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  1. Multilocus genotypic data reveal high genetic diversity and low population genetic structure of Iranian indigenous sheep.

    PubMed

    Vahidi, S M F; Faruque, M O; Falahati Anbaran, M; Afraz, F; Mousavi, S M; Boettcher, P; Joost, S; Han, J L; Colli, L; Periasamy, K; Negrini, R; Ajmone-Marsan, P

    2016-08-01

    Iranian livestock diversity is still largely unexplored, in spite of the interest in the populations historically reared in this country located near the Fertile Crescent, a major livestock domestication centre. In this investigation, the genetic diversity and differentiation of 10 Iranian indigenous fat-tailed sheep breeds were investigated using 18 microsatellite markers. Iranian breeds were found to host a high level of diversity. This conclusion is substantiated by the large number of alleles observed across loci (average 13.83, range 7-22) and by the high within-breed expected heterozygosity (average 0.75, range 0.72-0.76). Iranian sheep have a low level of genetic differentiation, as indicated by the analysis of molecular variance, which allocated a very small proportion (1.67%) of total variation to the between-population component, and by the small fixation index (FST  = 0.02). Both Bayesian clustering and principal coordinates analysis revealed the absence of a detectable genetic structure. Also, no isolation by distance was observed through comparison of genetic and geographical distances. In spite of high within-breed variation, signatures of inbreeding were detected by the FIS indices, which were positive in all and statistically significant in three breeds. Possible factors explaining the patterns observed, such as considerable gene flow and inbreeding probably due to anthropogenic activities in the light of population management and conservation programmes, are discussed. PMID:26953226

  2. Essay Contest Reveals Misconceptions of High School Students in Genetics Content

    PubMed Central

    Mills Shaw, Kenna R.; Van Horne, Katie; Zhang, Hubert; Boughman, Joann

    2008-01-01

    National educational organizations have called upon scientists to become involved in K–12 education reform. From sporadic interaction with students to more sustained partnerships with teachers, the engagement of scientists takes many forms. In this case, scientists from the American Society of Human Genetics (ASHG), the Genetics Society of America (GSA), and the National Society of Genetic Counselors (NSGC) have partnered to organize an essay contest for high school students as part of the activities surrounding National DNA Day. We describe a systematic analysis of 500 of 2443 total essays submitted in response to this contest over 2 years. Our analysis reveals the nature of student misconceptions in genetics, the possible sources of these misconceptions, and potential ways to galvanize genetics education. PMID:18245328

  3. Essay contest reveals misconceptions of high school students in genetics content.

    PubMed

    Mills Shaw, Kenna R; Van Horne, Katie; Zhang, Hubert; Boughman, Joann

    2008-03-01

    National educational organizations have called upon scientists to become involved in K-12 education reform. From sporadic interaction with students to more sustained partnerships with teachers, the engagement of scientists takes many forms. In this case, scientists from the American Society of Human Genetics (ASHG), the Genetics Society of America (GSA), and the National Society of Genetic Counselors (NSGC) have partnered to organize an essay contest for high school students as part of the activities surrounding National DNA Day. We describe a systematic analysis of 500 of 2443 total essays submitted in response to this contest over 2 years. Our analysis reveals the nature of student misconceptions in genetics, the possible sources of these misconceptions, and potential ways to galvanize genetics education. PMID:18245328

  4. Genetic analyses reveal unusually high diversity of infectious haematopoietic necrosis virus in rainbow trout aquaculture

    USGS Publications Warehouse

    Troyer, Ryan M.; LaPatra, Scott E.; Kurath, Gael

    2000-01-01

    Infectious haematopoietic necrosis virus (IHNV) is the most significant virus pathogen of salmon and trout in North America. Previous studies have shown relatively low genetic diversity of IHNV within large geographical regions. In this study, the genetic heterogeneity of 84 IHNV isolates sampled from rainbow trout (Oncorhynchus mykiss) over a 20 year period at four aquaculture facilities within a 12 mile stretch of the Snake River in Idaho, USA was investigated. The virus isolates were characterized using an RNase protection assay (RPA) and nucleotide sequence analyses. Among the 84 isolates analysed, 46 RPA haplotypes were found and analyses revealed a high level of genetic heterogeneity relative to that detected in other regions. Sequence analyses revealed up to 7·6% nucleotide divergence, which is the highest level of diversity reported for IHNV to date. Phylogenetic analyses identified four distinct monophyletic clades representing four virus lineages. These lineages were distributed across facilities, and individual facilities contained multiple lineages. These results suggest that co-circulating IHNV lineages of relatively high genetic diversity are present in the IHNV populations in this rainbow trout culture study site. Three of the four lineages exhibited temporal trends consistent with rapid evolution.

  5. High-dimensional variance partitioning reveals the modular genetic basis of adaptive divergence in gene expression during reproductive character displacement.

    PubMed

    McGraw, Elizabeth A; Ye, Yixin H; Foley, Brad; Chenoweth, Stephen F; Higgie, Megan; Hine, Emma; Blows, Mark W

    2011-11-01

    Although adaptive change is usually associated with complex changes in phenotype, few genetic investigations have been conducted on adaptations that involve sets of high-dimensional traits. Microarrays have supplied high-dimensional descriptions of gene expression, and phenotypic change resulting from adaptation often results in large-scale changes in gene expression. We demonstrate how genetic analysis of large-scale changes in gene expression generated during adaptation can be accomplished by determining high-dimensional variance partitioning within classical genetic experimental designs. A microarray experiment conducted on a panel of recombinant inbred lines (RILs) generated from two populations of Drosophila serrata that have diverged in response to natural selection, revealed genetic divergence in 10.6% of 3762 gene products examined. Over 97% of the genetic divergence in transcript abundance was explained by only 12 genetic modules. The two most important modules, explaining 50% of the genetic variance in transcript abundance, were genetically correlated with the morphological traits that are known to be under selection. The expression of three candidate genes from these two important genetic modules was assessed in an independent experiment using qRT-PCR on 430 individuals from the panel of RILs, and confirmed the genetic association between transcript abundance and morphological traits under selection. PMID:22023580

  6. High Resolution Genomic Scans Reveal Genetic Architecture Controlling Alcohol Preference in Bidirectionally Selected Rat Model.

    PubMed

    Lo, Chiao-Ling; Lossie, Amy C; Liang, Tiebing; Liu, Yunlong; Xuei, Xiaoling; Lumeng, Lawrence; Zhou, Feng C; Muir, William M

    2016-08-01

    Investigations on the influence of nature vs. nurture on Alcoholism (Alcohol Use Disorder) in human have yet to provide a clear view on potential genomic etiologies. To address this issue, we sequenced a replicated animal model system bidirectionally-selected for alcohol preference (AP). This model is uniquely suited to map genetic effects with high reproducibility, and resolution. The origin of the rat lines (an 8-way cross) resulted in small haplotype blocks (HB) with a corresponding high level of resolution. We sequenced DNAs from 40 samples (10 per line of each replicate) to determine allele frequencies and HB. We achieved ~46X coverage per line and replicate. Excessive differentiation in the genomic architecture between lines, across replicates, termed signatures of selection (SS), were classified according to gene and region. We identified SS in 930 genes associated with AP. The majority (50%) of the SS were confined to single gene regions, the greatest numbers of which were in promoters (284) and intronic regions (169) with the least in exon's (4), suggesting that differences in AP were primarily due to alterations in regulatory regions. We confirmed previously identified genes and found many new genes associated with AP. Of those newly identified genes, several demonstrated neuronal function involved in synaptic memory and reward behavior, e.g. ion channels (Kcnf1, Kcnn3, Scn5a), excitatory receptors (Grin2a, Gria3, Grip1), neurotransmitters (Pomc), and synapses (Snap29). This study not only reveals the polygenic architecture of AP, but also emphasizes the importance of regulatory elements, consistent with other complex traits. PMID:27490364

  7. High Resolution Genomic Scans Reveal Genetic Architecture Controlling Alcohol Preference in Bidirectionally Selected Rat Model

    PubMed Central

    Lo, Chiao-Ling; Liang, Tiebing; Liu, Yunlong; Lumeng, Lawrence; Zhou, Feng C.; Muir, William M.

    2016-01-01

    Investigations on the influence of nature vs. nurture on Alcoholism (Alcohol Use Disorder) in human have yet to provide a clear view on potential genomic etiologies. To address this issue, we sequenced a replicated animal model system bidirectionally-selected for alcohol preference (AP). This model is uniquely suited to map genetic effects with high reproducibility, and resolution. The origin of the rat lines (an 8-way cross) resulted in small haplotype blocks (HB) with a corresponding high level of resolution. We sequenced DNAs from 40 samples (10 per line of each replicate) to determine allele frequencies and HB. We achieved ~46X coverage per line and replicate. Excessive differentiation in the genomic architecture between lines, across replicates, termed signatures of selection (SS), were classified according to gene and region. We identified SS in 930 genes associated with AP. The majority (50%) of the SS were confined to single gene regions, the greatest numbers of which were in promoters (284) and intronic regions (169) with the least in exon's (4), suggesting that differences in AP were primarily due to alterations in regulatory regions. We confirmed previously identified genes and found many new genes associated with AP. Of those newly identified genes, several demonstrated neuronal function involved in synaptic memory and reward behavior, e.g. ion channels (Kcnf1, Kcnn3, Scn5a), excitatory receptors (Grin2a, Gria3, Grip1), neurotransmitters (Pomc), and synapses (Snap29). This study not only reveals the polygenic architecture of AP, but also emphasizes the importance of regulatory elements, consistent with other complex traits. PMID:27490364

  8. Ladakh, India: the land of high passes and genetic heterogeneity reveals a confluence of migrations.

    PubMed

    Rowold, Diane J; Perez Benedico, David; Garcia-Bertrand, Ralph; Chennakrishnaiah, Shilpa; Alfonso-Sanchez, Miguel A; Gayden, Tenzin; Herrera, Rene J

    2016-03-01

    Owing to its geographic location near the longitudinal center of Asia, Ladakh, the land of high passes, has witnessed numerous demographic movements during the past millenniums of occupation. In an effort to view Ladakh's multicultural history from a paternal genetic perspective, we performed a high-resolution Y-chromosomal survey of Ladakh, within the context of Y haplogroup and haplotype distributions of 41 Asian reference populations. The results of this investigation highlight the rich ethnic and genetic diversity of Ladkah which includes genetic contributions from disparate regions of the continent including, West, East, South and Central Asia. The phylogenetic signals from Ladakh are consistent with the Indo-Aryans' occupation during the Neolithic age and its historic connection with Tibet, as well as the East-West gene flow associated with the Silk Road. PMID:25966630

  9. Analysis of STR markers reveals high genetic structure in Portuguese native cattle.

    PubMed

    Ginja, Catarina; Telo Da Gama, Luís; Penedo, Maria Cecilia T

    2010-01-01

    Genetic structure and diversity of 13 Portuguese native and 3 imported cattle breeds were assessed with 39 microsatellites. Allelic richness per locus was high, with an overall average of 8.3 +/- 2.5. The mean observed and expected heterozygosities were 0.673 +/- 0.043 and 0.691 +/- 0.034, respectively. The mean number of alleles per breed ranged between 5.36 +/- 1.27 and 7.87 +/- 2.66. Brava de Lide and Mirandesa breeds had the lowest genetic diversity, whereas Minhota, Arouquesa, and Mertolenga had the highest. Significant (P < 0.05) heterozygote deficit was detected in all breeds except Garvonesa, Marinhoa, Minhota, and Limousin. Hardy-Weinberg deviations are most probably due to inbreeding, particularly in Alentejana, Brava de Lide, Mertolenga, and Ramo Grande (F(is) > 0, P < 0.0001). Based on the principal component and the Neighbor-Net analyses, Mirandesa was the most genetically distinct breed. Even though admixture was detected across all breeds (6.7%, q < 0.800), the molecular structure was consistent with original breed designations, with the exception of Cachena that had a clear influence of Barrosã (K = 15). Mertolenga showed substructure with independent clustering of red speckled animals. The percentage animals correctly assigned was >or=90 in all breeds except Cachena, Garvonesa, and Preta (q >or= 0.800). The results obtained here confirmed that high levels of genetic diversity exist within Portuguese native cattle and that the breeds are highly structured. Conservation measures should be implemented for all native breeds to minimize inbreeding. PMID:19965912

  10. Multivariate genetic analysis of plant responses to water deficit and high temperature revealed contrasting adaptive strategies.

    PubMed

    Vasseur, François; Bontpart, Thibaut; Dauzat, Myriam; Granier, Christine; Vile, Denis

    2014-12-01

    How genetic factors control plant performance under stressful environmental conditions is a central question in ecology and for crop breeding. A multivariate framework was developed to examine the genetic architecture of performance-related traits in response to interacting environmental stresses. Ecophysiological and life history traits were quantified in the Arabidopsis thaliana Ler × Cvi mapping population exposed to constant soil water deficit and high air temperature. The plasticity of the genetic variance-covariance matrix (G-matrix) was examined using mixed-effects models after regression into principal components. Quantitative trait locus (QTL) analysis was performed on the predictors of genotype effects and genotype by environment interactions (G × E). Three QTLs previously identified for flowering time had antagonistic G × E effects on carbon acquisition and the other traits (phenology, growth, leaf morphology, and transpiration). This resulted in a size-dependent response of water use efficiency (WUE) to high temperature but not soil water deficit, indicating that most of the plasticity of carbon acquisition and WUE to temperature is controlled by the loci that control variation of development, size, growth, and transpiration. A fourth QTL, MSAT2.22, controlled the response of carbon acquisition to specific combinations of watering and temperature irrespective of plant size and development, growth, and transpiration rate, which resulted in size-independent plasticity of WUE. These findings highlight how the strategies to optimize plant performance may differ in response to water deficit and high temperature (or their combination), and how different G × E effects could be targeted to improve plant tolerance to these stresses. PMID:25246443

  11. Multilocus sequence analysis of nectar pseudomonads reveals high genetic diversity and contrasting recombination patterns.

    PubMed

    Alvarez-Pérez, Sergio; de Vega, Clara; Herrera, Carlos M

    2013-01-01

    The genetic and evolutionary relationships among floral nectar-dwelling Pseudomonas 'sensu stricto' isolates associated to South African and Mediterranean plants were investigated by multilocus sequence analysis (MLSA) of four core housekeeping genes (rrs, gyrB, rpoB and rpoD). A total of 35 different sequence types were found for the 38 nectar bacterial isolates characterised. Phylogenetic analyses resulted in the identification of three main clades [nectar groups (NGs) 1, 2 and 3] of nectar pseudomonads, which were closely related to five intrageneric groups: Pseudomonas oryzihabitans (NG 1); P. fluorescens, P. lutea and P. syringae (NG 2); and P. rhizosphaerae (NG 3). Linkage disequilibrium analysis pointed to a mostly clonal population structure, even when the analysis was restricted to isolates from the same floristic region or belonging to the same NG. Nevertheless, signatures of recombination were observed for NG 3, which exclusively included isolates retrieved from the floral nectar of insect-pollinated Mediterranean plants. In contrast, the other two NGs comprised both South African and Mediterranean isolates. Analyses relating diversification to floristic region and pollinator type revealed that there has been more unique evolution of the nectar pseudomonads within the Mediterranean region than would be expected by chance. This is the first work analysing the sequence of multiple loci to reveal geno- and ecotypes of nectar bacteria. PMID:24116076

  12. Multilocus Sequence Analysis of Nectar Pseudomonads Reveals High Genetic Diversity and Contrasting Recombination Patterns

    PubMed Central

    Álvarez-Pérez, Sergio; de Vega, Clara; Herrera, Carlos M.

    2013-01-01

    The genetic and evolutionary relationships among floral nectar-dwelling Pseudomonas ‘sensu stricto’ isolates associated to South African and Mediterranean plants were investigated by multilocus sequence analysis (MLSA) of four core housekeeping genes (rrs, gyrB, rpoB and rpoD). A total of 35 different sequence types were found for the 38 nectar bacterial isolates characterised. Phylogenetic analyses resulted in the identification of three main clades [nectar groups (NGs) 1, 2 and 3] of nectar pseudomonads, which were closely related to five intrageneric groups: Pseudomonas oryzihabitans (NG 1); P. fluorescens, P. lutea and P. syringae (NG 2); and P. rhizosphaerae (NG 3). Linkage disequilibrium analysis pointed to a mostly clonal population structure, even when the analysis was restricted to isolates from the same floristic region or belonging to the same NG. Nevertheless, signatures of recombination were observed for NG 3, which exclusively included isolates retrieved from the floral nectar of insect-pollinated Mediterranean plants. In contrast, the other two NGs comprised both South African and Mediterranean isolates. Analyses relating diversification to floristic region and pollinator type revealed that there has been more unique evolution of the nectar pseudomonads within the Mediterranean region than would be expected by chance. This is the first work analysing the sequence of multiple loci to reveal geno- and ecotypes of nectar bacteria. PMID:24116076

  13. Mark-recapture using tetracycline and genetics reveal record-high bear density

    USGS Publications Warehouse

    Peacock, E.; Titus, K.; Garshelis, D.L.; Peacock, M.M.; Kuc, M.

    2011-01-01

    We used tetracycline biomarking, augmented with genetic methods to estimate the size of an American black bear (Ursus americanus) population on an island in Southeast Alaska. We marked 132 and 189 bears that consumed remote, tetracycline-laced baits in 2 different years, respectively, and observed 39 marks in 692 bone samples subsequently collected from hunters. We genetically analyzed hair samples from bait sites to determine the sex of marked bears, facilitating derivation of sex-specific population estimates. We obtained harvest samples from beyond the study area to correct for emigration. We estimated a density of 155 independent bears/100 km2, which is equivalent to the highest recorded for this species. This high density appears to be maintained by abundant, accessible natural food. Our population estimate (approx. 1,000 bears) could be used as a baseline and to set hunting quotas. The refined biomarking method for abundance estimation is a useful alternative where physical captures or DNA-based estimates are precluded by cost or logistics. Copyright ?? 2011 The Wildlife Society.

  14. High-resolution mapping reveals hundreds of genetic incompatibilities in hybridizing fish species

    PubMed Central

    Schumer, Molly; Cui, Rongfeng; Powell, Daniel L; Dresner, Rebecca; Rosenthal, Gil G; Andolfatto, Peter

    2014-01-01

    Hybridization is increasingly being recognized as a common process in both animal and plant species. Negative epistatic interactions between genes from different parental genomes decrease the fitness of hybrids and can limit gene flow between species. However, little is known about the number and genome-wide distribution of genetic incompatibilities separating species. To detect interacting genes, we perform a high-resolution genome scan for linkage disequilibrium between unlinked genomic regions in naturally occurring hybrid populations of swordtail fish. We estimate that hundreds of pairs of genomic regions contribute to reproductive isolation between these species, despite them being recently diverged. Many of these incompatibilities are likely the result of natural or sexual selection on hybrids, since intrinsic isolation is known to be weak. Patterns of genomic divergence at these regions imply that genetic incompatibilities play a significant role in limiting gene flow even in young species. DOI: http://dx.doi.org/10.7554/eLife.02535.001 PMID:24898754

  15. Mosquito Surveillance for 15 Years Reveals High Genetic Diversity Among West Nile Viruses in Israel.

    PubMed

    Lustig, Yaniv; Hindiyeh, Musa; Orshan, Laor; Weiss, Leah; Koren, Ravit; Katz-Likvornik, Shiri; Zadka, Hila; Glatman-Freedman, Aharona; Mendelson, Ella; Shulman, Lester M

    2016-04-01

    West Nile Virus (WNV) is endemic in Israel and has been the cause of several outbreaks in recent years. In 2000, a countrywide mosquito survey was established to monitor WNV activity and characterize viral genotypes in Israel. We analyzed data from 7135 pools containing 277 186 mosquitoes collected over the past 15 years and, here, report partial sequences of WNV genomes obtained from 102 of the 336 positive mosquito pools. Phylogenetic analysis demonstrated that cluster 4 and the Mediterranean and Eastern European subtypes of cluster 2 within WNV lineage 1 circulated in Israel, as did WNV lineage 2, highlighting a high genetic diversity of WNV genotypes in our region. As a major crossroads for bird migration between Africa and Eurasia and with a long history of human infection, Israel serves as a resource hub for WNV in Africa and Eurasia and provides valuable information on WNV circulation in these regions. PMID:26597260

  16. High Resolution Genetic Mapping by Genome Sequencing Reveals Genome Duplication and Tetraploid Genetic Structure of the Diploid Miscanthus sinensis

    PubMed Central

    Ma, Xue-Feng; Jensen, Elaine; Alexandrov, Nickolai; Troukhan, Maxim; Zhang, Liping; Thomas-Jones, Sian; Farrar, Kerrie; Clifton-Brown, John; Donnison, Iain; Swaller, Timothy; Flavell, Richard

    2012-01-01

    We have created a high-resolution linkage map of Miscanthus sinensis, using genotyping-by-sequencing (GBS), identifying all 19 linkage groups for the first time. The result is technically significant since Miscanthus has a very large and highly heterozygous genome, but has no or limited genomics information to date. The composite linkage map containing markers from both parental linkage maps is composed of 3,745 SNP markers spanning 2,396 cM on 19 linkage groups with a 0.64 cM average resolution. Comparative genomics analyses of the M. sinensis composite linkage map to the genomes of sorghum, maize, rice, and Brachypodium distachyon indicate that sorghum has the closest syntenic relationship to Miscanthus compared to other species. The comparative results revealed that each pair of the 19 M. sinensis linkages aligned to one sorghum chromosome, except for LG8, which mapped to two sorghum chromosomes (4 and 7), presumably due to a chromosome fusion event after genome duplication. The data also revealed several other chromosome rearrangements relative to sorghum, including two telomere-centromere inversions of the sorghum syntenic chromosome 7 in LG8 of M. sinensis and two paracentric inversions of sorghum syntenic chromosome 4 in LG7 and LG8 of M. sinensis. The results clearly demonstrate, for the first time, that the diploid M. sinensis is tetraploid origin consisting of two sub-genomes. This complete and high resolution composite linkage map will not only serve as a useful resource for novel QTL discoveries, but also enable informed deployment of the wealth of existing genomics resources of other species to the improvement of Miscanthus as a high biomass energy crop. In addition, it has utility as a reference for genome sequence assembly for the forthcoming whole genome sequencing of the Miscanthus genus. PMID:22439001

  17. High resolution genetic mapping by genome sequencing reveals genome duplication and tetraploid genetic structure of the diploid Miscanthus sinensis.

    PubMed

    Ma, Xue-Feng; Jensen, Elaine; Alexandrov, Nickolai; Troukhan, Maxim; Zhang, Liping; Thomas-Jones, Sian; Farrar, Kerrie; Clifton-Brown, John; Donnison, Iain; Swaller, Timothy; Flavell, Richard

    2012-01-01

    We have created a high-resolution linkage map of Miscanthus sinensis, using genotyping-by-sequencing (GBS), identifying all 19 linkage groups for the first time. The result is technically significant since Miscanthus has a very large and highly heterozygous genome, but has no or limited genomics information to date. The composite linkage map containing markers from both parental linkage maps is composed of 3,745 SNP markers spanning 2,396 cM on 19 linkage groups with a 0.64 cM average resolution. Comparative genomics analyses of the M. sinensis composite linkage map to the genomes of sorghum, maize, rice, and Brachypodium distachyon indicate that sorghum has the closest syntenic relationship to Miscanthus compared to other species. The comparative results revealed that each pair of the 19 M. sinensis linkages aligned to one sorghum chromosome, except for LG8, which mapped to two sorghum chromosomes (4 and 7), presumably due to a chromosome fusion event after genome duplication. The data also revealed several other chromosome rearrangements relative to sorghum, including two telomere-centromere inversions of the sorghum syntenic chromosome 7 in LG8 of M. sinensis and two paracentric inversions of sorghum syntenic chromosome 4 in LG7 and LG8 of M. sinensis. The results clearly demonstrate, for the first time, that the diploid M. sinensis is tetraploid origin consisting of two sub-genomes. This complete and high resolution composite linkage map will not only serve as a useful resource for novel QTL discoveries, but also enable informed deployment of the wealth of existing genomics resources of other species to the improvement of Miscanthus as a high biomass energy crop. In addition, it has utility as a reference for genome sequence assembly for the forthcoming whole genome sequencing of the Miscanthus genus. PMID:22439001

  18. Molecular genetic variation in cultivated peanut cultivars and breeding lines revealed by highly informative SSR markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Groundnut or peanut (Arachis hypogaea L.) is an economically important crop worldwide as a source of protein and cooking oil, particularly in developing countries. Because of its narrow genetic background and shortage of polymorphic genetic markers, molecular characterization of cultivated peanuts e...

  19. Artificial Selection Reveals High Genetic Variation in Phenology at the Trailing Edge of a Species Range.

    PubMed

    Sheth, Seema Nayan; Angert, Amy Lauren

    2016-02-01

    Species responses to climate change depend on the interplay of migration and adaptation, yet we know relatively little about the potential for adaptation. Genetic adaptations to climate change often involve shifts in the timing of phenological events, such as flowering. If populations at the edge of a species range have lower genetic variation in phenological traits than central populations, then their persistence under climate change could be threatened. To test this hypothesis, we performed artificial selection experiments using the scarlet monkeyflower (Mimulus cardinalis) and compared genetic variation in flowering time among populations at the latitudinal center, northern edge, and southern edge of the species range. We also assessed whether selection on flowering time yielded correlated responses in functional traits, potentially representing a cost associated with early or late flowering. Contrary to prediction, southern populations exhibited greater responses to selection on flowering time than central or northern populations. Further, selection for early flowering resulted in correlated increases in specific leaf area and leaf nitrogen, whereas selection for late flowering led to decreases in these traits. These results provide critical insights about how spatial variation in the potential for adaptation may affect population persistence under changing climates. PMID:26807746

  20. Genetic map of the human pseudoautosomal region reveals a high rate of recombination in female meiosis at the Xp telomere

    SciTech Connect

    Henke, A.; Fischer, C.; Rappold, G.A. )

    1993-12-01

    This paper describes the genetic map of the pseudoautosomal region bounded by the telomere of the short arms of the X and Y chromosomes. In males, meiotic exchange on Xp/Yp is confined to this region, leading to highly elevated recombination rates. The map was constructed using 11 pseudoautosomal probes (six of which are new) and typing individuals from 38 CEPH families. All markers have been physically mapped, thus providing the opportunity to compare genetic distance to physical distance through all intervals of the map. This comparison reveals an unexpected high rate of recombination in female meiosis between loci DXYS20 and DXYS78, within 20-80 kb from the telomere. Within this telemore-adjacent region no differences in male and female recombination rates are seen. Furthermore, data from this genetic map support the hypothesis of a linear gradient of recombination across most of the region in male meiosis and provide densely spaced anchor points for linkage studies especially in the telomeric portion of the pseudoautosomal region. 34 refs., 4 figs., 4 tabs.

  1. Exome sequencing reveals a high genetic heterogeneity on familial Hirschsprung disease.

    PubMed

    Luzón-Toro, Berta; Gui, Hongsheng; Ruiz-Ferrer, Macarena; Sze-Man Tang, Clara; Fernández, Raquel M; Sham, Pak-Chung; Torroglosa, Ana; Kwong-Hang Tam, Paul; Espino-Paisán, Laura; Cherny, Stacey S; Bleda, Marta; Enguix-Riego, María Del Valle; Dopazo, Joaquín; Antiñolo, Guillermo; García-Barceló, María-Mercé; Borrego, Salud

    2015-01-01

    Hirschsprung disease (HSCR; OMIM 142623) is a developmental disorder characterized by aganglionosis along variable lengths of the distal gastrointestinal tract, which results in intestinal obstruction. Interactions among known HSCR genes and/or unknown disease susceptibility loci lead to variable severity of phenotype. Neither linkage nor genome-wide association studies have efficiently contributed to completely dissect the genetic pathways underlying this complex genetic disorder. We have performed whole exome sequencing of 16 HSCR patients from 8 unrelated families with SOLID platform. Variants shared by affected relatives were validated by Sanger sequencing. We searched for genes recurrently mutated across families. Only variations in the FAT3 gene were significantly enriched in five families. Within-family analysis identified compound heterozygotes for AHNAK and several genes (N = 23) with heterozygous variants that co-segregated with the phenotype. Network and pathway analyses facilitated the discovery of polygenic inheritance involving FAT3, HSCR known genes and their gene partners. Altogether, our approach has facilitated the detection of more than one damaging variant in biologically plausible genes that could jointly contribute to the phenotype. Our data may contribute to the understanding of the complex interactions that occur during enteric nervous system development and the etiopathology of familial HSCR. PMID:26559152

  2. Exome sequencing reveals a high genetic heterogeneity on familial Hirschsprung disease

    PubMed Central

    Luzón-Toro, Berta; Gui, Hongsheng; Ruiz-Ferrer, Macarena; Sze-Man Tang, Clara; Fernández, Raquel M.; Sham, Pak-Chung; Torroglosa, Ana; Kwong-Hang Tam, Paul; Espino-Paisán, Laura; Cherny, Stacey S.; Bleda, Marta; Enguix-Riego, María del Valle; Dopazo, Joaquín; Antiñolo, Guillermo; García-Barceló, María-Mercé; Borrego, Salud

    2015-01-01

    Hirschsprung disease (HSCR; OMIM 142623) is a developmental disorder characterized by aganglionosis along variable lengths of the distal gastrointestinal tract, which results in intestinal obstruction. Interactions among known HSCR genes and/or unknown disease susceptibility loci lead to variable severity of phenotype. Neither linkage nor genome-wide association studies have efficiently contributed to completely dissect the genetic pathways underlying this complex genetic disorder. We have performed whole exome sequencing of 16 HSCR patients from 8 unrelated families with SOLID platform. Variants shared by affected relatives were validated by Sanger sequencing. We searched for genes recurrently mutated across families. Only variations in the FAT3 gene were significantly enriched in five families. Within-family analysis identified compound heterozygotes for AHNAK and several genes (N = 23) with heterozygous variants that co-segregated with the phenotype. Network and pathway analyses facilitated the discovery of polygenic inheritance involving FAT3, HSCR known genes and their gene partners. Altogether, our approach has facilitated the detection of more than one damaging variant in biologically plausible genes that could jointly contribute to the phenotype. Our data may contribute to the understanding of the complex interactions that occur during enteric nervous system development and the etiopathology of familial HSCR. PMID:26559152

  3. Genetic analysis of long-lived families reveals novel variants influencing high density-lipoprotein cholesterol

    PubMed Central

    Feitosa, Mary F.; Wojczynski, Mary K.; Straka, Robert; Kammerer, Candace M.; Lee, Joseph H.; Kraja, Aldi T.; Christensen, Kaare; Newman, Anne B.; Province, Michael A.; Borecki, Ingrid B.

    2014-01-01

    The plasma levels of high-density lipoprotein cholesterol (HDL) have an inverse relationship to the risks of atherosclerosis and cardiovascular disease (CVD), and have also been associated with longevity. We sought to identify novel loci for HDL that could potentially provide new insights into biological regulation of HDL metabolism in healthy-longevous subjects. We performed a genome-wide association (GWA) scan on HDL using a mixed model approach to account for family structure using kinship coefficients. A total of 4114 subjects of European descent (480 families) were genotyped at ~2.3 million SNPs and ~38 million SNPs were imputed using the 1000 Genome Cosmopolitan reference panel in MACH. We identified novel variants near-NLRP1 (17p13) associated with an increase of HDL levels at genome-wide significant level (p < 5.0E-08). Additionally, several CETP (16q21) and ZNF259-APOA5-A4-C3-A1 (11q23.3) variants associated with HDL were found, replicating those previously reported in the literature. A possible regulatory variant upstream of NLRP1 that is associated with HDL in these elderly Long Life Family Study (LLFS) subjects may also contribute to their longevity and health. Our NLRP1 intergenic SNPs show a potential regulatory function in Encyclopedia of DNA Elements (ENCODE); however, it is not clear whether they regulate NLRP1 or other more remote gene. NLRP1 plays an important role in the induction of apoptosis, and its inflammasome is critical for mediating innate immune responses. Nlrp1a (a mouse ortholog of human NLRP1) interacts with SREBP-1a (17p11) which has a fundamental role in lipid concentration and composition, and is involved in innate immune response in macrophages. The NLRP1 region is conserved in mammals, but also has evolved adaptively showing signals of positive selection in European populations that might confer an advantage. NLRP1 intergenic SNPs have also been associated with immunity/inflammasome disorders which highlights the biological

  4. Chromosome rearrangements during domestication of cucumber as revealed from high-density genetic mapping and draft genome assembly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cucumber is an economically important vegetable crop, but available genetic and genomics resources for cucumber are limited that hinders progress in cucumber breeding. In this study, we made significant contributions to the cucumber research community by developing a high-density genetic map for cul...

  5. A Genetic Relationship between Phosphorus Efficiency and Photosynthetic Traits in Soybean As Revealed by QTL Analysis Using a High-Density Genetic Map

    PubMed Central

    Li, Hongyan; Yang, Yuming; Zhang, Hengyou; Chu, Shanshan; Zhang, Xingguo; Yin, Dongmei; Yu, Deyue; Zhang, Dan

    2016-01-01

    Plant productivity relies on photosynthesis, and the photosynthetic process relies on phosphorus (P). The genetic basis of photosynthesis and P efficiency (PE) affecting yield has been separately characterized in various crop plants. However, the genetic relationship between PE and photosynthesis remains to be elucidated. In this study, we used a combined analysis of phenotypic correlation, linkage mapping, and expression analysis to dissect the relationship between PE and photosynthesis. We found significant phenotypic correlations between PE and photosynthetic related traits, particularly under low P stress. A total of 172 QTLs for both traits were detected and classified into 29 genomic regions. 12 (41.4%) of 29 regions were detected to be associated with both PE and photosynthetic related traits. Three major QTLs, q14-2, q15-2, and q19-2, were found to be associated with both traits and explained 6.6–58.9% of phenotypic variation. A photosynthetic-specific QTL cluster, q12-1, was detected under both normal and low P conditions, suggesting that genes responsible for this region were less effected by low P stress, and could be used in high photosynthetic efficiency breeding programs. In addition, several candidate genes with significantly differential expression upon low P stress, such as a purple acid phosphatase gene (Glyma.19G193900) within q19-2 region, were considered as promising candidates involved in regulating both soybean PE and photosynthetic capacity. Our results reveal a significant genetic relationship between PE and photosynthetic traits, and uncover several major genomic regions specific or common to these traits. The markers linked closely to these major QTLs may be used for selection of soybean varieties with improved P efficiency and photosynthetic capacity. PMID:27446154

  6. A Genetic Relationship between Phosphorus Efficiency and Photosynthetic Traits in Soybean As Revealed by QTL Analysis Using a High-Density Genetic Map.

    PubMed

    Li, Hongyan; Yang, Yuming; Zhang, Hengyou; Chu, Shanshan; Zhang, Xingguo; Yin, Dongmei; Yu, Deyue; Zhang, Dan

    2016-01-01

    Plant productivity relies on photosynthesis, and the photosynthetic process relies on phosphorus (P). The genetic basis of photosynthesis and P efficiency (PE) affecting yield has been separately characterized in various crop plants. However, the genetic relationship between PE and photosynthesis remains to be elucidated. In this study, we used a combined analysis of phenotypic correlation, linkage mapping, and expression analysis to dissect the relationship between PE and photosynthesis. We found significant phenotypic correlations between PE and photosynthetic related traits, particularly under low P stress. A total of 172 QTLs for both traits were detected and classified into 29 genomic regions. 12 (41.4%) of 29 regions were detected to be associated with both PE and photosynthetic related traits. Three major QTLs, q14-2, q15-2, and q19-2, were found to be associated with both traits and explained 6.6-58.9% of phenotypic variation. A photosynthetic-specific QTL cluster, q12-1, was detected under both normal and low P conditions, suggesting that genes responsible for this region were less effected by low P stress, and could be used in high photosynthetic efficiency breeding programs. In addition, several candidate genes with significantly differential expression upon low P stress, such as a purple acid phosphatase gene (Glyma.19G193900) within q19-2 region, were considered as promising candidates involved in regulating both soybean PE and photosynthetic capacity. Our results reveal a significant genetic relationship between PE and photosynthetic traits, and uncover several major genomic regions specific or common to these traits. The markers linked closely to these major QTLs may be used for selection of soybean varieties with improved P efficiency and photosynthetic capacity. PMID:27446154

  7. AFLP analysis reveals high genetic diversity but low population structure in Coccidioides posadasii isolates from Mexico and Argentina

    PubMed Central

    2013-01-01

    Background Coccidioides immitis and C. posadasii cause coccidioidomycosis, a disease that is endemic to North and South America, but for Central America, the incidence of coccidioidomycosis has not been clearly established. Several studies suggest genetic variability in these fungi; however, little definitive information has been discovered about the variability of Coccidioides fungi in Mexico (MX) and Argentina (AR). Thus, the goals for this work were to study 32 Coccidioides spp. isolates from MX and AR, identify the species of these Coccidioides spp. isolates, analyse their phenotypic variability, examine their genetic variability and investigate the Coccidioides reproductive system and its level of genetic differentiation. Methods Coccidioides spp. isolates from MX and AR were taxonomically identified by phylogenetic inference analysis using partial sequences of the Ag2/PRA gene and their phenotypic characteristics analysed. The genetic variability, reproductive system and level of differentiation were estimated using AFLP markers. The level of genetic variability was assessed measuring the percentage of polymorphic loci, number of effective allele, expected heterocygosity and Index of Association (IA). The degree of genetic differentiation was determined by AMOVA. Genetic similarities among isolates were estimated using Jaccard index. The UPGMA was used to contsruct the corresponding dendrogram. Finally, a network of haplotypes was built to evaluate the genealogical relationships among AFLP haplotypes. Results All isolates of Coccidioides spp. from MX and AR were identified as C. posadasii. No phenotypic variability was observed among the C. posadasii isolates from MX and AR. Analyses of genetic diversity and population structure were conducted using AFLP markers. Different estimators of genetic variability indicated that the C. posadasii isolates from MX and AR had high genetic variability. Furthermore, AMOVA, dendrogram and haplotype network showed a small

  8. Distinct and diverse: range-wide phylogeography reveals ancient lineages and high genetic variation in the endangered okapi (Okapia johnstoni).

    PubMed

    Stanton, David W G; Hart, John; Galbusera, Peter; Helsen, Philippe; Shephard, Jill; Kümpel, Noëlle F; Wang, Jinliang; Ewen, John G; Bruford, Michael W

    2014-01-01

    The okapi is an endangered, evolutionarily distinctive even-toed ungulate classified within the giraffidae family that is endemic to the Democratic Republic of Congo. The okapi is currently under major anthropogenic threat, yet to date nothing is known about its genetic structure and evolutionary history, information important for conservation management given the species' current plight. The distribution of the okapi, being confined to the Congo Basin and yet spanning the Congo River, also makes it an important species for testing general biogeographic hypotheses for Congo Basin fauna, a currently understudied area of research. Here we describe the evolutionary history and genetic structure of okapi, in the context of other African ungulates including the giraffe, and use this information to shed light on the biogeographic history of Congo Basin fauna in general. Using nuclear and mitochondrial DNA sequence analysis of mainly non-invasively collected samples, we show that the okapi is both highly genetically distinct and highly genetically diverse, an unusual combination of genetic traits for an endangered species, and feature a complex evolutionary history. Genetic data are consistent with repeated climatic cycles leading to multiple Plio-Pleistocene refugia in isolated forests in the Congo catchment but also imply historic gene flow across the Congo River. PMID:25007188

  9. Distinct and Diverse: Range-Wide Phylogeography Reveals Ancient Lineages and High Genetic Variation in the Endangered Okapi (Okapia johnstoni)

    PubMed Central

    Stanton, David W. G.; Hart, John; Galbusera, Peter; Helsen, Philippe; Shephard, Jill; Kümpel, Noëlle F.; Wang, Jinliang; Ewen, John G.; Bruford, Michael W.

    2014-01-01

    The okapi is an endangered, evolutionarily distinctive even-toed ungulate classified within the giraffidae family that is endemic to the Democratic Republic of Congo. The okapi is currently under major anthropogenic threat, yet to date nothing is known about its genetic structure and evolutionary history, information important for conservation management given the species' current plight. The distribution of the okapi, being confined to the Congo Basin and yet spanning the Congo River, also makes it an important species for testing general biogeographic hypotheses for Congo Basin fauna, a currently understudied area of research. Here we describe the evolutionary history and genetic structure of okapi, in the context of other African ungulates including the giraffe, and use this information to shed light on the biogeographic history of Congo Basin fauna in general. Using nuclear and mitochondrial DNA sequence analysis of mainly non-invasively collected samples, we show that the okapi is both highly genetically distinct and highly genetically diverse, an unusual combination of genetic traits for an endangered species, and feature a complex evolutionary history. Genetic data are consistent with repeated climatic cycles leading to multiple Plio-Pleistocene refugia in isolated forests in the Congo catchment but also imply historic gene flow across the Congo River. PMID:25007188

  10. Bucking the trend: genetic analysis reveals high diversity, large population size and low differentiation in a deep ocean cetacean.

    PubMed

    Thompson, K F; Patel, S; Baker, C S; Constantine, R; Millar, C D

    2016-03-01

    Understanding the genetic structure of a population is essential to its conservation and management. We report the level of genetic diversity and determine the population structure of a cryptic deep ocean cetacean, the Gray's beaked whale (Mesoplodon grayi). We analysed 530 bp of mitochondrial control region and 12 microsatellite loci from 94 individuals stranded around New Zealand and Australia. The samples cover a large area of the species distribution (~6000 km) and were collected over a 22-year period. We show high genetic diversity (h=0.933-0.987, π=0.763-0.996% and Rs=4.22-4.37, He=0.624-0.675), and, in contrast to other cetaceans, we found a complete lack of genetic structure in both maternally and biparentally inherited markers. The oceanic habitats around New Zealand are diverse with extremely deep waters, seamounts and submarine canyons that are suitable for Gray's beaked whales and their prey. We propose that the abundance of this rich habitat has promoted genetic homogeneity in this species. Furthermore, it has been suggested that the lack of beaked whale sightings is the result of their low abundance, but this is in contrast to our estimates of female effective population size based on mitochondrial data. In conclusion, the high diversity and lack of genetic structure can be explained by a historically large population size, in combination with no known exploitation, few apparent behavioural barriers and abundant habitat. PMID:26626574

  11. Targeted high-throughput growth hormone 1 gene sequencing reveals high within-breed genetic diversity in South African goats.

    PubMed

    Ncube, K T; Mdladla, K; Dzomba, E F; Muchadeyi, F C

    2016-06-01

    This study assessed the genetic diversity in the growth hormone 1 gene (GH1) within and between South African goat breeds. Polymerase chain reaction-targeted gene amplification together with Illumina MiSeq next-generation sequencing (NGS) was used to generate the full length (2.54 kb) of the growth hormone 1 gene and screen for SNPs in the South African Boer (SAB) (n = 17), Tankwa (n = 15) and South African village (n = 35) goat populations. A range of 27-58 SNPs per population were observed. Mutations resulting in amino acid changes were observed at exons 2 and 5. Higher within-breed diversity of 97.37% was observed within the population category consisting of SA village ecotypes and the Tankwa goats. Highest pairwise FST values ranging from 0.148 to 0.356 were observed between the SAB and both the South African village and Tankwa feral goat populations. Phylogenetic analysis indicated nine genetic clusters, which reflected close relationships between the South African populations and the other international breeds with the exception of the Italian Sarda breeds. Results imply greater potential for within-population selection programs, particularly with SA village goats. PMID:26919178

  12. High genetic divergence in miniature breeds of Japanese native chickens compared to Red Junglefowl, as revealed by microsatellite analysis.

    PubMed

    Tadano, R; Nishibori, M; Imamura, Y; Matsuzaki, M; Kinoshita, K; Mizutani, M; Namikawa, T; Tsudzuki, M

    2008-02-01

    A wide diversity of domesticated chicken breeds exist due to artificial selection on the basis of human interests. Miniature variants (bantams) are eminently illustrative of the large changes from ancestral junglefowls. In this report, the genetic characterization of seven Japanese miniature chicken breeds and varieties, together with institute-kept Red Junglefowl, was conducted by means of typing 40 microsatellites located on 21 autosomes. We drew focus to genetic differentiation between the miniature chicken breeds and Red Junglefowl in particular. A total of 305 alleles were identified: 27 of these alleles (8.9%) were unique to the Red Junglefowl with high frequencies (>20%). Significantly high genetic differences (F(ST)) were obtained between Red Junglefowl and all other breeds with a range of 0.3901-0.5128. Individual clustering (constructed from combinations of the proportion of shared alleles and the neighbour-joining method) indicated high genetic divergence among breeds including Red Junglefowl. There were also individual assignments on the basis of the Bayesian and distance-based approaches. The microsatellite differences in the miniature chicken breeds compared to the presumed wild ancestor reflected the phenotypic diversity among them, indicating that each of these miniature chicken breeds is a unique gene pool. PMID:18254737

  13. Nuclear Genetic Diversity in Human Lice (Pediculus humanus) Reveals Continental Differences and High Inbreeding among Worldwide Populations

    PubMed Central

    Ascunce, Marina S.; Toups, Melissa A.; Kassu, Gebreyes; Fane, Jackie; Scholl, Katlyn; Reed, David L.

    2013-01-01

    Understanding the evolution of parasites is important to both basic and applied evolutionary biology. Knowledge of the genetic structure of parasite populations is critical for our ability to predict how an infection can spread through a host population and for the design of effective control methods. However, very little is known about the genetic structure of most human parasites, including the human louse (Pediculus humanus). This species is composed of two ecotypes: the head louse (Pediculus humanus capitis De Geer), and the clothing (body) louse (Pediculus humanus humanus Linnaeus). Hundreds of millions of head louse infestations affect children every year, and this number is on the rise, in part because of increased resistance to insecticides. Clothing lice affect mostly homeless and refugee-camp populations and although they are less prevalent than head lice, the medical consequences are more severe because they vector deadly bacterial pathogens. In this study we present the first assessment of the genetic structure of human louse populations by analyzing the nuclear genetic variation at 15 newly developed microsatellite loci in 93 human lice from 11 sites in four world regions. Both ecotypes showed heterozygote deficits relative to Hardy–Weinberg equilibrium and high inbreeding values, an expected pattern given their parasitic life history. Bayesian clustering analyses assigned lice to four distinct genetic clusters that were geographically structured. The low levels of gene flow among louse populations suggested that the evolution of insecticide resistance in lice would most likely be affected by local selection pressures, underscoring the importance of tailoring control strategies to population-specific genetic makeup and evolutionary history. Our panel of microsatellite markers provides powerful data to investigate not only ecological and evolutionary processes in lice, but also those in their human hosts because of the long-term coevolutionary

  14. Nuclear genetic diversity in human lice (Pediculus humanus) reveals continental differences and high inbreeding among worldwide populations.

    PubMed

    Ascunce, Marina S; Toups, Melissa A; Kassu, Gebreyes; Fane, Jackie; Scholl, Katlyn; Reed, David L

    2013-01-01

    Understanding the evolution of parasites is important to both basic and applied evolutionary biology. Knowledge of the genetic structure of parasite populations is critical for our ability to predict how an infection can spread through a host population and for the design of effective control methods. However, very little is known about the genetic structure of most human parasites, including the human louse (Pediculus humanus). This species is composed of two ecotypes: the head louse (Pediculus humanus capitis De Geer), and the clothing (body) louse (Pediculus humanus humanus Linnaeus). Hundreds of millions of head louse infestations affect children every year, and this number is on the rise, in part because of increased resistance to insecticides. Clothing lice affect mostly homeless and refugee-camp populations and although they are less prevalent than head lice, the medical consequences are more severe because they vector deadly bacterial pathogens. In this study we present the first assessment of the genetic structure of human louse populations by analyzing the nuclear genetic variation at 15 newly developed microsatellite loci in 93 human lice from 11 sites in four world regions. Both ecotypes showed heterozygote deficits relative to Hardy-Weinberg equilibrium and high inbreeding values, an expected pattern given their parasitic life history. Bayesian clustering analyses assigned lice to four distinct genetic clusters that were geographically structured. The low levels of gene flow among louse populations suggested that the evolution of insecticide resistance in lice would most likely be affected by local selection pressures, underscoring the importance of tailoring control strategies to population-specific genetic makeup and evolutionary history. Our panel of microsatellite markers provides powerful data to investigate not only ecological and evolutionary processes in lice, but also those in their human hosts because of the long-term coevolutionary

  15. Bridging the gap between high-throughput genetic and transcriptional data reveals cellular pathways responding to alpha-synuclein toxicity

    PubMed Central

    Yeger-Lotem, Esti; Riva, Laura; Su, Linhui Julie; Gitler, Aaron D.; Cashikar, Anil; King, Oliver D.; Auluck, Pavan K.; Geddie, Melissa L.; Valastyan, Julie S.; Karger, David R.; Lindquist, Susan; Fraenkel, Ernest

    2009-01-01

    Cells respond to stimuli by changes in various processes, including signaling pathways and gene expression. Efforts to identify components of these responses increasingly depend on mRNA profiling and genetic library screens, yet the functional roles of the genes identified by these assays often remain enigmatic. By comparing the results of these two assays across various cellular responses, we found that they are consistently distinct. Moreover, genetic screens tend to identify response regulators, while mRNA profiling frequently detects metabolic responses. We developed an integrative approach that bridges the gap between these data using known molecular interactions, thus highlighting major response pathways. We harnessed this approach to reveal cellular pathways related to alpha-synuclein, a small lipid-binding protein implicated in several neurodegenerative disorders including Parkinson disease. For this we screened an established yeast model for alpha-synuclein toxicity to identify genes that when overexpressed alter cellular survival. Application of our algorithm to these data and data from mRNA profiling provided functional explanations for many of these genes and revealed novel relations between alpha-synuclein toxicity and basic cellular pathways. PMID:19234470

  16. High genetic differentiation of Aegla longirostri (Crustacea, Decapoda, Anomura) populations in southern Brazil revealed by multi-loci microsatellite analysis.

    PubMed

    Bartholomei-Santos, M L; Roratto, P A; Santos, S

    2011-01-01

    Species with a broad distribution rarely have the same genetic make-up throughout their entire range. In some cases, they may constitute a cryptic complex consisting of a few species, each with a narrow distribution, instead of a single-, widely distributed species. These differences can have profound impacts for biodiversity conservation planning. The genetic differentiation of four populations of Aegla longirostri, a freshwater crab found in two geographically isolated basins in Rio Grande do Sul State, Brazil, was investigated by analyzing pentanucleotide multi-loci microsatellites in a heteroduplex assay. Although no morphological differences were evident, we found significant genetic differentiation among the four populations, based on F(ST) values and clustering analysis. This high level of differentiation may be indicative of cryptic species in these populations. If this hypothesis is correct, then the species occurring in the Ibicuí-Mirim River, at the southern limit of the Atlantic Rain Forest, would be under threat, considering its very restricted distribution. PMID:22179994

  17. The Genetic Linkage Map of the Medicinal Mushroom Agaricus subrufescens Reveals Highly Conserved Macrosynteny with the Congeneric Species Agaricus bisporus.

    PubMed

    Foulongne-Oriol, Marie; Rocha de Brito, Manuela; Cabannes, Delphine; Clément, Aurélien; Spataro, Cathy; Moinard, Magalie; Dias, Eustáquio Souza; Callac, Philippe; Savoie, Jean-Michel

    2016-01-01

    Comparative linkage mapping can rapidly facilitate the transfer of genetic information from model species to orphan species. This macrosynteny analysis approach has been extensively used in plant species, but few example are available in fungi, and even fewer in mushroom crop species. Among the latter, the Agaricus genus comprises the most cultivable or potentially cultivable species. Agaricus bisporus, the button mushroom, is the model for edible and cultivable mushrooms. We have developed the first genetic linkage map for the basidiomycete A. subrufescens, an emerging mushroom crop known for its therapeutic properties and potential medicinal applications. The map includes 202 markers distributed over 16 linkage groups (LG), and covers a total length of 1701 cM, with an average marker spacing of 8.2 cM. Using 96 homologous loci, we also demonstrated the high level of macrosynteny with the genome of A. bisporus The 13 main LG of A. subrufescens were syntenic to the 13 A. bisporus chromosomes. A disrupted synteny was observed for the three remaining A. subrufescens LG. Electronic mapping of a collection of A. subrufescens expressed sequence tags on A. bisporus genome showed that the homologous loci were evenly spread, with the exception of a few local hot or cold spots of homology. Our results were discussed in the light of Agaricus species evolution process. The map provides a framework for future genetic or genomic studies of the medicinal mushroom A. subrufescens. PMID:26921302

  18. The Genetic Linkage Map of the Medicinal Mushroom Agaricus subrufescens Reveals Highly Conserved Macrosynteny with the Congeneric Species Agaricus bisporus

    PubMed Central

    Foulongne-Oriol, Marie; Rocha de Brito, Manuela; Cabannes, Delphine; Clément, Aurélien; Spataro, Cathy; Moinard, Magalie; Dias, Eustáquio Souza; Callac, Philippe; Savoie, Jean-Michel

    2016-01-01

    Comparative linkage mapping can rapidly facilitate the transfer of genetic information from model species to orphan species. This macrosynteny analysis approach has been extensively used in plant species, but few example are available in fungi, and even fewer in mushroom crop species. Among the latter, the Agaricus genus comprises the most cultivable or potentially cultivable species. Agaricus bisporus, the button mushroom, is the model for edible and cultivable mushrooms. We have developed the first genetic linkage map for the basidiomycete A. subrufescens, an emerging mushroom crop known for its therapeutic properties and potential medicinal applications. The map includes 202 markers distributed over 16 linkage groups (LG), and covers a total length of 1701 cM, with an average marker spacing of 8.2 cM. Using 96 homologous loci, we also demonstrated the high level of macrosynteny with the genome of A. bisporus. The 13 main LG of A. subrufescens were syntenic to the 13 A. bisporus chromosomes. A disrupted synteny was observed for the three remaining A. subrufescens LG. Electronic mapping of a collection of A. subrufescens expressed sequence tags on A. bisporus genome showed that the homologous loci were evenly spread, with the exception of a few local hot or cold spots of homology. Our results were discussed in the light of Agaricus species evolution process. The map provides a framework for future genetic or genomic studies of the medicinal mushroom A. subrufescens. PMID:26921302

  19. High genetic diversity in gametophyte clones of Undaria pinnatifida from Vladivostok, Dalian and Qingdao revealed using microsatellite analysis

    NASA Astrophysics Data System (ADS)

    Shan, Tifeng; Pang, Shaojun; Liu, Feng; Xu, Na; Zhao, Xiaobo; Gao, Suqin

    2012-03-01

    Breeding practice for Undaria pinnatifida (Harvey) Suringar requires the screening of a large number of offspring from gametophyte crossings to obtain an elite variety for large-scale cultivation. To better understand the genetic relationships of different gametophyte cultures isolated from different sources, 20 microsatellite loci were screened and 53 gametophyte clone cultures analyzed for U. pinnatifida isolated from wild sporophytes in Vladivostok, Russia and from cultivated sporophytes from Dalian and Qingdao, China. One locus was abandoned because of poor amplification. At the sex-linked locus of Up-AC-2A8, 3 alleles were detected in 25 female gametophyte clones, with sizes ranging from 307 to 316 bp. At other loci, 3 to 7 alleles were detected with an average of 4.5 alleles per locus. The average number of alleles at each locus was 1.3 and 3.7 for Russian and Chinese gametophyte clones, respectively. The average gene diversity for Russian, Chinese, and for the combined total of gametophyte clones was 0.1, 0.4, and 0.5, respectively. Russian gametophyte clones had unique alleles at 7 out of the 19 loci. In cluster analysis, Russian and Chinese gametophyte clones were separated into two different groups according to genetic distance. Overall, high genetic diversity was detected in gametophyte clones isolated from the two countries. These gametophyte cultures were believed to be appropriate parental materials for conducting breeding programs in the future.

  20. Combining high-throughput phenotyping and genome-wide association studies to reveal natural genetic variation in rice

    PubMed Central

    Yang, Wanneng; Guo, Zilong; Huang, Chenglong; Duan, Lingfeng; Chen, Guoxing; Jiang, Ni; Fang, Wei; Feng, Hui; Xie, Weibo; Lian, Xingming; Wang, Gongwei; Luo, Qingming; Zhang, Qifa; Liu, Qian; Xiong, Lizhong

    2014-01-01

    Even as the study of plant genomics rapidly develops through the use of high-throughput sequencing techniques, traditional plant phenotyping lags far behind. Here we develop a high-throughput rice phenotyping facility (HRPF) to monitor 13 traditional agronomic traits and 2 newly defined traits during the rice growth period. Using genome-wide association studies (GWAS) of the 15 traits, we identify 141 associated loci, 25 of which contain known genes such as the Green Revolution semi-dwarf gene, SD1. Based on a performance evaluation of the HRPF and GWAS results, we demonstrate that high-throughput phenotyping has the potential to replace traditional phenotyping techniques and can provide valuable gene identification information. The combination of the multifunctional phenotyping tools HRPF and GWAS provides deep insights into the genetic architecture of important traits. PMID:25295980

  1. Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type

    USGS Publications Warehouse

    Dubey, J.P.; Velmurugan, G.V.; Ragendran, C.; Yabsley, M.J.; Thomas, N.J.; Beckmen, K.B.; Sinnett, D.; Ruid, D.; Hart, J.; Fair, P.A.; McFee, W.E.; Shearn-Bochsler, V.; Kwok, O.C.H.; Ferreira, L.R.; Choudhary, S.; Faria, E.B.; Zhou, H.; Felix, T.A.; Su, C.

    2011-01-01

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study wild animals, from the USA were examined for T. gondii infection. Tissues of naturally exposed animals were bioassayed in mice for isolation of viable parasites. Viable T. gondii was isolated from 31 animals including, to our knowledge for the first time, from a bald eagle (Haliaeetus leucocephalus), five gray wolves (Canis lupus), a woodrat (Neotoma micropus), and five Arctic foxes (Alopex lagopus). Additionally, 66 T. gondii isolates obtained previously, but not genetically characterised, were revived in mice. Toxoplasma gondii DNA isolated from these 97 samples (31+66) was characterised using 11 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). A total of 95 isolates were successfully genotyped. In addition to clonal Types II, and III, 12 different genotypes were found. These genotype data were combined with 74 T. gondii isolates previously characterised from wildlife from North America and a composite data set of 169 isolates comprised 22 genotypes, including clonal Types II, III and 20 atypical genotypes. Phylogenetic network analysis showed limited diversity with dominance of a recently designated fourth clonal type (Type 12) in North America, followed by the Type II and III lineages. These three major lineages together accounted for 85% of strains in North America. The Type 12 lineage includes previously identified Type A and X strains from sea otters. This study revealed that the Type 12 lineage accounts for 46.7% (79/169) of isolates and is dominant in wildlife of North America. No clonal Type I strain was identified among these wildlife isolates. These results suggest that T. gondii strains in wildlife from North America have limited diversity, with the occurrence of only a few major clonal types.

  2. Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type.

    PubMed

    Dubey, J P; Velmurugan, G V; Rajendran, C; Yabsley, M J; Thomas, N J; Beckmen, K B; Sinnett, D; Ruid, D; Hart, J; Fair, P A; McFee, W E; Shearn-Bochsler, V; Kwok, O C H; Ferreira, L R; Choudhary, S; Faria, E B; Zhou, H; Felix, T A; Su, C

    2011-09-01

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study wild animals, from the USA were examined for T. gondii infection. Tissues of naturally exposed animals were bioassayed in mice for isolation of viable parasites. Viable T. gondii was isolated from 31 animals including, to our knowledge for the first time, from a bald eagle (Haliaeetus leucocephalus), five gray wolves (Canis lupus), a woodrat (Neotoma micropus), and five Arctic foxes (Alopex lagopus). Additionally, 66 T. gondii isolates obtained previously, but not genetically characterised, were revived in mice. Toxoplasma gondii DNA isolated from these 97 samples (31+66) was characterised using 11 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). A total of 95 isolates were successfully genotyped. In addition to clonal Types II, and III, 12 different genotypes were found. These genotype data were combined with 74 T. gondii isolates previously characterised from wildlife from North America and a composite data set of 169 isolates comprised 22 genotypes, including clonal Types II, III and 20 atypical genotypes. Phylogenetic network analysis showed limited diversity with dominance of a recently designated fourth clonal type (Type 12) in North America, followed by the Type II and III lineages. These three major lineages together accounted for 85% of strains in North America. The Type 12 lineage includes previously identified Type A and X strains from sea otters. This study revealed that the Type 12 lineage accounts for 46.7% (79/169) of isolates and is dominant in wildlife of North America. No clonal Type I strain was identified among these wildlife isolates. These results suggest that T. gondii strains in wildlife from North America have limited diversity, with the occurrence of only a few major clonal types. PMID:21802422

  3. A Complex Recombination Pattern in the Genome of Allotetraploid Brassica napus as Revealed by a High-Density Genetic Map

    PubMed Central

    Yi, Bin; Fan, Chuchuan; Edwards, David; Batley, Jacqueline; Zhou, Yongming

    2014-01-01

    Polyploidy plays a crucial role in plant evolution. Brassica napus (2n = 38, AACC), the most important oil crop in the Brassica genus, is an allotetraploid that originated through natural doubling of chromosomes after the hybridization of its progenitor species, B. rapa (2n = 20, AA) and B. oleracea (2n = 18, CC). A better understanding of the evolutionary relationship between B. napus and B. rapa, B. oleracea, as well as Arabidopsis, which has a common ancestor with these three species, will provide valuable information about the generation and evolution of allopolyploidy. Based on a high-density genetic map with single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers, we performed a comparative genomic analysis of B. napus with Arabidopsis and its progenitor species B. rapa and B. oleracea. Based on the collinear relationship of B. rapa and B. oleracea in the B. napus genetic map, the B. napus genome was found to consist of 70.1% of the skeleton components of the chromosomes of B. rapa and B. oleracea, with 17.7% of sequences derived from reciprocal translocation between homoeologous chromosomes between the A- and C-genome and 3.6% of sequences derived from reciprocal translocation between non-homologous chromosomes at both intra- and inter-genomic levels. The current study thus provides insights into the formation and evolution of the allotetraploid B. napus genome, which will allow for more accurate transfer of genomic information from B. rapa, B. oleracea and Arabidopsis to B. napus. PMID:25356735

  4. Quartz-Seq: a highly reproducible and sensitive single-cell RNA sequencing method, reveals non-genetic gene-expression heterogeneity

    PubMed Central

    2013-01-01

    Development of a highly reproducible and sensitive single-cell RNA sequencing (RNA-seq) method would facilitate the understanding of the biological roles and underlying mechanisms of non-genetic cellular heterogeneity. In this study, we report a novel single-cell RNA-seq method called Quartz-Seq that has a simpler protocol and higher reproducibility and sensitivity than existing methods. We show that single-cell Quartz-Seq can quantitatively detect various kinds of non-genetic cellular heterogeneity, and can detect different cell types and different cell-cycle phases of a single cell type. Moreover, this method can comprehensively reveal gene-expression heterogeneity between single cells of the same cell type in the same cell-cycle phase. PMID:23594475

  5. Genetic characterization of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study, wild animals, including dolphins from the USA were examined for T. gondii infection. Tissues of naturally exposed animals were bioassayed in mice for isolation of viable parasites. Viable T. ...

  6. Integration of High-Resolution Physical and Genetic Map Reveals Differential Recombination Frequency between Chromosomes and the Genome Assembling Quality in Cucumber

    PubMed Central

    Cheng, Chunyan; Zhang, Zhonghua; Li, Ji; Huang, Sanwen; Chen, Jinfeng

    2013-01-01

    Cucumber is an important model crop and the first species sequenced in Cucurbitaceae family. Compared to the fast increasing genetic and genomics resources, the molecular cytogenetic researches in cucumber are still very limited, which results in directly the shortage of relation between plenty of physical sequences or genetic data and chromosome structure. We mapped twenty-three fosmids anchored by SSR markers from LG-3, the longest linkage group, and LG-4, the shortest linkage group on pachytene chromosomes 3 and 4, using uorescence in situ hybridization (FISH). Integrated molecular cytogenetic maps of chromosomes 3 and 4 were constructed. Except for three SSR markers located on heterochromatin region, the cytological order of markers was concordant with those on the linkage maps. Distinct structural differences between chromosomes 3 and 4 were revealed by the high resolution pachytene chromosomes. The extreme difference of genetic length between LG-3 and LG-4 was mainly attributed to the difference of overall recombination frequency. The significant differentiation of heterochromatin contents in chromosomes 3 and 4 might have a direct correlation with recombination frequency. Meanwhile, the uneven distribution of recombination frequency along chromosome 4 was observed, and recombination frequency of the long arm was nearly 3.5 times higher than that of the short arm. The severe suppression of recombination was exhibited in centromeric and heterochromatin domains of chromosome 4. Whereas a close correlation between the gene density and recombination frequency was observed in chromosome 4, no significant correlation was observed between them along chromosome 3. The comparison between cytogenetic and sequence maps revealed a large gap on the pericentromeric heterochromatin region of sequence map of chromosome 4. These results showed that integrated molecular cytogenetic maps can provide important information for the study of genetic and genomics in cucumber. PMID

  7. Genetic differentiation in the genus Lithops L. (Ruschioideae, Aizoaceae) reveals a high level of convergent evolution and reflects geographic distribution.

    PubMed

    Kellner, A; Ritz, C M; Schlittenhardt, P; Hellwig, F H

    2011-03-01

    Southern Africa is one of the hot spots for plant biodiversity, with ca. 80% of species endemic to this area. Rapid and recent radiations in Southern African plant genera were triggered by fine-scale differences in climate, topography and geology. The genus Lithops (Ruschioideae, Aizoaceae) contains 37 species and is widely distributed in Southern Africa. Species delimitation within the genus is challenging because the limited number of morphological characters in these reduced succulents varies intensely between populations, presumably as adaptations to local geological environments. We analysed phylogenetic relationships within Lithops using non-coding chloroplast DNA (trnS-trnG intergenic spacer), nuclear ribosomal internal transcribed spacer (nrITS) sequences and AFLP data. Genetic variability of the sequence data was very low, but AFLP data detected nine clades within Lithops that do not fit current morphology-based taxonomy. Two of these clades are separated by their distribution on the northern and eastern border of the distribution area, and four clades are found in the Gariep Centre in the estuary of the Orange River. Morphological similarities, especially colour of leaves, evolved repeatedly within the clades, thus we hypothesise that closely related species became adapted to different soil types in a mosaic-like geological environment. One-third of the species are found in the Gariep Centre, characterised by extremely diverse edaphic habitats. PMID:21309984

  8. Brief communication genotyping of Burkholderia pseudomallei revealed high genetic variability among isolates from a single population group

    PubMed Central

    Zueter, Abdelrahman Mohammad; Rahman, Zaidah Abdul; Yean, Chan Yean; Harun, Azian

    2015-01-01

    Burkholderia pseudomallei is a soil dwelling Gram-negative bacteria predominates in Southeast Asia zone and the tropical part of Australia. Genetic diversity has been explored among various populations and environments worldwide. To date, little data is available on MLST profiling of clinical B. pseudomallei isolates in peninsular Malaysia. In this brief report, thirteen culture positive B. pseudomallei cases collected from a single population of Terengganu state in the Western Peninsular Malaysia and were confirmed by In-house TTS1-PCR. Isolates were subjected for multi-locus sequence typing (MLST) to explore their genotypic diversity and to investigate for possible clonal clustering of a certain sequence type. Patient’s clinical information was examined to investigate for clinical correlation among the different genotypes. In spite of small sample set, MLST results indicated predictive results; considerable genotypic diversity, predominance and novelty among B. pseudomallei collected over a single geographically-located population in Malaysia. Massive genotypic heterogeneity was observed; 8 different sequence types with predominance of sequence type 54 and discovery of two novel sequence types. However, no clear pathogenomic or organ tropism clonal relationships were predicted. PMID:26417404

  9. Epidemiological investigation reveals genetic diversity and high co-infection rate of canine bocavirus strains circulating in Heilongjiang province, Northeast China.

    PubMed

    Guo, Donghua; Wang, Zhihui; Yao, Shuang; Li, Chunqiu; Geng, Yufei; Wang, Enyu; Zhao, Xiwen; Su, Mingjun; Wei, Shan; Wang, Xinyu; Feng, Li; Chang, Yung-Fu; Sun, Dongbo

    2016-06-01

    To trace evolution of CBoV in Northeast China, 201 fecal samples from rectal swabs of diarrheic dogs collected from May 2014 to April 2015 were investigated using PCR targeting partial NS1 gene (440bp). Furthermore, phylogenetic analysis of the identified CBoV strains was conducted using nucleotide sequences of the partial NS1 gene. The results indicated that 15 of 201 fecal samples (7.5%) were positive for CBoV; the partial NS1 genes of the 15 CBoV strains exhibited 83.1%-100% nucleotide identity, and 75.8%-100% amino acid identity; the entire VP2 gene of five selected CBoV strains exhibited 82.9%-96.8% nucleotide identity, and 90.4%-99.1% amino acid identity. The 15 CBoV strains exhibited high co-infection rates with CPV-2 (40%), CCoV (20%), and CaKV (26.67%). Phylogenetic analysis of the partial NS1 gene revealed that the 15 CBoV strains were divided into different subgroups of CBoV-2 when compared with CBoV-2 strains from South Korea, USA, Germany, and Hong Kong in China. Moreover, phylogenetic analysis of the VP2 gene indicated that five selected CBoV strains were divided into three different genetic groups of CBoV-2, involving in CBoV-2HK group, CBoV-2C group, and CBoV-2B group. The recombination analysis using the entire VP2 gene revealed three potential recombination events that occurred among five selected strains in our study. These data demonstrated that the CBoV strains circulating in Heilongjiang province, Northeast China showed genetic diversities, potential recombination events, and high co-infection rate. Further studies will be required to address the potential pathogenic role of these diverse CBoV strains. PMID:27234529

  10. Integrated Molecular Genetic Profiling of Pediatric High-Grade Gliomas Reveals Key Differences With the Adult Disease

    PubMed Central

    Paugh, Barbara S.; Qu, Chunxu; Jones, Chris; Liu, Zhaoli; Adamowicz-Brice, Martyna; Zhang, Junyuan; Bax, Dorine A.; Coyle, Beth; Barrow, Jennifer; Hargrave, Darren; Lowe, James; Gajjar, Amar; Zhao, Wei; Broniscer, Alberto; Ellison, David W.; Grundy, Richard G.; Baker, Suzanne J.

    2010-01-01

    Purpose To define copy number alterations and gene expression signatures underlying pediatric high-grade glioma (HGG). Patients and Methods We conducted a high-resolution analysis of genomic imbalances in 78 de novo pediatric HGGs, including seven diffuse intrinsic pontine gliomas, and 10 HGGs arising in children who received cranial irradiation for a previous cancer using single nucleotide polymorphism microarray analysis. Gene expression was analyzed with gene expression microarrays for 53 tumors. Results were compared with publicly available data from adult tumors. Results Significant differences in copy number alterations distinguish childhood and adult glioblastoma. PDGFRA was the predominant target of focal amplification in childhood HGG, including diffuse intrinsic pontine gliomas, and gene expression analyses supported an important role for deregulated PDGFRα signaling in pediatric HGG. No IDH1 hotspot mutations were found in pediatric tumors, highlighting molecular differences with adult secondary glioblastoma. Pediatric and adult glioblastomas were clearly distinguished by frequent gain of chromosome 1q (30% v 9%, respectively) and lower frequency of chromosome 7 gain (13% v 74%, respectively) and 10q loss (35% v 80%, respectively). PDGFRA amplification and 1q gain occurred at significantly higher frequency in irradiation-induced tumors, suggesting that these are initiating events in childhood gliomagenesis. A subset of pediatric HGGs showed minimal copy number changes. Conclusion Integrated molecular profiling showed substantial differences in the molecular features underlying pediatric and adult HGG, indicating that findings in adult tumors cannot be simply extrapolated to younger patients. PDGFRα may be a useful target for pediatric HGG, including diffuse pontine gliomas. PMID:20479398

  11. Genetic structure of Trypanosoma cruzi in Colombia revealed by a High-throughput Nuclear Multilocus Sequence Typing (nMLST) approach

    PubMed Central

    2013-01-01

    Background Chagas disease is a systemic pathology caused by Trypanosoma cruzi. This parasite reveals remarkable genetic variability, evinced in six Discrete Typing Units (DTUs) named from T. cruzi I to T. cruzi VI (TcI to TcVI). Recently newly identified genotypes have emerged such as TcBat in Brazil, Colombia and Panama associated to anthropogenic bats. The genotype with the broadest geographical distribution is TcI, which has recently been associated to severe cardiomyopathies in Argentina and Colombia. Therefore, new studies unraveling the genetic structure and natural history of this DTU must be pursued. Results We conducted a spatial and temporal analysis on 50 biological clones of T. cruzi I (TcI) isolated from humans with different clinical phenotypes, triatomine bugs and mammal reservoirs across three endemic regions for Chagas disease in Colombia. These clones were submitted to a nuclear Multilocus Sequence Typing (nMLST) analysis in order to elucidate its genetic diversity and clustering. After analyzing 13 nuclear housekeeping genes and obtaining a 5821 bp length alignment, we detected two robust genotypes within TcI henceforth named TcIDOM (associated to human infections) and a second cluster associated to peridomestic and sylvatic populations. Additionaly, we detected putative events of recombination and an intriguing lack of linkage disequilibrium. Conclusions These findings reinforce the emergence of an enigmatic domestic T. cruzi genotype (TcIDOM), and demonstrates the high frequency of recombination at nuclear level across natural populations of T. cruzi. Therefore, the need to pursue studies focused on the diferential virulence profiles of TcI strains. The biological and epidemiological implications of these findings are herein discussed. PMID:24079755

  12. Genotypic Analysis of Klebsiella pneumoniae Isolates in a Beijing Hospital Reveals High Genetic Diversity and Clonal Population Structure of Drug-Resistant Isolates

    PubMed Central

    Yi, Yong; Woo, Patrick C. Y.; Liu, Cui Hua

    2013-01-01

    Background The genetic diversity and the clinical relevance of the drug-resistant Klebsiella pneumoniae isolates from hospital settings are largely unknown. We thus conducted this prospective study to analyze the molecular epidemiology of K. pneumoniae isolates from patients being treated in the 306 Hospital in Beijing, China for the period of November 1, 2010–October 31, 2011. Methodology/Principal Findings Antibiotic susceptibility testing, PCR amplification and sequencing of the drug resistance-associated genes, and multilocus sequence typing (MLST) were conducted. A total of 163 isolates were analyzed. The percentage of MDR, XDR and PDR isolates were 63.8% (104), 20.9 (34), and 1.8% (3), respectively. MLST results showed that 60 sequence types (STs) were identified, which were further separated by eBURST into 13 clonal complexes and 18 singletons. The most dominant ST was ST15 (10.4%). Seven new alleles and 24 new STs were first identified in this study. Multiple logistic regression analysis revealed that certain clinical characteristics were associated with those prevalent STs such as: from ICU, from medical ward, from community acquired infection, from patients without heart disease, from patients with treatment success, susceptible to extended spectrum cephalosporin, susceptible to cephamycins, susceptible to fluoroquinolones, and with MDR. Conclusions/Significance Our data indicate that certain drug-resistant K. pneumoniae clones are highly prevalent and are associated with certain clinical characteristics in hospital settings. Our study provides evidence demonstrating that intensive nosocomial infection control measures are urgently needed. PMID:23437318

  13. High-Level Genetic Diversity and Complex Population Structure of Siberian Apricot (Prunus sibirica L.) in China as Revealed by Nuclear SSR Markers

    PubMed Central

    Wang, Zhe; Kang, Ming; Liu, Huabo; Gao, Jiao; Zhang, Zhengdong; Li, Yingyue; Wu, Rongling; Pang, Xiaoming

    2014-01-01

    Siberian apricot (Prunus sibirica L.), an ecologically and economically important tree species with a high degree of tolerance to a variety of extreme environmental conditions, is widely distributed across the mountains of northeastern and northern China, eastern and southeastern regions of Mongolia, Eastern Siberia, and the Maritime Territory of Russia. However, few studies have examined the genetic diversity and population structure of this species. Using 31 nuclear microsatellites, we investigated the level of genetic diversity and population structure of Siberian apricot sampled from 22 populations across China. The number of alleles per locus ranged from 5 to 33, with an average of 19.323 alleles. The observed heterozygosity and expected heterozygosity ranged from 0.037 to 0.874 and 0.040 to 0.924 with average values of 0.639 and 0.774, respectively. A STRUCTURE-based analysis clustered all of the populations into four genetic clusters. Significant genetic differentiation was observed between all population pairs. A hierarchical analysis of molecular variance attributed about 94% of the variation to within populations. No significant difference was detected between the wild and semi-wild groups, indicating that recent cultivation practices have had little impact on the genetic diversity of Siberian apricot. The Mantel test showed that the genetic distance among the populations was not significantly correlated with geographic distance (r = 0.4651, p = 0.9940). Our study represents the most comprehensive investigation of the genetic diversity and population structure of Siberian apricot in China to date, and it provides valuable information for the collection of genetic resources for the breeding of Siberian apricot and related species. PMID:24516551

  14. High-level genetic diversity and complex population structure of Siberian apricot (Prunus sibirica L.) in China as revealed by nuclear SSR markers.

    PubMed

    Wang, Zhe; Kang, Ming; Liu, Huabo; Gao, Jiao; Zhang, Zhengdong; Li, Yingyue; Wu, Rongling; Pang, Xiaoming

    2014-01-01

    Siberian apricot (Prunus sibirica L.), an ecologically and economically important tree species with a high degree of tolerance to a variety of extreme environmental conditions, is widely distributed across the mountains of northeastern and northern China, eastern and southeastern regions of Mongolia, Eastern Siberia, and the Maritime Territory of Russia. However, few studies have examined the genetic diversity and population structure of this species. Using 31 nuclear microsatellites, we investigated the level of genetic diversity and population structure of Siberian apricot sampled from 22 populations across China. The number of alleles per locus ranged from 5 to 33, with an average of 19.323 alleles. The observed heterozygosity and expected heterozygosity ranged from 0.037 to 0.874 and 0.040 to 0.924 with average values of 0.639 and 0.774, respectively. A STRUCTURE-based analysis clustered all of the populations into four genetic clusters. Significant genetic differentiation was observed between all population pairs. A hierarchical analysis of molecular variance attributed about 94% of the variation to within populations. No significant difference was detected between the wild and semi-wild groups, indicating that recent cultivation practices have had little impact on the genetic diversity of Siberian apricot. The Mantel test showed that the genetic distance among the populations was not significantly correlated with geographic distance (r = 0.4651, p = 0.9940). Our study represents the most comprehensive investigation of the genetic diversity and population structure of Siberian apricot in China to date, and it provides valuable information for the collection of genetic resources for the breeding of Siberian apricot and related species. PMID:24516551

  15. Global Population Genetic Structure of Caenorhabditis remanei Reveals Incipient Speciation

    PubMed Central

    Dey, Alivia; Jeon, Yong; Wang, Guo-Xiu; Cutter, Asher D.

    2012-01-01

    Mating system transitions dramatically alter the evolutionary trajectories of genomes that can be revealed by contrasts of species with disparate modes of reproduction. For such transitions in Caenorhabditis nematodes, some major causes of genome variation in selfing species have been discerned. And yet, we have only limited understanding of species-wide population genetic processes for their outcrossing relatives, which represent the reproductive state of the progenitors of selfing species. Multilocus–multipopulation sequence polymorphism data provide a powerful means to uncover the historical demography and evolutionary processes that shape genomes. Here we survey nucleotide polymorphism across the X chromosome for three populations of the outcrossing nematode Caenorhabditis remanei and demonstrate its divergence from a fourth population describing a closely related new species from China, C. sp. 23. We find high genetic variation globally and within each local population sample. Despite geographic barriers and moderate genetic differentiation between Europe and North America, considerable gene flow connects C. remanei populations. We discovered C. sp. 23 while investigating C. remanei, observing strong genetic differentiation characteristic of reproductive isolation that was confirmed by substantial F2 hybrid breakdown in interspecific crosses. That C. sp. 23 represents a distinct biological species provides a cautionary example of how standard practice can fail for mating tests of species identity in this group. This species pair permits full application of divergence population genetic methods to obligately outcrossing species of Caenorhabditis and also presents a new focus for interrogation of the genetics and evolution of speciation with the Caenorhabditis model system. PMID:22649079

  16. High regional genetic diversity and lack of host-specificity in Ostrinia nubilalis (Lepidoptera: Crambidae) as revealed by mtDNA variation.

    PubMed

    Piwczyński, M; Pabijan, M; Grzywacz, A; Glinkowski, W; Bereś, P K; Buszko, J

    2016-08-01

    The European corn borer (Ostrinia nubilalis) infests a wide array of host plants and is considered one of the most serious pests of maize in Europe. Recent studies suggest that individuals feeding on maize in Europe should be referred to O. nubilalis (sensu nov.), while those infesting dicots as Ostrinia scapulalis (sensu nov.). We test if the clear genetic distinctiveness among individuals of O. nubilalis living on maize vs. dicots is tracked by mitochondrial DNA (mtDNA). We used fragments of COI and COII genes of 32 individuals traditionally recognized as O. nubilalis collected on three host plants, maize, mugwort and hop, growing in different parts of Poland. In addition, we reconstructed the mtDNA phylogeny of Ostrinia species based on our data and sequences retrieved from GenBank to assess host and/or biogeographic patterns. We also compared haplotype variation found in Poland (east-central Europe) with other regions (Anatolia, Eastern Europe, Balkans, Far East, North America). Our study showed high mtDNA diversity of O. nubilalis in Poland in comparison with other regions and revealed rare haplotypes likely of Asian origin. We did not find distinct mtDNA haplotypes in larvae feeding on maize vs. dicotyledonous plants. Phylogenetic analyses showed an apparent lack of mtDNA divergence among putatively distinct lineages belonging to the O. nubilalis group as identical haplotypes are shared by Asian and European individuals. We argue that human-mediated dispersal, hybridization and sporadic host jumps are likely responsible for the lack of a geographic pattern in mtDNA variation. PMID:27019346

  17. Inter-Simple Sequence Repeat Data Reveals High Genetic Diversity in Wild Populations of the Narrowly Distributed Endemic Lilium regale in the Minjiang River Valley of China

    PubMed Central

    Wu, Zhu-hua; Shi, Jisen; Xi, Meng-li; Jiang, Fu-xing; Deng, Ming-wen; Dayanandan, Selvadurai

    2015-01-01

    Lilium regale E.H. Wilson is endemic to a narrow geographic area in the Minjiang River valley in southwestern China, and is considered an important germplasm for breeding commercially valuable lily varieties, due to its vigorous growth, resistance to diseases and tolerance for low moisture. We analyzed the genetic diversity of eight populations of L. regale sampled across the entire natural distribution range of the species using Inter-Simple Sequence Repeat markers. The genetic diversity (expected heterozygosity= 0.3356) was higher than those reported for other narrowly distributed endemic plants. The levels of inbreeding (Fst = 0.1897) were low, and most of the genetic variability was found to be within (80.91%) than amongpopulations (19.09%). An indirect estimate of historical levels of gene flow (Nm =1.0678) indicated high levels of gene flow among populations. The eight analyzed populations clustered into three genetically distinct groups. Based on these results, we recommend conservation of large populations representing these three genetically distinct groups. PMID:25799495

  18. High Levels of Genetic Connectivity among Populations of Yellowtail Snapper, Ocyurus chrysurus (Lutjanidae – Perciformes), in the Western South Atlantic Revealed through Multilocus Analysis

    PubMed Central

    da Silva, Raimundo; Veneza, Ivana; Sampaio, Iracilda; Araripe, Juliana; Schneider, Horacio; Gomes, Grazielle

    2015-01-01

    In the present study, five loci (mitochondrial and nuclear) were sequenced to determine the genetic diversity, population structure, and demographic history of populations of the yellowtail snapper, Ocyurus chrysurus, found along the coast of the western South Atlantic. O. chrysurus is a lutjanid species that is commonly associated with coral reefs and exhibits an ample geographic distribution, and it can therefore be considered a good model for the investigation of phylogeographic patterns and genetic connectivity in marine environments. The results reflected a marked congruence between the mitochondrial and nuclear markers as well as intense gene flow among the analyzed populations, which represent a single genetic stock along the entire coast of Brazil between the states of Pará and Espírito Santo. Our data also showed high levels of genetic diversity in the species (mainly mtDNA), as well a major historic population expansion, which most likely coincided with the sea level oscillations at the end of the Pleistocene. In addition, this species is intensively exploited by commercial fisheries, and data on the genetic structure of its populations will be essential for the development of effective conservation and management plans. PMID:25769032

  19. Sequence and phylogenetic analysis of highly pathogenic avian influenza H5N1 viruses isolated during 2006–2008 outbreaks in Pakistan reveals genetic diversity

    PubMed Central

    2012-01-01

    Background Since the first outbreak recorded in northern areas of Pakistan in early 2006, highly pathogenic avian influenza H5N1 viruses were isolated from commercial poultry and wild/domestic birds from different areas of Pakistan up to July 2008. Different isolates of H5N1 were sequenced to explore the genetic diversity of these viruses. Results Phylogenetic analysis revealed close clustering and highest sequence identity in all 8 genes to HPAI H5N1 isolates belonging to unified H5 clade 2.2, sub-lineage EMA-3 recovered from Afghanistan during the same time period. Two subgroups within Pakistani H5N1 viruses, from domestic and wild birds, were observed on the basis of their sequence homology and mutations. HPAI motif, preferred receptor specificity for α-(2, 3) linkages, potential N-linked glycosylation sites and an additional glycosylation site at the globular head of HA protein of four Pakistani H5N1 isolates. While, the amino acids associated with sensitivities to various antiviral drugs (Oseltamivir, Zanamivir, Amantadine) were found conserved for the Pakistani H5N1 isolates. Conspicuously, some important mutations observed at critical positions of antigenic sites (S141P, D155S, R162I & P181S) and at receptor binding pocket (A185T, R189K & S217P) of HA-1. A high sequence similarity between Pakistani HP H5N1 and LP H9N2 viruses was also observed. Avian like host specific markers with the exception of E627K in PB2, K356R in PA, V33I in NP, I28V in M2 and L107F in NS2 proteins were also observed. Conclusions Various point mutations in different genes of H5 viruses from Pakistan were observed during its circulation in the field. The outbreaks started in Khyber Pakhtoon Khawa (North West) province in 2006 and spread to the Southern regions over a period of time. Though migratory birds may have a role for this continued endemicity of clade 2.2 H5N1 viruses during 2006–2008 in Pakistan, the possibility of their transmission through legal or illegal poultry trade

  20. Polarity and Temporality of High-Resolution Y-Chromosome Distributions in India Identify Both Indigenous and Exogenous Expansions and Reveal Minor Genetic Influence of Central Asian Pastoralists

    PubMed Central

    Sengupta, Sanghamitra; Zhivotovsky, Lev A.; King, Roy; Mehdi, S. Q.; Edmonds, Christopher A.; Chow, Cheryl-Emiliane T.; Lin, Alice A.; Mitra, Mitashree; Sil, Samir K.; Ramesh, A.; Usha Rani, M. V.; Thakur, Chitra M.; Cavalli-Sforza, L. Luca; Majumder, Partha P.; Underhill, Peter A.

    2006-01-01

    Although considerable cultural impact on social hierarchy and language in South Asia is attributable to the arrival of nomadic Central Asian pastoralists, genetic data (mitochondrial and Y chromosomal) have yielded dramatically conflicting inferences on the genetic origins of tribes and castes of South Asia. We sought to resolve this conflict, using high-resolution data on 69 informative Y-chromosome binary markers and 10 microsatellite markers from a large set of geographically, socially, and linguistically representative ethnic groups of South Asia. We found that the influence of Central Asia on the pre-existing gene pool was minor. The ages of accumulated microsatellite variation in the majority of Indian haplogroups exceed 10,000–15,000 years, which attests to the antiquity of regional differentiation. Therefore, our data do not support models that invoke a pronounced recent genetic input from Central Asia to explain the observed genetic variation in South Asia. R1a1 and R2 haplogroups indicate demographic complexity that is inconsistent with a recent single history. Associated microsatellite analyses of the high-frequency R1a1 haplogroup chromosomes indicate independent recent histories of the Indus Valley and the peninsular Indian region. Our data are also more consistent with a peninsular origin of Dravidian speakers than a source with proximity to the Indus and with significant genetic input resulting from demic diffusion associated with agriculture. Our results underscore the importance of marker ascertainment for distinguishing phylogenetic terminal branches from basal nodes when attributing ancestral composition and temporality to either indigenous or exogenous sources. Our reappraisal indicates that pre-Holocene and Holocene-era—not Indo-European—expansions have shaped the distinctive South Asian Y-chromosome landscape. PMID:16400607

  1. High Points of Human Genetics

    ERIC Educational Resources Information Center

    Stern, Curt

    1975-01-01

    Discusses such high points of human genetics as the study of chromosomes, somatic cell hybrids, the population formula: the Hardy-Weinberg Law, biochemical genetics, the single-active X Theory, behavioral genetics and finally how genetics can serve humanity. (BR)

  2. Genetic substructure of Kuwaiti population reveals migration history.

    PubMed

    Alsmadi, Osama; Thareja, Gaurav; Alkayal, Fadi; Rajagopalan, Ramakrishnan; John, Sumi Elsa; Hebbar, Prashantha; Behbehani, Kazem; Thanaraj, Thangavel Alphonse

    2013-01-01

    The State of Kuwait is characterized by settlers from Saudi Arabia, Iran, and other regions of the Arabian Peninsula. The settlements and subsequent admixtures have shaped the genetics of Kuwait. High prevalence of recessive disorders and metabolic syndromes (that increase risk of diabetes) is seen in the peninsula. Understanding the genetic structure of its population will aid studies designed to decipher the underlying causes of these disorders. In this study, we analyzed 572,366 SNP markers from 273 Kuwaiti natives genotyped using the illumina HumanOmniExpress BeadChip. Model-based clustering identified three genetic subgroups with different levels of admixture. A high level of concordance (Mantel test, p=0.0001 for 9999 repeats) was observed between the derived genetic clusters and the surname-based ancestries. Use of Human Genome Diversity Project (HGDP) data to understand admixtures in each group reveals the following: the first group (Kuwait P) is largely of West Asian ancestry, representing Persians with European admixture; the second group (Kuwait S) is predominantly of city-dwelling Saudi Arabian tribe ancestry, and the third group (Kuwait B) includes most of the tent-dwelling Bedouin surnames and is characterized by the presence of 17% African ancestry. Identity by Descent and Homozygosity analyses find Kuwait's population to be heterogeneous (placed between populations that have large amount of ROH and the ones with low ROH) with Kuwait S as highly endogamous, and Kuwait B as diverse. Population differentiation FST estimates place Kuwait P near Asian populations, Kuwait S near Negev Bedouin tribes, and Kuwait B near the Mozabite population. FST distances between the groups are in the range of 0.005 to 0.008; distances of this magnitude are known to cause false positives in disease association studies. Results of analysis for genetic features such as linkage disequilibrium decay patterns conform to Kuwait's geographical location at the nexus of Africa

  3. High Genetic and Epigenetic Stability in Coffea arabica Plants Derived from Embryogenic Suspensions and Secondary Embryogenesis as Revealed by AFLP, MSAP and the Phenotypic Variation Rate

    PubMed Central

    Bobadilla Landey, Roberto; Cenci, Alberto; Georget, Frédéric; Bertrand, Benoît; Camayo, Gloria; Dechamp, Eveline; Herrera, Juan Carlos; Santoni, Sylvain; Lashermes, Philippe; Simpson, June; Etienne, Hervé

    2013-01-01

    Embryogenic suspensions that involve extensive cell division are risky in respect to genome and epigenome instability. Elevated frequencies of somaclonal variation in embryogenic suspension-derived plants were reported in many species, including coffee. This problem could be overcome by using culture conditions that allow moderate cell proliferation. In view of true-to-type large-scale propagation of C. arabica hybrids, suspension protocols based on low 2,4-D concentrations and short proliferation periods were developed. As mechanisms leading to somaclonal variation are often complex, the phenotypic, genetic and epigenetic changes were jointly assessed so as to accurately evaluate the conformity of suspension-derived plants. The effects of embryogenic suspensions and secondary embryogenesis, used as proliferation systems, on the genetic conformity of somatic embryogenesis-derived plants (emblings) were assessed in two hybrids. When applied over a 6 month period, both systems ensured very low somaclonal variation rates, as observed through massive phenotypic observations in field plots (0.74% from 200 000 plant). Molecular AFLP and MSAP analyses performed on 145 three year-old emblings showed that polymorphism between mother plants and emblings was extremely low, i.e. ranges of 0–0.003% and 0.07–0.18% respectively, with no significant difference between the proliferation systems for the two hybrids. No embling was found to cumulate more than three methylation polymorphisms. No relation was established between the variant phenotype (27 variants studied) and a particular MSAP pattern. Chromosome counting showed that 7 of the 11 variant emblings analyzed were characterized by the loss of 1–3 chromosomes. This work showed that both embryogenic suspensions and secondary embryogenesis are reliable for true-to-type propagation of elite material. Molecular analyses revealed that genetic and epigenetic alterations are particularly limited during coffee somatic

  4. Behavioral idiosyncrasy reveals genetic control of phenotypic variability

    PubMed Central

    Ayroles, Julien F.; Buchanan, Sean M.; O’Leary, Chelsea; Skutt-Kakaria, Kyobi; Grenier, Jennifer K.; Clark, Andrew G.; Hartl, Daniel L.; de Bivort, Benjamin L.

    2015-01-01

    Quantitative genetics has primarily focused on describing genetic effects on trait means and largely ignored the effect of alternative alleles on trait variability, potentially missing an important axis of genetic variation contributing to phenotypic differences among individuals. To study the genetic effects on individual-to-individual phenotypic variability (or intragenotypic variability), we used Drosophila inbred lines and measured the spontaneous locomotor behavior of flies walking individually in Y-shaped mazes, focusing on variability in locomotor handedness, an assay optimized to measure variability. We discovered that some lines had consistently high levels of intragenotypic variability among individuals, whereas lines with low variability behaved as although they tossed a coin at each left/right turn decision. We demonstrate that the degree of variability is itself heritable. Using a genome-wide association study (GWAS) for the degree of intragenotypic variability as the phenotype across lines, we identified several genes expressed in the brain that affect variability in handedness without affecting the mean. One of these genes, Ten-a, implicates a neuropil in the central complex of the fly brain as influencing the magnitude of behavioral variability, a brain region involved in sensory integration and locomotor coordination. We validated these results using genetic deficiencies, null alleles, and inducible RNAi transgenes. Our study reveals the constellation of phenotypes that can arise from a single genotype and shows that different genetic backgrounds differ dramatically in their propensity for phenotypic variabililty. Because traditional mean-focused GWASs ignore the contribution of variability to overall phenotypic variation, current methods may miss important links between genotype and phenotype. PMID:25953335

  5. Genetic control of juvenile growth and botanical architecture in an ornamental woody plant, Prunus mume Sieb. et Zucc. as revealed by a high-density linkage map

    PubMed Central

    2014-01-01

    Mei, Prunus mume Sieb. et Zucc., is an ornamental plant popular in East Asia and, as an important member of genus Prunus, has played a pivotal role in systematic studies of the Rosaceae. However, the genetic architecture of botanical traits in this species remains elusive. This paper represents the first genome-wide mapping study of quantitative trait loci (QTLs) that affect stem growth and form, leaf morphology and leaf anatomy in an intraspecific cross derived from two different mei cultivars. Genetic mapping based on a high-density linkage map constricted from 120 SSRs and 1,484 SNPs led to the detection of multiple QTLs for each trait, some of which exert pleiotropic effects on correlative traits. Each QTL explains 3-12% of the phenotypic variance. Several leaf size traits were found to share common QTLs, whereas growth-related traits and plant form traits might be controlled by a different set of QTLs. Our findings provide unique insights into the genetic control of tree growth and architecture in mei and help to develop an efficient breeding program for selecting superior mei cultivars. PMID:25078672

  6. Genetic Control of the Leaf Angle and Leaf Orientation Value as Revealed by Ultra-High Density Maps in Three Connected Maize Populations

    PubMed Central

    Li, Chunhui; Li, Yongxiang; Shi, Yunsu; Song, Yanchun; Zhang, Dengfeng; Buckler, Edward S.; Zhang, Zhiwu; Wang, Tianyu; Li, Yu

    2015-01-01

    Plant architecture is a key factor for high productivity maize because ideal plant architecture with an erect leaf angle and optimum leaf orientation value allow for more efficient light capture during photosynthesis and better wind circulation under dense planting conditions. To extend our understanding of the genetic mechanisms involved in leaf-related traits, three connected recombination inbred line (RIL) populations including 538 RILs were genotyped by genotyping-by-sequencing (GBS) method and phenotyped for the leaf angle and related traits in six environments. We conducted single population quantitative trait locus (QTL) mapping and joint linkage analysis based on high-density recombination bin maps constructed from GBS genotype data. A total of 45 QTLs with phenotypic effects ranging from 1.2% to 29.2% were detected for four leaf architecture traits by using joint linkage mapping across the three populations. All the QTLs identified for each trait could explain approximately 60% of the phenotypic variance. Four QTLs were located on small genomic regions where candidate genes were found. Genomic predictions from a genomic best linear unbiased prediction (GBLUP) model explained 45±9% to 68±8% of the variation in the remaining RILs for the four traits. These results extend our understanding of the genetics of leaf traits and can be used in genomic prediction to accelerate plant architecture improvement. PMID:25807369

  7. SNP Design from 454 Sequencing of Podosphaera plantaginis Transcriptome Reveals a Genetically Diverse Pathogen Metapopulation with High Levels of Mixed-Genotype Infection

    PubMed Central

    Tollenaere, Charlotte; Susi, Hanna; Nokso-Koivisto, Jussi; Koskinen, Patrik; Tack, Ayco; Auvinen, Petri; Paulin, Lars; Frilander, Mikko J.; Lehtonen, Rainer; Laine, Anna-Liisa

    2012-01-01

    Background Molecular tools may greatly improve our understanding of pathogen evolution and epidemiology but technical constraints have hindered the development of genetic resources for parasites compared to free-living organisms. This study aims at developing molecular tools for Podosphaera plantaginis, an obligate fungal pathogen of Plantago lanceolata. This interaction has been intensively studied in the Åland archipelago of Finland with epidemiological data collected from over 4,000 host populations annually since year 2001. Principal Findings A cDNA library of a pooled sample of fungal conidia was sequenced on the 454 GS-FLX platform. Over 549,411 reads were obtained and annotated into 45,245 contigs. Annotation data was acquired for 65.2% of the assembled sequences. The transcriptome assembly was screened for SNP loci, as well as for functionally important genes (mating-type genes and potential effector proteins). A genotyping assay of 27 SNP loci was designed and tested on 380 infected leaf samples from 80 populations within the Åland archipelago. With this panel we identified 85 multilocus genotypes (MLG) with uneven frequencies across the pathogen metapopulation. Approximately half of the sampled populations contain polymorphism. Our genotyping protocol revealed mixed-genotype infection within a single host leaf to be common. Mixed infection has been proposed as one of the main drivers of pathogen evolution, and hence may be an important process in this pathosystem. Significance The developed SNP panel offers exciting research perspectives for future studies in this well-characterized pathosystem. Also, the transcriptome provides an invaluable novel genomic resource for powdery mildews, which cause significant yield losses on commercially important crops annually. Furthermore, the features that render genetic studies in this system a challenge are shared with the majority of obligate parasitic species, and hence our results provide methodological insights

  8. A fifth major genetic group among honeybees revealed in Syria

    PubMed Central

    2013-01-01

    Background Apiculture has been practiced in North Africa and the Middle-East from antiquity. Several thousand years of selective breeding have left a mosaic of Apis mellifera subspecies in the Middle-East, many uniquely adapted and survived to local environmental conditions. In this study we explore the genetic diversity of A. mellifera from Syria (n = 1258), Lebanon (n = 169) and Iraq (n = 35) based on 14 short tandem repeat (STR) loci in the context of reference populations from throughout the Old World (n = 732). Results Our data suggest that the Syrian honeybee Apis mellifera syriaca occurs in both Syrian and Lebanese territories, with no significant genetic variability between respective populations from Syria and Lebanon. All studied populations clustered within a new fifth independent nuclear cluster, congruent with an mtDNA Z haplotype identified in a previous study. Syrian honeybee populations are not associated with Oriental lineage O, except for sporadic introgression into some populations close to the Turkish and Iraqi borders. Southern Syrian and Lebanese populations demonstrated high levels of genetic diversity compared to the northern populations. Conclusion This study revealed the effects of foreign queen importations on Syrian bee populations, especially for the region of Tartus, where extensive introgression of A. m. anatolica and/or A. m. caucasica alleles were identified. The policy of creating genetic conservation centers for the Syrian subspecies should take into consideration the influence of the oriental lineage O from the northern Syrian border and the large population of genetically divergent indigenous honeybees located in southern Syria. PMID:24314104

  9. Phylogeography of the South China Field Mouse (Apodemus draco) on the Southeastern Tibetan Plateau Reveals High Genetic Diversity and Glacial Refugia

    PubMed Central

    Liu, Yang; Liao, Lihuan; Zhang, Xiuyue; Yue, Bisong

    2012-01-01

    The southeastern margin of the Tibetan Plateau (SEMTP) is a particularly interesting region due to its topographic complexity and unique geologic history, but phylogeographic studies that focus on this region are rare. In this study, we investigated the phylogeography of the South China field mouse, Apodemus draco, in order to assess the role of geologic and climatic events on the Tibetan Plateau in shaping its genetic structure. We sequenced mitochondrial cytochrome b (cyt b) sequences in 103 individuals from 47 sampling sites. In addition, 23 cyt b sequences were collected from GenBank for analyses. Phylogenetic, demographic and landscape genetic methods were conducted. Seventy-six cyt b haplotypes were found and the genetic diversity was extremely high (π = 0.0368; h = 0.989). Five major evolutionary clades, based on geographic locations, were identified. Demographic analyses implied subclade 1A and subclade 1B experienced population expansions at about 0.052-0.013 Mya and 0.014-0.004 Mya, respectively. The divergence time analysis showed that the split between clade 1 and clade 2 occurred 0.26 Mya, which fell into the extensive glacial period (EGP, 0.5-0.17 Mya). The divergence times of other main clades (2.20-0.55 Mya) were congruent with the periods of the Qingzang Movement (3.6-1.7 Mya) and the Kun-Huang Movement (1.2-0.6 Mya), which were known as the most intense uplift events in the Tibetan Plateau. Our study supported the hypothesis that the SEMTP was a large late Pleistocene refugium, and further inferred that the Gongga Mountain Region and Hongya County were glacial refugia for A. draco in clade 1. We hypothesize that the evolutionary history of A. draco in the SEMTP primarily occurred in two stages. First, an initial divergence would have been shaped by uplift events of the Tibetan Plateau. Then, major glaciations in the Pleistocene added complexity to its demographic history and genetic structure. PMID:22666478

  10. Combined Genetic and Telemetry Data Reveal High Rates of Gene Flow, Migration, and Long-Distance Dispersal Potential in Arctic Ringed Seals (Pusa hispida)

    PubMed Central

    Martinez-Bakker, Micaela E.; Sell, Stephanie K.; Swanson, Bradley J.; Kelly, Brendan P.; Tallmon, David A.

    2013-01-01

    Ringed seals (Pusa hispida) are broadly distributed in seasonally ice covered seas, and their survival and reproductive success is intricately linked to sea ice and snow. Climatic warming is diminishing Arctic snow and sea ice and threatens to endanger ringed seals in the foreseeable future. We investigated the population structure and connectedness within and among three subspecies: Arctic (P. hispida hispida), Baltic (P. hispida botnica), and Lake Saimaa (P. hispida saimensis) ringed seals to assess their capacity to respond to rapid environmental changes. We consider (a) the geographical scale of migration, (b) use of sea ice, and (c) the amount of gene flow between subspecies. Seasonal movements and use of sea ice were determined for 27 seals tracked via satellite telemetry. Additionally, population genetic analyses were conducted using 354 seals representative of each subspecies and 11 breeding sites. Genetic analyses included sequences from two mitochondrial regions and genotypes of 9 microsatellite loci. We found that ringed seals disperse on a pan-Arctic scale and both males and females may migrate long distances during the summer months when sea ice extent is minimal. Gene flow among Arctic breeding sites and between the Arctic and the Baltic Sea subspecies was high; these two subspecies are interconnected as are breeding sites within the Arctic subspecies. PMID:24130843

  11. Multilocus microsatellite typing revealed high genetic variability of Leishmania donovani strains isolated during and after a Kala-azar epidemic in Libo Kemkem district, northwest Ethiopia.

    PubMed

    Gelanew, Tesfaye; Cruz, Israel; Kuhls, Katrin; Alvar, Jorge; Cañavate, Carmen; Hailu, Asrat; Schönian, Gabriele

    2011-06-01

    In 2004, an outbreak of kala-azar (KA) occurred for the first time in Libo Kemkem district, in the highland area of northwest Ethiopia. In order to track the possible origins of the outbreak parasites, we have investigated 19 strains of Leishmania donovani that were collected during (n = 6) and after (n = 13) the outbreak by using 14 highly polymorphic microsatellite markers. Unique microsatellite profiles were obtained for all strains from Libo Kemkem. When compared to those of L. donovani strains from different Ethiopian, Kenyan and Sudanese foci, by genetic distance and Bayesian clustering model analyses, most strains from Libo Kemkem grouped with strains from: (i) Humera and Metema in the lowlands and Belessa in the highland of Ethiopia, and (ii) Sudan, at different hierarchal levels. The strains from Libo Kemkem district were assigned at least to three genetically distinct clusters (A, B1 and B2) of which only one, cluster B2, consisted exclusively of strains from Libo Kemkem. The fact that most of the outbreak strains were found to be related to strains from well-known KA foci in northwest Ethiopia and Sudan might suggest multiple introductions of L. donovani strains from these foci into Libo Kemkem district. PMID:21382503

  12. Genetic assessment of connectivity in the common reef sponge, Callyspongia vaginalis (Demospongiae: Haplosclerida) reveals high population structure along the Florida reef tract

    NASA Astrophysics Data System (ADS)

    Debiasse, M. B.; Richards, V. P.; Shivji, M. S.

    2010-03-01

    The genetic population structure of the common branching vase sponge, Callyspongia vaginalis, was determined along the entire length (465 km) of the Florida reef system from Palm Beach to the Dry Tortugas based on sequences of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. Populations of C. vaginalis were highly structured (overall ΦST = 0.33), in some cases over distances as small as tens of kilometers. However, nonsignificant pairwise ΦST values were also found between a few relatively distant sampling sites suggesting that some long distance larval dispersal may occur via ocean currents or transport in sponge fragments along continuous, shallow coastlines. Indeed, sufficient gene flow appears to occur along the Florida reef tract to obscure a signal of isolation by distance, but not to homogenize COI haplotype frequencies. The strong genetic differentiation among most of the sampling locations suggests that recruitment in this species is largely local source-driven, pointing to the importance of further elucidating general connectivity patterns along the Florida reef tract to guide the spatial scale of management efforts.

  13. Biochemical analysis of encapsulated and non-encapsulated species of Trichinella (Nematoda, Trichinellidae) from cold- and warm-blooded animals reveals a high genetic divergence in the genus.

    PubMed

    La Rosa, Giuseppe; Marucci, Gianluca; Pozio, Edoardo

    2003-12-01

    Multilocus enzyme electrophoresis was used to analyse genetic variation in the genus Trichinella. Twenty-eight isolates belonging to eight species and six genotypes were analysed for 12 enzyme systems, producing 19 different phenotypes. According to Jaccard's similarity index, the isolates clustered into two main groups, specifically, encapsulated species/genotypes and non-encapsulated species/genotypes. Furthermore, the non-encapsulated species clustered into two other groups: the species infecting mammals and birds ( Trichinella pseudospiralis) and those infecting mammals and reptiles ( Trichinella papuaeand Trichinella zimbabwensis). The encapsulated species/genotypes, which only infect mammals, clustered into four main groups: the cosmopolitan species Trichinella spiralis, the species/genotypes of the temperate regions ( Trichinella britovi, Trichinella murrelli, Trichinella T8, and Trichinella T9), the species/genotype of the arctic region ( Trichinella nativa and Trichinella T6), and the equatorial species Trichinella nelsoni. These results are consistent with biological, epidemiological, and molecular data, which show a high genetic divergence in this genus. PMID:14557876

  14. Genetic structure of Tunisian ethnic groups revealed by paternal lineages.

    PubMed

    Fadhlaoui-Zid, Karima; Martinez-Cruz, Begoña; Khodjet-el-khil, Houssein; Mendizabal, Isabel; Benammar-Elgaaied, Amel; Comas, David

    2011-10-01

    Tunisia has experienced a variety of human migrations that have modeled the myriad cultural groups inhabiting the area. Both Arabic and Berber-speaking populations live in Tunisia. Berbers are commonly considered as in situ descendants of peoples who settled roughly in Palaeolithic times, and posterior demographic events such as the arrival of the Neolithic, the Arab migrations, and the expulsion of the "Moors" from Spain, had a strong cultural influence. Nonetheless, the genetic structure and the population relationships of the ethnic groups living in Tunisia have been poorly assessed. In order to gain insight into the paternal genetic landscape and population structure, more than 40 Y-chromosome single nucleotide polymorphisms and 17 short tandem repeats were analyzed in five Tunisian ethnic groups (three Berber-speaking isolates, one Andalusian, and one Cosmopolitan Arab). The most common lineage was the North African haplogroup E-M81 (71%), being fixed in two Berber samples (Chenini-Douiret and Jradou), suggesting isolation and genetic drift. Differential levels of paternal gene flow from the Near East were detected in the Tunisian samples (J-M267 lineage over 30%); however, no major sub-Saharan African or European influence was found. This result contrasts with the high amount of sub-Saharan and Eurasian maternal lineages previously described in Tunisia. Overall, our results reveal a certain genetic inter-population diversity, especially among Berber groups, and sexual asymmetry, paternal lineages being mostly of autochthonous origin. In addition, Andalusians, who are supposed to be migrants from southern Spain, do not exhibit any substantial contribution of European lineages, suggesting a North African origin for this ethnic group. PMID:21915847

  15. Genetic manipulation of cardiac Hsp72 levels does not alter substrate metabolism but reveals insights into high-fat feeding-induced cardiac insulin resistance.

    PubMed

    Henstridge, Darren C; Estevez, E; Allen, T L; Heywood, S E; Gardner, T; Yang, C; Mellett, N A; Kingwell, B A; Meikle, P J; Febbraio, M A

    2015-05-01

    Heat shock protein 72 (Hsp72) protects cells against a variety of stressors, and multiple studies have suggested that Hsp72 plays a cardioprotective role. As skeletal muscle Hsp72 overexpression can protect against high-fat diet (HFD)-induced insulin resistance, alterations in substrate metabolism may be a mechanism by which Hsp72 is cardioprotective. We investigated the impact of transgenically overexpressing (Hsp72 Tg) or deleting Hsp72 (Hsp72 KO) on various aspects of cardiac metabolism. Mice were fed a normal chow (NC) or HFD for 12 weeks from 8 weeks of age to examine the impact of diet-induced obesity on metabolic parameters in the heart. The HFD resulted in an increase in cardiac fatty acid oxidation and a decrease in cardiac glucose oxidation and insulin-stimulated cardiac glucose clearance; however, there was no difference in Hsp72 Tg or Hsp72 KO mice in these rates compared with their respective wild-type control mice. Although HFD-induced cardiac insulin resistance was not rescued in the Hsp72 Tg mice, it was preserved in the skeletal muscle, suggesting tissue-specific effects of Hsp72 overexpression on substrate metabolism. Comparison of two different strains of mice (BALB/c vs. C57BL/6J) also identified strain-specific differences in regard to HFD-induced cardiac lipid accumulation and insulin resistance. These strain differences suggest that cardiac lipid accumulation can be dissociated from cardiac insulin resistance. Our study finds that genetic manipulation of Hsp72 does not lead to alterations in metabolic processes in cardiac tissue under resting conditions, but identifies mouse strain-specific differences in cardiac lipid accumulation and insulin-stimulated glucose clearance. PMID:25618331

  16. Environmental and genetic perturbations reveal different networks of metabolic regulation

    PubMed Central

    Greenberg, Anthony J; Hackett, Sean R; Harshman, Lawrence G; Clark, Andrew G

    2011-01-01

    Progress in systems biology depends on accurate descriptions of biological networks. Connections in a regulatory network are identified as correlations of gene expression across a set of environmental or genetic perturbations. To use this information to predict system behavior, we must test how the nature of perturbations affects topologies of networks they reveal. To probe this question, we focused on metabolism of Drosophila melanogaster. Our source of perturbations is a set of crosses among 92 wild-derived lines from five populations, replicated in a manner permitting separate assessment of the effects of genetic variation and environmental fluctuation. We directly assayed activities of enzymes and levels of metabolites. Using a multivariate Bayesian model, we estimated covariance among metabolic parameters and built fine-grained probabilistic models of network topology. The environmental and genetic co-regulation networks are substantially the same among five populations. However, genetic and environmental perturbations reveal qualitative differences in metabolic regulation, suggesting that environmental shifts, such as diet modifications, produce different systemic effects than genetic changes, even if the primary targets are the same. PMID:22186737

  17. Screening Respiratory Samples for Detection of Human Rhinoviruses (HRVs) and Enteroviruses: Comprehensive VP4-VP2 Typing Reveals High Incidence and Genetic Diversity of HRV Species C▿

    PubMed Central

    Wisdom, A.; Leitch, E. C. McWilliam; Gaunt, E.; Harvala, H.; Simmonds, P.

    2009-01-01

    Rhinovirus infections are the most common cause of viral illness in humans, and there is increasing evidence of their etiological role in severe acute respiratory tract infections (ARTIs). Human rhinoviruses (HRVs) are classified into two species, species A and B, which contain over 100 serotypes, and a recently discovered genetically heterogeneous third species (HRV species C). To investigate their diversity and population turnover, screening for the detection and the genetic characterization of HRV variants in diagnostic respiratory samples was performed by using nested primers for the efficient amplification of the VP4-VP2 region of HRV (and enterovirus) species and serotype identification. HRV species A, B, and C variants were detected in 14%, 1.8%, and 6.8%, respectively, of 456 diagnostic respiratory samples from 345 subjects (6 samples also contained enteroviruses), predominantly among children under age 10 years. HRV species A and B variants were remarkably heterogeneous, with 22 and 6 different serotypes, respectively, detected among 73 positive samples. Similarly, by using a pairwise distance threshold of 0.1, species C variants occurring worldwide were provisionally assigned to 47 different types, of which 15 were present among samples from Edinburgh, United Kingdom. There was a rapid turnover of variants, with only 5 of 43 serotypes detected during both sampling periods. By using divergence thresholds and phylogenetic analysis, several species A and C variants could provisionally be assigned to new types. An initial investigation of the clinical differences between rhinovirus species found HRV species C to be nearly twice as frequently associated with ARTIs than other rhinovirus species, which matches the frequencies of detection of respiratory syncytial virus. The study demonstrates the extraordinary genetic diversity of HRVs, their rapid population turnover, and their extensive involvement in childhood respiratory disease. PMID:19828751

  18. Genetic investigation within Lactococcus garvieae revealed two genomic lineages.

    PubMed

    Ferrario, Chiara; Ricci, Giovanni; Borgo, Francesca; Rollando, Alessandro; Fortina, Maria Grazia

    2012-07-01

    The diversity of a collection of 49 Lactococcus garvieae strains, including isolates of dairy, fish, meat, vegetable and cereal origin, was explored using a molecular polyphasic approach comprising PCR-ribotyping, REP and RAPD-PCR analyses and a multilocus restriction typing (MLRT) carried out on six partial genes (atpA, tuf, dltA, als, gapC, and galP). This approach allowed high-resolution cluster analysis in which two major groups were distinguishable: one group included dairy isolates, the other group meat isolates. Unexpectedly, of the 12 strains coming from fish, four grouped with dairy isolates, whereas the others with meat isolates. Likewise, strains isolated from vegetables allocated between the two main groups. These findings revealed high variability within the species at both gene and genome levels. The observed genetic heterogeneity among L. garvieae strains was not entirely coherent with the ecological niche of origin of the strains, but rather supports the idea of an early separation of L. garvieae population into two independent genomic lineages. PMID:22568590

  19. Genetic mapping of legume orthologs reveals high conservation of synteny between lentil species and the sequenced genomes of Medicago and chickpea

    PubMed Central

    Gujaria-Verma, Neha; Vail, Sally L.; Carrasquilla-Garcia, Noelia; Penmetsa, R. Varma; Cook, Douglas R.; Farmer, Andrew D.; Vandenberg, Albert; Bett, Kirstin E.

    2014-01-01

    Lentil (Lens culinaris Medik.) is a global food crop with increasing importance for food security in south Asia and other regions. Lens ervoides, a wild relative of cultivated lentil, is an important source of agronomic trait variation. Lens is a member of the galegoid clade of the Papilionoideae family, which includes other important dietary legumes such as chickpea (Cicer arietinum) and pea (Pisum sativum), and the sequenced model legume Medicago truncatula. Understanding the genetic structure of Lens spp. in relation to more fully sequenced legumes would allow leveraging of genomic resources. A set of 1107 TOG-based amplicons were identified in L. ervoides and a subset thereof used to design SNP markers for mapping. A map of L. ervoides consisting of 377 SNP markers spread across seven linkage groups was developed using a GoldenGate genotyping array and single SNP marker assays. Comparison with maps of M. truncatula and L. culinaris documented considerable shared synteny and led to the identification of a few major translocations and a major inversion that distinguish Lens from M. truncatula, as well as a translocation that distinguishes L. culinaris from L. ervoides. The identification of chromosome-level differences among Lens spp. will aid in the understanding of introgression of genes from L. ervoides into cultivated L. culinaris, furthering genetic research and breeding applications in lentil. PMID:25538716

  20. Population Genetic Analysis Reveals a High Genetic Diversity in the Brazilian Cryptococcus gattii VGII Population and Shifts the Global Origin from the Amazon Rainforest to the Semi-arid Desert in the Northeast of Brazil.

    PubMed

    Souto, Ana C P; Bonfietti, Lucas X; Ferreira-Paim, Kennio; Trilles, Luciana; Martins, Marilena; Ribeiro-Alves, Marcelo; Pham, Cau D; Martins, Liline; Dos Santos, Wallace; Chang, Marilene; Brito-Santos, Fabio; Santos, Dayane C S; Fortes, Silvana; Lockhart, Shawn R; Wanke, Bodo; Melhem, Márcia S C; Lazéra, Márcia S; Meyer, Wieland

    2016-08-01

    Cryptococcus neoformans and Cryptococcus gattii are responsible globally for almost one million cryptococcosis cases yearly, mostly in immunocompromised patients, such as those living with HIV. Infections due to C. gattii have mainly been described in tropical and subtropical regions, but its adaptation to temperate regions was crucial in the species evolution and highlighted the importance of this pathogenic yeast in the context of disease. Cryptococcus gattii molecular type VGII has come to the forefront in connection with an on-going emergence in the Pacific North West of North America. Taking into account that previous work pointed towards South America as an origin of this species, the present work aimed to assess the genetic diversity within the Brazilian C. gattii VGII population in order to gain new insights into its origin and global dispersal from the South American continent using the ISHAM consensus MLST typing scheme. Our results corroborate the finding that the Brazilian C. gattii VGII population is highly diverse. The diversity is likely due to recombination generated from sexual reproduction, as evidenced by the presence of both mating types in clinical and environmental samples. The data presented herein strongly supports the emergence of highly virulent strains from ancestors in the Northern regions of Brazil, Amazonia and the Northeast. Numerous genotypes represent a link between Brazil and other parts of the world reinforcing South America as the most likely origin of the C. gattii VGII subtypes and their subsequent global spread, including their dispersal into North America, where they caused a major emergence. PMID:27529479

  1. Population Genetic Analysis Reveals a High Genetic Diversity in the Brazilian Cryptococcus gattii VGII Population and Shifts the Global Origin from the Amazon Rainforest to the Semi-arid Desert in the Northeast of Brazil

    PubMed Central

    Ferreira-Paim, Kennio; Trilles, Luciana; Martins, Marilena; Ribeiro-Alves, Marcelo; Pham, Cau D.; Martins, Liline; dos Santos, Wallace; Chang, Marilene; Brito-Santos, Fabio; Santos, Dayane C. S.; Fortes, Silvana; Lockhart, Shawn R.; Wanke, Bodo; Melhem, Márcia S. C.; Lazéra, Márcia S.; Meyer, Wieland

    2016-01-01

    Cryptococcus neoformans and Cryptococcus gattii are responsible globally for almost one million cryptococcosis cases yearly, mostly in immunocompromised patients, such as those living with HIV. Infections due to C. gattii have mainly been described in tropical and subtropical regions, but its adaptation to temperate regions was crucial in the species evolution and highlighted the importance of this pathogenic yeast in the context of disease. Cryptococcus gattii molecular type VGII has come to the forefront in connection with an on-going emergence in the Pacific North West of North America. Taking into account that previous work pointed towards South America as an origin of this species, the present work aimed to assess the genetic diversity within the Brazilian C. gattii VGII population in order to gain new insights into its origin and global dispersal from the South American continent using the ISHAM consensus MLST typing scheme. Our results corroborate the finding that the Brazilian C. gattii VGII population is highly diverse. The diversity is likely due to recombination generated from sexual reproduction, as evidenced by the presence of both mating types in clinical and environmental samples. The data presented herein strongly supports the emergence of highly virulent strains from ancestors in the Northern regions of Brazil, Amazonia and the Northeast. Numerous genotypes represent a link between Brazil and other parts of the world reinforcing South America as the most likely origin of the C. gattii VGII subtypes and their subsequent global spread, including their dispersal into North America, where they caused a major emergence. PMID:27529479

  2. Candida milleri species reveals intraspecific genetic and metabolic polymorphisms.

    PubMed

    Vigentini, Ileana; Antoniani, Davide; Roscini, Luca; Comasio, Andrea; Galafassi, Silvia; Picozzi, Claudia; Corte, Laura; Compagno, Concetta; Dal Bello, Fabio; Cardinali, Gianluigi; Foschino, Roberto

    2014-09-01

    Candida milleri, together with Candida humilis, is the most representative yeast species found in type I sourdough ecosystems. In this work, comparison of the ITS region and the D1/D2 domain of 26S rDNA gene partial sequences, karyotyping, mtDNA-RFLP analysis, Intron Splice Site dispersion (ISS-PCR) and (GTG)5 microsatellite analyses, assimilation test of different carbohydrates, and metabolome assessment by FT-IR analysis, were investigated in seventeen strains isolated from four different companies as well as in type strains CBS6897(T) and CBS5658(T). Most isolates were ascribed to C. milleri, even if a strong relatedness was confirmed with C. humilis as well, particularly for three strains. Genetic characterization showed a high degree of intraspecific polymorphism since 12 different genotypes were discriminated. The number of chromosomes varied from 9 to 13 and their size ranged from less than 0.3 to over 2 Mbp. Phenotypic traits let to recognize 9 different profiles of carbon sources assimilation. FT-IR spectra from yeast cells cultivated in different media and collected at different growth phases revealed a diversity of behaviour among strains in accordance with the results of PCR-based fingerprinting. A clear evidence of the polymorphic status of C. milleri species is provided thus representing an important feature for the development of technological applications in bakery industries. PMID:24929720

  3. High Genetic Diversity of Newcastle Disease Virus in Wild and Domestic Birds in Northeastern China from 2013 to 2015 Reveals Potential Epidemic Trends.

    PubMed

    Zhang, Pingze; Xie, Guangyao; Liu, Xinxin; Ai, Lili; Chen, Yanyu; Meng, Xin; Bi, Yuhai; Chen, Jianjun; Sun, Yuzhang; Stoeger, Tobias; Ding, Zhuang; Yin, Renfu

    2016-03-01

    Newcastle disease (ND), caused by the virulent Newcastle disease virus (NDV), is one of the most important viral diseases of birds globally, but little is currently known regarding enzootic trends of NDV in northeastern China, especially for class I viruses. Thus, we performed a surveillance study for NDV in northeastern China from 2013 to 2015. A total 755 samples from wild and domestic birds in wetlands and live bird markets (LBMs) were collected, and 10 isolates of NDV were identified. Genetic and phylogenetic analyses showed that five isolates from LBMs belong to class I subgenotype 1b, two (one from wild birds and one from LBMs) belong to the vaccine-like class II genotype II, and three (all from wild birds) belong to class II subgenotype Ib. Interestingly, the five class I isolates had epidemiological connections with viruses from southern, eastern, and southeastern China. Our findings, together with recent prevalence trends of class I and virulent class II NDV in China, suggest possible virus transmission between wild and domestic birds and the potential for an NDV epidemic in the future. PMID:26712543

  4. Analysis of HCV-6 isolates among Asian-born immigrants in North America reveals their high genetic diversity and a new subtype.

    PubMed

    Lu, Ling; Wu, Tao; Xiong, Lu; Li, Chunhua; Nguyen, Mindie H; Murphy, Donald G

    2016-05-01

    We characterized full-length genomes for 15 HCV-6 isolates, all from Asian immigrants living in North America. Among these isolates, nine were novel variants showing >15% nucleotide differences from their nearest relatives, representing lineages distinct from known subtypes. The other six were classified into subtypes 6c, 6h, 6q, 6r, and 6s. The partial sequences were also determined for five additional HCV-6 isolates, three from the US and two from Canada. The latter two were assigned to new subtype 6xf as they were found to classify with two other isolates for which we recently reported their full-length genomes. We further analyzed partial Core-E1 sequences of 100 HCV-6 isolates sampled in North America, seven from the US and 93 from Canada and all from Asian immigrants except for four from Caucasians. These 100 isolates belonged to 20 assigned subtypes and 16 unclassified lineages showing great genetic diversity and enhanced significance to public health. PMID:26896932

  5. Genetic heterogeneity in rhabdomyosarcoma revealed by SNP array analysis.

    PubMed

    Walther, Charles; Mayrhofer, Markus; Nilsson, Jenny; Hofvander, Jakob; Jonson, Tord; Mandahl, Nils; Øra, Ingrid; Gisselsson, David; Mertens, Fredrik

    2016-01-01

    Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents. Alveolar (ARMS) and embryonal (ERMS) histologies predominate, but rare cases are classified as spindle cell/sclerosing (SRMS). For treatment stratification, RMS is further subclassified as fusion-positive (FP-RMS) or fusion-negative (FN-RMS), depending on whether a gene fusion involving PAX3 or PAX7 is present or not. We investigated 19 cases of pediatric RMS using high resolution single-nucleotide polymorphism (SNP) array. FP-ARMS displayed, on average, more structural rearrangements than ERMS; the single FN-ARMS had a genomic profile similar to ERMS. Apart from previously known amplification (e.g., MYCN, CDK4, and MIR17HG) and deletion (e.g., NF1, CDKN2A, and CDKN2B) targets, amplification of ERBB2 and homozygous loss of ASCC3 or ODZ3 were seen. Combining SNP array with cytogenetic data revealed that most cases were polyploid, with at least one case having started as a near-haploid tumor. Further bioinformatic analysis of the SNP array data disclosed genetic heterogeneity, in the form of subclonal chromosomal imbalances, in five tumors. The outcome was worse for patients with FP-ARMS than ERMS or FN-ARMS (6/8 vs. 1/9 dead of disease), and the only children with ERMS showing intratumor diversity or with MYOD1 mutation-positive SRMS also died of disease. High resolution SNP array can be useful in evaluating genomic imbalances in pediatric RMS. PMID:26482321

  6. Argument in High School Genetics.

    ERIC Educational Resources Information Center

    Jimenez-Aleixandre, M. Pilar; Bugallo-Rodriguez, Anxela

    This paper reports on a case study focusing on the development of students' capacity to develop and assess arguments in the context of instruction in high school genetics. It is part of a wider project whose goals were: (1) the identification of the conditions for argument (and in general scientific reasoning) to occur in science classrooms; (2)…

  7. Noninvasive genetic sampling reveals intrasex territoriality in wolverines.

    PubMed

    Bischof, Richard; Gregersen, Espen R; Brøseth, Henrik; Ellegren, Hans; Flagstad, Øystein

    2016-03-01

    Due to its conspicuous manifestations and its capacity to shape the configuration and dynamics of wild populations, territorial behavior has long intrigued ecologists. Territoriality and other animal interactions in situ have traditionally been studied via direct observations and telemetry. Here, we explore whether noninvasive genetic sampling, which is increasingly supplementing traditional field methods in ecological research, can reveal territorial behavior in an elusive carnivore, the wolverine (Gulo gulo). Using the locations of genotyped wolverine scat samples collected annually over a period of 12 years in central Norway, we test three predictions: (1) male home ranges constructed from noninvasive genetic sampling data are larger than those of females, (2) individuals avoid areas used by other conspecifics of the same sex (intrasexual territoriality), and (3) avoidance of same-sex territories diminishes or disappears after the territory owner's death. Each of these predictions is substantiated by our results: sex-specific differences in home range size and intrasexual territoriality in wolverine are patently reflected in the spatial and temporal configuration of noninvasively collected genetic samples. Our study confirms that wildlife monitoring programs can utilize the spatial information in noninvasive genetic sampling data to detect and quantify home ranges and social organization. PMID:27087927

  8. High Genetic Diversity among Strains of the Unindustrialized Lactic Acid Bacterium Carnobacterium maltaromaticum in Dairy Products as Revealed by Multilocus Sequence Typing

    PubMed Central

    Rahman, Abdur; Cailliez-Grimal, Catherine; Bontemps, Cyril; Payot, Sophie; Chaillou, Stéphane; Revol-Junelles, Anne-Marie

    2014-01-01

    Dairy products are colonized with three main classes of lactic acid bacteria (LAB): opportunistic bacteria, traditional starters, and industrial starters. Most of the population structure studies were previously performed with LAB species belonging to these three classes and give interesting knowledge about the population structure of LAB at the stage where they are already industrialized. However, these studies give little information about the population structure of LAB prior their use as an industrial starter. Carnobacterium maltaromaticum is a LAB colonizing diverse environments, including dairy products. Since this bacterium was discovered relatively recently, it is not yet commercialized as an industrial starter, which makes C. maltaromaticum an interesting model for the study of unindustrialized LAB population structure in dairy products. A multilocus sequence typing scheme based on an analysis of fragments of the genes dapE, ddlA, glpQ, ilvE, pyc, pyrE, and leuS was applied to a collection of 47 strains, including 28 strains isolated from dairy products. The scheme allowed detecting 36 sequence types with a discriminatory index of 0.98. The whole population was clustered in four deeply branched lineages, in which the dairy strains were spread. Moreover, the dairy strains could exhibit a high diversity within these lineages, leading to an overall dairy population with a diversity level as high as that of the nondairy population. These results are in agreement with the hypothesis according to which the industrialization of LAB leads to a diversity reduction in dairy products. PMID:24747901

  9. Ultra-Deep Sequencing of HIV-1 near Full-Length and Partial Proviral Genomes Reveals High Genetic Diversity among Brazilian Blood Donors

    PubMed Central

    Pessôa, Rodrigo; Loureiro, Paula; Esther Lopes, Maria; Carneiro-Proietti, Anna B. F.; Sabino, Ester C; Busch, Michael P.; Sanabani, Sabri S

    2016-01-01

    Background Here, we aimed to gain a comprehensive picture of the HIV-1 diversity in the northeast and southeast part of Brazil. To this end, a high-throughput sequencing-by-synthesis protocol and instrument were used to characterize the near full length (NFLG) and partial HIV-1 proviral genome in 259 HIV-1 infected blood donors at four major blood centers in Brazil: Pro-Sangue foundation (São Paulo state (SP), n 51), Hemominas foundation (Minas Gerais state (MG), n 41), Hemope foundation (Recife state (PE), n 96) and Hemorio blood bank (Rio de Janeiro (RJ), n 70). Materials and Methods A total of 259 blood samples were obtained from 195 donors with long-standing infections and 64 donors with a lack of stage information. DNA was extracted from the peripheral blood mononuclear cells (PBMCs) to amplify the HIV-1 NFLGs from five overlapping fragments. The amplicons were molecularly bar-coded, pooled, and sequenced by Illumina paired-end protocol. Results Of the 259 samples studied, 208 (80%) NFLGs and 49 (18.8%) partial fragments were de novo assembled into contiguous sequences and successfully subtyped. Of these 257 samples, 183 (71.2%) were pure subtypes consisting of clade B (n = 167, 65%), C (n = 10, 3.9%), F1 (n = 4, 1.5%), and D (n = 2, 0.7%). Recombinant viruses were detected in 74 (28.8%) samples and consist of unique BF1 (n = 41, 15.9%), BC (n = 7, 2.7%), BCF1 (n = 4, 1.5%), CF1 and CDK (n = 1, 0.4%, each), CRF70_BF1 (n = 4, 1.5%), CRF71_BF1 (n = 12, 4.7%), and CRF72_BF1 (n = 4, 1.5%). Evidence of dual infection was detected in four patients coinfected with the same subtype (n = 3) and distinct subtype (n = 1). Conclusion Based on this work, subtype B appears to be the prevalent subtype followed by a high proportion of intersubtype recombinants that appeared to be arising continually in this country. Our study represents the largest analysis of the viral NFLG ever undertaken worldwide and provides insights into the understanding the genesis of the HIV-1

  10. Comparative RNA sequencing reveals substantial genetic variation in endangered primates

    PubMed Central

    Perry, George H.; Melsted, Páll; Marioni, John C.; Wang, Ying; Bainer, Russell; Pickrell, Joseph K.; Michelini, Katelyn; Zehr, Sarah; Yoder, Anne D.; Stephens, Matthew; Pritchard, Jonathan K.; Gilad, Yoav

    2012-01-01

    Comparative genomic studies in primates have yielded important insights into the evolutionary forces that shape genetic diversity and revealed the likely genetic basis for certain species-specific adaptations. To date, however, these studies have focused on only a small number of species. For the majority of nonhuman primates, including some of the most critically endangered, genome-level data are not yet available. In this study, we have taken the first steps toward addressing this gap by sequencing RNA from the livers of multiple individuals from each of 16 mammalian species, including humans and 11 nonhuman primates. Of the nonhuman primate species, five are lemurs and two are lorisoids, for which little or no genomic data were previously available. To analyze these data, we developed a method for de novo assembly and alignment of orthologous gene sequences across species. We assembled an average of 5721 gene sequences per species and characterized diversity and divergence of both gene sequences and gene expression levels. We identified patterns of variation that are consistent with the action of positive or directional selection, including an 18-fold enrichment of peroxisomal genes among genes whose regulation likely evolved under directional selection in the ancestral primate lineage. Importantly, we found no relationship between genetic diversity and endangered status, with the two most endangered species in our study, the black and white ruffed lemur and the Coquerel's sifaka, having the highest genetic diversity among all primates. Our observations imply that many endangered lemur populations still harbor considerable genetic variation. Timely efforts to conserve these species alongside their habitats have, therefore, strong potential to achieve long-term success. PMID:22207615

  11. Adolescent non-adherence reveals a genetic cause for diabetes

    PubMed Central

    Carmody, D.; Lindauer, K. L.; Naylor, R. N.

    2015-01-01

    Background GCK-MODY is a form of monogenic diabetes characterized by mildly elevated fasting blood sugars and HbA1c typically ranging from 38 to 60 mmol/mol (5.6–7.6%). It is frequently unrecognized or misdiagnosed as Type 1 or Type 2 diabetes, resulting in unnecessary pharmacologic therapy. Case report Two brothers were initially diagnosed with Type 1 diabetes mellitus. The brothers were maintained on a total daily insulin dose of 0.3–0.5 units/kg/day and had HbA1c values of 40–51 mmol/mol (5.8–6.8%) throughout childhood. After over 10 years of insulin treatment, the younger brother chose to discontinue his insulin therapy without informing his family or his clinician. Following cessation of insulin treatment, he did not experience any change in overall glycaemic control. Subsequent research-based genetic testing revealed a deleterious mutation in GCK in both brothers (p.Val182Met). The older brother subsequently discontinued insulin therapy and both have remained off all pharmacological therapy with good glycaemic control (HbA1c < 53 mmol/mol, < 7%) and no adverse complications. The family was advised to seek confirmatory genetic testing in the father and other relatives with hyperglycaemia. Conclusion The family described above exemplifies the rationale behind considering a genetic cause when evaluating every person with new-onset hyperglycaemia or those with atypical diabetes. The cost of genetic testing for the most common maturity-onset diabetes of the young (MODY)-causing genes may be offset by savings made in therapeutic costs. It is important that all clinicians supervising diabetes care recognize the cardinal features that distinguish GCK-MODY from other forms of diabetes. PMID:25494859

  12. The integration of quantitative genetics, paleontology, and neontology reveals genetic underpinnings of primate dental evolution.

    PubMed

    Hlusko, Leslea J; Schmitt, Christopher A; Monson, Tesla A; Brasil, Marianne F; Mahaney, Michael C

    2016-08-16

    Developmental genetics research on mice provides a relatively sound understanding of the genes necessary and sufficient to make mammalian teeth. However, mouse dentitions are highly derived compared with human dentitions, complicating the application of these insights to human biology. We used quantitative genetic analyses of data from living nonhuman primates and extensive osteological and paleontological collections to refine our assessment of dental phenotypes so that they better represent how the underlying genetic mechanisms actually influence anatomical variation. We identify ratios that better characterize the output of two dental genetic patterning mechanisms for primate dentitions. These two newly defined phenotypes are heritable with no measurable pleiotropic effects. When we consider how these two phenotypes vary across neontological and paleontological datasets, we find that the major Middle Miocene taxonomic shift in primate diversity is characterized by a shift in these two genetic outputs. Our results build on the mouse model by combining quantitative genetics and paleontology, and thereby elucidate how genetic mechanisms likely underlie major events in primate evolution. PMID:27402751

  13. The integration of quantitative genetics, paleontology, and neontology reveals genetic underpinnings of primate dental evolution

    PubMed Central

    Hlusko, Leslea J.; Schmitt, Christopher A.; Monson, Tesla A.; Brasil, Marianne F.; Mahaney, Michael C.

    2016-01-01

    Developmental genetics research on mice provides a relatively sound understanding of the genes necessary and sufficient to make mammalian teeth. However, mouse dentitions are highly derived compared with human dentitions, complicating the application of these insights to human biology. We used quantitative genetic analyses of data from living nonhuman primates and extensive osteological and paleontological collections to refine our assessment of dental phenotypes so that they better represent how the underlying genetic mechanisms actually influence anatomical variation. We identify ratios that better characterize the output of two dental genetic patterning mechanisms for primate dentitions. These two newly defined phenotypes are heritable with no measurable pleiotropic effects. When we consider how these two phenotypes vary across neontological and paleontological datasets, we find that the major Middle Miocene taxonomic shift in primate diversity is characterized by a shift in these two genetic outputs. Our results build on the mouse model by combining quantitative genetics and paleontology, and thereby elucidate how genetic mechanisms likely underlie major events in primate evolution. PMID:27402751

  14. Individual olfactory perception reveals meaningful nonolfactory genetic information

    PubMed Central

    Secundo, Lavi; Snitz, Kobi; Weissler, Kineret; Pinchover, Liron; Shoenfeld, Yehuda; Loewenthal, Ron; Agmon-Levin, Nancy; Frumin, Idan; Bar-Zvi, Dana; Shushan, Sagit; Sobel, Noam

    2015-01-01

    Each person expresses a potentially unique subset of ∼400 different olfactory receptor subtypes. Given that the receptors we express partially determine the odors we smell, it follows that each person may have a unique nose; to capture this, we devised a sensitive test of olfactory perception we termed the “olfactory fingerprint.” Olfactory fingerprints relied on matrices of perceived odorant similarity derived from descriptors applied to the odorants. We initially fingerprinted 89 individuals using 28 odors and 54 descriptors. We found that each person had a unique olfactory fingerprint (P < 10−10), which was odor specific but descriptor independent. We could identify individuals from this pool using randomly selected sets of 7 odors and 11 descriptors alone. Extrapolating from this data, we determined that using 34 odors and 35 descriptors we could individually identify each of the 7 billion people on earth. Olfactory perception, however, fluctuates over time, calling into question our proposed perceptual readout of presumably stable genetic makeup. To test whether fingerprints remain informative despite this temporal fluctuation, building on the linkage between olfactory receptors and HLA, we hypothesized that olfactory perception may relate to HLA. We obtained olfactory fingerprints and HLA typing for 130 individuals, and found that olfactory fingerprint matching using only four odorants was significantly related to HLA matching (P < 10−4), such that olfactory fingerprints can save 32% of HLA tests in a population screen (P < 10−6). In conclusion, a precise measure of olfactory perception reveals meaningful nonolfactory genetic information. PMID:26100865

  15. Genetic relationships among four minorities in Guangxi revealed by analysis of 15 STRs.

    PubMed

    Deng, Qiongying; Xu, Lin; Gong, Jichun; Zhou, Lining; Li, Songfeng; Deng, Xiangfa; Luo, Guorong; Xie, Xiaoxun

    2007-12-01

    The aim of this study is to investigate the genetic diversity in 15 STRs (short tandem repeats) loci of four minorities in Guangxi Province and to probe into the genetic variation and relationships among these ethnic groups. Allele frequencies of 15 STR loci were collected from 766 unrelated Mulao, Maonan, Miao, and Yao ethnic individuals by PCR-STR and sequencing, and their allele-frequency distribution were compared with each other. The genetic parameters and genetic distances were calculated, and the phylogenetic tree was constructed. Based on the results from this study, 135, 134, 148, and 145 alleles and 424, 432, 445, and 436 genotypes for 15 STR loci were observed in the Mulao, Maonan, Miao, and Yao minorities, respectively. The average heterozygosity of all ethnic groups analyzed was above 0.7; the cumulative power of discrimination (DP), the probabilities of paternity exclusion (EPP), and the polymorphic information content (PIC) were greater than 0.99999. Comparison of the allele-frequency distribution indicated that there were significant differences at most loci between Maonan vs. Miao, Yao vs. other groups, but no distinct differences between Mulao vs. Maonan, and Mulao vs. Miao minorities. The NJ tree based on the genetic distance showed that the four minorities were separated into two groups. Mulao and Maonan were clustered into one group, whereas Miao and Yao into the other. Our results revealed that 15 STR loci of the four minorities possessed high genetic diversities. Therefore, the combination of these 15 STRs is a powerful tool for forensic individual identification and paternity investigation, as well as anthropologic and genetic researches. The genetic variation and relationships among the 4 populations revealed by 15 STRs are basically consistent with their linguistic culture and ethical history. PMID:18155619

  16. Genetically engineered immunoglobulins reveal structural features controlling segmental flexibility.

    PubMed Central

    Schneider, W P; Wensel, T G; Stryer, L; Oi, V T

    1988-01-01

    We have carried out nanosecond fluorescence polarization studies of genetically engineered immunoglobulins to determine the structural features controlling their segmental flexibility. The proteins studied were hybrids of a relatively rigid isotype (mouse IgG1) and a relatively flexible one (mouse IgG2a). They have identical light chains and heavy chain variable regions and have the same combining sites for epsilon-dansyl-L-lysine, a fluorescent hapten. The fluorescence of the bound dansyl chromophore was excited at 348 nm with subnanosecond laser pulses, and the emission in the nanosecond time range was measured with a single-photon-counting apparatus. The emission anisotropy kinetics of the hybrid antibodies revealed that segmental flexibility is controlled by the heavy chain constant region 1 (CH1) as well as by the hinge. In contrast, the CH2 and CH3 domains did not influence segmental flexibility. The hinge and CH1 domains must be properly matched to allow facile movement of the Fab units. Studies of hybrids of IgG1 and IgG2a within CH1 showed that the loop formed by residues 131-139 is important in controlling segmental flexibility. X-ray crystallographic studies by others of human IgG1 have shown that this loop makes several van der Waals contacts with the hinge. Images PMID:3128789

  17. New Genetic Susceptibility Factors for Sjögren's Syndrome Revealed

    MedlinePlus

    ... 1999 Spotlight on Research 2014 March 2014 (historical) New Genetic Susceptibility Factors for Sjögren’s Syndrome Revealed By ... the journal Nature Genetics, could help researchers develop new strategies to diagnose and treat the condition. In ...

  18. Microsatellite markers reveal genetic divergence among wild and cultured populations of Chinese sucker Myxocyprinus asiaticus.

    PubMed

    Cheng, W W; Wang, D Q; Wang, C Y; Du, H; Wei, Q W

    2016-01-01

    Studies of genetic diversity and genetic population structure are critical for the conservation and management of endangered species. The Chinese sucker Myxocyprinus asiaticus is a vulnerable monotypic species in China, which is at a risk of decline owing to fluctuations in effective population size and other demographic and environmental factors. We screened 11 microsatellite loci in 214 individuals to assess genetic differentiation in both wild and cultured populations. The single extant wild population had a higher number of alleles (13) than the cultured populations (average 7.3). High levels of genetic diversity, expressed as observed and expected heterozygosity (HO = 0.771, HE = 0.748, respectively), were found in both wild and cultured populations. We also report significant differentiation among wild and cultured populations (global FST = 0.023, P < 0.001). Both STRUCTURE analysis and neighbor-joining tree revealed three moderately divergent primary genetic clusters: the wild Yangtze population and the Sichuan population were each identified as an individual cluster, with the remaining populations clustered together. Twenty-two samples collected from the Yangtze River were assigned to the cultured population, demonstrating the efficacy of artificial propagation to avoid drastic reduction in the population size of M. asiaticus. These genetic data support the endangered status of the M. asiaticus and have implications for conservation management planning. PMID:27173283

  19. Lack of Genetic Variation of Bursaphelenchus xylophilus in Portugal Revealed by RAPD-PCR Analyses.

    PubMed

    Vieira, Paulo; Burgermeister, Wolfgang; Mota, Manuel; Metge, Kai; Silva, Gonçalo

    2007-06-01

    Random Amplified Polymorphic DNA (RAPD-PCR) technique was used to assess the level of genetic variability and genetic relationships among 24 Portuguese isolates of pinewood nematode, Bursaphelenchus xylophilus. The isolates represent the main infested areas of Portugal. Two additional isolates of B. xylophilus representing North America and East Asia were included, and B. mucronatus was used as out-group. Twenty-eight random primers generated a total of 640 DNA fragments. The Nei and Li similarity index revealed a high genetic similarity among the Portuguese isolates (above 90%). Hierarchical cluster analysis was performed to illustrate the relatedness among the isolates. No indication for separate groups among the Portuguese isolates was obtained, and the low level of genetic diversity strongly suggests that they were dispersed recently from a single introduction. The lack of apparent relationship between the genetic and the geographic matrices of the Portuguese isolates limits the use of this technique for following recent pathways of distribution. Genetic distance of the Portuguese isolates towards an isolate from China was much lower as compared to an isolate from the USA. This confirmed previous results suggesting an East Asian origin of the Portuguese B. xylophilus. PMID:19259480

  20. Genetic Interaction Maps in Escherichia coli Reveal Functional Crosstalk among Cell Envelope Biogenesis Pathways

    PubMed Central

    Vlasblom, James; Gagarinova, Alla; Phanse, Sadhna; Graham, Chris; Yousif, Fouad; Ding, Huiming; Xiong, Xuejian; Nazarians-Armavil, Anaies; Alamgir, Md; Ali, Mehrab; Pogoutse, Oxana; Pe'er, Asaf; Arnold, Roland; Michaut, Magali; Parkinson, John; Golshani, Ashkan; Whitfield, Chris; Wodak, Shoshana J.; Moreno-Hagelsieb, Gabriel; Greenblatt, Jack F.; Emili, Andrew

    2011-01-01

    As the interface between a microbe and its environment, the bacterial cell envelope has broad biological and clinical significance. While numerous biosynthesis genes and pathways have been identified and studied in isolation, how these intersect functionally to ensure envelope integrity during adaptive responses to environmental challenge remains unclear. To this end, we performed high-density synthetic genetic screens to generate quantitative functional association maps encompassing virtually the entire cell envelope biosynthetic machinery of Escherichia coli under both auxotrophic (rich medium) and prototrophic (minimal medium) culture conditions. The differential patterns of genetic interactions detected among >235,000 digenic mutant combinations tested reveal unexpected condition-specific functional crosstalk and genetic backup mechanisms that ensure stress-resistant envelope assembly and maintenance. These networks also provide insights into the global systems connectivity and dynamic functional reorganization of a universal bacterial structure that is both broadly conserved among eubacteria (including pathogens) and an important target. PMID:22125496

  1. A negative genetic interaction map in isogenic cancer cell lines reveals cancer cell vulnerabilities

    PubMed Central

    Vizeacoumar, Franco J; Arnold, Roland; Vizeacoumar, Frederick S; Chandrashekhar, Megha; Buzina, Alla; Young, Jordan T F; Kwan, Julian H M; Sayad, Azin; Mero, Patricia; Lawo, Steffen; Tanaka, Hiromasa; Brown, Kevin R; Baryshnikova, Anastasia; Mak, Anthony B; Fedyshyn, Yaroslav; Wang, Yadong; Brito, Glauber C; Kasimer, Dahlia; Makhnevych, Taras; Ketela, Troy; Datti, Alessandro; Babu, Mohan; Emili, Andrew; Pelletier, Laurence; Wrana, Jeff; Wainberg, Zev; Kim, Philip M; Rottapel, Robert; O'Brien, Catherine A; Andrews, Brenda; Boone, Charles; Moffat, Jason

    2013-01-01

    Improved efforts are necessary to define the functional product of cancer mutations currently being revealed through large-scale sequencing efforts. Using genome-scale pooled shRNA screening technology, we mapped negative genetic interactions across a set of isogenic cancer cell lines and confirmed hundreds of these interactions in orthogonal co-culture competition assays to generate a high-confidence genetic interaction network of differentially essential or differential essentiality (DiE) genes. The network uncovered examples of conserved genetic interactions, densely connected functional modules derived from comparative genomics with model systems data, functions for uncharacterized genes in the human genome and targetable vulnerabilities. Finally, we demonstrate a general applicability of DiE gene signatures in determining genetic dependencies of other non-isogenic cancer cell lines. For example, the PTEN−/− DiE genes reveal a signature that can preferentially classify PTEN-dependent genotypes across a series of non-isogenic cell lines derived from the breast, pancreas and ovarian cancers. Our reference network suggests that many cancer vulnerabilities remain to be discovered through systematic derivation of a network of differentially essential genes in an isogenic cancer cell model. PMID:24104479

  2. Genetic scores based on risk-associated single nucleotide polymorphisms (SNPs) can reveal inherited risk of renal cell carcinoma

    PubMed Central

    Chen, Haitao; Lin, Xiaolin; Yu, Yang; Gou, Yuancheng; Hou, Jiangang; Jiang, Deke; Na, Rong; Wang, Xiang; Ding, Qiang; Xu, Jianfeng

    2016-01-01

    The objective of this study was to evaluate whether renal cell carcinoma (RCC) risk-associated single nucleotide polymorphisms (SNPs) could reflect the individual inherited risks of RCC. A total of 346 RCC patients and 1,130 controls were recruited in this case-control study. Genetic scores were calculated for each individual based on the odds ratios and frequencies of risk-associated SNPs. Four SNPs were significantly associated with RCC in Chinese population. Two genetic score models were established, genetic score 1 (rs10054504, rs7023329 and rs718314) and genetic score 2 (rs10054504, rs7023329 and rs1049380). For genetic score 1, the individual likelihood of RCC with low (<0.8), medium (0.8-1.2) and high (≥1.2) genetic score 1 was 15.61%, 22.25% and 33.92% respectively (P-trend=6.88×10−7). For genetic score 2, individual with low (<0.8), medium (0.8-1.2) and high (≥1.2) genetic score 2 would have likelihood of RCC as 14.39%, 24.54% and 36.48%, respectively (P-trend=1.27×10−10). The area under the receiver operating curve (AUC) of genetic score 1 was 0.626, and AUC of genetic score 2 was 0.658. We concluded that genetic score can reveal personal risk and inherited risk of RCC, especially when family history is not available. PMID:27229762

  3. Genetic diversity of Cosmos species revealed by RAPD and ISSR markers.

    PubMed

    Rodríguez-Bernal, A; Piña-Escutia, J L; Vázquez-García, L M; Arzate-Fernández, A M

    2013-01-01

    The genus Cosmos is native of America and is constituted by 34 species; 28 of them are endemic of Mexico. The cosmos are used as a nematicide, antimalarial, and antioxidative agent. The aim of this study was to estimate the genetic diversity among 7 cosmos species based on random amplified polymorphic DNA (RAPD) and inter-simple sequences repeats (ISSR) markers. With RAPD markers, the obtained polymorphism was 91.7 % and the genetic diversity was 0.33, whereas these values were 65.6%, and 0.22 from ISSR markers, respectively, indicating the presence of high genetic diversity among the Cosmos species that were analyzed. The unweighted pair group method with arithmetic mean dendrograms that were obtained with both markers were notably similar, revealing 2 clusters and indicating a clear genetic differentiation among the Cosmos species that were assessed. The first cluster comprised the species Cosmos sulphureus, Cosmos pacificus, and Cosmos diversifolius, while the second cluster included the species Cosmos purpureus, Cosmos crithmifolius, Cosmos bipinnatus, and Cosmos parviflorus. Besides this, the Cosmos species were clustered according to their collection sites. The Mantel test corroborates the correlation between the genetic distance and the geographic altitude of each Cosmos species. The results suggest that it is necessary to preserve the Cosmos species in their natural habitat in addition to the germoplasm collection for ex situ conservation. PMID:24338421

  4. High levels of genetic variability and differentiation in hilsa shad, Tenualosa ilisha (Clupeidae, Clupeiformes) populations revealed by PCR-RFLP analysis of the mitochondrial DNA D-loop region

    PubMed Central

    2009-01-01

    The hilsa shad, Tenualosa ilisha (Clupeidae, Clupeiformes) is an important anadromous clupeid species from the Western division of the Indo-Pacific region. It constitutes the largest single fishable species in Bangladesh. Information on genetic variability and population structure is very important for both management and conservation purposes. Past reports on the population structure of T. ilisha involving morphometric, allozyme and RAPD analyses are contradictory. We examined genetic variability and divergence in two riverine (the Jamuna and the Meghna), two estuarine (Kuakata and Sundarbans) and one marine (Cox's Bazar) populations of T. ilisha by applying PCR-RFLP analysis of the mtDNA D-loop region. The amplified PCR products were restricted with four restriction enzymes namely, XbaI, EcoRI, EcoRV, and HaeIII. High levels of haplotype and gene diversity within and significant differentiations among, populations of T. ilisha were observed in this study. Significant FST values indicated differentiation among the river, estuary and marine populations. The UPGMA dendrogram based on genetic distance resulted in two major clusters, although, these were subsequently divided into three, corresponding to the riverine, estuarine and marine populations. The study underlines the usefulness of RFLP of mtDNA D-loop region as molecular markers, and detected at least two differentiated populations of T. ilisha in Bangladesh waters. PMID:21637667

  5. Bovine Genetic Diversity Revealed By mtDNA Sequence Variation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mitochondrial DNA single nucleotide polymorphism (SNP) data were used to determine genetic distance, nucleotide diversity, construction of haplotypes, estimation of information contents, and phylogenic relationships in bovine HapMap breeds. The Bovine International HapMap panel consists of 720 anima...

  6. Population genetics of Sargassum horneri (Fucales, Phaeophyta) in China revealed by ISSR and SRAP markers

    NASA Astrophysics Data System (ADS)

    Yu, Shenhui; Chong, Zhuo; Zhao, Fengjuan; Yao, Jianting; Duan, Delin

    2013-05-01

    Sargassum horneri is a common brown macro-alga that is found in the inter-tidal ecosystems of China. To investigate the current status of seaweed resources and provide basic data for its sustainable development, ISSR (inter simple sequence repeat) and SRAP (sequence related amplified polymorphism) markers were used to analyze the population genetics among nine natural populations of S. horneri. The nine studied populations were distributed over 2 000 km from northeast to south China. The percentage of polymorphic loci P % (ISSR, 99.44%; SRAP, 100.00%), Nei's genetic diversity H (ISSR, 0.107-0.199; SRAP, 0.100-0.153), and Shannon's information index I (ISSR, 0.157-0.291; SRAP, 0.148-0.219) indicated a fair amount of genetic variability among the nine populations. Moreover, the high degree of gene differentiation G st (ISSR, 0.654; SRAP, 0.718) and low gene flow N m (ISSR, 0.265; SRAP, 0.196) implied that there was significant among-population differentiation, possibly as a result of habitat fragmentation. The matrices of genetic distances and fixation indices ( F st) among the populations correlated well with their geographical distribution (Mantel test R =0.541 5, 0.541 8; P =0.005 0, 0.002 0 and R =0.728 6, 0.641 2; P =0.001 0, 0.001 0, respectively); the Rongcheng population in the Shandong peninsula was the only exception. Overall, the genetic differentiation agreed with the geographic isolation. The fair amount of genetic diversity that was revealed in the S. horneri populations in China indicated that the seaweed resources had not been seriously affected by external factors.

  7. Comparative genomics for mycobacterial peptidoglycan remodelling enzymes reveals extensive genetic multiplicity

    PubMed Central

    2014-01-01

    Background Mycobacteria comprise diverse species including non-pathogenic, environmental organisms, animal disease agents and human pathogens, notably Mycobacterium tuberculosis. Considering that the mycobacterial cell wall constitutes a significant barrier to drug penetration, the aim of this study was to conduct a comparative genomics analysis of the repertoire of enzymes involved in peptidoglycan (PG) remodelling to determine the potential of exploiting this area of bacterial metabolism for the discovery of new drug targets. Results We conducted an in silico analysis of 19 mycobacterial species/clinical strains for the presence of genes encoding resuscitation promoting factors (Rpfs), penicillin binding proteins, endopeptidases, L,D-transpeptidases and N-acetylmuramoyl-L-alanine amidases. Our analysis reveals extensive genetic multiplicity, allowing for classification of mycobacterial species into three main categories, primarily based on their rpf gene complement. These include the M. tuberculosis Complex (MTBC), other pathogenic mycobacteria and environmental species. The complement of these genes within the MTBC and other mycobacterial pathogens is highly conserved. In contrast, environmental strains display significant genetic expansion in most of these gene families. Mycobacterium leprae retains more than one functional gene from each enzyme family, underscoring the importance of genetic multiplicity for PG remodelling. Notably, the highest degree of conservation is observed for N-acetylmuramoyl-L-alanine amidases suggesting that these enzymes are essential for growth and survival. Conclusion PG remodelling enzymes in a range of mycobacterial species are associated with extensive genetic multiplicity, suggesting functional diversification within these families of enzymes to allow organisms to adapt. PMID:24661741

  8. Landscape Genetics Reveals Focal Transmission of a Human Macroparasite

    PubMed Central

    Criscione, Charles D.; Anderson, Joel D.; Sudimack, Dan; Subedi, Janardan; Upadhayay, Ram P.; Jha, Bharat; Williams, Kimberly D.; Williams-Blangero, Sarah; Anderson, Timothy J. C.

    2010-01-01

    Macroparasite infections (e.g., helminths) remain a major human health concern. However, assessing transmission dynamics is problematic because the direct observation of macroparasite dispersal among hosts is not possible. We used a novel landscape genetics approach to examine transmission of the human roundworm Ascaris lumbricoides in a small human population in Jiri, Nepal. Unexpectedly, we found significant genetic structuring of parasites, indicating the presence of multiple transmission foci within a small sampling area (∼14 km2). We analyzed several epidemiological variables, and found that transmission is spatially autocorrelated around households and that transmission foci are stable over time despite extensive human movement. These results would not have been obtainable via a traditional epidemiological study based on worm counts alone. Our data refute the assumption that a single host population corresponds to a single parasite transmission unit, an assumption implicit in many classic models of macroparasite transmission. Newer models have shown that the metapopulation-like pattern observed in our data can adversely affect targeted control strategies aimed at community-wide impacts. Furthermore, the observed metapopulation structure and local mating patterns generate an excess of homozygotes that can accelerate the spread of recessive traits such as drug resistance. Our study illustrates how molecular analyses complement traditional epidemiological information in providing a better understanding of parasite transmission. Similar landscape genetic approaches in other macroparasite systems will be warranted if an accurate depiction of the transmission process is to be used to inform effective control strategies. PMID:20421919

  9. Systems genetics reveals key genetic elements of drought induced gene regulation in diploid potato.

    PubMed

    van Muijen, Dennis; Anithakumari, A M; Maliepaard, Chris; Visser, Richard G F; van der Linden, C Gerard

    2016-09-01

    In plants, tolerance to drought stress is a result of numerous minor effect loci in which transcriptional regulation contributes significantly to the observed phenotypes. Under severe drought conditions, a major expression quantitative trait loci hotspot was identified on chromosome five in potato. A putative Nuclear factor y subunit C4 was identified as key candidate in the regulatory cascade in response to drought. Further investigation of the eQTL hotspots suggests a role for a putative Homeobox leucine zipper protein 12 in relation to drought in potato. Genes strongly co-expressed with Homeobox leucine zipper protein 12 were plant growth regulators responsive to water deficit stress in Arabidopsis thaliana, implying a possible conserved mechanism. Integrative analysis of genetic, genomic, phenotypic and transcriptomic data provided insights in the downstream functional components of the drought response. The abscisic acid- and environmental stress-inducible protein TAS14 was highly induced by severe drought in potato and acts as a reliable biomarker for the level of stress perceived by the plant. The systems genetics approach supported a role for multiple genes responsive to severe drought stress of Solanum tuberosum. The combination of gene regulatory networks, expression quantitative trait loci mapping and phenotypic analysis proved useful for candidate gene selection. PMID:27353051

  10. Comparative sequence and genetic analyses of asparagus BACs reveal no microsynteny with onion or rice.

    PubMed

    Jakse, Jernej; Telgmann, Alexa; Jung, Christian; Khar, Anil; Melgar, Sergio; Cheung, Foo; Town, Christopher D; Havey, Michael J

    2006-12-01

    The Poales (includes the grasses) and Asparagales [includes onion (Allium cepa L.) and asparagus (Asparagus officinalis L.)] are the two most economically important monocot orders. The Poales are a member of the commelinoid monocots, a group of orders sister to the Asparagales. Comparative genomic analyses have revealed a high degree of synteny among the grasses; however, it is not known if this synteny extends to other major monocot groups such as the Asparagales. Although we previously reported no evidence for synteny at the recombinational level between onion and rice, microsynteny may exist across shorter genomic regions in the grasses and Asparagales. We sequenced nine asparagus BACs to reveal physically linked genic-like sequences and determined their most similar positions in the onion and rice genomes. Four of the asparagus BACs were selected using molecular markers tightly linked to the sex-determining M locus on chromosome 5 of asparagus. These BACs possessed only two putative coding regions and had long tracts of degenerated retroviral elements and transposons. Five asparagus BACs were selected after hybridization of three onion cDNAs that mapped to three different onion chromosomes. Genic-like sequences that were physically linked on the cDNA-selected BACs or genetically linked on the M-linked BACs showed significant similarities (e < -20) to expressed sequences on different rice chromosomes, revealing no evidence for microsynteny between asparagus and rice across these regions. Genic-like sequences that were linked in asparagus were used to identify highly similar (e < -20) expressed sequence tags (ESTs) of onion. These onion ESTs mapped to different onion chromosomes and no relationship was observed between physical or genetic linkages in asparagus and genetic linkages in onion. These results further indicate that synteny among grass genomes does not extend to a sister order in the monocots and that asparagus may not be an appropriate smaller genome

  11. The loss of genetic diversity in Sichuan taimen as revealed by DNA fingerprinting.

    PubMed

    Wu, Xue-Chang

    2006-06-01

    Species endangerment often derives from the "endangerment" of genetic diversity, thus loss of genetic diversity is an important cause of species extinction. Since historical specimens were unavailable, previous studies mainly described the genetic diversity status in the current population rather than the loss of genetic variation over time. In this study, we collected samples during 1998-1999 and obtained historical specimens from 1957 to 1958. Based on the two sets of fish, we determined the changes in genetic diversity of Sichuan taimen using DNA fingerprinting. The differences in genetic parameters between the present samples and historical taimens revealed their loss of genetic variation. As a result, the existing populations have lower viability, and proper management has to be implemented to preserve genetic diversity. PMID:16944294

  12. Quantitative Genetic Interactions Reveal Layers of Biological Modularity

    PubMed Central

    Beltrao, Pedro; Cagney, Gerard; Krogan, Nevan J.

    2010-01-01

    In the past, biomedical research has embraced a reductionist approach, primarily focused on characterizing the individual components that comprise a system of interest. Recent technical developments have significantly increased the size and scope of data describing biological systems. At the same time, advances in the field of systems biology have evoked a broader view of how the underlying components are interconnected. In this essay, we discuss how quantitative genetic interaction mapping has enhanced our view of biological systems, allowing a deeper functional interrogation at different biological scales. PMID:20510918

  13. Comparative riverscape genetics reveals reservoirs of genetic diversity for conservation and restoration of Great Plains fishes

    PubMed Central

    Osborne, Megan J; Perkin, Joshuah S.; Gido, Keith B.; Turner, Thomas F.

    2014-01-01

    We used comparative landscape genetics to examine the relative roles of historical events, intrinsic traits, and landscape factors in determining the distribution of genetic diversity of river fishes across the North American Great Plains. Spatial patterns of diversity were overlaid on a patch-based graphical model, and then compared within and among three species that co-occurred across five Great Plains watersheds. Species differing in reproductive strategy (benthic vs. pelagic spawning) were hypothesized to have different patterns of genetic diversity, but the overriding factor shaping contemporary patterns of diversity was the signature of past climates and geological history. Allelic diversity was significantly higher at southern latitudes for Cyprinella lutrensis and Hybognathus placitus, consistent with northward expansion from southern Pleistocene refugia. Within the historical context, all species exhibited lowered occupancy and abundance in heavily fragmented and drier upstream reaches, particularly H. placitus; a pelagic-spawning species, suggesting rates of extirpation have outpaced losses of genetic diversity in this species. Within most basins, genetically diverse populations of each species persisted. Hence, reconnecting genetically diverse populations with those characterized by reduced diversity (regardless of their position within the riverine network) would provide populations with greater genetic and demographic resilience. We discuss cases where cross-basin transfer may be appropriate to enhance genetic diversity and mitigate negative effects of climate change. Overall, striking similarities in genetic patterns and response to fragmentation and dewatering suggest a common strategy for genetic resource management in this unique riverine fish assemblage. PMID:25327780

  14. A Comprehensive Genomic Analysis Reveals the Genetic Landscape of Mitochondrial Respiratory Chain Complex Deficiencies

    PubMed Central

    Nyuzuki, Hiromi; Moriyama, Yohsuke; Mizuno, Yosuke; Hirata, Tomoko; Yatsuka, Yukiko; Yamashita-Sugahara, Yzumi; Nakachi, Yutaka; Kato, Hidemasa; Okuda, Akihiko; Tamaru, Shunsuke; Borna, Nurun Nahar; Banshoya, Kengo; Aigaki, Toshiro; Sato-Miyata, Yukiko; Ohnuma, Kohei; Suzuki, Tsutomu; Nagao, Asuteka; Maehata, Hazuki; Matsuda, Fumihiko; Higasa, Koichiro; Nagasaki, Masao; Yasuda, Jun; Yamamoto, Masayuki; Fushimi, Takuya; Shimura, Masaru; Kaiho-Ichimoto, Keiko; Harashima, Hiroko; Yamazaki, Taro; Mori, Masato; Murayama, Kei; Ohtake, Akira; Okazaki, Yasushi

    2016-01-01

    Mitochondrial disorders have the highest incidence among congenital metabolic disorders characterized by biochemical respiratory chain complex deficiencies. It occurs at a rate of 1 in 5,000 births, and has phenotypic and genetic heterogeneity. Mutations in about 1,500 nuclear encoded mitochondrial proteins may cause mitochondrial dysfunction of energy production and mitochondrial disorders. More than 250 genes that cause mitochondrial disorders have been reported to date. However exact genetic diagnosis for patients still remained largely unknown. To reveal this heterogeneity, we performed comprehensive genomic analyses for 142 patients with childhood-onset mitochondrial respiratory chain complex deficiencies. The approach includes whole mtDNA and exome analyses using high-throughput sequencing, and chromosomal aberration analyses using high-density oligonucleotide arrays. We identified 37 novel mutations in known mitochondrial disease genes and 3 mitochondria-related genes (MRPS23, QRSL1, and PNPLA4) as novel causative genes. We also identified 2 genes known to cause monogenic diseases (MECP2 and TNNI3) and 3 chromosomal aberrations (6q24.3-q25.1, 17p12, and 22q11.21) as causes in this cohort. Our approaches enhance the ability to identify pathogenic gene mutations in patients with biochemically defined mitochondrial respiratory chain complex deficiencies in clinical settings. They also underscore clinical and genetic heterogeneity and will improve patient care of this complex disorder. PMID:26741492

  15. A Comprehensive Genomic Analysis Reveals the Genetic Landscape of Mitochondrial Respiratory Chain Complex Deficiencies.

    PubMed

    Kohda, Masakazu; Tokuzawa, Yoshimi; Kishita, Yoshihito; Nyuzuki, Hiromi; Moriyama, Yohsuke; Mizuno, Yosuke; Hirata, Tomoko; Yatsuka, Yukiko; Yamashita-Sugahara, Yzumi; Nakachi, Yutaka; Kato, Hidemasa; Okuda, Akihiko; Tamaru, Shunsuke; Borna, Nurun Nahar; Banshoya, Kengo; Aigaki, Toshiro; Sato-Miyata, Yukiko; Ohnuma, Kohei; Suzuki, Tsutomu; Nagao, Asuteka; Maehata, Hazuki; Matsuda, Fumihiko; Higasa, Koichiro; Nagasaki, Masao; Yasuda, Jun; Yamamoto, Masayuki; Fushimi, Takuya; Shimura, Masaru; Kaiho-Ichimoto, Keiko; Harashima, Hiroko; Yamazaki, Taro; Mori, Masato; Murayama, Kei; Ohtake, Akira; Okazaki, Yasushi

    2016-01-01

    Mitochondrial disorders have the highest incidence among congenital metabolic disorders characterized by biochemical respiratory chain complex deficiencies. It occurs at a rate of 1 in 5,000 births, and has phenotypic and genetic heterogeneity. Mutations in about 1,500 nuclear encoded mitochondrial proteins may cause mitochondrial dysfunction of energy production and mitochondrial disorders. More than 250 genes that cause mitochondrial disorders have been reported to date. However exact genetic diagnosis for patients still remained largely unknown. To reveal this heterogeneity, we performed comprehensive genomic analyses for 142 patients with childhood-onset mitochondrial respiratory chain complex deficiencies. The approach includes whole mtDNA and exome analyses using high-throughput sequencing, and chromosomal aberration analyses using high-density oligonucleotide arrays. We identified 37 novel mutations in known mitochondrial disease genes and 3 mitochondria-related genes (MRPS23, QRSL1, and PNPLA4) as novel causative genes. We also identified 2 genes known to cause monogenic diseases (MECP2 and TNNI3) and 3 chromosomal aberrations (6q24.3-q25.1, 17p12, and 22q11.21) as causes in this cohort. Our approaches enhance the ability to identify pathogenic gene mutations in patients with biochemically defined mitochondrial respiratory chain complex deficiencies in clinical settings. They also underscore clinical and genetic heterogeneity and will improve patient care of this complex disorder. PMID:26741492

  16. Genetic structure along an elevational gradient in Hawaiian honeycreepers reveals contrasting evolutionary responses to avian malaria

    USGS Publications Warehouse

    Eggert, L.S.; Terwilliger, L.A.; Woodworth, B.L.; Hart, P.J.; Palmer, D.; Fleischer, R.C.

    2008-01-01

    Background. The Hawaiian honeycreepers (Drepanidinae) are one of the best-known examples of an adaptive radiation, but their persistence today is threatened by the introduction of exotic pathogens and their vector, the mosquito Culex quinquefasciatus. Historically, species such as the amakihi (Hemignathus virens), the apapane (Himatione sanguinea), and the iiwi (Vestiaria coccinea) were found from the coastal lowlands to the high elevation forests, but by the late 1800's they had become extremely rare in habitats below 900 m. Recently, however, populations of amakihi and apapane have been observed in low elevation habitats. We used twelve polymorphic microsatellite loci to investigate patterns of genetic structure, and to infer responses of these species to introduced avian malaria along an elevational gradient on the eastern flanks of Mauna Loa and Kilauea volcanoes on the island of Hawaii. Results. Our results indicate that amakihi have genetically distinct, spatially structured populations that correspond with altitude. We detected very few apapane and no iiwi in low-elevation habitats, and genetic results reveal only minimal differentiation between populations at different altitudes in either of these species. Conclusion. Our results suggest that amakihi populations in low elevation habitats have not been recolonized by individuals from mid or high elevation refuges. After generations of strong selection for pathogen resistance, these populations have rebounded and amakihi have become common in regions in which they were previously rare or absent. ?? 2008 Eggert et al; licensee BioMed Central Ltd.

  17. Genetic structure along an elevational gradient in Hawaiian honeycreepers reveals contrasting evolutionary responses to avian malaria

    PubMed Central

    2008-01-01

    Background The Hawaiian honeycreepers (Drepanidinae) are one of the best-known examples of an adaptive radiation, but their persistence today is threatened by the introduction of exotic pathogens and their vector, the mosquito Culex quinquefasciatus. Historically, species such as the amakihi (Hemignathus virens), the apapane (Himatione sanguinea), and the iiwi (Vestiaria coccinea) were found from the coastal lowlands to the high elevation forests, but by the late 1800's they had become extremely rare in habitats below 900 m. Recently, however, populations of amakihi and apapane have been observed in low elevation habitats. We used twelve polymorphic microsatellite loci to investigate patterns of genetic structure, and to infer responses of these species to introduced avian malaria along an elevational gradient on the eastern flanks of Mauna Loa and Kilauea volcanoes on the island of Hawaii. Results Our results indicate that amakihi have genetically distinct, spatially structured populations that correspond with altitude. We detected very few apapane and no iiwi in low-elevation habitats, and genetic results reveal only minimal differentiation between populations at different altitudes in either of these species. Conclusion Our results suggest that amakihi populations in low elevation habitats have not been recolonized by individuals from mid or high elevation refuges. After generations of strong selection for pathogen resistance, these populations have rebounded and amakihi have become common in regions in which they were previously rare or absent. PMID:19014596

  18. Population Genetics of Streptococcus dysgalactiae Subspecies equisimilis Reveals Widely Dispersed Clones and Extensive Recombination

    PubMed Central

    Pinho, Marcos; Ford, Candace; Hall, Gerod S.; Melo-Cristino, José

    2010-01-01

    Background Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an emerging global pathogen that can colonize and infect humans. Although most SDSE isolates possess the Lancefield group G carbohydrate, a significant minority have the group C carbohydrate. Isolates are further sub-typed on the basis of differences within the emm gene. To gain a better understanding of their molecular epidemiology and evolutionary relationships, multilocus sequence typing (MLST) analysis was performed on SDSE isolates collected from Australia, Europe and North America. Methodology/Principal Findings The 178 SDSE isolates, representing 37 emm types, segregate into 80 distinct sequence types (STs) that form 17 clonal complexes (CCs). Eight STs recovered from all three continents account for >50% of the isolates. Thus, a small number of STs are highly prevalent and have a wide geographic distribution. Both ST and CC strongly correlate with group carbohydrate. In contrast, eleven STs were associated with >1 emm type, suggestive of recombinational replacements involving the emm gene; furthermore, 35% of the emm types are associated with genetically distant STs. Data also reveal a history of extensive inter- and intra-species recombination involving the housekeeping genes used for MLST. Sequence analysis of single locus variants identified through goeBURST indicates that genetic change mediated by recombination occurred ∼4.4 times more frequently than by point mutation. Conclusions/Significance A few genetic lineages with an intercontinental distribution dominate among SDSE causing infections in humans. The distinction between group C and G isolates reflects recent evolution, and no long-term genetic isolation between them was found. Lateral gene transfer and recombination involving housekeeping genes and the emm gene are important mechanisms driving genetic variability in the SDSE population. PMID:20668530

  19. Genetic diversity and structure in Leishmania infantum populations from southeastern Europe revealed by microsatellite analysis

    PubMed Central

    2013-01-01

    Background The dynamic re-emergence of visceral leishmaniasis (VL) in south Europe and the northward shift to Leishmania-free European countries are well-documented. However, the epidemiology of VL due to Leishmania infantum in southeastern (SE) Europe and the Balkans is inadequately examined. Herein, we aim to re-evaluate and compare the population structure of L. infantum in SE and southwestern (SW) Europe. Methods Leishmania strains collected from humans and canines in Turkey, Cyprus, Bulgaria, Greece, Albania and Croatia, were characterized by the K26-PCR assay and multilocus enzyme electrophoresis (MLEE). Genetic diversity was assessed by multilocus microsatellite typing (MLMT) and MLM Types were analyzed by model- and distance- based algorithms to infer the population structure of 128 L. infantum strains. Results L. infantum MON-1 was found predominant in SE Europe, whilst 16.8% of strains were MON-98. Distinct genetic populations revealed clear differentiation between SE and SW European strains. Interestingly, Cypriot canine isolates were genetically isolated and formed a monophyletic group, suggesting the constitution of a clonal MON-1 population circulating among dogs. In contrast, two highly heterogeneous populations enclosed all MON-1 and MON-98 strains from the other SE European countries. Structure sub-clustering, phylogenetic and Splitstree analysis also revealed two distinct Croatian subpopulations. A mosaic of evolutionary effects resulted in consecutive sub-structuring, which indicated substantial differentiation and gene flow among strains of both zymodemes. Conclusions This is the first population genetic study of L. infantum in SE Europe and the Balkans. Our findings demonstrate the differentiation between SE and SW European strains; revealing the partition of Croatian strains between these populations and the genetic isolation of Cypriot strains. This mirrors the geographic position of Croatia located in central Europe and the natural

  20. Genotyping of ancient Mycobacterium tuberculosis strains reveals historic genetic diversity

    PubMed Central

    Müller, Romy; Roberts, Charlotte A.; Brown, Terence A.

    2014-01-01

    The evolutionary history of the Mycobacterium tuberculosis complex (MTBC) has previously been studied by analysis of sequence diversity in extant strains, but not addressed by direct examination of strain genotypes in archaeological remains. Here, we use ancient DNA sequencing to type 11 single nucleotide polymorphisms and two large sequence polymorphisms in the MTBC strains present in 10 archaeological samples from skeletons from Britain and Europe dating to the second–nineteenth centuries AD. The results enable us to assign the strains to groupings and lineages recognized in the extant MTBC. We show that at least during the eighteenth–nineteenth centuries AD, strains of M. tuberculosis belonging to different genetic groups were present in Britain at the same time, possibly even at a single location, and we present evidence for a mixed infection in at least one individual. Our study shows that ancient DNA typing applied to multiple samples can provide sufficiently detailed information to contribute to both archaeological and evolutionary knowledge of the history of tuberculosis. PMID:24573854

  1. Genomic View of Bipolar Disorder Revealed by Whole Genome Sequencing in a Genetic Isolate

    PubMed Central

    Georgi, Benjamin; Craig, David; Kember, Rachel L.; Liu, Wencheng; Lindquist, Ingrid; Nasser, Sara; Brown, Christopher; Egeland, Janice A.; Paul, Steven M.; Bućan, Maja

    2014-01-01

    Bipolar disorder is a common, heritable mental illness characterized by recurrent episodes of mania and depression. Despite considerable effort to elucidate the genetic underpinnings of bipolar disorder, causative genetic risk factors remain elusive. We conducted a comprehensive genomic analysis of bipolar disorder in a large Old Order Amish pedigree. Microsatellite genotypes and high-density SNP-array genotypes of 388 family members were combined with whole genome sequence data for 50 of these subjects, comprising 18 parent-child trios. This study design permitted evaluation of candidate variants within the context of haplotype structure by resolving the phase in sequenced parent-child trios and by imputation of variants into multiple unsequenced siblings. Non-parametric and parametric linkage analysis of the entire pedigree as well as on smaller clusters of families identified several nominally significant linkage peaks, each of which included dozens of predicted deleterious variants. Close inspection of exonic and regulatory variants in genes under the linkage peaks using family-based association tests revealed additional credible candidate genes for functional studies and further replication in population-based cohorts. However, despite the in-depth genomic characterization of this unique, large and multigenerational pedigree from a genetic isolate, there was no convergence of evidence implicating a particular set of risk loci or common pathways. The striking haplotype and locus heterogeneity we observed has profound implications for the design of studies of bipolar and other related disorders. PMID:24625924

  2. Analysis of Dengue Virus Genetic Diversity during Human and Mosquito Infection Reveals Genetic Constraints

    PubMed Central

    Sessions, October M.; Wilm, Andreas; Kamaraj, Uma Sangumathi; Choy, Milly M.; Chow, Angelia; Chong, Yuwen; Ong, Xin Mei; Nagarajan, Niranjan; Cook, Alex R.; Ooi, Eng Eong

    2015-01-01

    Dengue viruses (DENV) cause debilitating and potentially life-threatening acute disease throughout the tropical world. While drug development efforts are underway, there are concerns that resistant strains will emerge rapidly. Indeed, antiviral drugs that target even conserved regions in other RNA viruses lose efficacy over time as the virus mutates. Here, we sought to determine if there are regions in the DENV genome that are not only evolutionarily conserved but genetically constrained in their ability to mutate and could hence serve as better antiviral targets. High-throughput sequencing of DENV-1 genome directly from twelve, paired dengue patients’ sera and then passaging these sera into the two primary mosquito vectors showed consistent and distinct sequence changes during infection. In particular, two residues in the NS5 protein coding sequence appear to be specifically acquired during infection in Ae. aegypti but not Ae. albopictus. Importantly, we identified a region within the NS3 protein coding sequence that is refractory to mutation during human and mosquito infection. Collectively, these findings provide fresh insights into antiviral targets and could serve as an approach to defining evolutionarily constrained regions for therapeutic targeting in other RNA viruses. PMID:26327586

  3. Thinking positively: The genetics of high intelligence

    PubMed Central

    Shakeshaft, Nicholas G.; Trzaskowski, Maciej; McMillan, Andrew; Krapohl, Eva; Simpson, Michael A.; Reichenberg, Avi; Cederlöf, Martin; Larsson, Henrik; Lichtenstein, Paul; Plomin, Robert

    2015-01-01

    High intelligence (general cognitive ability) is fundamental to the human capital that drives societies in the information age. Understanding the origins of this intellectual capital is important for government policy, for neuroscience, and for genetics. For genetics, a key question is whether the genetic causes of high intelligence are qualitatively or quantitatively different from the normal distribution of intelligence. We report results from a sibling and twin study of high intelligence and its links with the normal distribution. We identified 360,000 sibling pairs and 9000 twin pairs from 3 million 18-year-old males with cognitive assessments administered as part of conscription to military service in Sweden between 1968 and 2010. We found that high intelligence is familial, heritable, and caused by the same genetic and environmental factors responsible for the normal distribution of intelligence. High intelligence is a good candidate for “positive genetics” — going beyond the negative effects of DNA sequence variation on disease and disorders to consider the positive end of the distribution of genetic effects. PMID:25593376

  4. High Spatial Genetic Structure and Genetic Diversity in Chinese Populations of Sitobion miscanthi (Hemiptera: Aphididae).

    PubMed

    Wang, Yongmo; Hereward, James P; Zhang, Guoan

    2016-02-01

    The wheat aphid, Sitobion miscanthi Takahashi, a serious wheat pest, was previously considered to be highly migratory and anholocyclic in China. We recorded 69 alleles and 346 multilocus genotypes among 708 aphid individuals from 12 populations in China using 5 microsatellite loci. This genotypic diversity indicates that at least some holocyclic lineages exist. Bayesian clustering analysis revealed that there are two differentiated genetic groups of S. misanthi, one northern and one southern, in China. Principal coordinates analysis of population genetic distance, pairwise F(ST)'s, and network analysis of individual minimum spanning distance also supported the division. Low levels of migration were detected between the northern and southern sampling sites, but the high genetic differentiation does not support the hypothesis S. miscanthi overwinters in the south and migrates to the north in the spring annually. PMID:26487744

  5. Genetic diversity among cucumis metuliferus populations revealed by cucumber microsatellites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cucumis metuliferus E. Mey. ex Naud (African horned cucumber, AHC) is native to Africa and is a relative of cultivated cucumber (C. sativus L.) and melon (C. melo L.). AHC is being promoted as a specialty fruit crop in a number of countries. In addition, several traits in C. metuliferus such as high...

  6. Genetic diversity of cultivated and wild tomatoes revealed by morphological traits and SSR markers.

    PubMed

    Zhou, R; Wu, Z; Cao, X; Jiang, F L

    2015-01-01

    In the current study, morphological traits and molecular markers were used to assess the genetic diversity of 29 cultivated tomatoes, 14 wild tomatoes and seven introgression lines. The three components of the principal component analysis (PCA) explained 78.54% of the total morphological variation in the 50 tomato genotypes assessed. Based on these morphological traits, a three-dimensional PCA plot separated the 50 genotypes into distinct groups, and a dendrogram divided them into six clusters. Fifteen polymorphic genomic simple- sequence repeat (genomic-SSR) and 13 polymorphic expressed sequence tag-derived SSR (EST-SSR) markers amplified 1115 and 780 clear fragments, respectively. Genomic-SSRs detected a total of 64 alleles, with a mean of 4 alleles per primer, while EST-SSRs detected 52 alleles, with a mean of 4 alleles per primer. The polymorphism information content was slightly higher in genomic-SSRs (0.49) than in EST-SSRs (0.45). The mean similarity coefficient among the wild tomatoes was lower than the mean similarity coefficient among the cultivated tomatoes. The dendrogram based on genetic distance divided the 50 tomato genotypes into eight clusters. The Mantel test between genomic-SSR and EST-SSR matrices revealed a good correlation, whereas the morphological matrices and the molecular matrices were weakly correlated. We confirm the applicability of EST-SSRs in analyzing genetic diversity among cultivated and wild tomatoes. High variability of the 50 tomato genotypes was observed at the morphological and molecular level, indicating valuable tomato germplasm, especially in the wild tomatoes, which could be used for further genetic studies. PMID:26535702

  7. The intergenerational correlation in weight: How genetic resemblance reveals the social role of families*

    PubMed Central

    Martin, Molly A.

    2009-01-01

    According to behavioral genetics research, the intergenerational correlation in weight derives solely from shared genetic predispositions, but complete genetic determinism contradicts the scientific consensus that social and behavioral change underlies the modern obesity epidemic. To address this conundrum, this article utilizes sibling data from the National Longitudinal Study of Adolescent Health and extends structural equation sibling models to incorporate siblings’ genetic relationships to explore the role of families’ social characteristics for adolescent weight. The article is the first to demonstrate that the association between parents’ obesity and adolescent weight is both social and genetic. Furthermore, by incorporating genetic information, the shared and social origins of the correlation between inactivity and weight are better revealed. PMID:19569401

  8. The genetic basis for ecological adaptation of the Atlantic herring revealed by genome sequencing

    PubMed Central

    Martinez Barrio, Alvaro; Lamichhaney, Sangeet; Fan, Guangyi; Rafati, Nima; Pettersson, Mats; Zhang, He; Dainat, Jacques; Ekman, Diana; Höppner, Marc; Jern, Patric; Martin, Marcel; Nystedt, Björn; Liu, Xin; Chen, Wenbin; Liang, Xinming; Shi, Chengcheng; Fu, Yuanyuan; Ma, Kailong; Zhan, Xiao; Feng, Chungang; Gustafson, Ulla; Rubin, Carl-Johan; Sällman Almén, Markus; Blass, Martina; Casini, Michele; Folkvord, Arild; Laikre, Linda; Ryman, Nils; Ming-Yuen Lee, Simon; Xu, Xun; Andersson, Leif

    2016-01-01

    Ecological adaptation is of major relevance to speciation and sustainable population management, but the underlying genetic factors are typically hard to study in natural populations due to genetic differentiation caused by natural selection being confounded with genetic drift in subdivided populations. Here, we use whole genome population sequencing of Atlantic and Baltic herring to reveal the underlying genetic architecture at an unprecedented detailed resolution for both adaptation to a new niche environment and timing of reproduction. We identify almost 500 independent loci associated with a recent niche expansion from marine (Atlantic Ocean) to brackish waters (Baltic Sea), and more than 100 independent loci showing genetic differentiation between spring- and autumn-spawning populations irrespective of geographic origin. Our results show that both coding and non-coding changes contribute to adaptation. Haplotype blocks, often spanning multiple genes and maintained by selection, are associated with genetic differentiation. DOI: http://dx.doi.org/10.7554/eLife.12081.001 PMID:27138043

  9. The genetic basis for ecological adaptation of the Atlantic herring revealed by genome sequencing.

    PubMed

    Martinez Barrio, Alvaro; Lamichhaney, Sangeet; Fan, Guangyi; Rafati, Nima; Pettersson, Mats; Zhang, He; Dainat, Jacques; Ekman, Diana; Höppner, Marc; Jern, Patric; Martin, Marcel; Nystedt, Björn; Liu, Xin; Chen, Wenbin; Liang, Xinming; Shi, Chengcheng; Fu, Yuanyuan; Ma, Kailong; Zhan, Xiao; Feng, Chungang; Gustafson, Ulla; Rubin, Carl-Johan; Sällman Almén, Markus; Blass, Martina; Casini, Michele; Folkvord, Arild; Laikre, Linda; Ryman, Nils; Ming-Yuen Lee, Simon; Xu, Xun; Andersson, Leif

    2016-01-01

    Ecological adaptation is of major relevance to speciation and sustainable population management, but the underlying genetic factors are typically hard to study in natural populations due to genetic differentiation caused by natural selection being confounded with genetic drift in subdivided populations. Here, we use whole genome population sequencing of Atlantic and Baltic herring to reveal the underlying genetic architecture at an unprecedented detailed resolution for both adaptation to a new niche environment and timing of reproduction. We identify almost 500 independent loci associated with a recent niche expansion from marine (Atlantic Ocean) to brackish waters (Baltic Sea), and more than 100 independent loci showing genetic differentiation between spring- and autumn-spawning populations irrespective of geographic origin. Our results show that both coding and non-coding changes contribute to adaptation. Haplotype blocks, often spanning multiple genes and maintained by selection, are associated with genetic differentiation. PMID:27138043

  10. The non-structural (NS) gene segment of H9N2 influenza virus isolated from backyard poultry in Pakistan reveals strong genetic and functional similarities to the NS gene of highly pathogenic H5N1

    PubMed Central

    Munir, Muhammad; Zohari, Siamak; Iqbal, Munir; Abbas, Muhammad; Perez, Daniel Roberto; Berg, Mikael

    2013-01-01

    Apart from natural reassortment, co-circulation of different avian influenza virus strains in poultry populations can lead to generation of novel variants and reassortant viruses. In this report, we studied the genetics and functions of a reassorted non-structural gene (NS) of H9N2 influenza virus collected from back yard poultry (BYP) flock. Phylogenetic reconstruction based on hemagglutinin and neuraminidase genes indicates that an isolate from BYP belongs to H9N2. However, the NS gene-segment of this isolate cluster into genotype Z, clade 2.2 of the highly pathogenic H5N1. The NS gene plays essential roles in the host-adaptation, cell-tropism, and virulence of influenza viruses. However, such interpretations have not been investigated in naturally recombinant H9N2 viruses. Therefore, we compared the NS1 protein of H9N2 (H9N2/NS1) and highly pathogenic H5N1 (H5N1/NS1) in parallel for their abilities to regulate different signaling pathways, and investigated the molecular mechanisms of IFN-β production in human, avian, and mink lung cells. We found that H9N2/NS1 and H5N1/NS1 are comparably similar in inhibiting TNF-α induced nuclear factor κB and double stranded RNA induced activator protein 1 and interferon regulatory factor 3 transcription factors. Thus, the production of IFN-β was inhibited equally by both NS1s as demonstrated by IFN stimulatory response element and IFN-β promoter activation. Moreover, both NS1s predominantly localized in the nucleus when transfected to human A549 cells. This study therefore suggests the possible increased virulence of natural reassortant viruses for their efficient invasion of host immune responses, and proposes that these should not be overlooked for their epizootic and zoonotic potential. PMID:23959028

  11. The non-structural (NS) gene segment of H9N2 influenza virus isolated from backyard poultry in Pakistan reveals strong genetic and functional similarities to the NS gene of highly pathogenic H5N1.

    PubMed

    Munir, Muhammad; Zohari, Siamak; Iqbal, Munir; Abbas, Muhammad; Perez, Daniel Roberto; Berg, Mikael

    2013-10-01

    Apart from natural reassortment, co-circulation of different avian influenza virus strains in poultry populations can lead to generation of novel variants and reassortant viruses. In this report, we studied the genetics and functions of a reassorted non-structural gene (NS) of H9N2 influenza virus collected from back yard poultry (BYP) flock. Phylogenetic reconstruction based on hemagglutinin and neuraminidase genes indicates that an isolate from BYP belongs to H9N2. However, the NS gene-segment of this isolate cluster into genotype Z, clade 2.2 of the highly pathogenic H5N1. The NS gene plays essential roles in the host-adaptation, cell-tropism, and virulence of influenza viruses. However, such interpretations have not been investigated in naturally recombinant H9N2 viruses. Therefore, we compared the NS1 protein of H9N2 (H9N2/NS1) and highly pathogenic H5N1 (H5N1/NS1) in parallel for their abilities to regulate different signaling pathways, and investigated the molecular mechanisms of IFN-β production in human, avian, and mink lung cells. We found that H9N2/NS1 and H5N1/NS1 are comparably similar in inhibiting TNF-α induced nuclear factor κB and double stranded RNA induced activator protein 1 and interferon regulatory factor 3 transcription factors. Thus, the production of IFN-β was inhibited equally by both NS1s as demonstrated by IFN stimulatory response element and IFN-β promoter activation. Moreover, both NS1s predominantly localized in the nucleus when transfected to human A549 cells. This study therefore suggests the possible increased virulence of natural reassortant viruses for their efficient invasion of host immune responses, and proposes that these should not be overlooked for their epizootic and zoonotic potential. PMID:23959028

  12. Population genetic structure and migration patterns of Liriomyza sativae in China: moderate subdivision and no Bridgehead effect revealed by microsatellites.

    PubMed

    Tang, X-T; Ji, Y; Chang, Y-W; Shen, Y; Tian, Z-H; Gong, W-R; Du, Y-Z

    2016-02-01

    While Liriomyza sativae (Diptera: Agromyzidae), an important invasive pest of ornamentals and vegetables has been found in China for the past two decades, few studies have focused on its genetics or route of invasive. In this study, we collected 288 L. sativae individuals across 12 provinces to explore its population genetic structure and migration patterns in China using seven microsatellites. We found relatively low levels of genetic diversity but moderate population genetic structure (0.05 < F ST < 0.15) in L. sativae from China. All populations deviated significantly from the Hardy-Weinberg equilibrium due to heterozygote deficiency. Molecular variance analysis revealed that more than 89% of variation was among samples within populations. A UPGMA dendrogram revealed that SH and GXNN populations formed one cluster separate from the other populations, which is in accordance with STRUCTURE and GENELAND analyses. A Mantel test indicated that genetic distance was not correlated to geographic distance (r = -0.0814, P = 0.7610), coupled with high levels of gene flow (M = 40.1-817.7), suggesting a possible anthropogenic influence on the spread of L. sativae in China and on the effect of hosts. The trend of asymmetrical gene flow was from southern to northern populations in general and did not exhibit a Bridgehead effect during the course of invasion, as can be seen by the low genetic diversity of southern populations. PMID:26615869

  13. Microsatellites reveal substantial among-population genetic differentiation and strong inbreeding in the relict fern Dryopteris aemula

    PubMed Central

    Jiménez, Ares; Holderegger, Rolf; Csencsics, Daniela; Quintanilla, Luis G.

    2010-01-01

    Background and Aims A previous study detected no allozyme diversity in Iberian populations of the buckler-fern Dryopteris aemula. The use of a more sensitive marker, such as microsatellites, was thus needed to reveal the genetic diversity, breeding system and spatial genetic structure of this species in natural populations. Methods Eight microsatellite loci for D. aemula were developed and their cross-amplification with other ferns was tested. Five polymorphic loci were used to characterize the amount and distribution of genetic diversity of D. aemula in three populations from the Iberian Peninsula and one population from the Azores. Key Results Most microsatellite markers developed were transferable to taxa close to D. aemula. Overall genetic variation was low (HT = 0·447), but was higher in the Azorean population than in the Iberian populations of this species. Among-population genetic differentiation was high (FST = 0·520). All loci strongly departed from Hardy–Weinberg equilibrium. In the population where genetic structure was studied, no spatial autocorrelation was found in any distance class. Conclusions The higher genetic diversity observed in the Azorean population studied suggested a possible refugium in this region from which mainland Europe has been recolonized after the Pleistocene glaciations. High among-population genetic differentiation indicated restricted gene flow (i.e. lack of spore exchange) across the highly fragmented area occupied by D. aemula. The deviations from Hardy–Weinberg equilibrium reflected strong inbreeding in D. aemula, a trait rarely observed in homosporous ferns. The absence of spatial genetic structure indicated effective spore dispersal over short distances. Additionally, the cross-amplification of some D. aemula microsatellites makes them suitable for use in other Dryopteris taxa. PMID:20495199

  14. Genetic variation in wild populations of the tuber crop Amorphophallus konjac (Araceae) in central China as revealed by AFLP markers.

    PubMed

    Pan, C; Gichira, A W; Chen, J M

    2015-01-01

    Amorphophallus konjac is an economically important crop. In order to provide baseline information for sustainable development and conservation of the wild plant resources of A. konjac, we studied the genetic diversity and population structure of this species using amplified fragment length polymorphism (AFLP) molecular markers. We sampled 139 individuals from 10 wild populations of A. konjac in central China. Using five AFLP primer combinations, we scored a total of 270 DNA fragments, most of which were polymorphic (98.2%). Percentage of polymorphic loci, Nei's genetic diversity index, and Shannon's information index showed high levels of genetic variation within A. konjac populations. Analysis of molecular variance indicated that most of the variance (68%) resided within populations. The coefficient of genetic differentiation between populations was 0.348 and the estimated gene flow was 0.469, indicating that there was limited gene flow among the populations. Unweighted pair group method with arithmetic mean cluster analysis and principal coordinates analysis indicated that geographically close populations were more likely to cluster together. The Mantel test revealed a significant correlation between geographic and genetic distances (R2 = 0.2521, P < 0.05). The special insect-pollination system of A. konjac and the complex geography of central China are likely to have contributed to the current pattern of genetic variation of this species. In the present study, we provide several suggestions on the future protection of the wild plant genetic resources of A. konjac. PMID:26782525

  15. Genetic characterization of Toxoplasma gondii from Brazilian wildlife revealed abundant new genotypes

    PubMed Central

    Vitaliano, S.N.; Soares, H.S.; Minervino, A.H.H.; Santos, A.L.Q.; Werther, K.; Marvulo, M.F.V.; Siqueira, D.B.; Pena, H.F.J.; Soares, R.M.; Su, C.; Gennari, S.M.

    2014-01-01

    This study aimed to isolate and genotype T. gondii from Brazilian wildlife. For this purpose, 226 samples were submitted to mice bioassay and screened by PCR based on 18S rRNA sequences. A total of 15 T. gondii isolates were obtained, including samples from four armadillos (three Dasypus novemcinctus, one Euphractus sexcinctus), three collared anteaters (Tamandua tetradactyla), three whited-lipped peccaries (Tayassu pecari), one spotted paca (Cuniculus paca), one oncilla (Leopardus tigrinus), one hoary fox (Pseudalopex vetulus), one lineated woodpecker (Dryocopus lineatus) and one maned wolf (Chrysocyon brachyurus). DNA from the isolates, originated from mice bioassay, and from the tissues of the wild animal, designated as “primary samples”, were genotyped by PCR–restriction fragment length polymorphism (PCR/RFLP), using 12 genetic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L258, PK1, CS3 and Apico). A total of 17 genotypes were identified, with 13 identified for the first time and four already reported in published literature. Results herein obtained corroborate previous studies in Brazil, confirming high diversity and revealing unique genotypes in this region. Given most of genotypes here identified are different from previous studies in domestic animals, future studies on T. gondii from wildlife is of interest to understand population genetics and structure of this parasite. PMID:25426424

  16. Genetic characterization of Toxoplasma gondii from Brazilian wildlife revealed abundant new genotypes.

    PubMed

    Vitaliano, S N; Soares, H S; Minervino, A H H; Santos, A L Q; Werther, K; Marvulo, M F V; Siqueira, D B; Pena, H F J; Soares, R M; Su, C; Gennari, S M

    2014-12-01

    This study aimed to isolate and genotype T. gondii from Brazilian wildlife. For this purpose, 226 samples were submitted to mice bioassay and screened by PCR based on 18S rRNA sequences. A total of 15 T. gondii isolates were obtained, including samples from four armadillos (three Dasypus novemcinctus, one Euphractus sexcinctus), three collared anteaters (Tamandua tetradactyla), three whited-lipped peccaries (Tayassu pecari), one spotted paca (Cuniculus paca), one oncilla (Leopardus tigrinus), one hoary fox (Pseudalopex vetulus), one lineated woodpecker (Dryocopus lineatus) and one maned wolf (Chrysocyon brachyurus). DNA from the isolates, originated from mice bioassay, and from the tissues of the wild animal, designated as "primary samples", were genotyped by PCR-restriction fragment length polymorphism (PCR/RFLP), using 12 genetic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L258, PK1, CS3 and Apico). A total of 17 genotypes were identified, with 13 identified for the first time and four already reported in published literature. Results herein obtained corroborate previous studies in Brazil, confirming high diversity and revealing unique genotypes in this region. Given most of genotypes here identified are different from previous studies in domestic animals, future studies on T. gondii from wildlife is of interest to understand population genetics and structure of this parasite. PMID:25426424

  17. Genetic analysis reveals the wild ancestors of the llama and the alpaca.

    PubMed Central

    Kadwell, M.; Fernandez, M.; Stanley, H. F.; Baldi, R.; Wheeler, J. C.; Rosadio, R.; Bruford, M. W.

    2001-01-01

    The origins of South America's domestic alpaca and llama remain controversial due to hybridization, near extirpation during the Spanish conquest and difficulties in archaeological interpretation. Traditionally, the ancestry of both forms is attributed to the guanaco, while the vicuña is assumed never to have been domesticated. Recent research has, however, linked the alpaca to the vicuña, dating domestication to 6000-7000 years before present in the Peruvian Andes. Here, we examine in detail the genetic relationships between the South American camelids in order to determine the origins of the domestic forms, using mitochondrial (mt) and microsatellite DNA. MtDNA analysis places 80% of llama and alpaca sequences in the guanaco lineage, with those possessing vicuña mtDNA being nearly all alpaca or alpaca-vicuña hybrids. We also examined four microsatellites in wild known-provenance vicuña and guanaco, including two loci with non-overlapping allele size ranges in the wild species. In contrast to the mtDNA, these markers show high genetic similarity between alpaca and vicuña, and between llama and guanaco, although bidirectional hybridization is also revealed. Finally, combined marker analysis on a subset of samples confirms the microsatellite interpretation and suggests that the alpaca is descended from the vicuña, and should be reclassified as Vicugna pacos. This result has major implications for the future management of wild and domestic camelids in South America. PMID:11749713

  18. Genetic Signature of Histiocytic Sarcoma Revealed by a Sleeping Beauty Transposon Genetic Screen in Mice

    PubMed Central

    Been, Raha A.; Linden, Michael A.; Hager, Courtney J.; DeCoursin, Krista J.; Abrahante, Juan E.; Landman, Sean R.; Steinbach, Michael; Sarver, Aaron L.; Largaespada, David A.; Starr, Timothy K.

    2014-01-01

    Histiocytic sarcoma is a rare, aggressive neoplasm that responds poorly to therapy. Histiocytic sarcoma is thought to arise from macrophage precursor cells via genetic changes that are largely undefined. To improve our understanding of the etiology of histiocytic sarcoma we conducted a forward genetic screen in mice using the Sleeping Beauty transposon as a mutagen to identify genetic drivers of histiocytic sarcoma. Sleeping Beauty mutagenesis was targeted to myeloid lineage cells using the Lysozyme2 promoter. Mice with activated Sleeping Beauty mutagenesis had significantly shortened lifespan and the majority of these mice developed tumors resembling human histiocytic sarcoma. Analysis of transposon insertions identified 27 common insertion sites containing 28 candidate cancer genes. Several of these genes are known drivers of hematological neoplasms, like Raf1, Fli1, and Mitf, while others are well-known cancer genes, including Nf1, Myc, Jak2, and Pten. Importantly, several new potential drivers of histiocytic sarcoma were identified and could serve as targets for therapy for histiocytic sarcoma patients. PMID:24827933

  19. Microsatellite marker based genetic linkage maps of Oreochromis aureus and O. niloticus (Cichlidae): extensive linkage group segment homologies revealed.

    PubMed

    McConnell, S K; Beynon, C; Leamon, J; Skibinski, D O

    2000-06-01

    Partial genetic linkage maps, based on microsatellite markers, were constructed for two tilapia species, Oreochromis aureus and Oreochromis niloticus using an interspecific backcross population. The linkage map for O. aureus comprised 28 markers on 10 linkage groups and covered 212.8 CM. Nine markers were mapped to four linkage groups on an O. niloticus female linkage map covering 40.6 CM. Results revealed a high degree of conservation of synteny between the linkage groups defined in O. aureus and the previously published genetic linkage map of O. niloticus. PMID:10895314

  20. Complete genomes reveal signatures of demographic and genetic declines in the woolly mammoth

    PubMed Central

    Palkopoulou, Eleftheria; Mallick, Swapan; Skoglund, Pontus; Enk, Jacob; Rohland, Nadin; Li, Heng; Omrak, Ayça; Vartanyan, Sergey; Poinar, Hendrik; Götherström, Anders; Reich, David; Dalén, Love

    2015-01-01

    Summary The processes leading up to species extinctions are typically characterized by prolonged declines in population size and geographic distribution, followed by a phase in which populations are very small and may be subject to intrinsic threats, including loss of genetic diversity and inbreeding [1]. However, whether such genetic factors have had an impact on species prior to their extinction is unclear [2, 3]; examining this would require a detailed reconstruction of a species’ demographic history as well as changes in genome-wide diversity leading up to its extinction. Here, we present high-quality complete genome sequences from two woolly mammoths (Mammuthus primigenius). The first mammoth was sequenced at 17.1-fold coverage, and dates to ~4,300 years before present, constituting one of the last surviving individuals on Wrangel Island. The second mammoth, sequenced at 11.2-fold coverage, was obtained from a ~44,800 year old specimen from the Late Pleistocene population in northeastern Siberia. The demographic trajectories inferred from the two genomes are qualitatively similar and reveal a population bottleneck during the Middle or Early Pleistocene, and a more recent severe decline in the ancestors of the Wrangel mammoth at the end of the last glaciation. A comparison of the two genomes shows that the Wrangel mammoth has a 20% reduction in heterozygosity as well as a 28-fold increase in the fraction of the genome that is comprised of runs of homozygosity. We conclude that the population on Wrangel Island, which was the last surviving woolly mammoth population, was subject to reduced genetic diversity shortly before it became extinct. PMID:25913407

  1. Complete genomes reveal signatures of demographic and genetic declines in the woolly mammoth.

    PubMed

    Palkopoulou, Eleftheria; Mallick, Swapan; Skoglund, Pontus; Enk, Jacob; Rohland, Nadin; Li, Heng; Omrak, Ayça; Vartanyan, Sergey; Poinar, Hendrik; Götherström, Anders; Reich, David; Dalén, Love

    2015-05-18

    The processes leading up to species extinctions are typically characterized by prolonged declines in population size and geographic distribution, followed by a phase in which populations are very small and may be subject to intrinsic threats, including loss of genetic diversity and inbreeding. However, whether such genetic factors have had an impact on species prior to their extinction is unclear; examining this would require a detailed reconstruction of a species' demographic history as well as changes in genome-wide diversity leading up to its extinction. Here, we present high-quality complete genome sequences from two woolly mammoths (Mammuthus primigenius). The first mammoth was sequenced at 17.1-fold coverage and dates to ∼4,300 years before present, representing one of the last surviving individuals on Wrangel Island. The second mammoth, sequenced at 11.2-fold coverage, was obtained from an ∼44,800-year-old specimen from the Late Pleistocene population in northeastern Siberia. The demographic trajectories inferred from the two genomes are qualitatively similar and reveal a population bottleneck during the Middle or Early Pleistocene, and a more recent severe decline in the ancestors of the Wrangel mammoth at the end of the last glaciation. A comparison of the two genomes shows that the Wrangel mammoth has a 20% reduction in heterozygosity as well as a 28-fold increase in the fraction of the genome that comprises runs of homozygosity. We conclude that the population on Wrangel Island, which was the last surviving woolly mammoth population, was subject to reduced genetic diversity shortly before it became extinct. PMID:25913407

  2. Genetic variation and population differentiation in a medical herb Houttuynia cordata in China revealed by inter-simple sequence repeats (ISSRs).

    PubMed

    Wei, Lin; Wu, Xian-Jin

    2012-01-01

    Houttuynia cordata is an important traditional Chinese herb with unresolved genetics and taxonomy, which lead to potential problems in the conservation and utilization of the resource. Inter-simple sequence repeat (ISSR) markers were used to assess the level and distribution of genetic diversity in 226 individuals from 15 populations of H. cordata in China. ISSR analysis revealed low genetic variations within populations but high genetic differentiations among populations. This genetic structure probably mainly reflects the historical association among populations. Genetic cluster analysis showed that the basal clade is composed of populations from Southwest China, and the other populations have continuous and eastward distributions. The structure of genetic diversity in H. cordata demonstrated that this species might have survived in Southwest China during the glacial age, and subsequently experienced an eastern postglacial expansion. Based on the results of genetic analysis, it was proposed that as many as possible targeted populations for conservation be included. PMID:22942696

  3. Genetic characterization of Toxoplasma gondii isolates from Portugal, Austria and Israel reveals higher genetic variability within the type II lineage.

    PubMed

    Verma, S K; Ajzenberg, D; Rivera-Sanchez, A; Su, C; Dubey, J P

    2015-06-01

    This study compared genetic diversity of Toxoplasma gondii isolates from Portugal, Austria and Israel. For this, we genotyped 90 T. gondii isolates (16 from Portugal, 67 from Austria and 7 from Israel) using 10 nested PCR-restriction length polymorphism (RFLP) genetic markers and 15 microsatellite (MS) markers. By PCR-RFLP typing, 7 isolates from Portugal chickens were identified as type II (ToxoDB #1 or #3), 4 were type III (ToxoDB #2) and the remaining 4 isolates have unique genotype pattern were designated as ToxoDB #254. One mouse virulent isolate from a bovine fetus (Bos taurus) in Portugal was type I (ToxoDB #10) at all loci and designated as TgCowPr1. All 67 isolates from Austria and 7 from Israel were type II (ToxoDB #1 or #3). By MS typing, many additional genetic variations were revealed among the type II and type III isolates. Phylogenetic analysis showed that isolates from the same geographical locations tend to cluster together, and there is little overlapping of genotypes among different locations. This study demonstrated that the MS markers can provide higher discriminatory power to reveal association of genotypes with geographical locations. Future studies of the type II strains in Europe by these MS markers will be useful to reveal transmission patterns of the parasite. PMID:25677825

  4. Genetic analysis reveals candidate species in the Scinax catharinae clade (Amphibia: Anura) from Central Brazil

    PubMed Central

    Nogueira, Lídia; Solé, Mirco; Siqueira, Sérgio; Affonso, Paulo Roberto Antunes de Mello; Strüssmann, Christine; Sampaio, Iracilda

    2016-01-01

    Abstract Scinax (Anura: Hylidae) is a species-rich genus of amphibians (113 spp.), divided into five species groups by morphological features. Cladistic analyses however revealed only two monophyletic clades in these groups: Scinax catharinae and Scinax ruber. Most species from the S. catharinae clade are found in Atlantic rainforest, except for Scinax canastrensis,S. centralis, S. luizotavioi, S. machadoi,S. pombali and S. skaios. In the present work, specimens of Scinax collected in Chapada dos Guimarães, central Brazil, were morphologically compatible with species from theS. catharinae group. On the other hand, genetic analysis based on mitochondrial (16S and 12S) and nuclear (rhodopsin) sequences revealed a nucleotide divergence of 6 to 20% between Scinax sp. and other congeners from the Brazilian savannah (Cerrado). Accordingly, Bayesian inference placed Scinax sp. in the S. catharinae clade with high support values. Hence, these findings strongly indicate the presence of a new species in the S. catharinae clade from the southwestern portion of the Brazilian savannah. To be properly validated as a novel species, detailed comparative morphological and bioacustic studies with other taxa from Brazil such asS. canastrensis, S. centralis, S. luizotavioi, S. machadoi, S. pombali and S. skaios are required. PMID:27007898

  5. Transcription closed and open complex dynamics studies reveal balance between genetic determinants and co-factors

    NASA Astrophysics Data System (ADS)

    Sala, Adrien; Shoaib, Muhammad; Anufrieva, Olga; Mutharasu, Gnanavel; Jahan Hoque, Rawnak; Yli-Harja, Olli; Kandhavelu, Meenakshisundaram

    2015-05-01

    In E. coli, promoter closed and open complexes are key steps in transcription initiation, where magnesium-dependent RNA polymerase catalyzes RNA synthesis. However, the exact mechanism of initiation remains to be fully elucidated. Here, using single mRNA detection and dual reporter studies, we show that increased intracellular magnesium concentration affects Plac initiation complex formation resulting in a highly dynamic process over the cell growth phases. Mg2+ regulates transcription transition, which modulates bimodality of mRNA distribution in the exponential phase. We reveal that Mg2+ regulates the size and frequency of the mRNA burst by changing the open complex duration. Moreover, increasing magnesium concentration leads to higher intrinsic and extrinsic noise in the exponential phase. RNAP-Mg2+ interaction simulation reveals critical movements creating a shorter contact distance between aspartic acid residues and Nucleotide Triphosphate residues and increasing electrostatic charges in the active site. Our findings provide unique biophysical insights into the balanced mechanism of genetic determinants and magnesium ion in transcription initiation regulation during cell growth.

  6. Genetic analysis reveals candidate species in the Scinax catharinae clade (Amphibia: Anura) from Central Brazil.

    PubMed

    Nogueira, Lídia; Solé, Mirco; Siqueira, Sérgio; Affonso, Paulo Roberto Antunes de Mello; Strüssmann, Christine; Sampaio, Iracilda

    2016-03-01

    Scinax (Anura: Hylidae) is a species-rich genus of amphibians (113 spp.), divided into five species groups by morphological features. Cladistic analyses however revealed only two monophyletic clades in these groups: Scinax catharinae and Scinax ruber. Most species from the S. catharinae clade are found in Atlantic rainforest, except for Scinax canastrensis,S. centralis, S. luizotavioi, S. machadoi,S. pombali and S. skaios. In the present work, specimens of Scinax collected in Chapada dos Guimarães, central Brazil, were morphologically compatible with species from theS. catharinae group. On the other hand, genetic analysis based on mitochondrial (16S and 12S) and nuclear (rhodopsin) sequences revealed a nucleotide divergence of 6 to 20% between Scinax sp. and other congeners from the Brazilian savannah (Cerrado). Accordingly, Bayesian inference placed Scinax sp. in the S. catharinae clade with high support values. Hence, these findings strongly indicate the presence of a new species in the S. catharinae clade from the southwestern portion of the Brazilian savannah. To be properly validated as a novel species, detailed comparative morphological and bioacustic studies with other taxa from Brazil such asS. canastrensis, S. centralis, S. luizotavioi, S. machadoi, S. pombali and S. skaios are required. PMID:27007898

  7. Twin and family studies reveal strong environmental and weaker genetic cues explaining heritability of eosinophilic esophagitis

    PubMed Central

    Alexander, Eileen S.; Martin, Lisa J.; Collins, Margaret H.; Kottyan, Leah; Sucharew, Heidi; He, Hua; Mukkada, Vincent A.; Succop, Paul A.; Abonia, J. Pablo; Foote, Heather; Eby, Michael D.; Grotjan, Tommie M.; Greenler, Alexandria J.; Dellon, Evan S.; Demain, Jeffrey G.; Furuta, Glenn T.; Gurian, Larry E.; Harley, John B.; Hopp, Russell J.; Kaul, Ajay; Nadeau, Kari C.; Noel, Richard J.; Putnam, Philip E.; von Tiehl, Karl F.; Rothenberg, Marc E.

    2014-01-01

    Background Eosinophilic esophagitis (EoE) is a chronic antigen-driven allergic inflammatory disease, likely involving the interplay of genetic and environmental factors, yet their respective contributions to heritability are unknown. Objective To quantify risk associated with genes and environment on familial clustering of EoE. Methods Family history was obtained from a hospital-based cohort of 914 EoE probands, (n=2192 first-degree “Nuclear-Family” relatives) and the new international registry of monozygotic and dizygotic twins/triplets (n=63 EoE “Twins” probands). Frequencies, recurrence risk ratios (RRRs), heritability and twin concordance were estimated. Environmental exposures were preliminarily examined. Results Analysis of the Nuclear-Family–based cohort revealed that the rate of EoE, in first-degree relatives of a proband, was 1.8% (unadjusted) and 2.3% (sex-adjusted). RRRs ranged from 10–64, depending on the family relationship, and were higher in brothers (64.0; p=0.04), fathers (42.9; p=0.004) and males (50.7; p<0.001) compared to sisters, mothers and females, respectively. Risk of EoE for other siblings was 2.4%. In the Nuclear-Families, combined gene and common environment heritability (hgc2) was 72.0±2.7% (p<0.001). In the Twins cohort, genetic heritability was 14.5±4.0% (p<0.001), and common family environment contributed 81.0±4% (p<0.001) to phenotypic variance. Proband-wise concordance in MZ co-twins was 57.9±9.5% compared to 36.4±9.3% in DZ (p=0.11). Greater birth-weight difference between twins (p=0.01), breastfeeding (p=0.15) and Fall birth season (p=0.02) were associated with twin discordance in disease status. Conclusions EoE recurrence risk ratios are increased 10–64-fold compared with the general population. EoE in relatives is 1.8–2.4%, depending upon relationship and sex. Nuclear-Family heritability appeared to be high (72.0%). However, Twins cohort analysis revealed a powerful role for common environment (81

  8. Whole genome comparison of a large collection of mycobacteriophages reveals a continuum of phage genetic diversity.

    PubMed

    Pope, Welkin H; Bowman, Charles A; Russell, Daniel A; Jacobs-Sera, Deborah; Asai, David J; Cresawn, Steven G; Jacobs, William R; Hendrix, Roger W; Lawrence, Jeffrey G; Hatfull, Graham F

    2015-01-01

    The bacteriophage population is large, dynamic, ancient, and genetically diverse. Limited genomic information shows that phage genomes are mosaic, and the genetic architecture of phage populations remains ill-defined. To understand the population structure of phages infecting a single host strain, we isolated, sequenced, and compared 627 phages of Mycobacterium smegmatis. Their genetic diversity is considerable, and there are 28 distinct genomic types (clusters) with related nucleotide sequences. However, amino acid sequence comparisons show pervasive genomic mosaicism, and quantification of inter-cluster and intra-cluster relatedness reveals a continuum of genetic diversity, albeit with uneven representation of different phages. Furthermore, rarefaction analysis shows that the mycobacteriophage population is not closed, and there is a constant influx of genes from other sources. Phage isolation and analysis was performed by a large consortium of academic institutions, illustrating the substantial benefits of a disseminated, structured program involving large numbers of freshman undergraduates in scientific discovery. PMID:25919952

  9. Comparative Transcriptome Analysis Reveals the Genetic Basis of Skin Color Variation in Common Carp

    PubMed Central

    Jiang, Yanliang; Zhang, Songhao; Xu, Jian; Feng, Jianxin; Mahboob, Shahid; Al-Ghanim, Khalid A.; Sun, Xiaowen; Xu, Peng

    2014-01-01

    Background The common carp is an important aquaculture species that is widely distributed across the world. During the long history of carp domestication, numerous carp strains with diverse skin colors have been established. Skin color is used as a visual criterion to determine the market value of carp. However, the genetic basis of common carp skin color has not been extensively studied. Methodology/Principal Findings In this study, we performed Illumina sequencing on two common carp strains: the reddish Xingguo red carp and the brownish-black Yellow River carp. A total of 435,348,868 reads were generated, resulting in 198,781 assembled contigs that were used as reference sequences. Comparisons of skin transcriptome files revealed 2,012 unigenes with significantly different expression in the two common carp strains, including 874 genes that were up-regulated in Xingguo red carp and 1,138 genes that were up-regulated in Yellow River carp. The expression patterns of 20 randomly selected differentially expressed genes were validated using quantitative RT-PCR. Gene pathway analysis of the differentially expressed genes indicated that melanin biosynthesis, along with the Wnt and MAPK signaling pathways, is highly likely to affect the skin pigmentation process. Several key genes involved in the skin pigmentation process, including TYRP1, SILV, ASIP and xCT, showed significant differences in their expression patterns between the two strains. Conclusions In this study, we conducted a comparative transcriptome analysis of Xingguo red carp and Yellow River carp skins, and we detected key genes involved in the common carp skin pigmentation process. We propose that common carp skin pigmentation depends upon at least three pathways. Understanding fish skin color genetics will facilitate future molecular selection of the fish skin colors with high market values. PMID:25255374

  10. De novo genetic variation revealed in somatic sectors of single Arabidopsis plants

    PubMed Central

    Hopkins, Marianne T; Khalid, Aaron M; Chang, Pei-Chun; Vanderhoek, Karen C; Lai, Dulcie; Doerr, Meghan D; Lolle, Susan J

    2013-01-01

    Concern over the tremendous loss of genetic diversity among many of our most important crops has prompted major efforts to preserve seed stocks derived from cultivated species and their wild relatives.  Arabidopsis thaliana propagates mainly by self-fertilizing, and therefore, like many crop plants, theoretically has a limited potential for producing genetically diverse offspring. Despite this, inbreeding has persisted in Arabidopsis for over a million years suggesting that some underlying adaptive mechanism buffers the deleterious consequences of this reproductive strategy. Using presence-absence molecular markers we demonstrate that single Arabidopsis plants can have multiple genotypes. Sequence analyses reveal single nucleotide changes, loss of sequences and, surprisingly, acquisition of unique genomic insertions. Estimates based on quantitative analyses suggest that these genetically discordant sectors are very small but can have a complex genetic makeup. In ruling out more trivial explanations for these data, our findings raise the possibility that intrinsic drivers of genetic variation are responsible for the targeted sequence changes we detect. Given the evolutionary advantage afforded to populations with greater genetic diversity, we hypothesize that organisms that primarily self-fertilize or propagate clonally counteract the genetic cost of such reproductive strategies by leveraging a cryptic reserve of extra-genomic information. PMID:24555023

  11. A Novel Multi-Locus Sequence Typing Scheme Reveals High Genetic Diversity of Human Pathogenic Members of the Fusarium incarnatum-F. equiseti and F. chlamydosporum Species Complexes within the U. S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Results of the present study reveal that members of the Fusarium incarnatum-equiseti (FIESC) and F. chlamydosporum species complexes (FCSC) collectively account for approximately 15% of all fusarial infections of humans and other animals within the U. S. Moreover, the diverse toxins these fungi pro...

  12. Genetic variability of mutans streptococci revealed by wide whole-genome sequencing

    PubMed Central

    2013-01-01

    Background Mutans streptococci are a group of bacteria significantly contributing to tooth decay. Their genetic variability is however still not well understood. Results Genomes of 6 clinical S. mutans isolates of different origins, one isolate of S. sobrinus (DSM 20742) and one isolate of S. ratti (DSM 20564) were sequenced and comparatively analyzed. Genome alignment revealed a mosaic-like structure of genome arrangement. Genes related to pathogenicity are found to have high variations among the strains, whereas genes for oxidative stress resistance are well conserved, indicating the importance of this trait in the dental biofilm community. Analysis of genome-scale metabolic networks revealed significant differences in 42 pathways. A striking dissimilarity is the unique presence of two lactate oxidases in S. sobrinus DSM 20742, probably indicating an unusual capability of this strain in producing H2O2 and expanding its ecological niche. In addition, lactate oxidases may form with other enzymes a novel energetic pathway in S. sobrinus DSM 20742 that can remedy its deficiency in citrate utilization pathway. Using 67 S. mutans genomes currently available including the strains sequenced in this study, we estimates the theoretical core genome size of S. mutans, and performed modeling of S. mutans pan-genome by applying different fitting models. An “open” pan-genome was inferred. Conclusions The comparative genome analyses revealed diversities in the mutans streptococci group, especially with respect to the virulence related genes and metabolic pathways. The results are helpful for better understanding the evolution and adaptive mechanisms of these oral pathogen microorganisms and for combating them. PMID:23805886

  13. Genetic Differentiation and Genetic Diversity of Castanopsis (Fagaceae), the Dominant Tree Species in Japanese Broadleaved Evergreen Forests, Revealed by Analysis of EST-Associated Microsatellites

    PubMed Central

    Aoki, Kyoko; Ueno, Saneyoshi; Kamijo, Takashi; Setoguchi, Hiroaki; Murakami, Noriaki; Kato, Makoto; Tsumura, Yoshihiko

    2014-01-01

    The broadleaved evergreen forests of the East Asian warm temperate zone are characterised by their high biodiversity and endemism, and there is therefore a need to extend our understanding of its genetic diversity and phylogeographic patterns. Castanopsis (Fagaceae) is one of the dominant tree species in the broadleaved evergreen forests of Japan. In this study we investigate the genetic diversity, genetic structure and leaf epidermal morphology of 63 natural populations of C. sieboldii and C. cuspidata, using 32 Expressed Sequence Tag associated microsatellites. The overall genetic differentiation between populations was low (GST = 0.069 in C. sieboldii and GST = 0.057 in C. cuspidata). Neighbor-joining tree and Bayesian clustering analyses revealed that the populations of C. sieboldii and C. cuspidata were genetically clearly differentiated, a result which is consistent with the morphology of their epidermal cell layers. This suggests that C. sieboldii and C. cuspidata should be treated as independent species, although intermediate morphologies are often observed, especially at sites where the two species coexist. The higher level of genetic diversity observed in the Kyushu region (for both species) and the Ryukyu Islands (for C. sieboldii) is consistent with the available fossil pollen data for Castanopsis-type broadleaved evergreen trees during the Last Glacial Maximum and suggests the existence of refugia for Castanopsis forests in southern Japan. Within the C. sieboldii populations, Bayesian clustering analyses detected three clusters, in the western and eastern parts of the main islands and in the Ryukyu Islands. The west-east genetic differentiation observed for this species in the main islands, a pattern which is also found in several plant and animal species inhabiting Castanopsis forests in Japan, suggests that they have been isolated from each other in the western and eastern populations for an extended period of time, and may imply the

  14. Genetic differentiation and genetic diversity of Castanopsis (Fagaceae), the dominant tree species in Japanese broadleaved evergreen forests, revealed by analysis of EST-associated microsatellites.

    PubMed

    Aoki, Kyoko; Ueno, Saneyoshi; Kamijo, Takashi; Setoguchi, Hiroaki; Murakami, Noriaki; Kato, Makoto; Tsumura, Yoshihiko

    2014-01-01

    The broadleaved evergreen forests of the East Asian warm temperate zone are characterised by their high biodiversity and endemism, and there is therefore a need to extend our understanding of its genetic diversity and phylogeographic patterns. Castanopsis (Fagaceae) is one of the dominant tree species in the broadleaved evergreen forests of Japan. In this study we investigate the genetic diversity, genetic structure and leaf epidermal morphology of 63 natural populations of C. sieboldii and C. cuspidata, using 32 Expressed Sequence Tag associated microsatellites. The overall genetic differentiation between populations was low (GST = 0.069 in C. sieboldii and GST = 0.057 in C. cuspidata). Neighbor-joining tree and Bayesian clustering analyses revealed that the populations of C. sieboldii and C. cuspidata were genetically clearly differentiated, a result which is consistent with the morphology of their epidermal cell layers. This suggests that C. sieboldii and C. cuspidata should be treated as independent species, although intermediate morphologies are often observed, especially at sites where the two species coexist. The higher level of genetic diversity observed in the Kyushu region (for both species) and the Ryukyu Islands (for C. sieboldii) is consistent with the available fossil pollen data for Castanopsis-type broadleaved evergreen trees during the Last Glacial Maximum and suggests the existence of refugia for Castanopsis forests in southern Japan. Within the C. sieboldii populations, Bayesian clustering analyses detected three clusters, in the western and eastern parts of the main islands and in the Ryukyu Islands. The west-east genetic differentiation observed for this species in the main islands, a pattern which is also found in several plant and animal species inhabiting Castanopsis forests in Japan, suggests that they have been isolated from each other in the western and eastern populations for an extended period of time, and may imply the

  15. Taking the chaos out of genetic patchiness: seascape genetics reveals ecological and oceanographic drivers of genetic patterns in three temperate reef species.

    PubMed

    Selkoe, Kimberly A; Watson, James R; White, Crow; Horin, Tal Ben; Iacchei, Matthew; Mitarai, Satoshi; Siegel, David A; Gaines, Steven D; Toonen, Robert J

    2010-09-01

    Marine species frequently show weak and/or complex genetic structuring that is commonly dismissed as 'chaotic' genetic patchiness and ecologically uninformative. Here, using three datasets that individually feature weak chaotic patchiness, we demonstrate that combining inferences across species and incorporating environmental data can greatly improve the predictive value of marine population genetics studies on small spatial scales. Significant correlations in genetic patterns of microsatellite markers among three species, kelp bass Paralabrax clathratus, Kellet's whelk Kelletia kelletii and California spiny lobster Panulirus interruptus, in the Southern California Bight suggest that slight differences in diversity and pairwise differentiation across sampling sites are not simply noise or chaotic patchiness, but are ecologically meaningful. To test whether interspecies correlations potentially result from shared environmental drivers of genetic patterns, we assembled data on kelp bed size, sea surface temperature and estimates of site-to-site migration probability derived from a high resolution multi-year ocean circulation model. These data served as predictor variables in linear models of genetic diversity and linear mixed models of genetic differentiation that were assessed with information-theoretic model selection. Kelp was the most informative predictor of genetics for all three species, but ocean circulation also played a minor role for kelp bass. The shared patterns suggest a single spatial marine management strategy may effectively protect genetic diversity of multiple species. This study demonstrates the power of environmental and ecological data to shed light on weak genetic patterns and highlights the need for future focus on a mechanistic understanding of the links between oceanography, ecology and genetic structure. PMID:20723063

  16. Revealing cryptic spatial patterns in genetic variability by a new multivariate method.

    PubMed

    Jombart, T; Devillard, S; Dufour, A-B; Pontier, D

    2008-07-01

    Increasing attention is being devoted to taking landscape information into account in genetic studies. Among landscape variables, space is often considered as one of the most important. To reveal spatial patterns, a statistical method should be spatially explicit, that is, it should directly take spatial information into account as a component of the adjusted model or of the optimized criterion. In this paper we propose a new spatially explicit multivariate method, spatial principal component analysis (sPCA), to investigate the spatial pattern of genetic variability using allelic frequency data of individuals or populations. This analysis does not require data to meet Hardy-Weinberg expectations or linkage equilibrium to exist between loci. The sPCA yields scores summarizing both the genetic variability and the spatial structure among individuals (or populations). Global structures (patches, clines and intermediates) are disentangled from local ones (strong genetic differences between neighbors) and from random noise. Two statistical tests are proposed to detect the existence of both types of patterns. As an illustration, the results of principal component analysis (PCA) and sPCA are compared using simulated datasets and real georeferenced microsatellite data of Scandinavian brown bear individuals (Ursus arctos). sPCA performed better than PCA to reveal spatial genetic patterns. The proposed methodology is implemented in the adegenet package of the free software R. PMID:18446182

  17. Genetic analysis of incurvata mutants reveals three independent genetic operations at work in Arabidopsis leaf morphogenesis.

    PubMed Central

    Serrano-Cartagena, J; Candela, H; Robles, P; Ponce, M R; Pérez-Pérez, J M; Piqueras, P; Micol, J L

    2000-01-01

    In an attempt to identify genes involved in the control of leaf morphogenesis, we have studied 13 Arabidopsis thaliana mutants with curled, involute leaves, a phenotype herein referred to as Incurvata (Icu), which were isolated by G. Röbbelen and belong to the Arabidopsis Information Service Form Mutants collection. The Icu phenotype was inherited as a single recessive trait in 10 mutants, with semidominance in 2 mutants and with complete dominance in the remaining 1. Complementation analyses indicated that the studied mutations correspond to five genes, representative alleles of which were mapped relative to polymorphic microsatellites. Although most double-mutant combinations displayed additivity of the Icu phenotypes, those of icu1 icu2 and icu3 icu4 double mutants were interpreted as synergistic, which suggests that the five genes studied represent three independent genetic operations that are at work for the leaf to acquire its final form at full expansion. We have shown that icu1 mutations are alleles of the Polycomb group gene CURLY LEAF (CLF) and that the leaf phenotype of the icu2 mutant is suppressed in an agamous background, as is known for clf mutants. In addition, we have tested by means of multiplex RT-PCR the transcription of several floral genes in Icu leaves. Ectopic expression of AGAMOUS and APETALA3 was observed in clf and icu2, but not in icu3, icu4, and icu5 mutants. Taken together, these results suggest that CLF and ICU2 play related roles, the latter being a candidate to belong to the Polycomb group of regulatory genes. We propose that, as flowers evolved, a new major class of genes, including CLF and ICU2, may have been recruited to prevent the expression of floral homeotic genes in the leaves. PMID:11063708

  18. Temporal analysis of mtDNA variation reveals decreased genetic diversity in least terns

    USGS Publications Warehouse

    Draheim, Hope M.; Baird, Patricia; Haig, Susan M.

    2012-01-01

    The Least Tern (Sternula antillarum) has undergone large population declines over the last century as a result of direct and indirect anthropogenic factors. The genetic implications of these declines are unknown. We used historical museum specimens (pre-1960) and contemporary (2001–2005) samples to examine range-wide phylogeographic patterns and investigate potential loss in the species' genetic variation. We obtained sequences (522 bp) of the mitochondrial gene for NADH dehydrogenase subunit 6 (ND6) from 268 individuals from across the species' range. Phylogeographic analysis revealed no association with geography or traditional subspecies designations. However, we detected potential reductions in genetic diversity in contemporary samples from California and the Atlantic coast Least Tern from that in historical samples, suggesting that current genetic diversity in Least Tern populations is lower than in their pre-1960 counterparts. Our results offer unique insights into changes in the Least Tern's genetic diversity over the past century and highlight the importance and utility of museum specimens in studies of conservation genetics.

  19. Genetic affinities within the herring gull Larus argentatus assemblage revealed by AFLP genotyping.

    PubMed

    de Knijff P; Denkers, F; van Swelm, N D; Kuiper, M

    2001-01-01

    To date, the taxonomic status of circumpolar breeding populations of the Herring Gull Larus argentatus, the Lesser Black-backed Gull Larus fuscus, and the closely related Yellow-legged Gull Larus cachinnans has been based on differences or similarities in phenotype, morphology, and feeding and premating behavior. To shed some new light on the many taxonomic uncertainties surrounding these taxa, we describe the results of a large DNA study based on comparing the distribution of 209 biallelic markers among 109 gulls, representing 11 gull taxa of the Herring Gull assemblage and the Common Gull Larus canus. A detailed phylogenetic analysis failed to show clustering of individuals into groups representing either geographic origin or phenotype. Alternatively, birds were grouped into taxa defined on the basis of phenotype and geographic origin or phenotype alone. Genetic analyses revealed significantly different genetic distances between all pairs of taxa. However, based on these genetic distances, again no consistent phylogenetic tree could be constructed. Analysis of molecular variance indicated that about 77% of the total genetic variability among these gulls could be explained by within-taxon differences. Only 23% of the total genetic variability was due to genetic differences between taxa, irrespective of their species or subspecies status. Although this seems to challenge the current taxonomic treatment of the herring gull assemblage, our results are too premature and too incomplete to recommend a drastic change. PMID:11139298

  20. Modeling development and quantitative trait mapping reveal independent genetic modules for leaf size and shape.

    PubMed

    Baker, Robert L; Leong, Wen Fung; Brock, Marcus T; Markelz, R J Cody; Covington, Michael F; Devisetty, Upendra K; Edwards, Christine E; Maloof, Julin; Welch, Stephen; Weinig, Cynthia

    2015-10-01

    Improved predictions of fitness and yield may be obtained by characterizing the genetic controls and environmental dependencies of organismal ontogeny. Elucidating the shape of growth curves may reveal novel genetic controls that single-time-point (STP) analyses do not because, in theory, infinite numbers of growth curves can result in the same final measurement. We measured leaf lengths and widths in Brassica rapa recombinant inbred lines (RILs) throughout ontogeny. We modeled leaf growth and allometry as function valued traits (FVT), and examined genetic correlations between these traits and aspects of phenology, physiology, circadian rhythms and fitness. We used RNA-seq to construct a SNP linkage map and mapped trait quantitative trait loci (QTL). We found genetic trade-offs between leaf size and growth rate FVT and uncovered differences in genotypic and QTL correlations involving FVT vs STPs. We identified leaf shape (allometry) as a genetic module independent of length and width and identified selection on FVT parameters of development. Leaf shape is associated with venation features that affect desiccation resistance. The genetic independence of leaf shape from other leaf traits may therefore enable crop optimization in leaf shape without negative effects on traits such as size, growth rate, duration or gas exchange. PMID:26083847

  1. Genetic characterization of Hawaiian isolates of Plasmodium relictum reveals mixed-genotype infections

    USGS Publications Warehouse

    Jarvi, S.I.; Farias, M.E.M.; Atkinson, C.T.

    2008-01-01

    Background: The relatively recent introduction of a highly efficient mosquito vector and an avian pathogen (Plasmodium relictum) to an isolated island ecosystem with nai??ve, highly susceptible avian hosts provides a unique opportunity to investigate evolution of virulence in a natural system. Mixed infections can significantly contribute to the uncertainty in host-pathogen dynamics with direct impacts on virulence. Toward further understanding of how host-parasite and parasite-parasite relationships may impact virulence, this study characterizes within-host diversity of malaria parasite populations based on genetic analysis of the trap (thrombospondin-related anonymous protein) gene in isolates originating from Hawaii, Maui and Kauai Islands. Methods: A total of 397 clones were produced by nested PCR amplification and cloning of a 1664 bp fragment of the trap gene from two malarial isolates, K1 (Kauai) and KV115 (Hawaii) that have been used for experimental studies, and from additional isolates from wild birds on Kauai, Maui and Hawaii Islands. Diversity of clones was evaluated initially by RFLP-based screening, followed by complete sequencing of 33 selected clones. Results: RFLP analysis of trap revealed a minimum of 28 distinct RFLP haplotypes among the 397 clones from 18 birds. Multiple trap haplotypes were detected in every bird evaluated, with an average of 5.9 haplotypes per bird. Overall diversity did not differ between the experimental isolates, however, a greater number of unique haplotypes were detected in K1 than in KV115. We detected high levels of clonal diversity with clear delineation between isolates K1 and KV115 in a haplotype network. The patterns of within-host haplotype clustering are consistent with the possibility of a clonal genetic structure and rapid within-host mutation after infection. Conclusion: Avian malaria (P. relictum) and Avipoxvirus are the significant infectious diseases currently affecting the native Hawaiian avifauna. This

  2. Genetic characterization of Hawaiian isolates of Plasmodium relictum reveals mixed-genotype infections

    PubMed Central

    Jarvi, Susan I; Farias, Margaret EM; Atkinson, Carter T

    2008-01-01

    Background The relatively recent introduction of a highly efficient mosquito vector and an avian pathogen (Plasmodium relictum) to an isolated island ecosystem with naïve, highly susceptible avian hosts provides a unique opportunity to investigate evolution of virulence in a natural system. Mixed infections can significantly contribute to the uncertainty in host-pathogen dynamics with direct impacts on virulence. Toward further understanding of how host-parasite and parasite-parasite relationships may impact virulence, this study characterizes within-host diversity of malaria parasite populations based on genetic analysis of the trap (thrombospondin-related anonymous protein) gene in isolates originating from Hawaii, Maui and Kauai Islands. Methods A total of 397 clones were produced by nested PCR amplification and cloning of a 1664 bp fragment of the trap gene from two malarial isolates, K1 (Kauai) and KV115 (Hawaii) that have been used for experimental studies, and from additional isolates from wild birds on Kauai, Maui and Hawaii Islands. Diversity of clones was evaluated initially by RFLP-based screening, followed by complete sequencing of 33 selected clones. Results RFLP analysis of trap revealed a minimum of 28 distinct RFLP haplotypes among the 397 clones from 18 birds. Multiple trap haplotypes were detected in every bird evaluated, with an average of 5.9 haplotypes per bird. Overall diversity did not differ between the experimental isolates, however, a greater number of unique haplotypes were detected in K1 than in KV115. We detected high levels of clonal diversity with clear delineation between isolates K1 and KV115 in a haplotype network. The patterns of within-host haplotype clustering are consistent with the possibility of a clonal genetic structure and rapid within-host mutation after infection. Conclusion Avian malaria (P. relictum) and Avipoxvirus are the significant infectious diseases currently affecting the native Hawaiian avifauna. This study

  3. Genetic diversity across natural populations of three montane plant species from the Western Ghats, India revealed by intersimple sequence repeats.

    PubMed

    Deshpande, A U; Apte, G S; Bahulikar, R A; Lagu, M D; Kulkarni, B G; Suresh, H S; Singh, N P; Rao, M K; Gupta, V S; Pant, A; Ranjekar, P K

    2001-10-01

    We analysed genetic diversity across the natural populations of three montane plant species in the Western Ghats, India; Symplocos laurina, Gaultheria fragrantissima and Eurya nitida using intersimple sequence repeat (ISSR) markers. These markers revealed genetic diversity within the populations of these plants from Nilgiri and also between two populations of S. laurina from Nilgiri and Amboli. Genetic variation within and between populations was analysed using various parameters such as total heterozygosity (HT), heterozygosity within population (HS), diversity between populations (DST), coefficient of population differentiation (GST), genetic distance (D) and gene flow (Nm). Total heterozygosity (HT) was higher for S. laurina (0.238) than for G. fragrantissima (0.172) and E. nitida (0.182). Two populations of S. laurina, separated by > 1000 km, showed a high within-population variation (53.7%) and a low gene flow (Nm = 0.447). upgma phenograms depicted a tendency of accessions to group according to their geographical locations in all the three plant species. The insight gained into the genetic structure of these plant populations might have implications in developing in situ and ex situ conservation strategies. PMID:11742544

  4. Genetic diversity of worldwide Jerusalem artichoke (Helianthus tuberosus) germplasm as revealed by RAPD markers.

    PubMed

    Wangsomnuk, P P; Khampa, S; Wangsomnuk, P; Jogloy, S; Mornkham, T; Ruttawat, B; Patanothai, A; Fu, Y B

    2011-01-01

    Jerusalem artichoke (Helianthus tuberosus) is a wild relative of the cultivated sunflower (H. annuus); it is an old tuber crop that has recently received renewed interest. We used RAPD markers to characterize 147 Jerusalem artichoke accessions from nine countries. Thirty RAPD primers were screened; 13 of them detected 357 reproducible RAPD bands, of which 337 were polymorphic. Various diversity analyses revealed several different patterns of RAPD variation. More than 93% of the RAPD variation was found within accessions of a country. Weak genetic differentiation was observed between wild and cultivated accessions. Six groups were detected in this germplasm set. Four ancestral groups were found for the Canadian germplasm. The most genetically distinct accessions were identified. These findings provide useful diversity information for understanding the Jerusalem artichoke gene pool, for conserving Jerusalem artichoke germplasm, and for choosing germplasm for genetic improvement. PMID:22194201

  5. Genetic Code Evolution Reveals the Neutral Emergence of Mutational Robustness, and Information as an Evolutionary Constraint

    PubMed Central

    Massey, Steven E.

    2015-01-01

    The standard genetic code (SGC) is central to molecular biology and its origin and evolution is a fundamental problem in evolutionary biology, the elucidation of which promises to reveal much about the origins of life. In addition, we propose that study of its origin can also reveal some fundamental and generalizable insights into mechanisms of molecular evolution, utilizing concepts from complexity theory. The first is that beneficial traits may arise by non-adaptive processes, via a process of “neutral emergence”. The structure of the SGC is optimized for the property of error minimization, which reduces the deleterious impact of point mutations. Via simulation, it can be shown that genetic codes with error minimization superior to the SGC can emerge in a neutral fashion simply by a process of genetic code expansion via tRNA and aminoacyl-tRNA synthetase duplication, whereby similar amino acids are added to codons related to that of the parent amino acid. This process of neutral emergence has implications beyond that of the genetic code, as it suggests that not all beneficial traits have arisen by the direct action of natural selection; we term these “pseudaptations”, and discuss a range of potential examples. Secondly, consideration of genetic code deviations (codon reassignments) reveals that these are mostly associated with a reduction in proteome size. This code malleability implies the existence of a proteomic constraint on the genetic code, proportional to the size of the proteome (P), and that its reduction in size leads to an “unfreezing” of the codon – amino acid mapping that defines the genetic code, consistent with Crick’s Frozen Accident theory. The concept of a proteomic constraint may be extended to propose a general informational constraint on genetic fidelity, which may be used to explain variously, differences in mutation rates in genomes with differing proteome sizes, differences in DNA repair capacity and genome GC content

  6. Genetic code evolution reveals the neutral emergence of mutational robustness, and information as an evolutionary constraint.

    PubMed

    Massey, Steven E

    2015-01-01

    The standard genetic code (SGC) is central to molecular biology and its origin and evolution is a fundamental problem in evolutionary biology, the elucidation of which promises to reveal much about the origins of life. In addition, we propose that study of its origin can also reveal some fundamental and generalizable insights into mechanisms of molecular evolution, utilizing concepts from complexity theory. The first is that beneficial traits may arise by non-adaptive processes, via a process of "neutral emergence". The structure of the SGC is optimized for the property of error minimization, which reduces the deleterious impact of point mutations. Via simulation, it can be shown that genetic codes with error minimization superior to the SGC can emerge in a neutral fashion simply by a process of genetic code expansion via tRNA and aminoacyl-tRNA synthetase duplication, whereby similar amino acids are added to codons related to that of the parent amino acid. This process of neutral emergence has implications beyond that of the genetic code, as it suggests that not all beneficial traits have arisen by the direct action of natural selection; we term these "pseudaptations", and discuss a range of potential examples. Secondly, consideration of genetic code deviations (codon reassignments) reveals that these are mostly associated with a reduction in proteome size. This code malleability implies the existence of a proteomic constraint on the genetic code, proportional to the size of the proteome (P), and that its reduction in size leads to an "unfreezing" of the codon - amino acid mapping that defines the genetic code, consistent with Crick's Frozen Accident theory. The concept of a proteomic constraint may be extended to propose a general informational constraint on genetic fidelity, which may be used to explain variously, differences in mutation rates in genomes with differing proteome sizes, differences in DNA repair capacity and genome GC content between organisms, a

  7. An integrated systems genetics screen reveals the transcriptional structure of inherited predisposition to metastatic disease

    PubMed Central

    Faraji, Farhoud; Hu, Ying; Wu, Gang; Goldberger, Natalie E.; Walker, Renard C.; Zhang, Jinghui; Hunter, Kent W.

    2014-01-01

    Metastasis is the result of stochastic genomic and epigenetic events leading to gene expression profiles that drive tumor dissemination. Here we exploit the principle that metastatic propensity is modified by the genetic background to generate prognostic gene expression signatures that illuminate regulators of metastasis. We also identify multiple microRNAs whose germline variation is causally linked to tumor progression and metastasis. We employ network analysis of global gene expression profiles in tumors derived from a panel of recombinant inbred mice to identify a network of co-expressed genes centered on Cnot2 that predicts metastasis-free survival. Modulating Cnot2 expression changes tumor cell metastatic potential in vivo, supporting a functional role for Cnot2 in metastasis. Small RNA sequencing of the same tumor set revealed a negative correlation between expression of the Mir216/217 cluster and tumor progression. Expression quantitative trait locus analysis (eQTL) identified cis-eQTLs at the Mir216/217 locus, indicating that differences in expression may be inherited. Ectopic expression of Mir216/217 in tumor cells suppressed metastasis in vivo. Finally, small RNA sequencing and mRNA expression profiling data were integrated to reveal that miR-3470a/b target a high proportion of network transcripts. In vivo analysis of Mir3470a/b demonstrated that both promote metastasis. Moreover, Mir3470b is a likely regulator of the Cnot2 network as its overexpression down-regulated expression of network hub genes and enhanced metastasis in vivo, phenocopying Cnot2 knockdown. The resulting data from this strategy identify Cnot2 as a novel regulator of metastasis and demonstrate the power of our systems-level approach in identifying modifiers of metastasis. PMID:24322557

  8. The human splicing code reveals new insights into the genetic determinants of disease

    PubMed Central

    Xiong, Hui Y.; Alipanahi, Babak; Lee, Leo J.; Bretschneider, Hannes; Merico, Daniele; Yuen, Ryan K.C.; Hua, Yimin; Gueroussov, Serge; Najafabadi, Hamed S.; Hughes, Timothy R.; Morris, Quaid; Barash, Yoseph; Krainer, Adrian R.; Jojic, Nebojsa; Scherer, Stephen W.; Blencowe, Benjamin J.; Frey, Brendan J.

    2015-01-01

    Introduction Advancing whole-genome precision medicine requires understanding how gene expression is altered by genetic variants, especially those that are outside of protein-coding regions. We developed a computational technique that scores how strongly genetic variants alter RNA splicing, a critical step in gene expression whose disruption contributes to many diseases, including cancers and neurological disorders. A genome-wide analysis reveals tens of thousands of variants that alter splicing and are enriched with a wide range of known diseases. Our results provide insight into the genetic basis of spinal muscular atrophy, hereditary nonpolyposis colorectal cancer and autism spectrum disorder. Methods We used machine learning to derive a computational model that takes as input DNA sequences and applies general rules to predict splicing in human tissues. Given a test variant, our model computes a score that predicts how much the variant disrupts splicing. The model was derived in such a way that it can be used to study diverse diseases and disorders, and to determine the consequences of common, rare, and even spontaneous variants. Results Our technique is able to accurately classify disease-causing variants and provides insights into the role of aberrant splicing in disease. We scored over 650,000 DNA variants and found that disease-causing variants have higher scores than common variants and even those associated with disease in genome-wide association studies. Our model predicts substantial and unexpected aberrant splicing due to variants within introns and exons, including those far from the splice site. For example, among intronic variants that are more than 30 nucleotides away from a splice site, known disease variants alter splicing nine times more often than common variants; among missense exonic disease variants, those that least impact protein function are over five times more likely to alter splicing than other variants. Autism has been associated with

  9. Tracing the genetic origin of Europe's first farmers reveals insights into their social organization

    PubMed Central

    Szécsényi-Nagy, Anna; Brandt, Guido; Haak, Wolfgang; Keerl, Victoria; Jakucs, János; Möller-Rieker, Sabine; Köhler, Kitti; Mende, Balázs Gusztáv; Oross, Krisztián; Marton, Tibor; Osztás, Anett; Kiss, Viktória; Fecher, Marc; Pálfi, György; Molnár, Erika; Sebők, Katalin; Czene, András; Paluch, Tibor; Šlaus, Mario; Novak, Mario; Pećina-Šlaus, Nives; Ősz, Brigitta; Voicsek, Vanda; Somogyi, Krisztina; Tóth, Gábor; Kromer, Bernd; Bánffy, Eszter; Alt, Kurt W.

    2015-01-01

    Farming was established in Central Europe by the Linearbandkeramik culture (LBK), a well-investigated archaeological horizon, which emerged in the Carpathian Basin, in today's Hungary. However, the genetic background of the LBK genesis is yet unclear. Here we present 9 Y chromosomal and 84 mitochondrial DNA profiles from Mesolithic, Neolithic Starčevo and LBK sites (seventh/sixth millennia BC) from the Carpathian Basin and southeastern Europe. We detect genetic continuity of both maternal and paternal elements during the initial spread of agriculture, and confirm the substantial genetic impact of early southeastern European and Carpathian Basin farming cultures on Central European populations of the sixth–fourth millennia BC. Comprehensive Y chromosomal and mitochondrial DNA population genetic analyses demonstrate a clear affinity of the early farmers to the modern Near East and Caucasus, tracing the expansion from that region through southeastern Europe and the Carpathian Basin into Central Europe. However, our results also reveal contrasting patterns for male and female genetic diversity in the European Neolithic, suggesting a system of patrilineal descent and patrilocal residential rules among the early farmers. PMID:25808890

  10. Health trajectories reveal the dynamic contributions of host genetic resistance and tolerance to infection outcome

    PubMed Central

    Lough, Graham; Kyriazakis, Ilias; Bergmann, Silke; Lengeling, Andreas; Doeschl-Wilson, Andrea B.

    2015-01-01

    Resistance and tolerance are two alternative strategies hosts can adopt to survive infections. Both strategies may be genetically controlled. To date, the relative contribution of resistance and tolerance to infection outcome is poorly understood. Here, we use a bioluminescent Listeria monocytogenes (Lm) infection challenge model to study the genetic determination and dynamic contributions of host resistance and tolerance to listeriosis in four genetically diverse mouse strains. Using conventional statistical analyses, we detect significant genetic variation in both resistance and tolerance, but cannot capture the time-dependent relative importance of either host strategy. We overcome these limitations through the development of novel statistical tools to analyse individual infection trajectories portraying simultaneous changes in infection severity and health. Based on these tools, early expression of resistance followed by expression of tolerance emerge as important hallmarks for surviving Lm infections. Our trajectory analysis further reveals that survivors and non-survivors follow distinct infection paths (which are also genetically determined) and provides new survival thresholds as objective endpoints in infection experiments. Future studies may use trajectories as novel traits for mapping and identifying genes that control infection dynamics and outcome. A Matlab script for user-friendly trajectory analysis is provided. PMID:26582028

  11. Tracing the genetic origin of Europe's first farmers reveals insights into their social organization.

    PubMed

    Szécsényi-Nagy, Anna; Brandt, Guido; Haak, Wolfgang; Keerl, Victoria; Jakucs, János; Möller-Rieker, Sabine; Köhler, Kitti; Mende, Balázs Gusztáv; Oross, Krisztián; Marton, Tibor; Osztás, Anett; Kiss, Viktória; Fecher, Marc; Pálfi, György; Molnár, Erika; Sebők, Katalin; Czene, András; Paluch, Tibor; Šlaus, Mario; Novak, Mario; Pećina-Šlaus, Nives; Ősz, Brigitta; Voicsek, Vanda; Somogyi, Krisztina; Tóth, Gábor; Kromer, Bernd; Bánffy, Eszter; Alt, Kurt W

    2015-04-22

    Farming was established in Central Europe by the Linearbandkeramik culture (LBK), a well-investigated archaeological horizon, which emerged in the Carpathian Basin, in today's Hungary. However, the genetic background of the LBK genesis is yet unclear. Here we present 9 Y chromosomal and 84 mitochondrial DNA profiles from Mesolithic, Neolithic Starčevo and LBK sites (seventh/sixth millennia BC) from the Carpathian Basin and southeastern Europe. We detect genetic continuity of both maternal and paternal elements during the initial spread of agriculture, and confirm the substantial genetic impact of early southeastern European and Carpathian Basin farming cultures on Central European populations of the sixth-fourth millennia BC. Comprehensive Y chromosomal and mitochondrial DNA population genetic analyses demonstrate a clear affinity of the early farmers to the modern Near East and Caucasus, tracing the expansion from that region through southeastern Europe and the Carpathian Basin into Central Europe. However, our results also reveal contrasting patterns for male and female genetic diversity in the European Neolithic, suggesting a system of patrilineal descent and patrilocal residential rules among the early farmers. PMID:25808890

  12. Landscape genetics of high mountain frog metapopulations

    USGS Publications Warehouse

    Murphy, M.A.; Dezzani, R.; Pilliod, D.S.; Storfer, A.

    2010-01-01

    Explaining functional connectivity among occupied habitats is crucial for understanding metapopulation dynamics and species ecology. Landscape genetics has primarily focused on elucidating how ecological features between observations influence gene flow. Functional connectivity, however, may be the result of both these between-site (landscape resistance) landscape characteristics and at-site (patch quality) landscape processes that can be captured using network based models. We test hypotheses of functional connectivity that include both between-site and at-site landscape processes in metapopulations of Columbia spotted frogs (Rana luteiventris) by employing a novel justification of gravity models for landscape genetics (eight microsatellite loci, 37 sites, n = 441). Primarily used in transportation and economic geography, gravity models are a unique approach as flow (e.g. gene flow) is explained as a function of three basic components: distance between sites, production/attraction (e.g. at-site landscape process) and resistance (e.g. between-site landscape process). The study system contains a network of nutrient poor high mountain lakes where we hypothesized a short growing season and complex topography between sites limit R. luteiventris gene flow. In addition, we hypothesized production of offspring is limited by breeding site characteristics such as the introduction of predatory fish and inherent site productivity. We found that R. luteiventris connectivity was negatively correlated with distance between sites, presence of predatory fish (at-site) and topographic complexity (between-site). Conversely, site productivity (as measured by heat load index, at-site) and growing season (as measured by frost-free period between-sites) were positively correlated with gene flow. The negative effect of predation and positive effect of site productivity, in concert with bottleneck tests, support the presence of source-sink dynamics. In conclusion, gravity models provide a

  13. Landscape genetics of high mountain frog metapopulations.

    PubMed

    Murphy, Melanie A; Dezzani, R; Pilliod, D S; Storfer, A

    2010-09-01

    Explaining functional connectivity among occupied habitats is crucial for understanding metapopulation dynamics and species ecology. Landscape genetics has primarily focused on elucidating how ecological features between observations influence gene flow. Functional connectivity, however, may be the result of both these between-site (landscape resistance) landscape characteristics and at-site (patch quality) landscape processes that can be captured using network based models. We test hypotheses of functional connectivity that include both between-site and at-site landscape processes in metapopulations of Columbia spotted frogs (Rana luteiventris) by employing a novel justification of gravity models for landscape genetics (eight microsatellite loci, 37 sites, n = 441). Primarily used in transportation and economic geography, gravity models are a unique approach as flow (e.g. gene flow) is explained as a function of three basic components: distance between sites, production/attraction (e.g. at-site landscape process) and resistance (e.g. between-site landscape process). The study system contains a network of nutrient poor high mountain lakes where we hypothesized a short growing season and complex topography between sites limit R. luteiventris gene flow. In addition, we hypothesized production of offspring is limited by breeding site characteristics such as the introduction of predatory fish and inherent site productivity. We found that R. luteiventris connectivity was negatively correlated with distance between sites, presence of predatory fish (at-site) and topographic complexity (between-site). Conversely, site productivity (as measured by heat load index, at-site) and growing season (as measured by frost-free period between-sites) were positively correlated with gene flow. The negative effect of predation and positive effect of site productivity, in concert with bottleneck tests, support the presence of source-sink dynamics. In conclusion, gravity models provide a

  14. Population genetic data of a model symbiotic cnidarian system reveal remarkable symbiotic specificity and vectored introductions across ocean basins.

    PubMed

    Thornhill, Daniel J; Xiang, Yu; Pettay, D Tye; Zhong, Min; Santos, Scott R

    2013-09-01

    The Aiptasia-Symbiodinium symbiosis is a promising model for experimental studies of cnidarian-dinoflagellate associations, yet relatively little is known regarding the genetic diversity of either symbiotic partner. To address this, we collected Aiptasia from 16 localities throughout the world and examined the genetic diversity of both anemones and their endosymbionts. Based on newly developed SCAR markers, Aiptasia consisted of two genetically distinct populations: one Aiptasia lineage from Florida and a second network of Aiptasia genotypes found at other localities. These populations did not conform to the distributions of described Aiptasia species, suggesting that taxonomic re-evaluation is needed in the light of molecular genetics. Associations with Symbiodinium further demonstrated the distinctions among Aiptasia populations. According to 18S RFLP, ITS2-DGGE and microsatellite flanker region sequencing, Florida anemones engaged in diverse symbioses predominantly with members of Symbiodinium Clades A and B, but also C, whereas anemones from elsewhere harboured only S. minutum within Clade B. Symbiodinium minutum apparently does not form a stable symbiosis with other hosts, which implies a highly specific symbiosis. Fine-scale differences among S. minutum populations were quantified using six microsatellite loci. Populations of S. minutum had low genotypic diversity and high clonality (R = 0.14). Furthermore, minimal population structure was observed among regions and ocean basins, due to allele and genotype sharing. The lack of genetic structure and low genotypic diversity suggest recent vectoring of Aiptasia and S. minutum across localities. This first ever molecular-genetic study of a globally distributed cnidarian and its Symbiodinium assemblages reveals host-symbiont specificity and widely distributed populations in an important model system. PMID:23980764

  15. Precision phenotyping of biomass accumulation in triticale reveals temporal genetic patterns of regulation

    NASA Astrophysics Data System (ADS)

    Busemeyer, Lucas; Ruckelshausen, Arno; Möller, Kim; Melchinger, Albrecht E.; Alheit, Katharina V.; Maurer, Hans Peter; Hahn, Volker; Weissmann, Elmar A.; Reif, Jochen C.; Würschum, Tobias

    2013-08-01

    To extend agricultural productivity by knowledge-based breeding and tailor varieties adapted to specific environmental conditions, it is imperative to improve our ability to assess the dynamic changes of the phenome of crops under field conditions. To this end, we have developed a precision phenotyping platform that combines various sensors for a non-invasive, high-throughput and high-dimensional phenotyping of small grain cereals. This platform yielded high prediction accuracies and heritabilities for biomass of triticale. Genetic variation for biomass accumulation was dissected with 647 doubled haploid lines derived from four families. Employing a genome-wide association mapping approach, two major quantitative trait loci (QTL) for biomass were identified and the genetic architecture of biomass accumulation was found to be characterized by dynamic temporal patterns. Our findings highlight the potential of precision phenotyping to assess the dynamic genetics of complex traits, especially those not amenable to traditional phenotyping.

  16. Precision phenotyping of biomass accumulation in triticale reveals temporal genetic patterns of regulation

    PubMed Central

    Busemeyer, Lucas; Ruckelshausen, Arno; Möller, Kim; Melchinger, Albrecht E.; Alheit, Katharina V.; Maurer, Hans Peter; Hahn, Volker; Weissmann, Elmar A.; Reif, Jochen C.; Würschum, Tobias

    2013-01-01

    To extend agricultural productivity by knowledge-based breeding and tailor varieties adapted to specific environmental conditions, it is imperative to improve our ability to assess the dynamic changes of the phenome of crops under field conditions. To this end, we have developed a precision phenotyping platform that combines various sensors for a non-invasive, high-throughput and high-dimensional phenotyping of small grain cereals. This platform yielded high prediction accuracies and heritabilities for biomass of triticale. Genetic variation for biomass accumulation was dissected with 647 doubled haploid lines derived from four families. Employing a genome-wide association mapping approach, two major quantitative trait loci (QTL) for biomass were identified and the genetic architecture of biomass accumulation was found to be characterized by dynamic temporal patterns. Our findings highlight the potential of precision phenotyping to assess the dynamic genetics of complex traits, especially those not amenable to traditional phenotyping. PMID:23942574

  17. Genetic High-Cholesterol Condition More Common Than Thought

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_157755.html Genetic High-Cholesterol Condition More Common Than Thought Researchers ... the United States, she said. Rates of the genetic disorder vary based on racial/ethnic background, but ...

  18. Rock outcrop orchids reveal the genetic connectivity and diversity of inselbergs of northeastern Brazil

    PubMed Central

    2014-01-01

    Background Because of their fragmented nature, inselberg species are interesting biological models for studying the genetic consequences of disjoint populations. Inselbergs are commonly compared with oceanic islands, as most of them display a marked ecological isolation from the surrounding area. The isolation of these rock outcrops is reflected in the high number of recorded endemic species and the strong floristic differences between individual inselbergs and adjacent habitats. We examined the genetic connectivity of orchids Epidendrum cinnabarinum and E. secundum adapted to Neotropical inselbergs of northeastern Brazil. Our goals were to identify major genetic divergences or disjunctions across the range of the species and to investigate potential demographic and evolutionary mechanisms leading to lineage divergence in Neotropical mountain ecosystems. Results Based on plastid markers, high genetic differentiation was found for E. cinnabarinum (FST = 0.644) and E. secundum (FST = 0.636). Haplotypes were not geographically structured in either taxon, suggesting that restricted gene flow and genetic drift may be significant factors influencing the diversification of these inselberg populations. Moreover, strong differentiation was found between populations over short spatial scales, indicating substantial periods of isolation among populations. For E. secundum, nuclear markers indicated higher gene flow by pollen than by seeds. Conclusions The comparative approach adopted in this study contributed to the elucidation of patterns in both species. Our results confirm the ancient and highly isolated nature of inselberg populations. Both species showed similar patterns of genetic diversity and structure, highlighting the importance of seed-restricted gene flow and genetic drift as drivers of plant diversification in terrestrial islands such as inselbergs. PMID:24629134

  19. Microsatellite Markers Reveal Strong Genetic Structure in the Endemic Chilean Dolphin

    PubMed Central

    Pérez-Alvarez, María José; Olavarría, Carlos; Moraga, Rodrigo; Baker, C. Scott; Hamner, Rebecca M.; Poulin, Elie

    2015-01-01

    Understanding genetic differentiation and speciation processes in marine species with high dispersal capabilities is challenging. The Chilean dolphin, Cephalorhynchus eutropia, is the only endemic cetacean of Chile and is found in two different coastal habitats: a northern habitat with exposed coastlines, bays and estuaries from Valparaíso (33°02′S) to Chiloé (42°00′S), and a southern habitat with highly fragmented inshore coastline, channels and fjords between Chiloé and Navarino Island (55°14′S). With the aim of evaluating the potential existence of conservation units for this species, we analyzed the genetic diversity and population structure of the Chilean dolphin along its entire range. We genotyped 21 dinucleotide microsatellites for 53 skin samples collected between 1998 and 2012 (swab: n = 8, biopsy: n = 38, entanglement n = 7). Bayesian clustering and spatial model analyses identified two genetically distinct populations corresponding to the northern and southern habitats. Genetic diversity levels were similar in the two populations (He: 0.42 v/s 0.45 for southern and northern populations, respectively), while effective size population was higher in the southern area (Ne: 101 v/s 39). Genetic differentiation between these two populations was high and significant (FST = 0.15 and RST = 0.19), indicating little or no current gene flow. Because of the absence of evident geographical barriers between the northern and southern populations, we propose that genetic differentiation may reflect ecological adaptation to the different habitat conditions and resource uses. Therefore, the two genetic populations of this endemic and Near Threatened species should be considered as different conservation units with independent management strategies. PMID:25898340

  20. Genetic diversity and population structure of the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) as revealed by mitochondrial and microsatellite DNA.

    PubMed

    Chen, Minmin; Zheng, Jinsong; Wu, Min; Ruan, Rui; Zhao, Qingzhong; Wang, Ding

    2014-01-01

    Ecological surveys have indicated that the population of the critically endangered Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis asiaeorientalis) is becoming increasingly small and fragmented, and will be at high risk of extinction in the near future. Genetic conservation of this population will be an important component of the long-term conservation effort. We used a 597 base pair mitochondrial DNA (mtDNA) control region and 11 microsatellite loci to analyze the genetic diversity and population structure of the YFP. The analysis of both mtDNA and microsatellite loci suggested that the genetic diversity of the YFP will possibly decrease in the future if the population keeps declining at a rapid rate, even though these two types of markers revealed different levels of genetic diversity. In addition, mtDNA revealed strong genetic differentiation between one local population, Xingchang-Shishou (XCSS), and the other five downstream local populations; furthermore, microsatellite DNA unveiled fine but significant genetic differentiation between three of the local populations (not only XCSS but also Poyang Lake (PY) and Tongling (TL)) and the other local populations. With an increasing number of distribution gaps appearing in the Yangtze main steam, the genetic differentiation of local populations will likely intensify in the future. The YFP is becoming a genetically fragmented population. Therefore, we recommend attention should be paid to the genetic conservation of the YFP. PMID:24968271

  1. Genetic Diversity and Population Structure of the Critically Endangered Yangtze Finless Porpoise (Neophocaena asiaeorientalis asiaeorientalis) as Revealed by Mitochondrial and Microsatellite DNA

    PubMed Central

    Chen, Minmin; Zheng, Jinsong; Wu, Min; Ruan, Rui; Zhao, Qingzhong; Wang, Ding

    2014-01-01

    Ecological surveys have indicated that the population of the critically endangered Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis asiaeorientalis) is becoming increasingly small and fragmented, and will be at high risk of extinction in the near future. Genetic conservation of this population will be an important component of the long-term conservation effort. We used a 597 base pair mitochondrial DNA (mtDNA) control region and 11 microsatellite loci to analyze the genetic diversity and population structure of the YFP. The analysis of both mtDNA and microsatellite loci suggested that the genetic diversity of the YFP will possibly decrease in the future if the population keeps declining at a rapid rate, even though these two types of markers revealed different levels of genetic diversity. In addition, mtDNA revealed strong genetic differentiation between one local population, Xingchang–Shishou (XCSS), and the other five downstream local populations; furthermore, microsatellite DNA unveiled fine but significant genetic differentiation between three of the local populations (not only XCSS but also Poyang Lake (PY) and Tongling (TL)) and the other local populations. With an increasing number of distribution gaps appearing in the Yangtze main steam, the genetic differentiation of local populations will likely intensify in the future. The YFP is becoming a genetically fragmented population. Therefore, we recommend attention should be paid to the genetic conservation of the YFP. PMID:24968271

  2. RAD-QTL Mapping Reveals Both Genome-Level Parallelism and Different Genetic Architecture Underlying the Evolution of Body Shape in Lake Whitefish (Coregonus clupeaformis) Species Pairs

    PubMed Central

    Laporte, Martin; Rogers, Sean M.; Dion-Côté, Anne-Marie; Normandeau, Eric; Gagnaire, Pierre-Alexandre; Dalziel, Anne C.; Chebib, Jobran; Bernatchez, Louis

    2015-01-01

    Parallel changes in body shape may evolve in response to similar environmental conditions, but whether such parallel phenotypic changes share a common genetic basis is still debated. The goal of this study was to assess whether parallel phenotypic changes could be explained by genetic parallelism, multiple genetic routes, or both. We first provide evidence for parallelism in fish shape by using geometric morphometrics among 300 fish representing five species pairs of Lake Whitefish. Using a genetic map comprising 3438 restriction site−associated DNA sequencing single-nucleotide polymorphisms, we then identified quantitative trait loci underlying body shape traits in a backcross family reared in the laboratory. A total of 138 body shape quantitative trait loci were identified in this cross, thus revealing a highly polygenic architecture of body shape in Lake Whitefish. Third, we tested for evidence of genetic parallelism among independent wild populations using both a single-locus method (outlier analysis) and a polygenic approach (analysis of covariation among markers). The single-locus approach provided limited evidence for genetic parallelism. However, the polygenic analysis revealed genetic parallelism for three of the five lakes, which differed from the two other lakes. These results provide evidence for both genetic parallelism and multiple genetic routes underlying parallel phenotypic evolution in fish shape among populations occupying similar ecological niches. PMID:26002924

  3. Genetic changes in grapevine genomes after stress induced by in vitro cultivation, thermotherapy and virus infection, as revealed by AFLP

    PubMed Central

    2009-01-01

    The Amplification Fragment Length Polymorphism (AFLP) technique was employed to study genetic variations which can be induced in vines by the stress occurring during different aspects of viticulture (in vitro cultivation, in vitro thermotherapy and virus infection). Analysis of AFLP banding patterns, generated by using 15 primer combinations, pointed to negligible genetic variation among plants exposed to individual stress. The average of similarity coefficients between differently stressed plants of the cultivars Müller Thurgau and Riesling were 0.984 and 0.991, respectively, as revealed by AFLP analysis. The low incidence of observed polymorphism demonstrates the high level of genome uniformity in plants reproduced by in vitro micropropagation via nodes, those subjected to in vitro thermotherapy and virus-infected plants. PMID:21637461

  4. Genetic Sharing with Cardiovascular Disease Risk Factors and Diabetes Reveals Novel Bone Mineral Density Loci

    PubMed Central

    Thompson, Wesley K.; McEvoy, Linda K.; Schork, Andrew J.; Zuber, Verena; LeBlanc, Marissa; Bettella, Francesco; Mills, Ian G.; Desikan, Rahul S.; Djurovic, Srdjan; Gautvik, Kaare M.; Dale, Anders M.; Andreassen, Ole A.

    2015-01-01

    Bone Mineral Density (BMD) is a highly heritable trait, but genome-wide association studies have identified few genetic risk factors. Epidemiological studies suggest associations between BMD and several traits and diseases, but the nature of the suggestive comorbidity is still unknown. We used a novel genetic pleiotropy-informed conditional False Discovery Rate (FDR) method to identify single nucleotide polymorphisms (SNPs) associated with BMD by leveraging cardiovascular disease (CVD) associated disorders and metabolic traits. By conditioning on SNPs associated with the CVD-related phenotypes, type 1 diabetes, type 2 diabetes, systolic blood pressure, diastolic blood pressure, high density lipoprotein, low density lipoprotein, triglycerides and waist hip ratio, we identified 65 novel independent BMD loci (26 with femoral neck BMD and 47 with lumbar spine BMD) at conditional FDR < 0.01. Many of the loci were confirmed in genetic expression studies. Genes validated at the mRNA levels were characteristic for the osteoblast/osteocyte lineage, Wnt signaling pathway and bone metabolism. The results provide new insight into genetic mechanisms of variability in BMD, and a better understanding of the genetic underpinnings of clinical comorbidity. PMID:26695485

  5. Pronounced genetic differentiation and recent secondary contact in the mangrove tree Lumnitzera racemosa revealed by population genomic analyses

    PubMed Central

    Li, Jianfang; Yang, Yuchen; Chen, Qipian; Fang, Lu; He, Ziwen; Guo, Wuxia; Qiao, Sitan; Wang, Zhengzhen; Guo, Miaomiao; Zhong, Cairong; Zhou, Renchao; Shi, Suhua

    2016-01-01

    Systematically investigating the impacts of Pleistocene sea-level fluctuations on mangrove plants may provide a better understanding of their demographic history and useful information for their conservation. Therefore, we conducted population genomic analyses of 88 nuclear genes to explore the population dynamics of a mangrove tree Lumnitzera racemosa across the Indo-West Pacific region. Our results revealed pronounced genetic differentiation in this species between the populations from the Indian Ocean and the Pacific Ocean, which may be attributable to the long-term isolation between the western and eastern coasts of the Malay Peninsula during sea-level drops in the Pleistocene glacial periods. The mixing of haplotypes from the two highly divergent groups was identified in a Cambodian population at almost all 88 nuclear genes, suggesting genetic admixture of the two lineages at the boundary region. Similar genetic admixture was also found in other populations from Southeast Asia based on the Bayesian clustering analysis of six nuclear genes, which suggests extensive and recent secondary contact of the two divergent lineages in Southeast Asia. Computer simulations indicated substantial migration from the Indian Ocean towards the South China Sea, which likely results in the genetic admixture in Southeast Asia. PMID:27380895

  6. Pronounced genetic differentiation and recent secondary contact in the mangrove tree Lumnitzera racemosa revealed by population genomic analyses.

    PubMed

    Li, Jianfang; Yang, Yuchen; Chen, Qipian; Fang, Lu; He, Ziwen; Guo, Wuxia; Qiao, Sitan; Wang, Zhengzhen; Guo, Miaomiao; Zhong, Cairong; Zhou, Renchao; Shi, Suhua

    2016-01-01

    Systematically investigating the impacts of Pleistocene sea-level fluctuations on mangrove plants may provide a better understanding of their demographic history and useful information for their conservation. Therefore, we conducted population genomic analyses of 88 nuclear genes to explore the population dynamics of a mangrove tree Lumnitzera racemosa across the Indo-West Pacific region. Our results revealed pronounced genetic differentiation in this species between the populations from the Indian Ocean and the Pacific Ocean, which may be attributable to the long-term isolation between the western and eastern coasts of the Malay Peninsula during sea-level drops in the Pleistocene glacial periods. The mixing of haplotypes from the two highly divergent groups was identified in a Cambodian population at almost all 88 nuclear genes, suggesting genetic admixture of the two lineages at the boundary region. Similar genetic admixture was also found in other populations from Southeast Asia based on the Bayesian clustering analysis of six nuclear genes, which suggests extensive and recent secondary contact of the two divergent lineages in Southeast Asia. Computer simulations indicated substantial migration from the Indian Ocean towards the South China Sea, which likely results in the genetic admixture in Southeast Asia. PMID:27380895

  7. Turkish Population Structure and Genetic Ancestry Reveal Relatedness among Eurasian Populations

    PubMed Central

    Hodoğlugil, Uğur; Mahley, Robert W.

    2013-01-01

    Summary Turkey connects the Middle East, Europe, and Asia and has experienced major population movements. We examined the population structure and genetic relatedness of samples from three regions of Turkey using over 500,000 SNP genotypes. The data were analyzed together with Human Genome Diversity Panel data. To obtain a more representative sampling from Central Asia, Kyrgyz samples (Bishkek, Kyrgyzstan) were genotyped and analyzed. Principal component (PC) analysis reveals a significant overlap between Turks and Middle Easterners and a relationship with Europeans and South and Central Asians; however, the Turkish genetic structure is unique. FRAPPE, STRUCTURE, and phylogenetic analyses support the PC analysis depending upon the number of parental ancestry components chosen. For example, supervised STRUCTURE (K = 3) illustrates a genetic ancestry for the Turks of 45% Middle Eastern (95% CI, 42–49), 40% European (95% CI, 36–44), and 15% Central Asian (95% CI, 13–16), whereas at K = 4 the genetic ancestry of the Turks was 38% European (95% CI, 35–42), 35% Middle Eastern (95% CI, 33–38), 18% South Asian (95% CI, 16–19), and 9% Central Asian (95% CI, 7–11). PC analysis and FRAPPE/STRUCTURE results from three regions in Turkey (Aydin, Istanbul, and Kayseri) were superimposed, without clear subpopulation structure, suggesting the selected samples were rather homogeneous. Thus, this study demonstrates admixture of Turkish people reflecting the population migration patterns. PMID:22332727

  8. Whole genome comparison of a large collection of mycobacteriophages reveals a continuum of phage genetic diversity

    PubMed Central

    Pope, Welkin H; Bowman, Charles A; Russell, Daniel A; Jacobs-Sera, Deborah; Asai, David J; Cresawn, Steven G; Jacobs, William R; Hendrix, Roger W; Lawrence, Jeffrey G; Hatfull, Graham F; Abbazia, Patrick; Ababio, Amma; Adam, Naazneen

    2015-01-01

    The bacteriophage population is large, dynamic, ancient, and genetically diverse. Limited genomic information shows that phage genomes are mosaic, and the genetic architecture of phage populations remains ill-defined. To understand the population structure of phages infecting a single host strain, we isolated, sequenced, and compared 627 phages of Mycobacterium smegmatis. Their genetic diversity is considerable, and there are 28 distinct genomic types (clusters) with related nucleotide sequences. However, amino acid sequence comparisons show pervasive genomic mosaicism, and quantification of inter-cluster and intra-cluster relatedness reveals a continuum of genetic diversity, albeit with uneven representation of different phages. Furthermore, rarefaction analysis shows that the mycobacteriophage population is not closed, and there is a constant influx of genes from other sources. Phage isolation and analysis was performed by a large consortium of academic institutions, illustrating the substantial benefits of a disseminated, structured program involving large numbers of freshman undergraduates in scientific discovery. DOI: http://dx.doi.org/10.7554/eLife.06416.001 PMID:25919952

  9. A New BSCS Project: Human Genetics Education for High School.

    ERIC Educational Resources Information Center

    Biological Sciences Curriculum Study Journal, 1980

    1980-01-01

    Described is the BSCS Center for Education in Human and Medical Genetics, established to design, develop, and evaluate an instructional module in human genetics for high school students. This module will be a self-contained curricular program and will provide individualized open-ended experiences which present basic genetics content in the context…

  10. Genetic Networking of the Bemisia tabaci Cryptic Species Complex Reveals Pattern of Biological Invasions

    PubMed Central

    De Barro, Paul; Ahmed, Muhammad Z.

    2011-01-01

    Background A challenge within the context of cryptic species is the delimitation of individual species within the complex. Statistical parsimony network analytics offers the opportunity to explore limits in situations where there are insufficient species-specific morphological characters to separate taxa. The results also enable us to explore the spread in taxa that have invaded globally. Methodology/Principal Findings Using a 657 bp portion of mitochondrial cytochrome oxidase 1 from 352 unique haplotypes belonging to the Bemisia tabaci cryptic species complex, the analysis revealed 28 networks plus 7 unconnected individual haplotypes. Of the networks, 24 corresponded to the putative species identified using the rule set devised by Dinsdale et al. (2010). Only two species proposed in Dinsdale et al. (2010) departed substantially from the structure suggested by the analysis. The analysis of the two invasive members of the complex, Mediterranean (MED) and Middle East – Asia Minor 1 (MEAM1), showed that in both cases only a small number of haplotypes represent the majority that have spread beyond the home range; one MEAM1 and three MED haplotypes account for >80% of the GenBank records. Israel is a possible source of the globally invasive MEAM1 whereas MED has two possible sources. The first is the eastern Mediterranean which has invaded only the USA, primarily Florida and to a lesser extent California. The second are western Mediterranean haplotypes that have spread to the USA, Asia and South America. The structure for MED supports two home range distributions, a Sub-Saharan range and a Mediterranean range. The MEAM1 network supports the Middle East - Asia Minor region. Conclusion/Significance The network analyses show a high level of congruence with the species identified in a previous phylogenetic analysis. The analysis of the two globally invasive members of the complex support the view that global invasion often involve very small portions of the available

  11. Genetic triple dissociation reveals multiple roles for dopamine in reinforcement learning.

    PubMed

    Frank, Michael J; Moustafa, Ahmed A; Haughey, Heather M; Curran, Tim; Hutchison, Kent E

    2007-10-01

    What are the genetic and neural components that support adaptive learning from positive and negative outcomes? Here, we show with genetic analyses that three independent dopaminergic mechanisms contribute to reward and avoidance learning in humans. A polymorphism in the DARPP-32 gene, associated with striatal dopamine function, predicted relatively better probabilistic reward learning. Conversely, the C957T polymorphism of the DRD2 gene, associated with striatal D2 receptor function, predicted the degree to which participants learned to avoid choices that had been probabilistically associated with negative outcomes. The Val/Met polymorphism of the COMT gene, associated with prefrontal cortical dopamine function, predicted participants' ability to rapidly adapt behavior on a trial-to-trial basis. These findings support a neurocomputational dissociation between striatal and prefrontal dopaminergic mechanisms in reinforcement learning. Computational maximum likelihood analyses reveal independent gene effects on three reinforcement learning parameters that can explain the observed dissociations. PMID:17913879

  12. Genetic interactions of separase regulatory subunits reveal the diverged Drosophila Cenp-C homolog

    PubMed Central

    Heeger, Sebastian; Leismann, Oliver; Schittenhelm, Ralf; Schraidt, Oliver; Heidmann, Stefan; Lehner, Christian F.

    2005-01-01

    Faithful transmission of genetic information during mitotic divisions depends on bipolar attachment of sister kinetochores to the mitotic spindle and on complete resolution of sister-chromatid cohesion immediately before the metaphase-to-anaphase transition. Separase is thought to be responsible for sister-chromatid separation, but its regulation is not completely understood. Therefore, we have screened for genetic loci that modify the aberrant phenotypes caused by overexpression of the regulatory separase complex subunits Pimples/securin and Three rows in Drosophila. An interacting gene was found to encode a constitutive centromere protein. Characterization of its centromere localization domain revealed the presence of a diverged CENPC motif. While direct evidence for an involvement of this Drosophila Cenp-C homolog in separase activation at centromeres could not be obtained, in vivo imaging clearly demonstrated that it is required for normal attachment of kinetochores to the spindle. PMID:16140985

  13. Genetic relationships of ethnic minorities in Southwest China revealed by microsatellite markers.

    PubMed

    Lin, Hongbin; Fan, Hao; Zhang, Feng; Huang, Xiaoqin; Lin, Keqin; Shi, Lei; Hu, Songnian; Chu, Jiayou; Wang, Duen-Mei

    2010-01-01

    Population migrations in Southwest and South China have played an important role in the formation of East Asian populations and led to a high degree of cultural diversity among ethnic minorities living in these areas. To explore the genetic relationships of these ethnic minorities, we systematically surveyed the variation of 10 autosomal STR markers of 1,538 individuals from 30 populations of 25 ethnic minorities, of which the majority were chosen from Southwest China, especially Yunnan Province. With genotyped data of the markers, we constructed phylogenies of these populations with both D(A) and D(C) measures and performed a principal component analysis, as well as a clustering analysis by structure. Results showed that we successfully recovered the genetic structure of analyzed populations formed by historical migrations. Aggregation patterns of these populations accord well with their linguistic affiliations, suggesting that deciphering of genetic relationships does in fact offer clues for study of ethnic differentiation. PMID:20360948

  14. AFLPs Reveal Different Population Genetic Structure under Contrasting Environments in the Marine Snail Nucella lapillus L.

    PubMed Central

    Carro, Belén; Quintela, María; Ruiz, José Miguel; Barreiro, Rodolfo

    2012-01-01

    Dispersal has received growing attention in marine ecology, particularly since evidence obtained with up-to-date techniques challenged the traditional view. The dogwhelk Nucella lapillus L., a sedentary gastropod with direct development, is a good example: dispersal was traditionally assumed to be limited until studies with microsatellites disputed this idea. To shed some light on this controversy, the genetic structure of dogwhelk populations in northwest Spain was investigated with highly polymorphic AFLP markers giving special attention to the influence of hydrodynamic stress. In agreement with the expectations for a poor disperser, our results show a significant genetic structure at regional (<200 km) and areal scales (<15 km). However, the spatial genetic structure varied with wave-exposure in the present case study: IBD was evident under sheltered conditions but absent from the exposed area where genetic differentiation was stronger. Our results provide evidence that differences in wave-exposure can exert a detectable influence on the genetic structure of coastal organisms, even in species without a planktonic larva. PMID:23185435

  15. Genetic diversity and population structure of Celosia argentea and related species revealed by SRAP.

    PubMed

    Feng, Na; Xue, Qie; Guo, Qinghua; Zhao, Ru; Guo, Meili

    2009-08-01

    Genetic diversity of 16 populations of Celosia argentea L. and 6 populations of Celosia cristata L. in China was investigated using sequence-related amplified polymorphism (SRAP). Ten SRAP primer combinations generated 507 scorable amplification bands ranging from 50 to 2000 bp, among which 274 were polymorphic, with an average of 54 polymorphic bands per primer combination. The unweighted pair group method of arithmetic averages (UPGMA) cluster analysis enabled construction of a phylogenetic tree for estimating genetic distance among populations, which agreed well with the geographic origin information. Twenty-two populations were distinctly separated into two major genetic groups. One typical representative fragment, M1E6 in C. argentea, provided an alternative approach to distinguish C. argentea from C. cristata. Also, great genetic diversity found in C. argentea populations by significant geographic difference was confirmed by a high level of population genetics parameters. The information may be beneficial to future breeding selection and conservation management for populations of C. argentea. PMID:19521763

  16. Microsatellite analysis reveals genetically distinct populations of red pine (Pinus resinosa, Pinaceae).

    PubMed

    Boys, Jacquelyn; Cherry, Marilyn; Dayanandan, Selvadurai

    2005-05-01

    Red pine (Pinus resinosa Ait.) is an ecologically and economically important forest tree species of northeastern North America and is considered one of the most genetically depauperate conifer species in the region. We have isolated and characterized 13 nuclear microsatellite loci by screening a partial genomic library with di-, tri-, and tetranucleotide repeat oligonucleotide probes. In an analysis of over 500 individuals representing 17 red pine populations from Manitoba through Newfoundland, five polymorphic microsatellite loci with an average of nine alleles per locus were identified. The mean expected and observed heterozygosity values were 0.508 and 0.185, respectively. Significant departures from Hardy-Weinberg equilibrium with excess homozygosity indicating high levels of inbreeding were evident in all populations studied. The population differentiation was high with 28-35% of genetic variation partitioned among populations. The genetic distance analysis showed that three northeastern (two Newfoundland and one New Brunswick) populations are genetically distinct from the remaining populations. The coalescence-based analysis suggests that "northeastern" and "main" populations likely became isolated during the most recent Pleistocene glacial period, and severe population bottlenecks may have led to the evolution of a highly selfing mating system in red pine. PMID:21652464

  17. Student Problem Solving in High School Genetics.

    ERIC Educational Resources Information Center

    Stewart, James

    1983-01-01

    Describes set of specific steps (procedural knowledge) used when solving monohybrid/dihybrid cross problems and extent to which students could justify execution of each step in terms of their conceptual knowledge of genetics and meiosis. Implications for genetics instruction are discussed. (JN)

  18. Admixture facilitates genetic adaptations to high altitude in Tibet

    PubMed Central

    Jeong, Choongwon; Alkorta-Aranburu, Gorka; Basnyat, Buddha; Neupane, Maniraj; Witonsky, David B.; Pritchard, Jonathan K.; Beall, Cynthia M.; Di Rienzo, Anna

    2015-01-01

    Admixture is recognized as a widespread feature of human populations, renewing interest in the possibility that genetic exchange can facilitate adaptations to new environments. Studies of Tibetans revealed candidates for high-altitude adaptations in the EGLN1 and EPAS1 genes, associated with lower hemoglobin concentration. However, the history of these variants or that of Tibetans remains poorly understood. Here, we analyze genotype data for the Nepalese Sherpa, and find that Tibetans are a mixture of ancestral populations related to the Sherpa and Han Chinese. EGLN1 and EPAS1 genes show a striking enrichment of high-altitude ancestry in the Tibetan genome, indicating that migrants from low altitude acquired adaptive alleles from the highlanders. Accordingly, the Sherpa and Tibetans share adaptive hemoglobin traits. This admixture-mediated adaptation shares important features with adaptive introgression. Therefore, we identify a novel mechanism, beyond selection on new mutations or on standing variation, through which populations can adapt to local environments. PMID:24513612

  19. Functional genomic and advanced genetic studies reveal novel insights into the metabolism, regulation, and biology of Haloferax volcanii.

    PubMed

    Soppa, Jörg

    2011-01-01

    The genome sequence of Haloferax volcanii is available and several comparative genomic in silico studies were performed that yielded novel insight for example into protein export, RNA modifications, small non-coding RNAs, and ubiquitin-like Small Archaeal Modifier Proteins. The full range of functional genomic methods has been established and results from transcriptomic, proteomic and metabolomic studies are discussed. Notably, Hfx. volcanii is together with Halobacterium salinarum the only prokaryotic species for which a translatome analysis has been performed. The results revealed that the fraction of translationally-regulated genes in haloarchaea is as high as in eukaryotes. A highly efficient genetic system has been established that enables the application of libraries as well as the parallel generation of genomic deletion mutants. Facile mutant generation is complemented by the possibility to culture Hfx. volcanii in microtiter plates, allowing the phenotyping of mutant collections. Genetic approaches are currently used to study diverse biological questions-from replication to posttranslational modification-and selected results are discussed. Taken together, the wealth of functional genomic and genetic tools make Hfx. volcanii a bona fide archaeal model species, which has enabled the generation of important results in recent years and will most likely generate further breakthroughs in the future. PMID:22190865

  20. Genetic structure of pike (Esox lucius) reveals a complex and previously unrecognized colonization history of Ireland

    PubMed Central

    Pedreschi, Debbi; Kelly-Quinn, Mary; Caffrey, Joe; O’Grady, Martin; Mariani, Stefano; Phillimore, Albert

    2014-01-01

    Aim We investigated genetic variation of Irish pike populations and their relationship with European outgroups, in order to elucidate the origin of this species to the island, which is largely assumed to have occurred as a human-mediated introduction over the past few hundred years. We aimed thereby to provide new insights into population structure to improve fisheries and biodiversity management in Irish freshwaters. Location Ireland, Britain and continental Europe. Methods A total of 752 pike (Esox lucius) were sampled from 15 locations around Ireland, and 9 continental European sites, and genotyped at six polymorphic microsatellite loci. Patterns and mechanisms of population genetic structure were assessed through a diverse array of methods, including Bayesian clustering, hierarchical analysis of molecular variance, and approximate Bayesian computation. Results Varying levels of genetic diversity and a high degree of population genetic differentiation were detected. Clear substructure within Ireland was identified, with two main groups being evident. One of the Irish populations showed high similarity with British populations. The other, more widespread, Irish strain did not group with any European population examined. Approximate Bayesian computation suggested that this widespread Irish strain is older, and may have colonized Ireland independently of humans. Main conclusions Population genetic substructure in Irish pike is high and comparable to the levels observed elsewhere in Europe. A comparison of evolutionary scenarios upholds the possibility that pike may have colonized Ireland in two ‘waves’, the first of which, being independent of human colonization, would represent the first evidence for natural colonization of a non-anadromous freshwater fish to the island of Ireland. Although further investigations using comprehensive genomic techniques will be necessary to confirm this, the present results warrant a reappraisal of current management strategies

  1. RNA splicing. The human splicing code reveals new insights into the genetic determinants of disease.

    PubMed

    Xiong, Hui Y; Alipanahi, Babak; Lee, Leo J; Bretschneider, Hannes; Merico, Daniele; Yuen, Ryan K C; Hua, Yimin; Gueroussov, Serge; Najafabadi, Hamed S; Hughes, Timothy R; Morris, Quaid; Barash, Yoseph; Krainer, Adrian R; Jojic, Nebojsa; Scherer, Stephen W; Blencowe, Benjamin J; Frey, Brendan J

    2015-01-01

    To facilitate precision medicine and whole-genome annotation, we developed a machine-learning technique that scores how strongly genetic variants affect RNA splicing, whose alteration contributes to many diseases. Analysis of more than 650,000 intronic and exonic variants revealed widespread patterns of mutation-driven aberrant splicing. Intronic disease mutations that are more than 30 nucleotides from any splice site alter splicing nine times as often as common variants, and missense exonic disease mutations that have the least impact on protein function are five times as likely as others to alter splicing. We detected tens of thousands of disease-causing mutations, including those involved in cancers and spinal muscular atrophy. Examination of intronic and exonic variants found using whole-genome sequencing of individuals with autism revealed misspliced genes with neurodevelopmental phenotypes. Our approach provides evidence for causal variants and should enable new discoveries in precision medicine. PMID:25525159

  2. HLA variation reveals genetic continuity rather than population group structure in East Asia.

    PubMed

    Di, Da; Sanchez-Mazas, Alicia

    2014-03-01

    Genetic differences between Northeast Asian (NEA) and Southeast Asian (SEA) populations have been observed in numerous studies. At the among-population level, despite a clear north-south differentiation observed for many genetic markers, debates were led between abrupt differences and a continuous pattern. At the within-population level, whether NEA or SEA populations have higher genetic diversity is also highly controversial. In this study, we analyzed a large set of HLA data from East Asia in order to map the genetic variation among and within populations in this continent and to clarify the distribution pattern of HLA lineages and alleles. We observed a genetic differentiation between NEA and SEA populations following a continuous pattern from north to south, and we show a significant and continuous decrease of HLA diversity by the same direction. This continuity is shaped by clinal distributions of many HLA lineages and alleles with increasing or decreasing frequencies along the latitude. These results bring new evidence in favor of the "overlapping model" proposed previously for East Asian peopling history, whereby modern humans migrated eastward from western Eurasia via two independent routes along each side of the Himalayas and, later, overlapped in East Asia across open land areas. Our study strongly suggests that intensive gene flow between NEA and SEA populations occurred and shaped the latitude-related continuous pattern of genetic variation and the peculiar HLA lineage and allele distributions observed in this continent. Probably for a very long period, the exact duration of these events remains to be estimated. PMID:24449274

  3. Systems Genetics Reveals the Functional Context of PCOS Loci and Identifies Genetic and Molecular Mechanisms of Disease Heterogeneity

    PubMed Central

    Xu, Ning; Cui, Jinrui; Mengesha, Emebet; Chen, Yii-Der I.; Taylor, Kent D.; Azziz, Ricardo; Goodarzi, Mark O.

    2015-01-01

    Genome wide association studies (GWAS) have revealed 11 independent risk loci for polycystic ovary syndrome (PCOS), a common disorder in young women characterized by androgen excess and oligomenorrhea. To put these risk loci and the single nucleotide polymorphisms (SNPs) therein into functional context, we measured DNA methylation and gene expression in subcutaneous adipose tissue biopsies to identify PCOS-specific alterations. Two genes from the LHCGR region, STON1-GTF2A1L and LHCGR, were overexpressed in PCOS. In analysis stratified by obesity, LHCGR was overexpressed only in non-obese PCOS women. Although not differentially expressed in the entire PCOS group, INSR was underexpressed in obese PCOS subjects only. Alterations in gene expression in the LHCGR, RAB5B and INSR regions suggest that SNPs in these loci may be functional and could affect gene expression directly or indirectly via epigenetic alterations. We identified reduced methylation in the LHCGR locus and increased methylation in the INSR locus, changes that are concordant with the altered gene expression profiles. Complex patterns of meQTL and eQTL were identified in these loci, suggesting that local genetic variation plays an important role in gene regulation. We propose that non-obese PCOS women possess significant alterations in LH receptor expression, which drives excess androgen secretion from the ovary. Alternatively, obese women with PCOS possess alterations in insulin receptor expression, with underexpression in metabolic tissues and overexpression in the ovary, resulting in peripheral insulin resistance and excess ovarian androgen production. These studies provide a genetic and molecular basis for the reported clinical heterogeneity of PCOS. PMID:26305227

  4. Systems Genetics Reveals the Functional Context of PCOS Loci and Identifies Genetic and Molecular Mechanisms of Disease Heterogeneity.

    PubMed

    Jones, Michelle R; Brower, Meredith A; Xu, Ning; Cui, Jinrui; Mengesha, Emebet; Chen, Yii-Der I; Taylor, Kent D; Azziz, Ricardo; Goodarzi, Mark O

    2015-08-01

    Genome wide association studies (GWAS) have revealed 11 independent risk loci for polycystic ovary syndrome (PCOS), a common disorder in young women characterized by androgen excess and oligomenorrhea. To put these risk loci and the single nucleotide polymorphisms (SNPs) therein into functional context, we measured DNA methylation and gene expression in subcutaneous adipose tissue biopsies to identify PCOS-specific alterations. Two genes from the LHCGR region, STON1-GTF2A1L and LHCGR, were overexpressed in PCOS. In analysis stratified by obesity, LHCGR was overexpressed only in non-obese PCOS women. Although not differentially expressed in the entire PCOS group, INSR was underexpressed in obese PCOS subjects only. Alterations in gene expression in the LHCGR, RAB5B and INSR regions suggest that SNPs in these loci may be functional and could affect gene expression directly or indirectly via epigenetic alterations. We identified reduced methylation in the LHCGR locus and increased methylation in the INSR locus, changes that are concordant with the altered gene expression profiles. Complex patterns of meQTL and eQTL were identified in these loci, suggesting that local genetic variation plays an important role in gene regulation. We propose that non-obese PCOS women possess significant alterations in LH receptor expression, which drives excess androgen secretion from the ovary. Alternatively, obese women with PCOS possess alterations in insulin receptor expression, with underexpression in metabolic tissues and overexpression in the ovary, resulting in peripheral insulin resistance and excess ovarian androgen production. These studies provide a genetic and molecular basis for the reported clinical heterogeneity of PCOS. PMID:26305227

  5. Time-series analysis reveals genetic responses to intensive management of razorback sucker (Xyrauchen texanus)

    PubMed Central

    Dowling, Thomas E; Turner, Thomas F; Carson, Evan W; Saltzgiver, Melody J; Adams, Deborah; Kesner, Brian; Marsh, Paul C

    2014-01-01

    Time-series analysis is used widely in ecology to study complex phenomena and may have considerable potential to clarify relationships of genetic and demographic processes in natural and exploited populations. We explored the utility of this approach to evaluate population responses to management in razorback sucker, a long-lived and fecund, but declining freshwater fish species. A core population in Lake Mohave (Arizona-Nevada, USA) has experienced no natural recruitment for decades and is maintained by harvesting naturally produced larvae from the lake, rearing them in protective custody, and repatriating them at sizes less vulnerable to predation. Analyses of mtDNA and 15 microsatellites characterized for sequential larval cohorts collected over a 15-year time series revealed no changes in geographic structuring but indicated significant increase in mtDNA diversity for the entire population over time. Likewise, ratios of annual effective breeders to annual census size (Nb/Na) increased significantly despite sevenfold reduction of Na. These results indicated that conservation actions diminished near-term extinction risk due to genetic factors and should now focus on increasing numbers of fish in Lake Mohave to ameliorate longer-term risks. More generally, time-series analysis permitted robust testing of trends in genetic diversity, despite low precision of some metrics. PMID:24665337

  6. Whole-Genome Sequencing Reveals Genetic Variation in the Asian House Rat.

    PubMed

    Teng, Huajing; Zhang, Yaohua; Shi, Chengmin; Mao, Fengbiao; Hou, Lingling; Guo, Hongling; Sun, Zhongsheng; Zhang, Jianxu

    2016-01-01

    Whole-genome sequencing of wild-derived rat species can provide novel genomic resources, which may help decipher the genetics underlying complex phenotypes. As a notorious pest, reservoir of human pathogens, and colonizer, the Asian house rat, Rattus tanezumi, is successfully adapted to its habitat. However, little is known regarding genetic variation in this species. In this study, we identified over 41,000,000 single-nucleotide polymorphisms, plus insertions and deletions, through whole-genome sequencing and bioinformatics analyses. Moreover, we identified over 12,000 structural variants, including 143 chromosomal inversions. Further functional analyses revealed several fixed nonsense mutations associated with infection and immunity-related adaptations, and a number of fixed missense mutations that may be related to anticoagulant resistance. A genome-wide scan for loci under selection identified various genes related to neural activity. Our whole-genome sequencing data provide a genomic resource for future genetic studies of the Asian house rat species and have the potential to facilitate understanding of the molecular adaptations of rats to their ecological niches. PMID:27172215

  7. Genetic Diversity of Grasspea and Its Relative Species Revealed by SSR Markers

    PubMed Central

    Wang, Fang; Yang, Tao; Burlyaeva, Marina; Li, Ling; Jiang, Junye; Fang, Li; Redden, Robert; Zong, Xuxiao

    2015-01-01

    The study of genetic diversity between Lathyrus sativus L. and its relative species may yield fundamental insights into evolutionary history and provide options to meet the challenge of climate changes. 30 SSR loci were employed to assess the genetic diversity and population structure of 283 individuals from wild and domesticated populations from Africa, Europe, Asia and ICARDA. The allele number per loci ranged from 3 to 14. The average gene diversity index and average polymorphism information content (PIC) was 0.5340 and 0.4817, respectively. A model based population structure analysis divided the germplasm resources into three subgroups: the relative species, the grasspea from Asia, and the grasspea from Europe and Africa. The UPGMA dendrogram and PCA cluster also demonstrated that Asian group was convincingly separated from the other group. The AMOVA result showed that the cultivated species was quite distinct from its relative species, however a low level of differentiation was revealed among their geographic origins. In all, these results provided a molecular basis for understanding genetic diversity of L. sativus and its relatives. PMID:25793712

  8. Mitochondrial DNA Reveals Genetic Structuring of Pinna nobilis across the Mediterranean Sea

    PubMed Central

    Sanna, Daria; Cossu, Piero; Dedola, Gian Luca; Scarpa, Fabio; Maltagliati, Ferruccio; Castelli, Alberto; Franzoi, Piero; Lai, Tiziana; Cristo, Benedetto; Curini-Galletti, Marco; Francalacci, Paolo; Casu, Marco

    2013-01-01

    Pinna nobilis is the largest endemic Mediterranean marine bivalve. During past centuries, various human activities have promoted the regression of its populations. As a consequence of stringent standards of protection, demographic expansions are currently reported in many sites. The aim of this study was to provide the first large broad-scale insight into the genetic variability of P. nobilis in the area that encompasses the western Mediterranean, Ionian Sea, and Adriatic Sea marine ecoregions. To accomplish this objective twenty-five populations from this area were surveyed using two mitochondrial DNA markers (COI and 16S). Our dataset was then merged with those obtained in other studies for the Aegean and Tunisian populations (eastern Mediterranean), and statistical analyses (Bayesian model-based clustering, median-joining network, AMOVA, mismatch distribution, Tajima’s and Fu’s neutrality tests and Bayesian skyline plots) were performed. The results revealed genetic divergence among three distinguishable areas: (1) western Mediterranean and Ionian Sea; (2) Adriatic Sea; and (3) Aegean Sea and Tunisian coastal areas. From a conservational point of view, populations from the three genetically divergent groups found may be considered as different management units. PMID:23840684

  9. Mitochondrial DNA reveals genetic structuring of Pinna nobilis across the Mediterranean Sea.

    PubMed

    Sanna, Daria; Cossu, Piero; Dedola, Gian Luca; Scarpa, Fabio; Maltagliati, Ferruccio; Castelli, Alberto; Franzoi, Piero; Lai, Tiziana; Cristo, Benedetto; Curini-Galletti, Marco; Francalacci, Paolo; Casu, Marco

    2013-01-01

    Pinna nobilis is the largest endemic Mediterranean marine bivalve. During past centuries, various human activities have promoted the regression of its populations. As a consequence of stringent standards of protection, demographic expansions are currently reported in many sites. The aim of this study was to provide the first large broad-scale insight into the genetic variability of P. nobilis in the area that encompasses the western Mediterranean, Ionian Sea, and Adriatic Sea marine ecoregions. To accomplish this objective twenty-five populations from this area were surveyed using two mitochondrial DNA markers (COI and 16S). Our dataset was then merged with those obtained in other studies for the Aegean and Tunisian populations (eastern Mediterranean), and statistical analyses (Bayesian model-based clustering, median-joining network, AMOVA, mismatch distribution, Tajima's and Fu's neutrality tests and Bayesian skyline plots) were performed. The results revealed genetic divergence among three distinguishable areas: (1) western Mediterranean and Ionian Sea; (2) Adriatic Sea; and (3) Aegean Sea and Tunisian coastal areas. From a conservational point of view, populations from the three genetically divergent groups found may be considered as different management units. PMID:23840684

  10. Time-series analysis reveals genetic responses to intensive management of razorback sucker (Xyrauchen texanus).

    PubMed

    Dowling, Thomas E; Turner, Thomas F; Carson, Evan W; Saltzgiver, Melody J; Adams, Deborah; Kesner, Brian; Marsh, Paul C

    2014-03-01

    Time-series analysis is used widely in ecology to study complex phenomena and may have considerable potential to clarify relationships of genetic and demographic processes in natural and exploited populations. We explored the utility of this approach to evaluate population responses to management in razorback sucker, a long-lived and fecund, but declining freshwater fish species. A core population in Lake Mohave (Arizona-Nevada, USA) has experienced no natural recruitment for decades and is maintained by harvesting naturally produced larvae from the lake, rearing them in protective custody, and repatriating them at sizes less vulnerable to predation. Analyses of mtDNA and 15 microsatellites characterized for sequential larval cohorts collected over a 15-year time series revealed no changes in geographic structuring but indicated significant increase in mtDNA diversity for the entire population over time. Likewise, ratios of annual effective breeders to annual census size (N b /N a) increased significantly despite sevenfold reduction of N a. These results indicated that conservation actions diminished near-term extinction risk due to genetic factors and should now focus on increasing numbers of fish in Lake Mohave to ameliorate longer-term risks. More generally, time-series analysis permitted robust testing of trends in genetic diversity, despite low precision of some metrics. PMID:24665337

  11. Whole-Genome Sequencing Reveals Genetic Variation in the Asian House Rat

    PubMed Central

    Teng, Huajing; Zhang, Yaohua; Shi, Chengmin; Mao, Fengbiao; Hou, Lingling; Guo, Hongling; Sun, Zhongsheng; Zhang, Jianxu

    2016-01-01

    Whole-genome sequencing of wild-derived rat species can provide novel genomic resources, which may help decipher the genetics underlying complex phenotypes. As a notorious pest, reservoir of human pathogens, and colonizer, the Asian house rat, Rattus tanezumi, is successfully adapted to its habitat. However, little is known regarding genetic variation in this species. In this study, we identified over 41,000,000 single-nucleotide polymorphisms, plus insertions and deletions, through whole-genome sequencing and bioinformatics analyses. Moreover, we identified over 12,000 structural variants, including 143 chromosomal inversions. Further functional analyses revealed several fixed nonsense mutations associated with infection and immunity-related adaptations, and a number of fixed missense mutations that may be related to anticoagulant resistance. A genome-wide scan for loci under selection identified various genes related to neural activity. Our whole-genome sequencing data provide a genomic resource for future genetic studies of the Asian house rat species and have the potential to facilitate understanding of the molecular adaptations of rats to their ecological niches. PMID:27172215

  12. Comparative genomic analysis of Lactobacillus plantarum ZJ316 reveals its genetic adaptation and potential probiotic profiles* #

    PubMed Central

    Li, Ping; Li, Xuan; Gu, Qing; Lou, Xiu-yu; Zhang, Xiao-mei; Song, Da-feng; Zhang, Chen

    2016-01-01

    Objective: In previous studies, Lactobacillus plantarum ZJ316 showed probiotic properties, such as antimicrobial activity against various pathogens and the capacity to significantly improve pig growth and pork quality. The purpose of this study was to reveal the genes potentially related to its genetic adaptation and probiotic profiles based on comparative genomic analysis. Methods: The genome sequence of L. plantarum ZJ316 was compared with those of eight L. plantarum strains deposited in GenBank. BLASTN, Mauve, and MUMmer programs were used for genome alignment and comparison. CRISPRFinder was applied for searching the clustered regularly interspaced short palindromic repeats (CRISPRs). Results: We identified genes that encode proteins related to genetic adaptation and probiotic profiles, including carbohydrate transport and metabolism, proteolytic enzyme systems and amino acid biosynthesis, CRISPR adaptive immunity, stress responses, bile salt resistance, ability to adhere to the host intestinal wall, exopolysaccharide (EPS) biosynthesis, and bacteriocin biosynthesis. Conclusions: Comparative characterization of the L. plantarum ZJ316 genome provided the genetic basis for further elucidating the functional mechanisms of its probiotic properties. ZJ316 could be considered a potential probiotic candidate. PMID:27487802

  13. Microsatellite variation reveals weak genetic structure and retention of genetic variability in threatened Chinook salmon (Oncorhynchus tshawytscha) within a Snake River watershed

    USGS Publications Warehouse

    Neville, Helen; Issacs, Frank B.; Thurow, Russel; Dunham, J.B.; Rieman, B.

    2007-01-01

    Pacific salmon (Oncorhynchus spp.) have been central to the development of management concepts associated with evolutionarily significant units (ESUs), yet there are still relatively few studies of genetic diversity within threatened and endangered ESUs for salmon or other species. We analyzed genetic variation at 10 microsatellite loci to evaluate spatial population structure and genetic variability in indigenous Chinook salmon (Oncorhynchus tshawytscha) across a large wilderness basin within a Snake River ESU. Despite dramatic 20th century declines in abundance, these populations retained robust levels of genetic variability. No significant genetic bottlenecks were found, although the bottleneck metric (M ratio) was significantly correlated with average population size and variability. Weak but significant genetic structure existed among tributaries despite evidence of high levels of gene flow, with the strongest genetic differentiation mirroring the physical segregation of fish from two sub-basins. Despite the more recent colonization of one sub-basin and differences between sub-basins in the natural level of fragmentation, gene diversity and genetic differentiation were similar between sub-basins. Various factors, such as the (unknown) genetic contribution of precocial males, genetic compensation, lack of hatchery influence, and high levels of current gene flow may have contributed to the persistence of genetic variability in this system in spite of historical declines. This unique study of indigenous Chinook salmon underscores the importance of maintaining natural populations in interconnected and complex habitats to minimize losses of genetic diversity within ESUs.

  14. Babesia canis: evidence for genetic diversity among isolates revealed by restriction fragment length polymorphism analysis.

    PubMed

    Citard, T; Mähl, P; Boulouis, H J; Chavigny, C; Druilhe, P

    1995-09-01

    The genetic diversity of B. canis was investigated by restriction fragment length polymorphism analysis. For this purpose, we identified a Babesia canis specific DNA probe named pS8. This 1.2 kbp probe can detect as low as 20 pg of B. canis DNA. Results suggest that the pS8 probe is distributed in multiple copies throughout the genome though is probably not itself internally repetitious, i.e. not structured into blocks of tandem units. This probe reveals discrete hybridizing fragments in B. canis enzyme-digested genomic DNA. RFLP patterns obtained with the pS8 probe revealed a large genetic diversity between various isolates and led us to distinguish several clones derived from a single isolate. Results suggest that for a single isolate, the fingerprints obtained reflect those of a few quantitatively dominant clones. This technique can now be routinely applied and provides a convenient tool for the characterization and the identification of B. canis isolates, strains and clones. PMID:8533020

  15. Comparison of a Modern and Fossil Pithovirus Reveals Its Genetic Conservation and Evolution

    PubMed Central

    Levasseur, Anthony; Andreani, Julien; Delerce, Jeremy; Bou Khalil, Jacques; Robert, Catherine; La Scola, Bernard; Raoult, Didier

    2016-01-01

    Most theories on viral evolution are speculative and lack fossil comparison. Here, we isolated a modern Pithovirus-like virus from sewage samples. This giant virus, named Pithovirus massiliensis, was compared with its prehistoric counterpart, Pithovirus sibericum, found in Siberian permafrost. Our analysis revealed near-complete gene repertoire conservation, including horizontal gene transfer and ORFans. Furthermore, all orthologous genes evolved under strong purifying selection with a non-synonymous and synonymous ratio in the same range as the ratio found in the prokaryotic world. The comparison between fossil and modern Pithovirus species provided an estimation of the cadence of the molecular clock, reaching up to 3 × 10−6 mutations/site/year. In addition, the strict conservation of HGTs and ORFans in P. massiliensis revealed the stable genetic mosaicism in giant viruses and excludes the concept of a bag of genes. The genetic stability for 30,000 years of P. massiliensis demonstrates that giant viruses evolve similarly to prokaryotes by classical mechanisms of evolution, including selection and fixation of genes, followed by selective constraints. PMID:27389688

  16. Genetic introgression and species boundary of two geographically overlapping pine species revealed by molecular markers.

    PubMed

    Zhang, Defang; Xia, Tao; Yan, Maomao; Dai, Xiaogang; Xu, Jin; Li, Shuxian; Yin, Tongming

    2014-01-01

    Gene introgression and hybrid barriers have long been a major focus of studies of geographically overlapping species. Two pine species, Pinus massoniana and P. hwangshanensis, are frequently observed growing adjacent to each other, where they overlap in a narrow hybrid zone. As a consequence, these species constitute an ideal system for studying genetic introgression and reproductive barriers between naturally hybridizing, adjacently distributed species. In this study, we sampled 270 pine trees along an elevation gradient in Anhui Province, China and analyzed these samples using EST-SSR markers. The molecular data revealed that direct gene flow between the two species was fairly low, and that the majority of gene introgression was intermediated by backcrossing. On the basis of empirical observation, the on-site distribution of pines was divided into a P. massoniana zone, a hybrid zone, and a P. hwangshanensis zone. STRUCTURE analysis revealed the existence of a distinct species boundary between the two pine species. The genetic boundary of the hybrid zone, on the other hand, was indistinct owing to intensive backcrossing with parental species. Compared with P. massoniana, P. hwangshanensis was found to backcross with the hybrids more intensively, consistent with the observation that morphological and anatomical characteristics of trees in the contact zone were biased towards P. hwangshanensis. The introgression ability of amplified alleles varied across species, with some being completely blocked from interspecific introgression. Our study has provided a living example to help explain the persistence of adjacently distributed species coexisting with their interfertile hybrids. PMID:24977711

  17. The Genetic Relationship between Leishmania aethiopica and Leishmania tropica Revealed by Comparing Microsatellite Profiles

    PubMed Central

    Krayter, Lena; Schnur, Lionel F.; Schönian, Gabriele

    2015-01-01

    Background Leishmania (Leishmania) aethiopica and L. (L.) tropica cause cutaneous leishmaniases and appear to be related. L. aethiopica is geographically restricted to Ethiopia and Kenya; L. tropica is widely dispersed from the Eastern Mediterranean, through the Middle East into eastern India and in north, east and south Africa. Their phylogenetic inter-relationship is only partially revealed. Some studies indicate a close relationship. Here, eight strains of L. aethiopica were characterized genetically and compared with 156 strains of L. tropica from most of the latter species' geographical range to discern the closeness. Methodology/Principal Findings Twelve unlinked microsatellite markers previously used to genotype strains of L. tropica were successfully applied to the eight strains of L. aethiopica and their microsatellite profiles were compared to those of 156 strains of L. tropica from various geographical locations that were isolated from human cases of cutaneous and visceral leishmaniasis, hyraxes and sand fly vectors. All the microsatellite profiles were subjected to various analytical algorithms: Bayesian statistics, distance-based and factorial correspondence analysis, revealing: (i) the species L. aethiopica, though geographically restricted, is genetically very heterogeneous; (ii) the strains of L. aethiopica formed a distinct genetic cluster; and (iii) strains of L. aethiopica are closely related to strains of L. tropica and more so to the African ones, although, by factorial correspondence analysis, clearly separate from them. Conclusions/Significance The successful application of the 12 microsatellite markers, originally considered species-specific for the species L. tropica, to strains of L. aethiopica confirmed the close relationship between these two species. The Bayesian and distance-based methods clustered the strains of L. aethiopica among African strains of L. tropica, while the factorial correspondence analysis indicated a clear separation

  18. Association genetics and transcriptome analysis reveal a gibberellin-responsive pathway involved in regulating photosynthesis.

    PubMed

    Xie, Jianbo; Tian, Jiaxing; Du, Qingzhang; Chen, Jinhui; Li, Ying; Yang, Xiaohui; Li, Bailian; Zhang, Deqiang

    2016-05-01

    Gibberellins (GAs) regulate a wide range of important processes in plant growth and development, including photosynthesis. However, the mechanism by which GAs regulate photosynthesis remains to be understood. Here, we used multi-gene association to investigate the effect of genes in the GA-responsive pathway, as constructed by RNA sequencing, on photosynthesis, growth, and wood property traits, in a population of 435 Populus tomentosa By analyzing changes in the transcriptome following GA treatment, we identified many key photosynthetic genes, in agreement with the observed increase in measurements of photosynthesis. Regulatory motif enrichment analysis revealed that 37 differentially expressed genes related to photosynthesis shared two essential GA-related cis-regulatory elements, the GA response element and the pyrimidine box. Thus, we constructed a GA-responsive pathway consisting of 47 genes involved in regulating photosynthesis, including GID1, RGA, GID2, MYBGa, and 37 photosynthetic differentially expressed genes. Single nucleotide polymorphism (SNP)-based association analysis showed that 142 SNPs, representing 40 candidate genes in this pathway, were significantly associated with photosynthesis, growth, and wood property traits. Epistasis analysis uncovered interactions between 310 SNP-SNP pairs from 37 genes in this pathway, revealing possible genetic interactions. Moreover, a structural gene-gene matrix based on a time-course of transcript abundances provided a better understanding of the multi-gene pathway affecting photosynthesis. The results imply a functional role for these genes in mediating photosynthesis, growth, and wood properties, demonstrating the potential of combining transcriptome-based regulatory pathway construction and genetic association approaches to detect the complex genetic networks underlying quantitative traits. PMID:27091876

  19. Rangewide genetic analysis of Lesser Prairie-Chicken reveals population structure, range expansion, and possible introgression

    USGS Publications Warehouse

    Oyler-McCance, Sara J.; DeYoung, Randall W; Fike, Jennifer; Hagen, Christian A.; Johnson, Jeff A.; Larsson, Lena C; Patten, Michael

    2016-01-01

    The distribution of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) has been markedly reduced due to loss and fragmentation of habitat. Portions of the historical range, however, have been recolonized and even expanded due to planting of conservation reserve program (CRP) fields that provide favorable vegetation structure for Lesser Prairie-Chickens. The source population(s) feeding the range expansion is unknown, yet has resulted in overlap between Lesser and Greater Prairie-Chickens (T. cupido) increasing the potential for hybridization. Our objectives were to characterize connectivity and genetic diversity among populations, identify source population(s) of recent range expansion, and examine hybridization with the Greater Prairie-Chicken. We analyzed 640 samples from across the range using 13 microsatellites. We identified three to four populations corresponding largely to ecoregions. The Shinnery Oak Prairie and Sand Sagebrush Prairie represented genetically distinct populations (F ST > 0.034 and F ST > 0.023 respectively). The Shortgrass/CRP Mosaic and Mixed Grass ecoregions appeared admixed (F ST = 0.009). Genetic diversity was similar among ecoregions and N e ranged from 142 (95 % CI 99–236) for the Shortgrass/CRP Mosaic to 296 (95 % CI 233–396) in the Mixed Grass Prairie. No recent migration was detected among ecoregions, except asymmetric dispersal from both the Mixed Grass Prairie and to a lesser extent the Sand Sagebrush Prairie north into adjacent Shortgrass/CRP Mosaic (m = 0.207, 95 % CI 0.116–0.298, m = 0.097, 95 % CI 0.010–0.183, respectively). Indices investigating potential hybridization in the Shortgrass/CRP Mosaic revealed that six of the 13 individuals with hybrid phenotypes were significantly admixed suggesting hybridization. Continued monitoring of diversity within and among ecoregions is warranted as are actions promoting genetic connectivity and range expansion.

  20. Partitioning the Heritability of Tourette Syndrome and Obsessive Compulsive Disorder Reveals Differences in Genetic Architecture

    PubMed Central

    Davis, Lea K.; Yu, Dongmei; Keenan, Clare L.; Gamazon, Eric R.; Konkashbaev, Anuar I.; Derks, Eske M.; Neale, Benjamin M.; Yang, Jian; Lee, S. Hong; Evans, Patrick; Barr, Cathy L.; Bellodi, Laura; Benarroch, Fortu; Berrio, Gabriel Bedoya; Bienvenu, Oscar J.; Bloch, Michael H.; Blom, Rianne M.; Bruun, Ruth D.; Budman, Cathy L.; Camarena, Beatriz; Campbell, Desmond; Cappi, Carolina; Cardona Silgado, Julio C.; Cath, Danielle C.; Cavallini, Maria C.; Chavira, Denise A.; Chouinard, Sylvain; Conti, David V.; Cook, Edwin H.; Coric, Vladimir; Cullen, Bernadette A.; Deforce, Dieter; Delorme, Richard; Dion, Yves; Edlund, Christopher K.; Egberts, Karin; Falkai, Peter; Fernandez, Thomas V.; Gallagher, Patience J.; Garrido, Helena; Geller, Daniel; Girard, Simon L.; Grabe, Hans J.; Grados, Marco A.; Greenberg, Benjamin D.; Gross-Tsur, Varda; Haddad, Stephen; Heiman, Gary A.; Hemmings, Sian M. J.; Hounie, Ana G.; Illmann, Cornelia; Jankovic, Joseph; Jenike, Michael A.; Kennedy, James L.; King, Robert A.; Kremeyer, Barbara; Kurlan, Roger; Lanzagorta, Nuria; Leboyer, Marion; Leckman, James F.; Lennertz, Leonhard; Liu, Chunyu; Lochner, Christine; Lowe, Thomas L.; Macciardi, Fabio; McCracken, James T.; McGrath, Lauren M.; Mesa Restrepo, Sandra C.; Moessner, Rainald; Morgan, Jubel; Muller, Heike; Murphy, Dennis L.; Naarden, Allan L.; Ochoa, William Cornejo; Ophoff, Roel A.; Osiecki, Lisa; Pakstis, Andrew J.; Pato, Michele T.; Pato, Carlos N.; Piacentini, John; Pittenger, Christopher; Pollak, Yehuda; Rauch, Scott L.; Renner, Tobias J.; Reus, Victor I.; Richter, Margaret A.; Riddle, Mark A.; Robertson, Mary M.; Romero, Roxana; Rosàrio, Maria C.; Rosenberg, David; Rouleau, Guy A.; Ruhrmann, Stephan; Ruiz-Linares, Andres; Sampaio, Aline S.; Samuels, Jack; Sandor, Paul; Sheppard, Brooke; Singer, Harvey S.; Smit, Jan H.; Stein, Dan J.; Strengman, E.; Tischfield, Jay A.; Valencia Duarte, Ana V.; Vallada, Homero; Van Nieuwerburgh, Filip; Veenstra-VanderWeele, Jeremy; Walitza, Susanne; Wang, Ying; Wendland, Jens R.; Westenberg, Herman G. M.; Shugart, Yin Yao; Miguel, Euripedes C.; McMahon, William; Wagner, Michael; Nicolini, Humberto; Posthuma, Danielle; Hanna, Gregory L.; Heutink, Peter; Denys, Damiaan; Arnold, Paul D.; Oostra, Ben A.; Nestadt, Gerald; Freimer, Nelson B.; Pauls, David L.; Wray, Naomi R.

    2013-01-01

    The direct estimation of heritability from genome-wide common variant data as implemented in the program Genome-wide Complex Trait Analysis (GCTA) has provided a means to quantify heritability attributable to all interrogated variants. We have quantified the variance in liability to disease explained by all SNPs for two phenotypically-related neurobehavioral disorders, obsessive-compulsive disorder (OCD) and Tourette Syndrome (TS), using GCTA. Our analysis yielded a heritability point estimate of 0.58 (se = 0.09, p = 5.64e-12) for TS, and 0.37 (se = 0.07, p = 1.5e-07) for OCD. In addition, we conducted multiple genomic partitioning analyses to identify genomic elements that concentrate this heritability. We examined genomic architectures of TS and OCD by chromosome, MAF bin, and functional annotations. In addition, we assessed heritability for early onset and adult onset OCD. Among other notable results, we found that SNPs with a minor allele frequency of less than 5% accounted for 21% of the TS heritability and 0% of the OCD heritability. Additionally, we identified a significant contribution to TS and OCD heritability by variants significantly associated with gene expression in two regions of the brain (parietal cortex and cerebellum) for which we had available expression quantitative trait loci (eQTLs). Finally we analyzed the genetic correlation between TS and OCD, revealing a genetic correlation of 0.41 (se = 0.15, p = 0.002). These results are very close to previous heritability estimates for TS and OCD based on twin and family studies, suggesting that very little, if any, heritability is truly missing (i.e., unassayed) from TS and OCD GWAS studies of common variation. The results also indicate that there is some genetic overlap between these two phenotypically-related neuropsychiatric disorders, but suggest that the two disorders have distinct genetic architectures. PMID:24204291

  1. Genetic and Genomic Diversity Studies of Acacia Symbionts in Senegal Reveal New Species of Mesorhizobium with a Putative Geographical Pattern

    PubMed Central

    Diouf, Fatou; Diouf, Diegane; Klonowska, Agnieszka; Le Queré, Antoine; Bakhoum, Niokhor; Fall, Dioumacor; Neyra, Marc; Parrinello, Hugues; Diouf, Mayecor; Ndoye, Ibrahima; Moulin, Lionel

    2015-01-01

    Acacia senegal (L) Willd. and Acacia seyal Del. are highly nitrogen-fixing and moderately salt tolerant species. In this study we focused on the genetic and genomic diversity of Acacia mesorhizobia symbionts from diverse origins in Senegal and investigated possible correlations between the genetic diversity of the strains, their soil of origin, and their tolerance to salinity. We first performed a multi-locus sequence analysis on five markers gene fragments on a collection of 47 mesorhizobia strains of A. senegal and A. seyal from 8 localities. Most of the strains (60%) clustered with the M. plurifarium type strain ORS 1032T, while the others form four new clades (MSP1 to MSP4). We sequenced and assembled seven draft genomes: four in the M. plurifarium clade (ORS3356, ORS3365, STM8773 and ORS1032T), one in MSP1 (STM8789), MSP2 (ORS3359) and MSP3 (ORS3324). The average nucleotide identities between these genomes together with the MLSA analysis reveal three new species of Mesorhizobium. A great variability of salt tolerance was found among the strains with a lack of correlation between the genetic diversity of mesorhizobia, their salt tolerance and the soils samples characteristics. A putative geographical pattern of A. senegal symbionts between the dryland north part and the center of Senegal was found, reflecting adaptations to specific local conditions such as the water regime. However, the presence of salt does not seem to be an important structuring factor of Mesorhizobium species. PMID:25658650

  2. The Genetics of Bene Israel from India Reveals Both Substantial Jewish and Indian Ancestry

    PubMed Central

    Davidson, Natalie R.; Billing-Ross, Paul; Dubrovsky, Maya; Campbell, Christopher L.; Oddoux, Carole; Friedman, Eitan; Atzmon, Gil; Halperin, Eran; Ostrer, Harry; Keinan, Alon

    2016-01-01

    The Bene Israel Jewish community from West India is a unique population whose history before the 18th century remains largely unknown. Bene Israel members consider themselves as descendants of Jews, yet the identity of Jewish ancestors and their arrival time to India are unknown, with speculations on arrival time varying between the 8th century BCE and the 6th century CE. Here, we characterize the genetic history of Bene Israel by collecting and genotyping 18 Bene Israel individuals. Combining with 486 individuals from 41 other Jewish, Indian and Pakistani populations, and additional individuals from worldwide populations, we conducted comprehensive genome-wide analyses based on FST, principal component analysis, ADMIXTURE, identity-by-descent sharing, admixture linkage disequilibrium decay, haplotype sharing and allele sharing autocorrelation decay, as well as contrasted patterns between the X chromosome and the autosomes. The genetics of Bene Israel individuals resemble local Indian populations, while at the same time constituting a clearly separated and unique population in India. They are unique among Indian and Pakistani populations we analyzed in sharing considerable genetic ancestry with other Jewish populations. Putting together the results from all analyses point to Bene Israel being an admixed population with both Jewish and Indian ancestry, with the genetic contribution of each of these ancestral populations being substantial. The admixture took place in the last millennium, about 19–33 generations ago. It involved Middle-Eastern Jews and was sex-biased, with more male Jewish and local female contribution. It was followed by a population bottleneck and high endogamy, which can lead to increased prevalence of recessive diseases in this population. This study provides an example of how genetic analysis advances our knowledge of human history in cases where other disciplines lack the relevant data to do so. PMID:27010569

  3. The Genetics of Bene Israel from India Reveals Both Substantial Jewish and Indian Ancestry.

    PubMed

    Waldman, Yedael Y; Biddanda, Arjun; Davidson, Natalie R; Billing-Ross, Paul; Dubrovsky, Maya; Campbell, Christopher L; Oddoux, Carole; Friedman, Eitan; Atzmon, Gil; Halperin, Eran; Ostrer, Harry; Keinan, Alon

    2016-01-01

    The Bene Israel Jewish community from West India is a unique population whose history before the 18th century remains largely unknown. Bene Israel members consider themselves as descendants of Jews, yet the identity of Jewish ancestors and their arrival time to India are unknown, with speculations on arrival time varying between the 8th century BCE and the 6th century CE. Here, we characterize the genetic history of Bene Israel by collecting and genotyping 18 Bene Israel individuals. Combining with 486 individuals from 41 other Jewish, Indian and Pakistani populations, and additional individuals from worldwide populations, we conducted comprehensive genome-wide analyses based on FST, principal component analysis, ADMIXTURE, identity-by-descent sharing, admixture linkage disequilibrium decay, haplotype sharing and allele sharing autocorrelation decay, as well as contrasted patterns between the X chromosome and the autosomes. The genetics of Bene Israel individuals resemble local Indian populations, while at the same time constituting a clearly separated and unique population in India. They are unique among Indian and Pakistani populations we analyzed in sharing considerable genetic ancestry with other Jewish populations. Putting together the results from all analyses point to Bene Israel being an admixed population with both Jewish and Indian ancestry, with the genetic contribution of each of these ancestral populations being substantial. The admixture took place in the last millennium, about 19-33 generations ago. It involved Middle-Eastern Jews and was sex-biased, with more male Jewish and local female contribution. It was followed by a population bottleneck and high endogamy, which can lead to increased prevalence of recessive diseases in this population. This study provides an example of how genetic analysis advances our knowledge of human history in cases where other disciplines lack the relevant data to do so. PMID:27010569

  4. Genetic diversity revealed by morphological traits and ISSR markers in 48 Okras (Abelmoschus escullentus L.).

    PubMed

    Yuan, Cong-Ying; Wang, Ping; Chen, Pang-Pang; Xiao, Wen-Jun; Zhang, Cheng; Hu, Shuai; Zhou, Ping; Chang, Hong-Ping; He, Zhuang; Hu, Rong; Lu, Xiu-Tao; Ye, Jia-Zhuo; Guo, Xin-Hong

    2015-07-01

    Okra is a widely distributed crop in the tropics, subtropics, and warmer areas of the temperate zones. Its major potential uses as a vegetable, oil and protein source, and source of paper pulp and fuel, or biomass are compatible. It is expected to have high value of exploitation and application. Due to the limited number of molecular studies focused on okras, the methods of morphological and ISSR markers were used to analysis the genetic diversity of 48 okras in the present study. The 22 primers were picked for ISSR-PCR, and a total of 154 fragments were amplified with an overall average polymorphism of 54.55 %. We used the 154 markers to construct the dendrogram based on the unweighted pair group method with arithmetic means (UPGMA). A high level of genetic diversity was found among 48 individuals. The 48 Okras was divided into four clusters at Dice's coefficient of 0.19 with clustering analysis. Based on these data of the genetic diversity, it will be possible to exploit the available resources of okra in more valuable ways. PMID:26261400

  5. A Genome Wide Survey of SNP Variation Reveals the Genetic Structure of Sheep Breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic structure of sheep reflects their domestication and subsequent formation into discrete breeds. Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. After identi...

  6. Dengue in China: Comprehensive Phylogenetic Evaluation Reveals Evidence of Endemicity and Complex Genetic Diversity.

    PubMed

    Chen, Rubing; Han, Guan-Zhu

    2016-01-01

    Despite the increasing threat of dengue outbreaks in China, it is still considered as an imported disease and its introduction and/or circulation patterns remain obscure. On the basis of the most extensive phylogenetic analysis to date, we showed highly complex genetic diversity of dengue viruses (DENVs) in south China with up to 20 different clades/lineages from multiple serotypes co-circulating in the same year. Despite that most of these clades/lineages were resulted from imported cases, evidence of local persistence of DENV serotype 1 (DENV-1) was observed, indicating its potential endemicity in Guangdong province. This study, therefore, provided an overview of DENV genetic diversity and evolutionary dynamics in China, which will be useful for developing policies to prevent and control future dengue outbreaks in China. PMID:26458780

  7. Characterization of the Active Microbiotas Associated with Honey Bees Reveals Healthier and Broader Communities when Colonies are Genetically Diverse

    PubMed Central

    Mattila, Heather R.; Rios, Daniela; Walker-Sperling, Victoria E.; Roeselers, Guus; Newton, Irene L. G.

    2012-01-01

    Recent losses of honey bee colonies have led to increased interest in the microbial communities that are associated with these important pollinators. A critical function that bacteria perform for their honey bee hosts, but one that is poorly understood, is the transformation of worker-collected pollen into bee bread, a nutritious food product that can be stored for long periods in colonies. We used 16S rRNA pyrosequencing to comprehensively characterize in genetically diverse and genetically uniform colonies the active bacterial communities that are found on honey bees, in their digestive tracts, and in bee bread. This method provided insights that have not been revealed by past studies into the content and benefits of honey bee-associated microbial communities. Colony microbiotas differed substantially between sampling environments and were dominated by several anaerobic bacterial genera never before associated with honey bees, but renowned for their use by humans to ferment food. Colonies with genetically diverse populations of workers, a result of the highly promiscuous mating behavior of queens, benefited from greater microbial diversity, reduced pathogen loads, and increased abundance of putatively helpful bacteria, particularly species from the potentially probiotic genus Bifidobacterium. Across all colonies, Bifidobacterium activity was negatively correlated with the activity of genera that include pathogenic microbes; this relationship suggests a possible target for understanding whether microbes provide protective benefits to honey bees. Within-colony diversity shapes microbiotas associated with honey bees in ways that may have important repercussions for colony function and health. Our findings illuminate the importance of honey bee-bacteria symbioses and examine their intersection with nutrition, pathogen load, and genetic diversity, factors that are considered key to understanding honey bee decline. PMID:22427917

  8. Characterization of the active microbiotas associated with honey bees reveals healthier and broader communities when colonies are genetically diverse.

    PubMed

    Mattila, Heather R; Rios, Daniela; Walker-Sperling, Victoria E; Roeselers, Guus; Newton, Irene L G

    2012-01-01

    Recent losses of honey bee colonies have led to increased interest in the microbial communities that are associated with these important pollinators. A critical function that bacteria perform for their honey bee hosts, but one that is poorly understood, is the transformation of worker-collected pollen into bee bread, a nutritious food product that can be stored for long periods in colonies. We used 16S rRNA pyrosequencing to comprehensively characterize in genetically diverse and genetically uniform colonies the active bacterial communities that are found on honey bees, in their digestive tracts, and in bee bread. This method provided insights that have not been revealed by past studies into the content and benefits of honey bee-associated microbial communities. Colony microbiotas differed substantially between sampling environments and were dominated by several anaerobic bacterial genera never before associated with honey bees, but renowned for their use by humans to ferment food. Colonies with genetically diverse populations of workers, a result of the highly promiscuous mating behavior of queens, benefited from greater microbial diversity, reduced pathogen loads, and increased abundance of putatively helpful bacteria, particularly species from the potentially probiotic genus Bifidobacterium. Across all colonies, Bifidobacterium activity was negatively correlated with the activity of genera that include pathogenic microbes; this relationship suggests a possible target for understanding whether microbes provide protective benefits to honey bees. Within-colony diversity shapes microbiotas associated with honey bees in ways that may have important repercussions for colony function and health. Our findings illuminate the importance of honey bee-bacteria symbioses and examine their intersection with nutrition, pathogen load, and genetic diversity, factors that are considered key to understanding honey bee decline. PMID:22427917

  9. Massively parallel high-order combinatorial genetics in human cells

    PubMed Central

    Wong, Alan S L; Choi, Gigi C G; Cheng, Allen A; Purcell, Oliver; Lu, Timothy K

    2016-01-01

    The systematic functional analysis of combinatorial genetics has been limited by the throughput that can be achieved and the order of complexity that can be studied. To enable massively parallel characterization of genetic combinations in human cells, we developed a technology for rapid, scalable assembly of high-order barcoded combinatorial genetic libraries that can be quantified with high-throughput sequencing. We applied this technology, combinatorial genetics en masse (CombiGEM), to create high-coverage libraries of 1,521 two-wise and 51,770 three-wise barcoded combinations of 39 human microRNA (miRNA) precursors. We identified miRNA combinations that synergistically sensitize drug-resistant cancer cells to chemotherapy and/or inhibit cancer cell proliferation, providing insights into complex miRNA networks. More broadly, our method will enable high-throughput profiling of multifactorial genetic combinations that regulate phenotypes of relevance to biomedicine, biotechnology and basic science. PMID:26280411

  10. The genome of Romanomermis culicivorax: revealing fundamental changes in the core developmental genetic toolkit in Nematoda

    PubMed Central

    2013-01-01

    Background The genetics of development in the nematode Caenorhabditis elegans has been described in exquisite detail. The phylum Nematoda has two classes: Chromadorea (which includes C. elegans) and the Enoplea. While the development of many chromadorean species resembles closely that of C. elegans, enoplean nematodes show markedly different patterns of early cell division and cell fate assignment. Embryogenesis of the enoplean Romanomermis culicivorax has been studied in detail, but the genetic circuitry underpinning development in this species has not been explored. Results We generated a draft genome for R. culicivorax and compared its gene content with that of C. elegans, a second enoplean, the vertebrate parasite Trichinella spiralis, and a representative arthropod, Tribolium castaneum. This comparison revealed that R. culicivorax has retained components of the conserved ecdysozoan developmental gene toolkit lost in C. elegans. T. spiralis has independently lost even more of this toolkit than has C. elegans. However, the C. elegans toolkit is not simply depauperate, as many novel genes essential for embryogenesis in C. elegans are not found in, or have only extremely divergent homologues in R. culicivorax and T. spiralis. Our data imply fundamental differences in the genetic programmes not only for early cell specification but also others such as vulva formation and sex determination. Conclusions Despite the apparent morphological conservatism, major differences in the molecular logic of development have evolved within the phylum Nematoda. R. culicivorax serves as a tractable system to contrast C. elegans and understand how divergent genomic and thus regulatory backgrounds nevertheless generate a conserved phenotype. The R. culicivorax draft genome will promote use of this species as a research model. PMID:24373391

  11. Genetic Patterns in European Geometrid Moths Revealed by the Barcode Index Number (BIN) System

    PubMed Central

    Hausmann, Axel; Godfray, H. Charles J.; Huemer, Peter; Mutanen, Marko; Rougerie, Rodolphe; van Nieukerken, Erik J.; Ratnasingham, Sujeevan; Hebert, Paul D. N.

    2013-01-01

    Background The geometrid moths of Europe are one of the best investigated insect groups in traditional taxonomy making them an ideal model group to test the accuracy of the Barcode Index Number (BIN) system of BOLD (Barcode of Life Datasystems), a method that supports automated, rapid species delineation and identification. Methodology/Principal Findings This study provides a DNA barcode library for 219 of the 249 European geometrid moth species (88%) in five selected subfamilies. The data set includes COI sequences for 2130 specimens. Most species (93%) were found to possess diagnostic barcode sequences at the European level while only three species pairs (3%) were genetically indistinguishable in areas of sympatry. As a consequence, 97% of the European species we examined were unequivocally discriminated by barcodes within their natural areas of distribution. We found a 1:1 correspondence between BINs and traditionally recognized species for 67% of these species. Another 17% of the species (15 pairs, three triads) shared BINs, while specimens from the remaining species (18%) were divided among two or more BINs. Five of these species are mixtures, both sharing and splitting BINs. For 82% of the species with two or more BINs, the genetic splits involved allopatric populations, many of which have previously been hypothesized to represent distinct species or subspecies. Conclusions/Significance This study confirms the effectiveness of DNA barcoding as a tool for species identification and illustrates the potential of the BIN system to characterize formal genetic units independently of an existing classification. This suggests the system can be used to efficiently assess the biodiversity of large, poorly known assemblages of organisms. For the moths examined in this study, cases of discordance between traditionally recognized species and BINs arose from several causes including overlooked species, synonymy, and cases where DNA barcodes revealed regional variation of

  12. Genetic diversity of Clavispora lusitaniae isolated from Agave fourcroydes Lem, as revealed by DNA fingerprinting.

    PubMed

    Pérez-Brito, Daisy; Magaña-Alvarez, Anuar; Lappe-Oliveras, Patricia; Cortes-Velazquez, Alberto; Torres-Calzada, Claudia; Herrera-Suarez, Teófilo; Larqué-Saavedra, Alfonso; Tapia-Tussell, Raul

    2015-01-01

    This study characterized Clavispora lusitaniae strains isolated from different stages of the processing and early fermentation of a henequen (Agave fourcroydes) spirit produced in Yucatan, Mexico using a molecular technique. Sixteen strains identified based on morphological features, obtained from different substrates, were typed molecularly. Nine different versions of the divergent D1/D2 domain of the large-subunit ribosomal DNA sequence were identified among the C. lusitaniae strains. The greatest degree of polymorphism was found in the 90-bp structural motif of the D2 domain. The MSP-PCR technique was able to differentiate 100% of the isolates. This study provides significant insight into the genetic diversity of the mycobiota present during the henequen fermentation process, especially that of C. lusitaniae, for which only a few studies in plants have been published. The applied MSP-PCR markers were very efficient in revealing olymorphisms between isolates of this species. PMID:25557477

  13. Genome mining of ascomycetous fungi reveals their genetic potential for ergot alkaloid production.

    PubMed

    Gerhards, Nina; Matuschek, Marco; Wallwey, Christiane; Li, Shu-Ming

    2015-06-01

    Ergot alkaloids are important as mycotoxins or as drugs. Naturally occurring ergot alkaloids as well as their semisynthetic derivatives have been used as pharmaceuticals in modern medicine for decades. We identified 196 putative ergot alkaloid biosynthetic genes belonging to at least 31 putative gene clusters in 31 fungal species by genome mining of the 360 available genome sequences of ascomycetous fungi with known proteins. Detailed analysis showed that these fungi belong to the families Aspergillaceae, Clavicipitaceae, Arthrodermataceae, Helotiaceae and Thermoascaceae. Within the identified families, only a small number of taxa are represented. Literature search revealed a large diversity of ergot alkaloid structures in different fungi of the phylum Ascomycota. However, ergot alkaloid accumulation was only observed in 15 of the sequenced species. Therefore, this study provides genetic basis for further study on ergot alkaloid production in the sequenced strains. PMID:25796201

  14. Notch2 genetic fate mapping reveals two previously unrecognized mammary epithelial lineages

    PubMed Central

    Šale, Sanja; Lafkas, Daniel; Artavanis-Tsakonas, Spyros

    2013-01-01

    Notch signalling is implicated in stem and progenitor cell fate control in numerous organs. Using conditional in vivo genetic labelling we traced the fate of cells expressing the Notch2 receptor paralogue and uncovered the existence of two previously unrecognized mammary epithelial cell lineages that we term S (Small) and L (Large). S cells appear in a bead-on-a-string formation and are embedded between the luminal and basal/myoepithelial layers in a unique reiterative pattern, whereas single or paired L cells appear among ductal and alveolar cells. Long-term lineage tracing and functional studies indicate that S and L cells regulate ipsi- and contralateral spatial placement of tertiary branches and formation of alveolar clusters. Our findings revise present models of mammary epithelial cell hierarchy, reveal a hitherto undescribed mechanism regulating branching morphogenesis and may have important implications for identification of the cell-of-origin of distinct breast cancer subtypes. PMID:23604318

  15. A pangenomic analysis of the Nannochloropsis organellar genomes reveals novel genetic variations in key metabolic genes

    PubMed Central

    2014-01-01

    Background Microalgae in the genus Nannochloropsis are photosynthetic marine Eustigmatophytes of significant interest to the bioenergy and aquaculture sectors due to their ability to efficiently accumulate biomass and lipids for utilization in renewable transportation fuels, aquaculture feed, and other useful bioproducts. To better understand the genetic complement that drives the metabolic processes of these organisms, we present the assembly and comparative pangenomic analysis of the chloroplast and mitochondrial genomes from Nannochloropsis salina CCMP1776. Results The chloroplast and mitochondrial genomes of N. salina are 98.4% and 97% identical to their counterparts in Nannochloropsis gaditana. Comparison of the Nannochloropsis pangenome to other algae within and outside of the same phyla revealed regions of significant genetic divergence in key genes that encode proteins needed for regulation of branched chain amino synthesis (acetohydroxyacid synthase), carbon fixation (RuBisCO activase), energy conservation (ATP synthase), protein synthesis and homeostasis (Clp protease, ribosome). Conclusions Many organellar gene modifications in Nannochloropsis are unique and deviate from conserved orthologs found across the tree of life. Implementation of secondary and tertiary structure prediction was crucial to functionally characterize many proteins and therefore should be implemented in automated annotation pipelines. The exceptional similarity of the N. salina and N. gaditana organellar genomes suggests that N. gaditana be reclassified as a strain of N. salina. PMID:24646409

  16. Morphologic diversity of cutaneous sensory afferents revealed by genetically directed sparse labeling

    PubMed Central

    Wu, Hao; Williams, John; Nathans, Jeremy

    2012-01-01

    The diversity of cutaneous sensory afferents has been studied by many investigators using behavioral, physiologic, molecular, and genetic approaches. Largely missing, thus far, is an analysis of the complete morphologies of individual afferent arbors. Here we present a survey of cutaneous sensory arbor morphologies in hairy skin of the mouse using genetically-directed sparse labeling with a sensory neuron-specific alkaline phosphatase reporter. Quantitative analyses of 719 arbors, among which 77 were fully reconstructed, reveal 10 morphologically distinct types. Among the two types with the largest arbors, one contacts ∼200 hair follicles with circumferential endings and a second is characterized by a densely ramifying arbor with one to several thousand branches and a total axon length between one-half and one meter. These observations constrain models of receptive field size and structure among cutaneous sensory neurons, and they raise intriguing questions regarding the cellular and developmental mechanisms responsible for this morphological diversity. DOI: http://dx.doi.org/10.7554/eLife.00181.001 PMID:23256042

  17. Genetic Manipulations Reveal Dynamic Cell and Gene Functions: Cre-ating a New View of Myogenesis

    PubMed Central

    Hutcheson, David A.; Kardon, Gabrielle

    2010-01-01

    Development of multicellular organisms is temporally and spatially complex. The Cre/loxP and Flp/FRT systems for genetic manipulation in mammals now enable researchers to explicitly examine in vivo the temporal and spatial role of cells and genes during development via cell lineage and ablation studies and conditional gene inactivation and activation. Recently we have used these methods to genetically dissect the role of Pax3+ and Pax7+ progenitor populations and the function of β-catenin, an important regulator of myogenesis, in vertebrate limb myogenesis. Our lineage and ablation studies of Pax3+ and Pax7+ progenitors revealed surprising insights into myogenesis not apparent from Pax3 and Pax7 expression and functional studies. In addition, conditional inactivation and activation of β-catenin in different progenitor populations and their progeny demonstrated that β-catenin plays several cell-autonomous roles in myogenesis. Our studies highlight the hierarchical (i.e. genes versus cells), temporal, and spatial complexity of development and demonstrate that manipulations of both cells and genes will be required to obtain a full understanding of the development of multicellular organisms. PMID:19844163

  18. Uniparental Markers in Italy Reveal a Sex-Biased Genetic Structure and Different Historical Strata

    PubMed Central

    Sarno, Stefania; Harmant, Christine; Useli, Antonella; Sanz, Paula; Yang-Yao, Daniele; Manry, Jeremy; Ciani, Graziella; Luiselli, Donata; Quintana-Murci, Lluis; Comas, David; Pettener, Davide

    2013-01-01

    Located in the center of the Mediterranean landscape and with an extensive coastal line, the territory of what is today Italy has played an important role in the history of human settlements and movements of Southern Europe and the Mediterranean Basin. Populated since Paleolithic times, the complexity of human movements during the Neolithic, the Metal Ages and the most recent history of the two last millennia (involving the overlapping of different cultural and demic strata) has shaped the pattern of the modern Italian genetic structure. With the aim of disentangling this pattern and understanding which processes more importantly shaped the distribution of diversity, we have analyzed the uniparentally-inherited markers in ∼900 individuals from an extensive sampling across the Italian peninsula, Sardinia and Sicily. Spatial PCAs and DAPCs revealed a sex-biased pattern indicating different demographic histories for males and females. Besides the genetic outlier position of Sardinians, a North West–South East Y-chromosome structure is found in continental Italy. Such structure is in agreement with recent archeological syntheses indicating two independent and parallel processes of Neolithisation. In addition, date estimates pinpoint the importance of the cultural and demographic events during the late Neolithic and Metal Ages. On the other hand, mitochondrial diversity is distributed more homogeneously in agreement with older population events that might be related to the presence of an Italian Refugium during the last glacial period in Europe. PMID:23734255

  19. Computational dissection of human episodic memory reveals mental process-specific genetic profiles

    PubMed Central

    Luksys, Gediminas; Fastenrath, Matthias; Coynel, David; Freytag, Virginie; Gschwind, Leo; Heck, Angela; Jessen, Frank; Maier, Wolfgang; Milnik, Annette; Riedel-Heller, Steffi G.; Scherer, Martin; Spalek, Klara; Vogler, Christian; Wagner, Michael; Wolfsgruber, Steffen; Papassotiropoulos, Andreas; de Quervain, Dominique J.-F.

    2015-01-01

    Episodic memory performance is the result of distinct mental processes, such as learning, memory maintenance, and emotional modulation of memory strength. Such processes can be effectively dissociated using computational models. Here we performed gene set enrichment analyses of model parameters estimated from the episodic memory performance of 1,765 healthy young adults. We report robust and replicated associations of the amine compound SLC (solute-carrier) transporters gene set with the learning rate, of the collagen formation and transmembrane receptor protein tyrosine kinase activity gene sets with the modulation of memory strength by negative emotional arousal, and of the L1 cell adhesion molecule (L1CAM) interactions gene set with the repetition-based memory improvement. Furthermore, in a large functional MRI sample of 795 subjects we found that the association between L1CAM interactions and memory maintenance revealed large clusters of differences in brain activity in frontal cortical areas. Our findings provide converging evidence that distinct genetic profiles underlie specific mental processes of human episodic memory. They also provide empirical support to previous theoretical and neurobiological studies linking specific neuromodulators to the learning rate and linking neural cell adhesion molecules to memory maintenance. Furthermore, our study suggests additional memory-related genetic pathways, which may contribute to a better understanding of the neurobiology of human memory. PMID:26261317

  20. Ethiopian Genetic Diversity Reveals Linguistic Stratification and Complex Influences on the Ethiopian Gene Pool

    PubMed Central

    Pagani, Luca; Kivisild, Toomas; Tarekegn, Ayele; Ekong, Rosemary; Plaster, Chris; Gallego Romero, Irene; Ayub, Qasim; Mehdi, S. Qasim; Thomas, Mark G.; Luiselli, Donata; Bekele, Endashaw; Bradman, Neil; Balding, David J.; Tyler-Smith, Chris

    2012-01-01

    Humans and their ancestors have traversed the Ethiopian landscape for millions of years, and present-day Ethiopians show great cultural, linguistic, and historical diversity, which makes them essential for understanding African variability and human origins. We genotyped 235 individuals from ten Ethiopian and two neighboring (South Sudanese and Somali) populations on an Illumina Omni 1M chip. Genotypes were compared with published data from several African and non-African populations. Principal-component and STRUCTURE-like analyses confirmed substantial genetic diversity both within and between populations, and revealed a match between genetic data and linguistic affiliation. Using comparisons with African and non-African reference samples in 40-SNP genomic windows, we identified “African” and “non-African” haplotypic components for each Ethiopian individual. The non-African component, which includes the SLC24A5 allele associated with light skin pigmentation in Europeans, may represent gene flow into Africa, which we estimate to have occurred ∼3 thousand years ago (kya). The non-African component was found to be more similar to populations inhabiting the Levant rather than the Arabian Peninsula, but the principal route for the expansion out of Africa ∼60 kya remains unresolved. Linkage-disequilibrium decay with genomic distance was less rapid in both the whole genome and the African component than in southern African samples, suggesting a less ancient history for Ethiopian populations. PMID:22726845

  1. Genetic dissection of an elite rice hybrid revealed that heterozygotes are not always advantageous for performance.

    PubMed Central

    Hua, J P; Xing, Y Z; Xu, C G; Sun, X L; Yu, S B; Zhang, Qifa

    2002-01-01

    We introduced an experimental design that produced an "immortalized F(2)" population allowing for complete dissection of genetic components underlying quantitative traits. Data for yield and three component traits of the immortalized F(2) were collected from replicated field trials over 2 years. Using 231 marker loci, we resolved the genetic effects into individual components and assessed relative performance of all the genotypes at both single- and two-locus levels. Single-locus analysis detected 40 QTL for the four traits. Dominance effects for about one-half of the QTL were negative, resulting in little "net" positive dominance effect. Correlation between genotype heterozygosity and trait performance was low. Large numbers of digenic interactions, including AA, AD, and DD, were detected for all the traits, with AA as the most prevalent interaction. Complementary two-locus homozygotes frequently performed the best among the nine genotypes of many two-locus combinations. While cumulative small advantages over two-locus combinations may partly explain the genetic basis of heterosis of the hybrid as double heterozygotes frequently demonstrated marginal advantages, double heterozygotes were never the best genotypes in any of the two-locus combinations. It was concluded that heterozygotes were not necessarily advantageous for trait performance even among genotypes derived from such a highly heterotic hybrid. PMID:12524357

  2. Allele Mining in Barley Genetic Resources Reveals Genes of Race-Non-Specific Powdery Mildew Resistance

    PubMed Central

    Spies, Annika; Korzun, Viktor; Bayles, Rosemary; Rajaraman, Jeyaraman; Himmelbach, Axel; Hedley, Pete E.; Schweizer, Patrick

    2012-01-01

    Race-non-specific, or quantitative, pathogen resistance is of high importance to plant breeders due to its expected durability. However, it is usually controlled by multiple quantitative trait loci (QTL) and therefore difficult to handle in practice. Knowing the genes that underlie race-non-specific resistance (NR) would allow its exploitation in a more targeted manner. Here, we performed an association-genetic study in a customized worldwide collection of spring barley accessions for candidate genes of race-NR to the powdery mildew fungus Blumeria graminis f. sp. hordei (Bgh) and combined data with results from QTL mapping as well as functional-genomics approaches. This led to the identification of 11 associated genes with converging evidence for an important role in race-NR in the presence of the Mlo gene for basal susceptibility. Outstanding in this respect was the gene encoding the transcription factor WRKY2. The results suggest that unlocking plant genetic resources and integrating functional-genomic with genetic approaches can accelerate the discovery of genes underlying race-NR in barley and other crop plants. PMID:22629270

  3. The Genome of a Mongolian Individual Reveals the Genetic Imprints of Mongolians on Modern Human Populations

    PubMed Central

    Wu, Qizhu; Yin, Ye; Zhou, Huanmin

    2014-01-01

    Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]–1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians. PMID:25377941

  4. The genome of a Mongolian individual reveals the genetic imprints of Mongolians on modern human populations.

    PubMed

    Bai, Haihua; Guo, Xiaosen; Zhang, Dong; Narisu, Narisu; Bu, Junjie; Jirimutu, Jirimutu; Liang, Fan; Zhao, Xiang; Xing, Yanping; Wang, Dingzhu; Li, Tongda; Zhang, Yanru; Guan, Baozhu; Yang, Xukui; Yang, Zili; Shuangshan, Shuangshan; Su, Zhe; Wu, Huiguang; Li, Wenjing; Chen, Ming; Zhu, Shilin; Bayinnamula, Bayinnamula; Chang, Yuqi; Gao, Ying; Lan, Tianming; Suyalatu, Suyalatu; Huang, Hui; Su, Yan; Chen, Yujie; Li, Wenqi; Yang, Xu; Feng, Qiang; Wang, Jian; Yang, Huanming; Wang, Jun; Wu, Qizhu; Yin, Ye; Zhou, Huanmin

    2014-12-01

    Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]-1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians. PMID:25377941

  5. Genetic characterization of Toxoplasma gondii isolates from Portugal, Austria, and Israel reveals higher genetic variability within the type II lineage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compared genetic diversity of Toxoplasma gondii isolates from Portugal, Austria and Israel. For this, we genotyped 90 T. gondii isolates (16 from Portugal, 67 from Austria and 7 from Israel) using 10 nested PCR-restriction length polymorphism (RFLP) genetic markers and 15 microsatellite (...

  6. Genetic diversity and phylogenetic relationship in AA Oryza species as revealed by Rim2/Hipa CACTA transposon display.

    PubMed

    Kwon, Soon-Jae; Lee, Ju Kyong; Hong, Sung-Won; Park, Yong-Jin; McNally, Kenneth L; Kim, Nam-Soo

    2006-04-01

    CACTA is a class 2 transposon, that is very abundantly present in plant genomes. Using Rim2/Hipa CACTA transposon display (hereafter Rim2/Hipa-TD), we analyzed several A-genome diploid Oryza species that have a high distribution of the CACTA motifs. High levels of polymorphism were detected within and between the Oryza species. The African taxa, O. glaberrima and O. barthii, both showed lower levels of polymorphism than the Asian taxa, O. sativa, O. rufipogon, and O. nivara. However, O. longistaminata, another African taxon, showed levels of polymorphism that were similar to the Asian taxa. The Latin American taxon, O. glumaepatula, and the Australian taxon, O. meridionalis, exhibited intermediate levels of polymorphism between those of the Asian and African taxa. The lowest level of polymorphism was observed in O. glaberrima (32.1%) and the highest level of polymorphism was observed in O. rufipogon (95.7%). The phylogenetic tree revealed three major groups at the genetic similarity level of 0.409. The first group consisted of three Asian taxa, O. sativa, O. rufipogon and O. nivara. The second group consisted of three African taxa, O. glaberrima, O. barthii, O. longistaminata, and an American taxon, O. glumaepatula. The third group contained an Australian taxon, O. meridionalis. The clustering patterns of these species matched well with their geographical origins. Rim2/Hipa-TD appears to be a useful marker system for studying the genetic diversity and species relationships among the AA diploid Oryza species. PMID:16755133

  7. Genetic Aberrations in Childhood Acute Lymphoblastic Leukaemia: Application of High-Density Single Nucleotide Polymorphism Array

    PubMed Central

    Sulong, Sarina

    2010-01-01

    Screening of the entire human genome using high-density single nucleotide polymorphism array (SNPA) has become a powerful technique used in cancer genetics and population genetics studies. The GeneChip® Mapping Array, introduced by Affymetrix, is one SNPA platform utilised for genotyping studies. This GeneChip system allows researchers to gain a comprehensive view of cancer biology on a single platform for the quantification of chromosomal amplifications, deletions, and loss of heterozygosity or for allelic imbalance studies. Importantly, this array analysis has the potential to reveal novel genetic findings involved in the multistep development of cancer. Given the importance of genetic factors in leukaemogenesis and the usefulness of screening the whole genome, SNPA analysis has been utilised in many studies to characterise genetic aberrations in childhood acute lymphoblastic leukaemia. PMID:22135543

  8. Haploid Genetic Screen Reveals a Profound and Direct Dependence on Cholesterol for Hantavirus Membrane Fusion

    PubMed Central

    Kleinfelter, Lara M.; Jangra, Rohit K.; Jae, Lucas T.; Herbert, Andrew S.; Mittler, Eva; Stiles, Katie M.; Wirchnianski, Ariel S.; Kielian, Margaret; Brummelkamp, Thijn R.

    2015-01-01

    ABSTRACT Hantaviruses cause hemorrhagic fever with renal syndrome (HFRS) in the Old World and a highly fatal hantavirus cardiopulmonary syndrome (HCPS) in the New World. No vaccines or antiviral therapies are currently available to prevent or treat hantavirus disease, and gaps in our understanding of how hantaviruses enter cells challenge the search for therapeutics. We performed a haploid genetic screen in human cells to identify host factors required for entry by Andes virus, a highly virulent New World hantavirus. We found that multiple genes involved in cholesterol sensing, regulation, and biosynthesis, including key components of the sterol response element-binding protein (SREBP) pathway, are critical for Andes virus entry. Genetic or pharmacological disruption of the membrane-bound transcription factor peptidase/site-1 protease (MBTPS1/S1P), an SREBP control element, dramatically reduced infection by virulent hantaviruses of both the Old World and New World clades but not by rhabdoviruses or alphaviruses, indicating that this pathway is broadly, but selectively, required by hantaviruses. These results could be fully explained as arising from the modest depletion of cellular membrane cholesterol that accompanied S1P disruption. Mechanistic studies of cells and with protein-free liposomes suggested that high levels of cholesterol are specifically needed for hantavirus membrane fusion. Taken together, our results indicate that the profound dependence on target membrane cholesterol is a fundamental, and unusual, biophysical property of hantavirus glycoprotein-membrane interactions during entry. PMID:26126854

  9. A genetic relationship between nitrogen use efficiency and seedling root traits in maize as revealed by QTL analysis.

    PubMed

    Li, Pengcheng; Chen, Fanjun; Cai, Hongguang; Liu, Jianchao; Pan, Qingchun; Liu, Zhigang; Gu, Riliang; Mi, Guohua; Zhang, Fusuo; Yuan, Lixing

    2015-06-01

    That root system architecture (RSA) has an essential role in nitrogen acquisition is expected in maize, but the genetic relationship between RSA and nitrogen use efficiency (NUE) traits remains to be elucidated. Here, the genetic basis of RSA and NUE traits was investigated in maize using a recombination inbred line population that was derived from two lines contrasted for both traits. Under high-nitrogen and low-nitrogen conditions, 10 NUE- and 9 RSA-related traits were evaluated in four field environments and three hydroponic experiments, respectively. In contrast to nitrogen utilization efficiency (NutE), nitrogen uptake efficiency (NupE) had significant phenotypic correlations with RSA, particularly the traits of seminal roots (r = 0.15-0.31) and crown roots (r = 0.15-0.18). A total of 331 quantitative trait loci (QTLs) were detected, including 184 and 147 QTLs for NUE- and RSA-related traits, respectively. These QTLs were assigned into 64 distinct QTL clusters, and ~70% of QTLs for nitrogen-efficiency (NUE, NupE, and NutE) coincided in clusters with those for RSA. Five important QTLs clusters at the chromosomal regions bin1.04, 2.04, 3.04, 3.05/3.06, and 6.07/6.08 were found in which QTLs for both traits had favourable effects from alleles coming from the large-rooted and high-NupE parent. Introgression of these QTL clusters in the advanced backcross-derived lines conferred mean increases in grain yield of ~14.8% for the line per se and ~15.9% in the testcross. These results reveal a significant genetic relationship between RSA and NUE traits, and uncover the most promising genomic regions for marker-assisted selection of RSA to improve NUE in maize. PMID:25873660

  10. A genetic relationship between nitrogen use efficiency and seedling root traits in maize as revealed by QTL analysis

    PubMed Central

    Li, Pengcheng; Chen, Fanjun; Cai, Hongguang; Liu, Jianchao; Pan, Qingchun; Liu, Zhigang; Gu, Riliang; Mi, Guohua; Zhang, Fusuo; Yuan, Lixing

    2015-01-01

    That root system architecture (RSA) has an essential role in nitrogen acquisition is expected in maize, but the genetic relationship between RSA and nitrogen use efficiency (NUE) traits remains to be elucidated. Here, the genetic basis of RSA and NUE traits was investigated in maize using a recombination inbred line population that was derived from two lines contrasted for both traits. Under high-nitrogen and low-nitrogen conditions, 10 NUE- and 9 RSA-related traits were evaluated in four field environments and three hydroponic experiments, respectively. In contrast to nitrogen utilization efficiency (NutE), nitrogen uptake efficiency (NupE) had significant phenotypic correlations with RSA, particularly the traits of seminal roots (r = 0.15–0.31) and crown roots (r = 0.15–0.18). A total of 331 quantitative trait loci (QTLs) were detected, including 184 and 147 QTLs for NUE- and RSA-related traits, respectively. These QTLs were assigned into 64 distinct QTL clusters, and ~70% of QTLs for nitrogen-efficiency (NUE, NupE, and NutE) coincided in clusters with those for RSA. Five important QTLs clusters at the chromosomal regions bin1.04, 2.04, 3.04, 3.05/3.06, and 6.07/6.08 were found in which QTLs for both traits had favourable effects from alleles coming from the large-rooted and high-NupE parent. Introgression of these QTL clusters in the advanced backcross-derived lines conferred mean increases in grain yield of ~14.8% for the line per se and ~15.9% in the testcross. These results reveal a significant genetic relationship between RSA and NUE traits, and uncover the most promising genomic regions for marker-assisted selection of RSA to improve NUE in maize. PMID:25873660

  11. A Chemical Genetics Approach Reveals H,K-ATPase-Mediated Membrane Voltage is Required for Planarian Head Regeneration

    PubMed Central

    Beane, Wendy Scott; Morokuma, Junji; Adams, Dany Spencer; Levin, Michael

    2012-01-01

    SUMMARY Biophysical signaling is required for both embryonic polarity and regenerative outgrowth. Exploiting endogenous ion transport for regenerative therapies will require direct regulation of membrane voltage. Here, we develop a pharmacological method to target ion transporters, uncovering a novel role for membrane voltage as a key regulator of anterior polarity in regenerating planaria. Utilizing the highly specific inhibitor, SCH-28080, our data reveal that H+,K+-ATPase-mediated membrane depolarization is essential for anterior gene expression and brain induction. H+,K+-ATPase-independent manipulation of membrane potential with ivermectin confirms that depolarization drives head formation, even at posterior-facing wounds. Using this chemical genetics approach, we demonstrate that membrane voltage controls head-vs.-tail identity during planarian regeneration. Our data suggest well-characterized drugs (already approved for human use) might be exploited to control adult stem cell-driven pattern formation during the regeneration of complex structures. PMID:21276941

  12. Genetic divergence in wild population of endangered yellowtail catfish Pangasius pangasius (Hamilton-Buchanan, 1822) revealed by mtDNA.

    PubMed

    Mohindra, Vindhya; Singh, Rajeev K; Kumar, Rajesh; Sah, R S; Lal, Kuldeep K

    2015-04-01

    Pangasius pangasius, an endangered freshwater fish species, is an important component of capture fishery from Indian rivers. Samples collected through commercial catches from three riverine populations were analyzed with cytb (307 bp) and ATPase6&8 (842 bp) regions for population variation and differentiation. The sequences of the both the mitochondrial regions revealed high haplotype and low nucleotide diversity. Shallow genetic diversity based on ATPase6&8 was observed, however its haplotypes network clearly indicated two distinct mitochondrial lineages. Mismatch distribution suggested population bottlenecks followed by expansion in Mahanadi population. The present study indicated the ATPase6&8 to be a potential mitochondrial marker for studying the population sub-structuring in the wild population of P. pangasius. PMID:24409876

  13. Multilocus Sequence Typing of Genital Chlamydia trachomatis in Norway Reveals Multiple New Sequence Types and a Large Genetic Diversity

    PubMed Central

    Gravningen, Kirsten; Christerson, Linus; Furberg, Anne-Sofie; Simonsen, Gunnar Skov; Ödman, Kristina; Ståhlsten, Anna; Herrmann, Björn

    2012-01-01

    Background The Chlamydia trachomatis incidence rate in Finnmark, the most northern and sparsely populated county in Norway, has been twice the national average. This population based cross-sectional study among Finnmark high school students had the following aims: i) to examine distribution of multilocus sequence types (STs) of C. trachomatis in a previously unmapped area, ii) to compare chlamydia genetic diversity in Finnmark with that of two urban regions, and iii) to compare discriminatory capacity of multilocus sequence typing (MLST) with conventional ompA sequencing in a large number of chlamydia specimens. Methodology ompA sequencing and a high-resolution MLST system based on PCR amplification and DNA sequencing of five highly variable genetic regions were used. Eighty chlamydia specimens from adolescents aged 15–20 years in Finnmark were collected in five high schools (n = 60) and from routine clinical samples in the laboratory (n = 20). These were compared to routine clinical samples from adolescents in Tromsø (n = 80) and Trondheim (n = 88), capitals of North and Central Norway, respectively. Principal Findings ompA sequencing detected 11 genotypes in 248 specimens from all three areas. MLST displayed 50 STs providing a five-fold higher resolution. Two-thirds of all STs were novel. The common ompA E/Bour genotype comprised 46% and resolved into 24 different STs. MLST identified the Swedish new variant of C. trachomatis not discriminated by ompA sequencing. Simpson's discriminatory index (D) was 0.93 for MLST, while a corrected Dc was 0.97. There were no statistically significant differences in ST genetic diversity between geographic areas. Finnmark had an atypical genovar distribution with G being predominant. This was mainly due to expansion of specific STs of which the novel ST161 was unique for Finnmark. Conclusions/Significance MLST revealed multiple new STs and a larger genetic diversity in comparison to ompA sequencing and proved

  14. Genetic integrity of somaclonal variants in tea (Camellia sinensis (L.) O Kuntze) as revealed by inter simple sequence repeats.

    PubMed

    Thomas, Jibu; Vijayan, Deepu; Joshi, Sarvottam D; Joseph Lopez, S; Raj Kumar, R

    2006-05-17

    Adoption of inter simple sequence repeats (ISSR) technique to analyze the genetic variability of somatic embryo derived tea plants was evaluated. Morphological characterisation of the field grown plants revealed no identical character aligning with the parent, UPASI-10. Out of 40 primers, 15 exhibited concurrent polymorphism were selected for the study. Genetic variability of somaclones derived from single line cotyledonary culture ranged from 33.0 to 55.0%. A unique fragment of 1.2Kb was visible in majority of the accessions whereas the fragments below the length of 0.6Kb were noticed only in 50% of the variants. Out of 120 interactions attempted using Pearson's coefficient correlation, only 9.2% of somaclones exhibited significant similarity at genetic level. Dendrogram constructed based on simple matching coefficient revealed a distance of 2.257-3.317 between the final clusters. This strengthens the existence of wide genetic variation among the somaclones. PMID:16360228

  15. Population variation revealed high-altitude adaptation of Tibetan mastiffs.

    PubMed

    Li, Yan; Wu, Dong-Dong; Boyko, Adam R; Wang, Guo-Dong; Wu, Shi-Fang; Irwin, David M; Zhang, Ya-Ping

    2014-05-01

    With the assistance of their human companions, dogs have dispersed into new environments during the expansion of human civilization. Tibetan Mastiff (TM), a native of the Tibetan Plateau, was derived from the domesticated Chinese native dog and, like Tibetans, has adapted to the extreme environment of high altitude. Here, we genotyped genome-wide single-nucleotide polymorphisms (SNPs) from 32 TMs and compared them with SNPs from 20 Chinese native dogs and 14 gray wolves (Canis lupus). We identified 16 genes with signals of positive selection in the TM, with 12 of these candidate genes associated with functions that have roles in adaptation to high-altitude adaptation, such as EPAS1, SIRT7, PLXNA4, and MAFG that have roles in responses to hypoxia. This study provides important information on the genetic diversity of the TM and potential mechanisms for adaptation to hypoxia. PMID:24520091

  16. Mammalian Reverse Genetics without Crossing Reveals Nr3a as a Short-Sleeper Gene.

    PubMed

    Sunagawa, Genshiro A; Sumiyama, Kenta; Ukai-Tadenuma, Maki; Perrin, Dimitri; Fujishima, Hiroshi; Ukai, Hideki; Nishimura, Osamu; Shi, Shoi; Ohno, Rei-ichiro; Narumi, Ryohei; Shimizu, Yoshihiro; Tone, Daisuke; Ode, Koji L; Kuraku, Shigehiro; Ueda, Hiroki R

    2016-01-26

    The identification of molecular networks at the system level in mammals is accelerated by next-generation mammalian genetics without crossing, which requires both the efficient production of whole-body biallelic knockout (KO) mice in a single generation and high-performance phenotype analyses. Here, we show that the triple targeting of a single gene using the CRISPR/Cas9 system achieves almost perfect KO efficiency (96%-100%). In addition, we developed a respiration-based fully automated non-invasive sleep phenotyping system, the Snappy Sleep Stager (SSS), for high-performance (95.3% accuracy) sleep/wake staging. Using the triple-target CRISPR and SSS in tandem, we reliably obtained sleep/wake phenotypes, even in double-KO mice. By using this system to comprehensively analyze all of the N-methyl-D-aspartate (NMDA) receptor family members, we found Nr3a as a short-sleeper gene, which is verified by an independent set of triple-target CRISPR. These results demonstrate the application of mammalian reverse genetics without crossing to organism-level systems biology in sleep research. PMID:26774482

  17. Genetic Structure of the Han Chinese Population Revealed by Genome-wide SNP Variation

    PubMed Central

    Chen, Jieming; Zheng, Houfeng; Bei, Jin-Xin; Sun, Liangdan; Jia, Wei-hua; Li, Tao; Zhang, Furen; Seielstad, Mark; Zeng, Yi-Xin; Zhang, Xuejun; Liu, Jianjun

    2009-01-01

    Population stratification is a potential problem for genome-wide association studies (GWAS), confounding results and causing spurious associations. Hence, understanding how allele frequencies vary across geographic regions or among subpopulations is an important prelude to analyzing GWAS data. Using over 350,000 genome-wide autosomal SNPs in over 6000 Han Chinese samples from ten provinces of China, our study revealed a one-dimensional “north-south” population structure and a close correlation between geography and the genetic structure of the Han Chinese. The north-south population structure is consistent with the historical migration pattern of the Han Chinese population. Metropolitan cities in China were, however, more diffused “outliers,” probably because of the impact of modern migration of peoples. At a very local scale within the Guangdong province, we observed evidence of population structure among dialect groups, probably on account of endogamy within these dialects. Via simulation, we show that empirical levels of population structure observed across modern China can cause spurious associations in GWAS if not properly handled. In the Han Chinese, geographic matching is a good proxy for genetic matching, particularly in validation and candidate-gene studies in which population stratification cannot be directly accessed and accounted for because of the lack of genome-wide data, with the exception of the metropolitan cities, where geographical location is no longer a good indicator of ancestral origin. Our findings are important for designing GWAS in the Chinese population, an activity that is expected to intensify greatly in the near future. PMID:19944401

  18. High volume molecular genetic identification of single nucleotide polymorphisms using Genetic Bit Analysis Application to human genetic diagnosis

    SciTech Connect

    Boyce-Jacino, M.T.; Reynolds, J.; Nikiforov, T.

    1994-09-01

    The most common type of genetic disease-associated mutation is the single nucleotide polymorphism (SNP). Because most genetic diseases can be caused by multiple SNPs in the same gene, effective routine diagnosis of complex genetic diseases is dependent on a simple and reliable method of interrogating SNP sites. Molecular Tool`s solid phase assay capable of direct genotyping (single base sequencing) of SNP sites, Genetic Bit Analysis (GBA), involves hybridization-capture of a single-stranded PCR product to a sequence-specific, microtiter plate-bound oligonucleotide primer. The captured PCR product then acts as template for single-base extension of the capture primer across the polymorphic site, enabling direct determination of the base composition of the polymorphism through a simple colormetric assay. Genotyping in a high volume, semi-automated, processing system with a current capacity of 100 SNP interrogations per technician per day enables the screening of candidate mutations rapidly and cost-effectively, critically important to comprehensive genetic diagnosis. Using this gel-free technology, we have developed prototype diagnostic tests for CFTR and ApoE polymorphisms which enable direct sequencing of the polymorphic base at each site of interest. Routine clinical diagnosis of genetically complex diseases such as cystic fibrosis is dependent on this combination of robust biochemistry and simple format. Additionally, the ability to transfer the format and biochemistry to any disease gene of interest enables the broad application of this technology to clinical diagnostics, especially for genetically complex diseases.

  19. Systems Genetics Analysis of GWAS reveals Novel Associations between Key Biological Processes and Coronary Artery Disease

    PubMed Central

    Ghosh, Sujoy; Vivar, Juan; Nelson, Christopher P; Willenborg, Christina; Segrè, Ayellet V; Mäkinen, Ville-Petteri; Nikpay, Majid; Erdmann, Jeannette; Blankenberg, Stefan; O'Donnell, Christopher; März, Winfried; Laaksonen, Reijo; Stewart, Alexandre FR; Epstein, Stephen E; Shah, Svati H; Granger, Christopher B; Hazen, Stanley L; Kathiresan, Sekar; Reilly, Muredach P; Yang, Xia; Quertermous, Thomas; Samani, Nilesh J; Schunkert, Heribert; Assimes, Themistocles L; McPherson, Ruth

    2016-01-01

    Objective Genome-wide association (GWA) studies have identified multiple genetic variants affecting the risk of coronary artery disease (CAD). However, individually these explain only a small fraction of the heritability of CAD and for most, the causal biological mechanisms remain unclear. We sought to obtain further insights into potential causal processes of CAD by integrating large-scale GWA data with expertly curated databases of core human pathways and functional networks. Approaches and Results Employing pathways (gene sets) from Reactome, we carried out a two-stage gene set enrichment analysis strategy. From a meta-analyzed discovery cohort of 7 CADGWAS data sets (9,889 cases/11,089 controls), nominally significant gene-sets were tested for replication in a meta-analysis of 9 additional studies (15,502 cases/55,730 controls) from the CARDIoGRAM Consortium. A total of 32 of 639 Reactome pathways tested showed convincing association with CAD (replication p<0.05). These pathways resided in 9 of 21 core biological processes represented in Reactome, and included pathways relevant to extracellular matrix integrity, innate immunity, axon guidance, and signaling by PDRF, NOTCH, and the TGF-β/SMAD receptor complex. Many of these pathways had strengths of association comparable to those observed in lipid transport pathways. Network analysis of unique genes within the replicated pathways further revealed several interconnected functional and topologically interacting modules representing novel associations (e.g. semaphorin regulated axonal guidance pathway) besides confirming known processes (lipid metabolism). The connectivity in the observed networks was statistically significant compared to random networks (p<0.001). Network centrality analysis (‘degree’ and ‘betweenness’) further identified genes (e.g. NCAM1, FYN, FURIN etc.) likely to play critical roles in the maintenance and functioning of several of the replicated pathways. Conclusions These findings

  20. Characterisation of worldwide Helicobacter pylori strains reveals genetic conservation and essentiality of serine protease HtrA.

    PubMed

    Tegtmeyer, Nicole; Moodley, Yoshan; Yamaoka, Yoshio; Pernitzsch, Sandy Ramona; Schmidt, Vanessa; Traverso, Francisco Rivas; Schmidt, Thomas P; Rad, Roland; Yeoh, Khay Guan; Bow, Ho; Torres, Javier; Gerhard, Markus; Schneider, Gisbert; Wessler, Silja; Backert, Steffen

    2016-03-01

    HtrA proteases and chaperones exhibit important roles in periplasmic protein quality control and stress responses. The genetic inactivation of htrA has been described for many bacterial pathogens. However, in some cases such as the gastric pathogen Helicobacter pylori, HtrA is secreted where it cleaves the tumour-suppressor E-cadherin interfering with gastric disease development, but the generation of htrA mutants is still lacking. Here, we show that the htrA gene locus is highly conserved in worldwide strains. HtrA presence was confirmed in 992 H. pylori isolates in gastric biopsy material from infected patients. Differential RNA-sequencing (dRNA-seq) indicated that htrA is encoded in an operon with two subsequent genes, HP1020 and HP1021. Genetic mutagenesis and complementation studies revealed that HP1020 and HP1021, but not htrA, can be mutated. In addition, we demonstrate that suppression of HtrA proteolytic activity with a newly developed inhibitor is sufficient to effectively kill H. pylori, but not other bacteria. We show that Helicobacter htrA is an essential bifunctional gene with crucial intracellular and extracellular functions. Thus, we describe here the first microbe in which htrA is an indispensable gene, a situation unique in the bacterial kingdom. HtrA can therefore be considered a promising new target for anti-bacterial therapy. PMID:26568477

  1. Characterisation of worldwide Helicobacter pylori strains reveals genetic conservation and essentiality of serine protease HtrA

    PubMed Central

    Tegtmeyer, Nicole; Moodley, Yoshan; Yamaoka, Yoshio; Pernitzsch, Sandy Ramona; Schmidt, Vanessa; Traverso, Francisco Rivas; Schmidt, Thomas P.; Rad, Roland; Yeoh, Khay Guan; Bow, Ho; Torres, Javier; Gerhard, Markus; Schneider, Gisbert; Wessler, Silja

    2015-01-01

    Summary HtrA proteases and chaperones exhibit important roles in periplasmic protein quality control and stress responses. The genetic inactivation of htrA has been described for many bacterial pathogens. However, in some cases such as the gastric pathogen H elicobacter pylori, HtrA is secreted where it cleaves the tumour‐suppressor E‐cadherin interfering with gastric disease development, but the generation of htrA mutants is still lacking. Here, we show that the htrA gene locus is highly conserved in worldwide strains. HtrA presence was confirmed in 992 H . pylori isolates in gastric biopsy material from infected patients. Differential RNA‐sequencing (dRNA‐seq) indicated that htrA is encoded in an operon with two subsequent genes, HP1020 and HP1021. Genetic mutagenesis and complementation studies revealed that HP1020 and HP1021, but not htrA, can be mutated. In addition, we demonstrate that suppression of HtrA proteolytic activity with a newly developed inhibitor is sufficient to effectively kill H . pylori, but not other bacteria. We show that H elicobacter  htrA is an essential bifunctional gene with crucial intracellular and extracellular functions. Thus, we describe here the first microbe in which htrA is an indispensable gene, a situation unique in the bacterial kingdom. HtrA can therefore be considered a promising new target for anti‐bacterial therapy. PMID:26568477

  2. Runs of homozygosity reveal highly penetrant recessive loci in schizophrenia

    PubMed Central

    Lencz, Todd; Lambert, Christophe; DeRosse, Pamela; Burdick, Katherine E.; Morgan, T. Vance; Kane, John M.; Kucherlapati, Raju; Malhotra, Anil K.

    2007-01-01

    Evolutionarily significant selective sweeps may result in long stretches of homozygous polymorphisms in individuals from outbred populations. We developed whole-genome homozygosity association (WGHA) methodology to characterize this phenomenon in healthy individuals and to use this genomic feature to identify genetic risk loci for schizophrenia (SCZ). Applying WGHA to 178 SCZ cases and 144 healthy controls genotyped at 500,000 markers, we found that runs of homozygosity (ROHs), ranging in size from 200 kb to 15 mb, were common in unrelated Caucasians. Properties of common ROHs in healthy subjects, including chromosomal location and presence of nonancestral haplotypes, converged with prior reports identifying regions under selective pressure. This interpretation was further supported by analysis of multiethnic HapMap samples genotyped with the same markers. ROHs were significantly more common in SCZ cases, and a set of nine ROHs significantly differentiated cases from controls. Four of these 9 “risk ROHs” contained or neighbored genes associated with SCZ (NOS1AP, ATF2, NSF, and PIK3C3). Several of these risk ROHs were very rare in healthy subjects, suggesting that recessive effects of relatively high penetrance may explain a proportion of the genetic liability for SCZ. Other risk ROHs feature haplotypes that are also common in healthy individuals, possibly indicating a source of balancing selection. PMID:18077426

  3. High genetic variability and polychromatism in Pachycoris torridus (Heteroptera: Scutelleridae).

    PubMed

    Souza-Firmino, T S; Alevi, K C C; Pereira, L L V; Souza, E R S; Júnior, F C S; Banho, C A; Carmo, G O; Itoyama, M M

    2015-01-01

    The stink bug Pachycoris torridus is listed among the most polyphagous insects in the world and it is a major pest of diverse crops, in particular the physic nut Jatropha curcas, which is used as a raw material for biodiesel production. A peculiar characteristic of this species is its high phenotypic variability, a characteristic that makes identification difficult: P. torridus has been described as a new species eight times. Thus, to aid in identification, genetic characterization of this insect was performed. We verified that, due to the high genetic variability of P. torridus, several genetic patterns exist that result in the same phenotype. PMID:26600488

  4. Multivariate analysis reveals genetic associations of the resting default mode network in psychotic bipolar disorder and schizophrenia

    PubMed Central

    Meda, Shashwath A.; Ruaño, Gualberto; Windemuth, Andreas; O’Neil, Kasey; Berwise, Clifton; Dunn, Sabra M.; Boccaccio, Leah E.; Narayanan, Balaji; Kocherla, Mohan; Sprooten, Emma; Keshavan, Matcheri S.; Tamminga, Carol A.; Sweeney, John A.; Clementz, Brett A.; Calhoun, Vince D.; Pearlson, Godfrey D.

    2014-01-01

    The brain’s default mode network (DMN) is highly heritable and is compromised in a variety of psychiatric disorders. However, genetic control over the DMN in schizophrenia (SZ) and psychotic bipolar disorder (PBP) is largely unknown. Study subjects (n = 1,305) underwent a resting-state functional MRI scan and were analyzed by a two-stage approach. The initial analysis used independent component analysis (ICA) in 324 healthy controls, 296 SZ probands, 300 PBP probands, 179 unaffected first-degree relatives of SZ probands (SZREL), and 206 unaffected first-degree relatives of PBP probands to identify DMNs and to test their biomarker and/or endophenotype status. A subset of controls and probands (n = 549) then was subjected to a parallel ICA (para-ICA) to identify imaging–genetic relationships. ICA identified three DMNs. Hypo-connectivity was observed in both patient groups in all DMNs. Similar patterns observed in SZREL were restricted to only one network. DMN connectivity also correlated with several symptom measures. Para-ICA identified five sub-DMNs that were significantly associated with five different genetic networks. Several top-ranking SNPs across these networks belonged to previously identified, well-known psychosis/mood disorder genes. Global enrichment analyses revealed processes including NMDA-related long-term potentiation, PKA, immune response signaling, axon guidance, and synaptogenesis that significantly influenced DMN modulation in psychoses. In summary, we observed both unique and shared impairments in functional connectivity across the SZ and PBP cohorts; these impairments were selectively familial only for SZREL. Genes regulating specific neurodevelopment/transmission processes primarily mediated DMN disconnectivity. The study thus identifies biological pathways related to a widely researched quantitative trait that might suggest novel, targeted drug treatments for these diseases. PMID:24778245

  5. Molecular and iridescent feather reflectance data reveal recent genetic diversification and phenotypic differentiation in a cloud forest hummingbird.

    PubMed

    Ornelas, Juan Francisco; González, Clementina; Hernández-Baños, Blanca E; García-Moreno, Jaime

    2016-02-01

    The present day distribution and spatial genetic diversity of Mesoamerican biota reflects a long history of responses to habitat change. The hummingbird Lampornis amethystinus is distributed in northern Mesoamerica, with geographically disjunct populations. Based on sampling across the species range using mitochondrial DNA (mtDNA) sequences and nuclear microsatellites jointly analysed with phenotypic and climatic data, we (1) test whether the fragmented distribution is correlated with main evolutionary lineages, (2) assess body size and plumage color differentiation of populations in geographic isolation, and (3) evaluate a set of divergence scenarios and demographic patterns of the hummingbird populations. Analysis of genetic variation revealed four main groups: blue-throated populations (Sierra Madre del Sur); two groups of amethyst-throated populations (Trans-Mexican Volcanic Belt and Sierra Madre Oriental); and populations east of the Isthmus of Tehuantepec (IT) with males showing an amethyst throat. The most basal split is estimated to have originated in the Pleistocene, 2.39-0.57 million years ago (MYA), and corresponded to groups of populations separated by the IT. However, the estimated recent divergence time between blue- and amethyst-throated populations does not correspond to the 2-MY needed to be in isolation for substantial plumage divergence, likely because structurally iridescent colors are more malleable than others. Results of species distribution modeling and Approximate Bayesian Computation analysis fit a model of lineage divergence west of the Isthmus after the Last Glacial Maximum (LGM), and that the species' suitable habitat was disjunct during past and current conditions. These results challenge the generality of the contraction/expansion glacial model to cloud forest-interior species and urges management of cloud forest, a highly vulnerable ecosystem to climate change and currently facing destruction, to prevent further loss of genetic

  6. Phylogenetic Studies of the Three RNA Silencing Suppressor Genes of South American CTV Isolates Reveal the Circulation of a Novel Genetic Lineage.

    PubMed

    Benítez-Galeano, María José; Rubio, Leticia; Bertalmío, Ana; Maeso, Diego; Rivas, Fernando; Colina, Rodney

    2015-07-01

    Citrus Tristeza Virus (CTV) is the most economically important virus of citrus worldwide. Genetic diversity and population structure of CTV isolates from all citrus growing areas from Uruguay were analyzed by RT-PCR and cloning of the three RNA silencing suppressor genes (p25, p20 and p23). Bayesian phylogenetic analysis revealed the circulation of three known genotypes (VT, T3, T36) in the country, and the presence of a new genetic lineage composed by isolates from around the world, mainly from South America. Nucleotide and amino acid identity values for this new genetic lineage were both higher than 97% for the three analyzed regions. Due to incongruent phylogenetic relationships, recombination analysis was performed using Genetic Algorithms for Recombination Detection (GARD) and SimPlot software. Recombination events between previously described CTV isolates were detected. High intra-sample variation was found, confirming the co-existence of different genotypes into the same plant. This is the first report describing: (1) the genetic diversity of Uruguayan CTV isolates circulating in the country and (2) the circulation of a novel CTV genetic lineage, highly present in the South American region. This information may provide assistance to develop an effective cross-protection program. PMID:26205407

  7. Phylogenetic Studies of the Three RNA Silencing Suppressor Genes of South American CTV Isolates Reveal the Circulation of a Novel Genetic Lineage

    PubMed Central

    Benítez-Galeano, María José; Rubio, Leticia; Bertalmío, Ana; Maeso, Diego; Rivas, Fernando; Colina, Rodney

    2015-01-01

    Citrus Tristeza Virus (CTV) is the most economically important virus of citrus worldwide. Genetic diversity and population structure of CTV isolates from all citrus growing areas from Uruguay were analyzed by RT-PCR and cloning of the three RNA silencing suppressor genes (p25, p20 and p23). Bayesian phylogenetic analysis revealed the circulation of three known genotypes (VT, T3, T36) in the country, and the presence of a new genetic lineage composed by isolates from around the world, mainly from South America. Nucleotide and amino acid identity values for this new genetic lineage were both higher than 97% for the three analyzed regions. Due to incongruent phylogenetic relationships, recombination analysis was performed using Genetic Algorithms for Recombination Detection (GARD) and SimPlot software. Recombination events between previously described CTV isolates were detected. High intra-sample variation was found, confirming the co-existence of different genotypes into the same plant. This is the first report describing: (1) the genetic diversity of Uruguayan CTV isolates circulating in the country and (2) the circulation of a novel CTV genetic lineage, highly present in the South American region. This information may provide assistance to develop an effective cross-protection program. PMID:26205407

  8. Population genetic analysis reveals cryptic sex in the phytopathogenic fungus Alternaria alternata

    PubMed Central

    Meng, Jing-Wen; Zhu, Wen; He, Meng-Han; Wu, E-Jiao; Duan, Guo-Hua; Xie, Ye-Kun; Jin, Yu-Jia; Yang, Li-Na; Shang, Li-Ping; Zhan, Jiasui

    2015-01-01

    Reproductive mode can impact population genetic dynamics and evolutionary landscape of plant pathogens as well as on disease epidemiology and management. In this study, we monitored the spatial dynamics and mating type idiomorphs in ~700 Alternaria alternata isolates sampled from the main potato production areas in China to infer the mating system of potato early blight. Consistent with the expectation of asexual species, identical genotypes were recovered from different locations separated by hundreds of kilometers of geographic distance and spanned across many years. However, high genotype diversity, equal MAT1-1 and MAT1-2 frequencies within and among populations, no genetic differentiation and phylogenetic association between two mating types, combined with random association amongst neutral markers in some field populations, suggested that sexual reproduction may also play an important role in the epidemics and evolution of the pathogen in at least half of the populations assayed despite the fact that no teleomorphs have been observed yet naturally or artificially. Our results indicated that A. alternata may adopt an epidemic mode of reproduction by combining many cycles of asexual propagation with fewer cycles of sexual reproduction, facilitating its adaptation to changing environments and making the disease management on potato fields even more difficult. PMID:26666175

  9. Population genetic analysis reveals cryptic sex in the phytopathogenic fungus Alternaria alternata.

    PubMed

    Meng, Jing-Wen; Zhu, Wen; He, Meng-Han; Wu, E-Jiao; Duan, Guo-Hua; Xie, Ye-Kun; Jin, Yu-Jia; Yang, Li-Na; Shang, Li-Ping; Zhan, Jiasui

    2015-01-01

    Reproductive mode can impact population genetic dynamics and evolutionary landscape of plant pathogens as well as on disease epidemiology and management. In this study, we monitored the spatial dynamics and mating type idiomorphs in ~700 Alternaria alternata isolates sampled from the main potato production areas in China to infer the mating system of potato early blight. Consistent with the expectation of asexual species, identical genotypes were recovered from different locations separated by hundreds of kilometers of geographic distance and spanned across many years. However, high genotype diversity, equal MAT1-1 and MAT1-2 frequencies within and among populations, no genetic differentiation and phylogenetic association between two mating types, combined with random association amongst neutral markers in some field populations, suggested that sexual reproduction may also play an important role in the epidemics and evolution of the pathogen in at least half of the populations assayed despite the fact that no teleomorphs have been observed yet naturally or artificially. Our results indicated that A. alternata may adopt an epidemic mode of reproduction by combining many cycles of asexual propagation with fewer cycles of sexual reproduction, facilitating its adaptation to changing environments and making the disease management on potato fields even more difficult. PMID:26666175

  10. A forward genetic screen reveals that calcium-dependent protein kinase 3 regulates egress in Toxoplasma.

    PubMed

    Garrison, Erin; Treeck, Moritz; Ehret, Emma; Butz, Heidi; Garbuz, Tamila; Oswald, Benji P; Settles, Matt; Boothroyd, John; Arrizabalaga, Gustavo

    2012-01-01

    Egress from the host cell is a crucial and highly regulated step in the biology of the obligate intracellular parasite, Toxoplasma gondii. Active egress depends on calcium fluxes and appears to be a crucial step in escaping the attack from the immune system and, potentially, in enabling the parasites to shuttle into appropriate cells for entry into the brain of the host. Previous genetic screens have yielded mutants defective in both ionophore-induced egress and ionophore-induced death. Using whole genome sequencing of one mutant and subsequent analysis of all mutants from these screens, we find that, remarkably, four independent mutants harbor a mis-sense mutation in the same gene, TgCDPK3, encoding a calcium-dependent protein kinase. All four mutations are predicted to alter key regions of TgCDPK3 and this is confirmed by biochemical studies of recombinant forms of each. By complementation we confirm a crucial role for TgCDPK3 in the rapid induction of parasite egress and we establish that TgCDPK3 is critical for formation of latent stages in the brains of mice. Genetic knockout of TgCDPK3 confirms a crucial role for this kinase in parasite egress and a non-essential role for it in the lytic cycle. PMID:23209419

  11. The genetic landscape of Ceratocystis albifundus populations in South Africa reveals a recent fungal introduction event.

    PubMed

    Lee, Dong-Hyeon; Roux, Jolanda; Wingfield, Brenda D; Barnes, Irene; Mostert, Lizel; Wingfield, Michael J

    2016-05-01

    Geographical range expansion or host shifts is amongst the various evolutionary forces that underlie numerous emerging diseases caused by fungal pathogens. In this regard, Ceratocystis albifundus, the causal agent of a serious wilt disease of Acacia mearnsii trees in Africa, was recently identified killing cultivated Protea cynaroides in the Western Cape (WC) Province of South Africa. Protea cynaroides is an important native plant in the area and a key component of the Cape Floristic Region. The appearance of this new disease outbreak, together with isolates of C. albifundus from natural ecosystems as well as plantations of nonnative trees, provided an opportunity to consider questions relating to the possible origin and movement of the pathogen in South Africa. Ten microsatellite markers were used to determine the genetic diversity, population structure, and possible gene flow in a collection of 193 C. albifundus isolates. All populations, other than those from the WC, showed high levels of genetic diversity. An intermediate level of gene flow was found amongst populations of the pathogen. The results suggest that a limited number of individuals have recently been introduced into the WC, resulting in a novel disease problem in the area. PMID:27109366

  12. Genetics Reveal the Origin and Timing of a Cryptic Insular Introduction of Muskrats in North America

    PubMed Central

    Mychajliw, Alexis M.; Harrison, Richard G.

    2014-01-01

    The muskrat, Ondatra zibethicus, is a semiaquatic rodent native to North America that has become a highly successful invader across Europe, Asia, and South America. It can inflict ecological and economic damage on wetland systems outside of its native range. Anecdotal evidence suggests that, in the early 1900s, a population of muskrats was introduced to the Isles of Shoals archipelago, located within the Gulf of Maine, for the purposes of fur harvest. However, because muskrats are native to the northeastern coast of North America, their presence on the Isles of Shoals could be interpreted as part of the native range of the species, potentially obscuring management planning and biogeographic inferences. To investigate their introduced status and identify a historic source population, muskrats from Appledore Island of the Isles of Shoals, and from the adjacent mainland of Maine and New Hampshire, were compared for mitochondrial cytochrome b sequences and allele frequencies at eight microsatellite loci. Appledore Island muskrats consistently exhibited reduced genetic diversity compared with mainland populations, and displayed signatures of a historic bottleneck. The distribution of mitochondrial haplotypes is suggestive of a New Hampshire source population. The data presented here are consistent with a human-mediated introduction that took place in the early 1900s. This scenario is further supported by the zooarchaeological record and island biogeographic patterns. This is the first genetic study of an introduced muskrat population within US borders and of any island muskrat population, and provides an important contrast with other studies of introduced muskrat populations worldwide. PMID:25360617

  13. Genetics reveal the origin and timing of a cryptic insular introduction of muskrats in North America.

    PubMed

    Mychajliw, Alexis M; Harrison, Richard G

    2014-01-01

    The muskrat, Ondatra zibethicus, is a semiaquatic rodent native to North America that has become a highly successful invader across Europe, Asia, and South America. It can inflict ecological and economic damage on wetland systems outside of its native range. Anecdotal evidence suggests that, in the early 1900s, a population of muskrats was introduced to the Isles of Shoals archipelago, located within the Gulf of Maine, for the purposes of fur harvest. However, because muskrats are native to the northeastern coast of North America, their presence on the Isles of Shoals could be interpreted as part of the native range of the species, potentially obscuring management planning and biogeographic inferences. To investigate their introduced status and identify a historic source population, muskrats from Appledore Island of the Isles of Shoals, and from the adjacent mainland of Maine and New Hampshire, were compared for mitochondrial cytochrome b sequences and allele frequencies at eight microsatellite loci. Appledore Island muskrats consistently exhibited reduced genetic diversity compared with mainland populations, and displayed signatures of a historic bottleneck. The distribution of mitochondrial haplotypes is suggestive of a New Hampshire source population. The data presented here are consistent with a human-mediated introduction that took place in the early 1900s. This scenario is further supported by the zooarchaeological record and island biogeographic patterns. This is the first genetic study of an introduced muskrat population within US borders and of any island muskrat population, and provides an important contrast with other studies of introduced muskrat populations worldwide. PMID:25360617

  14. Genetic engineering for high methionine grain legumes.

    PubMed

    Müntz, K; Christov, V; Saalbach, G; Saalbach, I; Waddell, D; Pickardt, T; Schieder, O; Wüstenhagen, T

    1998-08-01

    Methionine (Met) is the primary limiting essential amino acid in grain legumes. The imbalance in amino acid composition restricts their biological value (BV) to 55 to 75% of that of animal protein. So far improvement of the BV could not be achieved by conventional breeding. Therefore, genetic engineering was employed by several laboratories to resolve the problem. Three strategies have been followed. A) Engineering for increased free Met levels; B) engineering of endogenous storage proteins with increased numbers of Met residues; C) transfer of foreign genes encoding Met-rich proteins, e.g. the Brazil nut 2S albumin (BNA) and its homologue from sunflower, into grain legumes. The latter strategy turned out to be most promising. In all cases the gene was put under the control of a developmentally regulated seed specific promoter and transferred into grain legumes using the bacterial Agrobacterium tumefaciens-system. Integration into and copy numbers in the plant genome as well as Mendelian inheritance and gene dosage effects were verified. After correct precursor processing the mature 2S albumin was intracellularly deposited in protein bodies which are part of the vacuolar compartment. The foreign protein amounted to 5 to 10% of the total seed protein in the best transgenic lines of narbon bean (Vicia narbonensis L., used in the authors' laboratories), lupins (Lupinus angustifolius L., used in CSIRO, Australia), and soybean (Glycine max (L.) Merr., used by Pioneer Hi-Bred, Inc., USA). In the narbon bean the increase of Met was directly related to the amount of 2S albumin in the transgenic seeds, but in soybean it remained below the theoretically expected value. Nevertheless, trangenic soybean reached 100%, whereas narbon bean and lupins reached approximately 80% of the FAO-standard for nutritionally balanced food proteins. These results document that the Met problem of grain legumes can be resolved by genetic engineering. PMID:9739551

  15. Admixture and the organization of genetic diversity in a butterfly species complex revealed through common and rare genetic variants.

    PubMed

    Gompert, Zachariah; Lucas, Lauren K; Buerkle, C Alex; Forister, Matthew L; Fordyce, James A; Nice, Chris C

    2014-09-01

    Detailed information about the geographic distribution of genetic and genomic variation is necessary to better understand the organization and structure of biological diversity. In particular, spatial isolation within species and hybridization between them can blur species boundaries and create evolutionary relationships that are inconsistent with a strictly bifurcating tree model. Here, we analyse genome-wide DNA sequence and genetic ancestry variation in Lycaeides butterflies to quantify the effects of admixture and spatial isolation on how biological diversity is organized in this group. We document geographically widespread and pervasive historical admixture, with more restricted recent hybridization. This includes evidence supporting previously known and unknown instances of admixture. The genome composition of admixed individuals varies much more among than within populations, and tree- and genetic ancestry-based analyses indicate that multiple distinct admixed lineages or populations exist. We find that most genetic variants in Lycaeides are rare (minor allele frequency <0.5%). Because the spatial and taxonomic distributions of alleles reflect demographic and selective processes since mutation, rare alleles, which are presumably younger than common alleles, were spatially and taxonomically restricted compared with common variants. Thus, we show patterns of genetic variation in this group are multifaceted, and we argue that this complexity challenges simplistic notions concerning the organization of biological diversity into discrete, easily delineated and hierarchically structured entities. PMID:24866941

  16. Adaptation to High Ethanol Reveals Complex Evolutionary Pathways.

    PubMed

    Voordeckers, Karin; Kominek, Jacek; Das, Anupam; Espinosa-Cantú, Adriana; De Maeyer, Dries; Arslan, Ahmed; Van Pee, Michiel; van der Zande, Elisa; Meert, Wim; Yang, Yudi; Zhu, Bo; Marchal, Kathleen; DeLuna, Alexander; Van Noort, Vera; Jelier, Rob; Verstrepen, Kevin J

    2015-11-01

    Tolerance to high levels of ethanol is an ecologically and industrially relevant phenotype of microbes, but the molecular mechanisms underlying this complex trait remain largely unknown. Here, we use long-term experimental evolution of isogenic yeast populations of different initial ploidy to study adaptation to increasing levels of ethanol. Whole-genome sequencing of more than 30 evolved populations and over 100 adapted clones isolated throughout this two-year evolution experiment revealed how a complex interplay of de novo single nucleotide mutations, copy number variation, ploidy changes, mutator phenotypes, and clonal interference led to a significant increase in ethanol tolerance. Although the specific mutations differ between different evolved lineages, application of a novel computational pipeline, PheNetic, revealed that many mutations target functional modules involved in stress response, cell cycle regulation, DNA repair and respiration. Measuring the fitness effects of selected mutations introduced in non-evolved ethanol-sensitive cells revealed several adaptive mutations that had previously not been implicated in ethanol tolerance, including mutations in PRT1, VPS70 and MEX67. Interestingly, variation in VPS70 was recently identified as a QTL for ethanol tolerance in an industrial bio-ethanol strain. Taken together, our results show how, in contrast to adaptation to some other stresses, adaptation to a continuous complex and severe stress involves interplay of different evolutionary mechanisms. In addition, our study reveals functional modules involved in ethanol resistance and identifies several mutations that could help to improve the ethanol tolerance of industrial yeasts. PMID:26545090

  17. Adaptation to High Ethanol Reveals Complex Evolutionary Pathways

    PubMed Central

    Das, Anupam; Espinosa-Cantú, Adriana; De Maeyer, Dries; Arslan, Ahmed; Van Pee, Michiel; van der Zande, Elisa; Meert, Wim; Yang, Yudi; Zhu, Bo; Marchal, Kathleen; DeLuna, Alexander; Van Noort, Vera; Jelier, Rob; Verstrepen, Kevin J.

    2015-01-01

    Tolerance to high levels of ethanol is an ecologically and industrially relevant phenotype of microbes, but the molecular mechanisms underlying this complex trait remain largely unknown. Here, we use long-term experimental evolution of isogenic yeast populations of different initial ploidy to study adaptation to increasing levels of ethanol. Whole-genome sequencing of more than 30 evolved populations and over 100 adapted clones isolated throughout this two-year evolution experiment revealed how a complex interplay of de novo single nucleotide mutations, copy number variation, ploidy changes, mutator phenotypes, and clonal interference led to a significant increase in ethanol tolerance. Although the specific mutations differ between different evolved lineages, application of a novel computational pipeline, PheNetic, revealed that many mutations target functional modules involved in stress response, cell cycle regulation, DNA repair and respiration. Measuring the fitness effects of selected mutations introduced in non-evolved ethanol-sensitive cells revealed several adaptive mutations that had previously not been implicated in ethanol tolerance, including mutations in PRT1, VPS70 and MEX67. Interestingly, variation in VPS70 was recently identified as a QTL for ethanol tolerance in an industrial bio-ethanol strain. Taken together, our results show how, in contrast to adaptation to some other stresses, adaptation to a continuous complex and severe stress involves interplay of different evolutionary mechanisms. In addition, our study reveals functional modules involved in ethanol resistance and identifies several mutations that could help to improve the ethanol tolerance of industrial yeasts. PMID:26545090

  18. Distinct genetic lineages of Bactrocera caudata (Insecta: Tephritidae) revealed by COI and 16S DNA sequences.

    PubMed

    Lim, Phaik-Eem; Tan, Ji; Suana, I Wayan; Eamsobhana, Praphathip; Yong, Hoi Sen

    2012-01-01

    The fruit fly Bactrocera caudata is a pest species of economic importance in Asia. Its larvae feed on the flowers of Cucurbitaceae such as Cucurbita moschata. To-date it is distinguished from related species based on morphological characters. Specimens of B. caudata from Peninsular Malaysia and Indonesia (Bali and Lombok) were analysed using the partial DNA sequences of cytochrome c oxidase subunit I (COI) and 16S rRNA genes. Both gene sequences revealed that B. caudata from Peninsular Malaysia was distinctly different from B. caudata of Bali and Lombok, without common haplotype between them. Phylogenetic analysis revealed two distinct clades, indicating distinct genetic lineage. The uncorrected 'p' distance for COI sequences between B. caudata of Malaysia-Thailand-China and B. caudata of Bali-Lombok was 5.65%, for 16S sequences from 2.76 to 2.99%, and for combined COI and 16S sequences 4.45 to 4.46%. The 'p' values are distinctly different from intraspecific 'p' distance (0-0.23%). Both the B. caudata lineages are distinctly separated from related species in the subgenus Zeugodacus - B. ascita, B. scutellata, B. ishigakiensis, B. diaphora, B. tau, B. cucurbitae, and B. depressa. Molecular phylogenetic analysis indicates that the B. caudata lineages are closely related to B. ascita sp. B, and form a clade with B. scutellata, B. ishigakiensis, B. diaphora and B. ascita sp. A. This study provides additional baseline for the phylogenetic relationships of Bactrocera fruit flies of the subgenus Zeugodacus. Both the COI and 16S genes could be useful markers for the molecular differentiation and phylogenetic analysis of tephritid fruit flies. PMID:22615962

  19. Gene invasion in distant eukaryotic lineages: discovery of mutually exclusive genetic elements reveals marine biodiversity.

    PubMed

    Monier, Adam; Sudek, Sebastian; Fast, Naomi M; Worden, Alexandra Z

    2013-09-01

    Inteins are rare, translated genetic parasites mainly found in bacteria and archaea, while spliceosomal introns are distinctly eukaryotic features abundant in most nuclear genomes. Using targeted metagenomics, we discovered an intein in an Atlantic population of the photosynthetic eukaryote, Bathycoccus, harbored by the essential spliceosomal protein PRP8 (processing factor 8 protein). Although previously thought exclusive to fungi, we also identified PRP8 inteins in parasitic (Capsaspora) and predatory (Salpingoeca) protists. Most new PRP8 inteins were at novel insertion sites that, surprisingly, were not in the most conserved regions of the gene. Evolutionarily, Dikarya fungal inteins at PRP8 insertion site a appeared more related to the Bathycoccus intein at a unique insertion site, than to other fungal and opisthokont inteins. Strikingly, independent analyses of Pacific and Atlantic samples revealed an intron at the same codon as the Bathycoccus PRP8 intein. The two elements are mutually exclusive and neither was found in cultured Bathycoccus or other picoprasinophyte genomes. Thus, wild Bathycoccus contain one of few non-fungal eukaryotic inteins known and a rare polymorphic intron. Our data indicate at least two Bathycoccus ecotypes exist, associated respectively with oceanic or mesotrophic environments. We hypothesize that intein propagation is facilitated by marine viruses; and, while intron gain is still poorly understood, presence of a spliceosomal intron where a locus lacks an intein raises the possibility of new, intein-primed mechanisms for intron gain. The discovery of nucleus-encoded inteins and associated sequence polymorphisms in uncultivated marine eukaryotes highlights their diversity and reveals potential sexual boundaries between populations indistinguishable by common marker genes. PMID:23635865

  20. Gene invasion in distant eukaryotic lineages: discovery of mutually exclusive genetic elements reveals marine biodiversity

    PubMed Central

    Monier, Adam; Sudek, Sebastian; Fast, Naomi M; Worden, Alexandra Z

    2013-01-01

    Inteins are rare, translated genetic parasites mainly found in bacteria and archaea, while spliceosomal introns are distinctly eukaryotic features abundant in most nuclear genomes. Using targeted metagenomics, we discovered an intein in an Atlantic population of the photosynthetic eukaryote, Bathycoccus, harbored by the essential spliceosomal protein PRP8 (processing factor 8 protein). Although previously thought exclusive to fungi, we also identified PRP8 inteins in parasitic (Capsaspora) and predatory (Salpingoeca) protists. Most new PRP8 inteins were at novel insertion sites that, surprisingly, were not in the most conserved regions of the gene. Evolutionarily, Dikarya fungal inteins at PRP8 insertion site a appeared more related to the Bathycoccus intein at a unique insertion site, than to other fungal and opisthokont inteins. Strikingly, independent analyses of Pacific and Atlantic samples revealed an intron at the same codon as the Bathycoccus PRP8 intein. The two elements are mutually exclusive and neither was found in cultured Bathycoccus or other picoprasinophyte genomes. Thus, wild Bathycoccus contain one of few non-fungal eukaryotic inteins known and a rare polymorphic intron. Our data indicate at least two Bathycoccus ecotypes exist, associated respectively with oceanic or mesotrophic environments. We hypothesize that intein propagation is facilitated by marine viruses; and, while intron gain is still poorly understood, presence of a spliceosomal intron where a locus lacks an intein raises the possibility of new, intein-primed mechanisms for intron gain. The discovery of nucleus-encoded inteins and associated sequence polymorphisms in uncultivated marine eukaryotes highlights their diversity and reveals potential sexual boundaries between populations indistinguishable by common marker genes. PMID:23635865

  1. Distinct Genetic Lineages of Bactrocera caudata (Insecta: Tephritidae) Revealed by COI and 16S DNA Sequences

    PubMed Central

    Lim, Phaik-Eem; Tan, Ji; Suana, I. Wayan; Eamsobhana, Praphathip; Yong, Hoi Sen

    2012-01-01

    The fruit fly Bactrocera caudata is a pest species of economic importance in Asia. Its larvae feed on the flowers of Cucurbitaceae such as Cucurbita moschata. To-date it is distinguished from related species based on morphological characters. Specimens of B. caudata from Peninsular Malaysia and Indonesia (Bali and Lombok) were analysed using the partial DNA sequences of cytochrome c oxidase subunit I (COI) and 16S rRNA genes. Both gene sequences revealed that B. caudata from Peninsular Malaysia was distinctly different from B. caudata of Bali and Lombok, without common haplotype between them. Phylogenetic analysis revealed two distinct clades, indicating distinct genetic lineage. The uncorrected ‘p’ distance for COI sequences between B. caudata of Malaysia-Thailand-China and B. caudata of Bali-Lombok was 5.65%, for 16S sequences from 2.76 to 2.99%, and for combined COI and 16S sequences 4.45 to 4.46%. The ‘p’ values are distinctly different from intraspecific ‘p’ distance (0–0.23%). Both the B. caudata lineages are distinctly separated from related species in the subgenus Zeugodacus – B. ascita, B. scutellata, B. ishigakiensis, B. diaphora, B. tau, B. cucurbitae, and B. depressa. Molecular phylogenetic analysis indicates that the B. caudata lineages are closely related to B. ascita sp. B, and form a clade with B. scutellata, B. ishigakiensis, B. diaphora and B. ascita sp. A. This study provides additional baseline for the phylogenetic relationships of Bactrocera fruit flies of the subgenus Zeugodacus. Both the COI and 16S genes could be useful markers for the molecular differentiation and phylogenetic analysis of tephritid fruit flies. PMID:22615962

  2. RAD genotyping reveals fine-scale genetic structuring and provides powerful population assignment in a widely distributed marine species, the American lobster (Homarus americanus).

    PubMed

    Benestan, Laura; Gosselin, Thierry; Perrier, Charles; Sainte-Marie, Bernard; Rochette, Rémy; Bernatchez, Louis

    2015-07-01

    Deciphering genetic structure and inferring connectivity in marine species have been challenging due to weak genetic differentiation and limited resolution offered by traditional genotypic methods. The main goal of this study was to assess how a population genomics framework could help delineate the genetic structure of the American lobster (Homarus americanus) throughout much of the species' range and increase the assignment success of individuals to their location of origin. We genotyped 10 156 filtered SNPs using RAD sequencing to delineate genetic structure and perform population assignment for 586 American lobsters collected in 17 locations distributed across a large portion of the species' natural distribution range. Our results revealed the existence of a hierarchical genetic structure, first separating lobsters from the northern and southern part of the range (FCT  = 0.0011; P-value = 0.0002) and then revealing a total of 11 genetically distinguishable populations (mean FST  = 0.00185; CI: 0.0007-0.0021, P-value < 0.0002), providing strong evidence for weak, albeit fine-scale population structuring within each region. A resampling procedure showed that assignment success was highest with a subset of 3000 SNPs having the highest FST . Applying Anderson's (Molecular Ecology Resources, 2010, 10, 701) method to avoid 'high-grading bias', 94.2% and 80.8% of individuals were correctly assigned to their region and location of origin, respectively. Lastly, we showed that assignment success was positively associated with sample size. These results demonstrate that using a large number of SNPs improves fine-scale population structure delineation and population assignment success in a context of weak genetic structure. We discuss the implications of these findings for the conservation and management of highly connected marine species, particularly regarding the geographic scale of demographic independence. PMID:25977167

  3. Genetic characterization of Amazonian bovine papillomavirus reveals the existence of four new putative types.

    PubMed

    da Silva, Flavio R C; Daudt, Cíntia; Streck, André F; Weber, Matheus N; Filho, Ronaldo V Leite; Driemeier, David; Canal, Cláudio W

    2015-08-01

    Papillomaviruses are small and complex viruses that belong to the Papillomaviridae family, which comprises 39 genera. The bovine papillomavirus (BPV) causes an infectious disease that is characterized by chronic and proliferative benign tumors that affect cattle worldwide. Different genotypes of BPVs can cause distinct skin and mucosal lesions and the immunity they raise has low cross-protection. This report aimed to genotype BPVs in cattle from Northern Brazil based on nucleotide partial sequences of the L1 ORF. Skin wart samples from 39 bovines clinically and histopathologically diagnosed as cutaneous papillomatosis from Acre and Rondônia States were analyzed. The results revealed four already reported BPV types (BPVs 1, 2, 11, and 13), nine putative new BPV subtypes and four putative new BPV types as well as two putative new BPV types that were already reported. To our knowledge, this is the first record of BPVs from the Brazilian Amazon region that identified new possible BPV types and subtypes circulating in this population. These findings point to the great genetic diversity of BPVs that are present in this region and highlight the importance of this knowledge before further studies about vaccination are attempted. PMID:26116287

  4. Genetic and environmental determinants of human NK cell diversity revealed by mass cytometry

    PubMed Central

    Horowitz, Amir; Strauss-Albee, Dara M.; Leipold, Michael; Kubo, Jessica; Nemat-Gorgani, Neda; Dogan, Ozge C.; Dekker, Cornelia L.; Mackey, Sally; Maecker, Holden; Swan, Gary E.; Davis, Mark M.; Norman, Paul J.; Guethlein, Lisbeth A.; Desai, Manisha; Parham, Peter; Blish, Catherine A.

    2013-01-01

    Natural Killer (NK) cells play critical roles in immune defense and reproduction, yet remain the most poorly understood major lymphocyte population. Because their activation is controlled by a variety of combinatorially expressed activating and inhibitory receptors, NK cell diversity and function are closely linked. To provide an unprecedented understanding of NK cell repertoire diversity, we used mass cytometry to simultaneously analyze 35 parameters, including 28 NK cell receptors, on peripheral blood NK cells from five sets of monozygotic twins and twelve unrelated donors of defined HLA and killer cell immunoglobulin-like receptor (KIR) genotype. This analysis revealed a remarkable degree of NK cell diversity, with an estimated 6,000-30,000 phenotypic populations within an individual and >100,000 phenotypes in this population. Genetics largely determined inhibitory receptor expression, whereas activation receptor expression was heavily environmentally influenced. Therefore, NK cells may maintain self-tolerance through strictly regulated expression of inhibitory receptors, while using adaptable expression patterns of activating and costimulatory receptors to respond to pathogens and tumors. These findings further suggest the possibility that discrete NK cell subpopulations could be harnessed for immunotherapeutic strategies in the settings of infection, reproduction, and transplantation. PMID:24154599

  5. Heme dynamics and trafficking factors revealed by genetically encoded fluorescent heme sensors.

    PubMed

    Hanna, David A; Harvey, Raven M; Martinez-Guzman, Osiris; Yuan, Xiaojing; Chandrasekharan, Bindu; Raju, Gheevarghese; Outten, F Wayne; Hamza, Iqbal; Reddi, Amit R

    2016-07-01

    Heme is an essential cofactor and signaling molecule. Heme acquisition by proteins and heme signaling are ultimately reliant on the ability to mobilize labile heme (LH). However, the properties of LH pools, including concentration, oxidation state, distribution, speciation, and dynamics, are poorly understood. Herein, we elucidate the nature and dynamics of LH using genetically encoded ratiometric fluorescent heme sensors in the unicellular eukaryote Saccharomyces cerevisiae We find that the subcellular distribution of LH is heterogeneous; the cytosol maintains LH at ∼20-40 nM, whereas the mitochondria and nucleus maintain it at concentrations below 2.5 nM. Further, we find that the signaling molecule nitric oxide can initiate the rapid mobilization of heme in the cytosol and nucleus from certain thiol-containing factors. We also find that the glycolytic enzyme glyceraldehyde phosphate dehydrogenase constitutes a major cellular heme buffer, and is responsible for maintaining the activity of the heme-dependent nuclear transcription factor heme activator protein (Hap1p). Altogether, we demonstrate that the heme sensors can be used to reveal fundamental aspects of heme trafficking and dynamics and can be used across multiple organisms, including Escherichia coli, yeast, and human cell lines. PMID:27247412

  6. Genetic sequence data reveals widespread sharing of Leucocytozoon lineages in corvids.

    PubMed

    Freund, Dave; Wheeler, Sarah S; Townsend, Andrea K; Boyce, Walter M; Ernest, Holly B; Cicero, Carla; Sehgal, Ravinder N M

    2016-09-01

    Leucocytozoon, a widespread hemosporidian blood parasite that infects a broad group of avian families, has been studied in corvids (family: Corvidae) for over a century. Current taxonomic classification indicates that Leucocytozoon sakharoffi infects crows and related Corvus spp., while Leucocytozoon berestneffi infects magpies (Pica spp.) and blue jays (Cyanocitta sp.). This intrafamily host specificity was based on the experimental transmissibility of the parasites, as well as slight differences in their morphology and life cycle development. Genetic sequence data from Leucocytozoon spp. infecting corvids is scarce, and until the present study, sequence data has not been analyzed to confirm the current taxonomic distinctions. Here, we predict the phylogenetic relationships of Leucocytozoon cytochrome b lineages recovered from infected American Crows (Corvus brachyrhynchos), yellow-billed magpies (Pica nuttalli), and Steller's jays (Cyanocitta stelleri) to explore the host specificity pattern of L. sakharoffi and L. berestneffi. Phylogenetic reconstruction revealed a single large clade containing nearly every lineage recovered from the three host species, while showing no evidence of the expected distinction between L. sakharoffi and L. berestneffi. In addition, five of the detected lineages were recovered from both crows and magpies. This absence of the previously described host specificity in corvid Leucocytozoon spp. suggests that L. sakharoffi and L. berestneffi be reexamined from a taxonomic perspective. PMID:27189064

  7. Genetic architecture of trout from Albania as revealed by mtDNA control region variation

    PubMed Central

    2009-01-01

    To determine the genetic architecture of trout in Albania, 87 individuals were collected from 19 riverine and lacustrine sites in Albania, FYROM and Greece. All individuals were analyzed for sequence variation in the mtDNA control region. Among fourteen haplotypes detected, four previously unpublished haplotypes, bearing a close relationship to haplotypes of the Adriatic and marmoratus lineages of Salmo trutta, were revealed. Ten previously described haplotypes, characteristic of S. ohridanus, S. letnica and the Adriatic and Mediterranean lineages of S. trutta, were also detected. Haplotypes detected in this study were placed in a well supported branch of S. ohridanus, and a cluster of Mediterranean – Adriatic – marmoratus haplotypes, which were further delimited into three subdivisions of Mediterranean, marmoratus, and a previously non-described formation of four Adriatic haplotypes (Balkan cluster). Haplotypes of the Balkan cluster and the other Adriatic haplotypes, do not represent a contiguous haplotype lineage and appear not to be closely related, indicating independent arrivals into the Adriatic drainage and suggesting successive colonization events. Despite the presence of marmoratus haplotypes in Albania, no marbled phenotype was found, confirming previously reported findings that there is no association between this phenotype and marmoratus haplotypes. PMID:19284692

  8. Genetic architecture dissection by genome-wide association analysis reveals avian eggshell ultrastructure traits.

    PubMed

    Duan, Zhongyi; Sun, Congjiao; Shen, ManMan; Wang, Kehua; Yang, Ning; Zheng, Jiangxia; Xu, Guiyun

    2016-01-01

    The ultrastructure of an eggshell is considered the major determinant of eggshell quality, which has biological and economic significance for the avian and poultry industries. However, the interrelationships and genome-wide architecture of eggshell ultrastructure remain to be elucidated. Herein, we measured eggshell thickness (EST), effective layer thickness (ET), mammillary layer thickness (MT), and mammillary density (MD) and conducted genome-wide association studies in 927 F2 hens. The SNP-based heritabilities of eggshell ultrastructure traits were estimated to be 0.39, 0.36, 0.17 and 0.19 for EST, ET, MT and MD, respectively, and a total of 719, 784, 1 and 10 genome-wide significant SNPs were associated with EST, ET, MT and MD, respectively. ABCC9, ITPR2, KCNJ8 and WNK1, which are involved in ion transport, were suggested to be the key genes regulating EST and ET. ITM2C and KNDC1 likely affect MT and MD, respectively. Additionally, there were linear relationships between the chromosome lengths and the variance explained per chromosome for EST (R(2) = 0.57) and ET (R(2) = 0.67). In conclusion, the interrelationships and genetic architecture of eggshell ultrastructure traits revealed in this study are valuable for our understanding of the avian eggshell and contribute to research on a variety of other calcified shells. PMID:27456605

  9. Reveal, A General Reverse Engineering Algorithm for Inference of Genetic Network Architectures

    NASA Technical Reports Server (NTRS)

    Liang, Shoudan; Fuhrman, Stefanie; Somogyi, Roland

    1998-01-01

    Given the immanent gene expression mapping covering whole genomes during development, health and disease, we seek computational methods to maximize functional inference from such large data sets. Is it possible, in principle, to completely infer a complex regulatory network architecture from input/output patterns of its variables? We investigated this possibility using binary models of genetic networks. Trajectories, or state transition tables of Boolean nets, resemble time series of gene expression. By systematically analyzing the mutual information between input states and output states, one is able to infer the sets of input elements controlling each element or gene in the network. This process is unequivocal and exact for complete state transition tables. We implemented this REVerse Engineering ALgorithm (REVEAL) in a C program, and found the problem to be tractable within the conditions tested so far. For n = 50 (elements) and k = 3 (inputs per element), the analysis of incomplete state transition tables (100 state transition pairs out of a possible 10(exp 15)) reliably produced the original rule and wiring sets. While this study is limited to synchronous Boolean networks, the algorithm is generalizable to include multi-state models, essentially allowing direct application to realistic biological data sets. The ability to adequately solve the inverse problem may enable in-depth analysis of complex dynamic systems in biology and other fields.

  10. Genetic architecture dissection by genome-wide association analysis reveals avian eggshell ultrastructure traits

    PubMed Central

    Duan, Zhongyi; Sun, Congjiao; Shen, ManMan; Wang, Kehua; Yang, Ning; Zheng, Jiangxia; Xu, Guiyun

    2016-01-01

    The ultrastructure of an eggshell is considered the major determinant of eggshell quality, which has biological and economic significance for the avian and poultry industries. However, the interrelationships and genome-wide architecture of eggshell ultrastructure remain to be elucidated. Herein, we measured eggshell thickness (EST), effective layer thickness (ET), mammillary layer thickness (MT), and mammillary density (MD) and conducted genome-wide association studies in 927 F2 hens. The SNP-based heritabilities of eggshell ultrastructure traits were estimated to be 0.39, 0.36, 0.17 and 0.19 for EST, ET, MT and MD, respectively, and a total of 719, 784, 1 and 10 genome-wide significant SNPs were associated with EST, ET, MT and MD, respectively. ABCC9, ITPR2, KCNJ8 and WNK1, which are involved in ion transport, were suggested to be the key genes regulating EST and ET. ITM2C and KNDC1 likely affect MT and MD, respectively. Additionally, there were linear relationships between the chromosome lengths and the variance explained per chromosome for EST (R2 = 0.57) and ET (R2 = 0.67). In conclusion, the interrelationships and genetic architecture of eggshell ultrastructure traits revealed in this study are valuable for our understanding of the avian eggshell and contribute to research on a variety of other calcified shells. PMID:27456605

  11. Genetic Diversity Revealed by Single Nucleotide Polymorphism Markers in a Worldwide Germplasm Collection of Durum Wheat

    PubMed Central

    Ren, Jing; Sun, Daokun; Chen, Liang; You, Frank M.; Wang, Jirui; Peng, Yunliang; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

    2013-01-01

    Evaluation of genetic diversity and genetic structure in crops has important implications for plant breeding programs and the conservation of genetic resources. Newly developed single nucleotide polymorphism (SNP) markers are effective in detecting genetic diversity. In the present study, a worldwide durum wheat collection consisting of 150 accessions was used. Genetic diversity and genetic structure were investigated using 946 polymorphic SNP markers covering the whole genome of tetraploid wheat. Genetic structure was greatly impacted by multiple factors, such as environmental conditions, breeding methods reflected by release periods of varieties, and gene flows via human activities. A loss of genetic diversity was observed from landraces and old cultivars to the modern cultivars released during periods of the Early Green Revolution, but an increase in cultivars released during the Post Green Revolution. Furthermore, a comparative analysis of genetic diversity among the 10 mega ecogeographical regions indicated that South America, North America, and Europe possessed the richest genetic variability, while the Middle East showed moderate levels of genetic diversity. PMID:23538839

  12. Mixed reproductive strategies of the Common moorhen on a microscale as revealed by genetic data.

    PubMed

    Loyau, Adeline; Schmeller, Dirk S

    2012-01-01

    External factors shaping reproductive strategies within a population are still poorly understood. How individuals use space and where they decide to build a nest may influence reproductive strategies, as individuals that are close in space may more frequently interact socially. Here, we investigated a population (n=58 from 15 nests) of the Common moorhen in the Loir river (Western France) using microsatellite data (54 alleles). We found a surprisingly low level of genetic monogamy, a low relatedness among offspring in some nests and a low relatedness between the social parents and the offspring. Nest heterozygosity was highest close to the geographic center of the population. The mating strategies of the Common moorhen were highly variable, despite the social monogamy of the species, and were, to some extent, influenced by the microspatial structure. We discuss how our results contribute to the understanding of parent-offspring and offspring-offspring relationships. PMID:23199635

  13. Male and Female Subpopulations of Salix viminalis Present High Genetic Diversity and High Long-Term Migration Rates between Them.

    PubMed

    Zhai, Feifei; Mao, Jinmei; Liu, Junxiang; Peng, Xiangyong; Han, Lei; Sun, Zhenyuan

    2016-01-01

    Dioecy distributed in 157 flowering plant families and 959 flowering plant genera. Morphological and physiological differences between male and female plants have been studied extensively, but studies of sex-specific genetic diversity are relatively scarce in dioecious plants. In this study, 20 SSR loci were employed to examine the genetic variance of male subpopulations and female subpopulations in Salix viminalis. The results showed that all of the markers were polymorphic (Na = 14.15, He = 0.7566) and workable to reveal the genetic diversity of S. viminalis. No statistically significant difference was detected between male and female subpopulations, but the average genetic diversity of male subpopulations (Na = 7.12, He = 0.7071) and female subpopulations (Na = 7.31, He = 0.7226) were high. Under unfavorable environments (West Liao basin), the genetic diversity between male and female subpopulations was still not significantly different, but the genetic diversity of sexual subpopulations were lower. The differentiation of the ten subpopulations in S. viminalis was moderate (FST = 0.0858), which was conformed by AMOVA that most of genetic variance (94%) existed within subpopulations. Pairwise FST indicated no differentiation between sexual subpopulations, which was accompanied by high long-term migrate between them (M = 0.73~1.26). However, little recent migration was found between sexual subpopulations. Therefore, artificial crossing or/and transplantation by cutting propagation should be carried out so as to increase the migration during the process of ex situ conservation. PMID:27047511

  14. Male and Female Subpopulations of Salix viminalis Present High Genetic Diversity and High Long-Term Migration Rates between Them

    PubMed Central

    Zhai, Feifei; Mao, Jinmei; Liu, Junxiang; Peng, Xiangyong; Han, Lei; Sun, Zhenyuan

    2016-01-01

    Dioecy distributed in 157 flowering plant families and 959 flowering plant genera. Morphological and physiological differences between male and female plants have been studied extensively, but studies of sex-specific genetic diversity are relatively scarce in dioecious plants. In this study, 20 SSR loci were employed to examine the genetic variance of male subpopulations and female subpopulations in Salix viminalis. The results showed that all of the markers were polymorphic (Na = 14.15, He = 0.7566) and workable to reveal the genetic diversity of S. viminalis. No statistically significant difference was detected between male and female subpopulations, but the average genetic diversity of male subpopulations (Na = 7.12, He = 0.7071) and female subpopulations (Na = 7.31, He = 0.7226) were high. Under unfavorable environments (West Liao basin), the genetic diversity between male and female subpopulations was still not significantly different, but the genetic diversity of sexual subpopulations were lower. The differentiation of the ten subpopulations in S. viminalis was moderate (FST = 0.0858), which was conformed by AMOVA that most of genetic variance (94%) existed within subpopulations. Pairwise FST indicated no differentiation between sexual subpopulations, which was accompanied by high long-term migrate between them (M = 0.73~1.26). However, little recent migration was found between sexual subpopulations. Therefore, artificial crossing or/and transplantation by cutting propagation should be carried out so as to increase the migration during the process of ex situ conservation. PMID:27047511

  15. Ancient Genetic Signatures of Orang Asli Revealed by Killer Immunoglobulin-Like Receptor Gene Polymorphisms.

    PubMed

    NurWaliyuddin, Hanis Z A; Norazmi, Mohd N; Edinur, Hisham A; Chambers, Geoffrey K; Panneerchelvam, Sundararajulu; Zafarina, Zainuddin

    2015-01-01

    The aboriginal populations of Peninsular Malaysia, also known as Orang Asli (OA), comprise three major groups; Semang, Senoi and Proto-Malays. Here, we analyzed for the first time KIR gene polymorphisms for 167 OA individuals, including those from four smallest OA subgroups (Che Wong, Orang Kanaq, Lanoh and Kensiu) using polymerase chain reaction-sequence specific primer (PCR-SSP) analyses. The observed distribution of KIR profiles of OA is heterogenous; Haplotype B is the most frequent in the Semang subgroups (especially Batek) while Haplotype A is the most common type in the Senoi. The Semang subgroups were clustered together with the Africans, Indians, Papuans and Australian Aborigines in a principal component analysis (PCA) plot and shared many common genotypes (AB6, BB71, BB73 and BB159) observed in these other populations. Given that these populations also display high frequencies of Haplotype B, it is interesting to speculate that Haplotype B may be generally more frequent in ancient populations. In contrast, the two Senoi subgroups, Che Wong and Semai are displaced toward Southeast Asian and African populations in the PCA scatter plot, respectively. Orang Kanaq, the smallest and the most endangered of all OA subgroups, has lost some degree of genetic variation, as shown by their relatively high frequency of the AB2 genotype (0.73) and a total absence of KIR2DL2 and KIR2DS2 genes. Orang Kanaq tradition that strictly prohibits intermarriage with outsiders seems to have posed a serious threat to their survival. This present survey is a demonstration of the value of KIR polymorphisms in elucidating genetic relationships among human populations. PMID:26565719

  16. Ancient Genetic Signatures of Orang Asli Revealed by Killer Immunoglobulin-Like Receptor Gene Polymorphisms

    PubMed Central

    NurWaliyuddin, Hanis Z. A.; Norazmi, Mohd N.; Edinur, Hisham A.; Chambers, Geoffrey K.; Panneerchelvam, Sundararajulu; Zafarina, Zainuddin

    2015-01-01

    The aboriginal populations of Peninsular Malaysia, also known as Orang Asli (OA), comprise three major groups; Semang, Senoi and Proto-Malays. Here, we analyzed for the first time KIR gene polymorphisms for 167 OA individuals, including those from four smallest OA subgroups (Che Wong, Orang Kanaq, Lanoh and Kensiu) using polymerase chain reaction-sequence specific primer (PCR-SSP) analyses. The observed distribution of KIR profiles of OA is heterogenous; Haplotype B is the most frequent in the Semang subgroups (especially Batek) while Haplotype A is the most common type in the Senoi. The Semang subgroups were clustered together with the Africans, Indians, Papuans and Australian Aborigines in a principal component analysis (PCA) plot and shared many common genotypes (AB6, BB71, BB73 and BB159) observed in these other populations. Given that these populations also display high frequencies of Haplotype B, it is interesting to speculate that Haplotype B may be generally more frequent in ancient populations. In contrast, the two Senoi subgroups, Che Wong and Semai are displaced toward Southeast Asian and African populations in the PCA scatter plot, respectively. Orang Kanaq, the smallest and the most endangered of all OA subgroups, has lost some degree of genetic variation, as shown by their relatively high frequency of the AB2 genotype (0.73) and a total absence of KIR2DL2 and KIR2DS2 genes. Orang Kanaq tradition that strictly prohibits intermarriage with outsiders seems to have posed a serious threat to their survival. This present survey is a demonstration of the value of KIR polymorphisms in elucidating genetic relationships among human populations. PMID:26565719

  17. High genetic structuring of Tula hantavirus.

    PubMed

    Schmidt, Sabrina; Saxenhofer, Moritz; Drewes, Stephan; Schlegel, Mathias; Wanka, Konrad M; Frank, Raphael; Klimpel, Sven; von Blanckenhagen, Felix; Maaz, Denny; Herden, Christiane; Freise, Jona; Wolf, Ronny; Stubbe, Michael; Borkenhagen, Peter; Ansorge, Hermann; Eccard, Jana A; Lang, Johannes; Jourdain, Elsa; Jacob, Jens; Marianneau, Philippe; Heckel, Gerald; Ulrich, Rainer G

    2016-05-01

    Tula virus (TULV) is a vole-associated hantavirus with low or no pathogenicity to humans. In the present study, 686 common voles (Microtus arvalis), 249 field voles (Microtus agrestis) and 30 water voles (Arvicola spec.) were collected at 79 sites in Germany, Luxembourg and France and screened by RT-PCR and TULV-IgG ELISA. TULV-specific RNA and/or antibodies were detected at 43 of the sites, demonstrating a geographically widespread distribution of the virus in the studied area. The TULV prevalence in common voles (16.7 %) was higher than that in field voles (9.2 %) and water voles (10.0 %). Time series data at ten trapping sites showed evidence of a lasting presence of TULV RNA within common vole populations for up to 34 months, although usually at low prevalence. Phylogenetic analysis demonstrated a strong genetic structuring of TULV sequences according to geography and independent of the rodent species, confirming the common vole as the preferential host, with spillover infections to co-occurring field and water voles. TULV phylogenetic clades showed a general association with evolutionary lineages in the common vole as assessed by mitochondrial DNA sequences on a large geographical scale, but with local-scale discrepancies in the contact areas. PMID:26831932

  18. Homozygosity Mapping and Targeted Sanger Sequencing Reveal Genetic Defects Underlying Inherited Retinal Disease in Families from Pakistan

    PubMed Central

    Waheed, Nadia Khalida; Siddiqui, Sorath Noorani; Mustafa, Bilal; Ayub, Humaira; Ali, Liaqat; Ahmad, Shakeel; Micheal, Shazia; Hussain, Alamdar; Shah, Syed Tahir Abbas; Ali, Syeda Hafiza Benish; Ahmed, Waqas; Khan, Yar Muhammad; den Hollander, Anneke I.; Haer-Wigman, Lonneke; Collin, Rob W. J.; Khan, Muhammad Imran; Qamar, Raheel; Cremers, Frans P. M.

    2015-01-01

    Background Homozygosity mapping has facilitated the identification of the genetic causes underlying inherited diseases, particularly in consanguineous families with multiple affected individuals. This knowledge has also resulted in a mutation dataset that can be used in a cost and time effective manner to screen frequent population-specific genetic variations associated with diseases such as inherited retinal disease (IRD). Methods We genetically screened 13 families from a cohort of 81 Pakistani IRD families diagnosed with Leber congenital amaurosis (LCA), retinitis pigmentosa (RP), congenital stationary night blindness (CSNB), or cone dystrophy (CD). We employed genome-wide single nucleotide polymorphism (SNP) array analysis to identify homozygous regions shared by affected individuals and performed Sanger sequencing of IRD-associated genes located in the sizeable homozygous regions. In addition, based on population specific mutation data we performed targeted Sanger sequencing (TSS) of frequent variants in AIPL1, CEP290, CRB1, GUCY2D, LCA5, RPGRIP1 and TULP1, in probands from 28 LCA families. Results Homozygosity mapping and Sanger sequencing of IRD-associated genes revealed the underlying mutations in 10 families. TSS revealed causative variants in three families. In these 13 families four novel mutations were identified in CNGA1, CNGB1, GUCY2D, and RPGRIP1. Conclusions Homozygosity mapping and TSS revealed the underlying genetic cause in 13 IRD families, which is useful for genetic counseling as well as therapeutic interventions that are likely to become available in the near future. PMID:25775262

  19. Degenerate in vitro genetic selection reveals mutations that diminish alfalfa mosaic virus RNA replication without affecting coat protein binding.

    PubMed

    Rocheleau, Gail; Petrillo, Jessica; Guogas, Laura; Gehrke, Lee

    2004-08-01

    The alfalfa mosaic virus (AMV) RNAs are infectious only in the presence of the viral coat protein; however, the mechanisms describing coat protein's role during replication are disputed. We reasoned that mechanistic details might be revealed by identifying RNA mutations in the 3'-terminal coat protein binding domain that increased or decreased RNA replication without affecting coat protein binding. Degenerate (doped) in vitro genetic selection, based on a pool of randomized 39-mers, was used to select 30 variant RNAs that bound coat protein with high affinity. AUGC sequences that are conserved among AMV and ilarvirus RNAs were among the invariant nucleotides in the selected RNAs. Five representative clones were analyzed in functional assays, revealing diminished viral RNA expression resulting from apparent defects in replication and/or translation. These data identify a set of mutations, including G-U wobble pairs and nucleotide mismatches in the 5' hairpin, which affect viral RNA functions without significant impact on coat protein binding. Because the mutations associated with diminished function were scattered over the 3'-terminal nucleotides, we considered the possibility that RNA conformational changes rather than disruption of a precise motif might limit activity. Native polyacrylamide gel electrophoresis experiments showed that the 3' RNA conformation was indeed altered by nucleotide substitutions. One interpretation of the data is that coat protein binding to the AUGC sequences determines the orientation of the 3' hairpins relative to one another, while local structural features within these hairpins are also critical determinants of functional activity. PMID:15254175

  20. High-density linkage mapping revealed suppression of recombination at the sex determination locus in papaya.

    PubMed Central

    Ma, Hao; Moore, Paul H; Liu, Zhiyong; Kim, Minna S; Yu, Qingyi; Fitch, Maureen M M; Sekioka, Terry; Paterson, Andrew H; Ming, Ray

    2004-01-01

    A high-density genetic map of papaya (Carica papaya L.) was constructed using 54 F(2) plants derived from cultivars Kapoho and SunUp with 1501 markers, including 1498 amplified fragment length polymorphism (AFLP) markers, the papaya ringspot virus coat protein marker, morphological sex type, and fruit flesh color. These markers were mapped into 12 linkage groups at a LOD score of 5.0 and recombination frequency of 0.25. The 12 major linkage groups covered a total length of 3294.2 cM, with an average distance of 2.2 cM between adjacent markers. This map revealed severe suppression of recombination around the sex determination locus with a total of 225 markers cosegregating with sex types. The cytosine bases were highly methylated in this region on the basis of the distribution of methylation-sensitive and -insensitive markers. This high-density genetic map is essential for cloning of specific genes of interest such as the sex determination gene and for the integration of genetic and physical maps of papaya. PMID:15020433

  1. New view of population genetics of zooplankton: RAD-seq analysis reveals population structure of the North Atlantic planktonic copepod Centropages typicus.

    PubMed

    Blanco-Bercial, L; Bucklin, A

    2016-04-01

    Detection of population genetic structure of zooplankton at medium-to-small spatial scales in the absence of physical barriers has remained challenging and controversial. The large population sizes and high rates of gene flow characteristic of zooplankton have made resolution of geographical differentiation very difficult, especially when using few genetic markers and assuming equilibrium conditions. Next-generation sequencing now allows simultaneous sampling of hundreds to thousands of genetic markers; new analytical approaches allow studies under nonequilibrium conditions and directional migration. Samples of the North Atlantic Ocean planktonic copepod, Centropages typicus, were analysed using restriction site-associated DNA (RAD) sequencing on a PROTON platform. Although prior studies revealed no genetic differentiation of populations across the geographical range of the species, analysis of RAD tags showed significant structure across the North Atlantic Ocean. We also compared the likelihood for models of connectivity among NW Atlantic populations under various directional flow scenarios that replicate oceanographic conditions of the sampled domain. High-density marker sampling with RAD sequencing markedly outperformed other technical and analytical approaches in detection of population genetic structure and characterization of connectivity of this high geneflow zooplankton species. PMID:26857348

  2. Divergence genetics analysis reveals historical population genetic processes leading to contrasting phylogeographic patterns in co-distributed species.

    PubMed

    McGovern, Tamara M; Keever, Carson C; Saski, Christopher A; Hart, Michael W; Marko, Peter B

    2010-11-01

    Coalescent samplers are computational time machines for inferring the historical demographic genetic processes that have given rise to observable patterns of spatial genetic variation among contemporary populations. We have used traditional characterizations of population structure and coalescent-based inferences about demographic processes to reconstruct the population histories of two co-distributed marine species, the frilled dog whelk, Nucella lamellosa, and the bat star, Patiria miniata. Analyses of population structure were consistent with previous work in both species except that additional samples of N. lamellosa showed a larger regional genetic break on Vancouver Island (VI) rather than between the southern Alexander Archipelago as in P. miniata. Our understanding of the causes, rather than just the patterns, of spatial genetic variation was dramatically improved by coalescent analyses that emphasized variation in population divergence times. Overall, gene flow was greater in bat stars (planktonic development) than snails (benthic development) but spatially homogeneous within species. In both species, these large phylogeographic breaks corresponded to relatively ancient divergence times between populations rather than regionally restricted gene flow. Although only N. lamellosa shows a large break on VI, population separation times on VI are congruent between species, suggesting a similar response to late Pleistocene ice sheet expansion. The absence of a phylogeographic break in P. miniata on VI can be attributed to greater gene flow and larger effective population size in this species. Such insights put the relative significance of gene flow into a more comprehensive historical biogeographic context and have important implications for conservation and landscape genetic studies that emphasize the role of contemporary gene flow and connectivity in shaping patterns of population differentiation. PMID:21040048

  3. Fine-Scale Genetic Structure and Cryptic Associations Reveal Evidence of Kin-Based Sociality in the African Forest Elephant

    PubMed Central

    Schuttler, Stephanie G.; Philbrick, Jessica A.; Jeffery, Kathryn J.; Eggert, Lori S.

    2014-01-01

    Spatial patterns of relatedness within animal populations are important in the evolution of mating and social systems, and have the potential to reveal information on species that are difficult to observe in the wild. This study examines the fine-scale genetic structure and connectivity of groups within African forest elephants, Loxodonta cyclotis, which are often difficult to observe due to forest habitat. We tested the hypothesis that genetic similarity will decline with increasing geographic distance, as we expect kin to be in closer proximity, using spatial autocorrelation analyses and Tau Kr tests. Associations between individuals were investigated through a non-invasive genetic capture-recapture approach using network models, and were predicted to be more extensive than the small groups found in observational studies, similar to fission-fusion sociality found in African savanna (Loxodonta africana) and Asian (Elephas maximus) species. Dung samples were collected in Lopé National Park, Gabon in 2008 and 2010 and genotyped at 10 microsatellite loci, genetically sexed, and sequenced at the mitochondrial DNA control region. We conducted analyses on samples collected at three different temporal scales: a day, within six-day sampling sessions, and within each year. Spatial autocorrelation and Tau Kr tests revealed genetic structure, but results were weak and inconsistent between sampling sessions. Positive spatial autocorrelation was found in distance classes of 0–5 km, and was strongest for the single day session. Despite weak genetic structure, individuals within groups were significantly more related to each other than to individuals between groups. Social networks revealed some components to have large, extensive groups of up to 22 individuals, and most groups were composed of individuals of the same matriline. Although fine-scale population genetic structure was weak, forest elephants are typically found in groups consisting of kin and based on matrilines

  4. Comparative Genomic Analysis of Drechmeria coniospora Reveals Core and Specific Genetic Requirements for Fungal Endoparasitism of Nematodes

    PubMed Central

    Thakur, Nishant; Arguel, Marie-Jeanne; Polanowska, Jolanta; Henrissat, Bernard; Record, Eric; Magdelenat, Ghislaine; Barbe, Valérie; Raffaele, Sylvain; Barbry, Pascal

    2016-01-01

    Drechmeria coniospora is an obligate fungal pathogen that infects nematodes via the adhesion of specialized spores to the host cuticle. D. coniospora is frequently found associated with Caenorhabditis elegans in environmental samples. It is used in the study of the nematode’s response to fungal infection. Full understanding of this bi-partite interaction requires knowledge of the pathogen’s genome, analysis of its gene expression program and a capacity for genetic engineering. The acquisition of all three is reported here. A phylogenetic analysis placed D. coniospora close to the truffle parasite Tolypocladium ophioglossoides, and Hirsutella minnesotensis, another nematophagous fungus. Ascomycete nematopathogenicity is polyphyletic; D. coniospora represents a branch that has not been molecularly characterized. A detailed in silico functional analysis, comparing D. coniospora to 11 fungal species, revealed genes and gene families potentially involved in virulence and showed it to be a highly specialized pathogen. A targeted comparison with nematophagous fungi highlighted D. coniospora-specific genes and a core set of genes associated with nematode parasitism. A comparative gene expression analysis of samples from fungal spores and mycelia, and infected C. elegans, gave a molecular view of the different stages of the D. coniospora lifecycle. Transformation of D. coniospora allowed targeted gene knock-out and the production of fungus that expresses fluorescent reporter genes. It also permitted the initial characterisation of a potential fungal counter-defensive strategy, involving interference with a host antimicrobial mechanism. This high-quality annotated genome for D. coniospora gives insights into the evolution and virulence of nematode-destroying fungi. Coupled with genetic transformation, it opens the way for molecular dissection of D. coniospora physiology, and will allow both sides of the interaction between D. coniospora and C. elegans, as well as the

  5. Fine mapping of type 1 diabetes regions Idd9.1 and Idd9.2 reveals genetic complexity.

    PubMed

    Hamilton-Williams, Emma E; Rainbow, Daniel B; Cheung, Jocelyn; Christensen, Mikkel; Lyons, Paul A; Peterson, Laurence B; Steward, Charles A; Sherman, Linda A; Wicker, Linda S

    2013-10-01

    Nonobese diabetic (NOD) mice congenic for C57BL/10 (B10)-derived genes in the Idd9 region of chromosome 4 are highly protected from type 1 diabetes (T1D). Idd9 has been divided into three protective subregions (Idd9.1, 9.2, and 9.3), each of which partially prevents disease. In this study we have fine-mapped the Idd9.1 and Idd9.2 regions, revealing further genetic complexity with at least two additional subregions contributing to protection from T1D. Using the NOD sequence from bacterial artificial chromosome clones of the Idd9.1 and Idd9.2 regions as well as whole-genome sequence data recently made available, sequence polymorphisms within the regions highlight a high degree of polymorphism between the NOD and B10 strains in the Idd9 regions. Among numerous candidate genes are several with immunological importance. The Idd9.1 region has been separated into Idd9.1 and Idd9.4, with Lck remaining a candidate gene within Idd9.1. One of the Idd9.2 regions contains the candidate genes Masp2 (encoding mannan-binding lectin serine peptidase 2) and Mtor (encoding mammalian target of rapamycin). From mRNA expression analyses, we have also identified several other differentially expressed candidate genes within the Idd9.1 and Idd9.2 regions. These findings highlight that multiple, relatively small genetic effects combine and interact to produce significant changes in immune tolerance and diabetes onset. PMID:23934554

  6. Comparative Genomic Analysis of Drechmeria coniospora Reveals Core and Specific Genetic Requirements for Fungal Endoparasitism of Nematodes.

    PubMed

    Lebrigand, Kevin; He, Le D; Thakur, Nishant; Arguel, Marie-Jeanne; Polanowska, Jolanta; Henrissat, Bernard; Record, Eric; Magdelenat, Ghislaine; Barbe, Valérie; Raffaele, Sylvain; Barbry, Pascal; Ewbank, Jonathan J

    2016-05-01

    Drechmeria coniospora is an obligate fungal pathogen that infects nematodes via the adhesion of specialized spores to the host cuticle. D. coniospora is frequently found associated with Caenorhabditis elegans in environmental samples. It is used in the study of the nematode's response to fungal infection. Full understanding of this bi-partite interaction requires knowledge of the pathogen's genome, analysis of its gene expression program and a capacity for genetic engineering. The acquisition of all three is reported here. A phylogenetic analysis placed D. coniospora close to the truffle parasite Tolypocladium ophioglossoides, and Hirsutella minnesotensis, another nematophagous fungus. Ascomycete nematopathogenicity is polyphyletic; D. coniospora represents a branch that has not been molecularly characterized. A detailed in silico functional analysis, comparing D. coniospora to 11 fungal species, revealed genes and gene families potentially involved in virulence and showed it to be a highly specialized pathogen. A targeted comparison with nematophagous fungi highlighted D. coniospora-specific genes and a core set of genes associated with nematode parasitism. A comparative gene expression analysis of samples from fungal spores and mycelia, and infected C. elegans, gave a molecular view of the different stages of the D. coniospora lifecycle. Transformation of D. coniospora allowed targeted gene knock-out and the production of fungus that expresses fluorescent reporter genes. It also permitted the initial characterisation of a potential fungal counter-defensive strategy, involving interference with a host antimicrobial mechanism. This high-quality annotated genome for D. coniospora gives insights into the evolution and virulence of nematode-destroying fungi. Coupled with genetic transformation, it opens the way for molecular dissection of D. coniospora physiology, and will allow both sides of the interaction between D. coniospora and C. elegans, as well as the

  7. Comparative genomics of Campylobacter concisus isolates reveals genetic diversity and provides insights into disease association

    PubMed Central

    2013-01-01

    Background In spite of its association with gastroenteritis and inflammatory bowel diseases, the isolation of Campylobacter concisus from both diseased and healthy individuals has led to controversy regarding its role as an intestinal pathogen. One proposed reason for this is the presence of high genetic diversity among the genomes of C. concisus strains. Results In this study the genomes of six C. concisus strains were sequenced, assembled and annotated including two strains isolated from Crohn’s disease patients (UNSW2 and UNSW3), three from gastroenteritis patients (UNSW1, UNSWCS and ATCC 51562) and one from a healthy individual (ATCC 51561). The genomes of C. concisus BAA-1457 and UNSWCD, available from NCBI, were included in subsequent comparative genomic analyses. The Pan and Core genomes for the sequenced C. concisus strains consisted of 3254 and 1556 protein coding genes, respectively. Conclusion Genes were identified with specific conservation in C. concisus strains grouped by phenotypes such as invasiveness, adherence, motility and diseased states. Phylogenetic trees based on ribosomal RNA sequences and concatenated host-related pathways for the eight C. concisus strains were generated using the neighbor-joining method, of which the 16S rRNA gene and peptidoglycan biosynthesis grouped the C. concisus strains according to their pathogenic phenotypes. Furthermore, 25 non-synonymous amino acid changes with 14 affecting functional domains, were identified within proteins of conserved host-related pathways, which had possible associations with the pathogenic potential of C. concisus strains. Finally, the genomes of the eight C. concisus strains were compared to the nine available genomes of the well-established pathogen Campylobacter jejuni, which identified several important differences in the respiration pathways of these two species. Our findings indicate that C. concisus strains are genetically diverse, and suggest the genomes of this bacterium contain

  8. Genetic Dissection of Acute Anterior Uveitis Reveals Similarities and Differences in Associations observed with Ankylosing Spondylitis

    PubMed Central

    Robinson, Philip C.; Claushuis, Theodora A.M.; Cortes, Adrian; Martin, Tammy M.; Evans, David M.; Leo, Paul; Mukhopadhyay, Pamela; Bradbury, Linda A.; Cremin, Katie; Harris, Jessica; Maksymowych, Walter P.; Inman, Robert D.; Rahman, Proton; Haroon, Nigil; Gensler, Lianne; Powell, Joseph E.; van der Horst-Bruinsma, Irene E.; Hewitt, Alex W.; Craig, Jamie E.; Lim, Lyndell L.; Wakefield, Denis; McCluskey, Peter; Voigt, Valentina; Fleming, Peter; Degli-Esposti, Mariapia; Pointon, Jennifer J.; Weisman, Michael H.; Wordsworth, B. Paul; Reveille, John D.; Rosenbaum, James T.; Brown, Matthew A.

    2015-01-01

    Objective To use high density genotyping to investigate the genetic associations of acute anterior uveitis (AAU) in patients both with and without ankylosing spondylitis (AS). Method We genotyped 1,711 patients with AAU (either primary or with AAU and AS), 2,339 AS patients without AAU, and 10,000 controls on the Illumina Immunochip Infinium microarray. We also used data on AS patients from previous genomewide association studies to investigate the AS risk locus ANTXR2 for its putative effect in AAU. ANTXR2 expression in mouse eyes was investigated by RT-PCR. Results Comparing all AAU cases with HC, strong association was seen over HLA-B corresponding to the HLA-B27 tag SNP rs116488202. Three non-MHC loci IL23R, the intergenic region 2p15 and ERAP1 were associated at genome-wide significance (P < 5×10−8). Five loci harboring the immune-related genes IL10-IL19, IL18R1-IL1R1, IL6R, the chromosome 1q32 locus harboring KIF21B, as well as the eye related gene EYS, were also associated at a suggestive level of significance (P < 5×10−6). A number of previously confirmed AS associations demonstrated significant differences in effect size between AS patients with AAU and AS patients without AAU. ANTXR2 expression was found to vary across eye compartments. Conclusion These findings, with both novel AAU specific associations, and associations shared with AS demonstrate overlapping but also distinct genetic susceptibility loci for AAU and AS. The associations in IL10 and IL18R1 are shared with inflammatory bowel disease, suggesting common etiologic pathways. PMID:25200001

  9. Exome sequencing improves genetic diagnosis of structural fetal abnormalities revealed by ultrasound

    PubMed Central

    Carss, Keren J.; Hillman, Sarah C.; Parthiban, Vijaya; McMullan, Dominic J.; Maher, Eamonn R.; Kilby, Mark D.; Hurles, Matthew E.

    2014-01-01

    The genetic etiology of non-aneuploid fetal structural abnormalities is typically investigated by karyotyping and array-based detection of microscopically detectable rearrangements, and submicroscopic copy-number variants (CNVs), which collectively yield a pathogenic finding in up to 10% of cases. We propose that exome sequencing may substantially increase the identification of underlying etiologies. We performed exome sequencing on a cohort of 30 non-aneuploid fetuses and neonates (along with their parents) with diverse structural abnormalities first identified by prenatal ultrasound. We identified candidate pathogenic variants with a range of inheritance models, and evaluated these in the context of detailed phenotypic information. We identified 35 de novo single-nucleotide variants (SNVs), small indels, deletions or duplications, of which three (accounting for 10% of the cohort) are highly likely to be causative. These are de novo missense variants in FGFR3 and COL2A1, and a de novo 16.8 kb deletion that includes most of OFD1. In five further cases (17%) we identified de novo or inherited recessive or X-linked variants in plausible candidate genes, which require additional validation to determine pathogenicity. Our diagnostic yield of 10% is comparable to, and supplementary to, the diagnostic yield of existing microarray testing for large chromosomal rearrangements and targeted CNV detection. The de novo nature of these events could enable couples to be counseled as to their low recurrence risk. This study outlines the way for a substantial improvement in the diagnostic yield of prenatal genetic abnormalities through the application of next-generation sequencing. PMID:24476948

  10. Phylogenetic analysis of European Scutovertex mites (Acari, Oribatida, Scutoverticidae) reveals paraphyly and cryptic diversity – a molecular genetic and morphological approach

    PubMed Central

    Schäffer, Sylvia; Pfingstl, Tobias; Koblmüller, Stephan; Winkler, Kathrin A.; Sturmbauer, Christian; Krisper, Günther

    2014-01-01

    The soil and moss dwelling oribatid mite family Scutoverticidae is considered to represent an assemblage of distantly related but morphologically similar genera. We used nucleotide sequences of one mitochondrial (COI) and two nuclear (28S rDNA, ef-1α) genes, and 79 morphological characters to elucidate the phylogenetic relationships among eleven nominal plus two undescribed European mite species of the family Scutoverticidae with a particular focus on the genus Scutovertex. Both molecular genetic and morphological data revealed a paraphyletic genus Scutovertex, with S. pictus probably representing a distinct genus, and Provertex kuehnelti was confirmed as member of the family Scutoverticidae. Molecular genetic data confirmed several recently described Scutovertex species and thus the high species diversity within this genus in Europe and suggest that S. sculptus represents a complex of several cryptic species exhibiting marked genetic, but hardly any morphological divergence. PMID:20006724

  11. Evolutionary history of barley cultivation in Europe revealed by genetic analysis of extant landraces

    PubMed Central

    2011-01-01

    Background Understanding the evolution of cultivated barley is important for two reasons. First, the evolutionary relationships between different landraces might provide information on the spread and subsequent development of barley cultivation, including the adaptation of the crop to new environments and its response to human selection. Second, evolutionary information would enable landraces with similar traits but different genetic backgrounds to be identified, providing alternative strategies for the introduction of these traits into modern germplasm. Results The evolutionary relationships between 651 barley landraces were inferred from the genotypes for 24 microsatellites. The landraces could be divided into nine populations, each with a different geographical distribution. Comparisons with ear row number, caryopsis structure, seasonal growth habit and flowering time revealed a degree of association between population structure and phenotype, and analysis of climate variables indicated that the landraces are adapted, at least to some extent, to their environment. Human selection and/or environmental adaptation may therefore have played a role in the origin and/or maintenance of one or more of the barley landrace populations. There was also evidence that at least some of the population structure derived from geographical partitioning set up during the initial spread of barley cultivation into Europe, or reflected the later introduction of novel varieties. In particular, three closely-related populations were made up almost entirely of plants with the daylength nonresponsive version of the photoperiod response gene PPD-H1, conferring adaptation to the long annual growth season of northern Europe. These three populations probably originated in the eastern Fertile Crescent and entered Europe after the initial spread of agriculture. Conclusions The discovery of population structure, combined with knowledge of associated phenotypes and environmental adaptations

  12. Genetic and Ultrastructural Analysis Reveals the Key Players and Initial Steps of Bacterial Magnetosome Membrane Biogenesis.

    PubMed

    Raschdorf, Oliver; Forstner, Yvonne; Kolinko, Isabel; Uebe, René; Plitzko, Jürgen M; Schüler, Dirk

    2016-06-01

    Magnetosomes of magnetotactic bacteria contain well-ordered nanocrystals for magnetic navigation and have recently emerged as the most sophisticated model system to study the formation of membrane bounded organelles in prokaryotes. Magnetosome biosynthesis is thought to begin with the formation of a dedicated compartment, the magnetosome membrane (MM), in which the biosynthesis of a magnetic mineral is strictly controlled. While the biomineralization of magnetosomes and their subsequent assembly into linear chains recently have become increasingly well studied, the molecular mechanisms and early stages involved in MM formation remained poorly understood. In the Alphaproteobacterium Magnetospirillum gryphiswaldense, approximately 30 genes were found to control magnetosome biosynthesis. By cryo-electron tomography of several key mutant strains we identified the gene complement controlling MM formation in this model organism. Whereas the putative magnetosomal iron transporter MamB was most crucial for the process and caused the most severe MM phenotype upon elimination, MamM, MamQ and MamL were also required for the formation of wild-type-like MMs. A subset of seven genes (mamLQBIEMO) combined within a synthetic operon was sufficient to restore the formation of intracellular membranes in the absence of other genes from the key mamAB operon. Tracking of de novo magnetosome membrane formation by genetic induction revealed that magnetosomes originate from unspecific cytoplasmic membrane locations before alignment into coherent chains. Our results indicate that no single factor alone is essential for MM formation, which instead is orchestrated by the cumulative action of several magnetosome proteins. PMID:27286560

  13. Analysis of Genome Sequences from Plant Pathogenic Rhodococcus Reveals Genetic Novelties in Virulence Loci

    PubMed Central

    Davis, Edward W.; Putnam, Melodie L.; Hu, Erdong; Swader-Hines, David; Mol, Adeline; Baucher, Marie; Prinsen, Els; Zdanowska, Magdalena; Givan, Scott A.; Jaziri, Mondher El; Loper, Joyce E.; Mahmud, Taifo; Chang, Jeff H.

    2014-01-01

    Members of Gram-positive Actinobacteria cause economically important diseases to plants. Within the Rhodococcus genus, some members can cause growth deformities and persist as pathogens on a wide range of host plants. The current model predicts that phytopathogenic isolates require a cluster of three loci present on a linear plasmid, with the fas operon central to virulence. The Fas proteins synthesize, modify, and activate a mixture of growth regulating cytokinins, which cause a hormonal imbalance in plants, resulting in abnormal growth. We sequenced and compared the genomes of 20 isolates of Rhodococcus to gain insights into the mechanisms and evolution of virulence in these bacteria. Horizontal gene transfer was identified as critical but limited in the scale of virulence evolution, as few loci are conserved and exclusive to phytopathogenic isolates. Although the fas operon is present in most phytopathogenic isolates, it is absent from phytopathogenic isolate A21d2. Instead, this isolate has a horizontally acquired gene chimera that encodes a novel fusion protein with isopentyltransferase and phosphoribohydrolase domains, predicted to be capable of catalyzing and activating cytokinins, respectively. Cytokinin profiling of the archetypal D188 isolate revealed only one activate cytokinin type that was specifically synthesized in a fas-dependent manner. These results suggest that only the isopentenyladenine cytokinin type is synthesized and necessary for Rhodococcus phytopathogenicity, which is not consistent with the extant model stating that a mixture of cytokinins is necessary for Rhodococcus to cause leafy gall symptoms. In all, data indicate that only four horizontally acquired functions are sufficient to confer the trait of phytopathogenicity to members of the genetically diverse clade of Rhodococcus. PMID:25010934

  14. Genetic and Ultrastructural Analysis Reveals the Key Players and Initial Steps of Bacterial Magnetosome Membrane Biogenesis

    PubMed Central

    Kolinko, Isabel; Uebe, René; Schüler, Dirk

    2016-01-01

    Magnetosomes of magnetotactic bacteria contain well-ordered nanocrystals for magnetic navigation and have recently emerged as the most sophisticated model system to study the formation of membrane bounded organelles in prokaryotes. Magnetosome biosynthesis is thought to begin with the formation of a dedicated compartment, the magnetosome membrane (MM), in which the biosynthesis of a magnetic mineral is strictly controlled. While the biomineralization of magnetosomes and their subsequent assembly into linear chains recently have become increasingly well studied, the molecular mechanisms and early stages involved in MM formation remained poorly understood. In the Alphaproteobacterium Magnetospirillum gryphiswaldense, approximately 30 genes were found to control magnetosome biosynthesis. By cryo-electron tomography of several key mutant strains we identified the gene complement controlling MM formation in this model organism. Whereas the putative magnetosomal iron transporter MamB was most crucial for the process and caused the most severe MM phenotype upon elimination, MamM, MamQ and MamL were also required for the formation of wild-type-like MMs. A subset of seven genes (mamLQBIEMO) combined within a synthetic operon was sufficient to restore the formation of intracellular membranes in the absence of other genes from the key mamAB operon. Tracking of de novo magnetosome membrane formation by genetic induction revealed that magnetosomes originate from unspecific cytoplasmic membrane locations before alignment into coherent chains. Our results indicate that no single factor alone is essential for MM formation, which instead is orchestrated by the cumulative action of several magnetosome proteins. PMID:27286560

  15. Genetically targeted single-channel optical recording reveals multiple Orai1 gating states and oscillations in calcium influx.

    PubMed

    Dynes, Joseph L; Amcheslavsky, Anna; Cahalan, Michael D

    2016-01-12

    Orai1 comprises the pore-forming subunit of the Ca(2+) release-activated Ca(2+) (CRAC) channel. When bound and activated by stromal interacting molecule 1 (STIM1), an endoplasmic reticulum (ER)-resident calcium sensor, Orai1 channels possess high selectivity for calcium but extremely small conductance that has precluded direct recording of single-channel currents. We have developed an approach to visualize Orai1 activity by fusing Orai1 to fluorescent, genetically encoded calcium indicators (GECIs). The GECI-Orai1 probes reveal local Ca(2+) influx at STIM1-Orai1 puncta. By whole cell recording, these fusions are fully functional as CRAC channels. When GECI-Orai1 and the CRAC-activating domain (CAD) of STIM1 were coexpressed at low levels and imaged using a total internal reflectance fluorescence microscope, cells exhibited sporadic fluorescence transients the size of diffraction-limited spots and the brightness of a few activated GECI proteins. Transients typically rose rapidly and fell into two classes according to duration: briefer "flickers" lasting only a few hundred milliseconds, and longer "pulses" lasting one to several seconds. The size, intensity, trace shape, frequency, distribution, physiological characteristics, and association with CAD binding together demonstrate that GECI-Orai1 fluorescence transients correspond to single-channel Orai1 responses. Single Orai1 channels gated by CAD, and small Orai1 puncta gated by STIM1, exhibit repetitive fluctuations in single-channel output. CAD binding supports a role in open state maintenance and reveals a second phase of CAD/STIM1 binding after channel opening. These first recordings of single-channel Orai1 currents reveal unexpected dynamics, and when paired with CAD association, support multiple single-channel states. PMID:26712003

  16. Genetically targeted single-channel optical recording reveals multiple Orai1 gating states and oscillations in calcium influx

    PubMed Central

    Dynes, Joseph L.; Amcheslavsky, Anna; Cahalan, Michael D.

    2016-01-01

    Orai1 comprises the pore-forming subunit of the Ca2+ release-activated Ca2+ (CRAC) channel. When bound and activated by stromal interacting molecule 1 (STIM1), an endoplasmic reticulum (ER)-resident calcium sensor, Orai1 channels possess high selectivity for calcium but extremely small conductance that has precluded direct recording of single-channel currents. We have developed an approach to visualize Orai1 activity by fusing Orai1 to fluorescent, genetically encoded calcium indicators (GECIs). The GECI–Orai1 probes reveal local Ca2+ influx at STIM1–Orai1 puncta. By whole cell recording, these fusions are fully functional as CRAC channels. When GECI–Orai1 and the CRAC-activating domain (CAD) of STIM1 were coexpressed at low levels and imaged using a total internal reflectance fluorescence microscope, cells exhibited sporadic fluorescence transients the size of diffraction-limited spots and the brightness of a few activated GECI proteins. Transients typically rose rapidly and fell into two classes according to duration: briefer “flickers” lasting only a few hundred milliseconds, and longer “pulses” lasting one to several seconds. The size, intensity, trace shape, frequency, distribution, physiological characteristics, and association with CAD binding together demonstrate that GECI–Orai1 fluorescence transients correspond to single-channel Orai1 responses. Single Orai1 channels gated by CAD, and small Orai1 puncta gated by STIM1, exhibit repetitive fluctuations in single-channel output. CAD binding supports a role in open state maintenance and reveals a second phase of CAD/STIM1 binding after channel opening. These first recordings of single-channel Orai1 currents reveal unexpected dynamics, and when paired with CAD association, support multiple single-channel states. PMID:26712003

  17. Phylogeography of postglacial range expansion in Juglans mandshurica (Juglandaceae) reveals no evidence of bottleneck, loss of genetic diversity, or isolation by distance in the leading-edge populations.

    PubMed

    Wang, Wen-Ting; Xu, Bing; Zhang, Da-Yong; Bai, Wei-Ning

    2016-09-01

    The past studies of postglacial recolonization patterns in high latitude regions have revealed a significant role of dispersal capacity in shaping the genetic diversity and population structure of temperate trees. However, most of these studies have focused on species with long-distance dispersal followed by exponential population growth and were therefore unable to reveal the patterns in the case of a gradual expansion. Here we studied the impacts of postglacial range expansions on the distribution of genetic diversity in the Manchurian walnut (Juglans mandshurica), a common tree of East Asian cool-temperate deciduous forests that apparently lacks long-distance seed dispersal ability. The genetic diversity and structure of 19 natural walnut populations in Northeast China and the Korean Peninsula were examined using 17 nuclear simple sequence repeat (SSR) loci. Potential habitats under current and past climatic conditions were predicted using the ecological niche modelling (ENM) method. Bayesian clustering analysis revealed three groups, which were inferred to have diverged through multiple glacial-interglacial cycles in multiple refugia during the Quaternary Period. ENM estimated a southward range shift at the LGM, but high suitability scores still occurred in the western parts of the Changbai Mountains (Northeast China), the Korean peninsula and the exposed seafloor of the Yellow Sea. In contrast to most other cool-temperate trees co-occurring in the same region, the Manchurian walnut did not show any evidence of a population bottleneck, loss of genetic diversity or isolation by distance during the postglacial expansion. Our study clearly indicates that current northern populations originated from one glacial lineage and recolonization via a gradually advancing front due to the lack of a long-distance seed dispersal mechanism led to no latitudinal decrease in genetic diversity. PMID:27346642

  18. Single Nucleus Genome Sequencing Reveals High Similarity among Nuclei of an Endomycorrhizal Fungus

    PubMed Central

    Zhang, Zhonghua; Ivanov, Sergey; Saunders, Diane G. O.; Mu, Desheng; Pang, Erli; Cao, Huifen; Cha, Hwangho; Lin, Tao; Zhou, Qian; Shang, Yi; Li, Ying; Sharma, Trupti; van Velzen, Robin; de Ruijter, Norbert; Aanen, Duur K.; Win, Joe; Kamoun, Sophien; Bisseling, Ton; Geurts, René; Huang, Sanwen

    2014-01-01

    Nuclei of arbuscular endomycorrhizal fungi have been described as highly diverse due to their asexual nature and absence of a single cell stage with only one nucleus. This has raised fundamental questions concerning speciation, selection and transmission of the genetic make-up to next generations. Although this concept has become textbook knowledge, it is only based on studying a few loci, including 45S rDNA. To provide a more comprehensive insight into the genetic makeup of arbuscular endomycorrhizal fungi, we applied de novo genome sequencing of individual nuclei of Rhizophagus irregularis. This revealed a surprisingly low level of polymorphism between nuclei. In contrast, within a nucleus, the 45S rDNA repeat unit turned out to be highly diverged. This finding demystifies a long-lasting hypothesis on the complex genetic makeup of arbuscular endomycorrhizal fungi. Subsequent genome assembly resulted in the first draft reference genome sequence of an arbuscular endomycorrhizal fungus. Its length is 141 Mbps, representing over 27,000 protein-coding gene models. We used the genomic sequence to reinvestigate the phylogenetic relationships of Rhizophagus irregularis with other fungal phyla. This unambiguously demonstrated that Glomeromycota are more closely related to Mucoromycotina than to its postulated sister Dikarya. PMID:24415955

  19. Molecular genetics of blood-fleshed peach reveals activation of anthocyanin biosynthesis by NAC transcription factors.

    PubMed

    Zhou, Hui; Lin-Wang, Kui; Wang, Huiliang; Gu, Chao; Dare, Andrew P; Espley, Richard V; He, Huaping; Allan, Andrew C; Han, Yuepeng

    2015-04-01

    Anthocyanin pigmentation is an important consumer trait in peach (Prunus persica). In this study, the genetic basis of the blood-flesh trait was investigated using the cultivar Dahongpao, which shows high levels of cyanidin-3-glucoside in the mesocarp. Elevation of anthocyanin levels in the flesh was correlated with the expression of an R2R3 MYB transcription factor, PpMYB10.1. However, PpMYB10.1 did not co-segregate with the blood-flesh trait. The blood-flesh trait was mapped to a 200-kb interval on peach linkage group (LG) 5. Within this interval, a gene encoding a NAC domain transcription factor (TF) was found to be highly up-regulated in blood-fleshed peaches when compared with non-red-fleshed peaches. This NAC TF, designated blood (BL), acts as a heterodimer with PpNAC1 which shows high levels of expression in fruit at late developmental stages. We show that the heterodimer of BL and PpNAC1 can activate the transcription of PpMYB10.1, resulting in anthocyanin pigmentation in tobacco. Furthermore, silencing the BL gene reduces anthocyanin pigmentation in blood-fleshed peaches. The transactivation activity of the BL-PpNAC1 heterodimer is repressed by a SQUAMOSA promoter-binding protein-like TF, PpSPL1. Low levels of PpMYB10.1 expression in fruit at early developmental stages is probably attributable to lower levels of expression of PpNAC1 plus the presence of high levels of repressors such as PpSPL1. We present a mechanism whereby BL is the key gene for the blood-flesh trait in peach via its activation of PpMYB10.1 in maturing fruit. Partner TFs such as basic helix-loop-helix proteins and NAC1 are required, as is the removal of transcriptional repressors. PMID:25688923

  20. SNP-revealed genetic diversity in wild emmer wheat correlates with ecological factors

    PubMed Central

    2013-01-01

    Background Patterns of genetic diversity between and within natural plant populations and their driving forces are of great interest in evolutionary biology. However, few studies have been performed on the genetic structure and population divergence in wild emmer wheat using a large number of EST-related single nucleotide polymorphism (SNP) markers. Results In the present study, twenty-five natural wild emmer wheat populations representing a wide range of ecological conditions in Israel and Turkey were used. Genetic diversity and genetic structure were investigated using over 1,000 SNP markers. A moderate level of genetic diversity was detected due to the biallelic property of SNP markers. Clustering based on Bayesian model showed that grouping pattern is related to the geographical distribution of the wild emmer wheat. However, genetic differentiation between populations was not necessarily dependent on the geographical distances. A total of 33 outlier loci under positive selection were identified using a FST-outlier method. Significant correlations between loci and ecogeographical factors were observed. Conclusions Natural selection appears to play a major role in generating adaptive structures in wild emmer wheat. SNP markers are appropriate for detecting selectively-channeled adaptive genetic diversity in natural populations of wild emmer wheat. This adaptive genetic diversity is significantly associated with ecological factors. PMID:23937410

  1. Genotyping by sequencing reveals the genetic diversity of the USDA pisum diversity collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA expanded Pisum Single Plant (PSP) core collection is a unique resource that represents the breadth of the genetic diversity of the genus in an inbred format that facilitates genetic study. The collection includes inbred accessions from the refined pea core collection, parent lines of USDA r...

  2. A Genome Wide Survey of SNP Variation Reveals the Genetic Structure of Sheep Breeds

    PubMed Central

    Kijas, James W.; Townley, David; Dalrymple, Brian P.; Heaton, Michael P.; Maddox, Jillian F.; McGrath, Annette; Wilson, Peter; Ingersoll, Roxann G.; McCulloch, Russell; McWilliam, Sean; Tang, Dave; McEwan, John; Cockett, Noelle; Oddy, V. Hutton; Nicholas, Frank W.; Raadsma, Herman

    2009-01-01

    The genetic structure of sheep reflects their domestication and subsequent formation into discrete breeds. Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. After identifying the first genome-wide set of SNP for sheep, we report on levels of genetic variability both within and between a diverse sample of ovine populations. Then, using cluster analysis and the partitioning of genetic variation, we demonstrate sheep are characterised by weak phylogeographic structure, overlapping genetic similarity and generally low differentiation which is consistent with their short evolutionary history. The degree of population substructure was, however, sufficient to cluster individuals based on geographic origin and known breed history. Specifically, African and Asian populations clustered separately from breeds of European origin sampled from Australia, New Zealand, Europe and North America. Furthermore, we demonstrate the presence of stratification within some, but not all, ovine breeds. The results emphasize that careful documentation of genetic structure will be an essential prerequisite when mapping the genetic basis of complex traits. Furthermore, the identification of a subset of SNP able to assign individuals into broad groupings demonstrates even a small panel of markers may be suitable for applications such as traceability. PMID:19270757

  3. Genetic diversity of carrot (Daucus carota L.) cultivars revealed by analysis of SSR loci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this work we evaluate a collection of 88 carrot cultivars and landraces for polymorphisms at SSR loci and use the obtained markers to assess the genetic diversity, and we show molecular evidence for divergence between Asiatic and Western carrot genetic pools. The use of primer pairs flanking repe...

  4. Genome-wide scan revealed genetic loci for energy metabolism in Hispanic children and adolescents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genome-wide scans were conducted in a search for genetic locations linked to energy expenditure and substrate oxidation in children. Pedigreed data of 1030 Hispanic children and adolescents were from the Viva La Familia Study, which was designed to investigate genetic and environmental risk factors ...

  5. Genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maintaining genetic variation in wild populations of Arctic organisms is fundamental to the long-term persistence of high latitude biodiversity. Variability is important because it provides options for species to respond to changing environmental conditions and novel challenges such as emerging path...

  6. Genome-wide view of genetic diversity reveals paths of selection and cultivar differentiation in peach domestication.

    PubMed

    Akagi, Takashi; Hanada, Toshio; Yaegaki, Hideaki; Gradziel, Thomas M; Tao, Ryutaro

    2016-06-01

    Domestication and cultivar differentiation are requisite processes for establishing cultivated crops. These processes inherently involve substantial changes in population structure, including those from artificial selection of key genes. In this study, accessions of peach (Prunus persica) and its wild relatives were analysed genome-wide to identify changes in genetic structures and gene selections associated with their differentiation. Analysis of genome-wide informative single-nucleotide polymorphism loci revealed distinct changes in genetic structures and delineations among domesticated peach and its wild relatives and among peach landraces and modern fruit (F) and modern ornamental (O-A) cultivars. Indications of distinct changes in linkage disequilibrium extension/decay and of strong population bottlenecks or inbreeding were identified. Site frequency spectrum- and extended haplotype homozygosity-based evaluation of genome-wide genetic diversities supported selective sweeps distinguishing the domesticated peach from its wild relatives and each F/O-A cluster from the landrace clusters. The regions with strong selective sweeps harboured promising candidates for genes subjected to selection. Further sequence-based evaluation further defined the candidates and revealed their characteristics. All results suggest opportunities for identifying critical genes associated with each differentiation by analysing genome-wide genetic diversity in currently established populations. This approach obviates the special development of genetic populations, which is particularly difficult for long-lived tree crops. PMID:27085183

  7. Genome-wide view of genetic diversity reveals paths of selection and cultivar differentiation in peach domestication

    PubMed Central

    Akagi, Takashi; Hanada, Toshio; Yaegaki, Hideaki; Gradziel, Thomas M.; Tao, Ryutaro

    2016-01-01

    Domestication and cultivar differentiation are requisite processes for establishing cultivated crops. These processes inherently involve substantial changes in population structure, including those from artificial selection of key genes. In this study, accessions of peach (Prunus persica) and its wild relatives were analysed genome-wide to identify changes in genetic structures and gene selections associated with their differentiation. Analysis of genome-wide informative single-nucleotide polymorphism loci revealed distinct changes in genetic structures and delineations among domesticated peach and its wild relatives and among peach landraces and modern fruit (F) and modern ornamental (O-A) cultivars. Indications of distinct changes in linkage disequilibrium extension/decay and of strong population bottlenecks or inbreeding were identified. Site frequency spectrum- and extended haplotype homozygosity-based evaluation of genome-wide genetic diversities supported selective sweeps distinguishing the domesticated peach from its wild relatives and each F/O-A cluster from the landrace clusters. The regions with strong selective sweeps harboured promising candidates for genes subjected to selection. Further sequence-based evaluation further defined the candidates and revealed their characteristics. All results suggest opportunities for identifying critical genes associated with each differentiation by analysing genome-wide genetic diversity in currently established populations. This approach obviates the special development of genetic populations, which is particularly difficult for long-lived tree crops. PMID:27085183

  8. High-Pitched Notes during Vocal Contests Signal Genetic Diversity in Ocellated Antbirds

    PubMed Central

    Araya-Ajoy, Yi-men; Chaves-Campos, Johel; Kalko, Elisabeth K. V.; DeWoody, J. Andrew

    2009-01-01

    Animals use honest signals to assess the quality of competitors during aggressive interactions. Current theory predicts that honest signals should be costly to produce and thus reveal some aspects of the phenotypic or genetic quality of the sender. In songbirds, research indicates that biomechanical constraints make the production of some acoustic features costly. Furthermore, recent studies have found that vocal features are related to genetic diversity. We linked these two lines of research by evaluating if constrained acoustic features reveal male genetic diversity during aggressive interactions in ocellated antbirds (Phaenostictus mcleannani). We recorded the aggressive vocalizations of radiotagged males at La Selva Biological Station in Costa Rica, and found significant variation in the highest frequency produced among individuals. Moreover, we detected a negative relationship between the frequency of the highest pitched note and vocalization duration, suggesting that high pitched notes might constrain the duration of vocalizations through biomechanical and/or energetic limitations. When we experimentally exposed wild radiotagged males to simulated acoustic challenges, the birds increased the pitch of their vocalization. We also found that individuals with higher genetic diversity (as measured by zygosity across 9 microsatellite loci) produced notes of higher pitch during aggressive interactions. Overall, our results suggest that the ability to produce high pitched notes is an honest indicator of male genetic diversity in male-male aggressive interactions. PMID:19956580

  9. Facial emotion perception differs in young persons at genetic and clinical high-risk for psychosis.

    PubMed

    Kohler, Christian G; Richard, Jan A; Brensinger, Colleen M; Borgmann-Winter, Karin E; Conroy, Catherine G; Moberg, Paul J; Gur, Ruben C; Gur, Raquel E; Calkins, Monica E

    2014-05-15

    A large body of literature has documented facial emotion perception impairments in schizophrenia. More recently, emotion perception has been investigated in persons at genetic and clinical high-risk for psychosis. This study compared emotion perception abilities in groups of young persons with schizophrenia, clinical high-risk, genetic risk and healthy controls. Groups, ages 13-25, included 24 persons at clinical high-risk, 52 first-degree relatives at genetic risk, 91 persons with schizophrenia and 90 low risk persons who completed computerized testing of emotion recognition and differentiation. Groups differed by overall emotion recognition abilities and recognition of happy, sad, anger and fear expressions. Pairwise comparisons revealed comparable impairments in recognition of happy, angry, and fearful expressions for persons at clinical high-risk and schizophrenia, while genetic risk participants were less impaired, showing reduced recognition of fearful expressions. Groups also differed for differentiation of happy and sad expressions, but differences were mainly between schizophrenia and control groups. Emotion perception impairments are observable in young persons at-risk for psychosis. Preliminary results with clinical high-risk participants, when considered along findings in genetic risk relatives, suggest social cognition abilities to reflect pathophysiological processes involved in risk of schizophrenia. PMID:24582775

  10. Phylogeographic analyses of submesophotic snappers Etelis coruscans and Etelis "marshi" (family Lutjanidae) reveal concordant genetic structure across the Hawaiian Archipelago.

    PubMed

    Andrews, Kimberly R; Moriwake, Virginia N; Wilcox, Christie; Grau, E Gordon; Kelley, Christopher; Pyle, Richard L; Bowen, Brian W

    2014-01-01

    The Hawaiian Archipelago has become a natural laboratory for understanding genetic connectivity in marine organisms as a result of the large number of population genetics studies that have been conducted across this island chain for a wide taxonomic range of organisms. However, population genetic studies have been conducted for only two species occurring in the mesophotic or submesophotic zones (30+m) in this archipelago. To gain a greater understanding of genetic connectivity in these deepwater habitats, we investigated the genetic structure of two submesophotic fish species (occurring ∼200-360 m) in this archipelago. We surveyed 16 locations across the archipelago for submesophotic snappers Etelis coruscans (N = 787) and E. "marshi" (formerly E. carbunculus; N = 770) with 436-490 bp of mtDNA cytochrome b and 10-11 microsatellite loci. Phylogeographic analyses reveal no geographic structuring of mtDNA lineages and recent coalescence times that are typical of shallow reef fauna. Population genetic analyses reveal no overall structure across most of the archipelago, a pattern also typical of dispersive shallow fishes. However some sites in the mid-archipelago (Raita Bank to French Frigate Shoals) had significant population differentiation. This pattern of no structure between ends of the Hawaiian range, and significant structure in the middle, was previously observed in a submesophotic snapper (Pristipomoides filamentosus) and a submesophotic grouper (Hyporthodus quernus). Three of these four species also have elevated genetic diversity in the mid-archipelago. Biophysical larval dispersal models from previous studies indicate that this elevated diversity may result from larval supplement from Johnston Atoll, ∼800 km southwest of Hawaii. In this case the boundaries of stocks for fishery management cannot be defined simply in terms of geography, and fishery management in Hawaii may need to incorporate external larval supply into management plans. PMID

  11. Evolutionary study of leporid CD4 reveals a hotspot of genetic variability within the D2 domain.

    PubMed

    de Sousa-Pereira, Patricia; Abrantes, Joana; Baldauf, Hanna-Mari; Keppler, Oliver T; Esteves, Pedro J

    2016-07-01

    CD4 is the major receptor on T helper cells involved in the uptake of human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) into their host cells. Evolutionary studies of CD4 in primates revealed signatures of positive selection in the D1 domain that interacts with primate exogenous lentivirus gp120 proteins. Here, we studied the evolution of CD4 in lagomorphs by comparing sequences obtained for the genera Oryctolagus, Sylvilagus, Lepus, and Ochotona. Our results reveal an overall higher divergence in lagomorphs compared to primates with highest divergence in the D2 domain. A detailed analysis of a small fragment of 33 nucleotides coding for amino acids 169 to 179 in the D2 domain showed dramatic amino acid alterations with a dN/dS value of 3.2 for lagomorphs, suggesting that CD4 is under strong positive selection in this particular region. Within each leporid genus, no significant amino acid changes were observed for the D2 domain which indicates that the genetic differentiation occurred in the ancestor of each genus before the species radiation. The rabbit endogenous lentivirus type K (RELIK) found in leporids shares high structural similarity with HIV which suggests a possible interaction between RELIK and CD4. The presence of RELIK in the studied leporids, the high structural similarity to modern-day exogenous lentiviruses and the absence of exogenous lentiviruses in leporids, allows us to hypothesize that this endogenous retrovirus, that was most probably exogenous in the past, drove the divergent evolution of leporid CD4. PMID:26979977

  12. Genetic footprints reveal geographic patterns of expansion in Fennoscandian red foxes.

    PubMed

    Norén, Karin; Statham, Mark J; Ågren, Erik O; Isomursu, Marja; Flagstad, Øystein; Eide, Nina E; Berg, Thomas Bjørneboe G; Bech-Sanderhoff, Lene; Sacks, Benjamin N

    2015-09-01

    Population expansions of boreal species are among the most substantial ecological consequences of climate change, potentially transforming both structure and processes of northern ecosystems. Despite their importance, little is known about expansion dynamics of boreal species. Red foxes (Vulpes vulpes) are forecasted to become a keystone species in northern Europe, a process stemming from population expansions that began in the 19th century. To identify the relative roles of geographic and demographic factors and the sources of northern European red fox population expansion, we genotyped 21 microsatellite loci in modern and historical (1835-1941) Fennoscandian red foxes. Using Bayesian clustering and Bayesian inference of migration rates, we identified high connectivity and asymmetric migration rates across the region, consistent with source-sink dynamics, whereby more recently colonized sampling regions received immigrants from multiple sources. There were no clear clines in allele frequency or genetic diversity as would be expected from a unidirectional range expansion from south to north. Instead, migration inferences, demographic models and comparison to historical red fox genotypes suggested that the population expansion of the red fox is a consequence of dispersal from multiple sources, as well as in situ demographic growth. Together, these findings provide a rare glimpse into the anatomy of a boreal range expansion and enable informed predictions about future changes in boreal communities. PMID:26058388

  13. Comparison of morphological and genetic analyses reveals cryptic divergence and morphological plasticity in Stylophora (Cnidaria, Scleractinia)

    NASA Astrophysics Data System (ADS)

    Stefani, Fabrizio; Benzoni, F.; Yang, S.-Y.; Pichon, M.; Galli, P.; Chen, C. A.

    2011-12-01

    A combined morphological and genetic study of the coral genus Stylophora investigated species boundaries in the Gulf of Aden, Yemen. Two mitochondrial regions, including the hypervariable IGS9 spacer and the control region, and a fragment of rDNA were used for phylogenetic analysis. Results were compared by multivariate analysis on the basis of branch morphology and corallite morphometry. Two species were clearly discriminated by both approaches. The first species was characterised by small corallites and a low morphological variability and was ascribed to a new geographical record of Stylophora madagascarensis on the basis of its phylogenetic distinction and its morphological similarity to the type material. The second species was characterised by larger corallite size and greater morphological variability and was ascribed to Stylophora pistillata. The analysis was extended to the intrageneric level for other S. pistillata populations from the Red Sea and the Pacific Ocean. Strong internal divergence was evident in the genus Sty lophora. S. pistillata populations were split into two highly divergent Red Sea/Gulf of Aden and western Pacific lineages with significant morphological overlap, which suggests they represent two distinct cryptic species. The combined use of morphological and molecular approaches, so far proved to be a powerful tool for the re-delineation of species boundaries in corals, provided novel evidence of cryptic divergence in this group of marine metazoans.

  14. Genetic relationships among Enterococcus faecalis isolates from different sources as revealed by multilocus sequence typing.

    PubMed

    Chen, X; Song, Y Q; Xu, H Y; Menghe, B L G; Zhang, H P; Sun, Z H

    2015-08-01

    Enterococcus faecalis is part of the natural gut flora of humans and other mammals; some isolates are also used in food production. So, it is important to evaluate the genetic diversity and phylogenetic relationships among E. faecalis isolates from different sources. Multilocus sequence typing protocol was used to compare 39 E. faecalis isolates from Chinese traditional food products (including dairy products, acidic gruel) and 4 published E. faecalis isolates from other sources including human-derived isolates employing 5 housekeeping genes (groEL, clpX, recA, rpoB, and pepC). A total of 23 unique sequence types were identified, which were grouped into 5 clonal complexes and 10 singletons. The value of standardized index of association of the alleles (IA(S)=0.1465) and network structure indicated a high frequency of intraspecies recombination across these isolates. Enterococcus faecalis lineages also exhibited clearly source-clustered distributions. The isolates from dairy source were clustered together. However, the relationship between isolates from acidic gruel and one isolate from a human source was close. The MLST scheme presented in this study provides a sharable and continuously growing sequence database enabling global comparison of strains from different sources, and will further advance our understanding of the microbial ecology of this important species. PMID:26074239

  15. Integrative transcriptome, proteome, phosphoproteome and genetic mapping reveals new aspects in a fiberless mutant of cotton

    PubMed Central

    Ma, Qi-Feng; Wu, Chun-Hui; Wu, Man; Pei, Wen-Feng; Li, Xing-Li; Wang, Wen-Kui; Zhang, Jinfa; Yu, Ji-Wen; Yu, Shu-Xun

    2016-01-01

    To investigate the molecular mechanisms of fiber initiation in cotton (Gossypium spp.), an integrated approach combining transcriptome, iTRAQ-based proteome and genetic mapping was taken to compare the ovules of the Xuzhou 142 wild type (WT) with its fuzzless-lintless (fl) mutant at −3 and 0 day post-anthesis. A total of 1,953 mRNAs, 187 proteins, and 131 phosphoproteins were differentially expressed (DE) between WT and fl, and the levels of transcripts and their encoded proteins and phosphoproteins were highly congruent. A functional analysis suggested that the abundance of proteins were mainly involved in amino sugar, nucleotide sugar and fatty acid metabolism, one carbon pool for folate metabolism and flavonoid biosynthesis. qRT-PCR, Western blotting, and enzymatic assays were performed to confirm the regulation of these transcripts and proteins. A molecular mapping located the lintless gene li3 in the fl mutant on chromosome 26 for the first time. A further in-silico physical mapping of DE genes with sequence variations between fl and WT identified one and four candidate genes in the li3 and n2 regions, respectively. Taken together, the transcript abundance, phosphorylation status of proteins at the fiber initiation stage and candidate genes have provided insights into regulatory processes underlying cotton fiber initiation. PMID:27075604

  16. Comparative analysis of the domestic cat genome reveals genetic signatures underlying feline biology and domestication.

    PubMed

    Montague, Michael J; Li, Gang; Gandolfi, Barbara; Khan, Razib; Aken, Bronwen L; Searle, Steven M J; Minx, Patrick; Hillier, LaDeana W; Koboldt, Daniel C; Davis, Brian W; Driscoll, Carlos A; Barr, Christina S; Blackistone, Kevin; Quilez, Javier; Lorente-Galdos, Belen; Marques-Bonet, Tomas; Alkan, Can; Thomas, Gregg W C; Hahn, Matthew W; Menotti-Raymond, Marilyn; O'Brien, Stephen J; Wilson, Richard K; Lyons, Leslie A; Murphy, William J; Warren, Wesley C

    2014-12-01

    Little is known about the genetic changes that distinguish domestic cat populations from their wild progenitors. Here we describe a high-quality domestic cat reference genome assembly and comparative inferences made with other cat breeds, wildcats, and other mammals. Based upon these comparisons, we identified positively selected genes enriched for genes involved in lipid metabolism that underpin adaptations to a hypercarnivorous diet. We also found positive selection signals within genes underlying sensory processes, especially those affecting vision and hearing in the carnivore lineage. We observed an evolutionary tradeoff between functional olfactory and vomeronasal receptor gene repertoires in the cat and dog genomes, with an expansion of the feline chemosensory system for detecting pheromones at the expense of odorant detection. Genomic regions harboring signatures of natural selection that distinguish domestic cats from their wild congeners are enriched in neural crest-related genes associated with behavior and reward in mouse models, as predicted by the domestication syndrome hypothesis. Our description of a previously unidentified allele for the gloving pigmentation pattern found in the Birman breed supports the hypothesis that cat breeds experienced strong selection on specific mutations drawn from random bred populations. Collectively, these findings provide insight into how the process of domestication altered the ancestral wildcat genome and build a resource for future disease mapping and phylogenomic studies across all members of the Felidae. PMID:25385592

  17. Integrative transcriptome, proteome, phosphoproteome and genetic mapping reveals new aspects in a fiberless mutant of cotton.

    PubMed

    Ma, Qi-Feng; Wu, Chun-Hui; Wu, Man; Pei, Wen-Feng; Li, Xing-Li; Wang, Wen-Kui; Zhang, Jinfa; Yu, Ji-Wen; Yu, Shu-Xun

    2016-01-01

    To investigate the molecular mechanisms of fiber initiation in cotton (Gossypium spp.), an integrated approach combining transcriptome, iTRAQ-based proteome and genetic mapping was taken to compare the ovules of the Xuzhou 142 wild type (WT) with its fuzzless-lintless (fl) mutant at -3 and 0 day post-anthesis. A total of 1,953 mRNAs, 187 proteins, and 131 phosphoproteins were differentially expressed (DE) between WT and fl, and the levels of transcripts and their encoded proteins and phosphoproteins were highly congruent. A functional analysis suggested that the abundance of proteins were mainly involved in amino sugar, nucleotide sugar and fatty acid metabolism, one carbon pool for folate metabolism and flavonoid biosynthesis. qRT-PCR, Western blotting, and enzymatic assays were performed to confirm the regulation of these transcripts and proteins. A molecular mapping located the lintless gene li3 in the fl mutant on chromosome 26 for the first time. A further in-silico physical mapping of DE genes with sequence variations between fl and WT identified one and four candidate genes in the li3 and n2 regions, respectively. Taken together, the transcript abundance, phosphorylation status of proteins at the fiber initiation stage and candidate genes have provided insights into regulatory processes underlying cotton fiber initiation. PMID:27075604

  18. Chemical genetic analysis reveals the effects of NMU2R on the expression of peptide hormones.

    PubMed

    Fang, Liyan; Zhang, Mancang; Li, Chunxia; Dong, Suzhen; Hu, Yinghe

    2006-08-14

    Neuromedin U 2 receptor (NMU2R) plays important roles for the regulation of food intake and body weight. However, the molecular mechanism underlying the action of NMU2R has not been clearly defined. We have taken chemical genetic approach to examine the involvement of peptides in the regulation of NMU2R effects. A cell-based reporter gene assay has been developed and used for the screening of human NMU2R agonist. Three natural product compounds, EUK2010, EUK2011 and EUK2012, were identified that could activate the reporter gene expression in the cell-based functional assay. Although these compounds showed high EC50 at hundreds micro-molar range, in vitro pharmacological analysis suggested that they were specific agonists for the human NMU2R. The natural compounds could decrease food intake and lead to the reduction of body weight in different animal models. To understand the molecular basis of the NMU2R regulation of food intake and body weight, we examined the expression of a number of key genes in hypothalamus and adipose tissues after oral administration of EUK2010 in mice. Our results demonstrated that the expression levels of a number of neuropeptide genes were altered after the treatment of EUK2010. Interestingly, EUK2010 increased the expression of Leptin in white fat. These results suggested that these peptides may participate in the regulation of NMU2R effects in mice. PMID:16781063

  19. Comparative analysis of the domestic cat genome reveals genetic signatures underlying feline biology and domestication

    PubMed Central

    Li, Gang; Gandolfi, Barbara; Khan, Razib; Aken, Bronwen L.; Searle, Steven M. J.; Minx, Patrick; Hillier, LaDeana W.; Koboldt, Daniel C.; Davis, Brian W.; Driscoll, Carlos A.; Barr, Christina S.; Blackistone, Kevin; Quilez, Javier; Lorente-Galdos, Belen; Marques-Bonet, Tomas; Alkan, Can; Thomas, Gregg W. C.; Hahn, Matthew W.; Menotti-Raymond, Marilyn; O’Brien, Stephen J.; Wilson, Richard K.; Lyons, Leslie A.; Murphy, William J.; Warren, Wesley C.

    2014-01-01

    Little is known about the genetic changes that distinguish domestic cat populations from their wild progenitors. Here we describe a high-quality domestic cat reference genome assembly and comparative inferences made with other cat breeds, wildcats, and other mammals. Based upon these comparisons, we identified positively selected genes enriched for genes involved in lipid metabolism that underpin adaptations to a hypercarnivorous diet. We also found positive selection signals within genes underlying sensory processes, especially those affecting vision and hearing in the carnivore lineage. We observed an evolutionary tradeoff between functional olfactory and vomeronasal receptor gene repertoires in the cat and dog genomes, with an expansion of the feline chemosensory system for detecting pheromones at the expense of odorant detection. Genomic regions harboring signatures of natural selection that distinguish domestic cats from their wild congeners are enriched in neural crest-related genes associated with behavior and reward in mouse models, as predicted by the domestication syndrome hypothesis. Our description of a previously unidentified allele for the gloving pigmentation pattern found in the Birman breed supports the hypothesis that cat breeds experienced strong selection on specific mutations drawn from random bred populations. Collectively, these findings provide insight into how the process of domestication altered the ancestral wildcat genome and build a resource for future disease mapping and phylogenomic studies across all members of the Felidae. PMID:25385592

  20. The genetic ghost of an invasion past: colonization and extinction revealed by historical hybridization in Senecio.

    PubMed

    Pelser, Pieter B; Abbott, Richard J; Comes, Hans P; Milton, Joseph J; Möller, Michael; Looseley, Mark E; Cron, Glynis V; Barcelona, Julie F; Kennedy, Aaron H; Watson, Linda E; Barone, Rubén; Hernández, Fabián; Kadereit, Joachim W

    2012-01-01

    Hybridization is an important evolutionary factor in the diversification of many plant and animal species. Of particular interest is that historical hybridization resulting in the origin of new species or introgressants has occurred between species now geographically separated by great distances. Here, we report that Senecio massaicus, a tetraploid species native to Morocco and the Canary Islands, contains genetic material of two distinct, geographically separated lineages: a Mediterranean lineage and a mainly southern African lineage. A time-calibrated internal transcribed spacer phylogeny indicates that the hybridization event took place up to 6.18 Ma. Because the southern African lineage has never been recorded from Morocco or the Canary Islands, we hypothesize that it reached this area in the distant past, but never became permanently established. Interestingly, the southern African lineage includes S. inaequidens, a highly invasive species that has recently become widespread throughout Europe and was introduced at the end of the 19th century as a 'wool alien'. Our results suggest that this more recent invasion of Europe by S. inaequidens represents the second arrival of this lineage into the region. PMID:22171696

  1. Sequencing wild and cultivated cassava and related species reveals extensive interspecific hybridization and genetic diversity.

    PubMed

    Bredeson, Jessen V; Lyons, Jessica B; Prochnik, Simon E; Wu, G Albert; Ha, Cindy M; Edsinger-Gonzales, Eric; Grimwood, Jane; Schmutz, Jeremy; Rabbi, Ismail Y; Egesi, Chiedozie; Nauluvula, Poasa; Lebot, Vincent; Ndunguru, Joseph; Mkamilo, Geoffrey; Bart, Rebecca S; Setter, Tim L; Gleadow, Roslyn M; Kulakow, Peter; Ferguson, Morag E; Rounsley, Steve; Rokhsar, Daniel S

    2016-05-01

    Cassava (Manihot esculenta) provides calories and nutrition for more than half a billion people. It was domesticated by native Amazonian peoples through cultivation of the wild progenitor M. esculenta ssp. flabellifolia and is now grown in tropical regions worldwide. Here we provide a high-quality genome assembly for cassava with improved contiguity, linkage, and completeness; almost 97% of genes are anchored to chromosomes. We find that paleotetraploidy in cassava is shared with the related rubber tree Hevea, providing a resource for comparative studies. We also sequence a global collection of 58 Manihot accessions, including cultivated and wild cassava accessions and related species such as Ceará or India rubber (M. glaziovii), and genotype 268 African cassava varieties. We find widespread interspecific admixture, and detect the genetic signature of past cassava breeding programs. As a clonally propagated crop, cassava is especially vulnerable to pathogens and abiotic stresses. This genomic resource will inform future genome-enabled breeding efforts to improve this staple crop. PMID:27088722

  2. Fine-Scale Analysis Reveals Cryptic Landscape Genetic Structure in Desert Tortoises

    PubMed Central

    Latch, Emily K.; Boarman, William I.; Walde, Andrew; Fleischer, Robert C.

    2011-01-01

    Characterizing the effects of landscape features on genetic variation is essential for understanding how landscapes shape patterns of gene flow and spatial genetic structure of populations. Most landscape genetics studies have focused on patterns of gene flow at a regional scale. However, the genetic structure of populations at a local scale may be influenced by a unique suite of landscape variables that have little bearing on connectivity patterns observed at broader spatial scales. We investigated fine-scale spatial patterns of genetic variation and gene flow in relation to features of the landscape in desert tortoise (Gopherus agassizii), using 859 tortoises genotyped at 16 microsatellite loci with associated data on geographic location, sex, elevation, slope, and soil type, and spatial relationship to putative barriers (power lines, roads). We used spatially explicit and non-explicit Bayesian clustering algorithms to partition the sample into discrete clusters, and characterize the relationships between genetic distance and ecological variables to identify factors with the greatest influence on gene flow at a local scale. Desert tortoises exhibit weak genetic structure at a local scale, and we identified two subpopulations across the study area. Although genetic differentiation between the subpopulations was low, our landscape genetic analysis identified both natural (slope) and anthropogenic (roads) landscape variables that have significantly influenced gene flow within this local population. We show that desert tortoise movements at a local scale are influenced by features of the landscape, and that these features are different than those that influence gene flow at larger scales. Our findings are important for desert tortoise conservation and management, particularly in light of recent translocation efforts in the region. More generally, our results indicate that recent landscape changes can affect gene flow at a local scale and that their effects can be

  3. Fine-scale analysis reveals cryptic landscape genetic structure in desert tortoises.

    PubMed

    Latch, Emily K; Boarman, William I; Walde, Andrew; Fleischer, Robert C

    2011-01-01

    Characterizing the effects of landscape features on genetic variation is essential for understanding how landscapes shape patterns of gene flow and spatial genetic structure of populations. Most landscape genetics studies have focused on patterns of gene flow at a regional scale. However, the genetic structure of populations at a local scale may be influenced by a unique suite of landscape variables that have little bearing on connectivity patterns observed at broader spatial scales. We investigated fine-scale spatial patterns of genetic variation and gene flow in relation to features of the landscape in desert tortoise (Gopherus agassizii), using 859 tortoises genotyped at 16 microsatellite loci with associated data on geographic location, sex, elevation, slope, and soil type, and spatial relationship to putative barriers (power lines, roads). We used spatially explicit and non-explicit Bayesian clustering algorithms to partition the sample into discrete clusters, and characterize the relationships between genetic distance and ecological variables to identify factors with the greatest influence on gene flow at a local scale. Desert tortoises exhibit weak genetic structure at a local scale, and we identified two subpopulations across the study area. Although genetic differentiation between the subpopulations was low, our landscape genetic analysis identified both natural (slope) and anthropogenic (roads) landscape variables that have significantly influenced gene flow within this local population. We show that desert tortoise movements at a local scale are influenced by features of the landscape, and that these features are different than those that influence gene flow at larger scales. Our findings are important for desert tortoise conservation and management, particularly in light of recent translocation efforts in the region. More generally, our results indicate that recent landscape changes can affect gene flow at a local scale and that their effects can be

  4. Comparative Genetic Analysis of Mycobacterium ulcerans and Mycobacterium marinum Reveals Evidence of Recent Divergence

    PubMed Central

    Stinear, Timothy P.; Jenkin, Grant A.; Johnson, Paul D. R.; Davies, John K.

    2000-01-01

    Previous studies of the 16S rRNA genes from Mycobacterium ulcerans and Mycobacterium marinum have suggested a very close genetic relationship between these species (99.6% identity). However, these organisms are phenotypically distinct and cause diseases with very different pathologies. To investigate this apparent paradox, we compared 3,306 nucleotides from the partial sequences of eight housekeeping and structural genes derived from 18 M. ulcerans strains and 22 M. marinum strains. This analysis confirmed the close genetic relationship inferred from the 16S rRNA data, with nucleotide sequence identity ranging from 98.1 to 99.7%. The multilocus sequence analysis also confirmed previous genotype studies of M. ulcerans that have identified distinct genotypes within a geographical region. Single isolates of both M. ulcerans and M. marinum that were shown by the sequence analysis to be the most closely related were then selected for further study. One- and two-dimensional pulsed-field gel electrophoresis was employed to compare the architecture and size of the genome from each species. Genome sizes of approximately 4.4 and 4.6 Mb were obtained for M. ulcerans and M. marinum, respectively. Significant macrorestriction fragment polymorphism was observed between the species. However, hybridization analysis of DNA cleaved with more frequently cutting enzymes identified significant preservation of the flanking sequence at seven of the eight loci sequenced. The exception was the 16S rRNA locus. Two high-copy-number insertion sequences, IS2404 and IS2606, have recently been reported in M. ulcerans, and significantly, these elements are not present in M. marinum. Hybridization of the AseI restriction fragments from M. ulcerans with IS2404 and IS2606 indicated widespread genome distribution for both of these repeated sequences. Taken together, these data strongly suggest that M. ulcerans has recently diverged from M. marinum by the acquisition and concomitant loss of DNA in a

  5. High genetic diversity at the regional scale and possible speciation in Sebacina epigaea and S. incrustans

    PubMed Central

    2013-01-01

    Background Phylogenetic studies, particularly those based on rDNA sequences from plant roots and basidiomata, have revealed a strikingly high genetic diversity in the Sebacinales. However, the factors determining this genetic diversity at higher and lower taxonomic levels within this order are still unknown. In this study, we analysed patterns of genetic variation within two morphological species, Sebacina epigaea and S. incrustans, based on 340 DNA haplotype sequences of independent genetic markers from the nuclear (ITS + 5.8S + D1/D2, RPB2) and mitochondrial (ATP6) genomes for 98 population samples. By characterising the genetic population structure within these species, we provide insights into species boundaries and the possible factors responsible for genetic diversity at a regional geographic scale. Results We found that recombination events are relatively common between natural populations within Sebacina epigaea and S. incrustans, and play a significant role in generating intraspecific genetic diversity. Furthermore, we also found that RPB2 and ATP6 genes display higher levels of intraspecific synonymous polymorphism. Phylogenetic and demographic analyses based on nuclear and mitochondrial loci revealed three distinct phylogenetic lineages within of each of the morphospecies S. epigaea and S. incrustans: one major and widely distributed lineage, and two geographically restricted lineages, respectively. We found almost no differential morphological or ecological characteristics that could be used to discriminate between these lineages. Conclusions Our results suggest that recombination and negative selection have played significant roles in generating genetic diversity within these morphological species at small geographical scales. Concordance between gene genealogies identified lineages/cryptic species that have evolved independently for a relatively long period of time. These putative species were not associated with geographic provenance

  6. High Risks of Losing Genetic Diversity in an Endemic Mauritian Gecko: Implications for Conservation

    PubMed Central

    Buckland, Steeves; Cole, Nik C.; Groombridge, Jim J.; Küpper, Clemens; Burke, Terry; Dawson, Deborah A.; Gallagher, Laura E.; Harris, Stephen

    2014-01-01

    Genetic structure can be a consequence of recent population fragmentation and isolation, or a remnant of historical localised adaptation. This poses a challenge for conservationists since misinterpreting patterns of genetic structure may lead to inappropriate management. Of 17 species of reptile originally found in Mauritius, only five survive on the main island. One of these, Phelsuma guimbeaui (lowland forest day gecko), is now restricted to 30 small isolated subpopulations following severe forest fragmentation and isolation due to human colonisation. We used 20 microsatellites in ten subpopulations and two mitochondrial DNA (mtDNA) markers in 13 subpopulations to: (i) assess genetic diversity, population structure and genetic differentiation of subpopulations; (ii) estimate effective population sizes and migration rates of subpopulations; and (iii) examine the phylogenetic relationships of haplotypes found in different subpopulations. Microsatellite data revealed significant population structure with high levels of genetic diversity and isolation by distance, substantial genetic differentiation and no migration between most subpopulations. MtDNA, however, showed no evidence of population structure, indicating that there was once a genetically panmictic population. Effective population sizes of ten subpopulations, based on microsatellite markers, were small, ranging from 44 to 167. Simulations suggested that the chance of survival and allelic diversity of some subpopulations will decrease dramatically over the next 50 years if no migration occurs. Our DNA-based evidence reveals an urgent need for a management plan for the conservation of P. guimbeaui. We identified 18 threatened and 12 viable subpopulations and discuss a range of management options that include translocation of threatened subpopulations to retain maximum allelic diversity, and habitat restoration and assisted migration to decrease genetic erosion and inbreeding for the viable subpopulations. PMID

  7. Bayesian coalescent inference reveals high evolutionary rates and diversification of Zika virus populations.

    PubMed

    Fajardo, Alvaro; Soñora, Martín; Moreno, Pilar; Moratorio, Gonzalo; Cristina, Juan

    2016-10-01

    Zika virus (ZIKV) is a member of the family Flaviviridae. In 2015, ZIKV triggered an epidemic in Brazil and spread across Latin America. By May of 2016, the World Health Organization warns over spread of ZIKV beyond this region. Detailed studies on the mode of evolution of ZIKV strains are extremely important for our understanding of the emergence and spread of ZIKV populations. In order to gain insight into these matters, a Bayesian coalescent Markov Chain Monte Carlo analysis of complete genome sequences of recently isolated ZIKV strains was performed. The results of these studies revealed a mean rate of evolution of 1.20 × 10(-3) nucleotide substitutions per site per year (s/s/y) for ZIKV strains enrolled in this study. Several variants isolated in China are grouped together with all strains isolated in Latin America. Another genetic group composed exclusively by Chinese strains were also observed, suggesting the co-circulation of different genetic lineages in China. These findings indicate a high level of diversification of ZIKV populations. Strains isolated from microcephaly cases do not share amino acid substitutions, suggesting that other factors besides viral genetic differences may play a role for the proposed pathogenesis caused by ZIKV infection. J. Med. Virol. 88:1672-1676, 2016. © 2016 Wiley Periodicals, Inc. PMID:27278855

  8. The draft genome of Tibetan hulless barley reveals adaptive patterns to the high stressful Tibetan Plateau

    PubMed Central

    Zeng, Xingquan; Long, Hai; Wang, Zhuo; Zhao, Shancen; Tang, Yawei; Huang, Zhiyong; Wang, Yulin; Xu, Qijun; Mao, Likai; Deng, Guangbing; Yao, Xiaoming; Li, Xiangfeng; Bai, Lijun; Yuan, Hongjun; Pan, Zhifen; Liu, Renjian; Chen, Xin; WangMu, QiMei; Chen, Ming; Yu, Lili; Liang, Junjun; DunZhu, DaWa; Zheng, Yuan; Yu, Shuiyang; LuoBu, ZhaXi; Guang, Xuanmin; Li, Jiang; Deng, Cao; Hu, Wushu; Chen, Chunhai; TaBa, XiongNu; Gao, Liyun; Lv, Xiaodan; Abu, Yuval Ben; Fang, Xiaodong; Nevo, Eviatar; Yu, Maoqun; Wang, Jun; Tashi, Nyima

    2015-01-01

    The Tibetan hulless barley (Hordeum vulgare L. var. nudum), also called “Qingke” in Chinese and “Ne” in Tibetan, is the staple food for Tibetans and an important livestock feed in the Tibetan Plateau. The diploid nature and adaptation to diverse environments of the highland give it unique resources for genetic research and crop improvement. Here we produced a 3.89-Gb draft assembly of Tibetan hulless barley with 36,151 predicted protein-coding genes. Comparative analyses revealed the divergence times and synteny between barley and other representative Poaceae genomes. The expansion of the gene family related to stress responses was found in Tibetan hulless barley. Resequencing of 10 barley accessions uncovered high levels of genetic variation in Tibetan wild barley and genetic divergence between Tibetan and non-Tibetan barley genomes. Selective sweep analyses demonstrate adaptive correlations of genes under selection with extensive environmental variables. Our results not only construct a genomic framework for crop improvement but also provide evolutionary insights of highland adaptation of Tibetan hulless barley. PMID:25583503

  9. The draft genome of Tibetan hulless barley reveals adaptive patterns to the high stressful Tibetan Plateau.

    PubMed

    Zeng, Xingquan; Long, Hai; Wang, Zhuo; Zhao, Shancen; Tang, Yawei; Huang, Zhiyong; Wang, Yulin; Xu, Qijun; Mao, Likai; Deng, Guangbing; Yao, Xiaoming; Li, Xiangfeng; Bai, Lijun; Yuan, Hongjun; Pan, Zhifen; Liu, Renjian; Chen, Xin; WangMu, QiMei; Chen, Ming; Yu, Lili; Liang, Junjun; DunZhu, DaWa; Zheng, Yuan; Yu, Shuiyang; LuoBu, ZhaXi; Guang, Xuanmin; Li, Jiang; Deng, Cao; Hu, Wushu; Chen, Chunhai; TaBa, XiongNu; Gao, Liyun; Lv, Xiaodan; Abu, Yuval Ben; Fang, Xiaodong; Nevo, Eviatar; Yu, Maoqun; Wang, Jun; Tashi, Nyima

    2015-01-27

    The Tibetan hulless barley (Hordeum vulgare L. var. nudum), also called "Qingke" in Chinese and "Ne" in Tibetan, is the staple food for Tibetans and an important livestock feed in the Tibetan Plateau. The diploid nature and adaptation to diverse environments of the highland give it unique resources for genetic research and crop improvement. Here we produced a 3.89-Gb draft assembly of Tibetan hulless barley with 36,151 predicted protein-coding genes. Comparative analyses revealed the divergence times and synteny between barley and other representative Poaceae genomes. The expansion of the gene family related to stress responses was found in Tibetan hulless barley. Resequencing of 10 barley accessions uncovered high levels of genetic variation in Tibetan wild barley and genetic divergence between Tibetan and non-Tibetan barley genomes. Selective sweep analyses demonstrate adaptive correlations of genes under selection with extensive environmental variables. Our results not only construct a genomic framework for crop improvement but also provide evolutionary insights of highland adaptation of Tibetan hulless barley. PMID:25583503

  10. AFLP marker analysis revealing genetic structure of the tree Parapiptadenia rigida (Benth.) Brenan (Leguminosae-Mimosoideae) in the southern Brazilian Tropical Rainforest.

    PubMed

    de Souza, Laís Bérgamo; Ruas, Eduardo A; Rodrigues, Luana A; Ruas, Claudete F; Ruas, Paulo M

    2013-12-01

    Parapiptadenia rigida is a tropical early secondary succession tree characteristic of the Tropical Atlantic Rainforest. This species is of great ecological importance in the recovery of degraded areas. In this study we investigated the variability and population genetic structure of eight populations of P. rigida. Five AFLP primer combinations were used in a sample of 159 individuals representing these eight populations, rendering a total of 126 polymorphic fragments. The averages of percentage of polymorphic loci, gene diversity, and Shannon index were 60.45%, 0.217, and 0.322, respectively. A significant correlation between the population genetic variability and the population sizes was observed. The genetic variability within populations (72.20%) was higher than between these (22.80%). No perfect correlation was observed between geographic and genetic distances, which might be explained by differences in deforestation intensities that occurred in these areas. A dendrogram constructed by the UPGMA method revealed the formation of two clusters, these also confirmed by Bayesian analysis for the number of K cluster. These results show that it is necessary to develop urgent management strategies for the conservation of certain populations of P. rigida, while other populations still preserve reasonably high levels of genetic variability. PMID:24385857

  11. Baiji genomes reveal low genetic variability and new insights into secondary aquatic adaptations

    PubMed Central

    Zhou, Xuming; Sun, Fengming; Xu, Shixia; Fan, Guangyi; Zhu, Kangli; Liu, Xin; Chen, Yuan; Shi, Chengcheng; Yang, Yunxia; Huang, Zhiyong; Chen, Jing; Hou, Haolong; Guo, Xuejiang; Chen, Wenbin; Chen, Yuefeng; Wang, Xiaohong; Lv, Tian; Yang, Dan; Zhou, Jiajian; Huang, Bangqing; Wang, Zhengfei; Zhao, Wei; Tian, Ran; Xiong, Zhiqiang; Xu, Junxiao; Liang, Xinming; Chen, Bingyao; Liu, Weiqing; Wang, Junyi; Pan, Shengkai; Fang, Xiaodong; Li, Ming; Wei, Fuwen; Xu, Xun; Zhou, Kaiya; Wang, Jun; Yang, Guang

    2013-01-01

    The baiji, or Yangtze River dolphin (Lipotes vexillifer), is a flagship species for the conservation of aquatic animals and ecosystems in the Yangtze River of China; however, this species has now been recognized as functionally extinct. Here we report a high-quality draft genome and three re-sequenced genomes of L. vexillifer using Illumina short-read sequencing technology. Comparative genomic analyses reveal that cetaceans have a slow molecular clock and molecular adaptations to their aquatic lifestyle. We also find a significantly lower number of heterozygous single nucleotide polymorphisms in the baiji compared to all other mammalian genomes reported thus far. A reconstruction of the demographic history of the baiji indicates that a bottleneck occurred near the end of the last deglaciation, a time coinciding with a rapid decrease in temperature and the rise of eustatic sea level. PMID:24169659

  12. Baiji genomes reveal low genetic variability and new insights into secondary aquatic adaptations.

    PubMed

    Zhou, Xuming; Sun, Fengming; Xu, Shixia; Fan, Guangyi; Zhu, Kangli; Liu, Xin; Chen, Yuan; Shi, Chengcheng; Yang, Yunxia; Huang, Zhiyong; Chen, Jing; Hou, Haolong; Guo, Xuejiang; Chen, Wenbin; Chen, Yuefeng; Wang, Xiaohong; Lv, Tian; Yang, Dan; Zhou, Jiajian; Huang, Bangqing; Wang, Zhengfei; Zhao, Wei; Tian, Ran; Xiong, Zhiqiang; Xu, Junxiao; Liang, Xinming; Chen, Bingyao; Liu, Weiqing; Wang, Junyi; Pan, Shengkai; Fang, Xiaodong; Li, Ming; Wei, Fuwen; Xu, Xun; Zhou, Kaiya; Wang, Jun; Yang, Guang

    2013-01-01

    The baiji, or Yangtze River dolphin (Lipotes vexillifer), is a flagship species for the conservation of aquatic animals and ecosystems in the Yangtze River of China; however, this species has now been recognized as functionally extinct. Here we report a high-quality draft genome and three re-sequenced genomes of L. vexillifer using Illumina short-read sequencing technology. Comparative genomic analyses reveal that cetaceans have a slow molecular clock and molecular adaptations to their aquatic lifestyle. We also find a significantly lower number of heterozygous single nucleotide polymorphisms in the baiji compared to all other mammalian genomes reported thus far. A reconstruction of the demographic history of the baiji indicates that a bottleneck occurred near the end of the last deglaciation, a time coinciding with a rapid decrease in temperature and the rise of eustatic sea level. PMID:24169659

  13. Genetic diversity and differentiation of the Ryukyu endemic frog Babina holsti as revealed by mitochondrial DNA.

    PubMed

    Tominaga, Atsushi; Matsui, Masafumi; Nakata, Katsushi

    2014-02-01

    We surveyed the genetic diversity and genetic differentiation of an endangered frog, Babina holsti, endemic to Okinawajima and Tokashikijima Islands of the Ryukyus, to elucidate its divergence history and obtain basic data for its conservation. Genetic differentiation between the two island lineages is moderate (3.1% p-distance in the cyt b gene). This result suggests that the two island lineages have been isolated between the late Pliocene and the middle Pleistocene and have never migrated between the current northern part of Okinawajima and Tokashikijima Islands, which were once connected in the late Pleistocene glacial age. On Okinawajima Island, the southernmost sample was constituted by a unique haplotype, without considerable genetic distance from haplotypes detected from northern samples. This unique haplotype composition in the southernmost sample would have resulted from the restricted gene flow between the southernmost population and the other populations in Okinawajima Island. Furthermore, the absence of genetic diversity within the southernmost sample indicates that this population has recently experienced population size reduction, possibly by predation pressure from an introduced mongoose, which is more abundant in the southern part than in the northern part of the island. Lower genetic diversity in the Tokashikijima sample implies a small effective population size for mitochondrial DNA (mtDNA) in B. holsti on the island. Immediate conservation measures should be taken for the populations from the southernmost range in Okinawajima and Tokashikijima. PMID:24521314

  14. Population expansions shared among coexisting bacterial lineages are revealed by genetic evidence

    PubMed Central

    Avitia, Morena; Escalante, Ana E.; Rebollar, Eria A.; Moreno-Letelier, Alejandra; Eguiarte, Luis E.

    2014-01-01

    Comparative population studies can help elucidate the influence of historical events upon current patterns of biodiversity among taxa that coexist in a given geographic area. In particular, comparative assessments derived from population genetics and coalescent theory have been used to investigate population dynamics of bacterial pathogens in order to understand disease epidemics. In contrast, and despite the ecological relevance of non-host associated and naturally occurring bacteria, there is little understanding of the processes determining their diversity. Here we analyzed the patterns of genetic diversity in coexisting populations of three genera of bacteria (Bacillus, Exiguobacterium, and Pseudomonas) that are abundant in the aquatic systems of the Cuatro Cienegas Basin, Mexico. We tested the hypothesis that a common habitat leaves a signature upon the genetic variation present in bacterial populations, independent of phylogenetic relationships. We used multilocus markers to assess genetic diversity and (1) performed comparative phylogenetic analyses, (2) described the genetic structure of bacterial populations, (3) calculated descriptive parameters of genetic diversity, (4) performed neutrality tests, and (5) conducted coalescent-based historical reconstructions. Our results show a trend of synchronic expansions across most populations independent of both lineage and sampling site. Thus, we provide empirical evidence supporting the analysis of coexisting bacterial lineages in natural environments to advance our understanding of bacterial evolution beyond medical or health-related microbes. PMID:25548732

  15. Population expansions shared among coexisting bacterial lineages are revealed by genetic evidence.

    PubMed

    Avitia, Morena; Escalante, Ana E; Rebollar, Eria A; Moreno-Letelier, Alejandra; Eguiarte, Luis E; Souza, Valeria

    2014-01-01

    Comparative population studies can help elucidate the influence of historical events upon current patterns of biodiversity among taxa that coexist in a given geographic area. In particular, comparative assessments derived from population genetics and coalescent theory have been used to investigate population dynamics of bacterial pathogens in order to understand disease epidemics. In contrast, and despite the ecological relevance of non-host associated and naturally occurring bacteria, there is little understanding of the processes determining their diversity. Here we analyzed the patterns of genetic diversity in coexisting populations of three genera of bacteria (Bacillus, Exiguobacterium, and Pseudomonas) that are abundant in the aquatic systems of the Cuatro Cienegas Basin, Mexico. We tested the hypothesis that a common habitat leaves a signature upon the genetic variation present in bacterial populations, independent of phylogenetic relationships. We used multilocus markers to assess genetic diversity and (1) performed comparative phylogenetic analyses, (2) described the genetic structure of bacterial populations, (3) calculated descriptive parameters of genetic diversity, (4) performed neutrality tests, and (5) conducted coalescent-based historical reconstructions. Our results show a trend of synchronic expansions across most populations independent of both lineage and sampling site. Thus, we provide empirical evidence supporting the analysis of coexisting bacterial lineages in natural environments to advance our understanding of bacterial evolution beyond medical or health-related microbes. PMID:25548732

  16. Molecular typing of canine distemper virus strains reveals the presence of a new genetic variant in South America.

    PubMed

    Sarute, Nicolás; Pérez, Ruben; Aldaz, Jaime; Alfieri, Amauri A; Alfieri, Alice F; Name, Daniela; Llanes, Jessika; Hernández, Martín; Francia, Lourdes; Panzera, Yanina

    2014-06-01

    Canine distemper virus (CDV, Paramyxoviridae, Morbillivirus) is the causative agent of a severe infectious disease affecting terrestrial and marine carnivores worldwide. Phylogenetic relationships and the genetic variability of the hemagglutinin (H) protein and the fusion protein signal-peptide (Fsp) allow for the classification of field strains into genetic lineages. Currently, there are nine CDV lineages worldwide, two of them co-circulating in South America. Using the Fsp-coding region, we analyzed the genetic variability of strains from Uruguay, Brazil, and Ecuador, and compared them with those described previously in South America and other geographical areas. The results revealed that the Brazilian and Uruguayan strains belong to the already described South America lineage (EU1/SA1), whereas the Ecuadorian strains cluster in a new clade, here named South America 3, which may represent the third CDV lineage described in South America. PMID:24647552

  17. Transcriptome Profiling of Human Ulcerative Colitis Mucosa Reveals Altered Expression of Pathways Enriched in Genetic Susceptibility Loci

    PubMed Central

    Li, Jin; Zhu, Junfei; Gu, Mengnan; Baldassano, Robert N.; Grant, Struan F. A.; Hakonarson, Hakon

    2014-01-01

    Human colonic mucosa altered by inflammation due to ulcerative colitis (UC) displays a drastically altered pattern of gene expression compared with healthy tissue. We aimed to understand the underlying molecular pathways influencing these differences by analyzing three publically-available, independently-generated microarray datasets of gene expression from endoscopic biopsies of the colon. Gene set enrichment analysis (GSEA) revealed that all three datasets share 87 gene sets upregulated in UC lesions and 8 gene sets downregulated (false discovery rate <0.05). The upregulated pathways were dominated by gene sets involved in immune function and signaling, as well as the control of mitosis. We applied pathway analysis to genotype data derived from genome-wide association studies (GWAS) of UC, consisting of 5,584 cases and 11,587 controls assembled from eight European-ancestry cohorts. The upregulated pathways derived from the gene expression data showed a highly significant overlap with pathways derived from the genotype data (33 of 56 gene sets, hypergeometric P = 1.49×10–19). This study supports the hypothesis that heritable variation in gene expression as measured by GWAS signals can influence key pathways in the development of disease, and that comparison of genetic susceptibility loci with gene expression signatures can differentiate key drivers of inflammation from secondary effects on gene expression of the inflammatory process. PMID:24788701

  18. A mitochondrial-focused genetic interaction map reveals a scaffold-like complex required for inner membrane organization in mitochondria

    PubMed Central

    Hoppins, Suzanne; Collins, Sean R.; Cassidy-Stone, Ann; Hummel, Eric; DeVay, Rachel M.; Lackner, Laura L.; Westermann, Benedikt; Schuldiner, Maya

    2011-01-01

    To broadly explore mitochondrial structure and function as well as the communication of mitochondria with other cellular pathways, we constructed a quantitative, high-density genetic interaction map (the MITO-MAP) in Saccharomyces cerevisiae. The MITO-MAP provides a comprehensive view of mitochondrial function including insights into the activity of uncharacterized mitochondrial proteins and the functional connection between mitochondria and the ER. The MITO-MAP also reveals a large inner membrane–associated complex, which we term MitOS for mitochondrial organizing structure, comprised of Fcj1/Mitofilin, a conserved inner membrane protein, and five additional components. MitOS physically and functionally interacts with both outer and inner membrane components and localizes to extended structures that wrap around the inner membrane. We show that MitOS acts in concert with ATP synthase dimers to organize the inner membrane and promote normal mitochondrial morphology. We propose that MitOS acts as a conserved mitochondrial skeletal structure that differentiates regions of the inner membrane to establish the normal internal architecture of mitochondria. PMID:21987634

  19. Genetic Differentiation between Natural and Hatchery Stocks of Japanese Scallop (Mizuhopecten yessoensis) as Revealed by AFLP Analysis

    PubMed Central

    Liu, Wei-Dong; Li, Hong-Jun; Bao, Xiang-Bo; Gao, Xiang-gang; Li, Yun-feng; He, Chong-Bo; Liu, Zhan-Jiang

    2010-01-01

    Japanese scallop (Mizuhopecten yessoensis) is a cold-tolerant bivalve that was introduced to China for aquaculture in 1982. In this study, amplified fragment length polymorphism (AFLP) markers were used to investigate levels of genetic diversity within M. yessoensis cultured stocks and compare them with wild populations. Six pairs of primer combinations generated 368 loci among 332 individuals, in four cultured and three wild populations. High polymorphism at AFLP markers was found within both cultured and wild M. yessoensis populations. The percentage of polymorphic loci ranged from 61.04% to 72.08%, while the mean heterozygosity ranged from 0.2116 to 0.2596. Compared with wild populations, the four hatchery populations showed significant genetic changes, such as lower expected heterozygosity and percentage of polymorphic loci, and smaller frequency of private alleles, all indicative of a reduction in genetic diversity. Some genetic structures were associated with the geographical distribution of samples; with all samples from Dalian and Japan being closely related, while the population from Russia fell into a distinct clade in the phylogenetic analysis. The genetic information derived from this study indicated that intentional or accidental release of selected Japanese scallops into natural sea areas might result in disturbance of local gene pools and loss of genetic variability. We recommend monitoring the genetic variability of selected hatchery populations to enhance conservation of natural Japanese scallop resources. PMID:21152310

  20. Genetic Analyses Reveal Functions for MAP2K3 and MAP2K6 in Mouse Testis Determination.

    PubMed

    Warr, Nick; Siggers, Pam; Carré, Gwenn-Aël; Wells, Sara; Greenfield, Andy

    2016-05-01

    Testis determination in mammals is initiated by expression of SRY in somatic cells of the embryonic gonad. Genetic analyses in the mouse have revealed a requirement for mitogen-activated protein kinase (MAPK) signaling in testis determination: targeted loss of the kinases MAP3K4 and p38 MAPK causes complete XY embryonic gonadal sex reversal. These kinases occupy positions at the top and bottom level, respectively, in the canonical three-tier MAPK-signaling cascade: MAP3K, MAP2K, MAPK. To date, no role in sex determination has been attributed to a MAP2K, although such a function is predicted to exist. Here, we report roles for the kinases MAP2K3 and MAP2K6 in testis determination. C57BL/6J (B6) embryos lacking MAP2K3 exhibited no significant abnormalities of testis development, whilst those lacking MAP2K6 exhibited a minor delay in testis determination. Compound mutants lacking three out of four functional alleles at the two loci also exhibited delayed testis determination and transient ovotestis formation as a consequence, suggestive of partially redundant roles for these kinases in testis determination. Early lethality of double-knockout embryos precludes analysis of sexual development. To reveal their roles in testis determination more clearly, we generated Map2k mutant B6 embryos using a weaker Sry allele (Sry(AKR)). Loss of Map2k3 on this highly sensitized background exacerbates ovotestis development, whilst loss of Map2k6 results in complete XY gonadal sex reversal associated with reduction of Sry expression at 11.25 days postcoitum. Our data suggest that MAP2K6 functions in mouse testis determination, via positive effects on Sry, and also indicate a minor role for MAP2K3. PMID:27009039

  1. Genetic Structure and Demographic History Reveal Migration of the Diamondback Moth Plutella xylostella (Lepidoptera: Plutellidae) from the Southern to Northern Regions of China

    PubMed Central

    Wei, Shu-Jun; Shi, Bao-Cai; Gong, Ya-Jun; Jin, Gui-Hua; Chen, Xue-Xin; Meng, Xiang-Feng

    2013-01-01

    The diamondback moth Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae) is one of the most destructive insect pests of cruciferous plants worldwide. Biological, ecological and genetic studies have indicated that this moth is migratory in many regions around the world. Although outbreaks of this pest occur annually in China and cause heavy damage, little is known concerning its migration. To better understand its migration pattern, we investigated the population genetic structure and demographic history of the diamondback moth by analyzing 27 geographical populations across China using four mitochondrial genes and nine microsatellite loci. The results showed that high haplotype diversity and low nucleotide diversity occurred in the diamondback moth populations, a finding that is typical for migratory species. No genetic differentiation among all populations and no correlation between genetic and geographical distance were found. However, pairwise analysis of the mitochondrial genes has indicated that populations from the southern region were more differentiated than those from the northern region. Gene flow analysis revealed that the effective number of migrants per generation into populations of the northern region is very high, whereas that into populations of the southern region is quite low. Neutrality testing, mismatch distribution and Bayesian Skyline Plot analyses based on mitochondrial genes all revealed that deviation from Hardy-Weinberg equilibrium and sudden expansion of the effective population size were present in populations from the northern region but not in those from the southern region. In conclusion, all our analyses strongly demonstrated that the diamondback moth migrates within China from the southern to northern regions with rare effective migration in the reverse direction. Our research provides a successful example of using population genetic approaches to resolve the seasonal migration of insects. PMID:23565158

  2. Molecular Mechanisms of Fiber Differential Development between G. barbadense and G. hirsutum Revealed by Genetical Genomics

    PubMed Central

    Chen, Xiangdong; Guo, Wangzhen; Liu, Bingliang; Zhang, Yuanming; Song, Xianliang; Cheng, Yu; Zhang, Lili; Zhang, Tianzhen

    2012-01-01

    Cotton fiber qualities including length, strength and fineness are known to be controlled by genes affecting cell elongation and secondary cell wall (SCW) biosynthesis, but the molecular mechanisms that govern development of fiber traits are largely unknown. Here, we evaluated an interspecific backcrossed population from G. barbadense cv. Hai7124 and G. hirsutum acc. TM-1 for fiber characteristics in four-year environments under field conditions, and detected 12 quantitative trait loci (QTL) and QTL-by-environment interactions by multi-QTL joint analysis. Further analysis of fiber growth and gene expression between TM-1 and Hai7124 showed greater differences at 10 and 25 days post-anthesis (DPA). In this two period important for fiber performances, we integrated genome-wide expression profiling with linkage analysis using the same genetic materials and identified in total 916 expression QTL (eQTL) significantly (P<0.05) affecting the expression of 394 differential genes. Many positional cis-/trans-acting eQTL and eQTL hotspots were detected across the genome. By comparative mapping of eQTL and fiber QTL, a dataset of candidate genes affecting fiber qualities was generated. Real-time quantitative RT-PCR (qRT-PCR) analysis confirmed the major differential genes regulating fiber cell elongation or SCW synthesis. These data collectively support molecular mechanism for G. hirsutum and G. barbadense through differential gene regulation causing difference of fiber qualities. The down-regulated expression of abscisic acid (ABA) and ethylene signaling pathway genes and high-level and long-term expression of positive regulators including auxin and cell wall enzyme genes for fiber cell elongation at the fiber developmental transition stage may account for superior fiber qualities. PMID:22253876

  3. Molecular mechanisms of fiber differential development between G. barbadense and G. hirsutum revealed by genetical genomics.

    PubMed

    Chen, Xiangdong; Guo, Wangzhen; Liu, Bingliang; Zhang, Yuanming; Song, Xianliang; Cheng, Yu; Zhang, Lili; Zhang, Tianzhen

    2012-01-01

    Cotton fiber qualities including length, strength and fineness are known to be controlled by genes affecting cell elongation and secondary cell wall (SCW) biosynthesis, but the molecular mechanisms that govern development of fiber traits are largely unknown. Here, we evaluated an interspecific backcrossed population from G. barbadense cv. Hai7124 and G. hirsutum acc. TM-1 for fiber characteristics in four-year environments under field conditions, and detected 12 quantitative trait loci (QTL) and QTL-by-environment interactions by multi-QTL joint analysis. Further analysis of fiber growth and gene expression between TM-1 and Hai7124 showed greater differences at 10 and 25 days post-anthesis (DPA). In this two period important for fiber performances, we integrated genome-wide expression profiling with linkage analysis using the same genetic materials and identified in total 916 expression QTL (eQTL) significantly (P<0.05) affecting the expression of 394 differential genes. Many positional cis-/trans-acting eQTL and eQTL hotspots were detected across the genome. By comparative mapping of eQTL and fiber QTL, a dataset of candidate genes affecting fiber qualities was generated. Real-time quantitative RT-PCR (qRT-PCR) analysis confirmed the major differential genes regulating fiber cell elongation or SCW synthesis. These data collectively support molecular mechanism for G. hirsutum and G. barbadense through differential gene regulation causing difference of fiber qualities. The down-regulated expression of abscisic acid (ABA) and ethylene signaling pathway genes and high-level and long-term expression of positive regulators including auxin and cell wall enzyme genes for fiber cell elongation at the fiber developmental transition stage may account for superior fiber qualities. PMID:22253876

  4. Genetic Rearrangements of Six Wheat–Agropyron cristatum 6P Addition Lines Revealed by Molecular Markers

    PubMed Central

    Su, Junji; Zhang, Jinpeng; Song, Liqiang; Gao, Ainong; Yang, Xinming; Li, Xiuquan; Liu, Weihua; Li, Lihui

    2014-01-01

    Agropyron cristatum (L.) Gaertn. (2n = 4x = 28, PPPP) not only is cultivated as pasture fodder but also could provide many desirable genes for wheat improvement. It is critical to obtain common wheat–A. cristatum alien disomic addition lines to locate the desired genes on the P genome chromosomes. Comparative analysis of the homoeologous relationships between the P genome chromosome and wheat genome chromosomes is a key step in transferring different desirable genes into common wheat and producing the desired alien translocation line while compensating for the loss of wheat chromatin. In this study, six common wheat–A. cristatum disomic addition lines were produced and analyzed by phenotypic examination, genomic in situ hybridization (GISH), SSR markers from the ABD genomes and STS markers from the P genome. Comparative maps, six in total, were generated and demonstrated that all six addition lines belonged to homoeologous group 6. However, chromosome 6P had undergone obvious rearrangements in different addition lines compared with the wheat chromosome, indicating that to obtain a genetic compensating alien translocation line, one should recombine alien chromosomal regions with homoeologous wheat chromosomes. Indeed, these addition lines were classified into four types based on the comparative mapping: 6PI, 6PII, 6PIII, and 6PIV. The different types of chromosome 6P possessed different desirable genes. For example, the 6PI type, containing three addition lines, carried genes conferring high numbers of kernels per spike and resistance to powdery mildew, important traits for wheat improvement. These results may prove valuable for promoting the development of conventional chromosome engineering techniques toward molecular chromosome engineering. PMID:24595330

  5. Genome-wide Association Study of Dermatomyositis Reveals Genetic Overlap with other Autoimmune Disorders

    PubMed Central

    Miller, Frederick W.; Cooper, Robert G.; Vencovsky, Jiri; Rider, Lisa G.; Danko, Katalin; Wedderburn, Lucy R.; Lundberg, Ingrid E.; Pachman, Lauren M.; Reed, Ann M.; Ytterberg, Steven R.; Padyukov, Leonid; Selva-O’Callaghan, Albert; Radstake, Timothy; Isenberg, David A.; Chinoy, Hector; Ollier, William E. R.; O’Hanlon, Terrance P.; Peng, Bo; Lee, Annette; Lamb, Janine A.; Chen, Wei; Amos, Christopher I.; Gregersen, Peter K.

    2014-01-01

    Objective To identify new genetic associations with juvenile and adult dermatomyositis (DM). Methods We performed a genome-wide association study (GWAS) of adult and juvenile DM patients of European ancestry (n = 1178) and controls (n = 4724). To assess genetic overlap with other autoimmune disorders, we examined whether 141 single nucleotide polymorphisms (SNPs) outside the major histocompatibility complex (MHC) locus, and previously associated with autoimmune diseases, predispose to DM. Results Compared to controls, patients with DM had a strong signal in the MHC region consisting of GWAS-level significance (P < 5x10−8) at 80 genotyped SNPs. An analysis of 141 non-MHC SNPs previously associated with autoimmune diseases showed that three SNPs linked with three genes were associated with DM, with a false discovery rate (FDR) < 0.05. These genes were phospholipase C like 1 (PLCL1, rs6738825, FDR=0.00089), B lymphoid tyrosine kinase (BLK, rs2736340, FDR=0.00031), and chemokine (C-C motif) ligand 21 (CCL21, rs951005, FDR=0.0076). None of these genes was previously reported to be associated with DM. Conclusion Our findings confirm the MHC as the major genetic region associated with DM and indicate that DM shares non-MHC genetic features with other autoimmune diseases, suggesting the presence of additional novel risk loci. This first identification of autoimmune disease genetic predispositions shared with DM may lead to enhanced understanding of pathogenesis and novel diagnostic and therapeutic approaches. PMID:23983088

  6. Genetic Diversity in Lens Species Revealed by EST and Genomic Simple Sequence Repeat Analysis.

    PubMed

    Dikshit, Harsh Kumar; Singh, Akanksha; Singh, Dharmendra; Aski, Muraleedhar Sidaram; Prakash, Prapti; Jain, Neelu; Meena, Suresh; Kumar, Shiv; Sarker, Ashutosh

    2015-01-01

    Low productivity of pilosae type lentils grown in South Asia is attributed to narrow genetic base of the released cultivars which results in susceptibility to biotic and abiotic stresses. For enhancement of productivity and production, broadening of genetic base is essentially required. The genetic base of released cultivars can be broadened by using diverse types including bold seeded and early maturing lentils from Mediterranean region and related wild species. Genetic diversity in eighty six accessions of three species of genus Lens was assessed based on twelve genomic and thirty one EST-SSR markers. The evaluated set of genotypes included diverse lentil varieties and advanced breeding lines from Indian programme, two early maturing ICARDA lines and five related wild subspecies/species endemic to the Mediterranean region. Genomic SSRs exhibited higher polymorphism in comparison to EST SSRs. GLLC 598 produced 5 alleles with highest gene diversity value of 0.80. Among the studied subspecies/species 43 SSRs detected maximum number of alleles in L. orientalis. Based on Nei's genetic distance cultivated lentil L. culinaris subsp. culinaris was found to be close to its wild progenitor L. culinaris subsp. orientalis. The Prichard's structure of 86 genotypes distinguished different subspecies/species. Higher variability was recorded among individuals within population than among populations. PMID:26381889

  7. Genetic homogeneity in the commercial pink shrimp Farfantepenaeus paulensis revealed by COI barcoding gene

    NASA Astrophysics Data System (ADS)

    Teodoro, S. S. A.; Terossi, M.; Costa, R. C.; Mantelatto, F. L.

    2015-12-01

    The pink shrimp Farfantepenaeus paulensis is one of the most commercially exploited species in Brazil's South and Southeastern regions. Specific information about the status of its genetic variation is necessary to promote more effective management procedures. The genetic variation of the population of F. paulensis was investigated in five localities along southern and southeastern coast of Brazil. Sampling was performed with a commercial fishing boat. Total genomic DNA was extracted from abdominal muscle tissues and was used to DNA amplification by PCR. The COI gene was used as a DNA barcoding marker. The 570 bp COI gene sequences were obtained from all 45 individuals. The haplotype network showed no genetic variability among the population stocks, which was confirmed by Molecular Variance Analysis. The final alignment showed that inside species there is haplotype sharing among the sampled localities, since one haplotype is shared by 38 individuals belonging to all the five sampled regions, with no biogeographic pattern. This result is reasonable since there are no geographical barriers or habitat disjunction that might serve as a barrier to gene flow among the sampled localities. Possible reasons and consequences of the genetic homogeneity found are discussed. The results complement ecological studies concerning the offseason: since it is a single stock, the same protection strategy can be applied. However, the genetic homogeneity found in this study combined with the intensive fishery effort and the species biology can result in severe consequences for the F. paulensis.

  8. Genetic Diversity in Lens Species Revealed by EST and Genomic Simple Sequence Repeat Analysis

    PubMed Central

    Dikshit, Harsh Kumar; Singh, Akanksha; Singh, Dharmendra; Aski, Muraleedhar Sidaram; Prakash, Prapti; Jain, Neelu; Meena, Suresh; Kumar, Shiv; Sarker, Ashutosh

    2015-01-01

    Low productivity of pilosae type lentils grown in South Asia is attributed to narrow genetic base of the released cultivars which results in susceptibility to biotic and abiotic stresses. For enhancement of productivity and production, broadening of genetic base is essentially required. The genetic base of released cultivars can be broadened by using diverse types including bold seeded and early maturing lentils from Mediterranean region and related wild species. Genetic diversity in eighty six accessions of three species of genus Lens was assessed based on twelve genomic and thirty one EST-SSR markers. The evaluated set of genotypes included diverse lentil varieties and advanced breeding lines from Indian programme, two early maturing ICARDA lines and five related wild subspecies/species endemic to the Mediterranean region. Genomic SSRs exhibited higher polymorphism in comparison to EST SSRs. GLLC 598 produced 5 alleles with highest gene diversity value of 0.80. Among the studied subspecies/species 43 SSRs detected maximum number of alleles in L. orientalis. Based on Nei’s genetic distance cultivated lentil L. culinaris subsp. culinaris was found to be close to its wild progenitor L. culinaris subsp. orientalis. The Prichard’s structure of 86 genotypes distinguished different subspecies/species. Higher variability was recorded among individuals within population than among populations. PMID:26381889

  9. High HIV-1 Genetic Diversity in Patients from Northern Brazil.

    PubMed

    da Costa, Carolina Marinho; Costa de Oliveira, Cintia Mara; Chehuan de Melo, Yonne Francis; Delatorre, Edson; Bello, Gonzalo; Couto-Fernandez, Jose Carlos

    2016-09-01

    The HIV-1 epidemic in Brazil is driven by subtypes B, F1, and C and recombinants forms among those subtypes. The distribution of HIV-1 subtypes, however, may vary across different Brazilian regions and the molecular epidemiologic profile in Northern Brazil remains poorly explored. HIV-1 pol sequences were obtained from 305 patients failing antiretroviral therapy followed at outpatient clinics from five Northern Brazilian states. The most prevalent HIV-1 clade observed in the Northern Brazilian region was subtype B (81%), followed by BF1 recombinants (10%), subtype F1 (4%), subtype C (3%), BC recombinants (2%), and BU recombinants (1%). Although HIV-1 subtype B was the predominant HIV-1 clade in Northern Brazil, its prevalence greatly varies among different states, ranging from 63% in Rondônia to 92% in Acre. Among the 37 HIV-1 recombinant sequences detected in the Northern Brazilian region, nine (24%) displayed a unique recombinant form structure, five (14%) a CRF28/29_BF-like structure, and four (11%) a CRF31_BC-like structure. Two other BF1 recombinant patterns were identified in 16 (43%) and three (8%) samples that may correspond to two potentially new CRFs_BF characteristic of the Northern region. This study reveals that despite the low spatial connectivity with other Brazilian regions, the genetic complexity of the HIV-1 epidemic in Northern Brazil is very high and that the molecular epidemiologic pattern may vary across different northern states, reflecting a complex epidemic with multiple independent viral introductions into this Brazilian region. PMID:27091699

  10. High-Resolution CRISPR Screens Reveal Fitness Genes and Genotype-Specific Cancer Liabilities.

    PubMed

    Hart, Traver; Chandrashekhar, Megha; Aregger, Michael; Steinhart, Zachary; Brown, Kevin R; MacLeod, Graham; Mis, Monika; Zimmermann, Michal; Fradet-Turcotte, Amelie; Sun, Song; Mero, Patricia; Dirks, Peter; Sidhu, Sachdev; Roth, Frederick P; Rissland, Olivia S; Durocher, Daniel; Angers, Stephane; Moffat, Jason

    2015-12-01

    The ability to perturb genes in human cells is crucial for elucidating gene function and holds great potential for finding therapeutic targets for diseases such as cancer. To extend the catalog of human core and context-dependent fitness genes, we have developed a high-complexity second-generation genome-scale CRISPR-Cas9 gRNA library and applied it to fitness screens in five human cell lines. Using an improved Bayesian analytical approach, we consistently discover 5-fold more fitness genes than were previously observed. We present a list of 1,580 human core fitness genes and describe their general properties. Moreover, we demonstrate that context-dependent fitness genes accurately recapitulate pathway-specific genetic vulnerabilities induced by known oncogenes and reveal cell-type-specific dependencies for specific receptor tyrosine kinases, even in oncogenic KRAS backgrounds. Thus, rigorous identification of human cell line fitness genes using a high-complexity CRISPR-Cas9 library affords a high-resolution view of the genetic vulnerabilities of a cell. PMID:26627737

  11. Dietary Differentiation and the Evolution of Population Genetic Structure in a Highly Mobile Carnivore

    PubMed Central

    Pilot, Małgorzata; Jędrzejewski, Włodzimierz; Sidorovich, Vadim E.; Meier-Augenstein, Wolfram; Hoelzel, A. Rus

    2012-01-01

    Recent studies on highly mobile carnivores revealed cryptic population genetic structures correlated to transitions in habitat types and prey species composition. This led to the hypothesis that natal-habitat-biased dispersal may be responsible for generating population genetic structure. However, direct evidence for the concordant ecological and genetic differentiation between populations of highly mobile mammals is rare. To address this we analyzed stable isotope profiles (δ13C and δ15N values) for Eastern European wolves (Canis lupus) as a quantifiable proxy measure of diet for individuals that had been genotyped in an earlier study (showing cryptic genetic structure), to provide a quantitative assessment of the relationship between individual foraging behavior and genotype. We found a significant correlation between genetic distances and dietary differentiation (explaining 46% of the variation) in both the marginal test and crucially, when geographic distance was accounted for as a co-variable. These results, interpreted in the context of other possible mechanisms such as allopatry and isolation by distance, reinforce earlier studies suggesting that diet and associated habitat choice are influencing the structuring of populations in highly mobile carnivores. PMID:22768075

  12. Dietary differentiation and the evolution of population genetic structure in a highly mobile carnivore.

    PubMed

    Pilot, Małgorzata; Jędrzejewski, Włodzimierz; Sidorovich, Vadim E; Meier-Augenstein, Wolfram; Hoelzel, A Rus

    2012-01-01

    Recent studies on highly mobile carnivores revealed cryptic population genetic structures correlated to transitions in habitat types and prey species composition. This led to the hypothesis that natal-habitat-biased dispersal may be responsible for generating population genetic structure. However, direct evidence for the concordant ecological and genetic differentiation between populations of highly mobile mammals is rare. To address this we analyzed stable isotope profiles (δ(13)C and δ(15)N values) for Eastern European wolves (Canis lupus) as a quantifiable proxy measure of diet for individuals that had been genotyped in an earlier study (showing cryptic genetic structure), to provide a quantitative assessment of the relationship between individual foraging behavior and genotype. We found a significant correlation between genetic distances and dietary differentiation (explaining 46% of the variation) in both the marginal test and crucially, when geographic distance was accounted for as a co-variable. These results, interpreted in the context of other possible mechanisms such as allopatry and isolation by distance, reinforce earlier studies suggesting that diet and associated habitat choice are influencing the structuring of populations in highly mobile carnivores. PMID:22768075

  13. Heterogeneous genetic structure in a Fagus crenata population in an old-growth beech forest revealed by microsatellite markers.

    PubMed

    Asuka, Y; Tomaru, N; Nisimura, N; Tsumura, Y; Yamamoto, S

    2004-05-01

    The within-population genetic structure of Fagus crenata in a 4-ha plot (200 x 200 m) of an old-growth beech forest was analysed using microsatellite markers. To assess the genetic structure, Moran's I spatial autocorrelation coefficient was calculated. Correlograms of Moran's I showed significant positive values less than 0.100 for short-distance classes, indicating weak genetic structure. The genetic structure within the population is created by limited seed dispersal, and is probably weakened by overlapping seed shadow, secondary seed dispersal, extensive pollen flow and the thinning process. Genetic structure was detected in a western subplot of 50 x 200 m with immature soils and almost no dwarf bamboos (Sasa spp.), where small and intermediate-sized individuals were distributed in aggregations with high density because of successful regeneration. By contrast, genetic structure was not found in an eastern subplot of the same size with mature soils and Sasa cover, where successful regeneration was prevented, and the density of the small and intermediate-sized individuals was low. Moreover, genetic structure of individuals in a small-size class (diameter at breast height < 12 cm) was more obvious than in a large-size class (diameter at breast height >/= 12 cm). The apparent genetic structure detected in the 4-ha plot was therefore probably the result of the structure in the western portion of the plot and in small and intermediate-sized individuals that successfully regenerated under the favourable environment. The heterogeneity in genetic structure presumably reflects variation in the density that should be affected by differences in regeneration dynamics associated with heterogeneity in environmental conditions. PMID:15078459

  14. Microsatellites reveal a strong subdivision of genetic structure in Chinese populations of the mite Tetranychus urticae Koch (Acari: Tetranychidae)

    PubMed Central

    2012-01-01

    Background Two colour forms of the two-spotted spider mite (Tetranychus urticae Koch) coexist in China: a red (carmine) form, which is considered to be native and a green form which is considered to be invasive. The population genetic diversity and population genetic structure of this organism were unclear in China, and there is a controversy over whether they constitute distinct species. To address these issues, we genotyped a total of 1,055 individuals from 18 red populations and 7 green populations in China using eight microsatellite loci. Results We identified 109 alleles. We found a highly significant genetic differentiation among the 25 populations (global FST = 0.506, global FST {ENA} = 0.473) and a low genetic diversity in each population. In addition, genetic diversity of the red form mites was found to be higher than the green form. Pearson correlations between statistics of variation (AR and HE) and geographic coordinates (latitude and longitude) showed that the genetic diversity of the red form was correlated with latitude. Using Bayesian clustering, we divided the Chinese mite populations into five clades which were well congruent with their geographic distributions. Conclusions Spider mites possess low levels of genetic diversity, limit gene flow between populations and significant and IBD (isolation by distance) effect. These factors in turn contribute to the strong subdivision of genetic structure. In addition, population genetic structure results don't support the separation of the two forms of spider mite into two species. The morphological differences between the two forms of mites may be a result of epigenetic effects. PMID:22348504

  15. Genetic characterization of Greek population isolates reveals strong genetic drift at missense and trait-associated variants

    PubMed Central

    Panoutsopoulou, Kalliope; Hatzikotoulas, Konstantinos; Xifara, Dionysia Kiara; Colonna, Vincenza; Farmaki, Aliki-Eleni; Ritchie, Graham R. S.; Southam, Lorraine; Gilly, Arthur; Tachmazidou, Ioanna; Fatumo, Segun; Matchan, Angela; Rayner, Nigel W.; Ntalla, Ioanna; Mezzavilla, Massimo; Chen, Yuan; Kiagiadaki, Chrysoula; Zengini, Eleni; Mamakou, Vasiliki; Athanasiadis, Antonis; Giannakopoulou, Margarita; Kariakli, Vassiliki-Eirini; Nsubuga, Rebecca N.; Karabarinde, Alex; Sandhu, Manjinder; McVean, Gil; Tyler-Smith, Chris; Tsafantakis, Emmanouil; Karaleftheri, Maria; Xue, Yali; Dedoussis, George; Zeggini, Eleftheria

    2014-01-01

    Isolated populations are emerging as a powerful study design in the search for low-frequency and rare variant associations with complex phenotypes. Here we genotype 2,296 samples from two isolated Greek populations, the Pomak villages (HELIC-Pomak) in the North of Greece and the Mylopotamos villages (HELIC-MANOLIS) in Crete. We compare their genomic characteristics to the general Greek population and establish them as genetic isolates. In the MANOLIS cohort, we observe an enrichment of missense variants among the variants that have drifted up in frequency by more than fivefold. In the Pomak cohort, we find novel associations at variants on chr11p15.4 showing large allele frequency increases (from 0.2% in the general Greek population to 4.6% in the isolate) with haematological traits, for example, with mean corpuscular volume (rs7116019, P=2.3 × 10−26). We replicate this association in a second set of Pomak samples (combined P=2.0 × 10−36). We demonstrate significant power gains in detecting medical trait associations. PMID:25373335

  16. Genetic analysis reveals multiple parentage in captive reared eastern hellbender salamanders (Cryptobranchus alleganiensis).

    PubMed

    Unger, Shem D; Williams, Rod N

    2015-11-01

    Information on the parentage of captive reared clutches is vital for conservation head-starting programs. Molecular methods, such as genotyping individuals with hyper-variable markers, can elucidate the genealogical contribution of captive-reared, reintroduced individuals to native populations. In this study, we used 12 polymorphic microsatellite loci to infer parentage of a clutch of 18 eastern hellbenders collected from a single nest from Buffalo Creek, West Virginia, subsequently reared in captivity, and used for translocations in Indiana. Collectively, these markers successfully detected the presence of multiple parentage for this species of conservation concern presently used in captive management programs in zoos across many states. This study highlights the need for genetic analysis of captive reared clutches used in translocations to minimize the loss of genetic diversity and potential for genetic swamping at release sites. PMID:26301598

  17. Spatial and temporal genetic structure of the planktonic Sagitta setosa (Chaetognatha) in European seas as revealed by mitochondrial and nuclear DNA markers.

    PubMed

    Peijnenburg, K T C A; Fauvelot, C; Breeuwer, J A J; Menken, S B J

    2006-10-01

    Little is known about the spatial and temporal scales at which planktonic organisms are genetically structured. A previous study of mitochondrial DNA (mtDNA) in the holoplanktonic chaetognath Sagitta setosa revealed strong phylogeographic structuring suggesting that Northeast (NE) Atlantic, Mediterranean and Black Sea populations are genetically disjunct. The present study used a higher sampling intensity and a combination of mitochondrial and four microsatellite markers to reveal population structuring between and within basins. Between basins, both marker sets indicated significant differentiation confirming earlier results that gene flow is probably absent between the respective S. setosa populations. At the within-basin scale, we found no evidence of spatial or temporal structuring within the NE Atlantic. In the Mediterranean basin, both marker sets indicated significant structuring, but only the mtDNA data indicated a sharp genetic division between Adriatic and all other Mediterranean populations. Data were inconclusive about population structuring in the Black Sea. The levels of differentiation indicated by the two marker sets differed substantially, with far less pronounced structure detected by microsatellite than mtDNA data. This study also uncovered the presence of highly divergent mitochondrial lineages that were discordant with morphology, geography and nuclear DNA. We thus propose the hypothesis that highly divergent mitochondrial lineages may be present within interbreeding S. setosa populations. PMID:16968273

  18. Genetic markers of white matter integrity in schizophrenia revealed by parallel ICA

    PubMed Central

    Gupta, Cota Navin; Chen, Jiayu; Liu, Jingyu; Damaraju, Eswar; Wright, Carrie; Perrone-Bizzozero, Nora I.; Pearlson, Godfrey; Luo, Li; Michael, Andrew M.; Turner, Jessica A.; Calhoun, Vince D.

    2015-01-01

    It is becoming a consensus that white matter integrity is compromised in schizophrenia (SZ), however the underlying genetics remains elusive. Evidence suggests a polygenic basis of the disorder, which involves various genetic variants with modest individual effect sizes. In this work, we used a multivariate approach, parallel independent component analysis (P-ICA), to explore the genetic underpinnings of white matter abnormalities in SZ. A pre-filtering step was first applied to locate 6527 single nucleotide polymorphisms (SNPs) discriminating patients from controls with a nominal uncorrected p-value of 0.01. These potential susceptibility loci were then investigated for associations with fractional anisotropy (FA) images in a cohort consisting of 73 SZ patients and 87 healthy controls (HC). A significant correlation (r = −0.37, p = 1.25 × 10−6) was identified between one genetic factor and one FA component after controlling for scanning site, ethnicity, age, and sex. The identified FA-SNP association remained stable in a 10-fold validation. A 5000-run permutation test yielded a p-value of 2.00 × 10−4. The FA component reflected decreased white matter integrity in the forceps major for SZ patients. The SNP component was overrepresented in genes whose products are involved in corpus callosum morphology (e.g., CNTNAP2, NPAS3, and NFIB) as well as canonical pathways of synaptic long term depression and protein kinase A signaling. Taken together, our finding delineates a part of genetic architecture underlying SZ-related FA reduction, emphasizing the important role of genetic variants involved in neural development. PMID:25784871

  19. The Arthrobacter arilaitensis Re117 Genome Sequence Reveals Its Genetic Adaptation to the Surface of Cheese

    PubMed Central

    Monnet, Christophe; Loux, Valentin; Gibrat, Jean-François; Spinnler, Eric; Barbe, Valérie; Vacherie, Benoit; Gavory, Frederick; Gourbeyre, Edith; Siguier, Patricia; Chandler, Michaël; Elleuch, Rayda

    2010-01-01

    Arthrobacter arilaitensis is one of the major bacterial species found at the surface of cheeses, especially in smear-ripened cheeses, where it contributes to the typical colour, flavour and texture properties of the final product. The A. arilaitensis Re117 genome is composed of a 3,859,257 bp chromosome and two plasmids of 50,407 and 8,528 bp. The chromosome shares large regions of synteny with the chromosomes of three environmental Arthrobacter strains for which genome sequences are available: A. aurescens TC1, A. chlorophenolicus A6 and Arthrobacter sp. FB24. In contrast however, 4.92% of the A. arilaitensis chromosome is composed of ISs elements, a portion that is at least 15 fold higher than for the other Arthrobacter strains. Comparative genomic analyses reveal an extensive loss of genes associated with catabolic activities, presumably as a result of adaptation to the properties of the cheese surface habitat. Like the environmental Arthrobacter strains, A. arilaitensis Re117 is well-equipped with enzymes required for the catabolism of major carbon substrates present at cheese surfaces such as fatty acids, amino acids and lactic acid. However, A. arilaitensis has several specificities which seem to be linked to its adaptation to its particular niche. These include the ability to catabolize D-galactonate, a high number of glycine betaine and related osmolyte transporters, two siderophore biosynthesis gene clusters and a high number of Fe3+/siderophore transport systems. In model cheese experiments, addition of small amounts of iron strongly stimulated the growth of A. arilaitensis, indicating that cheese is a highly iron-restricted medium. We suggest that there is a strong selective pressure at the surface of cheese for strains with efficient iron acquisition and salt-tolerance systems together with abilities to catabolize substrates such as lactic acid, lipids and amino acids. PMID:21124797

  20. High-precision Velocimetry Reveals δ Cephei's Secret Companion

    NASA Astrophysics Data System (ADS)

    Anderson, Richard I.; Sahlmann, Johannes; Holl, Berry; Eyer, Laurent

    2015-08-01

    The search for extra-solar planets has driven tremendous improvements in the precision of radial velocities measured with high-resolution echelle spectrographs. However, relatively few studies have as of yet exploited the present-day extreme (m/s) instrumental precision to study Cepheid variable stars.We have been observing the prototype of classical Cepheids, δ Cephei, since September 2011 using the HERMES spectrograph mounted to the Mercator telescope located at the Roque de los Muchachos Observatory on the island of La Palma. Being one of the most-studied variable stars, we originally chose δ Cephei as a maximum-precision reference for other Cepheids in our sample. To our great surprise however, we discovered a clear orbital signature in the homogeneous HERMES data. Adding in radial velocity data from the literature, we then determined δ Cephei's orbit (cf. Anderson et al. 2015, arXiv:1503.04116). The high orbital eccentricity (e=0.647) leads to close pericenter passages (rmin ~ 9.5 RδCep) which suggest an intriguing past that requires further study, since Cepheids are well-known magnifying glasses for stellar evolution (Kippenhahn & Weigert 1994). We furthermore determined a new parallax to δ Cephei (using Hipparcos data) that is in tension with previous estimates and shows that the orbit will have to be accounted for when measuring δ Cephei's parallax with Gaia.While some of our HERMES data are as precise as 9 m/s, we found correlated excess residuals when removing the reference pulsation model and orbital motion from the HERMES radial velocity data, leaving an RMS of 47 m/s. These higher-than-expected residuals are reminiscent of the "period-jitter" or "flickering" observed in high-precision photometry of Cepheids obtained with the Kepler and MOST satellites. This reveals a fortuitous synergy between variable stars studies and the field of exoplanet research and opens the window for a better understanding of Cepheid pulsations via high

  1. Subtle genetic structure reveals restricted connectivity among populations of a coral reef fish inhabiting remote atolls

    PubMed Central

    Underwood, Jim N; Travers, Michael J; Gilmour, James P

    2012-01-01

    We utilized a spatial and temporal analyses of genetic structure, supplemented with ecological and oceanographic analysis, to assess patterns of population connectivity in a coral reef fish Chromis margaritifer among the unique and remote atolls in the eastern Indian Ocean. A subtle, but significant genetic discontinuity at 10 microsatellite DNA loci was detected between atoll systems corresponding with a low (≤ 1%) probability of advection across the hundreds of kilometers of open ocean that separates them. Thus, although genetic connections between systems are likely maintained by occasional long-distance dispersal of C. margaritifer larvae, ecological population connectivity at this spatial scale appears to be restricted. Further, within one of these atoll systems, significant spatial differentiation among samples was accompanied by a lack of temporal pairwise differentiation between recruit and adult samples, indicating that restrictions to connectivity also occur at a local scale (tens of kilometers). In contrast, a signal of panmixia was detected at the other atoll system studied. Lastly, greater relatedness and reduced genetic diversity within recruit samples was associated with relatively large differences among them, indicating the presence of sweepstakes reproduction whereby a small proportion of adults contributes to recruitment in the next generation. These results are congruent with earlier work on hard corals, suggesting that local production of larvae drives population replenishment in these atoll systems for a range of coral reef species. PMID:22822442

  2. Genetic diversity and relationship of global faba bean (Vicia faba L.) germplasm revealed by ISSR markers.

    PubMed

    Wang, Hai-Fei; Zong, Xu-Xiao; Guan, Jian-Ping; Yang, Tao; Sun, Xue-Lian; Ma, Yu; Redden, Robert

    2012-03-01

    Genetic diversity and relationships of 802 faba bean (Vicia faba L.) landraces and varieties from different geographical locations of China and abroad were examined using ISSR markers. A total of 212 repeatable amplified bands were generated with 11 ISSR primers, of which 209 were polymorphic. Accessions from North China showed highest genetic diversity, while accessions from central China showed low level of diversity. Chinese spring faba bean germplasm was clearly separated from Chinese winter faba bean, based on principal component analysis and UPGMA clustering analysis. Winter accessions from Zhejiang (East China), Jiangxi (East China), Sichuan (Southwest China) and Guizhou (Southwest China) were quite distinct to that from other provinces in China. Great differentiation between Chinese accessions and those from rest of the world was shown with a UPGMA dendrogram. AMOVA analyses demonstrated large variation and differentiation within and among groups of accessions from China. As a continental geographic group, accessions from Europe were genetically closer to those from North Africa. Based on ISSR data, grouping results of accessions from Asia, Europe and Africa were obviously associated with their geographical origin. The overall results indicated that the genetic relationship of faba bean germplasm was closely associated with their geographical origin and their ecological habit. PMID:22204023

  3. Genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. However, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. Therefore, we investigated the physiological and ecological effects of tra...

  4. RNA-seq analysis reveals genetic response and tolerance mechanisms to ozone exposure in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidative stress caused by ground level ozone is a major contributor to yield loss in a number of important crop plants. Soybean (Glycine max) is especially ozone sensitive, and research into its response to oxidative stress is limited. To better understand the genetic response in soybean to oxida...

  5. Genetic Mapping of Sulfur Assimilation Genes Reveals a QTL for Onion Bulb Pungency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onion exhibits wide genetic and environmental variation in bioactive organosulfur compounds that impart pungency and health benefits. A PCR-based molecular marker map that included candidate genes for sulfur assimilation was used to identify genomic regions affecting pungency in the cross 'W202A' x ...

  6. Next-generation sequencing reveals substantial genetic contribution to dementia with Lewy bodies.

    PubMed

    Geiger, Joshua T; Ding, Jinhui; Crain, Barbara; Pletnikova, Olga; Letson, Christopher; Dawson, Ted M; Rosenthal, Liana S; Pantelyat, Alexander; Gibbs, J Raphael; Albert, Marilyn S; Hernandez, Dena G; Hillis, Argye E; Stone, David J; Singleton, Andrew B; Hardy, John A; Troncoso, Juan C; Scholz, Sonja W

    2016-10-01

    Dementia with Lewy bodies (DLB) is the second most common neurodegenerative dementia after Alzheimer's disease. Although an increasing number of genetic factors have been connected to this debilitating condition, the proportion of cases that can be attributed to distinct genetic defects is unknown. To provide a comprehensive analysis of the frequency and spectrum of pathogenic missense mutations and coding risk variants in nine genes previously implicated in DLB, we performed exome sequencing in 111 pathologically confirmed DLB patients. All patients were Caucasian individuals from North America. Allele frequencies of identified missense mutations were compared to 222 control exomes. Remarkably, ~25% of cases were found to carry a pathogenic mutation or risk variant in APP, GBA or PSEN1, highlighting that genetic defects play a central role in the pathogenesis of this common neurodegenerative disorder. In total, 13% of our cohort carried a pathogenic mutation in GBA, 10% of cases carried a risk variant or mutation in PSEN1, and 2% were found to carry an APP mutation. The APOE ε4 risk allele was significantly overrepresented in DLB patients (p-value <0.001). Our results conclusively show that mutations in GBA, PSEN1, and APP are common in DLB and consideration should be given to offer genetic testing to patients diagnosed with Lewy body dementia. PMID:27312774

  7. Genetics of the Pig Tapeworm in Madagascar Reveal a History of Human Dispersal and Colonization

    PubMed Central

    Yanagida, Tetsuya; Carod, Jean-François; Sako, Yasuhito; Nakao, Minoru; Hoberg, Eric P.; Ito, Akira

    2014-01-01

    An intricate history of human dispersal and geographic colonization has strongly affected the distribution of human pathogens. The pig tapeworm Taenia solium occurs throughout the world as the causative agent of cysticercosis, one of the most serious neglected tropical diseases. Discrete genetic lineages of T. solium in Asia and Africa/Latin America are geographically disjunct; only in Madagascar are they sympatric. Linguistic, archaeological and genetic evidence has indicated that the people in Madagascar have mixed ancestry from Island Southeast Asia and East Africa. Hence, anthropogenic introduction of the tapeworm from Southeast Asia and Africa had been postulated. This study shows that the major mitochondrial haplotype of T. solium in Madagascar is closely related to those from the Indian Subcontinent. Parasitological evidence presented here, and human genetics previously reported, support the hypothesis of an Indian influence on Malagasy culture coinciding with periods of early human migration onto the island. We also found evidence of nuclear-mitochondrial discordance in single tapeworms, indicating unexpected cross-fertilization between the two lineages of T. solium. Analyses of genetic and geographic populations of T. solium in Madagascar will shed light on apparently rapid evolution of this organism driven by recent (<2,000 yr) human migrations, following tens of thousands of years of geographic isolation. PMID:25329310

  8. NextGen sequencing reveals short double crossovers contribute disproportionately to genetic diversity in Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is a widespread protozoan parasite of animals that causes zoonotic disease in humans. Three clonal variants predominate in North America and Europe, while South American strains are genetically diverse, and undergo more frequent recombination. All three northern clonal variants s...

  9. Subtle genetic structure reveals restricted connectivity among populations of a coral reef fish inhabiting remote atolls.

    PubMed

    Underwood, Jim N; Travers, Michael J; Gilmour, James P

    2012-03-01

    We utilized a spatial and temporal analyses of genetic structure, supplemented with ecological and oceanographic analysis, to assess patterns of population connectivity in a coral reef fish Chromis margaritifer among the unique and remote atolls in the eastern Indian Ocean. A subtle, but significant genetic discontinuity at 10 microsatellite DNA loci was detected between atoll systems corresponding with a low (≤ 1%) probability of advection across the hundreds of kilometers of open ocean that separates them. Thus, although genetic connections between systems are likely maintained by occasional long-distance dispersal of C. margaritifer larvae, ecological population connectivity at this spatial scale appears to be restricted. Further, within one of these atoll systems, significant spatial differentiation among samples was accompanied by a lack of temporal pairwise differentiation between recruit and adult samples, indicating that restrictions to connectivity also occur at a local scale (tens of kilometers). In contrast, a signal of panmixia was detected at the other atoll system studied. Lastly, greater relatedness and reduced genetic diversity within recruit samples was associated with relatively large differences among them, indicating the presence of sweepstakes reproduction whereby a small proportion of adults contributes to recruitment in the next generation. These results are congruent with earlier work on hard corals, suggesting that local production of larvae drives population replenishment in these atoll systems for a range of coral reef species. PMID:22822442

  10. Genetic variation of Spiroplasma citri populations in California revealed by two genomic loci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus stubborn disease (CSD), known to be present in California since 1915, was confirmed to be caused by Spiroplasma citri in 1972. Hosts of S. citri include citrus and a wide range of annual weeds, ornamentals and crops such as carrots and sesame. Genetic variation of S. citri in California was e...

  11. New inducible genetic method reveals critical roles of GABA in the control of feeding and metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently available inducibleCre/loxPsystems, despite their considerable utility in gene manipulation, have pitfalls in certain scenarios, such as unsatisfactory recombination rates and deleterious effects on physiology and behavior. To overcome these limitations, we designed a new, inducible gene-t...

  12. Genome-wide association mapping reveals rich genetic architecture of complex traits in Oryza sativa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domesticated Asian rice, Oryza sativa, is a cultivated, inbreeding species that feeds over half of the world’s population. Understanding the genetic basis of diverse physiological, developmental, and morphological traits provides the basis for improving yield, quality and sustainability. Here, we pr...

  13. Molecular genetic diversity of Punica granatum L. (pomegranate) as revealed by microsatellite DNA markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pomegranate (Punica granatum L.) is one of the oldest known edible fruits and more and more it arouse interest of scientific community given its numerous biological activities. However, information about its genetic resources and characterization using reliable molecular markers are still scarce. In...

  14. Modifying Behavioral Phenotypes in Fmr1 KO Mice: Genetic Background Differences Reveal Autistic-Like Responses

    PubMed Central

    Spencer, Corinne M.; Alekseyenko, Olga; Hamilton, Shannon M.; Thomas, Alexia M.; Serysheva, Ekaterina; Yuva-Paylor, Lisa A.; Paylor, Richard

    2010-01-01

    Scientific Abstract Fragile X syndrome (FXS) is the most common inherited form of intellectual disability in humans. In addition to cognitive impairment, patients may exhibit hyperactivity, attention deficits, social difficulties and anxiety, and autistic-like behaviors. The degree to which patients display these behaviors varies considerably and is influenced by family history, suggesting that genetic modifiers play a role in the expression of behaviors in FXS. Several studies have examined behavior in a mouse model of FXS in which the Fmr1 gene has been ablated. Most of those studies were done in Fmr1 knockout mice on a pure C57BL/6 or FVB strain background. To gain a better understanding of the effects of genetic background on behaviors resulting from the loss of Fmr1 gene expression, we generated F1 hybrid lines from female Fmr1 heterozygous mice on a pure C57BL/6J background bred with male Fmr1 wild-type mice of various background strains (A/J, DBA/2J, FVB/NJ, 129S1/SvImJ and CD-1). Male Fmr1 knockout and wild-type littermates from each line were examined in an extensive behavioral test battery. Results clearly indicate that multiple behavioral responses are dependent on genetic background, including autistic-like traits that are present on limited genetic backgrounds. This approach has allowed us to identify improved models for different behavioral symptoms present in FXS including autistic-like traits. PMID:21268289

  15. Genetic Variability and Selection Criteria in Rice Mutant Lines as Revealed by Quantitative Traits

    PubMed Central

    Oladosu, Yusuff; Rafii, M. Y.; Abdullah, Norhani; Abdul Malek, Mohammad; Rahim, H. A.; Hussin, Ghazali; Abdul Latif, Mohammad; Kareem, Isiaka

    2014-01-01

    Genetic based knowledge of different vegetative and yield traits play a major role in varietal improvement of rice. Genetic variation gives room for recombinants which are essential for the development of a new variety in any crop. Based on this background, this work was carried out to evaluate genetic diversity of derived mutant lines and establish relationships between their yield and yield components using multivariate analysis. To achieve this objective, two field trials were carried out on 45 mutant rice genotypes to evaluate their growth and yield traits. Data were taken on vegetative traits and yield and its components, while genotypic and phenotypic coefficients, variance components, expected genetic advance, and heritability were calculated. All the genotypes showed variations for vegetative traits and yield and its components. Also, there was positive relationship between the quantitative traits and the final yield with the exception of number of tillers. Finally, the evaluated genotypes were grouped into five major clusters based on the assessed traits with the aid of UPGMA dendrogram. So hybridization of group I with group V or group VI could be used to attain higher heterosis or vigour among the genotypes. Also, this evaluation could be useful in developing reliable selection indices for important agronomic traits in rice. PMID:25431777

  16. Genetic and ecological data reveal species boundaries between viviparous and oviparous lizard lineages.

    PubMed

    Cornetti, L; Ficetola, G F; Hoban, S; Vernesi, C

    2015-12-01

    Identification of cryptic species is an essential aim for conservation biologists to avoid premature extinctions of 'unrecognized' species. Integrating different types of data can undoubtedly aid in resolving the issue of species delimitation. We studied here two lineages of the common lizard Zootoca vivipara that display different reproductive mode (the viviparous Z. v. vivipara and the oviparous Z. v. carniolica) and that overlap their distributional ranges in the European Alps. With the purpose of delimiting species' boundaries, we analyzed their ecological, genetic and natural history features. More than 300 samples were collected and analyzed at cytochrome b and 11 microsatellites loci for investigating genetic variation, population structure, individual relatedness and evolutionary histories of the two lineages. Additionally, we compared their ecological niches using eight ecological variables. Genetic data showed contrasting patterns of genetic structure between the two lineages, different demographic dynamics and no hybridization events. Also strong ecological differences (such as temperature) emerged between the two lineages, and niche overlap was limited. Taken together, these results indicate that Z. v. vivipara and Z. v. carniolica should be recognized as two separate species, and particular conservation consideration should be given to the oviparous lineage that tends to live in areas threatened by increasing impact of human activities. However, recent and rapid climate warming might determine an increasing risk for the persistence of the viviparous lineage, being adapted to cold environments. PMID:26126542

  17. Genetic Diversity among Sorghum Bicolor L. Moench Benotypes as Revealed by Prolamines and SSR Markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum (Sorghum bicolor L. Moench) is a leading cereal in the arid and semi-arid regions and ranks fifth in importance among the world’s grain crops. Given its importance as a staple food crop, a livestock feed crop and potentially a bioenergy crop, there is a constant need for its genetic improvem...

  18. Deep History of East Asian Populations Revealed Through Genetic Analysis of the Ainu.

    PubMed

    Jeong, Choongwon; Nakagome, Shigeki; Di Rienzo, Anna

    2016-01-01

    Despite recent advances in population genomics, much remains to be elucidated with regard to East Asian population history. The Ainu, a hunter-gatherer population of northern Japan and Sakhalin island of Russia, are thought to be key to elucidating the prehistory of Japan and the peopling of East Asia. Here, we study the genetic relationship of the Ainu with other East Asian and Siberian populations outside the Japanese archipelago using genome-wide genotyping data. We find that the Ainu represent a deep branch of East Asian diversity more basal than all present-day East Asian farmers. However, we did not find a genetic connection between the Ainu and populations of the Tibetan plateau, rejecting their long-held hypothetical connection based on Y chromosome data. Unlike all other East Asian populations investigated, the Ainu have a closer genetic relationship with northeast Siberians than with central Siberians, suggesting ancient connections among populations around the Sea of Okhotsk. We also detect a recent genetic contribution of the Ainu to nearby populations, but no evidence for reciprocal recent gene flow is observed. Whole genome sequencing of contemporary and ancient Ainu individuals will be helpful to understand the details of the deep history of East Asians. PMID:26500257

  19. Genetic admixture history of Eastern Indonesia as revealed by Y-chromosome and mitochondrial DNA analysis.

    PubMed

    Mona, Stefano; Grunz, Katharina E; Brauer, Silke; Pakendorf, Brigitte; Castrì, Loredana; Sudoyo, Herawati; Marzuki, Sangkot; Barnes, Robert H; Schmidtke, Jörg; Stoneking, Mark; Kayser, Manfred

    2009-08-01

    Eastern Indonesia possesses more linguistic diversity than any other region in Southeast Asia, with both Austronesian (AN) languages that are of East Asian origin, as well as non-Austronesian (NAN) languages of likely Melanesian origin. Here, we investigated the genetic history of human populations from seven eastern Indonesian islands, including AN and NAN speakers, as well as the relationship between languages and genes, by means of nonrecombining Y-chromosomal (NRY) and mitochondrial DNA (mtDNA) analysis. We found that the eastern Indonesian gene pool consists of East Asian as well as Melanesian components, as might be expected based on linguistic evidence, but also harbors putative indigenous eastern Indonesian signatures that perhaps reflect the initial occupation of the Wallacea by aboriginal hunter-gatherers already in Palaeolithic times. Furthermore, both NRY and mtDNA data showed a complete lack of correlation between linguistic and genetic relationships, most likely reflecting genetic admixture and/or language shift. In addition, we noted a small fraction of the NRY and mtDNA data shared between eastern Indonesians and Australian Aborigines likely reflecting an ancient link between Asia and Australia. Our data thus provide insights into the complex genetic ancestry history of eastern Indonesian islanders characterized by several admixture episodes and demonstrate a clear example of the lack of the often-assumed correlation between the genes and languages of human populations. PMID:19414523

  20. Candidate loci reveal genetic differentiation between temporally divergent migratory runs of Chinook salmon (Oncorhynchus tshawytscha)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Local adaptation is a dynamic process driven by selection that can vary both in space and time. One important temporal adaptation for migratory animals is the timing of migration and breeding within a reproductive season. Anadromous salmon are excellent subjects for studying the genetic basis of t...

  1. Geographical patterns of Toxoplasma gondii genetic diversity revealed by multilocus PCR-RFLP genotyping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, an extensive collection of Toxoplasma gondii samples have been typed by the multilocus PCR-RFLP method using a standardized set of 10 genetic markers. Here we summarize the data reported until the end of 2012. A total of 1457 samples were typed into 189 genotypes. Overall, only a fe...

  2. Isolated populations of a rare alpine plant show high genetic diversity and considerable population differentiation

    PubMed Central

    Ægisdóttir, Hafdís Hanna; Kuss, Patrick; Stöcklin, Jürg

    2009-01-01

    Background and Aims Gene flow and genetic variability within and among alpine plant populations can be greatly influenced by the steep environmental gradients and heterogeneous topography of alpine landscapes. In this study, the effects are examined of natural isolation of alpine habitats on genetic diversity and geographic structure in populations of C. thyrsoides, a rare and isolated European Alpine monocarpic perennial with limited seed dispersal capacity. Methods Molecular diversity was analysed for 736 individuals from 32 populations in the Swiss Alps and adjacent Jura mountains using five polymorphic microsatellite loci. Pollen flow was estimated using pollen grain-sized fluorescent powder. In addition, individual-based Bayesian approaches were applied to examine population structure. Key Results High within-population genetic diversity (HE = 0·76) and a relatively low inbreeding coefficient (FIS = 0·022) were found. Genetic differentiation among populations measured with a standardized measure was considerable (G′ST = 0·53). A significant isolation-by-distance relationship was found (r = 0·62, P < 0·001) and a significant geographic sub-structure, coinciding with proposed postglacial migration patterns. Altitudinal location and size of populations did not influence molecular variation. Direct measures of pollen flow revealed that insect-mediated pollen dispersal was restricted to short distances within a population. Conclusions The natural isolation of suitable habitats for C. thyrsoides restricts gene flow among the populations as expected for a monocarpic species with very limited seed dispersal capacities. The observed high within-population genetic diversity in this rare monocarpic perennial is best explained by its outcrossing behaviour, long-lived individuals and overlapping generations. Despite the high within-population genetic diversity, the considerable genetic differentiation and the clear western–eastern differentiation in this species

  3. Genetic Tagging During Human Mesoderm Differentiation Reveals Tripotent Lateral Plate Mesodermal Progenitors.

    PubMed

    Chin, Chee Jia; Cooper, Aaron R; Lill, Georgia R; Evseenko, Denis; Zhu, Yuhua; He, Chong Bin; Casero, David; Pellegrini, Matteo; Kohn, Donald B; Crooks, Gay M

    2016-05-01

    Although clonal studies of lineage potential have been extensively applied to organ specific stem and progenitor cells, much less is known about the clonal origins of lineages formed from the germ layers in early embryogenesis. We applied lentiviral tagging followed by vector integration site analysis (VISA) with high-throughput sequencing to investigate the ontogeny of the hematopoietic, endothelial and mesenchymal lineages as they emerge from human embryonic mesoderm. In contrast to studies that have used VISA to track differentiation of self-renewing stem cell clones that amplify significantly over time, we focused on a population of progenitor clones with limited self-renewal capability. Our analyses uncovered the critical influence of sampling on the interpretation of lentiviral tag sharing, particularly among complex populations with minimal clonal duplication. By applying a quantitative framework to estimate the degree of undersampling we revealed the existence of tripotent mesodermal progenitors derived from pluripotent stem cells, and the subsequent bifurcation of their differentiation into bipotent endothelial/hematopoietic or endothelial/mesenchymal progenitors. Stem Cells 2016;34:1239-1250. PMID:26934332

  4. Novel Polymorphic Microsatellite Markers Reveal Genetic Differentiation between Two Sympatric Types of Galaxea fascicularis

    PubMed Central

    Nakajima, Yuichi; Shinzato, Chuya; Satoh, Noriyuki; Mitarai, Satoshi

    2015-01-01

    The reef-building, scleractinian coral, Galaxea fascicularis, is classified into soft and hard types, based on nematocyst morphology. This character is correlated with the length of the mitochondrial non-coding region (mt-Long: soft colony type, and nematocysts with wide capsules and long shafts; mt-Short: hard colony type, and nematocysts with thin capsules and short shafts). We isolated and characterized novel polymorphic microsatellite markers for G. fascicularis using next-generation sequencing. Based upon the mitochondrial non-coding region, 53 of the 97 colonies collected were mt-Long (mt-L) and 44 were mt-Short (mt-S). Among the 53 mt-L colonies, 27 loci were identified as amplifiable, polymorphic microsatellite loci, devoid of somatic mutations and free of scoring errors. Eleven of those 27 loci were also amplifiable and polymorphic in the 44 mt-S colonies; these 11 are cross-type microsatellite loci. The other 16 loci were considered useful only for mt-L colonies. These 27 loci identified 10 multilocus lineages (MLLs) among the 53 mt-L colonies (NMLL/N = 0.189), and the 11 cross-type loci identified 7 MLLs in 44 mt-S colonies (NMLL/N = 0.159). Significant genetic differentiation between the two types was detected based on the genetic differentiation index (FST = 0.080, P = 0.001). Bayesian clustering also indicated that these two types are genetically isolated. While nuclear microsatellite genotypes also showed genetic differentiation between mitochondrial types, the mechanism of divergence is not yet clear. These markers will be useful to estimate genetic diversity, differentiation, and connectivity among populations, and to understand evolutionary processes, including divergence of types in G. fascicularis. PMID:26147677

  5. Prehistoric genomes reveal the genetic foundation and cost of horse domestication.

    PubMed

    Schubert, Mikkel; Jónsson, Hákon; Chang, Dan; Der Sarkissian, Clio; Ermini, Luca; Ginolhac, Aurélien; Albrechtsen, Anders; Dupanloup, Isabelle; Foucal, Adrien; Petersen, Bent; Fumagalli, Matteo; Raghavan, Maanasa; Seguin-Orlando, Andaine; Korneliussen, Thorfinn S; Velazquez, Amhed M V; Stenderup, Jesper; Hoover, Cindi A; Rubin, Carl-Johan; Alfarhan, Ahmed H; Alquraishi, Saleh A; Al-Rasheid, Khaled A S; MacHugh, David E; Kalbfleisch, Ted; MacLeod, James N; Rubin, Edward M; Sicheritz-Ponten, Thomas; Andersson, Leif; Hofreiter, Michael; Marques-Bonet, Tomas; Gilbert, M Thomas P; Nielsen, Rasmus; Excoffier, Laurent; Willerslev, Eske; Shapiro, Beth; Orlando, Ludovic

    2014-12-30

    The domestication of the horse ∼ 5.5 kya and the emergence of mounted riding, chariotry, and cavalry dramatically transformed human civilization. However, the genetics underlying horse domestication are difficult to reconstruct, given the near extinction of wild horses. We therefore sequenced two ancient horse genomes from Taymyr, Russia (at 7.4- and 24.3-fold coverage), both predating the earliest archeological evidence of domestication. We compared these genomes with genomes of domesticated horses and the wild Przewalski's horse and found genetic structure within Eurasia in the Late Pleistocene, with the ancient population contributing significantly to the genetic variation of domesticated breeds. We furthermore identified a conservative set of 125 potential domestication targets using four complementary scans for genes that have undergone positive selection. One group of genes is involved in muscular and limb development, articular junctions, and the cardiac system, and may represent physiological adaptations to human utilization. A second group consists of genes with cognitive functions, including social behavior, learning capabilities, fear response, and agreeableness, which may have been key for taming horses. We also found that domestication is associated with inbreeding and an excess of deleterious mutations. This genetic load is in line with the "cost of domestication" hypothesis also reported for rice, tomatoes, and dogs, and it is generally attributed to the relaxation of purifying selection resulting from the strong demographic bottlenecks accompanying domestication. Our work demonstrates the power of ancient genomes to reconstruct the complex genetic changes that transformed wild animals into their domesticated forms, and the population context in which this process took place. PMID:25512547

  6. Prehistoric genomes reveal the genetic foundation and cost of horse domestication

    PubMed Central

    Jónsson, Hákon; Chang, Dan; Der Sarkissian, Clio; Ermini, Luca; Ginolhac, Aurélien; Albrechtsen, Anders; Dupanloup, Isabelle; Foucal, Adrien; Petersen, Bent; Fumagalli, Matteo; Raghavan, Maanasa; Seguin-Orlando, Andaine; Velazquez, Amhed M. V.; Stenderup, Jesper; Hoover, Cindi A.; Rubin, Carl-Johan; Alfarhan, Ahmed H.; Alquraishi, Saleh A.; Al-Rasheid, Khaled A. S.; Kalbfleisch, Ted; MacLeod, James N.; Rubin, Edward M.; Andersson, Leif; Hofreiter, Michael; Marques-Bonet, Tomas; Gilbert, M. Thomas P.; Nielsen, Rasmus; Excoffier, Laurent; Willerslev, Eske; Shapiro, Beth; Orlando, Ludovic

    2014-01-01

    The domestication of the horse ∼5.5 kya and the emergence of mounted riding, chariotry, and cavalry dramatically transformed human civilization. However, the genetics underlying horse domestication are difficult to reconstruct, given the near extinction of wild horses. We therefore sequenced two ancient horse genomes from Taymyr, Russia (at 7.4- and 24.3-fold coverage), both predating the earliest archeological evidence of domestication. We compared these genomes with genomes of domesticated horses and the wild Przewalski’s horse and found genetic structure within Eurasia in the Late Pleistocene, with the ancient population contributing significantly to the genetic variation of domesticated breeds. We furthermore identified a conservative set of 125 potential domestication targets using four complementary scans for genes that have undergone positive selection. One group of genes is involved in muscular and limb development, articular junctions, and the cardiac system, and may represent physiological adaptations to human utilization. A second group consists of genes with cognitive functions, including social behavior, learning capabilities, fear response, and agreeableness, which may have been key for taming horses. We also found that domestication is associated with inbreeding and an excess of deleterious mutations. This genetic load is in line with the “cost of domestication” hypothesis also reported for rice, tomatoes, and dogs, and it is generally attributed to the relaxation of purifying selection resulting from the strong demographic bottlenecks accompanying domestication. Our work demonstrates the power of ancient genomes to reconstruct the complex genetic changes that transformed wild animals into their domesticated forms, and the population context in which this process took place. PMID:25512547

  7. Genetic diversity in cultured and wild marine cyanomyoviruses reveals phosphorus stress as a strong selective agent.

    PubMed

    Kelly, Libusha; Ding, Huiming; Huang, Katherine H; Osburne, Marcia S; Chisholm, Sallie W

    2013-09-01

    Viruses that infect marine cyanobacteria-cyanophages-often carry genes with orthologs in their cyanobacterial hosts, and the frequency of these genes can vary with habitat. To explore habitat-influenced genomic diversity more deeply, we used the genomes of 28 cultured cyanomyoviruses as references to identify phage genes in three ocean habitats. Only about 6-11% of genes were consistently observed in the wild, revealing high gene-content variability in these populations. Numerous shared phage/host genes differed in relative frequency between environments, including genes related to phosphorous acquisition, photorespiration, photosynthesis and the pentose phosphate pathway, possibly reflecting environmental selection for these genes in cyanomyovirus genomes. The strongest emergent signal was related to phosphorous availability; a higher fraction of genomes from relatively low-phosphorus environments-the Sargasso and Mediterranean Sea-contained host-like phosphorus assimilation genes compared with those from the N. Pacific Gyre. These genes are known to be upregulated when the host is phosphorous starved, a response mediated by pho box motifs in phage genomes that bind a host regulatory protein. Eleven cyanomyoviruses have predicted pho boxes upstream of the phosphate-acquisition genes pstS and phoA; eight of these have a conserved cyanophage-specific gene (PhCOG173) between the pho box and pstS. PhCOG173 is also found upstream of other shared phage/host genes, suggesting a unique regulatory role. Pho boxes are found upstream of high light-inducible (hli) genes in cyanomyoviruses, suggesting that this motif may have a broader role than regulating phosphorous-stress responses in infected hosts or that these hlis are involved in the phosphorous-stress response. PMID:23657361

  8. Molecular Genetic Analyses of Mating Pheromones Reveal Intervariety Mating or Hybridization in Cryptococcus neoformans

    PubMed Central

    Chaturvedi, Vishnu; Fan, Jinjiang; Stein, Birgit; Behr, Melissa J.; Samsonoff, William A.; Wickes, Brian L.; Chaturvedi, Sudha

    2002-01-01

    The sexual mating of the pathogenic yeast Cryptococcus neoformans is important for pathogenesis studies because the fungal virulence is linked to the α mating type (MATα). We characterized C. neoformans mating pheromones (MFα 1 and MFa1) from 122 strains to understand intervariety hybridization or mating and intervariety virulence. MFα 1 in three C. neoformans varieties showed (a) specific nucleotide polymorphisms, (b) different copy numbers and chromosomal localizations, and (c) unique deduced amino acids in two geographic populations of C. neoformans var. gattii. MFα 1 of different varieties cross-hybridized in Southern hybridizations. Their phylogenetic analyses showed purifying selection (neutral evolution). These observations suggested that MATα strains from any of the three C. neoformans varieties could mate or hybridize in nature with MATa strains of C. neoformans var. neoformans. A few serotype A/D diploid strains provided evidence for mating or hybridization, while a majority of A/D strains tested positive for haploid MFα 1 identical to that of C. neoformans var. grubii. MFα 1 sequence and copy numbers in diploids were identical to those of C. neoformans var. grubii, while their MFa1 sequences were identical to those of C. neoformans var. neoformans; thus, these strains were hybrids. The mice survival curves and histological lesions revealed A/D diploids to be highly pathogenic, with pathogenicity levels similar to that of the C. neoformans var. grubii type strain and unlike the low pathogenicity levels of C. neoformans var. neoformans strains. In contrast to MFα 1 in three varieties, MFa1 amplicons and hybridization signals could be obtained only from two C. neoformans var. neoformans reference strains and eight A/D diploids. This suggested that a yet undiscovered MFa pheromone(s) in C. neoformans var. gattii and C. neoformans var. grubii is unrelated to, highly divergent from, or rarer than that in C. neoformans var. neoformans. These

  9. High genetic diversity declines towards the geographic range periphery of Adonis vernalis, a Eurasian dry grassland plant.

    PubMed

    Hirsch, H; Wagner, V; Danihelka, J; Ruprecht, E; Sánchez-Gómez, P; Seifert, M; Hensen, I

    2015-11-01

    Genetic diversity is important for species' fitness and evolutionary processes but our knowledge on how it varies across a species' distribution range is limited. The abundant centre hypothesis (ACH) predicts that populations become smaller and more isolated towards the geographic range periphery - a pattern that in turn should be associated with decreasing genetic diversity and increasing genetic differentiation. We tested this hypothesis in Adonis vernalis, a dry grassland plant with an extensive Eurasian distribution. Its life-history traits and distribution characteristics suggest a low genetic diversity that decreases and a high genetic differentiation that increases towards the range edge. We analysed AFLP fingerprints in 28 populations along a 4698-km transect from the geographic range core in Russia to the western range periphery in Central and Western Europe. Contrary to our expectation, our analysis revealed high genetic diversity (range of proportion of polymorphic bands = 56-81%, He = 0.168-0.238) and low genetic differentiation across populations (Φ(ST) = 0.18). However, in congruence with the genetic predictions of the ACH, genetic diversity decreased and genetic differentiation increased towards the range periphery. Spanish populations were genetically distinct, suggesting a divergent post-glacial history in this region. The high genetic diversity and low genetic differentiation in the remaining A. vernalis populations is surprising given the species' life-history traits and points to the possibility that the species has been widely distributed in the studied region or that it has migrated from a diverse source in an East-West direction, in the past. PMID:26122089

  10. Genomic Analyses Reveal Potential Independent Adaptation to High Altitude in Tibetan Chickens.

    PubMed

    Wang, Ming-Shan; Li, Yan; Peng, Min-Sheng; Zhong, Li; Wang, Zong-Ji; Li, Qi-Ye; Tu, Xiao-Long; Dong, Yang; Zhu, Chun-Ling; Wang, Lu; Yang, Min-Min; Wu, Shi-Fang; Miao, Yong-Wang; Liu, Jian-Ping; Irwin, David M; Wang, Wen; Wu, Dong-Dong; Zhang, Ya-Ping

    2015-07-01

    Much like other indigenous domesticated animals, Tibetan chickens living at high altitudes (2,200-4,100 m) show specific physiological adaptations to the extreme environmental conditions of the Tibetan Plateau, but the genetic bases of these adaptations are not well characterized. Here, we assembled a de novo genome of a Tibetan chicken and resequenced whole genomes of 32 additional chickens, including Tibetan chickens, village chickens, game fowl, and Red Junglefowl, and found that the Tibetan chickens could broadly be placed into two groups. Further analyses revealed that several candidate genes in the calcium-signaling pathway are possibly involved in adaptation to the hypoxia experienced by these chickens, as these genes appear to have experienced directional selection in the two Tibetan chicken populations, suggesting a potential genetic mechanism underlying high altitude adaptation in Tibetan chickens. The candidate selected genes identified in this study, and their variants, may be useful targets for clarifying our understanding of the domestication of chickens in Tibet, and might be useful in current breeding efforts to develop improved breeds for the highlands. PMID:25788450

  11. Why Are High Altitude Natives So Strong at High Altitude? Nature vs. Nurture: Genetic Factors vs. Growth and Development.

    PubMed

    Brutsaert, Tom

    2016-01-01

    Among high-altitude natives there is evidence of a general hypoxia tolerance leading to enhanced performance and/or increased capacity in several important domains. These domains likely include an enhanced physical work capacity, an enhanced reproductive capacity, and an ability to resist several common pathologies of chronic high-altitude exposure. The "strength" of the high-altitude native in this regard may have both a developmental and a genetic basis, although there is better evidence for the former (developmental effects) than for the latter. For example, early-life hypoxia exposure clearly results in lung growth and remodeling leading to an increased O2 diffusing capacity in adulthood. Genetic research has yet to reveal a population genetic basis for enhanced capacity in high-altitude natives, but several traits are clearly under genetic control in Andean and Tibetan populations e.g., resting and exercise arterial O2 saturation (SaO2). This chapter reviews the effects of nature and nurture on traits that are relevant to the process of gas exchange, including pulmonary volumes and diffusion capacity, the maximal oxygen consumption (VO2max), the SaO2, and the alveolar-arterial oxygen partial pressure difference (A-aDO2) during exercise. PMID:27343091

  12. Genetic diversity of the black gram [Vigna mungo (L.) Hepper] gene pool as revealed by SSR markers

    PubMed Central

    Kaewwongwal, Anochar; Kongjaimun, Alisa; Somta, Prakit; Chankaew, Sompong; Yimram, Tarikar; Srinives, Peerasak

    2015-01-01

    In this study, 520 cultivated and 14 wild accessions of black gram (Vigna mungo (L.) Hepper) were assessed for diversity using 22 SSR markers. Totally, 199 alleles were detected with a mean of 9.05 alleles per locus. Wild black gram showed higher gene diversity than cultivated black gram. Gene diversity of cultivated accessions among regions was comparable, while allelic richness of South Asia was higher than that of other regions. 78.67% of the wild gene diversity presented in cultivated accessions, indicating that the domestication bottleneck effect in black gram is relatively low. Genetic distance analysis revealed that cultivated black gram was more closely related to wild black gram from South Asia than that from Southeast Asia. STRUCTURE, principal coordinate and neighbor-joining analyses consistently revealed that 534 black gram accessions were grouped into three major subpopulations. The analyses also revealed that cultivated black gram from South Asia was genetically distinct from that from West Asia. Comparison by SSR analysis with other closely related Vigna species, including mungbean, azuki bean, and rice bean, revealed that level of gene diversity of black gram is comparable to that of mungbean and rice bean but lower than that of azuki bean. PMID:26069442

  13. High and Distinct Range-Edge Genetic Diversity despite Local Bottlenecks

    PubMed Central

    Assis, Jorge; Castilho Coelho, Nelson; Alberto, Filipe; Valero, Myriam; Raimondi, Pete; Reed, Dan; Alvares Serrão, Ester

    2013-01-01

    The genetic consequences of living on the edge of distributional ranges have been the subject of a largely unresolved debate. Populations occurring along persistent low latitude ranges (rear-edge) are expected to retain high and unique genetic diversity. In contrast, currently less favourable environmental conditions limiting population size at such range-edges may have caused genetic erosion that prevails over past historical effects, with potential consequences on reducing future adaptive capacity. The present study provides an empirical test of whether population declines towards a peripheral range might be reflected on decreasing diversity and increasing population isolation and differentiation. We compare population genetic differentiation and diversity with trends in abundance along a latitudinal gradient towards the peripheral distribution range of Saccorhizapolyschides, a large brown seaweed that is the main structural species of kelp forests in SW Europe. Signatures of recent bottleneck events were also evaluated to determine whether the recently recorded distributional shifts had a negative influence on effective population size. Our findings show decreasing population density and increasing spatial fragmentation and local extinctions towards the southern edge. Genetic data revealed two well supported groups with a central contact zone. As predicted, higher differentiation and signs of bottlenecks were found at the southern edge region. However, a decrease in genetic diversity associated with this pattern was not verified. Surprisingly, genetic diversity increased towards the edge despite bottlenecks and much lower densities, suggesting that extinctions and recolonizations have not strongly reduced diversity or that diversity might have been even higher there in the past, a process of shifting genetic baselines. PMID:23967038

  14. High and distinct range-edge genetic diversity despite local bottlenecks.

    PubMed

    Assis, Jorge; Castilho Coelho, Nelson; Alberto, Filipe; Valero, Myriam; Raimondi, Pete; Reed, Dan; Serrão, Ester Alvares

    2013-01-01

    The genetic consequences of living on the edge of distributional ranges have been the subject of a largely unresolved debate. Populations occurring along persistent low latitude ranges (rear-edge) are expected to retain high and unique genetic diversity. In contrast, currently less favourable environmental conditions limiting population size at such range-edges may have caused genetic erosion that prevails over past historical effects, with potential consequences on reducing future adaptive capacity. The present study provides an empirical test of whether population declines towards a peripheral range might be reflected on decreasing diversity and increasing population isolation and differentiation. We compare population genetic differentiation and diversity with trends in abundance along a latitudinal gradient towards the peripheral distribution range of Saccorhiza polyschides, a large brown seaweed that is the main structural species of kelp forests in SW Europe. Signatures of recent bottleneck events were also evaluated to determine whether the recently recorded distributional shifts had a negative influence on effective population size. Our findings show decreasing population density and increasing spatial fragmentation and local extinctions towards the southern edge. Genetic data revealed two well supported groups with a central contact zone. As predicted, higher differentiation and signs of bottlenecks were found at the southern edge region. However, a decrease in genetic diversity associated with this pattern was not verified. Surprisingly, genetic diversity increased towards the edge despite bottlenecks and much lower densities, suggesting that extinctions and recolonizations have not strongly reduced diversity or that diversity might have been even higher there in the past, a process of shifting genetic baselines. PMID:23967038

  15. Genetics

    MedlinePlus

    Homozygous; Inheritance; Heterozygous; Inheritance patterns; Heredity and disease; Heritable; Genetic markers ... The chromosomes are made up of strands of genetic information called DNA. Each chromosome contains sections of ...

  16. Genetics

    MedlinePlus

    ... Inheritance; Heterozygous; Inheritance patterns; Heredity and disease; Heritable; Genetic markers ... The chromosomes are made up of strands of genetic information called DNA. Each chromosome contains sections of ...

  17. Multilocus analysis reveals large genetic diversity in Kluyveromyces marxianus strains isolated from Parmigiano Reggiano and Pecorino di Farindola cheeses.

    PubMed

    Fasoli, Giuseppe; Barrio, Eladio; Tofalo, Rosanna; Suzzi, Giovanna; Belloch, Carmela

    2016-09-16

    In the present study, we have analysed the genetic diversity in Kluyveromyces marxianus isolated from Parmigiano Reggiano and Pecorino di Farindola cheesemaking environment. Molecular typing methods inter-RTL fingerprint and mtDNA RFLPs, as well as, sequence diversity and heterozygosity in the intergenic region between KmSSB1 and KmRIO2 genes and analysis of the mating locus were applied to 54 K. marxianus strains. Inter-RTL fingerprint revealed a large degree of genetic heterogeneity and clustering allowed differentiation of K. marxianus strains from different geographical origins. In general, inter-LTR profiles were more discriminating than RFLPs of mtDNA; however our results also indicate that both techniques could be complementary unveiling different degrees of genetic diversity. Sequence analysis of the intergenic region between KmSSB1 and KmRIO2 genes revealed 26 variable positions in which a double peak could be observed in the sequence chromatogram. Further analysis revealed the presence of heterozygous strains in the K. marxianus population isolated from Parmigiano Reggiano. On the other hand, all strains isolated from Pecorino di Farindola were homozygous. Two very different groups of haplotypes could be observed as well as mixtures between them. Phylogenetic reconstruction divided K. marxianus dairy strains into two separate populations. A few heterozygous strains in an intermediate position between them could also be observed. Mating type locus analysis revealed a large population of diploid strains containing both MATa and MATα alleles and few haploid strains, most of them presenting the MATα allele. Different scenarios explaining the presence and maintaining of homozygous and heterozygous diploids as well as hybrids between them in the Parmigiano Reggiano K. marxianus population are proposed. A principal component analysis supported the large differences between K. marxianus isolated from Parmigiano Reggiano and Pecorino di Farindola. PMID:27294555

  18. Isolates of Cryptococcus neoformans from infected animals reveal genetic exchange in unisexual, alpha mating type populations.

    PubMed

    Bui, Tien; Lin, Xiaorong; Malik, Richard; Heitman, Joseph; Carter, Dee

    2008-10-01

    Sexual reproduction and genetic exchange are important for the evolution of fungal pathogens and for producing potentially infective spores. Studies to determine whether sex occurs in the pathogenic yeast Cryptococcus neoformans var. grubii have produced enigmatic results, however: basidiospores are the most likely infective propagules, and clinical isolates are fertile and genetically diverse, consistent with a sexual species, but almost all populations examined consist of a single mating type and have little evidence for genetic recombination. The choice of population is critical when looking for recombination, particularly when significant asexual propagation is likely and when latency may complicate assessing the origin of an isolate. We therefore selected isolates from infected animals living in the region of Sydney, Australia, with the assumption that the relatively short life spans and limited travels of the animal hosts would provide a very defined population. All isolates were mating type alpha and were of molecular genotype VNI or VNII. A lack of linkage disequilibrium among loci suggested that genetic exchange occurred within both genotype groups. Four diploid VNII isolates that produced filaments and basidium-like structures when cultured in proximity to an a mating type strain were found. Recent studies suggest that compatible alpha-alpha unions can occur in C. neoformans var. neoformans populations and in populations of the sibling species Cryptococcus gattii. As a mating type strains of C. neoformans var. grubii have never been found in Australia, or in the VNII molecular type globally, the potential for alpha-alpha unions is evidence that alpha-alpha unisexual mating maintains sexual recombination and diversity in this pathogen and may produce infectious propagules. PMID:18552280

  19. Investigating Arsenic Susceptibility from a Genetic Perspective in Drosophila Reveals a Key Role for Glutathione Synthetase

    PubMed Central

    Muñiz Ortiz, Jorge G.; Opoka, Robert; Kane, Daniel; Cartwright, Iain L.

    2009-01-01

    Chronic exposure to arsenic-contaminated drinking water can lead to a variety of serious pathological outcomes. However, differential responsiveness within human populations suggests that interindividual genetic variation plays an important role. We are using Drosophila to study toxic metal response pathways because of unrivalled access to varied genetic approaches and significant demonstrable overlap with many aspects of mammalian physiology and disease phenotypes. Genetic analysis (via chromosomal segregation and microsatellite marker-based recombination) of various wild-type strains exhibiting relative susceptibility or tolerance to the lethal toxic effects of arsenite identified a limited X-chromosomal region (16D-F) able to confer a differential response phenotype. Using an FRT-based recombination approach, we created lines harboring small, overlapping deficiencies within this region and found that relative arsenite sensitivity arose when the dose of the glutathione synthetase (GS) gene (located at 16F1) was reduced by half. Knockdown of GS expression by RNA interference (RNAi) in cultured S2 cells led to enhanced arsenite sensitivity, while GS RNAi applied to intact organisms dramatically reduced the concentration of food-borne arsenite compatible with successful growth and development. Our analyses, initially guided by observations on naturally occurring variants, provide genetic proof that an optimally functioning two-step glutathione (GSH) biosynthetic pathway is required in vivo for a robust defense against arsenite; the enzymatic implications of this are discussed in the context of GSH supply and demand under arsenite-induced stress. Given an identical pathway for human GSH biosynthesis, we suggest that polymorphisms in GSH biosynthetic genes may be an important contributor to differential arsenic sensitivity and exposure risk in human populations. PMID:18779381

  20. Genetic and genomic dissection of Prolactin revealed potential association with milk production traits in riverine buffalo.

    PubMed

    Nadeem, A; Maryam, J

    2016-08-01

    Milk yield and quality has been a major selection criterion for genetic improvement in livestock species. Role of Prolactin gene in determining milk quality in terms of protein profile, lactose, lipids and other imperative macromolecules is very important. In this context, genetic profiling of Prolactin gene in riverine buffalo of Pakistan was performed and potential genetic markers were identified illustrating worth of this gene in marker-assisted selection of superior dairy buffaloes. Series of wet and dry lab experimentation was performed starting with genomic DNA isolation from true to breed representatives of indigenous river buffalo (Nili-Ravi). After amplification of coding regions of Prolactin gene, products were eluted and sequenced by Sanger's chain termination method and aligned to get variations in genomic region. A total of 15 novel variations were identified and analyzed statistically for their significance at population level, haplotypes were constructed, and association was estimated. Phylogenetic analysis was performed to evaluate the rate of evolution for Prolactin gene in various mammalian species. Lastly, biological networking for this molecule was predicted to get the bigger pictorial of its functional machinery. Pathway analysis was performed to find its physiological mode of action in milk synthesis. This is a first report toward complete genetic screening of Prolactin gene in Pakistani buffaloes. Results of this study not only provide an insight for potential role of Prolactin gene in milk-producing abilities of buffalo but also suggest new directions for exploration of more genes that may have promising role to enhance future milk production capabilities of river buffalo breeds of Asian region through marker-assisted selection. PMID:27240674

  1. Joint assembly and genetic mapping of the Atlantic horseshoe crab genome reveals ancient whole genome duplication

    PubMed Central

    2014-01-01

    Background Horseshoe crabs are marine arthropods with a fossil record extending back approximately 450 million years. They exhibit remarkable morphological stability over their long evolutionary history, retaining a number of ancestral arthropod traits, and are often cited as examples of “living fossils.” As arthropods, they belong to the Ecdysozoa, an ancient super-phylum whose sequenced genomes (including insects and nematodes) have thus far shown more divergence from the ancestral pattern of eumetazoan genome organization than cnidarians, deuterostomes and lophotrochozoans. However, much of ecdysozoan diversity remains unrepresented in comparative genomic analyses. Results Here we apply a new strategy of combined de novo assembly and genetic mapping to examine the chromosome-scale genome organization of the Atlantic horseshoe crab, Limulus polyphemus. We constructed a genetic linkage map of this 2.7 Gbp genome by sequencing the nuclear DNA of 34 wild-collected, full-sibling embryos and their parents at a mean redundancy of 1.1x per sample. The map includes 84,307 sequence markers grouped into 1,876 distinct genetic intervals and 5,775 candidate conserved protein coding genes. Conclusions Comparison with other metazoan genomes shows that the L. polyphemus genome preserves ancestral bilaterian linkage groups, and that a common ancestor of modern horseshoe crabs underwent one or more ancient whole genome duplications 300 million years ago, followed by extensive chromosome fusion. These results provide a counter-example to the often noted correlation between whole genome duplication and evolutionary radiations. The new, low-cost genetic mapping method for obtaining a chromosome-scale view of non-model organism genomes that we demonstrate here does not require laboratory culture, and is potentially applicable to a broad range of other species. PMID:24987520

  2. Cells deficient in base-excision repair reveal cancer hallmarks originating from adjustments to genetic instability

    PubMed Central

    Markkanen, Enni; Fischer, Roman; Ledentcova, Marina; Kessler, Benedikt M.; Dianov, Grigory L.

    2015-01-01

    Genetic instability, provoked by exogenous mutagens, is well linked to initiation of cancer. However, even in unstressed cells, DNA undergoes a plethora of spontaneous alterations provoked by its inherent chemical instability and the intracellular milieu. Base excision repair (BER) is the major cellular pathway responsible for repair of these lesions, and as deficiency in BER activity results in DNA damage it has been proposed that it may trigger the development of sporadic cancers. Nevertheless, experimental evidence for this model remains inconsistent and elusive. Here, we performed a proteomic analysis of BER deficient human cells using stable isotope labelling with amino acids in cell culture (SILAC), and demonstrate that BER deficiency, which induces genetic instability, results in dramatic changes in gene expression, resembling changes found in many cancers. We observed profound alterations in tissue homeostasis, serine biosynthesis, and one-carbon- and amino acid metabolism, all of which have been identified as cancer cell ‘hallmarks’. For the first time, this study describes gene expression changes characteristic for cells deficient in repair of endogenous DNA lesions by BER. These expression changes resemble those observed in cancer cells, suggesting that genetically unstable BER deficient cells may be a source of pre-cancerous cells. PMID:25800737

  3. Evidence from Cameroon reveals differences in the genetic structure and histories of chimpanzee populations.

    PubMed

    Gonder, Mary Katherine; Locatelli, Sabrina; Ghobrial, Lora; Mitchell, Matthew W; Kujawski, Joseph T; Lankester, Felix J; Stewart, Caro-Beth; Tishkoff, Sarah A

    2011-03-22

    The history of the genus Pan is a topic of enduring interest. Chimpanzees (Pan troglodytes) are often divided into subspecies, but the population structure and genetic history of chimpanzees across Africa remain unclear. Some population genetics studies have led to speculation that, until recently, this species constituted a single population with ongoing gene flow across its range, which resulted in a continuous gradient of allele frequencies. Chimpanzees, designated here as P. t. ellioti, occupy the Gulf of Guinea region that spans southern Nigeria and western Cameroon at the center of the distribution of this species. Remarkably, few studies have included individuals from this region, hindering the examination of chimpanzee population structure across Africa. Here, we analyzed microsatellite genotypes of 94 chimpanzees, including 32 designated as P. t. ellioti. We find that chimpanzees fall into three major populations: (i) Upper Guinea in western Africa (P. t. verus); (ii) the Gulf of Guinea region (P. t. ellioti); and (iii) equatorial Africa (P. t. troglodytes and P. t. schweinfurthii). Importantly, the Gulf of Guinea population is significantly different genetically from the others, sharing a last common ancestor with the populations in Upper Guinea ~0.46 million years ago (mya) and equatorial Africa ~0.32 mya. Equatorial chimpanzees are subdivided into up to three populations occupying southern Cameroon, central Africa, and eastern Africa, which may have constituted a single population until ~0.10-0.11 mya. Finally, occasional hybridization may be occurring between the Gulf of Guinea and southern Cameroon populations. PMID:21368170

  4. Environmental sampling reveals that Pythium insidiosum is ubiquitous and genetically diverse in North Central Florida.

    PubMed

    Presser, Jackson W; Goss, Erica M

    2015-09-01

    Pythiosis is a deadly disease of horses, dogs, and other mammals, including humans, in tropical and subtropical regions. In the United States, the disease has been reported in the Southeast as well as in the temperate North and the dry Southwest. The causal agent of pythiosis is Pythium insidiosum, one of few mammalian pathogens in the fungus-like Oomycetes. P. insidiosum has not been studied in the environment in the United States. Given anecdotal reports of pythiosis in Gainesville, Florida dogs, we hypothesized that warm standing water in lakes and ponds in North Central Florida is suitable habitat for P. insidiosum. We sampled 19 lakes or ponds to examine the environmental distribution of P. insidiosum and to determine which of the three previously described genetic clusters of P. insidiosum are present. We found P. insidiosum in 11 of the sampled lakes and ponds. Sequencing of the ITS region separated isolates into three genetic clusters, including a distinct group previously represented by a single isolate from South Carolina. AFLP genotyping of isolates showed genetic variation in Cluster I, which is the group associated with the majority of characterized clinical isolates from the Americas. Our results indicate that animal exposure to P. insidiosum in North Central Florida is common. This study provides the first evidence that P. insidiosum may be more widely distributed in freshwater lakes and ponds in the Southeastern United States than previously appreciated. PMID:26229152

  5. A Novel Conditional Genetic System Reveals That Increasing Neuronal cAMP Enhances Memory and Retrieval

    PubMed Central

    Isiegas, Carolina; McDonough, Conor; Huang, Ted; Havekes, Robbert; Fabian, Sara; Wu, Long-Jun; Xu, Hui; Zhao, Ming-Gao; Kim, Jae-Ick; Lee, Yong-Seok; Lee, Hye-Ryeon; Ko, Hyoung-Gon; Lee, Nuribalhae; Choi, Sun-Lim; Lee, Jeong-Sik; Son, Hyeon; Zhuo, Min; Kaang, Bong-Kiun; Abel, Ted

    2010-01-01

    Consistent evidence from pharmacological and genetic studies shows that cAMP is a critical modulator of synaptic plasticity and memory formation. However, the potential of the cAMP signaling pathway as a target for memory enhancement remains unclear because of contradictory findings from pharmacological and genetic approaches. To address these issues, we have developed a novel conditional genetic system in mice based on the heterologous expression of an Aplysia octopamine receptor, a G-protein-coupled receptor whose activation by its natural ligand octopamine leads to rapid and transient increases in cAMP. We find that activation of this receptor transgenically expressed in mouse forebrain neurons induces a rapid elevation of hippocampal cAMP levels, facilitates hippocampus synaptic plasticity, and enhances the consolidation and retrieval of fear memory. Our findings clearly demonstrate that acute increases in cAMP levels selectively in neurons facilitate synaptic plasticity and memory, and illustrate the potential of this heterologous system to study cAMP-mediated processes in mammalian systems. PMID:18550764

  6. Whole-exome sequencing reveals genetic variability among lung cancer cases subphenotyped for emphysema.

    PubMed

    Lusk, Christine M; Wenzlaff, Angela S; Dyson, Greg; Purrington, Kristen S; Watza, Donovan; Land, Susan; Soubani, Ayman O; Gadgeel, Shirish M; Schwartz, Ann G

    2016-02-01

    Lung cancer continues to be a major public health challenge in the United States despite efforts to decrease the prevalence of smoking; outcomes are especially poor for African-American patients compared to other races/ethnicities. Chronic obstructive pulmonary disease (COPD) co-occurs with lung cancer frequently, but not always, suggesting both shared and distinct risk factors for these two diseases. To identify germline genetic variation that distinguishes between lung cancer in the presence and absence of emphysema, we performed whole-exome sequencing on 46 African-American lung cancer cases (23 with and 23 without emphysema frequency matched on age, sex, histology and pack years). Using conditional logistic regression, we found 6305 variants (of 168 150 varying sites) significantly associated with lung cancer subphenotype (P ≤ 0.05). Next, we validated 10 of these variants in an independent set of 612 lung cancer cases (267 with emphysema and 345 without emphysema) from the same population of inference as the sequenced cases. We found one variant that was significantly associated with lung cancer subphenotype in the validation sample. These findings contribute to teasing apart shared genetic factors from independent genetic factors for lung cancer and COPD. PMID:26717996

  7. New inducible genetic method reveals critical roles of GABA in the control of feeding and metabolism.

    PubMed

    Meng, Fantao; Han, Yong; Srisai, Dollada; Belakhov, Valery; Farias, Monica; Xu, Yong; Palmiter, Richard D; Baasov, Timor; Wu, Qi

    2016-03-29

    Currently available inducible Cre/loxP systems, despite their considerable utility in gene manipulation, have pitfalls in certain scenarios, such as unsatisfactory recombination rates and deleterious effects on physiology and behavior. To overcome these limitations, we designed a new, inducible gene-targeting system by introducing an in-frame nonsense mutation into the coding sequence of Cre recombinase (nsCre). Mutant mRNAs transcribed from nsCre transgene can be efficiently translated into full-length, functional Cre recombinase in the presence of nonsense suppressors such as aminoglycosides. In a proof-of-concept model, GABA signaling from hypothalamic neurons expressing agouti-related peptide (AgRP) was genetically inactivated within 4 d after treatment with a synthetic aminoglycoside. Disruption of GABA synthesis in AgRP neurons in young adult mice led to a dramatic loss of body weight due to reduced food intake and elevated energy expenditure; they also manifested glucose intolerance. In contrast, older mice with genetic inactivation of GABA signaling by AgRP neurons had only transient reduction of feeding and body weight; their energy expenditure and glucose tolerance were unaffected. These results indicate that GABAergic signaling from AgRP neurons plays a key role in the control of feeding and metabolism through an age-dependent mechanism. This new genetic technique will augment current tools used to elucidate mechanisms underlying many physiological and neurological processes. PMID:26976589

  8. Forward Genetics by Genome Sequencing Reveals That Rapid Cyanide Release Deters Insect Herbivory of Sorghum bicolor

    PubMed Central

    Krothapalli, Kartikeya; Buescher, Elizabeth M.; Li, Xu; Brown, Elliot; Chapple, Clint; Dilkes, Brian P.; Tuinstra, Mitchell R.

    2013-01-01

    Whole genome sequencing has allowed rapid progress in the application of forward genetics in model species. In this study, we demonstrated an application of next-generation sequencing for forward genetics in a complex crop genome. We sequenced an ethyl methanesulfonate-induced mutant of Sorghum bicolor defective in hydrogen cyanide release and identified the causal mutation. A workflow identified the causal polymorphism relative to the reference BTx623 genome by integrating data from single nucleotide polymorphism identification, prior information about candidate gene(s) implicated in cyanogenesis, mutation spectra, and polymorphisms likely to affect phenotypic changes. A point mutation resulting in a premature stop codon in the coding sequence of dhurrinase2, which encodes a protein involved in the dhurrin catabolic pathway, was responsible for the acyanogenic phenotype. Cyanogenic glucosides are not cyanogenic compounds but their cyanohydrins derivatives do release cyanide. The mutant accumulated the glucoside, dhurrin, but failed to efficiently release cyanide upon tissue disruption. Thus, we tested the effects of cyanide release on insect herbivory in a genetic background in which accumulation of cyanogenic glucoside is unchanged. Insect preference choice experiments and herbivory measurements demonstrate a deterrent effect of cyanide release capacity, even in the presence of wild-type levels of cyanogenic glucoside accumulation. Our gene cloning method substantiates the value of (1) a sequenced genome, (2) a strongly penetrant and easily measurable phenotype, and (3) a workflow to pinpoint a causal mutation in crop genomes and accelerate in the discovery of gene function in the postgenomic era. PMID:23893483

  9. The genetic regulatory network centered on Pto-Wuschela and its targets involved in wood formation revealed by association studies

    PubMed Central

    Yang, Xiaohui; Wei, Zunzheng; Du, Qingzhang; Chen, Jinhui; Wang, Qingshi; Quan, Mingyang; Song, Yuepeng; Xie, Jianbo; Zhang, Deqiang

    2015-01-01

    Transcription factors (TFs) regulate gene expression and can strongly affect phenotypes. However, few studies have examined TF variants and TF interactions with their targets in plants. Here, we used genetic association in 435 unrelated individuals of Populus tomentosa to explore the variants in Pto-Wuschela and its targets to decipher the genetic regulatory network of Pto-Wuschela. Our bioinformatics and co-expression analysis identified 53 genes with the motif TCACGTGA as putative targets of Pto-Wuschela. Single-marker association analysis showed that Pto-Wuschela was associated with wood properties, which is in agreement with the observation that it has higher expression in stem vascular tissues in Populus. Also, SNPs in the 53 targets were associated with growth or wood properties under additive or dominance effects, suggesting these genes and Pto-Wuschela may act in the same genetic pathways that affect variation in these quantitative traits. Epistasis analysis indicated that 75.5% of these genes directly or indirectly interacted Pto-Wuschela, revealing the coordinated genetic regulatory network formed by Pto-Wuschela and its targets. Thus, our study provides an alternative method for dissection of the interactions between a TF and its targets, which will strength our understanding of the regulatory roles of TFs in complex traits in plants. PMID:26549216

  10. Morphological and genetic analyses reveal a cryptic species complex in the echinoid Echinocardium cordatum and rule out a stabilizing selection explanation.

    PubMed

    Egea, E; David, B; Choné, T; Laurin, B; Féral, J P; Chenuil, A

    2016-01-01

    Preliminary analyses revealed the presence of at least five mitochondrial clades within the widespread sea urchin Echinocardium cordatum (Spatangoida). In this study, we analyzed the genetic (two mitochondrial and two nuclear sequence loci) and morphological characteristics (20 indices) from worldwide samples of this taxon to establish the species limits, morphological diversity and differentiation. Co-occurring spatangoid species were also analyzed with mitochondrial DNA. The nuclear sequences confirm that mitochondrial lineages correspond to true genetic entities and reveal that two clades (named A and B1) hybridize in their sympatry area, although a more closely related pair of clades (B1 and B2), whose distributions widely overlap, does not display hybridization. The morphology of all E. cordatum clade pairs was significantly differentiated, but no morphological diagnostic character was evidenced. By contrast, other spatangoid species pairs that diverged more recently than the E. cordatum clades display clear diagnostic characters. Morphological diversity thus appears responsible for the absence of diagnostic characters, ruling out stabilizing selection, a classical explanation for cryptic species. Alternative classical explanations are (i) environmental plasticity or (ii) a high diversity of genes determining morphology, maintained by varying environmental conditions. We suggest a new hypothesis that the observed morphological diversity is selectively neutral and reflects high effective population sizes in the E. cordatum complex. It is supported by the higher abundance of this taxon compared with other taxa, a trend for the genetic and morphological diversity to be correlated in Europe, and the higher genetic and morphological diversities found in clades of E cordatum (except B1) than in other spatangoid samples in Europe. However, the Pacific clades do not confirm these trends. PMID:26265259

  11. Genetic identity and parentage in farmer selections of cacao from Southern Sulawesi, Indonesia revealed by molecular markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Indonesia is the 3rd largest cocoa producing countries in the world and 71% of its production is from Sulawesi Island. Knowledge about the genetic background of farmer selections is highly important for effective identification and rational deployment of superior cacao clones in farmers’ fields. Mor...

  12. Structural and genetic analyses reveal the protein SepF as a new membrane anchor for the Z ring

    PubMed Central

    Duman, Ramona; Ishikawa, Shu; Celik, Ilkay; Strahl, Henrik; Ogasawara, Naotake; Troc, Paulina; Löwe, Jan; Hamoen, Leendert W.

    2013-01-01

    A key step in bacterial cell division is the polymerization of the tubulin homolog FtsZ at midcell. FtsZ polymers are anchored to the cell membrane by FtsA and are required for the assembly of all other cell division proteins. In Gram-positive and cyanobacteria, FtsZ filaments are aligned by the protein SepF, which in vitro polymerizes into large rings that bundle FtsZ filaments. Here we describe the crystal structure of the only globular domain of SepF, located within the C-terminal region. Two-hybrid data revealed that this domain comprises the FtsZ binding site, and EM analyses showed that it is sufficient for ring formation, which is explained by the filaments in the crystals of SepF. Site-directed mutagenesis, gel filtration, and analytical ultracentrifugation indicated that dimers form the basic units of SepF filaments. High-resolution structured illumination microscopy suggested that SepF is membrane associated, and it turned out that purified SepF not only binds to lipid membranes, but also recruits FtsZ. Further genetic and biochemical analyses showed that an amphipathic helix at the N terminus functions as the membrane-binding domain, making SepF a unique membrane anchor for the FtsZ ring. This clarifies why Bacillus subtilis grows without FtsA or the putative membrane anchor EzrA and why bacteria lacking FtsA contain SepF homologs. Both FtsA and SepF use an amphipathic helix for membrane binding. These helices prefer positively curved membranes due to relaxed lipid density; therefore this type of membrane anchor may assist in keeping the Z ring positioned at the strongly curved leading edge of the developing septum. PMID:24218584

  13. A cryptic species of Aphis gossypii (Hemiptera: Aphididae) complex revealed by genetic divergence and different host plant association.

    PubMed

    Lee, Y; Lee, W; Lee, S; Kim, H

    2015-02-01

    Three cryptic species, Aphis gossypii, Aphis glycines, and Aphis rhamnicola sp. nov., are recognized as sharing buckthorn plant, Rhamnus spp. as primary hosts. These aphid species have morphological similarities; however, there are significant genetic differences between the three cryptic species. Based on the high level of genetic divergence and the different secondary host association, we described a new species, Aphis rhamnicola sp. nov., for apterous and alate vivipara, fundatrix, ovipara, and gynopara, including diagnostic key for the host sharing species in the genus Aphis. PMID:25413997

  14. Genetic variability and genetic structure of wild and semi-domestic populations of tasar silkworm (Antheraea mylitta ) ecorace Daba as revealed through ISSR markers.

    PubMed

    Kar, P K; Vijayan, K; Mohandas, T P; Nair, C V; Saratchandra, B; Thangavelu, K

    2005-11-01

    The genetic diversity in the wild and semi-domestic populations of Daba ecorace of Antheraea mylitta was studied to ascertain the distribution of variability within and among populations of semi-domestic bivoltine (DB), trivoltine (DT) and nature grown wild populations (DN) with inter-simple sequence repeat (ISSR) markers. A total of 138 markers were produced among 56 individuals of the three populations, of which 98% were polymorphic. For the individual populations, the percentage polymorphism was 58.69, 52.9 and 77.54 for DB, DT and DN, respectively. Average number of observed (1.791+/- 0.408) and effective alleles (1.389+/-0.348) was also high in the wild populations in comparison to the bivoltine and trivoltine semi-domestic populations. Genetic diversity (H(t)) in DB, DT and DN was 0.180+/- 0.033, 0.153+/- 0.032 and 0.235+/- 0.033, respectively and within-population genetic diversity (H(s)) ranged from 0.166 to 0.259 with a mean of 0.189. Mean gene differentiation (G(ST)) was found to be 0.25. Shanon's diversity index was 0.278, 0.237 and 0.361 for DB, DT and DN and overall it was 0.391. Gene flow (N(m)) among the populations was 1.509. The dendrogram produced by UPGMA with Dice's genetic distance matrices resulted in the formation of three major clusters separating the three populations. Considerable intra- and inter-population variability is found in all three populations. The population structure analysis further suggests that the semi-domestic populations of Daba ecorace are at the threshold of differentiating themselves. The high genetic variability present within wild Daba population of A. mylitta is of much importance for conservation as well as utilization in systematic breeding program. PMID:16247690

  15. Genetic characteristics of porcine epidemic diarrhea virus in Chinese mainland, revealing genetic markers of classical and variant virulent parental/attenuated strains.

    PubMed

    Chen, Fangzhou; Ku, Xugang; Li, Zhonghua; Memon, Atta Muhammad; Ye, Shiyi; Zhu, Yinxing; Zhou, Chunling; Yao, Li; Meng, Xianrong; He, Qigai

    2016-08-15

    Since October 2010, porcine epidemic diarrhea (PED) caused by variant porcine epidemic diarrhea virus (PEDV) has led great economic losses to the global pig industry, especially in China. To study the genetic characteristics of PEDV strains in Chinese mainland, a total of 603 clinical samples from nine provinces/districts of Chinese mainland from January 2014 to December 2015 were collected for RT-PCR detection and 1-1323bp of S gene of 91 isolates and ORF3 gene of 46 isolates were sequenced. The results showed that the variant PEDV were the dominant pathogens of viral diarrhea diseases in these areas. Six novel variant PEDV strains (FJAX1, FJAX2, HeNPDS1, HeNPDS2, HeNPY3, and HeNPY4) with two amino acids (aa) deletion at the 56-57 aa of S protein were identified. A total of 405 Chinese PEDV strains were subjected to phylogenetic and phylogeographic analysis. The results revealed that the subgroup Va in variant PEDV group were the dominant subgroup and the spread trend of variant PEDV strains seemed to be from the southeast coastal districts to other coastal districts and interior districts. The N-terminal of S gene (1-750bp), to some extent, could represent S1 or full length S gene for phylogenetic, similarity, antigen index, hydrophilicity plot, and differentiation analyses. The 404-472bp of S gene contained the three genetic markers, i.e., "TAA" insertion at 404-405bp, "ACAGGT" deletion at 430-435bp, and "ATA" deletion at 455-457bp can be used to differentiate the classical and variant virulent parental/attenuated PEDV strains and help us to learn the infectious and genetic characteristics of PEDV strains more convenient and cheaper. This study has important implication for understanding the infectious, genetic, and evolutionary aspects of PEDV strains in Chinese mainland. PMID:27178127

  16. Transcriptome Sequencing Reveals the Virulence and Environmental Genetic Programs of Vibrio vulnificus Exposed to Host and Estuarine Conditions

    PubMed Central

    Williams, Tiffany C.; Blackman, Elliot R.; Morrison, Shatavia S.; Gibas, Cynthia J.; Oliver, James D.

    2014-01-01

    Vibrio vulnificus is a natural inhabitant of estuarine waters worldwide and is of medical relevance due to its ability to cause grievous wound infections and/or fatal septicemia. Genetic polymorphisms within the virulence-correlated gene (vcg) serve as a primary feature to distinguish clinical (C-) genotypes from environmental (E-) genotypes. C-genotypes demonstrate superior survival in human serum relative to E-genotypes, and genome comparisons have allowed for the identification of several putative virulence factors that could potentially aid C-genotypes in disease progression. We used RNA sequencing to analyze the transcriptome of C-genotypes exposed to human serum relative to seawater, which revealed two divergent genetic programs under these two conditions. In human serum, cells displayed a distinct “virulence profile” in which a number of putative virulence factors were upregulated, including genes involved in intracellular signaling, substrate binding and transport, toxin and exoenzyme production, and the heat shock response. Conversely, the “environmental profile” exhibited by cells in seawater revealed upregulation of transcription factors such as rpoS, rpoN, and iscR, as well as genes involved in intracellular signaling, chemotaxis, adherence, and biofilm formation. This dichotomous genetic switch appears to be largely governed by cyclic-di-GMP signaling, and remarkably resembles the dual life-style of V. cholerae as it transitions from host to environment. Furthermore, we found a “general stress response” module, known as the stressosome, to be upregulated in seawater. This signaling system has been well characterized in Gram-positive bacteria, however its role in V. vulnificus is not clear. We examined temporal gene expression patterns of the stressosome and found it to be upregulated in natural estuarine waters indicating that this system plays a role in sensing and responding to the environment. This study advances our understanding of

  17. Comparative analysis of the Oenococcus oeni pan genome reveals genetic diversity in industrially-relevant pathways

    PubMed Central

    2012-01-01