sala, Cinzia F; Sarju, Ralhan; Shimokawa, Kazuro; Snieder, Harold; Sparsø, Thomas; Spiering, Wilko; Starr, John M; Stott, David J; Stram, Daniel O; Sugiyama, Takao; Szymczak, Silke; Tang, W H Wilson; Tong, Lin; Trompet, Stella; Turjanmaa, Väinö; Ueshima, Hirotsugu; Uitterlinden, André G; Umemura, Satoshi; Vaarasmaki, Marja; van Dam, Rob M; van Gilst, Wiek H; van Veldhuisen, Dirk J; Viikari, Jorma S; Waldenberger, Melanie; Wang, Yiqin; Wang, Aili; Wilson, Rory; Wong, Tien-Yin; Xiang, Yong-Bing; Yamaguchi, Shuhei; Ye, Xingwang; Young, Robin D; Young, Terri L; Yuan, Jian-Min; Zhou, Xueya; Asselbergs, Folkert W; Ciullo, Marina; Clarke, Robert; Deloukas, Panos; Franke, Andre; Franks, Paul W; Franks, Steve; Friedlander, Yechiel; Gross, Myron D; Guo, Zhirong; Hansen, Torben; Jarvelin, Marjo-Riitta; Jørgensen, Torben; Jukema, J Wouter; Kähönen, Mika; Kajio, Hiroshi; Kivimaki, Mika; Lee, Jong-Young; Lehtimäki, Terho; Linneberg, Allan; Miki, Tetsuro; Pedersen, Oluf; Samani, Nilesh J; Sørensen, Thorkild I A; Takayanagi, Ryoichi; Toniolo, Daniela; Ahsan, Habibul; Allayee, Hooman; Chen, Yuan-Tsong; Danesh, John; Deary, Ian J; Franco, Oscar H; Franke, Lude; Heijman, Bastiaan T; Holbrook, Joanna D; Isaacs, Aaron; Kim, Bong-Jo; Lin, Xu; Liu, Jianjun; März, Winfried; Metspalu, Andres; Mohlke, Karen L; Sanghera, Dharambir K; Shu, Xiao-Ou; van Meurs, Joyce B J; Vithana, Eranga; Wickremasinghe, Ananda R; Wijmenga, Cisca; Wolffenbuttel, Bruce H W; Yokota, Mitsuhiro; Zheng, Wei; Zhu, Dingliang; Vineis, Paolo; Kyrtopoulos, Soterios A; Kleinjans, Jos C S; McCarthy, Mark I; Soong, Richie; Gieger, Christian; Scott, James; Teo, Yik-Ying; He, Jiang; Elliott, Paul; Tai, E Shyong; van der Harst, Pim; Kooner, Jaspal S; Chambers, John C

2015-11-01

We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10(-11) to 5.0 × 10(-21)). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10(-6)). Our results provide new evidence for the role of DNA methylation in blood pressure regulation.

An extension of the Maximum Lod Score method to X-linked loci.

PubMed

Cordell, H J; Kawaguchi, Y; Todd, J A; Farrall, M

1995-10-01

The Maximum Lod Score method for affected relative-pair analysis, introduced by Risch, is a powerful method for detecting linkage between an autosomal marker locus and disease. In order to use the method to detect linkage to markers on the X-chromosome, some modification is necessary. Here we extend the method to be applicable to X-chromosomal data, and derive genetic restrictions on the haplotype-sharing probabilities analogous to the 'possible triangle' restrictions described by Holmans for the autosomal case. Size criteria are derived using asymptotic theory and simulation, and the power is calculated for a number of possible underlying models. The method is applied to data from 284 type 1 diabetic families and evidence is found for the presence of one or more diabetogenic loci on the X-chromosome.

Molecular characterization of Verocytotoxigenic Escherichia coli O157:H7 isolates from Argentina by Multiple-Loci VNTR Analysis (MLVA).

PubMed

Bustamante, Ana V; Lucchesi, Paula M A; Parma, Alberto E

2009-10-01

The aim of this work was to adapt described MLVA protocols to the molecular typing and characterization of VTEC O157:H7 isolates from Argentina. Nine VNTR loci were amplified by PCR showing diversity values from 0.49 to 0.73. Nine MLVA profiles were observed and the cluster analysis indicated both unrelated and closely related VTEC O157:H7 strains. In spite of the limited number of isolates studied, the panel of VNTR used made it possible to perform a first approach of the high genetic diversity of native strains of O157:H7 by MLVA.

Association Mapping Reveals Genetic Loci Associated with Important Agronomic Traits in Lentinula edodes, Shiitake Mushroom

PubMed Central

Li, Chuang; Gong, Wenbing; Zhang, Lin; Yang, Zhiquan; Nong, Wenyan; Bian, Yinbing; Kwan, Hoi-Shan; Cheung, Man-Kit; Xiao, Yang

2017-01-01

Association mapping is a robust approach for the detection of quantitative trait loci (QTLs). Here, by genotyping 297 genome-wide molecular markers of 89 Lentinula edodes cultivars in China, the genetic diversity, population structure and genetic loci associated with 11 agronomic traits were examined. A total of 873 alleles were detected in the tested strains with a mean of 2.939 alleles per locus, and the Shannon's information index was 0.734. Population structure analysis revealed two robustly differentiated groups among the Chinese L. edodes cultivars (FST = 0.247). Using the mixed linear model, a total of 43 markers were detected to be significantly associated with four traits. The number of markers associated with traits ranged from 9 to 26, and the phenotypic variations explained by each marker varied from 12.07% to 31.32%. Apart from five previously reported markers, the remaining 38 markers were newly reported here. Twenty-one markers were identified as simultaneously linked to two to four traits, and five markers were associated with the same traits in cultivation tests performed in two consecutive years. The 43 traits-associated markers were related to 97 genes, and 24 of them were related to 10 traits-associated markers detected in both years or identified previously, 13 of which had a >2-fold expression change between the mycelium and primordium stages. Our study has provided candidate markers for marker-assisted selection (MAS) and useful clues for understanding the genetic architecture of agronomic traits in the shiitake mushroom. PMID:28261189

Genetic variation of growth dynamics in maize (Zea mays L.) revealed through automated non-invasive phenotyping.

PubMed

Muraya, Moses M; Chu, Jianting; Zhao, Yusheng; Junker, Astrid; Klukas, Christian; Reif, Jochen C; Altmann, Thomas

2017-01-01

Hitherto, most quantitative trait loci of maize growth and biomass yield have been identified for a single time point, usually the final harvest stage. Through this approach cumulative effects are detected, without considering genetic factors causing phase-specific differences in growth rates. To assess the genetics of growth dynamics, we employed automated non-invasive phenotyping to monitor the plant sizes of 252 diverse maize inbred lines at 11 different developmental time points; 50 k SNP array genotype data were used for genome-wide association mapping and genomic selection. The heritability of biomass was estimated to be over 71%, and the average prediction accuracy amounted to 0.39. Using the individual time point data, 12 main effect marker-trait associations (MTAs) and six pairs of epistatic interactions were detected that displayed different patterns of expression at various developmental time points. A subset of them also showed significant effects on relative growth rates in different intervals. The detected MTAs jointly explained up to 12% of the total phenotypic variation, decreasing with developmental progression. Using non-parametric functional mapping and multivariate mapping approaches, four additional marker loci affecting growth dynamics were detected. Our results demonstrate that plant biomass accumulation is a complex trait governed by many small effect loci, most of which act at certain restricted developmental phases. This highlights the need for investigation of stage-specific growth affecting genes to elucidate important processes operating at different developmental phases. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

mCAL: A New Approach for Versatile Multiplex Action of Cas9 Using One sgRNA and Loci Flanked by a Programmed Target Sequence.

PubMed

Finnigan, Gregory C; Thorner, Jeremy

2016-07-07

Genome editing exploiting CRISPR/Cas9 has been adopted widely in academia and in the biotechnology industry to manipulate DNA sequences in diverse organisms. Molecular engineering of Cas9 itself and its guide RNA, and the strategies for using them, have increased efficiency, optimized specificity, reduced inappropriate off-target effects, and introduced modifications for performing other functions (transcriptional regulation, high-resolution imaging, protein recruitment, and high-throughput screening). Moreover, Cas9 has the ability to multiplex, i.e., to act at different genomic targets within the same nucleus. Currently, however, introducing concurrent changes at multiple loci involves: (i) identification of appropriate genomic sites, especially the availability of suitable PAM sequences; (ii) the design, construction, and expression of multiple sgRNA directed against those sites; (iii) potential difficulties in altering essential genes; and (iv) lingering concerns about "off-target" effects. We have devised a new approach that circumvents these drawbacks, as we demonstrate here using the yeast Saccharomyces cerevisiae First, any gene(s) of interest are flanked upstream and downstream with a single unique target sequence that does not normally exist in the genome. Thereafter, expression of one sgRNA and cotransformation with appropriate PCR fragments permits concomitant Cas9-mediated alteration of multiple genes (both essential and nonessential). The system we developed also allows for maintenance of the integrated, inducible Cas9-expression cassette or its simultaneous scarless excision. Our scheme-dubbed mCAL for " M: ultiplexing of C: as9 at A: rtificial L: oci"-can be applied to any organism in which the CRISPR/Cas9 methodology is currently being utilized. In principle, it can be applied to install synthetic sequences into the genome, to generate genomic libraries, and to program strains or cell lines so that they can be conveniently (and repeatedly) manipulated at multiple loci with extremely high efficiency. Copyright © 2016 Finnigan and Thorner.

Two New Loci for Body-Weight Regulation Identified in a Joint Analysis of Genome-Wide Association Studies for Early-Onset Extreme Obesity in French and German Study Groups

PubMed Central

Scherag, André; Dina, Christian; Hinney, Anke; Vatin, Vincent; Scherag, Susann; Vogel, Carla I. G.; Müller, Timo D.; Grallert, Harald; Wichmann, H.-Erich; Balkau, Beverley; Heude, Barbara; Jarvelin, Marjo-Riitta; Hartikainen, Anna-Liisa; Levy-Marchal, Claire; Weill, Jacques; Delplanque, Jérôme; Körner, Antje; Kiess, Wieland; Kovacs, Peter; Rayner, Nigel W.; Prokopenko, Inga; McCarthy, Mark I.; Schäfer, Helmut; Jarick, Ivonne; Boeing, Heiner; Fisher, Eva; Reinehr, Thomas; Heinrich, Joachim; Rzehak, Peter; Berdel, Dietrich; Borte, Michael; Biebermann, Heike; Krude, Heiko; Rosskopf, Dieter; Rimmbach, Christian; Rief, Winfried; Fromme, Tobias; Klingenspor, Martin; Schürmann, Annette; Schulz, Nadja; Nöthen, Markus M.; Mühleisen, Thomas W.; Erbel, Raimund; Jöckel, Karl-Heinz; Moebus, Susanne; Boes, Tanja; Illig, Thomas; Froguel, Philippe; Hebebrand, Johannes; Meyre, David

2010-01-01

Meta-analyses of population-based genome-wide association studies (GWAS) in adults have recently led to the detection of new genetic loci for obesity. Here we aimed to discover additional obesity loci in extremely obese children and adolescents. We also investigated if these results generalize by estimating the effects of these obesity loci in adults and in population-based samples including both children and adults. We jointly analysed two GWAS of 2,258 individuals and followed-up the best, according to lowest p-values, 44 single nucleotide polymorphisms (SNP) from 21 genomic regions in 3,141 individuals. After this DISCOVERY step, we explored if the findings derived from the extremely obese children and adolescents (10 SNPs from 5 genomic regions) generalized to (i) the population level and (ii) to adults by genotyping another 31,182 individuals (GENERALIZATION step). Apart from previously identified FTO, MC4R, and TMEM18, we detected two new loci for obesity: one in SDCCAG8 (serologically defined colon cancer antigen 8 gene; p = 1.85×10−8 in the DISCOVERY step) and one between TNKS (tankyrase, TRF1-interacting ankyrin-related ADP-ribose polymerase gene) and MSRA (methionine sulfoxide reductase A gene; p = 4.84×10−7), the latter finding being limited to children and adolescents as demonstrated in the GENERALIZATION step. The odds ratios for early-onset obesity were estimated at ∼1.10 per risk allele for both loci. Interestingly, the TNKS/MSRA locus has recently been found to be associated with adult waist circumference. In summary, we have completed a meta-analysis of two GWAS which both focus on extremely obese children and adolescents and replicated our findings in a large followed-up data set. We observed that genetic variants in or near FTO, MC4R, TMEM18, SDCCAG8, and TNKS/MSRA were robustly associated with early-onset obesity. We conclude that the currently known major common variants related to obesity overlap to a substantial degree between children and adults. PMID:20421936

Multiple SNPs Within and Surrounding the Apolipoprotein E Gene Influence Cerebrospinal Fluid Apolipoprotein E Protein Levels

PubMed Central

Bekris, Lynn M.; Millard, Steven P.; Galloway, Nichole M.; Vuletic, Simona; Albers, John J.; Li, Ge; Galasko, Douglas R.; DeCarli, Charles; Farlow, Martin R.; Clark, Chris M.; Quinn, Joseph F.; Kaye, Jeffrey A.; Schellenberg, Gerard D.; Tsuang, Debby; Peskind, Elaine R.; Yu, Chang-En

2010-01-01

The ε4 allele of the apolipoprotein E gene (APOE) is associated with increased risk and earlier age at onset in late onset Alzheimer’s disease (AD). Other factors, such as expression level of apolipoprotein E protein (apoE), have been postulated to modify the APOE related risk of developing AD. Multiple loci in and outside of APOE are associated with a high risk of AD. The aim of this exploratory hypothesis generating investigation was to determine if some of these loci predict cerebrospinal fluid (CSF) apoE levels in healthy non-demented subjects. CSF apoE levels were measured from healthy non-demented subjects 21–87 years of age (n = 134). Backward regression models were used to evaluate the influence of 21 SNPs, within and surrounding APOE, on CSF apoE levels while taking into account age, gender, APOE ε4 and correlation between SNPs (linkage disequilibrium). APOE ε4 genotype does not predict CSF apoE levels. Three SNPs within the TOMM40 gene, one APOE promoter SNP and two SNPs within distal APOE enhancer elements (ME1 and BCR) predict CSF apoE levels. Further investigation of the genetic influence of these loci on apoE expression levels in the central nervous system is likely to provide new insight into apoE regulation as well as AD pathogenesis. PMID:18430993

QTL detection for rice grain quality traits using an interspecific backcross population derived from cultivated Asian (O. sativa L.) and African (O. glaberrima S.) rice.

PubMed

Li, Jiming; Xiao, Jinhua; Grandillo, Silvana; Jiang, Longying; Wan, Yizhen; Deng, Qiyun; Yuan, Longping; McCouch, Susan R

2004-08-01

An interspecific advanced backcross population derived from a cross between Oryza sativa "V20A" (a popular male-sterile line used in Chinese rice hybrids) and Oryza glaberrima (accession IRGC No. 103544 from Mali) was used to identify quantitative trait loci (QTL) associated with grain quality and grain morphology. A total of 308 BC3F1 hybrid families were evaluated for 16 grain-related traits under field conditions in Changsha, China, and the same families were evaluated for RFLP and SSR marker segregation at Cornell University (Ithaca, N.Y.). Eleven QTL associated with seven traits were detected in six chromosomal regions, with the favorable allele coming from O. glaberrima at eight loci. Favorable O. glaberrima alleles were associated with improvements in grain shape and appearance, resulting in an increase in kernel length, transgressive variation for thinner grains, and increased length to width ratio. Oryza glaberrima alleles at other loci were associated with potential improvements in crude protein content and brown rice yield. These results suggested that genes from O. glaberrima may be useful in improving specific grain quality characteristics in high-yielding O. sativa hybrid cultivars.

Time scale matters: genetic analysis does not support adaptation-by-time as the mechanism for adaptive seasonal declines in kokanee reproductive life span

PubMed Central

Morbey, Yolanda E; Jensen, Evelyn L; Russello, Michael A

2014-01-01

Seasonal declines of fitness-related traits are often attributed to environmental effects or individual-level decisions about reproductive timing and effort, but genetic variation may also play a role. In populations of Pacific salmon (Oncorhynchus spp.), seasonal declines in reproductive life span have been attributed to adaptation-by-time, in which divergent selection for different traits occurs among reproductively isolated temporal components of a population. We evaluated this hypothesis in kokanee (freshwater obligate Oncorhynchus nerka) by testing for temporal genetic structure in neutral and circadian-linked loci. We detected no genetic differences in presumably neutral loci among kokanee with different arrival and maturation dates within a spawning season. Similarly, we detected no temporal genetic structure in OtsClock1b, Omy1009uw, or OmyFbxw11, candidate loci associated with circadian function. The genetic evidence from this study and others indicates a lack of support for adaptation-by-time as an important evolutionary mechanism underlying seasonal declines in reproductive life span and a need for greater consideration of other mechanisms such as time-dependent, adaptive adjustment of reproductive effort. PMID:25478160

Plasmodium falciparum malaria: Convergent evolutionary trajectories towards delayed clearance following artemisinin treatment.

PubMed

Wilairat, Prapon; Kümpornsin, Krittikorn; Chookajorn, Thanat

2016-05-01

Malaria is a major global health challenge with 300million new cases every year. The most effective regimen for treating Plasmodium falciparum malaria is based on artemisinin and its derivatives. The drugs are highly effective, resulting in rapid clearance of parasites even in severe P. falciparum malaria patients. During the last five years, artemisinin-resistant parasites have begun to emerge first in Cambodia and now in Thailand and Myanmar. At present, the level of artemisinin resistance is relatively low with clinical presentation of delayed artemisinin clearance (a longer time to reduce parasite load) and a small decrease in artemisinin sensitivity in cultured isolates. Nevertheless, multiple genetic loci associated with delayed parasite clearance have been reported, but they cannot account for a large portion of cases. Even the most well-studied kelch 13 propeller mutations cannot always predict the outcome of artemisinin treatment in vitro and in vivo. Here we propose that delayed clearance by artemisinin could be the result of convergent evolution, driven by multiple trajectories to overcome artemisinin-induced stress, but precluded to become full blown resistance by high fitness cost. Genetic association studies by several genome-wide approaches reveal linkage disequilibrium between multiple loci and delayed parasite clearance. Genetic manipulations at some of these loci already have resulted in loss in artemisinin sensitivity. The notion presented here is by itself consistent with existing evidence on artemisinin resistance and has the potential to be explored using available genomic data. Most important of all, molecular surveillance of artemisinin resistance based on multi-genic markers could be more informative than relying on any one particular molecular marker. Copyright © 2016 Elsevier Ltd. All rights reserved.

A genome scan for selection signatures comparing farmed Atlantic salmon with two wild populations: Testing colocalization among outlier markers, candidate genes, and quantitative trait loci for production traits.

PubMed

Liu, Lei; Ang, Keng Pee; Elliott, J A K; Kent, Matthew Peter; Lien, Sigbjørn; MacDonald, Danielle; Boulding, Elizabeth Grace

2017-03-01

Comparative genome scans can be used to identify chromosome regions, but not traits, that are putatively under selection. Identification of targeted traits may be more likely in recently domesticated populations under strong artificial selection for increased production. We used a North American Atlantic salmon 6K SNP dataset to locate genome regions of an aquaculture strain (Saint John River) that were highly diverged from that of its putative wild founder population (Tobique River). First, admixed individuals with partial European ancestry were detected using STRUCTURE and removed from the dataset. Outlier loci were then identified as those showing extreme differentiation between the aquaculture population and the founder population. All Arlequin methods identified an overlapping subset of 17 outlier loci, three of which were also identified by BayeScan. Many outlier loci were near candidate genes and some were near published quantitative trait loci (QTLs) for growth, appetite, maturity, or disease resistance. Parallel comparisons using a wild, nonfounder population (Stewiacke River) yielded only one overlapping outlier locus as well as a known maturity QTL. We conclude that genome scans comparing a recently domesticated strain with its wild founder population can facilitate identification of candidate genes for traits known to have been under strong artificial selection.

Analysis of microsatellite instability in CRISPR/Cas9 editing mice.

PubMed

Huo, Xueyun; Du, Yating; Lu, Jing; Guo, Meng; Li, Zhenkun; Zhang, Shuangyue; Li, Xiaohong; Chen, Zhenwen; Du, Xiaoyan

2017-03-01

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR- associated (Cas) protein 9 system is a novel and powerful tool which is widely used for genome editing. CRISPR/Cas9 is RNA-guided and can lead to desired genomic modifications. However, whether the CRISPR/Cas9-mediated genome editing causes genomic alterations and genomic instability, such as microsatellite instability (MSI), is still unknown. Here we detected MSI in 21 CRISPR/Cas9 mouse strains using a panel of 42 microsatellite loci which were selected from our previous studies. Surprisingly, MSI occurrence was common in CRISPR/Cas9 modified genome, and most of the strains (19/21, 90.5%) examined showed MSI. Of 42 loci examined, 8 loci (8/42, 19.05%) exhibited MSI in the Cas9 editing mice. The Ttll9 (4/42, 9.5%) were the most unstable strains, and D10Mit3 and D10Mit198 (9/21, 42.9%) were considered to be the most "hot" loci in the Cas9 strains we tested. Through analyzing the mutation of microsatellite loci, we provide new insights into the genomic alterations of CRISPR/Cas9 models and it will help us for a better understanding of this powerful technology. Copyright © 2017 Elsevier B.V. All rights reserved.

Genetic control of the root system in rice under normal and drought stress conditions by genome-wide association study

PubMed Central

Li, Xiaokai; Guo, Zilong; Lv, Yan; Cen, Xiang; Ding, Xipeng; Wu, Hua; Li, Xianghua; Huang, Jianping

2017-01-01

A variety of adverse conditions including drought stress severely affect rice production. Root system plays a critical role in drought avoidance, which is one of the major mechanisms of drought resistance. In this study, we adopted genome-wide association study (GWAS) to dissect the genetic basis controlling various root traits by using a natural population consisting of 529 representative rice accessions. A total of 413 suggestive associations, containing 143 significant associations, were identified for 21 root traits, such as maximum root length, root volume, and root dry weight under normal and drought stress conditions at the maturation stage. More than 80 percent of the suggestive loci were located in the region of reported QTLs for root traits, while about 20 percent of suggestive loci were novel loci detected in this study. Besides, 11 reported root-related genes, including DRO1, WOX11, and OsPID, were found to co-locate with the association loci. We further proved that the association results can facilitate the efficient identification of causal genes for root traits by the two case studies of Nal1 and OsJAZ1. These loci and their candidate causal genes provide an important basis for the genetic improvement of root traits and drought resistance. PMID:28686596

Determination of Yield and Flow Surfaces for Inconel 718 Under Axial-Torsional Loading at Temperatures Up to 649 C

NASA Technical Reports Server (NTRS)

Gil, Christopher M.

1998-01-01

An experimental program to determine flow surfaces has been established and implemented for solution annealed and aged IN718. The procedure involved subjecting tubular specimens to various ratios of axial-torsional stress at temperatures between 23 and 649 C and measuring strain with a biaxial extensometer. Each stress probe corresponds to a different direction in stress space, and unloading occurs when a 30 microstrain (1 micro eplison = 10(exp -6) mm/mm) offset is detected. This technique was used to map out yield loci in axial-torsional stress space. Flow surfaces were determined by post-processing the experimental data to determine the inelastic strain rate components. Surfaces of constant inelastic strain rate (SCISRS) and surfaces of constant inelastic power (SCIPS) were mapped out in the axial-shear stress plane. The von Mises yield criterion appeared to closely fit the initial loci for solutioned IN718 at 23 C. However, the initial loci for solutioned IN718 at 371 and 454 C, and all of the initial loci for aged IN718 were offset in the compression direction. Subsequent loci showed translation, distortion, and for the case of solutioned IN718, a slight cross effect. Aged IN718 showed significantly more hardening behavior than solutioned IN718.

Rheumatoid arthritis: identifying and characterising polymorphisms using rat models

PubMed Central

2016-01-01

ABSTRACT Rheumatoid arthritis is a chronic inflammatory joint disorder characterised by erosive inflammation of the articular cartilage and by destruction of the synovial joints. It is regulated by both genetic and environmental factors, and, currently, there is no preventative treatment or cure for this disease. Genome-wide association studies have identified ∼100 new loci associated with rheumatoid arthritis, in addition to the already known locus within the major histocompatibility complex II region. However, together, these loci account for only a modest fraction of the genetic variance associated with this disease and very little is known about the pathogenic roles of most of the risk loci identified. Here, we discuss how rat models of rheumatoid arthritis are being used to detect quantitative trait loci that regulate different arthritic traits by genetic linkage analysis and to positionally clone the underlying causative genes using congenic strains. By isolating specific loci on a fixed genetic background, congenic strains overcome the challenges of genetic heterogeneity and environmental interactions associated with human studies. Most importantly, congenic strains allow functional experimental studies be performed to investigate the pathological consequences of natural genetic polymorphisms, as illustrated by the discovery of several major disease genes that contribute to arthritis in rats. We discuss how these advances have provided new biological insights into arthritis in humans. PMID:27736747

Sequencing of Pax6 Loci from the Elephant Shark Reveals a Family of Pax6 Genes in Vertebrate Genomes, Forged by Ancient Duplications and Divergences

PubMed Central

Gautier, Philippe; Loosli, Felix; Tay, Boon-Hui; Tay, Alice; Murdoch, Emma; Coutinho, Pedro; van Heyningen, Veronica; Brenner, Sydney; Venkatesh, Byrappa; Kleinjan, Dirk A.

2013-01-01

Pax6 is a developmental control gene essential for eye development throughout the animal kingdom. In addition, Pax6 plays key roles in other parts of the CNS, olfactory system, and pancreas. In mammals a single Pax6 gene encoding multiple isoforms delivers these pleiotropic functions. Here we provide evidence that the genomes of many other vertebrate species contain multiple Pax6 loci. We sequenced Pax6-containing BACs from the cartilaginous elephant shark (Callorhinchus milii) and found two distinct Pax6 loci. Pax6.1 is highly similar to mammalian Pax6, while Pax6.2 encodes a paired-less Pax6. Using synteny relationships, we identify homologs of this novel paired-less Pax6.2 gene in lizard and in frog, as well as in zebrafish and in other teleosts. In zebrafish two full-length Pax6 duplicates were known previously, originating from the fish-specific genome duplication (FSGD) and expressed in divergent patterns due to paralog-specific loss of cis-elements. We show that teleosts other than zebrafish also maintain duplicate full-length Pax6 loci, but differences in gene and regulatory domain structure suggest that these Pax6 paralogs originate from a more ancient duplication event and are hence renamed as Pax6.3. Sequence comparisons between mammalian and elephant shark Pax6.1 loci highlight the presence of short- and long-range conserved noncoding elements (CNEs). Functional analysis demonstrates the ancient role of long-range enhancers for Pax6 transcription. We show that the paired-less Pax6.2 ortholog in zebrafish is expressed specifically in the developing retina. Transgenic analysis of elephant shark and zebrafish Pax6.2 CNEs with homology to the mouse NRE/Pα internal promoter revealed highly specific retinal expression. Finally, morpholino depletion of zebrafish Pax6.2 resulted in a “small eye” phenotype, supporting a role in retinal development. In summary, our study reveals that the pleiotropic functions of Pax6 in vertebrates are served by a divergent family of Pax6 genes, forged by ancient duplication events and by independent, lineage-specific gene losses. PMID:23359656

AFLPs and Mitochondrial Haplotypes Reveal Local Adaptation to Extreme Thermal Environments in a Freshwater Gastropod

PubMed Central

Quintela, María; Johansson, Magnus P.; Kristjánsson, Bjarni K.; Barreiro, Rodolfo; Laurila, Anssi

2014-01-01

The way environmental variation shapes neutral and adaptive genetic variation in natural populations is a key issue in evolutionary biology. Genome scans allow the identification of the genetic basis of local adaptation without previous knowledge of genetic variation or traits under selection. Candidate loci for divergent adaptation are expected to show higher FST than neutral loci influenced solely by random genetic drift, migration and mutation. The comparison of spatial patterns of neutral markers and loci under selection may help disentangle the effects of gene flow, genetic drift and selection among populations living in contrasting environments. Using the gastropod Radix balthica as a system, we analyzed 376 AFLP markers and 25 mtDNA COI haplotypes for candidate loci and associations with local adaptation among contrasting thermal environments in Lake Mývatn, a volcanic lake in northern Iceland. We found that 2% of the analysed AFLP markers were under directional selection and 12% of the mitochondrial haplotypes correlated with differing thermal habitats. The genetic networks were concordant for AFLP markers and mitochondrial haplotypes, depicting distinct topologies at neutral and candidate loci. Neutral topologies were characterized by intense gene flow revealed by dense nets with edges connecting contrasting thermal habitats, whereas the connections at candidate loci were mostly restricted to populations within each thermal habitat and the number of edges decreased with temperature. Our results suggest microgeographic adaptation within Lake Mývatn and highlight the utility of genome scans in detecting adaptive divergence. PMID:25007329

Patterns of genetic diversity and candidate genes for ecological divergence in a homoploid hybrid sunflower, Helianthus anomalus

PubMed Central

SAPIR, YUVAL; MOODY, MICHAEL L.; BROUILLETTE, LARRY C.; DONOVAN, LISA A.; RIESEBERG, LOREN H.

2008-01-01

Natural hybridization accompanied by a shift in niche preference by hybrid genotypes can lead to hybrid speciation. Natural selection may cause the fixation of advantageous alleles in the ecologically diverged hybrids, and the loci experiencing selection should exhibit a reduction in allelic diversity relative to neutral loci. Here, we analyzed patterns of genetic diversity at 59 microsatellite loci associated with expressed sequence tags (ESTs) in a homoploid hybrid sunflower species, Helianthus anomalus. We used two indices, ln RV and ln RH, to compare variation and heterozygosity (respectively) at each locus between the hybrid species and its two parental species, H. annuus and H. petiolaris. Mean values of ln RV and ln RH were significantly lower than zero, which implies that H. anomalus experienced a population bottleneck during its recent evolutionary history. After correcting for the apparent bottleneck, we found six loci with a significant reduction in variation or with heterozygosity in the hybrid species, compared to one or both of the parental species. These loci should be viewed as a ranked list of candidate loci, pending further sequencing and functional analyses. Sequence data were generated for two of the candidate loci, but population genetics tests failed to detect deviations from neutral evolution at either locus. Nonetheless, a greater than eight-fold excess of nonsynonymous substitutions was found near a putative N-myristoylation motif at the second locus (HT998), and likelihood-based models indicated that the protein has been under selection in H. anomalus in the past and, perhaps, in one or both parental species. Finally, our data suggest that selective sweeps may have united populations of H. anomalus isolated by a mountain range, indicating that even low gene-flow species may be held together by the spread of advantageous alleles. PMID:17944850

Simultaneous site-directed mutagenesis of duplicated loci in soybean using a single guide RNA.

PubMed

Kanazashi, Yuhei; Hirose, Aya; Takahashi, Ippei; Mikami, Masafumi; Endo, Masaki; Hirose, Sakiko; Toki, Seiichi; Kaga, Akito; Naito, Ken; Ishimoto, Masao; Abe, Jun; Yamada, Tetsuya

2018-03-01

Using a gRNA and Agrobacterium-mediated transformation, we performed simultaneous site-directed mutagenesis of two GmPPD loci in soybean. Mutations in GmPPD loci were confirmed in at least 33% of T 2 seeds. The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated endonuclease 9 (Cas9) system is a powerful tool for site-directed mutagenesis in crops. Using a single guide RNA (gRNA) and Agrobacterium-mediated transformation, we performed simultaneous site-directed mutagenesis of two homoeologous loci in soybean (Glycine max), GmPPD1 and GmPPD2, which encode the orthologs of Arabidopsis thaliana PEAPOD (PPD). Most of the T 1 plants had heterozygous and/or chimeric mutations for the targeted loci. The sequencing analysis of T 1 and T 2 generations indicates that putative mutation induced in the T 0 plant is transmitted to the T 1 generation. The inheritable mutation induced in the T 1 plant was also detected. This result indicates that continuous induction of mutations during T 1 plant development increases the occurrence of mutations in germ cells, which ensures the transmission of mutations to the next generation. Simultaneous site-directed mutagenesis in both GmPPD loci was confirmed in at least 33% of T 2 seeds examined. Approximately 19% of double mutants did not contain the Cas9/gRNA expression construct. Double mutants with frameshift mutations in both GmPPD1 and GmPPD2 had dome-shaped trifoliate leaves, extremely twisted pods, and produced few seeds. Taken together, our data indicate that continuous induction of mutations in the whole plant and advancing generations of transgenic plants enable efficient simultaneous site-directed mutagenesis in duplicated loci in soybean.

[Mutation Analysis of 19 STR Loci in 20 723 Cases of Paternity Testing].

PubMed

Bi, J; Chang, J J; Li, M X; Yu, C Y

2017-06-01

To observe and analyze the confirmed cases of paternity testing, and to explore the mutation rules of STR loci. The mutant STR loci were screened from 20 723 confirmed cases of paternity testing by Goldeneye 20A system．The mutation rates, and the sources, fragment length, steps and increased or decreased repeat sequences of mutant alleles were counted for the analysis of the characteristics of mutation-related factors. A total of 548 mutations were found on 19 STR loci, and 557 mutation events were observed. The loci mutation rate was 0.07‰-2.23‰. The ratio of paternal to maternal mutant events was 3.06:1. One step mutation was the main mutation, and the number of the increased repeat sequences was almost the same as the decreased repeat sequences. The repeat sequences were more likely to decrease in two steps mutation and above. Mutation mainly occurred in the medium allele, and the number of the increased repeat sequences was almost the same as the decreased repeat sequences. In long allele mutations, the decreased repeat sequences were significantly more than the increased repeat sequences. The number of the increased repeat sequences was almost the same as the decreased repeat sequences in paternal mutation, while the decreased repeat sequences were more than the increased in maternal mutation. There are significant differences in the mutation rate of each locus. When one or two loci do not conform to the genetic law, other detection system should be added, and PI value should be calculated combined with the information of the mutate STR loci in order to further clarify the identification opinions. Copyright© by the Editorial Department of Journal of Forensic Medicine

Sequence capture of ultraconserved elements from bird museum specimens.

PubMed

McCormack, John E; Tsai, Whitney L E; Faircloth, Brant C

2016-09-01

New DNA sequencing technologies are allowing researchers to explore the genomes of the millions of natural history specimens collected prior to the molecular era. Yet, we know little about how well specific next-generation sequencing (NGS) techniques work with the degraded DNA typically extracted from museum specimens. Here, we use one type of NGS approach, sequence capture of ultraconserved elements (UCEs), to collect data from bird museum specimens as old as 120 years. We targeted 5060 UCE loci in 27 western scrub-jays (Aphelocoma californica) representing three evolutionary lineages that could be species, and we collected an average of 3749 UCE loci containing 4460 single nucleotide polymorphisms (SNPs). Despite older specimens producing fewer and shorter loci in general, we collected thousands of markers from even the oldest specimens. More sequencing reads per individual helped to boost the number of UCE loci we recovered from older specimens, but more sequencing was not as successful at increasing the length of loci. We detected contamination in some samples and determined that contamination was more prevalent in older samples that were subject to less sequencing. For the phylogeny generated from concatenated UCE loci, contamination led to incorrect placement of some individuals. In contrast, a species tree constructed from SNPs called within UCE loci correctly placed individuals into three monophyletic groups, perhaps because of the stricter analytical procedures used for SNP calling. This study and other recent studies on the genomics of museum specimens have profound implications for natural history collections, where millions of older specimens should now be considered genomic resources. © 2015 The Authors. Molecular Ecology Resources Published by John Wiley & Sons Ltd.

LASER BIOLOGY AND MEDICINE: Combination of fluorescence imaging and local spectrophotometry in fluorescence diagnostics of early cancer of larynx and bronchi

NASA Astrophysics Data System (ADS)

Sokolov, Vladimir V.; Filonenko, E. V.; Telegina, L. V.; Boulgakova, N. N.; Smirnov, V. V.

2002-11-01

The results of comparative studies of autofluorescence and 5-ALA-induced fluorescence of protoporphyrin IX, used in the diagnostics of early cancer of larynx and bronchi, are presented. The autofluorescence and 5-ALA-induced fluorescence images of larynx and bronchial tissues are analysed during the endoscopic study. The method of local spectrophotometry is used to verify findings obtained from fluorescence images. It is shown that such a combined approach can be efficiently used to improve the diagnostics of precancer and early cancer, to detect a primary multiple tumours, as well as for the diagnostics of a residual tumour or an early recurrence after the endoscopic, surgery or X-ray treatment. The developed approach allows one to minimise the number of false-positive results and to reduce the number of biopsies, which are commonly used in the white-light bronchoscopy search for occult cancerous loci.

Genetics of autism spectrum disorders.

PubMed

Kumar, Ravinesh A; Christian, Susan L

2009-05-01

Autism spectrum disorders (ASDs) are a clinically complex group of childhood disorders that have firm evidence of an underlying genetic etiology. Many techniques have been used to characterize the genetic bases of ASDs. Linkage studies have identified several replicated susceptibility loci, including 2q24-2q31, 7q, and 17q11-17q21. Association studies and mutation analysis of candidate genes have implicated the synaptic genes NRXN1, NLGN3, NLGN4, SHANK3, and CNTNAP2 in ASDs. Traditional cytogenetic approaches highlight the high frequency of large chromosomal abnormalities (3%-7% of patients), including the most frequently observed maternal 15q11-13 duplications (1%-3% of patients). Newly developed techniques include high-resolution DNA microarray technologies, which have discovered formerly undetectable submicroscopic copy number variants, and genomewide association studies, which allow simultaneous detection of multiple genes associated with ASDs. Although great progress has been made in autism genetics, the molecular bases of most ASDs remains enigmatic.

Transposition of the maize transposable element Ac in barley (Hordeum vulgare L.).

PubMed

Scholz, S; Lörz, H; Lütticke, S

2001-01-01

Transposition of the maize autonomous element Ac (Activator) was investigated in barley (Hordeum vulgare L.) with the aim of developing a transposon tagging system for the latter. The Ac element was introduced into meristematic tissue of barley by microprojectile bombardment. Transposon activity was then examined in the resulting transgenic plants. Multiple excision events were detected in leaf tissue of all plant lines. The mobile elements generated empty donor sites with small DNA sequence alterations, similar to those found in maize. Reintegration of Ac at independent genomic loci in somatic tissue was demonstrated by isolation of new element-flanking regions by AIMS-PCR (amplification of insertion-mutagenized sites). In addition, transmission of transposed Ac elements to progeny plants was confirmed. The results indicate that the introduced Ac element is able to transpose in barley. This is a first step towards the establishment of a transposon tagging system in this economically important crop.

Development of microsatellite markers for Anadenanthera colubrina (Leguminosae), a neotropical tree species.

PubMed

Feres, Juliana Massimino; Monteiro, Mariza; Zucchi, Maria I; Pinheiro, José B; Mestriner, Moacyr A; Alzate-Marin, Ana Lilia

2012-04-01

We developed and characterized nuclear microsatellite markers for Anadenanthera colubrina, a tropical tree species widely distributed in South America. Leaf samples of mature A. colubrina trees, popularly called "angico," were collected from an area that is greatly impacted by agricultural practices in the region of Ribeirão Preto in São Paulo State in southeastern Brazil. Twenty simple sequence repeat (SSR) markers were developed, 14 of which had polymorphic loci. A total of 96 alleles were detected with an average of 6.86 alleles per polymorphic locus. The expected heterozygosity, calculated at polymorphic loci, ranged from 0.18 to 0.83. Finally, we demonstrated that 18 loci were cross-amplified in A. peregrina. A total of 14 polymorphic markers suggest a high potential for genetic diversity, gene flow, and mating system analyses in A. colubrina.

Identification of seven new prostate cancer susceptibility loci through a genome-wide association study

PubMed Central

Eeles, Rosalind A.; Kote-Jarai, Zsofia; Olama, Ali Amin Al; Giles, Graham G.; Guy, Michelle; Severi, Gianluca; Muir, Kenneth; Hopper, John L.; Henderson, Brian E.; Haiman, Christopher A.; Schleutker, Johanna; Hamdy, Freddie C.; Neal, David E.; Donovan, Jenny L.; Stanford, Janet L.; Ostrander, Elaine A.; Ingles, Sue A.; John, Esther M.; Thibodeau, Stephen N.; Schaid, Daniel; Park, Jong Y.; Spurdle, Amanda; Clements, Judith; Dickinson, Joanne L.; Maier, Christiane; Vogel, Walther; Dörk, Thilo; Rebbeck, Timothy R.; Cooney, Kathleen A.; Cannon-Albright, Lisa; Chappuis, Pierre O.; Hutter, Pierre; Zeegers, Maurice; Kaneva, Radka; Zhang, Hong-Wei; Lu, Yong-Jie; Foulkes, William D.; English, Dallas R.; Leongamornlert, Daniel A.; Tymrakiewicz, Malgorzata; Morrison, Jonathan; Ardern-Jones, Audrey T.; Hall, Amanda L.; O’Brien, Lynne T.; Wilkinson, Rosemary A.; Saunders, Edward J.; Page, Elizabeth C.; Sawyer, Emma J.; Edwards, Stephen M.; Dearnaley, David P.; Horwich, Alan; Huddart, Robert A.; Khoo, Vincent S.; Parker, Christopher C.; Van As, Nicholas; Woodhouse, Christopher J.; Thompson, Alan; Christmas, Tim; Ogden, Chris; Cooper, Colin S.; Southey, Melissa C.; Lophatananon, Artitaya; Liu, Jo-Fen; Kolonel, Laurence N.; Le Marchand, Loic; Wahlfors, Tiina; Tammela, Teuvo L.; Auvinen, Anssi; Lewis, Sarah J.; Cox, Angela; FitzGerald, Liesel M.; Koopmeiners, Joseph S.; Karyadi, Danielle M.; Kwon, Erika M.; Stern, Mariana C.; Corral, Roman; Joshi, Amit D.; Shahabi, Ahva; McDonnell, Shannon K.; Sellers, Thomas A; Pow-Sang, Julio; Chambers, Suzanne; Aitken, Joanne; Gardiner, R.A. (Frank); Batra, Jyotsna; Kedda, Mary Anne; Lose, Felicity; Polanowski, Andrea; Patterson, Briony; Serth, Jürgen; Meyer, Andreas; Luedeke, Manuel; Stefflova, Klara; Ray, Anna M.; Lange, Ethan M.; Farnham, Jim; Khan, Humera; Slavov, Chavdar; Mitkova, Atanaska; Cao, Guangwen; Easton, Douglas F.

2010-01-01

Prostate cancer (PrCa) is the most frequently diagnosed male cancer in developed countries. To identify common PrCa susceptibility alleles, we have previously conducted a genome-wide association study in which 541, 129 SNPs were genotyped in 1,854 PrCa cases with clinically detected disease and 1,894 controls. We have now evaluated promising associations in a second stage, in which we genotyped 43,671 SNPs in 3,650 PrCa cases and 3,940 controls, and a third stage, involving an additional 16,229 cases and 14,821 controls from 21 studies. In addition to previously identified loci, we identified a further seven new prostate cancer susceptibility loci on chromosomes 2, 4, 8, 11, and 22 (P=1.6×10−8 to P=2.7×10−33). PMID:19767753