Isolation of prolactin and growth hormone from the pituitary of the holostean fish Amia calva.

PubMed

Dores, R M; Noso, T; Rand-Weaver, M; Kawauchi, H

1993-06-01

Pituitaries from adult male and female Amia calva (Order Holostei) were acid extracted and fractionated by gel filtration column chromatography and reversed-phase high performance liquid chromatography. This two-step isolation procedure yielded homogeneous pools of Amia prolaction (PRL) and growth hormone (GH). The amino acid composition of both purified polypeptides was determined. Primary sequence analysis of the first 22 positions at the N-terminal of Amia PRL revealed that this region has 63% sequence identity with eel PRL-1. The N-terminal region of Amia PRL lacks the disulfide bridge which is characteristic of tetrapod PRLs. Primary sequence analysis of the first 24 positions at the N-terminal of Amia GH revealed that this region has 62% sequence identity with eel GH and 54% sequence identity with both blue shark GH and sea turtle GH. Based on N-terminal analysis, it appears that Amia PRL and GH are more closely related to teleost PRLs and GHs than they are to tetrapod PRLs and GHs.

Statistical properties of DNA sequences

NASA Technical Reports Server (NTRS)

Peng, C. K.; Buldyrev, S. V.; Goldberger, A. L.; Havlin, S.; Mantegna, R. N.; Simons, M.; Stanley, H. E.

1995-01-01

We review evidence supporting the idea that the DNA sequence in genes containing non-coding regions is correlated, and that the correlation is remarkably long range--indeed, nucleotides thousands of base pairs distant are correlated. We do not find such a long-range correlation in the coding regions of the gene. We resolve the problem of the "non-stationarity" feature of the sequence of base pairs by applying a new algorithm called detrended fluctuation analysis (DFA). We address the claim of Voss that there is no difference in the statistical properties of coding and non-coding regions of DNA by systematically applying the DFA algorithm, as well as standard FFT analysis, to every DNA sequence (33301 coding and 29453 non-coding) in the entire GenBank database. Finally, we describe briefly some recent work showing that the non-coding sequences have certain statistical features in common with natural and artificial languages. Specifically, we adapt to DNA the Zipf approach to analyzing linguistic texts. These statistical properties of non-coding sequences support the possibility that non-coding regions of DNA may carry biological information.

Correlation approach to identify coding regions in DNA sequences

NASA Technical Reports Server (NTRS)

Ossadnik, S. M.; Buldyrev, S. V.; Goldberger, A. L.; Havlin, S.; Mantegna, R. N.; Peng, C. K.; Simons, M.; Stanley, H. E.

1994-01-01

Recently, it was observed that noncoding regions of DNA sequences possess long-range power-law correlations, whereas coding regions typically display only short-range correlations. We develop an algorithm based on this finding that enables investigators to perform a statistical analysis on long DNA sequences to locate possible coding regions. The algorithm is particularly successful in predicting the location of lengthy coding regions. For example, for the complete genome of yeast chromosome III (315,344 nucleotides), at least 82% of the predictions correspond to putative coding regions; the algorithm correctly identified all coding regions larger than 3000 nucleotides, 92% of coding regions between 2000 and 3000 nucleotides long, and 79% of coding regions between 1000 and 2000 nucleotides. The predictive ability of this new algorithm supports the claim that there is a fundamental difference in the correlation property between coding and noncoding sequences. This algorithm, which is not species-dependent, can be implemented with other techniques for rapidly and accurately locating relatively long coding regions in genomic sequences.

Analysis of the regulatory region of the protease III (ptr) gene of Escherichia coli K-12.

PubMed

Claverie-Martin, F; Diaz-Torres, M R; Kushner, S R

1987-01-01

The ptr gene of Escherichia coli encodes protease III (Mr 110,000) and a 50-kDa polypeptide, both of which are found in the periplasmic space. The gene is physically located between the recC and recB loci on the E. coli chromosome. The nucleotide sequence of a 1167-bp EcoRV-ClaI fragment of chromosomal DNA containing the promoter region and 885 bp of the ptr coding sequence has been determined. S1 nuclease mapping analysis showed that the major 5' end of the ptr mRNA was localized 127 bp upstream from the ATG start codon. The open reading frame (ORF), preceded by a Shine-Dalgarno sequence, extends to the end of the sequenced DNA. Downstream from the -35 and -10 regions is a sequence that strongly fits the consensus sequence of known nitrogen-regulated promoters. A signal peptide of 23 amino acids residues is present at the N terminus of the derived amino acid sequence. The cleavage site as well as the ORF were confirmed by sequencing the N terminus of mature protease III.

Identification of Medically Important Yeasts Using PCR-Based Detection of DNA Sequence Polymorphisms in the Internal Transcribed Spacer 2 Region of the rRNA Genes

PubMed Central

Chen, Y. C.; Eisner, J. D.; Kattar, M. M.; Rassoulian-Barrett, S. L.; LaFe, K.; Yarfitz, S. L.; Limaye, A. P.; Cookson, B. T.

2000-01-01

Identification of medically relevant yeasts can be time-consuming and inaccurate with current methods. We evaluated PCR-based detection of sequence polymorphisms in the internal transcribed spacer 2 (ITS2) region of the rRNA genes as a means of fungal identification. Clinical isolates (401), reference strains (6), and type strains (27), representing 34 species of yeasts were examined. The length of PCR-amplified ITS2 region DNA was determined with single-base precision in less than 30 min by using automated capillary electrophoresis. Unique, species-specific PCR products ranging from 237 to 429 bp were obtained from 92% of the clinical isolates. The remaining 8%, divided into groups with ITS2 regions which differed by ≤2 bp in mean length, all contained species-specific DNA sequences easily distinguishable by restriction enzyme analysis. These data, and the specificity of length polymorphisms for identifying yeasts, were confirmed by DNA sequence analysis of the ITS2 region from 93 isolates. Phenotypic and ITS2-based identification was concordant for 427 of 434 yeast isolates examined using sequence identity of ≥99%. Seven clinical isolates contained ITS2 sequences that did not agree with their phenotypic identification, and ITS2-based phylogenetic analyses indicate the possibility of new or clinically unusual species in the Rhodotorula and Candida genera. This work establishes an initial database, validated with over 400 clinical isolates, of ITS2 length and sequence polymorphisms for 34 species of yeasts. We conclude that size and restriction analysis of PCR-amplified ITS2 region DNA is a rapid and reliable method to identify clinically significant yeasts, including potentially new or emerging pathogenic species. PMID:10834993

Genomic DNA sequence and cytosine methylation changes of adult rice leaves after seeds space flight

NASA Astrophysics Data System (ADS)

Shi, Jinming

In this study, cytosine methylation on CCGG site and genomic DNA sequence changes of adult leaves of rice after seeds space flight were detected by methylation-sensitive amplification polymorphism (MSAP) and Amplified fragment length polymorphism (AFLP) technique respectively. Rice seeds were planted in the trial field after 4 days space flight on the shenzhou-6 Spaceship of China. Adult leaves of space-treated rice including 8 plants chosen randomly and 2 plants with phenotypic mutation were used for AFLP and MSAP analysis. Polymorphism of both DNA sequence and cytosine methylation were detected. For MSAP analysis, the average polymorphic frequency of the on-ground controls, space-treated plants and mutants are 1.3%, 3.1% and 11% respectively. For AFLP analysis, the average polymorphic frequencies are 1.4%, 2.9%and 8%respectively. Total 27 and 22 polymorphic fragments were cloned sequenced from MSAP and AFLP analysis respectively. Nine of the 27 fragments from MSAP analysis show homology to coding sequence. For the 22 polymorphic fragments from AFLP analysis, no one shows homology to mRNA sequence and eight fragments show homology to repeat region or retrotransposon sequence. These results suggest that although both genomic DNA sequence and cytosine methylation status can be effected by space flight, the genomic region homology to the fragments from genome DNA and cytosine methylation analysis were different.

Nucleotide sequence determination of guinea-pig casein B mRNA reveals homology with bovine and rat alpha s1 caseins and conservation of the non-coding regions of the mRNA.

PubMed Central

Hall, L; Laird, J E; Craig, R K

1984-01-01

Nucleotide sequence analysis of cloned guinea-pig casein B cDNA sequences has identified two casein B variants related to the bovine and rat alpha s1 caseins. Amino acid homology was largely confined to the known bovine or predicted rat phosphorylation sites and within the 'signal' precursor sequence. Comparison of the deduced nucleotide sequence of the guinea-pig and rat alpha s1 casein mRNA species showed greater sequence conservation in the non-coding than in the coding regions, suggesting a functional and possibly regulatory role for the non-coding regions of casein mRNA. The results provide insight into the evolution of the casein genes, and raise questions as to the role of conserved nucleotide sequences within the non-coding regions of mRNA species. Images Fig. 1. PMID:6548375

Characterization of Dermanyssus gallinae (Acarina: Dermanissydae) by sequence analysis of the ribosomal internal transcribed spacer regions.

PubMed

Potenza, L; Cafiero, M A; Camarda, A; La Salandra, G; Cucchiarini, L; Dachà, M

2009-10-01

In the present work mites previously identified as Dermanyssus gallinae De Geer (Acari, Mesostigmata) using morphological keys were investigated by molecular tools. The complete internal transcribed spacer 1 (ITS1), 5.8S ribosomal DNA, and ITS2 region of the ribosomal DNA from mites were amplified and sequenced to examine the level of sequence variations and to explore the feasibility of using this region in the identification of this mite. Conserved primers located at the 3'end of 18S and at the 5'start of 28S rRNA genes were used first, and amplified fragments were sequenced. Sequence analyses showed no variation in 5.8S and ITS2 region while slight intraspecific variations involving substitutions as well as deletions concentrated in the ITS1 region. Based on the sequence analyses a nested PCR of the ITS2 region followed by RFLP analyses has been set up in the attempt to provide a rapid molecular diagnostic tool of D. gallinae.

DNA sequence analysis of the photosynthesis region of Rhodobacter sphaeroides 2.4.1.

PubMed

Choudhary, M; Kaplan, S

2000-02-15

This paper describes the DNA sequence of the photosynthesis region of Rhodobacter sphaeroides 2.4.1 (T). The photosynthesis gene cluster is located within a approximately 73 kb Ase I genomic DNA fragment containing the puf, puhA, cycA and puc operons. A total of 65 open reading frames (ORFs) have been identified, of which 61 showed significant similarity to genes/proteins of other organisms while only four did not reveal any significant sequence similarity to any gene/protein sequences in the database. The data were compared with the corresponding genes/ORFs from a different strain of R.sphaeroides and Rhodobacter capsulatus, a close relative of R. sphaeroides. A detailed analysis of the gene organization in the photosynthesis region revealed a similar gene order in both species with some notable differences located to the pucBAC = cycA region. In addition, photosynthesis gene regulatory protein (PpsR, FNR, IHF) binding motifs in upstream sequences of a number of photosynthesis genes have been identified and shown to differ between these two species. The difference in gene organization relative to pucBAC and cycA suggests that this region originated independently of the photosynthesis gene cluster of R.sphaeroides.

Designing a Bioengine for Detection and Analysis of Base String on an Affected Sequence in High-Concentration Regions

PubMed Central

Mandal, Bijoy Kumar; Kim, Tai-hoon

2013-01-01

We design an Algorithm for bioengine. As a program are enable optimal alignments searching between two sequences, the host sequence (normal plant) as well as query sequence (virus). Searching for homologues has become a routine operation of biological sequences in 4 × 4 combination with different subsequence (word size). This program takes the advantage of the high degree of homology between such sequences to construct an alignment of the matching regions. There is a main aim which is to detect the overlapping reading frames. This program also enables to find out the highly infected colones selection highest matching region with minimum gap or mismatch zones and unique virus colones matches. This is a small, portable, interactive, front-end program intended to be used to find out the regions of matching between host sequence and query subsequences. All the operations are carried out in fraction of seconds, depending on the required task and on the sequence length. PMID:24000321

Identification of Human Lineage-Specific Transcriptional Coregulators Enabled by a Glossary of Binding Modules and Tunable Genomic Backgrounds.

PubMed

Mariani, Luca; Weinand, Kathryn; Vedenko, Anastasia; Barrera, Luis A; Bulyk, Martha L

2017-09-27

Transcription factors (TFs) control cellular processes by binding specific DNA motifs to modulate gene expression. Motif enrichment analysis of regulatory regions can identify direct and indirect TF binding sites. Here, we created a glossary of 108 non-redundant TF-8mer "modules" of shared specificity for 671 metazoan TFs from publicly available and new universal protein binding microarray data. Analysis of 239 ENCODE TF chromatin immunoprecipitation sequencing datasets and associated RNA sequencing profiles suggest the 8mer modules are more precise than position weight matrices in identifying indirect binding motifs and their associated tethering TFs. We also developed GENRE (genomically equivalent negative regions), a tunable tool for construction of matched genomic background sequences for analysis of regulatory regions. GENRE outperformed four state-of-the-art approaches to background sequence construction. We used our TF-8mer glossary and GENRE in the analysis of the indirect binding motifs for the co-occurrence of tethering factors, suggesting novel TF-TF interactions. We anticipate that these tools will aid in elucidating tissue-specific gene-regulatory programs. Copyright © 2017 Elsevier Inc. All rights reserved.

Analysis of the complete genome of subgroup A' hepatitis B virus isolates from South Africa.

PubMed

Kramvis, Anna; Weitzmann, Louise; Owiredu, William K B A; Kew, Michael C

2002-04-01

A phylogenetic analysis is presented of six complete and seven pre-S1/S2/S gene sequences of hepatitis B virus (HBV) isolates from South Africa. Five of the full-length sequences and all of the pre-S2/S sequences have been previously reported. Four of the six complete genomes and three of the five incomplete sequences clustered with subgroup A', a unique segment of genotype A of HBV previously identified in 60% of South African isolates using analysis of the pre-S2/S region alone. This separation was also evident when the polymerase open reading frame was analysed, but not on analysis of either the X or pre-core/core genes. Amino acids were identified in the pre-S1 and polymerase regions specific to subgroup A'. In common with genotype D, 10 of 11 genotype A South African isolates had an 11 amino acid deletion in the amino end of the pre-S1 region. This deletion is also found in hepadnaviruses from non-human primates.

Genomic Sequence around Butterfly Wing Development Genes: Annotation and Comparative Analysis

PubMed Central

Conceição, Inês C.; Long, Anthony D.; Gruber, Jonathan D.; Beldade, Patrícia

2011-01-01

Background Analysis of genomic sequence allows characterization of genome content and organization, and access beyond gene-coding regions for identification of functional elements. BAC libraries, where relatively large genomic regions are made readily available, are especially useful for species without a fully sequenced genome and can increase genomic coverage of phylogenetic and biological diversity. For example, no butterfly genome is yet available despite the unique genetic and biological properties of this group, such as diversified wing color patterns. The evolution and development of these patterns is being studied in a few target species, including Bicyclus anynana, where a whole-genome BAC library allows targeted access to large genomic regions. Methodology/Principal Findings We characterize ∼1.3 Mb of genomic sequence around 11 selected genes expressed in B. anynana developing wings. Extensive manual curation of in silico predictions, also making use of a large dataset of expressed genes for this species, identified repetitive elements and protein coding sequence, and highlighted an expansion of Alcohol dehydrogenase genes. Comparative analysis with orthologous regions of the lepidopteran reference genome allowed assessment of conservation of fine-scale synteny (with detection of new inversions and translocations) and of DNA sequence (with detection of high levels of conservation of non-coding regions around some, but not all, developmental genes). Conclusions The general properties and organization of the available B. anynana genomic sequence are similar to the lepidopteran reference, despite the more than 140 MY divergence. Our results lay the groundwork for further studies of new interesting findings in relation to both coding and non-coding sequence: 1) the Alcohol dehydrogenase expansion with higher similarity between the five tandemly-repeated B. anynana paralogs than with the corresponding B. mori orthologs, and 2) the high conservation of non-coding sequence around the genes wingless and Ecdysone receptor, both involved in multiple developmental processes including wing pattern formation. PMID:21909358

Species composition of the genus Saprolegnia in fin fish aquaculture environments, as determined by nucleotide sequence analysis of the nuclear rDNA ITS regions.

PubMed

de la Bastide, Paul Y; Leung, Wai Lam; Hintz, William E

2015-01-01

The ITS region of the rDNA gene was compared for Saprolegnia spp. in order to improve our understanding of nucleotide sequence variability within and between species of this genus, determine species composition in Canadian fin fish aquaculture facilities, and to assess the utility of ITS sequence variability in genetic marker development. From a collection of more than 400 field isolates, ITS region nucleotide sequences were studied and it was determined that there was sufficient consistent inter-specific variation to support the designation of species identity based on ITS sequence data. This non-subjective approach to species identification does not rely upon transient morphological features. Phylogenetic analyses comparing our ITS sequences and species designations with data from previous studies generally supported the clade scheme of Diéguez-Uribeondo et al. (2007) and found agreement with the molecular taxonomic cluster system of Sandoval-Sierra et al. (2014). Our Canadian ITS sequence collection will thus contribute to the public database and assist the clarification of Saprolegnia spp. taxonomy. The analysis of ITS region sequence variability facilitated genus- and species-level identification of unknown samples from aquaculture facilities and provided useful information on species composition. A unique ITS-RFLP for the identification of S. parasitica was also described. Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

The complete chloroplast genome of Cinnamomum camphora and its comparison with related Lauraceae species.

PubMed

Chen, Caihui; Zheng, Yongjie; Liu, Sian; Zhong, Yongda; Wu, Yanfang; Li, Jiang; Xu, Li-An; Xu, Meng

2017-01-01

Cinnamomum camphora , a member of the Lauraceae family, is a valuable aromatic and timber tree that is indigenous to the south of China and Japan. All parts of Cinnamomum camphora have secretory cells containing different volatile chemical compounds that are utilized as herbal medicines and essential oils. Here, we reported the complete sequencing of the chloroplast genome of Cinnamomum camphora using illumina technology. The chloroplast genome of Cinnamomum camphora is 152,570 bp in length and characterized by a relatively conserved quadripartite structure containing a large single copy region of 93,705 bp, a small single copy region of 19,093 bp and two inverted repeat (IR) regions of 19,886 bp. Overall, the genome contained 123 coding regions, of which 15 were repeated in the IR regions. An analysis of chloroplast sequence divergence revealed that the small single copy region was highly variable among the different genera in the Lauraceae family. A total of 40 repeat structures and 83 simple sequence repeats were detected in both the coding and non-coding regions. A phylogenetic analysis indicated that Calycanthus is most closely related to Lauraceae , both being members of Laurales , which forms a sister group to Magnoliids . The complete sequence of the chloroplast of Cinnamomum camphora will aid in in-depth taxonomical studies of the Lauraceae family in the future. The genetic sequence information will also have valuable applications for chloroplast genetic engineering.

Re-analysis of human immunodeficiency virus type 1 isolates from Cyprus and Greece, initially designated 'subtype I', reveals a unique complex A/G/H/K/? mosaic pattern.

PubMed

Paraskevis, D; Magiorkinis, M; Vandamme, A M; Kostrikis, L G; Hatzakis, A

2001-03-01

Human immunodeficiency virus type 1 (HIV-1) has been classified into three main groups and 11 distinct subtypes. Moreover, several circulating recombinant forms (CRFs) of HIV-1 have been recently documented to have spread widely causing extensive HIV-1 epidemics. A subtype, initially designated I (CRF04_cpx), was documented in Cyprus and Greece and was found to comprise regions of sequence derived from subtypes A and G as well as regions of unclassified sequence. Re-analysis of the three full-length CRF04_cpx sequences that were available revealed a mosaic genomic organization of unique complexity comprising regions of sequence from at least five distinct subtypes, A, G, H, K and unclassified regions. These strains account for approximately 2% of the total HIV-1-infected population in Greece, thus providing evidence of the great capability of HIV-1 to recombine and produce highly divergent strains which can be spread successfully through different infection routes.

Analysis of 16S-23S intergenic spacer regions of the rRNA operons in Edwardsiella ictaluri and Edwardsiella tarda isolates from fish.

PubMed

Panangala, V S; van Santen, V L; Shoemaker, C A; Klesius, P H

2005-01-01

To analyse interspecies and intraspecies differences based on the 16S-23S rRNA intergenic spacer region (ISR) sequences of the fish pathogens Edwardsiella ictaluri and Edwardsiella tarda. The 16S-23S rRNA spacer regions of 19 Edw. ictaluri and four Edw. tarda isolates from four geographical regions were amplified by PCR with primers complementary to conserved sequences within the flanking 16S-23S rRNA coding sequences. Two products were generated from all isolates, without interspecies or intraspecific size polymorphisms. Sequence analysis of the amplified fragments revealed a smaller ISR of 350 bp, which contained a gene for tRNA(Glu), and a larger ISR of 441 bp, which contained genes for tRNA(Ile) and tRNA(Ala). The sequences of the smaller ISR of different Edw. ictaluri isolates were essentially identical to each other. Partial sequences of larger ISR from several Edw. ictaluri isolates also revealed no differences from the one complete Edw. ictaluri large ISR sequence obtained. The sequences of the smaller ISR of Edw. tarda were 97% identical to the Edw. ictaluri smaller ISR and the larger ISR were 96-98% identical to the Edw. ictaluri larger ISR sequence. The Edw. tarda isolates displayed limited ISR sequence heterogeneity, with > or =97% sequence identity among isolates for both small and large ISR. There is a high degree of size and sequence similarity of 16S-23S ISR both among isolates within Edw. ictaluri and Edw. tarda species and between the two species. Our results confirm a close genetic relationship between Edw. ictaluri and Edw. tarda and the relative homogeneity of Edw. ictaluri isolates compared with Edw. tarda isolates. Because no differences were found in ISR sequences among Edw. ictaluri isolates, sequence analysis of the ISR will not be useful to distinguish isolates of Edw. ictaluri. However, we identified restriction sites that differ between ISR sequences of Edw. ictaluri and Edw. tarda, which will be useful in distinguishing the two species.

Combined sequence and structure analysis of the fungal laccase family.

PubMed

Kumar, S V Suresh; Phale, Prashant S; Durani, S; Wangikar, Pramod P

2003-08-20

Plant and fungal laccases belong to the family of multi-copper oxidases and show much broader substrate specificity than other members of the family. Laccases have consequently been of interest for potential industrial applications. We have analyzed the essential sequence features of fungal laccases based on multiple sequence alignments of more than 100 laccases. This has resulted in identification of a set of four ungapped sequence regions, L1-L4, as the overall signature sequences that can be used to identify the laccases, distinguishing them within the broader class of multi-copper oxidases. The 12 amino acid residues in the enzymes serving as the copper ligands are housed within these four identified conserved regions, of which L2 and L4 conform to the earlier reported copper signature sequences of multi-copper oxidases while L1 and L3 are distinctive to the laccases. The mapping of regions L1-L4 on to the three-dimensional structure of the Coprinus cinerius laccase indicates that many of the non-copper-ligating residues of the conserved regions could be critical in maintaining a specific, more or less C-2 symmetric, protein conformational motif characterizing the active site apparatus of the enzymes. The observed intraprotein homologies between L1 and L3 and between L2 and L4 at both the structure and the sequence levels suggest that the quasi C-2 symmetric active site conformational motif may have arisen from a structural duplication event that neither the sequence homology analysis nor the structure homology analysis alone would have unraveled. Although the sequence and structure homology is not detectable in the rest of the protein, the relative orientation of region L1 with L2 is similar to that of L3 with L4. The structure duplication of first-shell and second-shell residues has become cryptic because the intraprotein sequence homology noticeable for a given laccase becomes significant only after comparing the conservation pattern in several fungal laccases. The identified motifs, L1-L4, can be useful in searching the newly sequenced genomes for putative laccase enzymes. Copyright 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 386-394, 2003.

The complete chloroplast genome sequence of the medicinal plant Salvia miltiorrhiza.

PubMed

Qian, Jun; Song, Jingyuan; Gao, Huanhuan; Zhu, Yingjie; Xu, Jiang; Pang, Xiaohui; Yao, Hui; Sun, Chao; Li, Xian'en; Li, Chuyuan; Liu, Juyan; Xu, Haibin; Chen, Shilin

2013-01-01

Salvia miltiorrhiza is an important medicinal plant with great economic and medicinal value. The complete chloroplast (cp) genome sequence of Salvia miltiorrhiza, the first sequenced member of the Lamiaceae family, is reported here. The genome is 151,328 bp in length and exhibits a typical quadripartite structure of the large (LSC, 82,695 bp) and small (SSC, 17,555 bp) single-copy regions, separated by a pair of inverted repeats (IRs, 25,539 bp). It contains 114 unique genes, including 80 protein-coding genes, 30 tRNAs and four rRNAs. The genome structure, gene order, GC content and codon usage are similar to the typical angiosperm cp genomes. Four forward, three inverted and seven tandem repeats were detected in the Salvia miltiorrhiza cp genome. Simple sequence repeat (SSR) analysis among the 30 asterid cp genomes revealed that most SSRs are AT-rich, which contribute to the overall AT richness of these cp genomes. Additionally, fewer SSRs are distributed in the protein-coding sequences compared to the non-coding regions, indicating an uneven distribution of SSRs within the cp genomes. Entire cp genome comparison of Salvia miltiorrhiza and three other Lamiales cp genomes showed a high degree of sequence similarity and a relatively high divergence of intergenic spacers. Sequence divergence analysis discovered the ten most divergent and ten most conserved genes as well as their length variation, which will be helpful for phylogenetic studies in asterids. Our analysis also supports that both regional and functional constraints affect gene sequence evolution. Further, phylogenetic analysis demonstrated a sister relationship between Salvia miltiorrhiza and Sesamum indicum. The complete cp genome sequence of Salvia miltiorrhiza reported in this paper will facilitate population, phylogenetic and cp genetic engineering studies of this medicinal plant.

Small subunit ribosomal RNA genes of tabanids and hippoboscids (Diptera: Brachycera): evolutionary relationships and comparison with other Diptera.

PubMed

Carreno, R A; Barta, J R

1998-11-01

The small subunit ribosomal RNA (SSU rRNA) genes of hippoboscid (Ornithoica vicina Walker) and tabanid (Chrysops niger Macquart) Diptera were sequenced to determine their phylogenetic position within the order and to determine whether or not extensive hypervariable regions in this gene are widespread in the Diptera. A parsimony analysis of an alignment containing 8 dipteran sequences produced a single most parsimonious tree that placed O. vicina as sister group to Drosophila melanogaster Meigen. The tabanid Chrysops niger was sister group to the asilomorphan taxa, and the sister group to the Brachycera was a Tipula sp. although this relationship was not supported by bootstrap analysis. The hippoboscid and tabanid sequences contain extensive hypervariable regions in the V2, V4, V6, and V7 regions as do other Diptera. When these regions of the alignment were excluded from the phylogenetic analysis, a single most parsimonious tree was found. This tree had an identical overall topology to the tree obtained from the total data set. The hypervariable regions in parts of the dipteran SSU rRNA genes were more extensive in the nematocerous dipteran sequences used in this study than in the other dipteran representatives; these hypervariable regions may be of more utility in inferring relationship among species and subspecies than at the suprageneric level.

Sequence analysis of the mitochondrial DNA control region of ciscoes (genus Coregonus): taxonomic implications for the Great Lakes species flock.

PubMed

Reed, K M; Dorschner, M O; Todd, T N; Phillips, R B

1998-09-01

Sequence variation in the control region (D-loop) of the mitochondrial DNA (mtDNA) was examined to assess the genetic distinctiveness of the shortjaw cisco (Coregonus zenithicus). Individuals from within the Great Lakes Basin as well as inland lakes outside the basin were sampled. DNA fragments containing the entire D-loop were amplified by PCR from specimens of C. zenithicus and the related species C. artedi, C. hoyi, C. kiyi, and C. clupeaformis. DNA sequence analysis revealed high similarity within and among species and shared polymorphism for length variants. Based on this analysis, the shortjaw cisco is not genetically distinct from other cisco species.

Regional spread of HIV-1 M subtype B in middle-aged patients by random env-C2V4 region sequencing

PubMed Central

Stürmer, Martin; Zimmermann, Katrin; Fritzsche, Carlos; Reisinger, Emil; Doelken, Gottfried; Berger, Annemarie; Doerr, Hans W.; Eberle, Josef

2010-01-01

A transmission cluster of HIV-1 M:B was identified in 11 patients with a median age of 52 (range 26–65) in North-East Germany by C2V4 region sequencing of the env gene of HIV-1, who—except of one—were not aware of any risky behaviour. The 10 male and 1 female patients deteriorated immunologically, according to their information made available, within 4 years after a putative HIV acquisition. Nucleic acid sequence analysis showed a R5 virus in all patients and in 7 of 11 a crown motif of the V3 loop, GPGSALFTT, which is found rarely. Analysis of formation of this cluster showed that there is still a huge discrepancy between awareness and behaviour regarding HIV transmission in middle-aged patients, and that a local outbreak can be detected by nucleic acid analysis of the hypervariable env region. PMID:20217125

Earthquake Forecasting Through Semi-periodicity Analysis of Labeled Point Processes

NASA Astrophysics Data System (ADS)

Quinteros Cartaya, C. B. M.; Nava Pichardo, F. A.; Glowacka, E.; Gomez-Trevino, E.

2015-12-01

Large earthquakes have semi-periodic behavior as result of critically self-organized processes of stress accumulation and release in some seismogenic region. Thus, large earthquakes in a region constitute semi-periodic sequences with recurrence times varying slightly from periodicity. Nava et al., 2013 and Quinteros et al., 2013 realized that not all earthquakes in a given region need belong to the same sequence, since there can be more than one process of stress accumulation and release in it; they also proposed a method to identify semi-periodic sequences through analytic Fourier analysis. This work presents improvements on the above-mentioned method: the influence of earthquake size on the spectral analysis, and its importance in semi-periodic events identification, which means that earthquake occurrence times are treated as a labeled point process; the estimation of appropriate upper limit uncertainties to use in forecasts; and the use of Bayesian analysis to evaluate the forecast performance. This improved method is applied to specific regions: the southwestern coast of Mexico, the northeastern Japan Arc, the San Andreas Fault zone at Parkfield, and northeastern Venezuela.

Detection of hyper-conserved regions in hepatitis B virus X gene potentially useful for gene therapy.

PubMed

González, Carolina; Tabernero, David; Cortese, Maria Francesca; Gregori, Josep; Casillas, Rosario; Riveiro-Barciela, Mar; Godoy, Cristina; Sopena, Sara; Rando, Ariadna; Yll, Marçal; Lopez-Martinez, Rosa; Quer, Josep; Esteban, Rafael; Buti, Maria; Rodríguez-Frías, Francisco

2018-05-21

To detect hyper-conserved regions in the hepatitis B virus (HBV) X gene ( HBX ) 5' region that could be candidates for gene therapy. The study included 27 chronic hepatitis B treatment-naive patients in various clinical stages (from chronic infection to cirrhosis and hepatocellular carcinoma, both HBeAg-negative and HBeAg-positive), and infected with HBV genotypes A-F and H. In a serum sample from each patient with viremia > 3.5 log IU/mL, the HBX 5' end region [nucleotide (nt) 1255-1611] was PCR-amplified and submitted to next-generation sequencing (NGS). We assessed genotype variants by phylogenetic analysis, and evaluated conservation of this region by calculating the information content of each nucleotide position in a multiple alignment of all unique sequences (haplotypes) obtained by NGS. Conservation at the HBx protein amino acid (aa) level was also analyzed. NGS yielded 1333069 sequences from the 27 samples, with a median of 4578 sequences/sample (2487-9279, IQR 2817). In 14/27 patients (51.8%), phylogenetic analysis of viral nucleotide haplotypes showed a complex mixture of genotypic variants. Analysis of the information content in the haplotype multiple alignments detected 2 hyper-conserved nucleotide regions, one in the HBX upstream non-coding region (nt 1255-1286) and the other in the 5' end coding region (nt 1519-1603). This last region coded for a conserved amino acid region (aa 63-76) that partially overlaps a Kunitz-like domain. Two hyper-conserved regions detected in the HBX 5' end may be of value for targeted gene therapy, regardless of the patients' clinical stage or HBV genotype.

Statistical and linguistic features of DNA sequences

NASA Technical Reports Server (NTRS)

Havlin, S.; Buldyrev, S. V.; Goldberger, A. L.; Mantegna, R. N.; Peng, C. K.; Simons, M.; Stanley, H. E.

1995-01-01

We present evidence supporting the idea that the DNA sequence in genes containing noncoding regions is correlated, and that the correlation is remarkably long range--indeed, base pairs thousands of base pairs distant are correlated. We do not find such a long-range correlation in the coding regions of the gene. We resolve the problem of the "non-stationary" feature of the sequence of base pairs by applying a new algorithm called Detrended Fluctuation Analysis (DFA). We address the claim of Voss that there is no difference in the statistical properties of coding and noncoding regions of DNA by systematically applying the DFA algorithm, as well as standard FFT analysis, to all eukaryotic DNA sequences (33 301 coding and 29 453 noncoding) in the entire GenBank database. We describe a simple model to account for the presence of long-range power-law correlations which is based upon a generalization of the classic Levy walk. Finally, we describe briefly some recent work showing that the noncoding sequences have certain statistical features in common with natural languages. Specifically, we adapt to DNA the Zipf approach to analyzing linguistic texts, and the Shannon approach to quantifying the "redundancy" of a linguistic text in terms of a measurable entropy function. We suggest that noncoding regions in plants and invertebrates may display a smaller entropy and larger redundancy than coding regions, further supporting the possibility that noncoding regions of DNA may carry biological information.

The Prevalence of Gap Junction Protein Beta 2 (GJB2) Mutations in Non Syndromic Sensorineural Hearing Loss in Çukurova Region.

PubMed

Bozdoğan, Sevcan Tuğ; Kuran, Gökhan; Yüregir, Özge Özalp; Aslan, Hüseyin; Haytoğlu, Süheyl; Ayaz, Akif; Arıkan, Osman Kürşat

2015-08-01

To date, studies in all populations showed that mutations in the gene of Gap junction protein beta 2 (GJB2) play an important role in non-syndromic autosomal recessive congenital hearing loss. The aim of this study was to evaluate GJB2 gene of patients with hearing loss in our region using deoxyribonucleic acid (DNA) sequencing method and to demonstrate region-specific mutation and polymorphism distribution. Patients who had bilateral severe sensorineural non-syndromic hearing loss identified by audiologic evaluation were included. Peripheral blood samples were collected and the GJB2 gene exon1 and exon 2 regions were amplified by polymerase chain reaction (PCR). Obtained PCR products were sequenced by the DNA sequence analysis method (SeqFinder Sequencing System; ABI 3130; Foster City, CA, USA) and analyzed using the SeqScape software. Of the 77 patients, 16 had homozygous or heterozygous mutation. The mutation of 35delG, which is known as the most frequent mutation of GJB2 gene, was also the most frequently seen mutation at a ratio of 5.5% in patients with hearing loss in our region; this was followed by the V27I mutation. As this is the first study conducted by sequence analysis in our region, it was worth to be presented in terms of showing the distribution of mutation.

The complete sequence of Cymbidium mosaic virus from Vanilla fragrans in Hainan, China.

PubMed

He, Zhen; Jiang, Dongmei; Liu, Aiqin; Sang, Liwei; Li, Wenfeng; Li, Shifang

2011-06-01

The complete nucleotide sequence of Cymbidium mosaic virus (CymMV) isolated from vanilla in Hainan province, China was determined for the first time. It comprised 6,224 nucleotides; sequence analysis suggested that the isolate we obtained was a member of the genus Potexvirus, and its sequence shared 86.67-96.61% identities with previously reported sequences. Phylogenetic analysis suggested that CymMV from vanilla fragrans was clustered into subgroup A and the isolates in this subgroup displayed little regional difference.

A new polymorphic and multicopy MHC gene family related to nonmammalian class I

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

Leelayuwat, C.; Degli-Esposti, M.A.; Abraham, L.J.

1994-12-31

The authors have used genomic analysis to characterize a region of the central major histocompatibility complex (MHC) spanning {approximately} 300 kilobases (kb) between TNF and HLA-B. This region has been suggested to carry genetic factors relevant to the development of autoimmune diseases such as myasthenia gravis (MG) and insulin dependent diabetes mellitus (IDDM). Genomic sequence was analyzed for coding potential, using two neural network programs, GRAIL and GeneParser. A genomic probe, JAB, containing putative coding sequences (PERB11) located 60 kb centromeric of HLA-B, was used for northern analysis of human tissues. Multiple transcripts were detected. Southern analysis of genomic DNAmore » and overlapping YAC clones, covering the region from BAT1 to HLA-F, indicated that there are at least five copies of PERB11, four of which are located within this region of the MHC. The partial cDNA sequence of PERB11 was obtained from poly-A RNA derived from skeletal muscle. The putative amino acid sequence of PERB11 shares {approximately} 30% identity to MHC class I molecules from various species, including reptiles, chickens, and frogs, as well as to other MHC class I-like molecules, such as the IgG FcR of the mouse and rat and the human Zn-{alpha}2-glycoprotein. From direct comparison of amino acid sequences, it is concluded that PERB11 is a distinct molecule more closely related to nonmammalian than known mammalian MHC class I molecules. Genomic sequence analysis of PERB11 from five MHC ancestral haplotypes (AH) indicated that the gene is polymorphic at both DNA and protein level. The results suggest that the authors have identified a novel polymorphic gene family with multiple copies within the MHC. 48 refs., 10 figs., 2 tabs.« less

Cloning and sequence analysis of complementary DNA encoding an aberrantly rearranged human T-cell gamma chain.

PubMed Central

Dialynas, D P; Murre, C; Quertermous, T; Boss, J M; Leiden, J M; Seidman, J G; Strominger, J L

1986-01-01

Complementary DNA (cDNA) encoding a human T-cell gamma chain has been cloned and sequenced. At the junction of the variable and joining regions, there is an apparent deletion of two nucleotides in the human cDNA sequence relative to the murine gamma-chain cDNA sequence, resulting simultaneously in the generation of an in-frame stop codon and in a translational frameshift. For this reason, the sequence presented here encodes an aberrantly rearranged human T-cell gamma chain. There are several surprising differences between the deduced human and murine gamma-chain amino acid sequences. These include poor homology in the variable region, poor homology in a discrete segment of the constant region precisely bounded by the expected junctions of exon CII, and the presence in the human sequence of five potential sites for N-linked glycosylation. Images PMID:3458221

Identification and molecular analysis of infectious bursal disease in broiler farms in the Kurdistan Regional Government of Iraq.

PubMed

Amin, Oumed Gerjis M; Jackwood, Daral J

2014-10-01

The present study was undertaken to characterize field isolates of infectious bursal disease virus (IBDV). The identification was done using reverse transcription-polymerase chain reaction (RT-PCR) and partial sequencing of the VP2 gene. Pooled bursal samples were collected from commercial broiler farms located in the Kurdistan Regional Government (KRG) of Iraq. The genetic material of the IBDV was detected in 10 out of 29 field samples. Sequences of the hypervariable VP2 region were determined for 10 of these viruses. Molecular analysis of the VP2 gene of five IBDVs showed amino acid sequences consistent with the very virulent (vv) IBDV. Two samples were identified as classic vaccine viruses, and three samples were classic vaccine viruses that appear to have mutated during replication in the field. Phylogenetic analysis showed that all five field IBDV strains of the present study were closely related to each other. On the basis of nucleotide sequencing and phylogenetic analysis, it is very likely that IBD-causing viruses in this part of Iraq are of the very virulent type. These IBDVs appear to be evolving relative to their type strains.

Molecular phylogeny for marine turtles based on sequences of the ND4-leucine tRNA and control regions of mitochondrial DNA.

PubMed

Dutton, P H; Davis, S K; Guerra, T; Owens, D

1996-06-01

Marine turtles are divided into two families, the Dermochelyidae and the Cheloniidae. The majority of species are currently placed within the two tribes of the Cheloniidae, the Chelonini and the Carettini, but debate continues over generic and tribal affinities as well as species boundaries. We used nucleotide sequences (907 bp) from the ND4-LEU tRNA region and the control region (526 bp) of mitochondrial DNA to resolve areas of uncertainty in marine turtle (Chelonioidae) systematics. The ND4-LEU tRNA fragment was more conserved than the fragment from the control region, with sequence divergences ranging from 0.026 to 0.148 and 0.067 to 0.267, respectively. Parsimony analysis based only on the ND4-LEU tRNA data suggests that the hawksbill, Eretmochelys imbricata, lies within the tribe Carettni and is closely related to the genus Caretta, but could not resolve the position of the flatback, Natator depressus. A similar analysis based only on the control region sequence data suggested that N. depressus is affiliated with the Chelonini, but failed to resolve the position of E. imbricata and the loggerhead, Caretta caretta. In contrast to these results, the combination of both data sets with published cytochrome b data produced a phylogeny based on 1924 bp of sequence data which resolves the position of E. imbricata relative to Caretta and Lepidochelys and joins N. depressus as sister to the Carettini. Based on the molecular data, the Chelonini contains the Chelonia species, while the Carettini contains the remaining species of Cheloniidae. The control region sequence divergence between Pacific and Atlantic populations of the leatherback, Dermochelys coriacea, was relatively low (0.0081) when compared with the green turtle, Chelonia mydas (0.071-0.074). Atlantic and Pacific populations of Ch. mydas were found to be paraphyletic with respect to the black turtle, Ch. agassizi, suggesting that the current taxonomic designations within the Pacific Chelonia are questionable. This analysis shows the utility of combining sequence data for different regions of mtDNA that by themselves are insufficient to obtain robust phylogenies.

Forensic strategy to ensure the quality of sequencing data of mitochondrial DNA in highly degraded samples.

PubMed

Adachi, Noboru; Umetsu, Kazuo; Shojo, Hideki

2014-01-01

Mitochondrial DNA (mtDNA) is widely used for DNA analysis of highly degraded samples because of its polymorphic nature and high number of copies in a cell. However, as endogenous mtDNA in deteriorated samples is scarce and highly fragmented, it is not easy to obtain reliable data. In the current study, we report the risks of direct sequencing mtDNA in highly degraded material, and suggest a strategy to ensure the quality of sequencing data. It was observed that direct sequencing data of the hypervariable segment (HVS) 1 by using primer sets that generate an amplicon of 407 bp (long-primer sets) was different from results obtained by using newly designed primer sets that produce an amplicon of 120-139 bp (mini-primer sets). The data aligned with the results of mini-primer sets analysis in an amplicon length-dependent manner; the shorter the amplicon, the more evident the endogenous sequence became. Coding region analysis using multiplex amplified product-length polymorphisms revealed the incongruence of single nucleotide polymorphisms between the coding region and HVS 1 caused by contamination with exogenous mtDNA. Although the sequencing data obtained using long-primer sets turned out to be erroneous, it was unambiguous and reproducible. These findings suggest that PCR primers that produce amplicons shorter than those currently recognized should be used for mtDNA analysis in highly degraded samples. Haplogroup motif analysis of the coding region and HVS should also be performed to improve the reliability of forensic mtDNA data. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Identification of G-quadruplex forming sequences in three manatee papillomaviruses

PubMed Central

Zahin, Maryam; Dean, William L.; Ghim, Shin-je; Joh, Joongho; Gray, Robert D.; Khanal, Sujita; Bossart, Gregory D.; Mignucci-Giannoni, Antonio A.; Rouchka, Eric C.; Jenson, Alfred B.; Trent, John O.; Chaires, Jonathan B.

2018-01-01

The Florida manatee (Trichechus manatus latirotris) is a threatened aquatic mammal in United States coastal waters. Over the past decade, the appearance of papillomavirus-induced lesions and viral papillomatosis in manatees has been a concern for those involved in the management and rehabilitation of this species. To date, three manatee papillomaviruses (TmPVs) have been identified in Florida manatees, one forming cutaneous lesions (TmPV1) and two forming genital lesions (TmPV3 and TmPV4). We identified DNA sequences with the potential to form G-quadruplex structures (G4) across the three genomes. G4 were located on both DNA strands and across coding and non-coding regions on all TmPVs, offering multiple targets for viral control. Although G4 have been identified in several viral genomes, including human PVs, most research has focused on canonical structures comprised of three G-tetrads. In contrast, the vast majority of sequences we identified would allow the formation of non-canonical structures with only two G-tetrads. Our biophysical analysis confirmed the formation of G4 with parallel topology in three such sequences from the E2 region. Two of the structures appear comprised of multiple stacked two G-tetrad structures, perhaps serving to increase structural stability. Computational analysis demonstrated enrichment of G4 sequences on all TmPVs on the reverse strand in the E2/E4 region and on both strands in the L2 region. Several G4 sequences occurred at similar regional locations on all PVs, most notably on the reverse strand in the E2 region. In other cases, G4 were identified at similar regional locations only on PVs forming genital lesions. On all TmPVs, G4 sequences were located in the non-coding region near putative E2 binding sites. Together, these findings suggest that G4 are possible regulatory elements in TmPVs. PMID:29630682

Validation of Skeletal Muscle cis-Regulatory Module Predictions Reveals Nucleotide Composition Bias in Functional Enhancers

PubMed Central

Kwon, Andrew T.; Chou, Alice Yi; Arenillas, David J.; Wasserman, Wyeth W.

2011-01-01

We performed a genome-wide scan for muscle-specific cis-regulatory modules (CRMs) using three computational prediction programs. Based on the predictions, 339 candidate CRMs were tested in cell culture with NIH3T3 fibroblasts and C2C12 myoblasts for capacity to direct selective reporter gene expression to differentiated C2C12 myotubes. A subset of 19 CRMs validated as functional in the assay. The rate of predictive success reveals striking limitations of computational regulatory sequence analysis methods for CRM discovery. Motif-based methods performed no better than predictions based only on sequence conservation. Analysis of the properties of the functional sequences relative to inactive sequences identifies nucleotide sequence composition can be an important characteristic to incorporate in future methods for improved predictive specificity. Muscle-related TFBSs predicted within the functional sequences display greater sequence conservation than non-TFBS flanking regions. Comparison with recent MyoD and histone modification ChIP-Seq data supports the validity of the functional regions. PMID:22144875

Analysis of S-RNase alleles of almond (Prunus dulcis): characterization of new sequences, resolution of synonyms and evidence of intragenic recombination.

PubMed

Ortega, Encarnación; Bosković, Radovan I; Sargent, Daniel J; Tobutt, Kenneth R

2006-11-01

Cross-compatibility relationships in almond are controlled by a gametophytically expressed incompatibility system partly mediated by stylar RNases, of which 29 have been reported. To resolve possible synonyms and to provide data for phylogenetic analysis, 21 almond S-RNase alleles were cloned and sequenced from SP (signal peptide region) or C1 (first conserved region) to C5, except for the S29 allele, which could be cloned only from SP to C1. Nineteen sequences (S4, S6, S11-S22, S25-S29)) were potentially new whereas S10 and S24 had previously been published but with different labels. The sequences for S16 and S17 were identical to that for S1, published previously; likewise, S15 was identical to S5. In addition, S4 and S20 were identical, as were S13 and S19. A revised version of the standard table of almond incompatibility genotypes is presented. Several alleles had AT or GA tandem repeats in their introns. Sequences of the 23 distinct newly cloned or already published alleles were aligned. Sliding windows analysis of Ka/Ks identified regions where positive selection may operate; in contrast to the Maloideae, most of the region from the beginning of C3 to the beginning of RC4 appeared not to be under positive selection. Phylogenetic analysis indicated four pairs of alleles had "bootstrap" support > 80%: S5/S10, S4/S8, S11/S24, and S3/S6. Various motifs up to 19 residues long occurred in at least two alleles, and their distributions were consistent with intragenic recombination, as were separate phylogenetic analyses of the 5' and 3' sections. Sequence comparison of phylogenetically related alleles indicated the significance of the region between RC4 and C5 in defining specificity.

Sequence-structure mapping errors in the PDB: OB-fold domains

PubMed Central

Venclovas, Česlovas; Ginalski, Krzysztof; Kang, Chulhee

2004-01-01

The Protein Data Bank (PDB) is the single most important repository of structural data for proteins and other biologically relevant molecules. Therefore, it is critically important to keep the PDB data, as much as possible, error-free. In this study, we have analyzed PDB crystal structures possessing oligonucleotide/oligosaccharide binding (OB)-fold, one of the highly populated folds, for the presence of sequence-structure mapping errors. Using energy-based structure quality assessment coupled with sequence analyses, we have found that there are at least five OB-structures in the PDB that have regions where sequences have been incorrectly mapped onto the structure. We have demonstrated that the combination of these computation techniques is effective not only in detecting sequence-structure mapping errors, but also in providing guidance to correct them. Namely, we have used results of computational analysis to direct a revision of X-ray data for one of the PDB entries containing a fairly inconspicuous sequence-structure mapping error. The revised structure has been deposited with the PDB. We suggest use of computational energy assessment and sequence analysis techniques to facilitate structure determination when homologs having known structure are available to use as a reference. Such computational analysis may be useful in either guiding the sequence-structure assignment process or verifying the sequence mapping within poorly defined regions. PMID:15133161

Importance of Viral Sequence Length and Number of Variable and Informative Sites in Analysis of HIV Clustering.

PubMed

Novitsky, Vlad; Moyo, Sikhulile; Lei, Quanhong; DeGruttola, Victor; Essex, M

2015-05-01

To improve the methodology of HIV cluster analysis, we addressed how analysis of HIV clustering is associated with parameters that can affect the outcome of viral clustering. The extent of HIV clustering and tree certainty was compared between 401 HIV-1C near full-length genome sequences and subgenomic regions retrieved from the LANL HIV Database. Sliding window analysis was based on 99 windows of 1,000 bp and 45 windows of 2,000 bp. Potential associations between the extent of HIV clustering and sequence length and the number of variable and informative sites were evaluated. The near full-length genome HIV sequences showed the highest extent of HIV clustering and the highest tree certainty. At the bootstrap threshold of 0.80 in maximum likelihood (ML) analysis, 58.9% of near full-length HIV-1C sequences but only 15.5% of partial pol sequences (ViroSeq) were found in clusters. Among HIV-1 structural genes, pol showed the highest extent of clustering (38.9% at a bootstrap threshold of 0.80), although it was significantly lower than in the near full-length genome sequences. The extent of HIV clustering was significantly higher for sliding windows of 2,000 bp than 1,000 bp. We found a strong association between the sequence length and proportion of HIV sequences in clusters, and a moderate association between the number of variable and informative sites and the proportion of HIV sequences in clusters. In HIV cluster analysis, the extent of detectable HIV clustering is directly associated with the length of viral sequences used, as well as the number of variable and informative sites. Near full-length genome sequences could provide the most informative HIV cluster analysis. Selected subgenomic regions with a high extent of HIV clustering and high tree certainty could also be considered as a second choice.

Importance of Viral Sequence Length and Number of Variable and Informative Sites in Analysis of HIV Clustering

PubMed Central

Novitsky, Vlad; Moyo, Sikhulile; Lei, Quanhong; DeGruttola, Victor

2015-01-01

Abstract To improve the methodology of HIV cluster analysis, we addressed how analysis of HIV clustering is associated with parameters that can affect the outcome of viral clustering. The extent of HIV clustering and tree certainty was compared between 401 HIV-1C near full-length genome sequences and subgenomic regions retrieved from the LANL HIV Database. Sliding window analysis was based on 99 windows of 1,000 bp and 45 windows of 2,000 bp. Potential associations between the extent of HIV clustering and sequence length and the number of variable and informative sites were evaluated. The near full-length genome HIV sequences showed the highest extent of HIV clustering and the highest tree certainty. At the bootstrap threshold of 0.80 in maximum likelihood (ML) analysis, 58.9% of near full-length HIV-1C sequences but only 15.5% of partial pol sequences (ViroSeq) were found in clusters. Among HIV-1 structural genes, pol showed the highest extent of clustering (38.9% at a bootstrap threshold of 0.80), although it was significantly lower than in the near full-length genome sequences. The extent of HIV clustering was significantly higher for sliding windows of 2,000 bp than 1,000 bp. We found a strong association between the sequence length and proportion of HIV sequences in clusters, and a moderate association between the number of variable and informative sites and the proportion of HIV sequences in clusters. In HIV cluster analysis, the extent of detectable HIV clustering is directly associated with the length of viral sequences used, as well as the number of variable and informative sites. Near full-length genome sequences could provide the most informative HIV cluster analysis. Selected subgenomic regions with a high extent of HIV clustering and high tree certainty could also be considered as a second choice. PMID:25560745

Sequence-dependent modelling of local DNA bending phenomena: curvature prediction and vibrational analysis.

PubMed

Vlahovicek, K; Munteanu, M G; Pongor, S

1999-01-01

Bending is a local conformational micropolymorphism of DNA in which the original B-DNA structure is only distorted but not extensively modified. Bending can be predicted by simple static geometry models as well as by a recently developed elastic model that incorporate sequence dependent anisotropic bendability (SDAB). The SDAB model qualitatively explains phenomena including affinity of protein binding, kinking, as well as sequence-dependent vibrational properties of DNA. The vibrational properties of DNA segments can be studied by finite element analysis of a model subjected to an initial bending moment. The frequency spectrum is obtained by applying Fourier analysis to the displacement values in the time domain. This analysis shows that the spectrum of the bending vibrations quite sensitively depends on the sequence, for example the spectrum of a curved sequence is characteristically different from the spectrum of straight sequence motifs of identical basepair composition. Curvature distributions are genome-specific, and pronounced differences are found between protein-coding and regulatory regions, respectively, that is, sites of extreme curvature and/or bendability are less frequent in protein-coding regions. A WWW server is set up for the prediction of curvature and generation of 3D models from DNA sequences (http:@www.icgeb.trieste.it/dna).

Sequences required for induction of neurotensin receptor gene expression during neuronal differentiation of N1E-115 neuroblastoma cells.

PubMed

Tavares, D; Tully, K; Dobner, P R

1999-10-15

The promoter region of the mouse high affinity neurotensin receptor (Ntr-1) gene was characterized, and sequences required for expression in neuroblastoma cell lines that express high affinity NT-binding sites were characterized. Me(2)SO-induced neuronal differentiation of N1E-115 neuroblastoma cells increased both the expression of the endogenous Ntr-1 gene and reporter genes driven by NTR-1 promoter sequences by 3-4-fold. Deletion analysis revealed that an 83-base pair promoter region containing the transcriptional start site is required for Me(2)SO activation. Detailed mutational analysis of this region revealed that a CACCC box and the central region of a large GC-rich palindrome are the crucial cis-regulatory elements required for Me(2)SO induction. The CACCC box is bound by at least one factor that is induced upon Me(2)SO treatment of N1E-115 cells. The Me(2)SO effect was found to be both selective and cell type-restricted. Basal expression in the neuroblastoma cell lines required a distinct set of sequences, including an Sp1-like sequence, and a sequence resembling an NGFI-A-binding site; however, a more distal 5' sequence was found to repress basal activity in N1E-115 cells. These results provide evidence that Ntr-1 gene regulation involves both positive and negative regulatory elements located in the 5'-flanking region and that Ntr-1 gene activation involves the coordinate activation or induction of several factors, including a CACCC box binding complex.

Discrete Ramanujan transform for distinguishing the protein coding regions from other regions.

PubMed

Hua, Wei; Wang, Jiasong; Zhao, Jian

2014-01-01

Based on the study of Ramanujan sum and Ramanujan coefficient, this paper suggests the concepts of discrete Ramanujan transform and spectrum. Using Voss numerical representation, one maps a symbolic DNA strand as a numerical DNA sequence, and deduces the discrete Ramanujan spectrum of the numerical DNA sequence. It is well known that of discrete Fourier power spectrum of protein coding sequence has an important feature of 3-base periodicity, which is widely used for DNA sequence analysis by the technique of discrete Fourier transform. It is performed by testing the signal-to-noise ratio at frequency N/3 as a criterion for the analysis, where N is the length of the sequence. The results presented in this paper show that the property of 3-base periodicity can be only identified as a prominent spike of the discrete Ramanujan spectrum at period 3 for the protein coding regions. The signal-to-noise ratio for discrete Ramanujan spectrum is defined for numerical measurement. Therefore, the discrete Ramanujan spectrum and the signal-to-noise ratio of a DNA sequence can be used for distinguishing the protein coding regions from the noncoding regions. All the exon and intron sequences in whole chromosomes 1, 2, 3 and 4 of Caenorhabditis elegans have been tested and the histograms and tables from the computational results illustrate the reliability of our method. In addition, we have analyzed theoretically and gotten the conclusion that the algorithm for calculating discrete Ramanujan spectrum owns the lower computational complexity and higher computational accuracy. The computational experiments show that the technique by using discrete Ramanujan spectrum for classifying different DNA sequences is a fast and effective method. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sequence analysis of porcine kobuvirus VP1 region detected in pigs in Japan and Thailand.

PubMed

Okitsu, Shoko; Khamrin, Pattara; Thongprachum, Aksara; Hidaka, Satoshi; Kongkaew, Sompreeya; Kongkaew, Apisek; Maneekarn, Niwat; Mizuguchi, Masashi; Hayakawa, Satoshi; Ushijima, Hiroshi

2012-04-01

Porcine kobuvirus is a new candidate species of the genus Kobuvirus in the family Picornaviridae, and information is still limited. The identification of porcine kobuvirus has been performed by the sequence analyses of the 3D region of the viruses. Therefore, the purpose of this study was to characterize the molecular properties of VP1 nucleotide sequences of the porcine kobuviruses isolated from porcine stool samples in Japan during 2009 and Thailand between 2006 and 2008. In addition, previous identification of a unique porcine kobuvirus; Japanese H023/2009/JP, which is a bovine kobuvirus-like strain based on sequence analysis of the 3D region, was also included in this study. All of the strains were amplified by the VP1-specific primer pair: the amplicons were subjected to direct sequencing and compared with the VP1 nucleotide sequences of reference strains. The VP1 sequences of strains from the GenBank database revealed high nucleotide sequence identity at 84.3-100%. On the other hand, the nucleotide identities among the 15 porcine kobuvirus strains analyzed in this study ranged from 78.8 to 99.8%. The results revealed that diversity of the strains in this study were higher than those of the strains in previous studies. Furthermore, it was found that the VP1 region of the bovine kobuvirus-like strain, H023/2009/JP, clustered with nine porcine kobuvirus strains that were isolated in Thailand and Japan. Since this strain was previously found to be closely related to bovine kobuviruses in the 3D gene region, it may be a natural recombinant.

Sequence analysis of the mitochondrial DNA control region of ciscoes (genus Coregonus): Taxonomic implications for the Great Lakes species flock

USGS Publications Warehouse

Reed, Kent M.; Dorschner, Michael O.; Todd, Thomas N.; Phillips, Ruth B.

1998-01-01

Sequence variation in the control region (D-loop) of the mitochondrial DNA (mtDNA) was examined to assess the genetic distinctiveness of the shortjaw cisco (Coregonus zenithicus). Individuals from within the Great Lakes Basin as well as inland lakes outside the basin were sampled. DNA fragments containing the entire D-loop were amplified by PCR from specimens ofC. zenithicus and the related species C. artedi, C. hoyi, C. kiyi, and C. clupeaformis. DNA sequence analysis revealed high similarity within and among species and shared polymorphism for length variants. Based on this analysis, the shortjaw cisco is not genetically distinct from other cisco species.

The Genome Sequencer FLX System--longer reads, more applications, straight forward bioinformatics and more complete data sets.

PubMed

Droege, Marcus; Hill, Brendon

2008-08-31

The Genome Sequencer FLX System (GS FLX), powered by 454 Sequencing, is a next-generation DNA sequencing technology featuring a unique mix of long reads, exceptional accuracy, and ultra-high throughput. It has been proven to be the most versatile of all currently available next-generation sequencing technologies, supporting many high-profile studies in over seven applications categories. GS FLX users have pursued innovative research in de novo sequencing, re-sequencing of whole genomes and target DNA regions, metagenomics, and RNA analysis. 454 Sequencing is a powerful tool for human genetics research, having recently re-sequenced the genome of an individual human, currently re-sequencing the complete human exome and targeted genomic regions using the NimbleGen sequence capture process, and detected low-frequency somatic mutations linked to cancer.

Analysis of Pteridium ribosomal RNA sequences by rapid direct sequencing.

PubMed

Tan, M K

1991-08-01

A total of 864 bases from 5 regions interspersed in the 18S and 26S rRNA molecules from various clones of Pteridium covering the general geographical distribution of the genus was analysed using a rapid rRNA sequencing technique. No base difference has been detected amongst the three major lineages, two of which apparently separated before the breakup of the ancient supercontinent, Pangaea. These regions of the rRNA sequences have thus been conserved for at least 160 million years and are here compared with other eukaryotic, especially plant rRNAs.

Analysis of simian immunodeficiency virus sequence variation in tissues of rhesus macaques with simian AIDS.

PubMed Central

Kodama, T; Mori, K; Kawahara, T; Ringler, D J; Desrosiers, R C

1993-01-01

One rhesus macaque displayed severe encephalomyelitis and another displayed severe enterocolitis following infection with molecularly cloned simian immunodeficiency virus (SIV) strain SIVmac239. Little or no free anti-SIV antibody developed in these two macaques, and they died relatively quickly (4 to 6 months) after infection. Manifestation of the tissue-specific disease in these macaques was associated with the emergence of variants with high replicative capacity for macrophages and primary infection of tissue macrophages. The nature of sequence variation in the central region (vif, vpr, and vpx), the env gene, and the nef long terminal repeat (LTR) region in brain, colon, and other tissues was examined to see whether specific genetic changes were associated with SIV replication in brain or gut. Sequence analysis revealed strong conservation of the intergenic central region, nef, and the LTR. However, analysis of env sequences in these two macaques and one other revealed significant, interesting patterns of sequence variation. (i) Changes in env that were found previously to contribute to the replicative ability of SIVmac for macrophages in culture were present in the tissues of these animals. (ii) The greatest variability was located in the regions between V1 and V2 and from "V3" through C3 in gp120, which are different in location from the variable regions observed previously in animals with strong antibody responses and long-term persistent infection. (iii) The predominant sequence change of D-->N at position 385 in C3 is most surprising, since this change in both SIV and human immunodeficiency virus type 1 has been associated with dramatically diminished affinity for CD4 and replication in vitro. (iv) The nature of sequence changes at some positions (146, 178, 345, 385, and "V3") suggests that viral replication in brain and gut may be facilitated by specific sequence changes in env in addition to those that impart a general ability to replicate well in macrophages. These results demonstrate that complex selective pressures, including immune responses and varying cell and tissue specificity, can influence the nature of sequence changes in env. Images PMID:8411355

Molecular cloning and nucleotide sequence of the alpha and beta subunits of allophycocyanin from the cyanelle genome of Cyanophora paradoxa.

PubMed Central

Bryant, D A; de Lorimier, R; Lambert, D H; Dubbs, J M; Stirewalt, V L; Stevens, S E; Porter, R D; Tam, J; Jay, E

1985-01-01

The genes for the alpha- and beta-subunit apoproteins of allophycocyanin (AP) were isolated from the cyanelle genome of Cyanophora paradoxa and subjected to nucleotide sequence analysis. The AP beta-subunit apoprotein gene was localized to a 7.8-kilobase-pair Pst I restriction fragment from cyanelle DNA by hybridization with a tetradecameric oligonucleotide probe. Sequence analysis using that oligonucleotide and its complement as primers for the dideoxy chain-termination sequencing method confirmed the presence of both AP alpha- and beta-subunit genes on this restriction fragment. Additional oligonucleotide primers were synthesized as sequencing progressed and were used to determine rapidly the nucleotide sequence of a 1336-base-pair region of this cloned fragment. This strategy allowed the sequencing to be completed without a detailed restriction map and without extensive and time-consuming subcloning. The sequenced region contains two open reading frames whose deduced amino acid sequences are 81-85% homologous to cyanobacterial and red algal AP subunits whose amino acid sequences have been determined. The two open reading frames are in the same orientation and are separated by 39 base pairs. AP alpha is 5' to AP beta and both coding sequences are preceded by a polypurine, Shine-Dalgarno-type sequence. Sequences upstream from AP alpha closely resemble the Escherichia coli consensus promoter sequences and also show considerable homology to promoter sequences for several chloroplast-encoded psbA genes. A 56-base-pair palindromic sequence downstream from the AP beta gene could play a role in the termination of transcription or translation. The allophycocyanin apoprotein subunit genes are located on the large single-copy region of the cyanelle genome. PMID:2987916

Phylogeny of flowering plants by the chloroplast genome sequences: in search of a "lucky gene".

PubMed

Logacheva, M D; Penin, A A; Samigullin, T H; Vallejo-Roman, C M; Antonov, A S

2007-12-01

One of the most complicated remaining problems of molecular-phylogenetic analysis is choosing an appropriate genome region. In an ideal case, such a region should have two specific properties: (i) results of analysis using this region should be similar to the results of multigene analysis using the maximal number of regions; (ii) this region should be arranged compactly and be significantly shorter than the multigene set. The second condition is necessary to facilitate sequencing and extension of taxons under analysis, the number of which is also crucial for molecular phylogenetic analysis. Such regions have been revealed for some groups of animals and have been designated as "lucky genes". We have carried out a computational experiment on analysis of 41 complete chloroplast genomes of flowering plants aimed at searching for a "lucky gene" for reconstruction of their phylogeny. It is shown that the phylogenetic tree inferred from a combination of translated nucleotide sequences of genes encoding subunits of plastid RNA polymerase is closest to the tree constructed using all protein coding sites of the chloroplast genome. The only node for which a contradiction is observed is unstable according to the different type analyses. For all the other genes or their combinations, the coincidence is significantly worse. The RNA polymerase genes are compactly arranged in the genome and are fourfold shorter than the total length of protein coding genes used for phylogenetic analysis. The combination of all necessary features makes this group of genes main candidates for the role of "lucky gene" in studying phylogeny of flowering plants.

Conservation of tubulin-binding sequences in TRPV1 throughout evolution.

PubMed

Sardar, Puspendu; Kumar, Abhishek; Bhandari, Anita; Goswami, Chandan

2012-01-01

Transient Receptor Potential Vanilloid sub type 1 (TRPV1), commonly known as capsaicin receptor can detect multiple stimuli ranging from noxious compounds, low pH, temperature as well as electromagnetic wave at different ranges. In addition, this receptor is involved in multiple physiological and sensory processes. Therefore, functions of TRPV1 have direct influences on adaptation and further evolution also. Availability of various eukaryotic genomic sequences in public domain facilitates us in studying the molecular evolution of TRPV1 protein and the respective conservation of certain domains, motifs and interacting regions that are functionally important. Using statistical and bioinformatics tools, our analysis reveals that TRPV1 has evolved about ∼420 million years ago (MYA). Our analysis reveals that specific regions, domains and motifs of TRPV1 has gone through different selection pressure and thus have different levels of conservation. We found that among all, TRP box is the most conserved and thus have functional significance. Our results also indicate that the tubulin binding sequences (TBS) have evolutionary significance as these stretch sequences are more conserved than many other essential regions of TRPV1. The overall distribution of positively charged residues within the TBS motifs is conserved throughout evolution. In silico analysis reveals that the TBS-1 and TBS-2 of TRPV1 can form helical structures and may play important role in TRPV1 function. Our analysis identifies the regions of TRPV1, which are important for structure-function relationship. This analysis indicates that tubulin binding sequence-1 (TBS-1) near the TRP-box forms a potential helix and the tubulin interactions with TRPV1 via TBS-1 have evolutionary significance. This interaction may be required for the proper channel function and regulation and may also have significance in the context of Taxol®-induced neuropathy.

Advantages of genome sequencing by long-read sequencer using SMRT technology in medical area.

PubMed

Nakano, Kazuma; Shiroma, Akino; Shimoji, Makiko; Tamotsu, Hinako; Ashimine, Noriko; Ohki, Shun; Shinzato, Misuzu; Minami, Maiko; Nakanishi, Tetsuhiro; Teruya, Kuniko; Satou, Kazuhito; Hirano, Takashi

2017-07-01

PacBio RS II is the first commercialized third-generation DNA sequencer able to sequence a single molecule DNA in real-time without amplification. PacBio RS II's sequencing technology is novel and unique, enabling the direct observation of DNA synthesis by DNA polymerase. PacBio RS II confers four major advantages compared to other sequencing technologies: long read lengths, high consensus accuracy, a low degree of bias, and simultaneous capability of epigenetic characterization. These advantages surmount the obstacle of sequencing genomic regions such as high/low G+C, tandem repeat, and interspersed repeat regions. Moreover, PacBio RS II is ideal for whole genome sequencing, targeted sequencing, complex population analysis, RNA sequencing, and epigenetics characterization. With PacBio RS II, we have sequenced and analyzed the genomes of many species, from viruses to humans. Herein, we summarize and review some of our key genome sequencing projects, including full-length viral sequencing, complete bacterial genome and almost-complete plant genome assemblies, and long amplicon sequencing of a disease-associated gene region. We believe that PacBio RS II is not only an effective tool for use in the basic biological sciences but also in the medical/clinical setting.

SeqFIRE: a web application for automated extraction of indel regions and conserved blocks from protein multiple sequence alignments.

PubMed

Ajawatanawong, Pravech; Atkinson, Gemma C; Watson-Haigh, Nathan S; Mackenzie, Bryony; Baldauf, Sandra L

2012-07-01

Analyses of multiple sequence alignments generally focus on well-defined conserved sequence blocks, while the rest of the alignment is largely ignored or discarded. This is especially true in phylogenomics, where large multigene datasets are produced through automated pipelines. However, some of the most powerful phylogenetic markers have been found in the variable length regions of multiple alignments, particularly insertions/deletions (indels) in protein sequences. We have developed Sequence Feature and Indel Region Extractor (SeqFIRE) to enable the automated identification and extraction of indels from protein sequence alignments. The program can also extract conserved blocks and identify fast evolving sites using a combination of conservation and entropy. All major variables can be adjusted by the user, allowing them to identify the sets of variables most suited to a particular analysis or dataset. Thus, all major tasks in preparing an alignment for further analysis are combined in a single flexible and user-friendly program. The output includes a numbered list of indels, alignments in NEXUS format with indels annotated or removed and indel-only matrices. SeqFIRE is a user-friendly web application, freely available online at www.seqfire.org/.

HLA genotyping by next-generation sequencing of complementary DNA.

PubMed

Segawa, Hidenobu; Kukita, Yoji; Kato, Kikuya

2017-11-28

Genotyping of the human leucocyte antigen (HLA) is indispensable for various medical treatments. However, unambiguous genotyping is technically challenging due to high polymorphism of the corresponding genomic region. Next-generation sequencing is changing the landscape of genotyping. In addition to high throughput of data, its additional advantage is that DNA templates are derived from single molecules, which is a strong merit for the phasing problem. Although most currently developed technologies use genomic DNA, use of cDNA could enable genotyping with reduced costs in data production and analysis. We thus developed an HLA genotyping system based on next-generation sequencing of cDNA. Each HLA gene was divided into 3 or 4 target regions subjected to PCR amplification and subsequent sequencing with Ion Torrent PGM. The sequence data were then subjected to an automated analysis. The principle of the analysis was to construct candidate sequences generated from all possible combinations of variable bases and arrange them in decreasing order of the number of reads. Upon collecting candidate sequences from all target regions, 2 haplotypes were usually assigned. Cases not assigned 2 haplotypes were forwarded to 4 additional processes: selection of candidate sequences applying more stringent criteria, removal of artificial haplotypes, selection of candidate sequences with a relaxed threshold for sequence matching, and countermeasure for incomplete sequences in the HLA database. The genotyping system was evaluated using 30 samples; the overall accuracy was 97.0% at the field 3 level and 98.3% at the G group level. With one sample, genotyping of DPB1 was not completed due to short read size. We then developed a method for complete sequencing of individual molecules of the DPB1 gene, using the molecular barcode technology. The performance of the automatic genotyping system was comparable to that of systems developed in previous studies. Thus, next-generation sequencing of cDNA is a viable option for HLA genotyping.

Classification of Fowl Adenovirus Serotypes by Use of High-Resolution Melting-Curve Analysis of the Hexon Gene Region▿

PubMed Central

Steer, Penelope A.; Kirkpatrick, Naomi C.; O'Rourke, Denise; Noormohammadi, Amir H.

2009-01-01

Identification of fowl adenovirus (FAdV) serotypes is of importance in epidemiological studies of disease outbreaks and the adoption of vaccination strategies. In this study, real-time PCR and subsequent high-resolution melting (HRM)-curve analysis of three regions of the hexon gene were developed and assessed for their potential in differentiating 12 FAdV reference serotypes. The results were compared to previously described PCR and restriction enzyme analyses of the hexon gene. Both HRM-curve analysis of a 191-bp region of the hexon gene and restriction enzyme analysis failed to distinguish a number of serotypes used in this study. In addition, PCR of the region spanning nucleotides (nt) 144 to 1040 failed to amplify FAdV-5 in sufficient quantities for further analysis. However, HRM-curve analysis of the region spanning nt 301 to 890 proved a sensitive and specific method of differentiating all 12 serotypes. All melt curves were highly reproducible, and replicates of each serotype were correctly genotyped with a mean confidence value of more than 99% using normalized HRM curves. Sequencing analysis revealed that each profile was related to a unique sequence, with some sequences sharing greater than 94% identity. Melting-curve profiles were found to be related mainly to GC composition and distribution throughout the amplicons, regardless of sequence identity. The results presented in this study show that the closed-tube method of PCR and HRM-curve analysis provides an accurate, rapid, and robust genotyping technique for the identification of FAdV serotypes and can be used as a model for developing genotyping techniques for other pathogens. PMID:19036935

A Partial Least Squares Based Procedure for Upstream Sequence Classification in Prokaryotes.

PubMed

Mehmood, Tahir; Bohlin, Jon; Snipen, Lars

2015-01-01

The upstream region of coding genes is important for several reasons, for instance locating transcription factor, binding sites, and start site initiation in genomic DNA. Motivated by a recently conducted study, where multivariate approach was successfully applied to coding sequence modeling, we have introduced a partial least squares (PLS) based procedure for the classification of true upstream prokaryotic sequence from background upstream sequence. The upstream sequences of conserved coding genes over genomes were considered in analysis, where conserved coding genes were found by using pan-genomics concept for each considered prokaryotic species. PLS uses position specific scoring matrix (PSSM) to study the characteristics of upstream region. Results obtained by PLS based method were compared with Gini importance of random forest (RF) and support vector machine (SVM), which is much used method for sequence classification. The upstream sequence classification performance was evaluated by using cross validation, and suggested approach identifies prokaryotic upstream region significantly better to RF (p-value < 0.01) and SVM (p-value < 0.01). Further, the proposed method also produced results that concurred with known biological characteristics of the upstream region.

Functional analysis of the upstream regulatory region of chicken miR-17-92 cluster.

PubMed

Cheng, Min; Zhang, Wen-jian; Xing, Tian-yu; Yan, Xiao-hong; Li, Yu-mao; Li, Hui; Wang, Ning

2016-08-01

miR-17-92 cluster plays important roles in cell proliferation, differentiation, apoptosis, animal development and tumorigenesis. The transcriptional regulation of miR-17-92 cluster has been extensively studied in mammals, but not in birds. To date, avian miR-17-92 cluster genomic structure has not been fully determined. The promoter location and sequence of miR-17-92 cluster have not been determined, due to the existence of a genomic gap sequence upstream of miR-17-92 cluster in all the birds whose genomes have been sequenced. In this study, genome walking was used to close the genomic gap upstream of chicken miR-17-92 cluster. In addition, bioinformatics analysis, reporter gene assay and truncation mutagenesis were used to investigate functional role of the genomic gap sequence. Genome walking analysis showed that the gap region was 1704 bp long, and its GC content was 80.11%. Bioinformatics analysis showed that in the gap region, there was a 200 bp conserved sequence among the tested 10 species (Gallus gallus, Homo sapiens, Pan troglodytes, Bos taurus, Sus scrofa, Rattus norvegicus, Mus musculus, Possum, Danio rerio, Rana nigromaculata), which is core promoter region of mammalian miR-17-92 host gene (MIR17HG). Promoter luciferase reporter gene vector of the gap region was constructed and reporter assay was performed. The result showed that the promoter activity of pGL3-cMIR17HG (-4228/-2506) was 417 times than that of negative control (empty pGL3 basic vector), suggesting that chicken miR-17-92 cluster promoter exists in the gap region. To further gain insight into the promoter structure, two different truncations for the cloned gap sequence were generated by PCR. One had a truncation of 448 bp at the 5'-end and the other had a truncation of 894 bp at the 3'-end. Further reporter analysis showed that compared with the promoter activity of pGL3-cMIR17HG (-4228/-2506), the reporter activities of the 5'-end truncation and the 3'-end truncation were reduced by 19.82% and 60.14%, respectively. These data demonstrated that the important promoter region of chicken miR-17-92 cluster is located in the -3400/-2506 bp region. Our results lay the foundation for revealing the transcriptional regulatory mechanisms of chicken miR-17-92 cluster.

A novel tandem repeat sequence located on human chromosome 4p: isolation and characterization.

PubMed

Kogi, M; Fukushige, S; Lefevre, C; Hadano, S; Ikeda, J E

1997-06-01

In an effort to analyze the genomic region of the distal half of human chromosome 4p, to where Huntington disease and other diseases have been mapped, we have isolated the cosmid clone (CRS447) that was likely to contain a region with specific repeat sequences. Clone CRS447 was subjected to detailed analysis, including chromosome mapping, restriction mapping, and DNA sequencing. Chromosome mapping by both a human-CHO hybrid cell panel and FISH revealed that CRS447 was predominantly located in the 4p15.1-15.3 region. CRS447 was shown to consist of tandem repeats of 4.7-kb units present on chromosome 4p. A single EcoRI unit was subcloned (pRS447), and the complete sequence was determined as 4752 nucleotides. When pRS447 was used as a probe, the number of copies of this repeat per haploid genome was estimated to be 50-70. Sequence analysis revealed that it contained two internal CA repeats and one putative ORF. Database search established that this sequence was unreported. However, two homologous STS markers were found in the database. We concluded that CRS447/pRS447 is a novel tandem repeat sequence that is mainly specific to human chromosome 4p.

A Phylogenetic and Phenotypic Analysis of Salmonella enterica Serovar Weltevreden, an Emerging Agent of Diarrheal Disease in Tropical Regions

PubMed Central

Makendi, Carine; Page, Andrew J.; Wren, Brendan W.; Le Thi Phuong, Tu; Clare, Simon; Hale, Christine; Goulding, David; Klemm, Elizabeth J.; Pickard, Derek; Okoro, Chinyere; Hunt, Martin; Thompson, Corinne N.; Phu Huong Lan, Nguyen; Tran Do Hoang, Nhu; Thwaites, Guy E.; Le Hello, Simon; Brisabois, Anne; Weill, François-Xavier; Baker, Stephen; Dougan, Gordon

2016-01-01

Salmonella enterica serovar Weltevreden (S. Weltevreden) is an emerging cause of diarrheal and invasive disease in humans residing in tropical regions. Despite the regional and international emergence of this Salmonella serovar, relatively little is known about its genetic diversity, genomics or virulence potential in model systems. Here we used whole genome sequencing and bioinformatics analyses to define the phylogenetic structure of a diverse global selection of S. Weltevreden. Phylogenetic analysis of more than 100 isolates demonstrated that the population of S. Weltevreden can be segregated into two main phylogenetic clusters, one associated predominantly with continental Southeast Asia and the other more internationally dispersed. Subcluster analysis suggested the local evolution of S. Weltevreden within specific geographical regions. Four of the isolates were sequenced using long read sequencing to produce high quality reference genomes. Phenotypic analysis in Hep-2 cells and in a murine infection model indicated that S. Weltevreden were significantly attenuated in these models compared to the classical S. Typhimurium reference strain SL1344. Our work outlines novel insights into this important emerging pathogen and provides a baseline understanding for future research studies. PMID:26867150

A computational proposal for designing structured RNA pools for in vitro selection of RNAs.

PubMed

Kim, Namhee; Gan, Hin Hark; Schlick, Tamar

2007-04-01

Although in vitro selection technology is a versatile experimental tool for discovering novel synthetic RNA molecules, finding complex RNA molecules is difficult because most RNAs identified from random sequence pools are simple motifs, consistent with recent computational analysis of such sequence pools. Thus, enriching in vitro selection pools with complex structures could increase the probability of discovering novel RNAs. Here we develop an approach for engineering sequence pools that links RNA sequence space regions with corresponding structural distributions via a "mixing matrix" approach combined with a graph theory analysis. We define five classes of mixing matrices motivated by covariance mutations in RNA; these constructs define nucleotide transition rates and are applied to chosen starting sequences to yield specific nonrandom pools. We examine the coverage of sequence space as a function of the mixing matrix and starting sequence via clustering analysis. We show that, in contrast to random sequences, which are associated only with a local region of sequence space, our designed pools, including a structured pool for GTP aptamers, can target specific motifs. It follows that experimental synthesis of designed pools can benefit from using optimized starting sequences, mixing matrices, and pool fractions associated with each of our constructed pools as a guide. Automation of our approach could provide practical tools for pool design applications for in vitro selection of RNAs and related problems.

Recurrence time statistics: versatile tools for genomic DNA sequence analysis.

PubMed

Cao, Yinhe; Tung, Wen-Wen; Gao, J B

2004-01-01

With the completion of the human and a few model organisms' genomes, and the genomes of many other organisms waiting to be sequenced, it has become increasingly important to develop faster computational tools which are capable of easily identifying the structures and extracting features from DNA sequences. One of the more important structures in a DNA sequence is repeat-related. Often they have to be masked before protein coding regions along a DNA sequence are to be identified or redundant expressed sequence tags (ESTs) are to be sequenced. Here we report a novel recurrence time based method for sequence analysis. The method can conveniently study all kinds of periodicity and exhaustively find all repeat-related features from a genomic DNA sequence. An efficient codon index is also derived from the recurrence time statistics, which has the salient features of being largely species-independent and working well on very short sequences. Efficient codon indices are key elements of successful gene finding algorithms, and are particularly useful for determining whether a suspected EST belongs to a coding or non-coding region. We illustrate the power of the method by studying the genomes of E. coli, the yeast S. cervisivae, the nematode worm C. elegans, and the human, Homo sapiens. Computationally, our method is very efficient. It allows us to carry out analysis of genomes on the whole genomic scale by a PC.

[Cloning and sequence analysis of full-length cDNA of secoisolariciresinol dehydrogenase of Dysosma versipellis].

PubMed

Xu, Li; Ding, Zhi-Shan; Zhou, Yun-Kai; Tao, Xue-Fen

2009-06-01

To obtain the full-length cDNA sequence of Secoisolariciresinol Dehydrogenase gene from Dysosma versipellis by RACE PCR,then investigate the character of Secoisolariciresinol Dehydrogenase gene. The full-length cDNA sequence of Secoisolariciresinol Dehydrogenase gene was obtained by 3'-RACE and 5'-RACE from Dysosma versipellis. We first reported the full cDNA sequences of Secoisolariciresinol Dehydrogenase in Dysosma versipellis. The acquired gene was 991bp in full length, including 5' untranslated region of 42bp, 3' untranslated region of 112bp with Poly (A). The open reading frame (ORF) encoding 278 amino acid with molecular weight 29253.3 Daltons and isolectric point 6.328. The gene accession nucleotide sequence number in GeneBank was EU573789. Semi-quantitative RT-PCR analysis revealed that the Secoisolariciresinol Dehydrogenase gene was highly expressed in stem. Alignment of the amino acid sequence of Secoisolariciresinol Dehydrogenase indicated there may be some significant amino acid sequence difference among different species. Obtain the full-length cDNA sequence of Secoisolariciresinol Dehydrogenase gene from Dysosma versipellis.

Mitochondrial gene sequences alone or combined with ITS region sequences provide firm molecular criteria for the classification of Lecanicillium species.

PubMed

Kouvelis, Vassili N; Sialakouma, Aphrodite; Typas, Milton A

2008-07-01

The recent revision of Verticillium sect. Prostrata led to the introduction of the genus Lecanicillium, which comprises the majority of the entomopathogenic strains. Sixty-five strains previously classified as Verticillium lecanii or Verticillium sp. from different geographical regions and hosts were examined and their phylogenetic relationships were determined using sequences from three mitochondrial (mt) genes [the small rRNA subunit (rns), the NADH dehydrogenase subunits 1 (nad1) and 3 (nad3)] and the ITS region. In general, single gene phylogenetic trees differentiated and placed the strains examined in well-supported (by BS analysis) groups of L. lecanii, L. longisporum, L. muscarium, and L. nodulosum, although in some cases a few uncertainties still remained. nad1 was the most informative single gene in phylogenetic analyses and was also found to contain group I introns with putative open reading frames (ORFs) encoding for GIY-YIG endonucleases. The combined use of mt gene sequences resolved taxonomic uncertainties arisen from ITS analysis and, alone or in combination with ITS sequences, helped in placing uncharacterised Verticillium lecanii and Verticillium sp. firmly into Lecanicillium species. Combined gene data from all the mt genes and all the mt genes and the ITS region together, were very similar. Furthermore, a relaxed correlation with host specificity -- at least for Homoptera -- was indicated for the rns and the combined mt gene sequences. Thus, the usefulness of mt gene sequences as a convenient molecular tool in phylogenetic studies of entomopathogenic fungi was demonstrated.

Secondary structure prediction and structure-specific sequence analysis of single-stranded DNA.

PubMed

Dong, F; Allawi, H T; Anderson, T; Neri, B P; Lyamichev, V I

2001-08-01

DNA sequence analysis by oligonucleotide binding is often affected by interference with the secondary structure of the target DNA. Here we describe an approach that improves DNA secondary structure prediction by combining enzymatic probing of DNA by structure-specific 5'-nucleases with an energy minimization algorithm that utilizes the 5'-nuclease cleavage sites as constraints. The method can identify structural differences between two DNA molecules caused by minor sequence variations such as a single nucleotide mutation. It also demonstrates the existence of long-range interactions between DNA regions separated by >300 nt and the formation of multiple alternative structures by a 244 nt DNA molecule. The differences in the secondary structure of DNA molecules revealed by 5'-nuclease probing were used to design structure-specific probes for mutation discrimination that target the regions of structural, rather than sequence, differences. We also demonstrate the performance of structure-specific 'bridge' probes complementary to non-contiguous regions of the target molecule. The structure-specific probes do not require the high stringency binding conditions necessary for methods based on mismatch formation and permit mutation detection at temperatures from 4 to 37 degrees C. Structure-specific sequence analysis is applied for mutation detection in the Mycobacterium tuberculosis katG gene and for genotyping of the hepatitis C virus.

Porcine MYF6 gene: sequence, homology analysis, and variation in the promoter region.

PubMed

Wyszyńska-Koko, J; Kurył, J

2004-01-01

MYF6 gene codes for the bHLH transcription factor belonging to MyoD family. Its expression accompanies the processes of differentiation and maturation of myotubes during embriogenesis and continues on a relatively high level after birth, affecting the muscle phenotype. The porcine MYF6 gene was amplified and sequenced and compared with MYF6 gene sequences of other species. The amino acid sequence was deduced and an interspecies homology analysis was performed. Myf-6 protein shows a high conservation among species of 99 and 97% identity when comparing pig with cow and human, respectively, and of 93% when comparing pig with mouse and rat. The single nucleotide polymorphism (SNP) was revealed within the promoter region, which appeared to be T --> C transition recognized by a MspI restriction enzyme.

Sequence-based analysis of pQBR103; a representative of a unique, transfer-proficient mega plasmid resident in the microbial community of sugar beet

PubMed Central

Tett, Adrian; Spiers, Andrew J; Crossman, Lisa C; Ager, Duane; Ciric, Lena; Dow, J Maxwell; Fry, John C; Harris, David; Lilley, Andrew; Oliver, Anna; Parkhill, Julian; Quail, Michael A; Rainey, Paul B; Saunders, Nigel J; Seeger, Kathy; Snyder, Lori AS; Squares, Rob; Thomas, Christopher M; Turner, Sarah L; Zhang, Xue-Xian; Field, Dawn; Bailey, Mark J

2009-01-01

The plasmid pQBR103 was found within Pseudomonas populations colonizing the leaf and root surfaces of sugar beet plants growing at Wytham, Oxfordshire, UK. At 425 kb it is the largest self-transmissible plasmid yet sequenced from the phytosphere. It is known to enhance the competitive fitness of its host, and parts of the plasmid are known to be actively transcribed in the plant environment. Analysis of the complete sequence of this plasmid predicts a coding sequence (CDS)-rich genome containing 478 CDSs and an exceptional degree of genetic novelty; 80% of predicted coding sequences cannot be ascribed a function and 60% are orphans. Of those to which function could be assigned, 40% bore greatest similarity to sequences from Pseudomonas spp, and the majority of the remainder showed similarity to other c-proteobacterial genera and plasmids. pQBR103 has identifiable regions presumed responsible for replication and partitioning, but despite being tra+ lacks the full complement of any previously described conjugal transfer functions. The DNA sequence provided few insights into the functional significance of plant-induced transcriptional regions, but suggests that 14% of CDSs may be expressed (11 CDSs with functional annotation and 54 without), further highlighting the ecological importance of these novel CDSs. Comparative analysis indicates that pQBR103 shares significant regions of sequence with other plasmids isolated from sugar beet plants grown at the same geographic location. These plasmid sequences indicate there is more novelty in the mobile DNA pool accessible to phytosphere pseudomonas than is currently appreciated or understood. PMID:18043644

Analysis of Two Cosmid Clones from Chromosome 4 of Drosophila melanogaster Reveals Two New Genes Amid an Unusual Arrangement of Repeated Sequences

PubMed Central

Locke, John; Podemski, Lynn; Roy, Ken; Pilgrim, David; Hodgetts, Ross

1999-01-01

Chromosome 4 from Drosophila melanogaster has several unusual features that distinguish it from the other chromosomes. These include a diffuse appearance in salivary gland polytene chromosomes, an absence of recombination, and the variegated expression of P-element transgenes. As part of a larger project to understand these properties, we are assembling a physical map of this chromosome. Here we report the sequence of two cosmids representing ∼5% of the polytenized region. Both cosmid clones contain numerous repeated DNA sequences, as identified by cross hybridization with labeled genomic DNA, BLAST searches, and dot matrix analysis, which are positioned between and within the transcribed sequences. The repetitive sequences include three copies of the mobile element Hoppel, one copy of the mobile element HB, and 18 DINE repeats. DINE is a novel, short repeated sequence dispersed throughout both cosmid sequences. One cosmid includes the previously described cubitus interruptus (ci) gene and two new genes: that a gene with a predicted amino acid sequence similar to ribosomal protein S3a which is consistent with the Minute(4)101 locus thought to be in the region, and a novel member of the protein family that includes plexin and met–hepatocyte growth factor receptor. The other cosmid contains only the two short 5′-most exons from the zinc-finger-homolog-2 (zfh-2) gene. This is the first extensive sequence analysis of noncoding DNA from chromosome 4. The distribution of the various repeats suggests its organization is similar to the β-heterochromatic regions near the base of the major chromosome arms. Such a pattern may account for the diffuse banding of the polytene chromosome 4 and the variegation of many P-element transgenes on the chromosome. PMID:10022978

Sequence analysis of the canine mitochondrial DNA control region from shed hair samples in criminal investigations.

PubMed

Berger, C; Berger, B; Parson, W

2012-01-01

In recent years, evidence from domestic dogs has increasingly been analyzed by forensic DNA testing. Especially, canine hairs have proved most suitable and practical due to the high rate of hair transfer occurring between dogs and humans. Starting with the description of a contamination-free sample handling procedure, we give a detailed workflow for sequencing hypervariable segments (HVS) of the mtDNA control region from canine evidence. After the hair material is lysed and the DNA extracted by Phenol/Chloroform, the amplification and sequencing strategy comprises the HVS I and II of the canine control region and is optimized for DNA of medium-to-low quality and quantity. The sequencing procedure is based on the Sanger Big-dye deoxy-terminator method and the separation of the sequencing reaction products is performed on a conventional multicolor fluorescence detection capillary electrophoresis platform. Finally, software-aided base calling and sequence interpretation are addressed exemplarily.

Adenovirus EIIA early promoter: transcriptional control elements and induction by the viral pre-early EIA gene, which appears to be sequence independent.

PubMed Central

Murthy, S C; Bhat, G P; Thimmappaya, B

1985-01-01

A molecular dissection of the adenovirus EIIA early (E) promoter was undertaken to study the sequence elements required for transcription and to examine the nucleotide sequences, if any, specific for its trans-activation by the viral pre-early EIA gene product. A chimeric gene in which the EIIA-E promoter region fused to the coding sequences of the bacterial chloramphenicol acetyltransferase (CAT) gene was used in transient assays to identify the transcriptional control regions. Deletion mapping studies revealed that the upstream DNA sequences up to -86 were sufficient for the optimal basal level transcription in HeLa cells and also for the EIA-induced transcription. A series of linker-scanning (LS) mutants were constructed to precisely identify the nucleotide sequences that control transcription. Analysis of these LS mutants allowed us to identify two regions of the promoter that are critical for the EIIA-E transcription. These regions are located between -29 and -21 (region I) and between -82 and -66 (region II). Mutations in region I affected initiation and appeared functionally similar to the "TATA" sequence of the commonly studied promoters. To examine whether or not the EIIA-E promoter contained DNA sequences specific for the trans-activation by the EIA, the LS mutants were analyzed in a cotransfection assay containing a plasmid carrying the EIA gene. CAT activity of all of the LS mutants was induced by the EIA gene in this assay, suggesting that the induction of transcription of the EIIA-E promoter by the EIA gene is not sequence-specific. Images PMID:3857577

Characterization and phylogenetic analysis of the swine leukocyte antigen 3 gene from Korean native pigs.

PubMed

Chung, H Y; Choi, Y C; Park, H N

2015-05-18

We investigated the phylogenetic relationships between pig breeds, compared the genetic similarity between humans and pigs, and provided basic genetic information on Korean native pigs (KNPs), using genetic variants of the swine leukocyte antigen 3 (SLA-3) gene. Primers were based on sequences from GenBank (accession Nos. AF464010 and AF464009). Polymerase chain reaction analysis amplified approximately 1727 bp of segments, which contained 1086 bp of coding regions and 641 bp of the 3'- and 5'-untranslated regions. Bacterial artificial chromosome clones of miniature pigs were used for sequencing the SLA-3 genomic region, which was 3114 bp in total length, including the coding (1086 bp) and non-coding (2028 bp) regions. Sequence analysis detected 53 single nucleotide polymorphisms (SNPs), based on a minor allele frequency greater than 0.01, which is low compared with other pig breeds, and the results suggest that there is low genetic variability in KNPs. Comparative analysis revealed that humans possess approximately three times more genetic variation than do pigs. Approximately 71% of SNPs in exons 2 and 3 were detected in KNPs, and exon 5 in humans is a highly polymorphic region. Newly identified sequences of SLA-3 using KNPs were submitted to GenBank (accession No. DQ992512-18). Cluster analysis revealed that KNPs were grouped according to three major alleles: SLA-3*0502 (DQ992518), SLA-3*0302 (DQ992513 and DQ992516), and SLA-3*0303 (DQ992512, DQ992514, DQ992515, and DQ992517). Alignments revealed that humans have a relatively close genetic relationship with pigs and chimpanzees. The information provided by this study may be useful in KNP management.

Genetic diversity of Histoplasma and Sporothrix complexes based on sequences of their ITS1-5.8S-ITS2 regions from the BOLD System.

PubMed

Estrada-Bárcenas, Daniel Alfonso; Vite-Garín, Tania; Navarro-Barranco, Hortensia; de la Torre-Arciniega, Raúl; Pérez-Mejía, Amelia; Rodríguez-Arellanes, Gabriela; Ramirez, Jose Antonio; Humberto Sahaza, Jorge; Taylor, Maria Lucia; Toriello, Conchita

2014-01-01

High sensitivity and specificity of molecular biology techniques have proven usefulness for the detection, identification and typing of different pathogens. The ITS (Internal Transcribed Spacer) regions of the ribosomal DNA are highly conserved non-coding regions, and have been widely used in different studies including the determination of the genetic diversity of human fungal pathogens. This article wants to contribute to the understanding of the intra- and interspecific genetic diversity of isolates of the Histoplasma capsulatum and Sporothrix schenckii species complexes by an analysis of the available sequences of the ITS regions from different sequence databases. ITS1-5.8S-ITS2 sequences of each fungus, either deposited in GenBank, or from our research groups (registered in the Fungi Barcode of Life Database), were analyzed using the maximum likelihood (ML) method. ML analysis of the ITS sequences discriminated isolates from distant geographic origins and particular wild hosts, depending on the fungal species analyzed. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Development of an Analysis Pipeline Characterizing Multiple Hypervariable Regions of 16S rRNA Using Mock Samples.

PubMed

Barb, Jennifer J; Oler, Andrew J; Kim, Hyung-Suk; Chalmers, Natalia; Wallen, Gwenyth R; Cashion, Ann; Munson, Peter J; Ames, Nancy J

2016-01-01

There is much speculation on which hypervariable region provides the highest bacterial specificity in 16S rRNA sequencing. The optimum solution to prevent bias and to obtain a comprehensive view of complex bacterial communities would be to sequence the entire 16S rRNA gene; however, this is not possible with second generation standard library design and short-read next-generation sequencing technology. This paper examines a new process using seven hypervariable or V regions of the 16S rRNA (six amplicons: V2, V3, V4, V6-7, V8, and V9) processed simultaneously on the Ion Torrent Personal Genome Machine (Life Technologies, Grand Island, NY). Four mock samples were amplified using the 16S Ion Metagenomics Kit™ (Life Technologies) and their sequencing data is subjected to a novel analytical pipeline. Results are presented at family and genus level. The Kullback-Leibler divergence (DKL), a measure of the departure of the computed from the nominal bacterial distribution in the mock samples, was used to infer which region performed best at the family and genus levels. Three different hypervariable regions, V2, V4, and V6-7, produced the lowest divergence compared to the known mock sample. The V9 region gave the highest (worst) average DKL while the V4 gave the lowest (best) average DKL. In addition to having a high DKL, the V9 region in both the forward and reverse directions performed the worst finding only 17% and 53% of the known family level and 12% and 47% of the genus level bacteria, while results from the forward and reverse V4 region identified all 17 family level bacteria. The results of our analysis have shown that our sequencing methods using 6 hypervariable regions of the 16S rRNA and subsequent analysis is valid. This method also allowed for the assessment of how well each of the variable regions might perform simultaneously. Our findings will provide the basis for future work intended to assess microbial abundance at different time points throughout a clinical protocol.

DMRT gene cluster analysis in the platypus: new insights into genomic organization and regulatory regions.

PubMed

El-Mogharbel, Nisrine; Wakefield, Matthew; Deakin, Janine E; Tsend-Ayush, Enkhjargal; Grützner, Frank; Alsop, Amber; Ezaz, Tariq; Marshall Graves, Jennifer A

2007-01-01

We isolated and characterized a cluster of platypus DMRT genes and compared their arrangement, location, and sequence across vertebrates. The DMRT gene cluster on human 9p24.3 harbors, in order, DMRT1, DMRT3, and DMRT2, which share a DM domain. DMRT1 is highly conserved and involved in sexual development in vertebrates, and deletions in this region cause sex reversal in humans. Sequence comparisons of DMRT genes between species have been valuable in identifying exons, control regions, and conserved nongenic regions (CNGs). The addition of platypus sequences is expected to be particularly valuable, since monotremes fill a gap in the vertebrate genome coverage. We therefore isolated and fully sequenced platypus BAC clones containing DMRT3 and DMRT2 as well as DMRT1 and then generated multispecies alignments and ran prediction programs followed by experimental verification to annotate this gene cluster. We found that the three genes have 58-66% identity to their human orthologues, lie in the same order as in other vertebrates, and colocate on 1 of the 10 platypus sex chromosomes, X5. We also predict that optimal annotation of the newly sequenced platypus genome will be challenging. The analysis of platypus sequence revealed differences in structure and sequence of the DMRT gene cluster. Multispecies comparison was particularly effective for detecting CNGs, revealing several novel potential regulatory regions within DMRT3 and DMRT2 as well as DMRT1. RT-PCR indicated that platypus DMRT1 and DMRT3 are expressed specifically in the adult testis (and not ovary), but DMRT2 has a wider expression profile, as it does for other mammals. The platypus DMRT1 expression pattern, and its location on an X chromosome, suggests an involvement in monotreme sexual development.

IG and TR single chain fragment variable (scFv) sequence analysis: a new advanced functionality of IMGT/V-QUEST and IMGT/HighV-QUEST.

PubMed

Giudicelli, Véronique; Duroux, Patrice; Kossida, Sofia; Lefranc, Marie-Paule

2017-06-26

IMGT®, the international ImMunoGeneTics information system® ( http://www.imgt.org ), was created in 1989 in Montpellier, France (CNRS and Montpellier University) to manage the huge and complex diversity of the antigen receptors, and is at the origin of immunoinformatics, a science at the interface between immunogenetics and bioinformatics. Immunoglobulins (IG) or antibodies and T cell receptors (TR) are managed and described in the IMGT® databases and tools at the level of receptor, chain and domain. The analysis of the IG and TR variable (V) domain rearranged nucleotide sequences is performed by IMGT/V-QUEST (online since 1997, 50 sequences per batch) and, for next generation sequencing (NGS), by IMGT/HighV-QUEST, the high throughput version of IMGT/V-QUEST (portal begun in 2010, 500,000 sequences per batch). In vitro combinatorial libraries of engineered antibody single chain Fragment variable (scFv) which mimic the in vivo natural diversity of the immune adaptive responses are extensively screened for the discovery of novel antigen binding specificities. However the analysis of NGS full length scFv (~850 bp) represents a challenge as they contain two V domains connected by a linker and there is no tool for the analysis of two V domains in a single chain. The functionality "Analyis of single chain Fragment variable (scFv)" has been implemented in IMGT/V-QUEST and, for NGS, in IMGT/HighV-QUEST for the analysis of the two V domains of IG and TR scFv. It proceeds in five steps: search for a first closest V-REGION, full characterization of the first V-(D)-J-REGION, then search for a second V-REGION and full characterization of the second V-(D)-J-REGION, and finally linker delimitation. For each sequence or NGS read, positions of the 5'V-DOMAIN, linker and 3'V-DOMAIN in the scFv are provided in the 'V-orientated' sense. Each V-DOMAIN is fully characterized (gene identification, sequence description, junction analysis, characterization of mutations and amino changes). The functionality is generic and can analyse any IG or TR single chain nucleotide sequence containing two V domains, provided that the corresponding species IMGT reference directory is available. The "Analysis of single chain Fragment variable (scFv)" implemented in IMGT/V-QUEST and, for NGS, in IMGT/HighV-QUEST provides the identification and full characterization of the two V domains of full-length scFv (~850 bp) nucleotide sequences from combinatorial libraries. The analysis can also be performed on concatenated paired chains of expressed antigen receptor IG or TR repertoires.

The European Classical Swine Fever Virus Database: Blueprint for a Pathogen-Specific Sequence Database with Integrated Sequence Analysis Tools

PubMed Central

Postel, Alexander; Schmeiser, Stefanie; Zimmermann, Bernd; Becher, Paul

2016-01-01

Molecular epidemiology has become an indispensable tool in the diagnosis of diseases and in tracing the infection routes of pathogens. Due to advances in conventional sequencing and the development of high throughput technologies, the field of sequence determination is in the process of being revolutionized. Platforms for sharing sequence information and providing standardized tools for phylogenetic analyses are becoming increasingly important. The database (DB) of the European Union (EU) and World Organisation for Animal Health (OIE) Reference Laboratory for classical swine fever offers one of the world’s largest semi-public virus-specific sequence collections combined with a module for phylogenetic analysis. The classical swine fever (CSF) DB (CSF-DB) became a valuable tool for supporting diagnosis and epidemiological investigations of this highly contagious disease in pigs with high socio-economic impacts worldwide. The DB has been re-designed and now allows for the storage and analysis of traditionally used, well established genomic regions and of larger genomic regions including complete viral genomes. We present an application example for the analysis of highly similar viral sequences obtained in an endemic disease situation and introduce the new geographic “CSF Maps” tool. The concept of this standardized and easy-to-use DB with an integrated genetic typing module is suited to serve as a blueprint for similar platforms for other human or animal viruses. PMID:27827988

Presence of a Shared 5'-Leader Sequence in Ancestral Human and Mammalian Retroviruses and Its Transduction into Feline Leukemia Virus.

PubMed

Kawasaki, Junna; Kawamura, Maki; Ohsato, Yoshiharu; Ito, Jumpei; Nishigaki, Kazuo

2017-10-15

Recombination events induce significant genetic changes, and this process can result in virus genetic diversity or in the generation of novel pathogenicity. We discovered a new recombinant feline leukemia virus (FeLV) gag gene harboring an unrelated insertion, termed the X region, which was derived from Felis catus endogenous gammaretrovirus 4 (FcERV-gamma4). The identified FcERV-gamma4 proviruses have lost their coding capabilities, but some can express their viral RNA in feline tissues. Although the X-region-carrying recombinant FeLVs appeared to be replication-defective viruses, they were detected in 6.4% of tested FeLV-infected cats. All isolated recombinant FeLV clones commonly incorporated a middle part of the FcERV-gamma4 5'-leader region as an X region. Surprisingly, a sequence corresponding to the portion contained in all X regions is also present in at least 13 endogenous retroviruses (ERVs) observed in the cat, human, primate, and pig genomes. We termed this shared genetic feature the commonly shared (CS) sequence. Despite our phylogenetic analysis indicating that all CS-sequence-carrying ERVs are classified as gammaretroviruses, no obvious closeness was revealed among these ERVs. However, the Shannon entropy in the CS sequence was lower than that in other parts of the provirus genome. Notably, the CS sequence of human endogenous retrovirus T had 73.8% similarity with that of FcERV-gamma4, and specific signals were detected in the human genome by Southern blot analysis using a probe for the FcERV-gamma4 CS sequence. Our results provide an interesting evolutionary history for CS-sequence circulation among several distinct ancestral viruses and a novel recombined virus over a prolonged period. IMPORTANCE Recombination among ERVs or modern viral genomes causes a rapid evolution of retroviruses, and this phenomenon can result in the serious situation of viral disease reemergence. We identified a novel recombinant FeLV gag gene that contains an unrelated sequence, termed the X region. This region originated from the 5' leader of FcERV-gamma4, a replication-incompetent feline ERV. Surprisingly, a sequence corresponding to the X region is also present in the 5' portion of other ERVs, including human endogenous retroviruses. Scattered copies of the ERVs carrying the unique genetic feature, here named the commonly shared (CS) sequence, were found in each host genome, suggesting that ancestral viruses may have captured and maintained the CS sequence. More recently, a novel recombinant FeLV hijacked the CS sequence from inactivated FcERV-gamma4 as the X region. Therefore, tracing the CS sequences can provide unique models for not only the modern reservoir of new recombinant viruses but also the genetic features shared among ancient retroviruses. Copyright © 2017 American Society for Microbiology.

Regularized rare variant enrichment analysis for case-control exome sequencing data.

PubMed

Larson, Nicholas B; Schaid, Daniel J

2014-02-01

Rare variants have recently garnered an immense amount of attention in genetic association analysis. However, unlike methods traditionally used for single marker analysis in GWAS, rare variant analysis often requires some method of aggregation, since single marker approaches are poorly powered for typical sequencing study sample sizes. Advancements in sequencing technologies have rendered next-generation sequencing platforms a realistic alternative to traditional genotyping arrays. Exome sequencing in particular not only provides base-level resolution of genetic coding regions, but also a natural paradigm for aggregation via genes and exons. Here, we propose the use of penalized regression in combination with variant aggregation measures to identify rare variant enrichment in exome sequencing data. In contrast to marginal gene-level testing, we simultaneously evaluate the effects of rare variants in multiple genes, focusing on gene-based least absolute shrinkage and selection operator (LASSO) and exon-based sparse group LASSO models. By using gene membership as a grouping variable, the sparse group LASSO can be used as a gene-centric analysis of rare variants while also providing a penalized approach toward identifying specific regions of interest. We apply extensive simulations to evaluate the performance of these approaches with respect to specificity and sensitivity, comparing these results to multiple competing marginal testing methods. Finally, we discuss our findings and outline future research. © 2013 WILEY PERIODICALS, INC.

Sequencing Complex Genomic Regions

ScienceCinema

Eichler, Evan

2018-02-12

Evan Eichler, Howard Hughes Medical Investigator at the University of Washington, gives the May 28, 2009 keynote speech at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM. Part 1 of 2

CSReport: A New Computational Tool Designed for Automatic Analysis of Class Switch Recombination Junctions Sequenced by High-Throughput Sequencing.

PubMed

Boyer, François; Boutouil, Hend; Dalloul, Iman; Dalloul, Zeinab; Cook-Moreau, Jeanne; Aldigier, Jean-Claude; Carrion, Claire; Herve, Bastien; Scaon, Erwan; Cogné, Michel; Péron, Sophie

2017-05-15

B cells ensure humoral immune responses due to the production of Ag-specific memory B cells and Ab-secreting plasma cells. In secondary lymphoid organs, Ag-driven B cell activation induces terminal maturation and Ig isotype class switch (class switch recombination [CSR]). CSR creates a virtually unique IgH locus in every B cell clone by intrachromosomal recombination between two switch (S) regions upstream of each C region gene. Amount and structural features of CSR junctions reveal valuable information about the CSR mechanism, and analysis of CSR junctions is useful in basic and clinical research studies of B cell functions. To provide an automated tool able to analyze large data sets of CSR junction sequences produced by high-throughput sequencing (HTS), we designed CSReport, a software program dedicated to support analysis of CSR recombination junctions sequenced with a HTS-based protocol (Ion Torrent technology). CSReport was assessed using simulated data sets of CSR junctions and then used for analysis of Sμ-Sα and Sμ-Sγ1 junctions from CH12F3 cells and primary murine B cells, respectively. CSReport identifies junction segment breakpoints on reference sequences and junction structure (blunt-ended junctions or junctions with insertions or microhomology). Besides the ability to analyze unprecedentedly large libraries of junction sequences, CSReport will provide a unified framework for CSR junction studies. Our results show that CSReport is an accurate tool for analysis of sequences from our HTS-based protocol for CSR junctions, thereby facilitating and accelerating their study. Copyright © 2017 by The American Association of Immunologists, Inc.

Bacterial community comparisons by taxonomy-supervised analysis independent of sequence alignment and clustering

PubMed Central

Sul, Woo Jun; Cole, James R.; Jesus, Ederson da C.; Wang, Qiong; Farris, Ryan J.; Fish, Jordan A.; Tiedje, James M.

2011-01-01

High-throughput sequencing of 16S rRNA genes has increased our understanding of microbial community structure, but now even higher-throughput methods to the Illumina scale allow the creation of much larger datasets with more samples and orders-of-magnitude more sequences that swamp current analytic methods. We developed a method capable of handling these larger datasets on the basis of assignment of sequences into an existing taxonomy using a supervised learning approach (taxonomy-supervised analysis). We compared this method with a commonly used clustering approach based on sequence similarity (taxonomy-unsupervised analysis). We sampled 211 different bacterial communities from various habitats and obtained ∼1.3 million 16S rRNA sequences spanning the V4 hypervariable region by pyrosequencing. Both methodologies gave similar ecological conclusions in that β-diversity measures calculated by using these two types of matrices were significantly correlated to each other, as were the ordination configurations and hierarchical clustering dendrograms. In addition, our taxonomy-supervised analyses were also highly correlated with phylogenetic methods, such as UniFrac. The taxonomy-supervised analysis has the advantages that it is not limited by the exhaustive computation required for the alignment and clustering necessary for the taxonomy-unsupervised analysis, is more tolerant of sequencing errors, and allows comparisons when sequences are from different regions of the 16S rRNA gene. With the tremendous expansion in 16S rRNA data acquisition underway, the taxonomy-supervised approach offers the potential to provide more rapid and extensive community comparisons across habitats and samples. PMID:21873204

Partial Shotgun Sequencing of the Boechera stricta Genome Reveals Extensive Microsynteny and Promoter Conservation with Arabidopsis1[W

PubMed Central

Windsor, Aaron J.; Schranz, M. Eric; Formanová, Nataša; Gebauer-Jung, Steffi; Bishop, John G.; Schnabelrauch, Domenica; Kroymann, Juergen; Mitchell-Olds, Thomas

2006-01-01

Comparative genomics provides insight into the evolutionary dynamics that shape discrete sequences as well as whole genomes. To advance comparative genomics within the Brassicaceae, we have end sequenced 23,136 medium-sized insert clones from Boechera stricta, a wild relative of Arabidopsis (Arabidopsis thaliana). A significant proportion of these sequences, 18,797, are nonredundant and display highly significant similarity (BLASTn e-value ≤ 10−30) to low copy number Arabidopsis genomic regions, including more than 9,000 annotated coding sequences. We have used this dataset to identify orthologous gene pairs in the two species and to perform a global comparison of DNA regions 5′ to annotated coding regions. On average, the 500 nucleotides upstream to coding sequences display 71.4% identity between the two species. In a similar analysis, 61.4% identity was observed between 5′ noncoding sequences of Brassica oleracea and Arabidopsis, indicating that regulatory regions are not as diverged among these lineages as previously anticipated. By mapping the B. stricta end sequences onto the Arabidopsis genome, we have identified nearly 2,000 conserved blocks of microsynteny (bracketing 26% of the Arabidopsis genome). A comparison of fully sequenced B. stricta inserts to their homologous Arabidopsis genomic regions indicates that indel polymorphisms >5 kb contribute substantially to the genome size difference observed between the two species. Further, we demonstrate that microsynteny inferred from end-sequence data can be applied to the rapid identification and cloning of genomic regions of interest from nonmodel species. These results suggest that among diploid relatives of Arabidopsis, small- to medium-scale shotgun sequencing approaches can provide rapid and cost-effective benefits to evolutionary and/or functional comparative genomic frameworks. PMID:16607030

In-silico mining, type and frequency analysis of genic microsatellites of finger millet (Eleusine coracana (L.) Gaertn.): a comparative genomic analysis of NBS-LRR regions of finger millet with rice.

PubMed

Kalyana Babu, B; Pandey, Dinesh; Agrawal, P K; Sood, Salej; Kumar, Anil

2014-05-01

In recent years, the increased availability of the DNA sequences has given the possibility to develop and explore the expressed sequence tags (ESTs) derived SSR markers. In the present study, a total of 1956 ESTs of finger millet were used to find the microsatellite type, distribution, frequency and developed a total of 545 primer pairs from the ESTs of finger millet. Thirty-two EST sequences had more than two microsatellites and 1357 sequences did not have any SSR repeats. The most frequent type of repeats was trimeric motif, however the second place was occupied by dimeric motif followed by tetra-, hexa- and penta repeat motifs. The most common dimer repeat motif was GA and in case of trimeric SSRs, it was CGG. The EST sequences of NBS-LRR region of finger millet and rice showed higher synteny and were found on nearly same positions on the rice chromosome map. A total of eight, out of 15 EST based SSR primers were polymorphic among the selected resistant and susceptible finger millet genotypes. The primer FMBLEST5 could able to differentiate them into resistant and susceptible genotypes. The alleles specific to the resistant and susceptible genotypes were sequenced using the ABI 3130XL genetic analyzer and found similarity to NBS-LRR regions of rice and finger millet and contained the characteristic kinase-2 and kinase 3a motifs of plant R-genes belonged to NBS-LRR region. The In-silico and comparative analysis showed that the genes responsible for blast resistance can be identified, mapped and further introgressed through molecular breeding approaches for enhancing the blast resistance in finger millet.

'Mitominis': multiplex PCR analysis of reduced size amplicons for compound sequence analysis of the entire mtDNA control region in highly degraded samples.

PubMed

Eichmann, Cordula; Parson, Walther

2008-09-01

The traditional protocol for forensic mitochondrial DNA (mtDNA) analyses involves the amplification and sequencing of the two hypervariable segments HVS-I and HVS-II of the mtDNA control region. The primers usually span fragment sizes of 300-400 bp each region, which may result in weak or failed amplification in highly degraded samples. Here we introduce an improved and more stable approach using shortened amplicons in the fragment range between 144 and 237 bp. Ten such amplicons were required to produce overlapping fragments that cover the entire human mtDNA control region. These were co-amplified in two multiplex polymerase chain reactions and sequenced with the individual amplification primers. The primers were carefully selected to minimize binding on homoplasic and haplogroup-specific sites that would otherwise result in loss of amplification due to mis-priming. The multiplexes have successfully been applied to ancient and forensic samples such as bones and teeth that showed a high degree of degradation.

Phylogenetic Relationship in Different Commercial Strains of Pleurotus nebrodensis Based on ITS Sequence and RAPD.

PubMed

Alam, Nuhu; Shim, Mi Ja; Lee, Min Woong; Shin, Pyeong Gyun; Yoo, Young Bok; Lee, Tae Soo

2009-09-01

The molecular phylogeny in nine different commercial cultivated strains of Pleurotus nebrodensis was studied based on their internal transcribed spacer (ITS) region and RAPD. In the sequence of ITS region of selected strains, it was revealed that the total length ranged from 592 to 614 bp. The size of ITS1 and ITS2 regions varied among the strains from 219 to 228 bp and 211 to 229 bp, respectively. The sequence of ITS2 was more variable than ITS1 and the region of 5.8S sequences were identical. Phylogenetic tree of the ITS region sequences indicated that selected strains were classified into five clusters. The reciprocal homologies of the ITS region sequences ranged from 99 to 100%. The strains were also analyzed by RAPD with 20 arbitrary primers. Twelve primers were efficient to applying amplification of the genomic DNA. The sizes of the polymorphic fragments obtained were in the range of 200 to 2000 bp. RAPD and ITS analysis techniques were able to detect genetic variation among the tested strains. Experimental results suggested that IUM-1381, IUM-3914, IUM-1495 and AY-581431 strains were genetically very similar. Therefore, all IUM and NCBI gene bank strains of P. nebrodensis were genetically same with some variations.

Comparative analysis of complete chloroplast genome sequence and inversion variation in Lasthenia burkei (Madieae, Asteraceae).

PubMed

Walker, Joseph F; Zanis, Michael J; Emery, Nancy C

2014-04-01

Complete chloroplast genome studies can help resolve relationships among large, complex plant lineages such as Asteraceae. We present the first whole plastome from the Madieae tribe and compare its sequence variation to other chloroplast genomes in Asteraceae. We used high throughput sequencing to obtain the Lasthenia burkei chloroplast genome. We compared sequence structure and rates of molecular evolution in the small single copy (SSC), large single copy (LSC), and inverted repeat (IR) regions to those for eight Asteraceae accessions and one Solanaceae accession. The chloroplast sequence of L. burkei is 150 746 bp and contains 81 unique protein coding genes and 4 coding ribosomal RNA sequences. We identified three major inversions in the L. burkei chloroplast, all of which have been found in other Asteraceae lineages, and a previously unreported inversion in Lactuca sativa. Regions flanking inversions contained tRNA sequences, but did not have particularly high G + C content. Substitution rates varied among the SSC, LSC, and IR regions, and rates of evolution within each region varied among species. Some observed differences in rates of molecular evolution may be explained by the relative proportion of coding to noncoding sequence within regions. Rates of molecular evolution vary substantially within and among chloroplast genomes, and major inversion events may be promoted by the presence of tRNAs. Collectively, these results provide insight into different mechanisms that may promote intramolecular recombination and the inversion of large genomic regions in the plastome.

[Study of a family with epidermolysis bullosa simplex resulting from a novel mutation of KRT14 gene].

PubMed

Meng, Lanlan; Du, Juan; Li, Wen; Lu, Guangxiu; Tan, Yueqiu

2017-08-10

To determine the molecular etiology for a Chinese pedigree affected with epidermolysis bullosa simplex (EBS). Target region sequencing using a hereditary epidermolysis bullosa capture array combined with Sanger sequencing and bioinformatics analysis were used. Mutation taster, PolyPhen-2, Provean, and SIFT software and NCBI online were employed to assess the pathogenicity and conservation of detected mutations. One hundred healthy unrelated individuals were used as controls. Target region sequencing showed that the proband has carried a unreported heterozygous c.1234A>G (p.Ile412Val) mutation of the KRT14 gene, which was confirmed by Sanger sequencing in other 8 affected individuals but not among healthy members of the pedigree. Bioinformatics analysis indicated that the mutation is highly pathogenic. Remarkably, 3 members of the family (2 affected and 1 unaffected) have carried a heterozygous c.1237G>A (p.Ala413Thr) mutation of the KRT14 gene, which was collected in Human Gene Mutation Database (HGMD). Bioinformatics analysis indicated that the mutation may not be pathogenic. Both mutations were not detected among the 100 healthy controls. The novel c.1234A>G(p.Ile412Val) mutation of the KRT14 gene is probably responsible for the disease, while c.1237G>A (p.Ala413Thr) mutation of KRT14 gene may be a polymorphism. Compared with Sanger sequencing, target region capture sequencing is more efficient and can significantly reduce the cost of genetic testing for EBS.

Identification and nucleotide sequence analysis of the repetitive DNA element in the genome of fish lymphocystis disease virus.

PubMed

Schnitzler, P; Delius, H; Scholz, J; Touray, M; Orth, E; Darai, G

1987-12-01

The genome of the fish lymphocystis disease virus (FLDV) was screened for the existence of repetitive DNA sequences using a defined and complete gene library of the viral genome (98 kbp) by DNA-DNA hybridization, heteroduplex analysis, and restriction fine mapping. A repetitive DNA sequence was detected at the coordinates 0.034 to 0.057 and 0.718 to 0.736 map units (m.u.) of the FLDV genome. The first region (0.034 to 0.057 m.u.) corresponds to the 5' terminus of the EcoRI FLDV DNA fragment B (0.034 to 0.165 m.u.) and the second region (0.718 to 0.736 m.u.) is identical to the EcoRI DNA fragment M of the viral genome. The DNA nucleotide sequence of the EcoRI FLDV DNA fragment M was determined. This analysis revealed the presence of many short direct and inverted repetitions, e.g., a 18-mer direct repetition (TTTAAAATTTAATTAA) that started at nucleotide positions 812 and 942 and a 14-mer inverted repeat (TTAAATTTAAATTT) at nucleotide positions 820 and 959. Only short open reading frames were detected within this region. The DNA repetitions are discussed as sequences that play a possible regulatory role for virus replication. Furthermore, hybridization experiments revealed that the repetitive DNA sequences are conserved in the genome of different strains of fish lymphocystis disease virus isolated from two species of Pleuronectidae (flounder and dab).

Variability and transmission by Aphis glycines of North American and Asian Soybean mosaic virus isolates.

PubMed

Domier, L L; Latorre, I J; Steinlage, T A; McCoppin, N; Hartman, G L

2003-10-01

The variability of North American and Asian strains and isolates of Soybean mosaic virus was investigated. First, polymerase chain reaction (PCR) products representing the coat protein (CP)-coding regions of 38 SMVs were analyzed for restriction fragment length polymorphisms (RFLP). Second, the nucleotide and predicted amino acid sequence variability of the P1-coding region of 18 SMVs and the helper component/protease (HC/Pro) and CP-coding regions of 25 SMVs were assessed. The CP nucleotide and predicted amino acid sequences were the most similar and predicted phylogenetic relationships similar to those obtained from RFLP analysis. Neither RFLP nor sequence analyses of the CP-coding regions grouped the SMVs by geographical origin. The P1 and HC/Pro sequences were more variable and separated the North American and Asian SMV isolates into two groups similar to previously reported differences in pathogenic diversity of the two sets of SMV isolates. The P1 region was the most informative of the three regions analyzed. To assess the biological relevance of the sequence differences in the HC/Pro and CP coding regions, the transmissibility of 14 SMV isolates by Aphis glycines was tested. All field isolates of SMV were transmitted efficiently by A. glycines, but the laboratory isolates analyzed were transmitted poorly. The amino acid sequences from most, but not all, of the poorly transmitted isolates contained mutations in the aphid transmission-associated DAG and/or KLSC amino acid sequence motifs of CP and HC/Pro, respectively.

Association analysis of rare variants near the APOE region with CSF and neuroimaging biomarkers of Alzheimer's disease.

PubMed

Nho, Kwangsik; Kim, Sungeun; Horgusluoglu, Emrin; Risacher, Shannon L; Shen, Li; Kim, Dokyoon; Lee, Seunggeun; Foroud, Tatiana; Shaw, Leslie M; Trojanowski, John Q; Aisen, Paul S; Petersen, Ronald C; Jack, Clifford R; Weiner, Michael W; Green, Robert C; Toga, Arthur W; Saykin, Andrew J

2017-05-24

The APOE ε4 allele is the most significant common genetic risk factor for late-onset Alzheimer's disease (LOAD). The region surrounding APOE on chromosome 19 has also shown consistent association with LOAD. However, no common variants in the region remain significant after adjusting for APOE genotype. We report a rare variant association analysis of genes in the vicinity of APOE with cerebrospinal fluid (CSF) and neuroimaging biomarkers of LOAD. Whole genome sequencing (WGS) was performed on 817 blood DNA samples from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Sequence data from 757 non-Hispanic Caucasian participants was used in the present analysis. We extracted all rare variants (MAF (minor allele frequency) < 0.05) within a 312 kb window in APOE's vicinity encompassing 12 genes. We assessed CSF and neuroimaging (MRI and PET) biomarkers as LOAD-related quantitative endophenotypes. Gene-based analyses of rare variants were performed using the optimal Sequence Kernel Association Test (SKAT-O). A total of 3,334 rare variants (MAF < 0.05) were found within the APOE region. Among them, 72 rare non-synonymous variants were observed. Eight genes spanning the APOE region were significantly associated with CSF Aβ 1-42 (p < 1.0 × 10 -3 ). After controlling for APOE genotype and adjusting for multiple comparisons, 4 genes (CBLC, BCAM, APOE, and RELB) remained significant. Whole-brain surface-based analysis identified highly significant clusters associated with rare variants of CBLC in the temporal lobe region including the entorhinal cortex, as well as frontal lobe regions. Whole-brain voxel-wise analysis of amyloid PET identified significant clusters in the bilateral frontal and parietal lobes showing associations of rare variants of RELB with cortical amyloid burden. Rare variants within genes spanning the APOE region are significantly associated with LOAD-related CSF Aβ 1-42 and neuroimaging biomarkers after adjusting for APOE genotype. These findings warrant further investigation and illustrate the role of next generation sequencing and quantitative endophenotypes in assessing rare variants which may help explain missing heritability in AD and other complex diseases.

Differentiation of BHV-1 isolates from vaccine virus by high-resolution melting analysis.

PubMed

Ostertag-Hill, Claire; Fang, Liang; Izume, Satoko; Lee, Megan; Reed, Aimee; Jin, Ling

2015-02-16

An efficacious bovine herpesvirus type-1 (BHV-1) vaccine has been used for many years. However, in the past few years, abortion and respiratory diseases have occurred after administration of the modified live vaccine. To investigate whether BHV-1 isolates from disease outbreaks are identical to those of the vaccines used, selected regions of the BHV-1 genome were investigated by high-resolution melting (HRM) analysis and PCR-DNA sequencing. When a target region within the thymidine kinase (TK) gene was examined by HRM analysis, 6 out of the 11 isolates from abortion cases and 22 out of the 25 isolates from bovine respiratory disease (BRD) cases had different melting curves compared to the vaccine virus. Surprisingly, when a conserved region within the US6 gene that encodes glycoprotein D (gD) was examined by HRM analysis, 5 out of the 11 abortion isolates and 18 out of the 23 BRD isolates had different melting curves from the vaccine virus. To determine whether SNPs within the coding regions of glycoprotein E (gE) and TK genes can be used to differentiate the isolates from the vaccine virus, PCR-DNA sequencing was used to examine these SNPs in all the isolates. This revealed that only 1 out of 11 of the abortion isolates and 4 out of 24 of the BRD isolates are different in the target region of gE from the vaccine virus, while 5 out of 11 abortion isolates and 4 out of 22 BRD isolates are different in the target region of TK from the vaccine virus. No DNA sequence differences were observed in glycoprotein G (gG) region between disease and vaccine isolates. Our study demonstrated that many disease isolates had genetic differences from the vaccine virus in regions examined by HRM and PCR-DNA sequencing analysis. In addition, many isolates contained more than one type of mutation and were composed of mixed variants. Our study suggests that a mixture of variants were present in isolates collected post-vaccination. HRM is a rapid diagnostic method that can be used for rapid differentiation of clinical isolates from vaccine strains. Copyright © 2014 Elsevier B.V. All rights reserved.

Spatiotemporal Phylogenetic Analysis and Molecular Characterisation of Infectious Bursal Disease Viruses Based on the VP2 Hyper-Variable Region

PubMed Central

Dolz, Roser; Valle, Rosa; Perera, Carmen L.; Bertran, Kateri; Frías, Maria T.; Majó, Natàlia; Ganges, Llilianne; Pérez, Lester J.

2013-01-01

Background Infectious bursal disease is a highly contagious and acute viral disease caused by the infectious bursal disease virus (IBDV); it affects all major poultry producing areas of the world. The current study was designed to rigorously measure the global phylogeographic dynamics of IBDV strains to gain insight into viral population expansion as well as the emergence, spread and pattern of the geographical structure of very virulent IBDV (vvIBDV) strains. Methodology/Principal Findings Sequences of the hyper-variable region of the VP2 (HVR-VP2) gene from IBDV strains isolated from diverse geographic locations were obtained from the GenBank database; Cuban sequences were obtained in the current work. All sequences were analysed by Bayesian phylogeographic analysis, implemented in the Bayesian Evolutionary Analysis Sampling Trees (BEAST), Bayesian Tip-association Significance testing (BaTS) and Spatial Phylogenetic Reconstruction of Evolutionary Dynamics (SPREAD) software packages. Selection pressure on the HVR-VP2 was also assessed. The phylogeographic association-trait analysis showed that viruses sampled from individual countries tend to cluster together, suggesting a geographic pattern for IBDV strains. Spatial analysis from this study revealed that strains carrying sequences that were linked to increased virulence of IBDV appeared in Iran in 1981 and spread to Western Europe (Belgium) in 1987, Africa (Egypt) around 1990, East Asia (China and Japan) in 1993, the Caribbean Region (Cuba) by 1995 and South America (Brazil) around 2000. Selection pressure analysis showed that several codons in the HVR-VP2 region were under purifying selection. Conclusions/Significance To our knowledge, this work is the first study applying the Bayesian phylogeographic reconstruction approach to analyse the emergence and spread of vvIBDV strains worldwide. PMID:23805195

Spatiotemporal Phylogenetic Analysis and Molecular Characterisation of Infectious Bursal Disease Viruses Based on the VP2 Hyper-Variable Region.

PubMed

Alfonso-Morales, Abdulahi; Martínez-Pérez, Orlando; Dolz, Roser; Valle, Rosa; Perera, Carmen L; Bertran, Kateri; Frías, Maria T; Majó, Natàlia; Ganges, Llilianne; Pérez, Lester J

2013-01-01

Infectious bursal disease is a highly contagious and acute viral disease caused by the infectious bursal disease virus (IBDV); it affects all major poultry producing areas of the world. The current study was designed to rigorously measure the global phylogeographic dynamics of IBDV strains to gain insight into viral population expansion as well as the emergence, spread and pattern of the geographical structure of very virulent IBDV (vvIBDV) strains. Sequences of the hyper-variable region of the VP2 (HVR-VP2) gene from IBDV strains isolated from diverse geographic locations were obtained from the GenBank database; Cuban sequences were obtained in the current work. All sequences were analysed by Bayesian phylogeographic analysis, implemented in the Bayesian Evolutionary Analysis Sampling Trees (BEAST), Bayesian Tip-association Significance testing (BaTS) and Spatial Phylogenetic Reconstruction of Evolutionary Dynamics (SPREAD) software packages. Selection pressure on the HVR-VP2 was also assessed. The phylogeographic association-trait analysis showed that viruses sampled from individual countries tend to cluster together, suggesting a geographic pattern for IBDV strains. Spatial analysis from this study revealed that strains carrying sequences that were linked to increased virulence of IBDV appeared in Iran in 1981 and spread to Western Europe (Belgium) in 1987, Africa (Egypt) around 1990, East Asia (China and Japan) in 1993, the Caribbean Region (Cuba) by 1995 and South America (Brazil) around 2000. Selection pressure analysis showed that several codons in the HVR-VP2 region were under purifying selection. To our knowledge, this work is the first study applying the Bayesian phylogeographic reconstruction approach to analyse the emergence and spread of vvIBDV strains worldwide.

Analysis of complex repeat sequences within the spinal muscular atrophy (SMA) candidate region in 5q13

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

Davies, K.E.; Morrison, K.E.; Daniels, R.I.

1994-09-01

We previously reported that the 400 kb interval flanked the polymorphic loci D5S435 and D5S557 contains blocks of a chromosome 5 specific repeat. This interval also defines the SMA candidate region by genetic analysis of recombinant families. A YAC contig of 2-3 Mb encompassing this area has been constructed and a 5.5 kb conserved fragment, isolated from a YAC end clone within the above interval, was used to obtain cDNAs from both fetal and adult brain libraries. We describe the identification of cDNAs with stretches of high DNA sequence homology to exons of {beta} glucuronidase on human chromosome 7. Themore » cDNAs map both to the candidate region and to an area of 5p using FISH and deletion hybrid analysis. Hybridization to bacteriophage and cosmid clones from the YACs localizes the {beta} glucuronidase related sequences within the 400 kb region of the YAC contig. The cDNAs show a polymorphic pattern on hybridization to genomic BamH1 fragments in the size range of 10-250 kb. Further analysis using YAC fragmentation vectors is being used to determine how these {beta} glucuronidase related cDNAs are distributed within 5q13. Dinucleotide repeats within the region are being investigated to determine linkage disequilibrium with the disease locus.« less

Identification of two allelic IgG1 C(H) coding regions (Cgamma1) of cat.

PubMed

Kanai, T H; Ueda, S; Nakamura, T

2000-01-31

Two types of cDNA encoding IgG1 heavy chain (gamma1) were isolated from a single domestic short-hair cat. Sequence analysis indicated a higher level of similarity of these Cgamma1 sequences to human Cgamma1 sequence (76.9 and 77.0%) than to mouse sequence (70.0 and 69.7%) at the nucleotide level. Predicted primary structures of both the feline Cgamma1 genes, designated as Cgamma1a and Cgamma1b, were similar to that of human Cgamma1 gene, for instance, as to the size of constant domains, the presence of six conserved cysteine residues involved in formation of the domain structure, and the location of a conserved N-linked glycosylation site. Sequence comparison between the two alleles showed that 7 out of 10 nucleotide differences were within the C(H)3 domain coding region, all leading to nonsynonymous changes in amino acid residues. Partial sequence analysis of genomic clones showed three nucleotide substitutions between the two Cgamma1 alleles in the intron between the CH2 and C(H)3 domain coding regions. In 12 domestic short-hair cats used in this study, the frequency of Cgamma1a allele (62.5%) was higher than that of the Cgamma1b allele (37.5%).

Genotypic analysis of Xylella fastidiosa isolates from different hosts using sequences homologous to the Xanthomonas rpf genes.

PubMed

Meinhardt, Lyndel W; Ribeiro, Milena P M A; Coletta-Filho, Helvécio D; Dumenyo, C Korsi; Tsai, Sui M; De M Bellato, Cláudia

2003-09-01

SUMMARY This is the first report of a genotypic analysis of the phytopathogenic bacteria Xylella fastidiosa (Xf) using differences within intra- and intergenic regions of pathogenic genes. Orthologous sequences from the genome of Xf were identified for genes involved in the regulation of pathogenicity factors (rpf) from Xanthomonas campestris pv. campestris (Xcc). While the rpf genes were conserved, the chromosomal region revealed differences in gene sizes and intergenic spacings and a major translocational event when compared to Xcc. Primers were designed to amplify three regions: the intragenic region of rpfA (2354 bp), the intergenic region between rpfA and rpfB (5772 bp), and the intergenic region between rpfC and rpfF (2314 bp). Amplicons were obtained for all three regions from 32 of the 33 Xf isolates tested from citrus, grape, coffee, plum, hibiscus and periwinkle. Three Xcc isolates from cruciferous plants only generated PCR products for the rpfC-F region. Cleaved amplified polymorphic sequences (CAPS) (Taq(alpha)I) revealed differential banding profiles for the rpfA-B and rpfC-F regions. Xylella isolates were separated into seven groups via rpfA-B, of which five contained only citrus, while the other two had citrus, grape and coffee, and citrus, coffee, plum and hibiscus isolates. rpfC-F separated the isolates into three host-related groups. Citrus, coffee and hibiscus isolates formed one group, while the other two groups were comprised solely of grape and plum isolates. Xcc isolates formed an out-group. In silico analysis supports these results, which reveal the potential of the rpf genes for genotypic analysis of Xylella fastidiosa.

Molecular characterization of a wild poliovirus type 3 epidemic in The Netherlands (1992 and 1993).

PubMed Central

Mulders, M N; van Loon, A M; van der Avoort, H G; Reimerink, J H; Ras, A; Bestebroer, T M; Drebot, M A; Kew, O M; Koopmans, M P

1995-01-01

An outbreak of poliomyelitis due to wild poliovirus type 3 (PV3) occurred in an unvaccinated community in The Netherlands between September 1992 and February 1993. The outbreak involved 71 patients. The aim of this study was to characterize the virus at the molecular level and to analyze the molecular evolution of the epidemic virus. Molecular analysis was carried out by sequencing the VP1/2A junction region (150 nucleotides) of 50 PV3 strains isolated in association with this outbreak and the entire VP1 gene of 14 strains. In addition, the sequence of the VP1/2A junction region of strains from geographical regions endemic for PV3 (Egypt, India, and Central Asia) was analyzed and compared with the nucleotide sequence of the epidemic strain from The Netherlands. The earliest isolate was obtained from river water sampled 3 weeks before diagnosis of the first poliomyelitis patient and was found by VP1/2A sequence analysis to be genetically identical to the strain isolated from the first patient. Sequence divergence among the strains from the epidemic in The Netherlands was less than 2%. The closest genetic similarity (97.3%) was found with an Indian isolate (New Delhi, December 1991), indicating the likely source of the virus. A more than 99% sequence similarity was found in the VP1/2A region. Finally, the sequence information was used to design primers for the specific and highly sensitive molecular detection of PV3 strains during the epidemic. PMID:8586711

Detection and characterization of hepatitis A virus circulating in Egypt.

PubMed

Hamza, Hazem; Abd-Elshafy, Dina Nadeem; Fayed, Sayed A; Bahgat, Mahmoud Mohamed; El-Esnawy, Nagwa Abass; Abdel-Mobdy, Emam

2017-07-01

Hepatitis A virus (HAV) still poses a considerable problem worldwide. In the current study, hepatitis A virus was recovered from wastewater samples collected from three wastewater treatment plants over one year. Using RT-PCR, HAV was detected in 43 out of 68 samples (63.2%) representing both inlet and outlet. Eleven positive samples were subjected to sequencing targeting the VP1-2A junction region. Phylogenetic analysis revealed that all samples belonged to subgenotype IB with few substitutions at the amino acid level. The complete sequence of one isolate (HAV/Egy/BI-11/2015) showed that the similarity at the amino acid level was not reflected at the nucleotide level. However, the deduced amino acid sequence derived from the complete nucleotide sequence showed distinct substitutions in the 2B, 2C, and 3A regions. Recombination analysis revealed a recombination event between X75215 (subgenotype IA) and AF268396 (subgenotype IB) involving a portion of the 2B nonstructural protein coding region (nucleotides 3757-3868) assuming the herein characterized sequence an actual recombinant. Despite the role of recombination in picornaviruses evolution, its involvement in HAV evolution has rarely been reported, and this may be due to the limited available complete HAV sequences. To our knowledge, this represents the first characterized complete sequence of an Egyptian isolate and the described recombination event provides an important update on the circulating HAV strains in Egypt.

Accuracy for detection of simulated lesions: comparison of fluid-attenuated inversion-recovery, proton density--weighted, and T2-weighted synthetic brain MR imaging

NASA Technical Reports Server (NTRS)

Herskovits, E. H.; Itoh, R.; Melhem, E. R.

2001-01-01

OBJECTIVE: The objective of our study was to determine the effects of MR sequence (fluid-attenuated inversion-recovery [FLAIR], proton density--weighted, and T2-weighted) and of lesion location on sensitivity and specificity of lesion detection. MATERIALS AND METHODS: We generated FLAIR, proton density-weighted, and T2-weighted brain images with 3-mm lesions using published parameters for acute multiple sclerosis plaques. Each image contained from zero to five lesions that were distributed among cortical-subcortical, periventricular, and deep white matter regions; on either side; and anterior or posterior in position. We presented images of 540 lesions, distributed among 2592 image regions, to six neuroradiologists. We constructed a contingency table for image regions with lesions and another for image regions without lesions (normal). Each table included the following: the reviewer's number (1--6); the MR sequence; the side, position, and region of the lesion; and the reviewer's response (lesion present or absent [normal]). We performed chi-square and log-linear analyses. RESULTS: The FLAIR sequence yielded the highest true-positive rates (p < 0.001) and the highest true-negative rates (p < 0.001). Regions also differed in reviewers' true-positive rates (p < 0.001) and true-negative rates (p = 0.002). The true-positive rate model generated by log-linear analysis contained an additional sequence-location interaction. The true-negative rate model generated by log-linear analysis confirmed these associations, but no higher order interactions were added. CONCLUSION: We developed software with which we can generate brain images of a wide range of pulse sequences and that allows us to specify the location, size, shape, and intrinsic characteristics of simulated lesions. We found that the use of FLAIR sequences increases detection accuracy for cortical-subcortical and periventricular lesions over that associated with proton density- and T2-weighted sequences.

Nucleotide sequencing analysis of a LEU gene of Candida maltosa which complements leuB mutation of Escherichia coli and leu2 mutation of Saccharomyces cerevisiae.

PubMed

Takagi, M; Kobayashi, N; Sugimoto, M; Fujii, T; Watari, J; Yano, K

1987-01-01

The expression of a LEU gene from Candida maltosa (designated as C-LEU2) isolated previously (Kawamura et al. 1983) was shown to be regulated, when transferred into Saccharomyces cerevisiae, by leucine and threonine in the medium, as in the case of LEU2 gene of S. cerevisiae. The coding region together with the regulatory region was subcloned and the nucleotide sequence was determined. When the sequence of the coding region was compared with that of LEU2, the homology was 72% for base pairs and 76% for deduced amino acids. Comparison of the regulatory region of C-LEU2 with those of LEU1 and LEU2 suggested a few short consensus sequences which are involved in regulation of gene expression by leucine and threonine in the medium.

Spatiotemporal attention operator using isotropic contrast and regional homogeneity

NASA Astrophysics Data System (ADS)

Palenichka, Roman; Lakhssassi, Ahmed; Zaremba, Marek

2011-04-01

A multiscale operator for spatiotemporal isotropic attention is proposed to reliably extract attention points during image sequence analysis. Its consecutive local maxima indicate attention points as the centers of image fragments of variable size with high intensity contrast, region homogeneity, regional shape saliency, and temporal change presence. The scale-adaptive estimation of temporal change (motion) and its aggregation with the regional shape saliency contribute to the accurate determination of attention points in image sequences. Multilocation descriptors of an image sequence are extracted at the attention points in the form of a set of multidimensional descriptor vectors. A fast recursive implementation is also proposed to make the operator's computational complexity independent from the spatial scale size, which is the window size in the spatial averaging filter. Experiments on the accuracy of attention-point detection have proved the operator consistency and its high potential for multiscale feature extraction from image sequences.

Identification and positional distribution analysis of transcription factor binding sites for genes from the wheat fl-cDNA sequences.

PubMed

Chen, Zhen-Yong; Guo, Xiao-Jiang; Chen, Zhong-Xu; Chen, Wei-Ying; Wang, Ji-Rui

2017-06-01

The binding sites of transcription factors (TFs) in upstream DNA regions are called transcription factor binding sites (TFBSs). TFBSs are important elements for regulating gene expression. To date, there have been few studies on the profiles of TFBSs in plants. In total, 4,873 sequences with 5' upstream regions from 8530 wheat fl-cDNA sequences were used to predict TFBSs. We found 4572 TFBSs for the MADS TF family, which was twice as many as for bHLH (1951), B3 (1951), HB superfamily (1914), ERF (1820), and AP2/ERF (1725) TFs, and was approximately four times higher than the remaining TFBS types. The percentage of TFBSs and TF members showed a distinct distribution in different tissues. Overall, the distribution of TFBSs in the upstream regions of wheat fl-cDNA sequences had significant difference. Meanwhile, high frequencies of some types of TFBSs were found in specific regions in the upstream sequences. Both TFs and fl-cDNA with TFBSs predicted in the same tissues exhibited specific distribution preferences for regulating gene expression. The tissue-specific analysis of TFs and fl-cDNA with TFBSs provides useful information for functional research, and can be used to identify relationships between tissue-specific TFs and fl-cDNA with TFBSs. Moreover, the positional distribution of TFBSs indicates that some types of wheat TFBS have different positional distribution preferences in the upstream regions of genes.

Clinical and Molecular Consequences of NF1 Microdeletion

DTIC Science & Technology

2006-05-01

service based on meta -PCR/sequencing, dosage analysis , and loss of heterozygosity analysis . Genet Test 2004;8(4):368-80. 51. Kluwe L, Mautner VF. Mosaicism...neurofibromin in normal centrosome function and in maintaining genome stability. Our detailed analysis of human and chimpanzee genome sequences were...chromosomes and DNA fibers (1). Tandem duplication of the region would have significant impact on many aspects of NF1 research, e.g., mutational analysis

Re-sequencing regions of the ovine Y chromosome in domestic and wild sheep reveals novel paternal haplotypes.

PubMed

Meadows, J R S; Kijas, J W

2009-02-01

The male-specific region of the ovine Y chromosome (MSY) remains poorly characterized, yet sequence variants from this region have the potential to reveal the wild progenitor of domestic sheep or examples of domestic and wild paternal introgression. The 5' promoter region of the sex-determining gene SRY was re-sequenced using a subset of wild sheep including bighorn (Ovis canadensis), thinhorn (Ovis dalli spp.), urial (Ovis vignei), argali (Ovis ammon), mouflon (Ovis musimon) and domestic sheep (Ovis aries). Seven novel SNPs (oY2-oY8) were revealed; these were polymorphic between but not within species. Re-sequencing and fragment analysis was applied to the MSY microsatellite SRYM18. It contains a complex compound repeat structure and sequencing of three novel size fragments revealed that a pentanucleotide element remained fixed, whilst a dinucleotide element displayed variability within species. Comparison of the sequence between species revealed that urial and argali sheep grouped more closely to the mouflon and domestic breeds than the pachyceriforms (bighorn and thinhorn). SNP and microsatellite data were combined to define six previously undetected haplotypes. Analysis revealed the mouflon as the only species to share a haplotype with domestic sheep, consistent with its status as a feral domesticate that has undergone male-mediated exchange with domestic animals. A comparison of the remaining wild species and domestic sheep revealed that O. aries is free from signatures of wild sheep introgression.

Molecular analysis of the glucocerebrosidase gene locus

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

Winfield, S.L.; Martin, B.M.; Fandino, A.

1994-09-01

Gaucher disease is due to a deficiency in the activity of the lysosomal enzyme glucocerebrosidase. Both the functional gene for this enzyme and a pseudogene are located in close proximity on chromosome 1q21. Analysis of the mutations present in patient samples has suggested interaction between the functional gene and the pseudogene in the origin of mutant genotypes. To investigate the involvement of regions flanking the functional gene and pseudogene in the origin of mutations found in Gaucher disease, a YAC clone containing DNA from this locus has been subcloned and characterized. The original YAC containing {approximately}360 kb was truncated withmore » the use of fragmentation plasmids to about 85 kb. A lambda library derived from this YAC was screened to obtain clones containing glucocerebrosidase sequences. PCR amplification was used to identify subclones containing 5{prime}, central, or 3{prime} sequences of the functional gene or of the pseudogene. Clones spanning the entire distance from the last exon of the functional gene to intron 1 of the pseudogene, the 5{prime} end of the functional gene and 16 kb of 5{prime} flanking region and approximately 15 kb of 3{prime} flanking region of the pseudogene were sequenced. Sequence data from 48 kb of intergenic and flanking regions of the glucocerebrosidase gene and its pseudogene has been generated. A large number of Alu sequences and several simple repeats have been found. Two of these repeats exhibit fragment length polymorphism. There is almost 100% homology between the 3{prime} flanking regions of the functional gene and the pseudogene, extending to about 4 kb past the termination codons. A much lower degree of homology is observed in the 5{prime} flanking region. Patient samples are currently being screened for polymorphisms in these flanking regions.« less

Direct identification of non-polio enteroviruses in residual paralysis cases by analysis of VP1 sequences.

PubMed

Rahimi, Pooneh; Tabatabaie, H; Gouya, Mohammad M; Mahmudi, M; Musavi, T; Rad, K Samimi; Azad, T Mokhtari; Nategh, R

2009-06-01

The 66 serotypes of human enteroviruses (EVs) are classified into four species A-D, based on phylogenetic relationships in multiple genome regions. Partial VP(1) amplification and sequence analysis are reliable methods for identifying non-polio enterovirus serotypes, especially in negative cell culture specimens from patients with residual paralysis. In Iran during the years 2000-2002, there were 29 residual paralysis cases with negative cell (RD, HEp(2) and L(20)B) culture results. The genomic RNA was extracted from stool specimens from cases of residual paralysis and detected by amplification of the 5'-nontranslated region using RT-PCR with Pan-EV primers. Partial VP(1) amplification by semi-nested RT-PCR (snRT-PCR) and sequence analysis were done. Specimens from the 29 culture-negative cases contained echoviruses of six different serotypes. The global eradication of wild polioviruses is near and study of non-polio enteroviruses, which can cause poliomyelitis, is increasingly important to understand their pathogenesis. The VP(1) sequences, derived from the snRT-PCR products, allowed rapid molecular analysis of these non-polio strains.

The complete chloroplast genome sequence of Aconitum coreanum and Aconitum carmichaelii and comparative analysis with other Aconitum species

PubMed Central

Park, Inkyu; Kim, Wook-jin; Yang, Sungyu; Yeo, Sang-Min; Li, Hulin

2017-01-01

Aconitum species (belonging to the Ranunculaceae) are well known herbaceous medicinal ingredients and have great economic value in Asian countries. However, there are still limited genomic resources available for Aconitum species. In this study, we sequenced the chloroplast (cp) genomes of two Aconitum species, A. coreanum and A. carmichaelii, using the MiSeq platform. The two Aconitum chloroplast genomes were 155,880 and 157,040 bp in length, respectively, and exhibited LSC and SSC regions separated by a pair of inverted repeat regions. Both cp genomes had 38% GC content and contained 131 unique functional genes including 86 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. The gene order, content, and orientation of the two Aconitum cp genomes exhibited the general structure of angiosperms, and were similar to those of other Aconitum species. Comparison of the cp genome structure and gene order with that of other Aconitum species revealed general contraction and expansion of the inverted repeat regions and single copy boundary regions. Divergent regions were also identified. In phylogenetic analysis, Aconitum species positon among the Ranunculaceae was determined with other family cp genomes in the Ranunculales. We obtained a barcoding target sequence in a divergent region, ndhC–trnV, and successfully developed a SCAR (sequence characterized amplified region) marker for discrimination of A. coreanum. Our results provide useful genetic information and a specific barcode for discrimination of Aconitum species. PMID:28863163

The complete chloroplast genome sequence of Aconitum coreanum and Aconitum carmichaelii and comparative analysis with other Aconitum species.

PubMed

Park, Inkyu; Kim, Wook-Jin; Yang, Sungyu; Yeo, Sang-Min; Li, Hulin; Moon, Byeong Cheol

2017-01-01

Aconitum species (belonging to the Ranunculaceae) are well known herbaceous medicinal ingredients and have great economic value in Asian countries. However, there are still limited genomic resources available for Aconitum species. In this study, we sequenced the chloroplast (cp) genomes of two Aconitum species, A. coreanum and A. carmichaelii, using the MiSeq platform. The two Aconitum chloroplast genomes were 155,880 and 157,040 bp in length, respectively, and exhibited LSC and SSC regions separated by a pair of inverted repeat regions. Both cp genomes had 38% GC content and contained 131 unique functional genes including 86 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. The gene order, content, and orientation of the two Aconitum cp genomes exhibited the general structure of angiosperms, and were similar to those of other Aconitum species. Comparison of the cp genome structure and gene order with that of other Aconitum species revealed general contraction and expansion of the inverted repeat regions and single copy boundary regions. Divergent regions were also identified. In phylogenetic analysis, Aconitum species positon among the Ranunculaceae was determined with other family cp genomes in the Ranunculales. We obtained a barcoding target sequence in a divergent region, ndhC-trnV, and successfully developed a SCAR (sequence characterized amplified region) marker for discrimination of A. coreanum. Our results provide useful genetic information and a specific barcode for discrimination of Aconitum species.

Phylogenetic analysis of mtDNA lineages in South American mummies.

PubMed

Monsalve, M V; Cardenas, F; Guhl, F; Delaney, A D; Devine, D V

1996-07-01

Some studies of mtDNA propose that contemporary Amerindians have descended from four haplotype groups, each defined by specific sets of polymorphisms. One recent study also found evidence of other potential founder haplotypes. We wanted to determine whether the four haplotypes in modern populations were also present in ancient South American aboriginals. We subjected mtDNA from Colombian mummies (470 to 1849 AD) to PCR amplification and restriction endonuclease analysis. The mtDNA D-loop region was surveyed for sequence variation by restriction analysis and a segment of this region was sequenced for each mummy to characterize the haplotypes. Our mummies exhibited three of the four major characteristic haplotypes of Amerindian populations defined by four markers. With sequence data obtained in the ancient samples and published data on contemporary Amerindians it was possible to infer the origin of these six mummies.

Universal primers for amplification of the complete mitochondrial control region in marine fish species.

PubMed

Cheng, Y Z; Xu, T J; Jin, X X; Tang, D; Wei, T; Sun, Y Y; Meng, F Q; Shi, G; Wang, R X

2012-01-01

Through multiple alignment analysis of mitochondrial tRNA-Thr and tRNA-Phe sequences from 161 fishes, new universal primers specially targeting the entire mitochondrial control region were designed. This new primer set successfully amplified the expected PCR products from various kinds of marine fish species, belonging to various families, and the amplified segments were confirmed to be the control region by sequencing. These primers provide a useful tool to study the control region diversity in economically important fish species, the possible mechanism of control region evolution, and the functions of the conserved motifs in the control region.

Sequences of 95 human MHC haplotypes reveal extreme coding variation in genes other than highly polymorphic HLA class I and II

PubMed Central

Norman, Paul J.; Norberg, Steven J.; Guethlein, Lisbeth A.; Nemat-Gorgani, Neda; Royce, Thomas; Wroblewski, Emily E.; Dunn, Tamsen; Mann, Tobias; Alicata, Claudia; Hollenbach, Jill A.; Chang, Weihua; Shults Won, Melissa; Gunderson, Kevin L.; Abi-Rached, Laurent; Ronaghi, Mostafa; Parham, Peter

2017-01-01

The most polymorphic part of the human genome, the MHC, encodes over 160 proteins of diverse function. Half of them, including the HLA class I and II genes, are directly involved in immune responses. Consequently, the MHC region strongly associates with numerous diseases and clinical therapies. Notoriously, the MHC region has been intractable to high-throughput analysis at complete sequence resolution, and current reference haplotypes are inadequate for large-scale studies. To address these challenges, we developed a method that specifically captures and sequences the 4.8-Mbp MHC region from genomic DNA. For 95 MHC homozygous cell lines we assembled, de novo, a set of high-fidelity contigs and a sequence scaffold, representing a mean 98% of the target region. Included are six alternative MHC reference sequences of the human genome that we completed and refined. Characterization of the sequence and structural diversity of the MHC region shows the approach accurately determines the sequences of the highly polymorphic HLA class I and HLA class II genes and the complex structural diversity of complement factor C4A/C4B. It has also uncovered extensive and unexpected diversity in other MHC genes; an example is MUC22, which encodes a lung mucin and exhibits more coding sequence alleles than any HLA class I or II gene studied here. More than 60% of the coding sequence alleles analyzed were previously uncharacterized. We have created a substantial database of robust reference MHC haplotype sequences that will enable future population scale studies of this complicated and clinically important region of the human genome. PMID:28360230

Characterization of HIV Type 1 Envelope Sequence Among Viral Isolates Circulating in the Northern Region of Colombia, South America

PubMed Central

Villarreal, José-Luis; Gutiérrez, Jaime; Palacio, Lucy; Peñuela, Martha; Hernández, Robin; Lemay, Guy

2012-01-01

Abstract To characterize human immunodeficiency virus (HIV-1) strains circulating in the Northern region of Colombia in South America, sequences of the viral envelope C2V3C3 region were obtained from patients with different high-risk practices. Close to 60% of the sequences were predicted to belong to macrophage-tropic viruses, according to the positions of acidic amino acids and putative N-linked glycosylation sites. This is in agreement with the fact that most of the patients were recently diagnosed individuals. Phylogenic analysis then allowed assignment of all 35 samples to subtype B viruses. This same subtype was found in previous studies carried out in other Colombian regions. This study thus expands previous analyses with previously missing data from the Northern region of the country. The number and the length of the sequences examined also help to provide a clearer picture of the prevailing situation of the present HIV epidemics in this country. PMID:22482735

Complete chloroplast genome sequence of a major invasive species, crofton weed (Ageratina adenophora).

PubMed

Nie, Xiaojun; Lv, Shuzuo; Zhang, Yingxin; Du, Xianghong; Wang, Le; Biradar, Siddanagouda S; Tan, Xiufang; Wan, Fanghao; Weining, Song

2012-01-01

Crofton weed (Ageratina adenophora) is one of the most hazardous invasive plant species, which causes serious economic losses and environmental damages worldwide. However, the sequence resource and genome information of A. adenophora are rather limited, making phylogenetic identification and evolutionary studies very difficult. Here, we report the complete sequence of the A. adenophora chloroplast (cp) genome based on Illumina sequencing. The A. adenophora cp genome is 150, 689 bp in length including a small single-copy (SSC) region of 18, 358 bp and a large single-copy (LSC) region of 84, 815 bp separated by a pair of inverted repeats (IRs) of 23, 755 bp. The genome contains 130 unique genes and 18 duplicated in the IR regions, with the gene content and organization similar to other Asteraceae cp genomes. Comparative analysis identified five DNA regions (ndhD-ccsA, psbI-trnS, ndhF-ycf1, ndhI-ndhG and atpA-trnR) containing parsimony-informative characters higher than 2%, which may be potential informative markers for barcoding and phylogenetic analysis. Repeat structure, codon usage and contraction of the IR were also investigated to reveal the pattern of evolution. Phylogenetic analysis demonstrated a sister relationship between A. adenophora and Guizotia abyssinica and supported a monophyly of the Asterales. We have assembled and analyzed the chloroplast genome of A. adenophora in this study, which was the first sequenced plastome in the Eupatorieae tribe. The complete chloroplast genome information is useful for plant phylogenetic and evolutionary studies within this invasive species and also within the Asteraceae family.

Outbreak of poliomyelitis in Finland in 1984-85 - Re-analysis of viral sequences using the current standard approach.

PubMed

Simonen, Marja-Leena; Roivainen, Merja; Iber, Jane; Burns, Cara; Hovi, Tapani

2010-01-01

In 1984, a wild type 3 poliovirus (PV3/FIN84) spread all over Finland causing nine cases of paralytic poliomyelitis and one case of aseptic meningitis. The outbreak was ended in 1985 with an intensive vaccination campaign. By limited sequence comparison with previously isolated PV3 strains, closest relatives of PV3/FIN84 were found among strains circulating in the Mediterranean region. Now we wanted to reanalyse the relationships using approaches currently exploited in poliovirus surveillance. Cell lysates of 22 strains isolated during the outbreak and stored frozen were subjected to RT-PCR amplification in three genomic regions without prior subculture. Sequences of the entire VP1 coding region, 150 nucleotides in the VP1-2A junction, most of the 5' non-coding region, partial sequences of the 3D RNA polymerase coding region and partial 3' non-coding region were compared within the outbreak and with sequences available in data banks. In addition, complete nucleotide sequences were obtained for 2 strains isolated from two different cases of disease during the outbreak. The results confirmed the previously described wide intraepidemic variation of the strains, including amino acid substitutions in antigenic sites, as well as the likely Mediterranean region origin of the strains. Simplot and bootscanning analyses of the complete genomes indicated complicated evolutionary history of the non-capsid coding regions of the genome suggesting several recombinations with different HEV-C viruses in the past.

Partial sequencing analysis of the NS5B region confirmed the predominance of hepatitis C virus genotype 1 infection in Jeddah, Saudi Arabia.

PubMed

El Hadad, Sahar; Al-Hamdan, Hesa; Linjawi, Sabah

2017-01-01

Chronic hepatitis C virus (HCV) infection and its progression are major health problems that many countries including Saudi Arabia are facing. Determination of HCV genotypes and subgenotypes is critical for epidemiological and clinical analysis and aids in the determination of the ideal treatment strategy that needs to be followed and the expected therapy response. Although HCV infection has been identified as the second most predominant type of hepatitis in Saudi Arabia, little is known about the molecular epidemiology and genetic variability of HCV circulating in the Jeddah province of Saudi Arabia. The aim of this study was to determine the dominance of various HCV genotypes and subgenotypes circulating in Jeddah using partial sequencing of the NS5B region. To the best of our knowledge, this is the first study of its kind in Saudi Arabia. To characterize HCV genotypes and subgenotypes, serum samples from 56 patients with chronic HCV infection were collected and subjected to partial NS5B gene amplification and sequence analysis. Phylogenetic analysis of the NS5B partial sequences revealed that HCV/1 was the predominant genotype (73%), followed by HCV/4 (24.49%) and HCV/3 (2.04%). Moreover, pairwise analysis also confirmed these results based on the average specific nucleotide distance identity: ±0.112, ±0.112, and ±0.179 for HCV/1, HCV/4, and HCV/3, respectively, without any interference between genotypes. Notably, the phylogenetic tree of the HCV/1 subgenotypes revealed that all the isolates (100%) from the present study belonged to the HCV/1a subgenotype. Our findings also revealed similarities in the nucleotide sequences between HCV circulating in Saudi Arabia and those circulating in countries such as Morocco, Egypt, Canada, India, Pakistan, and France. These results indicated that determination of HCV genotypes and subgenotypes based on partial sequence analysis of the NS5B region is accurate and reliable for HCV subtype determination.

General Framework for Meta-analysis of Rare Variants in Sequencing Association Studies

PubMed Central

Lee, Seunggeun; Teslovich, Tanya M.; Boehnke, Michael; Lin, Xihong

2013-01-01

We propose a general statistical framework for meta-analysis of gene- or region-based multimarker rare variant association tests in sequencing association studies. In genome-wide association studies, single-marker meta-analysis has been widely used to increase statistical power by combining results via regression coefficients and standard errors from different studies. In analysis of rare variants in sequencing studies, region-based multimarker tests are often used to increase power. We propose meta-analysis methods for commonly used gene- or region-based rare variants tests, such as burden tests and variance component tests. Because estimation of regression coefficients of individual rare variants is often unstable or not feasible, the proposed method avoids this difficulty by calculating score statistics instead that only require fitting the null model for each study and then aggregating these score statistics across studies. Our proposed meta-analysis rare variant association tests are conducted based on study-specific summary statistics, specifically score statistics for each variant and between-variant covariance-type (linkage disequilibrium) relationship statistics for each gene or region. The proposed methods are able to incorporate different levels of heterogeneity of genetic effects across studies and are applicable to meta-analysis of multiple ancestry groups. We show that the proposed methods are essentially as powerful as joint analysis by directly pooling individual level genotype data. We conduct extensive simulations to evaluate the performance of our methods by varying levels of heterogeneity across studies, and we apply the proposed methods to meta-analysis of rare variant effects in a multicohort study of the genetics of blood lipid levels. PMID:23768515

Structure and Evolution of Chlorate Reduction Composite Transposons

PubMed Central

Clark, Iain C.; Melnyk, Ryan A.; Engelbrektson, Anna; Coates, John D.

2013-01-01

ABSTRACT The genes for chlorate reduction in six bacterial strains were analyzed in order to gain insight into the metabolism. A newly isolated chlorate-reducing bacterium (Shewanella algae ACDC) and three previously isolated strains (Ideonella dechloratans, Pseudomonas sp. strain PK, and Dechloromarinus chlorophilus NSS) were genome sequenced and compared to published sequences (Alicycliphilus denitrificans BC plasmid pALIDE01 and Pseudomonas chloritidismutans AW-1). De novo assembly of genomes failed to join regions adjacent to genes involved in chlorate reduction, suggesting the presence of repeat regions. Using a bioinformatics approach and finishing PCRs to connect fragmented contigs, we discovered that chlorate reduction genes are flanked by insertion sequences, forming composite transposons in all four newly sequenced strains. These insertion sequences delineate regions with the potential to move horizontally and define a set of genes that may be important for chlorate reduction. In addition to core metabolic components, we have highlighted several such genes through comparative analysis and visualization. Phylogenetic analysis places chlorate reductase within a functionally diverse clade of type II dimethyl sulfoxide (DMSO) reductases, part of a larger family of enzymes with reactivity toward chlorate. Nucleotide-level forensics of regions surrounding chlorite dismutase (cld), as well as its phylogenetic clustering in a betaproteobacterial Cld clade, indicate that cld has been mobilized at least once from a perchlorate reducer to build chlorate respiration. PMID:23919996

Trading genes along the silk road: mtDNA sequences and the origin of central Asian populations.

PubMed Central

Comas, D; Calafell, F; Mateu, E; Pérez-Lezaun, A; Bosch, E; Martínez-Arias, R; Clarimon, J; Facchini, F; Fiori, G; Luiselli, D; Pettener, D; Bertranpetit, J

1998-01-01

Central Asia is a vast region at the crossroads of different habitats, cultures, and trade routes. Little is known about the genetics and the history of the population of this region. We present the analysis of mtDNA control-region sequences in samples of the Kazakh, the Uighurs, the lowland Kirghiz, and the highland Kirghiz, which we have used to address both the population history of the region and the possible selective pressures that high altitude has on mtDNA genes. Central Asian mtDNA sequences present features intermediate between European and eastern Asian sequences, in several parameters-such as the frequencies of certain nucleotides, the levels of nucleotide diversity, mean pairwise differences, and genetic distances. Several hypotheses could explain the intermediate position of central Asia between Europe and eastern Asia, but the most plausible would involve extensive levels of admixture between Europeans and eastern Asians in central Asia, possibly enhanced during the Silk Road trade and clearly after the eastern and western Eurasian human groups had diverged. Lowland and highland Kirghiz mtDNA sequences are very similar, and the analysis of molecular variance has revealed that the fraction of mitochondrial genetic variance due to altitude is not significantly different from zero. Thus, it seems unlikely that altitude has exerted a major selective pressure on mitochondrial genes in central Asian populations. PMID:9837835

Reduced-median-network analysis of complete mitochondrial DNA coding-region sequences for the major African, Asian, and European haplogroups.

PubMed

Herrnstadt, Corinna; Elson, Joanna L; Fahy, Eoin; Preston, Gwen; Turnbull, Douglass M; Anderson, Christen; Ghosh, Soumitra S; Olefsky, Jerrold M; Beal, M Flint; Davis, Robert E; Howell, Neil

2002-05-01

The evolution of the human mitochondrial genome is characterized by the emergence of ethnically distinct lineages or haplogroups. Nine European, seven Asian (including Native American), and three African mitochondrial DNA (mtDNA) haplogroups have been identified previously on the basis of the presence or absence of a relatively small number of restriction-enzyme recognition sites or on the basis of nucleotide sequences of the D-loop region. We have used reduced-median-network approaches to analyze 560 complete European, Asian, and African mtDNA coding-region sequences from unrelated individuals to develop a more complete understanding of sequence diversity both within and between haplogroups. A total of 497 haplogroup-associated polymorphisms were identified, 323 (65%) of which were associated with one haplogroup and 174 (35%) of which were associated with two or more haplogroups. Approximately one-half of these polymorphisms are reported for the first time here. Our results confirm and substantially extend the phylogenetic relationships among mitochondrial genomes described elsewhere from the major human ethnic groups. Another important result is that there were numerous instances both of parallel mutations at the same site and of reversion (i.e., homoplasy). It is likely that homoplasy in the coding region will confound evolutionary analysis of small sequence sets. By a linkage-disequilibrium approach, additional evidence for the absence of human mtDNA recombination is presented here.

Phylogenetic analysis of Hungarian goose parvovirus isolates and vaccine strains.

PubMed

Tatár-Kis, Tímea; Mató, Tamás; Markos, Béla; Palya, Vilmos

2004-08-01

Polymerase chain reaction and sequencing were used to analyse goose parvovirus field isolates and vaccine strains. Two fragments of the genome were amplified. Fragment "A" represents a region of VP3 gene, while fragment "B" represents a region upstream of the VP3 gene, encompassing part of the VP1 gene. In the region of fragment "A" the deduced amino acid sequence of the strains was identical, therefore differentiation among strains could be done only at the nucleotide level, which resulted in the formation of three groups: Hungarian, West-European and Asian strains. In the region of fragment "B", separation of groups could be done by both nucleotide and deduced amino acid sequence level. The nucleotide sequences resulted in the same groups as for fragment "A" but with a different clustering pattern among the Hungarian strains. Within the "Hungarian" group most of the recent field isolates fell into one cluster, very closely related or identical to each other, indicating a very slow evolutionary change. The attenuated strains and field isolates from 1979/80 formed a separate cluster. When vaccine strains and field isolates were compared, two specific amino acid differences were found that can be considered as possible markers for vaccinal strains. Sequence analysis of fragment "B" seems to be a suitable method for differentiation of attenuated vaccine strains from virulent strains. Copyright 2004 Houghton Trust Ltd

Sequence Variation in the Small-Subunit rRNA Gene of Plasmodium malariae and Prevalence of Isolates with the Variant Sequence in Sichuan, China

PubMed Central

Liu, Qing; Zhu, Shenghua; Mizuno, Sahoko; Kimura, Masatsugu; Liu, Peina; Isomura, Shin; Wang, Xingzhen; Kawamoto, Fumihiko

1998-01-01

By two PCR-based diagnostic methods, Plasmodium malariae infections have been rediscovered at two foci in the Sichuan province of China, a region where no cases of P. malariae have been officially reported for the last 2 decades. In addition, a variant form of P. malariae which has a deletion of 19 bp and seven substitutions of base pairs in the target sequence of the small-subunit (SSU) rRNA gene was detected with high frequency. Alignment analysis of Plasmodium sp. SSU rRNA gene sequences revealed that the 5′ region of the variant sequence is identical to that of P. vivax or P. knowlesi and its 3′ region is identical to that of P. malariae. The same sequence variations were also found in P. malariae isolates collected along the Thai-Myanmar border, suggesting a wide distribution of this variant form from southern China to Southeast Asia. PMID:9774600

Phylogenetic relations of humans and African apes from DNA sequences in the Psi eta-globin region

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

Miyamoto, M.M.; Slightom, J.L.; Goodman, M.

Sequences from the upstream and downstream flanking DNA regions of the Psi eta-globin locus in Pan troglodytes (common chimpanzee), Gorilla gorilla (gorilla), and Pongo pygmaeus (orangutan, the closest living relative to Homo, Pan, and Gorilla) provided further data for evaluating the phylogenetic relations of humans and African apes. These newly sequenced orthologs (an additional 4.9 kilobase pairs (kbp) for each species) were combined with published Psi eta-gene sequences and then compared to the same orthologous stretch (a continuous 7.1-kbp region) available for humans. Phylogenetic analysis of these nucleotide sequences by the parsimony method indicated (i) that human and chimpanzee aremore » more closely related to each other than either is to gorilla and (ii) that the slowdown in the rate of sequence evolution evident in higher primates is especially pronounced in humans. These results indicate that features unique to African apes (but not to humans) are primitive and that even local molecular clocks should be applied with caution.« less

Sequence analysis of 497 mouse brain ESTs expressed in the substantia nigra

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

Stewart, G.J.; Savioz, A.; Davies, R.W.

1997-01-15

The use of subtracted, region-specific cDNA libraries combined with single-pass cDNA sequencing allows the discovery of novel genes and facilitates molecular description of the tissue or region involved. We report the sequence of 497 mouse expressed sequence tags (ESTs) from two subtracted libraries enriched for cDNAs expressed in the substantia nigra, a brain region with important roles in movement control and Parkinson disease. Of these, 238 ESTs give no database matches and therefore derive from novel genes. A further 115 ESTs show sequence similarity to ESTs from other organisms, which themselves do not yield any significant database matches to genesmore » of known function. Fifty-six ESTs show sequence similarity to previously identified genes whose mouse homologues have not been reported. The total number of ESTs reported that are new for the mouse is 407, which, together with the 90 ESTs corresponding to known mouse genes or cDNAs, contributes to the molecular description of the substantia nigra. 21 refs., 4 tabs.« less

Mitochondrial sequence analysis for forensic identification using pyrosequencing technology.

PubMed

Andréasson, H; Asp, A; Alderborn, A; Gyllensten, U; Allen, M

2002-01-01

Over recent years, requests for mtDNA analysis in the field of forensic medicine have notably increased, and the results of such analyses have proved to be very useful in forensic cases where nuclear DNA analysis cannot be performed. Traditionally, mtDNA has been analyzed by DNA sequencing of the two hypervariable regions, HVI and HVII, in the D-loop. DNA sequence analysis using the conventional Sanger sequencing is very robust but time consuming and labor intensive. By contrast, mtDNA analysis based on the pyrosequencing technology provides fast and accurate results from the human mtDNA present in many types of evidence materials in forensic casework. The assay has been developed to determine polymorphic sites in the mitochondrial D-loop as well as the coding region to further increase the discrimination power of mtDNA analysis. The pyrosequencing technology for analysis of mtDNA polymorphisms has been tested with regard to sensitivity, reproducibility, and success rate when applied to control samples and actual casework materials. The results show that the method is very accurate and sensitive; the results are easily interpreted and provide a high success rate on casework samples. The panel of pyrosequencing reactions for the mtDNA polymorphisms were chosen to result in an optimal discrimination power in relation to the number of bases determined.

Genetic diversity of the captive Asian tapir population in Thailand, based on mitochondrial control region sequence data and the comparison of its nucleotide structure with Brazilian tapir.

PubMed

Muangkram, Yuttamol; Amano, Akira; Wajjwalku, Worawidh; Pinyopummintr, Tanu; Thongtip, Nikorn; Kaolim, Nongnid; Sukmak, Manakorn; Kamolnorranath, Sumate; Siriaroonrat, Boripat; Tipkantha, Wanlaya; Maikaew, Umaporn; Thomas, Warisara; Polsrila, Kanda; Dongsaard, Kwanreaun; Sanannu, Saowaphang; Wattananorrasate, Anuwat

2017-07-01

The Asian tapir (Tapirus indicus) has been classified as Endangered on the IUCN Red List of Threatened Species (2008). Genetic diversity data provide important information for the management of captive breeding and conservation of this species. We analyzed mitochondrial control region (CR) sequences from 37 captive Asian tapirs in Thailand. Multiple alignments of the full-length CR sequences sized 1268 bp comprised three domains as described in other mammal species. Analysis of 16 parsimony-informative variable sites revealed 11 haplotypes. Furthermore, the phylogenetic analysis using median-joining network clearly showed three clades correlated with our earlier cytochrome b gene study in this endangered species. The repetitive motif is located between first and second conserved sequence blocks, similar to the Brazilian tapir. The highest polymorphic site was located in the extended termination associated sequences domain. The results could be applied for future genetic management based in captivity and wild that shows stable populations.

Comprehensive analysis of the T-cell receptor beta chain gene in rhesus monkey by high throughput sequencing

PubMed Central

Li, Zhoufang; Liu, Guangjie; Tong, Yin; Zhang, Meng; Xu, Ying; Qin, Li; Wang, Zhanhui; Chen, Xiaoping; He, Jiankui

2015-01-01

Profiling immune repertoires by high throughput sequencing enhances our understanding of immune system complexity and immune-related diseases in humans. Previously, cloning and Sanger sequencing identified limited numbers of T cell receptor (TCR) nucleotide sequences in rhesus monkeys, thus their full immune repertoire is unknown. We applied multiplex PCR and Illumina high throughput sequencing to study the TCRβ of rhesus monkeys. We identified 1.26 million TCRβ sequences corresponding to 643,570 unique TCRβ sequences and 270,557 unique complementarity-determining region 3 (CDR3) gene sequences. Precise measurements of CDR3 length distribution, CDR3 amino acid distribution, length distribution of N nucleotide of junctional region, and TCRV and TCRJ gene usage preferences were performed. A comprehensive profile of rhesus monkey immune repertoire might aid human infectious disease studies using rhesus monkeys. PMID:25961410

Accurate, Rapid Taxonomic Classification of Fungal Large-Subunit rRNA Genes

PubMed Central

Liu, Kuan-Liang; Porras-Alfaro, Andrea; Eichorst, Stephanie A.

2012-01-01

Taxonomic and phylogenetic fingerprinting based on sequence analysis of gene fragments from the large-subunit rRNA (LSU) gene or the internal transcribed spacer (ITS) region is becoming an integral part of fungal classification. The lack of an accurate and robust classification tool trained by a validated sequence database for taxonomic placement of fungal LSU genes is a severe limitation in taxonomic analysis of fungal isolates or large data sets obtained from environmental surveys. Using a hand-curated set of 8,506 fungal LSU gene fragments, we determined the performance characteristics of a naïve Bayesian classifier across multiple taxonomic levels and compared the classifier performance to that of a sequence similarity-based (BLASTN) approach. The naïve Bayesian classifier was computationally more rapid (>460-fold with our system) than the BLASTN approach, and it provided equal or superior classification accuracy. Classifier accuracies were compared using sequence fragments of 100 bp and 400 bp and two different PCR primer anchor points to mimic sequence read lengths commonly obtained using current high-throughput sequencing technologies. Accuracy was higher with 400-bp sequence reads than with 100-bp reads. It was also significantly affected by sequence location across the 1,400-bp test region. The highest accuracy was obtained across either the D1 or D2 variable region. The naïve Bayesian classifier provides an effective and rapid means to classify fungal LSU sequences from large environmental surveys. The training set and tool are publicly available through the Ribosomal Database Project (http://rdp.cme.msu.edu/classifier/classifier.jsp). PMID:22194300

Structure and regulation of an archaebacterial promoter: An in vivo study. Progress report, August 1, 1991--March 31, 1993

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

Daniels, C.J.

1993-06-01

We have established that a 100 bp DNA fragment from the Haloferax volcanii tRNALys gene directs transcription in vivo. This element served as the starting point for a detailed analysis of the requirements for in vivo transcription. Among several gene tentatively identified as reporter elements, we selected a eukaryotic intron-containing tRNAPro gene for when it is driven by the H. volcanii tRNALys promoter fragment, produces a single small transcript. Transcript analysis, by Sl mapping and primer extension, showed that this RNA initiated at the expected tRNALys BoxB sequence and terminated in the tRNAPro RNA Pol III termination element present onmore » the DNA fragment. In initial studies we determined that the 3 inches proximal region of this tRNALys promoter element was sufficient for transcription initiation in vivo. This 40 bp region contains only the BoxA and BoxB regions and short purine rich regions 5 inches to the BoxA and BoxB sequence. Using the tRNAPro gene as the reporter and this minimal promoter, we performed a comprehensive analysis of the BoxA region. Each position of the BoxA region was converted to an four possible nucleotides and the transcription of 36 mutants was quantitated. Among the sites analyzed, only five of the positions showed high levels of discrimination; the preferred BoxA element was 5 inches-TT({sub T}/A)({sup A}/T) ANNNN-3 inches. Mutational analysis demonstrated that a transition from T-rich to A-rich sequences in the BoxA element is essential and that there is some flexibility in the location of the ``TA`` sequence. Additionally the TA sequence appears to determine the location of the transcription start site. The BoxA element defined in this study is similar to those observed for Sulfolobus and the methanogen promoters, and supports the hypothesis that a similar core promoter element is used by all archaeal RNA polymerases.« less

Complete chloroplast genome sequence of MD-2 pineapple and its comparative analysis among nine other plants from the subclass Commelinidae.

PubMed

Redwan, R M; Saidin, A; Kumar, S V

2015-08-12

Pineapple (Ananas comosus var. comosus) is known as the king of fruits for its crown and is the third most important tropical fruit after banana and citrus. The plant, which is indigenous to South America, is the most important species in the Bromeliaceae family and is largely traded for fresh fruit consumption. Here, we report the complete chloroplast sequence of the MD-2 pineapple that was sequenced using the PacBio sequencing technology. In this study, the high error rate of PacBio long sequence reads of A. comosus's total genomic DNA were improved by leveraging on the high accuracy but short Illumina reads for error-correction via the latest error correction module from Novocraft. Error corrected long PacBio reads were assembled by using a single tool to produce a contig representing the pineapple chloroplast genome. The genome of 159,636 bp in length is featured with the conserved quadripartite structure of chloroplast containing a large single copy region (LSC) with a size of 87,482 bp, a small single copy region (SSC) with a size of 18,622 bp and two inverted repeat regions (IRA and IRB) each with the size of 26,766 bp. Overall, the genome contained 117 unique coding regions and 30 were repeated in the IR region with its genes contents, structure and arrangement similar to its sister taxon, Typha latifolia. A total of 35 repeats structure were detected in both the coding and non-coding regions with a majority being tandem repeats. In addition, 205 SSRs were detected in the genome with six protein-coding genes contained more than two SSRs. Comparative chloroplast genomes from the subclass Commelinidae revealed a conservative protein coding gene albeit located in a highly divergence region. Analysis of selection pressure on protein-coding genes using Ka/Ks ratio showed significant positive selection exerted on the rps7 gene of the pineapple chloroplast with P less than 0.05. Phylogenetic analysis confirmed the recent taxonomical relation among the member of commelinids which support the monophyly relationship between Arecales and Dasypogonaceae and between Zingiberales to the Poales, which includes the A. comosus. The complete sequence of the chloroplast of pineapple provides insights to the divergence of genic chloroplast sequences from the members of the subclass Commelinidae. The complete pineapple chloroplast will serve as a reference for in-depth taxonomical studies in the Bromeliaceae family when more species under the family are sequenced in the future. The genetic sequence information will also make feasible other molecular applications of the pineapple chloroplast for plant genetic improvement.

mtDNAmanager: a Web-based tool for the management and quality analysis of mitochondrial DNA control-region sequences

PubMed Central

Lee, Hwan Young; Song, Injee; Ha, Eunho; Cho, Sung-Bae; Yang, Woo Ick; Shin, Kyoung-Jin

2008-01-01

Background For the past few years, scientific controversy has surrounded the large number of errors in forensic and literature mitochondrial DNA (mtDNA) data. However, recent research has shown that using mtDNA phylogeny and referring to known mtDNA haplotypes can be useful for checking the quality of sequence data. Results We developed a Web-based bioinformatics resource "mtDNAmanager" that offers a convenient interface supporting the management and quality analysis of mtDNA sequence data. The mtDNAmanager performs computations on mtDNA control-region sequences to estimate the most-probable mtDNA haplogroups and retrieves similar sequences from a selected database. By the phased designation of the most-probable haplogroups (both expected and estimated haplogroups), mtDNAmanager enables users to systematically detect errors whilst allowing for confirmation of the presence of clear key diagnostic mutations and accompanying mutations. The query tools of mtDNAmanager also facilitate database screening with two options of "match" and "include the queried nucleotide polymorphism". In addition, mtDNAmanager provides Web interfaces for users to manage and analyse their own data in batch mode. Conclusion The mtDNAmanager will provide systematic routines for mtDNA sequence data management and analysis via easily accessible Web interfaces, and thus should be very useful for population, medical and forensic studies that employ mtDNA analysis. mtDNAmanager can be accessed at . PMID:19014619

Development and application of a PCR assay to detect chicken and turkey parvoviruses in commercial poultry flocks in the United States.

USDA-ARS?s Scientific Manuscript database

Comparative sequence analysis of six independent chicken and turkey parvovirus nonstructural (NS) genes revealed specific genomic regions with 100% nucleotide sequence identity. A PCR assay with primers targeting these conserved genome sequences proved to be highly specific and sensitive to detect p...

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

Quantification of the methylation status of the PWS/AS imprinted region: comparison of two approaches based on bisulfite sequencing and methylation-sensitive MLPA.

PubMed

Dikow, Nicola; Nygren, Anders Oh; Schouten, Jan P; Hartmann, Carolin; Krämer, Nikola; Janssen, Bart; Zschocke, Johannes

2007-06-01

Standard methods used for genomic methylation analysis allow the detection of complete absence of either methylated or non-methylated alleles but are usually unable to detect changes in the proportion of methylated and unmethylated alleles. We compare two methods for quantitative methylation analysis, using the chromosome 15q11-q13 imprinted region as model. Absence of the non-methylated paternal allele in this region leads to Prader-Willi syndrome (PWS) whilst absence of the methylated maternal allele results in Angelman syndrome (AS). A proportion of AS is caused by mosaic imprinting defects which may be missed with standard methods and require quantitative analysis for their detection. Sequence-based quantitative methylation analysis (SeQMA) involves quantitative comparison of peaks generated through sequencing reactions after bisulfite treatment. It is simple, cost-effective and can be easily established for a large number of genes. However, our results support previous suggestions that methods based on bisulfite treatment may be problematic for exact quantification of methylation status. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) avoids bisulfite treatment. It detects changes in both CpG methylation as well as copy number of up to 40 chromosomal sequences in one simple reaction. Once established in a laboratory setting, the method is more accurate, reliable and less time consuming.

[Comparative analysis of clustered regularly interspaced short palindromic repeats (CRISPRs) loci in the genomes of halophilic archaea].

PubMed

Zhang, Fan; Zhang, Bing; Xiang, Hua; Hu, Songnian

2009-11-01

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is a widespread system that provides acquired resistance against phages in bacteria and archaea. Here we aim to genome-widely analyze the CRISPR in extreme halophilic archaea, of which the whole genome sequences are available at present time. We used bioinformatics methods including alignment, conservation analysis, GC content and RNA structure prediction to analyze the CRISPR structures of 7 haloarchaeal genomes. We identified the CRISPR structures in 5 halophilic archaea and revealed a conserved palindromic motif in the flanking regions of these CRISPR structures. In addition, we found that the repeat sequences of large CRISPR structures in halophilic archaea were greatly conserved, and two types of predicted RNA secondary structures derived from the repeat sequences were likely determined by the fourth base of the repeat sequence. Our results support the proposal that the leader sequence may function as recognition site by having palindromic structures in flanking regions, and the stem-loop secondary structure formed by repeat sequences may function in mediating the interaction between foreign genetic elements and CAS-encoded proteins.

LINE-1 retrotransposons: from 'parasite' sequences to functional elements.

PubMed

Paço, Ana; Adega, Filomena; Chaves, Raquel

2015-02-01

Long interspersed nuclear elements-1 (LINE-1) are the most abundant and active retrotransposons in the mammalian genomes. Traditionally, the occurrence of LINE-1 sequences in the genome of mammals has been explained by the selfish DNA hypothesis. Nevertheless, recently, it has also been argued that these sequences could play important roles in these genomes, as in the regulation of gene expression, genome modelling and X-chromosome inactivation. The non-random chromosomal distribution is a striking feature of these retroelements that somehow reflects its functionality. In the present study, we have isolated and analysed a fraction of the open reading frame 2 (ORF2) LINE-1 sequence from three rodent species, Cricetus cricetus, Peromyscus eremicus and Praomys tullbergi. Physical mapping of the isolated sequences revealed an interspersed longitudinal AT pattern of distribution along all the chromosomes of the complement in the three genomes. A detailed analysis shows that these sequences are preferentially located in the euchromatic regions, although some signals could be detected in the heterochromatin. In addition, a coincidence between the location of imprinted gene regions (as Xist and Tsix gene regions) and the LINE-1 retroelements was also observed. According to these results, we propose an involvement of LINE-1 sequences in different genomic events as gene imprinting, X-chromosome inactivation and evolution of repetitive sequences located at the heterochromatic regions (e.g. satellite DNA sequences) of the rodents' genomes analysed.

Interspecific and intraspecific gene variability in a 1-Mb region containing the highest density of NBS-LRR genes found in the melon genome.

PubMed

González, Víctor M; Aventín, Núria; Centeno, Emilio; Puigdomènech, Pere

2014-12-17

Plant NBS-LRR -resistance genes tend to be found in clusters, which have been shown to be hot spots of genome variability. In melon, half of the 81 predicted NBS-LRR genes group in nine clusters, and a 1 Mb region on linkage group V contains the highest density of R-genes and presence/absence gene polymorphisms found in the melon genome. This region is known to contain the locus of Vat, an agronomically important gene that confers resistance to aphids. However, the presence of duplications makes the sequencing and annotation of R-gene clusters difficult, usually resulting in multi-gapped sequences with higher than average errors. A 1-Mb sequence that contains the largest NBS-LRR gene cluster found in melon was improved using a strategy that combines Illumina paired-end mapping and PCR-based gap closing. Unknown sequence was decreased by 70% while about 3,000 SNPs and small indels were corrected. As a result, the annotations of 18 of a total of 23 NBS-LRR genes found in this region were modified, including additional coding sequences, amino acid changes, correction of splicing boundaries, or fussion of ORFs in common transcription units. A phylogeny analysis of the R-genes and their comparison with syntenic sequences in other cucurbits point to a pattern of local gene amplifications since the diversification of cucurbits from other families, and through speciation within the family. A candidate Vat gene is proposed based on the sequence similarity between a reported Vat gene from a Korean melon cultivar and a sequence fragment previously absent in the unrefined sequence. A sequence refinement strategy allowed substantial improvement of a 1 Mb fragment of the melon genome and the re-annotation of the largest cluster of NBS-LRR gene homologues found in melon. Analysis of the cluster revealed that resistance genes have been produced by sequence duplication in adjacent genome locations since the divergence of cucurbits from other close families, and through the process of speciation within the family a candidate Vat gene was also identified using sequence previously unavailable, which demonstrates the advantages of genome assembly refinements when analyzing complex regions such as those containing clusters of highly similar genes.

Molecular variation and horizontal gene transfer of the homocysteine methyltransferase gene mmuM and its distribution in clinical pathogens.

PubMed

Ying, Jianchao; Wang, Huifeng; Bao, Bokan; Zhang, Ying; Zhang, Jinfang; Zhang, Cheng; Li, Aifang; Lu, Junwan; Li, Peizhen; Ying, Jun; Liu, Qi; Xu, Teng; Yi, Huiguang; Li, Jinsong; Zhou, Li; Zhou, Tieli; Xu, Zuyuan; Ni, Liyan; Bao, Qiyu

2015-01-01

The homocysteine methyltransferase encoded by mmuM is widely distributed among microbial organisms. It is the key enzyme that catalyzes the last step in methionine biosynthesis and plays an important role in the metabolism process. It also enables the microbial organisms to tolerate high concentrations of selenium in the environment. In this research, 533 mmuM gene sequences covering 70 genera of the bacteria were selected from GenBank database. The distribution frequency of mmuM is different in the investigated genera of bacteria. The mapping results of 160 mmuM reference sequences showed that the mmuM genes were found in 7 species of pathogen genomes sequenced in this work. The polymerase chain reaction products of one mmuM genotype (NC_013951 as the reference) were sequenced and the sequencing results confirmed the mapping results. Furthermore, 144 representative sequences were chosen for phylogenetic analysis and some mmuM genes from totally different genera (such as the genes between Escherichia and Klebsiella and between Enterobacter and Kosakonia) shared closer phylogenetic relationship than those from the same genus. Comparative genomic analysis of the mmuM encoding regions on plasmids and bacterial chromosomes showed that pKF3-140 and pIP1206 plasmids shared a 21 kb homology region and a 4.9 kb fragment in this region was in fact originated from the Escherichia coli chromosome. These results further suggested that mmuM gene did go through the gene horizontal transfer among different species or genera of bacteria. High-throughput sequencing combined with comparative genomics analysis would explore distribution and dissemination of the mmuM gene among bacteria and its evolution at a molecular level.

Molecular Tracing of Hepatitis C Virus Genotype 1 Isolates in Iran: A NS5B Phylogenetic Analysis with Systematic Review.

PubMed

Hesamizadeh, Khashayar; Alavian, Seyed Moayed; Najafi Tireh Shabankareh, Azar; Sharafi, Heidar

2016-12-01

Hepatitis C virus (HCV) is characterized by a high degree of genetic heterogeneity and classified into 7 genotypes and different subtypes. It heterogeneously distributed through various risk groups and geographical regions. A well-established phylogenetic relationship can simplify the tracing of HCV hierarchical strata into geographical regions. The current study aimed to find genetic phylogeny of subtypes 1a and 1b of HCV isolates based on NS5B nucleotide sequences in Iran and other members of Eastern Mediterranean regional office of world health organization, as well as other Middle Eastern countries, with a systematic review of available published and unpublished studies. The phylogenetic analyses were performed based on the nucleotide sequences of NS5B gene of HCV genotype 1 (HCV-1), which were registered in the GenBank database. The literature review was performed in two steps: 1) searching studies evaluating the NS5B sequences of HCV-1, on PubMed, Scopus, and Web of Science, and 2) Searching sequences of unpublished studies registered in the GenBank database. In this study, 442 sequences from HCV-1a and 232 from HCV-1b underwent phylogenetic analysis. Phylogenetic analysis of all sequences revealed different clusters in the phylogenetic trees. The results showed that the proportion of HCV-1a and -1b isolates from Iranian patients probably originated from domestic sources. Moreover, the HCV-1b isolates from Iranian patients may have similarities with the European ones. In this study, phylogenetic reconstruction of HCV-1 sequences clearly indicated for molecular tracing and ancestral relationships of the HCV genotypes in Iran, and showed the likelihood of domestic origin for HCV-1a and various origin for HCV-1b.

ScaffoldSeq: Software for characterization of directed evolution populations.

PubMed

Woldring, Daniel R; Holec, Patrick V; Hackel, Benjamin J

2016-07-01

ScaffoldSeq is software designed for the numerous applications-including directed evolution analysis-in which a user generates a population of DNA sequences encoding for partially diverse proteins with related functions and would like to characterize the single site and pairwise amino acid frequencies across the population. A common scenario for enzyme maturation, antibody screening, and alternative scaffold engineering involves naïve and evolved populations that contain diversified regions, varying in both sequence and length, within a conserved framework. Analyzing the diversified regions of such populations is facilitated by high-throughput sequencing platforms; however, length variability within these regions (e.g., antibody CDRs) encumbers the alignment process. To overcome this challenge, the ScaffoldSeq algorithm takes advantage of conserved framework sequences to quickly identify diverse regions. Beyond this, unintended biases in sequence frequency are generated throughout the experimental workflow required to evolve and isolate clones of interest prior to DNA sequencing. ScaffoldSeq software uniquely handles this issue by providing tools to quantify and remove background sequences, cluster similar protein families, and dampen the impact of dominant clones. The software produces graphical and tabular summaries for each region of interest, allowing users to evaluate diversity in a site-specific manner as well as identify epistatic pairwise interactions. The code and detailed information are freely available at http://research.cems.umn.edu/hackel. Proteins 2016; 84:869-874. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Genomic sequences of murine gamma B- and gamma C-crystallin-encoding genes: promoter analysis and complete evolutionary pattern of mouse, rat and human gamma-crystallins.

PubMed

Graw, J; Liebstein, A; Pietrowski, D; Schmitt-John, T; Werner, T

1993-12-22

The murine genes, gamma B-cry and gamma C-cry, encoding the gamma B- and gamma C-crystallins, were isolated from a genomic DNA library. The complete nucleotide (nt) sequences of both genes were determined from 661 and 711 bp, respectively, upstream from the first exon to the corresponding polyadenylation sites, comprising more than 2650 and 2890 bp, respectively. The new sequences were compared to the partial cDNA sequences available for the murine gamma B-cry and gamma C-cry, as well as to the corresponding genomic sequences from rat and man, at both the nt and predicted amino acid (aa) sequence levels. In the gamma B-cry promoter region, a canonical CCAAT-box, a TATA-box, putative NF-I and C/EBP sites were detected. An R-repeat is inserted 366 bp upstream from the transcription start point. In contrast, the gamma C-cry promoter does not contain a CCAAT-box, but some other putative binding sites for transcription factors (AP-2, UBP-1, LBP-1) were located by computer analysis. The promoter regions of all six gamma-cry from mouse, rat and human, except human psi gamma F-cry, were analyzed for common sequence elements. A complex sequence element of about 70-80 bp was found in the proximal promoter, which contains a gamma-cry-specific and almost invariant sequence (crygpel) of 14 nt, and ends with the also invariant TATA-box. Within the complex sequence element, a minimum of three further features specific for the gamma A-, gamma B- and gamma D/E/F-cry genes can be defined, at least two of which were recently shown to be functional. In addition to these four sequence elements, a subtype-specific structure of inverted repeats with different-sized spacers can be deduced from the multiple sequence alignment. A phylogenetic analysis based on the promoter region, as well as the complete exon 3 of all gamma-cry from mouse, rat and man, suggests separation of only five gamma-cry subtypes (gamma A-, gamma B-, gamma C-, gamma D- and gamma E/F-cry) prior to species separation.

Phylogeny of sipunculan worms: A combined analysis of four gene regions and morphology.

PubMed

Schulze, Anja; Cutler, Edward B; Giribet, Gonzalo

2007-01-01

The intra-phyletic relationships of sipunculan worms were analyzed based on DNA sequence data from four gene regions and 58 morphological characters. Initially we analyzed the data under direct optimization using parsimony as optimality criterion. An implied alignment resulting from the direct optimization analysis was subsequently utilized to perform a Bayesian analysis with mixed models for the different data partitions. For this we applied a doublet model for the stem regions of the 18S rRNA. Both analyses support monophyly of Sipuncula and most of the same clades within the phylum. The analyses differ with respect to the relationships among the major groups but whereas the deep nodes in the direct optimization analysis generally show low jackknife support, they are supported by 100% posterior probability in the Bayesian analysis. Direct optimization has been useful for handling sequences of unequal length and generating conservative phylogenetic hypotheses whereas the Bayesian analysis under mixed models provided high resolution in the basal nodes of the tree.

A Fast Alignment-Free Approach for De Novo Detection of Protein Conserved Regions

PubMed Central

Abnousi, Armen; Broschat, Shira L.; Kalyanaraman, Ananth

2016-01-01

Background Identifying conserved regions in protein sequences is a fundamental operation, occurring in numerous sequence-driven analysis pipelines. It is used as a way to decode domain-rich regions within proteins, to compute protein clusters, to annotate sequence function, and to compute evolutionary relationships among protein sequences. A number of approaches exist for identifying and characterizing protein families based on their domains, and because domains represent conserved portions of a protein sequence, the primary computation involved in protein family characterization is identification of such conserved regions. However, identifying conserved regions from large collections (millions) of protein sequences presents significant challenges. Methods In this paper we present a new, alignment-free method for detecting conserved regions in protein sequences called NADDA (No-Alignment Domain Detection Algorithm). Our method exploits the abundance of exact matching short subsequences (k-mers) to quickly detect conserved regions, and the power of machine learning is used to improve the prediction accuracy of detection. We present a parallel implementation of NADDA using the MapReduce framework and show that our method is highly scalable. Results We have compared NADDA with Pfam and InterPro databases. For known domains annotated by Pfam, accuracy is 83%, sensitivity 96%, and specificity 44%. For sequences with new domains not present in the training set an average accuracy of 63% is achieved when compared to Pfam. A boost in results in comparison with InterPro demonstrates the ability of NADDA to capture conserved regions beyond those present in Pfam. We have also compared NADDA with ADDA and MKDOM2, assuming Pfam as ground-truth. On average NADDA shows comparable accuracy, more balanced sensitivity and specificity, and being alignment-free, is significantly faster. Excluding the one-time cost of training, runtimes on a single processor were 49s, 10,566s, and 456s for NADDA, ADDA, and MKDOM2, respectively, for a data set comprised of approximately 2500 sequences. PMID:27552220

The kinetoplast DNA of the Australian trypanosome, Trypanosoma copemani, shares features with Trypanosoma cruzi and Trypanosoma lewisi.

PubMed

Botero, Adriana; Kapeller, Irit; Cooper, Crystal; Clode, Peta L; Shlomai, Joseph; Thompson, R C Andrew

2018-05-17

Kinetoplast DNA (kDNA) is the mitochondrial genome of trypanosomatids. It consists of a few dozen maxicircles and several thousand minicircles, all catenated topologically to form a two-dimensional DNA network. Minicircles are heterogeneous in size and sequence among species. They present one or several conserved regions that contain three highly conserved sequence blocks. CSB-1 (10 bp sequence) and CSB-2 (8 bp sequence) present lower interspecies homology, while CSB-3 (12 bp sequence) or the Universal Minicircle Sequence is conserved within most trypanosomatids. The Universal Minicircle Sequence is located at the replication origin of the minicircles, and is the binding site for the UMS binding protein, a protein involved in trypanosomatid survival and virulence. Here, we describe the structure and organisation of the kDNA of Trypanosoma copemani, a parasite that has been shown to infect mammalian cells and has been associated with the drastic decline of the endangered Australian marsupial, the woylie (Bettongia penicillata). Deep genomic sequencing showed that T. copemani presents two classes of minicircles that share sequence identity and organisation in the conserved sequence blocks with those of Trypanosoma cruzi and Trypanosoma lewisi. A 19,257 bp partial region of the maxicircle of T. copemani that contained the entire coding region was obtained. Comparative analysis of the T. copemani entire maxicircle coding region with the coding regions of T. cruzi and T. lewisi showed they share 71.05% and 71.28% identity, respectively. The shared features in the maxicircle/minicircle organisation and sequence between T. copemani and T. cruzi/T. lewisi suggest similarities in their process of kDNA replication, and are of significance in understanding the evolution of Australian trypanosomes. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Cell proteins bind to multiple sites within the 5' untranslated region of poliovirus RNA.

PubMed Central

del Angel, R M; Papavassiliou, A G; Fernández-Tomás, C; Silverstein, S J; Racaniello, V R

1989-01-01

The 5' noncoding region of poliovirus RNA contains sequences necessary for translation and replication. These functions are probably carried out by recognition of poliovirus RNA by cellular and/or viral proteins. Using a mobility-shift electrophoresis assay and 1,10-phenanthroline/Cu+ footprinting, we demonstrate specific binding of cytoplasmic factors with a sequence from nucleotides 510-629 within the 5' untranslated region (UTR). Complex formation was also observed with a second sequence (nucleotides 97-182) within the 5' UTR. These two regions of the 5' UTR appear to be recognized by distinct cell factors as determined by competition analysis and the effects of ionic strength on complex formation. However, both complexes contain eukaryotic initiation factor 2 alpha, as revealed by their reaction with specific antibody. Images PMID:2554308

The complete sequence and structural analysis of human apolipoprotein B-100: relationship between apoB-100 and apoB-48 forms.

PubMed Central

Cladaras, C; Hadzopoulou-Cladaras, M; Nolte, R T; Atkinson, D; Zannis, V I

1986-01-01

We have isolated and sequenced overlapping cDNA clones covering the entire sequence of human apolipoprotein B-100 (apoB-100). DNA sequence analysis and determination of the mRNA transcription initiation site by S1 nuclease mapping showed that the apoB mRNA consists of 14,112 nucleotides including the 5' and 3' untranslated regions which are 128 and 301 nucleotides respectively. The DNA-derived protein sequence shows that apoB-100 is 513,000 daltons and contains 4560 amino acids including a 24-amino-acid-long signal peptide. The mol. wt of apoB-100 implies that there is one apoB molecule per LDL particle. Computer analysis of the predicted secondary structure of the protein showed that some of the potential alpha helical and beta sheet structures are amphipathic, whereas others have non-amphipathic neutral to apolar character. These latter regions may contribute to the formation of the lipid-binding domains of apoB-100. The protein contains 25 cysteines and 20 potential N-glycosylation sites. The majority of cysteines are distributed in the amino terminal portion of the protein. Four of the potential glycosylation sites are in predicted beta turn structures and may represent true glycosylation positions. ApoB lacks the tandem repeats which are characteristic of other apolipoproteins. The mean hydrophobicity the mean value of H1 and helical hydrophobic moment the mean value of microH profiles of apoB showed the presence of several potential helical regions with strong polar character and high hydrophobic moment. The region with the highest hydrophobic moment, between amino acid residues 3352 and 3369, contains five closely spaced, positively charged residues, and has sequence homology to the LDL receptor binding site of apoE. This region is flanked by three neighbouring regions with positively charged amino acids and high hydrophobic moment that are located between residues 3174 and 3681. One or more of these closely spaced apoB sequences may be involved in the formation of the LDL receptor-binding domain of apoB-100. Blotting analysis of intestinal RNA and hybridization of the blots with carboxy apoB cDNA probes produced a single 15-kb hybridization band whereas hybridization with amino terminal probes produced two hybridization bands of 15 and 8 kb. Our data indicate that both forms of apoB mRNA contain common sequences which extend from the amino terminal of apoB-100 to the vicinity of nucleotide residue 6300. These two messages may have resulted from differential splicing of the same primary apoB mRNA transcript. Images Fig. 4. Fig. 6. PMID:3030729

Comparative analysis of the mating-type loci from Neurospora crassa and Sordaria macrospora: identification of novel transcribed ORFs.

PubMed

Pöggeler, S; Kück, U

2000-03-01

The mating-type locus controls mating and sexual development in filamentous ascomycetes. In the heterothallic ascomycete Neurospora crassa, the genes that confer mating behavior comprise dissimilar DNA sequences (idiomorphs) in the mat a and mat A mating partners. In the homothallic fungus Sordaria macrospora, sequences corresponding to both idiomorphs are located contiguously in the mating-type locus, which contains one chimeric gene, Smt A-3, that includes sequences which are similar to sequences found at the mat A and mat a mating-type idiomorphs in N. crassa. In this study, we describe the comparative transcriptional analysis of the chimeric mating-type region of S. macrospora and the corresponding region of the N. crassa mat a idiomorph. By means of RT-PCR experiments, we identified novel intervening sequences in the mating-type loci of both ascomycetes and, hence, concluded that an additional ORF, encoding a putative polypeptide of 79 amino acids, is present in the N. crassa mat a idiomorph. Furthermore, our analysis revealed co-transcription of the novel gene with the mat a-1 gene in N. crassa. The same mode of transcription was found in the corresponding mating-type region of S. macrospora, where the chimeric Smt A-3 gene is co-transcribed with the mat a-specific Smt a-1 gene. Analysis of a Smt A-3 cDNA revealed optional splicing of two introns. We believe that this is the first report of co-transcription of protein-encoding nuclear genes in filamentous fungi. Possible functions of the novel ORFs in regulating mating-type gene expression are discussed.

Sequence analysis of the PIP5K locus in Eimeria maxima provides further evidence for eimerian genome plasticity and segmental organization.

PubMed

Song, B K; Pan, M Z; Lau, Y L; Wan, K L

2014-07-29

Commercial flocks infected by Eimeria species parasites, including Eimeria maxima, have an increased risk of developing clinical or subclinical coccidiosis; an intestinal enteritis associated with increased mortality rates in poultry. Currently, infection control is largely based on chemotherapy or live vaccines; however, drug resistance is common and vaccines are relatively expensive. The development of new cost-effective intervention measures will benefit from unraveling the complex genetic mechanisms that underlie host-parasite interactions, including the identification and characterization of genes encoding proteins such as phosphatidylinositol 4-phosphate 5-kinase (PIP5K). We previously identified a PIP5K coding sequence within the E. maxima genome. In this study, we analyzed two bacterial artificial chromosome clones presenting a ~145-kb E. maxima (Weybridge strain) genomic region spanning the PIP5K gene locus. Sequence analysis revealed that ~95% of the simple sequence repeats detected were located within regions comparable to the previously described feature-rich segments of the Eimeria tenella genome. Comparative sequence analysis with the orthologous E. maxima (Houghton strain) region revealed a moderate level of conserved synteny. Unique segmental organizations and telomere-like repeats were also observed in both genomes. A number of incomplete transposable elements were detected and further scrutiny of these elements in both orthologous segments revealed interesting nesting events, which may play a role in facilitating genome plasticity in E. maxima. The current analysis provides more detailed information about the genome organization of E. maxima and may help to reveal genotypic differences that are important for expression of traits related to pathogenicity and virulence.

DNA Sequence Analysis of Sry Alleles (Subgenus Mus) Implicates Misregulation as the Cause of C57bl/6j-Y(pos) Sex Reversal and Defines the Sry Functional Unit

PubMed Central

Albrecht, K. H.; Eicher, E. M.

1997-01-01

The Sry (sex determining region, Y chromosome) open reading frame from mice representing four species of the genus Mus was sequenced in an effort to understand the conditional dysfunction of some M. domesticus Sry alleles when present on the C57BL/6J inbred strain genetic background and to delimit the functionally important protein regions. Twenty-two Sry alleles were sequenced, most from wild-derived Y chromosomes, including 11 M. domesticus alleles, seven M. musculus alleles and two alleles each from the related species M. spicilegus and M. spretus. We found that the HMG domain (high mobility group DNA binding domain) and the unique regions are well conserved, while the glutamine repeat cluster (GRC) region is quite variable. No correlation was found between the predicted protein isoforms and the ability of a Sry allele to allow differentiation of ovarian tissue when on the C57BL/6J genetic background, strongly suggesting that the cause of this sex reversal is not the Sry protein itself, but rather the regulation of SRY expression. Furthermore, our interspecies sequence analysis provides compelling evidence that the M. musculus and M. domesticus SRY functional domain is contained in the first 143 amino acids, which includes the HMG domain and adjacent unique region (UR-2). PMID:9383069

Analysis of CHRNA7 rare variants in autism spectrum disorder susceptibility.

PubMed

Bacchelli, Elena; Battaglia, Agatino; Cameli, Cinzia; Lomartire, Silvia; Tancredi, Raffaella; Thomson, Susanne; Sutcliffe, James S; Maestrini, Elena

2015-04-01

Chromosome 15q13.3 recurrent microdeletions are causally associated with a wide range of phenotypes, including autism spectrum disorder (ASD), seizures, intellectual disability, and other psychiatric conditions. Whether the reciprocal microduplication is pathogenic is less certain. CHRNA7, encoding for the alpha7 subunit of the neuronal nicotinic acetylcholine receptor, is considered the likely culprit gene in mediating neurological phenotypes in 15q13.3 deletion cases. To assess if CHRNA7 rare variants confer risk to ASD, we performed copy number variant analysis and Sanger sequencing of the CHRNA7 coding sequence in a sample of 135 ASD cases. Sequence variation in this gene remains largely unexplored, given the existence of a fusion gene, CHRFAM7A, which includes a nearly identical partial duplication of CHRNA7. Hence, attempts to sequence coding exons must distinguish between CHRNA7 and CHRFAM7A, making next-generation sequencing approaches unreliable for this purpose. A CHRNA7 microduplication was detected in a patient with autism and moderate cognitive impairment; while no rare damaging variants were identified in the coding region, we detected rare variants in the promoter region, previously described to functionally reduce transcription. This study represents the first sequence variant analysis of CHRNA7 in a sample of idiopathic autism. © 2015 Wiley Periodicals, Inc.

The phosphotransferase system-dependent sucrose utilization regulon in enteropathogenic Escherichia coli strains is located in a variable chromosomal region containing iap sequences.

PubMed

Treviño-Quintanilla, Luis Gerardo; Escalante, Adelfo; Caro, Alma Delia; Martínez, Alfredo; González, Ricardo; Puente, José Luis; Bolívar, Francisco; Gosset, Guillermo

2007-01-01

The capacity to utilize sucrose as a carbon and energy source (Scr(+) phenotype) is a highly variable trait among Escherichia coli strains. In this study, seven enteropathogenic E. coli (EPEC) strains from different sources were studied for their capacity to grow using sucrose. Liquid media cultures showed that all analyzed strains have the Scr(+) phenotype and two distinct groups were defined: one of five and another of two strains displaying doubling times of 67 and 125 min, respectively. The genes conferring the Scr(+) phenotype in one of the fast-growing strains (T19) were cloned and sequenced. Comparative sequence analysis revealed that this strain possesses the scr regulon genes scrKYABR, encoding phosphoenolpyruvate:phosphotransferase system-dependent sucrose transport and utilization activities. Transcript level quantification revealed sucrose-dependent induction of scrK and scrR genes in fast-growing strains, whereas no transcripts were detected in slow-growing strains. Sequence comparison analysis revealed that the scr genes in strain T19 are almost identical to those present in the scr regulon of prototype EPEC E2348/69 and in both strains, the scr genes are inserted in the chromosomal intergenic region of hypothetical genes ygcE and ygcF. Comparison of the ygcE-ygcF intergenic region sequence of strains MG1655, enterohemorrhagic EDL933, uropathogenic ECFT073 and EPEC T19-E2348/69 revealed that the number of extragenic highly repeated iap sequences corresponded to nine, four, two and none, respectively. These results show that the iap sequence-containing chromosomal ygcE-ygcF intergenic region is highly variable in E. coli. Copyright (c) 2007 S. Karger AG, Basel.

A Rapid Method of Genomic Array Analysis of Scaffold/Matrix Attachment Regions (S/MARs) Identifies a 2.5-Mb Region of Enhanced Scaffold/Matrix Attachment at a Human Neocentromere

PubMed Central

Sumer, Huseyin; Craig, Jeffrey M.; Sibson, Mandy; Choo, K.H. Andy

2003-01-01

Human neocentromeres are fully functional centromeres that arise at previously noncentromeric regions of the genome. We have tested a rapid procedure of genomic array analysis of chromosome scaffold/matrix attachment regions (S/MARs), involving the isolation of S/MAR DNA and hybridization of this DNA to a genomic BAC/PAC array. Using this procedure, we have defined a 2.5-Mb domain of S/MAR-enriched chromatin that fully encompasses a previously mapped centromere protein-A (CENP-A)-associated domain at a human neocentromere. We have independently verified this procedure using a previously established fluorescence in situ hybridization method on salt-treated metaphase chromosomes. In silico sequence analysis of the S/MAR-enriched and surrounding regions has revealed no outstanding sequence-related predisposition. This study defines the S/MAR-enriched domain of a higher eukaryotic centromere and provides a method that has broad application for the mapping of S/MAR attachment sites over large genomic regions or throughout a genome. PMID:12840048

HIV Transmission Networks in the San Diego–Tijuana Border Region

PubMed Central

Mehta, Sanjay R.; Wertheim, Joel O.; Brouwer, Kimberly C.; Wagner, Karla D.; Chaillon, Antoine; Strathdee, Steffanie; Patterson, Thomas L.; Rangel, Maria G.; Vargas, Mlenka; Murrell, Ben; Garfein, Richard; Little, Susan J.; Smith, Davey M.

2015-01-01

Background HIV sequence data can be used to reconstruct local transmission networks. Along international borders, like the San Diego–Tijuana region, understanding the dynamics of HIV transmission across reported risks, racial/ethnic groups, and geography can help direct effective prevention efforts on both sides of the border. Methods We gathered sociodemographic, geographic, clinical, and viral sequence data from HIV infected individuals participating in ten studies in the San Diego–Tijuana border region. Phylogenetic and network analysis was performed to infer putative relationships between HIV sequences. Correlates of identified clusters were evaluated and spatiotemporal relationships were explored using Bayesian phylogeographic analysis. Findings After quality filtering, 843 HIV sequences with associated demographic data and 263 background sequences from the region were analyzed, and 138 clusters were inferred (2–23 individuals). Overall, the rate of clustering did not differ by ethnicity, residence, or sex, but bisexuals were less likely to cluster than heterosexuals or men who have sex with men (p = 0.043), and individuals identifying as white (p ≤ 0.01) were more likely to cluster than other races. Clustering individuals were also 3.5 years younger than non-clustering individuals (p < 0.001). Although the sampled San Diego and Tijuana epidemics were phylogenetically compartmentalized, five clusters contained individuals residing on both sides of the border. Interpretation This study sampled ~ 7% of HIV infected individuals in the border region, and although the sampled networks on each side of the border were largely separate, there was evidence of persistent bidirectional cross-border transmissions that linked risk groups, thus highlighting the importance of the border region as a “melting pot” of risk groups. Funding NIH, VA, and Pendleton Foundation. PMID:26629540

HIV Transmission Networks in the San Diego-Tijuana Border Region.

PubMed

Mehta, Sanjay R; Wertheim, Joel O; Brouwer, Kimberly C; Wagner, Karla D; Chaillon, Antoine; Strathdee, Steffanie; Patterson, Thomas L; Rangel, Maria G; Vargas, Mlenka; Murrell, Ben; Garfein, Richard; Little, Susan J; Smith, Davey M

2015-10-01

HIV sequence data can be used to reconstruct local transmission networks. Along international borders, like the San Diego-Tijuana region, understanding the dynamics of HIV transmission across reported risks, racial/ethnic groups, and geography can help direct effective prevention efforts on both sides of the border. We gathered sociodemographic, geographic, clinical, and viral sequence data from HIV infected individuals participating in ten studies in the San Diego-Tijuana border region. Phylogenetic and network analysis was performed to infer putative relationships between HIV sequences. Correlates of identified clusters were evaluated and spatiotemporal relationships were explored using Bayesian phylogeographic analysis. After quality filtering, 843 HIV sequences with associated demographic data and 263 background sequences from the region were analyzed, and 138 clusters were inferred (2-23 individuals). Overall, the rate of clustering did not differ by ethnicity, residence, or sex, but bisexuals were less likely to cluster than heterosexuals or men who have sex with men (p = 0.043), and individuals identifying as white (p ≤ 0.01) were more likely to cluster than other races. Clustering individuals were also 3.5 years younger than non-clustering individuals (p < 0.001). Although the sampled San Diego and Tijuana epidemics were phylogenetically compartmentalized, five clusters contained individuals residing on both sides of the border. This study sampled ~ 7% of HIV infected individuals in the border region, and although the sampled networks on each side of the border were largely separate, there was evidence of persistent bidirectional cross-border transmissions that linked risk groups, thus highlighting the importance of the border region as a "melting pot" of risk groups. NIH, VA, and Pendleton Foundation.

Sequence of the amino-terminal region of rat liver ribosomal proteins S4, S6, S8, L6, L7a, L18, L27, L30, L37, L37a, and L39.

PubMed

Wittmann-Liebold, B; Geissler, A W; Lin, A; Wool, I G

1979-01-01

The sequence of the amino-terminal region of eleven rat liver ribosomal proteins--S4, S6, S8, L6, L7a, L18, L27, L30, L37a, and L39--was determined. The analysis confirmed the homogeneity of the proteins and suggests that they are unique, since no extensive common sequences were found. The N-terminal regions of the rat liver proteins were compared with amino acid sequences in Saccharomyces cerevisiae and in Escherichia coli ribosomal proteins. It seems likely that the proteins L37 from rat liver and Y55 from yeast ribosomes are homologous. It is possible that rat liver L7a or L37a or both are related to S cerevisiae Y44, although the similar sequences are at the amino-terminus of the rat liver proteins and in an internal region of Y44. A number of similarities in the sequences of rat liver and E coli ribosomal proteins have been found; however, it is not yet possible to say whether they connote a common ancestry.

Comparative structural analysis of Bru1 region homeologs in Saccharum spontaneum and S. officinarum

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

Zhang, Jisen; Sharma, Anupma; Yu, Qingyi

Here, sugarcane is a major sugar and biofuel crop, but genomic research and molecular breeding have lagged behind other major crops due to the complexity of auto-allopolyploid genomes. Sugarcane cultivars are frequently aneuploid with chromosome number ranging from 100 to 130, consisting of 70-80 % S. officinarum, 10-20 % S. spontaneum, and 10 % recombinants between these two species. Analysis of a genomic region in the progenitor autoploid genomes of sugarcane hybrid cultivars will reveal the nature and divergence of homologous chromosomes. As a result, to investigate the origin and evolution of haplotypes in the Bru1 genomic regions in sugarcanemore » cultivars, we identified two BAC clones from S. spontaneum and four from S. officinarum and compared to seven haplotype sequences from sugarcane hybrid R570. The results clarified the origin of seven homologous haplotypes in R570, four haplotypes originated from S. officinarum, two from S. spontaneum and one recombinant.. Retrotransposon insertions and sequences variations among the homologous haplotypes sequence divergence ranged from 18.2 % to 60.5 % with an average of 33. 7 %. Gene content and gene structure were relatively well conserved among the homologous haplotypes. Exon splitting occurred in haplotypes of the hybrid genome but not in its progenitor genomes. Tajima's D analysis revealed that S. spontaneum hapotypes in the Bru1 genomic regions were under strong directional selection. Numerous inversions, deletions, insertions and translocations were found between haplotypes within each genome. In conclusion, this is the first comparison among haplotypes of a modern sugarcane hybrid and its two progenitors. Tajima's D results emphasized the crucial role of this fungal disease resistance gene for enhancing the fitness of this species and indicating that the brown rust resistance gene in R570 is from S. spontaneum. Species-specific InDel, sequences similarity and phylogenetic analysis of homologous genes can be used for identifying the origin of S. spontaneum and S. officinarum haplotype in Saccharum hybrids. Comparison of exon splitting among the homologous haplotypes suggested that the genome rearrangements in Saccharum hybrids S. officinarum would be sufficient for proper genome assembly of this autopolyploid genome. Retrotransposon insertions and sequences variations among the homologous haplotypes sequence divergence may allow sequencing and assembling the autopolyploid Saccharum genomes and the auto-allopolyploid hybrid genomes using whole genome shotgun sequencing.« less

Comparative structural analysis of Bru1 region homeologs in Saccharum spontaneum and S. officinarum

DOE PAGES

Zhang, Jisen; Sharma, Anupma; Yu, Qingyi; ...

2016-06-10

Here, sugarcane is a major sugar and biofuel crop, but genomic research and molecular breeding have lagged behind other major crops due to the complexity of auto-allopolyploid genomes. Sugarcane cultivars are frequently aneuploid with chromosome number ranging from 100 to 130, consisting of 70-80 % S. officinarum, 10-20 % S. spontaneum, and 10 % recombinants between these two species. Analysis of a genomic region in the progenitor autoploid genomes of sugarcane hybrid cultivars will reveal the nature and divergence of homologous chromosomes. As a result, to investigate the origin and evolution of haplotypes in the Bru1 genomic regions in sugarcanemore » cultivars, we identified two BAC clones from S. spontaneum and four from S. officinarum and compared to seven haplotype sequences from sugarcane hybrid R570. The results clarified the origin of seven homologous haplotypes in R570, four haplotypes originated from S. officinarum, two from S. spontaneum and one recombinant.. Retrotransposon insertions and sequences variations among the homologous haplotypes sequence divergence ranged from 18.2 % to 60.5 % with an average of 33. 7 %. Gene content and gene structure were relatively well conserved among the homologous haplotypes. Exon splitting occurred in haplotypes of the hybrid genome but not in its progenitor genomes. Tajima's D analysis revealed that S. spontaneum hapotypes in the Bru1 genomic regions were under strong directional selection. Numerous inversions, deletions, insertions and translocations were found between haplotypes within each genome. In conclusion, this is the first comparison among haplotypes of a modern sugarcane hybrid and its two progenitors. Tajima's D results emphasized the crucial role of this fungal disease resistance gene for enhancing the fitness of this species and indicating that the brown rust resistance gene in R570 is from S. spontaneum. Species-specific InDel, sequences similarity and phylogenetic analysis of homologous genes can be used for identifying the origin of S. spontaneum and S. officinarum haplotype in Saccharum hybrids. Comparison of exon splitting among the homologous haplotypes suggested that the genome rearrangements in Saccharum hybrids S. officinarum would be sufficient for proper genome assembly of this autopolyploid genome. Retrotransposon insertions and sequences variations among the homologous haplotypes sequence divergence may allow sequencing and assembling the autopolyploid Saccharum genomes and the auto-allopolyploid hybrid genomes using whole genome shotgun sequencing.« less

DNA barcode analysis of butterfly species from Pakistan points towards regional endemism

PubMed Central

Ashfaq, Muhammad; Akhtar, Saleem; Khan, Arif M; Adamowicz, Sarah J; Hebert, Paul D N

2013-01-01

DNA barcodes were obtained for 81 butterfly species belonging to 52 genera from sites in north-central Pakistan to test the utility of barcoding for their identification and to gain a better understanding of regional barcode variation. These species represent 25% of the butterfly fauna of Pakistan and belong to five families, although the Nymphalidae were dominant, comprising 38% of the total specimens. Barcode analysis showed that maximum conspecific divergence was 1.6%, while there was 1.7–14.3% divergence from the nearest neighbour species. Barcode records for 55 species showed <2% sequence divergence to records in the Barcode of Life Data Systems (BOLD), but only 26 of these cases involved specimens from neighbouring India and Central Asia. Analysis revealed that most species showed little incremental sequence variation when specimens from other regions were considered, but a threefold increase was noted in a few cases. There was a clear gap between maximum intraspecific and minimum nearest neighbour distance for all 81 species. Neighbour-joining cluster analysis showed that members of each species formed a monophyletic cluster with strong bootstrap support. The barcode results revealed two provisional species that could not be clearly linked to known taxa, while 24 other species gained their first coverage. Future work should extend the barcode reference library to include all butterfly species from Pakistan as well as neighbouring countries to gain a better understanding of regional variation in barcode sequences in this topographically and climatically complex region. PMID:23789612

Comparative analysis on the structural features of the 5' flanking region of κ-casein genes from six different species

PubMed Central

Gerencsér, Ákos; Barta, Endre; Boa, Simon; Kastanis, Petros; Bösze, Zsuzsanna; Whitelaw, C Bruce A

2002-01-01

κ-casein plays an essential role in the formation, stabilisation and aggregation of milk micelles. Control of κ-casein expression reflects this essential role, although an understanding of the mechanisms involved lags behind that of the other milk protein genes. We determined the 5'-flanking sequences for the murine, rabbit and human κ-casein genes and compared them to the published ruminant sequences. The most conserved region was not the proximal promoter region but an approximately 400 bp long region centred 800 bp upstream of the TATA box. This region contained two highly conserved MGF/STAT5 sites with common spacing relative to each other. In this region, six conserved short stretches of similarity were also found which did not correspond to known transcription factor consensus sites. On the contrary to ruminant and human 5' regulatory sequences, the rabbit and murine 5'-flanking regions did not harbour any kind of repetitive elements. We generated a phylogenetic tree of the six species based on multiple alignment of the κ-casein sequences. This study identified conserved candidate transcriptional regulatory elements within the κ-casein gene promoter. PMID:11929628

Complete Genome Sequence of the Circulatory Foot-and-Mouth Disease Virus Serotype Asia1 in Bangladesh

PubMed Central

Ali, M. Rahmat; Alam, A. S. M. Rubayet Ul; Amin, M. Al; Ullah, Huzzat; Siddique, Mohammad Anwar; Momtaz, Samina; Sultana, Munawar

2017-01-01

ABSTRACT The complete genome sequence of foot-and-mouth disease virus (FMDV) serotype Asia1 isolated from Bangladesh is reported here. Genome analysis revealed amino acid substitutions in the VP1 antigenic region and deletions in both the 5′ and 3′ untranslated regions (UTRs) compared to the genome of the existing vaccine strain (GenBank accession no. AY304994). PMID:29074654

Molecular studies on larvae of Pseudoterranova parasite of Trichiurus lepturus Linnaeus, 1758 and Pomatomus saltatrix (Linnaeus, 1766) off Brazilian waters.

PubMed

Borges, Juliana N; Cunha, Luiz F G; Miranda, Daniele F; Monteiro-Neto, Cassiano; Santos, Cláudia P

2015-12-01

Pseudoterranova larvae parasitizing cutlassfish Trichiurus lepturus and bluefish Pomatomus saltatrix from Southwest Atlantic coast of Brazil were studied in this work by morphological, ultrastructural and molecular approaches. The genetic analysis were performed for the ITS2 intergenic region specific for Pseudoterranova decipiens, the partial 28S (LSU) of ribosomal DNA and the mtDNA cox-1 region. We obtained results for the 28S region and mtDNA cox-1 that was amplified using the polymerase chain reaction and sequenced to evaluate the phylogenetic relationships between sequences of this study and sequences from the GenBank. The morphological profile indicated that all the nine specimens collected from both fish were L3 larvae of Pseudoterranova sp. The genetic profile confirmed the generic level but due to the absence of similar sequences for adult parasites on GenBank for the regions amplifyied, it was not possible to identify them to the species level. The sequences obtained presented 89% of similarity with Pseudoterranova decipiens (28S sequences) and Contracaecum osculatum B (mtDNA cox-1). The low similarity allied to the fact that the amplification with the specific primer for P. decipiens didn't occur, lead us to conclude that our sequences don't belong to P. decipiens complex.

Classification of European Mtdnas from an Analysis of Three European Populations

PubMed Central

Torroni, A.; Huoponen, K.; Francalacci, P.; Petrozzi, M.; Morelli, L.; Scozzari, R.; Obinu, D.; Savontaus, M. L.; Wallace, D. C.

1996-01-01

Mitochondrial DNA (mtDNA) sequence variation was examined in Finns, Swedes and Tuscans by PCR amplification and restriction analysis. About 99% of the mtDNAs were subsumed within 10 mtDNA haplogroups (H, I, J, K, M, T, U, V, W, and X) suggesting that the identified haplogroups could encompass virtually all European mtDNAs. Because both hypervariable segments of the mtDNA control region were previously sequenced in the Tuscan samples, the mtDNA haplogroups and control region sequences could be compared. Using a combination of haplogroup-specific restriction site changes and control region nucleotide substitutions, the distribution of the haplogroups was surveyed through the published restriction site polymorphism and control region sequence data of Caucasoids. This supported the conclusion that most haplogroups observed in Europe are Caucasoid-specific, and that at least some of them occur at varying frequencies in different Caucasoid populations. The classification of almost all European mtDNA variation in a number of well defined haplogroups could provide additional insights about the origin and relationships of Caucasoid populations and the process of human colonization of Europe, and is valuable for the definition of the role played by mtDNA backgrounds in the expression of pathological mtDNA mutations PMID:8978068

Mitochondrial DNA variation of indigenous goats in Narok and Isiolo counties of Kenya.

PubMed

Kibegwa, F M; Githui, K E; Jung'a, J O; Badamana, M S; Nyamu, M N

2016-06-01

Phylogenetic relationships among and genetic variability within 60 goats from two different indigenous breeds in Narok and Isiolo counties in Kenya and 22 published goat samples were analysed using mitochondrial control region sequences. The results showed that there were 54 polymorphic sites in a 481-bp sequence and 29 haplotypes were determined. The mean haplotype diversity and nucleotide diversity were 0.981 ± 0.006 and 0.019 ± 0.001, respectively. The phylogenetic analysis in combination with goat haplogroup reference sequences from GenBank showed that all goat sequences were clustered into two haplogroups (A and G), of which haplogroup A was the commonest in the two populations. A very high percentage (99.90%) of the genetic variation was distributed within the regions, and a smaller percentage (0.10%) distributed among regions as revealed by the analysis of molecular variance (amova). This amova results showed that the divergence between regions was not statistically significant. We concluded that the high levels of intrapopulation diversity in Isiolo and Narok goats and the weak phylogeographic structuring suggested that there existed strong gene flow among goat populations probably caused by extensive transportation of goats in history. © 2015 Blackwell Verlag GmbH.

Characterization of Cer-1 cis-regulatory region during early Xenopus development.

PubMed

Silva, Ana Cristina; Filipe, Mário; Steinbeisser, Herbert; Belo, José António

2011-05-01

Cerberus-related molecules are well-known Wnt, Nodal, and BMP inhibitors that have been implicated in different processes including anterior–posterior patterning and left–right asymmetry. In both mouse and frog, two Cerberus-related genes have been isolated, mCer-1 and mCer-2, and Xcer and Xcoco, respectively. Until now, little is known about the mechanisms involved in their transcriptional regulation. Here, we report a heterologous analysis of the mouse Cerberus-1 gene upstream regulatory regions, responsible for its expression in the visceral endodermal cells. Our analysis showed that the consensus sequences for a TATA, CAAT, or GC boxes were absent but a TGTGG sequence was present at position -172 to -168 bp, relative to the ATG. Using a series of deletion constructs and transient expression in Xenopus embryos, we found that a fragment of 1.4 kb of Cer-1 promoter sequence could reproduce the endogenous expression pattern of Xenopus cerberus. A 0.7-kb mcer-1 upstream region was able to drive reporter expression to the involuting mesendodermal cells, while further deletions abolished reporter gene expression. Our results suggest that although no sequence similarity was found between mouse and Xenopus cerberus cis-regulatory regions, the signaling cascades regulating cerberus expression, during gastrulation, is conserved.

Skin Microbiome Surveys Are Strongly Influenced by Experimental Design.

PubMed

Meisel, Jacquelyn S; Hannigan, Geoffrey D; Tyldsley, Amanda S; SanMiguel, Adam J; Hodkinson, Brendan P; Zheng, Qi; Grice, Elizabeth A

2016-05-01

Culture-independent studies to characterize skin microbiota are increasingly common, due in part to affordable and accessible sequencing and analysis platforms. Compared to culture-based techniques, DNA sequencing of the bacterial 16S ribosomal RNA (rRNA) gene or whole metagenome shotgun (WMS) sequencing provides more precise microbial community characterizations. Most widely used protocols were developed to characterize microbiota of other habitats (i.e., gastrointestinal) and have not been systematically compared for their utility in skin microbiome surveys. Here we establish a resource for the cutaneous research community to guide experimental design in characterizing skin microbiota. We compare two widely sequenced regions of the 16S rRNA gene to WMS sequencing for recapitulating skin microbiome community composition, diversity, and genetic functional enrichment. We show that WMS sequencing most accurately recapitulates microbial communities, but sequencing of hypervariable regions 1-3 of the 16S rRNA gene provides highly similar results. Sequencing of hypervariable region 4 poorly captures skin commensal microbiota, especially Propionibacterium. WMS sequencing, which is resource and cost intensive, provides evidence of a community's functional potential; however, metagenome predictions based on 16S rRNA sequence tags closely approximate WMS genetic functional profiles. This study highlights the importance of experimental design for downstream results in skin microbiome surveys. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Skin microbiome surveys are strongly influenced by experimental design

PubMed Central

Meisel, Jacquelyn S.; Hannigan, Geoffrey D.; Tyldsley, Amanda S.; SanMiguel, Adam J.; Hodkinson, Brendan P.; Zheng, Qi; Grice, Elizabeth A.

2016-01-01

Culture-independent studies to characterize skin microbiota are increasingly common, due in part to affordable and accessible sequencing and analysis platforms. Compared to culture-based techniques, DNA sequencing of the bacterial 16S ribosomal RNA (rRNA) gene or whole metagenome shotgun (WMS) sequencing provide more precise microbial community characterizations. Most widely used protocols were developed to characterize microbiota of other habitats (i.e. gastrointestinal), and have not been systematically compared for their utility in skin microbiome surveys. Here we establish a resource for the cutaneous research community to guide experimental design in characterizing skin microbiota. We compare two widely sequenced regions of the 16S rRNA gene to WMS sequencing for recapitulating skin microbiome community composition, diversity, and genetic functional enrichment. We show that WMS sequencing most accurately recapitulates microbial communities, but sequencing of hypervariable regions 1-3 of the 16S rRNA gene provides highly similar results. Sequencing of hypervariable region 4 poorly captures skin commensal microbiota, especially Propionibacterium. WMS sequencing, which is resource- and cost-intensive, provides evidence of a community’s functional potential; however, metagenome predictions based on 16S rRNA sequence tags closely approximate WMS genetic functional profiles. This work highlights the importance of experimental design for downstream results in skin microbiome surveys. PMID:26829039

Sequence Ready Characterization of the Pericentromeric Region of 19p12

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

Evan E. Eichler

2006-08-31

Current mapping and sequencing strategies have been inadequate within the proximal portion of 19p12 due, in part, to the presence of a recently expanded ZNF (zinc-finger) gene family and the presence of large (25-50 kb) inverted beta-satellite repeat structures which bracket this tandemly duplicated gene family. The virtual of absence of classically defined “unique” sequence within the region has hampered efforts to identify and characterize a suitable minimal tiling path of clones which can be used as templates required for finished sequencing of the region. The goal of this proposal is to develop and implement a novel sequence-anchor strategy tomore » generate a contiguous BAC map of the most proximal portion of chromosome 19p12 for the purpose of complete sequence characterization. The target region will be an estimated 4.5 Mb of DNA extending from STS marker D19S450 (the beginning of the ZNF gene cluster) to the centromeric (alpha-satellite) junction of 19p11. The approach will entail 1) pre-selection of 19p12 BAC and cosmid clones (NIH approved library) utilizing both 19p12 -unique and 19p12-SPECIFIC repeat probes (Eichler et al., 1998); 2) the generation of a BAC/cosmid end-sequence map across the region with a density of one marker every 8kb; 3) the development of a second-generation of STS (sequence tagged sites) which will be used to identify and verify clonal overlap at the level of the sequence; 4) incorporation of these sequence-anchored overlapping clones into existing cosmid/BAC restriction maps developed at Livermore National Laboratory; and 5) validation of the organization of this region utilizing high-resolution FISH techniques (extended chromatin analysis) on monochromosomal 19 somatic cell hybrids and parental cell lines of source material. The data generated will be used in the selection of the most parsimonious tiling path of BAC clones to be sequenced as part of the JGI effort on chromosome 19 and should serve as a model for the sequence characterization of other difficult regions of the human genome« less

A comparative study of retrotransposons in the centromeric regions of A and B chromosomes of maize.

PubMed

Theuri, J; Phelps-Durr, T; Mathews, S; Birchler, J

2005-01-01

Bacterial Artificial Chromosomes (BACs) derived from the B chromosome, based on homology with the B specific sequence, were subcloned and sequenced. Analysis of DNA sequence data indicated the presence of 23 common retroelements, as well as novel sequences of B chromosome origin. Generally, where the same retrotransposon type was observed in both A and B chromosomes, there were more copies per unit of sequence in the B centromeric region (the major site of B repeat) than in the A centromere, except for Huck-1. Based on previous estimates of the age of the major burst of transposition into the maize genome, the oldest retrotransposons (Ji-6 and Tekay, approximately 5.0 and 5.2 million years ago, respectively) were found in the B centromere region only, while the next two oldest (Huck-1 and Opie-1) were found in both the A and B sequences. Phylogenetic analysis of Opie retroelements from both A and B centromeres indicated that some of the B Opie centromeric sequences share a more recent common ancestor with A Opie retroelements than they do with other B Opie centromeric sequences. These results imply that the supernumerary maize B chromosome has coexisted with the A chromosomes during that period of transposition. They also support the hypothesis that the B chromosome had its origins from A chromosome elements, or that alternative origins, such as being donated to the maize genome in a wide species cross, preceded six million years ago, because the spectrum of retrotransposons in the two chromosomes is quite similar.

A metagenomic viral discovery approach identifies potential zoonotic and novel mammalian viruses in Neoromicia bats within South Africa.

PubMed

Geldenhuys, Marike; Mortlock, Marinda; Weyer, Jacqueline; Bezuidt, Oliver; Seamark, Ernest C J; Kearney, Teresa; Gleasner, Cheryl; Erkkila, Tracy H; Cui, Helen; Markotter, Wanda

2018-01-01

Species within the Neoromicia bat genus are abundant and widely distributed in Africa. It is common for these insectivorous bats to roost in anthropogenic structures in urban regions. Additionally, Neoromicia capensis have previously been identified as potential hosts for Middle East respiratory syndrome (MERS)-related coronaviruses. This study aimed to ascertain the gastrointestinal virome of these bats, as viruses excreted in fecal material or which may be replicating in rectal or intestinal tissues have the greatest opportunities of coming into contact with other hosts. Samples were collected in five regions of South Africa over eight years. Initial virome composition was determined by viral metagenomic sequencing by pooling samples and enriching for viral particles. Libraries were sequenced on the Illumina MiSeq and NextSeq500 platforms, producing a combined 37 million reads. Bioinformatics analysis of the high throughput sequencing data detected the full genome of a novel species of the Circoviridae family, and also identified sequence data from the Adenoviridae, Coronaviridae, Herpesviridae, Parvoviridae, Papillomaviridae, Phenuiviridae, and Picornaviridae families. Metagenomic sequencing data was insufficient to determine the viral diversity of certain families due to the fragmented coverage of genomes and lack of suitable sequencing depth, as some viruses were detected from the analysis of reads-data only. Follow up conventional PCR assays targeting conserved gene regions for the Adenoviridae, Coronaviridae, and Herpesviridae families were used to confirm metagenomic data and generate additional sequences to determine genetic diversity. The complete coding genome of a MERS-related coronavirus was recovered with additional amplicon sequencing on the MiSeq platform. The new genome shared 97.2% overall nucleotide identity to a previous Neoromicia-associated MERS-related virus, also from South Africa. Conventional PCR analysis detected diverse adenovirus and herpesvirus sequences that were widespread throughout Neoromicia populations in South Africa. Furthermore, similar adenovirus sequences were detected within these populations throughout several years. With the exception of the coronaviruses, the study represents the first report of sequence data from several viral families within a Southern African insectivorous bat genus; highlighting the need for continued investigations in this regard.

A metagenomic viral discovery approach identifies potential zoonotic and novel mammalian viruses in Neoromicia bats within South Africa

PubMed Central

Geldenhuys, Marike; Mortlock, Marinda; Weyer, Jacqueline; Bezuidt, Oliver; Seamark, Ernest C. J.; Kearney, Teresa; Gleasner, Cheryl; Erkkila, Tracy H.; Cui, Helen; Markotter, Wanda

2018-01-01

Species within the Neoromicia bat genus are abundant and widely distributed in Africa. It is common for these insectivorous bats to roost in anthropogenic structures in urban regions. Additionally, Neoromicia capensis have previously been identified as potential hosts for Middle East respiratory syndrome (MERS)-related coronaviruses. This study aimed to ascertain the gastrointestinal virome of these bats, as viruses excreted in fecal material or which may be replicating in rectal or intestinal tissues have the greatest opportunities of coming into contact with other hosts. Samples were collected in five regions of South Africa over eight years. Initial virome composition was determined by viral metagenomic sequencing by pooling samples and enriching for viral particles. Libraries were sequenced on the Illumina MiSeq and NextSeq500 platforms, producing a combined 37 million reads. Bioinformatics analysis of the high throughput sequencing data detected the full genome of a novel species of the Circoviridae family, and also identified sequence data from the Adenoviridae, Coronaviridae, Herpesviridae, Parvoviridae, Papillomaviridae, Phenuiviridae, and Picornaviridae families. Metagenomic sequencing data was insufficient to determine the viral diversity of certain families due to the fragmented coverage of genomes and lack of suitable sequencing depth, as some viruses were detected from the analysis of reads-data only. Follow up conventional PCR assays targeting conserved gene regions for the Adenoviridae, Coronaviridae, and Herpesviridae families were used to confirm metagenomic data and generate additional sequences to determine genetic diversity. The complete coding genome of a MERS-related coronavirus was recovered with additional amplicon sequencing on the MiSeq platform. The new genome shared 97.2% overall nucleotide identity to a previous Neoromicia-associated MERS-related virus, also from South Africa. Conventional PCR analysis detected diverse adenovirus and herpesvirus sequences that were widespread throughout Neoromicia populations in South Africa. Furthermore, similar adenovirus sequences were detected within these populations throughout several years. With the exception of the coronaviruses, the study represents the first report of sequence data from several viral families within a Southern African insectivorous bat genus; highlighting the need for continued investigations in this regard. PMID:29579103

Non-biological synthetic spike-in controls and the AMPtk software pipeline improve mycobiome data

Treesearch

Jonathan M. Palmer; Michelle A. Jusino; Mark T. Banik; Daniel L. Lindner

2018-01-01

High-throughput amplicon sequencing (HTAS) of conserved DNA regions is a powerful technique to characterize microbial communities. Recently, spike-in mock communities have been used to measure accuracy of sequencing platforms and data analysis pipelines. To assess the ability of sequencing platforms and data processing pipelines using fungal internal transcribed spacer...

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

Kerr, J.M.; Fisher, L.W.; Termine, J.D.

The authors have isolated and partially sequenced the human bone sialoprotein gene (IBSP). IBSP has been sublocalized by in situ hybridization to chromosome 4q38-q31 and is composed of six small exons (51 to 159 bp) and 1 large exon ([approximately]2.6 kb). The intron/exon junctions defined by sequence analysis are of class O, retaining an intact coding triplet. Sequence analysis of the 5[prime] upstream region revealed a TATAA (nucleotides -30 to-25 from the transcriptional start point) and a CCAAT (nucleotides -56 to-52) box, both in the reverse orientation. Intron 1 contains interesting structural elements composed of polypyrimidine repeats followed by amore » poly(AC)[sub n] tract. Both types of structural elements have been detected in promoter regions of other genes and have been implicated in transcriptional regulation. Several differences between the previously published cDNA sequence and the authors' sequence have been identified, most of which are contained within the untranslated exon 1. Three base revisions in the coding region include a G to T (Gly to Val, amino acid 195), T to C (Val to Ala, amino acid 268), and T to A (Glu to Asp, amino acid 270). In conclusion, the genomic organization and potential regulatory elements of human IBSP have been elucidated. 42 refs., 4 figs., 1 tab.« less

The campaign to DNA barcode all fishes, FISH-BOL.

PubMed

Ward, R D; Hanner, R; Hebert, P D N

2009-02-01

FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.

Complexity: an internet resource for analysis of DNA sequence complexity

PubMed Central

Orlov, Y. L.; Potapov, V. N.

2004-01-01

The search for DNA regions with low complexity is one of the pivotal tasks of modern structural analysis of complete genomes. The low complexity may be preconditioned by strong inequality in nucleotide content (biased composition), by tandem or dispersed repeats or by palindrome-hairpin structures, as well as by a combination of all these factors. Several numerical measures of textual complexity, including combinatorial and linguistic ones, together with complexity estimation using a modified Lempel–Ziv algorithm, have been implemented in a software tool called ‘Complexity’ (http://wwwmgs.bionet.nsc.ru/mgs/programs/low_complexity/). The software enables a user to search for low-complexity regions in long sequences, e.g. complete bacterial genomes or eukaryotic chromosomes. In addition, it estimates the complexity of groups of aligned sequences. PMID:15215465

A family of long intergenic non-coding RNA genes in human chromosomal region 22q11.2 carry a DNA translocation breakpoint/AT-rich sequence

PubMed Central

2018-01-01

FAM230C, a long intergenic non-coding RNA (lincRNA) gene in human chromosome 13 (chr13) is a member of lincRNA genes termed family with sequence similarity 230. An analysis using bioinformatics search tools and alignment programs was undertaken to determine properties of FAM230C and its related genes. Results reveal that the DNA translocation element, the Translocation Breakpoint Type A (TBTA) sequence, which consists of satellite DNA, Alu elements, and AT-rich sequences is embedded in the FAM230C gene. Eight lincRNA genes related to FAM230C also carry the TBTA sequences. These genes were formed from a large segment of the 3’ half of the FAM230C sequence duplicated in chr22, and are specifically in regions of low copy repeats (LCR22)s, in or close to the 22q.11.2 region. 22q11.2 is a chromosomal segment that undergoes a high rate of DNA translocation and is prone to genetic deletions. FAM230C-related genes present in other chromosomes do not carry the TBTA motif and were formed from the 5’ half region of the FAM230C sequence. These findings identify a high specificity in lincRNA gene formation by gene sequence duplication in different chromosomes. PMID:29668722

Epistasis analysis for quantitative traits by functional regression model.

PubMed

Zhang, Futao; Boerwinkle, Eric; Xiong, Momiao

2014-06-01

The critical barrier in interaction analysis for rare variants is that most traditional statistical methods for testing interactions were originally designed for testing the interaction between common variants and are difficult to apply to rare variants because of their prohibitive computational time and poor ability. The great challenges for successful detection of interactions with next-generation sequencing (NGS) data are (1) lack of methods for interaction analysis with rare variants, (2) severe multiple testing, and (3) time-consuming computations. To meet these challenges, we shift the paradigm of interaction analysis between two loci to interaction analysis between two sets of loci or genomic regions and collectively test interactions between all possible pairs of SNPs within two genomic regions. In other words, we take a genome region as a basic unit of interaction analysis and use high-dimensional data reduction and functional data analysis techniques to develop a novel functional regression model to collectively test interactions between all possible pairs of single nucleotide polymorphisms (SNPs) within two genome regions. By intensive simulations, we demonstrate that the functional regression models for interaction analysis of the quantitative trait have the correct type 1 error rates and a much better ability to detect interactions than the current pairwise interaction analysis. The proposed method was applied to exome sequence data from the NHLBI's Exome Sequencing Project (ESP) and CHARGE-S study. We discovered 27 pairs of genes showing significant interactions after applying the Bonferroni correction (P-values < 4.58 × 10(-10)) in the ESP, and 11 were replicated in the CHARGE-S study. © 2014 Zhang et al.; Published by Cold Spring Harbor Laboratory Press.

Mapping analysis of scaffold/matrix attachment regions (s/MARs) from two different mammalian cell lines

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

Pilus, Nur Shazwani Mohd; Ahmad, Azrin; Yusof, Nurul Yuziana Mohd

Scaffold/matrix attachment regions (S/MARs) are potential element that can be integrated into expression vector to increase expression of recombinant protein. Many studies on S/MAR have been done but none has revealed the distribution of S/MAR in a genome. In this study, we have isolated S/MAR sequences from HEK293 and Chinese hamster ovary cell lines (CHO DG44) using two different methods utilizing 2 M NaCl and lithium-3,5-diiodosalicylate (LIS). The isolated S/MARs were sequenced using Next Generation Sequencing (NGS) platform. Based on reference mapping analysis against human genome database, a total of 8,994,856 and 8,412,672 contigs of S/MAR sequences were retrieved frommore » 2M NaCl and LIS extraction of HEK293 respectively. On the other hand, reference mapping analysis of S/MAR derived from CHO DG44 against our own CHO DG44 database have generated a total of 7,204,348 and 4,672,913 contigs from 2 M NaCl and LIS extraction method respectively.« less

Mapping the pericentric heterochromatin by comparative genomic hybridization analysis and chromosome deletions in Drosophila melanogaster

PubMed Central

He, Bing; Caudy, Amy; Parsons, Lance; Rosebrock, Adam; Pane, Attilio; Raj, Sandeep; Wieschaus, Eric

2012-01-01

Heterochromatin represents a significant portion of eukaryotic genomes and has essential structural and regulatory functions. Its molecular organization is largely unknown due to difficulties in sequencing through and assembling repetitive sequences enriched in the heterochromatin. Here we developed a novel strategy using chromosomal rearrangements and embryonic phenotypes to position unmapped Drosophila melanogaster heterochromatic sequence to specific chromosomal regions. By excluding sequences that can be mapped to the assembled euchromatic arms, we identified sequences that are specific to heterochromatin and used them to design heterochromatin specific probes (“H-probes”) for microarray. By comparative genomic hybridization (CGH) analyses of embryos deficient for each chromosome or chromosome arm, we were able to map most of our H-probes to specific chromosome arms. We also positioned sequences mapped to the second and X chromosomes to finer intervals by analyzing smaller deletions with breakpoints in heterochromatin. Using this approach, we were able to map >40% (13.9 Mb) of the previously unmapped heterochromatin sequences assembled by the whole-genome sequencing effort on arm U and arm Uextra to specific locations. We also identified and mapped 110 kb of novel heterochromatic sequences. Subsequent analyses revealed that sequences located within different heterochromatic regions have distinct properties, such as sequence composition, degree of repetitiveness, and level of underreplication in polytenized tissues. Surprisingly, although heterochromatin is generally considered to be transcriptionally silent, we detected region-specific temporal patterns of transcription in heterochromatin during oogenesis and early embryonic development. Our study provides a useful approach to elucidate the molecular organization and function of heterochromatin and reveals region-specific variation of heterochromatin. PMID:22745230

Segmental duplications and evolutionary plasticity at tumor chromosome break-prone regions

PubMed Central

Darai-Ramqvist, Eva; Sandlund, Agneta; Müller, Stefan; Klein, George; Imreh, Stefan; Kost-Alimova, Maria

2008-01-01

We have previously found that the borders of evolutionarily conserved chromosomal regions often coincide with tumor-associated deletion breakpoints within human 3p12-p22. Moreover, a detailed analysis of a frequently deleted region at 3p21.3 (CER1) showed associations between tumor breaks and gene duplications. We now report on the analysis of 54 chromosome 3 breaks by multipoint FISH (mpFISH) in 10 carcinoma-derived cell lines. The centromeric region was broken in five lines. In lines with highly complex karyotypes, breaks were clustered near known fragile sites, FRA3B, FRA3C, and FRA3D (three lines), and in two other regions: 3p12.3-p13 (∼75 Mb position) and 3q21.3-q22.1 (∼130 Mb position) (six lines). All locations are shown based on NCBI Build 36.1 human genome sequence. The last two regions participated in three of four chromosome 3 inversions during primate evolution. Regions at 75, 127, and 131 Mb positions carry a large (∼250 kb) segmental duplication (tumor break-prone segmental duplication [TBSD]). TBSD homologous sequences were found at 15 sites on different chromosomes. They were located within bands frequently involved in carcinoma-associated breaks. Thirteen of them have been involved in inversions during primate evolution; 10 were reused by breaks during mammalian evolution; 14 showed copy number polymorphism in man. TBSD sites showed an increase in satellite repeats, retrotransposed sequences, and other segmental duplications. We propose that the instability of these sites stems from specific organization of the chromosomal region, associated with location at a boundary between different CG-content isochores and with the presence of TBSDs and “instability elements,” including satellite repeats and retroviral sequences. PMID:18230801

Segmental duplications and evolutionary plasticity at tumor chromosome break-prone regions.

PubMed

Darai-Ramqvist, Eva; Sandlund, Agneta; Müller, Stefan; Klein, George; Imreh, Stefan; Kost-Alimova, Maria

2008-03-01

We have previously found that the borders of evolutionarily conserved chromosomal regions often coincide with tumor-associated deletion breakpoints within human 3p12-p22. Moreover, a detailed analysis of a frequently deleted region at 3p21.3 (CER1) showed associations between tumor breaks and gene duplications. We now report on the analysis of 54 chromosome 3 breaks by multipoint FISH (mpFISH) in 10 carcinoma-derived cell lines. The centromeric region was broken in five lines. In lines with highly complex karyotypes, breaks were clustered near known fragile sites, FRA3B, FRA3C, and FRA3D (three lines), and in two other regions: 3p12.3-p13 ( approximately 75 Mb position) and 3q21.3-q22.1 ( approximately 130 Mb position) (six lines). All locations are shown based on NCBI Build 36.1 human genome sequence. The last two regions participated in three of four chromosome 3 inversions during primate evolution. Regions at 75, 127, and 131 Mb positions carry a large ( approximately 250 kb) segmental duplication (tumor break-prone segmental duplication [TBSD]). TBSD homologous sequences were found at 15 sites on different chromosomes. They were located within bands frequently involved in carcinoma-associated breaks. Thirteen of them have been involved in inversions during primate evolution; 10 were reused by breaks during mammalian evolution; 14 showed copy number polymorphism in man. TBSD sites showed an increase in satellite repeats, retrotransposed sequences, and other segmental duplications. We propose that the instability of these sites stems from specific organization of the chromosomal region, associated with location at a boundary between different CG-content isochores and with the presence of TBSDs and "instability elements," including satellite repeats and retroviral sequences.

Identification of a cis-Regulatory Element Involved in Phytochrome Down-Regulated Expression of the Pea Small GTPase Gene pra21

PubMed Central

Inaba, Takehito; Nagano, Yukio; Sakakibara, Toshihiro; Sasaki, Yukiko

1999-01-01

The pra2 gene encodes a pea (Pisum sativum) small GTPase belonging to the YPT/rab family, and its expression is down-regulated by light, mediated by phytochrome. We have isolated and characterized a genomic clone of this gene and constructed a fusion DNA of its 5′-upstream region in front of the gene for firefly luciferase. Using this construct in a transient assay, we determined a pra2 cis-regulatory region sufficient to direct the light down-regulation of the luciferase reporter gene. Both 5′- and internal deletion analyses revealed that the 93-bp sequence between −734 and −642 from the transcriptional start site was important for phytochrome down-regulation. Gain-of-function analysis showed that this 93-bp region could confer light down-regulation when fused to the cauliflower mosaic virus 35S promoter. Furthermore, linker-scanning analysis showed that a 12-bp sequence within the 93-bp region mediated phytochrome down-regulation. Gel-retardation analysis showed the presence of a nuclear factor that was specifically bound to the 12-bp sequence in vitro. These results indicate that this element is a cis-regulatory element involved in phytochrome down-regulated expression. PMID:10364400

Phylogenetic analysis of phenotypically characterized Cryptococcus laurentii isolates reveals high frequency of cryptic species.

PubMed

Ferreira-Paim, Kennio; Ferreira, Thatiana Bragine; Andrade-Silva, Leonardo; Mora, Delio Jose; Springer, Deborah J; Heitman, Joseph; Fonseca, Fernanda Machado; Matos, Dulcilena; Melhem, Márcia Souza Carvalho; Silva-Vergara, Mario León

2014-01-01

Although Cryptococcus laurentii has been considered saprophytic and its taxonomy is still being described, several cases of human infections have already reported. This study aimed to evaluate molecular aspects of C. laurentii isolates from Brazil, Botswana, Canada, and the United States. In this study, 100 phenotypically identified C. laurentii isolates were evaluated by sequencing the 18S nuclear ribosomal small subunit rRNA gene (18S-SSU), D1/D2 region of 28S nuclear ribosomal large subunit rRNA gene (28S-LSU), and the internal transcribed spacer (ITS) of the ribosomal region. BLAST searches using 550-bp, 650-bp, and 550-bp sequenced amplicons obtained from the 18S-SSU, 28S-LSU, and the ITS region led to the identification of 75 C. laurentii strains that shared 99-100% identity with C. laurentii CBS 139. A total of nine isolates shared 99% identity with both Bullera sp. VY-68 and C. laurentii RY1. One isolate shared 99% identity with Cryptococcus rajasthanensis CBS 10406, and eight isolates shared 100% identity with Cryptococcus sp. APSS 862 according to the 28S-LSU and ITS regions and designated as Cryptococcus aspenensis sp. nov. (CBS 13867). While 16 isolates shared 99% identity with Cryptococcus flavescens CBS 942 according to the 18S-SSU sequence, only six were confirmed using the 28S-LSU and ITS region sequences. The remaining 10 shared 99% identity with Cryptococcus terrestris CBS 10810, which was recently described in Brazil. Through concatenated sequence analyses, seven sequence types in C. laurentii, three in C. flavescens, one in C. terrestris, and one in the C. aspenensis sp. nov. were identified. Sequencing permitted the characterization of 75% of the environmental C. laurentii isolates from different geographical areas and the identification of seven haplotypes of this species. Among sequenced regions, the increased variability of the ITS region in comparison to the 18S-SSU and 28S-LSU regions reinforces its applicability as a DNA barcode.

Complete genome sequencing and phylogenetic analysis of dengue type 1 virus isolated from Jeddah, Saudi Arabia.

PubMed

Azhar, Esam I; Hashem, Anwar M; El-Kafrawy, Sherif A; Abol-Ela, Said; Abd-Alla, Adly M M; Sohrab, Sayed Sartaj; Farraj, Suha A; Othman, Norah A; Ben-Helaby, Huda G; Ashshi, Ahmed; Madani, Tariq A; Jamjoom, Ghazi

2015-01-16

Dengue viruses (DENVs) are mosquito-borne viruses which can cause disease ranging from mild fever to severe dengue infection. These viruses are endemic in several tropical and subtropical regions. Multiple outbreaks of DENV serotypes 1, 2 and 3 (DENV-1, DENV-2 and DENV-3) have been reported from the western region in Saudi Arabia since 1994. Strains from at least two genotypes of DENV-1 (Asia and America/Africa genotypes) have been circulating in western Saudi Arabia until 2006. However, all previous studies reported from Saudi Arabia were based on partial sequencing data of the envelope (E) gene without any reports of full genome sequences for any DENV serotypes circulating in Saudi Arabia. Here, we report the isolation and the first complete genome sequence of a DENV-1 strain (DENV-1-Jeddah-1-2011) isolated from a patient from Jeddah, Saudi Arabia in 2011. Whole genome sequence alignment and phylogenetic analysis showed high similarity between DENV-1-Jeddah-1-2011 strain and D1/H/IMTSSA/98/606 isolate (Asian genotype) reported from Djibouti in 1998. Further analysis of the full envelope gene revealed a close relationship between DENV-1-Jeddah-1-2011 strain and isolates reported between 2004-2006 from Jeddah as well as recent isolates from Somalia, suggesting the widespread of the Asian genotype in this region. These data suggest that strains belonging to the Asian genotype might have been introduced into Saudi Arabia long before 2004 most probably by African pilgrims and continued to circulate in western Saudi Arabia at least until 2011. Most importantly, these results indicate that pilgrims from dengue endemic regions can play an important role in the spread of new DENVs in Saudi Arabia and the rest of the world. Therefore, availability of complete genome sequences would serve as a reference for future epidemiological studies of DENV-1 viruses.

PredictProtein—an open resource for online prediction of protein structural and functional features

PubMed Central

Yachdav, Guy; Kloppmann, Edda; Kajan, Laszlo; Hecht, Maximilian; Goldberg, Tatyana; Hamp, Tobias; Hönigschmid, Peter; Schafferhans, Andrea; Roos, Manfred; Bernhofer, Michael; Richter, Lothar; Ashkenazy, Haim; Punta, Marco; Schlessinger, Avner; Bromberg, Yana; Schneider, Reinhard; Vriend, Gerrit; Sander, Chris; Ben-Tal, Nir; Rost, Burkhard

2014-01-01

PredictProtein is a meta-service for sequence analysis that has been predicting structural and functional features of proteins since 1992. Queried with a protein sequence it returns: multiple sequence alignments, predicted aspects of structure (secondary structure, solvent accessibility, transmembrane helices (TMSEG) and strands, coiled-coil regions, disulfide bonds and disordered regions) and function. The service incorporates analysis methods for the identification of functional regions (ConSurf), homology-based inference of Gene Ontology terms (metastudent), comprehensive subcellular localization prediction (LocTree3), protein–protein binding sites (ISIS2), protein–polynucleotide binding sites (SomeNA) and predictions of the effect of point mutations (non-synonymous SNPs) on protein function (SNAP2). Our goal has always been to develop a system optimized to meet the demands of experimentalists not highly experienced in bioinformatics. To this end, the PredictProtein results are presented as both text and a series of intuitive, interactive and visually appealing figures. The web server and sources are available at http://ppopen.rostlab.org. PMID:24799431

Modified midi- and mini-multiplex PCR systems for mitochondrial DNA control region sequence analysis in degraded samples.

PubMed

Kim, Na Young; Lee, Hwan Young; Park, Sun Joo; Yang, Woo Ick; Shin, Kyoung-Jin

2013-05-01

Two multiplex polymerase chain reaction (PCR) systems (Midiplex and Miniplex) were developed for the amplification of the mitochondrial DNA (mtDNA) control region, and the efficiencies of the multiplexes for amplifying degraded DNA were validated using old skeletal remains. The Midiplex system consisted of two multiplex PCRs to amplify six overlapping amplicons ranging in length from 227 to 267 bp. The Miniplex system consisted of three multiplex PCRs to amplify 10 overlapping short amplicons ranging in length from 142 to 185 bp. Most mtDNA control region sequences of several 60-year-old and 400-500-year-old skeletal remains were successfully obtained using both PCR systems and consistent with those previously obtained by monoplex amplification. The multiplex system consisting of smaller amplicons is effective for mtDNA sequence analyses of ancient and forensic degraded samples, saving time, cost, and the amount of DNA sample consumed during analysis. © 2013 American Academy of Forensic Sciences.

Intraspecific Variation and Phylogenetic Relationships Are Revealed by ITS1 Secondary Structure Analysis and Single-Nucleotide Polymorphism in Ganoderma lucidum

PubMed Central

Pei, Haisheng; Chen, Zhou; Tan, Xiaoyan; Hu, Jing; Yang, Bin; Sun, Junshe

2017-01-01

Ganoderma lucidum is a typical polypore fungus used for traditional Chinese medical purposes. The taxonomic delimitation of Ganoderma lucidum is still debated. In this study, we sequenced seven internal transcribed spacer (ITS) sequences of Ganoderma lucidum strains and annotated the ITS1 and ITS2 regions. Phylogenetic analysis of ITS1 differentiated the strains into three geographic groups. Groups 1–3 were originated from Europe, tropical Asia, and eastern Asia, respectively. While ITS2 could only differentiate the strains into two groups in which Group 2 originated from tropical Asia gathered with Groups 1 and 3 originated from Europe and eastern Asia. By determining the secondary structures of the ITS1 sequences, these three groups exhibited similar structures with a conserved central core and differed helices. While compared to Group 2, Groups 1 and 3 of ITS2 sequences shared similar structures with the difference in helix 4. Large-scale evaluation of ITS1 and ITS2 both exhibited that the majority of subgroups in the same group shared the similar structures. Further Weblogo analysis of ITS1 sequences revealed two main variable regions located in helix 2 in which C/T or A/G substitutions frequently occurred and ITS1 exhibited more nucleotide variances compared to ITS2. ITS1 multi-alignment of seven spawn strains and culture tests indicated that a single-nucleotide polymorphism (SNP) site at position 180 correlated with strain antagonism. The HZ, TK and 203 fusion strains of Ganoderma lucidum had a T at position 180, whereas other strains exhibiting antagonism, including DB, RB, JQ, and YS, had a C. Taken together, compared to ITS2 region, ITS1 region could differentiated Ganoderma lucidum into three geographic originations based on phylogenetic analysis and secondary structure prediction. Besides, a SNP in ITS 1 could delineate Ganoderma lucidum strains at the intraspecific level. These findings will be implemented to improve species quality control in the Ganoderma industry. PMID:28056060

Intraspecific Variation and Phylogenetic Relationships Are Revealed by ITS1 Secondary Structure Analysis and Single-Nucleotide Polymorphism in Ganoderma lucidum.

PubMed

Zhang, Xiuqing; Xu, Zhangyang; Pei, Haisheng; Chen, Zhou; Tan, Xiaoyan; Hu, Jing; Yang, Bin; Sun, Junshe

2017-01-01

Ganoderma lucidum is a typical polypore fungus used for traditional Chinese medical purposes. The taxonomic delimitation of Ganoderma lucidum is still debated. In this study, we sequenced seven internal transcribed spacer (ITS) sequences of Ganoderma lucidum strains and annotated the ITS1 and ITS2 regions. Phylogenetic analysis of ITS1 differentiated the strains into three geographic groups. Groups 1-3 were originated from Europe, tropical Asia, and eastern Asia, respectively. While ITS2 could only differentiate the strains into two groups in which Group 2 originated from tropical Asia gathered with Groups 1 and 3 originated from Europe and eastern Asia. By determining the secondary structures of the ITS1 sequences, these three groups exhibited similar structures with a conserved central core and differed helices. While compared to Group 2, Groups 1 and 3 of ITS2 sequences shared similar structures with the difference in helix 4. Large-scale evaluation of ITS1 and ITS2 both exhibited that the majority of subgroups in the same group shared the similar structures. Further Weblogo analysis of ITS1 sequences revealed two main variable regions located in helix 2 in which C/T or A/G substitutions frequently occurred and ITS1 exhibited more nucleotide variances compared to ITS2. ITS1 multi-alignment of seven spawn strains and culture tests indicated that a single-nucleotide polymorphism (SNP) site at position 180 correlated with strain antagonism. The HZ, TK and 203 fusion strains of Ganoderma lucidum had a T at position 180, whereas other strains exhibiting antagonism, including DB, RB, JQ, and YS, had a C. Taken together, compared to ITS2 region, ITS1 region could differentiated Ganoderma lucidum into three geographic originations based on phylogenetic analysis and secondary structure prediction. Besides, a SNP in ITS 1 could delineate Ganoderma lucidum strains at the intraspecific level. These findings will be implemented to improve species quality control in the Ganoderma industry.

Intragenomic sequence variation at the ITS1 - ITS2 region and at the 18S and 28S nuclear ribosomal DNA genes of the New Zealand mud snail, Potamopyrgus antipodarum (Hydrobiidae: mollusca)

USGS Publications Warehouse

Hoy, Marshal S.; Rodriguez, Rusty J.

2013-01-01

Molecular genetic analysis was conducted on two populations of the invasive non-native New Zealand mud snail (Potamopyrgus antipodarum), one from a freshwater ecosystem in Devil's Lake (Oregon, USA) and the other from an ecosystem of higher salinity in the Columbia River estuary (Hammond Harbor, Oregon, USA). To elucidate potential genetic differences between the two populations, three segments of nuclear ribosomal DNA (rDNA), the ITS1-ITS2 regions and the 18S and 28S rDNA genes were cloned and sequenced. Variant sequences within each individual were found in all three rDNA segments. Folding models were utilized for secondary structure analysis and results indicated that there were many sequences which contained structure-altering polymorphisms, which suggests they could be nonfunctional pseudogenes. In addition, analysis of molecular variance (AMOVA) was used for hierarchical analysis of genetic variance to estimate variation within and among populations and within individuals. AMOVA revealed significant variation in the ITS region between the populations and among clones within individuals, while in the 5.8S rDNA significant variation was revealed among individuals within the two populations. High levels of intragenomic variation were found in the ITS regions, which are known to be highly variable in many organisms. More interestingly, intragenomic variation was also found in the 18S and 28S rDNA, which has rarely been observed in animals and is so far unreported in Mollusca. We postulate that in these P. antipodarum populations the effects of concerted evolution are diminished due to the fact that not all of the rDNA genes in their polyploid genome should be essential for sustaining cellular function. This could lead to a lessening of selection pressures, allowing mutations to accumulate in some copies, changing them into variant sequences.                   

Analysis of HIV-1 intersubtype recombination breakpoints suggests region with high pairing probability may be a more fundamental factor than sequence similarity affecting HIV-1 recombination.

PubMed

Jia, Lei; Li, Lin; Gui, Tao; Liu, Siyang; Li, Hanping; Han, Jingwan; Guo, Wei; Liu, Yongjian; Li, Jingyun

2016-09-21

With increasing data on HIV-1, a more relevant molecular model describing mechanism details of HIV-1 genetic recombination usually requires upgrades. Currently an incomplete structural understanding of the copy choice mechanism along with several other issues in the field that lack elucidation led us to perform an analysis of the correlation between breakpoint distributions and (1) the probability of base pairing, and (2) intersubtype genetic similarity to further explore structural mechanisms. Near full length sequences of URFs from Asia, Europe, and Africa (one sequence/patient), and representative sequences of worldwide CRFs were retrieved from the Los Alamos HIV database. Their recombination patterns were analyzed by jpHMM in detail. Then the relationships between breakpoint distributions and (1) the probability of base pairing, and (2) intersubtype genetic similarities were investigated. Pearson correlation test showed that all URF groups and the CRF group exhibit the same breakpoint distribution pattern. Additionally, the Wilcoxon two-sample test indicated a significant and inexplicable limitation of recombination in regions with high pairing probability. These regions have been found to be strongly conserved across distinct biological states (i.e., strong intersubtype similarity), and genetic similarity has been determined to be a very important factor promoting recombination. Thus, the results revealed an unexpected disagreement between intersubtype similarity and breakpoint distribution, which were further confirmed by genetic similarity analysis. Our analysis reveals a critical conflict between results from natural HIV-1 isolates and those from HIV-1-based assay vectors in which genetic similarity has been shown to be a very critical factor promoting recombination. These results indicate the region with high-pairing probabilities may be a more fundamental factor affecting HIV-1 recombination than sequence similarity in natural HIV-1 infections. Our findings will be relevant in furthering the understanding of HIV-1 recombination mechanisms.

Genome Sequences of Akhmeta Virus, an Early Divergent Old World Orthopoxvirus.

PubMed

Gao, Jinxin; Gigante, Crystal; Khmaladze, Ekaterine; Liu, Pengbo; Tang, Shiyuyun; Wilkins, Kimberly; Zhao, Kun; Davidson, Whitni; Nakazawa, Yoshinori; Maghlakelidze, Giorgi; Geleishvili, Marika; Kokhreidze, Maka; Carroll, Darin S; Emerson, Ginny; Li, Yu

2018-05-12

Annotated whole genome sequences of three isolates of the Akhmeta virus (AKMV), a novel species of orthopoxvirus (OPXV), isolated from the Akhmeta and Vani regions of the country Georgia, are presented and discussed. The AKMV genome is similar in genomic content and structure to that of the cowpox virus (CPXV), but a lower sequence identity was found between AKMV and Old World OPXVs than between other known species of Old World OPXVs. Phylogenetic analysis showed that AKMV diverged prior to other Old World OPXV. AKMV isolates formed a monophyletic clade in the OPXV phylogeny, yet the sequence variability between AKMV isolates was higher than between the monkeypox virus strains in the Congo basin and West Africa. An AKMV isolate from Vani contained approximately six kb sequence in the left terminal region that shared a higher similarity with CPXV than with other AKMV isolates, whereas the rest of the genome was most similar to AKMV, suggesting recombination between AKMV and CPXV in a region containing several host range and virulence genes.

Two sequence-ready contigs spanning the two copies of a 200-kb duplication on human 21q: partial sequence and polymorphisms.

PubMed

Potier, M; Dutriaux, A; Orti, R; Groet, J; Gibelin, N; Karadima, G; Lutfalla, G; Lynn, A; Van Broeckhoven, C; Chakravarti, A; Petersen, M; Nizetic, D; Delabar, J; Rossier, J

1998-08-01

Physical mapping across a duplication can be a tour de force if the region is larger than the size of a bacterial clone. This was the case of the 170- to 275-kb duplication present on the long arm of chromosome 21 in normal human at 21q11.1 (proximal region) and at 21q22.1 (distal region), which we described previously. We have constructed sequence-ready contigs of the two copies of the duplication of which all the clones are genuine representatives of one copy or the other. This required the identification of four duplicon polymorphisms that are copy-specific and nonallelic variations in the sequence of the STSs. Thirteen STSs were mapped inside the duplicated region and 5 outside but close to the boundaries. Among these STSs 10 were end clones from YACs, PACs, or cosmids, and the average interval between two markers in the duplicated region was 16 kb. Eight PACs and cosmids showing minimal overlaps were selected in both copies of the duplication. Comparative sequence analysis along the duplication showed three single-basepair changes between the two copies over 659 bp sequenced (4 STSs), suggesting that the duplication is recent (less than 4 mya). Two CpG islands were located in the duplication, but no genes were identified after a 36-kb cosmid from the proximal copy of the duplication was sequenced. The homology of this chromosome 21 duplicated region with the pericentromeric regions of chromosomes 13, 2, and 18 suggests that the mechanism involved is probably similar to pericentromeric-directed mechanisms described in interchromosomal duplications. Copyright 1998 Academic Press.

Full-genome sequences of hepatitis B virus subgenotype D3 isolates from the Brazilian Amazon Region.

PubMed

Spitz, Natália; Mello, Francisco C A; Araujo, Natalia Motta

2015-02-01

The Brazilian Amazon Region is a highly endemic area for hepatitis B virus (HBV). However, little is known regarding the genetic variability of the strains circulating in this geographical region. Here, we describe the first full-length genomes of HBV isolated in the Brazilian Amazon Region; these genomes are also the first complete HBV subgenotype D3 genomes reported for Brazil. The genomes of the five Brazilian isolates were all 3,182 base pairs in length and the isolates were classified as belonging to subgenotype D3, subtypes ayw2 (n = 3) and ayw3 (n = 2). Phylogenetic analysis suggested that the Brazilian sequences are not likely to be closely related to European D3 sequences. Such results will contribute to further epidemiological and evolutionary studies of HBV.

Analysis of sequence repeats of proteins in the PDB.

PubMed

Mary Rajathei, David; Selvaraj, Samuel

2013-12-01

Internal repeats in protein sequences play a significant role in the evolution of protein structure and function. Applications of different bioinformatics tools help in the identification and characterization of these repeats. In the present study, we analyzed sequence repeats in a non-redundant set of proteins available in the Protein Data Bank (PDB). We used RADAR for detecting internal repeats in a protein, PDBeFOLD for assessing structural similarity, PDBsum for finding functional involvement and Pfam for domain assignment of the repeats in a protein. Through the analysis of sequence repeats, we found that identity of the sequence repeats falls in the range of 20-40% and, the superimposed structures of the most of the sequence repeats maintain similar overall folding. Analysis sequence repeats at the functional level reveals that most of the sequence repeats are involved in the function of the protein through functionally involved residues in the repeat regions. We also found that sequence repeats in single and two domain proteins often contained conserved sequence motifs for the function of the domain. Copyright © 2013 Elsevier Ltd. All rights reserved.

Next-generation sequencing for identification of candidate genes for Fusarium wilt and sterility mosaic disease in pigeonpea (Cajanus cajan).

PubMed

Singh, Vikas K; Khan, Aamir W; Saxena, Rachit K; Kumar, Vinay; Kale, Sandip M; Sinha, Pallavi; Chitikineni, Annapurna; Pazhamala, Lekha T; Garg, Vanika; Sharma, Mamta; Sameer Kumar, Chanda Venkata; Parupalli, Swathi; Vechalapu, Suryanarayana; Patil, Suyash; Muniswamy, Sonnappa; Ghanta, Anuradha; Yamini, Kalinati Narasimhan; Dharmaraj, Pallavi Subbanna; Varshney, Rajeev K

2016-05-01

To map resistance genes for Fusarium wilt (FW) and sterility mosaic disease (SMD) in pigeonpea, sequencing-based bulked segregant analysis (Seq-BSA) was used. Resistant (R) and susceptible (S) bulks from the extreme recombinant inbred lines of ICPL 20096 × ICPL 332 were sequenced. Subsequently, SNP index was calculated between R- and S-bulks with the help of draft genome sequence and reference-guided assembly of ICPL 20096 (resistant parent). Seq-BSA has provided seven candidate SNPs for FW and SMD resistance in pigeonpea. In parallel, four additional genotypes were re-sequenced and their combined analysis with R- and S-bulks has provided a total of 8362 nonsynonymous (ns) SNPs. Of 8362 nsSNPs, 60 were found within the 2-Mb flanking regions of seven candidate SNPs identified through Seq-BSA. Haplotype analysis narrowed down to eight nsSNPs in seven genes. These eight nsSNPs were further validated by re-sequencing 11 genotypes that are resistant and susceptible to FW and SMD. This analysis revealed association of four candidate nsSNPs in four genes with FW resistance and four candidate nsSNPs in three genes with SMD resistance. Further, In silico protein analysis and expression profiling identified two most promising candidate genes namely C.cajan_01839 for SMD resistance and C.cajan_03203 for FW resistance. Identified candidate genomic regions/SNPs will be useful for genomics-assisted breeding in pigeonpea. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

[Comparative analysis of variable regions in the genomes of variola virus].

PubMed

Babkin, I V; Nepomniashchikh, T S; Maksiutov, R A; Gutorov, V V; Babkina, I N; Shchelkunov, S N

2008-01-01

Nucleotide sequences of two extended segments of the terminal variable regions in variola virus genome were determined. The size of the left segment was 13.5 kbp and of the right, 10.5 kbp. Totally, over 540 kbp were sequenced for 22 variola virus strains. The conducted phylogenetic analysis and the data published earlier allowed us to find the interrelations between 70 variola virus isolates, the character of their clustering, and the degree of intergroup and intragroup variations of the clusters of variola virus strains. The most polymorphic loci of the genome segments studied were determined. It was demonstrated that that these loci are localized to either noncoding genome regions or to the regions of destroyed open reading frames, characteristic of the ancestor virus. These loci are promising for development of the strategy for genotyping variola virus strains. Analysis of recombination using various methods demonstrated that, with the only exception, no statistically significant recombinational events in the genomes of variola virus strains studied were detectable.

Identification, characterization and functional analysis of regulatory region of nanos gene from half-smooth tongue sole (Cynoglossus semilaevis).

PubMed

Huang, Jinqiang; Li, Yongjuan; Shao, Changwei; Wang, Na; Chen, Songlin

2017-06-20

The nanos gene encodes an RNA-binding zinc finger protein, which is required in the development and maintenance of germ cells. However, there is very limited information about nanos in flatfish, which impedes its application in fish breeding. In this study, we report the molecular cloning, characterization and functional analysis of the 3'-untranslated region of the nanos gene (Csnanos) from half-smooth tongue sole (Cynoglossus semilaevis), which is an economically important flatfish in China. The 1233-bp cDNA sequence, 1709-bp genomic sequence and flanking sequences (2.8-kb 5'- and 1.6-kb 3'-flanking regions) of Csnanos were cloned and characterized. Sequence analysis revealed that CsNanos shares low homology with Nanos in other species, but the zinc finger domain of CsNanos is highly similar. Phylogenetic analysis indicated that CsNanos belongs to the Nanos2 subfamily. Csnanos expression was widely detected in various tissues, but the expression level was higher in testis and ovary. During early development and sex differentiation, Csnanos expression exhibited a clear sexually dimorphic pattern, suggesting its different roles in the migration and differentiation of primordial germ cells (PGCs). Higher expression levels of Csnanos mRNA in normal females and males than in neomales indicated that the nanos gene may play key roles in maintaining the differentiation of gonad. Moreover, medaka PGCs were successfully labeled by the microinjection of synthesized mRNA consisting of green fluorescence protein and the 3'-untranslated region of Csnanos. These findings provide new insights into nanos gene expression and function, and lay the foundation for further study of PGC development and applications in tongue sole breeding. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of Claviceps africana and C. sorghi from India using AFLPs, EF-1alpha gene intron 4, and beta-tubulin gene intron 3.

PubMed

Tooley, Paul W; Bandyopadhyay, Ranajit; Carras, Marie M; Pazoutová, Sylvie

2006-04-01

Isolates of Claviceps causing ergot on sorghum in India were analysed by AFLP analysis, and by analysis of DNA sequences of the EF-1alpha gene intron 4 and beta-tubulin gene intron 3 region. Of 89 isolates assayed from six states in India, four were determined to be C. sorghi, and the rest C. africana. A relatively low level of genetic diversity was observed within the Indian C. africana population. No evidence of genetic exchange between C. africana and C. sorghi was observed in either AFLP or DNA sequence analysis. Phylogenetic analysis was conducted using DNA sequences from 14 different Claviceps species. A multigene phylogeny based on the EF-1alpha gene intron 4, the beta-tubulin gene intron 3 region, and rDNA showed that C. sorghi grouped most closely with C. gigantea and C. africana. Although the Claviceps species we analysed were closely related, they colonize hosts that are taxonomically very distinct suggesting that there is no direct coevolution of Claviceps with its hosts.

Ultra-Deep Sequencing Analysis of the Hepatitis A Virus 5'-Untranslated Region among Cases of the Same Outbreak from a Single Source

PubMed Central

Wu, Shuang; Nakamoto, Shingo; Kanda, Tatsuo; Jiang, Xia; Nakamura, Masato; Miyamura, Tatsuo; Shirasawa, Hiroshi; Sugiura, Nobuyuki; Takahashi-Nakaguchi, Azusa; Gonoi, Tohru; Yokosuka, Osamu

2014-01-01

Hepatitis A virus (HAV) is a causative agent of acute viral hepatitis for which an effective vaccine has been developed. Here we describe ultra-deep pyrosequences (UDPSs) of HAV 5'-untranslated region (5'UTR) among cases of the same outbreak, which arose from a single source, associated with a revolving sushi bar. We determined the reference sequence from HAV-derived clone from an attendant by the Sanger method. Sixteen UDPSs from this outbreak and one from another sporadic case were compared with this reference. Nucleotide errors yielded a UDPS error rate of < 1%. This study confirmed that nucleotide substitutions of this region are transition mutations in outbreak cases, that insertion was observed only in non-severe cases, and that these nucleotide substitutions were different from those of the sporadic case. Analysis of UDPSs detected low-prevalence HAV variations in 5'UTR, but no specific mutations associated with severity in these outbreak cases. To our surprise, HAV strains in this outbreak conserved HAV IRES sequence even if we performed analysis of UDPSs. UDPS analysis of HAV 5'UTR gave us no association between the disease severity of hepatitis A and HAV 5'UTR substitutions. It might be more interesting to perform ultra-deep sequencing of full length HAV genome in order to reveal possible unknown genomic determinants associated with disease severity. Further studies will be needed. PMID:24396287

First Pass Annotation of Promoters on Human Chromosome 22

PubMed Central

Scherf, Matthias; Klingenhoff, Andreas; Frech, Kornelie; Quandt, Kerstin; Schneider, Ralf; Grote, Korbinian; Frisch, Matthias; Gailus-Durner, Valérie; Seidel, Alexander; Brack-Werner, Ruth; Werner, Thomas

2001-01-01

The publication of the first almost complete sequence of a human chromosome (chromosome 22) is a major milestone in human genomics. Together with the sequence, an excellent annotation of genes was published which certainly will serve as an information resource for numerous future projects. We noted that the annotation did not cover regulatory regions; in particular, no promoter annotation has been provided. Here we present an analysis of the complete published chromosome 22 sequence for promoters. A recent breakthrough in specific in silico prediction of promoter regions enabled us to attempt large-scale prediction of promoter regions on chromosome 22. Scanning of sequence databases revealed only 20 experimentally verified promoters, of which 10 were correctly predicted by our approach. Nearly 40% of our 465 predicted promoter regions are supported by the currently available gene annotation. Promoter finding also provides a biologically meaningful method for “chromosomal scaffolding”, by which long genomic sequences can be divided into segments starting with a gene. As one example, the combination of promoter region prediction with exon/intron structure predictions greatly enhances the specificity of de novo gene finding. The present study demonstrates that it is possible to identify promoters in silico on the chromosomal level with sufficient reliability for experimental planning and indicates that a wealth of information about regulatory regions can be extracted from current large-scale (megabase) sequencing projects. Results are available on-line at http://genomatix.gsf.de/chr22/. PMID:11230158

Bioinformatic Analysis of the Contribution of Primer Sequences to Aptamer Structures

PubMed Central

Ellington, Andrew D.

2009-01-01

Aptamers are nucleic acid molecules selected in vitro to bind a particular ligand. While numerous experimental studies have examined the sequences, structures, and functions of individual aptamers, considerably fewer studies have applied bioinformatics approaches to try to infer more general principles from these individual studies. We have used a large Aptamer Database to parse the contributions of both random and constant regions to the secondary structures of more than 2000 aptamers. We find that the constant, primer-binding regions do not, in general, contribute significantly to aptamer structures. These results suggest that (a) binding function is not contributed to nor constrained by constant regions; (b) in consequence, the landscape of functional binding sequences is sparse but robust, favoring scenarios for short, functional nucleic acid sequences near origins; and (c) many pool designs for the selection of aptamers are likely to prove robust. PMID:18594898

Genomic structure and paralogous regions of the inversion breakpoint occurring between human chromosome 3p12.3 and orangutan chromosome 2.

PubMed

Yue, Y; Grossmann, B; Tsend-Ayush, E; Grützner, F; Ferguson-Smith, M A; Yang, F; Haaf, T

2005-01-01

Intrachromosomal duplications play a significant role in human genome pathology and evolution. To better understand the molecular basis of evolutionary chromosome rearrangements, we performed molecular cytogenetic and sequence analyses of the breakpoint region that distinguishes human chromosome 3p12.3 and orangutan chromosome 2. FISH with region-specific BAC clones demonstrated that the breakpoint-flanking sequences are duplicated intrachromosomally on orangutan 2 and human 3q21 as well as at many pericentromeric and subtelomeric sites throughout the genomes. Breakage and rearrangement of the human 3p12.3-homologous region in the orangutan lineage were associated with a partial loss of duplicated sequences in the breakpoint region. Consistent with our FISH mapping results, computational analysis of the human chromosome 3 genomic sequence revealed three 3p12.3-paralogous sequence blocks on human chromosome 3q21 and smaller blocks on the short arm end 3p26-->p25. This is consistent with the view that sequences from an ancestral site at 3q21 were duplicated at 3p12.3 in a common ancestor of orangutan and humans. Our results show that evolutionary chromosome rearrangements are associated with microduplications and microdeletions, contributing to the DNA differences between closely related species. Copyright (c) 2005 S. Karger AG, Basel.

The mitochondrial genome of Polistes jokahamae and a phylogenetic analysis of the Vespoidea (Insecta: Hymenoptera).

PubMed

Song, Sheng-Nan; Chen, Peng-Yan; Wei, Shu-Jun; Chen, Xue-Xin

2016-07-01

The mitochondrial genome sequence of Polistes jokahamae (Radoszkowski, 1887) (Hymenoptera: Vespidae) (GenBank accession no. KR052468) was sequenced. The current length with partial A + T-rich region of this mitochondrial genome is 16,616 bp. All the typical mitochondrial genes were sequenced except for three tRNAs (trnI, trnQ, and trnY) located between the A + T-rich region and nad2. At least three rearrangement events occurred in the sequenced region compared with the pupative ancestral arrangement of insects, corresponding to the shuffling of trnK and trnD, translocation or remote inversion of tnnY and translocation of trnL1. All protein-coding genes start with ATN codons. Eleven, one, and another one protein-coding genes stop with termination codon TAA, TA, and T, respectively. Phylogenetic analysis using the Bayesian method based on all codon positions of the 13 protein-coding genes supports the monophyly of Vespidae and Formicidae. Within the Formicidae, the Myrmicinae and Formicinae form a sister lineage and then sister to the Dolichoderinae, while within the Vespidae, the Eumeninae is sister to the lineage of Vespinae + Polistinae.

First complete genome sequence of infectious laryngotracheitis virus

PubMed Central

2011-01-01

Background Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that causes acute respiratory disease in chickens worldwide. To date, only one complete genomic sequence of ILTV has been reported. This sequence was generated by concatenating partial sequences from six different ILTV strains. Thus, the full genomic sequence of a single (individual) strain of ILTV has not been determined previously. This study aimed to use high throughput sequencing technology to determine the complete genomic sequence of a live attenuated vaccine strain of ILTV. Results The complete genomic sequence of the Serva vaccine strain of ILTV was determined, annotated and compared to the concatenated ILTV reference sequence. The genome size of the Serva strain was 152,628 bp, with a G + C content of 48%. A total of 80 predicted open reading frames were identified. The Serva strain had 96.5% DNA sequence identity with the concatenated ILTV sequence. Notably, the concatenated ILTV sequence was found to lack four large regions of sequence, including 528 bp and 594 bp of sequence in the UL29 and UL36 genes, respectively, and two copies of a 1,563 bp sequence in the repeat regions. Considerable differences in the size of the predicted translation products of 4 other genes (UL54, UL30, UL37 and UL38) were also identified. More than 530 single-nucleotide polymorphisms (SNPs) were identified. Most SNPs were located within three genomic regions, corresponding to sequence from the SA-2 ILTV vaccine strain in the concatenated ILTV sequence. Conclusions This is the first complete genomic sequence of an individual ILTV strain. This sequence will facilitate future comparative genomic studies of ILTV by providing an appropriate reference sequence for the sequence analysis of other ILTV strains. PMID:21501528

Next-generation sequencing using a pre-designed gene panel for the molecular diagnosis of congenital disorders in pediatric patients.

PubMed

Lim, Eileen C P; Brett, Maggie; Lai, Angeline H M; Lee, Siew-Peng; Tan, Ee-Shien; Jamuar, Saumya S; Ng, Ivy S L; Tan, Ene-Choo

2015-12-14

Next-generation sequencing (NGS) has revolutionized genetic research and offers enormous potential for clinical application. Sequencing the exome has the advantage of casting the net wide for all known coding regions while targeted gene panel sequencing provides enhanced sequencing depths and can be designed to avoid incidental findings in adult-onset conditions. A HaloPlex panel consisting of 180 genes within commonly altered chromosomal regions is available for use on both the Ion Personal Genome Machine (PGM) and MiSeq platforms to screen for causative mutations in these genes. We used this Haloplex ICCG panel for targeted sequencing of 15 patients with clinical presentations indicative of an abnormality in one of the 180 genes. Sequencing runs were done using the Ion 318 Chips on the Ion Torrent PGM. Variants were filtered for known polymorphisms and analysis was done to identify possible disease-causing variants before validation by Sanger sequencing. When possible, segregation of variants with phenotype in family members was performed to ascertain the pathogenicity of the variant. More than 97% of the target bases were covered at >20×. There was an average of 9.6 novel variants per patient. Pathogenic mutations were identified in five genes for six patients, with two novel variants. There were another five likely pathogenic variants, some of which were unreported novel variants. In a cohort of 15 patients, we were able to identify a likely genetic etiology in six patients (40%). Another five patients had candidate variants for which further evaluation and segregation analysis are ongoing. Our results indicate that the HaloPlex ICCG panel is useful as a rapid, high-throughput and cost-effective screening tool for 170 of the 180 genes. There is low coverage for some regions in several genes which might have to be supplemented by Sanger sequencing. However, comparing the cost, ease of analysis, and shorter turnaround time, it is a good alternative to exome sequencing for patients whose features are suggestive of a genetic etiology involving one of the genes in the panel.

Long interspersed repeated DNA (LINE) causes polymorphism at the rat insulin 1 locus.

PubMed

Lakshmikumaran, M S; D'Ambrosio, E; Laimins, L A; Lin, D T; Furano, A V

1985-09-01

The insulin 1, but not the insulin 2, locus is polymorphic (i.e., exhibits allelic variation) in rats. Restriction enzyme analysis and hybridization studies showed that the polymorphic region is 2.2 kilobases upstream of the insulin 1 coding region and is due to the presence or absence of an approximately 2.7-kilobase repeated DNA element. DNA sequence determination showed that this DNA element is a member of a long interspersed repeated DNA family (LINE) that is highly repeated (greater than 50,000 copies) and highly transcribed in the rat. Although the presence or absence of LINE sequences at the insulin 1 locus occurs in both the homozygous and heterozygous states, LINE-containing insulin 1 alleles are more prevalent in the rat population than are alleles without LINEs. Restriction enzyme analysis of the LINE-containing alleles indicated that at least two versions of the LINE sequence may be present at the insulin 1 locus in different rats. Either repeated transposition of LINE sequences or gene conversion between the resident insulin 1 LINE and other sequences in the genome are possible explanations for this.

The mitochondrial genome of the multicolored Asian lady beetle Harmonia axyridis (Pallas) and a phylogenetic analysis of the Polyphaga (Insecta: Coleoptera).

PubMed

Niu, Fang-Fang; Zhu, Liang; Wang, Su; Wei, Shu-Jun

2016-07-01

Here, we report the mitochondrial genome sequence of the multicolored Asian lady beetle Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) (GenBank accession No. KR108208). This is the first species with sequenced mitochondrial genome from the genus Harmonia. The current length with partitial A + T-rich region of this mitochondrial genome is 16,387 bp. All the typical genes were sequenced except the trnI and trnQ. As in most other sequenced mitochondrial genomes of Coleoptera, there is no re-arrangement in the sequenced region compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN codons. Five, five and three protein-coding genes stop with termination codon TAA, TA and T, respectively. Phylogenetic analysis using Bayesian method based on the first and second codon positions of the protein-coding genes supported that the Scirtidae is a basal lineage of Polyphaga. The Harmonia and the Coccinella form a sister lineage. The monophyly of Staphyliniformia, Scarabaeiformia and Cucujiformia was supported. The Buprestidae was found to be a sister group to the Bostrichiformia.

Characterization of expressed sequence tag-derived simple sequence repeat markers for Aspergillus flavus: emphasis on variability of isolates from the southern United States.

PubMed

Wang, Xinwang; Wadl, Phillip A; Wood-Jones, Alicia; Windham, Gary; Trigiano, Robert N; Scruggs, Mary; Pilgrim, Candace; Baird, Richard

2012-12-01

Simple sequence repeat (SSR) markers were developed from Aspergillus flavus expressed sequence tag (EST) database to conduct an analysis of genetic relationships of Aspergillus isolates from numerous host species and geographical regions, but primarily from the United States. Twenty-nine primers were designed from 362 tri-nucleotide EST-SSR sequences. Eighteen polymorphic loci were used to genotype 96 Aspergillus species isolates. The number of alleles detected per locus ranged from 2 to 24 with a mean of 8.2 alleles. Haploid diversity ranged from 0.28 to 0.91. Genetic distance matrix was used to perform principal coordinates analysis (PCA) and to generate dendrograms using unweighted pair group method with arithmetic mean (UPGMA). Two principal coordinates explained more than 75 % of the total variation among the isolates. One clade was identified for A. flavus isolates (n = 87) with the other Aspergillus species (n = 7) using PCA, but five distinct clusters were present when the others taxa were excluded from the analysis. Six groups were noted when the EST-SSR data were compared using UPGMA. However, the latter PCA or UPGMA comparison resulted in no direct associations with host species, geographical region or aflatoxin production. Furthermore, there was no direct correlation to visible morphological features such as sclerotial types. The isolates from Mississippi Delta region, which contained the largest percentage of isolates, did not show any unusual clustering except for isolates K32, K55, and 199. Further studies of these three isolates are warranted to evaluate their pathogenicity, aflatoxin production potential, additional gene sequences (e.g., RPB2), and morphological comparisons.

Organizational heterogeneity of vertebrate genomes.

PubMed

Frenkel, Svetlana; Kirzhner, Valery; Korol, Abraham

2012-01-01

Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS) analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers) in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM) allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

Genome-wide gene–gene interaction analysis for next-generation sequencing

PubMed Central

Zhao, Jinying; Zhu, Yun; Xiong, Momiao

2016-01-01

The critical barrier in interaction analysis for next-generation sequencing (NGS) data is that the traditional pairwise interaction analysis that is suitable for common variants is difficult to apply to rare variants because of their prohibitive computational time, large number of tests and low power. The great challenges for successful detection of interactions with NGS data are (1) the demands in the paradigm of changes in interaction analysis; (2) severe multiple testing; and (3) heavy computations. To meet these challenges, we shift the paradigm of interaction analysis between two SNPs to interaction analysis between two genomic regions. In other words, we take a gene as a unit of analysis and use functional data analysis techniques as dimensional reduction tools to develop a novel statistic to collectively test interaction between all possible pairs of SNPs within two genome regions. By intensive simulations, we demonstrate that the functional logistic regression for interaction analysis has the correct type 1 error rates and higher power to detect interaction than the currently used methods. The proposed method was applied to a coronary artery disease dataset from the Wellcome Trust Case Control Consortium (WTCCC) study and the Framingham Heart Study (FHS) dataset, and the early-onset myocardial infarction (EOMI) exome sequence datasets with European origin from the NHLBI's Exome Sequencing Project. We discovered that 6 of 27 pairs of significantly interacted genes in the FHS were replicated in the independent WTCCC study and 24 pairs of significantly interacted genes after applying Bonferroni correction in the EOMI study. PMID:26173972

Organization, chromosomal localization and promoter analysis of the gene encoding human acidic fibroblast growth factor intracellular binding protein.

PubMed Central

Kolpakova, E; Frengen, E; Stokke, T; Olsnes, S

2000-01-01

Acidic fibroblast growth factor (aFGF) intracellular binding protein (FIBP) is a protein found mainly in the nucleus that might be involved in the intracellular function of aFGF. Here we present a comparative analysis of the deduced amino acid sequences of human, murine and Drosophila FIBP analogues and demonstrate that FIBP is an evolutionarily conserved protein. The human gene spans more than 5 kb, comprising ten exons and nine introns, and maps to chromosome 11q13.1. Two slightly different splice variants found in different tissues were isolated and characterized. Sequence analysis of the region surrounding the translation start revealed a CpG island, a classical feature of widely expressed genes. Functional studies of the promoter region with a luciferase reporter system suggested a strong transcriptional activity residing within 600 bp of the 5' flanking region. PMID:11104667

Polyomavirus BK non-coding control region rearrangements in health and disease.

PubMed

Sharma, Preety M; Gupta, Gaurav; Vats, Abhay; Shapiro, Ron; Randhawa, Parmjeet S

2007-08-01

BK virus is an increasingly recognized pathogen in transplanted patients. DNA sequencing of this virus shows considerable genomic variability. To understand the clinical significance of rearrangements in the non-coding control region (NCCR) of BK virus (BKV), we report a meta-analysis of 507 sequences, including 40 sequences generated in our own laboratory, for associations between rearrangements and disease, tissue tropism, geographic origin, and viral genotype. NCCR rearrangements were less frequent in (a) asymptomatic BKV viruria compared to patients viral nephropathy (1.7% vs. 22.5%), and (b) viral genotype 1 compared to other genotypes (2.4% vs. 11.2%). Rearrangements were commoner in malignancy (78.6%), and Norwegians (45.7%), and less common in East Indians (0%), and Japanese (4.3%). A surprising number of rearranged sequences were reported from mononuclear cells of healthy subjects, whereas most plasma sequences were archetypal. This difference could not be related to potential recombinase activity in lymphocytes, as consensus recombination signal sequences could not be found in the NCCR region. NCCR rearrangements are neither required nor a sufficient condition to produce clinical disease. BKV nephropathy and hemorrhagic cystitis are not associated with any unique NCCR configuration or nucleotide sequence.

Detection of Emerging Vaccine-Related Polioviruses by Deep Sequencing.

PubMed

Sahoo, Malaya K; Holubar, Marisa; Huang, ChunHong; Mohamed-Hadley, Alisha; Liu, Yuanyuan; Waggoner, Jesse J; Troy, Stephanie B; Garcia-Garcia, Lourdes; Ferreyra-Reyes, Leticia; Maldonado, Yvonne; Pinsky, Benjamin A

2017-07-01

Oral poliovirus vaccine can mutate to regain neurovirulence. To date, evaluation of these mutations has been performed primarily on culture-enriched isolates by using conventional Sanger sequencing. We therefore developed a culture-independent, deep-sequencing method targeting the 5' untranslated region (UTR) and P1 genomic region to characterize vaccine-related poliovirus variants. Error analysis of the deep-sequencing method demonstrated reliable detection of poliovirus mutations at levels of <1%, depending on read depth. Sequencing of viral nucleic acids from the stool of vaccinated, asymptomatic children and their close contacts collected during a prospective cohort study in Veracruz, Mexico, revealed no vaccine-derived polioviruses. This was expected given that the longest duration between sequenced sample collection and the end of the most recent national immunization week was 66 days. However, we identified many low-level variants (<5%) distributed across the 5' UTR and P1 genomic region in all three Sabin serotypes, as well as vaccine-related viruses with multiple canonical mutations associated with phenotypic reversion present at high levels (>90%). These results suggest that monitoring emerging vaccine-related poliovirus variants by deep sequencing may aid in the poliovirus endgame and efforts to ensure global polio eradication. Copyright © 2017 Sahoo et al.

Phylogenetic shadowing of primate sequences to find functional regions of the human genome.

PubMed

Boffelli, Dario; McAuliffe, Jon; Ovcharenko, Dmitriy; Lewis, Keith D; Ovcharenko, Ivan; Pachter, Lior; Rubin, Edward M

2003-02-28

Nonhuman primates represent the most relevant model organisms to understand the biology of Homo sapiens. The recent divergence and associated overall sequence conservation between individual members of this taxon have nonetheless largely precluded the use of primates in comparative sequence studies. We used sequence comparisons of an extensive set of Old World and New World monkeys and hominoids to identify functional regions in the human genome. Analysis of these data enabled the discovery of primate-specific gene regulatory elements and the demarcation of the exons of multiple genes. Much of the information content of the comprehensive primate sequence comparisons could be captured with a small subset of phylogenetically close primates. These results demonstrate the utility of intraprimate sequence comparisons to discover common mammalian as well as primate-specific functional elements in the human genome, which are unattainable through the evaluation of more evolutionarily distant species.

Comparative Sequence Analysis of the X-Inactivation Center Region in Mouse, Human, and Bovine

PubMed Central

Chureau, Corinne; Prissette, Marine; Bourdet, Agnès; Barbe, Valérie; Cattolico, Laurence; Jones, Louis; Eggen, André; Avner, Philip; Duret, Laurent

2002-01-01

We have sequenced to high levels of accuracy 714-kb and 233-kb regions of the mouse and bovine X-inactivation centers (Xic), respectively, centered on the Xist gene. This has provided the basis for a fully annotated comparative analysis of the mouse Xic with the 2.3-Mb orthologous region in human and has allowed a three-way species comparison of the core central region, including the Xist gene. These comparisons have revealed conserved genes, both coding and noncoding, conserved CpG islands and, more surprisingly, conserved pseudogenes. The distribution of repeated elements, especially LINE repeats, in the mouse Xic region when compared to the rest of the genome does not support the hypothesis of a role for these repeat elements in the spreading of X inactivation. Interestingly, an asymmetric distribution of LINE elements on the two DNA strands was observed in the three species, not only within introns but also in intergenic regions. This feature is suggestive of important transcriptional activity within these intergenic regions. In silico prediction followed by experimental analysis has allowed four new genes, Cnbp2, Ftx, Jpx, and Ppnx, to be identified and novel, widespread, complex, and apparently noncoding transcriptional activity to be characterized in a region 5′ of Xist that was recently shown to attract histone modification early after the onset of X inactivation. [The sequence data described in this paper have been submitted to the EMBL data library under accession nos. AJ421478, AJ421479, AJ421480, and AJ421481. Online supplemental data are available at http://pbil.univ-lyon1.fr/datasets/Xic2002/data.html and www.genome.org.] PMID:12045143

Defining the transcriptome assembly and its use for genome dynamics and transcriptome profiling studies in pigeonpea (Cajanus cajan L.).

PubMed

Dubey, Anuja; Farmer, Andrew; Schlueter, Jessica; Cannon, Steven B; Abernathy, Brian; Tuteja, Reetu; Woodward, Jimmy; Shah, Trushar; Mulasmanovic, Benjamin; Kudapa, Himabindu; Raju, Nikku L; Gothalwal, Ragini; Pande, Suresh; Xiao, Yongli; Town, Chris D; Singh, Nagendra K; May, Gregory D; Jackson, Scott; Varshney, Rajeev K

2011-06-01

This study reports generation of large-scale genomic resources for pigeonpea, a so-called 'orphan crop species' of the semi-arid tropic regions. FLX/454 sequencing carried out on a normalized cDNA pool prepared from 31 tissues produced 494 353 short transcript reads (STRs). Cluster analysis of these STRs, together with 10 817 Sanger ESTs, resulted in a pigeonpea trancriptome assembly (CcTA) comprising of 127 754 tentative unique sequences (TUSs). Functional analysis of these TUSs highlights several active pathways and processes in the sampled tissues. Comparison of the CcTA with the soybean genome showed similarity to 10 857 and 16 367 soybean gene models (depending on alignment methods). Additionally, Illumina 1G sequencing was performed on Fusarium wilt (FW)- and sterility mosaic disease (SMD)-challenged root tissues of 10 resistant and susceptible genotypes. More than 160 million sequence tags were used to identify FW- and SMD-responsive genes. Sequence analysis of CcTA and the Illumina tags identified a large new set of markers for use in genetics and breeding, including 8137 simple sequence repeats, 12 141 single-nucleotide polymorphisms and 5845 intron-spanning regions. Genomic resources developed in this study should be useful for basic and applied research, not only for pigeonpea improvement but also for other related, agronomically important legumes.

Analysis of blaCTX-M-Carrying Plasmids from Escherichia coli Isolates Collected in the BfT-GermVet Study ▿

PubMed Central

Schink, Anne-Kathrin; Kadlec, Kristina; Schwarz, Stefan

2011-01-01

In this study, 417 Escherichia coli isolates from defined disease conditions of companion and farm animals collected in the BfT-GermVet study were investigated for the presence of extended-spectrum β-lactamase (ESBL) genes. Three ESBL-producing E. coli isolates were identified among the 100 ampicillin-resistant isolates. The E. coli isolates 168 and 246, of canine and porcine origins, respectively, harbored blaCTX-M-1, and the canine isolate 913 harbored blaCTX-M-15, as confirmed by PCR and sequence analysis. The isolates 168 and 246 belonged to the novel multilocus sequence typing (MLST) types ST1576 and ST1153, respectively, while isolate 913 had the MLST type ST410. The ESBL genes were located on structurally related IncN plasmids in isolates 168 and 246 and on an IncF plasmid in isolate 913. The blaCTX-M-1 upstream regions of plasmids pCTX168 and pCTX246 were similar, whereas the downstream regions showed structural differences. The genetic environment of the blaCTX-M-15 gene on plasmid pCTX913 differed distinctly from that of both blaCTX-M-1 genes. Detailed sequence analysis showed that the integration of insertion sequences, as well as interplasmid recombination events, accounted for the structural variability in the blaCTX-M gene regions. PMID:21685166

Molecular and bioinformatic analysis of the FB-NOF transposable element.

PubMed

Badal, Martí; Portela, Anna; Xamena, Noel; Cabré, Oriol

2006-04-12

The Drosophila melanogaster transposable element FB-NOF is known to play a role in genome plasticity through the generation of all sort of genomic rearrangements. Moreover, several insertional mutants due to FB mobilizations have been reported. Its structure and sequence, however, have been poorly studied mainly as a consequence of the long, complex and repetitive sequence of FB inverted repeats. This repetitive region is composed of several 154 bp blocks, each with five almost identical repeats. In this paper, we report the sequencing process of 2 kb long FB inverted repeats of a complete FB-NOF element, with high precision and reliability. This achievement has been possible using a new map of the FB repetitive region, which identifies unambiguously each repeat with new features that can be used as landmarks. With this new vision of the element, a list of FB-NOF in the D. melanogaster genomic clones has been done, improving previous works that used only bioinformatic algorithms. The availability of many FB and FB-NOF sequences allowed an analysis of the FB insertion sequences that showed no sequence specificity, but a preference for A/T rich sequences. The position of NOF into FB is also studied, revealing that it is always located after a second repeat in a random block. With the results of this analysis, we propose a model of transposition in which NOF jumps from FB to FB, using an unidentified transposase enzyme that should specifically recognize the second repeat end of the FB blocks.

The Danish STR sequence database: duplicate typing of 363 Danes with the ForenSeq™ DNA Signature Prep Kit.

PubMed

Hussing, C; Bytyci, R; Huber, C; Morling, N; Børsting, C

2018-05-24

Some STR loci have internal sequence variations, which are not revealed by the standard STR typing methods used in forensic genetics (PCR and fragment length analysis by capillary electrophoresis (CE)). Typing of STRs with next-generation sequencing (NGS) uncovers the sequence variation in the repeat region and in the flanking regions. In this study, 363 Danish individuals were typed for 56 STRs (26 autosomal STRs, 24 Y-STRs, and 6 X-STRs) using the ForenSeq™ DNA Signature Prep Kit to establish a Danish STR sequence database. Increased allelic diversity was observed in 34 STRs by the PCR-NGS assay. The largest increases were found in DYS389II and D12S391, where the numbers of sequenced alleles were around four times larger than the numbers of alleles determined by repeat length alone. Thirteen SNPs and one InDel were identified in the flanking regions of 12 STRs. Furthermore, 36 single positions and five longer stretches in the STR flanking regions were found to have dubious genotyping quality. The combined match probability of the 26 autosomal STRs was 10,000 times larger using the PCR-NGS assay than by using PCR-CE. The typical paternity indices for trios and duos were 500 and 100 times larger, respectively, than those obtained with PCR-CE. The assay also amplified 94 SNPs selected for human identification. Eleven of these loci were not in Hardy-Weinberg equilibrium in the Danish population, most likely because the minimum threshold for allele calling (30 reads) in the ForenSeq™ Universal Analysis Software was too low and frequent allele dropouts were not detected.

Identification of new polymorphic regions and differentiation of cultivated olives (Olea europaea L.) through plastome sequence comparison

PubMed Central

2010-01-01

Background The cultivated olive (Olea europaea L.) is the most agriculturally important species of the Oleaceae family. Although many studies have been performed on plastid polymorphisms to evaluate taxonomy, phylogeny and phylogeography of Olea subspecies, only few polymorphic regions discriminating among the agronomically and economically important olive cultivars have been identified. The objective of this study was to sequence the entire plastome of olive and analyze many potential polymorphic regions to develop new inter-cultivar genetic markers. Results The complete plastid genome of the olive cultivar Frantoio was determined by direct sequence analysis using universal and novel PCR primers designed to amplify all overlapping regions. The chloroplast genome of the olive has an organisation and gene order that is conserved among numerous Angiosperm species and do not contain any of the inversions, gene duplications, insertions, inverted repeat expansions and gene/intron losses that have been found in the chloroplast genomes of the genera Jasminum and Menodora, from the same family as Olea. The annotated sequence was used to evaluate the content of coding genes, the extent, and distribution of repeated and long dispersed sequences and the nucleotide composition pattern. These analyses provided essential information for structural, functional and comparative genomic studies in olive plastids. Furthermore, the alignment of the olive plastome sequence to those of other varieties and species identified 30 new organellar polymorphisms within the cultivated olive. Conclusions In addition to identifying mutations that may play a functional role in modifying the metabolism and adaptation of olive cultivars, the new chloroplast markers represent a valuable tool to assess the level of olive intercultivar plastome variation for use in population genetic analysis, phylogenesis, cultivar characterisation and DNA food tracking. PMID:20868482

Molecular Population Genetics of the Alcohol Dehydrogenase Gene Region of DROSOPHILA MELANOGASTER

PubMed Central

Aquadro, Charles F.; Desse, Susan F.; Bland, Molly M.; Langley, Charles H.; Laurie-Ahlberg, Cathy C.

1986-01-01

Variation in the DNA restriction map of a 13-kb region of chromosome II including the alcohol dehydrogenase structural gene (Adh) was examined in Drosophila melanogaster from natural populations. Detailed analysis of 48 D. melanogaster lines representing four eastern United States populations revealed extensive DNA sequence variation due to base substitutions, insertions and deletions. Cloning of this region from several lines allowed characterization of length variation as due to unique sequence insertions or deletions [nine sizes; 21–200 base pairs (bp)] or transposable element insertions (several sizes, 340 bp to 10.2 kb, representing four different elements). Despite this extensive variation in sequences flanking the Adh gene, only one length polymorphism is clearly associated with altered Adh expression (a copia element approximately 250 bp 5' to the distal transcript start site). Nonetheless, the frequency spectra of transposable elements within and between Drosophila species suggests they are slightly deleterious. Strong nonrandom associations are observed among Adh region sequence variants, ADH allozyme (Fast vs. Slow), ADH enzyme activity and the chromosome inversion ln(2L) t. Phylogenetic analysis of restriction map haplotypes suggest that the major twofold component of ADH activity variation (high vs. low, typical of Fast and Slow allozymes, respectively) is due to sequence variation tightly linked to and possibly distinct from that underlying the allozyme difference. The patterns of nucleotide and haplotype variation for Fast and Slow allozyme lines are consistent with the recent increase in frequency and spread of the Fast haplotype associated with high ADH activity. These data emphasize the important role of evolutionary history and strong nonrandom associations among tightly linked sequence variation as determinants of the patterns of variation observed in natural populations. PMID:3026893

DNA barcode analysis of butterfly species from Pakistan points towards regional endemism.

PubMed

Ashfaq, Muhammad; Akhtar, Saleem; Khan, Arif M; Adamowicz, Sarah J; Hebert, Paul D N

2013-09-01

DNA barcodes were obtained for 81 butterfly species belonging to 52 genera from sites in north-central Pakistan to test the utility of barcoding for their identification and to gain a better understanding of regional barcode variation. These species represent 25% of the butterfly fauna of Pakistan and belong to five families, although the Nymphalidae were dominant, comprising 38% of the total specimens. Barcode analysis showed that maximum conspecific divergence was 1.6%, while there was 1.7-14.3% divergence from the nearest neighbour species. Barcode records for 55 species showed <2% sequence divergence to records in the Barcode of Life Data Systems (BOLD), but only 26 of these cases involved specimens from neighbouring India and Central Asia. Analysis revealed that most species showed little incremental sequence variation when specimens from other regions were considered, but a threefold increase was noted in a few cases. There was a clear gap between maximum intraspecific and minimum nearest neighbour distance for all 81 species. Neighbour-joining cluster analysis showed that members of each species formed a monophyletic cluster with strong bootstrap support. The barcode results revealed two provisional species that could not be clearly linked to known taxa, while 24 other species gained their first coverage. Future work should extend the barcode reference library to include all butterfly species from Pakistan as well as neighbouring countries to gain a better understanding of regional variation in barcode sequences in this topographically and climatically complex region. © 2013 The Authors. Molecular Ecology Resources published by John Wiley & Sons Ltd.

Sequence information gain based motif analysis.

PubMed

Maynou, Joan; Pairó, Erola; Marco, Santiago; Perera, Alexandre

2015-11-09

The detection of regulatory regions in candidate sequences is essential for the understanding of the regulation of a particular gene and the mechanisms involved. This paper proposes a novel methodology based on information theoretic metrics for finding regulatory sequences in promoter regions. This methodology (SIGMA) has been tested on genomic sequence data for Homo sapiens and Mus musculus. SIGMA has been compared with different publicly available alternatives for motif detection, such as MEME/MAST, Biostrings (Bioconductor package), MotifRegressor, and previous work such Qresiduals projections or information theoretic based detectors. Comparative results, in the form of Receiver Operating Characteristic curves, show how, in 70% of the studied Transcription Factor Binding Sites, the SIGMA detector has a better performance and behaves more robustly than the methods compared, while having a similar computational time. The performance of SIGMA can be explained by its parametric simplicity in the modelling of the non-linear co-variability in the binding motif positions. Sequence Information Gain based Motif Analysis is a generalisation of a non-linear model of the cis-regulatory sequences detection based on Information Theory. This generalisation allows us to detect transcription factor binding sites with maximum performance disregarding the covariability observed in the positions of the training set of sequences. SIGMA is freely available to the public at http://b2slab.upc.edu.

Microbial and viral-like rhodopsins present in coastal marine sediments from four polar and subpolar regions

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

López, José L.; Golemba, Marcelo; Hernández, Edgardo

Rhodopsins are broadly distributed. In this work, we analyzed 23 metagenomes corresponding to marine sediment samples from four regions that share cold climate conditions (Norway; Sweden; Argentina and Antarctica). In order to investigate the genes evolution of viral rhodopsins, an initial set of 6224 bacterial rhodopsin sequences according to COG5524 were retrieved from the 23 metagenomes. After selection by the presence of transmembrane domains and alignment, 123 viral (51) and non-viral (72) sequences (>50 amino acids) were finally included in further analysis. Viral rhodopsin genes were homologs of Phaeocystis globosa virus and Organic lake Phycodnavirus. Non-viral microbial rhodopsin genes weremore » ascribed to Bacteroidetes, Planctomycetes, Firmicutes, Actinobacteria, Cyanobacteria, Proteobacteria, Deinococcus-Thermus and Cryptophyta and Fungi. A rescreening using Blastp, using as queries the viral sequences previously described, retrieved 30 sequences (>100 amino acids). Phylogeographic analysis revealed a geographical clustering of the sequences affiliated to the viral group. This clustering was not observed for the microbial non-viral sequences. The phylogenetic reconstruction allowed us to propose the existence of a putative ancestor of viral rhodopsin genes related to Actinobacteria and Chloroflexi. This is the first report about the existence of a phylogeographic association of the viral rhodopsin sequences from marine sediments.« less

Illuminator, a desktop program for mutation detection using short-read clonal sequencing.

PubMed

Carr, Ian M; Morgan, Joanne E; Diggle, Christine P; Sheridan, Eamonn; Markham, Alexander F; Logan, Clare V; Inglehearn, Chris F; Taylor, Graham R; Bonthron, David T

2011-10-01

Current methods for sequencing clonal populations of DNA molecules yield several gigabases of data per day, typically comprising reads of < 100 nt. Such datasets permit widespread genome resequencing and transcriptome analysis or other quantitative tasks. However, this huge capacity can also be harnessed for the resequencing of smaller (gene-sized) target regions, through the simultaneous parallel analysis of multiple subjects, using sample "tagging" or "indexing". These methods promise to have a huge impact on diagnostic mutation analysis and candidate gene testing. Here we describe a software package developed for such studies, offering the ability to resolve pooled samples carrying barcode tags and to align reads to a reference sequence using a mutation-tolerant process. The program, Illuminator, can identify rare sequence variants, including insertions and deletions, and permits interactive data analysis on standard desktop computers. It facilitates the effective analysis of targeted clonal sequencer data without dedicated computational infrastructure or specialized training. Copyright © 2011 Elsevier Inc. All rights reserved.

Comparative analysis of myostatin gene and promoter sequences of Qinchuan and Red Angus cattle.

PubMed

He, Y L; Wu, Y H; Quan, F S; Liu, Y G; Zhang, Y

2013-09-04

To better understand the function of the myostatin gene and its promoter region in bovine, we amplified and sequenced the myostatin gene and promoter from the blood of Qinchuan and Red Angus cattle by using polymerase chain reaction. The sequences of Qinchuan and Red Angus cattle were compared with those of other cattle breeds available in GenBank. Exon splice sites were confirmed by mRNA sequencing. Compared to the published sequence (GenBank accession No. AF320998), 69 single nucleotide polymorphisms (SNPs) were identified in the Qinchuan myostatin gene, only one of which was an insertion mutation in Qinchuan cattle. There was a 16-bp insertion in the first 705-bp intron in 3 Qinchuan cattle. A total of 7 SNPs were identified in exon 3, in which the mutation occurred in the third base of the codon and was synonymous. On comparing the Qinchuan myostatin gene sequence to that of Red Angus cattle, a total of 50 SNPs were identified in the first and third exons. In addition, there were 18 SNPs identified in the Qinchuan cattle promoter region compared with those of other cattle compared to the Red Angus cattle myostatin promoter region. breeds (GenBank accession No. AF348479), but only 14 SNPs when compared to the Red Angus cattle myostatin promoter region.

The siRNA Non-seed Region and Its Target Sequences Are Auxiliary Determinants of Off-Target Effects.

PubMed

Kamola, Piotr J; Nakano, Yuko; Takahashi, Tomoko; Wilson, Paul A; Ui-Tei, Kumiko

2015-12-01

RNA interference (RNAi) is a powerful tool for post-transcriptional gene silencing. However, the siRNA guide strand may bind unintended off-target transcripts via partial sequence complementarity by a mechanism closely mirroring micro RNA (miRNA) silencing. To better understand these off-target effects, we investigated the correlation between sequence features within various subsections of siRNA guide strands, and its corresponding target sequences, with off-target activities. Our results confirm previous reports that strength of base-pairing in the siRNA seed region is the primary factor determining the efficiency of off-target silencing. However, the degree of downregulation of off-target transcripts with shared seed sequence is not necessarily similar, suggesting that there are additional auxiliary factors that influence the silencing potential. Here, we demonstrate that both the melting temperature (Tm) in a subsection of siRNA non-seed region, and the GC contents of its corresponding target sequences, are negatively correlated with the efficiency of off-target effect. Analysis of experimentally validated miRNA targets demonstrated a similar trend, indicating a putative conserved mechanistic feature of seed region-dependent targeting mechanism. These observations may prove useful as parameters for off-target prediction algorithms and improve siRNA 'specificity' design rules.

Differential recognition of the ORF2 region in a complete genome sequence of porcine circovirus type 2 (PCV2) isolated from boar bone marrow in Korea.

PubMed

Kweon, Chang-Hee; Nguyen, Lien Thi Kim; Yoo, Mi-Sun; Kang, Seung-Won

2015-09-15

Porcine circovirus type 2 (PCV2) is the causative agent of post-weaning multisystemic wasting syndrome (PMWS) in swine. Here, a phylogenetic tree was constructed using PCV2 nucleotide sequences derived from the bone marrow of Korean boar and previously reported PCV2 sequences isolated from various countries. PCV2 from Korean boar bone marrow (KC188796) was classified into the group containing PCV2a-Canada and other PCV2 strain from Korea. While the ORF1 region of the PCV2 genome was highly conserved, ORF2 (the capsid protein coding region) was relatively variable. The nucleotide sequences for bone marrow-derived PCV2 were 93.4-99.0% homologous to the other reference sequences. The deduced amino acid sequences for the ORF1 and ORF2 coding regions were 97.4-99.3% and 84.5-97.4% homologous with the other reference strains, respectively, indicating that KC188796 did not differ markedly from the other PCV2 strains. Phylogenetic analysis demonstrated that bone marrow-derived PCV2 was highly similar to PCV2a from Canada and may be related to persistent PCV2 infections in swine. Copyright © 2015 Elsevier B.V. All rights reserved.

Mosaic organization of DNA nucleotides

NASA Technical Reports Server (NTRS)

Peng, C. K.; Buldyrev, S. V.; Havlin, S.; Simons, M.; Stanley, H. E.; Goldberger, A. L.

1994-01-01

Long-range power-law correlations have been reported recently for DNA sequences containing noncoding regions. We address the question of whether such correlations may be a trivial consequence of the known mosaic structure ("patchiness") of DNA. We analyze two classes of controls consisting of patchy nucleotide sequences generated by different algorithms--one without and one with long-range power-law correlations. Although both types of sequences are highly heterogenous, they are quantitatively distinguishable by an alternative fluctuation analysis method that differentiates local patchiness from long-range correlations. Application of this analysis to selected DNA sequences demonstrates that patchiness is not sufficient to account for long-range correlation properties.

Systematic analysis of transcribed loci in ENCODE regions using RACE sequencing reveals extensive transcription in the human genome.

PubMed

Wu, Jia Qian; Du, Jiang; Rozowsky, Joel; Zhang, Zhengdong; Urban, Alexander E; Euskirchen, Ghia; Weissman, Sherman; Gerstein, Mark; Snyder, Michael

2008-01-03

Recent studies of the mammalian transcriptome have revealed a large number of additional transcribed regions and extraordinary complexity in transcript diversity. However, there is still much uncertainty regarding precisely what portion of the genome is transcribed, the exact structures of these novel transcripts, and the levels of the transcripts produced. We have interrogated the transcribed loci in 420 selected ENCyclopedia Of DNA Elements (ENCODE) regions using rapid amplification of cDNA ends (RACE) sequencing. We analyzed annotated known gene regions, but primarily we focused on novel transcriptionally active regions (TARs), which were previously identified by high-density oligonucleotide tiling arrays and on random regions that were not believed to be transcribed. We found RACE sequencing to be very sensitive and were able to detect low levels of transcripts in specific cell types that were not detectable by microarrays. We also observed many instances of sense-antisense transcripts; further analysis suggests that many of the antisense transcripts (but not all) may be artifacts generated from the reverse transcription reaction. Our results show that the majority of the novel TARs analyzed (60%) are connected to other novel TARs or known exons. Of previously unannotated random regions, 17% were shown to produce overlapping transcripts. Furthermore, it is estimated that 9% of the novel transcripts encode proteins. We conclude that RACE sequencing is an efficient, sensitive, and highly accurate method for characterization of the transcriptome of specific cell/tissue types. Using this method, it appears that much of the genome is represented in polyA+ RNA. Moreover, a fraction of the novel RNAs can encode protein and are likely to be functional.

Beta-keratins of differentiating epidermis of snake comprise glycine-proline-serine-rich proteins with an avian-like gene organization.

PubMed

Dalla Valle, Luisa; Nardi, Alessia; Belvedere, Paola; Toni, Mattia; Alibardi, Lorenzo

2007-07-01

Beta-keratins of reptilian scales have been recently cloned and characterized in some lizards. Here we report for the first time the sequence of some beta-keratins from the snake Elaphe guttata. Five different cDNAs were obtained using 5'- and 3'-RACE analyses. Four sequences differ by only few nucleotides in the coding region, whereas the last cDNA shows, in this region, only 84% of identity. The gene corresponding to one of the cDNA sequences has a single intron present in the 5'-untranslated region. This genomic organization is similar to that of birds' beta-keratins. Cloning and Southern blotting analysis suggest that snake beta-keratins belong to a family of high-related genes as for geckos. PCR analysis suggests a head-to-tail orientation of genes in the same chromosome. In situ hybridization detected beta-keratin transcripts almost exclusively in differentiating oberhautchen and beta-cells of the snake epidermis in renewal phase. This is confirmed by Northern blotting that showed, in this phase, a high expression of two different transcripts whereas only the longer transcript is expressed at a much lower level in resting skin. The cDNA coding sequences encoded putative glycine-proline-serine rich proteins containing 137-139 amino acids, with apparent isoelectric point at 7.5 and 8.2. A central region, rich in proline, shows over 50% homology with avian scale, claw, and feather keratins. The prediction of secondary structure shows mainly a random coil conformation and few beta-strand regions in the central region, likely involved in the formation of a fibrous framework of beta-keratins. This region was possibly present in basic reptiles that originated reptiles and birds. Copyright 2007 Wiley-Liss, Inc.

Sequence variation and phylogenetic analysis of envelope glycoprotein of hepatitis G virus.

PubMed

Lim, M Y; Fry, K; Yun, A; Chong, S; Linnen, J; Fung, K; Kim, J P

1997-11-01

A transfusion-transmissible agent provisionally designated hepatitis G virus (HGV) was recently identified. In this study, we examined the variability of the HGV genome by analysing sequences in the putative envelope region from 72 isolates obtained from diverse geographical sources. The 1561 nucleotide sequence of the E1/E2/NS2a region of HGV was determined from 12 isolates, and compared with three published sequences. The most variability was observed in 400 nucleotides at the N terminus of E2. We next analysed this 400 nucleotide envelope variable region (EV) from an additional 60 HGV isolates. This sequence varied considerably among the 75 isolates, with overall identity ranging from 79.3% to 99.5% at the nucleotide level, and from 83.5% to 100% at the amino acid level. However, hypervariable regions were not identified. Phylogenetic analyses indicated that the 75 HGV isolates belong to a single genotype. A single-tier distribution of evolutionary distances was observed among the 15 E1/E2/NS2a sequences and the 75 EV sequences. In contrast, 11 isolates of HCV were analysed and showed a three-tiered distribution, representing genotypes, subtypes, and isolates. The 75 isolates of HGV fell into four clusters on the phylogenetic tree. Tight geographical clustering was observed among the HGV isolates from Japan and Korea.

Novel splice mutation in microthalmia-associated transcription factor in Waardenburg Syndrome.

PubMed

Brenner, Laura; Burke, Kelly; Leduc, Charles A; Guha, Saurav; Guo, Jiancheng; Chung, Wendy K

2011-01-01

Waardenburg Syndrome (WS) is a syndromic form of hearing loss associated with mutations in six different genes. We identified a large family with WS that had previously undergone clinical testing, with no reported pathogenic mutation. Using linkage analysis, a region on 3p14.1 with an LOD score of 6.6 was identified. Microthalmia-Associated Transcription Factor, a gene known to cause WS, is located within this region of linkage. Sequencing of Microthalmia-Associated Transcription Factor demonstrated a c.1212 G>A synonymous variant that segregated with the WS in the family and was predicted to cause a novel splicing site that was confirmed with expression analysis of the mRNA. This case illustrates the need to computationally analyze novel synonymous sequence variants for possible effects on splicing to maximize the clinical sensitivity of sequence-based genetic testing.

A novel species-specific tandem repeat DNA family from Sinapis arvensis: detection of telomere-like sequences.

PubMed

Kapila, R; Das, S; Srivastava, P S; Lakshmikumaran, M

1996-08-01

DNA sequences representing a tandemly repeated DNA family of the Sinapis arvensis genome were cloned and characterized. The 700-bp tandem repeat family is represented by two clones, pSA35 and pSA52, which are 697 and 709 bp in length, respectively. Dot matrix analysis of the sequences indicates the presence of repeated elements within each monomeric unit. Sequence analysis of the repetitive region of clones pSA35 and pSA52 shows that there are several copies of a 7-bp repeat element organized in tandem. The consensus sequence of this repeat element is 5'-TTTAGGG-3'. These elements are highly mutated and the difference in length between the two clones is due to different copy numbers of these elements. The repetitive region of clone pSA35 has 26 copies of the element TTTAGGG, whereas clone pSA52 has 28 copies. The repetitive region in both clones is flanked on either side by inverted repeats that may be footprints of a transposition event. Sequence comparison indicates that the element TTTAGGG is identical to telomeric repeats present in Arabidopsis, maize, tomato, and other plants. However, Bal31 digestion kinetics indicates non-telomeric localization of the 700-bp tandem repeats. The clones represent a novel repeat family as (i) they contain telomere-like motifs as subrepeats within each unit; and (ii) they do not hybridize to related crucifers and are species-specific in nature.

BayesPI-BAR: a new biophysical model for characterization of regulatory sequence variations

PubMed Central

Wang, Junbai; Batmanov, Kirill

2015-01-01

Sequence variations in regulatory DNA regions are known to cause functionally important consequences for gene expression. DNA sequence variations may have an essential role in determining phenotypes and may be linked to disease; however, their identification through analysis of massive genome-wide sequencing data is a great challenge. In this work, a new computational pipeline, a Bayesian method for protein–DNA interaction with binding affinity ranking (BayesPI-BAR), is proposed for quantifying the effect of sequence variations on protein binding. BayesPI-BAR uses biophysical modeling of protein–DNA interactions to predict single nucleotide polymorphisms (SNPs) that cause significant changes in the binding affinity of a regulatory region for transcription factors (TFs). The method includes two new parameters (TF chemical potentials or protein concentrations and direct TF binding targets) that are neglected by previous methods. The new method is verified on 67 known human regulatory SNPs, of which 47 (70%) have predicted true TFs ranked in the top 10. Importantly, the performance of BayesPI-BAR, which uses principal component analysis to integrate multiple predictions from various TF chemical potentials, is found to be better than that of existing programs, such as sTRAP and is-rSNP, when evaluated on the same SNPs. BayesPI-BAR is a publicly available tool and is able to carry out parallelized computation, which helps to investigate a large number of TFs or SNPs and to detect disease-associated regulatory sequence variations in the sea of genome-wide noncoding regions. PMID:26202972

Analyses of mitochondrial amino acid sequence datasets support the proposal that specimens of Hypodontus macropi from three species of macropodid hosts represent distinct species

PubMed Central

2013-01-01

Background Hypodontus macropi is a common intestinal nematode of a range of kangaroos and wallabies (macropodid marsupials). Based on previous multilocus enzyme electrophoresis (MEE) and nuclear ribosomal DNA sequence data sets, H. macropi has been proposed to be complex of species. To test this proposal using independent molecular data, we sequenced the whole mitochondrial (mt) genomes of individuals of H. macropi from three different species of hosts (Macropus robustus robustus, Thylogale billardierii and Macropus [Wallabia] bicolor) as well as that of Macropicola ocydromi (a related nematode), and undertook a comparative analysis of the amino acid sequence datasets derived from these genomes. Results The mt genomes sequenced by next-generation (454) technology from H. macropi from the three host species varied from 13,634 bp to 13,699 bp in size. Pairwise comparisons of the amino acid sequences predicted from these three mt genomes revealed differences of 5.8% to 18%. Phylogenetic analysis of the amino acid sequence data sets using Bayesian Inference (BI) showed that H. macropi from the three different host species formed distinct, well-supported clades. In addition, sliding window analysis of the mt genomes defined variable regions for future population genetic studies of H. macropi in different macropodid hosts and geographical regions around Australia. Conclusions The present analyses of inferred mt protein sequence datasets clearly supported the hypothesis that H. macropi from M. robustus robustus, M. bicolor and T. billardierii represent distinct species. PMID:24261823

Draft genome sequence of bitter gourd (Momordica charantia), a vegetable and medicinal plant in tropical and subtropical regions.

PubMed

Urasaki, Naoya; Takagi, Hiroki; Natsume, Satoshi; Uemura, Aiko; Taniai, Naoki; Miyagi, Norimichi; Fukushima, Mai; Suzuki, Shouta; Tarora, Kazuhiko; Tamaki, Moritoshi; Sakamoto, Moriaki; Terauchi, Ryohei; Matsumura, Hideo

2017-02-01

Bitter gourd (Momordica charantia) is an important vegetable and medicinal plant in tropical and subtropical regions globally. In this study, the draft genome sequence of a monoecious bitter gourd inbred line, OHB3-1, was analyzed. Through Illumina sequencing and de novo assembly, scaffolds of 285.5 Mb in length were generated, corresponding to ∼84% of the estimated genome size of bitter gourd (339 Mb). In this draft genome sequence, 45,859 protein-coding gene loci were identified, and transposable elements accounted for 15.3% of the whole genome. According to synteny mapping and phylogenetic analysis of conserved genes, bitter gourd was more related to watermelon (Citrullus lanatus) than to cucumber (Cucumis sativus) or melon (C. melo). Using RAD-seq analysis, 1507 marker loci were genotyped in an F2 progeny of two bitter gourd lines, resulting in an improved linkage map, comprising 11 linkage groups. By anchoring RAD tag markers, 255 scaffolds were assigned to the linkage map. Comparative analysis of genome sequences and predicted genes determined that putative trypsin-inhibitor and ribosome-inactivating genes were distinctive in the bitter gourd genome. These genes could characterize the bitter gourd as a medicinal plant. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Genomic region operation kit for flexible processing of deep sequencing data.

PubMed

Ovaska, Kristian; Lyly, Lauri; Sahu, Biswajyoti; Jänne, Olli A; Hautaniemi, Sampsa

2013-01-01

Computational analysis of data produced in deep sequencing (DS) experiments is challenging due to large data volumes and requirements for flexible analysis approaches. Here, we present a mathematical formalism based on set algebra for frequently performed operations in DS data analysis to facilitate translation of biomedical research questions to language amenable for computational analysis. With the help of this formalism, we implemented the Genomic Region Operation Kit (GROK), which supports various DS-related operations such as preprocessing, filtering, file conversion, and sample comparison. GROK provides high-level interfaces for R, Python, Lua, and command line, as well as an extension C++ API. It supports major genomic file formats and allows storing custom genomic regions in efficient data structures such as red-black trees and SQL databases. To demonstrate the utility of GROK, we have characterized the roles of two major transcription factors (TFs) in prostate cancer using data from 10 DS experiments. GROK is freely available with a user guide from >http://csbi.ltdk.helsinki.fi/grok/.

In silico Analysis of 3′-End-Processing Signals in Aspergillus oryzae Using Expressed Sequence Tags and Genomic Sequencing Data

PubMed Central

Tanaka, Mizuki; Sakai, Yoshifumi; Yamada, Osamu; Shintani, Takahiro; Gomi, Katsuya

2011-01-01

To investigate 3′-end-processing signals in Aspergillus oryzae, we created a nucleotide sequence data set of the 3′-untranslated region (3′ UTR) plus 100 nucleotides (nt) sequence downstream of the poly(A) site using A. oryzae expressed sequence tags and genomic sequencing data. This data set comprised 1065 sequences derived from 1042 unique genes. The average 3′ UTR length in A. oryzae was 241 nt, which is greater than that in yeast but similar to that in plants. The 3′ UTR and 100 nt sequence downstream of the poly(A) site is notably U-rich, while the region located 15–30 nt upstream of the poly(A) site is markedly A-rich. The most frequently found hexanucleotide in this A-rich region is AAUGAA, although this sequence accounts for only 6% of all transcripts. These data suggested that A. oryzae has no highly conserved sequence element equivalent to AAUAAA, a mammalian polyadenylation signal. We identified that putative 3′-end-processing signals in A. oryzae, while less well conserved than those in mammals, comprised four sequence elements: the furthest upstream U-rich element, A-rich sequence, cleavage site, and downstream U-rich element flanking the cleavage site. Although these putative 3′-end-processing signals are similar to those in yeast and plants, some notable differences exist between them. PMID:21586533

Genomic analysis of the chromosome 15q11-q13 Prader-Willi syndrome region and characterization of transcripts for GOLGA8E and WHCD1L1 from the proximal breakpoint region.

PubMed

Jiang, Yong-Hui; Wauki, Kekio; Liu, Qian; Bressler, Jan; Pan, Yanzhen; Kashork, Catherine D; Shaffer, Lisa G; Beaudet, Arthur L

2008-01-28

Prader-Willi syndrome (PWS) is a neurobehavioral disorder characterized by neonatal hypotonia, childhood obesity, dysmorphic features, hypogonadism, mental retardation, and behavioral problems. Although PWS is most often caused by a paternal interstitial deletion of a 6-Mb region of chromosome 15q11-q13, the identity of the exact protein coding or noncoding RNAs whose deficiency produces the PWS phenotype is uncertain. There are also reports describing a PWS-like phenotype in a subset of patients with full mutations in the FMR1 (fragile X mental retardation 1) gene. Taking advantage of the human genome sequence, we have performed extensive sequence analysis and molecular studies for the PWS candidate region. We have characterized transcripts for the first time for two UCSC Genome Browser predicted protein-coding genes, GOLGA8E (golgin subfamily a, 8E) and WHDC1L1 (WAS protein homology region containing 1-like 1) and have further characterized two previously reported genes, CYF1P1 and NIPA2; all four genes are in the region close to the proximal/centromeric deletion breakpoint (BP1). GOLGA8E belongs to the golgin subfamily of coiled-coil proteins associated with the Golgi apparatus. Six out of 16 golgin subfamily proteins in the human genome have been mapped in the chromosome 15q11-q13 and 15q24-q26 regions. We have also identified more than 38 copies of GOLGA8E-like sequence in the 15q11-q14 and 15q23-q26 regions which supports the presence of a GOLGA8E-associated low copy repeat (LCR). Analysis of the 15q11-q13 region by PFGE also revealed a polymorphic region between BP1 and BP2. WHDC1L1 is a novel gene with similarity to mouse Whdc1 (WAS protein homology region 2 domain containing 1) and human JMY protein (junction-mediating and regulatory protein). Expression analysis of cultured human cells and brain tissues from PWS patients indicates that CYFIP1 and NIPA2 are biallelically expressed. However, we were not able to determine the allele-specific expression pattern for GOLGA8E and WHDC1L1 because these two genes have highly related sequences that might also be expressed. We have presented an updated version of a sequence-based physical map for a complex chromosomal region, and we raise the possibility of polymorphism in the genomic orientation of the BP1 to BP2 region. The identification of two new proteins GOLGA8E and WHDC1L1 encoded by genes in the 15q11-q13 region may extend our understanding of the molecular basis of PWS. In terms of copy number variation and gene organization, this is one of the most polymorphic regions of the human genome, and perhaps the single most polymorphic region of this type.

Sequences within the 5' untranslated region regulate the levels of a kinetoplast DNA topoisomerase mRNA during the cell cycle.

PubMed Central

Pasion, S G; Hines, J C; Ou, X; Mahmood, R; Ray, D S

1996-01-01

Gene expression in trypanosomatids appears to be regulated largely at the posttranscriptional level and involves maturation of mRNA precursors by trans splicing of a 39-nucleotide miniexon sequence to the 5' end of the mRNA and cleavage and polyadenylation at the 3' end of the mRNA. To initiate the identification of sequences involved in the periodic expression of DNA replication genes in trypanosomatids, we have mapped splice acceptor sites in the 5' flanking region of the TOP2 gene, which encodes the kinetoplast DNA topoisomerase, and have carried out deletion analysis of this region on a plasmid-encoded TOP2 gene. Block deletions within the 5' untranslated region (UTR) identified two regions (-608 to -388 and -387 to -186) responsible for periodic accumulation of the mRNA. Deletion of one or the other of these sequences had no effect on periodic expression of the mRNA, while deletion of both regions resulted in constitutive expression of the mRNA throughout the cell cycle. Subcloning of these sequences into the 5' UTR of a construct lacking both regions of the TOP2 5' UTR has shown that an octamer consensus sequence present in the 5' UTR of the TOP2, RPA1, and DHFR-TS mRNAs is required for normal cycling of the TOP2 mRNA. Mutation of the consensus octamer sequence in the TOP2 5' UTR in a plasmid construct containing only a single consensus octamer and that shows normal cycling of the plasmid-encoded TOP2 mRNA resulted in substantial reduction of the cycling of the mRNA level. These results imply a negative regulation of TOP2 mRNA during the cell cycle by a mechanism involving redundant elements containing one or more copies of a conserved octamer sequence within the 5' UTR of TOP2 mRNA. PMID:8943327

Sequences within the 5' untranslated region regulate the levels of a kinetoplast DNA topoisomerase mRNA during the cell cycle.

PubMed

Pasion, S G; Hines, J C; Ou, X; Mahmood, R; Ray, D S

1996-12-01

Gene expression in trypanosomatids appears to be regulated largely at the posttranscriptional level and involves maturation of mRNA precursors by trans splicing of a 39-nucleotide miniexon sequence to the 5' end of the mRNA and cleavage and polyadenylation at the 3' end of the mRNA. To initiate the identification of sequences involved in the periodic expression of DNA replication genes in trypanosomatids, we have mapped splice acceptor sites in the 5' flanking region of the TOP2 gene, which encodes the kinetoplast DNA topoisomerase, and have carried out deletion analysis of this region on a plasmid-encoded TOP2 gene. Block deletions within the 5' untranslated region (UTR) identified two regions (-608 to -388 and -387 to -186) responsible for periodic accumulation of the mRNA. Deletion of one or the other of these sequences had no effect on periodic expression of the mRNA, while deletion of both regions resulted in constitutive expression of the mRNA throughout the cell cycle. Subcloning of these sequences into the 5' UTR of a construct lacking both regions of the TOP2 5' UTR has shown that an octamer consensus sequence present in the 5' UTR of the TOP2, RPA1, and DHFR-TS mRNAs is required for normal cycling of the TOP2 mRNA. Mutation of the consensus octamer sequence in the TOP2 5' UTR in a plasmid construct containing only a single consensus octamer and that shows normal cycling of the plasmid-encoded TOP2 mRNA resulted in substantial reduction of the cycling of the mRNA level. These results imply a negative regulation of TOP2 mRNA during the cell cycle by a mechanism involving redundant elements containing one or more copies of a conserved octamer sequence within the 5' UTR of TOP2 mRNA.

Comparative Analysis of the Shared Sex-Determination Region (SDR) among Salmonid Fishes.

PubMed

Faber-Hammond, Joshua J; Phillips, Ruth B; Brown, Kim H

2015-06-25

Salmonids present an excellent model for studying evolution of young sex-chromosomes. Within the genus, Oncorhynchus, at least six independent sex-chromosome pairs have evolved, many unique to individual species. This variation results from the movement of the sex-determining gene, sdY, throughout the salmonid genome. While sdY is known to define sexual differentiation in salmonids, the mechanism of its movement throughout the genome has remained elusive due to high frequencies of repetitive elements, rDNA sequences, and transposons surrounding the sex-determining regions (SDR). Despite these difficulties, bacterial artificial chromosome (BAC) library clones from both rainbow trout and Atlantic salmon containing the sdY region have been reported. Here, we report the sequences for these BACs as well as the extended sequence for the known SDR in Chinook gained through genome walking methods. Comparative analysis allowed us to study the overlapping SDRs from three unique salmonid Y chromosomes to define the specific content, size, and variation present between the species. We found approximately 4.1 kb of orthologous sequence common to all three species, which contains the genetic content necessary for masculinization. The regions contain transposable elements that may be responsible for the translocations of the SDR throughout salmonid genomes and we examine potential mechanistic roles of each one. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Sequence Evolution and Expression Regulation of Stress-Responsive Genes in Natural Populations of Wild Tomato

PubMed Central

Fischer, Iris; Steige, Kim A.; Stephan, Wolfgang; Mboup, Mamadou

2013-01-01

The wild tomato species Solanum chilense and S. peruvianum are a valuable non-model system for studying plant adaptation since they grow in diverse environments facing many abiotic constraints. Here we investigate the sequence evolution of regulatory regions of drought and cold responsive genes and their expression regulation. The coding regions of these genes were previously shown to exhibit signatures of positive selection. Expression profiles and sequence evolution of regulatory regions of members of the Asr (ABA/water stress/ripening induced) gene family and the dehydrin gene pLC30-15 were analyzed in wild tomato populations from contrasting environments. For S. chilense, we found that Asr4 and pLC30-15 appear to respond much faster to drought conditions in accessions from very dry environments than accessions from more mesic locations. Sequence analysis suggests that the promoter of Asr2 and the downstream region of pLC30-15 are under positive selection in some local populations of S. chilense. By investigating gene expression differences at the population level we provide further support of our previous conclusions that Asr2, Asr4, and pLC30-15 are promising candidates for functional studies of adaptation. Our analysis also demonstrates the power of the candidate gene approach in evolutionary biology research and highlights the importance of wild Solanum species as a genetic resource for their cultivated relatives. PMID:24205149

Regulation of iron assimilation: nucleotide sequence analysis of an iron-regulated promoter from a fluorescent pseudomonad.

PubMed

O'Sullivan, D J; O'Gara, F

1991-08-01

An iron-regulated promoter was cloned on a 2.1 kb Bg/II fragment from Pseudomonas sp. strain M114 and fused to the lacZ reporter gene. Iron-regulated lacZ expression from the resulting construct (pSP1) in strain M114 was mediated via the Fur-like repressor which also regulates siderophore production in this strain. A 390 bp StuI-PstI internal fragment contained the necessary information for iron-regulated promoter expression. This fragment was sequenced and the initiation point for transcription was determined by primer extension analysis. The region directly upstream of the transcription start point contained no significant homology to known promoter consensus sequences. However the -16 to -25 bp region contained homology to four other iron-regulated pseudomonad promoters. Deletion of bases downstream from the transcriptional start did not affect the iron-regulated expression of the promoter. The -37 and -43 bp regions exhibited some homology to the 19 bp Escherichia coli Fur-binding consensus sequence. When expressed in E. coli (via a cloned transacting factor from strain M114) lacZ expression from pSP1 was found to be regulated by iron. A region of greater than 77 bases but less than 131 upstream from the transcriptional start was found to be necessary for promoter activity, further suggesting that a transcriptional activator may be required for expression.

Y chromosomal haplotype characteristics of domestic sheep (Ovis aries) in China.

PubMed

Wang, Yutao; Xu, Lei; Yan, Wei; Li, Shaobin; Wang, Jiqing; Liu, Xiu; Hu, Jiang; Luo, Yuzhu

2015-07-10

Investigations on the variation present at the male-specific Y chromosome region provide strong information to understand the origin and evolution of domestic sheep. One SNP OY1 (g.88A>G) in the upstream region of SRY gene, and the microsatellite SRYM18 locus within ovine Y chromosome were analyzed in one hundred and forty five samples collected from eleven breeds in China. SNP OY1 was analyzed using PCR-SSCP method and sequencing. Two different PCR-SSCP patterns represented two specific sequences with sequence analysis revealing SNP-OY1 (g.88A>G) were observed, while SNP A-OY1 showed the most common frequency (82.8%). Sequencing of the SRYM18 region revealed one novel size fragment (A2) with different repetitive units. Seven haplotypes (H4, H5, H6, H7, H8, H9 and H12) and two novel haplotypes (Ha and Hb) were established using combined genotype analysis. H6 showed the highest frequency (43.4%) across all breeds, and H8 showed the second frequency (24.1%). Ha was only found in one breed (Tan), while Hb was present in three breeds (Gansu alpine, White Suffolk and Duolang). Our findings reveal one novel allele in SRYM18 region and two novel male haplotypes of domestic sheep in China. Copyright © 2015 Elsevier B.V. All rights reserved.

rpoB Gene Sequence-Based Identification of Aerobic Gram-Positive Cocci of the Genera Streptococcus, Enterococcus, Gemella, Abiotrophia, and Granulicatella

PubMed Central

Drancourt, Michel; Roux, Véronique; Fournier, Pierre-Edouard; Raoult, Didier

2004-01-01

We developed a new molecular tool based on rpoB gene (encoding the beta subunit of RNA polymerase) sequencing to identify streptococci. We first sequenced the complete rpoB gene for Streptococcus anginosus, S. equinus, and Abiotrophia defectiva. Sequences were aligned with these of S. pyogenes, S. agalactiae, and S. pneumoniae available in GenBank. Using an in-house analysis program (SVARAP), we identified a 740-bp variable region surrounded by conserved, 20-bp zones and, by using these conserved zones as PCR primer targets, we amplified and sequenced this variable region in an additional 30 Streptococcus, Enterococcus, Gemella, Granulicatella, and Abiotrophia species. This region exhibited 71.2 to 99.3% interspecies homology. We therefore applied our identification system by PCR amplification and sequencing to a collection of 102 streptococci and 60 bacterial isolates belonging to other genera. Amplicons were obtained in streptococci and Bacillus cereus, and sequencing allowed us to make a correct identification of streptococci. Molecular signatures were determined for the discrimination of closely related species within the S. pneumoniae-S. oralis-S. mitis group and the S. agalactiae-S. difficile group. These signatures allowed us to design a S. pneumoniae-specific PCR and sequencing primer pair. PMID:14766807

RAMICS: trainable, high-speed and biologically relevant alignment of high-throughput sequencing reads to coding DNA

PubMed Central

Wright, Imogen A.; Travers, Simon A.

2014-01-01

The challenge presented by high-throughput sequencing necessitates the development of novel tools for accurate alignment of reads to reference sequences. Current approaches focus on using heuristics to map reads quickly to large genomes, rather than generating highly accurate alignments in coding regions. Such approaches are, thus, unsuited for applications such as amplicon-based analysis and the realignment phase of exome sequencing and RNA-seq, where accurate and biologically relevant alignment of coding regions is critical. To facilitate such analyses, we have developed a novel tool, RAMICS, that is tailored to mapping large numbers of sequence reads to short lengths (<10 000 bp) of coding DNA. RAMICS utilizes profile hidden Markov models to discover the open reading frame of each sequence and aligns to the reference sequence in a biologically relevant manner, distinguishing between genuine codon-sized indels and frameshift mutations. This approach facilitates the generation of highly accurate alignments, accounting for the error biases of the sequencing machine used to generate reads, particularly at homopolymer regions. Performance improvements are gained through the use of graphics processing units, which increase the speed of mapping through parallelization. RAMICS substantially outperforms all other mapping approaches tested in terms of alignment quality while maintaining highly competitive speed performance. PMID:24861618

[Phylogenetic and diversity analysis of Acidithiobacillus spp. based on 16S rRNA and RubisCO genes homologues].

PubMed

Liu, Minrui; Lin, Pengwu; Qi, Xing'e; Ni, Yongqing

2016-04-14

The purpose of the study was to reveal geographic region-related Acidithiobacillus spp. distribution and allopatric speciation. Phylogenetic and diversity analysis was done to expand our knowledge on microbial phylogeography, diversity-maintaining mechanisms and molecular biogeography. We amplified 16S rRNA gene and RubisCO genes to construct corresponding phylogenetic trees based on the sequence homology and analyzed genetic diversity of Acidithiobacillus spp.. Thirty-five strains were isolated from three different regions in China (Yunnan, Hubei, Xinjiang). The whole isolates were classified into five groups. Four strains were identified as A. ferrivorans, six as A. ferridurans, YNTR4-15 Leptspirillum ferrooxidans and HBDY3-31 as Leptospirillum ferrodiazotrophum. The remaining strains were identified as A. ferrooxidans. Analysis of cbbL and cbbM genes sequences of representative 26 strains indicated that cbbL gene of 19 were two copies (cbbL1 and cbbL2) and 7 possessed only cbbL1. cbbM gene was single copy. In nucleotide-based trees, cbbL1 gene sequences of strains were separated into three sequence types, and the cbbL2 was similar to cbbL1 with three types. Codon bias of RubisCO genes was not obvious in Acidithiobacillus spp.. Strains isolated from three different regions in China indicated a great genetic diversity in Acidithiobacillus spp. and their 16S rRNA/RubisCO genes sequence was of significant difference. Phylogenetic tree based on 16S rRNA genes and RubisCO genes was different in Acidithiobacillus spp..

DNA replication-timing analysis of human chromosome 22 at high resolution and different developmental states.

PubMed

White, Eric J; Emanuelsson, Olof; Scalzo, David; Royce, Thomas; Kosak, Steven; Oakeley, Edward J; Weissman, Sherman; Gerstein, Mark; Groudine, Mark; Snyder, Michael; Schübeler, Dirk

2004-12-21

Duplication of the genome during the S phase of the cell cycle does not occur simultaneously; rather, different sequences are replicated at different times. The replication timing of specific sequences can change during development; however, the determinants of this dynamic process are poorly understood. To gain insights into the contribution of developmental state, genomic sequence, and transcriptional activity to replication timing, we investigated the timing of DNA replication at high resolution along an entire human chromosome (chromosome 22) in two different cell types. The pattern of replication timing was correlated with respect to annotated genes, gene expression, novel transcribed regions of unknown function, sequence composition, and cytological features. We observed that chromosome 22 contains regions of early- and late-replicating domains of 100 kb to 2 Mb, many (but not all) of which are associated with previously described chromosomal bands. In both cell types, expressed sequences are replicated earlier than nontranscribed regions. However, several highly transcribed regions replicate late. Overall, the DNA replication-timing profiles of the two different cell types are remarkably similar, with only nine regions of difference observed. In one case, this difference reflects the differential expression of an annotated gene that resides in this region. Novel transcribed regions with low coding potential exhibit a strong propensity for early DNA replication. Although the cellular function of such transcripts is poorly understood, our results suggest that their activity is linked to the replication-timing program.

Genetic differences between blood- and brain-derived viral sequences from human immunodeficiency virus type 1-infected patients: evidence of conserved elements in the V3 region of the envelope protein of brain-derived sequences.

PubMed Central

Korber, B T; Kunstman, K J; Patterson, B K; Furtado, M; McEvilly, M M; Levy, R; Wolinsky, S M

1994-01-01

Human immunodeficiency virus type 1 (HIV-1) sequences were generated from blood and from brain tissue obtained by stereotactic biopsy from six patients undergoing a diagnostic neurosurgical procedure. Proviral DNA was directly amplified by nested PCR, and 8 to 36 clones from each sample were sequenced. Phylogenetic analysis of intrapatient envelope V3-V5 region HIV-1 DNA sequence sets revealed that brain viral sequences were clustered relative to the blood viral sequences, suggestive of tissue-specific compartmentalization of the virus in four of the six cases. In the other two cases, the blood and brain virus sequences were intermingled in the phylogenetic analyses, suggesting trafficking of virus between the two tissues. Slide-based PCR-driven in situ hybridization of two of the patients' brain biopsy samples confirmed our interpretation of the intrapatient phylogenetic analyses. Interpatient V3 region brain-derived sequence distances were significantly less than blood-derived sequence distances. Relative to the tip of the loop, the set of brain-derived viral sequences had a tendency towards negative or neutral charge compared with the set of blood-derived viral sequences. Entropy calculations were used as a measure of the variability at each position in alignments of blood and brain viral sequences. A relatively conserved set of positions were found, with a significantly lower entropy in the brain-than in the blood-derived viral sequences. These sites constitute a brain "signature pattern," or a noncontiguous set of amino acids in the V3 region conserved in viral sequences derived from brain tissue. This brain-derived signature pattern was also well preserved among isolates previously characterized in vitro as macrophage tropic. Macrophage-monocyte tropism may be the biological constraint that results in the conservation of the viral brain signature pattern. Images PMID:7933130

Myostatin-2 gene structure and polymorphism of the promoter and first intron in the marine fish Sparus aurata: evidence for DNA duplications and/or translocations.

PubMed

Nadjar-Boger, Elisabeth; Funkenstein, Bruria

2011-02-01

Myostatin (MSTN) is a member of the transforming growth factor-ß superfamily that functions as a negative regulator of skeletal muscle development and growth in mammals. Fish express at least two genes for MSTN: MSTN-1 and MSTN-2. To date, MSTN-2 promoters have been cloned only from salmonids and zebrafish. Here we described the cloning and sequence analysis of MSTN-2 gene and its 5' flanking region in the marine fish Sparus aurata (saMSTN-2). We demonstrate the existence of three alleles of the promoter and three alleles of the first intron. Sequence comparison of the promoter region in the three alleles revealed that although the sequences of the first 1050 bp upstream of the translation start site are almost identical in the three alleles, a substantial sequence divergence is seen further upstream. Careful sequence analysis of the region upstream of the first 1050 bp in the three alleles identified several elements that appear to be repeated in some or all sequences, at different positions. This suggests that the promoter region of saMSTN-2 has been subjected to various chromosomal rearrangements during the course of evolution, reflecting either insertion or deletion events. Screening of several genomic DNA collections indicated differences in allele frequency, with allele 'b' being the most abundant, followed by allele 'c', whereas allele 'a' is relatively rare. Sequence analysis of saMSTN-2 gene also revealed polymorphism in the first intron, identifying three alleles. The length difference in alleles '1R' and '2R' of the first intron is due to the presence of one or two copies of a repeated block of approximately 150 bp, located at the 5' end of the first intron. The third allele, '4R', has an additional insertion of 323 bp located 116 bp upstream of the 3' end of the first intron. Analysis of several DNA collections showed that the '2R' allele is the most common, followed by the '4R' allele, whereas the '1R' allele is relatively rare. Progeny analysis of a full-sib family showed a Mendelian mode of inheritance of the two genetic loci. No clear association was found between the two genetic markers and growth rate. These results show for the first time a substantial degree of polymorphism in both the promoter and first intron of MSTN-2 gene in a perciform fish species which points to chromosomal rearrangements that took place during evolution.

Evidence for the Concerted Evolution between Short Linear Protein Motifs and Their Flanking Regions

PubMed Central

Chica, Claudia; Diella, Francesca; Gibson, Toby J.

2009-01-01

Background Linear motifs are short modules of protein sequences that play a crucial role in mediating and regulating many protein–protein interactions. The function of linear motifs strongly depends on the context, e.g. functional instances mainly occur inside flexible regions that are accessible for interaction. Sometimes linear motifs appear as isolated islands of conservation in multiple sequence alignments. However, they also occur in larger blocks of sequence conservation, suggesting an active role for the neighbouring amino acids. Results The evolution of regions flanking 116 functional linear motif instances was studied. The conservation of the amino acid sequence and order/disorder tendency of those regions was related to presence/absence of the instance. For the majority of the analysed instances, the pairs of sequences conserving the linear motif were also observed to maintain a similar local structural tendency and/or to have higher local sequence conservation when compared to pairs of sequences where one is missing the linear motif. Furthermore, those instances have a higher chance to co–evolve with the neighbouring residues in comparison to the distant ones. Those findings are supported by examples where the regulation of the linear motif–mediated interaction has been shown to depend on the modifications (e.g. phosphorylation) at neighbouring positions or is thought to benefit from the binding versatility of disordered regions. Conclusion The results suggest that flanking regions are relevant for linear motif–mediated interactions, both at the structural and sequence level. More interestingly, they indicate that the prediction of linear motif instances can be enriched with contextual information by performing a sequence analysis similar to the one presented here. This can facilitate the understanding of the role of these predicted instances in determining the protein function inside the broader context of the cellular network where they arise. PMID:19584925

Phylogenetic relationship of Paenibacillus species based on putative replication origin regions and analysis of an yheCD-like sequence found in this region.

PubMed

Iiyama, Kazuhiro; Otao, Masahiro; Mori, Kazuki; Mon, Hiroaki; Lee, Jae Man; Kusakabe, Takahiro; Tashiro, Kousuke; Asano, Shin-Ichiro; Yasunaga-Aoki, Chisa

2014-01-01

To determine the phylogenetic relationship among Paenibacillus species, putative replication origin regions were compared. In the rsmG-gyrA region, gene arrangements in Paenibacillus species were identical to those of Bacillus species, with the exception of an open reading frame (orf14) positioned between gyrB and gyrA, which was observed only in Paenibacillus species. The orf14 product was homologous to the endospore-associated proteins YheC and YheD of Bacillus subtilis. Phylogenetic analysis based on the YheCD proteins suggested that Orf14 could be categorized into the YheC group. In the Paenibacillus genome, DnaA box clusters were found in rpmH-dnaA and dnaA-dnaN intergenic regions, known as box regions C and R, respectively; this localization was similar to that observed in B. halodurans. A phylogenetic tree based on the nucleotide sequences of the whole replication origin regions suggested that P. popilliae, P. thiaminolyticus, and P. dendritiformis are closely related species.

Genome-wide comparisons of phylogenetic similarities between partial genomic regions and the full-length genome in Hepatitis E virus genotyping.

PubMed

Wang, Shuai; Wei, Wei; Luo, Xuenong; Cai, Xuepeng

2014-01-01

Besides the complete genome, different partial genomic sequences of Hepatitis E virus (HEV) have been used in genotyping studies, making it difficult to compare the results based on them. No commonly agreed partial region for HEV genotyping has been determined. In this study, we used a statistical method to evaluate the phylogenetic performance of each partial genomic sequence from a genome wide, by comparisons of evolutionary distances between genomic regions and the full-length genomes of 101 HEV isolates to identify short genomic regions that can reproduce HEV genotype assignments based on full-length genomes. Several genomic regions, especially one genomic region at the 3'-terminal of the papain-like cysteine protease domain, were detected to have relatively high phylogenetic correlations with the full-length genome. Phylogenetic analyses confirmed the identical performances between these regions and the full-length genome in genotyping, in which the HEV isolates involved could be divided into reasonable genotypes. This analysis may be of value in developing a partial sequence-based consensus classification of HEV species.

In Silico Analysis of Correlations between Protein Disorder and Post-Translational Modifications in Algae

PubMed Central

Kurotani, Atsushi; Sakurai, Tetsuya

2015-01-01

Recent proteome analyses have reported that intrinsically disordered regions (IDRs) of proteins play important roles in biological processes. In higher plants whose genomes have been sequenced, the correlation between IDRs and post-translational modifications (PTMs) has been reported. The genomes of various eukaryotic algae as common ancestors of plants have also been sequenced. However, no analysis of the relationship to protein properties such as structure and PTMs in algae has been reported. Here, we describe correlations between IDR content and the number of PTM sites for phosphorylation, glycosylation, and ubiquitination, and between IDR content and regions rich in proline, glutamic acid, serine, and threonine (PEST) and transmembrane helices in the sequences of 20 algae proteomes. Phosphorylation, O-glycosylation, ubiquitination, and PEST preferentially occurred in disordered regions. In contrast, transmembrane helices were favored in ordered regions. N-glycosylation tended to occur in ordered regions in most of the studied algae; however, it correlated positively with disordered protein content in diatoms. Additionally, we observed that disordered protein content and the number of PTM sites were significantly increased in the species-specific protein clusters compared to common protein clusters among the algae. Moreover, there were specific relationships between IDRs and PTMs among the algae from different groups. PMID:26307970

In Silico Analysis of Correlations between Protein Disorder and Post-Translational Modifications in Algae.

PubMed

Kurotani, Atsushi; Sakurai, Tetsuya

2015-08-20

Recent proteome analyses have reported that intrinsically disordered regions (IDRs) of proteins play important roles in biological processes. In higher plants whose genomes have been sequenced, the correlation between IDRs and post-translational modifications (PTMs) has been reported. The genomes of various eukaryotic algae as common ancestors of plants have also been sequenced. However, no analysis of the relationship to protein properties such as structure and PTMs in algae has been reported. Here, we describe correlations between IDR content and the number of PTM sites for phosphorylation, glycosylation, and ubiquitination, and between IDR content and regions rich in proline, glutamic acid, serine, and threonine (PEST) and transmembrane helices in the sequences of 20 algae proteomes. Phosphorylation, O-glycosylation, ubiquitination, and PEST preferentially occurred in disordered regions. In contrast, transmembrane helices were favored in ordered regions. N-glycosylation tended to occur in ordered regions in most of the studied algae; however, it correlated positively with disordered protein content in diatoms. Additionally, we observed that disordered protein content and the number of PTM sites were significantly increased in the species-specific protein clusters compared to common protein clusters among the algae. Moreover, there were specific relationships between IDRs and PTMs among the algae from different groups.

Isolation of a promoter region in mouse cytochrome P450 3A (Cyp3A16) gene and its transcriptional control.

PubMed

Itoh, S; Abe, Y; Kubo, A; Okuda, M; Shimoji, M; Nakayama, K; Kamataki, T

1997-02-07

An 11.5 kb fragment of the mouse Cyp3a16 gene containing the 5' flanking region was isolated from the lambda DASHII mouse genomic library. A part of the 5' flanking region and the first exon of Cyp3a16 gene were sequenced. S1 mapping analysis showed the presence of two transcriptional initiation sites. The first exon was completely identical to Cyp3a16 cDNA. The identity of 5' flanking sequences between Cyp3a16 and Cyp3a11 genes was about 69%. A typical TATA box and a basic transcription element (BTE) were found as seen with other CYP3A genes from various animal species Moreover, some putative transcriptional regulatory elements were also found in addition to the sequence motif seen for the formation of Z-type DNA. To examine the transcriptional activity of Cyp3a11 gene, DNA fragments in the 5'-flanking region of the gene were inserted front of the luciferase structural gene, and the constructs were transfected in primary hepatocytes. The analysis of the luciferase activity indicated that the region between -146 and -56 was necessary for the transcription of CYP3a16 gene.

Revealing representational content with pattern-information fMRI--an introductory guide.

PubMed

Mur, Marieke; Bandettini, Peter A; Kriegeskorte, Nikolaus

2009-03-01

Conventional statistical analysis methods for functional magnetic resonance imaging (fMRI) data are very successful at detecting brain regions that are activated as a whole during specific mental activities. The overall activation of a region is usually taken to indicate involvement of the region in the task. However, such activation analysis does not consider the multivoxel patterns of activity within a brain region. These patterns of activity, which are thought to reflect neuronal population codes, can be investigated by pattern-information analysis. In this framework, a region's multivariate pattern information is taken to indicate representational content. This tutorial introduction motivates pattern-information analysis, explains its underlying assumptions, introduces the most widespread methods in an intuitive way, and outlines the basic sequence of analysis steps.

The complete chloroplast genome sequence of Euonymus japonicus (Celastraceae).

PubMed

Choi, Kyoung Su; Park, SeonJoo

2016-09-01

The complete chloroplast (cp) genome sequence of the Euonymus japonicus, the first sequenced of the genus Euonymus, was reported in this study. The total length was 157 637 bp, containing a pair of 26 678 bp inverted repeat region (IR), which were separated by small single copy (SSC) region and large single copy (LSC) region of 18 340 bp and 85 941 bp, respectively. This genome contains 107 unique genes, including 74 coding genes, four rRNA genes, and 29 tRNA genes. Seventeen genes contain intron of E. japonicus, of which three genes (clpP, ycf3, and rps12) include two introns. The maximum likelihood (ML) phylogenetic analysis revealed that E. japonicus was closely related to Manihot and Populus.

Simultaneous mutation and copy number variation (CNV) detection by multiplex PCR-based GS-FLX sequencing.

PubMed

Goossens, Dirk; Moens, Lotte N; Nelis, Eva; Lenaerts, An-Sofie; Glassee, Wim; Kalbe, Andreas; Frey, Bruno; Kopal, Guido; De Jonghe, Peter; De Rijk, Peter; Del-Favero, Jurgen

2009-03-01

We evaluated multiplex PCR amplification as a front-end for high-throughput sequencing, to widen the applicability of massive parallel sequencers for the detailed analysis of complex genomes. Using multiplex PCR reactions, we sequenced the complete coding regions of seven genes implicated in peripheral neuropathies in 40 individuals on a GS-FLX genome sequencer (Roche). The resulting dataset showed highly specific and uniform amplification. Comparison of the GS-FLX sequencing data with the dataset generated by Sanger sequencing confirmed the detection of all variants present and proved the sensitivity of the method for mutation detection. In addition, we showed that we could exploit the multiplexed PCR amplicons to determine individual copy number variation (CNV), increasing the spectrum of detected variations to both genetic and genomic variants. We conclude that our straightforward procedure substantially expands the applicability of the massive parallel sequencers for sequencing projects of a moderate number of amplicons (50-500) with typical applications in resequencing exons in positional or functional candidate regions and molecular genetic diagnostics. 2008 Wiley-Liss, Inc.

Detecting cooperative sequences in the binding of RNA Polymerase-II

NASA Astrophysics Data System (ADS)

Glass, Kimberly; Rozenberg, Julian; Girvan, Michelle; Losert, Wolfgang; Ott, Ed; Vinson, Charles

2008-03-01

Regulation of the expression level of genes is a key biological process controlled largely by the 1000 base pair (bp) sequence preceding each gene (the promoter region). Within that region transcription factor binding sites (TFBS), 5-10 bp long sequences, act individually or cooperate together in the recruitment of, and therefore subsequent gene transcription by, RNA Polymerase-II (RNAP). We have measured the binding of RNAP to promoters on a genome-wide basis using Chromatin Immunoprecipitation (ChIP-on-Chip) microarray assays. Using all 8-base pair long sequences as a test set, we have identified the DNA sequences that are enriched in promoters with high RNAP binding values. We are able to demonstrate that virtually all sequences enriched in such promoters contain a CpG dinucleotide, indicating that TFBS that contain the CpG dinucleotide are involved in RNAP binding to promoters. Further analysis shows that the presence of pairs of CpG containing sequences cooperate to enhance the binding of RNAP to the promoter.

Extensive Variation and Sub-Structuring in Lineage A mtDNA in Indian Sheep: Genetic Evidence for Domestication of Sheep in India

PubMed Central

Singh, Sachin; Kumar Jr, Satish; Kolte, Atul P.; Kumar, Satish

2013-01-01

Previous studies on mitochondrial DNA analysis of sheep from different regions of the world have revealed the presence of two major- A and B, and three minor- C, D and E maternal lineages. Lineage A is more frequent in Asia and lineage B is more abundant in regions other than Asia. We have analyzed mitochondrial DNA sequences of 330 sheep from 12 different breeds of India. Neighbor-joining analysis revealed lineage A, B and C in Indian sheep. Surprisingly, multidimensional scaling plot based on FST values of control region of mtDNA sequences showed significant breed differentiation in contrast to poor geographical structuring reported earlier in this species. The breed differentiation in Indian sheep was essentially due to variable contribution of two major lineages to different breeds, and sub- structuring of lineage A, possibly the latter resulting from genetic drift. Nucleotide diversity of this lineage was higher in Indian sheep (0.014 ± 0.007) as compared to that of sheep from other regions of the world (0.009 ± 0.005 to 0.01 ± 0.005). Reduced median network analysis of control region and cytochrome b gene sequences of Indian sheep when analyzed along with available published sequences of sheep from other regions of the world showed that several haplotypes of lineage A were exclusive to Indian sheep. Given the high nucleotide diversity in Indian sheep and the poor sharing of lineage A haplotypes between Indian and non-Indian sheep, we propose that lineage A sheep has also been domesticated in the east of Near East, possibly in Indian sub-continent. Finally, our data provide support that lineage B and additional lineage A haplotypes of sheep might have been introduced to Indian sub-continent from Near East, probably by ancient sea trade route. PMID:24244282

Purification, developmental expression, and in silico characterization of α-amylase inhibitor from Echinochloa frumentacea.

PubMed

Panwar, Priyankar; Verma, A K; Dubey, Ashutosh

2018-05-01

Barnyard ( Echinochloa frumentacea ) and finger ( Eleusine coracana ) millet growing at northwestern Himalaya were explored for the α-amylase inhibitor (α-AI). The mature seeds of barnyard millet variety PRJ1 had maximum α-AI activity which increases in different developmental stage. α-AI was purified up to 22.25-fold from barnyard millet variety PRJ1. Semi-quantitative PCR of different developmental stages of barnyard millet seeds showed increased levels of the transcript from 7 to 28 days. Sequence analysis revealed that it contained 315 bp nucleotide which encodes 104 amino acid sequence with molecular weight 10.72 kDa. The predicted 3D structure of α-AI was 86.73% similar to a bifunctional inhibitor of ragi. In silico analysis of 71 α-AI protein sequences were carried out for biochemical features, homology search, multiple sequence alignment, phylogenetic tree construction, motif, and superfamily distribution of protein sequences. Analysis of multiple sequence alignment revealed the existence of conserved regions NPLP[S/G]CRWYVV[S/Q][Q/R]TCG[V/I] throughout sequences. Superfam analysis revealed that α-AI protein sequences were distributed among seven different superfamilies.

Sequence Polymorphisms and Structural Variations among Four Grapevine (Vitis vinifera L.) Cultivars Representing Sardinian Agriculture

PubMed Central

Mercenaro, Luca; Nieddu, Giovanni; Porceddu, Andrea; Pezzotti, Mario; Camiolo, Salvatore

2017-01-01

The genetic diversity among grapevine (Vitis vinifera L.) cultivars that underlies differences in agronomic performance and wine quality reflects the accumulation of single nucleotide polymorphisms (SNPs) and small indels as well as larger genomic variations. A combination of high throughput sequencing and mapping against the grapevine reference genome allows the creation of comprehensive sequence variation maps. We used next generation sequencing and bioinformatics to generate an inventory of SNPs and small indels in four widely cultivated Sardinian grape cultivars (Bovale sardo, Cannonau, Carignano and Vermentino). More than 3,200,000 SNPs were identified with high statistical confidence. Some of the SNPs caused the appearance of premature stop codons and thus identified putative pseudogenes. The analysis of SNP distribution along chromosomes led to the identification of large genomic regions with uninterrupted series of homozygous SNPs. We used a digital comparative genomic hybridization approach to identify 6526 genomic regions with significant differences in copy number among the four cultivars compared to the reference sequence, including 81 regions shared between all four cultivars and 4953 specific to single cultivars (representing 1.2 and 75.9% of total copy number variation, respectively). Reads mapping at a distance that was not compatible with the insert size were used to identify a dataset of putative large deletions with cultivar Cannonau revealing the highest number. The analysis of genes mapping to these regions provided a list of candidates that may explain some of the phenotypic differences among the Bovale sardo, Cannonau, Carignano and Vermentino cultivars. PMID:28775732

Analysis of the 16S–23S rRNA Gene Internal Transcribed Spacer Region in Klebsiella Species▿

PubMed Central

Wang, Min; Cao, Boyang; Yu, Qunfang; Liu, Lei; Gao, Qili; Wang, Lei; Feng, Lu

2008-01-01

The 16S-23S rRNA gene internal transcribed spacer (ITS) regions of Klebsiella spp., including Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. ozaenae, Klebsiella pneumoniae subsp. rhinoscleromatis, Klebsiella oxytoca, Klebsiella planticola, Klebsiella terrigena, and Klebsiella ornithinolytica, were characterized, and the feasibility of using ITS sequences to discriminate Klebsiella species and subspecies was explored. A total of 336 ITS sequences from 21 representative strains and 11 clinical isolates of Klebsiella were sequenced and analyzed. Three distinct ITS types—ITSnone (without tRNA genes), ITSglu [with a tRNAGlu (UUC) gene], and ITSile+ala [with tRNAIle (GAU) and tRNAAla (UGC) genes]—were detected in all species except for K. pneumoniae subsp. rhinoscleromatis, which has only ITSglu and ITSile+ala. The presence of ITSnone in Enterobacteriaceae had never been reported before. Both the length and the sequence of each ITS type are highly conserved within the species, with identity levels from 0.961 to 1.000 for ITSnone, from 0.967 to 1.000 for ITSglu, and from 0.968 to 1.000 for ITSile+ala. Interspecies sequence identities range from 0.775 to 0.989 for ITSnone, from 0.798 to 0.997 for ITSglu, and from 0.712 to 0.985 for ITSile+ala. Regions with significant interspecies variations but low intraspecies polymorphisms were identified; these may be targeted in the design of probes for the identification of Klebsiella to the species level. Phylogenetic analysis based on ITS regions reveals the relationships among Klebsiella species similarly to that based on 16S rRNA genes. PMID:18753345

Length variation and sequence divergence in mitochondrial control region of Schizothoracine (Teleostei: Cyperinidae) species.

PubMed

Syed, Mudasir Ahmad; Bhat, Farooz Ahmad; Balkhi, Masood-ul Hassan; Bhat, Bilal Ahmad

2016-01-01

Schizothoracine fish commonly called snow trouts inhibit the entire network of snow and spring fed cool waters of Kashmir, India. Over 10 species reported earlier, only five species have been found, these include Schizothorax niger, Schizothorax esocinus, Schizothorax plagiostomus, Schizothorax curvifrons and Schizothorax labiatus. The relationship between these species is contradicting. To understand the evolutionary relation of these species, we examined the sequence information of mitochondrial D-loop of 25 individuals representing five species. Sequence alignment showed D-loop region highly variable and length variation was observed in di-nucleotide (TA)n microsatellite between and within species. Interestingly, all these species have (TA)n microsatellite not associated with longer tandem repeats at the 3' end of the mitochondrial control region and do not show heteroplasmy. Our analysis also indicates the presence of four conserved sequence blocks (CSB), CSB-D, CSB-1, CSB-II and CSB-III, four (Termination Associated Sequence) TAS motifs and 15bp pyrimidine block within the mitochondrial control region, that are highly conserved within genus Schizothorax when compared with other species. The phylogenetic analysis carried by Maximum likelihood (ML), Neighbor Joining (NJ) and Bayesian inference (BI) generated almost identical results. The resultant BI tree showed a close genetic relationship of all the five species and supports two distinct grouping of S. esocinus species. Besides the species relation, the presence of length variation in tandem repeats is attributed to differences in predicting the stability of secondary structures. The role of CSBs and TASs, reported so far as main regulatory signals, would explain the conservation of these elements in evolution.

Immunoglobulin from Antarctic fish species of Rajidae family.

PubMed

Coscia, Maria Rosaria; Cocca, Ennio; Giacomelli, Stefano; Cuccaro, Fausta; Oreste, Umberto

2012-03-01

Immunoglobulins (Ig) of Chondroichthyes have been extensively studied in sharks; in contrast, in skates investigations on Ig remain scarce and fragmentary despite the high occurrence of skates in all of the major oceans of the world. To focus on Rajidae Igμ, the most abundant heavy chain isotype, we have chosen the Antarctic species Bathyraja eatonii, Bathyraja albomaculata, Bathyraja brachyurops, and Amblyraja georgiana which live at high latitudes in the Southern Ocean, and at very low temperatures. We prepared mRNA from the spleen of individuals of each species and performed RT-PCR experiments using two oligonucleotides designed on the alignment of various elasmobranch Igμ heavy chain sequences available in GenBank. The PCR products, about 1400-nt long, were cloned and sequenced. Nucleotide sequence identities calculated for the constant region domains ranged from 88.5% to 97.5% between species, and from 91.1% to 99.7% within species. In a distance tree, including also Raja erinacea sequences, two major branches were obtained, one containing Arhynchobatinae sequences, the other one Rajinae sequences. Four presumptive D gene segments were identified in the region of the VH/D/JH recombination; two different D segments were often found in the same sequence. Moreover, 5-15 genomic fragments of different lengths, carrying the gene locus encoding Igμ chain were revealed by Southern blotting analysis. B. eatonii amino acid sequences were analyzed for the positional diversity by Shannon entropy analysis, showing CH4 as the most conserved domain, and CH3 as the most variable one. B. eatonii CDR3 region length varied between 11 and 15 amino acid residues; the mean length (13.4 aa) was greater than that of Leucoraja eglanteria sequences (7.7 aa). An alignment of representative sequences of Antarctic species and R. erinacea showed that more cysteine residues not involved in the intradomain disulfide bridges were present in Antarctic species. Copyright © 2011 Elsevier B.V. All rights reserved.

Genetic Relatedness among Hepatitis A Virus Strains Associated with Food-Borne Outbreaks

PubMed Central

Vaughan, Gilberto; Xia, Guoliang; Forbi, Joseph C.; Purdy, Michael A.; Rossi, Lívia Maria Gonçalves; Spradling, Philip R.; Khudyakov, Yury E.

2013-01-01

The genetic characterization of hepatitis A virus (HAV) strains is commonly accomplished by sequencing subgenomic regions, such as the VP1/P2B junction. HAV genome is not extensively variable, thus presenting opportunity for sharing sequences of subgenomic regions among genetically unrelated isolates. The degree of misrepresentation of phylogenetic relationships by subgenomic regions is especially important for tracking transmissions. Here, we analyzed whole-genome (WG) sequences of 101 HAV strains identified from 4 major multi-state, food-borne outbreaks of hepatitis A in the Unites States and from 14 non-outbreak-related HAV strains that shared identical VP1/P2B sequences with the outbreak strains. Although HAV strains with an identical VP1/P2B sequence were specific to each outbreak, WG were different, with genetic diversity reaching 0.31% (mean 0.09%). Evaluation of different subgenomic regions did not identify any other section of the HAV genome that could accurately represent phylogenetic relationships observed using WG sequences. The identification of 2–3 dominant HAV strains in 3 out of 4 outbreaks indicates contamination of the implicated food items with a heterogeneous HAV population. However, analysis of intra-host HAV variants from eight patients involved in one outbreak showed that only a single sequence variant established infection in each patient. Four non-outbreak strains were found closely related to strains from 2 outbreaks, whereas ten were genetically different from the outbreak strains. Thus, accurate tracking of HAV strains can be accomplished using HAV WG sequences, while short subgenomic regions are useful for identification of transmissions only among cases with known epidemiological association. PMID:24223112

Regional differences in mitochondrial DNA methylation in human post-mortem brain tissue.

PubMed

Devall, Matthew; Smith, Rebecca G; Jeffries, Aaron; Hannon, Eilis; Davies, Matthew N; Schalkwyk, Leonard; Mill, Jonathan; Weedon, Michael; Lunnon, Katie

2017-01-01

DNA methylation is an important epigenetic mechanism involved in gene regulation, with alterations in DNA methylation in the nuclear genome being linked to numerous complex diseases. Mitochondrial DNA methylation is a phenomenon that is receiving ever-increasing interest, particularly in diseases characterized by mitochondrial dysfunction; however, most studies have been limited to the investigation of specific target regions. Analyses spanning the entire mitochondrial genome have been limited, potentially due to the amount of input DNA required. Further, mitochondrial genetic studies have been previously confounded by nuclear-mitochondrial pseudogenes. Methylated DNA Immunoprecipitation Sequencing is a technique widely used to profile DNA methylation across the nuclear genome; however, reads mapped to mitochondrial DNA are often discarded. Here, we have developed an approach to control for nuclear-mitochondrial pseudogenes within Methylated DNA Immunoprecipitation Sequencing data. We highlight the utility of this approach in identifying differences in mitochondrial DNA methylation across regions of the human brain and pre-mortem blood. We were able to correlate mitochondrial DNA methylation patterns between the cortex, cerebellum and blood. We identified 74 nominally significant differentially methylated regions ( p  < 0.05) in the mitochondrial genome, between anatomically separate cortical regions and the cerebellum in matched samples ( N  = 3 matched donors). Further analysis identified eight significant differentially methylated regions between the total cortex and cerebellum after correcting for multiple testing. Using unsupervised hierarchical clustering analysis of the mitochondrial DNA methylome, we were able to identify tissue-specific patterns of mitochondrial DNA methylation between blood, cerebellum and cortex. Our study represents a comprehensive analysis of the mitochondrial methylome using pre-existing Methylated DNA Immunoprecipitation Sequencing data to identify brain region-specific patterns of mitochondrial DNA methylation.

rpoB-Based Identification of Nonpigmented and Late-Pigmenting Rapidly Growing Mycobacteria

PubMed Central

Adékambi, Toïdi; Colson, Philippe; Drancourt, Michel

2003-01-01

Nonpigmented and late-pigmenting rapidly growing mycobacteria (RGM) are increasingly isolated in clinical microbiology laboratories. Their accurate identification remains problematic because classification is labor intensive work and because new taxa are not often incorporated into classification databases. Also, 16S rRNA gene sequence analysis underestimates RGM diversity and does not distinguish between all taxa. We determined the complete nucleotide sequence of the rpoB gene, which encodes the bacterial β subunit of the RNA polymerase, for 20 RGM type strains. After using in-house software which analyzes and graphically represents variability stretches of 60 bp along the nucleotide sequence, our analysis focused on a 723-bp variable region exhibiting 83.9 to 97% interspecies similarity and 0 to 1.7% intraspecific divergence. Primer pair Myco-F-Myco-R was designed as a tool for both PCR amplification and sequencing of this region for molecular identification of RGM. This tool was used for identification of 63 RGM clinical isolates previously identified at the species level on the basis of phenotypic characteristics and by 16S rRNA gene sequence analysis. Of 63 clinical isolates, 59 (94%) exhibited <2% partial rpoB gene sequence divergence from 1 of 20 species under study and were regarded as correctly identified at the species level. Mycobacterium abscessus and Mycobacterium mucogenicum isolates were clearly distinguished from Mycobacterium chelonae; Mycobacterium mageritense isolates were clearly distinguished from “Mycobacterium houstonense.” Four isolates were not identified at the species level because they exhibited >3% partial rpoB gene sequence divergence from the corresponding type strain; they belonged to three taxa related to M. mucogenicum, Mycobacterium smegmatis, and Mycobacterium porcinum. For M. abscessus and M. mucogenicum, this partial sequence yielded a high genetic heterogeneity within the clinical isolates. We conclude that molecular identification by analysis of the 723-bp rpoB sequence is a rapid and accurate tool for identification of RGM. PMID:14662964

Complete mitochondrial genome of endangered Yellow-shouldered Amazon (Amazona barbadensis): two control region copies in parrot species of the Amazona genus.

PubMed

Urantowka, Adam Dawid; Hajduk, Kacper; Kosowska, Barbara

2013-08-01

Amazona barbadensis is an endangered species of parrot living in northern coastal Venezuela and in several Caribbean islands. In this study, we sequenced full mitochondrial genome of the considered species. The total length of the mitogenome was 18,983 bp and contained 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, duplicated control region, and degenerate copies of ND6 and tRNA (Glu) genes. High degree of identity between two copies of control region suggests their coincident evolution and functionality. Comparative analysis of both the control region sequences from four Amazona species revealed their 89.1% identity over a region of 1300 bp and indicates the presence of distinctive parts of two control region copies.

The prediction of human exons by oligonucleotide composition and discriminant analysis of spliceable open reading frames

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

Solovyev, V.V.; Salamov, A.A.; Lawrence, C.B.

1994-12-31

Discriminant analysis is applied to the problem of recognition 5`-, internal and 3`-exons in human DNA sequences. Specific recognition functions were developed for revealing exons of particular types. The method based on a splice site prediction algorithm that uses the linear Fisher discriminant to combine the information about significant triplet frequencies of various functional parts of splice site regions and preferences of oligonucleotide in protein coding and nation regions. The accuracy of our splice site recognition function is about 97%. A discriminant function for 5`-exon prediction includes hexanucleotide composition of upstream region, triplet composition around the ATG codon, ORF codingmore » potential, donor splice site potential and composition of downstream introit region. For internal exon prediction, we combine in a discriminant function the characteristics describing the 5`- intron region, donor splice site, coding region, acceptor splice site and Y-intron region for each open reading frame flanked by GT and AG base pairs. The accuracy of precise internal exon recognition on a test set of 451 exon and 246693 pseudoexon sequences is 77% with a specificity of 79% and a level of pseudoexon ORF prediction of 99.96%. The recognition quality computed at the level of individual nucleotides is 89%, for exon sequences and 98% for intron sequences. A discriminant function for 3`-exon prediction includes octanucleolide composition of upstream nation region, triplet composition around the stop codon, ORF coding potential, acceptor splice site potential and hexanucleotide composition of downstream region. We unite these three discriminant functions in exon predicting program FEX (find exons). FEX exactly predicts 70% of 1016 exons from the test of 181 complete genes with specificity 73%, and 89% exons are exactly or partially predicted. On the average, 85% of nucleotides were predicted accurately with specificity 91%.« less

Analysis and Visualization of ChIP-Seq and RNA-Seq Sequence Alignments Using ngs.plot.

PubMed

Loh, Yong-Hwee Eddie; Shen, Li

2016-01-01

The continual maturation and increasing applications of next-generation sequencing technology in scientific research have yielded ever-increasing amounts of data that need to be effectively and efficiently analyzed and innovatively mined for new biological insights. We have developed ngs.plot-a quick and easy-to-use bioinformatics tool that performs visualizations of the spatial relationships between sequencing alignment enrichment and specific genomic features or regions. More importantly, ngs.plot is customizable beyond the use of standard genomic feature databases to allow the analysis and visualization of user-specified regions of interest generated by the user's own hypotheses. In this protocol, we demonstrate and explain the use of ngs.plot using command line executions, as well as a web-based workflow on the Galaxy framework. We replicate the underlying commands used in the analysis of a true biological dataset that we had reported and published earlier and demonstrate how ngs.plot can easily generate publication-ready figures. With ngs.plot, users would be able to efficiently and innovatively mine their own datasets without having to be involved in the technical aspects of sequence coverage calculations and genomic databases.

A palindrome-mediated mechanism distinguishes translocations involving LCR-B of chromosome 22q11.2.

PubMed

Gotter, Anthony L; Shaikh, Tamim H; Budarf, Marcia L; Rhodes, C Harker; Emanuel, Beverly S

2004-01-01

Two known recurrent constitutional translocations, t(11;22) and t(17;22), as well as a non-recurrent t(4;22), display derivative chromosomes that have joined to a common site within the low copy repeat B (LCR-B) region of 22q11.2. This breakpoint is located between two AT-rich inverted repeats that form a nearly perfect palindrome. Breakpoints within the 11q23, 17q11 and 4q35 partner chromosomes also fall near the center of palindromic sequences. In the present work the breakpoints of a fourth translocation involving LCR-B, a balanced ependymoma-associated t(1;22), were characterized not only to localize this junction relative to known genes, but also to further understand the mechanism underlying these rearrangements. FISH mapping was used to localize the 22q11.2 breakpoint to LCR-B and the 1p21 breakpoint to single BAC clones. STS mapping narrowed the 1p21.2 breakpoint to a 1990 bp AT-rich region, and junction fragments were amplified by nested PCR. Junction fragment-derived sequence indicates that the 1p21.2 breakpoint splits a 278 nt palindrome capable of forming stem-loop secondary structure. In contrast, the 1p21.2 reference genomic sequence from clones in the database does not exhibit this configuration, suggesting a predisposition for regional genomic instability perhaps etiologic for this rearrangement. Given its similarity to known chromosomal fragile site (FRA) sequences, this polymorphic 1p21.2 sequence may represent one of the FRA1 loci. Comparative analysis of the secondary structure of sequences surrounding translocation breakpoints that involve LCR-B with those not involving this region indicate a unique ability of the former to form stem-loop structures. The relative likelihood of forming these configurations appears to be related to the rate of translocation occurrence. Further analysis suggests that constitutional translocations in general occur between sequences of similar melting temperature and propensity for secondary structure.

A palindrome-mediated mechanism distinguishes translocations involving LCR-B of chromosome 22q11.2

PubMed Central

Gotter, Anthony L.; Shaikh, Tamim H.; Budarf, Marcia L.; Rhodes, C. Harker; Emanuel, Beverly S.

2010-01-01

Two known recurrent constitutional translocations, t(11;22) and t(17;22), as well as a non-recurrent t(4;22), display derivative chromosomes that have joined to a common site within the low copy repeat B (LCR-B) region of 22q11.2. This breakpoint is located between two AT-rich inverted repeats that form a nearly perfect palindrome. Breakpoints within the 11q23, 17q11 and 4q35 partner chromosomes also fall near the center of palindromic sequences. In the present work the breakpoints of a fourth translocation involving LCR-B, a balanced ependymoma-associated t(1;22), were characterized not only to localize this junction relative to known genes, but also to further understand the mechanism underlying these rearrangements. FISH mapping was used to localize the 22q11.2 breakpoint to LCR-B and the 1p21 breakpoint to single BAC clones. STS mapping narrowed the 1p21.2 breakpoint to a 1990 bp AT-rich region, and junction fragments were amplified by nested PCR. Junction fragment-derived sequence indicates that the 1p21.2 breakpoint splits a 278 nt palindrome capable of forming stem–loop secondary structure. In contrast, the 1p21.2 reference genomic sequence from clones in the database does not exhibit this configuration, suggesting a predisposition for regional genomic instability perhaps etiologic for this rearrangement. Given its similarity to known chromosomal fragile site (FRA) sequences, this polymorphic 1p21.2 sequence may represent one of the FRA1 loci. Comparative analysis of the secondary structure of sequences surrounding translocation breakpoints that involve LCR-B with those not involving this region indicate a unique ability of the former to form stem–loop structures. The relative likelihood of forming these configurations appears to be related to the rate of translocation occurrence. Further analysis suggests that constitutional translocations in general occur between sequences of similar melting temperature and propensity for secondary structure. PMID:14613967

Analysis of alterative cleavage and polyadenylation by 3′ region extraction and deep sequencing

PubMed Central

Hoque, Mainul; Ji, Zhe; Zheng, Dinghai; Luo, Wenting; Li, Wencheng; You, Bei; Park, Ji Yeon; Yehia, Ghassan; Tian, Bin

2012-01-01

Alternative cleavage and polyadenylation (APA) leads to mRNA isoforms with different coding sequences (CDS) and/or 3′ untranslated regions (3′UTRs). Using 3′ Region Extraction And Deep Sequencing (3′READS), a method which addresses the internal priming and oligo(A) tail issues that commonly plague polyA site (pA) identification, we comprehensively mapped pAs in the mouse genome, thoroughly annotating 3′ ends of genes and revealing over five thousand pAs (~8% of total) flanked by A-rich sequences, which have hitherto been overlooked. About 79% of mRNA genes and 66% of long non-coding RNA (lncRNA) genes have APA; but these two gene types have distinct usage patterns for pAs in introns and upstream exons. Promoter-distal pAs become relatively more abundant during embryonic development and cell differentiation, a trend affecting pAs in both 3′-most exons and upstream regions. Upregulated isoforms generally have stronger pAs, suggesting global modulation of the 3′ end processing activity in development and differentiation. PMID:23241633

The nucleotide sequence and genome organization of Plasmopara halstedii virus.

PubMed

Heller-Dohmen, Marion; Göpfert, Jens C; Pfannstiel, Jens; Spring, Otmar

2011-03-17

Only very few viruses of Oomycetes have been studied in detail. Isometric virions were found in different isolates of the oomycete Plasmopara halstedii, the downy mildew pathogen of sunflower. However, complete nucleotide sequences and data on the genome organization were lacking. Viral RNA of different P. halstedii isolates was subjected to nucleotide sequencing and analysis of the viral genome. The N-terminal sequence of the viral coat protein was determined using Top-Down MALDI-TOF analysis. The complete nucleotide sequences of both single-stranded RNA segments (RNA1 and RNA2) were established. RNA1 consisted of 2793 nucleotides (nt) exclusive its 3' poly(A) tract and a single open-reading frame (ORF1) of 2745 nt. ORF1 was framed by a 5' untranslated region (5' UTR) of 18 nt and a 3' untranslated region (3' UTR) of 30 nt. ORF1 contained motifs of RNA-dependent RNA polymerases (RdRp) and showed similarities to RdRp of Scleropthora macrospora virus A (SmV A) and viruses within the Nodaviridae family. RNA2 consisted of 1526 nt exclusive its 3' poly(A) tract and a second ORF (ORF2) of 1128 nt. ORF2 coded for the single viral coat protein (CP) and was framed by a 5' UTR of 164 nt and a 3' UTR of 234 nt. The deduced amino acid sequence of ORF2 was verified by nano-LC-ESI-MS/MS experiments. Top-Down MALDI-TOF analysis revealed the N-terminal sequence of the CP. The N-terminal sequence represented a region within ORF2 suggesting a proteolytic processing of the CP in vivo. The CP showed similarities to CP of SmV A and viruses within the Tombusviridae family. Fragments of RNA1 (ca. 1.9 kb) and RNA2 (ca. 1.4 kb) were used to analyze the nucleotide sequence variation of virions in different P. halstedii isolates. Viral sequence variation was 0.3% or less regardless of their host's pathotypes, the geographical origin and the sensitivity towards the fungicide metalaxyl. The results showed the presence of a single and new virus type in different P. halstedii isolates. Insignificant viral sequence variation indicated that the virus did not account for differences in pathogenicity of the oomycete P. halstedii.

The Papillomavirus Episteme: a central resource for papillomavirus sequence data and analysis.

PubMed

Van Doorslaer, Koenraad; Tan, Qina; Xirasagar, Sandhya; Bandaru, Sandya; Gopalan, Vivek; Mohamoud, Yasmin; Huyen, Yentram; McBride, Alison A

2013-01-01

The goal of the Papillomavirus Episteme (PaVE) is to provide an integrated resource for the analysis of papillomavirus (PV) genome sequences and related information. The PaVE is a freely accessible, web-based tool (http://pave.niaid.nih.gov) created around a relational database, which enables storage, analysis and exchange of sequence information. From a design perspective, the PaVE adopts an Open Source software approach and stresses the integration and reuse of existing tools. Reference PV genome sequences have been extracted from publicly available databases and reannotated using a custom-created tool. To date, the PaVE contains 241 annotated PV genomes, 2245 genes and regions, 2004 protein sequences and 47 protein structures, which users can explore, analyze or download. The PaVE provides scientists with the data and tools needed to accelerate scientific progress for the study and treatment of diseases caused by PVs.

Isolation and characterization of full-length putative alcohol dehydrogenase genes from polygonum minus

NASA Astrophysics Data System (ADS)

Hamid, Nur Athirah Abd; Ismail, Ismanizan

2013-11-01

Polygonum minus, locally named as Kesum is an aromatic herb which is high in secondary metabolite content. Alcohol dehydrogenase is an important enzyme that catalyzes the reversible oxidation of alcohol and aldehyde with the presence of NAD(P)(H) as co-factor. The main focus of this research is to identify the gene of ADH. The total RNA was extracted from leaves of P. minus which was treated with 150 μM Jasmonic acid. Full-length cDNA sequence of ADH was isolated via rapid amplification cDNA end (RACE). Subsequently, in silico analysis was conducted on the full-length cDNA sequence and PCR was done on genomic DNA to determine the exon and intron organization. Two sequences of ADH, designated as PmADH1 and PmADH2 were successfully isolated. Both sequences have ORF of 801 bp which encode 266 aa residues. Nucleotide sequence comparison of PmADH1 and PmADH2 indicated that both sequences are highly similar at the ORF region but divergent in the 3' untranslated regions (UTR). The amino acid is differ at the 107 residue; PmADH1 contains Gly (G) residue while PmADH2 contains Cys (C) residue. The intron-exon organization pattern of both sequences are also same, with 3 introns and 4 exons. Based on in silico analysis, both sequences contain "classical" short chain alcohol dehydrogenases/reductases ((c) SDRs) conserved domain. The results suggest that both sequences are the members of short chain alcohol dehydrogenase family.

Sequence variation in the env gene of simian immunodeficiency virus recovered from immunized macaques is predominantly in the V1 region.

PubMed

Almond, N; Jenkins, A; Heath, A B; Kitchin, P

1993-05-01

Three cynomolgus macaques were immunized with recombinant envelope protein preparations derived from simian immunodeficiency virus (SIV). Although humoral and cellular responses were elicited by the immunization regime, all macaques became infected upon challenge with 10 MID50 of the 11/88 virus challenge stock of SIVmac251-32H. The polymerase chain reaction was used to amplify proviral SIV gp120 sequences present in the blood of both immunized and control macaques at 2 months post-infection. A comparison of the predominant sequences found in the region from V2 to V5 of gp120 failed to differentiate provirus recovered from either immunized or control animals. A detailed investigation of sequences obtained from the hypervariable V1 region identified a mixture of sequences in both immunized and control macaques. Some sequences were identical to those previously detected in the virus challenge stock, whereas others had not been detected previously. Phenogram analysis of the new V1 sequences found in immunized animals revealed that they were quite distinct from those from the virus challenge stock and that they included alterations to potential N-linked glycosylation sites. In contrast, new sequence variants recovered from the control animals were closely related to sequences from the virus challenge stock. The difference in diversity of new V1 sequences recovered from immunized and control macaques was highly significant (P < 0.001). Thus, the presence of pre-existing immune responses to SIV envelope protein is associated with greater genetic change in the V1 region of gp120. These data are discussed in relation to the epitopes of SIV gp120 that may confer protection from in vivo challenge.

Analysis for complete genomic sequence of HLA-B and HLA-C alleles in the Chinese Han population.

PubMed

Zhu, F; He, Y; Zhang, W; He, J; He, J; Xu, X; Lv, H; Yan, L

2011-08-01

In the present study, we have determined the complete genomic sequence and analysed the intron polymorphism of partial HLA-B and HLA-C alleles in the Chinese Han population. Over 3.0 kb DNA fragments of HLA-B and HLA-C loci were amplified by polymerase chain reaction from partial 5' untranslated region to 3' noncoding region respectively, and then the amplified products were sequenced. Full-length nucleotide sequences of 14 HLA-B alleles and 10 HLA-C alleles were obtained and have been submitted to GenBank and IMGT/HLA database. Two novel alleles of HLA-B*52:01:01:02 and HLA-B*59:01:01:02 were identified, and the complete genomic sequence of HLA-B*52:01:01:01 was firstly reported. Totally 157 and 167 polymorphism positions were found in the full-length genomic sequence of HLA-B and HLA-C loci respectively. Our results suggested that many single nucleotide polymorphisms existed in the exon and intron regions, and the data can provide useful information for understanding the evolution of HLA-B and HLA-C alleles. © 2011 Blackwell Publishing Ltd.

Mitochondrial DNA variation and phylogenetic relationships among five tuna species based on sequencing of D-loop region.

PubMed

Kumar, Girish; Kocour, Martin; Kunal, Swaraj Priyaranjan

2016-05-01

In order to assess the DNA sequence variation and phylogenetic relationship among five tuna species (Auxis thazard, Euthynnus affinis, Katsuwonus pelamis, Thunnus tonggol, and T. albacares) out of all four tuna genera, partial sequences of the mitochondrial DNA (mtDNA) D-loop region were analyzed. The estimate of intra-specific sequence variation in studied species was low, ranging from 0.027 to 0.080 [Kimura's two parameter distance (K2P)], whereas values of inter-specific variation ranged from 0.049 to 0.491. The longtail tuna (T. tonggol) and yellowfin tuna (T. albacares) were found to share a close relationship (K2P = 0.049) while skipjack tuna (K. pelamis) was most divergent studied species. Phylogenetic analysis using Maximum-Likelihood (ML) and Neighbor-Joining (NJ) methods supported the monophyletic origin of Thunnus species. Similarly, phylogeny of Auxis and Euthynnus species substantiate the monophyly. However, results showed a distinct origin of K. pelamis from genus Thunnus as well as Auxis and Euthynnus. Thus, the mtDNA D-loop region sequence data supports the polyphyletic origin of tuna species.

Identification and subspecific differentiation of Mycobacterium scrofulaceum by automated sequencing of a region of the gene (hsp65) encoding a 65-kilodalton heat shock protein.

PubMed Central

Swanson, D S; Pan, X; Musser, J M

1996-01-01

Mycobacterium scrofulaceum is most commonly recovered from children with cervical lymphadenitis, although it also accounts for approximately 2% of the mycobacterial infections in AIDS patients. Species assignment of M. scrofulaceum isolated by conventional techniques can be difficult and time-consuming. To develop a strategy for rapid species assignment of these organisms, a 360-bp region of the gene (hsp65) encoding a 65-kDa heat shock protein in 37 isolates from diverse sources was sequenced. Eight hsp65 alleles were identified, and these sequences formed phylogenetic clusters and lineages largely distinct from other Mycobacterium species. There was incomplete correlation between serovar designation and hsp65 allele assignment. The hsp65 data correlated strongly with the results of sequence analysis of the gene coding for 16S rRNA. Automated DNA sequencing of a 360-bp region of the hsp65 gene provides a rapid and unambiguous method for species assignment of these acid-fast organisms for diagnostic purposes. PMID:8940463

Transcription Factor Map Alignment of Promoter Regions

PubMed Central

Blanco, Enrique; Messeguer, Xavier; Smith, Temple F; Guigó, Roderic

2006-01-01

We address the problem of comparing and characterizing the promoter regions of genes with similar expression patterns. This remains a challenging problem in sequence analysis, because often the promoter regions of co-expressed genes do not show discernible sequence conservation. In our approach, thus, we have not directly compared the nucleotide sequence of promoters. Instead, we have obtained predictions of transcription factor binding sites, annotated the predicted sites with the labels of the corresponding binding factors, and aligned the resulting sequences of labels—to which we refer here as transcription factor maps (TF-maps). To obtain the global pairwise alignment of two TF-maps, we have adapted an algorithm initially developed to align restriction enzyme maps. We have optimized the parameters of the algorithm in a small, but well-curated, collection of human–mouse orthologous gene pairs. Results in this dataset, as well as in an independent much larger dataset from the CISRED database, indicate that TF-map alignments are able to uncover conserved regulatory elements, which cannot be detected by the typical sequence alignments. PMID:16733547

Bacterial diversity of Taxus rhizosphere: culture-independent and culture-dependent approaches.

PubMed

Hao, Da Cheng; Ge, Guang Bo; Yang, Ling

2008-07-01

The regional variability of Taxus rhizosphere bacterial community composition and diversity was studied by comparative analysis of three large 16S rRNA gene clone libraries from the Taxus rhizosphere in different regions of China (subtropical and temperate regions). One hundred and forty-six clones were screened for three libraries. Phylogenetic analysis of 16S rRNA gene sequences demonstrated that the abundance of sequences affiliated with Gammaproteobacteria, Betaproteobacteria, and Actinobacteria was higher in the library from the T. xmedia rhizosphere of the temperate region compared with the subtropical Taxus mairei rhizosphere. On the other hand, Acidobacteria was more abundant in libraries from the subtropical Taxus mairei rhizosphere. Richness estimates and diversity indices of three libraries revealed major differences, indicating a higher richness in the Taxus rhizosphere bacterial communities of the subtropical region and considerable variability in the bacterial community composition within this region. By enrichment culture, a novel Actinobacteria strain DICP16 was isolated from the T. xmedia rhizosphere of the temperate region and was identified as Leifsonia shinshuensis sp. via 16S rRNA gene and gyrase B sequence analyses. DICP16 was able to remove the xylosyl group from 7-xylosyl-10-deacetylbaccatin III and 7-xylosyl-10-deacetylpaclitaxel, thereby making the xylosyltaxanes available as sources of 10-deacetylbaccatin III and the anticancer drug paclitaxel. Taken together, the present studies provide, for the first time, the knowledge of the biodiversity of microorganisms populating Taxus rhizospheres.

Mechanisms of haplotype divergence at the RGA08 nucleotide-binding leucine-rich repeat gene locus in wild banana (Musa balbisiana).

PubMed

Baurens, Franc-Christophe; Bocs, Stéphanie; Rouard, Mathieu; Matsumoto, Takashi; Miller, Robert N G; Rodier-Goud, Marguerite; MBéguié-A-MBéguié, Didier; Yahiaoui, Nabila

2010-07-16

Comparative sequence analysis of complex loci such as resistance gene analog clusters allows estimating the degree of sequence conservation and mechanisms of divergence at the intraspecies level. In banana (Musa sp.), two diploid wild species Musa acuminata (A genome) and Musa balbisiana (B genome) contribute to the polyploid genome of many cultivars. The M. balbisiana species is associated with vigour and tolerance to pests and disease and little is known on the genome structure and haplotype diversity within this species. Here, we compare two genomic sequences of 253 and 223 kb corresponding to two haplotypes of the RGA08 resistance gene analog locus in M. balbisiana "Pisang Klutuk Wulung" (PKW). Sequence comparison revealed two regions of contrasting features. The first is a highly colinear gene-rich region where the two haplotypes diverge only by single nucleotide polymorphisms and two repetitive element insertions. The second corresponds to a large cluster of RGA08 genes, with 13 and 18 predicted RGA genes and pseudogenes spread over 131 and 152 kb respectively on each haplotype. The RGA08 cluster is enriched in repetitive element insertions, in duplicated non-coding intergenic sequences including low complexity regions and shows structural variations between haplotypes. Although some allelic relationships are retained, a large diversity of RGA08 genes occurs in this single M. balbisiana genotype, with several RGA08 paralogs specific to each haplotype. The RGA08 gene family has evolved by mechanisms of unequal recombination, intragenic sequence exchange and diversifying selection. An unequal recombination event taking place between duplicated non-coding intergenic sequences resulted in a different RGA08 gene content between haplotypes pointing out the role of such duplicated regions in the evolution of RGA clusters. Based on the synonymous substitution rate in coding sequences, we estimated a 1 million year divergence time for these M. balbisiana haplotypes. A large RGA08 gene cluster identified in wild banana corresponds to a highly variable genomic region between haplotypes surrounded by conserved flanking regions. High level of sequence identity (70 to 99%) of the genic and intergenic regions suggests a recent and rapid evolution of this cluster in M. balbisiana.

Deep sequencing approaches for the analysis of prokaryotic transcriptional boundaries and dynamics.

PubMed

James, Katherine; Cockell, Simon J; Zenkin, Nikolay

2017-05-01

The identification of the protein-coding regions of a genome is straightforward due to the universality of start and stop codons. However, the boundaries of the transcribed regions, conditional operon structures, non-coding RNAs and the dynamics of transcription, such as pausing of elongation, are non-trivial to identify, even in the comparatively simple genomes of prokaryotes. Traditional methods for the study of these areas, such as tiling arrays, are noisy, labour-intensive and lack the resolution required for densely-packed bacterial genomes. Recently, deep sequencing has become increasingly popular for the study of the transcriptome due to its lower costs, higher accuracy and single nucleotide resolution. These methods have revolutionised our understanding of prokaryotic transcriptional dynamics. Here, we review the deep sequencing and data analysis techniques that are available for the study of transcription in prokaryotes, and discuss the bioinformatic considerations of these analyses. Copyright © 2017 Elsevier Inc. All rights reserved.

Recombination, rearrangement, reshuffling, and divergence in a centromeric region of rice.

PubMed

Ma, Jianxin; Bennetzen, Jeffrey L

2006-01-10

Centromeres have many unusual biological properties, including kinetochore attachment and severe repression of local meiotic recombination. These properties are partly an outcome, partly a cause, of unusual DNA structure in the centromeric region. Although several plant and animal genomes have been sequenced, most centromere sequences have not been completed or analyzed in depth. To shed light on the unique organization, variability, and evolution of centromeric DNA, detailed analysis of a 1.97-Mb sequence that includes centromere 8 (CEN8) of japonica rice was undertaken. Thirty-three long-terminal repeat (LTR)-retrotransposon families (including 11 previously unknown) were identified in the CEN8 region, totaling 245 elements and fragments that account for 67% of the region. The ratio of solo LTRs to intact elements in the CEN8 region is approximately 0.9:1, compared with approximately 2.2:1 in noncentromeric regions of rice. However, the ratio of solo LTRs to intact elements in the core of the CEN8 region ( approximately 2.5:1) is higher than in any other region investigated in rice, suggesting a hotspot for unequal recombination. Comparison of the CEN8 region of japonica and its orthologous segments from indica rice indicated that approximately 15% of the intact retrotransposons and solo LTRs were inserted into CEN8 after the divergence of japonica and indica from a common ancestor, compared with approximately 50% for previously studied euchromatic regions. Frequent DNA rearrangements were observed in the CEN8 region, including a 212-kb subregion that was found to be composed of three rearranged tandem repeats. Phylogenetic analysis also revealed recent segmental duplication and extensive rearrangement and reshuffling of the CentO satellite repeats.

Genome-wide association analysis of milk yield traits in Nordic Red Cattle using imputed whole genome sequence variants.

PubMed

Iso-Touru, T; Sahana, G; Guldbrandtsen, B; Lund, M S; Vilkki, J

2016-03-22

The Nordic Red Cattle consisting of three different populations from Finland, Sweden and Denmark are under a joint breeding value estimation system. The long history of recording of production and health traits offers a great opportunity to study production traits and identify causal variants behind them. In this study, we used whole genome sequence level data from 4280 progeny tested Nordic Red Cattle bulls to scan the genome for loci affecting milk, fat and protein yields. Using a genome-wise significance threshold, regions on Bos taurus chromosomes 5, 14, 23, 25 and 26 were associated with fat yield. Regions on chromosomes 5, 14, 16, 19, 20 and 25 were associated with milk yield and chromosomes 5, 14 and 25 had regions associated with protein yield. Significantly associated variations were found in 227 genes for fat yield, 72 genes for milk yield and 30 genes for protein yield. Ingenuity Pathway Analysis was used to identify networks connecting these genes displaying significant hits. When compared to previously mapped genomic regions associated with fertility, significantly associated variations were found in 5 genes common for fat yield and fertility, thus linking these two traits via biological networks. This is the first time when whole genome sequence data is utilized to study genomic regions affecting milk production in the Nordic Red Cattle population. Sequence level data offers the possibility to study quantitative traits in detail but still cannot unambiguously reveal which of the associated variations is causative. Linkage disequilibrium creates difficulties to pinpoint the causative genes and variations. One solution to overcome these difficulties is the identification of the functional gene networks and pathways to reveal important interacting genes as candidates for the observed effects. This information on target genomic regions may be exploited to improve genomic prediction.

A physical map, including a BAC/PAC clone contig, of the Williams-Beuren syndrome--deletion region at 7q11.23.

PubMed

Peoples, R; Franke, Y; Wang, Y K; Pérez-Jurado, L; Paperna, T; Cisco, M; Francke, U

2000-01-01

Williams-Beuren syndrome (WBS) is a developmental disorder caused by haploinsufficiency for genes in a 2-cM region of chromosome band 7q11.23. With the exception of vascular stenoses due to deletion of the elastin gene, the various features of WBS have not yet been attributed to specific genes. Although >/=16 genes have been identified within the WBS deletion, completion of a physical map of the region has been difficult because of the large duplicated regions flanking the deletion. We present a physical map of the WBS deletion and flanking regions, based on assembly of a bacterial artificial chromosome/P1-derived artificial chromosome contig, analysis of high-throughput genome-sequence data, and long-range restriction mapping of genomic and cloned DNA by pulsed-field gel electrophoresis. Our map encompasses 3 Mb, including 1.6 Mb within the deletion. Two large duplicons, flanking the deletion, of >/=320 kb contain unique sequence elements from the internal border regions of the deletion, such as sequences from GTF2I (telomeric) and FKBP6 (centromeric). A third copy of this duplicon exists in inverted orientation distal to the telomeric flanking one. These duplicons show stronger sequence conservation with regard to each other than to the presumptive ancestral loci within the common deletion region. Sequence elements originating from beyond 7q11.23 are also present in these duplicons. Although the duplicons are not present in mice, the order of the single-copy genes in the conserved syntenic region of mouse chromosome 5 is inverted relative to the human map. A model is presented for a mechanism of WBS-deletion formation, based on the orientation of duplicons' components relative to each other and to the ancestral elements within the deletion region.

Phylogenetic Analysis of Phenotypically Characterized Cryptococcus laurentii Isolates Reveals High Frequency of Cryptic Species

PubMed Central

Ferreira-Paim, Kennio; Ferreira, Thatiana Bragine; Andrade-Silva, Leonardo; Mora, Delio Jose; Springer, Deborah J.; Heitman, Joseph; Fonseca, Fernanda Machado; Matos, Dulcilena; Melhem, Márcia Souza Carvalho; Silva-Vergara, Mario León

2014-01-01

Background Although Cryptococcus laurentii has been considered saprophytic and its taxonomy is still being described, several cases of human infections have already reported. This study aimed to evaluate molecular aspects of C. laurentii isolates from Brazil, Botswana, Canada, and the United States. Methods In this study, 100 phenotypically identified C. laurentii isolates were evaluated by sequencing the 18S nuclear ribosomal small subunit rRNA gene (18S-SSU), D1/D2 region of 28S nuclear ribosomal large subunit rRNA gene (28S-LSU), and the internal transcribed spacer (ITS) of the ribosomal region. Results BLAST searches using 550-bp, 650-bp, and 550-bp sequenced amplicons obtained from the 18S-SSU, 28S-LSU, and the ITS region led to the identification of 75 C. laurentii strains that shared 99–100% identity with C. laurentii CBS 139. A total of nine isolates shared 99% identity with both Bullera sp. VY-68 and C. laurentii RY1. One isolate shared 99% identity with Cryptococcus rajasthanensis CBS 10406, and eight isolates shared 100% identity with Cryptococcus sp. APSS 862 according to the 28S-LSU and ITS regions and designated as Cryptococcus aspenensis sp. nov. (CBS 13867). While 16 isolates shared 99% identity with Cryptococcus flavescens CBS 942 according to the 18S-SSU sequence, only six were confirmed using the 28S-LSU and ITS region sequences. The remaining 10 shared 99% identity with Cryptococcus terrestris CBS 10810, which was recently described in Brazil. Through concatenated sequence analyses, seven sequence types in C. laurentii, three in C. flavescens, one in C. terrestris, and one in the C. aspenensis sp. nov. were identified. Conclusions Sequencing permitted the characterization of 75% of the environmental C. laurentii isolates from different geographical areas and the identification of seven haplotypes of this species. Among sequenced regions, the increased variability of the ITS region in comparison to the 18S-SSU and 28S-LSU regions reinforces its applicability as a DNA barcode. PMID:25251413

Complete sequence of two tick-borne flaviviruses isolated from Siberia and the UK: analysis and significance of the 5' and 3'-UTRs.

PubMed

Gritsun, T S; Venugopal, K; Zanotto, P M; Mikhailov, M V; Sall, A A; Holmes, E C; Polkinghorne, I; Frolova, T V; Pogodina, V V; Lashkevich, V A; Gould, E A

1997-05-01

The complete nucleotide sequence of two tick-transmitted flaviviruses, Vasilchenko (Vs) from Siberia and louping ill (LI) from the UK, have been determined. The genomes were respectively, 10928 and 10871 nucleotides (nt) in length. The coding strategy and functional protein sequence motifs of tick-borne flaviviruses are presented in both Vs and LI viruses. The phylogenies based on maximum likelihood, maximum parsimony and distance analysis of the polyproteins, identified Vs virus as a member of the tick-borne encephalitis virus subgroup within the tick-borne serocomplex, genus Flavivirus, family Flaviviridae. Comparative alignment of the 3'-untranslated regions revealed deletions of different lengths essentially at the same position downstream of the stop codon for all tick-borne viruses. Two direct 27 nucleotide repeats at the 3'-end were found only for Vs and LI virus. Immediately following the deletions a region of 332-334 nt with relatively conserved primary structure (67-94% identity) was observed at the 3'-non-coding end of the virus genome. Pairwise comparisons of the nucleotide sequence data revealed similar levels of variation between the coding region, and the 5' and 3'-termini of the genome, implying an equivalent strong selective control for translated and untranslated regions. Indeed the predicted folding of the 5' and 3'-untranslated regions revealed patterns of stem and loop structures conserved for all tick-borne flaviviruses suggesting a purifying selection for preservation of essential RNA secondary structures which could be involved in translational control and replication. The possible implications of these findings are discussed.

Genome sequencing of ovine isolates of Mycobacterium avium subspecies paratuberculosis offers insights into host association

PubMed Central

2012-01-01

Background The genome of Mycobacterium avium subspecies paratuberculosis (MAP) is remarkably homogeneous among the genomes of bovine, human and wildlife isolates. However, previous work in our laboratories with the bovine K-10 strain has revealed substantial differences compared to sheep isolates. To systematically characterize all genomic differences that may be associated with the specific hosts, we sequenced the genomes of three U.S. sheep isolates and also obtained an optical map. Results Our analysis of one of the isolates, MAP S397, revealed a genome 4.8 Mb in size with 4,700 open reading frames (ORFs). Comparative analysis of the MAP S397 isolate showed it acquired approximately 10 large sequence regions that are shared with the human M. avium subsp. hominissuis strain 104 and lost 2 large regions that are present in the bovine strain. In addition, optical mapping defined the presence of 7 large inversions between the bovine and ovine genomes (~ 2.36 Mb). Whole-genome sequencing of 2 additional sheep strains of MAP (JTC1074 and JTC7565) further confirmed genomic homogeneity of the sheep isolates despite the presence of polymorphisms on the nucleotide level. Conclusions Comparative sequence analysis employed here provided a better understanding of the host association, evolution of members of the M. avium complex and could help in deciphering the phenotypic differences observed among sheep and cattle strains of MAP. A similar approach based on whole-genome sequencing combined with optical mapping could be employed to examine closely related pathogens. We propose an evolutionary scenario for M. avium complex strains based on these genome sequences. PMID:22409516

TRDistiller: a rapid filter for enrichment of sequence datasets with proteins containing tandem repeats.

PubMed

Richard, François D; Kajava, Andrey V

2014-06-01

The dramatic growth of sequencing data evokes an urgent need to improve bioinformatics tools for large-scale proteome analysis. Over the last two decades, the foremost efforts of computer scientists were devoted to proteins with aperiodic sequences having globular 3D structures. However, a large portion of proteins contain periodic sequences representing arrays of repeats that are directly adjacent to each other (so called tandem repeats or TRs). These proteins frequently fold into elongated fibrous structures carrying different fundamental functions. Algorithms specific to the analysis of these regions are urgently required since the conventional approaches developed for globular domains have had limited success when applied to the TR regions. The protein TRs are frequently not perfect, containing a number of mutations, and some of them cannot be easily identified. To detect such "hidden" repeats several algorithms have been developed. However, the most sensitive among them are time-consuming and, therefore, inappropriate for large scale proteome analysis. To speed up the TR detection we developed a rapid filter that is based on the comparison of composition and order of short strings in the adjacent sequence motifs. Tests show that our filter discards up to 22.5% of proteins which are known to be without TRs while keeping almost all (99.2%) TR-containing sequences. Thus, we are able to decrease the size of the initial sequence dataset enriching it with TR-containing proteins which allows a faster subsequent TR detection by other methods. The program is available upon request. Copyright © 2014 Elsevier Inc. All rights reserved.

Directionality analysis on functional magnetic resonance imaging during motor task using Granger causality.

PubMed

Anwar, A R; Muthalib, M; Perrey, S; Galka, A; Granert, O; Wolff, S; Deuschl, G; Raethjen, J; Heute, U; Muthuraman, M

2012-01-01

Directionality analysis of signals originating from different parts of brain during motor tasks has gained a lot of interest. Since brain activity can be recorded over time, methods of time series analysis can be applied to medical time series as well. Granger Causality is a method to find a causal relationship between time series. Such causality can be referred to as a directional connection and is not necessarily bidirectional. The aim of this study is to differentiate between different motor tasks on the basis of activation maps and also to understand the nature of connections present between different parts of the brain. In this paper, three different motor tasks (finger tapping, simple finger sequencing, and complex finger sequencing) are analyzed. Time series for each task were extracted from functional magnetic resonance imaging (fMRI) data, which have a very good spatial resolution and can look into the sub-cortical regions of the brain. Activation maps based on fMRI images show that, in case of complex finger sequencing, most parts of the brain are active, unlike finger tapping during which only limited regions show activity. Directionality analysis on time series extracted from contralateral motor cortex (CMC), supplementary motor area (SMA), and cerebellum (CER) show bidirectional connections between these parts of the brain. In case of simple finger sequencing and complex finger sequencing, the strongest connections originate from SMA and CMC, while connections originating from CER in either direction are the weakest ones in magnitude during all paradigms.

Application of SCAR (sequence characterized amplified region) analysis to authenticate Lycium barbarum (wolfberry) and its adulterants.

PubMed

Sze, Stephen Cho-Wing; Song, Ju-Xian; Wong, Ricky Ngok-Shun; Feng, Yi-Bin; Ng, Tzi-Bun; Tong, Yao; Zhang, Kalin Yan-Bo

2008-09-01

Fructus Lycii (Gouqizi) is well known in Chinese herbal medicine for its restorative function of benefiting the liver and kidney, replenishing vital essence and improving eyesight. However, ten species and varieties of Lycium have benn found to be substitutes or adulterants of Lycium barbarum (wolfberry) in commercial markets in the Hong Kong Special Administrative Region and in China generally. L. barbarum cv. 'Tianjinense' and Lycium chinense var. potaninii are the most common examples. It is difficult to differentiate among the Lycium species by traditional morphological and histological analyses. An easy and reliable approach based on SCAR (sequence characterized amplified region) analysis was developed in the present study to differentiate L. barbarum from other Lycium species. Two characteristic bands of approx. 700 and 650 bp were detected on the RAPD (random amplification of polymorphic DNA) profiles generated from samples of L. barbarum and L. chinense var. potaninii using the primer OPC-7. They were isolated and sequenced. Two primer sets, based on the sequences, could amplify a single specific band in samples of L. barbarum respectively, whereas no bands were detected in samples of L. chinense var. potaninii. The results confirmed that the SCAR technique can be employed for authenticating L. barbarum and its adulterants.

Nucleotide Sequence and Genetic Structure of a Novel Carbaryl Hydrolase Gene (cehA) from Rhizobium sp. Strain AC100

PubMed Central

Hashimoto, Masayuki; Fukui, Mitsuru; Hayano, Kouichi; Hayatsu, Masahito

2002-01-01

Rhizobium sp. strain AC100, which is capable of degrading carbaryl (1-naphthyl-N-methylcarbamate), was isolated from soil treated with carbaryl. This bacterium hydrolyzed carbaryl to 1-naphthol and methylamine. Carbaryl hydrolase from the strain was purified to homogeneity, and its N-terminal sequence, molecular mass (82 kDa), and enzymatic properties were determined. The purified enzyme hydrolyzed 1-naphthyl acetate and 4-nitrophenyl acetate indicating that the enzyme is an esterase. We then cloned the carbaryl hydrolase gene (cehA) from the plasmid DNA of the strain and determined the nucleotide sequence of the 10-kb region containing cehA. No homologous sequences were found by a database homology search using the nucleotide and deduced amino acid sequences of the cehA gene. Six open reading frames including the cehA gene were found in the 10-kb region, and sequencing analysis shows that the cehA gene is flanked by two copies of insertion sequence-like sequence, suggesting that it makes part of a composite transposon. PMID:11872471

The maize stripe virus major noncapsid protein messenger RNA transcripts contain heterogeneous leader sequences at their 5' termini.

PubMed

Huiet, L; Feldstein, P A; Tsai, J H; Falk, B W

1993-12-01

Primer extension analyses and a PCR-based cloning strategy were used to identify and characterize 5' nucleotide sequences on the maize stripe virus (MStV) RNA4 mRNA transcripts encoding the major noncapsid protein (NCP). Direct RNA sequence analysis by primer extension showed that the NCP mRNA transcripts had 10-15 nucleotides beyond the 5' terminus of the MStV RNA4 nucleotide sequence. MStV genomic RNAs isolated from ribonucleoprotein particles (RNPs) lacked the additional 5' nucleotides. cDNA clones representing the 5' region of the mRNA transcripts were constructed, and the nucleotide sequences of the 5' regions were determined for 16 clones. Each was found to have a distinct 10-15 nucleotide sequence immediately 5' of the MStV RNA4 sequence. Eleven of 16 clones had the correct MStV RNA4 5' nucleotide sequence, while five showed minor variations at or near the 5' most MStV RNA4 nucleotide. These characteristics show strong similarities to other viral mRNA transcripts which are synthesized by cap snatching.

Microfluidic droplet enrichment for targeted sequencing

PubMed Central

Eastburn, Dennis J.; Huang, Yong; Pellegrino, Maurizio; Sciambi, Adam; Ptáček, Louis J.; Abate, Adam R.

2015-01-01

Targeted sequence enrichment enables better identification of genetic variation by providing increased sequencing coverage for genomic regions of interest. Here, we report the development of a new target enrichment technology that is highly differentiated from other approaches currently in use. Our method, MESA (Microfluidic droplet Enrichment for Sequence Analysis), isolates genomic DNA fragments in microfluidic droplets and performs TaqMan PCR reactions to identify droplets containing a desired target sequence. The TaqMan positive droplets are subsequently recovered via dielectrophoretic sorting, and the TaqMan amplicons are removed enzymatically prior to sequencing. We demonstrated the utility of this approach by generating an average 31.6-fold sequence enrichment across 250 kb of targeted genomic DNA from five unique genomic loci. Significantly, this enrichment enabled a more comprehensive identification of genetic polymorphisms within the targeted loci. MESA requires low amounts of input DNA, minimal prior locus sequence information and enriches the target region without PCR bias or artifacts. These features make it well suited for the study of genetic variation in a number of research and diagnostic applications. PMID:25873629

Sequence stratigraphy of the Triassic in the Barentsz Sea

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

Skjold, L.JU.; Van Veen, P.M.; Gjelberg, J.

1990-05-01

A regional study of the Triassic in the Barentsz Sea (20-32{degree}E, 71-74{degree}N) revealed sequences that correlate seismically for hundreds of kilometers. Recent offshore drilling results enabled them to establish a biostratigraphic time framework. Comparisons with information from onshore outcrops (such as the Svalbard Archipelago) aided the piecing together of these superregional sequences. Seismic character analysis identified three units with composite progradational patterns (Induan, Olenekian, and Anisian). Fluvial, deltaic, and marine deposits can be distinguished and located relative to the paleocoastlines. Corresponding downlap surfaces suggest the development of condensed intervals, predicted to consist of organic-rich source rocks, as was later confirmedmore » by drilling. Regional predictions based on this sequence-stratigraphic approach have proved valuable when correlating and evaluating well information. The sequences identified also help define third-order sea level curves for the area; these improve published curves thought to have global significance.« less

Sequence analysis of the 5.8S ribosomal DNA and internal transcribed spacers (ITS1 and ITS2) from five species of the Oxalis tuberosa alliance.

PubMed

Tosto, D S; Hopp, H E

1996-01-01

The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA sequence and the intervening 5.8S region from five species of the genus Oxalis was amplified by polymerase chain reaction and subjected to direct DNA sequencing. On the basis of cytogenetic studies some species of this genus were postulated to be related by the number of chromosomes. Sequence homologies in the ITS1, 5.8S and ITS2 among species are in good agreement with previous relationships established on the basis of chromosome numbers. We also identified a highly conserved sequence of six bp in the ITS1, reported to be present in a wide range of flowering plants, but not in the Oxalidaceae family to which the genus Oxalis belongs to.

Organization and transient expression of the gene for human U11 snRNA

PubMed Central

Clemens, Suter-Crazzolara; Walter, Keller

1991-01-01

The nucleotide sequence of U11 small nuclear RNA, a minor U RNA from HeLa cells, was determined. Computer analysis of the sequence (135 residues) predicts two strong hairpin loops which are separated by seventeen nucleotides containing an Sm binding site (AAUUUUUUGG). A synthetic gene was constructed in which the coding region of U11 RNA is under the control of a T7 promoter. This vector can be used to produce U11 RNA in vitro. Southern hybridization and PCR analysis of HeLa genomic DNA suggest that U11 RNA is encoded by a single copy gene, and that at least three genomic regions could be U11 RNA pseudogenes. A HeLa genomic copy of a U11 gene was isolated by inverted PCR. This gene contains the U11 RNA coding sequence and several sequence elements unique for the U RNA genes. These include a Distal Sequence Element (DSE, ATTTGCATA) present between positions −215 and −223 relative to the start of transcription; a Proximal Sequence Element (PSE, TTCACCTTTACCAAAAATG) located between positions −43 and −63 ; and a 3′box (GTTAGGCGAAATATTA) between positions +150 and +166. Transfection of HeLa cells with this gene revealed that it is functioning in vivo and can produce U11 RNA. PMID:1820214

Comprehensive Survey of Genetic Diversity in Chloroplast Genomes and 45S nrDNAs within Panax ginseng Species

PubMed Central

Kim, Kyunghee; Lee, Sang-Choon; Lee, Junki; Lee, Hyun Oh; Joh, Ho Jun; Kim, Nam-Hoon; Park, Hyun-Seung; Yang, Tae-Jin

2015-01-01

We report complete sequences of chloroplast (cp) genome and 45S nuclear ribosomal DNA (45S nrDNA) for 11 Panax ginseng cultivars. We have obtained complete sequences of cp and 45S nrDNA, the representative barcoding target sequences for cytoplasm and nuclear genome, respectively, based on low coverage NGS sequence of each cultivar. The cp genomes sizes ranged from 156,241 to 156,425 bp and the major size variation was derived from differences in copy number of tandem repeats in the ycf1 gene and in the intergenic regions of rps16-trnUUG and rpl32-trnUAG. The complete 45S nrDNA unit sequences were 11,091 bp, representing a consensus single transcriptional unit with an intergenic spacer region. Comparative analysis of these sequences as well as those previously reported for three Chinese accessions identified very rare but unique polymorphism in the cp genome within P. ginseng cultivars. There were 12 intra-species polymorphisms (six SNPs and six InDels) among 14 cultivars. We also identified five SNPs from 45S nrDNA of 11 Korean ginseng cultivars. From the 17 unique informative polymorphic sites, we developed six reliable markers for analysis of ginseng diversity and cultivar authentication. PMID:26061692

Mansonella ozzardi mitogenome and pseudogene characterisation provides new perspectives on filarial parasite systematics and CO-1 barcoding.

PubMed

Crainey, James Lee; Marín, Michel Abanto; Silva, Túllio Romão Ribeiro da; de Medeiros, Jansen Fernandes; Pessoa, Felipe Arley Costa; Santos, Yago Vinícius; Vicente, Ana Carolina Paulo; Luz, Sérgio Luiz Bessa

2018-04-18

Despite the broad distribution of M. ozzardi in Latin America and the Caribbean, there is still very little DNA sequence data available to study this neglected parasite's epidemiology. Mitochondrial DNA (mtDNA) sequences, especially the cytochrome oxidase (CO1) gene's barcoding region, have been targeted successfully for filarial diagnostics and for epidemiological, ecological and evolutionary studies. MtDNA-based studies can, however, be compromised by unrecognised mitochondrial pseudogenes, such as Numts. Here, we have used shot-gun Illumina-HiSeq sequencing to recover the first complete Mansonella genus mitogenome and to identify several mitochondrial-origin pseudogenes. Mitogenome phylogenetic analysis placed M. ozzardi in the Onchocercidae "ONC5" clade and suggested that Mansonella parasites are more closely related to Wuchereria and Brugia genera parasites than they are to Loa genus parasites. DNA sequence alignments, BLAST searches and conceptual translations have been used to compliment phylogenetic analysis showing that M. ozzardi from the Amazon and Caribbean regions are near-identical and that previously reported Peruvian M. ozzardi CO1 reference sequences are probably of pseudogene origin. In addition to adding a much-needed resource to the Mansonella genus's molecular tool-kit and providing evidence that some M. ozzardi CO1 sequence deposits are pseudogenes, our results suggest that all Neotropical M. ozzardi parasites are closely related.

An Outbreak of Acute Hepatitis Caused by Genotype IB Hepatitis A Viruses Contaminating the Water Supply in Thailand.

PubMed

Ruchusatsawat, Kriangsak; Wongpiyabovorn, Jongkonnee; Kawidam, Chonthicha; Thiemsing, Laddawan; Sangkitporn, Somchai; Yoshizaki, Sayaka; Tatsumi, Masashi; Takeda, Naokazu; Ishii, Koji

2016-01-01

In 2000, an outbreak of acute hepatitis A was reported in a province adjacent to Bangkok, Thailand. To investigate the cause of the 2000 hepatitis A outbreaks in Thailand using molecular epidemiological analysis. Serum and stool specimens were collected from patients who were clinically diagnosed with acute viral hepatitis. Water samples from drinking water and deep-drilled wells were also collected. These specimens were subjected to polymerase chain reaction (PCR) amplification and sequencing of the VP1/2A region of the hepatitis A virus (HAV) genome. The entire genome sequence of one of the fecal specimens was determined and phylogenetically analyzed with those of known HAV sequences. Eleven of 24 fecal specimens collected from acute viral hepatitis patients were positive as determined by semi- nested reverse transcription PCR targeting the VP1/2A region of HAV. The nucleotide sequence of these samples had an identical genotype IB sequence, suggesting that the same causative agent was present. The complete nucleotide sequence derived from one of the samples indicated that the Thai genotype IB strain should be classified in a unique phylogenetic cluster. The analysis using an adjusted odds ratio showed that the consumption of groundwater was the most likely risk factor associated with the disease. © 2017 S. Karger AG, Basel.

The Large Mitochondrial Genome of Symbiodinium minutum Reveals Conserved Noncoding Sequences between Dinoflagellates and Apicomplexans

PubMed Central

Shoguchi, Eiichi; Shinzato, Chuya; Hisata, Kanako; Satoh, Nori; Mungpakdee, Sutada

2015-01-01

Even though mitochondrial genomes, which characterize eukaryotic cells, were first discovered more than 50 years ago, mitochondrial genomics remains an important topic in molecular biology and genome sciences. The Phylum Alveolata comprises three major groups (ciliates, apicomplexans, and dinoflagellates), the mitochondrial genomes of which have diverged widely. Even though the gene content of dinoflagellate mitochondrial genomes is reportedly comparable to that of apicomplexans, the highly fragmented and rearranged genome structures of dinoflagellates have frustrated whole genomic analysis. Consequently, noncoding sequences and gene arrangements of dinoflagellate mitochondrial genomes have not been well characterized. Here we report that the continuous assembled genome (∼326 kb) of the dinoflagellate, Symbiodinium minutum, is AT-rich (∼64.3%) and that it contains three protein-coding genes. Based upon in silico analysis, the remaining 99% of the genome comprises transcriptomic noncoding sequences. RNA edited sites and unique, possible start and stop codons clarify conserved regions among dinoflagellates. Our massive transcriptome analysis shows that almost all regions of the genome are transcribed, including 27 possible fragmented ribosomal RNA genes and 12 uncharacterized small RNAs that are similar to mitochondrial RNA genes of the malarial parasite, Plasmodium falciparum. Gene map comparisons show that gene order is only slightly conserved between S. minutum and P. falciparum. However, small RNAs and intergenic sequences share sequence similarities with P. falciparum, suggesting that the function of noncoding sequences has been preserved despite development of very different genome structures. PMID:26199191

Toward the 1,000 dollars human genome.

PubMed

Bennett, Simon T; Barnes, Colin; Cox, Anthony; Davies, Lisa; Brown, Clive

2005-06-01

Revolutionary new technologies, capable of transforming the economics of sequencing, are providing an unparalleled opportunity to analyze human genetic variation comprehensively at the whole-genome level within a realistic timeframe and at affordable costs. Current estimates suggest that it would cost somewhere in the region of 30 million US dollars to sequence an entire human genome using Sanger-based sequencing, and on one machine it would take about 60 years. Solexa is widely regarded as a company with the necessary disruptive technology to be the first to achieve the ultimate goal of the so-called 1,000 dollars human genome - the conceptual cost-point needed for routine analysis of individual genomes. Solexa's technology is based on completely novel sequencing chemistry capable of sequencing billions of individual DNA molecules simultaneously, a base at a time, to enable highly accurate, low cost analysis of an entire human genome in a single experiment. When applied over a large enough genomic region, these new approaches to resequencing will enable the simultaneous detection and typing of known, as well as unknown, polymorphisms, and will also offer information about patterns of linkage disequilibrium in the population being studied. Technological progress, leading to the advent of single-molecule-based approaches, is beginning to dramatically drive down costs and increase throughput to unprecedented levels, each being several orders of magnitude better than that which is currently available. A new sequencing paradigm based on single molecules will be faster, cheaper and more sensitive, and will permit routine analysis at the whole-genome level.

Validation of a next-generation sequencing assay for clinical molecular oncology.

PubMed

Cottrell, Catherine E; Al-Kateb, Hussam; Bredemeyer, Andrew J; Duncavage, Eric J; Spencer, David H; Abel, Haley J; Lockwood, Christina M; Hagemann, Ian S; O'Guin, Stephanie M; Burcea, Lauren C; Sawyer, Christopher S; Oschwald, Dayna M; Stratman, Jennifer L; Sher, Dorie A; Johnson, Mark R; Brown, Justin T; Cliften, Paul F; George, Bijoy; McIntosh, Leslie D; Shrivastava, Savita; Nguyen, Tudung T; Payton, Jacqueline E; Watson, Mark A; Crosby, Seth D; Head, Richard D; Mitra, Robi D; Nagarajan, Rakesh; Kulkarni, Shashikant; Seibert, Karen; Virgin, Herbert W; Milbrandt, Jeffrey; Pfeifer, John D

2014-01-01

Currently, oncology testing includes molecular studies and cytogenetic analysis to detect genetic aberrations of clinical significance. Next-generation sequencing (NGS) allows rapid analysis of multiple genes for clinically actionable somatic variants. The WUCaMP assay uses targeted capture for NGS analysis of 25 cancer-associated genes to detect mutations at actionable loci. We present clinical validation of the assay and a detailed framework for design and validation of similar clinical assays. Deep sequencing of 78 tumor specimens (≥ 1000× average unique coverage across the capture region) achieved high sensitivity for detecting somatic variants at low allele fraction (AF). Validation revealed sensitivities and specificities of 100% for detection of single-nucleotide variants (SNVs) within coding regions, compared with SNP array sequence data (95% CI = 83.4-100.0 for sensitivity and 94.2-100.0 for specificity) or whole-genome sequencing (95% CI = 89.1-100.0 for sensitivity and 99.9-100.0 for specificity) of HapMap samples. Sensitivity for detecting variants at an observed 10% AF was 100% (95% CI = 93.2-100.0) in HapMap mixes. Analysis of 15 masked specimens harboring clinically reported variants yielded concordant calls for 13/13 variants at AF of ≥ 15%. The WUCaMP assay is a robust and sensitive method to detect somatic variants of clinical significance in molecular oncology laboratories, with reduced time and cost of genetic analysis allowing for strategic patient management. Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Genetic population structure in the yellow mongoose, Cynictis penicillata.

PubMed

Van Vuuren, B J; Robinson, T J

1997-12-01

Phylogeographic structure was determined for the yellow mongoose, Cynictis penicillata, using mtDNA RFLPs and control region sequences. The RFLP analysis revealed 13 haplotypes which showed weak geographical patterning consistent with a recent range expansion from a refugial population(s). An analysis of molecular variance (AMOVA) revealed no correspondence between mtDNA phylogeography and subspecies delimitation, nor between matrilines and areas characterized by a high incidence of the viverrid-type rabies, of which the yellow mongoose is the principal vector. The lack of structure was also shown by control region sequences although four of the maternal lineages shared a near-perfect 81 bp repeat. We speculate that regional hot spots of the viverrid rabies biotype reflect population density differences in the yellow mongoose that are not underscored by genetic partitioning, at least at the level of resolution provided by our analyses.

JCoDA: a tool for detecting evolutionary selection.

PubMed

Steinway, Steven N; Dannenfelser, Ruth; Laucius, Christopher D; Hayes, James E; Nayak, Sudhir

2010-05-27

The incorporation of annotated sequence information from multiple related species in commonly used databases (Ensembl, Flybase, Saccharomyces Genome Database, Wormbase, etc.) has increased dramatically over the last few years. This influx of information has provided a considerable amount of raw material for evaluation of evolutionary relationships. To aid in the process, we have developed JCoDA (Java Codon Delimited Alignment) as a simple-to-use visualization tool for the detection of site specific and regional positive/negative evolutionary selection amongst homologous coding sequences. JCoDA accepts user-inputted unaligned or pre-aligned coding sequences, performs a codon-delimited alignment using ClustalW, and determines the dN/dS calculations using PAML (Phylogenetic Analysis Using Maximum Likelihood, yn00 and codeml) in order to identify regions and sites under evolutionary selection. The JCoDA package includes a graphical interface for Phylip (Phylogeny Inference Package) to generate phylogenetic trees, manages formatting of all required file types, and streamlines passage of information between underlying programs. The raw data are output to user configurable graphs with sliding window options for straightforward visualization of pairwise or gene family comparisons. Additionally, codon-delimited alignments are output in a variety of common formats and all dN/dS calculations can be output in comma-separated value (CSV) format for downstream analysis. To illustrate the types of analyses that are facilitated by JCoDA, we have taken advantage of the well studied sex determination pathway in nematodes as well as the extensive sequence information available to identify genes under positive selection, examples of regional positive selection, and differences in selection based on the role of genes in the sex determination pathway. JCoDA is a configurable, open source, user-friendly visualization tool for performing evolutionary analysis on homologous coding sequences. JCoDA can be used to rapidly screen for genes and regions of genes under selection using PAML. It can be freely downloaded at http://www.tcnj.edu/~nayaklab/jcoda.

JCoDA: a tool for detecting evolutionary selection

PubMed Central

2010-01-01

Background The incorporation of annotated sequence information from multiple related species in commonly used databases (Ensembl, Flybase, Saccharomyces Genome Database, Wormbase, etc.) has increased dramatically over the last few years. This influx of information has provided a considerable amount of raw material for evaluation of evolutionary relationships. To aid in the process, we have developed JCoDA (Java Codon Delimited Alignment) as a simple-to-use visualization tool for the detection of site specific and regional positive/negative evolutionary selection amongst homologous coding sequences. Results JCoDA accepts user-inputted unaligned or pre-aligned coding sequences, performs a codon-delimited alignment using ClustalW, and determines the dN/dS calculations using PAML (Phylogenetic Analysis Using Maximum Likelihood, yn00 and codeml) in order to identify regions and sites under evolutionary selection. The JCoDA package includes a graphical interface for Phylip (Phylogeny Inference Package) to generate phylogenetic trees, manages formatting of all required file types, and streamlines passage of information between underlying programs. The raw data are output to user configurable graphs with sliding window options for straightforward visualization of pairwise or gene family comparisons. Additionally, codon-delimited alignments are output in a variety of common formats and all dN/dS calculations can be output in comma-separated value (CSV) format for downstream analysis. To illustrate the types of analyses that are facilitated by JCoDA, we have taken advantage of the well studied sex determination pathway in nematodes as well as the extensive sequence information available to identify genes under positive selection, examples of regional positive selection, and differences in selection based on the role of genes in the sex determination pathway. Conclusions JCoDA is a configurable, open source, user-friendly visualization tool for performing evolutionary analysis on homologous coding sequences. JCoDA can be used to rapidly screen for genes and regions of genes under selection using PAML. It can be freely downloaded at http://www.tcnj.edu/~nayaklab/jcoda. PMID:20507581

Next-Generation Sequencing Reveals Frequent Opportunities for Exposure to Hepatitis C Virus in Ghana

PubMed Central

Phillips, Richard O.; Mora, Nallely; Xia, Guo-liang; Campo, David S.; Purdy, Michael A.; Dimitrova, Zoya E.; Owusu, Dorcas O.; Punkova, Lili T.; Skums, Pavel; Owusu-Ofori, Shirley; Sarfo, Fred Stephen; Vaughan, Gilberto; Roh, Hajung; Opare-Sem, Ohene K.; Cooper, Richard S.; Khudyakov, Yury E.

2015-01-01

Globally, hepatitis C Virus (HCV) infection is responsible for a large proportion of persons with liver disease, including cancer. The infection is highly prevalent in sub-Saharan Africa. West Africa was identified as a geographic origin of two HCV genotypes. However, little is known about the genetic composition of HCV populations in many countries of the region. Using conventional and next-generation sequencing (NGS), we identified and genetically characterized 65 HCV strains circulating among HCV-positive blood donors in Kumasi, Ghana. Phylogenetic analysis using consensus sequences derived from 3 genomic regions of the HCV genome, 5'-untranslated region, hypervariable region 1 (HVR1) and NS5B gene, consistently classified the HCV variants (n = 65) into genotypes 1 (HCV-1, 15%) and genotype 2 (HCV-2, 85%). The Ghanaian and West African HCV-2 NS5B sequences were found completely intermixed in the phylogenetic tree, indicating a substantial genetic heterogeneity of HCV-2 in Ghana. Analysis of HVR1 sequences from intra-host HCV variants obtained by NGS showed that three donors were infected with >1 HCV strain, including infections with 2 genotypes. Two other donors share an HCV strain, indicating HCV transmission between them. The HCV-2 strain sampled from one donor was replaced with another HCV-2 strain after only 2 months of observation, indicating rapid strain switching. Bayesian analysis estimated that the HCV-2 strains in Ghana were expanding since the 16th century. The blood donors in Kumasi, Ghana, are infected with a very heterogeneous HCV population of HCV-1 and HCV-2, with HCV-2 being prevalent. The detection of three cases of co- or super-infections and transmission linkage between 2 cases suggests frequent opportunities for HCV exposure among the blood donors and is consistent with the reported high HCV prevalence. The conditions for effective HCV-2 transmission existed for ~ 3–4 centuries, indicating a long epidemic history of HCV-2 in Ghana. PMID:26683463

Genetic analysis of human immunodeficiency virus type 1 envelope V3 region isolates from mothers and infants after perinatal transmission.

PubMed Central

Ahmad, N; Baroudy, B M; Baker, R C; Chappey, C

1995-01-01

The human immunodeficiency virus type 1 (HIV-1) sequences from variable region 3 (V3) of the envelope gene were analyzed from seven infected mother-infant pairs following perinatal transmission. The V3 region sequences directly derived from the DNA of the uncultured peripheral blood mononuclear cells from infected mothers displayed a heterogeneous population. In contrast, the infants' sequences were less diverse than those of their mothers. In addition, the sequences from the younger infants' peripheral blood mononuclear cell DNA were more homogeneous than the older infants' sequences. All infants' sequences were different but displayed patterns similar to those seen in their mothers. In the mother-infant pair sequences analyzed, a minor genotype or subtype found in the mothers predominated in their infants. The conserved N-linked glycosylation site proximal to the first cysteine of the V3 loop was absent only in one infant's sequence set and in some variants of two other infants' sequences. Furthermore, the HIV-1 sequences of the epidemiologically linked mother-infant pairs were closer than the sequences of epidemiologically unlinked individuals, suggesting that the sequence comparison of mother-infant pairs done in order to identify genetic variants transmitted from mother to infant could be performed even in older infants. There was no evidence for transmission of a major genotype or multiple genotypes from mother to infant. In conclusion, a minor genotype of maternal virus is transmitted to the infants, and this finding could be useful in developing strategies to prevent maternal transmission of HIV-1 by means of perinatal interventions. PMID:7815476

Characterization of the variable-number tandem repeats in vrrA from different Bacillus anthracis isolates

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

Jackson, P.J.; Walthers, E.A.; Richmond, K.L.

1997-04-01

PCR analysis of 198 Bacillus anthracis isolates revealed a variable region of DNA sequence differing in length among the isolates. Five Polymorphisms differed by the presence Of two to six copies of the 12-bp tandem repeat 5{prime}-CAATATCAACAA-3{prime}. This variable-number tandem repeat (VNTR) region is located within a larger sequence containing one complete open reading frame that encodes a putative 30-kDa protein. Length variation did not change the reading frame of the encoded protein and only changed the copy number of a 4-amino-acid sequence (QYQQ) from 2 to 6. The structure of the VNTR region suggests that these multiple repeats aremore » generated by recombination or polymerase slippage. Protein structures predicted from the reverse-translated DNA sequence suggest that any structural changes in the encoded protein are confined to the region encoded by the VNTR sequence. Copy number differences in the VNTR region were used to define five different B. anthracis alleles. Characterization of 198 isolates revealed allele frequencies of 6.1, 17.7, 59.6, 5.6, and 11.1% sequentially from shorter to longer alleles. The high degree of polymorphism in the VNTR region provides a criterion for assigning isolates to five allelic categories. There is a correlation between categories and geographic distribution. Such molecular markers can be used to monitor the epidemiology of anthrax outbreaks in domestic and native herbivore populations. 22 refs., 4 figs., 3 tabs.« less

Synteny of Prunus and other model plant species

PubMed Central

Jung, Sook; Jiwan, Derick; Cho, Ilhyung; Lee, Taein; Abbott, Albert; Sosinski, Bryon; Main, Dorrie

2009-01-01

Background Fragmentary conservation of synteny has been reported between map-anchored Prunus sequences and Arabidopsis. With the availability of genome sequence for fellow rosid I members Populus and Medicago, we analyzed the synteny between Prunus and the three model genomes. Eight Prunus BAC sequences and map-anchored Prunus sequences were used in the comparison. Results We found a well conserved synteny across the Prunus species – peach, plum, and apricot – and Populus using a set of homologous Prunus BACs. Conversely, we could not detect any synteny with Arabidopsis in this region. Other peach BACs also showed extensive synteny with Populus. The syntenic regions detected were up to 477 kb in Populus. Two syntenic regions between Arabidopsis and these BACs were much shorter, around 10 kb. We also found syntenic regions that are conserved between the Prunus BACs and Medicago. The array of synteny corresponded with the proposed whole genome duplication events in Populus and Medicago. Using map-anchored Prunus sequences, we detected many syntenic blocks with several gene pairs between Prunus and Populus or Arabidopsis. We observed a more complex network of synteny between Prunus-Arabidopsis, indicative of multiple genome duplication and subsequence gene loss in Arabidopsis. Conclusion Our result shows the striking microsynteny between the Prunus BACs and the genome of Populus and Medicago. In macrosynteny analysis, more distinct Prunus regions were syntenic to Populus than to Arabidopsis. PMID:19208249

Context based computational analysis and characterization of ARS consensus sequences (ACS) of Saccharomyces cerevisiae genome.

PubMed

Singh, Vinod Kumar; Krishnamachari, Annangarachari

2016-09-01

Genome-wide experimental studies in Saccharomyces cerevisiae reveal that autonomous replicating sequence (ARS) requires an essential consensus sequence (ACS) for replication activity. Computational studies identified thousands of ACS like patterns in the genome. However, only a few hundreds of these sites act as replicating sites and the rest are considered as dormant or evolving sites. In a bid to understand the sequence makeup of replication sites, a content and context-based analysis was performed on a set of replicating ACS sequences that binds to origin-recognition complex (ORC) denoted as ORC-ACS and non-replicating ACS sequences (nrACS), that are not bound by ORC. In this study, DNA properties such as base composition, correlation, sequence dependent thermodynamic and DNA structural profiles, and their positions have been considered for characterizing ORC-ACS and nrACS. Analysis reveals that ORC-ACS depict marked differences in nucleotide composition and context features in its vicinity compared to nrACS. Interestingly, an A-rich motif was also discovered in ORC-ACS sequences within its nucleosome-free region. Profound changes in the conformational features, such as DNA helical twist, inclination angle and stacking energy between ORC-ACS and nrACS were observed. Distribution of ACS motifs in the non-coding segments points to the locations of ORC-ACS which are found far away from the adjacent gene start position compared to nrACS thereby enabling an accessible environment for ORC-proteins. Our attempt is novel in considering the contextual view of ACS and its flanking region along with nucleosome positioning in the S. cerevisiae genome and may be useful for any computational prediction scheme.

Long interspersed repeated DNA (LINE) causes polymorphism at the rat insulin 1 locus.

PubMed Central

Lakshmikumaran, M S; D'Ambrosio, E; Laimins, L A; Lin, D T; Furano, A V

1985-01-01

The insulin 1, but not the insulin 2, locus is polymorphic (i.e., exhibits allelic variation) in rats. Restriction enzyme analysis and hybridization studies showed that the polymorphic region is 2.2 kilobases upstream of the insulin 1 coding region and is due to the presence or absence of an approximately 2.7-kilobase repeated DNA element. DNA sequence determination showed that this DNA element is a member of a long interspersed repeated DNA family (LINE) that is highly repeated (greater than 50,000 copies) and highly transcribed in the rat. Although the presence or absence of LINE sequences at the insulin 1 locus occurs in both the homozygous and heterozygous states, LINE-containing insulin 1 alleles are more prevalent in the rat population than are alleles without LINEs. Restriction enzyme analysis of the LINE-containing alleles indicated that at least two versions of the LINE sequence may be present at the insulin 1 locus in different rats. Either repeated transposition of LINE sequences or gene conversion between the resident insulin 1 LINE and other sequences in the genome are possible explanations for this. Images PMID:3016521

Analysis of the intergenic region of tomato spotted wilt Tospovirus medium RNA segment.

PubMed

Bhat, A I; Pappu, S S; Pappu, H R; Deom, C M; Culbreath, A K

1999-06-01

The intergenic region (IGR) of the medium (M) RNA of tomato spotted wilt Tospovirus (TSWV) isolates naturally infecting peanut (groundnut), pepper, potato, stokesia, tobacco and watermelon in Georgia (GA) and a peanut isolate from Florida (FL) was cloned and sequenced. The IGR sequences were compared with one another and with respective M RNA IGRs of TSWV isolates from Brazil and Japan and other tospoviruses. The length of M IGR of GA and FL isolates varied from 271 to 277 nucleotides. The M IGRs of TSWV from potato and stokesia, and tobacco and watermelon were identical with each other in their length and sequence. IGR sequences were more conserved (95-100%) among the populations of TSWV from GA and FL, than when compared with those of TSWV isolates from other countries (83-94%). The conserved motif (CAAACTTTGG) present in the IGRs of both M and small (S) RNAs of a Brazilian isolate of TSWV was also conserved in the isolates studied. Cluster analysis of the IGR sequences showed that all GA and FL isolates are closely clustered and are distinct from the TSWV isolates from other countries as well as from other tospoviruses.

The primary structures of two yeast enolase genes. Homology between the 5' noncoding flanking regions of yeast enolase and glyceraldehyde-3-phosphate dehydrogenase genes.

PubMed

Holland, M J; Holland, J P; Thill, G P; Jackson, K A

1981-02-10

Segments of yeast genomic DNA containing two enolase structural genes have been isolated by subculture cloning procedures using a cDNA hybridization probe synthesized from purified yeast enolase mRNA. Based on restriction endonuclease and transcriptional maps of these two segments of yeast DNA, each hybrid plasmid contains a region of extensive nucleotide sequence homology which forms hybrids with the cDNA probe. The DNA sequences which flank this homologous region in the two hybrid plasmids are nonhomologous indicating that these sequences are nontandemly repeated in the yeast genome. The complete nucleotide sequence of the coding as well as the flanking noncoding regions of these genes has been determined. The amino acid sequence predicted from one reading frame of both structural genes is extremely similar to that determined for yeast enolase (Chin, C. C. Q., Brewer, J. M., Eckard, E., and Wold, F. (1981) J. Biol. Chem. 256, 1370-1376), confirming that these isolated structural genes encode yeast enolase. The nucleotide sequences of the coding regions of the genes are approximately 95% homologous, and neither gene contains an intervening sequence. Codon utilization in the enolase genes follows the same biased pattern previously described for two yeast glyceraldehyde-3-phosphate dehydrogenase structural genes (Holland, J. P., and Holland, M. J. (1980) J. Biol. Chem. 255, 2596-2605). DNA blotting analysis confirmed that the isolated segments of yeast DNA are colinear with yeast genomic DNA and that there are two nontandemly repeated enolase genes per haploid yeast genome. The noncoding portions of the two enolase genes adjacent to the initiation and termination codons are approximately 70% homologous and contain sequences thought to be involved in the synthesis and processing messenger RNA. Finally there are regions of extensive homology between the two enolase structural genes and two yeast glyceraldehyde-3-phosphate dehydrogenase structural genes within the 5- noncoding portions of these glycolytic genes.

REPPER—repeats and their periodicities in fibrous proteins

PubMed Central

Gruber, Markus; Söding, Johannes; Lupas, Andrei N.

2005-01-01

REPPER (REPeats and their PERiodicities) is an integrated server that detects and analyzes regions with short gapless repeats in protein sequences or alignments. It finds periodicities by Fourier Transform (FTwin) and internal similarity analysis (REPwin). FTwin assigns numerical values to amino acids that reflect certain properties, for instance hydrophobicity, and gives information on corresponding periodicities. REPwin uses self-alignments and displays repeats that reveal significant internal similarities. Both programs use a sliding window to ensure that different periodic regions within the same protein are detected independently. FTwin and REPwin are complemented by secondary structure prediction (PSIPRED) and coiled coil prediction (COILS), making the server a versatile analysis tool for sequences of fibrous proteins. REPPER is available at . PMID:15980460

VaDiR: an integrated approach to Variant Detection in RNA.

PubMed

Neums, Lisa; Suenaga, Seiji; Beyerlein, Peter; Anders, Sara; Koestler, Devin; Mariani, Andrea; Chien, Jeremy

2018-02-01

Advances in next-generation DNA sequencing technologies are now enabling detailed characterization of sequence variations in cancer genomes. With whole-genome sequencing, variations in coding and non-coding sequences can be discovered. But the cost associated with it is currently limiting its general use in research. Whole-exome sequencing is used to characterize sequence variations in coding regions, but the cost associated with capture reagents and biases in capture rate limit its full use in research. Additional limitations include uncertainty in assigning the functional significance of the mutations when these mutations are observed in the non-coding region or in genes that are not expressed in cancer tissue. We investigated the feasibility of uncovering mutations from expressed genes using RNA sequencing datasets with a method called Variant Detection in RNA(VaDiR) that integrates 3 variant callers, namely: SNPiR, RVBoost, and MuTect2. The combination of all 3 methods, which we called Tier 1 variants, produced the highest precision with true positive mutations from RNA-seq that could be validated at the DNA level. We also found that the integration of Tier 1 variants with those called by MuTect2 and SNPiR produced the highest recall with acceptable precision. Finally, we observed a higher rate of mutation discovery in genes that are expressed at higher levels. Our method, VaDiR, provides a possibility of uncovering mutations from RNA sequencing datasets that could be useful in further functional analysis. In addition, our approach allows orthogonal validation of DNA-based mutation discovery by providing complementary sequence variation analysis from paired RNA/DNA sequencing datasets.

Ebolavirus comparative genomics

DOE PAGES

Jun, Se-Ran; Leuze, Michael R.; Nookaew, Intawat; ...

2015-07-14

The 2014 Ebola outbreak in West Africa is the largest documented for this virus. We examine the dynamics of this genome, comparing more than one hundred currently available ebolavirus genomes to each other and to other viral genomes. Based on oligomer frequency analysis, the family Filoviridae forms a distinct group from all other sequenced viral genomes. All filovirus genomes sequenced to date encode proteins with similar functions and gene order, although there is considerable divergence in sequences between the three genera Ebolavirus, Cuevavirus, and Marburgvirus within the family Filoviridae. Whereas all ebolavirus genomes are quite similar (multiple sequences of themore » same strain are often identical), variation is most common in the intergenic regions and within specific areas of the genes encoding the glycoprotein (GP), nucleoprotein (NP), and polymerase (L). We predict regions that could contain epitope-binding sites, which might be good vaccine targets. In conclusion, this information, combined with glycosylation sites and experimentally determined epitopes, can identify the most promising regions for the development of therapeutic strategies.« less

Complete chloroplast genome sequences of Praxelis (Eupatorium catarium Veldkamp), an important invasive species.

PubMed

Zhang, Ying; Li, Lei; Yan, Ting Liang; Liu, Qiang

2014-10-01

Praxelis (Eupatorium catarium Veldkamp) is a new hazardous invasive plant species that has caused serious economic losses and environmental damage in the Northern hemisphere tropical and subtropical regions. Although previous studies focused on detecting the biological characteristics of this plant to prevent its expansion, little effort has been made to understand the impact of Praxelis on the ecosystem in an evolutionary process. The genetic information of Praxelis is required for further phylogenetic identification and evolutionary studies. Here, we report the complete Praxelis chloroplast (cp) genome sequence. The Praxelis chloroplast genome is 151,410 bp in length including a small single-copy region (18,547 bp) and a large single-copy region (85,311 bp) separated by a pair of inverted repeats (IRs; 23,776 bp). The genome contains 85 unique and 18 duplicated genes in the IR region. The gene content and organization are similar to other Asteraceae tribe cp genomes. We also analyzed the whole cp genome sequence, repeat structure, codon usage, contraction of the IR and gene structure/organization features between native and invasive Asteraceae plants, in order to understand the evolution of organelle genomes between native and invasive Asteraceae. Comparative analysis identified the 14 markers containing greater than 2% parsimony-informative characters, indicating that they are potential informative markers for barcoding and phylogenetic analysis. Moreover, a sister relationship between Praxelis and seven other species in Asteraceae was found based on phylogenetic analysis of 28 protein-coding sequences. Complete cp genome information is useful for plant phylogenetic and evolutionary studies within this invasive species and also within the Asteraceae family. Copyright © 2014 Elsevier B.V. All rights reserved.

Isolation and molecular characterization of partial FSH and LH receptor genes in Arabian camels (Camelus dromedarius)

PubMed Central

Jelokhani-Niaraki, Saber; Tahmoorespur, Mojtaba; Bitaraf-Sani, Morteza

2015-01-01

Very little is known about LHR and FSHR genes of domestic dromedary camels. The main objective of this study was to determine and analyze partial genomic regions of FSHR and LHR genes in dromedary camels for the first time. To this end, a total of50 DNA samples belonging to dromedary camels raised in Iran were sent for sequencing (25 samples of each gene). We compared the nucleotide sequences of Camelus dromedarius with corresponding sequences of previously published FSHR and LHR genes in bactrian camels and other species. According to the data, the same nucleotide variation was identified in both regions of the two camel species. The alignment of deduced protein sequences of the two different species revealed an amino acid variation at the FSHR region. No evidence of amino acid variation was observed, however, in LHR sequences. Phylogenetic analysis indicated that both camel species had a close relationship and clustered together in a separate branch. This was further confirmed by genetic distance values illustrating significant sequence identity between Camelus dromedarius and Camelus bactrianus. Interestingly, sequence comparisons revealed heterozygote patterns in FSHR sequences isolated from dromedary camels of Iran. In comparison to other species, this camel contains three amino acid substitutions at 5, 67, and 105 positions in the FSHR coding region. These positions are found exclusively in camels and can be considered as species specific. The results of our study can be used for hormone functionality research (FSHR and LHR) as well as reproduction-linked polymorphisms and breeding programs. PMID:27844002

Isolation and molecular characterization of partial FSH and LH receptor genes in Arabian camels (Camelus dromedarius).

PubMed

Jelokhani-Niaraki, Saber; Tahmoorespur, Mojtaba; Bitaraf-Sani, Morteza

2015-06-01

Very little is known about LHR and FSHR genes of domestic dromedary camels. The main objective of this study was to determine and analyze partial genomic regions of FSHR and LHR genes in dromedary camels for the first time. To this end, a total of50 DNA samples belonging to dromedary camels raised in Iran were sent for sequencing (25 samples of each gene). We compared the nucleotide sequences of Camelus dromedarius with corresponding sequences of previously published FSHR and LHR genes in bactrian camels and other species. According to the data, the same nucleotide variation was identified in both regions of the two camel species. The alignment of deduced protein sequences of the two different species revealed an amino acid variation at the FSHR region. No evidence of amino acid variation was observed, however, in LHR sequences. Phylogenetic analysis indicated that both camel species had a close relationship and clustered together in a separate branch. This was further confirmed by genetic distance values illustrating significant sequence identity between Camelus dromedarius and Camelus bactrianus . Interestingly, sequence comparisons revealed heterozygote patterns in FSHR sequences isolated from dromedary camels of Iran. In comparison to other species, this camel contains three amino acid substitutions at 5, 67, and 105 positions in the FSHR coding region. These positions are found exclusively in camels and can be considered as species specific. The results of our study can be used for hormone functionality research ( FSHR and LHR ) as well as reproduction-linked polymorphisms and breeding programs.

Diversity of human immunodeficiency virus type 1 subtypes in Kagera and Kilimanjaro regions, Tanzania.

PubMed

Nyombi, Balthazar M; Kristiansen, Knut I; Bjune, Gunnar; Müller, Fredrik; Holm-Hansen, Carol

2008-06-01

A strategy to prevent the spread of HIV-1 worldwide is complicated by the high genetic diversity of the virus. To gain a better understanding of the HIV-1 genetic diversity in Tanzania, a molecular epidemiological investigation was conducted in Kagera and Kilimanjaro regions. While several studies have addressed HIV-1 subtypes in Tanzania, this is the first study to describe the virus subtypes circulating in Kagera. The Kagera region is the epicenter of the HIV-1 epidemic in Africa, and it was therefore of interest to compare the prevalence of HIV subtypes in this region and Kilimanjaro. Blood samples were obtained from 246 HIV-1-infected pregnant women attending antenatal clinics. Plasma HIV-1 RNA was extracted, amplified, and sequenced in the env C2V3 and/or pol regions from 209 samples. Based on the analysis of env C2V3 and pol sequences, 47.4% had concordant subtypes, 19.1% were discordant indicating recombination, and for 33.5% sequences were obtained for only one region. The distribution HIV-1 subtypes based on the phylogenetic analysis of paired env C2V3/ pol sequences in Kagera region was A/A (27.8%), C/C (29.6%), D/D (16.7%), and unique recombinant forms (25.9%), and in Kilimanjaro region was A/A (32.9%), C/C (25.9%), D/D (10.6%), CRF10_CD (1.2%), and unique recombinant forms (29.4%). The env C2V3 subsubtype A2 and env C2V3/pol CRF10_CD were also observed indicating that these recombinants are circulating in Tanzania. The high diversity of HIV-1 subtypes and the high prevalence of recombinants demonstrated in this study necessitate expanded and continuous monitoring of the epidemic in Tanzania. The trend may have implications for current national control strategies against the HIV-1 epidemic.

Comparative sequence analysis of the X-inactivation center region in mouse, human, and bovine.

PubMed

Chureau, Corinne; Prissette, Marine; Bourdet, Agnès; Barbe, Valérie; Cattolico, Laurence; Jones, Louis; Eggen, André; Avner, Philip; Duret, Laurent

2002-06-01

We have sequenced to high levels of accuracy 714-kb and 233-kb regions of the mouse and bovine X-inactivation centers (Xic), respectively, centered on the Xist gene. This has provided the basis for a fully annotated comparative analysis of the mouse Xic with the 2.3-Mb orthologous region in human and has allowed a three-way species comparison of the core central region, including the Xist gene. These comparisons have revealed conserved genes, both coding and noncoding, conserved CpG islands and, more surprisingly, conserved pseudogenes. The distribution of repeated elements, especially LINE repeats, in the mouse Xic region when compared to the rest of the genome does not support the hypothesis of a role for these repeat elements in the spreading of X inactivation. Interestingly, an asymmetric distribution of LINE elements on the two DNA strands was observed in the three species, not only within introns but also in intergenic regions. This feature is suggestive of important transcriptional activity within these intergenic regions. In silico prediction followed by experimental analysis has allowed four new genes, Cnbp2, Ftx, Jpx, and Ppnx, to be identified and novel, widespread, complex, and apparently noncoding transcriptional activity to be characterized in a region 5' of Xist that was recently shown to attract histone modification early after the onset of X inactivation.

Characterization of shark complement factor I gene(s): genomic analysis of a novel shark-specific sequence.

PubMed

Shin, Dong-Ho; Webb, Barbara M; Nakao, Miki; Smith, Sylvia L

2009-07-01

Complement factor I is a crucial regulator of mammalian complement activity. Very little is known of complement regulators in non-mammalian species. We isolated and sequenced four highly similar complement factor I cDNAs from the liver of the nurse shark (Ginglymostoma cirratum), designated as GcIf-1, GcIf-2, GcIf-3 and GcIf-4 (previously referred to as nsFI-a, -b, -c and -d) which encode 689, 673, 673 and 657 amino acid residues, respectively. They share 95% (

Characterization of shark complement factor I gene(s): genomic analysis of a novel shark-specific sequence

PubMed Central

Shin, Dong-Ho; Webb, Barbara M.; Nakao, Miki; Smith, Sylvia L.

2009-01-01

Complement factor I is a crucial regulator of mammalian complement activity. Very little is known of complement regulators in non-mammalian species. We isolated and sequenced four highly similar complement factor I cDNAs from the liver of the nurse shark (Ginglymostoma cirratum), designated as GcIf-1, GcIf-2, GcIf-3 and GcIf-4 (previously referred to as nsFI-a, -b, -c and –d) which encode 689, 673, 673 and 657 amino acid residues, respectively. They share 95% (≤) amino acid identities with each other, 35.4 ~ 39.6% and 62.8 ~ 65.9% with factor I of mammals and banded houndshark (Triakis scyllium), respectively. The modular structure of the GcIf is similar to that of mammals with one notable exception, the presence of a novel shark-specific sequence between the leader peptide (LP) and the factor I membrane attack complex (FIMAC) domain. The cDNA sequences differ only in the size and composition of the shark-specific region (SSR). Sequence analysis of each SSR has identified within the region two novel short sequences (SS1 and SS2) and three repeat sequences (RS1, 2 and 3). Genomic analysis has revealed the existence of three introns between the leader peptide and the FIMAC domain, tentatively designated intron 1, intron 2, and intron 3 which span 4067, 2293 and 2082 bp, respectively. Southern blot analysis suggests the presence of a single gene copy for each cDNA type. Phylogenetic analysis suggests that complement factor I of cartilaginous fish diverged prior to the emergence of mammals. All four GcIf cDNA species are expressed in four different tissues and the liver is the main tissue in which expression level of all four is high. This suggests that the expression of GcIf isotypes is tissue-dependent. PMID:19423168

Mouse Vk gene classification by nucleic acid sequence similarity.

PubMed

Strohal, R; Helmberg, A; Kroemer, G; Kofler, R

1989-01-01

Analyses of immunoglobulin (Ig) variable (V) region gene usage in the immune response, estimates of V gene germline complexity, and other nucleic acid hybridization-based studies depend on the extent to which such genes are related (i.e., sequence similarity) and their organization in gene families. While mouse Igh heavy chain V region (VH) gene families are relatively well-established, a corresponding systematic classification of Igk light chain V region (Vk) genes has not been reported. The present analysis, in the course of which we reviewed the known extent of the Vk germline gene repertoire and Vk gene usage in a variety of responses to foreign and self antigens, provides a classification of mouse Vk genes in gene families composed of members with greater than 80% overall nucleic acid sequence similarity. This classification differed in several aspects from that of VH genes: only some Vk gene families were as clearly separated (by greater than 25% sequence dissimilarity) as typical VH gene families; most Vk gene families were closely related and, in several instances, members from different families were very similar (greater than 80%) over large sequence portions; frequently, classification by nucleic acid sequence similarity diverged from existing classifications based on amino-terminal protein sequence similarity. Our data have implications for Vk gene analyses by nucleic acid hybridization and describe potentially important differences in sequence organization between VH and Vk genes.

Genetic characterization of L-Zagreb mumps vaccine strain.

PubMed

Ivancic, Jelena; Gulija, Tanja Kosutic; Forcic, Dubravko; Baricevic, Marijana; Jug, Renata; Mesko-Prejac, Majda; Mazuran, Renata

2005-04-01

Eleven mumps vaccine strains, all containing live attenuated virus, have been used throughout the world. Although L-Zagreb mumps vaccine has been licensed since 1972, only its partial nucleotide sequence was previously determined (accession numbers , and ). Therefore, we sequenced the entire genome of L-Zagreb vaccine strain (Institute of Immunology Inc., Zagreb, Croatia). In order to investigate the genetic stability of the vaccine, sequences of both L-Zagreb master seed and currently produced vaccine batch were determined and no difference between them was observed. A phylogenetic analysis based on SH gene sequence has shown that L-Zagreb strain does not belong to any of established mumps genotypes and that it is most similar to old, laboratory preserved European strains (1950s-1970s). L-Zagreb nucleotide and deduced protein sequences were compared with other mumps virus sequences obtained from the GenBank. Emphasis was put on functionally important protein regions and known antigenic epitopes. The extensive comparisons of nucleotide and deduced protein sequences between L-Zagreb vaccine strain and other previously determined mumps virus sequences have shown that while the functional regions of HN, V, and L proteins are well conserved among various mumps strains, there can be a substantial amino acid difference in antigenic epitopes of all proteins and in functional regions of F protein. No molecular pattern was identified that can be used as a distinction marker between virulent and attenuated strains.

RAMICS: trainable, high-speed and biologically relevant alignment of high-throughput sequencing reads to coding DNA.

PubMed

Wright, Imogen A; Travers, Simon A

2014-07-01

The challenge presented by high-throughput sequencing necessitates the development of novel tools for accurate alignment of reads to reference sequences. Current approaches focus on using heuristics to map reads quickly to large genomes, rather than generating highly accurate alignments in coding regions. Such approaches are, thus, unsuited for applications such as amplicon-based analysis and the realignment phase of exome sequencing and RNA-seq, where accurate and biologically relevant alignment of coding regions is critical. To facilitate such analyses, we have developed a novel tool, RAMICS, that is tailored to mapping large numbers of sequence reads to short lengths (<10 000 bp) of coding DNA. RAMICS utilizes profile hidden Markov models to discover the open reading frame of each sequence and aligns to the reference sequence in a biologically relevant manner, distinguishing between genuine codon-sized indels and frameshift mutations. This approach facilitates the generation of highly accurate alignments, accounting for the error biases of the sequencing machine used to generate reads, particularly at homopolymer regions. Performance improvements are gained through the use of graphics processing units, which increase the speed of mapping through parallelization. RAMICS substantially outperforms all other mapping approaches tested in terms of alignment quality while maintaining highly competitive speed performance. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Molecular identification and phylogenetic analysis of important medicinal plant species in genus Paeonia based on rDNA-ITS, matK, and rbcL DNA barcode sequences.

PubMed

Kim, W J; Ji, Y; Choi, G; Kang, Y M; Yang, S; Moon, B C

2016-08-05

This study was performed to identify and analyze the phylogenetic relationship among four herbaceous species of the genus Paeonia, P. lactiflora, P. japonica, P. veitchii, and P. suffruticosa, using DNA barcodes. These four species, which are commonly used in traditional medicine as Paeoniae Radix and Moutan Radicis Cortex, are pharmaceutically defined in different ways in the national pharmacopoeias in Korea, Japan, and China. To authenticate the different species used in these medicines, we evaluated rDNA-internal transcribed spacers (ITS), matK and rbcL regions, which provide information capable of effectively distinguishing each species from one another. Seventeen samples were collected from different geographic regions in Korea and China, and DNA barcode regions were amplified using universal primers. Comparative analyses of these DNA barcode sequences revealed species-specific nucleotide sequences capable of discriminating the four Paeonia species. Among the entire sequences of three barcodes, marker nucleotides were identified at three positions in P. lactiflora, eleven in P. japonica, five in P. veitchii, and 25 in P. suffruticosa. Phylogenetic analyses also revealed four distinct clusters showing homogeneous clades with high resolution at the species level. The results demonstrate that the analysis of these three DNA barcode sequences is a reliable method for identifying the four Paeonia species and can be used to authenticate Paeoniae Radix and Moutan Radicis Cortex at the species level. Furthermore, based on the assessment of amplicon sizes, inter/intra-specific distances, marker nucleotides, and phylogenetic analysis, rDNA-ITS was the most suitable DNA barcode for identification of these species.

Transcription Factors Bind Thousands of Active and InactiveRegions in the Drosophila Blastoderm

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

Li, Xiao-Yong; MacArthur, Stewart; Bourgon, Richard

2008-01-10

Identifying the genomic regions bound by sequence-specific regulatory factors is central both to deciphering the complex DNA cis-regulatory code that controls transcription in metazoans and to determining the range of genes that shape animal morphogenesis. Here, we use whole-genome tiling arrays to map sequences bound in Drosophila melanogaster embryos by the six maternal and gap transcription factors that initiate anterior-posterior patterning. We find that these sequence-specific DNA binding proteins bind with quantitatively different specificities to highly overlapping sets of several thousand genomic regions in blastoderm embryos. Specific high- and moderate-affinity in vitro recognition sequences for each factor are enriched inmore » bound regions. This enrichment, however, is not sufficient to explain the pattern of binding in vivo and varies in a context-dependent manner, demonstrating that higher-order rules must govern targeting of transcription factors. The more highly bound regions include all of the over forty well-characterized enhancers known to respond to these factors as well as several hundred putative new cis-regulatory modules clustered near developmental regulators and other genes with patterned expression at this stage of embryogenesis. The new targets include most of the microRNAs (miRNAs) transcribed in the blastoderm, as well as all major zygotically transcribed dorsal-ventral patterning genes, whose expression we show to be quantitatively modulated by anterior-posterior factors. In addition to these highly bound regions, there are several thousand regions that are reproducibly bound at lower levels. However, these poorly bound regions are, collectively, far more distant from genes transcribed in the blastoderm than highly bound regions; are preferentially found in protein-coding sequences; and are less conserved than highly bound regions. Together these observations suggest that many of these poorly-bound regions are not involved in early-embryonic transcriptional regulation, and a significant proportion may be nonfunctional. Surprisingly, for five of the six factors, their recognition sites are not unambiguously more constrained evolutionarily than the immediate flanking DNA, even in more highly bound and presumably functional regions, indicating that comparative DNA sequence analysis is limited in its ability to identify functional transcription factor targets.« less

Evaluation of the arrestin gene in patients with retinitis pigmentosa or an allied disease

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

DeStefano, D.J.; Berson, E.L.; Dryja, T.P.

1994-09-01

Arrestin, also called 48K protein or S-antigen, plays a role in deactivating rhodopsin, the photosensitive, seven-helix, G-protein receptor found in rod photoreceptors. In Drosophila, null mutations in arrestin genes cause a light-dependent photoreceptor degeneration. It is possible that a comparable photoreceptor degeneration in humans is caused by defects in the rod arrestin gene. In order to evaluate this possibility, we are characterizing the human arrestin locus on chromosome 2q. We screened a genomic library (5 million plaques) using an arrestin cDNA clone. Sixty-eight hybridizing clones were identified; portions of 7 clones were sequenced to determine the intron sequence flanking themore » exons. We are using SSCP analysis and direct genomic sequencing to screen the entire coding region, splice donor and acceptor sites, and the promoter region of the arrestin gene in 188 patients with autosomal dominant and 104 patients with autosomal recessive retinitis pigmentosa. We have already obtained flanking intron sequences necessary for SSCP analysis for 13 of 16 exons. So far, we have identified 4 silent base changes at codons 67 (TGC-to-TGT), 107 (CTG-to-CTC), 163 (GCC-to-GCT), and 288 (CTG-to-TGT), all with allele frequencies at 1% or less. Several other variant bands detected by SSCP analysis are currently being sequenced.« less

Infectious hematopoietic necrosis virus: monophyletic origin of European isolates from North American genogroup M.

PubMed

Enzmann, P J; Kurath, G; Fichtner, D; Bergmann, S M

2005-09-23

Infectious hematopoietic necrosis virus (IHNV) was first detected in Europe in 1987 in France and Italy, and later, in 1992, in Germany. The source of the virus and the route of introduction are unknown. The present study investigates the molecular epidemiology of IHNV outbreaks in Germany since its first introduction. The complete nucleotide sequences of the glycoprotein (G) and non-virion (NV) genes from 9 IHNV isolates from Germany have been determined, and this has allowed the identification of characteristic differences between these isolates. Phylogenetic analysis of partial G gene sequences (mid-G, 303 nucleotides) from North American IHNV isolates (Kurath et al. 2003) has revealed 3 major genogroups, designated U, M and L. Using this gene region with 2 different North American IHNV data sets, it was possible to group the European IHNV strains within the M genogroup, but not in any previously defined subgroup. Analysis of the full length G gene sequences indicated that an independent evolution of IHN viruses had occurred in Europe. IHN viruses in Europe seem to be of a monophyletic origin, again most closely related to North American isolates in the M genogroup. Analysis of the NV gene sequences also showed the European isolates to be monophyletic, but resolution of the 3 genogroups was poor with this gene region. As a result of comparative sequence analyses, several different genotypes have been identified circulating in Europe.

Comparison of the nucleotide and amino acid sequences of the RsrI and EcoRI restriction endonucleases.

PubMed

Stephenson, F H; Ballard, B T; Boyer, H W; Rosenberg, J M; Greene, P J

1989-12-21

The RsrI endonuclease, a type-II restriction endonuclease (ENase) found in Rhodobacter sphaeroides, is an isoschizomer of the EcoRI ENase. A clone containing an 11-kb BamHI fragment was isolated from an R. sphaeroides genomic DNA library by hybridization with synthetic oligodeoxyribonucleotide probes based on the N-terminal amino acid (aa) sequence of RsrI. Extracts of E. coli containing a subclone of the 11-kb fragment display RsrI activity. Nucleotide sequence analysis reveals an 831-bp open reading frame encoding a polypeptide of 277 aa. A 50% identity exists within a 266-aa overlap between the deduced aa sequences of RsrI and EcoRI. Regions of 75-100% aa sequence identity correspond to key structural and functional regions of EcoRI. The type-II ENases have many common properties, and a common origin might have been expected. Nevertheless, this is the first demonstration of aa sequence similarity between ENases produced by different organisms.

Use of Genome Sequence Information for Meat Quality Trait QTL Mining for Causal Genes and Mutations on Pig Chromosome 17

PubMed Central

Hu, Zhi-Liang; Ramos, Antonio M.; Humphray, Sean J.; Rogers, Jane; Reecy, James M.; Rothschild, Max F.

2011-01-01

The newly available pig genome sequence has provided new information to fine map quantitative trait loci (QTL) in order to eventually identify causal variants. With targeted genomic sequencing efforts, we were able to obtain high quality BAC sequences that cover a region on pig chromosome 17 where a number of meat quality QTL have been previously discovered. Sequences from 70 BAC clones were assembled to form an 8-Mbp contig. Subsequently, we successfully mapped five previously identified QTL, three for meat color and two for lactate related traits, to the contig. With an additional 25 genetic markers that were identified by sequence comparison, we were able to carry out further linkage disequilibrium analysis to narrow down the genomic locations of these QTL, which allowed identification of the chromosomal regions that likely contain the causative variants. This research has provided one practical approach to combine genetic and molecular information for QTL mining. PMID:22303339

Phylogeographic analysis of porcine reproductive and respiratory syndrome virus 1 in Guangdong province, Southern China.

PubMed

Zhai, Shao-Lun; Lin, Tao; Zhou, Xia; Pei, Zhang-Fu; Wei, Zu-Zhang; Zhang, He; Wen, Xiao-Hui; Chen, Qin-Ling; Lv, Dian-Hong; Wei, Wen-Kang

2018-05-10

Porcine reproductive and respiratory syndrome virus (PRRSV) is considered an important economic pathogen for the international swine industry. At present, both PRRSV-1 and PRRSV-2 have been confirmed to be co-circulating in China. However, there is little available information about the prevalence or distribution of PRRSV-1 in Guangdong province, southern China. In this study, we performed molecular detection of PRRSV-1 in 750 samples collected from 50 farms in 15 major pig farming regions in this province. After RT-PCR testing, 64% (32/50) of farms were confirmed as PRRSV-1-positive. Surprisingly, PRRSV-1 was circulating on at least one pig farm in all 15 regions; of the 750 samples, 186 samples (24.8%) were positive for PRRSV-1. Furthermore, 15 representative PRRSV-1 ORF5 sequences (606 bp) (n = 1 per region) were obtained from those PRRSV-1-positive regions. Sequence alignment analysis indicated that they shared 81.8% ~ 100% nucleotide and 81.2% ~ 100% amino acid similarity with each other. Although all current PRRSV-1 sequences were divided into pandemic subtype 1, most of them had unique glycoprotein-5 amino acid sequences that are significantly different from other known PRRSV-1 isolates. To conclude, the present findings revealed wide geographical distribution of PRRSV-1 in Guangdong province, southern China. This study further extends the epidemiological significance of PRRSV-1 in China.

TIA: algorithms for development of identity-linked SNP islands for analysis by massively parallel DNA sequencing.

PubMed

Farris, M Heath; Scott, Andrew R; Texter, Pamela A; Bartlett, Marta; Coleman, Patricia; Masters, David

2018-04-11

Single nucleotide polymorphisms (SNPs) located within the human genome have been shown to have utility as markers of identity in the differentiation of DNA from individual contributors. Massively parallel DNA sequencing (MPS) technologies and human genome SNP databases allow for the design of suites of identity-linked target regions, amenable to sequencing in a multiplexed and massively parallel manner. Therefore, tools are needed for leveraging the genotypic information found within SNP databases for the discovery of genomic targets that can be evaluated on MPS platforms. The SNP island target identification algorithm (TIA) was developed as a user-tunable system to leverage SNP information within databases. Using data within the 1000 Genomes Project SNP database, human genome regions were identified that contain globally ubiquitous identity-linked SNPs and that were responsive to targeted resequencing on MPS platforms. Algorithmic filters were used to exclude target regions that did not conform to user-tunable SNP island target characteristics. To validate the accuracy of TIA for discovering these identity-linked SNP islands within the human genome, SNP island target regions were amplified from 70 contributor genomic DNA samples using the polymerase chain reaction. Multiplexed amplicons were sequenced using the Illumina MiSeq platform, and the resulting sequences were analyzed for SNP variations. 166 putative identity-linked SNPs were targeted in the identified genomic regions. Of the 309 SNPs that provided discerning power across individual SNP profiles, 74 previously undefined SNPs were identified during evaluation of targets from individual genomes. Overall, DNA samples of 70 individuals were uniquely identified using a subset of the suite of identity-linked SNP islands. TIA offers a tunable genome search tool for the discovery of targeted genomic regions that are scalable in the population frequency and numbers of SNPs contained within the SNP island regions. It also allows the definition of sequence length and sequence variability of the target region as well as the less variable flanking regions for tailoring to MPS platforms. As shown in this study, TIA can be used to discover identity-linked SNP islands within the human genome, useful for differentiating individuals by targeted resequencing on MPS technologies.

Genetic structure and evolution of natural populations of viruses causing the tomato yellow leaf curl disease in Spain.

PubMed

Font, María Isabel; Rubio, Luis; Martínez-Culebras, Pedro Vicente; Jordá, Concepción

2007-09-01

The population structure and genetic variation of two begomoviruses: tomato yellow leaf curl Sardinia virus (TYLCSV) and tomato yellow leaf curl virus (TYLCV) in tomato crops of Spain were studied from 1997 until 2001. Restriction digestion of a genomic region comprised of the CP coat protein gene (CPR) of 358 TYLC virus isolates enabled us to classify them into 14 haplotypes. Nucleotide sequences of two genomic regions: CPR, and the surrounding intergenic region (SIR) were determined for at least two isolates per haplotype. SIR was more variable than CPR and showed multiple recombination events whereas no recombination was detected within CPR. In all geographic regions except Murcia, the population was, or evolved to be composed of one predominant haplotype with a low genetic diversity (<0.0180). In Murcia, two successive changes of the predominant haplotype were observed in the best studied population. Phylogenetic analysis showed that the TYLCSV sequences determined clustered with sequences obtained from the GenBank of other TYLCSV Spanish isolates which were clearly separated from TYLCSV Italian isolates. Most of our TYLCV sequences were similar to those of isolates from Japan and Portugal, and the sequences obtained from TYLCV isolates from the Canary island of Lanzarote were similar to those of Caribbean TYLCV isolates.

A sequence-based genetic map of Medicago truncatula and comparison of marker colinearity with M. sativa.

PubMed Central

Choi, Hong-Kyu; Kim, Dongjin; Uhm, Taesik; Limpens, Eric; Lim, Hyunju; Mun, Jeong-Hwan; Kalo, Peter; Penmetsa, R Varma; Seres, Andrea; Kulikova, Olga; Roe, Bruce A; Bisseling, Ton; Kiss, Gyorgy B; Cook, Douglas R

2004-01-01

A core genetic map of the legume Medicago truncatula has been established by analyzing the segregation of 288 sequence-characterized genetic markers in an F(2) population composed of 93 individuals. These molecular markers correspond to 141 ESTs, 80 BAC end sequence tags, and 67 resistance gene analogs, covering 513 cM. In the case of EST-based markers we used an intron-targeted marker strategy with primers designed to anneal in conserved exon regions and to amplify across intron regions. Polymorphisms were significantly more frequent in intron vs. exon regions, thus providing an efficient mechanism to map transcribed genes. Genetic and cytogenetic analysis produced eight well-resolved linkage groups, which have been previously correlated with eight chromosomes by means of FISH with mapped BAC clones. We anticipated that mapping of conserved coding regions would have utility for comparative mapping among legumes; thus 60 of the EST-based primer pairs were designed to amplify orthologous sequences across a range of legume species. As an initial test of this strategy, we used primers designed against M. truncatula exon sequences to rapidly map genes in M. sativa. The resulting comparative map, which includes 68 bridging markers, indicates that the two Medicago genomes are highly similar and establishes the basis for a Medicago composite map. PMID:15082563

SNPs in putative regulatory regions identified by human mouse comparative sequencing and transcription factor binding site data

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

Banerjee, Poulabi; Bahlo, Melanie; Schwartz, Jody R.

2002-01-01

Genome wide disease association analysis using SNPs is being explored as a method for dissecting complex genetic traits and a vast number of SNPs have been generated for this purpose. As there are cost and throughput limitations of genotyping large numbers of SNPs and statistical issues regarding the large number of dependent tests on the same data set, to make association analysis practical it has been proposed that SNPs should be prioritized based on likely functional importance. The most easily identifiable functional SNPs are coding SNPs (cSNPs) and accordingly cSNPs have been screened in a number of studies. SNPs inmore » gene regulatory sequences embedded in noncoding DNA are another class of SNPs suggested for prioritization due to their predicted quantitative impact on gene expression. The main challenge in evaluating these SNPs, in contrast to cSNPs is a lack of robust algorithms and databases for recognizing regulatory sequences in noncoding DNA. Approaches that have been previously used to delineate noncoding sequences with gene regulatory activity include cross-species sequence comparisons and the search for sequences recognized by transcription factors. We combined these two methods to sift through mouse human genomic sequences to identify putative gene regulatory elements and subsequently localized SNPs within these sequences in a 1 Megabase (Mb) region of human chromosome 5q31, orthologous to mouse chromosome 11 containing the Interleukin cluster.« less

Investigation of bacterial and archaeal communities: novel protocols using modern sequencing by Illumina MiSeq and traditional DGGE-cloning.

PubMed

Kraková, Lucia; Šoltys, Katarína; Budiš, Jaroslav; Grivalský, Tomáš; Ďuriš, František; Pangallo, Domenico; Szemes, Tomáš

2016-09-01

Different protocols based on Illumina high-throughput DNA sequencing and denaturing gradient gel electrophoresis (DGGE)-cloning were developed and applied for investigating hot spring related samples. The study was focused on three target genes: archaeal and bacterial 16S rRNA and mcrA of methanogenic microflora. Shorter read lengths of the currently most popular technology of sequencing by Illumina do not allow analysis of the complete 16S rRNA region, or of longer gene fragments, as was the case of Sanger sequencing. Here, we demonstrate that there is no need for special indexed or tailed primer sets dedicated to short variable regions of 16S rRNA since the presented approach allows the analysis of complete bacterial 16S rRNA amplicons (V1-V9) and longer archaeal 16S rRNA and mcrA sequences. Sample augmented with transposon is represented by a set of approximately 300 bp long fragments that can be easily sequenced by Illumina MiSeq. Furthermore, a low proportion of chimeric sequences was observed. DGGE-cloning based strategies were performed combining semi-nested PCR, DGGE and clone library construction. Comparing both investigation methods, a certain degree of complementarity was observed confirming that the DGGE-cloning approach is not obsolete. Novel protocols were created for several types of laboratories, utilizing the traditional DGGE technique or using the most modern Illumina sequencing.

Identification of Giardia species and Giardia duodenalis assemblages by sequence analysis of the 5.8S rDNA gene and internal transcribed spacers.

PubMed

Cacciò, Simone M; Beck, Relja; Almeida, Andre; Bajer, Anna; Pozio, Edoardo

2010-05-01

PCR assays have been developed mainly to assist investigations into the epidemiology of Giardia duodenalis, the only species in the Giardia genus having zoonotic potential. However, a reliable identification of all species is of practical importance, particularly when water samples and samples from wild animals are investigated. The aim of the present work was to genotype Giardia species and G. duodenalis assemblages using as a target the region spanning the 5.8S gene and the 2 flanking internal transcribed spacers (ITS1 and ITS2) of the ribosomal gene. Primers were designed to match strongly conserved regions in the 3' end of the small subunit and in the 5' end of the large subunit ribosomal genes. The corresponding region (about 310 bp) was amplified from 49 isolates of both human and animal origin, representing all G. duodenalis assemblages as well as G. muris and G. microti. Sequence comparison and phylogenetic analysis showed that G. ardeae, G. muris, G. microti as well as the 7 G. duodenalis assemblages can be easily distinguished. Since the major subgroups within the zoonotic assemblages A and B can be identified by sequence analysis, this assay is also informative for molecular epidemiological studies.

A Protein Domain and Family Based Approach to Rare Variant Association Analysis.

PubMed

Richardson, Tom G; Shihab, Hashem A; Rivas, Manuel A; McCarthy, Mark I; Campbell, Colin; Timpson, Nicholas J; Gaunt, Tom R

2016-01-01

It has become common practice to analyse large scale sequencing data with statistical approaches based around the aggregation of rare variants within the same gene. We applied a novel approach to rare variant analysis by collapsing variants together using protein domain and family coordinates, regarded to be a more discrete definition of a biologically functional unit. Using Pfam definitions, we collapsed rare variants (Minor Allele Frequency ≤ 1%) together in three different ways 1) variants within single genomic regions which map to individual protein domains 2) variants within two individual protein domain regions which are predicted to be responsible for a protein-protein interaction 3) all variants within combined regions from multiple genes responsible for coding the same protein domain (i.e. protein families). A conventional collapsing analysis using gene coordinates was also undertaken for comparison. We used UK10K sequence data and investigated associations between regions of variants and lipid traits using the sequence kernel association test (SKAT). We observed no strong evidence of association between regions of variants based on Pfam domain definitions and lipid traits. Quantile-Quantile plots illustrated that the overall distributions of p-values from the protein domain analyses were comparable to that of a conventional gene-based approach. Deviations from this distribution suggested that collapsing by either protein domain or gene definitions may be favourable depending on the trait analysed. We have collapsed rare variants together using protein domain and family coordinates to present an alternative approach over collapsing across conventionally used gene-based regions. Although no strong evidence of association was detected in these analyses, future studies may still find value in adopting these approaches to detect previously unidentified association signals.

Molecular characterization and phylogenetic analysis of Citrus viroid VI variants from citrus in China

USDA-ARS?s Scientific Manuscript database

Citrus viroid VI (CVd-VI) was originally found from citrus and persimmon in Japan. We report here the identification and molecular characterization of CVd-VI from four production regions of China. A total of 90 cDNA clones from nine infected citrus cultivars were sequenced. The sequence homologies o...

Comparison and phylogenetic analysis of the ISS gene in two predominant avian pathogenic E. coli serogroups isolated from avian colibacillosis in Iran.

PubMed

Zahraei Salehi, Taghi; Derakhshandeh, Abdollah; Tadjbakhsh, Hasan; Karimi, Vahid

2013-02-01

The ISS (increased serum survival) gene and its protein product (ISS) of avian pathogenic Escherichia coli (APEC) are important characteristics of resistance to the complement system. The aims of this study were to clone, sequence and characterize sequence diversity of the ISS gene between two predominant serogroups in Iran and among those previously deposited in Genbank. The ISS gene of 309 bp from the APEC χ1390 strain was amplified by PCR, cloned and sequenced using pTZ57R/T vector. The ISS gene from the χ1390 strain has 100% identity among different serogroups of APEC in different geographical regions throughout the world. Phylogenetic analysis shows two different phylogenic groups among the different strains. Strong association of nucleotide sequences among different E. coli strains suggests that it may be a conserved gene and could be a suitable antigen to control and detect avian pathogenic E. coli, at least in our region. Currently, our group is working on the ISS protein as candidate vaccine in SPF poultry. Copyright © 2012 Elsevier Ltd. All rights reserved.

Human papillomavirus type 18 variant lineages in United States populations characterized by sequence analysis of LCR-E6, E2, and L1 regions.

PubMed

Arias-Pulido, Hugo; Peyton, Cheri L; Torrez-Martínez, Norah; Anderson, D Nelson; Wheeler, Cosette M

2005-07-20

While HPV 16 variant lineages have been well characterized, the knowledge about HPV 18 variants is limited. In this study, HPV 18 nucleotide variations in the E2 hinge region were characterized by sequence analysis in 47 control and 51 tumor specimens. Fifty of these specimens were randomly selected for sequencing of an LCR-E6 segment and 20 samples representative of LCR-E6 and E2 sequence variants were examined across the L1 region. A total of 2770 nucleotides per HPV 18 variant genome were considered in this study. HPV 18 variant nucleotides were linked among all gene segments analyzed and grouped into three main branches: Asian-American (AA), European (E), and African (Af). These three branches were equally distributed among controls and cases and when stratified by Hispanic and non-Hispanic ethnicities. Among invasive cervical cancer cases, no significant differences in the three HPV variant branches were observed among ethnic groups or when stratified by histopathology (squamous vs. adenocarcinoma). The Af branch showed the greatest nucleotide variability when compared to the HPV 18 reference sequence and was more closely related to HPV 45 than either AA or E branches. Our data also characterize nucleotide and amino acid variations in the L1 capsid gene among HPV 18 variants, which may be relevant to vaccine strategies and subsequent studies of naturally occurring HPV 18 variants. Several novel HPV 18 nucleotide variations were identified in this study.

[Homology analysis of the extended-V region of the surface proteins in different serotype Streptococcus mutans].

PubMed

He, Kui-Fang; Liu, Jian-Guo; Liu, Tian-Jia; Yang, De-Qin; Zhuang, Heng; Li, Song

2006-08-01

To analysis the homology among the extended-V region of the surface proteins in different serotype Streptococcus mutans (c, f, d, g) and to find out it's significance in anti-caries vaccine. The DNA of the bacteria (standarded serotype c, d, f, g and partial serotype c clinicals) was extracted and the extended-V region (SrV+, 1 384-2 514 bp) was amplified using polymerase chain reaction (PCR). Then the products were assessed using restriction fragment length polymorphism (RFLP) by endonuclease Dde I. The genotypings were sequenced and analysised using the program of BLAST on NCBI Gene Bank database. About 1.13 kb fragments were produced both in serotype c and f, the serotype d and g were failed. The RFLP results showed that five different patterns(A, B, C, D, E) among the 117 PCR products were reveled by Dde I. The ration of the genotypings A and B were the most among the strains, the C was lower, the D and E respectively was 1 and 3 strains per genotype. OMZ175 (serotype f) was belong to B genotype. Selected one of the A, B, C genotypings to sequenced and blasted. Then the results of the blastn showed that the identities of the gene sequence were 92%-98% between the serotype c and serotype f, part sequence of the serotype g was homology with the SrV+ of the serotype c, the protein sequence among serotype c, d, f, g were 77%-82%. It is reasonable to use some putative pipetides to study the anti-caries vaccine among the extended-V regions of the surface proteins in different serotype (c, d, f, g) in S. mutans.

Size and Content of the Sex-Determining Region of the Y Chromosome in Dioecious Mercurialis annua, a Plant with Homomorphic Sex Chromosomes.

PubMed

Veltsos, Paris; Cossard, Guillaume; Beaudoing, Emmanuel; Beydon, Genséric; Savova Bianchi, Dessislava; Roux, Camille; C González-Martínez, Santiago; R Pannell, John

2018-05-29

Dioecious plants vary in whether their sex chromosomes are heteromorphic or homomorphic, but even homomorphic sex chromosomes may show divergence between homologues in the non-recombining, sex-determining region (SDR). Very little is known about the SDR of these species, which might represent particularly early stages of sex-chromosome evolution. Here, we assess the size and content of the SDR of the diploid dioecious herb Mercurialis annua , a species with homomorphic sex chromosomes and mild Y-chromosome degeneration. We used RNA sequencing (RNAseq) to identify new Y-linked markers for M. annua. Twelve of 24 transcripts showing male-specific expression in a previous experiment could be amplified by polymerase chain reaction (PCR) only from males, and are thus likely to be Y-linked. Analysis of genome-capture data from multiple populations of M. annua pointed to an additional six male-limited (and thus Y-linked) sequences. We used these markers to identify and sequence 17 sex-linked bacterial artificial chromosomes (BACs), which form 11 groups of non-overlapping sequences, covering a total sequence length of about 1.5 Mb. Content analysis of this region suggests that it is enriched for repeats, has low gene density, and contains few candidate sex-determining genes. The BACs map to a subset of the sex-linked region of the genetic map, which we estimate to be at least 14.5 Mb. This is substantially larger than estimates for other dioecious plants with homomorphic sex chromosomes, both in absolute terms and relative to their genome sizes. Our data provide a rare, high-resolution view of the homomorphic Y chromosome of a dioecious plant.

The site-specific ribosomal insertion element type II of Bombyx mori (R2Bm) contains the coding sequence for a reverse transcriptase-like enzyme.

PubMed Central

Burke, W D; Calalang, C C; Eickbush, T H

1987-01-01

Two classes of DNA elements interrupt a fraction of the rRNA repeats of Bombyx mori. We have analyzed by genomic blotting and sequence analysis one class of these elements which we have named R2. These elements occupy approximately 9% of the rDNA units of B. mori and appear to be homologous to the type II rDNA insertions detected in Drosophila melanogaster. Approximately 25 copies of R2 exist within the B. mori genome, of which at least 20 are located at a precise location within otherwise typical rDNA units. Nucleotide sequence analysis has revealed that the 4.2-kilobase-pair R2 element has a single large open reading frame, occupying over 82% of the total length of the element. The central region of this 1,151-amino-acid open reading frame shows homology to the reverse transcriptase enzymes found in retroviruses and certain transposable elements. Amino acid homology of this region is highest to the mobile line 1 elements of mammals, followed by the mitochondrial type II introns of fungi, and the pol gene of retroviruses. Less homology exists with transposable elements of D. melanogaster and Saccharomyces cerevisiae. Two additional regions of sequence homology between L1 and R2 elements were also found outside the reverse transcriptase region. We suggest that the R2 elements are retrotransposons that are site specific in their insertion into the genome. Such mobility would enable these elements to occupy a small fraction of the rDNA units of B. mori despite their continual elimination from the rDNA locus by sequence turnover. Images PMID:2439905

Estimating Bacterial Diversity for Ecological Studies: Methods, Metrics, and Assumptions

PubMed Central

Birtel, Julia; Walser, Jean-Claude; Pichon, Samuel; Bürgmann, Helmut; Matthews, Blake

2015-01-01

Methods to estimate microbial diversity have developed rapidly in an effort to understand the distribution and diversity of microorganisms in natural environments. For bacterial communities, the 16S rRNA gene is the phylogenetic marker gene of choice, but most studies select only a specific region of the 16S rRNA to estimate bacterial diversity. Whereas biases derived from from DNA extraction, primer choice and PCR amplification are well documented, we here address how the choice of variable region can influence a wide range of standard ecological metrics, such as species richness, phylogenetic diversity, β-diversity and rank-abundance distributions. We have used Illumina paired-end sequencing to estimate the bacterial diversity of 20 natural lakes across Switzerland derived from three trimmed variable 16S rRNA regions (V3, V4, V5). Species richness, phylogenetic diversity, community composition, β-diversity, and rank-abundance distributions differed significantly between 16S rRNA regions. Overall, patterns of diversity quantified by the V3 and V5 regions were more similar to one another than those assessed by the V4 region. Similar results were obtained when analyzing the datasets with different sequence similarity thresholds used during sequences clustering and when the same analysis was used on a reference dataset of sequences from the Greengenes database. In addition we also measured species richness from the same lake samples using ARISA Fingerprinting, but did not find a strong relationship between species richness estimated by Illumina and ARISA. We conclude that the selection of 16S rRNA region significantly influences the estimation of bacterial diversity and species distributions and that caution is warranted when comparing data from different variable regions as well as when using different sequencing techniques. PMID:25915756

A modern regional geological analysis of Venezuela - lessons from a major new world oil province on exploration in mature areas

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

Daly, M.; Audemard, F.; Valdes, G.

1993-09-01

Venezuela has produced some 44 billion bbl of oil since the early part of the century. As such, it represents one of the world's major oil producers and a mature petroleum province. However, major tracts of Venezuela's sedimentary basins remain underexplored and large discoveries are still being made in new and old reservoir systems. A regional geological analysis of Venezuela, focusing on basin evolution and sequence stratigraphy and incorporating data from the three national oil companies, is presented. The analysis presents a regionally consistent tectonostratigraphic model capable of explaining the evolution of the Mesozoic and Cenozoic basins of Venezuela andmore » placing the major reservoir facies in their regional tectonic and sequence stratigraphic context. Four regional cross sections describe the stratigraphic and structural model. The model recognizes a Jurassic rifting event and inversion, succeeded by an Early Cretaceous passive margin. In western Venezuela, the Early Cretaceous passive subsidence is enhanced locally by extension related to the Colombian active margin. Venezuela experienced a major change in the Campanian with the initial collision of the Caribbean arc, recorded by foreland structuring and widespread stratigraphic changes. From the Campanian onward, the tectonostratigraphic evolution can be modeled in terms of a progressive southeast-directed arc-continent collision and the migration of the associated foredeep and rift basins. Within the tectonic framework, the major sequence stratigraphic units are identified and the reservoir distribution interpreted. This model provides a strong predictive tool to extrapolate reservoir systems into Venezuela's underexplored areas and to readdress its traditional areas.« less

Recombinant lactoferrin (Lf) of Vechur cow, the critical breed of Bos indicus and the Lf gene variants.

PubMed

Anisha, Shashidharan; Bhasker, Salini; Mohankumar, Chinnamma

2012-03-01

Vechur cow, categorized as a critically maintained breed by the FAO, is a unique breed of Bos indicus due to its extremely small size, less fodder intake, adaptability, easy domestication and traditional medicinal property of the milk. Lactoferrin (Lf) is an iron-binding glycoprotein that is found predominantly in the milk of mammals. The full coding region of Lf gene of Vechur cow was cloned, sequenced and expressed in a prokaryotic system. Antibacterial activity of the recombinant Lf showed suppression of bacterial growth. To the best of our knowledge this is the first time that the full coding region of Lf gene of B. indicus Vechur breed is sequenced, successfully expressed in a prokaryotic system and characterized. Comparative analysis of Lf gene sequence of five Vechur cows with B. taurus revealed 15 SNPs in the exon region associated with 11 amino acid substitutions. The amino acid arginine was noticed as a pronounced substitution and the tertiary structure analysis of the BLfV protein confirmed the positions of arginine in the β sheet region, random coil and helix region 1. Based on the recent reports on the nutritional therapies of arginine supplementation for wound healing and for cardiovascular diseases, the higher level of arginine in the lactoferrin protein of Vechur cow milk provides enormous scope for further therapeutic studies. Copyright © 2011 Elsevier B.V. All rights reserved.

Using expected sequence features to improve basecalling accuracy of amplicon pyrosequencing data.

PubMed

Rask, Thomas S; Petersen, Bent; Chen, Donald S; Day, Karen P; Pedersen, Anders Gorm

2016-04-22

Amplicon pyrosequencing targets a known genetic region and thus inherently produces reads highly anticipated to have certain features, such as conserved nucleotide sequence, and in the case of protein coding DNA, an open reading frame. Pyrosequencing errors, consisting mainly of nucleotide insertions and deletions, are on the other hand likely to disrupt open reading frames. Such an inverse relationship between errors and expectation based on prior knowledge can be used advantageously to guide the process known as basecalling, i.e. the inference of nucleotide sequence from raw sequencing data. The new basecalling method described here, named Multipass, implements a probabilistic framework for working with the raw flowgrams obtained by pyrosequencing. For each sequence variant Multipass calculates the likelihood and nucleotide sequence of several most likely sequences given the flowgram data. This probabilistic approach enables integration of basecalling into a larger model where other parameters can be incorporated, such as the likelihood for observing a full-length open reading frame at the targeted region. We apply the method to 454 amplicon pyrosequencing data obtained from a malaria virulence gene family, where Multipass generates 20 % more error-free sequences than current state of the art methods, and provides sequence characteristics that allow generation of a set of high confidence error-free sequences. This novel method can be used to increase accuracy of existing and future amplicon sequencing data, particularly where extensive prior knowledge is available about the obtained sequences, for example in analysis of the immunoglobulin VDJ region where Multipass can be combined with a model for the known recombining germline genes. Multipass is available for Roche 454 data at http://www.cbs.dtu.dk/services/MultiPass-1.0 , and the concept can potentially be implemented for other sequencing technologies as well.

Quantitation of base substitutions in eukaryotic 5S rRNA: selection for the maintenance of RNA secondary structure.

PubMed

Curtiss, W C; Vournakis, J N

1984-01-01

Eukaryotic 5S rRNA sequences from 34 diverse species were compared by the following method: (1) The sequences were aligned; (2) the positions of substitutions were located by comparison of all possible pairs of sequences; (3) the substitution sites were mapped to an assumed general base pairing model; and (4) the R-Y model of base stacking was used to study stacking pattern relationships in the structure. An analysis of the sequence and structure variability in each region of the molecule is presented. It was found that the degree of base substitution varies over a wide range, from absolute conservation to occurrence of over 90% of the possible observable substitutions. The substitutions are located primarily in stem regions of the 5S rRNA secondary structure. More than 88% of the substitutions in helical regions maintain base pairing. The disruptive substitutions are primarily located at the edges of helical regions, resulting in shortening of the helical regions and lengthening of the adjacent nonpaired regions. Base stacking patterns determined by the R-Y model are mapped onto the general secondary structure. Intrastrand and interstrand stacking could stabilize alternative coaxial structures and limit the conformational flexibility of nonpaired regions. Two short contiguous regions are 100% conserved in all species. This may reflect evolutionary constraints imposed at the DNA level by the requirement for binding of a 5S gene transcription initiation factor during gene expression.

Whole-Genome Sequence Variation among Multiple Isolates of Pseudomonas aeruginosa

PubMed Central

Spencer, David H.; Kas, Arnold; Smith, Eric E.; Raymond, Christopher K.; Sims, Elizabeth H.; Hastings, Michele; Burns, Jane L.; Kaul, Rajinder; Olson, Maynard V.

2003-01-01

Whole-genome shotgun sequencing was used to study the sequence variation of three Pseudomonas aeruginosa isolates, two from clonal infections of cystic fibrosis patients and one from an aquatic environment, relative to the genomic sequence of reference strain PAO1. The majority of the PAO1 genome is represented in these strains; however, at least three prominent islands of PAO1-specific sequence are apparent. Conversely, ∼10% of the sequencing reads derived from each isolate fail to align with the PAO1 backbone. While average sequence variation among all strains is roughly 0.5%, regions of pronounced differences were evident in whole-genome scans of nucleotide diversity. We analyzed two such divergent loci, the pyoverdine and O-antigen biosynthesis regions, by complete resequencing. A thorough analysis of isolates collected over time from one of the cystic fibrosis patients revealed independent mutations resulting in the loss of O-antigen synthesis alternating with a mucoid phenotype. Overall, we conclude that most of the PAO1 genome represents a core P. aeruginosa backbone sequence while the strains addressed in this study possess additional genetic material that accounts for at least 10% of their genomes. Approximately half of these additional sequences are novel. PMID:12562802

Evaluating the Detection of Hydrocarbon-Degrading Bacteria in 16S rRNA Gene Sequencing Surveys

PubMed Central

Berry, David; Gutierrez, Tony

2017-01-01

Hydrocarbonoclastic bacteria (HCB) play a key role in the biodegradation of oil hydrocarbons in marine and other environments. A small number of taxa have been identified as obligate HCB, notably the Gammaproteobacterial genera Alcanivorax, Cycloclasticus, Marinobacter, Neptumonas, Oleiphilus, Oleispira, and Thalassolituus, as well as the Alphaproteobacterial genus Thalassospira. Detection of HCB in amplicon-based sequencing surveys relies on high coverage by PCR primers and accurate taxonomic classification. In this study, we performed a phylogenetic analysis to identify 16S rRNA gene sequence regions that represent the breadth of sequence diversity within these taxa. Using validated sequences, we evaluated 449 universal 16S rRNA gene-targeted bacterial PCR primer pairs for their coverage of these taxa. The results of this analysis provide a practical framework for selection of suitable primer sets for optimal detection of HCB in sequencing surveys. PMID:28567035

Evaluating the Detection of Hydrocarbon-Degrading Bacteria in 16S rRNA Gene Sequencing Surveys.

PubMed

Berry, David; Gutierrez, Tony

2017-01-01

Hydrocarbonoclastic bacteria (HCB) play a key role in the biodegradation of oil hydrocarbons in marine and other environments. A small number of taxa have been identified as obligate HCB, notably the Gammaproteobacterial genera Alcanivorax, Cycloclasticus, Marinobacter, Neptumonas, Oleiphilus, Oleispira , and Thalassolituus , as well as the Alphaproteobacterial genus Thalassospira . Detection of HCB in amplicon-based sequencing surveys relies on high coverage by PCR primers and accurate taxonomic classification. In this study, we performed a phylogenetic analysis to identify 16S rRNA gene sequence regions that represent the breadth of sequence diversity within these taxa. Using validated sequences, we evaluated 449 universal 16S rRNA gene-targeted bacterial PCR primer pairs for their coverage of these taxa. The results of this analysis provide a practical framework for selection of suitable primer sets for optimal detection of HCB in sequencing surveys.

Cloning and expression of a nuclear encoded plastid specific 33 kDa ribonucleoprotein gene (33RNP) from pea that is light stimulated.

PubMed

Reddy, M K; Nair, S; Singh, B N; Mudgil, Y; Tewari, K K; Sopory, S K

2001-01-24

We report the cloning and sequencing of both cDNA and genomic DNA of a 33 kDa chloroplast ribonucleoprotein (33RNP) from pea. The analysis of the predicted amino acid sequence of the cDNA clone revealed that the encoded protein contains two RNA binding domains, including the conserved consensus ribonucleoprotein sequences CS-RNP1 and CS-RNP2, on the C-terminus half and the presence of a putative transit peptide sequence in the N-terminus region. The phylogenetic and multiple sequence alignment analysis of pea chloroplast RNP along with RNPs reported from the other plant sources revealed that the pea 33RNP is very closely related to Nicotiana sylvestris 31RNP and 28RNP and also to 31RNP and 28RNP of Arabidopsis and spinach, respectively. The pea 33RNP was expressed in Escherichia coli and purified to homogeneity. The in vitro import of precursor protein into chloroplasts confirmed that the N-terminus putative transit peptide is a bona fide transit peptide and 33RNP is localized in the chloroplast. The nucleic acid-binding properties of the recombinant protein, as revealed by South-Western analysis, showed that 33RNP has higher binding affinity for poly (U) and oligo dT than for ssDNA and dsDNA. The steady state transcript level was higher in leaves than in roots and the expression of this gene is light stimulated. Sequence analysis of the genomic clone revealed that the gene contains four exons and three introns. We have also isolated and analyzed the 5' flanking region of the pea 33RNP gene.

Centromere Locations in Brassica A and C Genomes Revealed Through Half-Tetrad Analysis

PubMed Central

Mason, Annaliese S.; Rousseau-Gueutin, Mathieu; Morice, Jérôme; Bayer, Philipp E.; Besharat, Naghmeh; Cousin, Anouska; Pradhan, Aneeta; Parkin, Isobel A. P.; Chèvre, Anne-Marie; Batley, Jacqueline; Nelson, Matthew N.

2016-01-01

Locating centromeres on genome sequences can be challenging. The high density of repetitive elements in these regions makes sequence assembly problematic, especially when using short-read sequencing technologies. It can also be difficult to distinguish between active and recently extinct centromeres through sequence analysis. An effective solution is to identify genetically active centromeres (functional in meiosis) by half-tetrad analysis. This genetic approach involves detecting heterozygosity along chromosomes in segregating populations derived from gametes (half-tetrads). Unreduced gametes produced by first division restitution mechanisms comprise complete sets of nonsister chromatids. Along these chromatids, heterozygosity is maximal at the centromeres, and homologous recombination events result in homozygosity toward the telomeres. We genotyped populations of half-tetrad-derived individuals (from Brassica interspecific hybrids) using a high-density array of physically anchored SNP markers (Illumina Brassica 60K Infinium array). Mapping the distribution of heterozygosity in these half-tetrad individuals allowed the genetic mapping of all 19 centromeres of the Brassica A and C genomes to the reference Brassica napus genome. Gene and transposable element density across the B. napus genome were also assessed and corresponded well to previously reported genetic map positions. Known centromere-specific sequences were located in the reference genome, but mostly matched unanchored sequences, suggesting that the core centromeric regions may not yet be assembled into the pseudochromosomes of the reference genome. The increasing availability of genetic markers physically anchored to reference genomes greatly simplifies the genetic and physical mapping of centromeres using half-tetrad analysis. We discuss possible applications of this approach, including in species where half-tetrads are currently difficult to isolate. PMID:26614742

Centromere Locations in Brassica A and C Genomes Revealed Through Half-Tetrad Analysis.

PubMed

Mason, Annaliese S; Rousseau-Gueutin, Mathieu; Morice, Jérôme; Bayer, Philipp E; Besharat, Naghmeh; Cousin, Anouska; Pradhan, Aneeta; Parkin, Isobel A P; Chèvre, Anne-Marie; Batley, Jacqueline; Nelson, Matthew N

2016-02-01

Locating centromeres on genome sequences can be challenging. The high density of repetitive elements in these regions makes sequence assembly problematic, especially when using short-read sequencing technologies. It can also be difficult to distinguish between active and recently extinct centromeres through sequence analysis. An effective solution is to identify genetically active centromeres (functional in meiosis) by half-tetrad analysis. This genetic approach involves detecting heterozygosity along chromosomes in segregating populations derived from gametes (half-tetrads). Unreduced gametes produced by first division restitution mechanisms comprise complete sets of nonsister chromatids. Along these chromatids, heterozygosity is maximal at the centromeres, and homologous recombination events result in homozygosity toward the telomeres. We genotyped populations of half-tetrad-derived individuals (from Brassica interspecific hybrids) using a high-density array of physically anchored SNP markers (Illumina Brassica 60K Infinium array). Mapping the distribution of heterozygosity in these half-tetrad individuals allowed the genetic mapping of all 19 centromeres of the Brassica A and C genomes to the reference Brassica napus genome. Gene and transposable element density across the B. napus genome were also assessed and corresponded well to previously reported genetic map positions. Known centromere-specific sequences were located in the reference genome, but mostly matched unanchored sequences, suggesting that the core centromeric regions may not yet be assembled into the pseudochromosomes of the reference genome. The increasing availability of genetic markers physically anchored to reference genomes greatly simplifies the genetic and physical mapping of centromeres using half-tetrad analysis. We discuss possible applications of this approach, including in species where half-tetrads are currently difficult to isolate. Copyright © 2016 by the Genetics Society of America.

The complete chloroplast genome of a medicinal plant Epimedium koreanum Nakai (Berberidaceae).

PubMed

Lee, Jung-Hoon; Kim, Kyunghee; Kim, Na-Rae; Lee, Sang-Choon; Yang, Tae-Jin; Kim, Young-Dong

2016-11-01

Epimedium koreanum is a perennial medicinal plant distributed in Eastern Asia. The complete chloroplast genome sequences of E. koreanum was obtained by de novo assembly using whole genome next-generation sequences. The chloroplast genome of E. koreanum was 157 218 bp in length and separated into four distinct regions such as large single copy region (89 600 bp), small single copy region (17 222 bp) and a pair of inverted repeat regions (25 198 bp). The genome contained a total of 112 genes including 78 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Phylogenetic analysis with the reported chloroplast genomes revealed that E. koreanum is most closely related to Berberis bealei, a traditional medicinal plant in the Berberidaceae family.

Tracking B-Cell Repertoires and Clonal Histories in Normal and Malignant Lymphocytes.

PubMed

Weston-Bell, Nicola J; Cowan, Graeme; Sahota, Surinder S

2017-01-01

Methods for tracking B-cell repertoires and clonal history in normal and malignant B-cells based on immunoglobulin variable region (IGV) gene analysis have developed rapidly with the advent of massive parallel next-generation sequencing (mpNGS) protocols. mpNGS permits a depth of analysis of IGV genes not hitherto feasible, and presents challenges of bioinformatics analysis, which can be readily met by current pipelines. This strategy offers a potential resolution of B-cell usage at a depth that may capture fully the natural state, in a given biological setting. Conventional methods based on RT-PCR amplification and Sanger sequencing are also available where mpNGS is not accessible. Each method offers distinct advantages. Conventional methods for IGV gene sequencing are readily adaptable to most laboratories and provide an ease of analysis to capture salient features of B-cell use. This chapter describes two methods in detail for analysis of IGV genes, mpNGS and conventional RT-PCR with Sanger sequencing.

Tomato (Solanum lycopersicum) variety discrimination and hybridization analysis based on the 5S rRNA region.

PubMed

Sun, Yan-Lin; Kang, Ho-Min; Kim, Young-Sik; Baek, Jun-Pill; Zheng, Shi-Lin; Xiang, Jin-Jun; Hong, Soon-Kwan

2014-05-04

The tomato ( Solanum lycopersicum ) is a major vegetable crop worldwide. To satisfy popular demand, more than 500 tomato varieties have been bred. However, a clear variety identification has not been found. Thorough understanding of the phylogenetic relationship and hybridization information of tomato varieties is very important for further variety breeding. Thus, in this study, we collected 26 tomato varieties and attempted to distinguish them based on the 5S rRNA region, which is widely used in the determination of phylogenetic relations. Sequence analysis of the 5S rRNA region suggested that a large number of nucleotide variations exist among tomato varieties. These variable nucleotide sites were also informative regarding hybridization. Chromas sequencing of Yellow Mountain View and Seuwiteuking varieties indicated three and one variable nucleotide sites in the non-transcribed spacer (NTS) of the 5S rRNA region showing hybridization, respectively. Based on a phylogenetic tree constructed using the 5S rRNA sequences, we observed that 16 tomato varieties were divided into three groups at 95% similarity. Rubiking and Sseommeoking, Lang Selection Procedure and Seuwiteuking, and Acorn Gold and Yellow Mountain View exhibited very high identity with their partners. This work will aid variety authentication and provides a basis for further tomato variety breeding.

Human papillomavirus infection in females with normal cervical cytology: Genotyping and phylogenetic analysis among women in Punjab, Pakistan.

PubMed

Aziz, Hafsa; Iqbal, Huma; Mahmood, Humera; Fatima, Shazia; Faheem, Mohammad; Sattar, Areej Abdul; Tabassum, Sobia; Napper, Sanum; Batool, Syeda; Rasheed, Nuzhat

2018-01-01

Globally, cervical cancer is the fourth most common cancer in women and the seventh most common cancer overall, accounting for an estimated 300 000 annual deaths. Human papillomavirus (HPV) is the second most common cause of cervical cancer worldwide. HPV screening is not a common practice in Pakistan. The aim of this study was to determine the prevalence of HPV and HPV types in women with a normal cytology of the cervix living in the upper and lower regions of Punjab, Pakistan, and to analyze the risk factors for HPV in this region. PCR analysis was performed for 1011 female patients with a normal cytology of the cervix from various districts of Punjab Province, Pakistan. Risk factors for the acquisition of HPV were studied. High-risk HPV types (HPV16 and HPV18) were detected using the Abbott Real Time HR HPV test. To determine the genotype, partial L1 region sequences of HPV-positive samples were subjected to sequencing using MY/09/MY11 primers, and a phylogenetic tree was constructed using CLC software. The study found a 4.74% prevalence of HPV, with the most frequent HPV type found being the low-risk HPV6 (in 25% of infected individuals), followed by HPV55 (22.9%), HPV11 (20.8%), and high-risk types HPV45 (12.5%), HPV33 (8.33%), HPV18 (6.25%), and HPV16 (4.16%). Phylogenetic analysis of all HPV types in this study showed 80-99% nucleotide identity with types related to the same species. The sequences were clustered with China, India, Mexico, Iran, Slovenia, and Germany, showing the diversity in origin of the various genotypes prevalent in Pakistan. In this population with a normal cervical cytology, the prevalence of high-risk HPV types was very low. The major prevalent HPV genotype in Punjab Province of Pakistan was the low-risk HPV type 6, followed by HPV type 55. Sequencing of the partial L1 region suggested that the region was highly conserved in all reported sequences. This study highlights the need to conduct robust epidemiological studies in the region and to develop regular HPV screening so that the situation does not reach an alarming stage resulting in cervical cancer. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Small indels induced by CRISPR/Cas9 in the 5' region of microRNA lead to its depletion and Drosha processing retardance.

PubMed

Jiang, Qian; Meng, Xing; Meng, Lingwei; Chang, Nannan; Xiong, Jingwei; Cao, Huiqing; Liang, Zicai

2014-01-01

MicroRNA knockout by genome editing technologies is promising. In order to extend the application of the technology and to investigate the function of a specific miRNA, we used CRISPR/Cas9 to deplete human miR-93 from a cluster by targeting its 5' region in HeLa cells. Various small indels were induced in the targeted region containing the Drosha processing site and seed sequences. Interestingly, we found that even a single nucleotide deletion led to complete knockout of the target miRNA with high specificity. Functional knockout was confirmed by phenotype analysis. Furthermore, de novo microRNAs were not found by RNA-seq. Nevertheless, expression of the pri-microRNAs was increased. When combined with structural analysis, the data indicated that biogenesis was impaired. Altogether, we showed that small indels in the 5' region of a microRNA result in sequence depletion as well as Drosha processing retard.

SUGAR: graphical user interface-based data refiner for high-throughput DNA sequencing.

PubMed

Sato, Yukuto; Kojima, Kaname; Nariai, Naoki; Yamaguchi-Kabata, Yumi; Kawai, Yosuke; Takahashi, Mamoru; Mimori, Takahiro; Nagasaki, Masao

2014-08-08

Next-generation sequencers (NGSs) have become one of the main tools for current biology. To obtain useful insights from the NGS data, it is essential to control low-quality portions of the data affected by technical errors such as air bubbles in sequencing fluidics. We develop a software SUGAR (subtile-based GUI-assisted refiner) which can handle ultra-high-throughput data with user-friendly graphical user interface (GUI) and interactive analysis capability. The SUGAR generates high-resolution quality heatmaps of the flowcell, enabling users to find possible signals of technical errors during the sequencing. The sequencing data generated from the error-affected regions of a flowcell can be selectively removed by automated analysis or GUI-assisted operations implemented in the SUGAR. The automated data-cleaning function based on sequence read quality (Phred) scores was applied to a public whole human genome sequencing data and we proved the overall mapping quality was improved. The detailed data evaluation and cleaning enabled by SUGAR would reduce technical problems in sequence read mapping, improving subsequent variant analysis that require high-quality sequence data and mapping results. Therefore, the software will be especially useful to control the quality of variant calls to the low population cells, e.g., cancers, in a sample with technical errors of sequencing procedures.

Comparison of base composition analysis and Sanger sequencing of mitochondrial DNA for four U.S. population groups.

PubMed

Kiesler, Kevin M; Coble, Michael D; Hall, Thomas A; Vallone, Peter M

2014-01-01

A set of 711 samples from four U.S. population groups was analyzed using a novel mass spectrometry based method for mitochondrial DNA (mtDNA) base composition profiling. Comparison of the mass spectrometry results with Sanger sequencing derived data yielded a concordance rate of 99.97%. Length heteroplasmy was identified in 46% of samples and point heteroplasmy was observed in 6.6% of samples in the combined mass spectral and Sanger data set. Using discrimination capacity as a metric, Sanger sequencing of the full control region had the highest discriminatory power, followed by the mass spectrometry base composition method, which was more discriminating than Sanger sequencing of just the hypervariable regions. This trend is in agreement with the number of nucleotides covered by each of the three assays. Published by Elsevier Ireland Ltd.

[Structural organization of 5S ribosomal DNA of Rosa rugosa].

PubMed

Tynkevych, Iu O; Volkov, R A

2014-01-01

In order to clarify molecular organization of the genomic region encoding 5S rRNA in diploid species Rosa rugosa several 5S rDNA repeated units were cloned and sequenced. Analysis of the obtained sequences revealed that only one length variant of 5S rDNA repeated units, which contains intact promoter elements in the intergenic spacer region (IGS) and appears to be transcriptionally active is present in the genome. Additionally, a limited number of 5S rDNA pseudogenes lacking a portion of coding sequence and the complete IGS was detected. A high level of sequence similarity (from 93.7 to 97.5%) between the IGS of major 5S rDNA variants of East Asian R. rugosa and North American R. nitida was found indicating comparatively recent divergence of these species.

Genetic analysis of Trichuris suis and Trichuris trichiura recovered from humans and pigs in a sympatric setting in Uganda.

PubMed

Nissen, Sofie; Al-Jubury, Azmi; Hansen, Tina V A; Olsen, Annette; Christensen, Henrik; Thamsborg, Stig M; Nejsum, Peter

2012-08-13

The whipworms Trichuris trichiura and Trichuris suis in humans and pigs, respectively, are believed to be two different species yet closely related. Morphologically, adult worms, eggs and larvae of the two species are indistinguishable. The aim of this study was to examine the genetic variation of Trichuris sp. mainly recovered from natural infected pigs and humans. Worm material isolated from humans and pigs living in the same geographical region in Uganda were analyzed by PCR, cloning and sequencing. Measurements of morphometric characters were also performed. The analysis of the ITS-2 (internal transcribed spacer) region showed a high genetic variation in the human-derived worms with two sequence types, designated type 1 and type 2, differing with up to 45%, the type 2 being identical to the sequence found in pig-derived worms. A single human-derived worm showed exclusively the type 2-genotype (T. suis-type) and three cases of 'heterozygote' worms in humans were identified. However, the analysis showed that sympatric Trichuris primarily assorted with host origin. Sequence analysis of a part of the genetically conserved β-tubulin gene confirmed two separate populations/species but also showed that the 'heterozygote' worms had a T. suis-like β-tubulin gene. A PCR-RFLP on the ITS-2 region was developed, that could distinguish between worms of the pig, human and 'heterozygote' type. The data suggest that Trichuris in pigs and humans belong to two different populations (i.e. are two different species). However, the data presented also suggest that cross-infections of humans with T. suis takes place. Further studies on sympatric Trichuris populations are highly warranted in order to explore transmission dynamics and unravel the zoonotic potential of T. suis. Copyright © 2012 Elsevier B.V. All rights reserved.

Occurrence of a Sequence in Marine Cyanophages Similar to That of T4 g20 and Its Application to PCR-Based Detection and Quantification Techniques†

PubMed Central

Fuller, Nicholas J.; Wilson, William H.; Joint, Ian R.; Mann, Nicholas H.

1998-01-01

Viruses are ubiquitous components of marine ecosystems and are known to infect unicellular phycoerythrin-containing cyanobacteria belonging to the genus Synechococcus. A conserved region from the cyanophage genome was identified in three genetically distinct cyanomyoviruses, and a sequence analysis revealed that this region exhibited significant similarity to a gene encoding a capsid assembly protein (gp20) from the enteric coliphage T4. The results of a comparison of gene 20 sequences from three cyanomyoviruses and T4 allowed us to design two degenerate PCR primers, CPS1 and CPS2, which specifically amplified a 165-bp region from the majority of cyanomyoviruses tested. A competitive PCR (cPCR) analysis revealed that cyanomyovirus strains could be accurately enumerated, and it was demonstrated that quantification was log-linear over ca. 3 orders of magnitude. Different calibration curves were obtained for each of the three cyanomyovirus strains tested; consequently, cPCR performed with primers CPS1 and CPS2 could lead to substantial inaccuracies in estimates of phage abundance in natural assemblages. Further sequence analysis of cyanomyovirus gene 20 homologs would be necessary in order to design primers which do not exhibit phage-to-phage variability in priming efficiency. It was demonstrated that PCR products of the correct size could be amplified from seawater samples following 100× concentration and even directly without any prior concentration. Hence, the use of degenerate primers in PCR analyses of cyanophage populations should provide valuable data on the diversity of cyanophages in natural assemblages. Further optimization of procedures may ultimately lead to a sensitive assay which can be used to analyze natural cyanophage populations both quantitatively (by cPCR) and qualitatively following phylogenetic analysis of amplified products. PMID:9603813

Molecular Characterization and Phylogenetic Analysis of Anaplasma spp. and Ehrlichia spp. Isolated from Various Ticks in Southeastern and Northwestern Regions of Iran.

PubMed

Jafar Bekloo, Ahmad; Ramzgouyan, Maryam Roya; Shirian, Sadegh; Faghihi, Faezeh; Bakhshi, Hassan; Naseri, Fatemeh; Sedaghat, Mehdi; Telmadarraiy, Zakkyeh

2018-05-01

Anaplasma/Ehrlichia species are tick-transmitted pathogens that cause infections in humans and numerous domestic and wild animal species. There is no information available on the molecular characteristics and phylogenetic position of Anaplasma/Ehrlichia spp. isolated from tick species from different geographic locations in Iran. The aim of this study was to determine the prevalence, molecular characteristics, and phylogenetic relationship of both Anaplasma spp. and Ehrlichia spp. in tick species isolated from different domestic animals from two different geographical locations of Iran. A total of 930 ticks were collected from 93 cattle, 250 sheep, and 587 goats inhabiting the study areas. The collected ticks were then investigated for the presence of Anaplasma/Ehrlichia spp. using nested PCR based on the 16S rRNA gene, followed by sequencing. Sequence analysis was done based on the data published in the GenBank on Anaplasma/Ehrlichia spp. isolates using bioinformatic tools such as the standard nucleotide BLAST. Genome of Anaplasma or Ehrlichia spp. was detected in 14 ticks collected in Heris, including 5 Dermacentor marginatus, 1 Haemaphysalis erinacei, 3 Hyalomma anatolicum, and 4 Rhipicephalus sanguineus, also in 29 ticks collected in Chabahar, including 14 R. sanguineus, 8 D. marginatus, 3 Hyalomma Anatolicum, and 4 Hyalomma dromedarii. Partial analysis of the 16S rRNA gene sequence of positive samples collected from goats and sheep showed that they were infected with Anaplasma/Ehrlichia spp. that were 94-98% identical to ovine Anaplasma and 91-96% identical to Neoehrlichia and Ehrlichia spp. The various ticks identified in this study suggest the possible emergence of tick-borne diseases in animals and humans in these regions. R. sanguineus and D. marginatus seem to be predominant vectors responsible for anaplasmosis in these regions. Partial sequence analysis of the 16S rRNA gene showed that A. ovis is genetically polymorphic in these regions. Furthermore, an association between the genetic heterogeneity of this microorganism and the geographical regions of Anaplasma strains was found. This study also showed that those ticks that were collected from the same geographical origin were infected with closely related strains of Anaplasma.

Characterisation of ATM mutations in Slavic Ataxia telangiectasia patients.

PubMed

Soukupova, Jana; Pohlreich, Petr; Seemanova, Eva

2011-09-01

Ataxia telangiectasia (AT) is a genomic instability syndrome characterised, among others, by progressive cerebellar degeneration, oculocutaneous telangiectases, immunodeficiency, elevated serum alpha-phetoprotein level, chromosomal breakage, hypersensitivity to ionising radiation and increased cancer risk. This autosomal recessive disorder is caused by mutations in the ataxia telangiectasia mutated (ATM) gene coding for serine/threonine protein kinase with a crucial role in response to DNA double-strand breaks. We characterised genotype and phenotype of 12 Slavic AT patients from 11 families. Mutation analysis included sequencing of the entire coding sequence, adjacent intron regions, 3'UTR and 5'UTR of the ATM gene and multiplex ligation-dependent probe amplification (MLPA) for the detection of large deletions/duplications at the ATM locus. The high incidence of new and individual mutations demonstrates a marked mutational heterogeneity of AT in the Czech Republic. Our data indicate that sequence analysis of the entire coding region of ATM is sufficient for a high detection rate of mutations in ATM and that MLPA analysis for the detection of deletions/duplications seems to be redundant in the Slavic population.

Glutenite bodies sequence division of the upper Es4 in northern Minfeng zone of Dongying Sag, Bohai Bay Basin, China

NASA Astrophysics Data System (ADS)

Shao, Xupeng

2017-04-01

Glutenite bodies are widely developed in northern Minfeng zone of Dongying Sag. Their litho-electric relationship is not clear. In addition, as the conventional sequence stratigraphic research method drawbacks of involving too many subjective human factors, it has limited deepening of the regional sequence stratigraphic research. The wavelet transform technique based on logging data and the time-frequency analysis technique based on seismic data have advantages of dividing sequence stratigraphy quantitatively comparing with the conventional methods. Under the basis of the conventional sequence research method, this paper used the above techniques to divide the fourth-order sequence of the upper Es4 in northern Minfeng zone of Dongying Sag. The research shows that the wavelet transform technique based on logging data and the time-frequency analysis technique based on seismic data are essentially consistent, both of which divide sequence stratigraphy quantitatively in the frequency domain; wavelet transform technique has high resolutions. It is suitable for areas with wells. The seismic time-frequency analysis technique has wide applicability, but a low resolution. Both of the techniques should be combined; the upper Es4 in northern Minfeng zone of Dongying Sag is a complete set of third-order sequence, which can be further subdivided into 5 fourth-order sequences that has the depositional characteristics of fine-upward sequence in granularity. Key words: Dongying sag, northern Minfeng zone, wavelet transform technique, time-frequency analysis technique ,the upper Es4, sequence stratigraphy

Compositional correlations in the chicken genome.

PubMed

Musto, H; Romero, H; Zavala, A; Bernardi, G

1999-09-01

This paper analyses the compositional correlations that hold in the chicken genome. Significant linear correlations were found among the regions studied-coding sequences (and their first, second, and third codon positions), flanking regions (5' and 3'), and introns-as is the case in the human genome. We found that these compositional correlations are not limited to global GC levels but even extend to individual bases. Furthermore, an analysis of 1037 coding sequences has confirmed a correlation among GC(3), GC(2), and GC(1). The implications of these results are discussed.

Molecular Identification of Dendrobium Species (Orchidaceae) Based on the DNA Barcode ITS2 Region and Its Application for Phylogenetic Study.

PubMed

Feng, Shangguo; Jiang, Yan; Wang, Shang; Jiang, Mengying; Chen, Zhe; Ying, Qicai; Wang, Huizhong

2015-09-11

The over-collection and habitat destruction of natural Dendrobium populations for their commercial medicinal value has led to these plants being under severe threat of extinction. In addition, many Dendrobium plants are similarly shaped and easily confused during the absence of flowering stages. In the present study, we examined the application of the ITS2 region in barcoding and phylogenetic analyses of Dendrobium species (Orchidaceae). For barcoding, ITS2 regions of 43 samples in Dendrobium were amplified. In combination with sequences from GenBank, the sequences were aligned using Clustal W and genetic distances were computed using MEGA V5.1. The success rate of PCR amplification and sequencing was 100%. There was a significant divergence between the inter- and intra-specific genetic distances of ITS2 regions, while the presence of a barcoding gap was obvious. Based on the BLAST1, nearest distance and TaxonGAP methods, our results showed that the ITS2 regions could successfully identify the species of most Dendrobium samples examined; Second, we used ITS2 as a DNA marker to infer phylogenetic relationships of 64 Dendrobium species. The results showed that cluster analysis using the ITS2 region mainly supported the relationship between the species of Dendrobium established by traditional morphological methods and many previous molecular analyses. To sum up, the ITS2 region can not only be used as an efficient barcode to identify Dendrobium species, but also has the potential to contribute to the phylogenetic analysis of the genus Dendrobium.

Intraspecific phylogeography of Lasmigona subviridis (Bivalvia: Unionidae): Conservation implications of range discontinuity

USGS Publications Warehouse

King, T.L.; Eackles, M.S.; Gjetvaj, B.; Hoeh, W.R.

1999-01-01

A nucleotide sequence analysis of the first internal transcribed spacer region (ITS-1) between the 5.8S and 18S ribosomal DNA genes (640 bp) and cytochrome c oxidase subunit I (COI) of mitochondrial DNA (mtDNA) (576 bp) was conducted for the freshwater bivalve Lasmigona subviridis and three congeners to determine the utility of these regions in identifying phylogeographic and phylogenetic structure. Sequence analysis of the ITS-1 region indicated a zone of discontinuity in the genetic population structure between a group of L. subviridis populations inhabiting the Susquehanna and Potomac Rivers and more southern populations. Moreover, haplotype patterns resulting from variation in the COI region suggested an absence of gene exchange between tributaries within two different river drainages, as well as between adjacent rivers systems. The authors recommend that the northern and southern populations, which are reproductively isolated and constitute evolutionarily significant lineages, be managed as separate conservation units. Results from the COI region suggest that, in some cases, unionid relocations should be avoided between tributaries of the same drainage because these populations may have been reproductively isolated for thousands of generations. Therefore, unionid bivalves distributed among discontinuous habitats (e.g. Atlantic slope drainages) potentially should be considered evolutionarily distinct. The DNA sequence divergences observed in the nuclear and mtDNA regions among the Lasmigona species were congruent, although the level of divergence in the COI region was up to three times greater. The genus Lasmigona, as represented by the four species surveyed in this study, may not be monophyletic.

Molecular Identification of Dendrobium Species (Orchidaceae) Based on the DNA Barcode ITS2 Region and Its Application for Phylogenetic Study

PubMed Central

Feng, Shangguo; Jiang, Yan; Wang, Shang; Jiang, Mengying; Chen, Zhe; Ying, Qicai; Wang, Huizhong

2015-01-01

The over-collection and habitat destruction of natural Dendrobium populations for their commercial medicinal value has led to these plants being under severe threat of extinction. In addition, many Dendrobium plants are similarly shaped and easily confused during the absence of flowering stages. In the present study, we examined the application of the ITS2 region in barcoding and phylogenetic analyses of Dendrobium species (Orchidaceae). For barcoding, ITS2 regions of 43 samples in Dendrobium were amplified. In combination with sequences from GenBank, the sequences were aligned using Clustal W and genetic distances were computed using MEGA V5.1. The success rate of PCR amplification and sequencing was 100%. There was a significant divergence between the inter- and intra-specific genetic distances of ITS2 regions, while the presence of a barcoding gap was obvious. Based on the BLAST1, nearest distance and TaxonGAP methods, our results showed that the ITS2 regions could successfully identify the species of most Dendrobium samples examined; Second, we used ITS2 as a DNA marker to infer phylogenetic relationships of 64 Dendrobium species. The results showed that cluster analysis using the ITS2 region mainly supported the relationship between the species of Dendrobium established by traditional morphological methods and many previous molecular analyses. To sum up, the ITS2 region can not only be used as an efficient barcode to identify Dendrobium species, but also has the potential to contribute to the phylogenetic analysis of the genus Dendrobium. PMID:26378526

Phylogenetic analysis of Sicilian goats reveals a new mtDNA lineage.

PubMed

Sardina, M T; Ballester, M; Marmi, J; Finocchiaro, R; van Kaam, J B C H M; Portolano, B; Folch, J M

2006-08-01

The mitochondrial hypervariable region 1 (HVR1) sequence of 67 goats belonging to the Girgentana, Maltese and Derivata di Siria breeds was partially sequenced in order to present the first phylogenetic characterization of Sicilian goat breeds. These sequences were compared with published sequences of Indian and Pakistani domestic goats and wild goats. Mitochondrial lineage A was observed in most of the Sicilian goats. However, three Girgentana haplotypes were highly divergent from the Capra hircus clade, indicating that a new mtDNA lineage in domestic goats was found.

Analysis of correlated mutations in HIV-1 protease using spectral clustering.

PubMed

Liu, Ying; Eyal, Eran; Bahar, Ivet

2008-05-15

The ability of human immunodeficiency virus-1 (HIV-1) protease to develop mutations that confer multi-drug resistance (MDR) has been a major obstacle in designing rational therapies against HIV. Resistance is usually imparted by a cooperative mechanism that can be elucidated by a covariance analysis of sequence data. Identification of such correlated substitutions of amino acids may be obscured by evolutionary noise. HIV-1 protease sequences from patients subjected to different specific treatments (set 1), and from untreated patients (set 2) were subjected to sequence covariance analysis by evaluating the mutual information (MI) between all residue pairs. Spectral clustering of the resulting covariance matrices disclosed two distinctive clusters of correlated residues: the first, observed in set 1 but absent in set 2, contained residues involved in MDR acquisition; and the second, included those residues differentiated in the various HIV-1 protease subtypes, shortly referred to as the phylogenetic cluster. The MDR cluster occupies sites close to the central symmetry axis of the enzyme, which overlap with the global hinge region identified from coarse-grained normal-mode analysis of the enzyme structure. The phylogenetic cluster, on the other hand, occupies solvent-exposed and highly mobile regions. This study demonstrates (i) the possibility of distinguishing between the correlated substitutions resulting from neutral mutations and those induced by MDR upon appropriate clustering analysis of sequence covariance data and (ii) a connection between global dynamics and functional substitution of amino acids.

Investigation of a Quadruplex-Forming Repeat Sequence Highly Enriched in Xanthomonas and Nostoc sp.

PubMed

Rehm, Charlotte; Wurmthaler, Lena A; Li, Yuanhao; Frickey, Tancred; Hartig, Jörg S

2015-01-01

In prokaryotes simple sequence repeats (SSRs) with unit sizes of 1-5 nucleotides (nt) are causative for phase and antigenic variation. Although an increased abundance of heptameric repeats was noticed in bacteria, reports about SSRs of 6-9 nt are rare. In particular G-rich repeat sequences with the propensity to fold into G-quadruplex (G4) structures have received little attention. In silico analysis of prokaryotic genomes show putative G4 forming sequences to be abundant. This report focuses on a surprisingly enriched G-rich repeat of the type GGGNATC in Xanthomonas and cyanobacteria such as Nostoc. We studied in detail the genomes of Xanthomonas campestris pv. campestris ATCC 33913 (Xcc), Xanthomonas axonopodis pv. citri str. 306 (Xac), and Nostoc sp. strain PCC7120 (Ana). In all three organisms repeats are spread all over the genome with an over-representation in non-coding regions. Extensive variation of the number of repetitive units was observed with repeat numbers ranging from two up to 26 units. However a clear preference for four units was detected. The strong bias for four units coincides with the requirement of four consecutive G-tracts for G4 formation. Evidence for G4 formation of the consensus repeat sequences was found in biophysical studies utilizing CD spectroscopy. The G-rich repeats are preferably located between aligned open reading frames (ORFs) and are under-represented in coding regions or between divergent ORFs. The G-rich repeats are preferentially located within a distance of 50 bp upstream of an ORF on the anti-sense strand or within 50 bp from the stop codon on the sense strand. Analysis of whole transcriptome sequence data showed that the majority of repeat sequences are transcribed. The genetic loci in the vicinity of repeat regions show increased genomic stability. In conclusion, we introduce and characterize a special class of highly abundant and wide-spread quadruplex-forming repeat sequences in bacteria.

Investigation of a Quadruplex-Forming Repeat Sequence Highly Enriched in Xanthomonas and Nostoc sp.

PubMed Central

Rehm, Charlotte; Wurmthaler, Lena A.; Li, Yuanhao; Frickey, Tancred; Hartig, Jörg S.

2015-01-01

In prokaryotes simple sequence repeats (SSRs) with unit sizes of 1–5 nucleotides (nt) are causative for phase and antigenic variation. Although an increased abundance of heptameric repeats was noticed in bacteria, reports about SSRs of 6–9 nt are rare. In particular G-rich repeat sequences with the propensity to fold into G-quadruplex (G4) structures have received little attention. In silico analysis of prokaryotic genomes show putative G4 forming sequences to be abundant. This report focuses on a surprisingly enriched G-rich repeat of the type GGGNATC in Xanthomonas and cyanobacteria such as Nostoc. We studied in detail the genomes of Xanthomonas campestris pv. campestris ATCC 33913 (Xcc), Xanthomonas axonopodis pv. citri str. 306 (Xac), and Nostoc sp. strain PCC7120 (Ana). In all three organisms repeats are spread all over the genome with an over-representation in non-coding regions. Extensive variation of the number of repetitive units was observed with repeat numbers ranging from two up to 26 units. However a clear preference for four units was detected. The strong bias for four units coincides with the requirement of four consecutive G-tracts for G4 formation. Evidence for G4 formation of the consensus repeat sequences was found in biophysical studies utilizing CD spectroscopy. The G-rich repeats are preferably located between aligned open reading frames (ORFs) and are under-represented in coding regions or between divergent ORFs. The G-rich repeats are preferentially located within a distance of 50 bp upstream of an ORF on the anti-sense strand or within 50 bp from the stop codon on the sense strand. Analysis of whole transcriptome sequence data showed that the majority of repeat sequences are transcribed. The genetic loci in the vicinity of repeat regions show increased genomic stability. In conclusion, we introduce and characterize a special class of highly abundant and wide-spread quadruplex-forming repeat sequences in bacteria. PMID:26695179

Simple sequence repeats in Escherichia coli: abundance, distribution, composition, and polymorphism.

PubMed

Gur-Arie, R; Cohen, C J; Eitan, Y; Shelef, L; Hallerman, E M; Kashi, Y

2000-01-01

Computer-based genome-wide screening of the DNA sequence of Escherichia coli strain K12 revealed tens of thousands of tandem simple sequence repeat (SSR) tracts, with motifs ranging from 1 to 6 nucleotides. SSRs were well distributed throughout the genome. Mononucleotide SSRs were over-represented in noncoding regions and under-represented in open reading frames (ORFs). Nucleotide composition of mono- and dinucleotide SSRs, both in ORFs and in noncoding regions, differed from that of the genomic region in which they occurred, with 93% of all mononucleotide SSRs proving to be of A or T. Computer-based analysis of the fine position of every SSR locus in the noncoding portion of the genome relative to downstream ORFs showed SSRs located in areas that could affect gene regulation. DNA sequences at 14 arbitrarily chosen SSR tracts were compared among E. coli strains. Polymorphisms of SSR copy number were observed at four of seven mononucleotide SSR tracts screened, with all polymorphisms occurring in noncoding regions. SSR polymorphism could prove important as a genome-wide source of variation, both for practical applications (including rapid detection, strain identification, and detection of loci affecting key phenotypes) and for evolutionary adaptation of microbes.

Proteins without unique 3D structures: biotechnological applications of intrinsically unstable/disordered proteins.

PubMed

Uversky, Vladimir N

2015-03-01

Intrinsically disordered proteins (IDPs) and intrinsically disordered protein regions (IDPRs) are functional proteins or regions that do not have unique 3D structures under functional conditions. Therefore, from the viewpoint of their lack of stable 3D structure, IDPs/IDPRs are inherently unstable. As much as structure and function of normal ordered globular proteins are determined by their amino acid sequences, the lack of unique 3D structure in IDPs/IDPRs and their disorder-based functionality are also encoded in the amino acid sequences. Because of their specific sequence features and distinctive conformational behavior, these intrinsically unstable proteins or regions have several applications in biotechnology. This review introduces some of the most characteristic features of IDPs/IDPRs (such as peculiarities of amino acid sequences of these proteins and regions, their major structural features, and peculiar responses to changes in their environment) and describes how these features can be used in the biotechnology, for example for the proteome-wide analysis of the abundance of extended IDPs, for recombinant protein isolation and purification, as polypeptide nanoparticles for drug delivery, as solubilization tools, and as thermally sensitive carriers of active peptides and proteins. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Variability among the Most Rapidly Evolving Plastid Genomic Regions is Lineage-Specific: Implications of Pairwise Genome Comparisons in Pyrus (Rosaceae) and Other Angiosperms for Marker Choice

PubMed Central

Ter-Voskanyan, Hasmik; Allgaier, Martin; Borsch, Thomas

2014-01-01

Plastid genomes exhibit different levels of variability in their sequences, depending on the respective kinds of genomic regions. Genes are usually more conserved while noncoding introns and spacers evolve at a faster pace. While a set of about thirty maximum variable noncoding genomic regions has been suggested to provide universally promising phylogenetic markers throughout angiosperms, applications often require several regions to be sequenced for many individuals. Our project aims to illuminate evolutionary relationships and species-limits in the genus Pyrus (Rosaceae)—a typical case with very low genetic distances between taxa. In this study, we have sequenced the plastid genome of Pyrus spinosa and aligned it to the already available P. pyrifolia sequence. The overall p-distance of the two Pyrus genomes was 0.00145. The intergenic spacers between ndhC–trnV, trnR–atpA, ndhF–rpl32, psbM–trnD, and trnQ–rps16 were the most variable regions, also comprising the highest total numbers of substitutions, indels and inversions (potentially informative characters). Our comparative analysis of further plastid genome pairs with similar low p-distances from Oenothera (representing another rosid), Olea (asterids) and Cymbidium (monocots) showed in each case a different ranking of genomic regions in terms of variability and potentially informative characters. Only two intergenic spacers (ndhF–rpl32 and trnK–rps16) were consistently found among the 30 top-ranked regions. We have mapped the occurrence of substitutions and microstructural mutations in the four genome pairs. High AT content in specific sequence elements seems to foster frequent mutations. We conclude that the variability among the fastest evolving plastid genomic regions is lineage-specific and thus cannot be precisely predicted across angiosperms. The often lineage-specific occurrence of stem-loop elements in the sequences of introns and spacers also governs lineage-specific mutations. Sequencing whole plastid genomes to find markers for evolutionary analyses is therefore particularly useful when overall genetic distances are low. PMID:25405773

Chloroplast genomes of Arabidopsis halleri ssp. gemmifera and Arabidopsis lyrata ssp. petraea: Structures and comparative analysis.

PubMed

Asaf, Sajjad; Khan, Abdul Latif; Khan, Muhammad Aaqil; Waqas, Muhammad; Kang, Sang-Mo; Yun, Byung-Wook; Lee, In-Jung

2017-08-08

We investigated the complete chloroplast (cp) genomes of non-model Arabidopsis halleri ssp. gemmifera and Arabidopsis lyrata ssp. petraea using Illumina paired-end sequencing to understand their genetic organization and structure. Detailed bioinformatics analysis revealed genome sizes of both subspecies ranging between 154.4~154.5 kbp, with a large single-copy region (84,197~84,158 bp), a small single-copy region (17,738~17,813 bp) and pair of inverted repeats (IRa/IRb; 26,264~26,259 bp). Both cp genomes encode 130 genes, including 85 protein-coding genes, eight ribosomal RNA genes and 37 transfer RNA genes. Whole cp genome comparison of A. halleri ssp. gemmifera and A. lyrata ssp. petraea, along with ten other Arabidopsis species, showed an overall high degree of sequence similarity, with divergence among some intergenic spacers. The location and distribution of repeat sequences were determined, and sequence divergences of shared genes were calculated among related species. Comparative phylogenetic analysis of the entire genomic data set and 70 shared genes between both cp genomes confirmed the previous phylogeny and generated phylogenetic trees with the same topologies. The sister species of A. halleri ssp. gemmifera is A. umezawana, whereas the closest relative of A. lyrata spp. petraea is A. arenicola.

Clustered regularly interspaced short palindromic repeats (CRISPRs) analysis of members of the Mycobacterium tuberculosis complex.

PubMed

Botelho, Ana; Canto, Ana; Leão, Célia; Cunha, Mónica V

2015-01-01

Typical CRISPR (clustered, regularly interspaced, short palindromic repeat) regions are constituted by short direct repeats (DRs), interspersed with similarly sized non-repetitive spacers, derived from transmissible genetic elements, acquired when the cell is challenged with foreign DNA. The analysis of the structure, in number and nature, of CRISPR spacers is a valuable tool for molecular typing since these loci are polymorphic among strains, originating characteristic signatures. The existence of CRISPR structures in the genome of the members of Mycobacterium tuberculosis complex (MTBC) enabled the development of a genotyping method, based on the analysis of the presence or absence of 43 oligonucleotide spacers separated by conserved DRs. This method, called spoligotyping, consists on PCR amplification of the DR chromosomal region and recognition after hybridization of the spacers that are present. The workflow beneath this methodology implies that the PCR products are brought onto a membrane containing synthetic oligonucleotides that have complementary sequences to the spacer sequences. Lack of hybridization of the PCR products to a specific oligonucleotide sequence indicates absence of the correspondent spacer sequence in the examined strain. Spoligotyping gained great notoriety as a robust identification and typing tool for members of MTBC, enabling multiple epidemiological studies on human and animal tuberculosis.

Genetic diversity and molecular evolution of Naga King Chili inferred from internal transcribed spacer sequence of nuclear ribosomal DNA.

PubMed

Kehie, Mechuselie; Kumaria, Suman; Devi, Khumuckcham Sangeeta; Tandon, Pramod

2016-02-01

Sequences of the Internal Transcribed Spacer (ITS1-5.8S-ITS2) of nuclear ribosomal DNAs were explored to study the genetic diversity and molecular evolution of Naga King Chili. Our study indicated the occurrence of nucleotide polymorphism and haplotypic diversity in the ITS regions. The present study demonstrated that the variability of ITS1 with respect to nucleotide diversity and sequence polymorphism exceeded that of ITS2. Sequence analysis of 5.8S gene revealed a much conserved region in all the accessions of Naga King Chili. However, strong phylogenetic information of this species is the distinct 13 bp deletion in the 5.8S gene which discriminated Naga King Chili from the rest of the Capsicum sp. Neutrality test results implied a neutral variation, and population seems to be evolving at drift-mutation equilibrium and free from directed selection pressure. Furthermore, mismatch analysis showed multimodal curve indicating a demographic equilibrium. Phylogenetic relationships revealed by Median Joining Network (MJN) analysis denoted a clear discrimination of Naga King Chili from its closest sister species (Capsicum chinense and Capsicum frutescens). The absence of star-like network of haplotypes suggested an ancient population expansion of this chili.

[Analysis of 4 clustered high risk acute flaccid paralysis cases in Shanxi Province in 2006].

PubMed

Yan, Dong-mei; Zhang, Yong; Wang, Dong-yan

2010-04-01

Analysis of epidemiology of 4 clustered high risk acute flaccid paralysis(AFP) cases reported by Shanxi province in 2006 and VP1 gene characteristic for type III poliovirus isolated from the four AFP cases. Virus isolation and identification were conducted according to the 4th edition of WHO polio laboratory manual. The sequence of VP1 region were amplified and sequenced. The phylogenetic trees based on VP1 region were constructed. Three of four high risk AFP cases were suspected as vaccine associated paralysis poliomyelitis (VAPP), the onset date of them were close. VP1 sequencing of the four type III isolates revealed that the identity were 99.7%, 99.9%, 99.4% and 99.9% respectively compared with vaccine reference strain-BJOPV3. According to WHO criteria, the four isolates were identified as type III vaccine-related poliovirus. Phylogenetic analysis based on VP1 coding sequence showed that the four type III poliovirus were not related significantly. The type III poliovirus isolated from 3 suspected VAPP cases shared one nucleotide mutation at 2637 (C-->U), which result in the amino acid mutation from Val into Ala. The improvement of laboratory surveillance for clustered high risk AFP cases should be strengthened so as to detect and prevent poliovirus circulation timely.

Phytoplasma phylogenetics based on analysis of secA and 23S rRNA gene sequences for improved resolution of candidate species of 'Candidatus Phytoplasma'.

PubMed

Hodgetts, Jennifer; Boonham, Neil; Mumford, Rick; Harrison, Nigel; Dickinson, Matthew

2008-08-01

Phytoplasma phylogenetics has focused primarily on sequences of the non-coding 16S rRNA gene and the 16S-23S rRNA intergenic spacer region (16-23S ISR), and primers that enable amplification of these regions from all phytoplasmas by PCR are well established. In this study, primers based on the secA gene have been developed into a semi-nested PCR assay that results in a sequence of the expected size (about 480 bp) from all 34 phytoplasmas examined, including strains representative of 12 16Sr groups. Phylogenetic analysis of secA gene sequences showed similar clustering of phytoplasmas when compared with clusters resolved by similar sequence analyses of a 16-23S ISR-23S rRNA gene contig or of the 16S rRNA gene alone. The main differences between trees were in the branch lengths, which were elongated in the 16-23S ISR-23S rRNA gene tree when compared with the 16S rRNA gene tree and elongated still further in the secA gene tree, despite this being a shorter sequence. The improved resolution in the secA gene-derived phylogenetic tree resulted in the 16SrII group splitting into two distinct clusters, while phytoplasmas associated with coconut lethal yellowing-type diseases split into three distinct groups, thereby supporting past proposals that they represent different candidate species within 'Candidatus Phytoplasma'. The ability to differentiate 16Sr groups and subgroups by virtual RFLP analysis of secA gene sequences suggests that this gene may provide an informative alternative molecular marker for pathogen identification and diagnosis of phytoplasma diseases.

Introduction on Using the FastPCR Software and the Related Java Web Tools for PCR and Oligonucleotide Assembly and Analysis.

PubMed

Kalendar, Ruslan; Tselykh, Timofey V; Khassenov, Bekbolat; Ramanculov, Erlan M

2017-01-01

This chapter introduces the FastPCR software as an integrated tool environment for PCR primer and probe design, which predicts properties of oligonucleotides based on experimental studies of the PCR efficiency. The software provides comprehensive facilities for designing primers for most PCR applications and their combinations. These include the standard PCR as well as the multiplex, long-distance, inverse, real-time, group-specific, unique, overlap extension PCR for multi-fragments assembling cloning and loop-mediated isothermal amplification (LAMP). It also contains a built-in program to design oligonucleotide sets both for long sequence assembly by ligase chain reaction and for design of amplicons that tile across a region(s) of interest. The software calculates the melting temperature for the standard and degenerate oligonucleotides including locked nucleic acid (LNA) and other modifications. It also provides analyses for a set of primers with the prediction of oligonucleotide properties, dimer and G/C-quadruplex detection, linguistic complexity as well as a primer dilution and resuspension calculator. The program consists of various bioinformatical tools for analysis of sequences with the GC or AT skew, CG% and GA% content, and the purine-pyrimidine skew. It also analyzes the linguistic sequence complexity and performs generation of random DNA sequence as well as restriction endonucleases analysis. The program allows to find or create restriction enzyme recognition sites for coding sequences and supports the clustering of sequences. It performs efficient and complete detection of various repeat types with visual display. The FastPCR software allows the sequence file batch processing that is essential for automation. The program is available for download at http://primerdigital.com/fastpcr.html , and its online version is located at http://primerdigital.com/tools/pcr.html .

Multilocus sequence typing and pulsed-field gel electrophoresis analysis of Oenococcus oeni from different wine-producing regions of China.

PubMed

Wang, Tao; Li, Hua; Wang, Hua; Su, Jing

2015-04-16

The present study established a typing method with NotI-based pulsed-field gel electrophoresis (PFGE) and stress response gene schemed multilocus sequence typing (MLST) for 55 Oenococcus oeni strains isolated from six individual regions in China and two model strains PSU-1 (CP000411) and ATCC BAA-1163 (AAUV00000000). Seven stress response genes, cfa, clpL, clpP, ctsR, mleA, mleP and omrA, were selected for MLST testing, and positive selective pressure was detected for these genes. Furthermore, both methods separated the strains into two clusters. The PFGE clusters are correlated with the region, whereas the sequence types (STs) formed by the MLST confirm the two clusters identified by PFGE. In addition, the population structure was a mixture of evolutionary pathways, and the strains exhibited both clonal and panmictic characteristics. Copyright © 2015 Elsevier B.V. All rights reserved.

Shallow phylogeographic structuring of Vimba vimba across Europe suggests two distinct refugia during the last glaciation.

PubMed

Hänfling, B; Dümpelmann, C; Bogutskaya, N G; Brandl, R; Brändle, M

2009-12-01

Genetic variation and geographical structuring of vimba Vimba vimba were analysed across 26 sites (80 individuals) by means of mtDNA sequences (cyt b gene, mitochondrial control region) to localize hypothesized glacial refugia and to reconstruct postglacial recoloniation routes. Although genetic diversity among sequenced individuals was low, a combined analysis of the two sequenced fragments revealed a western (central and northern Europe: Danube, Elbe and lakes of Sweden) and an eastern clade (eastern Europe: Dnieper-South Bug, Don, Neman). Furthermore, a number of divergent ancestral haplotypes distributed around the Black and Caspian Seas became apparent. Mismatch analyses supported a sudden expansion model for the populations of the western clade between 50 and 10 000 bp. Overall, the study provides strong evidence for a northward and westward expansion of V. vimba from two refugial regions located in the Danubian drainage and the northern Pontic regions respectively.

Structural analysis of the HLA-A/HLA-F subregion: Precise localization of two new multigene families closely associated with the HLA class I sequences

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

Pichon, L.; Carn, G.; Bouric, P.

1996-03-01

Positional cloning strategies for the hemochromatosis gene have previously concentrated on a target area restricted to a maximum genomic expanse of 400 kb around the HLA-A and HLA-F loci. Recently, the candidate region has been extended to 2-3 Mb on the distal side of the MHC. In this study, 10 coding sequences [hemochromatosis candidate genes (HCG) I to X] were isolated by cDNA selection using YACs covering the HLA-A/HLA-F subregion. Two of these (HCG II and HCG IV) belong to multigene families, as well as other sequences already described in this region, i.e., P5, pMC 6.7, and HLA class I.more » Fingerprinting of the four YACSs overlapping the region was performed and allowed partial localization of the different multigene family sequences on each YAC without defining their exact positions. Fingerprinting on cosmids isolated from the ICRF chromosome 6-specific cosmid library allowed more precise localization of the redundant sequences in all of the multigene families and revealed their apparent organization in clusters. Further examination of these intertwined sequences demonstrated that this structural organization resulted from a succession of complex phenomena, including duplications and contractions. This study presents a precise description of the structural organization of the HLA-A/HLA-F region and a determination of the sequences involved in the megabase size polymorphism observed among the A3, A24, and A31 haplotypes. 29 refs., 2 figs., 2 tabs.« less

A Dynamic Tandem Repeat in Monocotyledons Inferred from a Comparative Analysis of Chloroplast Genomes in Melanthiaceae.

PubMed

Do, Hoang Dang Khoa; Kim, Joo-Hwan

2017-01-01

Chloroplast genomes (cpDNA) are highly valuable resources for evolutionary studies of angiosperms, since they are highly conserved, are small in size, and play critical roles in plants. Slipped-strand mispairing (SSM) was assumed to be a mechanism for generating repeat units in cpDNA. However, research on the employment of different small repeated sequences through SSM events, which may induce the accumulation of distinct types of repeats within the same region in cpDNA, has not been documented. Here, we sequenced two chloroplast genomes from the endemic species Heloniopsis tubiflora (Korea) and Xerophyllum tenax (USA) to cover the gap between molecular data and explore "hot spots" for genomic events in Melanthiaceae. Comparative analysis of 23 complete cpDNA sequences revealed that there were different stages of deletion in the rps16 region across the Melanthiaceae. Based on the partial or complete loss of rps16 gene in cpDNA, we have firstly reported potential molecular markers for recognizing two sections ( Veratrum and Fuscoveratrum ) of Veratrum . Melathiaceae exhibits a significant change in the junction between large single copy and inverted repeat regions, ranging from trnH_GUG to a part of rps3 . Our results show an accumulation of tandem repeats in the rpl23-ycf2 regions of cpDNAs. Small conserved sequences exist and flank tandem repeats in further observation of this region across most of the examined taxa of Liliales. Therefore, we propose three scenarios in which different small repeated sequences were used during SSM events to generate newly distinct types of repeats. Occasionally, prior to the SSM process, point mutation event and double strand break repair occurred and induced the formation of initial repeat units which are indispensable in the SSM process. SSM may have likely occurred more frequently for short repeats than for long repeat sequences in tribe Parideae (Melanthiaceae, Liliales). Collectively, these findings add new evidence of dynamic results from SSM in chloroplast genomes which can be useful for further evolutionary studies in angiosperms. Additionally, genomics events in cpDNA are potential resources for mining molecular markers in Liliales.

FunGene: the functional gene pipeline and repository.

PubMed

Fish, Jordan A; Chai, Benli; Wang, Qiong; Sun, Yanni; Brown, C Titus; Tiedje, James M; Cole, James R

2013-01-01

Ribosomal RNA genes have become the standard molecular markers for microbial community analysis for good reasons, including universal occurrence in cellular organisms, availability of large databases, and ease of rRNA gene region amplification and analysis. As markers, however, rRNA genes have some significant limitations. The rRNA genes are often present in multiple copies, unlike most protein-coding genes. The slow rate of change in rRNA genes means that multiple species sometimes share identical 16S rRNA gene sequences, while many more species share identical sequences in the short 16S rRNA regions commonly analyzed. In addition, the genes involved in many important processes are not distributed in a phylogenetically coherent manner, potentially due to gene loss or horizontal gene transfer. While rRNA genes remain the most commonly used markers, key genes in ecologically important pathways, e.g., those involved in carbon and nitrogen cycling, can provide important insights into community composition and function not obtainable through rRNA analysis. However, working with ecofunctional gene data requires some tools beyond those required for rRNA analysis. To address this, our Functional Gene Pipeline and Repository (FunGene; http://fungene.cme.msu.edu/) offers databases of many common ecofunctional genes and proteins, as well as integrated tools that allow researchers to browse these collections and choose subsets for further analysis, build phylogenetic trees, test primers and probes for coverage, and download aligned sequences. Additional FunGene tools are specialized to process coding gene amplicon data. For example, FrameBot produces frameshift-corrected protein and DNA sequences from raw reads while finding the most closely related protein reference sequence. These tools can help provide better insight into microbial communities by directly studying key genes involved in important ecological processes.

HIA: a genome mapper using hybrid index-based sequence alignment.

PubMed

Choi, Jongpill; Park, Kiejung; Cho, Seong Beom; Chung, Myungguen

2015-01-01

A number of alignment tools have been developed to align sequencing reads to the human reference genome. The scale of information from next-generation sequencing (NGS) experiments, however, is increasing rapidly. Recent studies based on NGS technology have routinely produced exome or whole-genome sequences from several hundreds or thousands of samples. To accommodate the increasing need of analyzing very large NGS data sets, it is necessary to develop faster, more sensitive and accurate mapping tools. HIA uses two indices, a hash table index and a suffix array index. The hash table performs direct lookup of a q-gram, and the suffix array performs very fast lookup of variable-length strings by exploiting binary search. We observed that combining hash table and suffix array (hybrid index) is much faster than the suffix array method for finding a substring in the reference sequence. Here, we defined the matching region (MR) is a longest common substring between a reference and a read. And, we also defined the candidate alignment regions (CARs) as a list of MRs that is close to each other. The hybrid index is used to find candidate alignment regions (CARs) between a reference and a read. We found that aligning only the unmatched regions in the CAR is much faster than aligning the whole CAR. In benchmark analysis, HIA outperformed in mapping speed compared with the other aligners, without significant loss of mapping accuracy. Our experiments show that the hybrid of hash table and suffix array is useful in terms of speed for mapping NGS sequencing reads to the human reference genome sequence. In conclusion, our tool is appropriate for aligning massive data sets generated by NGS sequencing.

Subset of Kappa and Lambda Germline Sequences Result in Light Chains with a Higher Molecular Mass Phenotype.

PubMed

Barnidge, David R; Lundström, Susanna L; Zhang, Bo; Dasari, Surendra; Murray, David L; Zubarev, Roman A

2015-12-04

In our previous work, we showed that electrospray ionization of intact polyclonal kappa and lambda light chains isolated from normal serum generates two distinct, Gaussian-shaped, molecular mass distributions representing the light-chain repertoire. During the analysis of a large (>100) patient sample set, we noticed a low-intensity molecular mass distribution with a mean of approximately 24 250 Da, roughly 800 Da higher than the mean of the typical kappa molecular-mass distribution mean of 23 450 Da. We also observed distinct clones in this region that did not appear to contain any typical post-translational modifications that would account for such a large mass shift. To determine the origin of the high molecular mass clones, we performed de novo bottom-up mass spectrometry on a purified IgM monoclonal light chain that had a calculated molecular mass of 24 275.03 Da. The entire sequence of the monoclonal light chain was determined using multienzyme digestion and de novo sequence-alignment software and was found to belong to the germline allele IGKV2-30. The alignment of kappa germline sequences revealed ten IGKV2 and one IGKV4 sequences that contained additional amino acids in their CDR1 region, creating the high-molecular-mass phenotype. We also performed an alignment of lambda germline sequences, which showed additional amino acids in the CDR2 region, and the FR3 region of functional germline sequences that result in a high-molecular-mass phenotype. The work presented here illustrates the ability of mass spectrometry to provide information on the diversity of light-chain molecular mass phenotypes in circulation, which reflects the germline sequences selected by the immunoglobulin-secreting B-cell population.

Sequence analysis and expression of the M1 and M2 matrix protein genes of hirame rhabdovirus (HIRRV)

USGS Publications Warehouse

Nishizawa, T.; Kurath, G.; Winton, J.R.

1997-01-01

We have cloned and sequenced a 2318 nucleotide region of the genomic RNA of hirame rhabdovirus (HIRRV), an important viral pathogen of Japanese flounder Paralichthys olivaceus. This region comprises approximately two-thirds of the 3' end of the nucleocapsid protein (N) gene and the complete matrix protein (M1 and M2) genes with the associated intergenic regions. The partial N gene sequence was 812 nucleotides in length with an open reading frame (ORF) that encoded the carboxyl-terminal 250 amino acids of the N protein. The M1 and M2 genes were 771 and 700 nucleotides in length, respectively, with ORFs encoding proteins of 227 and 193 amino acids. The M1 gene sequence contained an additional small ORF that could encode a highly basic, arginine-rich protein of 25 amino acids. Comparisons of the N, M1, and M2 gene sequences of HIRRV with the corresponding sequences of the fish rhabdoviruses, infectious hematopoietic necrosis virus (IHNV) or viral hemorrhagic septicemia virus (VHSV) indicated that HIRRV was more closely related to IHNV than to VHSV, but was clearly distinct from either. The putative consensus gene termination sequence for IHNV and VHSV, AGAYAG(A)(7), was present in the N-M1, M1-M2, and M2-G intergenic regions of HIRRV as were the putative transcription initiation sequences YGGCAC and AACA. An Escherichia coli expression system was used to produce recombinant proteins from the M1 and M2 genes of HIRRV. These were the same size as the authentic M1 and M2 proteins and reacted with anti-HIRRV rabbit serum in western blots. These reagents can be used for further study of the fish immune response and to test novel control methods.

Comparison of a High-Resolution Melting Assay to Next-Generation Sequencing for Analysis of HIV Diversity

PubMed Central

Cousins, Matthew M.; Ou, San-San; Wawer, Maria J.; Munshaw, Supriya; Swan, David; Magaret, Craig A.; Mullis, Caroline E.; Serwadda, David; Porcella, Stephen F.; Gray, Ronald H.; Quinn, Thomas C.; Donnell, Deborah; Eshleman, Susan H.

2012-01-01

Next-generation sequencing (NGS) has recently been used for analysis of HIV diversity, but this method is labor-intensive, costly, and requires complex protocols for data analysis. We compared diversity measures obtained using NGS data to those obtained using a diversity assay based on high-resolution melting (HRM) of DNA duplexes. The HRM diversity assay provides a single numeric score that reflects the level of diversity in the region analyzed. HIV gag and env from individuals in Rakai, Uganda, were analyzed in a previous study using NGS (n = 220 samples from 110 individuals). Three sequence-based diversity measures were calculated from the NGS sequence data (percent diversity, percent complexity, and Shannon entropy). The amplicon pools used for NGS were analyzed with the HRM diversity assay. HRM scores were significantly associated with sequence-based measures of HIV diversity for both gag and env (P < 0.001 for all measures). The level of diversity measured by the HRM diversity assay and NGS increased over time in both regions analyzed (P < 0.001 for all measures except for percent complexity in gag), and similar amounts of diversification were observed with both methods (P < 0.001 for all measures except for percent complexity in gag). Diversity measures obtained using the HRM diversity assay were significantly associated with those from NGS, and similar increases in diversity over time were detected by both methods. The HRM diversity assay is faster and less expensive than NGS, facilitating rapid analysis of large studies of HIV diversity and evolution. PMID:22785188

Churchill: an ultra-fast, deterministic, highly scalable and balanced parallelization strategy for the discovery of human genetic variation in clinical and population-scale genomics.

PubMed

Kelly, Benjamin J; Fitch, James R; Hu, Yangqiu; Corsmeier, Donald J; Zhong, Huachun; Wetzel, Amy N; Nordquist, Russell D; Newsom, David L; White, Peter

2015-01-20

While advances in genome sequencing technology make population-scale genomics a possibility, current approaches for analysis of these data rely upon parallelization strategies that have limited scalability, complex implementation and lack reproducibility. Churchill, a balanced regional parallelization strategy, overcomes these challenges, fully automating the multiple steps required to go from raw sequencing reads to variant discovery. Through implementation of novel deterministic parallelization techniques, Churchill allows computationally efficient analysis of a high-depth whole genome sample in less than two hours. The method is highly scalable, enabling full analysis of the 1000 Genomes raw sequence dataset in a week using cloud resources. http://churchill.nchri.org/.

Genome sequence analysis of five Canadian isolates of strawberry mottle virus reveals extensive intra-species diversity and a longer RNA2 with increased coding capacity compared to a previously characterized European isolate.

PubMed

Bhagwat, Basdeo; Dickison, Virginia; Ding, Xinlun; Walker, Melanie; Bernardy, Michael; Bouthillier, Michel; Creelman, Alexa; DeYoung, Robyn; Li, Yinzi; Nie, Xianzhou; Wang, Aiming; Xiang, Yu; Sanfaçon, Hélène

2016-06-01

In this study, we report the genome sequence of five isolates of strawberry mottle virus (family Secoviridae, order Picornavirales) from strawberry field samples with decline symptoms collected in Eastern Canada. The Canadian isolates differed from the previously characterized European isolate 1134 in that they had a longer RNA2, resulting in a 239-amino-acid extension of the C-terminal region of the polyprotein. Sequence analysis suggests that reassortment and recombination occurred among the isolates. Phylogenetic analysis revealed that the Canadian isolates are diverse, grouping in two separate branches along with isolates from Europe and the Americas.

Identification and characterization of Theileria ovis surface protein (ToSp) resembled TaSp in Theileria annulata.

PubMed

Shayan, P; Jafari, S; Fattahi, R; Ebrahimzade, E; Amininia, N; Changizi, E

2016-05-01

Ovine theileriosis is an important hemoprotozoal disease of sheep and goats in tropical and subtropical regions which caused high economic loses in the livestock industry. Theileria annulata surface protein (TaSp) was used previously as a tool for serological analysis in livestock. Since the amino acid sequences of TaSp is, at least, in part very conserved in T. annulata, Theileria lestoquardi and Theileria china I and II, it is very important to determine the amino acid sequence of this protein in Theileria ovis as well, to avoid false interpretation of serological data based on this protein in small animal. In the present study, the nucleotide sequence and amino acid sequence of T. ovis surface protein (ToSp) were determined. The comparison of the nucleotide sequence of ToSp showed 96, 96, 99, and 86 % homology to the corresponding nucleotide sequence of TaSp genes by T. annulata, T. China I, T. China II and T. lestoquardi, previously registered in GenBank under accession nos. AJ316260.1, AY274329.1, DQ120058.1, and EF092924.1 respectively. The amino acid sequence analysis showed 95, 81, 98 and 70 % homology to the corresponding amino acid sequence of T. annulata, T chinaI, T china II and T. lestoquardi, registered in GenBank under accession nos. CAC87478.1, AAP36993.1, AAZ30365.1 and AAP36999.11, respectively. Interestingly, in contrast to the C terminus, a significant difference in amino acid sequence in the N teminus of the ToSp protein could be determined compared to the other known corresponding TaSp sequences, which make this region attractive for designing of a suitable tool for serological diagnosis.

The Large Mitochondrial Genome of Symbiodinium minutum Reveals Conserved Noncoding Sequences between Dinoflagellates and Apicomplexans.

PubMed

Shoguchi, Eiichi; Shinzato, Chuya; Hisata, Kanako; Satoh, Nori; Mungpakdee, Sutada

2015-07-20

Even though mitochondrial genomes, which characterize eukaryotic cells, were first discovered more than 50 years ago, mitochondrial genomics remains an important topic in molecular biology and genome sciences. The Phylum Alveolata comprises three major groups (ciliates, apicomplexans, and dinoflagellates), the mitochondrial genomes of which have diverged widely. Even though the gene content of dinoflagellate mitochondrial genomes is reportedly comparable to that of apicomplexans, the highly fragmented and rearranged genome structures of dinoflagellates have frustrated whole genomic analysis. Consequently, noncoding sequences and gene arrangements of dinoflagellate mitochondrial genomes have not been well characterized. Here we report that the continuous assembled genome (∼326 kb) of the dinoflagellate, Symbiodinium minutum, is AT-rich (∼64.3%) and that it contains three protein-coding genes. Based upon in silico analysis, the remaining 99% of the genome comprises transcriptomic noncoding sequences. RNA edited sites and unique, possible start and stop codons clarify conserved regions among dinoflagellates. Our massive transcriptome analysis shows that almost all regions of the genome are transcribed, including 27 possible fragmented ribosomal RNA genes and 12 uncharacterized small RNAs that are similar to mitochondrial RNA genes of the malarial parasite, Plasmodium falciparum. Gene map comparisons show that gene order is only slightly conserved between S. minutum and P. falciparum. However, small RNAs and intergenic sequences share sequence similarities with P. falciparum, suggesting that the function of noncoding sequences has been preserved despite development of very different genome structures. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Genetic Diagnosis in Consanguineous Families With Kidney Disease by Homozygosity Mapping Coupled With Whole-Exome Sequencing

PubMed Central

Al-Romaih, Khaldoun I.; Genovese, Giulio; Al-Mojalli, Hamad; Al-Othman, Saleh; Al-Manea, Hadeel; Al-Suleiman, Mohammed; Al-Jondubi, Mohammed; Atallah, Nourah; Al-Rodhyan, Maha; Weins, Astrid; Pollak, Martin R.; Adra, Chaker N.

2011-01-01

Background Accurate diagnosis of the primary cause of an individual’s kidney disease can be essential for proper management. Some kidney diseases have overlapping histopathological features despite being caused by defects in different genes. In this report we describe two consanguineous Saudi Arabian families in which individuals presented with kidney failure and mixed clinical and histological features initially thought consistent with focal segmental glomerulosclerosis. Study Design Case series. Setting and participants We studied members of two apparently unrelated families from Saudi Arabia with kidney disease. Measurements Whole-genome single-nucleotide polymorphism analysis followed by targeted isolation and sequencing of exons using genomic DNA samples from affected members of these families, followed by additional focused genotyping and sequence analysis. Results The two apparently unrelated families shared a region of homozygosity on chromosome 2q13. Exome sequence from the affected individuals lacked any sequence reads from the NPHP1 gene, which is located within this homozygous region. Additional PCR based genotyping confirmed that affected individuals had NPHP1 deletions, rather than defects in a known FSGS-associated gene. Limitations The methods used here may not result in a clear genetic diagnosis in many cases of apparent familial kidney disease. Conclusions This analysis demonstrates the power of new high-throughput genotyping and sequencing technologies to aid in the rapid genetic diagnosis of individuals with an inherited form of kidney disease. We believe it is likely that such tools may become useful clinical genetic tools and alter the manner in which diagnoses are made in nephrology. PMID:21658830

Re-examination of population structure and phylogeography of hawksbill turtles in the wider Caribbean using longer mtDNA sequences.

PubMed

Leroux, Robin A; Dutton, Peter H; Abreu-Grobois, F Alberto; Lagueux, Cynthia J; Campbell, Cathi L; Delcroix, Eric; Chevalier, Johan; Horrocks, Julia A; Hillis-Starr, Zandy; Troëng, Sebastian; Harrison, Emma; Stapleton, Seth

2012-01-01

Management of the critically endangered hawksbill turtle in the Wider Caribbean (WC) has been hampered by knowledge gaps regarding stock structure. We carried out a comprehensive stock structure re-assessment of 11 WC hawksbill rookeries using longer mtDNA sequences, larger sample sizes (N = 647), and additional rookeries compared to previous surveys. Additional variation detected by 740 bp sequences between populations allowed us to differentiate populations such as Barbados-Windward and Guadeloupe (F (st) = 0.683, P < 0.05) that appeared genetically indistinguishable based on shorter 380 bp sequences. POWSIM analysis showed that longer sequences improved power to detect population structure and that when N < 30, increasing the variation detected was as effective in increasing power as increasing sample size. Geographic patterns of genetic variation suggest a model of periodic long-distance colonization coupled with region-wide dispersal and subsequent secondary contact within the WC. Mismatch analysis results for individual clades suggest a general population expansion in the WC following a historic bottleneck about 100 000-300 000 years ago. We estimated an effective female population size (N (ef)) of 6000-9000 for the WC, similar to the current estimated numbers of breeding females, highlighting the importance of these regional rookeries to maintaining genetic diversity in hawksbills. Our results provide a basis for standardizing future work to 740 bp sequence reads and establish a more complete baseline for determining stock boundaries in this migratory marine species. Finally, our findings illustrate the value of maintaining an archive of specimens for re-analysis as new markers become available.

RAPD and Internal Transcribed Spacer Sequence Analyses Reveal Zea nicaraguensis as a Section Luxuriantes Species Close to Zea luxurians

PubMed Central

Wang, Pei; Lu, Yanli; Zheng, Mingmin; Rong, Tingzhao; Tang, Qilin

2011-01-01

Genetic relationship of a newly discovered teosinte from Nicaragua, Zea nicaraguensis with waterlogging tolerance, was determined based on randomly amplified polymorphic DNA (RAPD) markers and the internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA using 14 accessions from Zea species. RAPD analysis showed that a total of 5,303 fragments were produced by 136 random decamer primers, of which 84.86% bands were polymorphic. RAPD-based UPGMA analysis demonstrated that the genus Zea can be divided into section Luxuriantes including Zea diploperennis, Zea luxurians, Zea perennis and Zea nicaraguensis, and section Zea including Zea mays ssp. mexicana, Zea mays ssp. parviglumis, Zea mays ssp. huehuetenangensis and Zea mays ssp. mays. ITS sequence analysis showed the lengths of the entire ITS region of the 14 taxa in Zea varied from 597 to 605 bp. The average GC content was 67.8%. In addition to the insertion/deletions, 78 variable sites were recorded in the total ITS region with 47 in ITS1, 5 in 5.8S, and 26 in ITS2. Sequences of these taxa were analyzed with neighbor-joining (NJ) and maximum parsimony (MP) methods to construct the phylogenetic trees, selecting Tripsacum dactyloides L. as the outgroup. The phylogenetic relationships of Zea species inferred from the ITS sequences are highly concordant with the RAPD evidence that resolved two major subgenus clades. Both RAPD and ITS sequence analyses indicate that Zea nicaraguensis is more closely related to Zea luxurians than the other teosintes and cultivated maize, which should be regarded as a section Luxuriantes species. PMID:21525982

Recombination Analysis of Herpes Simplex Virus 1 Reveals a Bias toward GC Content and the Inverted Repeat Regions

PubMed Central

Lee, Kyubin; Kolb, Aaron W.; Sverchkov, Yuriy; Cuellar, Jacqueline A.; Craven, Mark

2015-01-01

ABSTRACT Herpes simplex virus 1 (HSV-1) causes recurrent mucocutaneous ulcers and is the leading cause of infectious blindness and sporadic encephalitis in the United States. HSV-1 has been shown to be highly recombinogenic; however, to date, there has been no genome-wide analysis of recombination. To address this, we generated 40 HSV-1 recombinants derived from two parental strains, OD4 and CJ994. The 40 OD4-CJ994 HSV-1 recombinants were sequenced using the Illumina sequencing system, and recombination breakpoints were determined for each of the recombinants using the Bootscan program. Breakpoints occurring in the terminal inverted repeats were excluded from analysis to prevent double counting, resulting in a total of 272 breakpoints in the data set. By placing windows around the 272 breakpoints followed by Monte Carlo analysis comparing actual data to simulated data, we identified a recombination bias toward both high GC content and intergenic regions. A Monte Carlo analysis also suggested that recombination did not appear to be responsible for the generation of the spontaneous nucleotide mutations detected following sequencing. Additionally, kernel density estimation analysis across the genome found that the large, inverted repeats comprise a recombination hot spot. IMPORTANCE Herpes simplex virus 1 (HSV-1) virus is the leading cause of sporadic encephalitis and blinding keratitis in developed countries. HSV-1 has been shown to be highly recombinogenic, and recombination itself appears to be a significant component of genome replication. To date, there has been no genome-wide analysis of recombination. Here we present the findings of the first genome-wide study of recombination performed by generating and sequencing 40 HSV-1 recombinants derived from the OD4 and CJ994 parental strains, followed by bioinformatics analysis. Recombination breakpoints were determined, yielding 272 breakpoints in the full data set. Kernel density analysis determined that the large inverted repeats constitute a recombination hot spot. Additionally, Monte Carlo analyses found biases toward high GC content and intergenic and repetitive regions. PMID:25926637

Infrared thermal facial image sequence registration analysis and verification

NASA Astrophysics Data System (ADS)

Chen, Chieh-Li; Jian, Bo-Lin

2015-03-01

To study the emotional responses of subjects to the International Affective Picture System (IAPS), infrared thermal facial image sequence is preprocessed for registration before further analysis such that the variance caused by minor and irregular subject movements is reduced. Without affecting the comfort level and inducing minimal harm, this study proposes an infrared thermal facial image sequence registration process that will reduce the deviations caused by the unconscious head shaking of the subjects. A fixed image for registration is produced through the localization of the centroid of the eye region as well as image translation and rotation processes. Thermal image sequencing will then be automatically registered using the two-stage genetic algorithm proposed. The deviation before and after image registration will be demonstrated by image quality indices. The results show that the infrared thermal image sequence registration process proposed in this study is effective in localizing facial images accurately, which will be beneficial to the correlation analysis of psychological information related to the facial area.

The Complete Chloroplast Genome Sequences of Five Epimedium Species: Lights into Phylogenetic and Taxonomic Analyses

PubMed Central

Zhang, Yanjun; Du, Liuwen; Liu, Ao; Chen, Jianjun; Wu, Li; Hu, Weiming; Zhang, Wei; Kim, Kyunghee; Lee, Sang-Choon; Yang, Tae-Jin; Wang, Ying

2016-01-01

Epimedium L. is a phylogenetically and economically important genus in the family Berberidaceae. We here sequenced the complete chloroplast (cp) genomes of four Epimedium species using Illumina sequencing technology via a combination of de novo and reference-guided assembly, which was also the first comprehensive cp genome analysis on Epimedium combining the cp genome sequence of E. koreanum previously reported. The five Epimedium cp genomes exhibited typical quadripartite and circular structure that was rather conserved in genomic structure and the synteny of gene order. However, these cp genomes presented obvious variations at the boundaries of the four regions because of the expansion and contraction of the inverted repeat (IR) region and the single-copy (SC) boundary regions. The trnQ-UUG duplication occurred in the five Epimedium cp genomes, which was not found in the other basal eudicotyledons. The rapidly evolving cp genome regions were detected among the five cp genomes, as well as the difference of simple sequence repeats (SSR) and repeat sequence were identified. Phylogenetic relationships among the five Epimedium species based on their cp genomes showed accordance with the updated system of the genus on the whole, but reminded that the evolutionary relationships and the divisions of the genus need further investigation applying more evidences. The availability of these cp genomes provided valuable genetic information for accurately identifying species, taxonomy and phylogenetic resolution and evolution of Epimedium, and assist in exploration and utilization of Epimedium plants. PMID:27014326

Taxonomy of the Rhizopogon vinicolor species complex based on analysis of ITS sequences and microsatellite loci.

Treesearch

Annette M. Kretzer; Daniel L. Luoma; Randy Molina; Joseph W. Spatafora

2003-01-01

We are re-addressing species concepts in the Rhizopogon vinicolor species complex (Boletales, Basidiomycota) using sequence data from the interna transcribed spacer (ITS) region of the nuclear ribosomal repeat, as well as genoLypic data from five microsatellite loci. The R. vinicolor species complex by our definition includes,...

Novel species including Mycobacterium fukienense sp. is found from tuberculosis patients in Fujian Province, China, using phylogenetic analysis of Mycobacterium chelonae/abscessus complex.

PubMed

Zhang, Yuan Yuan; Li, Yan Bing; Huang, Ming Xiang; Zhao, Xiu Qin; Zhang, Li Shui; Liu, Wen En; Wan, Kang Lin

2013-11-01

To identify the novel species 'Mycobacterium fukienense' sp. nov of Mycobacterium chelonae/abscessus complex from tuberculosis patients in Fujian Province, China. Five of 27 clinical Mycobacterium isolates (Cls) were previously identified as M. chelonae/abscessus complex by sequencing the hsp65, rpoB, 16S-23S rRNA internal transcribed spacer region (its), recA and sodA house-keeping genes commonly used to describe the molecular characteristics of Mycobacterium. Clinical Mycobacterium isolates were classified according to the gene sequence using a clustering analysis program. Sequence similarity within clusters and diversity between clusters were analyzed. The 5 isolates were identified with distinct sequences exhibiting 99.8% homology in the hsp65 gene. However, a complete lack of homology was observed among the sequences of the rpoB, 16S-23S rRNA internal transcribed spacer region (its), sodA, and recA genes as compared with the M. abscessus. Furthermore, no match for rpoB, sodA, and recA genes was identified among the published sequences. The novel species, Mycobacterium fukienense, is identified from tuberculosis patients in Fujian Province, China, which does not belong to any existing subspecies of M. chelonea/abscessus complex. Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Is the extraction by Whatman FTA filter matrix technology and sequencing of large ribosomal subunit D1-D2 region sufficient for identification of clinical fungi?

PubMed

Kiraz, Nuri; Oz, Yasemin; Aslan, Huseyin; Erturan, Zayre; Ener, Beyza; Akdagli, Sevtap Arikan; Muslumanoglu, Hamza; Cetinkaya, Zafer

2015-10-01

Although conventional identification of pathogenic fungi is based on the combination of tests evaluating their morphological and biochemical characteristics, they can fail to identify the less common species or the differentiation of closely related species. In addition these tests are time consuming, labour-intensive and require experienced personnel. We evaluated the feasibility and sufficiency of DNA extraction by Whatman FTA filter matrix technology and DNA sequencing of D1-D2 region of the large ribosomal subunit gene for identification of clinical isolates of 21 yeast and 160 moulds in our clinical mycology laboratory. While the yeast isolates were identified at species level with 100% homology, 102 (63.75%) clinically important mould isolates were identified at species level, 56 (35%) isolates at genus level against fungal sequences existing in DNA databases and two (1.25%) isolates could not be identified. Consequently, Whatman FTA filter matrix technology was a useful method for extraction of fungal DNA; extremely rapid, practical and successful. Sequence analysis strategy of D1-D2 region of the large ribosomal subunit gene was found considerably sufficient in identification to genus level for the most clinical fungi. However, the identification to species level and especially discrimination of closely related species may require additional analysis. © 2015 Blackwell Verlag GmbH.

Cloning, sequencing, and characterization of the Bacillus subtilis biotin biosynthetic operon.

PubMed

Bower, S; Perkins, J B; Yocum, R R; Howitt, C L; Rahaim, P; Pero, J

1996-07-01

A 10-kb region of the Bacillus subtilis genome that contains genes involved in biotin-biosynthesis was cloned and sequenced. DNA sequence analysis indicated that B. subtilis contains homologs of the Escherichia coli and Bacillus sphaericus bioA, bioB, bioD, and bioF genes. These four genes and a homolog of the B. sphaericus bioW gene are arranged in a single operon in the order bioWAFDR and are followed by two additional genes, bioI and orf2. bioI and orf2 show no similarity to any other known biotin biosynthetic genes. The bioI gene encodes a protein with similarity to cytochrome P-450s and was able to complement mutations in either bioC or bioH of E. coli. Mutations in bioI caused B. subtilis to grow poorly in the absence of biotin. The bradytroph phenotype of bioI mutants was overcome by pimelic acid, suggesting that the product of bioI functions at a step prior to pimelic acid synthesis. The B. subtilis bio operon is preceded by a putative vegetative promoter sequence and contains just downstream a region of dyad symmetry with homology to the bio regulatory region of B. sphaericus. Analysis of a bioW-lacZ translational fusion indicated that expression of the biotin operon is regulated by biotin and the B. subtilis birA gene.

Cloning, sequencing, and characterization of the Bacillus subtilis biotin biosynthetic operon.

PubMed Central

Bower, S; Perkins, J B; Yocum, R R; Howitt, C L; Rahaim, P; Pero, J

1996-01-01

A 10-kb region of the Bacillus subtilis genome that contains genes involved in biotin-biosynthesis was cloned and sequenced. DNA sequence analysis indicated that B. subtilis contains homologs of the Escherichia coli and Bacillus sphaericus bioA, bioB, bioD, and bioF genes. These four genes and a homolog of the B. sphaericus bioW gene are arranged in a single operon in the order bioWAFDR and are followed by two additional genes, bioI and orf2. bioI and orf2 show no similarity to any other known biotin biosynthetic genes. The bioI gene encodes a protein with similarity to cytochrome P-450s and was able to complement mutations in either bioC or bioH of E. coli. Mutations in bioI caused B. subtilis to grow poorly in the absence of biotin. The bradytroph phenotype of bioI mutants was overcome by pimelic acid, suggesting that the product of bioI functions at a step prior to pimelic acid synthesis. The B. subtilis bio operon is preceded by a putative vegetative promoter sequence and contains just downstream a region of dyad symmetry with homology to the bio regulatory region of B. sphaericus. Analysis of a bioW-lacZ translational fusion indicated that expression of the biotin operon is regulated by biotin and the B. subtilis birA gene. PMID:8763940

An evaluation of genotyping by sequencing (GBS) to map the Breviaristatum-e (ari-e) locus in cultivated barley.

PubMed

Liu, Hui; Bayer, Micha; Druka, Arnis; Russell, Joanne R; Hackett, Christine A; Poland, Jesse; Ramsay, Luke; Hedley, Pete E; Waugh, Robbie

2014-02-06

We explored the use of genotyping by sequencing (GBS) on a recombinant inbred line population (GPMx) derived from a cross between the two-rowed barley cultivar 'Golden Promise' (ari-e.GP/Vrs1) and the six-rowed cultivar 'Morex' (Ari-e/vrs1) to map plant height. We identified three Quantitative Trait Loci (QTL), the first in a region encompassing the spike architecture gene Vrs1 on chromosome 2H, the second in an uncharacterised centromeric region on chromosome 3H, and the third in a region of chromosome 5H coinciding with the previously described dwarfing gene Breviaristatum-e (Ari-e). Barley cultivars in North-western Europe largely contain either of two dwarfing genes; Denso on chromosome 3H, a presumed ortholog of the rice green revolution gene OsSd1, or Breviaristatum-e (ari-e) on chromosome 5H. A recessive mutant allele of the latter gene, ari-e.GP, was introduced into cultivation via the cv. 'Golden Promise' that was a favourite of the Scottish malt whisky industry for many years and is still used in agriculture today. Using GBS mapping data and phenotypic measurements we show that ari-e.GP maps to a small genetic interval on chromosome 5H and that alternative alleles at a region encompassing Vrs1 on 2H along with a region on chromosome 3H also influence plant height. The location of Ari-e is supported by analysis of near-isogenic lines containing different ari-e alleles. We explored use of the GBS to populate the region with sequence contigs from the recently released physically and genetically integrated barley genome sequence assembly as a step towards Ari-e gene identification. GBS was an effective and relatively low-cost approach to rapidly construct a genetic map of the GPMx population that was suitable for genetic analysis of row type and height traits, allowing us to precisely position ari-e.GP on chromosome 5H. Mapping resolution was lower than we anticipated. We found the GBS data more complex to analyse than other data types but it did directly provide linked SNP markers for subsequent higher resolution genetic analysis.

Inter- and Intraspecies Phylogenetic Analyses Reveal Extensive X–Y Gene Conversion in the Evolution of Gametologous Sequences of Human Sex Chromosomes

PubMed Central

Trombetta, Beniamino; Sellitto, Daniele; Scozzari, Rosaria; Cruciani, Fulvio

2014-01-01

It has long been believed that the male-specific region of the human Y chromosome (MSY) is genetically independent from the X chromosome. This idea has been recently dismissed due to the discovery that X–Y gametologous gene conversion may occur. However, the pervasiveness of this molecular process in the evolution of sex chromosomes has yet to be exhaustively analyzed. In this study, we explored how pervasive X–Y gene conversion has been during the evolution of the youngest stratum of the human sex chromosomes. By comparing about 0.5 Mb of human–chimpanzee gametologous sequences, we identified 19 regions in which extensive gene conversion has occurred. From our analysis, two major features of these emerged: 1) Several of them are evolutionarily conserved between the two species and 2) almost all of the 19 hotspots overlap with regions where X–Y crossing-over has been previously reported to be involved in sex reversal. Furthermore, in order to explore the dynamics of X–Y gametologous conversion in recent human evolution, we resequenced these 19 hotspots in 68 widely divergent Y haplogroups and used publicly available single nucleotide polymorphism data for the X chromosome. We found that at least ten hotspots are still active in humans. Hence, the results of the interspecific analysis are consistent with the hypothesis of widespread reticulate evolution within gametologous sequences in the differentiation of hominini sex chromosomes. In turn, intraspecific analysis demonstrates that X–Y gene conversion may modulate human sex-chromosome-sequence evolution to a greater extent than previously thought. PMID:24817545

Bacterial community composition in different sediments from the Eastern Mediterranean Sea: a comparison of four 16S ribosomal DNA clone libraries.

PubMed

Polymenakou, Paraskevi N; Bertilsson, Stefan; Tselepides, Anastasios; Stephanou, Euripides G

2005-10-01

The regional variability of sediment bacterial community composition and diversity was studied by comparative analysis of four large 16S ribosomal DNA (rDNA) clone libraries from sediments in different regions of the Eastern Mediterranean Sea (Thermaikos Gulf, Cretan Sea, and South lonian Sea). Amplified rDNA restriction analysis of 664 clones from the libraries indicate that the rDNA richness and evenness was high: for example, a near-1:1 relationship among screened clones and number of unique restriction patterns when up to 190 clones were screened for each library. Phylogenetic analysis of 207 bacterial 16S rDNA sequences from the sediment libraries demonstrated that Gamma-, Delta-, and Alphaproteobacteria, Holophaga/Acidobacteria, Planctomycetales, Actinobacteria, Bacteroidetes, and Verrucomicrobia were represented in all four libraries. A few clones also grouped with the Betaproteobacteria, Nitrospirae, Spirochaetales, Chlamydiae, Firmicutes, and candidate division OPl 1. The abundance of sequences affiliated with Gammaproteobacteria was higher in libraries from shallow sediments in the Thermaikos Gulf (30 m) and the Cretan Sea (100 m) compared to the deeper South Ionian station (2790 m). Most sequences in the four sediment libraries clustered with uncultured 16S rDNA phylotypes from marine habitats, and many of the closest matches were clones from hydrocarbon seeps, benzene-mineralizing consortia, sulfate reducers, sulk oxidizers, and ammonia oxidizers. LIBSHUFF statistics of 16S rDNA gene sequences from the four libraries revealed major differences, indicating either a very high richness in the sediment bacterial communities or considerable variability in bacterial community composition among regions, or both.

Mechanisms of haplotype divergence at the RGA08 nucleotide-binding leucine-rich repeat gene locus in wild banana (Musa balbisiana)

PubMed Central

2010-01-01

Background Comparative sequence analysis of complex loci such as resistance gene analog clusters allows estimating the degree of sequence conservation and mechanisms of divergence at the intraspecies level. In banana (Musa sp.), two diploid wild species Musa acuminata (A genome) and Musa balbisiana (B genome) contribute to the polyploid genome of many cultivars. The M. balbisiana species is associated with vigour and tolerance to pests and disease and little is known on the genome structure and haplotype diversity within this species. Here, we compare two genomic sequences of 253 and 223 kb corresponding to two haplotypes of the RGA08 resistance gene analog locus in M. balbisiana "Pisang Klutuk Wulung" (PKW). Results Sequence comparison revealed two regions of contrasting features. The first is a highly colinear gene-rich region where the two haplotypes diverge only by single nucleotide polymorphisms and two repetitive element insertions. The second corresponds to a large cluster of RGA08 genes, with 13 and 18 predicted RGA genes and pseudogenes spread over 131 and 152 kb respectively on each haplotype. The RGA08 cluster is enriched in repetitive element insertions, in duplicated non-coding intergenic sequences including low complexity regions and shows structural variations between haplotypes. Although some allelic relationships are retained, a large diversity of RGA08 genes occurs in this single M. balbisiana genotype, with several RGA08 paralogs specific to each haplotype. The RGA08 gene family has evolved by mechanisms of unequal recombination, intragenic sequence exchange and diversifying selection. An unequal recombination event taking place between duplicated non-coding intergenic sequences resulted in a different RGA08 gene content between haplotypes pointing out the role of such duplicated regions in the evolution of RGA clusters. Based on the synonymous substitution rate in coding sequences, we estimated a 1 million year divergence time for these M. balbisiana haplotypes. Conclusions A large RGA08 gene cluster identified in wild banana corresponds to a highly variable genomic region between haplotypes surrounded by conserved flanking regions. High level of sequence identity (70 to 99%) of the genic and intergenic regions suggests a recent and rapid evolution of this cluster in M. balbisiana. PMID:20637079

Complete coding regions of the prototypes enterovirus B93 and C95: phylogenetic analyses of the P1 and P3 regions of EV-B and EV-C strains.

PubMed

Junttila, N; Lévêque, N; Magnius, L O; Kabue, J P; Muyembe-Tamfum, J J; Maslin, J; Lina, B; Norder, H

2015-03-01

Complete coding regions were sequenced for two new enterovirus genomes: EV-B93 previously identified by VP1 sequencing, derived from a child with acute flaccid paralysis in the Democratic Republic of Congo; and EV-C95 from a French soldier with acute gastroenteritis in Djibouti. The EV-B93 P1 had more than 30% nucleotide divergence from other EV-B types, with highest similarity to E-15 and EV-B80. The P1 nucleotide sequence of EV-C95 was most similar, 71%, to CV-A21. Complete coding regions for the new enteroviruses were compared with those of 135 EV-B and 176 EV-C strains representing all types available in GenBank. When strains from the same outbreak or strains isolated during the same year in the same geographical region were excluded, 27 of the 58 EV-B, and 16 of the 23 EV-C types were represented by more than one sequence. However, for EV-B the P3 sequences formed three clades mainly according to origin or time of isolation, irrespective of type, while for EV-C the P3 sequences segregated mainly according to disease manifestation, with most strains causing paralysis, including polioviruses, forming one clade, and strains causing respiratory illness forming another. There was no intermixing of types between these two clades, apart from two EV-C96 strains. The EV-B P3 sequences had lower inter-clade and higher intra-clade variability as compared to the EV-C sequences, which may explain why inter-clade recombinations are more frequent in EV-B. Further analysis of more isolates may shed light on the role of recombinations in the evolution of EV-B in geographical context. © 2014 Wiley Periodicals, Inc.

Identification of human chromosome 22 transcribed sequences with ORF expressed sequence tags

PubMed Central

de Souza, Sandro J.; Camargo, Anamaria A.; Briones, Marcelo R. S.; Costa, Fernando F.; Nagai, Maria Aparecida; Verjovski-Almeida, Sergio; Zago, Marco A.; Andrade, Luis Eduardo C.; Carrer, Helaine; El-Dorry, Hamza F. A.; Espreafico, Enilza M.; Habr-Gama, Angelita; Giannella-Neto, Daniel; Goldman, Gustavo H.; Gruber, Arthur; Hackel, Christine; Kimura, Edna T.; Maciel, Rui M. B.; Marie, Suely K. N.; Martins, Elizabeth A. L.; Nóbrega, Marina P.; Paçó-Larson, Maria Luisa; Pardini, Maria Inês M. C.; Pereira, Gonçalo G.; Pesquero, João Bosco; Rodrigues, Vanderlei; Rogatto, Silvia R.; da Silva, Ismael D. C. G.; Sogayar, Mari C.; de Fátima Sonati, Maria; Tajara, Eloiza H.; Valentini, Sandro R.; Acencio, Marcio; Alberto, Fernando L.; Amaral, Maria Elisabete J.; Aneas, Ivy; Bengtson, Mário Henrique; Carraro, Dirce M.; Carvalho, Alex F.; Carvalho, Lúcia Helena; Cerutti, Janete M.; Corrêa, Maria Lucia C.; Costa, Maria Cristina R.; Curcio, Cyntia; Gushiken, Tsieko; Ho, Paulo L.; Kimura, Elza; Leite, Luciana C. C.; Maia, Gustavo; Majumder, Paromita; Marins, Mozart; Matsukuma, Adriana; Melo, Analy S. A.; Mestriner, Carlos Alberto; Miracca, Elisabete C.; Miranda, Daniela C.; Nascimento, Ana Lucia T. O.; Nóbrega, Francisco G.; Ojopi, Élida P. B.; Pandolfi, José Rodrigo C.; Pessoa, Luciana Gilbert; Rahal, Paula; Rainho, Claudia A.; da Ro's, Nancy; de Sá, Renata G.; Sales, Magaly M.; da Silva, Neusa P.; Silva, Tereza C.; da Silva, Wilson; Simão, Daniel F.; Sousa, Josane F.; Stecconi, Daniella; Tsukumo, Fernando; Valente, Valéria; Zalcberg, Heloisa; Brentani, Ricardo R.; Reis, Luis F. L.; Dias-Neto, Emmanuel; Simpson, Andrew J. G.

2000-01-01

Transcribed sequences in the human genome can be identified with confidence only by alignment with sequences derived from cDNAs synthesized from naturally occurring mRNAs. We constructed a set of 250,000 cDNAs that represent partial expressed gene sequences and that are biased toward the central coding regions of the resulting transcripts. They are termed ORF expressed sequence tags (ORESTES). The 250,000 ORESTES were assembled into 81,429 contigs. Of these, 1,181 (1.45%) were found to match sequences in chromosome 22 with at least one ORESTES contig for 162 (65.6%) of the 247 known genes, for 67 (44.6%) of the 150 related genes, and for 45 of the 148 (30.4%) EST-predicted genes on this chromosome. Using a set of stringent criteria to validate our sequences, we identified a further 219 previously unannotated transcribed sequences on chromosome 22. Of these, 171 were in fact also defined by EST or full length cDNA sequences available in GenBank but not utilized in the initial annotation of the first human chromosome sequence. Thus despite representing less than 15% of all expressed human sequences in the public databases at the time of the present analysis, ORESTES sequences defined 48 transcribed sequences on chromosome 22 not defined by other sequences. All of the transcribed sequences defined by ORESTES coincided with DNA regions predicted as encoding exons by genscan. (http://genes.mit.edu/GENSCAN.html). PMID:11070084

East Asian mtDNA haplogroup determination in Koreans: haplogroup-level coding region SNP analysis and subhaplogroup-level control region sequence analysis.

PubMed

Lee, Hwan Young; Yoo, Ji-Eun; Park, Myung Jin; Chung, Ukhee; Kim, Chong-Youl; Shin, Kyoung-Jin

2006-11-01

The present study analyzed 21 coding region SNP markers and one deletion motif for the determination of East Asian mitochondrial DNA (mtDNA) haplogroups by designing three multiplex systems which apply single base extension methods. Using two multiplex systems, all 593 Korean mtDNAs were allocated into 15 haplogroups: M, D, D4, D5, G, M7, M8, M9, M10, M11, R, R9, B, A, and N9. As the D4 haplotypes occurred most frequently in Koreans, the third multiplex system was used to further define D4 subhaplogroups: D4a, D4b, D4e, D4g, D4h, and D4j. This method allowed the complementation of coding region information with control region mutation motifs and the resultant findings also suggest reliable control region mutation motifs for the assignment of East Asian mtDNA haplogroups. These three multiplex systems produce good results in degraded samples as they contain small PCR products (101-154 bp) for single base extension reactions. SNP scoring was performed in 101 old skeletal remains using these three systems to prove their utility in degraded samples. The sequence analysis of mtDNA control region with high incidence of haplogroup-specific mutations and the selective scoring of highly informative coding region SNPs using the three multiplex systems are useful tools for most applications involving East Asian mtDNA haplogroup determination and haplogroup-directed stringent quality control.

Phylogenetic analysis of feline immunodeficiency virus strains from naturally infected cats in Belgium and The Netherlands.

PubMed

Roukaerts, Inge D M; Theuns, Sebastiaan; Taffin, Elien R L; Daminet, Sylvie; Nauwynck, Hans J

2015-01-22

Feline immunodeficiency virus (FIV) is a major pathogen in feline populations worldwide, with seroprevalences up to 26%. Virus strains circulating in domestic cats are subdivided into different phylogenetic clades (A-E), based on the genetic diversity of the V3-V4 region of the env gene. In this report, a phylogenetic analysis of the V3-V4 env region, and a variable region in the gag gene was made for 36 FIV strains isolated in Belgium and The Netherlands. All newly generated gag sequences clustered together with previously known clade A FIV viruses, confirming the dominance of clade A viruses in Northern Europe. The same was true for the obtained env sequences, with only one sample of an unknown env subtype. Overall, the genetic diversity of FIV strains sequenced in this report was low. This indicates a relatively recent introduction of FIV in Belgium and The Netherlands. However, the sample with an unknown env subtype indicates that new introductions of FIV from unknown origin do occur and this will likely increase genetic variability in time. Copyright © 2014 Elsevier B.V. All rights reserved.

HBV Genotypic Variability in Cuba

PubMed Central

Loureiro, Carmen L.; Aguilar, Julio C.; Aguiar, Jorge; Muzio, Verena; Pentón, Eduardo; Garcia, Daymir; Guillen, Gerardo; Pujol, Flor H.

2015-01-01

The genetic diversity of HBV in human population is often a reflection of its genetic admixture. The aim of this study was to explore the genotypic diversity of HBV in Cuba. The S genomic region of Cuban HBV isolates was sequenced and for selected isolates the complete genome or precore-core sequence was analyzed. The most frequent genotype was A (167/250, 67%), mainly A2 (149, 60%) but also A1 and one A4. A total of 77 isolates were classified as genotype D (31%), with co-circulation of several subgenotypes (56 D4, 2 D1, 5 D2, 7 D3/6 and 7 D7). Three isolates belonged to genotype E, two to H and one to B3. Complete genome sequence analysis of selected isolates confirmed the phylogenetic analysis performed with the S region. Mutations or polymorphisms in precore region were more common among genotype D compared to genotype A isolates. The HBV genotypic distribution in this Caribbean island correlates with the Y lineage genetic background of the population, where a European and African origin prevails. HBV genotypes E, B3 and H isolates might represent more recent introductions. PMID:25742179

Testing the utility of matK and ITS DNA regions for discrimination of Allium species

USDA-ARS?s Scientific Manuscript database

Molecular phylogenetic analysis of the genus Allium L. has been mainly based on the nucleotide sequences of ITS region. In 2009 matK and rbcL were accepted as a two-locus DNA barcode to classify plant species by the Consortium for the Barcode of Life (CBOL) Plant Working Group. MatK region has been ...

GANESH: software for customized annotation of genome regions.

PubMed

Huntley, Derek; Hummerich, Holger; Smedley, Damian; Kittivoravitkul, Sasivimol; McCarthy, Mark; Little, Peter; Sergot, Marek

2003-09-01

GANESH is a software package designed to support the genetic analysis of regions of human and other genomes. It provides a set of components that may be assembled to construct a self-updating database of DNA sequence, mapping data, and annotations of possible genome features. Once one or more remote sources of data for the target region have been identified, all sequences for that region are downloaded, assimilated, and subjected to a (configurable) set of standard database-searching and genome-analysis packages. The results are stored in compressed form in a relational database, and are updated automatically on a regular schedule so that they are always immediately available in their most up-to-date versions. A Java front-end, executed as a stand alone application or web applet, provides a graphical interface for navigating the database and for viewing the annotations. There are facilities for importing and exporting data in the format of the Distributed Annotation System (DAS), enabling a GANESH database to be used as a component of a DAS configuration. The system has been used to construct databases for about a dozen regions of human chromosomes and for three regions of mouse chromosomes.

Sequencing of the amylopullulanase (apu) gene of Thermoanaerobacter ethanolicus 39E, and identification of the active site by site-directed mutagenesis.

PubMed

Mathupala, S P; Lowe, S E; Podkovyrov, S M; Zeikus, J G

1993-08-05

The complete nucleotide sequence of the gene encoding the dual active amylopullulanase of Thermoanaerobacter ethanolicus 39E (formerly Clostridium thermohydrosulfuricum) was determined. The structural gene (apu) contained a single open reading frame 4443 base pairs in length, corresponding to 1481 amino acids, with an estimated molecular weight of 162,780. Analysis of the deduced sequence of apu with sequences of alpha-amylases and alpha-1,6 debranching enzymes enabled the identification of four conserved regions putatively involved in substrate binding and in catalysis. The conserved regions were localized within a 2.9-kilobase pair gene fragment, which encoded a M(r) 100,000 protein that maintained the dual activities and thermostability of the native enzyme. The catalytic residues of amylopullulanase were tentatively identified by using hydrophobic cluster analysis for comparison of amino acid sequences of amylopullulanase and other amylolytic enzymes. Asp597, Glu626, and Asp703 were individually modified to their respective amide form, or the alternate acid form, and in all cases both alpha-amylase and pullulanase activities were lost, suggesting the possible involvement of 3 residues in a catalytic triad, and the presence of a putative single catalytic site within the enzyme. These findings substantiate amylopullulanase as a new type of amylosaccharidase.

The complete chloroplast genome sequence of strawberry (Fragaria  × ananassa Duch.) and comparison with related species of Rosaceae

PubMed Central

Cheng, Hui; Li, Jinfeng; Zhang, Hong; Cai, Binhua; Gao, Zhihong

2017-01-01

Compared with other members of the family Rosaceae, the chloroplast genomes of Fragaria species exhibit low variation, and this situation has limited phylogenetic analyses; thus, complete chloroplast genome sequencing of Fragaria species is needed. In this study, we sequenced the complete chloroplast genome of F. × ananassa ‘Benihoppe’ using the Illumina HiSeq 2500-PE150 platform and then performed a combination of de novo assembly and reference-guided mapping of contigs to generate complete chloroplast genome sequences. The chloroplast genome exhibits a typical quadripartite structure with a pair of inverted repeats (IRs, 25,936 bp) separated by large (LSC, 85,531 bp) and small (SSC, 18,146 bp) single-copy (SC) regions. The length of the F. × ananassa ‘Benihoppe’ chloroplast genome is 155,549 bp, representing the smallest Fragaria chloroplast genome observed to date. The genome encodes 112 unique genes, comprising 78 protein-coding genes, 30 tRNA genes and four rRNA genes. Comparative analysis of the overall nucleotide sequence identity among ten complete chloroplast genomes confirmed that for both coding and non-coding regions in Rosaceae, SC regions exhibit higher sequence variation than IRs. The Ka/Ks ratio of most genes was less than 1, suggesting that most genes are under purifying selection. Moreover, the mVISTA results also showed a high degree of conservation in genome structure, gene order and gene content in Fragaria, particularly among three octoploid strawberries which were F. × ananassa ‘Benihoppe’, F. chiloensis (GP33) and F. virginiana (O477). However, when the sequences of the coding and non-coding regions of F. × ananassa ‘Benihoppe’ were compared in detail with those of F. chiloensis (GP33) and F. virginiana (O477), a number of SNPs and InDels were revealed by MEGA 7. Six non-coding regions (trnK-matK, trnS-trnG, atpF-atpH, trnC-petN, trnT-psbD and trnP-psaJ) with a percentage of variable sites greater than 1% and no less than five parsimony-informative sites were identified and may be useful for phylogenetic analysis of the genus Fragaria. PMID:29038765

Genetic analysis of the agrocinopine catabolic region of Agrobacterium tumefaciens Ti plasmid pTiC58, which encodes genes required for opine and agrocin 84 transport.

PubMed Central

Hayman, G T; Beck von Bodman, S; Kim, H; Jiang, P; Farrand, S K

1993-01-01

The acc region, subcloned from pTiC58 of classical nopaline and agrocinopine A and B Agrobacterium tumefaciens C58, allowed agrobacteria to grow using agrocinopine B as the sole source of carbon and energy. acc is approximately 6 kb in size. It consists of at least five genes, accA through accE, as defined by complementation analysis using subcloned fragments and transposon insertion mutations of acc carried on different plasmids within the same cell. All five regions are required for agrocin 84 sensitivity, and at least four are required for agrocinopine and agrocin 84 uptake. The complementation results are consistent with the hypothesis that each of the five regions is separately transcribed. Maxicell experiments showed that the first of these genes, accA, encodes a 60-kDa protein. Analysis of osmotic shock fractions showed this protein to be located in the periplasm. The DNA sequence of the accA region revealed an open reading frame encoding a predicted polypeptide of 59,147 Da. The amino acid sequence encoded by this open reading frame is similar to the periplasmic binding proteins OppA and DppA of Escherichia coli and Salmonella typhimurium and OppA of Bacillus subtilis. Images PMID:8366042

Optimal packaging of FIV genomic RNA depends upon a conserved long-range interaction and a palindromic sequence within gag.

PubMed

Rizvi, Tahir A; Kenyon, Julia C; Ali, Jahabar; Aktar, Suriya J; Phillip, Pretty S; Ghazawi, Akela; Mustafa, Farah; Lever, Andrew M L

2010-10-15

The feline immunodeficiency virus (FIV) is a lentivirus that is related to human immunodeficiency virus (HIV), causing a similar pathology in cats. It is a potential small animal model for AIDS and the FIV-based vectors are also being pursued for human gene therapy. Previous studies have mapped the FIV packaging signal (ψ) to two or more discontinuous regions within the 5' 511 nt of the genomic RNA and structural analyses have determined its secondary structure. The 5' and 3' sequences within ψ region interact through extensive long-range interactions (LRIs), including a conserved heptanucleotide interaction between R/U5 and gag. Other secondary structural elements identified include a conserved 150 nt stem-loop (SL2) and a small palindromic stem-loop within gag open reading frame that might act as a viral dimerization initiation site. We have performed extensive mutational analysis of these sequences and structures and ascertained their importance in FIV packaging using a trans-complementation assay. Disrupting the conserved heptanucleotide LRI to prevent base pairing between R/U5 and gag reduced packaging by 2.8-5.5 fold. Restoration of pairing using an alternative, non-wild type (wt) LRI sequence restored RNA packaging and propagation to wt levels, suggesting that it is the structure of the LRI, rather than its sequence, that is important for FIV packaging. Disrupting the palindrome within gag reduced packaging by 1.5-3-fold, but substitution with a different palindromic sequence did not restore packaging completely, suggesting that the sequence of this region as well as its palindromic nature is important. Mutation of individual regions of SL2 did not have a pronounced effect on FIV packaging, suggesting that either it is the structure of SL2 as a whole that is necessary for optimal packaging, or that there is redundancy within this structure. The mutational analysis presented here has further validated the previously predicted RNA secondary structure of FIV ψ. Copyright © 2010 Elsevier Ltd. All rights reserved.

PCR detection and DNA sequence analysis of the regulatory region of lymphotropic papovavirus in peripheral blood mononuclear cells of an immunocompromised rhesus macaque

NASA Technical Reports Server (NTRS)

Lednicky, John A.; Halvorson, Steven J.; Butel, Janet S.

2002-01-01

A lymphotropic papovavirus (LPV) archetypal regulatory region was amplified from DNA from the blood of an immunocompromised rhesus monkey. We believe this is the first nonserological evidence of LPV infection in rhesus monkeys.

Complete nucleotide sequence of Alfalfa mosaic virus isolated from alfalfa (Medicago sativa L.) in Argentina.

PubMed

Trucco, Verónica; de Breuil, Soledad; Bejerman, Nicolás; Lenardon, Sergio; Giolitti, Fabián

2014-06-01

The complete nucleotide sequence of an Alfalfa mosaic virus (AMV) isolate infecting alfalfa (Medicago sativa L.) in Argentina, AMV-Arg, was determined. The virus genome has the typical organization described for AMV, and comprises 3,643, 2,593, and 2,038 nucleotides for RNA1, 2 and 3, respectively. The whole genome sequence and each encoding region were compared with those of other four isolates that have been completely sequenced from China, Italy, Spain and USA. The nucleotide identity percentages ranged from 95.9 to 99.1 % for the three RNAs and from 93.7 to 99 % for the protein 1 (P1), protein 2 (P2), movement protein and coat protein (CP) encoding regions, whereas the amino acid identity percentages of these proteins ranged from 93.4 to 99.5 %, the lowest value corresponding to P2. CP sequences of AMV-Arg were compared with those of other 25 available isolates, and the phylogenetic analysis based on the CP gene was carried out. The highest percentage of nucleotide sequence identity of the CP gene was 98.3 % with a Chinese isolate and 98.6 % at the amino acid level with four isolates, two from Italy, one from Brazil and the remaining one from China. The phylogenetic analysis showed that AMV-Arg is closely related to subgroup I of AMV isolates. To our knowledge, this is the first report of a complete nucleotide sequence of AMV from South America and the first worldwide report of complete nucleotide sequence of AMV isolated from alfalfa as natural host.

[Analysis of COX1 sequences of Taenia isolates from four areas of Guangxi].

PubMed

Yang, Yi-Chao; Ou-Yang, Yi; Su, Ai-Rong; Wan, Xiao-Ling; Li, Shu-Lin

2012-06-01

To analyze the COX1 sequences of Taenia isolates from four areas of Guangxi Zhuang Autonomous Region, and to understand the distribution of Taenia asiatica in Guangxi. Patients with taeniasis in Luzhai, Rongshui, Tiandong and Sanjiang in Guangxi were treated by deworming, and the Taenia isolates were collected. Cyclooxygenase-1 (COX1) sequences of these isolates were amplified by PCR, and the PCR products were sequenced by T-A clone sequencing. The homogeneities and genetic distances were calculated and analyzed, and the phylogenic trees were constructed by some softwares. Meanwhile, the COX1 sequences of the isolates from the 4 areas were compared separately with the sequences of Taenia species in GenBank. The COX1 sequence of the 5 Taenia isolates collected had the same length of 444 bp. There were 5 variable positions between the Luzhai isolate and Taenia asiatica, the homogeneity was 98.87% and their genetic distance was 0.011. The phylogenetic tree analysis revealed that the Luzhai isolate and Taenia asiatica locating at the same node had a close relationship. The homogeneity between Rongshui isolate A and Taenia solium was 100%, while the homogeneity of Rongshui isolate B with Taeniasis saginata and Taenia asiatica were 98.20% and 96.17%, respectively. The homogeneities of the Tiandong and Sanjiang isolates with Taenia solium were 99.55% and 96.40%, respectively, and the genetic distances were 0.005 and 0.037, respectively. The homogeneity between the Luzhai isolate and Taeniasis saginate was 96.40%. Taenia asiatica exists in Luzhai and Taenia solium and Taenia saginata coexist in Rongshui, Guangxi Zhuang Autonomous Region.

Direct repeat sequences in the Streptomyces chitinase-63 promoter direct both glucose repression and chitin induction

PubMed Central

Ni, Xiangyang; Westpheling, Janet

1997-01-01

The chi63 promoter directs glucose-sensitive, chitin-dependent transcription of a gene involved in the utilization of chitin as carbon source. Analysis of 5′ and 3′ deletions of the promoter region revealed that a 350-bp segment is sufficient for wild-type levels of expression and regulation. The analysis of single base changes throughout the promoter region, introduced by random and site-directed mutagenesis, identified several sequences to be important for activity and regulation. Single base changes at −10, −12, −32, −33, −35, and −37 upstream of the transcription start site resulted in loss of activity from the promoter, suggesting that bases in these positions are important for RNA polymerase interaction. The sequences centered around −10 (TATTCT) and −35 (TTGACC) in this promoter are, in fact, prototypical of eubacterial promoters. Overlapping the RNA polymerase binding site is a perfect 12-bp direct repeat sequence. Some base changes within this direct repeat resulted in constitutive expression, suggesting that this sequence is an operator for negative regulation. Other base changes resulted in loss of glucose repression while retaining the requirement for chitin induction, suggesting that this sequence is also involved in glucose repression. The fact that cis-acting mutations resulted in glucose resistance but not inducer independence rules out the possibility that glucose repression acts exclusively by inducer exclusion. The fact that mutations that affect glucose repression and chitin induction fall within the same direct repeat sequence module suggests that the direct repeat sequence facilitates both chitin induction and glucose repression. PMID:9371809

The complete genome structure and phylogenetic relationship of infectious hematopoietic necrosis virus

USGS Publications Warehouse

Morzunov , Sergey P.; Winton, James R.; Nichol, Stuart T.

1995-01-01

Infectious hematopoietic necrosis virus (IHNV), a member of the family Rhabdoviridae, causes a severe disease with high mortality in salmonid fish. The nucleotide sequence (11, 131 bases) of the entire genome was determined for the pathogenic WRAC strain of IHNV from southern Idaho. This allowed detailed analysis of all 6 genes, the deduced amino acid sequences of their encoded proteins, and important control motifs including leader, trailer and gene junction regions. Sequence analysis revealed that the 6 virus genes are located along the genome in the 3′ to 5′ order: nucleocapsid (N), polymerase-associated phosphoprotein (P or M1), matrix protein (M or M2), surface glycoprotein (G), a unique non-virion protein (NV) and virus polymerase (L). The IHNV genome RNA was found to have highly complementary termini (15 of 16 nucleotides). The gene junction regions display the highly conserved sequence UCURUC(U)7RCCGUG(N)4CACR (in the vRNA sense), which includes the typical rhabdovirus transcription termination/polyadenylation signal and a novel putative transcription initiation signal. Phylogenetic analysis of M, G and L protein sequences allowed insights into the evolutionary and taxonomic relationship of rhabdoviruses of fish relative to those of insects or mammals, and a broader sense of the relationship of non-segmented negative-strand RNA viruses. Based on these data, a new genus, piscivirus, is proposed which will initially contain IHNV, viral hemorrhagic septicemia virus and Hirame rhabdovirus.

Infectious hematopoietic necrosis virus: Monophyletic origin of European isolates from North American Genogroup M

USGS Publications Warehouse

Enzmann, P.-J.; Kurath, G.; Fichtner, D.; Bergmann, S.M.

2005-01-01

Infectious hematopoietic necrosis virus (IHNV) was first detected in Europe in 1987 in France and Italy, and later, in 1992, in Germany. The source of the virus and the route of introduction are unknown. The present study investigates the molecular epidemiology of IHNV outbreaks in Germany since its first introduction. The complete nucleotide sequences of the glycoprotein (G) and non-virion (NV) genes from 9 IHNV isolates from Germany have been determined, and this has allowed the identification of characteristic differences between these isolates. Phylogenetic analysis of partial G gene sequences (mid-G, 303 nucleotides) from North American IHNV isolates (Kurath et al. 2003) has revealed 3 major genogroups, designated U, M and L. Using this gene region with 2 different North American IHNV data sets, it was possible to group the European IHNV strains within the M genogroup, but not in any previously defined subgroup. Analysis of the full length G gene sequences indicated that an independent evolution of IHN viruses had occurred in Europe. IHN viruses in Europe seem to be of a monophyletic origin, again most closely related to North American isolates in the M genogroup. Analysis of the NV gene sequences also showed the European isolates to be monophyletic, but resolution of the 3 genogroups was poor with this gene region. As a result of comparative sequence analyses, several different genotypes have been identified circulating in Europe. ?? Inter-Research 2005.

Comparison and correlation of Simple Sequence Repeats distribution in genomes of Brucella species

PubMed Central

Kiran, Jangampalli Adi Pradeep; Chakravarthi, Veeraraghavulu Praveen; Kumar, Yellapu Nanda; Rekha, Somesula Swapna; Kruti, Srinivasan Shanthi; Bhaskar, Matcha

2011-01-01

Computational genomics is one of the important tools to understand the distribution of closely related genomes including simple sequence repeats (SSRs) in an organism, which gives valuable information regarding genetic variations. The central objective of the present study was to screen the SSRs distributed in coding and non-coding regions among different human Brucella species which are involved in a range of pathological disorders. Computational analysis of the SSRs in the Brucella indicates few deviations from expected random models. Statistical analysis also reveals that tri-nucleotide SSRs are overrepresented and tetranucleotide SSRs underrepresented in Brucella genomes. From the data, it can be suggested that over expressed tri-nucleotide SSRs in genomic and coding regions might be responsible in the generation of functional variation of proteins expressed which in turn may lead to different pathogenicity, virulence determinants, stress response genes, transcription regulators and host adaptation proteins of Brucella genomes. Abbreviations SSRs - Simple Sequence Repeats, ORFs - Open Reading Frames. PMID:21738309

Sequencing and functional analysis of the nifENXorf1orf2 gene cluster of Herbaspirillum seropedicae.

PubMed

Klassen, G; Pedrosa, F O; Souza, E M; Yates, M G; Rigo, L U

1999-12-01

A 5.1-kb DNA fragment from the nifHDK region of H. seropedicae was isolated and sequenced. Sequence analysis showed the presence of nifENXorf1orf2 but nifTY were not present. No nif or consensus promoter was identified. Furthermore, orf1 expression occurred only under nitrogen-fixing conditions and no promoter activity was detected between nifK and nifE, suggesting that these genes are expressed from the upstream nifH promoter and are parts of a unique nif operon. Mutagenesis studies indicate that nifN was essential for nitrogenase activity whereas nifXorf1orf2 were not. High homology between the C-terminal region of the NifX and NifB proteins from H. seropedicae was observed. Since the NifX and NifY proteins are important for FeMo cofactor (FeMoco) synthesis, we propose that alternative proteins with similar activities exist in H. seropedicae.

Remarkable sequence conservation of the last intron in the PKD1 gene.

PubMed

Rodova, Marianna; Islam, M Rafiq; Peterson, Kenneth R; Calvet, James P

2003-10-01

The last intron of the PKD1 gene (intron 45) was found to have exceptionally high sequence conservation across four mammalian species: human, mouse, rat, and dog. This conservation did not extend to the comparable intron in pufferfish. Pairwise comparisons for intron 45 showed 91% identity (human vs. dog) to 100% identity (mouse vs. rat) for an average for all four species of 94% identity. In contrast, introns 43 and 44 of the PKD1 gene had average pairwise identities of 57% and 54%, and exons 43, 44, and 45 and the coding region of exon 46 had average pairwise identities of 80%, 84%, 82%, and 80%. Intron 45 is 90 to 95 bp in length, with the major region of sequence divergence being in a central 4-bp to 9-bp variable region. RNA secondary structure analysis of intron 45 predicts a branching stem-loop structure in which the central variable region lies in one loop and the putative branch point sequence lies in another loop, suggesting that the intron adopts a specific stem-loop structure that may be important for its removal. Although intron 45 appears to conform to the class of small, G-triplet-containing introns that are spliced by a mechanism utilizing intron definition, its high sequence conservation may be a reflection of constraints imposed by a unique mechanism that coordinates splicing of this last PKD1 intron with polyadenylation.

The internal transcribed spacer of ribosomal RNA genes in plant trypanosomes (Phytomonas spp.) resolves 10 groups.

PubMed

Dollet, Michel; Sturm, Nancy R; Campbell, David A

2012-03-01

The distinction between plant trypanosomatids and opportunistic monoxenous insect trypanosomatids has not been demarcated clearly due to the mass placement of all trypanosomatids isolated from plants into the arbitrary genus Phytomonas spp. The advent of molecular markers has been useful in distinguishing plant trypanosomatids from the rest of the Trypanosomatidae family. Here we have examined the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) locus for classification purposes. This region contains two distinct ITSs flanked by the small subunit and large subunit of ribosomal RNA genes and separated by the 5.8S ribosomal RNA gene. Sequences within the 5.8S ribosomal RNA gene and in the ITS sequences can serve as specific markers for several of the Phytomonas groups. Microsatellite sequences were identified in Phytomonas spp. in both ITS regions. Several classes of microsatellites were seen, with inter-isolate variation that has potential for future use. Maximum Likelihood analysis of the ITS sequences of 20 Phytomonas isolates representing the eight defined groups and a few unclassified isolates revealed a total of 10 distinct subgroups within our collection, of which two are new. The ITS region, which includes the 5.8S sequence, is a robust marker for the subdivisions within the genus Phytomonas spp. Copyright © 2011 Elsevier B.V. All rights reserved.

Simple Sequence Repeats in Escherichia coli: Abundance, Distribution, Composition, and Polymorphism

PubMed Central

Gur-Arie, Riva; Cohen, Cyril J.; Eitan, Yuval; Shelef, Leora; Hallerman, Eric M.; Kashi, Yechezkel

2000-01-01

Computer-based genome-wide screening of the DNA sequence of Escherichia coli strain K12 revealed tens of thousands of tandem simple sequence repeat (SSR) tracts, with motifs ranging from 1 to 6 nucleotides. SSRs were well distributed throughout the genome. Mononucleotide SSRs were over-represented in noncoding regions and under-represented in open reading frames (ORFs). Nucleotide composition of mono- and dinucleotide SSRs, both in ORFs and in noncoding regions, differed from that of the genomic region in which they occurred, with 93% of all mononucleotide SSRs proving to be of A or T. Computer-based analysis of the fine position of every SSR locus in the noncoding portion of the genome relative to downstream ORFs showed SSRs located in areas that could affect gene regulation. DNA sequences at 14 arbitrarily chosen SSR tracts were compared among E. coli strains. Polymorphisms of SSR copy number were observed at four of seven mononucleotide SSR tracts screened, with all polymorphisms occurring in noncoding regions. SSR polymorphism could prove important as a genome-wide source of variation, both for practical applications (including rapid detection, strain identification, and detection of loci affecting key phenotypes) and for evolutionary adaptation of microbes.[The sequence data described in this paper have been submitted to the GenBank data library under accession numbers AF209020–209030 and AF209508–209518.] PMID:10645951

Detection of a novel herpesvirus from bats in the Philippines.

PubMed

Sano, Kaori; Okazaki, Sachiko; Taniguchi, Satoshi; Masangkay, Joseph S; Puentespina, Roberto; Eres, Eduardo; Cosico, Edison; Quibod, Niña; Kondo, Taisuke; Shimoda, Hiroshi; Hatta, Yuuki; Mitomo, Shumpei; Oba, Mami; Katayama, Yukie; Sassa, Yukiko; Furuya, Tetsuya; Nagai, Makoto; Une, Yumi; Maeda, Ken; Kyuwa, Shigeru; Yoshikawa, Yasuhiro; Akashi, Hiroomi; Omatsu, Tsutomu; Mizutani, Tetsuya

2015-08-01

Bats are natural hosts of many zoonotic viruses. Monitoring bat viruses is important to detect novel bat-borne infectious diseases. In this study, next generation sequencing techniques and conventional PCR were used to analyze intestine, lung, and blood clot samples collected from wild bats captured at three locations in Davao region, in the Philippines in 2012. Different viral genes belonging to the Retroviridae and Herpesviridae families were identified using next generation sequencing. The existence of herpesvirus in the samples was confirmed by PCR using herpesvirus consensus primers. The nucleotide sequences of the resulting PCR amplicons were 166-bp. Further phylogenetic analysis identified that the virus from which this nucleotide sequence was obtained belonged to the Gammaherpesvirinae subfamily. PCR using primers specific to the nucleotide sequence obtained revealed that the infection rate among the captured bats was 30 %. In this study, we present the partial genome of a novel gammaherpesvirus detected from wild bats. Our observations also indicate that this herpesvirus may be widely distributed in bat populations in Davao region.

The rDNA ITS region in the lessepsian marine angiosperm Halophila stipulacea (Forssk.) Aschers. (Hydrocharitaceae): intragenomic variability and putative pseudogenic sequences.

PubMed

Ruggiero, Maria Valeria; Procaccini, Gabriele

2004-01-01

Halophila stipulacea is a dioecious marine angiosperm, widely distributed along the western coasts of the Indian Ocean and the Red Sea. This species is thought to be a Lessepsian immigrant that entered the Mediterranean Sea from the Red Sea after the opening of the Suez Canal (1869). Previous studies have revealed both high phenotypic and genetic variability in Halophila stipulacea populations from the western Mediterranean basin. In order to test the hypothesis of a Lessepsian introduction, we compare genetic polymorphism between putative native (Red Sea) and introduced (Mediterranean) populations through rDNA ITS region (ITS1-5.8S-ITS2) sequence analysis. A high degree of intraindividual variability of ITS sequences was found. Most of the intragenomic polymorphism was due to pseudogenic sequences, present in almost all individuals. Features of ITS functional sequences and pseudogenes are described. Possible causes for the lack of homogenization of ITS paralogues within individuals are discussed.

Molecular characterization of the canine mitochondrial DNA control region for forensic applications.

PubMed

Eichmann, Cordula; Parson, Walther

2007-09-01

The canine mitochondrial DNA (mtDNA) control region of 133 dogs living in the area around Innsbruck, Austria was sequenced. A total of 40 polymorphic sites were observed in the first hypervariable segment and 15 in the second, which resulted in the differentiation of 40 distinct haplotypes. We observed five nucleotide positions that were highly polymorphic within different haplogroups, and they represent good candidates for mtDNA screening. We found five point heteroplasmic positions; all located in HVS-I and a polythymine region in HVS-II, the latter often being associated with length heteroplasmy. In contrast to human mtDNA, the canine control region contains a hypervariable 10 nucleotide repeat region, which is located between the two hypervariable regions. In our population sample, we observed eight different repeat types, which we characterized by direct sequencing and fragment length analysis. The discrimination power of the canine mtDNA control region was 0.93, not taking the polymorphic repeat region into consideration.

RNAcode: Robust discrimination of coding and noncoding regions in comparative sequence data

PubMed Central

Washietl, Stefan; Findeiß, Sven; Müller, Stephan A.; Kalkhof, Stefan; von Bergen, Martin; Hofacker, Ivo L.; Stadler, Peter F.; Goldman, Nick

2011-01-01

With the availability of genome-wide transcription data and massive comparative sequencing, the discrimination of coding from noncoding RNAs and the assessment of coding potential in evolutionarily conserved regions arose as a core analysis task. Here we present RNAcode, a program to detect coding regions in multiple sequence alignments that is optimized for emerging applications not covered by current protein gene-finding software. Our algorithm combines information from nucleotide substitution and gap patterns in a unified framework and also deals with real-life issues such as alignment and sequencing errors. It uses an explicit statistical model with no machine learning component and can therefore be applied “out of the box,” without any training, to data from all domains of life. We describe the RNAcode method and apply it in combination with mass spectrometry experiments to predict and confirm seven novel short peptides in Escherichia coli and to analyze the coding potential of RNAs previously annotated as “noncoding.” RNAcode is open source software and available for all major platforms at http://wash.github.com/rnacode. PMID:21357752

Comprehensive Virus Detection Using Next Generation Sequencing in Grapevine Vascular Tissues of Plants Obtained from the Wine Regions of Bohemia and Moravia (Czech Republic)

PubMed Central

2016-01-01

Comprehensive next generation sequencing virus detection was used to detect the whole spectrum of viruses and viroids in selected grapevines from the Czech Republic. The novel NGS approach was based on sequencing libraries of small RNA isolated from grapevine vascular tissues. Eight previously partially-characterized grapevines of diverse varieties were selected and subjected to analysis: Chardonnay, Laurot, Guzal Kara, and rootstock Kober 125AA from the Moravia wine-producing region; plus Müller-Thurgau and Pinot Noir from the Bohemia wine-producing region, both in the Czech Republic. Using next generation sequencing of small RNA, the presence of 8 viruses and 2 viroids were detected in a set of eight grapevines; therefore, confirming the high effectiveness of the technique in plant virology and producing results supporting previous data on multiple infected grapevines in Czech vineyards. Among the pathogens detected, the Grapevine rupestris vein feathering virus and Grapevine yellow speckle viroid 1 were recorded in the Czech Republic for the first time. PMID:27959951

RNAcode: robust discrimination of coding and noncoding regions in comparative sequence data.

PubMed

Washietl, Stefan; Findeiss, Sven; Müller, Stephan A; Kalkhof, Stefan; von Bergen, Martin; Hofacker, Ivo L; Stadler, Peter F; Goldman, Nick

2011-04-01

With the availability of genome-wide transcription data and massive comparative sequencing, the discrimination of coding from noncoding RNAs and the assessment of coding potential in evolutionarily conserved regions arose as a core analysis task. Here we present RNAcode, a program to detect coding regions in multiple sequence alignments that is optimized for emerging applications not covered by current protein gene-finding software. Our algorithm combines information from nucleotide substitution and gap patterns in a unified framework and also deals with real-life issues such as alignment and sequencing errors. It uses an explicit statistical model with no machine learning component and can therefore be applied "out of the box," without any training, to data from all domains of life. We describe the RNAcode method and apply it in combination with mass spectrometry experiments to predict and confirm seven novel short peptides in Escherichia coli and to analyze the coding potential of RNAs previously annotated as "noncoding." RNAcode is open source software and available for all major platforms at http://wash.github.com/rnacode.

Comparative In silico Study of Sex-Determining Region Y (SRY) Protein Sequences Involved in Sex-Determining.

PubMed

Vakili Azghandi, Masoume; Nasiri, Mohammadreza; Shamsa, Ali; Jalali, Mohsen; Shariati, Mohammad Mahdi

2016-04-01

The SRY gene (SRY) provides instructions for making a transcription factor called the sex-determining region Y protein. The sex-determining region Y protein causes a fetus to develop as a male. In this study, SRY of 15 spices included of human, chimpanzee, dog, pig, rat, cattle, buffalo, goat, sheep, horse, zebra, frog, urial, dolphin and killer whale were used for determine of bioinformatic differences. Nucleotide sequences of SRY were retrieved from the NCBI databank. Bioinformatic analysis of SRY is done by CLC Main Workbench version 5.5 and ClustalW (http:/www.ebi.ac.uk/clustalw/) and MEGA6 softwares. The multiple sequence alignment results indicated that SRY protein sequences from Orcinus orca (killer whale) and Tursiopsaduncus (dolphin) have least genetic distance of 0.33 in these 15 species and are 99.67% identical at the amino acid level. Homosapiens and Pantroglodytes (chimpanzee) have the next lowest genetic distance of 1.35 and are 98.65% identical at the amino acid level. These findings indicate that the SRY proteins are conserved in the 15 species, and their evolutionary relationships are similar.

Comprehensive Virus Detection Using Next Generation Sequencing in Grapevine Vascular Tissues of Plants Obtained from the Wine Regions of Bohemia and Moravia (Czech Republic).

PubMed

Eichmeier, Aleš; Komínková, Marcela; Komínek, Petr; Baránek, Miroslav

2016-01-01

Comprehensive next generation sequencing virus detection was used to detect the whole spectrum of viruses and viroids in selected grapevines from the Czech Republic. The novel NGS approach was based on sequencing libraries of small RNA isolated from grapevine vascular tissues. Eight previously partially-characterized grapevines of diverse varieties were selected and subjected to analysis: Chardonnay, Laurot, Guzal Kara, and rootstock Kober 125AA from the Moravia wine-producing region; plus Müller-Thurgau and Pinot Noir from the Bohemia wine-producing region, both in the Czech Republic. Using next generation sequencing of small RNA, the presence of 8 viruses and 2 viroids were detected in a set of eight grapevines; therefore, confirming the high effectiveness of the technique in plant virology and producing results supporting previous data on multiple infected grapevines in Czech vineyards. Among the pathogens detected, the Grapevine rupestris vein feathering virus and Grapevine yellow speckle viroid 1 were recorded in the Czech Republic for the first time.

Genetic Characterization of Circulating African Swine Fever Viruses in Nigeria (2007-2015).

PubMed

Luka, P D; Achenbach, J E; Mwiine, F N; Lamien, C E; Shamaki, D; Unger, H; Erume, J

2017-10-01

Sequencing and analysis of three discrete genome regions of African swine fever viruses (ASFV) from archival samples collected in 2007-2011 and active and passive surveillance between 2012 and 2015 in Nigeria were carried out. Analysis was conducted by genotyping of three single-copy African swine fever (ASF) genes. The E183L and B646L genes that encode structural proteins p54 and p72, respectively, were utilized to delineate genotypes before intragenotypic resolution by characterization of the tetrameric amino acid repeat region within the hypervariable central variable region of the B602L gene. The results showed no variation in the p72 and p54 gene regions sequenced. Phylogeny of p72 sequences revealed that all the Nigerian isolates belonged to genotype I, while that of the p54 recovered the Ia genotype. Analysis of B602L gene revealed the differences in the number of tetrameric repeats. Four new variants (Tet-15, Tet-17a, Tet-17b and Tet-48) were recovered, while a fifth variant (Tet-20) was the most widely distributed in the country displacing Tet-36 reported previously in 2003-2006. The viruses responsible for ASF outbreaks in Nigeria are from very closely related but mutated variants of the virus that have been circulating since 1997. A practical implication of the genetic variability of the Nigerian viral isolates in this study is the need for continuous sampling and analysis of circulating viruses, which will provide epidemiological information on the evolution of ASFV in the field versus new incursion for informed strategic control of the disease in the country. © 2016 Blackwell Verlag GmbH.

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

Kurilla, M.G.; Stone, H.O.; Keene, J.D.

The 3' end of the genomic RNA of Newcastle disease virus (NDV) has been sequenced and the leader RNA defined. Using hybridization to a 3'-end-labeled genome, leader RNA species from in vitro transcription reactions and from infected cell extracts were found to be 47 and 53 nucleotides long. In addition, the start site of the 3'-proximal mRNA was determined by sequence analysis of in vitro (beta-32P)GTP-labeled transcription products. The genomic sequence extending beyond the leader region demonstrated an open reading frame for at least 42 amino acids and probably represents the amino terminus of the nucleocapsid protein (NP). The terminalmore » 8 nucleotides of the NDV genome were identical to those of measles virus and Sendai virus while the sequence of the distal half of the leader region was more similar to that of vesicular stomatitis virus. These data argue for strong evolutionary relatedness between the paramyxovirus and rhabdovirus groups.« less

Using RSAT to scan genome sequences for transcription factor binding sites and cis-regulatory modules.

PubMed

Turatsinze, Jean-Valery; Thomas-Chollier, Morgane; Defrance, Matthieu; van Helden, Jacques

2008-01-01

This protocol shows how to detect putative cis-regulatory elements and regions enriched in such elements with the regulatory sequence analysis tools (RSAT) web server (http://rsat.ulb.ac.be/rsat/). The approach applies to known transcription factors, whose binding specificity is represented by position-specific scoring matrices, using the program matrix-scan. The detection of individual binding sites is known to return many false predictions. However, results can be strongly improved by estimating P value, and by searching for combinations of sites (homotypic and heterotypic models). We illustrate the detection of sites and enriched regions with a study case, the upstream sequence of the Drosophila melanogaster gene even-skipped. This protocol is also tested on random control sequences to evaluate the reliability of the predictions. Each task requires a few minutes of computation time on the server. The complete protocol can be executed in about one hour.

Computational tools for copy number variation (CNV) detection using next-generation sequencing data: features and perspectives.

PubMed

Zhao, Min; Wang, Qingguo; Wang, Quan; Jia, Peilin; Zhao, Zhongming

2013-01-01

Copy number variation (CNV) is a prevalent form of critical genetic variation that leads to an abnormal number of copies of large genomic regions in a cell. Microarray-based comparative genome hybridization (arrayCGH) or genotyping arrays have been standard technologies to detect large regions subject to copy number changes in genomes until most recently high-resolution sequence data can be analyzed by next-generation sequencing (NGS). During the last several years, NGS-based analysis has been widely applied to identify CNVs in both healthy and diseased individuals. Correspondingly, the strong demand for NGS-based CNV analyses has fuelled development of numerous computational methods and tools for CNV detection. In this article, we review the recent advances in computational methods pertaining to CNV detection using whole genome and whole exome sequencing data. Additionally, we discuss their strengths and weaknesses and suggest directions for future development.

Computational tools for copy number variation (CNV) detection using next-generation sequencing data: features and perspectives

PubMed Central

2013-01-01

Copy number variation (CNV) is a prevalent form of critical genetic variation that leads to an abnormal number of copies of large genomic regions in a cell. Microarray-based comparative genome hybridization (arrayCGH) or genotyping arrays have been standard technologies to detect large regions subject to copy number changes in genomes until most recently high-resolution sequence data can be analyzed by next-generation sequencing (NGS). During the last several years, NGS-based analysis has been widely applied to identify CNVs in both healthy and diseased individuals. Correspondingly, the strong demand for NGS-based CNV analyses has fuelled development of numerous computational methods and tools for CNV detection. In this article, we review the recent advances in computational methods pertaining to CNV detection using whole genome and whole exome sequencing data. Additionally, we discuss their strengths and weaknesses and suggest directions for future development. PMID:24564169

Two‐phase designs for joint quantitative‐trait‐dependent and genotype‐dependent sampling in post‐GWAS regional sequencing

PubMed Central

Espin‐Garcia, Osvaldo; Craiu, Radu V.

2017-01-01

ABSTRACT We evaluate two‐phase designs to follow‐up findings from genome‐wide association study (GWAS) when the cost of regional sequencing in the entire cohort is prohibitive. We develop novel expectation‐maximization‐based inference under a semiparametric maximum likelihood formulation tailored for post‐GWAS inference. A GWAS‐SNP (where SNP is single nucleotide polymorphism) serves as a surrogate covariate in inferring association between a sequence variant and a normally distributed quantitative trait (QT). We assess test validity and quantify efficiency and power of joint QT‐SNP‐dependent sampling and analysis under alternative sample allocations by simulations. Joint allocation balanced on SNP genotype and extreme‐QT strata yields significant power improvements compared to marginal QT‐ or SNP‐based allocations. We illustrate the proposed method and evaluate the sensitivity of sample allocation to sampling variation using data from a sequencing study of systolic blood pressure. PMID:29239496

A Physical Map, Including a BAC/PAC Clone Contig, of the Williams-Beuren Syndrome–Deletion Region at 7q11.23

PubMed Central

Peoples, Risa; Franke, Yvonne; Wang, Yu-Ker; Pérez-Jurado, Luis; Paperna, Tamar; Cisco, Michael; Francke, Uta

2000-01-01

Summary Williams-Beuren syndrome (WBS) is a developmental disorder caused by haploinsufficiency for genes in a 2-cM region of chromosome band 7q11.23. With the exception of vascular stenoses due to deletion of the elastin gene, the various features of WBS have not yet been attributed to specific genes. Although ⩾16 genes have been identified within the WBS deletion, completion of a physical map of the region has been difficult because of the large duplicated regions flanking the deletion. We present a physical map of the WBS deletion and flanking regions, based on assembly of a bacterial artificial chromosome/P1-derived artificial chromosome contig, analysis of high-throughput genome-sequence data, and long-range restriction mapping of genomic and cloned DNA by pulsed-field gel electrophoresis. Our map encompasses 3 Mb, including 1.6 Mb within the deletion. Two large duplicons, flanking the deletion, of ⩾320 kb contain unique sequence elements from the internal border regions of the deletion, such as sequences from GTF2I (telomeric) and FKBP6 (centromeric). A third copy of this duplicon exists in inverted orientation distal to the telomeric flanking one. These duplicons show stronger sequence conservation with regard to each other than to the presumptive ancestral loci within the common deletion region. Sequence elements originating from beyond 7q11.23 are also present in these duplicons. Although the duplicons are not present in mice, the order of the single-copy genes in the conserved syntenic region of mouse chromosome 5 is inverted relative to the human map. A model is presented for a mechanism of WBS-deletion formation, based on the orientation of duplicons' components relative to each other and to the ancestral elements within the deletion region. PMID:10631136

VariantBam: filtering and profiling of next-generational sequencing data using region-specific rules.

PubMed

Wala, Jeremiah; Zhang, Cheng-Zhong; Meyerson, Matthew; Beroukhim, Rameen

2016-07-01

We developed VariantBam, a C ++ read filtering and profiling tool for use with BAM, CRAM and SAM sequencing files. VariantBam provides a flexible framework for extracting sequencing reads or read-pairs that satisfy combinations of rules, defined by any number of genomic intervals or variant sites. We have implemented filters based on alignment data, sequence motifs, regional coverage and base quality. For example, VariantBam achieved a median size reduction ratio of 3.1:1 when applied to 10 lung cancer whole genome BAMs by removing large tags and selecting for only high-quality variant-supporting reads and reads matching a large dictionary of sequence motifs. Thus VariantBam enables efficient storage of sequencing data while preserving the most relevant information for downstream analysis. VariantBam and full documentation are available at github.com/jwalabroad/VariantBam rameen@broadinstitute.org Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A comprehensive analysis of three Asiatic black bear mitochondrial genomes (subspecies ussuricus, formosanus and mupinensis), with emphasis on the complete mtDNA sequence of Ursus thibetanus ussuricus (Ursidae).

PubMed

Hwang, Dae-Sik; Ki, Jang-Seu; Jeong, Dong-Hyuk; Kim, Bo-Hyun; Lee, Bae-Keun; Han, Sang-Hoon; Lee, Jae-Seong

2008-08-01

In the present paper, we describe the mitochondrial genome sequence of the Asiatic black bear (Ursus thibetanus ussuricus) with particular emphasis on the control region (CR), and compared with mitochondrial genomes on molecular relationships among the bears. The mitochondrial genome sequence of U. thibetanus ussuricus was 16,700 bp in size with mostly conserved structures (e.g. 13 protein-coding, two rRNA genes, 22 tRNA genes). The CR consisted of several typical conserved domains such as F, E, D, and C boxes, and a conserved sequence block. Nucleotide sequences and the repeated motifs in the CR were different among the bear species, and their copy numbers were also variable according to populations, even within F1 generations of U. thibetanus ussuricus. Comparative analyses showed that the CR D1 region was highly informative for the discrimination of the bear family. These findings suggest that nucleotide sequences of both repeated motifs and CR D1 in the bear family are good markers for species discriminations.

Genetic diversity and geographical structure of the pitcher plant Nepenthes vieillardii in New Caledonia: A chloroplast DNA haplotype analysis.

PubMed

Kurata, Kaoruko; Jaffré, Tanguy; Setoguchi, Hiroaki

2008-12-01

Among the many species that grow in New Caledonia, the pitcher plant Nepenthes vieillardii (Nepenthaceae) has a high degree of morphological variation. In this study, we present the patterns of genetic differentiation of pitcher plant populations based on chloroplast DNA haplotype analysis using the sequences of five spacers. We analyzed 294 samples from 16 populations covering the entire range of the species, using 4660 bp of sequence. Our analysis identified 17 haplotypes, including one that is widely distributed across the islands, as well as regional and private haplotypes. The greatest haplotype diversity was detected on the eastern coast of the largest island and included several private haplotypes, while haplotype diversity was low in the southern plains region. The parsimony network analysis of the 17 haplotypes suggested that the genetic divergence is the result of long-term isolation of individual populations. Results from a spatial analysis of molecular variance and a cluster analysis suggest that the plants once covered the entire serpentine area of New Caledonia and that subsequent regional fragmentation resulted in the isolation of each population and significantly restricted seed flow. This isolation may have been an important factor in the development of the morphological and genetic variation among pitcher plants in New Caledonia.

High-resolution mapping and sequence analysis of 597 cDNA clones transcribed from the 1 Mb region in human chromosome 4q16.3 containing Huntington disease gene

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

Hadano, S.; Ishida, Y.; Tomiyasu, H.

1994-09-01

To complete a transcription map of the 1 Mb region in human chromosome 4p16.3 containing the Huntington disease (HD) gene, the isolation of cDNA clones are being performed throughout. Our method relies on a direct screening of the cDNA libraries probed with single copy microclones from 3 YAC clones spanning 1 Mbp of the HD gene region. AC-DNAs were isolated by a preparative pulsed-field gel electrophoresis, amplified by both a single unique primer (SUP)-PCR and a linker ligation PCR, and 6 microclone-DNA libraries were generated. Then, 8,640 microclones from these libraries were independently amplified by PCR, and arrayed onto themore » membranes. 800-900 microclones that were not cross-hybridized with total human and yeast genomic DNA, TAC vector DNA, and ribosomal cDNA on a dot hybridization (putatively carrying single copy sequences) were pooled to make 9 probe pools. A total of {approximately}1.8x10{sup 7} plaques from the human brain cDNA libraries was screened with 9 pool-probes, and then 672 positive cDNA clones were obtained. So far, 597 cDNA clones were defined and arrayed onto a map of the 1 Mbp of the HD gene region by hybridization with HD region-specific cosmid contigs and YAC clones. Further characterization including a DNA sequencing and Northern blot analysis is currently underway.« less

Differentiation of Trichophyton rubrum clinical isolates from Japanese and Chinese patients by randomly amplified polymorphic DNA and DNA sequence analysis of the non-transcribed spacer region of the rRNA gene.

PubMed

Yang, Xiumin; Sugita, Takashi; Takashima, Masako; Hiruma, Masataro; Li, Ruoyu; Sudo, Hajime; Ogawa, Hideoki; Ikeda, Shigaku

2009-04-01

Trichophyton rubrum is the most common pathogen causing dermatophytosis worldwide. Recent genetic investigations showed that the microorganism originated in Africa and then spread to Europe and North America via Asia. We investigated the intraspecific diversity of T. rubrum isolated from two closely located Asian countries, Japan and China. A total of 150 clinical isolates of T. rubrum obtained from Japanese and Chinese patients were analyzed by randomly amplified polymorphic DNA (RAPD) and DNA sequence analysis of the non-transcribed spacer (NTS) region in the rRNA gene. RAPD analysis divided the 150 strains into two major clusters, A and B. Of the Japanese isolates, 30% belonged to cluster A and 70% belonged to cluster B, whereas 91% of the Chinese isolates were in cluster A. The NTS region of the rRNA gene was divided into four major groups (I-IV) based on DNA sequencing. The majority of Japanese isolates were type IV (51%), and the majority of Chinese isolates were type III (75%). These results suggest that although Japan and China are neighboring countries, the origins of T. rubrum isolates from these countries may not be identical. These findings provide information useful for tracing the global transmission routes of T. rubrum.

How to use sequence analysis for life course epidemiology? An example on HIV-positive Sub-Saharan migrants in France.

PubMed

Gosselin, Anne; Desgrées du Loû, Annabel; Lelièvre, Eva

2018-06-01

Life course epidemiology is now an established field in social epidemiology; in sociodemography, the quantitative analysis of biographies recently experienced significant trend from event history analysis to sequence analysis. The purpose of this article is to introduce and adapt this methodology to a social epidemiology question, taking the example of the impact of HIV diagnosis on Sub-Saharan migrants' residential trajectories in the Paris region. The sample consists of 640 migrants born in Sub-Saharan Africa receiving HIV care. They were interviewed in healthcare facilities in the Paris region within the PARCOURS project, conducted from 2012 to 2013, using life event history calendars, which recorded year by year their health, family and residential histories. We introduce a two-step methodological approach consisting of (1) sequence analysis by optimal matching to build a typology of migrants' residential pathways before and after diagnosis, and (2) a Cox model of the probability to experience changes in the residential situation. The seven-clusters typology shows that for a majority, the HIV diagnosis did not entail changes in residential situation. However 30% of the migrants experienced a change in their residential situation at time of diagnosis. The Cox model analysis reveals that this residential change was in fact moving in with one's partner (HR 2.99, P<0.000) rather than network rejection. This original combination of sequence analysis and Cox models is a powerful process that could be applied to other themes and constitutes a new approach in the life course epidemiology toolbox. NCT02566148. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Complete genome sequencing and analysis of Saprospira grandis str. Lewin, a predatory marine bacterium

PubMed Central

Saw, Jimmy H. W.; Yuryev, Anton; Kanbe, Masaomi; Hou, Shaobin; Young, Aaron G.; Aizawa, Shin-Ichi

2012-01-01

Saprospira grandis is a coastal marine bacterium that can capture and prey upon other marine bacteria using a mechanism known as ‘ixotrophy’. Here, we present the complete genome sequence of Saprospira grandis str. Lewin isolated from La Jolla beach in San Diego, California. The complete genome sequence comprises a chromosome of 4.35 Mbp and a plasmid of 54.9 Kbp. Genome analysis revealed incomplete pathways for the biosynthesis of nine essential amino acids but presence of a large number of peptidases. The genome encodes multiple copies of sensor globin-coupled rsbR genes thought to be essential for stress response and the presence of such sensor globins in Bacteroidetes is unprecedented. A total of 429 spacer sequences within the three CRISPR repeat regions were identified in the genome and this number is the largest among all the Bacteroidetes sequenced to date. PMID:22675601

Sequence and analysis of chromosome 4 of the plant Arabidopsis thaliana.

PubMed

Mayer, K; Schüller, C; Wambutt, R; Murphy, G; Volckaert, G; Pohl, T; Düsterhöft, A; Stiekema, W; Entian, K D; Terryn, N; Harris, B; Ansorge, W; Brandt, P; Grivell, L; Rieger, M; Weichselgartner, M; de Simone, V; Obermaier, B; Mache, R; Müller, M; Kreis, M; Delseny, M; Puigdomenech, P; Watson, M; Schmidtheini, T; Reichert, B; Portatelle, D; Perez-Alonso, M; Boutry, M; Bancroft, I; Vos, P; Hoheisel, J; Zimmermann, W; Wedler, H; Ridley, P; Langham, S A; McCullagh, B; Bilham, L; Robben, J; Van der Schueren, J; Grymonprez, B; Chuang, Y J; Vandenbussche, F; Braeken, M; Weltjens, I; Voet, M; Bastiaens, I; Aert, R; Defoor, E; Weitzenegger, T; Bothe, G; Ramsperger, U; Hilbert, H; Braun, M; Holzer, E; Brandt, A; Peters, S; van Staveren, M; Dirske, W; Mooijman, P; Klein Lankhorst, R; Rose, M; Hauf, J; Kötter, P; Berneiser, S; Hempel, S; Feldpausch, M; Lamberth, S; Van den Daele, H; De Keyser, A; Buysshaert, C; Gielen, J; Villarroel, R; De Clercq, R; Van Montagu, M; Rogers, J; Cronin, A; Quail, M; Bray-Allen, S; Clark, L; Doggett, J; Hall, S; Kay, M; Lennard, N; McLay, K; Mayes, R; Pettett, A; Rajandream, M A; Lyne, M; Benes, V; Rechmann, S; Borkova, D; Blöcker, H; Scharfe, M; Grimm, M; Löhnert, T H; Dose, S; de Haan, M; Maarse, A; Schäfer, M; Müller-Auer, S; Gabel, C; Fuchs, M; Fartmann, B; Granderath, K; Dauner, D; Herzl, A; Neumann, S; Argiriou, A; Vitale, D; Liguori, R; Piravandi, E; Massenet, O; Quigley, F; Clabauld, G; Mündlein, A; Felber, R; Schnabl, S; Hiller, R; Schmidt, W; Lecharny, A; Aubourg, S; Chefdor, F; Cooke, R; Berger, C; Montfort, A; Casacuberta, E; Gibbons, T; Weber, N; Vandenbol, M; Bargues, M; Terol, J; Torres, A; Perez-Perez, A; Purnelle, B; Bent, E; Johnson, S; Tacon, D; Jesse, T; Heijnen, L; Schwarz, S; Scholler, P; Heber, S; Francs, P; Bielke, C; Frishman, D; Haase, D; Lemcke, K; Mewes, H W; Stocker, S; Zaccaria, P; Bevan, M; Wilson, R K; de la Bastide, M; Habermann, K; Parnell, L; Dedhia, N; Gnoj, L; Schutz, K; Huang, E; Spiegel, L; Sehkon, M; Murray, J; Sheet, P; Cordes, M; Abu-Threideh, J; Stoneking, T; Kalicki, J; Graves, T; Harmon, G; Edwards, J; Latreille, P; Courtney, L; Cloud, J; Abbott, A; Scott, K; Johnson, D; Minx, P; Bentley, D; Fulton, B; Miller, N; Greco, T; Kemp, K; Kramer, J; Fulton, L; Mardis, E; Dante, M; Pepin, K; Hillier, L; Nelson, J; Spieth, J; Ryan, E; Andrews, S; Geisel, C; Layman, D; Du, H; Ali, J; Berghoff, A; Jones, K; Drone, K; Cotton, M; Joshu, C; Antonoiu, B; Zidanic, M; Strong, C; Sun, H; Lamar, B; Yordan, C; Ma, P; Zhong, J; Preston, R; Vil, D; Shekher, M; Matero, A; Shah, R; Swaby, I K; O'Shaughnessy, A; Rodriguez, M; Hoffmann, J; Till, S; Granat, S; Shohdy, N; Hasegawa, A; Hameed, A; Lodhi, M; Johnson, A; Chen, E; Marra, M; Martienssen, R; McCombie, W R

1999-12-16

The higher plant Arabidopsis thaliana (Arabidopsis) is an important model for identifying plant genes and determining their function. To assist biological investigations and to define chromosome structure, a coordinated effort to sequence the Arabidopsis genome was initiated in late 1996. Here we report one of the first milestones of this project, the sequence of chromosome 4. Analysis of 17.38 megabases of unique sequence, representing about 17% of the genome, reveals 3,744 protein coding genes, 81 transfer RNAs and numerous repeat elements. Heterochromatic regions surrounding the putative centromere, which has not yet been completely sequenced, are characterized by an increased frequency of a variety of repeats, new repeats, reduced recombination, lowered gene density and lowered gene expression. Roughly 60% of the predicted protein-coding genes have been functionally characterized on the basis of their homology to known genes. Many genes encode predicted proteins that are homologous to human and Caenorhabditis elegans proteins.

Functional annotation of HOT regions in the human genome: implications for human disease and cancer

PubMed Central

Li, Hao; Chen, Hebing; Liu, Feng; Ren, Chao; Wang, Shengqi; Bo, Xiaochen; Shu, Wenjie

2015-01-01

Advances in genome-wide association studies (GWAS) and large-scale sequencing studies have resulted in an impressive and growing list of disease- and trait-associated genetic variants. Most studies have emphasised the discovery of genetic variation in coding sequences, however, the noncoding regulatory effects responsible for human disease and cancer biology have been substantially understudied. To better characterise the cis-regulatory effects of noncoding variation, we performed a comprehensive analysis of the genetic variants in HOT (high-occupancy target) regions, which are considered to be one of the most intriguing findings of recent large-scale sequencing studies. We observed that GWAS variants that map to HOT regions undergo a substantial net decrease and illustrate development-specific localisation during haematopoiesis. Additionally, genetic risk variants are disproportionally enriched in HOT regions compared with LOT (low-occupancy target) regions in both disease-relevant and cancer cells. Importantly, this enrichment is biased toward disease- or cancer-specific cell types. Furthermore, we observed that cancer cells generally acquire cancer-specific HOT regions at oncogenes through diverse mechanisms of cancer pathogenesis. Collectively, our findings demonstrate the key roles of HOT regions in human disease and cancer and represent a critical step toward further understanding disease biology, diagnosis, and therapy. PMID:26113264

Functional annotation of HOT regions in the human genome: implications for human disease and cancer.

PubMed

Li, Hao; Chen, Hebing; Liu, Feng; Ren, Chao; Wang, Shengqi; Bo, Xiaochen; Shu, Wenjie

2015-06-26

Advances in genome-wide association studies (GWAS) and large-scale sequencing studies have resulted in an impressive and growing list of disease- and trait-associated genetic variants. Most studies have emphasised the discovery of genetic variation in coding sequences, however, the noncoding regulatory effects responsible for human disease and cancer biology have been substantially understudied. To better characterise the cis-regulatory effects of noncoding variation, we performed a comprehensive analysis of the genetic variants in HOT (high-occupancy target) regions, which are considered to be one of the most intriguing findings of recent large-scale sequencing studies. We observed that GWAS variants that map to HOT regions undergo a substantial net decrease and illustrate development-specific localisation during haematopoiesis. Additionally, genetic risk variants are disproportionally enriched in HOT regions compared with LOT (low-occupancy target) regions in both disease-relevant and cancer cells. Importantly, this enrichment is biased toward disease- or cancer-specific cell types. Furthermore, we observed that cancer cells generally acquire cancer-specific HOT regions at oncogenes through diverse mechanisms of cancer pathogenesis. Collectively, our findings demonstrate the key roles of HOT regions in human disease and cancer and represent a critical step toward further understanding disease biology, diagnosis, and therapy.

The complete mitochondrial genome sequence of the maned wolf (Chrysocyon brachyurus).

PubMed

Zhao, Chao; Yang, Xiufeng; Zhang, Honghai; Zhang, Jin; Chen, Lei; Sha, Weilai; Liu, Guangshuai

2016-01-01

In this study, the complete mitochondrial genome of the maned wolf (Chrysocyon brachyurus), the unique species in Chrysocyon, was sequenced and reported for the first time using blood samples obtained from a female individual in Shanghai Zoo, China. Sequence analysis showed that the genome structure was in accordance with other Canidae species and it contained 12 S rRNA gene, 16 S rRNA gene, 22 tRNA genes, 13 protein-coding genes and 1 control region.

Sequence heterogeneity in the two 16S rRNA genes of Phormium yellow leaf phytoplasma.

PubMed Central

Liefting, L W; Andersen, M T; Beever, R E; Gardner, R C; Forster, R L

1996-01-01

Phormium yellow leaf (PYL) phytoplasma causes a lethal disease of the monocotyledon, New Zealand flax (Phormium tenax). The 16S rRNA genes of PYL phytoplasma were amplified from infected flax by PCR and cloned, and the nucleotide sequences were determined. DNA sequencing and Southern hybridization analysis of genomic DNA indicated the presence of two copies of the 16S rRNA gene. The two 16S rRNA genes exhibited sequence heterogeneity in 4 nucleotide positions and could be distinguished by the restriction enzymes BpmI and BsrI. This is the first record in which sequence heterogeneity in the 16S rRNA genes of a phytoplasma has been determined by sequence analysis. A phylogenetic tree based on 16S rRNA gene sequences showed that PYL phytoplasma is most closely related to the stolbur and German grapevine yellows phytoplasmas, which form the stolbur subgroup of the aster yellows group. This phylogenetic position of PYL phytoplasma was supported by 16S/23S spacer region sequence data. PMID:8795200

Database-independent Protein Sequencing (DiPS) Enables Full-length de Novo Protein and Antibody Sequence Determination.

PubMed

Savidor, Alon; Barzilay, Rotem; Elinger, Dalia; Yarden, Yosef; Lindzen, Moshit; Gabashvili, Alexandra; Adiv Tal, Ophir; Levin, Yishai

2017-06-01

Traditional "bottom-up" proteomic approaches use proteolytic digestion, LC-MS/MS, and database searching to elucidate peptide identities and their parent proteins. Protein sequences absent from the database cannot be identified, and even if present in the database, complete sequence coverage is rarely achieved even for the most abundant proteins in the sample. Thus, sequencing of unknown proteins such as antibodies or constituents of metaproteomes remains a challenging problem. To date, there is no available method for full-length protein sequencing, independent of a reference database, in high throughput. Here, we present Database-independent Protein Sequencing, a method for unambiguous, rapid, database-independent, full-length protein sequencing. The method is a novel combination of non-enzymatic, semi-random cleavage of the protein, LC-MS/MS analysis, peptide de novo sequencing, extraction of peptide tags, and their assembly into a consensus sequence using an algorithm named "Peptide Tag Assembler." As proof-of-concept, the method was applied to samples of three known proteins representing three size classes and to a previously un-sequenced, clinically relevant monoclonal antibody. Excluding leucine/isoleucine and glutamic acid/deamidated glutamine ambiguities, end-to-end full-length de novo sequencing was achieved with 99-100% accuracy for all benchmarking proteins and the antibody light chain. Accuracy of the sequenced antibody heavy chain, including the entire variable region, was also 100%, but there was a 23-residue gap in the constant region sequence. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Chromosome arm-specific BAC end sequences permit comparative analysis of homoeologous chromosomes and genomes of polyploid wheat

PubMed Central

2012-01-01

Background Bread wheat, one of the world’s staple food crops, has the largest, highly repetitive and polyploid genome among the cereal crops. The wheat genome holds the key to crop genetic improvement against challenges such as climate change, environmental degradation, and water scarcity. To unravel the complex wheat genome, the International Wheat Genome Sequencing Consortium (IWGSC) is pursuing a chromosome- and chromosome arm-based approach to physical mapping and sequencing. Here we report on the use of a BAC library made from flow-sorted telosomic chromosome 3A short arm (t3AS) for marker development and analysis of sequence composition and comparative evolution of homoeologous genomes of hexaploid wheat. Results The end-sequencing of 9,984 random BACs from a chromosome arm 3AS-specific library (TaaCsp3AShA) generated 11,014,359 bp of high quality sequence from 17,591 BAC-ends with an average length of 626 bp. The sequence represents 3.2% of t3AS with an average DNA sequence read every 19 kb. Overall, 79% of the sequence consisted of repetitive elements, 1.38% as coding regions (estimated 2,850 genes) and another 19% of unknown origin. Comparative sequence analysis suggested that 70-77% of the genes present in both 3A and 3B were syntenic with model species. Among the transposable elements, gypsy/sabrina (12.4%) was the most abundant repeat and was significantly more frequent in 3A compared to homoeologous chromosome 3B. Twenty novel repetitive sequences were also identified using de novo repeat identification. BESs were screened to identify simple sequence repeats (SSR) and transposable element junctions. A total of 1,057 SSRs were identified with a density of one per 10.4 kb, and 7,928 junctions between transposable elements (TE) and other sequences were identified with a density of one per 1.39 kb. With the objective of enhancing the marker density of chromosome 3AS, oligonucleotide primers were successfully designed from 758 SSRs and 695 Insertion Site Based Polymorphisms (ISBPs). Of the 96 ISBP primer pairs tested, 28 (29%) were 3A-specific and compared to 17 (18%) for 96 SSRs. Conclusion This work reports on the use of wheat chromosome arm 3AS-specific BAC library for the targeted generation of sequence data from a particular region of the huge genome of wheat. A large quantity of sequences were generated from the A genome of hexaploid wheat for comparative genome analysis with homoeologous B and D genomes and other model grass genomes. Hundreds of molecular markers were developed from the 3AS arm-specific sequences; these and other sequences will be useful in gene discovery and physical mapping. PMID:22559868

Contig Maps and Genomic Sequencing Identify Candidate Genes in the Usher 1C Locus

PubMed Central

Higgins, Michael J.; Day, Colleen D.; Smilinich, Nancy J.; Ni, L.; Cooper, Paul R.; Nowak, Norma J.; Davies, Chris; de Jong, Pieter J.; Hejtmancik, Fielding; Evans, Glen A.; Smith, Richard J.H.; Shows, Thomas B.

1998-01-01

Usher syndrome 1C (USH1C) is a congenital condition manifesting profound hearing loss, the absence of vestibular function, and eventual retinal degeneration. The USH1C locus has been mapped genetically to a 2- to 3-cM interval in 11p14–15.1 between D11S899 and D11S861. In an effort to identify the USH1C disease gene we have isolated the region between these markers in yeast artificial chromosomes (YACs) using a combination of STS content mapping and Alu–PCR hybridization. The YAC contig is ∼3.5 Mb and has located several other loci within this interval, resulting in the order CEN-LDHA-SAA1-TPH-D11S1310-(D11S1888/KCNC1)-MYOD1-D11S902D11S921-D11S1890-TEL. Subsequent haplotyping and homozygosity analysis refined the location of the disease gene to a 400-kb interval between D11S902 and D11S1890 with all affected individuals being homozygous for the internal marker D11S921. To facilitate gene identification, the critical region has been converted into P1 artificial chromosome (PAC) clones using sequence-tagged sites (STSs) mapped to the YAC contig, Alu–PCR products generated from the YACs, and PAC end probes. A contig of >50 PAC clones has been assembled between D11S1310 and D11S1890, confirming the order of markers used in haplotyping. Three PAC clones representing nearly two-thirds of the USH1C critical region have been sequenced. PowerBLAST analysis identified six clusters of expressed sequence tags (ESTs), two known genes (BIR,SUR1) mapped previously to this region, and a previously characterized but unmapped gene NEFA (DNA binding/EF hand/acidic amino-acid-rich). GRAIL analysis identified 11 CpG islands and 73 exons of excellent quality. These data allowed the construction of a transcription map for the USH1C critical region, consisting of three known genes and six or more novel transcripts. Based on their map location, these loci represent candidate disease loci for USH1C. The NEFA gene was assessed as the USH1C locus by the sequencing of an amplified NEFA cDNA from an USH1C patient; however, no mutations were detected. [The sequence data described in this paper have been submitted to GenBank under accession numbers AC000406–AC000407.] PMID:9445488

Investigation into the sequence structure of 23 Y chromosomal STR loci using massively parallel sequencing.

PubMed

Kwon, So Yeun; Lee, Hwan Young; Kim, Eun Hye; Lee, Eun Young; Shin, Kyoung-Jin

2016-11-01

Next-generation sequencing (NGS) can produce massively parallel sequencing (MPS) data for many targeted regions with a high depth of coverage, suggesting its successful application to the amplicons of forensic genetic markers. In the present study, we evaluated the practical utility of MPS in Y-chromosome short tandem repeat (Y-STR) analysis using a multiplex polymerase chain reaction (PCR) system. The multiplex PCR system simultaneously amplified 24 Y-chromosomal markers, including the PowerPlex ® Y23 loci (DYS19, DYS385ab, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS481, DYS533, DYS549, DYS570, DYS576, DYS635, DYS643, and YGATAH4) and the M175 marker with the small-sized amplicons ranging from 85 to 253bp. The barcoded libraries for the amplicons of the 24 Y-chromosomal markers were produced using a simplified PCR-based library preparation method and successfully sequenced using MPS on a MiSeq ® System with samples from 250 unrelated Korean males. The genotyping concordance between MPS and the capillary electrophoresis (CE) method, as well as the sequence structure of the 23 Y-STRs, were investigated. Three samples exhibited discordance between the MPS and CE results at DYS385, DYS439, and DYS576. There were 12 Y-STR loci that showed sequence variations in the alleles by a fragment size determination, and the most varied alleles occurred in DYS389II with a different sequence structure in the repeat region. The largest increase in gene diversity between the CE and MPS results was in DYS437 at +34.41%. Single nucleotide polymorphisms (SNPs), insertions, and deletions (indels) were observed in the flanking regions of DYS481, DYS576, and DYS385, respectively. Stutter and noise ratios of the 23 Y-STRs using the developed MPS system were also investigated. Based on these results, the MPS analysis system used in this study could facilitate the investigation into the sequences of the 23 Y-STRs in forensic genetics laboratories. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Comparative genomic analysis reveals occurrence of genetic recombination in virulent Cryptosporidium hominis subtypes and telomeric gene duplications in Cryptosporidium parvum.

PubMed

Guo, Yaqiong; Tang, Kevin; Rowe, Lori A; Li, Na; Roellig, Dawn M; Knipe, Kristine; Frace, Michael; Yang, Chunfu; Feng, Yaoyu; Xiao, Lihua

2015-04-18

Cryptosporidium hominis is a dominant species for human cryptosporidiosis. Within the species, IbA10G2 is the most virulent subtype responsible for all C. hominis-associated outbreaks in Europe and Australia, and is a dominant outbreak subtype in the United States. In recent yearsIaA28R4 is becoming a major new subtype in the United States. In this study, we sequenced the genomes of two field specimens from each of the two subtypes and conducted a comparative genomic analysis of the obtained sequences with those from the only fully sequenced Cryptosporidium parvum genome. Altogether, 8.59-9.05 Mb of Cryptosporidium sequences in 45-767 assembled contigs were obtained from the four specimens, representing 94.36-99.47% coverage of the expected genome. These genomes had complete synteny in gene organization and 96.86-97.0% and 99.72-99.83% nucleotide sequence similarities to the published genomes of C. parvum and C. hominis, respectively. Several major insertions and deletions were seen between C. hominis and C. parvum genomes, involving mostly members of multicopy gene families near telomeres. The four C. hominis genomes were highly similar to each other and divergent from the reference IaA25R3 genome in some highly polymorphic regions. Major sequence differences among the four specimens sequenced in this study were in the 5' and 3' ends of chromosome 6 and the gp60 region, largely the result of genetic recombination. The sequence similarity among specimens of the two dominant outbreak subtypes and genetic recombination in chromosome 6, especially around the putative virulence determinant gp60 region, suggest that genetic recombination plays a potential role in the emergence of hyper-transmissible C. hominis subtypes. The high sequence conservation between C. parvum and C. hominis genomes and significant differences in copy numbers of MEDLE family secreted proteins and insulinase-like proteases indicate that telomeric gene duplications could potentially contribute to host expansion in C. parvum.

The complete chloroplast genome sequence of Actinidia arguta using the PacBio RS II platform

PubMed Central

Lin, Miaomiao; Qi, Xiujuan; Chen, Jinyong; Sun, Leiming; Zhong, Yunpeng; Fang, Jinbao; Hu, Chungen

2018-01-01

Actinidia arguta is the most basal species in a phylogenetically and economically important genus in the family Actinidiaceae. To better understand the molecular basis of the Actinidia arguta chloroplast (cp), we sequenced the complete cp genome from A. arguta using Illumina and PacBio RS II sequencing technologies. The cp genome from A. arguta was 157,611 bp in length and composed of a pair of 24,232 bp inverted repeats (IRs) separated by a 20,463 bp small single copy region (SSC) and an 88,684 bp large single copy region (LSC). Overall, the cp genome contained 113 unique genes. The cp genomes from A. arguta and three other Actinidia species from GenBank were subjected to a comparative analysis. Indel mutation events and high frequencies of base substitution were identified, and the accD and ycf2 genes showed a high degree of variation within Actinidia. Forty-seven simple sequence repeats (SSRs) and 155 repetitive structures were identified, further demonstrating the rapid evolution in Actinidia. The cp genome analysis and the identification of variable loci provide vital information for understanding the evolution and function of the chloroplast and for characterizing Actinidia population genetics. PMID:29795601

End Joining-Mediated Gene Expression in Mammalian Cells Using PCR-Amplified DNA Constructs that Contain Terminator in Front of Promoter.

PubMed

Nakamura, Mikiko; Suzuki, Ayako; Akada, Junko; Tomiyoshi, Keisuke; Hoshida, Hisashi; Akada, Rinji

2015-12-01

Mammalian gene expression constructs are generally prepared in a plasmid vector, in which a promoter and terminator are located upstream and downstream of a protein-coding sequence, respectively. In this study, we found that front terminator constructs-DNA constructs containing a terminator upstream of a promoter rather than downstream of a coding region-could sufficiently express proteins as a result of end joining of the introduced DNA fragment. By taking advantage of front terminator constructs, FLAG substitutions, and deletions were generated using mutagenesis primers to identify amino acids specifically recognized by commercial FLAG antibodies. A minimal epitope sequence for polyclonal FLAG antibody recognition was also identified. In addition, we analyzed the sequence of a C-terminal Ser-Lys-Leu peroxisome localization signal, and identified the key residues necessary for peroxisome targeting. Moreover, front terminator constructs of hepatitis B surface antigen were used for deletion analysis, leading to the identification of regions required for the particle formation. Collectively, these results indicate that front terminator constructs allow for easy manipulations of C-terminal protein-coding sequences, and suggest that direct gene expression with PCR-amplified DNA is useful for high-throughput protein analysis in mammalian cells.

Genome Re-Sequencing of Semi-Wild Soybean Reveals a Complex Soja Population Structure and Deep Introgression

PubMed Central

Wu, Sanling; Wang, Ying-Ying; Ye, Chu-Yu; Bai, Xuefei; Li, Zefeng; Yan, Chenghai; Wang, Weidi; Wang, Ziqiang; Shu, Qingyao; Xie, Jiahua; Lee, Suk-Ha; Fan, Longjiang

2014-01-01

Semi-wild soybean is a unique type of soybean that retains both wild and domesticated characteristics, which provides an important intermediate type for understanding the evolution of the subgenus Soja population in the Glycine genus. In this study, a semi-wild soybean line (Maliaodou) and a wild line (Lanxi 1) collected from the lower Yangtze regions were deeply sequenced while nine other semi-wild lines were sequenced to a 3-fold genome coverage. Sequence analysis revealed that (1) no independent phylogenetic branch covering all 10 semi-wild lines was observed in the Soja phylogenetic tree; (2) besides two distinct subpopulations of wild and cultivated soybean in the Soja population structure, all semi-wild lines were mixed with some wild lines into a subpopulation rather than an independent one or an intermediate transition type of soybean domestication; (3) high heterozygous rates (0.19–0.49) were observed in several semi-wild lines; and (4) over 100 putative selective regions were identified by selective sweep analysis, including those related to the development of seed size. Our results suggested a hybridization origin for the semi-wild soybean, which makes a complex Soja population structure. PMID:25265539

Molecular diagnosis of populational variants of Anthonomus grandis (Coleoptera: Curculionidae) in North America.

PubMed

Barr, Norman; Ruiz-Arce, Raul; Obregón, Oscar; De Leon, Rosita; Foster, Nelson; Reuter, Chris; Boratynski, Theodore; Vacek, Don

2013-02-01

The utility of the cytochrome oxidase I (COI) DNA sequence used for DNA barcoding and a Sequence Characterized Amplified Region for diagnosing boll weevil, Anthonomus grandis Boheman, variants was evaluated. Maximum likelihood analysis of COI DNA sequences from 154 weevils collected from the United States and Mexico supports previous evidence for limited gene flow between weevil populations on wild cotton and commercial cotton in northern Mexico and southern United States. The wild cotton populations represent a variant of the species called the thurberia weevil, which is not regarded as a significant pest. The 31 boll weevil COI haplotypes observed in the study form two distinct haplogroups (A and B) that are supported by five fixed nucleotide differences and a phylogenetic analysis. Although wild and commercial cotton populations are closely associated with specific haplogroups, there is not a fixed difference between the thurberia weevil variant and other populations. The Sequence Characterized Amplified Region marker generated a larger number of inconclusive results than the COI gene but also supported evidence of shared genotypes between wild and commercial cotton weevil populations. These methods provide additional markers that can assist in the identification of pest weevil populations but not definitively diagnose samples.

A large scale analysis of cDNA in Arabidopsis thaliana: generation of 12,028 non-redundant expressed sequence tags from normalized and size-selected cDNA libraries.

PubMed

Asamizu, E; Nakamura, Y; Sato, S; Tabata, S

2000-06-30

For comprehensive analysis of genes expressed in the model dicotyledonous plant, Arabidopsis thaliana, expressed sequence tags (ESTs) were accumulated. Normalized and size-selected cDNA libraries were constructed from aboveground organs, flower buds, roots, green siliques and liquid-cultured seedlings, respectively, and a total of 14,026 5'-end ESTs and 39,207 3'-end ESTs were obtained. The 3'-end ESTs could be clustered into 12,028 non-redundant groups. Similarity search of the non-redundant ESTs against the public non-redundant protein database indicated that 4816 groups show similarity to genes of known function, 1864 to hypothetical genes, and the remaining 5348 are novel sequences. Gene coverage by the non-redundant ESTs was analyzed using the annotated genomic sequences of approximately 10 Mb on chromosomes 3 and 5. A total of 923 regions were hit by at least one EST, among which only 499 regions were hit by the ESTs deposited in the public database. The result indicates that the EST source generated in this project complements the EST data in the public database and facilitates new gene discovery.

Re-sequencing of the APOAI promoter region and the genetic association of the -75G > A polymorphism with increased cholesterol and low density lipoprotein levels among a sample of the Kuwaiti population

PubMed Central

2013-01-01

Background APOAI, a member of the APOAI/CIII/IV/V gene cluster on chromosome 11q23-24, encodes a major protein component of HDL that has been associated with serum lipid levels. The aim of this study was to determine the genetic association of polymorphisms in the APOAI promoter region with plasma lipid levels in a cohort of healthy Kuwaiti volunteers. Methods A 435 bp region of the APOAI promoter was analyzed by re-sequencing in 549 Kuwaiti samples. DNA was extracted from blood taken from 549 healthy Kuwaiti volunteers who had fasted for the previous 12 h. Univariate and multivariate analysis was used to determine allele association with serum lipid levels. Results The target sequence included a partial segment of the promoter region, 5’UTR and exon 1 located between nucleotides −141 to +294 upstream of the APOAI gene on chromosome 11. No novel single nucleotide polymorphisms (SNPs) were observed. The sequences obtained were deposited with the NCBI GenBank with accession number [GenBank: JX438706]. The allelic frequencies for the three SNPs were as follows: APOAI rs670G = 0.807; rs5069C = 0.964; rs1799837G = 0.997 and found to be in HWE. A significant association (p < 0.05) was observed for the APOAI rs670 polymorphism with increased serum LDL-C. Multivariate analysis showed that APOAI rs670 was an independent predictive factor when controlling for age, sex and BMI for both LDL-C (OR: 1.66, p = 0.014) and TC (OR: 1.77, p = 0.006) levels. Conclusion This study is the first to report sequence analysis of the APOAI promoter in an Arab population. The unexpected positive association found between the APOAI rs670 polymorphism and increased levels of LDL-C and TC may be due to linkage disequilibrium with other polymorphisms in candidate and neighboring genes known to be associated with lipid metabolism and transport. PMID:24028463

Re-sequencing of the APOAI promoter region and the genetic association of the -75G > A polymorphism with increased cholesterol and low density lipoprotein levels among a sample of the Kuwaiti population.

PubMed

Al-Bustan, Suzanne A; Al-Serri, Ahmad E; Annice, Babitha G; Alnaqeeb, Majed A; Ebrahim, Ghada A

2013-09-12

APOAI, a member of the APOAI/CIII/IV/V gene cluster on chromosome 11q23-24, encodes a major protein component of HDL that has been associated with serum lipid levels. The aim of this study was to determine the genetic association of polymorphisms in the APOAI promoter region with plasma lipid levels in a cohort of healthy Kuwaiti volunteers. A 435 bp region of the APOAI promoter was analyzed by re-sequencing in 549 Kuwaiti samples. DNA was extracted from blood taken from 549 healthy Kuwaiti volunteers who had fasted for the previous 12 h. Univariate and multivariate analysis was used to determine allele association with serum lipid levels. The target sequence included a partial segment of the promoter region, 5'UTR and exon 1 located between nucleotides -141 to +294 upstream of the APOAI gene on chromosome 11. No novel single nucleotide polymorphisms (SNPs) were observed. The sequences obtained were deposited with the NCBI GenBank with accession number [GenBank: JX438706]. The allelic frequencies for the three SNPs were as follows: APOAI rs670G = 0.807; rs5069C = 0.964; rs1799837G = 0.997 and found to be in HWE. A significant association (p < 0.05) was observed for the APOAI rs670 polymorphism with increased serum LDL-C. Multivariate analysis showed that APOAI rs670 was an independent predictive factor when controlling for age, sex and BMI for both LDL-C (OR: 1.66, p = 0.014) and TC (OR: 1.77, p = 0.006) levels. This study is the first to report sequence analysis of the APOAI promoter in an Arab population. The unexpected positive association found between the APOAI rs670 polymorphism and increased levels of LDL-C and TC may be due to linkage disequilibrium with other polymorphisms in candidate and neighboring genes known to be associated with lipid metabolism and transport.

Population analysis of Vibrio parahaemolyticus originating from different geographical regions demonstrates a high genetic diversity.

PubMed

Urmersbach, Sara; Alter, Thomas; Koralage, Madura Sanjeevani Gonsal; Sperling, Lisa; Gerdts, Gunnar; Messelhäusser, Ute; Huehn, Stephan

2014-03-08

Vibrio parahaemolyticus is frequently isolated from environmental and seafood samples and associated with gastroenteritis outbreakes in American, European, Asian and African countries. To distinguish between different lineages of V. parahaemolyticus various genotyping techniques have been used, incl. multilocus sequence typing (MLST). Even though some studies have already applied MLST analysis to characterize V. parahaemolyticus strain sets, these studies have been restricted to specific geographical areas (e.g. U.S. coast, Thailand and Peru), have focused exclusively on pandemic or non-pandemic pathogenic isolates or have been based on a limited strain number. To generate a global picture of V. parahaemolyticus genotype distribution, a collection of 130 environmental and seafood related V. parahaemolyticus isolates of different geographical origins (Sri Lanka, Ecuador, North Sea and Baltic Sea as well as German retail) was subjected to MLST analysis after modification of gyrB and recA PCRs. The V. parahaemolyticus population was composed of 82 unique Sequence Types (STs), of which 68 (82.9%) were new to the pubMLST database. After translating the in-frame nucleotide sequences into amino acid sequences, less diversity was detectable: a total of 31 different peptide Sequence Types (pSTs) with 19 (61.3%) new pSTs were generated from the analyzed isolates. Most STs did not show a global dissemination, but some were supra-regionally distributed and clusters of STs were dependent on geographical origin. On peptide level no general clustering of strains from specific geographical regions was observed, thereby the most common pSTs were found on all continents (Asia, South America and Europe) and rare pSTs were restricted to distinct countries or even geographical regions. One lineage of pSTs associated only with strains from North and Baltic Sea strains was identified. Our study reveals a high genetic diversity in the analyzed V. parahaemolyticus strain set as well as for geographical strain subsets, with a high proportion of newly discovered alleles and STs. Differences between the subsets were identified. Our data support the postulated population structure of V. parahaemolyticus which follows the 'epidemic' model of clonal expansion. Application of peptide based AA-MLST allowed the identification of reliable relationships between strains.

Sequence investigation of 34 forensic autosomal STRs with massively parallel sequencing.

PubMed

Zhang, Suhua; Niu, Yong; Bian, Yingnan; Dong, Rixia; Liu, Xiling; Bao, Yun; Jin, Chao; Zheng, Hancheng; Li, Chengtao

2018-05-01

STRs vary not only in the length of the repeat units and the number of repeats but also in the region with which they conform to an incremental repeat pattern. Massively parallel sequencing (MPS) offers new possibilities in the analysis of STRs since they can simultaneously sequence multiple targets in a single reaction and capture potential internal sequence variations. Here, we sequenced 34 STRs applied in the forensic community of China with a custom-designed panel. MPS performance were evaluated from sequencing reads analysis, concordance study and sensitivity testing. High coverage sequencing data were obtained to determine the constitute ratios and heterozygous balance. No actual inconsistent genotypes were observed between capillary electrophoresis (CE) and MPS, demonstrating the reliability of the panel and the MPS technology. With the sequencing data from the 200 investigated individuals, 346 and 418 alleles were obtained via CE and MPS technologies at the 34 STRs, indicating MPS technology provides higher discrimination than CE detection. The whole study demonstrated that STR genotyping with the custom panel and MPS technology has the potential not only to reveal length and sequence variations but also to satisfy the demands of high throughput and high multiplexing with acceptable sensitivity.