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Sample records for genome diversity hgd

  1. The Human Genome Diversity (HGD) Project. Summary document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    In 1991 a group of human geneticists and molecular biologists proposed to the scientific community that a world wide survey be undertaken of variation in the human genome. To aid their considerations, the committee therefore decided to hold a small series of international workshops to explore the major scientific issues involved. The intention was to define a framework for the project which could provide a basis for much wider and more detailed discussion and planning--it was recognized that the successful implementation of the proposed project, which has come to be known as the Human Genome Diversity (HGD) Project, would not only involve scientists but also various national and international non-scientific groups all of which should contribute to the project`s development. The international HGD workshop held in Sardinia in September 1993 was the last in the initial series of planning workshops. As such it not only explored new ground but also pulled together into a more coherent form much of the formal and informal discussion that had taken place in the preceding two years. This report presents the deliberations of the Sardinia workshop within a consideration of the overall development of the HGD Project to date.

  2. The Human Genome Diversity Project

    Energy Technology Data Exchange (ETDEWEB)

    Cavalli-Sforza, L. [Stanford Univ., CA (United States)

    1994-12-31

    The Human Genome Diversity Project (HGD Project) is an international anthropology project that seeks to study the genetic richness of the entire human species. This kind of genetic information can add a unique thread to the tapestry knowledge of humanity. Culture, environment, history, and other factors are often more important, but humanity`s genetic heritage, when analyzed with recent technology, brings another type of evidence for understanding species` past and present. The Project will deepen the understanding of this genetic richness and show both humanity`s diversity and its deep and underlying unity. The HGD Project is still largely in its planning stages, seeking the best ways to reach its goals. The continuing discussions of the Project, throughout the world, should improve the plans for the Project and their implementation. The Project is as global as humanity itself; its implementation will require the kinds of partnerships among different nations and cultures that make the involvement of UNESCO and other international organizations particularly appropriate. The author will briefly discuss the Project`s history, describe the Project, set out the core principles of the Project, and demonstrate how the Project will help combat the scourge of racism.

  3. Bacillus subtilis genome diversity.

    Science.gov (United States)

    Earl, Ashlee M; Losick, Richard; Kolter, Roberto

    2007-02-01

    Microarray-based comparative genomic hybridization (M-CGH) is a powerful method for rapidly identifying regions of genome diversity among closely related organisms. We used M-CGH to examine the genome diversity of 17 strains belonging to the nonpathogenic species Bacillus subtilis. Our M-CGH results indicate that there is considerable genetic heterogeneity among members of this species; nearly one-third of Bsu168-specific genes exhibited variability, as measured by the microarray hybridization intensities. The variable loci include those encoding proteins involved in antibiotic production, cell wall synthesis, sporulation, and germination. The diversity in these genes may reflect this organism's ability to survive in diverse natural settings.

  4. Genomic diversity of Lactobacillus salivarius

    OpenAIRE

    Raftis, Emma J.

    2015-01-01

    Lactobacillus salivarius is unusual among the lactobacilli due to its multireplicon genome architecture. The circular megaplasmids harboured by L. salivarius strains encode strain-specific traits for intestinal survival and probiotic activity. L. salivarius strains are increasingly being exploited for their probiotic properties in humans and animals. In terms of probiotic strain selection, it is important to have an understanding of the level of genomic diversity present in this species. Comp...

  5. India, Genomic diversity & Disease susceptibility

    Indian Academy of Sciences (India)

    Table of contents. India, Genomic diversity & Disease susceptibility · India, a paradise for Genetic Studies · Involved in earlier stages of Immune response protecting us from Diseases, Responsible for kidney and other transplant rejections Inherited from our parents · PowerPoint Presentation · Slide 5 · Slide 6 · Slide 7.

  6. Early-onset ocular ochronosis in a girl with alkaptonuria (AKU) and a novel mutation in homogentisate 1,2-dioxygenase (HGD).

    Science.gov (United States)

    Gucev, Z S; Slaveska, N; Laban, N; Danilovski, D; Tasic, V; Pop-Jordanova, N; Zatkova, A

    2011-01-01

    Alkaptonuria (AKU) is a disorder of phenylalanine/tyrosine metabolism due to a defect in the enzyme homogentisate 1,2-dioxygenase (HGD). This recessive disease is caused by mutations in the HGD gene. We report a 14-year-old girl who was referred after presenting black urine. Careful examination revealed ochronosis of the conjunctiva. There was no affection of the cardiac valves. Elevated excretion of homogentisic acid in urine was found. Sequence analysis of the HGD gene from genomic DNA revealed that the patient is a compound heterozygote with a previously described mutation (c.473C>T, p.Pro158Leu), and a novel one (c.821C>T, p.Pro274Leu). Her mother is heterozygous for the novel mutation, while the brother is heterozygous for the previously described mutation. In summary, we describe an alkaptonuric patient with ocular ochronosis and a novel HGD mutation, c.821C>T, p.Pro274Leu.

  7. First report of HGD mutations in a Chinese with alkaptonuria.

    Science.gov (United States)

    Yang, Yong-jia; Guo, Ji-hong; Chen, Wei-jian; Zhao, Rui; Tang, Jin-song; Meng, Xiao-hua; Zhao, Liu; Tu, Ming; He, Xin-yu; Wu, Ling-qian; Zhu, Yi-min

    2013-04-15

    Alkaptonuria (AKU) is one of the first prototypic inborn errors in metabolism and the first human disease found to be transmitted via Mendelian autosomal recessive inheritance. It is caused by HGD mutations, which leads to a deficiency in homogentisate 1,2-dioxygenase (HGD) activity. To date, several HGD mutations have been identified as the cause of the prototypic disease across different ethnic populations worldwide. However, in Asia, the HGD mutation is very rarely reported. For the Chinese population, no literature on HGD mutation screening is available to date. In this paper, we describe two novel HGD mutations in a Chinese AKU family, the splicing mutation of IVS7+1G>C, a donor splice site of exon 7, and a missense mutation of F329C in exon 12. The predicted new splicing site of the mutated exon 7 sequence demonstrated a 303bp extension after the mutation site. The F329C mutation most probably disturbed the stability of the conformation of the two loops critical to the Fe(2+) active site of the HGD enzyme. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Genomic Diversity of Lactobacillus salivarius▿ †

    OpenAIRE

    Raftis, Emma J.; Salvetti, Elisa; Torriani, Sandra; Felis, Giovanna E.; O'Toole, Paul W.

    2010-01-01

    Strains of Lactobacillus salivarius are increasingly employed as probiotic agents for humans or animals. Despite the diversity of environmental sources from which they have been isolated, the genomic diversity of L. salivarius has been poorly characterized, and the implications of this diversity for strain selection have not been examined. To tackle this, we applied comparative genomic hybridization (CGH) and multilocus sequence typing (MLST) to 33 strains derived from humans, animals, or foo...

  9. Comparative Genomics Reveals High Genomic Diversity in the Genus Photobacterium.

    Science.gov (United States)

    Machado, Henrique; Gram, Lone

    2017-01-01

    Vibrionaceae is a large marine bacterial family, which can constitute up to 50% of the prokaryotic population in marine waters. Photobacterium is the second largest genus in the family and we used comparative genomics on 35 strains representing 16 of the 28 species described so far, to understand the genomic diversity present in the Photobacterium genus. Such understanding is important for ecophysiology studies of the genus. We used whole genome sequences to evaluate phylogenetic relationships using several analyses (16S rRNA, MLSA, fur , amino-acid usage, ANI), which allowed us to identify two misidentified strains. Genome analyses also revealed occurrence of higher and lower GC content clades, correlating with phylogenetic clusters. Pan- and core-genome analysis revealed the conservation of 25% of the genome throughout the genus, with a large and open pan-genome. The major source of genomic diversity could be traced to the smaller chromosome and plasmids. Several of the physiological traits studied in the genus did not correlate with phylogenetic data. Since horizontal gene transfer (HGT) is often suggested as a source of genetic diversity and a potential driver of genomic evolution in bacterial species, we looked into evidence of such in Photobacterium genomes. Genomic islands were the source of genomic differences between strains of the same species. Also, we found transposase genes and CRISPR arrays that suggest multiple encounters with foreign DNA. Presence of genomic exchange traits was widespread and abundant in the genus, suggesting a role in genomic evolution. The high genetic variability and indications of genetic exchange make it difficult to elucidate genome evolutionary paths and raise the awareness of the roles of foreign DNA in the genomic evolution of environmental organisms.

  10. Genome Surfing As Driver of Microbial Genomic Diversity.

    Science.gov (United States)

    Choudoir, Mallory J; Panke-Buisse, Kevin; Andam, Cheryl P; Buckley, Daniel H

    2017-08-01

    Historical changes in population size, such as those caused by demographic range expansions, can produce nonadaptive changes in genomic diversity through mechanisms such as gene surfing. We propose that demographic range expansion of a microbial population capable of horizontal gene exchange can result in genome surfing, a mechanism that can cause widespread increase in the pan-genome frequency of genes acquired by horizontal gene exchange. We explain that patterns of genetic diversity within Streptomyces are consistent with genome surfing, and we describe several predictions for testing this hypothesis both in Streptomyces and in other microorganisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Mutation spectrum of homogentisic acid oxidase (HGD) in alkaptonuria.

    Science.gov (United States)

    Vilboux, Thierry; Kayser, Michael; Introne, Wendy; Suwannarat, Pim; Bernardini, Isa; Fischer, Roxanne; O'Brien, Kevin; Kleta, Robert; Huizing, Marjan; Gahl, William A

    2009-12-01

    Alkaptonuria (AKU) is a rare autosomal recessive metabolic disorder, characterized by accumulation of homogentisic acid, leading to darkened urine, pigmentation of connective tissue (ochronosis), joint and spine arthritis, and destruction of cardiac valves. AKU is due to mutations in the homogentisate dioxygenase gene (HGD) that converts homogentisic acid to maleylacetoacetic acid in the tyrosine catabolic pathway. Here we report a comprehensive mutation analysis of 93 patients enrolled in our study, as well as an extensive update of all previously published HGD mutations associated with AKU. Within our patient cohort, we identified 52 HGD variants, of which 22 were novel. This yields a total of 91 identified HGD variations associated with AKU to date, including 62 missense, 13 splice site, 10 frameshift, 5 nonsense, and 1 no-stop mutation. Most HGD variants reside in exons 3, 6, 8, and 13. We assessed the potential effect of all missense variations on protein function, using five bioinformatic tools specifically designed for interpretation of missense variants (SIFT, POLYPHEN, PANTHER, PMUT, and SNAP). We also analyzed the potential effect of splice-site variants using two different tools (BDGP and NetGene2). This study provides valuable resources for molecular analysis of alkaptonuria and expands our knowledge of the molecular basis of this disease.

  12. Comparative Genomics Reveals High Genomic Diversity in the Genus Photobacterium

    OpenAIRE

    Henrique Machado; Henrique Machado; Lone Gram

    2017-01-01

    Vibrionaceae is a large marine bacterial family, which can constitute up to 50% of the prokaryotic population in marine waters. Photobacterium is the second largest genus in the family and we used comparative genomics on 35 strains representing 16 of the 28 species described so far, to understand the genomic diversity present in the Photobacterium genus. Such understanding is important for ecophysiology studies of the genus. We used whole genome sequences to evaluate phylogenetic relationship...

  13. Genomic Diversity and Evolution of the Lyssaviruses

    Science.gov (United States)

    Delmas, Olivier; Holmes, Edward C.; Talbi, Chiraz; Larrous, Florence; Dacheux, Laurent; Bouchier, Christiane; Bourhy, Hervé

    2008-01-01

    Lyssaviruses are RNA viruses with single-strand, negative-sense genomes responsible for rabies-like diseases in mammals. To date, genomic and evolutionary studies have most often utilized partial genome sequences, particularly of the nucleoprotein and glycoprotein genes, with little consideration of genome-scale evolution. Herein, we report the first genomic and evolutionary analysis using complete genome sequences of all recognised lyssavirus genotypes, including 14 new complete genomes of field isolates from 6 genotypes and one genotype that is completely sequenced for the first time. In doing so we significantly increase the extent of genome sequence data available for these important viruses. Our analysis of these genome sequence data reveals that all lyssaviruses have the same genomic organization. A phylogenetic analysis reveals strong geographical structuring, with the greatest genetic diversity in Africa, and an independent origin for the two known genotypes that infect European bats. We also suggest that multiple genotypes may exist within the diversity of viruses currently classified as ‘Lagos Bat’. In sum, we show that rigorous phylogenetic techniques based on full length genome sequence provide the best discriminatory power for genotype classification within the lyssaviruses. PMID:18446239

  14. Genomic diversity and evolution of the lyssaviruses.

    Directory of Open Access Journals (Sweden)

    Olivier Delmas

    2008-04-01

    Full Text Available Lyssaviruses are RNA viruses with single-strand, negative-sense genomes responsible for rabies-like diseases in mammals. To date, genomic and evolutionary studies have most often utilized partial genome sequences, particularly of the nucleoprotein and glycoprotein genes, with little consideration of genome-scale evolution. Herein, we report the first genomic and evolutionary analysis using complete genome sequences of all recognised lyssavirus genotypes, including 14 new complete genomes of field isolates from 6 genotypes and one genotype that is completely sequenced for the first time. In doing so we significantly increase the extent of genome sequence data available for these important viruses. Our analysis of these genome sequence data reveals that all lyssaviruses have the same genomic organization. A phylogenetic analysis reveals strong geographical structuring, with the greatest genetic diversity in Africa, and an independent origin for the two known genotypes that infect European bats. We also suggest that multiple genotypes may exist within the diversity of viruses currently classified as 'Lagos Bat'. In sum, we show that rigorous phylogenetic techniques based on full length genome sequence provide the best discriminatory power for genotype classification within the lyssaviruses.

  15. Genomic Diversity of Lactobacillus salivarius▿ †

    Science.gov (United States)

    Raftis, Emma J.; Salvetti, Elisa; Torriani, Sandra; Felis, Giovanna E.; O'Toole, Paul W.

    2011-01-01

    Strains of Lactobacillus salivarius are increasingly employed as probiotic agents for humans or animals. Despite the diversity of environmental sources from which they have been isolated, the genomic diversity of L. salivarius has been poorly characterized, and the implications of this diversity for strain selection have not been examined. To tackle this, we applied comparative genomic hybridization (CGH) and multilocus sequence typing (MLST) to 33 strains derived from humans, animals, or food. The CGH, based on total genome content, including small plasmids, identified 18 major regions of genomic variation, or hot spots for variation. Three major divisions were thus identified, with only a subset of the human isolates constituting an ecologically discernible group. Omission of the small plasmids from the CGH or analysis by MLST provided broadly concordant fine divisions and separated human-derived and animal-derived strains more clearly. The two gene clusters for exopolysaccharide (EPS) biosynthesis corresponded to regions of significant genomic diversity. The CGH-based groupings of these regions did not correlate with levels of production of bound or released EPS. Furthermore, EPS production was significantly modulated by available carbohydrate. In addition to proving difficult to predict from the gene content, EPS production levels correlated inversely with production of biofilms, a trait considered desirable in probiotic commensals. L. salivarius displays a high level of genomic diversity, and while selection of L. salivarius strains for probiotic use can be informed by CGH or MLST, it also requires pragmatic experimental validation of desired phenotypic traits. PMID:21131523

  16. Comparative Genomics Reveals High Genomic Diversity in the Genus Photobacterium

    DEFF Research Database (Denmark)

    Machado, Henrique; Gram, Lone

    2017-01-01

    was widespread and abundant in the genus, suggesting a role in genomic evolution. The high genetic variability and indications of genetic exchange make it difficult to elucidate genome evolutionary paths and raise the awareness of the roles of foreign DNA in the genomic evolution of environmental organisms.......Vibrionaceae is a large marine bacterial family, which can constitute up to 50% of the prokaryotic population in marine waters. Photobacterium is the second largest genus in the family and we used comparative genomics on 35 strains representing 16 of the 28 species described so far, to understand...... the genomic diversity present in the Photobacterium genus. Such understanding is important for ecophysiology studies of the genus. We used whole genome sequences to evaluate phylogenetic relationships using several analyses (16S rRNA, MLSA, fur, amino-acid usage, ANI), which allowed us to identify two...

  17. Genomic Diversity in the Genus of Aspergillus

    DEFF Research Database (Denmark)

    Rasmussen, Jane Lind Nybo

    , sections and genus of Aspergillus. The work uncovers a large genomic diversity across all studied groups of species. The genomic diversity was especially evident on the section level, where the proteins shared by all species only represents ⇠55% of the proteome. This number decreases even further, to 38......, sections Nigri, Usti and Cavericolus, clade Tubingensis, and species A. niger. It lastly uses these results to predict genetic traits that take part in fungal speciation. Within a few years the Aspergillus whole-genus sequencing project will have published all currently-accepted Aspergillus genomes......Aspergillus is a highly important genus of saprotrophic filamentous fungi. It is a very diverse genus that is inextricably intertwined with human a↵airs on a daily basis, holding species relevant to plant and human pathology, enzyme and bulk chemistry production, food and beverage biotechnology...

  18. Consequences of genomic diversity in Mycobacterium tuberculosis

    Science.gov (United States)

    Coscolla, Mireia; Gagneux, Sebastien

    2014-01-01

    The causative agent of human tuberculosis, Mycobacterium tuberculosis complex (MTBC), comprises seven phylogenetically distinct lineages associated with different geographical regions. Here we review the latest findings on the nature and amount of genomic diversity within and between MTBC lineages. We then review recent evidence for the effect of this genomic diversity on mycobacterial phenotypes measured experimentally and in clinical settings. We conclude that overall, the most geographically widespread Lineage 2 (includes Beijing) and Lineage 4 (also known as Euro-American) are more virulent than other lineages that are more geographically restricted. This increased virulence is associated with delayed or reduced pro-inflammatory host immune responses, greater severity of disease, and enhanced transmission. Future work should focus on the interaction between MTBC and human genetic diversity, as well as on the environmental factors that modulate these interactions. PMID:25453224

  19. OryzaGenome: Genome Diversity Database of Wild Oryza Species

    KAUST Repository

    Ohyanagi, Hajime

    2015-11-18

    The species in the genus Oryza, encompassing nine genome types and 23 species, are a rich genetic resource and may have applications in deeper genomic analyses aiming to understand the evolution of plant genomes. With the advancement of next-generation sequencing (NGS) technology, a flood of Oryza species reference genomes and genomic variation information has become available in recent years. This genomic information, combined with the comprehensive phenotypic information that we are accumulating in our Oryzabase, can serve as an excellent genotype-phenotype association resource for analyzing rice functional and structural evolution, and the associated diversity of the Oryza genus. Here we integrate our previous and future phenotypic/habitat information and newly determined genotype information into a united repository, named OryzaGenome, providing the variant information with hyperlinks to Oryzabase. The current version of OryzaGenome includes genotype information of 446 O. rufipogon accessions derived by imputation and of 17 accessions derived by imputation-free deep sequencing. Two variant viewers are implemented: SNP Viewer as a conventional genome browser interface and Variant Table as a textbased browser for precise inspection of each variant one by one. Portable VCF (variant call format) file or tabdelimited file download is also available. Following these SNP (single nucleotide polymorphism) data, reference pseudomolecules/ scaffolds/contigs and genome-wide variation information for almost all of the closely and distantly related wild Oryza species from the NIG Wild Rice Collection will be available in future releases. All of the resources can be accessed through http://viewer.shigen.info/oryzagenome/.

  20. Genomic diversity within the haloalkaliphilic genus Thioalkalivibrio.

    Science.gov (United States)

    Ahn, Anne-Catherine; Meier-Kolthoff, Jan P; Overmars, Lex; Richter, Michael; Woyke, Tanja; Sorokin, Dimitry Y; Muyzer, Gerard

    2017-01-01

    Thioalkalivibrio is a genus of obligate chemolithoautotrophic haloalkaliphilic sulfur-oxidizing bacteria. Their habitat are soda lakes which are dual extreme environments with a pH range from 9.5 to 11 and salt concentrations up to saturation. More than 100 strains of this genus have been isolated from various soda lakes all over the world, but only ten species have been effectively described yet. Therefore, the assignment of the remaining strains to either existing or novel species is important and will further elucidate their genomic diversity as well as give a better general understanding of this genus. Recently, the genomes of 76 Thioalkalivibrio strains were sequenced. On these, we applied different methods including (i) 16S rRNA gene sequence analysis, (ii) Multilocus Sequence Analysis (MLSA) based on eight housekeeping genes, (iii) Average Nucleotide Identity based on BLAST (ANIb) and MUMmer (ANIm), (iv) Tetranucleotide frequency correlation coefficients (TETRA), (v) digital DNA:DNA hybridization (dDDH) as well as (vi) nucleotide- and amino acid-based Genome BLAST Distance Phylogeny (GBDP) analyses. We detected a high genomic diversity by revealing 15 new "genomic" species and 16 new "genomic" subspecies in addition to the ten already described species. Phylogenetic and phylogenomic analyses showed that the genus is not monophyletic, because four strains were clearly separated from the other Thioalkalivibrio by type strains from other genera. Therefore, it is recommended to classify the latter group as a novel genus. The biogeographic distribution of Thioalkalivibrio suggested that the different "genomic" species can be classified as candidate disjunct or candidate endemic species. This study is a detailed genome-based classification and identification of members within the genus Thioalkalivibrio. However, future phenotypical and chemotaxonomical studies will be needed for a full species description of this genus.

  1. HLA diversity in the 1000 genomes dataset.

    Directory of Open Access Journals (Sweden)

    Pierre-Antoine Gourraud

    Full Text Available The 1000 Genomes Project aims to provide a deep characterization of human genome sequence variation by sequencing at a level that should allow the genome-wide detection of most variants with frequencies as low as 1%. However, in the major histocompatibility complex (MHC, only the top 10 most frequent haplotypes are in the 1% frequency range whereas thousands of haplotypes are present at lower frequencies. Given the limitation of both the coverage and the read length of the sequences generated by the 1000 Genomes Project, the highly variable positions that define HLA alleles may be difficult to identify. We used classical Sanger sequencing techniques to type the HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1 genes in the available 1000 Genomes samples and combined the results with the 103,310 variants in the MHC region genotyped by the 1000 Genomes Project. Using pairwise identity-by-descent distances between individuals and principal component analysis, we established the relationship between ancestry and genetic diversity in the MHC region. As expected, both the MHC variants and the HLA phenotype can identify the major ancestry lineage, informed mainly by the most frequent HLA haplotypes. To some extent, regions of the genome with similar genetic or similar recombination rate have similar properties. An MHC-centric analysis underlines departures between the ancestral background of the MHC and the genome-wide picture. Our analysis of linkage disequilibrium (LD decay in these samples suggests that overestimation of pairwise LD occurs due to a limited sampling of the MHC diversity. This collection of HLA-specific MHC variants, available on the dbMHC portal, is a valuable resource for future analyses of the role of MHC in population and disease studies.

  2. Genomic diversity of Escherichia isolates from diverse habitats.

    Directory of Open Access Journals (Sweden)

    Seungdae Oh

    Full Text Available Our understanding of the Escherichia genus is heavily biased toward pathogenic or commensal isolates from human or animal hosts. Recent studies have recovered Escherichia isolates that persist, and even grow, outside these hosts. Although the environmental isolates are typically phylogenetically distinct, they are highly related to and phenotypically indistinguishable from their human counterparts, including for the coliform test. To gain insights into the genomic diversity of Escherichia isolates from diverse habitats, including freshwater, soil, animal, and human sources, we carried out comparative DNA-DNA hybridizations using a multi-genome E. coli DNA microarray. The microarray was validated based on hybridizations with selected strains whose genome sequences were available and used to assess the frequency of microarray false positive and negative signals. Our results showed that human fecal isolates share two sets of genes (n>90 that are rarely found among environmental isolates, including genes presumably important for evading host immune mechanisms (e.g., a multi-drug transporter for acids and antimicrobials and adhering to epithelial cells (e.g., hemolysin E and fimbrial-like adhesin protein. These results imply that environmental isolates are characterized by decreased ability to colonize host cells relative to human isolates. Our study also provides gene markers that can distinguish human isolates from those of warm-blooded animal and environmental origins, and thus can be used to more reliably assess fecal contamination in natural ecosystems.

  3. Genomic landscape of human diversity across Madagascar

    Science.gov (United States)

    Pierron, Denis; Heiske, Margit; Razafindrazaka, Harilanto; Rakoto, Ignace; Rabetokotany, Nelly; Ravololomanga, Bodo; Rakotozafy, Lucien M.-A.; Rakotomalala, Mireille Mialy; Razafiarivony, Michel; Rasoarifetra, Bako; Raharijesy, Miakabola Andriamampianina; Razafindralambo, Lolona; Ramilisonina; Fanony, Fulgence; Lejamble, Sendra; Thomas, Olivier; Mohamed Abdallah, Ahmed; Rocher, Christophe; Arachiche, Amal; Tonaso, Laure; Pereda-loth, Veronica; Schiavinato, Stéphanie; Brucato, Nicolas; Ricaut, Francois-Xavier; Kusuma, Pradiptajati; Sudoyo, Herawati; Ni, Shengyu; Boland, Anne; Deleuze, Jean-Francois; Beaujard, Philippe; Grange, Philippe; Adelaar, Sander; Stoneking, Mark; Rakotoarisoa, Jean-Aimé; Radimilahy, Chantal; Letellier, Thierry

    2017-01-01

    Although situated ∼400 km from the east coast of Africa, Madagascar exhibits cultural, linguistic, and genetic traits from both Southeast Asia and Eastern Africa. The settlement history remains contentious; we therefore used a grid-based approach to sample at high resolution the genomic diversity (including maternal lineages, paternal lineages, and genome-wide data) across 257 villages and 2,704 Malagasy individuals. We find a common Bantu and Austronesian descent for all Malagasy individuals with a limited paternal contribution from Europe and the Middle East. Admixture and demographic growth happened recently, suggesting a rapid settlement of Madagascar during the last millennium. However, the distribution of African and Asian ancestry across the island reveals that the admixture was sex biased and happened heterogeneously across Madagascar, suggesting independent colonization of Madagascar from Africa and Asia rather than settlement by an already admixed population. In addition, there are geographic influences on the present genomic diversity, independent of the admixture, showing that a few centuries is sufficient to produce detectable genetic structure in human populations. PMID:28716916

  4. Visualization of Genome Diversity in German Shepherd Dogs

    OpenAIRE

    Sally-Anne Mortlock; Rachel Booth; Hamutal Mazrier; Mehar S. Khatkar; Peter Williamson

    2016-01-01

    A loss of genetic diversity may lead to increased disease risks in subpopulations of dogs. The canine breed structure has contributed to relatively small effective population size in many breeds and can limit the options for selective breeding strategies to maintain diversity. With the completion of the canine genome sequencing project, and the subsequent reduction in the cost of genotyping on a genomic scale, evaluating diversity in dogs has become much more accurate and accessible. This pro...

  5. Preliminary Design Analysis of a HGD for the NHDD Program at Korea

    International Nuclear Information System (INIS)

    Song, Kee Nam; Lee, H. Y.; Lee, S. B.; Kim, Y. W.

    2007-01-01

    Korea Atomic Energy Research Institute is in the process of carrying out a Nuclear Hydrogen Development and Demonstration (NHDD) Program by considering the indirect cycle gas cooled reactors that produce heat at temperatures in the order of 950 .deg. C. A coaxial double-tube Hot Gas Duct (HGD) is a key component connecting the reactor pressure vessel and the intermediate heat exchanger for the NHDD program. Recently, a preliminary design evaluation for the hot gas duct of the NHDD program was carried out. These preliminary design activities include a decision on the geometric dimensions, a strength evaluation, an appropriate material selection, and identifying the design code for the HGD. In this study, a preliminary strength evaluation for the HGD of the NHDD program has been undertaken based on the HTR-10 design concepts. Also, a preliminary evaluation of the creep-fatigue damage for a high temperature HGD structure has been carried out according to the draft code case for Alloy 617. Preliminary strength evaluation results for the HGD showed that the geometric dimensions of the proposed HGD would be acceptable for the design requirements

  6. Genetic Competence Drives Genome Diversity in Bacillus subtilis

    Science.gov (United States)

    Chevreux, Bastien; Serra, Cláudia R; Schyns, Ghislain; Henriques, Adriano O

    2018-01-01

    Abstract Prokaryote genomes are the result of a dynamic flux of genes, with increases achieved via horizontal gene transfer and reductions occurring through gene loss. The ecological and selective forces that drive this genomic flexibility vary across species. Bacillus subtilis is a naturally competent bacterium that occupies various environments, including plant-associated, soil, and marine niches, and the gut of both invertebrates and vertebrates. Here, we quantify the genomic diversity of B. subtilis and infer the genome dynamics that explain the high genetic and phenotypic diversity observed. Phylogenomic and comparative genomic analyses of 42 B. subtilis genomes uncover a remarkable genome diversity that translates into a core genome of 1,659 genes and an asymptotic pangenome growth rate of 57 new genes per new genome added. This diversity is due to a large proportion of low-frequency genes that are acquired from closely related species. We find no gene-loss bias among wild isolates, which explains why the cloud genome, 43% of the species pangenome, represents only a small proportion of each genome. We show that B. subtilis can acquire xenologous copies of core genes that propagate laterally among strains within a niche. While not excluding the contributions of other mechanisms, our results strongly suggest a process of gene acquisition that is largely driven by competence, where the long-term maintenance of acquired genes depends on local and global fitness effects. This competence-driven genomic diversity provides B. subtilis with its generalist character, enabling it to occupy a wide range of ecological niches and cycle through them. PMID:29272410

  7. Two Tales of Prokaryotic Genomic Diversity: Escherichia coli and Halophiles

    Directory of Open Access Journals (Sweden)

    Lejla Pašić

    2014-01-01

    Full Text Available Prokaryotes are generally characterized by vast genomic diversity that has been shaped by mutations, horizontal gene transfer, bacteriocins and phage predation. Enormous genetic diversity has developed as a result of stresses imposed in harsh environments and the ability of microorganisms to adapt. Two examples of prokaryotic diversity are presented: on intraspecies level, exemplified by Escherichia coli, and the diversity of the hypersaline environment, with the discussion of food-related health issues and biotechnological potential.

  8. Intraclonal genome diversity of Pseudomonas aeruginosa clones CHA and TB

    Science.gov (United States)

    2013-01-01

    Background Adaptation of Pseudomonas aeruginosa to different living conditions is accompanied by microevolution resulting in genomic diversity between strains of the same clonal lineage. In order to detect the impact of colonized habitats on P. aeruginosa microevolution we determined the genomic diversity between the highly virulent cystic fibrosis (CF) isolate CHA and two temporally and geographically unrelated clonal variants. The outcome was compared with the intraclonal genome diversity between three more closely related isolates of another clonal complex. Results The three clone CHA isolates differed in their core genome in several dozen strain specific nucleotide exchanges and small deletions from each other. Loss of function mutations and non-conservative amino acid replacements affected several habitat- and lifestyle-associated traits, for example, the key regulator GacS of the switch between acute and chronic disease phenotypes was disrupted in strain CHA. Intraclonal genome diversity manifested in an individual composition of the respective accessory genome whereby the highest number of accessory DNA elements was observed for isolate PT22 from a polluted aquatic habitat. Little intraclonal diversity was observed between three spatiotemporally related outbreak isolates of clone TB. Although phenotypically different, only a few individual SNPs and deletions were detected in the clone TB isolates. Their accessory genome mainly differed in prophage-like DNA elements taken up by one of the strains. Conclusions The higher geographical and temporal distance of the clone CHA isolates was associated with an increased intraclonal genome diversity compared to the more closely related clone TB isolates derived from a common source demonstrating the impact of habitat adaptation on the microevolution of P. aeruginosa. However, even short-term habitat differentiation can cause major phenotypic diversification driven by single genomic variation events and uptake of phage

  9. OryzaGenome: Genome Diversity Database of Wild Oryza Species

    KAUST Repository

    Ohyanagi, Hajime; Ebata, Toshinobu; Huang, Xuehui; Gong, Hao; Fujita, Masahiro; Mochizuki, Takako; Toyoda, Atsushi; Fujiyama, Asao; Kaminuma, Eli; Nakamura, Yasukazu; Feng, Qi; Wang, Zi Xuan; Han, Bin; Kurata, Nori

    2015-01-01

    . Portable VCF (variant call format) file or tabdelimited file download is also available. Following these SNP (single nucleotide polymorphism) data, reference pseudomolecules/ scaffolds/contigs and genome-wide variation information for almost all

  10. A novel missense HGD gene mutation, K57N, in a patient with alkaptonuria.

    Science.gov (United States)

    Grasko, Jonathan M; Hooper, Amanda J; Brown, Jeffrey W; McKnight, C James; Burnett, John R

    2009-05-01

    Alkaptonuria is a rare recessive disorder of phenylalanine/tyrosine metabolism due to a defect in the enzyme homogentisate 1,2-dioxygenase (HGD) caused by mutations in the HGD gene. We report the case of a 38 year-old male with known alkaptonuria who was referred to an adult metabolic clinic after initially presenting to an emergency department with renal colic and subsequently passing black ureteric calculi. He complained of severe debilitating lower back pain, worsening over the last few years. A CT scan revealed marked degenerative changes and severe narrowing of the disc spaces along the entire lumbar spine. Sequencing of the HGD gene revealed that he was a compound heterozygote for a previously described missense mutation in exon 13 (G360R) and a novel missense mutation in exon 3 (K57N). Lys(57) is conserved among species and mutation of this residue is predicted to affect HGD protein function by interfering with substrate traffic at the active site. In summary, we describe an alkaptonuric patient and report a novel missense HGD mutation, K57N.

  11. Nucleotide diversity maps reveal variation in diversity among wheat genomes and chromosomes

    Directory of Open Access Journals (Sweden)

    McGuire Patrick E

    2010-12-01

    Full Text Available Abstract Background A genome-wide assessment of nucleotide diversity in a polyploid species must minimize the inclusion of homoeologous sequences into diversity estimates and reliably allocate individual haplotypes into their respective genomes. The same requirements complicate the development and deployment of single nucleotide polymorphism (SNP markers in polyploid species. We report here a strategy that satisfies these requirements and deploy it in the sequencing of genes in cultivated hexaploid wheat (Triticum aestivum, genomes AABBDD and wild tetraploid wheat (Triticum turgidum ssp. dicoccoides, genomes AABB from the putative site of wheat domestication in Turkey. Data are used to assess the distribution of diversity among and within wheat genomes and to develop a panel of SNP markers for polyploid wheat. Results Nucleotide diversity was estimated in 2114 wheat genes and was similar between the A and B genomes and reduced in the D genome. Within a genome, diversity was diminished on some chromosomes. Low diversity was always accompanied by an excess of rare alleles. A total of 5,471 SNPs was discovered in 1791 wheat genes. Totals of 1,271, 1,218, and 2,203 SNPs were discovered in 488, 463, and 641 genes of wheat putative diploid ancestors, T. urartu, Aegilops speltoides, and Ae. tauschii, respectively. A public database containing genome-specific primers, SNPs, and other information was constructed. A total of 987 genes with nucleotide diversity estimated in one or more of the wheat genomes was placed on an Ae. tauschii genetic map, and the map was superimposed on wheat deletion-bin maps. The agreement between the maps was assessed. Conclusions In a young polyploid, exemplified by T. aestivum, ancestral species are the primary source of genetic diversity. Low effective recombination due to self-pollination and a genetic mechanism precluding homoeologous chromosome pairing during polyploid meiosis can lead to the loss of diversity from large

  12. Genomic and Genetic Diversity within the Pseudomonas fluorescens Complex.

    Directory of Open Access Journals (Sweden)

    Daniel Garrido-Sanz

    Full Text Available The Pseudomonas fluorescens complex includes Pseudomonas strains that have been taxonomically assigned to more than fifty different species, many of which have been described as plant growth-promoting rhizobacteria (PGPR with potential applications in biocontrol and biofertilization. So far the phylogeny of this complex has been analyzed according to phenotypic traits, 16S rDNA, MLSA and inferred by whole-genome analysis. However, since most of the type strains have not been fully sequenced and new species are frequently described, correlation between taxonomy and phylogenomic analysis is missing. In recent years, the genomes of a large number of strains have been sequenced, showing important genomic heterogeneity and providing information suitable for genomic studies that are important to understand the genomic and genetic diversity shown by strains of this complex. Based on MLSA and several whole-genome sequence-based analyses of 93 sequenced strains, we have divided the P. fluorescens complex into eight phylogenomic groups that agree with previous works based on type strains. Digital DDH (dDDH identified 69 species and 75 subspecies within the 93 genomes. The eight groups corresponded to clustering with a threshold of 31.8% dDDH, in full agreement with our MLSA. The Average Nucleotide Identity (ANI approach showed inconsistencies regarding the assignment to species and to the eight groups. The small core genome of 1,334 CDSs and the large pan-genome of 30,848 CDSs, show the large diversity and genetic heterogeneity of the P. fluorescens complex. However, a low number of strains were enough to explain most of the CDSs diversity at core and strain-specific genomic fractions. Finally, the identification and analysis of group-specific genome and the screening for distinctive characters revealed a phylogenomic distribution of traits among the groups that provided insights into biocontrol and bioremediation applications as well as their role as

  13. Biodistribution of the GATA-3-specific DNAzyme hgd40 after inhalative exposure in mice, rats and dogs

    International Nuclear Information System (INIS)

    Turowska, Agnieszka; Librizzi, Damiano; Baumgartl, Nadja; Kuhlmann, Jens; Dicke, Tanja; Merkel, Olivia; Homburg, Ursula; Höffken, Helmut; Renz, Harald; Garn, Holger

    2013-01-01

    The DNAzyme hgd40 was shown to effectively reduce expression of the transcription factor GATA-3 RNA which plays an important role in the regulation of Th2-mediated immune mechanisms such as in allergic bronchial asthma. However, uptake, biodistribution and pharmacokinetics of hgd40 have not been investigated yet. We examined local and systemic distribution of hgd40 in naive mice and mice suffering from experimental asthma. Furthermore, we evaluated the pharmacokinetics as a function of dose following single and repeated administration in rats and dogs. Using intranasal administration of fluorescently labeled hgd40 we demonstrated that the DNAzyme was evenly distributed in inflamed asthmatic mouse lungs within minutes after single dose application. Systemic distribution was investigated in mice using radioactive labeled hgd40. After intratracheal application, highest amounts of hgd40 were detected in the lungs. High amounts were also detected in the bladder indicating urinary excretion as a major elimination pathway. In serum, low systemic hgd40 levels were detected already at 5 min post application (p.a.), subsequently decreasing over time to non-detectable levels at 2 h p.a. As revealed by Single Photon Emission Computed Tomography, trace amounts of hgd40 were detectable in lungs up to 7 days p.a. Also in the toxicologically relevant rats and dogs, hgd40 was detectable in blood only shortly after inhalative application. The plasma pharmacokinetic profile was dose and time dependent. Repeated administration did not lead to drug accumulation in plasma of dogs and rats. These pharmacokinetic of hgd40 provide guidance for clinical development, and support an infrequent and convenient dose administration regimen. - Highlights: • Local and systemic distribution of GATA-3-specific DNAzyme hgd40 was investigated. • Pharmacokinetics of hgd40 was tested in rats and dogs. • hgd40 dissolved in PBS was easily taken up into the lungs after local application. • No

  14. Biodistribution of the GATA-3-specific DNAzyme hgd40 after inhalative exposure in mice, rats and dogs

    Energy Technology Data Exchange (ETDEWEB)

    Turowska, Agnieszka [sterna biologicals GmbH and Co. KG, Marburg (Germany); Librizzi, Damiano [Department of Nuclear Medicine, University Hospital Giessen and Marburg GmbH, Baldingerstrasse, 35043 Marburg (Germany); Baumgartl, Nadja [Institute of Laboratory Medicine and Pathobiochemistry-Molecular Diagnostics, Philipps University of Marburg (Germany); Kuhlmann, Jens; Dicke, Tanja [sterna biologicals GmbH and Co. KG, Marburg (Germany); Merkel, Olivia [Department of Pharmaceutical Sciences, Wayne State University, Detroit (United States); Homburg, Ursula [sterna biologicals GmbH and Co. KG, Marburg (Germany); Höffken, Helmut [Department of Nuclear Medicine, University Hospital Giessen and Marburg GmbH, Baldingerstrasse, 35043 Marburg (Germany); Renz, Harald [Institute of Laboratory Medicine and Pathobiochemistry-Molecular Diagnostics, Philipps University of Marburg (Germany); Garn, Holger, E-mail: garn@staff.uni-marburg.de [Institute of Laboratory Medicine and Pathobiochemistry-Molecular Diagnostics, Philipps University of Marburg (Germany)

    2013-10-15

    The DNAzyme hgd40 was shown to effectively reduce expression of the transcription factor GATA-3 RNA which plays an important role in the regulation of Th2-mediated immune mechanisms such as in allergic bronchial asthma. However, uptake, biodistribution and pharmacokinetics of hgd40 have not been investigated yet. We examined local and systemic distribution of hgd40 in naive mice and mice suffering from experimental asthma. Furthermore, we evaluated the pharmacokinetics as a function of dose following single and repeated administration in rats and dogs. Using intranasal administration of fluorescently labeled hgd40 we demonstrated that the DNAzyme was evenly distributed in inflamed asthmatic mouse lungs within minutes after single dose application. Systemic distribution was investigated in mice using radioactive labeled hgd40. After intratracheal application, highest amounts of hgd40 were detected in the lungs. High amounts were also detected in the bladder indicating urinary excretion as a major elimination pathway. In serum, low systemic hgd40 levels were detected already at 5 min post application (p.a.), subsequently decreasing over time to non-detectable levels at 2 h p.a. As revealed by Single Photon Emission Computed Tomography, trace amounts of hgd40 were detectable in lungs up to 7 days p.a. Also in the toxicologically relevant rats and dogs, hgd40 was detectable in blood only shortly after inhalative application. The plasma pharmacokinetic profile was dose and time dependent. Repeated administration did not lead to drug accumulation in plasma of dogs and rats. These pharmacokinetic of hgd40 provide guidance for clinical development, and support an infrequent and convenient dose administration regimen. - Highlights: • Local and systemic distribution of GATA-3-specific DNAzyme hgd40 was investigated. • Pharmacokinetics of hgd40 was tested in rats and dogs. • hgd40 dissolved in PBS was easily taken up into the lungs after local application. • No

  15. Global biogeography of Prochlorococcus genome diversity in the surface ocean.

    Science.gov (United States)

    Kent, Alyssa G; Dupont, Chris L; Yooseph, Shibu; Martiny, Adam C

    2016-08-01

    Prochlorococcus, the smallest known photosynthetic bacterium, is abundant in the ocean's surface layer despite large variation in environmental conditions. There are several genetically divergent lineages within Prochlorococcus and superimposed on this phylogenetic diversity is extensive gene gain and loss. The environmental role in shaping the global ocean distribution of genome diversity in Prochlorococcus is largely unknown, particularly in a framework that considers the vertical and lateral mechanisms of evolution. Here we show that Prochlorococcus field populations from a global circumnavigation harbor extensive genome diversity across the surface ocean, but this diversity is not randomly distributed. We observed a significant correspondence between phylogenetic and gene content diversity, including regional differences in both phylogenetic composition and gene content that were related to environmental factors. Several gene families were strongly associated with specific regions and environmental factors, including the identification of a set of genes related to lower nutrient and temperature regions. Metagenomic assemblies of natural Prochlorococcus genomes reinforced this association by providing linkage of genes across genomic backbones. Overall, our results show that the phylogeography in Prochlorococcus taxonomy is echoed in its genome content. Thus environmental variation shapes the functional capabilities and associated ecosystem role of the globally abundant Prochlorococcus.

  16. Cancer Genomics: Diversity and Disparity Across Ethnicity and Geography.

    Science.gov (United States)

    Tan, Daniel S W; Mok, Tony S K; Rebbeck, Timothy R

    2016-01-01

    Ethnic and geographic differences in cancer incidence, prognosis, and treatment outcomes can be attributed to diversity in the inherited (germline) and somatic genome. Although international large-scale sequencing efforts are beginning to unravel the genomic underpinnings of cancer traits, much remains to be known about the underlying mechanisms and determinants of genomic diversity. Carcinogenesis is a dynamic, complex phenomenon representing the interplay between genetic and environmental factors that results in divergent phenotypes across ethnicities and geography. For example, compared with whites, there is a higher incidence of prostate cancer among Africans and African Americans, and the disease is generally more aggressive and fatal. Genome-wide association studies have identified germline susceptibility loci that may account for differences between the African and non-African patients, but the lack of availability of appropriate cohorts for replication studies and the incomplete understanding of genomic architecture across populations pose major limitations. We further discuss the transformative potential of routine diagnostic evaluation for actionable somatic alterations, using lung cancer as an example, highlighting implications of population disparities, current hurdles in implementation, and the far-reaching potential of clinical genomics in enhancing cancer prevention, diagnosis, and treatment. As we enter the era of precision cancer medicine, a concerted multinational effort is key to addressing population and genomic diversity as well as overcoming barriers and geographical disparities in research and health care delivery. © 2015 by American Society of Clinical Oncology.

  17. Evolution and Diversity of Transposable Elements in Vertebrate Genomes.

    Science.gov (United States)

    Sotero-Caio, Cibele G; Platt, Roy N; Suh, Alexander; Ray, David A

    2017-01-01

    Transposable elements (TEs) are selfish genetic elements that mobilize in genomes via transposition or retrotransposition and often make up large fractions of vertebrate genomes. Here, we review the current understanding of vertebrate TE diversity and evolution in the context of recent advances in genome sequencing and assembly techniques. TEs make up 4-60% of assembled vertebrate genomes, and deeply branching lineages such as ray-finned fishes and amphibians generally exhibit a higher TE diversity than the more recent radiations of birds and mammals. Furthermore, the list of taxa with exceptional TE landscapes is growing. We emphasize that the current bottleneck in genome analyses lies in the proper annotation of TEs and provide examples where superficial analyses led to misleading conclusions about genome evolution. Finally, recent advances in long-read sequencing will soon permit access to TE-rich genomic regions that previously resisted assembly including the gigantic, TE-rich genomes of salamanders and lungfishes. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Genomic diversity within the Enterobacter cloacae complex.

    Directory of Open Access Journals (Sweden)

    Armand Paauw

    Full Text Available BACKGROUND: Isolates of the Enterobacter cloacae complex have been increasingly isolated as nosocomial pathogens, but phenotypic identification of the E. cloacae complex is unreliable and irreproducible. Identification of species based on currently available genotyping tools is already superior to phenotypic identification, but the taxonomy of isolates belonging to this complex is cumbersome. METHODOLOGY/PRINCIPAL FINDINGS: This study shows that multilocus sequence analysis and comparative genomic hybridization based on a mixed genome array is a powerful method for studying species assignment within the E. cloacae complex. The E. cloacae complex is shown to be evolutionarily divided into two clades that are genetically distinct from each other. The younger first clade is genetically more homogenous, contains the Enterobacter hormaechei species and is the most frequently cultured Enterobacter species in hospitals. The second and older clade consists of several (subspecies that are genetically more heterogeneous. Genetic markers were identified that could discriminate between the two clades and cluster 1. CONCLUSIONS/SIGNIFICANCE: Based on genomic differences it is concluded that some previously defined (clonal and heterogenic (subspecies of the E. cloacae complex have to be redefined because of disagreements with known or proposed nomenclature. However, further improved identification of the redefined species will be possible based on novel markers presented here.

  19. Genomic diversity of Bombyx mori nucleopolyhedrovirus strains.

    Science.gov (United States)

    Xu, Yi-Peng; Cheng, Ruo-Lin; Xi, Yu; Zhang, Chuan-Xi

    2013-07-01

    Bombyx mori nucleopolyhedrovirus (BmNPV) is a baculovirus that selectively infects the domestic silkworm. In this study, six BmNPV strains were compared at the whole genome level. We found that the number of bro genes and the composition of the homologous regions (hrs) are the two primary areas of divergence within these genomes. When we compared the ORFs of these BmNPV variants, we noticed a high degree of sequence divergence in the ORFs that are not baculovirus core genes. This result is consistent with the results derived from phylogenetic trees and evolutionary pressure analyses of these ORFs, indicating that ORFs that are not core genes likely play important roles in the evolution of BmNPV strains. The evolutionary relationships of these BmNPV strains might be explained by their geographic origins or those of their hosts. In addition, the total number of hr palindromes seems to affect viral DNA replication in Bm5 cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Genomic Diversity and Evolution of the Fish Pathogen Flavobacterium psychrophilum

    Directory of Open Access Journals (Sweden)

    Eric Duchaud

    2018-02-01

    Full Text Available Flavobacterium psychrophilum, the etiological agent of rainbow trout fry syndrome and bacterial cold-water disease in salmonid fish, is currently one of the main bacterial pathogens hampering the productivity of salmonid farming worldwide. In this study, the genomic diversity of the F. psychrophilum species is analyzed using a set of 41 genomes, including 30 newly sequenced isolates. These were selected on the basis of available MLST data with the two-fold objective of maximizing the coverage of the species diversity and of allowing a focus on the main clonal complex (CC-ST10 infecting farmed rainbow trout (Oncorhynchus mykiss worldwide. The results reveal a bacterial species harboring a limited genomic diversity both in terms of nucleotide diversity, with ~0.3% nucleotide divergence inside CDSs in pairwise genome comparisons, and in terms of gene repertoire, with the core genome accounting for ~80% of the genes in each genome. The pan-genome seems nevertheless “open” according to the scaling exponent of a power-law fitted on the rate of new gene discovery when genomes are added one-by-one. Recombination is a key component of the evolutionary process of the species as seen in the high level of apparent homoplasy in the core genome. Using a Hidden Markov Model to delineate recombination tracts in pairs of closely related genomes, the average recombination tract length was estimated to ~4.0 Kbp and the typical ratio of the contributions of recombination and mutations to nucleotide-level differentiation (r/m was estimated to ~13. Within CC-ST10, evolutionary distances computed on non-recombined regions and comparisons between 22 isolates sampled up to 27 years apart suggest a most recent common ancestor in the second half of the nineteenth century in North America with subsequent diversification and transmission of this clonal complex coinciding with the worldwide expansion of rainbow trout farming. With the goal to promote the development of

  1. Reduced representation approaches to interrogate genome diversity in large repetitive plant genomes.

    Science.gov (United States)

    Hirsch, Cory D; Evans, Joseph; Buell, C Robin; Hirsch, Candice N

    2014-07-01

    Technology and software improvements in the last decade now provide methodologies to access the genome sequence of not only a single accession, but also multiple accessions of plant species. This provides a means to interrogate species diversity at the genome level. Ample diversity among accessions in a collection of species can be found, including single-nucleotide polymorphisms, insertions and deletions, copy number variation and presence/absence variation. For species with small, non-repetitive rich genomes, re-sequencing of query accessions is robust, highly informative, and economically feasible. However, for species with moderate to large sized repetitive-rich genomes, technical and economic barriers prevent en masse genome re-sequencing of accessions. Multiple approaches to access a focused subset of loci in species with larger genomes have been developed, including reduced representation sequencing, exome capture and transcriptome sequencing. Collectively, these approaches have enabled interrogation of diversity on a genome scale for large plant genomes, including crop species important to worldwide food security. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Evolution and Diversity in Human Herpes Simplex Virus Genomes

    Science.gov (United States)

    Gatherer, Derek; Ochoa, Alejandro; Greenbaum, Benjamin; Dolan, Aidan; Bowden, Rory J.; Enquist, Lynn W.; Legendre, Matthieu; Davison, Andrew J.

    2014-01-01

    Herpes simplex virus 1 (HSV-1) causes a chronic, lifelong infection in >60% of adults. Multiple recent vaccine trials have failed, with viral diversity likely contributing to these failures. To understand HSV-1 diversity better, we comprehensively compared 20 newly sequenced viral genomes from China, Japan, Kenya, and South Korea with six previously sequenced genomes from the United States, Europe, and Japan. In this diverse collection of passaged strains, we found that one-fifth of the newly sequenced members share a gene deletion and one-third exhibit homopolymeric frameshift mutations (HFMs). Individual strains exhibit genotypic and potential phenotypic variation via HFMs, deletions, short sequence repeats, and single-nucleotide polymorphisms, although the protein sequence identity between strains exceeds 90% on average. In the first genome-scale analysis of positive selection in HSV-1, we found signs of selection in specific proteins and residues, including the fusion protein glycoprotein H. We also confirmed previous results suggesting that recombination has occurred with high frequency throughout the HSV-1 genome. Despite this, the HSV-1 strains analyzed clustered by geographic origin during whole-genome distance analysis. These data shed light on likely routes of HSV-1 adaptation to changing environments and will aid in the selection of vaccine antigens that are invariant worldwide. PMID:24227835

  3. Using genomic information to conserve genetic diversity in livestock

    NARCIS (Netherlands)

    Eynard, Sonia E.

    2018-01-01

    Concern about the status of livestock breeds and their conservation has increased as selection and small population sizes caused loss of genetic diversity. Meanwhile, dense SNP chips and whole genome sequences (WGS) became available, providing opportunities to accurately quantify the impact of

  4. Lampreys as Diverse Model Organisms in the Genomics Era.

    Science.gov (United States)

    McCauley, David W; Docker, Margaret F; Whyard, Steve; Li, Weiming

    2015-11-01

    Lampreys, one of the two surviving groups of ancient vertebrates, have become important models for study in diverse fields of biology. Lampreys (of which there are approximately 40 species) are being studied, for example, (a) to control pest sea lamprey in the North American Great Lakes and to restore declining populations of native species elsewhere; (b) in biomedical research, focusing particularly on the regenerative capability of lampreys; and (c) by developmental biologists studying the evolution of key vertebrate characters. Although a lack of genetic resources has hindered research on the mechanisms regulating many aspects of lamprey life history and development, formerly intractable questions are now amenable to investigation following the recent publication of the sea lamprey genome. Here, we provide an overview of the ways in which genomic tools are currently being deployed to tackle diverse research questions and suggest several areas that may benefit from the availability of the sea lamprey genome.

  5. Natural Product Biosynthetic Diversity and Comparative Genomics of the Cyanobacteria.

    Science.gov (United States)

    Dittmann, Elke; Gugger, Muriel; Sivonen, Kaarina; Fewer, David P

    2015-10-01

    Cyanobacteria are an ancient lineage of slow-growing photosynthetic bacteria and a prolific source of natural products with intricate chemical structures and potent biological activities. The bulk of these natural products are known from just a handful of genera. Recent efforts have elucidated the mechanisms underpinning the biosynthesis of a diverse array of natural products from cyanobacteria. Many of the biosynthetic mechanisms are unique to cyanobacteria or rarely described from other organisms. Advances in genome sequence technology have precipitated a deluge of genome sequences for cyanobacteria. This makes it possible to link known natural products to biosynthetic gene clusters but also accelerates the discovery of new natural products through genome mining. These studies demonstrate that cyanobacteria encode a huge variety of cryptic gene clusters for the production of natural products, and the known chemical diversity is likely to be just a fraction of the true biosynthetic capabilities of this fascinating and ancient group of organisms. Copyright © 2015. Published by Elsevier Ltd.

  6. Absence of genome reduction in diverse, facultative endohyphal bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Baltrus, David A. [Univ. of Arizona, Tucson, AZ (United States); Dougherty, Kevin [Univ. of Arizona, Tucson, AZ (United States); Arendt, Kayla R. [Univ. of Arizona, Tucson, AZ (United States); Huntemann, Marcel [Joint Genome Institute, Walnut Creek, CA (United States); Clum, Alicia [Joint Genome Institute, Walnut Creek, CA (United States); Pillay, Manoj [Joint Genome Institute, Walnut Creek, CA (United States); Palaniappan, Krishnaveni [Joint Genome Institute, Walnut Creek, CA (United States); Varghese, Neha [Joint Genome Institute, Walnut Creek, CA (United States); Mikhailova, Natalia [Joint Genome Institute, Walnut Creek, CA (United States); Stamatis, Dimitrios [Joint Genome Institute, Walnut Creek, CA (United States); Reddy, T. B. K. [Joint Genome Institute, Walnut Creek, CA (United States); Ngan, Chew Yee [Joint Genome Institute, Walnut Creek, CA (United States); Daum, Chris [Joint Genome Institute, Walnut Creek, CA (United States); Shapiro, Nicole [Joint Genome Institute, Walnut Creek, CA (United States); Markowitz, Victor [Joint Genome Institute, Walnut Creek, CA (United States); Ivanova, Natalia [Joint Genome Institute, Walnut Creek, CA (United States); Kyrpides, Nikos [Joint Genome Institute, Walnut Creek, CA (United States); Woyke, Tanja [Joint Genome Institute, Walnut Creek, CA (United States); Arnold, A. Elizabeth [Univ. of Arizona, Tucson, AZ (United States)

    2017-02-28

    Fungi interact closely with bacteria, both on the surfaces of the hyphae and within their living tissues (i.e. endohyphal bacteria, EHB). These EHB can be obligate or facultative symbionts and can mediate diverse phenotypic traits in their hosts. Although EHB have been observed in many lineages of fungi, it remains unclear how widespread and general these associations are, and whether there are unifying ecological and genomic features can be found across EHB strains as a whole. We cultured 11 bacterial strains after they emerged from the hyphae of diverse Ascomycota that were isolated as foliar endophytes of cupressaceous trees, and generated nearly complete genome sequences for all. Unlike the genomes of largely obligate EHB, the genomes of these facultative EHB resembled those of closely related strains isolated from environmental sources. Although all analysed genomes encoded structures that could be used to interact with eukaryotic hosts, pathways previously implicated in maintenance and establishment of EHB symbiosis were not universally present across all strains. Independent isolation of two nearly identical pairs of strains from different classes of fungi, coupled with recent experimental evidence, suggests horizontal transfer of EHB across endophytic hosts. Given the potential for EHB to influence fungal phenotypes, these genomes could shed light on the mechanisms of plant growth promotion or stress mitigation by fungal endophytes during the symbiotic phase, as well as degradation of plant material during the saprotrophic phase. As such, these findings contribute to the illumination of a new dimension of functional biodiversity in fungi.

  7. Report of the second Human Genome Diversity workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    The Second Human Genome Diversity Workshop was successfully held at Penn State University from October 29--31, 1992. The Workshop was essentially organized around 7 groups, each comprising approximately 10 participants, representing the sampling issues in different regions of the world. These groups worked independently, using a common format provided by the organizers; this was adjusted as needed by the individual groups. The Workshop began with a presentation of the mandate to the participants, and of the procedures to be followed during the workshop. Dr. Feldman presented a summary of the results from the First Workshop. He and the other organizers also presented brief comments giving their perspective on the objectives of the Second Workshop. Dr. Julia Bodmer discussed the study of European genetic diversity, especially in the context of the HLA experience there, and of plans to extend such studies in the coming years. She also discussed surveys of world HLA laboratories in regard to resources related to Human Genome Diversity. Dr. Mark Weiss discussed the relevance of nonhuman primate studies for understanding how demographic processes, such as mate exchange between local groups, affected the local dispersion of genetic variation. Primate population geneticists have some relevant experience in interpreting variation at this local level, in particular, with various DNA fingerprinting methods. This experience may be relevant to the Human Genome Diversity Project, in terms of practical and statistical issues.

  8. Unraveling Mycobacterium tuberculosis genomic diversity and evolution in Lisbon, Portugal, a highly drug resistant setting

    KAUST Repository

    Perdigã o, Joã o; Silva, Hugo; Machado, Diana; Macedo, Rita; Maltez, Fernando; Silva, Carla; Jordao, Luisa; Couto, Isabel; Mallard, Kim; Coll, Francesc; Hill-Cawthorne, Grant A.; McNerney, Ruth; Pain, Arnab; Clark, Taane G; Viveiros, Miguel; Portugal, Isabel

    2014-01-01

    Globally, this study contributes with novel genome-wide phylogenetic data and has led to the identification of new genomic variants that support the notion of a growing genomic diversity facing both setting and host adaptation.

  9. Correlation exploration of metabolic and genomic diversity in rice

    Directory of Open Access Journals (Sweden)

    Shinozaki Kazuo

    2009-12-01

    Full Text Available Abstract Background It is essential to elucidate the relationship between metabolic and genomic diversity to understand the genetic regulatory networks associated with the changing metabolo-phenotype among natural variation and/or populations. Recent innovations in metabolomics technologies allow us to grasp the comprehensive features of the metabolome. Metabolite quantitative trait analysis is a key approach for the identification of genetic loci involved in metabolite variation using segregated populations. Although several attempts have been made to find correlative relationships between genetic and metabolic diversity among natural populations in various organisms, it is still unclear whether it is possible to discover such correlations between each metabolite and the polymorphisms found at each chromosomal location. To assess the correlative relationship between the metabolic and genomic diversity found in rice accessions, we compared the distance matrices for these two "omics" patterns in the rice accessions. Results We selected 18 accessions from the world rice collection based on their population structure. To determine the genomic diversity of the rice genome, we genotyped 128 restriction fragment length polymorphism (RFLP markers to calculate the genetic distance among the accessions. To identify the variations in the metabolic fingerprint, a soluble extract from the seed grain of each accession was analyzed with one dimensional 1H-nuclear magnetic resonance (NMR. We found no correlation between global metabolic diversity and the phylogenetic relationships among the rice accessions (rs = 0.14 by analyzing the distance matrices (calculated from the pattern of the metabolic fingerprint in the 4.29- to 0.71-ppm 1H chemical shift and the genetic distance on the basis of the RFLP markers. However, local correlation analysis between the distance matrices (derived from each 0.04-ppm integral region of the 1H chemical shift against genetic

  10. The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

    KAUST Repository

    Bracken-Grissom, Heather

    2013-12-12

    Over 95% of all metazoan (animal) species comprise the invertebrates, but very few genomes from these organisms have been sequenced. We have, therefore, formed a Global Invertebrate Genomics Alliance (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site () has been launched to facilitate this collaborative venture.

  11. Diversity of Pseudomonas Genomes, Including Populus-Associated Isolates, as Revealed by Comparative Genome Analysis.

    Science.gov (United States)

    Jun, Se-Ran; Wassenaar, Trudy M; Nookaew, Intawat; Hauser, Loren; Wanchai, Visanu; Land, Miriam; Timm, Collin M; Lu, Tse-Yuan S; Schadt, Christopher W; Doktycz, Mitchel J; Pelletier, Dale A; Ussery, David W

    2016-01-01

    The Pseudomonas genus contains a metabolically versatile group of organisms that are known to occupy numerous ecological niches, including the rhizosphere and endosphere of many plants. Their diversity influences the phylogenetic diversity and heterogeneity of these communities. On the basis of average amino acid identity, comparative genome analysis of >1,000 Pseudomonas genomes, including 21 Pseudomonas strains isolated from the roots of native Populus deltoides (eastern cottonwood) trees resulted in consistent and robust genomic clusters with phylogenetic homogeneity. All Pseudomonas aeruginosa genomes clustered together, and these were clearly distinct from other Pseudomonas species groups on the basis of pangenome and core genome analyses. In contrast, the genomes of Pseudomonas fluorescens were organized into 20 distinct genomic clusters, representing enormous diversity and heterogeneity. Most of our 21 Populus-associated isolates formed three distinct subgroups within the major P. fluorescens group, supported by pathway profile analysis, while two isolates were more closely related to Pseudomonas chlororaphis and Pseudomonas putida. Genes specific to Populus-associated subgroups were identified. Genes specific to subgroup 1 include several sensory systems that act in two-component signal transduction, a TonB-dependent receptor, and a phosphorelay sensor. Genes specific to subgroup 2 contain hypothetical genes, and genes specific to subgroup 3 were annotated with hydrolase activity. This study justifies the need to sequence multiple isolates, especially from P. fluorescens, which displays the most genetic variation, in order to study functional capabilities from a pangenomic perspective. This information will prove useful when choosing Pseudomonas strains for use to promote growth and increase disease resistance in plants. Copyright © 2015 Jun et al.

  12. Genomic diversity of drug-resistant Mycobacterium tuberculosis isolates in Lisbon Portugal: Towards tuberculosis genomic epidemiology

    Directory of Open Access Journals (Sweden)

    João Perdigão

    2015-01-01

    Full Text Available Multidrug- (MDR and extensively drug-resistant (XDR tuberculosis (TB present a challenge to disease control and elimination goals. Lisbon, Portugal, has a high TB incidencerate and unusual and successful XDR-TB strains that have been found in circulation foralmost two decades. For the last 20 years, a continued circulation of two phylogenetic clades, Lisboa3 and Q1, which are highly associated with MDR and XDR, have been observed. In recent years, these strains have been well characterized regarding the molecular basis of drug resistance and have been inclusively subjected to whole genome sequencing (WGS. Researchers have been studying the genomic diversity of strains circulating in Lisbon and its genomic determinants through cutting-edge next generation sequencing. An enormous amount of whole genome sequence data are now available for the most prevalent and clinically relevant strains circulating in Lisbon. It is the persistence, prevalence and rapid evolution towards drug resistance that has prompted researchers to investigate the properties of these strains at the genomic level and in the future at a global transcriptomic level. Seventy Mycobacterium tuberculosis (MTB isolates, mostly recovered in Lisbon, were genotyped by 24-loci Mycobacterial Interspersed Repetitive Unit – Variable Number of Tandem Repeats (MIRU-VNTR and the genomes sequenced using a next generation sequencing platform – Illumina HiSeq 2000. The genotyping data revealed three major clusters associated with MDR-TB (Lisboa3-A, Lisboa3-B and Q1, two of which are associated with XDR-TB (Lisboa3-B and Q1, whilst the genomic data contributed to elucidating the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of MTB clinical isolates, revealed two major clades responsible for MDR/XDR-TB in the region

  13. Genomic diversity of drug-resistant Mycobacterium tuberculosis isolates in Lisbon Portugal: Towards tuberculosis genomic epidemiology

    KAUST Repository

    Perdigã o, Joã o; Silva, Hugo; Machado, Diana; Macedo, Rita; Maltez, Fernando; Silva, Carla; Jordao, Luisa; Couto, Isabel; Mallard, Kim; Coll, Francesc; Hill-Cawthorne, Grant A.; McNerney, Ruth; Pain, Arnab; Clark, Taane G.; Viveiros, Miguel; Portugal, Isabel

    2015-01-01

    Multidrug- (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) present a challenge to disease control and elimination goals. Lisbon, Portugal, has a high TB incidence rate and unusual and successful XDR-TB strains that have been found in circulation for almost two decades. For the last 20. years, a continued circulation of two phylogenetic clades, Lisboa3 and Q1, which are highly associated with MDR and XDR, have been observed. In recent years, these strains have been well characterized regarding the molecular basis of drug resistance and have been inclusively subjected to whole genome sequencing (WGS). Researchers have been studying the genomic diversity of strains circulating in Lisbon and its genomic determinants through cutting-edge next generation sequencing. An enormous amount of whole genome sequence data are now available for the most prevalent and clinically relevant strains circulating in Lisbon.It is the persistence, prevalence and rapid evolution towards drug resistance that has prompted researchers to investigate the properties of these strains at the genomic level and in the future at a global transcriptomic level. Seventy Mycobacterium tuberculosis (MTB) isolates, mostly recovered in Lisbon, were genotyped by 24-. loci Mycobacterial Interspersed Repetitive Unit - Variable Number of Tandem Repeats (MIRU-VNTR) and the genomes sequenced using a next generation sequencing platform - Illumina HiSeq 2000.The genotyping data revealed three major clusters associated with MDR-TB (Lisboa3-A, Lisboa3-B and Q1), two of which are associated with XDR-TB (Lisboa3-B and Q1), whilst the genomic data contributed to elucidating the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of MTB clinical isolates, revealed two major clades responsible for MDR/XDR-TB in the region: Lisboa3 and Q

  14. Genomic diversity of drug-resistant Mycobacterium tuberculosis isolates in Lisbon Portugal: Towards tuberculosis genomic epidemiology

    KAUST Repository

    Perdigão, João

    2015-03-01

    Multidrug- (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) present a challenge to disease control and elimination goals. Lisbon, Portugal, has a high TB incidence rate and unusual and successful XDR-TB strains that have been found in circulation for almost two decades. For the last 20. years, a continued circulation of two phylogenetic clades, Lisboa3 and Q1, which are highly associated with MDR and XDR, have been observed. In recent years, these strains have been well characterized regarding the molecular basis of drug resistance and have been inclusively subjected to whole genome sequencing (WGS). Researchers have been studying the genomic diversity of strains circulating in Lisbon and its genomic determinants through cutting-edge next generation sequencing. An enormous amount of whole genome sequence data are now available for the most prevalent and clinically relevant strains circulating in Lisbon.It is the persistence, prevalence and rapid evolution towards drug resistance that has prompted researchers to investigate the properties of these strains at the genomic level and in the future at a global transcriptomic level. Seventy Mycobacterium tuberculosis (MTB) isolates, mostly recovered in Lisbon, were genotyped by 24-. loci Mycobacterial Interspersed Repetitive Unit - Variable Number of Tandem Repeats (MIRU-VNTR) and the genomes sequenced using a next generation sequencing platform - Illumina HiSeq 2000.The genotyping data revealed three major clusters associated with MDR-TB (Lisboa3-A, Lisboa3-B and Q1), two of which are associated with XDR-TB (Lisboa3-B and Q1), whilst the genomic data contributed to elucidating the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of MTB clinical isolates, revealed two major clades responsible for MDR/XDR-TB in the region: Lisboa3 and Q

  15. Comparative genomics reveals diversity among xanthomonads infecting tomato and pepper

    LENUS (Irish Health Repository)

    Potnis, Neha

    2011-03-11

    Abstract Background Bacterial spot of tomato and pepper is caused by four Xanthomonas species and is a major plant disease in warm humid climates. The four species are distinct from each other based on physiological and molecular characteristics. The genome sequence of strain 85-10, a member of one of the species, Xanthomonas euvesicatoria (Xcv) has been previously reported. To determine the relationship of the four species at the genome level and to investigate the molecular basis of their virulence and differing host ranges, draft genomic sequences of members of the other three species were determined and compared to strain 85-10. Results We sequenced the genomes of X. vesicatoria (Xv) strain 1111 (ATCC 35937), X. perforans (Xp) strain 91-118 and X. gardneri (Xg) strain 101 (ATCC 19865). The genomes were compared with each other and with the previously sequenced Xcv strain 85-10. In addition, the molecular features were predicted that may be required for pathogenicity including the type III secretion apparatus, type III effectors, other secretion systems, quorum sensing systems, adhesins, extracellular polysaccharide, and lipopolysaccharide determinants. Several novel type III effectors from Xg strain 101 and Xv strain 1111 genomes were computationally identified and their translocation was validated using a reporter gene assay. A homolog to Ax21, the elicitor of XA21-mediated resistance in rice, and a functional Ax21 sulfation system were identified in Xcv. Genes encoding proteins with functions mediated by type II and type IV secretion systems have also been compared, including enzymes involved in cell wall deconstruction, as contributors to pathogenicity. Conclusions Comparative genomic analyses revealed considerable diversity among bacterial spot pathogens, providing new insights into differences and similarities that may explain the diverse nature of these strains. Genes specific to pepper pathogens, such as the O-antigen of the lipopolysaccharide cluster

  16. Patterns of genome size diversity in bats (order Chiroptera).

    Science.gov (United States)

    Smith, Jillian D L; Bickham, John W; Gregory, T Ryan

    2013-08-01

    Despite being a group of particular interest in considering relationships between genome size and metabolic parameters, bats have not been well studied from this perspective. This study presents new estimates for 121 "microbat" species from 12 families and complements a previous study on members of the family Pteropodidae ("megabats"). The results confirm that diversity in genome size in bats is very limited even compared with other mammals, varying approximately 2-fold from 1.63 pg in Lophostoma carrikeri to 3.17 pg in Rhinopoma hardwickii and averaging only 2.35 pg ± 0.02 SE (versus 3.5 pg overall for mammals). However, contrary to some other vertebrate groups, and perhaps owing to the narrow range observed, genome size correlations were not apparent with any chromosomal, physiological, flight-related, developmental, or ecological characteristics within the order Chiroptera. Genome size is positively correlated with measures of body size in bats, though the strength of the relationships differs between pteropodids ("megabats") and nonpteropodids ("microbats").

  17. Extremely Low Genomic Diversity of Rickettsia japonica Distributed in Japan.

    Science.gov (United States)

    Akter, Arzuba; Ooka, Tadasuke; Gotoh, Yasuhiro; Yamamoto, Seigo; Fujita, Hiromi; Terasoma, Fumio; Kida, Kouji; Taira, Masakatsu; Nakadouzono, Fumiko; Gokuden, Mutsuyo; Hirano, Manabu; Miyashiro, Mamoru; Inari, Kouichi; Shimazu, Yukie; Tabara, Kenji; Toyoda, Atsushi; Yoshimura, Dai; Itoh, Takehiko; Kitano, Tomokazu; Sato, Mitsuhiko P; Katsura, Keisuke; Mondal, Shakhinur Islam; Ogura, Yoshitoshi; Ando, Shuji; Hayashi, Tetsuya

    2017-01-01

    Rickettsiae are obligate intracellular bacteria that have small genomes as a result of reductive evolution. Many Rickettsia species of the spotted fever group (SFG) cause tick-borne diseases known as "spotted fevers". The life cycle of SFG rickettsiae is closely associated with that of the tick, which is generally thought to act as a bacterial vector and reservoir that maintains the bacterium through transstadial and transovarial transmission. Each SFG member is thought to have adapted to a specific tick species, thus restricting the bacterial distribution to a relatively limited geographic region. These unique features of SFG rickettsiae allow investigation of how the genomes of such biologically and ecologically specialized bacteria evolve after genome reduction and the types of population structures that are generated. Here, we performed a nationwide, high-resolution phylogenetic analysis of Rickettsia japonica, an etiological agent of Japanese spotted fever that is distributed in Japan and Korea. The comparison of complete or nearly complete sequences obtained from 31 R. japonica strains isolated from various sources in Japan over the past 30 years demonstrated an extremely low level of genomic diversity. In particular, only 34 single nucleotide polymorphisms were identified among the 27 strains of the major lineage containing all clinical isolates and tick isolates from the three tick species. Our data provide novel insights into the biology and genome evolution of R. japonica, including the possibilities of recent clonal expansion and a long generation time in nature due to the long dormant phase associated with tick life cycles. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Genetics, Genomics and Evolution of Ergot Alkaloid Diversity

    Directory of Open Access Journals (Sweden)

    Carolyn A. Young

    2015-04-01

    Full Text Available The ergot alkaloid biosynthesis system has become an excellent model to study evolutionary diversification of specialized (secondary metabolites. This is a very diverse class of alkaloids with various neurotropic activities, produced by fungi in several orders of the phylum Ascomycota, including plant pathogens and protective plant symbionts in the family Clavicipitaceae. Results of comparative genomics and phylogenomic analyses reveal multiple examples of three evolutionary processes that have generated ergot-alkaloid diversity: gene gains, gene losses, and gene sequence changes that have led to altered substrates or product specificities of the enzymes that they encode (neofunctionalization. The chromosome ends appear to be particularly effective engines for gene gains, losses and rearrangements, but not necessarily for neofunctionalization. Changes in gene expression could lead to accumulation of various pathway intermediates and affect levels of different ergot alkaloids. Genetic alterations associated with interspecific hybrids of Epichloë species suggest that such variation is also selectively favored. The huge structural diversity of ergot alkaloids probably represents adaptations to a wide variety of ecological situations by affecting the biological spectra and mechanisms of defense against herbivores, as evidenced by the diverse pharmacological effects of ergot alkaloids used in medicine.

  19. Pervasive, Genome-Wide Transcription in the Organelle Genomes of Diverse Plastid-Bearing Protists

    Directory of Open Access Journals (Sweden)

    Matheus Sanitá Lima

    2017-11-01

    Full Text Available Organelle genomes are among the most sequenced kinds of chromosome. This is largely because they are small and widely used in molecular studies, but also because next-generation sequencing technologies made sequencing easier, faster, and cheaper. However, studies of organelle RNA have not kept pace with those of DNA, despite huge amounts of freely available eukaryotic RNA-sequencing (RNA-seq data. Little is known about organelle transcription in nonmodel species, and most of the available eukaryotic RNA-seq data have not been mined for organelle transcripts. Here, we use publicly available RNA-seq experiments to investigate organelle transcription in 30 diverse plastid-bearing protists with varying organelle genomic architectures. Mapping RNA-seq data to organelle genomes revealed pervasive, genome-wide transcription, regardless of the taxonomic grouping, gene organization, or noncoding content. For every species analyzed, transcripts covered ≥85% of the mitochondrial and/or plastid genomes (all of which were ≤105 kb, indicating that most of the organelle DNA—coding and noncoding—is transcriptionally active. These results follow earlier studies of model species showing that organellar transcription is coupled and ubiquitous across the genome, requiring significant downstream processing of polycistronic transcripts. Our findings suggest that noncoding organelle DNA can be transcriptionally active, raising questions about the underlying function of these transcripts and underscoring the utility of publicly available RNA-seq data for recovering complete genome sequences. If pervasive transcription is also found in bigger organelle genomes (>105 kb and across a broader range of eukaryotes, this could indicate that noncoding organelle RNAs are regulating fundamental processes within eukaryotic cells.

  20. Pervasive, Genome-Wide Transcription in the Organelle Genomes of Diverse Plastid-Bearing Protists.

    Science.gov (United States)

    Sanitá Lima, Matheus; Smith, David Roy

    2017-11-06

    Organelle genomes are among the most sequenced kinds of chromosome. This is largely because they are small and widely used in molecular studies, but also because next-generation sequencing technologies made sequencing easier, faster, and cheaper. However, studies of organelle RNA have not kept pace with those of DNA, despite huge amounts of freely available eukaryotic RNA-sequencing (RNA-seq) data. Little is known about organelle transcription in nonmodel species, and most of the available eukaryotic RNA-seq data have not been mined for organelle transcripts. Here, we use publicly available RNA-seq experiments to investigate organelle transcription in 30 diverse plastid-bearing protists with varying organelle genomic architectures. Mapping RNA-seq data to organelle genomes revealed pervasive, genome-wide transcription, regardless of the taxonomic grouping, gene organization, or noncoding content. For every species analyzed, transcripts covered ≥85% of the mitochondrial and/or plastid genomes (all of which were ≤105 kb), indicating that most of the organelle DNA-coding and noncoding-is transcriptionally active. These results follow earlier studies of model species showing that organellar transcription is coupled and ubiquitous across the genome, requiring significant downstream processing of polycistronic transcripts. Our findings suggest that noncoding organelle DNA can be transcriptionally active, raising questions about the underlying function of these transcripts and underscoring the utility of publicly available RNA-seq data for recovering complete genome sequences. If pervasive transcription is also found in bigger organelle genomes (>105 kb) and across a broader range of eukaryotes, this could indicate that noncoding organelle RNAs are regulating fundamental processes within eukaryotic cells. Copyright © 2017 Sanitá Lima and Smith.

  1. A Glimpse of the genomic diversity of haloarchaeal tailed viruses

    Directory of Open Access Journals (Sweden)

    Ana eSencilo

    2014-03-01

    Full Text Available Tailed viruses are the most common isolates infecting prokaryotic hosts residing hypersaline environments. Archaeal tailed viruses represent only a small portion of all characterized tailed viruses of prokaryotes. But even this small dataset revealed that archaeal tailed viruses have many similarities to their counterparts infecting bacteria, the bacteriophages. Shared functional homologues and similar genome organizations suggested that all microbial tailed viruses have common virion architectural and assembly principles. Recent structural studies have provided evidence justifying this thereby grouping archaeal and bacterial tailed viruses into a single lineage. Currently there are 17 haloarchaeal tailed viruses with entirely sequenced genomes. Nine viruses have at least one close relative among the 17 viruses and, according to the similarities, can be divided into three groups. Two other viruses share some homologues and therefore are distantly related, whereas the rest of the viruses are rather divergent (or singletons. Comparative genomics analysis of these viruses offers a glimpse into the genetic diversity and structure of haloarchaeal tailed virus communities.

  2. Phenotypic Heterogeneity of Genomically-Diverse Isolates of Streptococcus mutans

    Science.gov (United States)

    Palmer, Sara R.; Miller, James H.; Abranches, Jacqueline; Zeng, Lin; Lefebure, Tristan; Richards, Vincent P.; Lemos, José A.; Stanhope, Michael J.; Burne, Robert A.

    2013-01-01

    High coverage, whole genome shotgun (WGS) sequencing of 57 geographically- and genetically-diverse isolates of Streptococcus mutans from individuals of known dental caries status was recently completed. Of the 57 sequenced strains, fifteen isolates, were selected based primarily on differences in gene content and phenotypic characteristics known to affect virulence and compared with the reference strain UA159. A high degree of variability in these properties was observed between strains, with a broad spectrum of sensitivities to low pH, oxidative stress (air and paraquat) and exposure to competence stimulating peptide (CSP). Significant differences in autolytic behavior and in biofilm development in glucose or sucrose were also observed. Natural genetic competence varied among isolates, and this was correlated to the presence or absence of competence genes, comCDE and comX, and to bacteriocins. In general strains that lacked the ability to become competent possessed fewer genes for bacteriocins and immunity proteins or contained polymorphic variants of these genes. WGS sequence analysis of the pan-genome revealed, for the first time, components of a Type VII secretion system in several S. mutans strains, as well as two putative ORFs that encode possible collagen binding proteins located upstream of the cnm gene, which is associated with host cell invasiveness. The virulence of these particular strains was assessed in a wax-worm model. This is the first study to combine a comprehensive analysis of key virulence-related phenotypes with extensive genomic analysis of a pathogen that evolved closely with humans. Our analysis highlights the phenotypic diversity of S. mutans isolates and indicates that the species has evolved a variety of adaptive strategies to persist in the human oral cavity and, when conditions are favorable, to initiate disease. PMID:23613838

  3. Phenotypic heterogeneity of genomically-diverse isolates of Streptococcus mutans.

    Directory of Open Access Journals (Sweden)

    Sara R Palmer

    Full Text Available High coverage, whole genome shotgun (WGS sequencing of 57 geographically- and genetically-diverse isolates of Streptococcus mutans from individuals of known dental caries status was recently completed. Of the 57 sequenced strains, fifteen isolates, were selected based primarily on differences in gene content and phenotypic characteristics known to affect virulence and compared with the reference strain UA159. A high degree of variability in these properties was observed between strains, with a broad spectrum of sensitivities to low pH, oxidative stress (air and paraquat and exposure to competence stimulating peptide (CSP. Significant differences in autolytic behavior and in biofilm development in glucose or sucrose were also observed. Natural genetic competence varied among isolates, and this was correlated to the presence or absence of competence genes, comCDE and comX, and to bacteriocins. In general strains that lacked the ability to become competent possessed fewer genes for bacteriocins and immunity proteins or contained polymorphic variants of these genes. WGS sequence analysis of the pan-genome revealed, for the first time, components of a Type VII secretion system in several S. mutans strains, as well as two putative ORFs that encode possible collagen binding proteins located upstream of the cnm gene, which is associated with host cell invasiveness. The virulence of these particular strains was assessed in a wax-worm model. This is the first study to combine a comprehensive analysis of key virulence-related phenotypes with extensive genomic analysis of a pathogen that evolved closely with humans. Our analysis highlights the phenotypic diversity of S. mutans isolates and indicates that the species has evolved a variety of adaptive strategies to persist in the human oral cavity and, when conditions are favorable, to initiate disease.

  4. Genome Size Diversity and Its Impact on the Evolution of Land Plants

    Directory of Open Access Journals (Sweden)

    Jaume Pellicer

    2018-02-01

    Full Text Available Genome size is a biodiversity trait that shows staggering diversity across eukaryotes, varying over 64,000-fold. Of all major taxonomic groups, land plants stand out due to their staggering genome size diversity, ranging ca. 2400-fold. As our understanding of the implications and significance of this remarkable genome size diversity in land plants grows, it is becoming increasingly evident that this trait plays not only an important role in shaping the evolution of plant genomes, but also in influencing plant community assemblages at the ecosystem level. Recent advances and improvements in novel sequencing technologies, as well as analytical tools, make it possible to gain critical insights into the genomic and epigenetic mechanisms underpinning genome size changes. In this review we provide an overview of our current understanding of genome size diversity across the different land plant groups, its implications on the biology of the genome and what future directions need to be addressed to fill key knowledge gaps.

  5. Integrated analysis of whole genome and transcriptome sequencing reveals diverse transcriptomic aberrations driven by somatic genomic changes in liver cancers.

    Directory of Open Access Journals (Sweden)

    Yuichi Shiraishi

    Full Text Available Recent studies applying high-throughput sequencing technologies have identified several recurrently mutated genes and pathways in multiple cancer genomes. However, transcriptional consequences from these genomic alterations in cancer genome remain unclear. In this study, we performed integrated and comparative analyses of whole genomes and transcriptomes of 22 hepatitis B virus (HBV-related hepatocellular carcinomas (HCCs and their matched controls. Comparison of whole genome sequence (WGS and RNA-Seq revealed much evidence that various types of genomic mutations triggered diverse transcriptional changes. Not only splice-site mutations, but also silent mutations in coding regions, deep intronic mutations and structural changes caused splicing aberrations. HBV integrations generated diverse patterns of virus-human fusion transcripts depending on affected gene, such as TERT, CDK15, FN1 and MLL4. Structural variations could drive over-expression of genes such as WNT ligands, with/without creating gene fusions. Furthermore, by taking account of genomic mutations causing transcriptional aberrations, we could improve the sensitivity of deleterious mutation detection in known cancer driver genes (TP53, AXIN1, ARID2, RPS6KA3, and identified recurrent disruptions in putative cancer driver genes such as HNF4A, CPS1, TSC1 and THRAP3 in HCCs. These findings indicate genomic alterations in cancer genome have diverse transcriptomic effects, and integrated analysis of WGS and RNA-Seq can facilitate the interpretation of a large number of genomic alterations detected in cancer genome.

  6. Early Epstein-Barr Virus Genomic Diversity and Convergence toward the B95.8 Genome in Primary Infection.

    Science.gov (United States)

    Weiss, Eric R; Lamers, Susanna L; Henderson, Jennifer L; Melnikov, Alexandre; Somasundaran, Mohan; Garber, Manuel; Selin, Liisa; Nusbaum, Chad; Luzuriaga, Katherine

    2018-01-15

    Over 90% of the world's population is persistently infected with Epstein-Barr virus. While EBV does not cause disease in most individuals, it is the common cause of acute infectious mononucleosis (AIM) and has been associated with several cancers and autoimmune diseases, highlighting a need for a preventive vaccine. At present, very few primary, circulating EBV genomes have been sequenced directly from infected individuals. While low levels of diversity and low viral evolution rates have been predicted for double-stranded DNA (dsDNA) viruses, recent studies have demonstrated appreciable diversity in common dsDNA pathogens (e.g., cytomegalovirus). Here, we report 40 full-length EBV genome sequences obtained from matched oral wash and B cell fractions from a cohort of 10 AIM patients. Both intra- and interpatient diversity were observed across the length of the entire viral genome. Diversity was most pronounced in viral genes required for establishing latent infection and persistence, with appreciable levels of diversity also detected in structural genes, including envelope glycoproteins. Interestingly, intrapatient diversity declined significantly over time ( P < 0.01), and this was particularly evident on comparison of viral genomes sequenced from B cell fractions in early primary infection and convalescence ( P < 0.001). B cell-associated viral genomes were observed to converge, becoming nearly identical to the B95.8 reference genome over time (Spearman rank-order correlation test; r = -0.5589, P = 0.0264). The reduction in diversity was most marked in the EBV latency genes. In summary, our data suggest independent convergence of diverse viral genome sequences toward a reference-like strain within a relatively short period following primary EBV infection. IMPORTANCE Identification of viral proteins with low variability and high immunogenicity is important for the development of a protective vaccine. Knowledge of genome diversity within circulating viral

  7. Karyotype diversity and genome size variation in Neotropical Maxillariinae orchids.

    Science.gov (United States)

    Moraes, A P; Koehler, S; Cabral, J S; Gomes, S S L; Viccini, L F; Barros, F; Felix, L P; Guerra, M; Forni-Martins, E R

    2017-03-01

    Orchidaceae is a widely distributed plant family with very diverse vegetative and floral morphology, and such variability is also reflected in their karyotypes. However, since only a low proportion of Orchidaceae has been analysed for chromosome data, greater diversity may await to be unveiled. Here we analyse both genome size (GS) and karyotype in two subtribes recently included in the broadened Maxillariinea to detect how much chromosome and GS variation there is in these groups and to evaluate which genome rearrangements are involved in the species evolution. To do so, the GS (14 species), the karyotype - based on chromosome number, heterochromatic banding and 5S and 45S rDNA localisation (18 species) - was characterised and analysed along with published data using phylogenetic approaches. The GS presented a high phylogenetic correlation and it was related to morphological groups in Bifrenaria (larger plants - higher GS). The two largest GS found among genera were caused by different mechanisms: polyploidy in Bifrenaria tyrianthina and accumulation of repetitive DNA in Scuticaria hadwenii. The chromosome number variability was caused mainly through descending dysploidy, and x=20 was estimated as the base chromosome number. Combining GS and karyotype data with molecular phylogeny, our data provide a more complete scenario of the karyotype evolution in Maxillariinae orchids, allowing us to suggest, besides dysploidy, that inversions and transposable elements as two mechanisms involved in the karyotype evolution. Such karyotype modifications could be associated with niche changes that occurred during species evolution. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  8. The genome diversity and karyotype evolution of mammals

    Directory of Open Access Journals (Sweden)

    Trifonov Vladimir A

    2011-10-01

    Full Text Available Abstract The past decade has witnessed an explosion of genome sequencing and mapping in evolutionary diverse species. While full genome sequencing of mammals is rapidly progressing, the ability to assemble and align orthologous whole chromosome regions from more than a few species is still not possible. The intense focus on building of comparative maps for companion (dog and cat, laboratory (mice and rat and agricultural (cattle, pig, and horse animals has traditionally been used as a means to understand the underlying basis of disease-related or economically important phenotypes. However, these maps also provide an unprecedented opportunity to use multispecies analysis as a tool for inferring karyotype evolution. Comparative chromosome painting and related techniques are now considered to be the most powerful approaches in comparative genome studies. Homologies can be identified with high accuracy using molecularly defined DNA probes for fluorescence in situ hybridization (FISH on chromosomes of different species. Chromosome painting data are now available for members of nearly all mammalian orders. In most orders, there are species with rates of chromosome evolution that can be considered as 'default' rates. The number of rearrangements that have become fixed in evolutionary history seems comparatively low, bearing in mind the 180 million years of the mammalian radiation. Comparative chromosome maps record the history of karyotype changes that have occurred during evolution. The aim of this review is to provide an overview of these recent advances in our endeavor to decipher the karyotype evolution of mammals by integrating the published results together with some of our latest unpublished results.

  9. Genetic diversity and trait genomic prediction in a pea diversity panel.

    Science.gov (United States)

    Burstin, Judith; Salloignon, Pauline; Chabert-Martinello, Marianne; Magnin-Robert, Jean-Bernard; Siol, Mathieu; Jacquin, Françoise; Chauveau, Aurélie; Pont, Caroline; Aubert, Grégoire; Delaitre, Catherine; Truntzer, Caroline; Duc, Gérard

    2015-02-21

    Pea (Pisum sativum L.), a major pulse crop grown for its protein-rich seeds, is an important component of agroecological cropping systems in diverse regions of the world. New breeding challenges imposed by global climate change and new regulations urge pea breeders to undertake more efficient methods of selection and better take advantage of the large genetic diversity present in the Pisum sativum genepool. Diversity studies conducted so far in pea used Simple Sequence Repeat (SSR) and Retrotransposon Based Insertion Polymorphism (RBIP) markers. Recently, SNP marker panels have been developed that will be useful for genetic diversity assessment and marker-assisted selection. A collection of diverse pea accessions, including landraces and cultivars of garden, field or fodder peas as well as wild peas was characterised at the molecular level using newly developed SNP markers, as well as SSR markers and RBIP markers. The three types of markers were used to describe the structure of the collection and revealed different pictures of the genetic diversity among the collection. SSR showed the fastest rate of evolution and RBIP the slowest rate of evolution, pointing to their contrasted mode of evolution. SNP markers were then used to predict phenotypes -the date of flowering (BegFlo), the number of seeds per plant (Nseed) and thousand seed weight (TSW)- that were recorded for the collection. Different statistical methods were tested including the LASSO (Least Absolute Shrinkage ans Selection Operator), PLS (Partial Least Squares), SPLS (Sparse Partial Least Squares), Bayes A, Bayes B and GBLUP (Genomic Best Linear Unbiased Prediction) methods and the structure of the collection was taken into account in the prediction. Despite a limited number of 331 markers used for prediction, TSW was reliably predicted. The development of marker assisted selection has not reached its full potential in pea until now. This paper shows that the high-throughput SNP arrays that are being

  10. Comparative genomics of Geobacter chemotaxis genes reveals diverse signaling function

    Directory of Open Access Journals (Sweden)

    Antommattei Frances M

    2008-10-01

    Full Text Available Abstract Background Geobacter species are δ-Proteobacteria and are often the predominant species in a variety of sedimentary environments where Fe(III reduction is important. Their ability to remediate contaminated environments and produce electricity makes them attractive for further study. Cell motility, biofilm formation, and type IV pili all appear important for the growth of Geobacter in changing environments and for electricity production. Recent studies in other bacteria have demonstrated that signaling pathways homologous to the paradigm established for Escherichia coli chemotaxis can regulate type IV pili-dependent motility, the synthesis of flagella and type IV pili, the production of extracellular matrix material, and biofilm formation. The classification of these pathways by comparative genomics improves the ability to understand how Geobacter thrives in natural environments and better their use in microbial fuel cells. Results The genomes of G. sulfurreducens, G. metallireducens, and G. uraniireducens contain multiple (~70 homologs of chemotaxis genes arranged in several major clusters (six, seven, and seven, respectively. Unlike the single gene cluster of E. coli, the Geobacter clusters are not all located near the flagellar genes. The probable functions of some Geobacter clusters are assignable by homology to known pathways; others appear to be unique to the Geobacter sp. and contain genes of unknown function. We identified large numbers of methyl-accepting chemotaxis protein (MCP homologs that have diverse sensing domain architectures and generate a potential for sensing a great variety of environmental signals. We discuss mechanisms for class-specific segregation of the MCPs in the cell membrane, which serve to maintain pathway specificity and diminish crosstalk. Finally, the regulation of gene expression in Geobacter differs from E. coli. The sequences of predicted promoter elements suggest that the alternative sigma factors

  11. Mutation screening of the HGD gene identifies a novel alkaptonuria mutation with significant founder effect and high prevalence.

    Science.gov (United States)

    Sakthivel, Srinivasan; Zatkova, Andrea; Nemethova, Martina; Surovy, Milan; Kadasi, Ludevit; Saravanan, Madurai P

    2014-05-01

    Alkaptonuria (AKU) is an autosomal recessive disorder; caused by the mutations in the homogentisate 1, 2-dioxygenase (HGD) gene located on Chromosome 3q13.33. AKU is a rare disorder with an incidence of 1: 250,000 to 1: 1,000,000, but Slovakia and the Dominican Republic have a relatively higher incidence of 1: 19,000. Our study focused on studying the frequency of AKU and identification of HGD gene mutations in nomads. HGD gene sequencing was used to identify the mutations in alkaptonurics. For the past four years, from subjects suspected to be clinically affected, we found 16 positive cases among a randomly selected cohort of 41 Indian nomads (Narikuravar) settled in the specific area of Tamil Nadu, India. HGD gene mutation analysis showed that 11 of these patients carry the same homozygous splicing mutation c.87 + 1G > A; in five cases, this mutation was found to be heterozygous, while the second AKU-causing mutation was not identified in these patients. This result indicates that the founder effect and high degree of consanguineous marriages have contributed to AKU among nomads. Eleven positive samples were homozygous for a novel mutation c.87 + 1G > A, that abolishes an intron 2 donor splice site and most likely causes skipping of exon 2. The prevalence of AKU observed earlier seems to be highly increased in people of nomadic origin. © 2014 John Wiley & Sons Ltd/University College London.

  12. The Great Migration and African-American Genomic Diversity.

    Directory of Open Access Journals (Sweden)

    Soheil Baharian

    2016-05-01

    Full Text Available We present a comprehensive assessment of genomic diversity in the African-American population by studying three genotyped cohorts comprising 3,726 African-Americans from across the United States that provide a representative description of the population across all US states and socioeconomic status. An estimated 82.1% of ancestors to African-Americans lived in Africa prior to the advent of transatlantic travel, 16.7% in Europe, and 1.2% in the Americas, with increased African ancestry in the southern United States compared to the North and West. Combining demographic models of ancestry and those of relatedness suggests that admixture occurred predominantly in the South prior to the Civil War and that ancestry-biased migration is responsible for regional differences in ancestry. We find that recent migrations also caused a strong increase in genetic relatedness among geographically distant African-Americans. Long-range relatedness among African-Americans and between African-Americans and European-Americans thus track north- and west-bound migration routes followed during the Great Migration of the twentieth century. By contrast, short-range relatedness patterns suggest comparable mobility of ∼15-16km per generation for African-Americans and European-Americans, as estimated using a novel analytical model of isolation-by-distance.

  13. Comparative genomics of the marine bacterial genus Glaciecola reveals the high degree of genomic diversity and genomic characteristic for cold adaptation.

    Science.gov (United States)

    Qin, Qi-Long; Xie, Bin-Bin; Yu, Yong; Shu, Yan-Li; Rong, Jin-Cheng; Zhang, Yan-Jiao; Zhao, Dian-Li; Chen, Xiu-Lan; Zhang, Xi-Ying; Chen, Bo; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2014-06-01

    To what extent the genomes of different species belonging to one genus can be diverse and the relationship between genomic differentiation and environmental factor remain unclear for oceanic bacteria. With many new bacterial genera and species being isolated from marine environments, this question warrants attention. In this study, we sequenced all the type strains of the published species of Glaciecola, a recently defined cold-adapted genus with species from diverse marine locations, to study the genomic diversity and cold-adaptation strategy in this genus.The genome size diverged widely from 3.08 to 5.96 Mb, which can be explained by massive gene gain and loss events. Horizontal gene transfer and new gene emergence contributed substantially to the genome size expansion. The genus Glaciecola had an open pan-genome. Comparative genomic research indicated that species of the genus Glaciecola had high diversity in genome size, gene content and genetic relatedness. This may be prevalent in marine bacterial genera considering the dynamic and complex environments of the ocean. Species of Glaciecola had some common genomic features related to cold adaptation, which enable them to thrive and play a role in biogeochemical cycle in the cold marine environments.

  14. Evolution of genomic diversity and sex at extreme environments: Fungal life under hypersaline Dead Sea stress

    Science.gov (United States)

    Kis-Papo, Tamar; Kirzhner, Valery; Wasser, Solomon P.; Nevo, Eviatar

    2003-01-01

    We have found that genomic diversity is generally positively correlated with abiotic and biotic stress levels (1–3). However, beyond a high-threshold level of stress, the diversity declines to a few adapted genotypes. The Dead Sea is the harshest planetary hypersaline environment (340 g·liter–1 total dissolved salts, ≈10 times sea water). Hence, the Dead Sea is an excellent natural laboratory for testing the “rise and fall” pattern of genetic diversity with stress proposed in this article. Here, we examined genomic diversity of the ascomycete fungus Aspergillus versicolor from saline, nonsaline, and hypersaline Dead Sea environments. We screened the coding and noncoding genomes of A. versicolor isolates by using >600 AFLP (amplified fragment length polymorphism) markers (equal to loci). Genomic diversity was positively correlated with stress, culminating in the Dead Sea surface but dropped drastically in 50- to 280-m-deep seawater. The genomic diversity pattern paralleled the pattern of sexual reproduction of fungal species across the same southward gradient of increasing stress in Israel. This parallel may suggest that diversity and sex are intertwined intimately according to the rise and fall pattern and adaptively selected by natural selection in fungal genome evolution. Future large-scale verification in micromycetes will define further the trajectories of diversity and sex in the rise and fall pattern. PMID:14645702

  15. Diverse circovirus-like genome architectures revealed by environmental metagenomics.

    Science.gov (United States)

    Rosario, Karyna; Duffy, Siobain; Breitbart, Mya

    2009-10-01

    Single-stranded DNA (ssDNA) viruses with circular genomes are the smallest viruses known to infect eukaryotes. The present study identified 10 novel genomes similar to ssDNA circoviruses through data-mining of public viral metagenomes. The metagenomic libraries included samples from reclaimed water and three different marine environments (Chesapeake Bay, British Columbia coastal waters and Sargasso Sea). All the genomes have similarities to the replication (Rep) protein of circoviruses; however, only half have genomic features consistent with known circoviruses. Some of the genomes exhibit a mixture of genomic features associated with different families of ssDNA viruses (i.e. circoviruses, geminiviruses and parvoviruses). Unique genome architectures and phylogenetic analysis of the Rep protein suggest that these viruses belong to novel genera and/or families. Investigating the complex community of ssDNA viruses in the environment can lead to the discovery of divergent species and help elucidate evolutionary links between ssDNA viruses.

  16. Reconstruction of Diverse Verrucomicrobial Genomes from Metagenome Datasets of Freshwater Reservoirs

    Directory of Open Access Journals (Sweden)

    Pedro J. Cabello-Yeves

    2017-11-01

    Full Text Available The phylum Verrucomicrobia contains freshwater representatives which remain poorly studied at the genomic, taxonomic, and ecological levels. In this work we present eighteen new reconstructed verrucomicrobial genomes from two freshwater reservoirs located close to each other (Tous and Amadorio, Spain. These metagenome-assembled genomes (MAGs display a remarkable taxonomic diversity inside the phylum and comprise wide ranges of estimated genome sizes (from 1.8 to 6 Mb. Among all Verrucomicrobia studied we found some of the smallest genomes of the Spartobacteria and Opitutae classes described so far. Some of the Opitutae family MAGs were small, cosmopolitan, with a general heterotrophic metabolism with preference for carbohydrates, and capable of xylan, chitin, or cellulose degradation. Besides, we assembled large copiotroph genomes, which contain a higher number of transporters, polysaccharide degrading pathways and in general more strategies for the uptake of nutrients and carbohydrate-based metabolic pathways in comparison with the representatives with the smaller genomes. The diverse genomes revealed interesting features like green-light absorbing rhodopsins and a complete set of genes involved in nitrogen fixation. The large diversity in genome sizes and physiological properties emphasize the diversity of this clade in freshwaters enlarging even further the already broad eco-physiological range of these microbes.

  17. MBGD update 2013: the microbial genome database for exploring the diversity of microbial world.

    Science.gov (United States)

    Uchiyama, Ikuo; Mihara, Motohiro; Nishide, Hiroyo; Chiba, Hirokazu

    2013-01-01

    The microbial genome database for comparative analysis (MBGD, available at http://mbgd.genome.ad.jp/) is a platform for microbial genome comparison based on orthology analysis. As its unique feature, MBGD allows users to conduct orthology analysis among any specified set of organisms; this flexibility allows MBGD to adapt to a variety of microbial genomic study. Reflecting the huge diversity of microbial world, the number of microbial genome projects now becomes several thousands. To efficiently explore the diversity of the entire microbial genomic data, MBGD now provides summary pages for pre-calculated ortholog tables among various taxonomic groups. For some closely related taxa, MBGD also provides the conserved synteny information (core genome alignment) pre-calculated using the CoreAligner program. In addition, efficient incremental updating procedure can create extended ortholog table by adding additional genomes to the default ortholog table generated from the representative set of genomes. Combining with the functionalities of the dynamic orthology calculation of any specified set of organisms, MBGD is an efficient and flexible tool for exploring the microbial genome diversity.

  18. Genomic diversity and versatility of Lactobacillus plantarum, a natural metabolic engineer

    Science.gov (United States)

    2011-01-01

    In the past decade it has become clear that the lactic acid bacterium Lactobacillus plantarum occupies a diverse range of environmental niches and has an enormous diversity in phenotypic properties, metabolic capacity and industrial applications. In this review, we describe how genome sequencing, comparative genome hybridization and comparative genomics has provided insight into the underlying genomic diversity and versatility of L. plantarum. One of the main features appears to be genomic life-style islands consisting of numerous functional gene cassettes, in particular for carbohydrates utilization, which can be acquired, shuffled, substituted or deleted in response to niche requirements. In this sense, L. plantarum can be considered a “natural metabolic engineer”. PMID:21995294

  19. Genomic Diversity and Evolution of the Fish Pathogen Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Duchaud, Eric; Rochat, Tatiana; Habib, Christophe

    2018-01-01

    genome accounting for similar to 80% of the genes in each genome. The pan-genome seems nevertheless "open" according to the scaling exponent of a power-law fitted on the rate of new gene discovery when genomes are added one-by-one. Recombination is a key component of the evolutionary process...... of recombination and mutations to nucleotide-level differentiation (r/m) was estimated to similar to 13. Within CC-ST10, evolutionary distances computed on non-recombined regions and comparisons between 22 isolates sampled up to 27 years apart suggest a most recent common ancestor in the second half...

  20. Wild emmer genome architecture and diversity elucidate wheat evolution and domestication.

    Science.gov (United States)

    Avni, Raz; Nave, Moran; Barad, Omer; Baruch, Kobi; Twardziok, Sven O; Gundlach, Heidrun; Hale, Iago; Mascher, Martin; Spannagl, Manuel; Wiebe, Krystalee; Jordan, Katherine W; Golan, Guy; Deek, Jasline; Ben-Zvi, Batsheva; Ben-Zvi, Gil; Himmelbach, Axel; MacLachlan, Ron P; Sharpe, Andrew G; Fritz, Allan; Ben-David, Roi; Budak, Hikmet; Fahima, Tzion; Korol, Abraham; Faris, Justin D; Hernandez, Alvaro; Mikel, Mark A; Levy, Avraham A; Steffenson, Brian; Maccaferri, Marco; Tuberosa, Roberto; Cattivelli, Luigi; Faccioli, Primetta; Ceriotti, Aldo; Kashkush, Khalil; Pourkheirandish, Mohammad; Komatsuda, Takao; Eilam, Tamar; Sela, Hanan; Sharon, Amir; Ohad, Nir; Chamovitz, Daniel A; Mayer, Klaus F X; Stein, Nils; Ronen, Gil; Peleg, Zvi; Pozniak, Curtis J; Akhunov, Eduard D; Distelfeld, Assaf

    2017-07-07

    Wheat ( Triticum spp.) is one of the founder crops that likely drove the Neolithic transition to sedentary agrarian societies in the Fertile Crescent more than 10,000 years ago. Identifying genetic modifications underlying wheat's domestication requires knowledge about the genome of its allo-tetraploid progenitor, wild emmer ( T. turgidum ssp. dicoccoides ). We report a 10.1-gigabase assembly of the 14 chromosomes of wild tetraploid wheat, as well as analyses of gene content, genome architecture, and genetic diversity. With this fully assembled polyploid wheat genome, we identified the causal mutations in Brittle Rachis 1 ( TtBtr1 ) genes controlling shattering, a key domestication trait. A study of genomic diversity among wild and domesticated accessions revealed genomic regions bearing the signature of selection under domestication. This reference assembly will serve as a resource for accelerating the genome-assisted improvement of modern wheat varieties. Copyright © 2017, American Association for the Advancement of Science.

  1. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Dothideomycetes

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin A.; Feau, Nicolas; Henrissat, Bernard; Schoch, Conrad L.; Horwitz, Benjamin A.; Barry, Kerrie W.; Condon, Bradford J.; Copeland, Alex C.; Dhillon, Braham; Glaser, Fabian; Hesse, Cedar N.; Kosti, Idit; LaButti, Kurt; Lindquist, Erika A.; Lucas, Susan; Salamov, Asaf A.; Bradshaw, Rosie E.; Ciuffetti, Lynda; Hamelin, Richard C.; Kema, Gert H. J.; Lawrence, Christopher; Scott, James A.; Spatafora, Joseph W.; Turgeon, B. Gillian; de Wit, Pierre J. G. M.; Zhong, Shaobin; Goodwin, Stephen B.; Grigoriev, Igor V.

    2013-03-05

    The class of Dothideomycetes is one of the largest and most diverse groups of fungi. Many are plant pathogens and pose a serious threat to agricultural crops that are grown for biofuel, food or feed. Most Dothideomycetes have only a single host plant, and related species can have very diverse hosts. Eighteen genomes of Dothideomycetes have currently been sequenced by the Joint Genome Institute and other sequencing centers. Here we describe the results of comparative analyses of the fungi in this group.

  2. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Doethideomycetes Fungi

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin A.; Feau, Nicolas; Henrissat, Bernard; Schoch, Conrad L.; Horwitz, Benjamin A.; Barry, Kerrie W.; Condon, Bradford J.; Copeland, Alex C.; Dhillon, Braham; Glaser, Fabien; Hesse, Cedar N.; Kosti, Idit; LaButti, Kurt; Lindquist, Erika A.; Lucas, Susan; Salamov, Asaf A.; Bradshaw, Rosie E.; Ciuffetti, Lynda; Hamelin, Richard C.; Kema, Gert H. J.; Lawrence, Christopher; Scott, James A.; Spatafora, Joseph W.; Turgeon, B. Gillian; de Wit, Pierre J. G. M.; Zhong, Shaobin; Goodwin, Stephen B.; Grigoriev, Igor V.

    2012-03-13

    The class of Dothideomycetes is one of the largest and most diverse groups of fungi. Many are plant pathogens and pose a serious threat to agricultural crops grown for biofuel, food or feed. Most Dothideomycetes have only a single host and related species can have very diverse host plants. Eighteen genomes of Dothideomycetes have currently been sequenced by the Joint Genome Institute and other sequencing centers. Here we describe the results of comparative analyses of the fungi in this group.

  3. Genome sequence and genetic diversity of European ash trees

    DEFF Research Database (Denmark)

    Sollars, Elizabeth S A; Harper, Andrea L; Kelly, Laura J

    2017-01-01

    -heterozygosity Fraxinus excelsior tree from Gloucestershire, UK, annotating 38,852 protein-coding genes of which 25% appear ash specific when compared with the genomes of ten other plant species. Analyses of paralogous genes suggest a whole-genome duplication shared with olive (Olea europaea, Oleaceae). We also re...

  4. Genomic diversity and evolution of the head crest in the rock pigeon

    DEFF Research Database (Denmark)

    Shapiro, Michael D.; Kronenberg, Zev; Li, Cai

    2013-01-01

    The geographic origins of breeds and the genetic basis of variation within the widely distributed and phenotypically diverse domestic rock pigeon (Columba livia) remain largely unknown. We generated a rock pigeon reference genome and additional genome sequences representing domestic and feral...

  5. Relationship between metabolic and genomic diversity in sesame (Sesamum indicum L.

    Directory of Open Access Journals (Sweden)

    Karlovsky Petr

    2008-05-01

    Full Text Available Abstract Background Diversity estimates in cultivated plants provide a rationale for conservation strategies and support the selection of starting material for breeding programs. Diversity measures applied to crops usually have been limited to the assessment of genome polymorphism at the DNA level. Occasionally, selected morphological features are recorded and the content of key chemical constituents determined, but unbiased and comprehensive chemical phenotypes have not been included systematically in diversity surveys. Our objective in this study was to assess metabolic diversity in sesame by nontargeted metabolic profiling and elucidate the relationship between metabolic and genome diversity in this crop. Results Ten sesame accessions were selected that represent most of the genome diversity of sesame grown in India, Western Asia, Sudan and Venezuela based on previous AFLP studies. Ethanolic seed extracts were separated by HPLC, metabolites were ionized by positive and negative electrospray and ions were detected with an ion trap mass spectrometer in full-scan mode for m/z from 50 to 1000. Genome diversity was determined by Amplified Fragment Length Polymorphism (AFLP using eight primer pair combinations. The relationship between biodiversity at the genome and at the metabolome levels was assessed by correlation analysis and multivariate statistics. Conclusion Patterns of diversity at the genomic and metabolic levels differed, indicating that selection played a significant role in the evolution of metabolic diversity in sesame. This result implies that when used for the selection of genotypes in breeding and conservation, diversity assessment based on neutral DNA markers should be complemented with metabolic profiles. We hypothesize that this applies to all crops with a long history of domestication that possess commercially relevant traits affected by chemical phenotypes.

  6. Mitochondrial genome diversity in dagger and needle nematodes (Nematoda: Longidoridae).

    Science.gov (United States)

    Palomares-Rius, J E; Cantalapiedra-Navarrete, C; Archidona-Yuste, A; Blok, V C; Castillo, P

    2017-02-02

    Dagger and needle nematodes included in the family Longidoridae (viz. Longidorus, Paralongidorus, and Xiphinema) are highly polyphagous plant-parasitic nematodes in wild and cultivated plants and some of them are plant-virus vectors (nepovirus). The mitochondrial (mt) genomes of the dagger and needle nematodes, Xiphinema rivesi, Xiphinema pachtaicum, Longidorus vineacola and Paralongidorus litoralis were sequenced in this study. The four circular mt genomes have an estimated size of 12.6, 12.5, 13.5 and 12.7 kb, respectively. Up to date, the mt genome of X. pachtaicum is the smallest genome found in Nematoda. The four mt genomes contain 12 protein-coding genes (viz. cox1-3, nad1-6, nad4L, atp6 and cob) and two ribosomal RNA genes (rrnL and rrnS), but the atp8 gene was not detected. These mt genomes showed a gene arrangement very different within the Longidoridae species sequenced, with the exception of very closely related species (X. americanum and X. rivesi). The sizes of non-coding regions in the Longidoridae nematodes were very small and were present in a few places in the mt genome. Phylogenetic analysis of all coding genes showed a closer relationship between Longidorus and Paralongidorus and different phylogenetic possibilities for the three Xiphinema species.

  7. The human noncoding genome defined by genetic diversity.

    Science.gov (United States)

    di Iulio, Julia; Bartha, Istvan; Wong, Emily H M; Yu, Hung-Chun; Lavrenko, Victor; Yang, Dongchan; Jung, Inkyung; Hicks, Michael A; Shah, Naisha; Kirkness, Ewen F; Fabani, Martin M; Biggs, William H; Ren, Bing; Venter, J Craig; Telenti, Amalio

    2018-03-01

    Understanding the significance of genetic variants in the noncoding genome is emerging as the next challenge in human genomics. We used the power of 11,257 whole-genome sequences and 16,384 heptamers (7-nt motifs) to build a map of sequence constraint for the human species. This build differed substantially from traditional maps of interspecies conservation and identified regulatory elements among the most constrained regions of the genome. Using new Hi-C experimental data, we describe a strong pattern of coordination over 2 Mb where the most constrained regulatory elements associate with the most essential genes. Constrained regions of the noncoding genome are up to 52-fold enriched for known pathogenic variants as compared to unconstrained regions (21-fold when compared to the genome average). This map of sequence constraint across thousands of individuals is an asset to help interpret noncoding elements in the human genome, prioritize variants and reconsider gene units at a larger scale.

  8. Genome Size Diversity in Lilium (Liliaceae Is Correlated with Karyotype and Environmental Traits

    Directory of Open Access Journals (Sweden)

    Yun-peng Du

    2017-07-01

    Full Text Available Genome size (GS diversity is of fundamental biological importance. The occurrence of giant genomes in angiosperms is restricted to just a few lineages in the analyzed genome size of plant species so far. It is still an open question whether GS diversity is shaped by neutral or natural selection. The genus Lilium, with giant genomes, is phylogenetically and horticulturally important and is distributed throughout the northern hemisphere. GS diversity in Lilium and the underlying evolutionary mechanisms are poorly understood. We performed a comprehensive study involving phylogenetically independent analysis on 71 species to explore the diversity and evolution of GS and its correlation with karyological and environmental traits within Lilium (including Nomocharis. The strong phylogenetic signal detected for GS in the genus provides evidence consistent with that the repetitive DNA may be the primary contributors to the GS diversity, while the significant positive relationships detected between GS and the haploid chromosome length (HCL provide insights into patterns of genome evolution. The relationships between GS and karyotypes indicate that ancestral karyotypes of Lilium are likely to have exhibited small genomes, low diversity in centromeric index (CVCI values and relatively high relative variation in chromosome length (CVCL values. Significant relationships identified between GS and annual temperature and between GS and annual precipitation suggest that adaptation to habitat strongly influences GS diversity. We conclude that GS in Lilium is shaped by both neutral (genetic drift and adaptive evolution. These findings will have important consequences for understanding the evolution of giant plant genomes, and exploring the role of repetitive DNA fraction and chromosome changes in a plant group with large genomes and conservation of chromosome number.

  9. Twelve novel HGD gene variants identified in 99 alkaptonuria patients: focus on ‘black bone disease' in Italy

    Science.gov (United States)

    Nemethova, Martina; Radvanszky, Jan; Kadasi, Ludevit; Ascher, David B; Pires, Douglas E V; Blundell, Tom L; Porfirio, Berardino; Mannoni, Alessandro; Santucci, Annalisa; Milucci, Lia; Sestini, Silvia; Biolcati, Gianfranco; Sorge, Fiammetta; Aurizi, Caterina; Aquaron, Robert; Alsbou, Mohammed; Marques Lourenço, Charles; Ramadevi, Kanakasabapathi; Ranganath, Lakshminarayan R; Gallagher, James A; van Kan, Christa; Hall, Anthony K; Olsson, Birgitta; Sireau, Nicolas; Ayoob, Hana; Timmis, Oliver G; Le Quan Sang, Kim-Hanh; Genovese, Federica; Imrich, Richard; Rovensky, Jozef; Srinivasaraghavan, Rangan; Bharadwaj, Shruthi K; Spiegel, Ronen; Zatkova, Andrea

    2016-01-01

    Alkaptonuria (AKU) is an autosomal recessive disorder caused by mutations in homogentisate-1,2-dioxygenase (HGD) gene leading to the deficiency of HGD enzyme activity. The DevelopAKUre project is underway to test nitisinone as a specific treatment to counteract this derangement of the phenylalanine-tyrosine catabolic pathway. We analysed DNA of 40 AKU patients enrolled for SONIA1, the first study in DevelopAKUre, and of 59 other AKU patients sent to our laboratory for molecular diagnostics. We identified 12 novel DNA variants: one was identified in patients from Brazil (c.557T>A), Slovakia (c.500C>T) and France (c.440T>C), three in patients from India (c.469+6T>C, c.650–85A>G, c.158G>A), and six in patients from Italy (c.742A>G, c.614G>A, c.1057A>C, c.752G>A, c.119A>C, c.926G>T). Thus, the total number of potential AKU-causing variants found in 380 patients reported in the HGD mutation database is now 129. Using mCSM and DUET, computational approaches based on the protein 3D structure, the novel missense variants are predicted to affect the activity of the enzyme by three mechanisms: decrease of stability of individual protomers, disruption of protomer-protomer interactions or modification of residues in the region of the active site. We also present an overview of AKU in Italy, where so far about 60 AKU cases are known and DNA analysis has been reported for 34 of them. In this rather small group, 26 different HGD variants affecting function were described, indicating rather high heterogeneity. Twelve of these variants seem to be specific for Italy. PMID:25804398

  10. Twelve novel HGD gene variants identified in 99 alkaptonuria patients: focus on 'black bone disease' in Italy.

    Science.gov (United States)

    Nemethova, Martina; Radvanszky, Jan; Kadasi, Ludevit; Ascher, David B; Pires, Douglas E V; Blundell, Tom L; Porfirio, Berardino; Mannoni, Alessandro; Santucci, Annalisa; Milucci, Lia; Sestini, Silvia; Biolcati, Gianfranco; Sorge, Fiammetta; Aurizi, Caterina; Aquaron, Robert; Alsbou, Mohammed; Lourenço, Charles Marques; Ramadevi, Kanakasabapathi; Ranganath, Lakshminarayan R; Gallagher, James A; van Kan, Christa; Hall, Anthony K; Olsson, Birgitta; Sireau, Nicolas; Ayoob, Hana; Timmis, Oliver G; Sang, Kim-Hanh Le Quan; Genovese, Federica; Imrich, Richard; Rovensky, Jozef; Srinivasaraghavan, Rangan; Bharadwaj, Shruthi K; Spiegel, Ronen; Zatkova, Andrea

    2016-01-01

    Alkaptonuria (AKU) is an autosomal recessive disorder caused by mutations in homogentisate-1,2-dioxygenase (HGD) gene leading to the deficiency of HGD enzyme activity. The DevelopAKUre project is underway to test nitisinone as a specific treatment to counteract this derangement of the phenylalanine-tyrosine catabolic pathway. We analysed DNA of 40 AKU patients enrolled for SONIA1, the first study in DevelopAKUre, and of 59 other AKU patients sent to our laboratory for molecular diagnostics. We identified 12 novel DNA variants: one was identified in patients from Brazil (c.557T>A), Slovakia (c.500C>T) and France (c.440T>C), three in patients from India (c.469+6T>C, c.650-85A>G, c.158G>A), and six in patients from Italy (c.742A>G, c.614G>A, c.1057A>C, c.752G>A, c.119A>C, c.926G>T). Thus, the total number of potential AKU-causing variants found in 380 patients reported in the HGD mutation database is now 129. Using mCSM and DUET, computational approaches based on the protein 3D structure, the novel missense variants are predicted to affect the activity of the enzyme by three mechanisms: decrease of stability of individual protomers, disruption of protomer-protomer interactions or modification of residues in the region of the active site. We also present an overview of AKU in Italy, where so far about 60 AKU cases are known and DNA analysis has been reported for 34 of them. In this rather small group, 26 different HGD variants affecting function were described, indicating rather high heterogeneity. Twelve of these variants seem to be specific for Italy.

  11. Exceptionally diverse morphotypes and genomes of crenarchaeal hyperthermophilic viruses

    DEFF Research Database (Denmark)

    Prangishvili, D; Garrett, R A

    2004-01-01

    and Rudiviridae. They all have double-stranded DNA genomes and infect hyperthermophilic crenarchaea of the orders Sulfolobales and Thermoproteales. Representatives of the different viral families share a few homologous ORFs (open reading frames). However, about 90% of all ORFs in the seven sequenced genomes show...... no significant matches to sequences in public databases. This suggests that these hyperthermophilic viruses have exceptional biochemical solutions for biological functions. Specific features of genome organization, as well as strategies for DNA replication, suggest that phylogenetic relationships exist between...... crenarchaeal rudiviruses and the large eukaryal DNA viruses: poxviruses, the African swine fever virus and Chlorella viruses. Sequence patterns at the ends of the linear genome of the lipothrixvirus AFV1 are reminiscent of the telomeric ends of linear eukaryal chromosomes and suggest that a primitive telomeric...

  12. Mitochondrial genome diversity and population structure of the giant squid Architeuthis

    DEFF Research Database (Denmark)

    Winkelmann, Inger Eleanor Hall; Campos, Paula; Strugnell, Jan

    2013-01-01

    techniques, considerable controversy exists with regard to topics as varied as their taxonomy, biology and even behaviour. In this study, we have characterized the mitochondrial genome (mitogenome) diversity of 43 Architeuthis samples collected from across the range of the species, in order to use genetic...... a recent population expansion or selective sweep, which may explain the low level of genetic diversity....

  13. The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

    KAUST Repository

    Bracken-Grissom, Heather; Collins, Allen G.; Collins, Timothy; Crandall, Keith; Distel, Daniel; Dunn, Casey; Giribet, Gonzalo; Haddock, Steven; Knowlton, Nancy; Martindale, Mark; Medina, Monica; Messing, Charles; O'Brien, Stephen J.; Paulay, Gustav; Putnam, Nicolas; Ravasi, Timothy; Rouse, Greg W.; Ryan, Joseph F.; Schulze, Anja; Worheide, Gert; Adamska, Maja; Bailly, Xavier; Breinholt, Jesse; Browne, William E.; Diaz, M. Christina; Evans, Nathaniel; Flot, Jean-Francois; Fogarty, Nicole; Johnston, Matthew; Kamel, Bishoy; Kawahara, Akito Y.; Laberge, Tammy; Lavrov, Dennis; Michonneau, Francois; Moroz, Leonid L.; Oakley, Todd; Osborne, Karen; Pomponi, Shirley A.; Rhodes, Adelaide; Rodriguez-Lanetty, Mauricio; Santos, Scott R.; Satoh, Nori; Thacker, Robert W.; Van de Peer, Yves; Voolstra, Christian R.; Welch, David Mark; Winston, Judith; Zhou, Xin

    2013-01-01

    Over 95% of all metazoan (animal) species comprise the invertebrates, but very few genomes from these organisms have been sequenced. We have, therefore, formed a Global Invertebrate Genomics Alliance (GIGA). Our intent is to build a collaborative

  14. The characterization of goat genetic diversity : Towards a genomic approach

    NARCIS (Netherlands)

    Ajmone-Marsan, P.; Colli, L.; Han, J. L.; Achilli, A.; Lancioni, H.; Joost, S.; Crepaldi, P.; Pilla, F.; Stella, A.; Taberlet, P.; Boettcher, P.; Negrini, R.; Lenstra, J. A.

    2014-01-01

    The investigation of genetic diversity at molecular level has been proposed as a valuable complement and sometimes proxy to phenotypic diversity of local breeds and is presently considered as one of the FAO priorities for breed characterization. By recommending a set of selected molecular markers

  15. The B73 maize genome: complexity, diversity, and dynamics.

    Science.gov (United States)

    Schnable, Patrick S; Ware, Doreen; Fulton, Robert S; Stein, Joshua C; Wei, Fusheng; Pasternak, Shiran; Liang, Chengzhi; Zhang, Jianwei; Fulton, Lucinda; Graves, Tina A; Minx, Patrick; Reily, Amy Denise; Courtney, Laura; Kruchowski, Scott S; Tomlinson, Chad; Strong, Cindy; Delehaunty, Kim; Fronick, Catrina; Courtney, Bill; Rock, Susan M; Belter, Eddie; Du, Feiyu; Kim, Kyung; Abbott, Rachel M; Cotton, Marc; Levy, Andy; Marchetto, Pamela; Ochoa, Kerri; Jackson, Stephanie M; Gillam, Barbara; Chen, Weizu; Yan, Le; Higginbotham, Jamey; Cardenas, Marco; Waligorski, Jason; Applebaum, Elizabeth; Phelps, Lindsey; Falcone, Jason; Kanchi, Krishna; Thane, Thynn; Scimone, Adam; Thane, Nay; Henke, Jessica; Wang, Tom; Ruppert, Jessica; Shah, Neha; Rotter, Kelsi; Hodges, Jennifer; Ingenthron, Elizabeth; Cordes, Matt; Kohlberg, Sara; Sgro, Jennifer; Delgado, Brandon; Mead, Kelly; Chinwalla, Asif; Leonard, Shawn; Crouse, Kevin; Collura, Kristi; Kudrna, Dave; Currie, Jennifer; He, Ruifeng; Angelova, Angelina; Rajasekar, Shanmugam; Mueller, Teri; Lomeli, Rene; Scara, Gabriel; Ko, Ara; Delaney, Krista; Wissotski, Marina; Lopez, Georgina; Campos, David; Braidotti, Michele; Ashley, Elizabeth; Golser, Wolfgang; Kim, HyeRan; Lee, Seunghee; Lin, Jinke; Dujmic, Zeljko; Kim, Woojin; Talag, Jayson; Zuccolo, Andrea; Fan, Chuanzhu; Sebastian, Aswathy; Kramer, Melissa; Spiegel, Lori; Nascimento, Lidia; Zutavern, Theresa; Miller, Beth; Ambroise, Claude; Muller, Stephanie; Spooner, Will; Narechania, Apurva; Ren, Liya; Wei, Sharon; Kumari, Sunita; Faga, Ben; Levy, Michael J; McMahan, Linda; Van Buren, Peter; Vaughn, Matthew W; Ying, Kai; Yeh, Cheng-Ting; Emrich, Scott J; Jia, Yi; Kalyanaraman, Ananth; Hsia, An-Ping; Barbazuk, W Brad; Baucom, Regina S; Brutnell, Thomas P; Carpita, Nicholas C; Chaparro, Cristian; Chia, Jer-Ming; Deragon, Jean-Marc; Estill, James C; Fu, Yan; Jeddeloh, Jeffrey A; Han, Yujun; Lee, Hyeran; Li, Pinghua; Lisch, Damon R; Liu, Sanzhen; Liu, Zhijie; Nagel, Dawn Holligan; McCann, Maureen C; SanMiguel, Phillip; Myers, Alan M; Nettleton, Dan; Nguyen, John; Penning, Bryan W; Ponnala, Lalit; Schneider, Kevin L; Schwartz, David C; Sharma, Anupma; Soderlund, Carol; Springer, Nathan M; Sun, Qi; Wang, Hao; Waterman, Michael; Westerman, Richard; Wolfgruber, Thomas K; Yang, Lixing; Yu, Yeisoo; Zhang, Lifang; Zhou, Shiguo; Zhu, Qihui; Bennetzen, Jeffrey L; Dawe, R Kelly; Jiang, Jiming; Jiang, Ning; Presting, Gernot G; Wessler, Susan R; Aluru, Srinivas; Martienssen, Robert A; Clifton, Sandra W; McCombie, W Richard; Wing, Rod A; Wilson, Richard K

    2009-11-20

    We report an improved draft nucleotide sequence of the 2.3-gigabase genome of maize, an important crop plant and model for biological research. Over 32,000 genes were predicted, of which 99.8% were placed on reference chromosomes. Nearly 85% of the genome is composed of hundreds of families of transposable elements, dispersed nonuniformly across the genome. These were responsible for the capture and amplification of numerous gene fragments and affect the composition, sizes, and positions of centromeres. We also report on the correlation of methylation-poor regions with Mu transposon insertions and recombination, and copy number variants with insertions and/or deletions, as well as how uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. These analyses inform and set the stage for further investigations to improve our understanding of the domestication and agricultural improvements of maize.

  16. Chimpanzee genomic diversity reveals ancient admixture with bonobos

    DEFF Research Database (Denmark)

    de Manuel, Marc; Kuhlwilm, Martin; Frandsen, Peter

    2016-01-01

    Our closest living relatives, chimpanzees and bonobos, have a complex demographic history. We analyzed the high-coverage whole genomes of 75 wild-born chimpanzees and bonobos from 10 countries in Africa. We found that chimpanzee population substructure makes genetic information a good predictor...

  17. Exploring Lactobacillus plantarum genome diversity by using microarrays

    NARCIS (Netherlands)

    Molenaar, D.; Bringel, F.; Schuren, F.H.; Vos, de W.M.; Siezen, R.J.; Kleerebezem, M.

    2005-01-01

    Lactobacillus plantarum is a versatile and flexible species that is encountered in a variety of niches and can utilize a broad range of fermentable carbon sources. To assess if this versatility is linked to a variable gene pool, microarrays containing a subset of small genomic fragments of L.

  18. Ecology, Diversity and Comparative Genomics of Oceanic Cyanobacterial Viruses

    Science.gov (United States)

    2004-06-01

    A. P., Terenzi, M. F., Truffi, D., Tsai, S. M., Tsuhako, M. H., Vallada, H., Van Sluys, M. A., Verjovski-Almeida, S., Vettore, A. L., Zago , M. A...L., Zago , M. A., Zatz, M., Meidanis, J., and Setubal, J. C. (2000). The genome sequence of the plant pathogen Xylella fastidiosa. The Xylelia

  19. Impacts of Genome-Wide Analyses on Our Understanding of Human Herpesvirus Diversity and Evolution.

    Science.gov (United States)

    Renner, Daniel W; Szpara, Moriah L

    2018-01-01

    Until fairly recently, genome-wide evolutionary dynamics and within-host diversity were more commonly examined in the context of small viruses than in the context of large double-stranded DNA viruses such as herpesviruses. The high mutation rates and more compact genomes of RNA viruses have inspired the investigation of population dynamics for these species, and recent data now suggest that herpesviruses might also be considered candidates for population modeling. High-throughput sequencing (HTS) and bioinformatics have expanded our understanding of herpesviruses through genome-wide comparisons of sequence diversity, recombination, allele frequency, and selective pressures. Here we discuss recent data on the mechanisms that generate herpesvirus genomic diversity and underlie the evolution of these virus families. We focus on human herpesviruses, with key insights drawn from veterinary herpesviruses and other large DNA virus families. We consider the impacts of cell culture on herpesvirus genomes and how to accurately describe the viral populations under study. The need for a strong foundation of high-quality genomes is also discussed, since it underlies all secondary genomic analyses such as RNA sequencing (RNA-Seq), chromatin immunoprecipitation, and ribosome profiling. Areas where we foresee future progress, such as the linking of viral genetic differences to phenotypic or clinical outcomes, are highlighted as well. Copyright © 2017 Renner and Szpara.

  20. Impacts of Genome-Wide Analyses on Our Understanding of Human Herpesvirus Diversity and Evolution

    Science.gov (United States)

    Renner, Daniel W.

    2017-01-01

    ABSTRACT Until fairly recently, genome-wide evolutionary dynamics and within-host diversity were more commonly examined in the context of small viruses than in the context of large double-stranded DNA viruses such as herpesviruses. The high mutation rates and more compact genomes of RNA viruses have inspired the investigation of population dynamics for these species, and recent data now suggest that herpesviruses might also be considered candidates for population modeling. High-throughput sequencing (HTS) and bioinformatics have expanded our understanding of herpesviruses through genome-wide comparisons of sequence diversity, recombination, allele frequency, and selective pressures. Here we discuss recent data on the mechanisms that generate herpesvirus genomic diversity and underlie the evolution of these virus families. We focus on human herpesviruses, with key insights drawn from veterinary herpesviruses and other large DNA virus families. We consider the impacts of cell culture on herpesvirus genomes and how to accurately describe the viral populations under study. The need for a strong foundation of high-quality genomes is also discussed, since it underlies all secondary genomic analyses such as RNA sequencing (RNA-Seq), chromatin immunoprecipitation, and ribosome profiling. Areas where we foresee future progress, such as the linking of viral genetic differences to phenotypic or clinical outcomes, are highlighted as well. PMID:29046445

  1. The use of comparative genomic hybridization to characterize genome dynamics and diversity among the serotypes of Shigella

    Directory of Open Access Journals (Sweden)

    Sun Meisheng

    2006-08-01

    Full Text Available Abstract Background Compelling evidence indicates that Shigella species, the etiologic agents of bacillary dysentery, as well as enteroinvasive Escherichia coli, are derived from multiple origins of Escherichia coli and form a single pathovar. To further understand the genome diversity and virulence evolution of Shigella, comparative genomic hybridization microarray analysis was employed to compare the gene content of E. coli K-12 with those of 43 Shigella strains from all lineages. Results For the 43 strains subjected to CGH microarray analyses, the common backbone of the Shigella genome was estimated to contain more than 1,900 open reading frames (ORFs, with a mean number of 726 undetectable ORFs. The mosaic distribution of absent regions indicated that insertions and/or deletions have led to the highly diversified genomes of pathogenic strains. Conclusion These results support the hypothesis that by gain and loss of functions, Shigella species became successful human pathogens through convergent evolution from diverse genomic backgrounds. Moreover, we also found many specific differences between different lineages, providing a window into understanding bacterial speciation and taxonomic relationships.

  2. Genome wide characterization of simple sequence repeats in watermelon genome and their application in comparative mapping and genetic diversity analysis.

    Science.gov (United States)

    Zhu, Huayu; Song, Pengyao; Koo, Dal-Hoe; Guo, Luqin; Li, Yanman; Sun, Shouru; Weng, Yiqun; Yang, Luming

    2016-08-05

    Microsatellite markers are one of the most informative and versatile DNA-based markers used in plant genetic research, but their development has traditionally been difficult and costly. The whole genome sequencing with next-generation sequencing (NGS) technologies provides large amounts of sequence data to develop numerous microsatellite markers at whole genome scale. SSR markers have great advantage in cross-species comparisons and allow investigation of karyotype and genome evolution through highly efficient computation approaches such as in silico PCR. Here we described genome wide development and characterization of SSR markers in the watermelon (Citrullus lanatus) genome, which were then use in comparative analysis with two other important crop species in the Cucurbitaceae family: cucumber (Cucumis sativus L.) and melon (Cucumis melo L.). We further applied these markers in evaluating the genetic diversity and population structure in watermelon germplasm collections. A total of 39,523 microsatellite loci were identified from the watermelon draft genome with an overall density of 111 SSRs/Mbp, and 32,869 SSR primers were designed with suitable flanking sequences. The dinucleotide SSRs were the most common type representing 34.09 % of the total SSR loci and the AT-rich motifs were the most abundant in all nucleotide repeat types. In silico PCR analysis identified 832 and 925 SSR markers with each having a single amplicon in the cucumber and melon draft genome, respectively. Comparative analysis with these cross-species SSR markers revealed complicated mosaic patterns of syntenic blocks among the genomes of three species. In addition, genetic diversity analysis of 134 watermelon accessions with 32 highly informative SSR loci placed these lines into two groups with all accessions of C.lanatus var. citorides and three accessions of C. colocynthis clustered in one group and all accessions of C. lanatus var. lanatus and the remaining accessions of C. colocynthis

  3. Endozoicomonas genomes reveal functional adaptation and plasticity in bacterial strains symbiotically associated with diverse marine hosts

    KAUST Repository

    Neave, Matthew J.

    2017-01-17

    Endozoicomonas bacteria are globally distributed and often abundantly associated with diverse marine hosts including reef-building corals, yet their function remains unknown. In this study we generated novel Endozoicomonas genomes from single cells and metagenomes obtained directly from the corals Stylophora pistillata, Pocillopora verrucosa, and Acropora humilis. We then compared these culture-independent genomes to existing genomes of bacterial isolates acquired from a sponge, sea slug, and coral to examine the functional landscape of this enigmatic genus. Sequencing and analysis of single cells and metagenomes resulted in four novel genomes with 60–76% and 81–90% genome completeness, respectively. These data also confirmed that Endozoicomonas genomes are large and are not streamlined for an obligate endosymbiotic lifestyle, implying that they have free-living stages. All genomes show an enrichment of genes associated with carbon sugar transport and utilization and protein secretion, potentially indicating that Endozoicomonas contribute to the cycling of carbohydrates and the provision of proteins to their respective hosts. Importantly, besides these commonalities, the genomes showed evidence for differential functional specificity and diversification, including genes for the production of amino acids. Given this metabolic diversity of Endozoicomonas we propose that different genotypes play disparate roles and have diversified in concert with their hosts.

  4. Endozoicomonas genomes reveal functional adaptation and plasticity in bacterial strains symbiotically associated with diverse marine hosts

    KAUST Repository

    Neave, Matthew J.; Michell, Craig; Apprill, Amy; Voolstra, Christian R.

    2017-01-01

    Endozoicomonas bacteria are globally distributed and often abundantly associated with diverse marine hosts including reef-building corals, yet their function remains unknown. In this study we generated novel Endozoicomonas genomes from single cells and metagenomes obtained directly from the corals Stylophora pistillata, Pocillopora verrucosa, and Acropora humilis. We then compared these culture-independent genomes to existing genomes of bacterial isolates acquired from a sponge, sea slug, and coral to examine the functional landscape of this enigmatic genus. Sequencing and analysis of single cells and metagenomes resulted in four novel genomes with 60–76% and 81–90% genome completeness, respectively. These data also confirmed that Endozoicomonas genomes are large and are not streamlined for an obligate endosymbiotic lifestyle, implying that they have free-living stages. All genomes show an enrichment of genes associated with carbon sugar transport and utilization and protein secretion, potentially indicating that Endozoicomonas contribute to the cycling of carbohydrates and the provision of proteins to their respective hosts. Importantly, besides these commonalities, the genomes showed evidence for differential functional specificity and diversification, including genes for the production of amino acids. Given this metabolic diversity of Endozoicomonas we propose that different genotypes play disparate roles and have diversified in concert with their hosts.

  5. Aerobic mitochondria of parasitic protists: diverse genomes and complex functions

    Czech Academy of Sciences Publication Activity Database

    Zíková, Alena; Hampl, V.; Paris, Zdeněk; Týč, Jiří; Lukeš, Julius

    2016-01-01

    Roč. 209, 1-2 (2016), s. 46-57 ISSN 0166-6851 R&D Projects: GA ČR GA15-21974S; GA MŠk LL1205 Institutional support: RVO:60077344 Keywords : protists * mitochondrion * genomes * repliation * RNA editing * ribosomes * electron transport chain * iron-sulfur cluster * heme Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.536, year: 2016

  6. Natural selection shaped the rise and fall of passenger pigeon genomic diversity.

    Science.gov (United States)

    Murray, Gemma G R; Soares, André E R; Novak, Ben J; Schaefer, Nathan K; Cahill, James A; Baker, Allan J; Demboski, John R; Doll, Andrew; Da Fonseca, Rute R; Fulton, Tara L; Gilbert, M Thomas P; Heintzman, Peter D; Letts, Brandon; McIntosh, George; O'Connell, Brendan L; Peck, Mark; Pipes, Marie-Lorraine; Rice, Edward S; Santos, Kathryn M; Sohrweide, A Gregory; Vohr, Samuel H; Corbett-Detig, Russell B; Green, Richard E; Shapiro, Beth

    2017-11-17

    The extinct passenger pigeon was once the most abundant bird in North America, and possibly the world. Although theory predicts that large populations will be more genetically diverse, passenger pigeon genetic diversity was surprisingly low. To investigate this disconnect, we analyzed 41 mitochondrial and 4 nuclear genomes from passenger pigeons and 2 genomes from band-tailed pigeons, which are passenger pigeons' closest living relatives. Passenger pigeons' large population size appears to have allowed for faster adaptive evolution and removal of harmful mutations, driving a huge loss in their neutral genetic diversity. These results demonstrate the effect that selection can have on a vertebrate genome and contradict results that suggested that population instability contributed to this species's surprisingly rapid extinction. Copyright © 2017, American Association for the Advancement of Science.

  7. Genome sequence and genetic diversity of European ash trees.

    Science.gov (United States)

    Sollars, Elizabeth S A; Harper, Andrea L; Kelly, Laura J; Sambles, Christine M; Ramirez-Gonzalez, Ricardo H; Swarbreck, David; Kaithakottil, Gemy; Cooper, Endymion D; Uauy, Cristobal; Havlickova, Lenka; Worswick, Gemma; Studholme, David J; Zohren, Jasmin; Salmon, Deborah L; Clavijo, Bernardo J; Li, Yi; He, Zhesi; Fellgett, Alison; McKinney, Lea Vig; Nielsen, Lene Rostgaard; Douglas, Gerry C; Kjær, Erik Dahl; Downie, J Allan; Boshier, David; Lee, Steve; Clark, Jo; Grant, Murray; Bancroft, Ian; Caccamo, Mario; Buggs, Richard J A

    2017-01-12

    Ash trees (genus Fraxinus, family Oleaceae) are widespread throughout the Northern Hemisphere, but are being devastated in Europe by the fungus Hymenoscyphus fraxineus, causing ash dieback, and in North America by the herbivorous beetle Agrilus planipennis. Here we sequence the genome of a low-heterozygosity Fraxinus excelsior tree from Gloucestershire, UK, annotating 38,852 protein-coding genes of which 25% appear ash specific when compared with the genomes of ten other plant species. Analyses of paralogous genes suggest a whole-genome duplication shared with olive (Olea europaea, Oleaceae). We also re-sequence 37 F. excelsior trees from Europe, finding evidence for apparent long-term decline in effective population size. Using our reference sequence, we re-analyse association transcriptomic data, yielding improved markers for reduced susceptibility to ash dieback. Surveys of these markers in British populations suggest that reduced susceptibility to ash dieback may be more widespread in Great Britain than in Denmark. We also present evidence that susceptibility of trees to H. fraxineus is associated with their iridoid glycoside levels. This rapid, integrated, multidisciplinary research response to an emerging health threat in a non-model organism opens the way for mitigation of the epidemic.

  8. The family Rhabdoviridae: Mono- and bipartite negative-sense RNA viruses with diverse genome organization and common evolutionary origins

    Science.gov (United States)

    Dietzgen, Ralf G.; Kondo, Hideki; Goodin, Michael M.; Kurath, Gael; Vasilakis, Nikos

    2017-01-01

    The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- and bipartite genomes.

  9. Population Genomics of sub-saharan Drosophila melanogaster: African diversity and non-African admixture.

    Directory of Open Access Journals (Sweden)

    John E Pool

    Full Text Available Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia, while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa F(ST were found to be enriched in genomic regions of locally

  10. Population Genomics of Sub-Saharan Drosophila melanogaster: African Diversity and Non-African Admixture

    Science.gov (United States)

    Pool, John E.; Corbett-Detig, Russell B.; Sugino, Ryuichi P.; Stevens, Kristian A.; Cardeno, Charis M.; Crepeau, Marc W.; Duchen, Pablo; Emerson, J. J.; Saelao, Perot; Begun, David J.; Langley, Charles H.

    2012-01-01

    Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia), while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa FST were found to be enriched in genomic regions of locally elevated cosmopolitan

  11. Low diversity, activity, and density of transposable elements in five avian genomes.

    Science.gov (United States)

    Gao, Bo; Wang, Saisai; Wang, Yali; Shen, Dan; Xue, Songlei; Chen, Cai; Cui, Hengmi; Song, Chengyi

    2017-07-01

    In this study, we conducted the activity, diversity, and density analysis of transposable elements (TEs) across five avian genomes (budgerigar, chicken, turkey, medium ground finch, and zebra finch) to explore the potential reason of small genome sizes of birds. We found that these avian genomes exhibited low density of TEs by about 10% of genome coverages and low diversity of TEs with the TE landscapes dominated by CR1 and ERV elements, and contrasting proliferation dynamics both between TE types and between species were observed across the five avian genomes. Phylogenetic analysis revealed that CR1 clade was more diverse in the family structure compared with R2 clade in birds; avian ERVs were classified into four clades (alpha, beta, gamma, and ERV-L) and belonged to three classes of ERV with an uneven distributed in these lineages. The activities of DNA and SINE TEs were very low in the evolution history of avian genomes; most LINEs and LTRs were ancient copies with a substantial decrease of activity in recent, with only LTRs and LINEs in chicken and zebra finch exhibiting weak activity in very recent, and very few TEs were intact; however, the recent activity may be underestimated due to the sequencing/assembly technologies in some species. Overall, this study demonstrates low diversity, activity, and density of TEs in the five avian species; highlights the differences of TEs in these lineages; and suggests that the current and recent activity of TEs in avian genomes is very limited, which may be one of the reasons of small genome sizes in birds.

  12. First genomic survey of human skin fungal diversity

    Science.gov (United States)

    Fungal infections of the skin affect 29 million people in the United States. In the first study of human fungal skin diversity, National Institutes of Health researchers sequenced the DNA of fungi that thrive at different skin sites of healthy adults to d

  13. Population genomics diversity of Plasmodium falciparum in malaria ...

    African Journals Online (AJOL)

    Background: Plasmodium falciparum, the most dangerous malaria parasite species to humans remains an important public health concern in Okelele, a rural community in Ilorin, Kwara State, Nigeria. There is however little information about the genetic diversity of Plasmodium falciparum in Nigeria. Objective: To determine ...

  14. Tales of diversity: Genomic and morphological characteristics of forty-six Arthrobacter phages.

    Directory of Open Access Journals (Sweden)

    Karen K Klyczek

    Full Text Available The vast bacteriophage population harbors an immense reservoir of genetic information. Almost 2000 phage genomes have been sequenced from phages infecting hosts in the phylum Actinobacteria, and analysis of these genomes reveals substantial diversity, pervasive mosaicism, and novel mechanisms for phage replication and lysogeny. Here, we describe the isolation and genomic characterization of 46 phages from environmental samples at various geographic locations in the U.S. infecting a single Arthrobacter sp. strain. These phages include representatives of all three virion morphologies, and Jasmine is the first sequenced podovirus of an actinobacterial host. The phages also span considerable sequence diversity, and can be grouped into 10 clusters according to their nucleotide diversity, and two singletons each with no close relatives. However, the clusters/singletons appear to be genomically well separated from each other, and relatively few genes are shared between clusters. Genome size varies from among the smallest of siphoviral phages (15,319 bp to over 70 kbp, and G+C contents range from 45-68%, compared to 63.4% for the host genome. Although temperate phages are common among other actinobacterial hosts, these Arthrobacter phages are primarily lytic, and only the singleton Galaxy is likely temperate.

  15. Tales of diversity: Genomic and morphological characteristics of forty-six Arthrobacter phages.

    Science.gov (United States)

    Klyczek, Karen K; Bonilla, J Alfred; Jacobs-Sera, Deborah; Adair, Tamarah L; Afram, Patricia; Allen, Katherine G; Archambault, Megan L; Aziz, Rahat M; Bagnasco, Filippa G; Ball, Sarah L; Barrett, Natalie A; Benjamin, Robert C; Blasi, Christopher J; Borst, Katherine; Braun, Mary A; Broomell, Haley; Brown, Conner B; Brynell, Zachary S; Bue, Ashley B; Burke, Sydney O; Casazza, William; Cautela, Julia A; Chen, Kevin; Chimalakonda, Nitish S; Chudoff, Dylan; Connor, Jade A; Cross, Trevor S; Curtis, Kyra N; Dahlke, Jessica A; Deaton, Bethany M; Degroote, Sarah J; DeNigris, Danielle M; DeRuff, Katherine C; Dolan, Milan; Dunbar, David; Egan, Marisa S; Evans, Daniel R; Fahnestock, Abby K; Farooq, Amal; Finn, Garrett; Fratus, Christopher R; Gaffney, Bobby L; Garlena, Rebecca A; Garrigan, Kelly E; Gibbon, Bryan C; Goedde, Michael A; Guerrero Bustamante, Carlos A; Harrison, Melinda; Hartwell, Megan C; Heckman, Emily L; Huang, Jennifer; Hughes, Lee E; Hyduchak, Kathryn M; Jacob, Aswathi E; Kaku, Machika; Karstens, Allen W; Kenna, Margaret A; Khetarpal, Susheel; King, Rodney A; Kobokovich, Amanda L; Kolev, Hannah; Konde, Sai A; Kriese, Elizabeth; Lamey, Morgan E; Lantz, Carter N; Lapin, Jonathan S; Lawson, Temiloluwa O; Lee, In Young; Lee, Scott M; Lee-Soety, Julia Y; Lehmann, Emily M; London, Shawn C; Lopez, A Javier; Lynch, Kelly C; Mageeney, Catherine M; Martynyuk, Tetyana; Mathew, Kevin J; Mavrich, Travis N; McDaniel, Christopher M; McDonald, Hannah; McManus, C Joel; Medrano, Jessica E; Mele, Francis E; Menninger, Jennifer E; Miller, Sierra N; Minick, Josephine E; Nabua, Courtney T; Napoli, Caroline K; Nkangabwa, Martha; Oates, Elizabeth A; Ott, Cassandra T; Pellerino, Sarah K; Pinamont, William J; Pirnie, Ross T; Pizzorno, Marie C; Plautz, Emilee J; Pope, Welkin H; Pruett, Katelyn M; Rickstrew, Gabbi; Rimple, Patrick A; Rinehart, Claire A; Robinson, Kayla M; Rose, Victoria A; Russell, Daniel A; Schick, Amelia M; Schlossman, Julia; Schneider, Victoria M; Sells, Chloe A; Sieker, Jeremy W; Silva, Morgan P; Silvi, Marissa M; Simon, Stephanie E; Staples, Amanda K; Steed, Isabelle L; Stowe, Emily L; Stueven, Noah A; Swartz, Porter T; Sweet, Emma A; Sweetman, Abigail T; Tender, Corrina; Terry, Katrina; Thomas, Chrystal; Thomas, Daniel S; Thompson, Allison R; Vanderveen, Lorianna; Varma, Rohan; Vaught, Hannah L; Vo, Quynh D; Vonberg, Zachary T; Ware, Vassie C; Warrad, Yasmene M; Wathen, Kaitlyn E; Weinstein, Jonathan L; Wyper, Jacqueline F; Yankauskas, Jakob R; Zhang, Christine; Hatfull, Graham F

    2017-01-01

    The vast bacteriophage population harbors an immense reservoir of genetic information. Almost 2000 phage genomes have been sequenced from phages infecting hosts in the phylum Actinobacteria, and analysis of these genomes reveals substantial diversity, pervasive mosaicism, and novel mechanisms for phage replication and lysogeny. Here, we describe the isolation and genomic characterization of 46 phages from environmental samples at various geographic locations in the U.S. infecting a single Arthrobacter sp. strain. These phages include representatives of all three virion morphologies, and Jasmine is the first sequenced podovirus of an actinobacterial host. The phages also span considerable sequence diversity, and can be grouped into 10 clusters according to their nucleotide diversity, and two singletons each with no close relatives. However, the clusters/singletons appear to be genomically well separated from each other, and relatively few genes are shared between clusters. Genome size varies from among the smallest of siphoviral phages (15,319 bp) to over 70 kbp, and G+C contents range from 45-68%, compared to 63.4% for the host genome. Although temperate phages are common among other actinobacterial hosts, these Arthrobacter phages are primarily lytic, and only the singleton Galaxy is likely temperate.

  16. Lactobacillus paracasei comparative genomics: towards species pan-genome definition and exploitation of diversity.

    Directory of Open Access Journals (Sweden)

    Tamara Smokvina

    Full Text Available Lactobacillus paracasei is a member of the normal human and animal gut microbiota and is used extensively in the food industry in starter cultures for dairy products or as probiotics. With the development of low-cost, high-throughput sequencing techniques it has become feasible to sequence many different strains of one species and to determine its "pan-genome". We have sequenced the genomes of 34 different L. paracasei strains, and performed a comparative genomics analysis. We analysed genome synteny and content, focussing on the pan-genome, core genome and variable genome. Each genome was shown to contain around 2800-3100 protein-coding genes, and comparative analysis identified over 4200 ortholog groups that comprise the pan-genome of this species, of which about 1800 ortholog groups make up the conserved core. Several factors previously associated with host-microbe interactions such as pili, cell-envelope proteinase, hydrolases p40 and p75 or the capacity to produce short branched-chain fatty acids (bkd operon are part of the L. paracasei core genome present in all analysed strains. The variome consists mainly of hypothetical proteins, phages, plasmids, transposon/conjugative elements, and known functions such as sugar metabolism, cell-surface proteins, transporters, CRISPR-associated proteins, and EPS biosynthesis proteins. An enormous variety and variability of sugar utilization gene cassettes were identified, with each strain harbouring between 25-53 cassettes, reflecting the high adaptability of L. paracasei to different niches. A phylogenomic tree was constructed based on total genome contents, and together with an analysis of horizontal gene transfer events we conclude that evolution of these L. paracasei strains is complex and not always related to niche adaptation. The results of this genome content comparison was used, together with high-throughput growth experiments on various carbohydrates, to perform gene-trait matching analysis

  17. Expanding the Diversity of Mycobacteriophages: Insights into Genome Architecture and Evolution

    OpenAIRE

    Pope, Welkin H.; Jacobs-Sera, Deborah; Russell, Daniel A.; Peebles, Craig L.; Al-Atrache, Zein; Alcoser, Turi A.; Alexander, Lisa M.; Alfano, Matthew B.; Alford, Samantha T.; Amy, Nichols E.; Anderson, Marie D.; Anderson, Alexander G.; Ang, Andrew A. S.; Ares, Manuel; Barber, Amanda J.

    2011-01-01

    Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we repo...

  18. Aerobic mitochondria of parasitic protists: Diverse genomes and complex functions.

    Science.gov (United States)

    Zíková, Alena; Hampl, Vladimír; Paris, Zdeněk; Týč, Jiří; Lukeš, Julius

    In this review the main features of the mitochondria of aerobic parasitic protists are discussed. While the best characterized organelles are by far those of kinetoplastid flagellates and Plasmodium, we also consider amoebae Naegleria and Acanthamoeba, a ciliate Ichthyophthirius and related lineages. The simplistic view of the mitochondrion as just a power house of the cell has already been abandoned in multicellular organisms and available data indicate that this also does not apply for protists. We discuss in more details the following mitochondrial features: genomes, post-transcriptional processing, translation, biogenesis of iron-sulfur complexes, heme metabolism and the electron transport chain. Substantial differences in all these core mitochondrial features between lineages are compatible with the view that aerobic protists harbor organelles that are more complex and flexible than previously appreciated. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Tomato Fruits Show Wide Phenomic Diversity but Fruit Developmental Genes Show Low Genomic Diversity.

    Directory of Open Access Journals (Sweden)

    Vijee Mohan

    Full Text Available Domestication of tomato has resulted in large diversity in fruit phenotypes. An intensive phenotyping of 127 tomato accessions from 20 countries revealed extensive morphological diversity in fruit traits. The diversity in fruit traits clustered the accessions into nine classes and identified certain promising lines having desirable traits pertaining to total soluble salts (TSS, carotenoids, ripening index, weight and shape. Factor analysis of the morphometric data from Tomato Analyzer showed that the fruit shape is a complex trait shared by several factors. The 100% variance between round and flat fruit shapes was explained by one discriminant function having a canonical correlation of 0.874 by stepwise discriminant analysis. A set of 10 genes (ACS2, COP1, CYC-B, RIN, MSH2, NAC-NOR, PHOT1, PHYA, PHYB and PSY1 involved in various plant developmental processes were screened for SNP polymorphism by EcoTILLING. The genetic diversity in these genes revealed a total of 36 non-synonymous and 18 synonymous changes leading to the identification of 28 haplotypes. The average frequency of polymorphism across the genes was 0.038/Kb. Significant negative Tajima'D statistic in two of the genes, ACS2 and PHOT1 indicated the presence of rare alleles in low frequency. Our study indicates that while there is low polymorphic diversity in the genes regulating plant development, the population shows wider phenotype diversity. Nonetheless, morphological and genetic diversity of the present collection can be further exploited as potential resources in future.

  20. Expanding the Diversity of Mycobacteriophages: Insights into Genome Architecture and Evolution

    Science.gov (United States)

    Pope, Welkin H.; Jacobs-Sera, Deborah; Russell, Daniel A.; Peebles, Craig L.; Al-Atrache, Zein; Alcoser, Turi A.; Alexander, Lisa M.; Alfano, Matthew B.; Alford, Samantha T.; Amy, Nichols E.; Anderson, Marie D.; Anderson, Alexander G.; Ang, Andrew A. S.; Ares, Manuel; Barber, Amanda J.; Barker, Lucia P.; Barrett, Jonathan M.; Barshop, William D.; Bauerle, Cynthia M.; Bayles, Ian M.; Belfield, Katherine L.; Best, Aaron A.; Borjon, Agustin; Bowman, Charles A.; Boyer, Christine A.; Bradley, Kevin W.; Bradley, Victoria A.; Broadway, Lauren N.; Budwal, Keshav; Busby, Kayla N.; Campbell, Ian W.; Campbell, Anne M.; Carey, Alyssa; Caruso, Steven M.; Chew, Rebekah D.; Cockburn, Chelsea L.; Cohen, Lianne B.; Corajod, Jeffrey M.; Cresawn, Steven G.; Davis, Kimberly R.; Deng, Lisa; Denver, Dee R.; Dixon, Breyon R.; Ekram, Sahrish; Elgin, Sarah C. R.; Engelsen, Angela E.; English, Belle E. V.; Erb, Marcella L.; Estrada, Crystal; Filliger, Laura Z.; Findley, Ann M.; Forbes, Lauren; Forsyth, Mark H.; Fox, Tyler M.; Fritz, Melissa J.; Garcia, Roberto; George, Zindzi D.; Georges, Anne E.; Gissendanner, Christopher R.; Goff, Shannon; Goldstein, Rebecca; Gordon, Kobie C.; Green, Russell D.; Guerra, Stephanie L.; Guiney-Olsen, Krysta R.; Guiza, Bridget G.; Haghighat, Leila; Hagopian, Garrett V.; Harmon, Catherine J.; Harmson, Jeremy S.; Hartzog, Grant A.; Harvey, Samuel E.; He, Siping; He, Kevin J.; Healy, Kaitlin E.; Higinbotham, Ellen R.; Hildebrandt, Erin N.; Ho, Jason H.; Hogan, Gina M.; Hohenstein, Victoria G.; Holz, Nathan A.; Huang, Vincent J.; Hufford, Ericka L.; Hynes, Peter M.; Jackson, Arrykka S.; Jansen, Erica C.; Jarvik, Jonathan; Jasinto, Paul G.; Jordan, Tuajuanda C.; Kasza, Tomas; Katelyn, Murray A.; Kelsey, Jessica S.; Kerrigan, Larisa A.; Khaw, Daryl; Kim, Junghee; Knutter, Justin Z.; Ko, Ching-Chung; Larkin, Gail V.; Laroche, Jennifer R.; Latif, Asma; Leuba, Kohana D.; Leuba, Sequoia I.; Lewis, Lynn O.; Loesser-Casey, Kathryn E.; Long, Courtney A.; Lopez, A. Javier; Lowery, Nicholas; Lu, Tina Q.; Mac, Victor; Masters, Isaac R.; McCloud, Jazmyn J.; McDonough, Molly J.; Medenbach, Andrew J.; Menon, Anjali; Miller, Rachel; Morgan, Brandon K.; Ng, Patrick C.; Nguyen, Elvis; Nguyen, Katrina T.; Nguyen, Emilie T.; Nicholson, Kaylee M.; Parnell, Lindsay A.; Peirce, Caitlin E.; Perz, Allison M.; Peterson, Luke J.; Pferdehirt, Rachel E.; Philip, Seegren V.; Pogliano, Kit; Pogliano, Joe; Polley, Tamsen; Puopolo, Erica J.; Rabinowitz, Hannah S.; Resiss, Michael J.; Rhyan, Corwin N.; Robinson, Yetta M.; Rodriguez, Lauren L.; Rose, Andrew C.; Rubin, Jeffrey D.; Ruby, Jessica A.; Saha, Margaret S.; Sandoz, James W.; Savitskaya, Judith; Schipper, Dale J.; Schnitzler, Christine E.; Schott, Amanda R.; Segal, J. Bradley; Shaffer, Christopher D.; Sheldon, Kathryn E.; Shepard, Erica M.; Shepardson, Jonathan W.; Shroff, Madav K.; Simmons, Jessica M.; Simms, Erika F.; Simpson, Brandy M.; Sinclair, Kathryn M.; Sjoholm, Robert L.; Slette, Ingrid J.; Spaulding, Blaire C.; Straub, Clark L.; Stukey, Joseph; Sughrue, Trevor; Tang, Tin-Yun; Tatyana, Lyons M.; Taylor, Stephen B.; Taylor, Barbara J.; Temple, Louise M.; Thompson, Jasper V.; Tokarz, Michael P.; Trapani, Stephanie E.; Troum, Alexander P.; Tsay, Jonathan; Tubbs, Anthony T.; Walton, Jillian M.; Wang, Danielle H.; Wang, Hannah; Warner, John R.; Weisser, Emilie G.; Wendler, Samantha C.; Weston-Hafer, Kathleen A.; Whelan, Hilary M.; Williamson, Kurt E.; Willis, Angelica N.; Wirtshafter, Hannah S.; Wong, Theresa W.; Wu, Phillip; Yang, Yun jeong; Yee, Brandon C.; Zaidins, David A.; Zhang, Bo; Zúniga, Melina Y.; Hendrix, Roger W.; Hatfull, Graham F.

    2011-01-01

    Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists. PMID:21298013

  1. Salmonella enterica Prophage Sequence Profiles Reflect Genome Diversity and Can Be Used for High Discrimination Subtyping

    Directory of Open Access Journals (Sweden)

    Walid Mottawea

    2018-05-01

    Full Text Available Non-typhoidal Salmonella is a leading cause of foodborne illness worldwide. Prompt and accurate identification of the sources of Salmonella responsible for disease outbreaks is crucial to minimize infections and eliminate ongoing sources of contamination. Current subtyping tools including single nucleotide polymorphism (SNP typing may be inadequate, in some instances, to provide the required discrimination among epidemiologically unrelated Salmonella strains. Prophage genes represent the majority of the accessory genes in bacteria genomes and have potential to be used as high discrimination markers in Salmonella. In this study, the prophage sequence diversity in different Salmonella serovars and genetically related strains was investigated. Using whole genome sequences of 1,760 isolates of S. enterica representing 151 Salmonella serovars and 66 closely related bacteria, prophage sequences were identified from assembled contigs using PHASTER. We detected 154 different prophages in S. enterica genomes. Prophage sequences were highly variable among S. enterica serovars with a median ± interquartile range (IQR of 5 ± 3 prophage regions per genome. While some prophage sequences were highly conserved among the strains of specific serovars, few regions were lineage specific. Therefore, strains belonging to each serovar could be clustered separately based on their prophage content. Analysis of S. Enteritidis isolates from seven outbreaks generated distinct prophage profiles for each outbreak. Taken altogether, the diversity of the prophage sequences correlates with genome diversity. Prophage repertoires provide an additional marker for differentiating S. enterica subtypes during foodborne outbreaks.

  2. Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

    Directory of Open Access Journals (Sweden)

    Welkin H Pope

    2011-01-01

    Full Text Available Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists.

  3. Genomic diversity and phylogeography of norovirus in China.

    Science.gov (United States)

    Qiao, Niu; Ren, He; Liu, Lei

    2017-10-03

    Little is known about the phylogeography of norovirus (NoV) in China. In norovirus, a clear understanding for the characteristics of tree topology, migration patterns and its demographic dynamics in viral circulation are needed to identify its prevalence trends, which can help us better prepare for its epidemics as well as develop useful control strategies. The aim of this study was to explore the genetic diversity, temporal distribution, demographic dynamics and migration patterns of NoV that circulated in China. Our analysis showed that two major genogroups, GI and GII, were identified in China, in which GII.3, GII.4 and GII.17 accounted for the majority with a total proportion around 70%. Our demography inference suggested that during the long-term migration process, NoV evolved into multiple lineages and then experienced a selective sweep, which reduced its genetic diversity. The phylogeography results suggested that the norovirus may have originated form the South China (Hong Kong and Guangdong), followed by multicenter direction outbreaks across the country. From these analyses, we indicate that domestic poultry trade and frequent communications of people from different regions have all contributed to the spread of the NoV in China. Together with recent advances in phylogeographic inference, our researches also provide powerful illustrations of how coalescent-based methods can extract adequate information in molecular epidemiology.

  4. Consequences for diversity when prioritizing animals for conservation with pedigree or genomic information

    NARCIS (Netherlands)

    Engelsma, K.A.; Veerkamp, R.F.; Calus, M.P.L.; Windig, J.J.

    2011-01-01

    Up to now, prioritization of animals for conservation has been mainly based on pedigree information; however, genomic information may improve prioritization. In this study, we used two Holstein populations to investigate the consequences for genetic diversity when animals are prioritized with

  5. The genomic diversity and stability of field strains of Suid herpesvirus 1 (Aujeszky's disease virus)

    DEFF Research Database (Denmark)

    Christensen, Laurids Siig; Sørensen, K. J.

    1991-01-01

    The genomic diversity among isolates of suid herpesvirus 1 (SHV-1) collected in the same herd and among clones from the same isolate was studied by restriction fragment pattern (RFP) analysis using BamHI. Tentatively defining a field strain as a transmissible entity, it was concluded that strains...

  6. Plasmodium falciparum Erythrocyte Membrane Protein 1 Diversity in Seven Genomes – Divide and Conquer

    DEFF Research Database (Denmark)

    Rask, Thomas Salhøj; Hansen, Daniel Aaen; Theander, Thor G.

    2010-01-01

    of a PfEMP1 based vaccine mimicking natural acquired immunity depends on a thorough understanding of the evolved PfEMP1 diversity, balancing antigenic variation against conserved receptor binding affinities. This study redefines and reclassifies the domains of PfEMP1 from seven genomes. Analysis...

  7. Consequences for diversity when animals are prioritized for conservation of the whole genome or of one specific allele

    NARCIS (Netherlands)

    Engelsma, K.A.; Veerkamp, R.F.; Calus, M.P.L.; Windig, J.J.

    2014-01-01

    When animals are selected for one specific allele, for example for inclusion in a gene bank, this may result in the loss of diversity in other parts of the genome. The aim of this study was to quantify the risk of losing diversity across the genome when targeting a single allele for conservation

  8. Genetic diversity analysis of two commercial breeds of pigs using genomic and pedigree data.

    Science.gov (United States)

    Zanella, Ricardo; Peixoto, Jane O; Cardoso, Fernando F; Cardoso, Leandro L; Biegelmeyer, Patrícia; Cantão, Maurício E; Otaviano, Antonio; Freitas, Marcelo S; Caetano, Alexandre R; Ledur, Mônica C

    2016-03-30

    Genetic improvement in livestock populations can be achieved without significantly affecting genetic diversity if mating systems and selection decisions take genetic relationships among individuals into consideration. The objective of this study was to examine the genetic diversity of two commercial breeds of pigs. Genotypes from 1168 Landrace (LA) and 1094 Large White (LW) animals from a commercial breeding program in Brazil were obtained using the Illumina PorcineSNP60 Beadchip. Inbreeding estimates based on pedigree (F x) and genomic information using runs of homozygosity (F ROH) and the single nucleotide polymorphisms (SNP) by SNP inbreeding coefficient (F SNP) were obtained. Linkage disequilibrium (LD), correlation of linkage phase (r) and effective population size (N e ) were also estimated. Estimates of inbreeding obtained with pedigree information were lower than those obtained with genomic data in both breeds. We observed that the extent of LD was slightly larger at shorter distances between SNPs in the LW population than in the LA population, which indicates that the LW population was derived from a smaller N e . Estimates of N e based on genomic data were equal to 53 and 40 for the current populations of LA and LW, respectively. The correlation of linkage phase between the two breeds was equal to 0.77 at distances up to 50 kb, which suggests that genome-wide association and selection should be performed within breed. Although selection intensities have been stronger in the LA breed than in the LW breed, levels of genomic and pedigree inbreeding were lower for the LA than for the LW breed. The use of genomic data to evaluate population diversity in livestock animals can provide new and more precise insights about the effects of intense selection for production traits. Resulting information and knowledge can be used to effectively increase response to selection by appropriately managing the rate of inbreeding, minimizing negative effects of inbreeding

  9. Impact of marker ascertainment bias on genomic selection accuracy and estimates of genetic diversity.

    Directory of Open Access Journals (Sweden)

    Nicolas Heslot

    Full Text Available Genome-wide molecular markers are often being used to evaluate genetic diversity in germplasm collections and for making genomic selections in breeding programs. To accurately predict phenotypes and assay genetic diversity, molecular markers should assay a representative sample of the polymorphisms in the population under study. Ascertainment bias arises when marker data is not obtained from a random sample of the polymorphisms in the population of interest. Genotyping-by-sequencing (GBS is rapidly emerging as a low-cost genotyping platform, even for the large, complex, and polyploid wheat (Triticum aestivum L. genome. With GBS, marker discovery and genotyping occur simultaneously, resulting in minimal ascertainment bias. The previous platform of choice for whole-genome genotyping in many species such as wheat was DArT (Diversity Array Technology and has formed the basis of most of our knowledge about cereals genetic diversity. This study compared GBS and DArT marker platforms for measuring genetic diversity and genomic selection (GS accuracy in elite U.S. soft winter wheat. From a set of 365 breeding lines, 38,412 single nucleotide polymorphism GBS markers were discovered and genotyped. The GBS SNPs gave a higher GS accuracy than 1,544 DArT markers on the same lines, despite 43.9% missing data. Using a bootstrap approach, we observed significantly more clustering of markers and ascertainment bias with DArT relative to GBS. The minor allele frequency distribution of GBS markers had a deficit of rare variants compared to DArT markers. Despite the ascertainment bias of the DArT markers, GS accuracy for three traits out of four was not significantly different when an equal number of markers were used for each platform. This suggests that the gain in accuracy observed using GBS compared to DArT markers was mainly due to a large increase in the number of markers available for the analysis.

  10. Impact of Marker Ascertainment Bias on Genomic Selection Accuracy and Estimates of Genetic Diversity

    Science.gov (United States)

    Heslot, Nicolas; Rutkoski, Jessica; Poland, Jesse; Jannink, Jean-Luc; Sorrells, Mark E.

    2013-01-01

    Genome-wide molecular markers are often being used to evaluate genetic diversity in germplasm collections and for making genomic selections in breeding programs. To accurately predict phenotypes and assay genetic diversity, molecular markers should assay a representative sample of the polymorphisms in the population under study. Ascertainment bias arises when marker data is not obtained from a random sample of the polymorphisms in the population of interest. Genotyping-by-sequencing (GBS) is rapidly emerging as a low-cost genotyping platform, even for the large, complex, and polyploid wheat (Triticum aestivum L.) genome. With GBS, marker discovery and genotyping occur simultaneously, resulting in minimal ascertainment bias. The previous platform of choice for whole-genome genotyping in many species such as wheat was DArT (Diversity Array Technology) and has formed the basis of most of our knowledge about cereals genetic diversity. This study compared GBS and DArT marker platforms for measuring genetic diversity and genomic selection (GS) accuracy in elite U.S. soft winter wheat. From a set of 365 breeding lines, 38,412 single nucleotide polymorphism GBS markers were discovered and genotyped. The GBS SNPs gave a higher GS accuracy than 1,544 DArT markers on the same lines, despite 43.9% missing data. Using a bootstrap approach, we observed significantly more clustering of markers and ascertainment bias with DArT relative to GBS. The minor allele frequency distribution of GBS markers had a deficit of rare variants compared to DArT markers. Despite the ascertainment bias of the DArT markers, GS accuracy for three traits out of four was not significantly different when an equal number of markers were used for each platform. This suggests that the gain in accuracy observed using GBS compared to DArT markers was mainly due to a large increase in the number of markers available for the analysis. PMID:24040295

  11. Co-invading symbiotic mutualists of Medicago polymorpha retain high ancestral diversity and contain diverse accessory genomes.

    Science.gov (United States)

    Porter, Stephanie S; Faber-Hammond, Joshua J; Friesen, Maren L

    2018-01-01

    Exotic, invasive plants and animals can wreak havoc on ecosystems by displacing natives and altering environmental conditions. However, much less is known about the identities or evolutionary dynamics of the symbiotic microbes that accompany invasive species. Most leguminous plants rely upon symbiotic rhizobium bacteria to fix nitrogen and are incapable of colonizing areas devoid of compatible rhizobia. We compare the genomes of symbiotic rhizobia in a portion of the legume's invaded range with those of the rhizobium symbionts from across the legume's native range. We show that in an area of California the legume Medicago polymorpha has invaded, its Ensifer medicae symbionts: (i) exhibit genome-wide patterns of relatedness that together with historical evidence support host-symbiont co-invasion from Europe into California, (ii) exhibit population genomic patterns consistent with the introduction of the majority of deep diversity from the native range, rather than a genetic bottleneck during colonization of California and (iii) harbor a large set of accessory genes uniquely enriched in binding functions, which could play a role in habitat invasion. Examining microbial symbiont genome dynamics during biological invasions is critical for assessing host-symbiont co-invasions whereby microbial symbiont range expansion underlies plant and animal invasions. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Characterization of Human Cytomegalovirus Genome Diversity in Immunocompromised Hosts by Whole-Genome Sequencing Directly From Clinical Specimens.

    Science.gov (United States)

    Hage, Elias; Wilkie, Gavin S; Linnenweber-Held, Silvia; Dhingra, Akshay; Suárez, Nicolás M; Schmidt, Julius J; Kay-Fedorov, Penelope C; Mischak-Weissinger, Eva; Heim, Albert; Schwarz, Anke; Schulz, Thomas F; Davison, Andrew J; Ganzenmueller, Tina

    2017-06-01

    Advances in next-generation sequencing (NGS) technologies allow comprehensive studies of genetic diversity over the entire genome of human cytomegalovirus (HCMV), a significant pathogen for immunocompromised individuals. Next-generation sequencing was performed on target enriched sequence libraries prepared directly from a variety of clinical specimens (blood, urine, breast milk, respiratory samples, biopsies, and vitreous humor) obtained longitudinally or from different anatomical compartments from 20 HCMV-infected patients (renal transplant recipients, stem cell transplant recipients, and congenitally infected children). De novo-assembled HCMV genome sequences were obtained for 57 of 68 sequenced samples. Analysis of longitudinal or compartmental HCMV diversity revealed various patterns: no major differences were detected among longitudinal, intraindividual blood samples from 9 of 15 patients and in most of the patients with compartmental samples, whereas a switch of the major HCMV population was observed in 6 individuals with sequential blood samples and upon compartmental analysis of 1 patient with HCMV retinitis. Variant analysis revealed additional aspects of minor virus population dynamics and antiviral-resistance mutations. In immunosuppressed patients, HCMV can remain relatively stable or undergo drastic genomic changes that are suggestive of the emergence of minor resident strains or de novo infection. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  13. The draft genome of watermelon (Citrullus lanatus) and resequencing of 20 diverse accessions.

    Science.gov (United States)

    Guo, Shaogui; Zhang, Jianguo; Sun, Honghe; Salse, Jerome; Lucas, William J; Zhang, Haiying; Zheng, Yi; Mao, Linyong; Ren, Yi; Wang, Zhiwen; Min, Jiumeng; Guo, Xiaosen; Murat, Florent; Ham, Byung-Kook; Zhang, Zhaoliang; Gao, Shan; Huang, Mingyun; Xu, Yimin; Zhong, Silin; Bombarely, Aureliano; Mueller, Lukas A; Zhao, Hong; He, Hongju; Zhang, Yan; Zhang, Zhonghua; Huang, Sanwen; Tan, Tao; Pang, Erli; Lin, Kui; Hu, Qun; Kuang, Hanhui; Ni, Peixiang; Wang, Bo; Liu, Jingan; Kou, Qinghe; Hou, Wenju; Zou, Xiaohua; Jiang, Jiao; Gong, Guoyi; Klee, Kathrin; Schoof, Heiko; Huang, Ying; Hu, Xuesong; Dong, Shanshan; Liang, Dequan; Wang, Juan; Wu, Kui; Xia, Yang; Zhao, Xiang; Zheng, Zequn; Xing, Miao; Liang, Xinming; Huang, Bangqing; Lv, Tian; Wang, Junyi; Yin, Ye; Yi, Hongping; Li, Ruiqiang; Wu, Mingzhu; Levi, Amnon; Zhang, Xingping; Giovannoni, James J; Wang, Jun; Li, Yunfu; Fei, Zhangjun; Xu, Yong

    2013-01-01

    Watermelon, Citrullus lanatus, is an important cucurbit crop grown throughout the world. Here we report a high-quality draft genome sequence of the east Asia watermelon cultivar 97103 (2n = 2× = 22) containing 23,440 predicted protein-coding genes. Comparative genomics analysis provided an evolutionary scenario for the origin of the 11 watermelon chromosomes derived from a 7-chromosome paleohexaploid eudicot ancestor. Resequencing of 20 watermelon accessions representing three different C. lanatus subspecies produced numerous haplotypes and identified the extent of genetic diversity and population structure of watermelon germplasm. Genomic regions that were preferentially selected during domestication were identified. Many disease-resistance genes were also found to be lost during domestication. In addition, integrative genomic and transcriptomic analyses yielded important insights into aspects of phloem-based vascular signaling in common between watermelon and cucumber and identified genes crucial to valuable fruit-quality traits, including sugar accumulation and citrulline metabolism.

  14. Diversity of 23S rRNA genes within individual prokaryotic genomes.

    Directory of Open Access Journals (Sweden)

    Anna Pei

    Full Text Available BACKGROUND: The concept of ribosomal constraints on rRNA genes is deduced primarily based on the comparison of consensus rRNA sequences between closely related species, but recent advances in whole-genome sequencing allow evaluation of this concept within organisms with multiple rRNA operons. METHODOLOGY/PRINCIPAL FINDINGS: Using the 23S rRNA gene as an example, we analyzed the diversity among individual rRNA genes within a genome. Of 184 prokaryotic species containing multiple 23S rRNA genes, diversity was observed in 113 (61.4% genomes (mean 0.40%, range 0.01%-4.04%. Significant (1.17%-4.04% intragenomic variation was found in 8 species. In 5 of the 8 species, the diversity in the primary structure had only minimal effect on the secondary structure (stem versus loop transition. In the remaining 3 species, the diversity significantly altered local secondary structure, but the alteration appears minimized through complex rearrangement. Intervening sequences (IVS, ranging between 9 and 1471 nt in size, were found in 7 species. IVS in Deinococcus radiodurans and Nostoc sp. encode transposases. T. tengcongensis was the only species in which intragenomic diversity >3% was observed among 4 paralogous 23S rRNA genes. CONCLUSIONS/SIGNIFICANCE: These findings indicate tight ribosomal constraints on individual 23S rRNA genes within a genome. Although classification using primary 23S rRNA sequences could be erroneous, significant diversity among paralogous 23S rRNA genes was observed only once in the 184 species analyzed, indicating little overall impact on the mainstream of 23S rRNA gene-based prokaryotic taxonomy.

  15. Comparative genomics of Mycoplasma: analysis of conserved essential genes and diversity of the pan-genome.

    Directory of Open Access Journals (Sweden)

    Wei Liu

    Full Text Available Mycoplasma, the smallest self-replicating organism with a minimal metabolism and little genomic redundancy, is expected to be a close approximation to the minimal set of genes needed to sustain bacterial life. This study employs comparative evolutionary analysis of twenty Mycoplasma genomes to gain an improved understanding of essential genes. By analyzing the core genome of mycoplasmas, we finally revealed the conserved essential genes set for mycoplasma survival. Further analysis showed that the core genome set has many characteristics in common with experimentally identified essential genes. Several key genes, which are related to DNA replication and repair and can be disrupted in transposon mutagenesis studies, may be critical for bacteria survival especially over long period natural selection. Phylogenomic reconstructions based on 3,355 homologous groups allowed robust estimation of phylogenetic relatedness among mycoplasma strains. To obtain deeper insight into the relative roles of molecular evolution in pathogen adaptation to their hosts, we also analyzed the positive selection pressures on particular sites and lineages. There appears to be an approximate correlation between the divergence of species and the level of positive selection detected in corresponding lineages.

  16. Genomic diversity and introgression in O. sativa reveal the impact of domestication and breeding on the rice genome.

    Directory of Open Access Journals (Sweden)

    Keyan Zhao

    2010-05-01

    Full Text Available The domestication of Asian rice (Oryza sativa was a complex process punctuated by episodes of introgressive hybridization among and between subpopulations. Deep genetic divergence between the two main varietal groups (Indica and Japonica suggests domestication from at least two distinct wild populations. However, genetic uniformity surrounding key domestication genes across divergent subpopulations suggests cultural exchange of genetic material among ancient farmers.In this study, we utilize a novel 1,536 SNP panel genotyped across 395 diverse accessions of O. sativa to study genome-wide patterns of polymorphism, to characterize population structure, and to infer the introgression history of domesticated Asian rice. Our population structure analyses support the existence of five major subpopulations (indica, aus, tropical japonica, temperate japonica and GroupV consistent with previous analyses. Our introgression analysis shows that most accessions exhibit some degree of admixture, with many individuals within a population sharing the same introgressed segment due to artificial selection. Admixture mapping and association analysis of amylose content and grain length illustrate the potential for dissecting the genetic basis of complex traits in domesticated plant populations.Genes in these regions control a myriad of traits including plant stature, blast resistance, and amylose content. These analyses highlight the power of population genomics in agricultural systems to identify functionally important regions of the genome and to decipher the role of human-directed breeding in refashioning the genomes of a domesticated species.

  17. Genome-level comparisons provide insight into the phylogeny and metabolic diversity of species within the genus Lactococcus.

    Science.gov (United States)

    Yu, Jie; Song, Yuqin; Ren, Yan; Qing, Yanting; Liu, Wenjun; Sun, Zhihong

    2017-11-03

    The genomic diversity of different species within the genus Lactococcus and the relationships between genomic differentiation and environmental factors remain unclear. In this study, type isolates of ten Lactococcus species/subspecies were sequenced to assess their genomic characteristics, metabolic diversity, and phylogenetic relationships. The total genome sizes varied between 1.99 (Lactococcus plantarum) and 2.46 megabases (Mb; L. lactis subsp. lactis), and the G + C content ranged from 34.81 (L. lactis subsp. hordniae) to 39.67% (L. raffinolactis) with an average value of 37.02%. Analysis of genome dynamics indicated that the genus Lactococcus has an open pan-genome, while the core genome size decreased with sequential addition at the genus and species group levels. A phylogenetic dendrogram based on the concatenated amino acid sequences of 643 core genes was largely consistent with the phylogenetic tree obtained by 16S ribosomal RNA (rRNA) genes, but it provided a more robust phylogenetic resolution than the 16S rRNA gene-based analysis. Comparative genomics indicated that species in the genus Lactococcus had high degrees of diversity in genome size, gene content, and carbohydrate metabolism. This may be important for the specific adaptations that allow different Lactococcus species to survive in different environments. These results provide a quantitative basis for understanding the genomic and metabolic diversity within the genus Lactococcus, laying the foundation for future studies on taxonomy and functional genomics.

  18. The family Rhabdoviridae: mono- and bipartite negative-sense RNA viruses with diverse genome organization and common evolutionary origins

    OpenAIRE

    Dietzgen, Ralf G.; Kondo, Hideki; Goodin, Michael M.; Kurath, Gael; Vasilakis, Nikos

    2016-01-01

    The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the char...

  19. Genome-centric resolution of microbial diversity, metabolism and interactions in anaerobic digestion.

    Science.gov (United States)

    Vanwonterghem, Inka; Jensen, Paul D; Rabaey, Korneel; Tyson, Gene W

    2016-09-01

    Our understanding of the complex interconnected processes performed by microbial communities is hindered by our inability to culture the vast majority of microorganisms. Metagenomics provides a way to bypass this cultivation bottleneck and recent advances in this field now allow us to recover a growing number of genomes representing previously uncultured populations from increasingly complex environments. In this study, a temporal genome-centric metagenomic analysis was performed of lab-scale anaerobic digesters that host complex microbial communities fulfilling a series of interlinked metabolic processes to enable the conversion of cellulose to methane. In total, 101 population genomes that were moderate to near-complete were recovered based primarily on differential coverage binning. These populations span 19 phyla, represent mostly novel species and expand the genomic coverage of several rare phyla. Classification into functional guilds based on their metabolic potential revealed metabolic networks with a high level of functional redundancy as well as niche specialization, and allowed us to identify potential roles such as hydrolytic specialists for several rare, uncultured populations. Genome-centric analyses of complex microbial communities across diverse environments provide the key to understanding the phylogenetic and metabolic diversity of these interactive communities. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  20. Comparative Genomics of the Herbivore Gut Symbiont Lactobacillus reuteri Reveals Genetic Diversity and Lifestyle Adaptation

    Directory of Open Access Journals (Sweden)

    Jie Yu

    2018-06-01

    Full Text Available Lactobacillus reuteri is a catalase-negative, Gram-positive, non-motile, obligately heterofermentative bacterial species that has been used as a model to describe the ecology and evolution of vertebrate gut symbionts. However, the genetic features and evolutionary strategies of L. reuteri from the gastrointestinal tract of herbivores remain unknown. Therefore, 16 L. reuteri strains isolated from goat, sheep, cow, and horse in Inner Mongolia, China were sequenced in this study. A comparative genomic approach was used to assess genetic diversity and gain insight into the distinguishing features related to the different hosts based on 21 published genomic sequences. Genome size, G + C content, and average nucleotide identity values of the L. reuteri strains from different hosts indicated that the strains have broad genetic diversity. The pan-genome of 37 L. reuteri strains contained 8,680 gene families, and the core genome contained 726 gene families. A total of 92,270 nucleotide mutation sites were discovered among 37 L. reuteri strains, and all core genes displayed a Ka/Ks ratio much lower than 1, suggesting strong purifying selective pressure (negative selection. A highly robust maximum likelihood tree based on the core genes shown in the herbivore isolates were divided into three clades; clades A and B contained most of the herbivore isolates and were more closely related to human isolates and vastly distinct from clade C. Some functional genes may be attributable to host-specific of the herbivore, omnivore, and sourdough groups. Moreover, the numbers of genes encoding cell surface proteins and active carbohydrate enzymes were host-specific. This study provides new insight into the adaptation of L. reuteri to the intestinal habitat of herbivores, suggesting that the genomic diversity of L. reuteri from different ecological origins is closely associated with their living environment.

  1. Genome sequence diversity and clues to the evolution of variola (smallpox) virus.

    Science.gov (United States)

    Esposito, Joseph J; Sammons, Scott A; Frace, A Michael; Osborne, John D; Olsen-Rasmussen, Melissa; Zhang, Ming; Govil, Dhwani; Damon, Inger K; Kline, Richard; Laker, Miriam; Li, Yu; Smith, Geoffrey L; Meyer, Hermann; Leduc, James W; Wohlhueter, Robert M

    2006-08-11

    Comparative genomics of 45 epidemiologically varied variola virus isolates from the past 30 years of the smallpox era indicate low sequence diversity, suggesting that there is probably little difference in the isolates' functional gene content. Phylogenetic clustering inferred three clades coincident with their geographical origin and case-fatality rate; the latter implicated putative proteins that mediate viral virulence differences. Analysis of the viral linear DNA genome suggests that its evolution involved direct descent and DNA end-region recombination events. Knowing the sequences will help understand the viral proteome and improve diagnostic test precision, therapeutics, and systems for their assessment.

  2. Genomic diversity among Danish field strains of Mycoplasma hyosynoviae assessed by amplified fragment length polymorphism analysis

    DEFF Research Database (Denmark)

    Kokotovic, Branko; Friis, Niels F.; Nielsen, Elisabeth O.

    2002-01-01

    Genomic diversity among strains of Mycoplasma hyosynoviae isolated in Denmark was assessed by using amplified fragment length polymorphism (AFLP) analysis. Ninety-six strains, obtained from different specimens and geographical locations during 30 years and the type strain of M. hyosynoviae S16(T......) were concurrently examined for variance in BglII-MfeI and EcoRI-Csp6I-A AFLP markers. A total of 56 different genomic fingerprints having an overall similarity between 77 and 96% were detected. No correlation between AFLP variability and period of isolation or anatomical site of isolation could...

  3. Extensive Genomic Diversity among Bovine-Adapted Staphylococcus aureus: Evidence for a Genomic Rearrangement within CC97.

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    Kathleen E Budd

    Full Text Available Staphylococcus aureus is an important pathogen associated with both human and veterinary disease and is a common cause of bovine mastitis. Genomic heterogeneity exists between S. aureus strains and has been implicated in the adaptation of specific strains to colonise particular mammalian hosts. Knowledge of the factors required for host specificity and virulence is important for understanding the pathogenesis and management of S. aureus mastitis. In this study, a panel of mastitis-associated S. aureus isolates (n = 126 was tested for resistance to antibiotics commonly used to treat mastitis. Over half of the isolates (52% demonstrated resistance to penicillin and ampicillin but all were susceptible to the other antibiotics tested. S. aureus isolates were further examined for their clonal diversity by Multi-Locus Sequence Typing (MLST. In total, 18 different sequence types (STs were identified and eBURST analysis demonstrated that the majority of isolates grouped into clonal complexes CC97, CC151 or sequence type (ST 136. Analysis of the role of recombination events in determining S. aureus population structure determined that ST diversification through nucleotide substitutions were more likely to be due to recombination compared to point mutation, with regions of the genome possibly acting as recombination hotspots. DNA microarray analysis revealed a large number of differences amongst S. aureus STs in their variable genome content, including genes associated with capsule and biofilm formation and adhesion factors. Finally, evidence for a genomic arrangement was observed within isolates from CC97 with the ST71-like subgroup showing evidence of an IS431 insertion element having replaced approximately 30 kb of DNA including the ica operon and histidine biosynthesis genes, resulting in histidine auxotrophy. This genomic rearrangement may be responsible for the diversification of ST71 into an emerging bovine adapted subgroup.

  4. Genome-Based Studies of Marine Microorganisms to Maximize the Diversity of Natural Products Discovery for Medical Treatments

    Directory of Open Access Journals (Sweden)

    Xin-Qing Zhao

    2011-01-01

    Full Text Available Marine microorganisms are rich source for natural products which play important roles in pharmaceutical industry. Over the past decade, genome-based studies of marine microorganisms have unveiled the tremendous diversity of the producers of natural products and also contributed to the efficiency of harness the strain diversity and chemical diversity, as well as the genetic diversity of marine microorganisms for the rapid discovery and generation of new natural products. In the meantime, genomic information retrieved from marine symbiotic microorganisms can also be employed for the discovery of new medical molecules from yet-unculturable microorganisms. In this paper, the recent progress in the genomic research of marine microorganisms is reviewed; new tools of genome mining as well as the advance in the activation of orphan pathways and metagenomic studies are summarized. Genome-based research of marine microorganisms will maximize the biodiscovery process and solve the problems of supply and sustainability of drug molecules for medical treatments.

  5. Twenty-one genome sequences from Pseudomonas species and 19 genome sequences from diverse bacteria isolated from the rhizosphere and endosphere of Populus deltoides.

    Science.gov (United States)

    Brown, Steven D; Utturkar, Sagar M; Klingeman, Dawn M; Johnson, Courtney M; Martin, Stanton L; Land, Miriam L; Lu, Tse-Yuan S; Schadt, Christopher W; Doktycz, Mitchel J; Pelletier, Dale A

    2012-11-01

    To aid in the investigation of the Populus deltoides microbiome, we generated draft genome sequences for 21 Pseudomonas strains and 19 other diverse bacteria isolated from Populus deltoides roots. Genome sequences for isolates similar to Acidovorax, Bradyrhizobium, Brevibacillus, Caulobacter, Chryseobacterium, Flavobacterium, Herbaspirillum, Novosphingobium, Pantoea, Phyllobacterium, Polaromonas, Rhizobium, Sphingobium, and Variovorax were generated.

  6. Twenty-One Genome Sequences from Pseudomonas Species and 19 Genome Sequences from Diverse Bacteria Isolated from the Rhizosphere and Endosphere of Populus deltoides

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Steven D [ORNL; Utturkar, Sagar M [ORNL; Klingeman, Dawn Marie [ORNL; Johnson, Courtney M [ORNL; Martin, Stanton [ORNL; Land, Miriam L [ORNL; Lu, Tse-Yuan [ORNL; Schadt, Christopher Warren [ORNL; Doktycz, Mitchel John [ORNL; Pelletier, Dale A [ORNL

    2012-01-01

    To aid in the investigation of the Populus deltoides microbiome we generated draft genome sequences for twenty one Pseudomonas and twenty one other diverse bacteria isolated from Populus deltoides roots. Genome sequences for isolates similar to Acidovorax, Bradyrhizobium, Brevibacillus, Burkholderia, Caulobacter, Chryseobacterium, Flavobacterium, Herbaspirillum, Novosphingobium, Pantoea, Phyllobacterium, Polaromonas, Rhizobium, Sphingobium and Variovorax were generated.

  7. The impact of genomics on research in diversity and evolution of archaea.

    Science.gov (United States)

    Mardanov, A V; Ravin, N V

    2012-08-01

    Since the definition of archaea as a separate domain of life along with bacteria and eukaryotes, they have become one of the most interesting objects of modern microbiology, molecular biology, and biochemistry. Sequencing and analysis of archaeal genomes were especially important for studies on archaea because of a limited availability of genetic tools for the majority of these microorganisms and problems associated with their cultivation. Fifteen years since the publication of the first genome of an archaeon, more than one hundred complete genome sequences of representatives of different phylogenetic groups have been determined. Analysis of these genomes has expanded our knowledge of biology of archaea, their diversity and evolution, and allowed identification and characterization of new deep phylogenetic lineages of archaea. The development of genome technologies has allowed sequencing the genomes of uncultivated archaea directly from enrichment cultures, metagenomic samples, and even from single cells. Insights have been gained into the evolution of key biochemical processes in archaea, such as cell division and DNA replication, the role of horizontal gene transfer in the evolution of archaea, and new relationships between archaea and eukaryotes have been revealed.

  8. Genome Microscale Heterogeneity among Wild Potatoes Revealed by Diversity Arrays Technology Marker Sequences

    Directory of Open Access Journals (Sweden)

    Alessandra Traini

    2013-01-01

    Full Text Available Tuber-bearing potato species possess several genes that can be exploited to improve the genetic background of the cultivated potato Solanum tuberosum. Among them, S. bulbocastanum and S. commersonii are well known for their strong resistance to environmental stresses. However, scant information is available for these species in terms of genome organization, gene function, and regulatory networks. Consequently, genomic tools to assist breeding are meager, and efficient exploitation of these species has been limited so far. In this paper, we employed the reference genome sequences from cultivated potato and tomato and a collection of sequences of 1,423 potato Diversity Arrays Technology (DArT markers that show polymorphic representation across the genomes of S. bulbocastanum and/or S. commersonii genotypes. Our results highlighted microscale genome sequence heterogeneity that may play a significant role in functional and structural divergence between related species. Our analytical approach provides knowledge of genome structural and sequence variability that could not be detected by transcriptome and proteome approaches.

  9. Genome Microscale Heterogeneity among Wild Potatoes Revealed by Diversity Arrays Technology Marker Sequences.

    Science.gov (United States)

    Traini, Alessandra; Iorizzo, Massimo; Mann, Harpartap; Bradeen, James M; Carputo, Domenico; Frusciante, Luigi; Chiusano, Maria Luisa

    2013-01-01

    Tuber-bearing potato species possess several genes that can be exploited to improve the genetic background of the cultivated potato Solanum tuberosum. Among them, S. bulbocastanum and S. commersonii are well known for their strong resistance to environmental stresses. However, scant information is available for these species in terms of genome organization, gene function, and regulatory networks. Consequently, genomic tools to assist breeding are meager, and efficient exploitation of these species has been limited so far. In this paper, we employed the reference genome sequences from cultivated potato and tomato and a collection of sequences of 1,423 potato Diversity Arrays Technology (DArT) markers that show polymorphic representation across the genomes of S. bulbocastanum and/or S. commersonii genotypes. Our results highlighted microscale genome sequence heterogeneity that may play a significant role in functional and structural divergence between related species. Our analytical approach provides knowledge of genome structural and sequence variability that could not be detected by transcriptome and proteome approaches.

  10. Whole genome SNP discovery and analysis of genetic diversity in Turkey (Meleagris gallopavo)

    Science.gov (United States)

    2012-01-01

    Background The turkey (Meleagris gallopavo) is an important agricultural species and the second largest contributor to the world’s poultry meat production. Genetic improvement is attributed largely to selective breeding programs that rely on highly heritable phenotypic traits, such as body size and breast muscle development. Commercial breeding with small effective population sizes and epistasis can result in loss of genetic diversity, which in turn can lead to reduced individual fitness and reduced response to selection. The presence of genomic diversity in domestic livestock species therefore, is of great importance and a prerequisite for rapid and accurate genetic improvement of selected breeds in various environments, as well as to facilitate rapid adaptation to potential changes in breeding goals. Genomic selection requires a large number of genetic markers such as e.g. single nucleotide polymorphisms (SNPs) the most abundant source of genetic variation within the genome. Results Alignment of next generation sequencing data of 32 individual turkeys from different populations was used for the discovery of 5.49 million SNPs, which subsequently were used for the analysis of genetic diversity among the different populations. All of the commercial lines branched from a single node relative to the heritage varieties and the South Mexican turkey population. Heterozygosity of all individuals from the different turkey populations ranged from 0.17-2.73 SNPs/Kb, while heterozygosity of populations ranged from 0.73-1.64 SNPs/Kb. The average frequency of heterozygous SNPs in individual turkeys was 1.07 SNPs/Kb. Five genomic regions with very low nucleotide variation were identified in domestic turkeys that showed state of fixation towards alleles different than wild alleles. Conclusion The turkey genome is much less diverse with a relatively low frequency of heterozygous SNPs as compared to other livestock species like chicken and pig. The whole genome SNP discovery

  11. Whole genome SNP discovery and analysis of genetic diversity in Turkey (Meleagris gallopavo

    Directory of Open Access Journals (Sweden)

    Aslam Muhammad L

    2012-08-01

    Full Text Available Abstract Background The turkey (Meleagris gallopavo is an important agricultural species and the second largest contributor to the world’s poultry meat production. Genetic improvement is attributed largely to selective breeding programs that rely on highly heritable phenotypic traits, such as body size and breast muscle development. Commercial breeding with small effective population sizes and epistasis can result in loss of genetic diversity, which in turn can lead to reduced individual fitness and reduced response to selection. The presence of genomic diversity in domestic livestock species therefore, is of great importance and a prerequisite for rapid and accurate genetic improvement of selected breeds in various environments, as well as to facilitate rapid adaptation to potential changes in breeding goals. Genomic selection requires a large number of genetic markers such as e.g. single nucleotide polymorphisms (SNPs the most abundant source of genetic variation within the genome. Results Alignment of next generation sequencing data of 32 individual turkeys from different populations was used for the discovery of 5.49 million SNPs, which subsequently were used for the analysis of genetic diversity among the different populations. All of the commercial lines branched from a single node relative to the heritage varieties and the South Mexican turkey population. Heterozygosity of all individuals from the different turkey populations ranged from 0.17-2.73 SNPs/Kb, while heterozygosity of populations ranged from 0.73-1.64 SNPs/Kb. The average frequency of heterozygous SNPs in individual turkeys was 1.07 SNPs/Kb. Five genomic regions with very low nucleotide variation were identified in domestic turkeys that showed state of fixation towards alleles different than wild alleles. Conclusion The turkey genome is much less diverse with a relatively low frequency of heterozygous SNPs as compared to other livestock species like chicken and pig. The

  12. A LDA-based approach to promoting ranking diversity for genomics information retrieval.

    Science.gov (United States)

    Chen, Yan; Yin, Xiaoshi; Li, Zhoujun; Hu, Xiaohua; Huang, Jimmy Xiangji

    2012-06-11

    In the biomedical domain, there are immense data and tremendous increase of genomics and biomedical relevant publications. The wealth of information has led to an increasing amount of interest in and need for applying information retrieval techniques to access the scientific literature in genomics and related biomedical disciplines. In many cases, the desired information of a query asked by biologists is a list of a certain type of entities covering different aspects that are related to the question, such as cells, genes, diseases, proteins, mutations, etc. Hence, it is important of a biomedical IR system to be able to provide relevant and diverse answers to fulfill biologists' information needs. However traditional IR model only concerns with the relevance between retrieved documents and user query, but does not take redundancy between retrieved documents into account. This will lead to high redundancy and low diversity in the retrieval ranked lists. In this paper, we propose an approach which employs a topic generative model called Latent Dirichlet Allocation (LDA) to promoting ranking diversity for biomedical information retrieval. Different from other approaches or models which consider aspects on word level, our approach assumes that aspects should be identified by the topics of retrieved documents. We present LDA model to discover topic distribution of retrieval passages and word distribution of each topic dimension, and then re-rank retrieval results with topic distribution similarity between passages based on N-size slide window. We perform our approach on TREC 2007 Genomics collection and two distinctive IR baseline runs, which can achieve 8% improvement over the highest Aspect MAP reported in TREC 2007 Genomics track. The proposed method is the first study of adopting topic model to genomics information retrieval, and demonstrates its effectiveness in promoting ranking diversity as well as in improving relevance of ranked lists of genomics search

  13. Switchgrass genomic diversity, ploidy, and evolution: novel insights from a network-based SNP discovery protocol.

    Directory of Open Access Journals (Sweden)

    Fei Lu

    Full Text Available Switchgrass (Panicum virgatum L. is a perennial grass that has been designated as an herbaceous model biofuel crop for the United States of America. To facilitate accelerated breeding programs of switchgrass, we developed both an association panel and linkage populations for genome-wide association study (GWAS and genomic selection (GS. All of the 840 individuals were then genotyped using genotyping by sequencing (GBS, generating 350 GB of sequence in total. As a highly heterozygous polyploid (tetraploid and octoploid species lacking a reference genome, switchgrass is highly intractable with earlier methodologies of single nucleotide polymorphism (SNP discovery. To access the genetic diversity of species like switchgrass, we developed a SNP discovery pipeline based on a network approach called the Universal Network-Enabled Analysis Kit (UNEAK. Complexities that hinder single nucleotide polymorphism discovery, such as repeats, paralogs, and sequencing errors, are easily resolved with UNEAK. Here, 1.2 million putative SNPs were discovered in a diverse collection of primarily upland, northern-adapted switchgrass populations. Further analysis of this data set revealed the fundamentally diploid nature of tetraploid switchgrass. Taking advantage of the high conservation of genome structure between switchgrass and foxtail millet (Setaria italica (L. P. Beauv., two parent-specific, synteny-based, ultra high-density linkage maps containing a total of 88,217 SNPs were constructed. Also, our results showed clear patterns of isolation-by-distance and isolation-by-ploidy in natural populations of switchgrass. Phylogenetic analysis supported a general south-to-north migration path of switchgrass. In addition, this analysis suggested that upland tetraploid arose from upland octoploid. All together, this study provides unparalleled insights into the diversity, genomic complexity, population structure, phylogeny, phylogeography, ploidy, and evolutionary dynamics

  14. European Chlamydia abortus livestock isolate genomes reveal unusual stability and limited diversity, reflected in geographical signatures.

    Science.gov (United States)

    Seth-Smith, H M B; Busó, Leonor Sánchez; Livingstone, M; Sait, M; Harris, S R; Aitchison, K D; Vretou, Evangelia; Siarkou, V I; Laroucau, K; Sachse, K; Longbottom, D; Thomson, N R

    2017-05-04

    Chlamydia abortus (formerly Chlamydophila abortus) is an economically important livestock pathogen, causing ovine enzootic abortion (OEA), and can also cause zoonotic infections in humans affecting pregnancy outcome. Large-scale genomic studies on other chlamydial species are giving insights into the biology of these organisms but have not yet been performed on C. abortus. Our aim was to investigate a broad collection of European isolates of C. abortus, using next generation sequencing methods, looking at diversity, geographic distribution and genome dynamics. Whole genome sequencing was performed on our collection of 57 C. abortus isolates originating primarily from the UK, Germany, France and Greece, but also from Tunisia, Namibia and the USA. Phylogenetic analysis of a total of 64 genomes shows a deep structural division within the C. abortus species with a major clade displaying limited diversity, in addition to a branch carrying two more distantly related Greek isolates, LLG and POS. Within the major clade, seven further phylogenetic groups can be identified, demonstrating geographical associations. The number of variable nucleotide positions across the sampled isolates is significantly lower than those published for C. trachomatis and C. psittaci. No recombination was identified within C. abortus, and no plasmid was found. Analysis of pseudogenes showed lineage specific loss of some functions, notably with several Pmp and TMH/Inc proteins predicted to be inactivated in many of the isolates studied. The diversity within C. abortus appears to be much lower compared to other species within the genus. There are strong geographical signatures within the phylogeny, indicating clonal expansion within areas of limited livestock transport. No recombination has been identified within this species, showing that different species of Chlamydia may demonstrate different evolutionary dynamics, and that the genome of C. abortus is highly stable.

  15. Pantoea ananatis Genetic Diversity Analysis Reveals Limited Genomic Diversity as Well as Accessory Genes Correlated with Onion Pathogenicity

    Directory of Open Access Journals (Sweden)

    Shaun P. Stice

    2018-02-01

    Full Text Available Pantoea ananatis is a member of the family Enterobacteriaceae and an enigmatic plant pathogen with a broad host range. Although P. ananatis strains can be aggressive on onion causing foliar necrosis and onion center rot, previous genomic analysis has shown that P. ananatis lacks the primary virulence secretion systems associated with other plant pathogens. We assessed a collection of fifty P. ananatis strains collected from Georgia over three decades to determine genetic factors that correlated with onion pathogenic potential. Previous genetic analysis studies have compared strains isolated from different hosts with varying diseases potential and isolation sources. Strains varied greatly in their pathogenic potential and aggressiveness on different cultivated Allium species like onion, leek, shallot, and chive. Using multi-locus sequence analysis (MLSA and repetitive extragenic palindrome repeat (rep-PCR techniques, we did not observe any correlation between onion pathogenic potential and genetic diversity among strains. Whole genome sequencing and pan-genomic analysis of a sub-set of 10 strains aided in the identification of a novel series of genetic regions, likely plasmid borne, and correlating with onion pathogenicity observed on single contigs of the genetic assemblies. We named these loci Onion Virulence Regions (OVR A-D. The OVR loci contain genes involved in redox regulation as well as pectate lyase and rhamnogalacturonase genes. Previous studies have not identified distinct genetic loci or plasmids correlating with onion foliar pathogenicity or pathogenicity on a single host pathosystem. The lack of focus on a single host system for this phytopathgenic disease necessitates the pan-genomic analysis performed in this study.

  16. Diverse lifestyles and strategies of plant pathogenesis encoded in the genomes of eighteen Dothideomycetes fungi.

    Directory of Open Access Journals (Sweden)

    Robin A Ohm

    Full Text Available The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here, we compare genome features of 18 members of this class, including 6 necrotrophs, 9 (hemibiotrophs and 3 saprotrophs, to analyze genome structure, evolution, and the diverse strategies of pathogenesis. The Dothideomycetes most likely evolved from a common ancestor more than 280 million years ago. The 18 genome sequences differ dramatically in size due to variation in repetitive content, but show much less variation in number of (core genes. Gene order appears to have been rearranged mostly within chromosomal boundaries by multiple inversions, in extant genomes frequently demarcated by adjacent simple repeats. Several Dothideomycetes contain one or more gene-poor, transposable element (TE-rich putatively dispensable chromosomes of unknown function. The 18 Dothideomycetes offer an extensive catalogue of genes involved in cellulose degradation, proteolysis, secondary metabolism, and cysteine-rich small secreted proteins. Ancestors of the two major orders of plant pathogens in the Dothideomycetes, the Capnodiales and Pleosporales, may have had different modes of pathogenesis, with the former having fewer of these genes than the latter. Many of these genes are enriched in proximity to transposable elements, suggesting faster evolution because of the effects of repeat induced point (RIP mutations. A syntenic block of genes, including oxidoreductases, is conserved in most Dothideomycetes and upregulated during infection in L. maculans, suggesting a possible function in response to oxidative stress.

  17. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Dothideomycetes Fungi

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin A.; Feau, Nicolas; Henrissat, Bernard; Schoch, Conrad L.; Horwitz, Benjamin A.; Barry, Kerrie W.; Condon, Bradford J.; Copeland, Alex C.; Dhillon, Braham; Glaser, Fabian; Hesse, Cedar N.; Kosti, Idit; LaButti, Kurt; Lindquist, Erika A.; Lucas, Susan; Salamov, Asaf A.; Bradshaw, Rosie E.; Ciuffetti, Lynda; Hamelin, Richard C.; Kema, Gert H. J.; Lawrence, Christopher; Scott, James A.; Spatafora, Joseph W.; Turgeon, B. Gillian; Wit, Pierre J. G. M. de; Zhong, Shaobin; Goodwin, Stephen B.; Grigoriev, Igor V.

    2012-02-29

    The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here, we compare genome features of 18 members of this class, including 6 necrotrophs, 9 (hemi)biotrophs and 3 saprotrophs, to analyze genome structure, evolution, and the diverse strategies of pathogenesis. The Dothideomycetes most likely evolved from a common ancestor more than 280 million years ago. The 18 genome sequences differ dramatically in size due to variation in repetitive content, but show much less variation in number of (core) genes. Gene order appears to have been rearranged mostly within chromosomal boundaries by multiple inversions, in extant genomes frequently demarcated by adjacent simple repeats. Several Dothideomycetes contain one or more gene-poor, transposable element (TE)-rich putatively dispensable chromosomes of unknown function. The 18 Dothideomycetes offer an extensive catalogue of genes involved in cellulose degradation, proteolysis, secondary metabolism, and cysteine-rich small secreted proteins. Ancestors of the two major orders of plant pathogens in the Dothideomycetes, the Capnodiales and Pleosporales, may have had different modes of pathogenesis, with the former having fewer of these genes than the latter. Many of these genes are enriched in proximity to transposable elements, suggesting faster evolution because of the effects of repeat induced point (RIP) mutations. A syntenic block of genes, including oxidoreductases, is conserved in most Dothideomycetes and upregulated during infection in L. maculans, suggesting a possible function in response to oxidative stress.

  18. PGG.Population: a database for understanding the genomic diversity and genetic ancestry of human populations.

    Science.gov (United States)

    Zhang, Chao; Gao, Yang; Liu, Jiaojiao; Xue, Zhe; Lu, Yan; Deng, Lian; Tian, Lei; Feng, Qidi; Xu, Shuhua

    2018-01-04

    There are a growing number of studies focusing on delineating genetic variations that are associated with complex human traits and diseases due to recent advances in next-generation sequencing technologies. However, identifying and prioritizing disease-associated causal variants relies on understanding the distribution of genetic variations within and among populations. The PGG.Population database documents 7122 genomes representing 356 global populations from 107 countries and provides essential information for researchers to understand human genomic diversity and genetic ancestry. These data and information can facilitate the design of research studies and the interpretation of results of both evolutionary and medical studies involving human populations. The database is carefully maintained and constantly updated when new data are available. We included miscellaneous functions and a user-friendly graphical interface for visualization of genomic diversity, population relationships (genetic affinity), ancestral makeup, footprints of natural selection, and population history etc. Moreover, PGG.Population provides a useful feature for users to analyze data and visualize results in a dynamic style via online illustration. The long-term ambition of the PGG.Population, together with the joint efforts from other researchers who contribute their data to our database, is to create a comprehensive depository of geographic and ethnic variation of human genome, as well as a platform bringing influence on future practitioners of medicine and clinical investigators. PGG.Population is available at https://www.pggpopulation.org. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  19. Comparative Analysis of 35 Basidiomycete Genomes Reveals Diversity and Uniqueness of the Phylum

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Robert; Salamov, Asaf; Otillar, Robert; Fagnan, Kirsten; Boussau, Bastien; Brown, Daren; Henrissat, Bernard; Levasseur, Anthony; Held, Benjamin; Nagy, Laszlo; Floudas, Dimitris; Morin, Emmanuelle; Manning, Gerard; Baker, Scott; Martin, Francis; Blanchette, Robert; Hibbett, David; Grigoriev, Igor V.

    2013-03-11

    Fungi of the phylum Basidiomycota (basidiomycetes), make up some 37percent of the described fungi, and are important in forestry, agriculture, medicine, and bioenergy. This diverse phylum includes symbionts, pathogens, and saprobes including wood decaying fungi. To better understand the diversity of this phylum we compared the genomes of 35 basidiomycete fungi including 6 newly sequenced genomes. The genomes of basidiomycetes span extremes of genome size, gene number, and repeat content. A phylogenetic tree of Basidiomycota was generated using the Phyldog software, which uses all available protein sequence data to simultaneously infer gene and species trees. Analysis of core genes reveals that some 48percent of basidiomycete proteins are unique to the phylum with nearly half of those (22percent) comprising proteins found in only one organism. Phylogenetic patterns of plant biomass-degrading genes suggest a continuum rather than a sharp dichotomy between the white rot and brown rot modes of wood decay among the members of Agaricomycotina subphylum. There is a correlation of the profile of certain gene families to nutritional mode in Agaricomycotina. Based on phylogenetically-informed PCA analysis of such profiles, we predict that that Botryobasidium botryosum and Jaapia argillacea have properties similar to white rot species, although neither has liginolytic class II fungal peroxidases. Furthermore, we find that both fungi exhibit wood decay with white rot-like characteristics in growth assays. Analysis of the rate of discovery of proteins with no or few homologs suggests the high value of continued sequencing of basidiomycete fungi.

  20. High intraspecific genome diversity in the model arbuscular mycorrhizal symbiont Rhizophagus irregularis.

    Science.gov (United States)

    Chen, Eric C H; Morin, Emmanuelle; Beaudet, Denis; Noel, Jessica; Yildirir, Gokalp; Ndikumana, Steve; Charron, Philippe; St-Onge, Camille; Giorgi, John; Krüger, Manuela; Marton, Timea; Ropars, Jeanne; Grigoriev, Igor V; Hainaut, Matthieu; Henrissat, Bernard; Roux, Christophe; Martin, Francis; Corradi, Nicolas

    2018-01-22

    Arbuscular mycorrhizal fungi (AMF) are known to improve plant fitness through the establishment of mycorrhizal symbioses. Genetic and phenotypic variations among closely related AMF isolates can significantly affect plant growth, but the genomic changes underlying this variability are unclear. To address this issue, we improved the genome assembly and gene annotation of the model strain Rhizophagus irregularis DAOM197198, and compared its gene content with five isolates of R. irregularis sampled in the same field. All isolates harbor striking genome variations, with large numbers of isolate-specific genes, gene family expansions, and evidence of interisolate genetic exchange. The observed variability affects all gene ontology terms and PFAM protein domains, as well as putative mycorrhiza-induced small secreted effector-like proteins and other symbiosis differentially expressed genes. High variability is also found in active transposable elements. Overall, these findings indicate a substantial divergence in the functioning capacity of isolates harvested from the same field, and thus their genetic potential for adaptation to biotic and abiotic changes. Our data also provide a first glimpse into the genome diversity that resides within natural populations of these symbionts, and open avenues for future analyses of plant-AMF interactions that link AMF genome variation with plant phenotype and fitness. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  1. Entangled fates of holobiont genomes during invasion: nested bacterial and host diversities in Caulerpa taxifolia

    KAUST Repository

    Arnaud-Haond, S.; Aires, T.; Candeias, R.; Teixeira, S. J. L; Duarte, Carlos M.; Valero, M.; Serrã o, E. A.

    2017-01-01

    Successful prevention and mitigation of biological invasions requires retracing the initial steps of introduction, as well as understanding key elements enhancing the adaptability of invasive species. We studied the genetic diversity of the green alga Caulerpa taxifolia and its associated bacterial communities in several areas around the world. The striking congruence of α and ß diversity of the algal genome and endophytic communities reveals a tight association, supporting the holobiont concept as best describing the unit of spreading and invasion. Both genomic compartments support the hypotheses of a unique accidental introduction in the Mediterranean and of multiple invasion events in Southern Australia. In addition to helping with tracing the origin of invasion, bacterial communities exhibit metabolic functions that can potentially enhance adaptability and competitiveness of the consortium they form with their host. We thus hypothesize that low genetic diversities of both host and symbiont communities may contribute to the recent regression in the Mediterranean, in contrast with the persistence of highly diverse assemblages in southern Australia. This study supports the importance of scaling up from the host to the holobiont for a comprehensive understanding of invasions. This article is protected by copyright. All rights reserved.

  2. Entangled fates of holobiont genomes during invasion: nested bacterial and host diversities in Caulerpa taxifolia

    KAUST Repository

    Arnaud-Haond, S.

    2017-01-30

    Successful prevention and mitigation of biological invasions requires retracing the initial steps of introduction, as well as understanding key elements enhancing the adaptability of invasive species. We studied the genetic diversity of the green alga Caulerpa taxifolia and its associated bacterial communities in several areas around the world. The striking congruence of α and ß diversity of the algal genome and endophytic communities reveals a tight association, supporting the holobiont concept as best describing the unit of spreading and invasion. Both genomic compartments support the hypotheses of a unique accidental introduction in the Mediterranean and of multiple invasion events in Southern Australia. In addition to helping with tracing the origin of invasion, bacterial communities exhibit metabolic functions that can potentially enhance adaptability and competitiveness of the consortium they form with their host. We thus hypothesize that low genetic diversities of both host and symbiont communities may contribute to the recent regression in the Mediterranean, in contrast with the persistence of highly diverse assemblages in southern Australia. This study supports the importance of scaling up from the host to the holobiont for a comprehensive understanding of invasions. This article is protected by copyright. All rights reserved.

  3. Unraveling Mycobacterium tuberculosis genomic diversity and evolution in Lisbon, Portugal, a highly drug resistant setting

    KAUST Repository

    Perdigão, João

    2014-11-18

    Background Multidrug- (MDR) and extensively drug resistant (XDR) tuberculosis (TB) presents a challenge to disease control and elimination goals. In Lisbon, Portugal, specific and successful XDR-TB strains have been found in circulation for almost two decades. Results In the present study we have genotyped and sequenced the genomes of 56 Mycobacterium tuberculosis isolates recovered mostly from Lisbon. The genotyping data revealed three major clusters associated with MDR-TB, two of which are associated with XDR-TB. Whilst the genomic data contributed to elucidate the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of Mycobacterium tuberculosis clinical isolates, revealed two major clades responsible for M/XDR-TB in the region: Lisboa3 and Q1 (LAM). The data presented by this study yielded insights on microevolution and identification of novel compensatory mutations associated with rifampicin resistance in rpoB and rpoC. The screening for other structural variations revealed putative clade-defining variants. One deletion in PPE41, found among Lisboa3 isolates, is proposed to contribute to immune evasion and as a selective advantage. Insertion sequence (IS) mapping has also demonstrated the role of IS6110 as a major driver in mycobacterial evolution by affecting gene integrity and regulation. Conclusions Globally, this study contributes with novel genome-wide phylogenetic data and has led to the identification of new genomic variants that support the notion of a growing genomic diversity facing both setting and host adaptation.

  4. Diversity and Genome Analysis of Australian and Global Oilseed Brassica napus L. Germplasm Using Transcriptomics and Whole Genome Re-sequencing

    Directory of Open Access Journals (Sweden)

    M. Michelle Malmberg

    2018-04-01

    Full Text Available Intensive breeding of Brassica napus has resulted in relatively low diversity, such that B. napus would benefit from germplasm improvement schemes that sustain diversity. As such, samples representative of global germplasm pools need to be assessed for existing population structure, diversity and linkage disequilibrium (LD. Complexity reduction genotyping-by-sequencing (GBS methods, including GBS-transcriptomics (GBS-t, enable cost-effective screening of a large number of samples, while whole genome re-sequencing (WGR delivers the ability to generate large numbers of unbiased genomic single nucleotide polymorphisms (SNPs, and identify structural variants (SVs. Furthermore, the development of genomic tools based on whole genomes representative of global oilseed diversity and orientated by the reference genome has substantial industry relevance and will be highly beneficial for canola breeding. As recent studies have focused on European and Chinese varieties, a global diversity panel as well as a substantial number of Australian spring types were included in this study. Focusing on industry relevance, 633 varieties were initially genotyped using GBS-t to examine population structure using 61,037 SNPs. Subsequently, 149 samples representative of global diversity were selected for WGR and both data sets used for a side-by-side evaluation of diversity and LD. The WGR data was further used to develop genomic resources consisting of a list of 4,029,750 high-confidence SNPs annotated using SnpEff, and SVs in the form of 10,976 deletions and 2,556 insertions. These resources form the basis of a reliable and repeatable system allowing greater integration between canola genomics studies, with a strong focus on breeding germplasm and industry applicability.

  5. The family Rhabdoviridae: mono- and bipartite negative-sense RNA viruses with diverse genome organization and common evolutionary origins.

    Science.gov (United States)

    Dietzgen, Ralf G; Kondo, Hideki; Goodin, Michael M; Kurath, Gael; Vasilakis, Nikos

    2017-01-02

    The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- and bipartite genomes. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Whole mitochondrial genome sequencing of domestic horses reveals incorporation of extensive wild horse diversity during domestication

    Directory of Open Access Journals (Sweden)

    Lippold Sebastian

    2011-11-01

    Full Text Available Abstract Background DNA target enrichment by micro-array capture combined with high throughput sequencing technologies provides the possibility to obtain large amounts of sequence data (e.g. whole mitochondrial DNA genomes from multiple individuals at relatively low costs. Previously, whole mitochondrial genome data for domestic horses (Equus caballus were limited to only a few specimens and only short parts of the mtDNA genome (especially the hypervariable region were investigated for larger sample sets. Results In this study we investigated whole mitochondrial genomes of 59 domestic horses from 44 breeds and a single Przewalski horse (Equus przewalski using a recently described multiplex micro-array capture approach. We found 473 variable positions within the domestic horses, 292 of which are parsimony-informative, providing a well resolved phylogenetic tree. Our divergence time estimate suggests that the mitochondrial genomes of modern horse breeds shared a common ancestor around 93,000 years ago and no later than 38,000 years ago. A Bayesian skyline plot (BSP reveals a significant population expansion beginning 6,000-8,000 years ago with an ongoing exponential growth until the present, similar to other domestic animal species. Our data further suggest that a large sample of wild horse diversity was incorporated into the domestic population; specifically, at least 46 of the mtDNA lineages observed in domestic horses (73% already existed before the beginning of domestication about 5,000 years ago. Conclusions Our study provides a window into the maternal origins of extant domestic horses and confirms that modern domestic breeds present a wide sample of the mtDNA diversity found in ancestral, now extinct, wild horse populations. The data obtained allow us to detect a population expansion event coinciding with the beginning of domestication and to estimate both the minimum number of female horses incorporated into the domestic gene pool and the

  7. Evolution of sociality in spiders leads to depleted genomic diversity at both population and species levels.

    Science.gov (United States)

    Settepani, V; Schou, M F; Greve, M; Grinsted, L; Bechsgaard, J; Bilde, T

    2017-08-01

    Across several animal taxa, the evolution of sociality involves a suite of characteristics, a "social syndrome," that includes cooperative breeding, reproductive skew, primary female-biased sex ratio, and the transition from outcrossing to inbreeding mating system, factors that are expected to reduce effective population size (Ne). This social syndrome may be favoured by short-term benefits but come with long-term costs, because the reduction in Ne amplifies loss of genetic diversity by genetic drift, ultimately restricting the potential of populations to respond to environmental change. To investigate the consequences of this social life form on genetic diversity, we used a comparative RAD-sequencing approach to estimate genomewide diversity in spider species that differ in level of sociality, reproductive skew and mating system. We analysed multiple populations of three independent sister-species pairs of social inbreeding and subsocial outcrossing Stegodyphus spiders, and a subsocial outgroup. Heterozygosity and within-population diversity were sixfold to 10-fold lower in social compared to subsocial species, and demographic modelling revealed a tenfold reduction in Ne of social populations. Species-wide genetic diversity depends on population divergence and the viability of genetic lineages. Population genomic patterns were consistent with high lineage turnover, which homogenizes the genetic structure that builds up between inbreeding populations, ultimately depleting genetic diversity at the species level. Indeed, species-wide genetic diversity of social species was 5-8 times lower than that of subsocial species. The repeated evolution of species with this social syndrome is associated with severe loss of genomewide diversity, likely to limit their evolutionary potential. © 2017 John Wiley & Sons Ltd.

  8. Structural and sequence diversity of the transposon Galileo in the Drosophila willistoni genome.

    Science.gov (United States)

    Gonçalves, Juliana W; Valiati, Victor Hugo; Delprat, Alejandra; Valente, Vera L S; Ruiz, Alfredo

    2014-09-13

    Galileo is one of three members of the P superfamily of DNA transposons. It was originally discovered in Drosophila buzzatii, in which three segregating chromosomal inversions were shown to have been generated by ectopic recombination between Galileo copies. Subsequently, Galileo was identified in six of 12 sequenced Drosophila genomes, indicating its widespread distribution within this genus. Galileo is strikingly abundant in Drosophila willistoni, a neotropical species that is highly polymorphic for chromosomal inversions, suggesting a role for this transposon in the evolution of its genome. We carried out a detailed characterization of all Galileo copies present in the D. willistoni genome. A total of 191 copies, including 133 with two terminal inverted repeats (TIRs), were classified according to structure in six groups. The TIRs exhibited remarkable variation in their length and structure compared to the most complete copy. Three copies showed extended TIRs due to internal tandem repeats, the insertion of other transposable elements (TEs), or the incorporation of non-TIR sequences into the TIRs. Phylogenetic analyses of the transposase (TPase)-encoding and TIR segments yielded two divergent clades, which we termed Galileo subfamilies V and W. Target-site duplications (TSDs) in D. willistoni Galileo copies were 7- or 8-bp in length, with the consensus sequence GTATTAC. Analysis of the region around the TSDs revealed a target site motif (TSM) with a 15-bp palindrome that may give rise to a stem-loop secondary structure. There is a remarkable abundance and diversity of Galileo copies in the D. willistoni genome, although no functional copies were found. The TIRs in particular have a dynamic structure and extend in different ways, but their ends (required for transposition) are more conserved than the rest of the element. The D. willistoni genome harbors two Galileo subfamilies (V and W) that diverged ~9 million years ago and may have descended from an ancestral

  9. Diversity of chloroplast genome among local clones of cocoa (Theobroma cacao, L.) from Central Sulawesi

    Science.gov (United States)

    Suwastika, I. Nengah; Pakawaru, Nurul Aisyah; Rifka, Rahmansyah, Muslimin, Ishizaki, Yoko; Cruz, André Freire; Basri, Zainuddin; Shiina, Takashi

    2017-02-01

    Chloroplast genomes typically range in size from 120 to 170 kilo base pairs (kb), which relatively conserved among plant species. Recent evaluation on several species, certain unique regions showed high variability which can be utilized in the phylogenetic analysis. Many fragments of coding regions, introns, and intergenic spacers, such as atpB-rbcL, ndhF, rbcL, rpl16, trnH-psbA, trnL-F, trnS-G, etc., have been used for phylogenetic reconstructions at various taxonomic levels. Based on that status, we would like to analysis the diversity of chloroplast genome within species of local cacao (Theobroma cacao L.) from Central Sulawesi. Our recent data showed, there were more than 20 clones from local farming in Central Sulawesi, and it can be detected based on phenotypic and nuclear-genome-based characterization (RAPD- Random Amplified Polymorphic DNA and SSR- Simple Sequences Repeat) markers. In developing DNA marker for this local cacao, here we also included analysis based on the variation of chloroplast genome. At least several regions such as rpl32-TurnL, it can be considered as chloroplast markers on our local clone of cocoa. Furthermore, we could develop phylogenetic analysis in between clones of cocoa.

  10. A common genomic framework for a diverse assembly of plasmids in the symbiotic nitrogen fixing bacteria.

    Directory of Open Access Journals (Sweden)

    Lisa C Crossman

    2008-07-01

    Full Text Available This work centres on the genomic comparisons of two closely-related nitrogen-fixing symbiotic bacteria, Rhizobium leguminosarum biovar viciae 3841 and Rhizobium etli CFN42. These strains maintain a stable genomic core that is also common to other rhizobia species plus a very variable and significant accessory component. The chromosomes are highly syntenic, whereas plasmids are related by fewer syntenic blocks and have mosaic structures. The pairs of plasmids p42f-pRL12, p42e-pRL11 and p42b-pRL9 as well large parts of p42c with pRL10 are shown to be similar, whereas the symbiotic plasmids (p42d and pRL10 are structurally unrelated and seem to follow distinct evolutionary paths. Even though purifying selection is acting on the whole genome, the accessory component is evolving more rapidly. This component is constituted largely for proteins for transport of diverse metabolites and elements of external origin. The present analysis allows us to conclude that a heterogeneous and quickly diversifying group of plasmids co-exists in a common genomic framework.

  11. Genomic diversity and evolution of the head crest in the rock pigeon.

    Science.gov (United States)

    Shapiro, Michael D; Kronenberg, Zev; Li, Cai; Domyan, Eric T; Pan, Hailin; Campbell, Michael; Tan, Hao; Huff, Chad D; Hu, Haofu; Vickrey, Anna I; Nielsen, Sandra C A; Stringham, Sydney A; Hu, Hao; Willerslev, Eske; Gilbert, M Thomas P; Yandell, Mark; Zhang, Guojie; Wang, Jun

    2013-03-01

    The geographic origins of breeds and the genetic basis of variation within the widely distributed and phenotypically diverse domestic rock pigeon (Columba livia) remain largely unknown. We generated a rock pigeon reference genome and additional genome sequences representing domestic and feral populations. We found evidence for the origins of major breed groups in the Middle East and contributions from a racing breed to North American feral populations. We identified the gene EphB2 as a strong candidate for the derived head crest phenotype shared by numerous breeds, an important trait in mate selection in many avian species. We also found evidence that this trait evolved just once and spread throughout the species, and that the crest originates early in development by the localized molecular reversal of feather bud polarity.

  12. A genomic insight into diversity among tribal and nontribal population groups of Manipur, India.

    Science.gov (United States)

    Saraswathy, K N; Kiranmala, Naorem; Murry, Benrithung; Sinha, Ekata; Saksena, Deepti; Kaur, Harpreet; Sachdeva, M P; Kalla, A K

    2009-10-01

    Twenty autosomal markers, including linked markers at two gene markers, are used to understand the genomic similarity and diversity among three tribal (Paite, Thadou, and Kom) and one nontribal communities of Manipur (Northeast India). Two of the markers (CD4 and HB9) are monomorphic in Paite and one (the CD4 marker) in Kom. Data suggest the Meitei (nontribal groups) stand apart from the three tribal groups with respect to higher heterozygosity (0.366) and presence of the highest ancestor haplotypes of DRD2 markers (0.228); this is also supported by principal co-ordinate analysis. These populations are found to be genomically closer to the Chinese population than to other Indian populations.

  13. Penicillium arizonense, a new, genome sequenced fungal species, reveals a high chemical diversity in secreted metabolites

    DEFF Research Database (Denmark)

    Grijseels, Sietske; Nielsen, Jens Christian; Randelovic, Milica

    2016-01-01

    A new soil-borne species belonging to the Penicillium section Canescentia is described, Penicillium arizonense sp. nov. (type strain CBS 141311T = IBT 12289T). The genome was sequenced and assembled into 33.7 Mb containing 12,502 predicted genes. A phylogenetic assessment based on marker genes...... confirmed the grouping of P. arizonense within section Canescentia. Compared to related species, P. arizonense proved to encode a high number of proteins involved in carbohydrate metabolism, in particular hemicellulases. Mining the genome for genes involved in secondary metabolite biosynthesis resulted...... of biosynthetic gene clusters in P. arizonense responsible for the synthesis of all detected compounds except curvulinic acid. The capacity to produce biomass degrading enzymes and the identification of a high chemical diversity in secreted bioactive secondary metabolites, offers a broad range of potential...

  14. Acidobacteria form a coherent but highly diverse group within the bacterial domain: evidence from environmental genomics

    DEFF Research Database (Denmark)

    Quaiser, Achim; Ochsenreiter, Torsten; Lanz, Christa

    2003-01-01

    fragments differed between 2.3% and 19.9% and were placed into two different subgroups of Acidobacteria (groups III and V). Although partial co-linearity was found between genomic fragments, the gene content around the rRNA operons was generally not conserved. Phylogenetic reconstructions with orthologues......Acidobacteria have been established as a novel phylum of Bacteria that is consistently detected in many different habitats around the globe by 16S rDNA-based molecular surveys. The phylogenetic diversity, ubiquity and abundance of this group, particularly in soil habitats, suggest an important...... palustris and Bradyrhizobium japonicum, including a conserved two-component system. Phylogenetic analysis of the putative response regulator confirmed that this similarity between Rhizobiales and Acidobacteria might be due to a horizontal gene transfer. In total, our data give first insight into the genome...

  15. Combining genomic sequencing methods to explore viral diversity and reveal potential virus-host interactions

    Directory of Open Access Journals (Sweden)

    Cheryl-Emiliane Tien Chow

    2015-04-01

    Full Text Available Viral diversity and virus-host interactions in oxygen-starved regions of the ocean, also known as oxygen minimum zones (OMZs, remain relatively unexplored. Microbial community metabolism in OMZs alters nutrient and energy flow through marine food webs, resulting in biological nitrogen loss and greenhouse gas production. Thus, viruses infecting OMZ microbes have the potential to modulate community metabolism with resulting feedback on ecosystem function. Here, we describe viral communities inhabiting oxic surface (10m and oxygen-starved basin (200m waters of Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island, British Columbia using viral metagenomics and complete viral fosmid sequencing on samples collected between April 2007 and April 2010. Of 6459 open reading frames (ORFs predicted across all 34 viral fosmids, 77.6% (n=5010 had no homology to reference viral genomes. These fosmids recruited a higher proportion of viral metagenomic sequences from Saanich Inlet than from nearby northeastern subarctic Pacific Ocean (Line P waters, indicating differences in the viral communities between coastal and open ocean locations. While functional annotations of fosmid ORFs were limited, recruitment to NCBI’s non-redundant ‘nr’ database and publicly available single-cell genomes identified putative viruses infecting marine thaumarchaeal and SUP05 proteobacteria to provide potential host linkages with relevance to coupled biogeochemical cycling processes in OMZ waters. Taken together, these results highlight the power of coupled analyses of multiple sequence data types, such as viral metagenomic and fosmid sequence data with prokaryotic single cell genomes, to chart viral diversity, elucidate genomic and ecological contexts for previously unclassifiable viral sequences, and identify novel host interactions in natural and engineered ecosystems.

  16. Genomic and Metagenomic Analysis of Diversity-Generating Retroelements Associated with Treponema denticola

    Directory of Open Access Journals (Sweden)

    Sutichot eNimkulrat

    2016-06-01

    Full Text Available Diversity-generating retroelements (DGRs are genetic cassettes that can produce massive protein sequence variation in prokaryotes. Presumably DGRs confer selective advantages to their hosts (bacteria or viruses by generating variants of target genes—typically resulting in target proteins with altered ligand-binding specificity—through a specialized error-prone reverse transcription process. The only extensively studied DGR system is from the Bordetella phage BPP-1, although DGRs are predicted to exist in other species. Using bioinformatics analysis, we discovered that the DGR system associated with the Treponema denticola species (a human oral-associated periopathogen is dynamic (with gains/losses of the system found in the isolates and diverse (with multiple types found in isolated genomes and the human microbiota. The T. denticola DGR is found in only nine of the 17 sequenced T. denticola strains. Analysis of the DGR-associated template regions and reverse transcriptase gene sequences revealed two types of DGR systems in T. denticola: the ATCC35405-type shared by seven isolates including ATCC35405; and the SP32-type shared by two isolates (SP32 and SP33, suggesting multiple DGR acquisitions. We detected additional variants of the T. denticola DGR systems in the human microbiomes, and found that the SP32-type DGR is more abundant than the ATCC35405-type in the healthy human oral microbiome, although the latter is found in more sequenced isolates. This is the first comprehensive study to characterize the DGRs associated with T. denticola in individual genomes as well as human microbiomes, demonstrating the importance of utilizing both individual genomes and metagenomes for characterizing the elements, and for analyzing their diversity and distribution in human populations.

  17. Characterizing neutral genomic diversity and selection signatures in indigenous populations of Moroccan goats (Capra hircus using WGS data

    Directory of Open Access Journals (Sweden)

    Badr eBenjelloun

    2015-04-01

    Full Text Available Since the time of their domestication, goats (Capra hircus have evolved in a large variety of locally adapted populations in response to different human and environmental pressures. In the present era, many indigenous populations are threatened with extinction due to their substitution by cosmopolitan breeds, while they might represent highly valuable genomic resources. It is thus crucial to characterize the neutral and adaptive genetic diversity of indigenous populations. A fine characterization of whole genome variation in farm animals is now possible by using new sequencing technologies. We sequenced the complete genome at 12X coverage of 44 goats geographically representative of the three phenotypically distinct indigenous populations in Morocco. The study of mitochondrial genomes showed a high diversity exclusively restricted to the haplogroup A. The 44 nuclear genomes showed a very high diversity (24 million variants associated with low linkage disequilibrium. The overall genetic diversity was weakly structured according to geography and phenotypes. When looking for signals of positive selection in each population we identified many candidate genes, several of which gave insights into the metabolic pathways or biological processes involved in the adaptation to local conditions (e.g. panting in warm/desert conditions. This study highlights the interest of WGS data to characterize livestock genomic diversity. It illustrates the valuable genetic richness present in indigenous populations that have to be sustainably managed and may represent valuable genetic resources for the long-term preservation of the species.

  18. Unprecedented genomic diversity of RNA viruses in arthropods reveals the ancestry of negative-sense RNA viruses.

    Science.gov (United States)

    Li, Ci-Xiu; Shi, Mang; Tian, Jun-Hua; Lin, Xian-Dan; Kang, Yan-Jun; Chen, Liang-Jun; Qin, Xin-Cheng; Xu, Jianguo; Holmes, Edward C; Zhang, Yong-Zhen

    2015-01-29

    Although arthropods are important viral vectors, the biodiversity of arthropod viruses, as well as the role that arthropods have played in viral origins and evolution, is unclear. Through RNA sequencing of 70 arthropod species we discovered 112 novel viruses that appear to be ancestral to much of the documented genetic diversity of negative-sense RNA viruses, a number of which are also present as endogenous genomic copies. With this greatly enriched diversity we revealed that arthropods contain viruses that fall basal to major virus groups, including the vertebrate-specific arenaviruses, filoviruses, hantaviruses, influenza viruses, lyssaviruses, and paramyxoviruses. We similarly documented a remarkable diversity of genome structures in arthropod viruses, including a putative circular form, that sheds new light on the evolution of genome organization. Hence, arthropods are a major reservoir of viral genetic diversity and have likely been central to viral evolution.

  19. Genus-wide comparison of Pseudovibrio bacterial genomes reveal diverse adaptations to different marine invertebrate hosts.

    Science.gov (United States)

    Alex, Anoop; Antunes, Agostinho

    2018-01-01

    Bacteria belonging to the genus Pseudovibrio have been frequently found in association with a wide variety of marine eukaryotic invertebrate hosts, indicative of their versatile and symbiotic lifestyle. A recent comparison of the sponge-associated Pseudovibrio genomes has shed light on the mechanisms influencing a successful symbiotic association with sponges. In contrast, the genomic architecture of Pseudovibrio bacteria associated with other marine hosts has received less attention. Here, we performed genus-wide comparative analyses of 18 Pseudovibrio isolated from sponges, coral, tunicates, flatworm, and seawater. The analyses revealed a certain degree of commonality among the majority of sponge- and coral-associated bacteria. Isolates from other marine invertebrate host, tunicates, exhibited a genetic repertoire for cold adaptation and specific metabolic abilities including mucin degradation in the Antarctic tunicate-associated bacterium Pseudovibrio sp. Tun.PHSC04_5.I4. Reductive genome evolution was simultaneously detected in the flatworm-associated bacteria and the sponge-associated bacterium P. axinellae AD2, through the loss of major secretion systems (type III/VI) and virulence/symbioses factors such as proteins involved in adhesion and attachment to the host. Our study also unraveled the presence of a CRISPR-Cas system in P. stylochi UST20140214-052 a flatworm-associated bacterium possibly suggesting the role of CRISPR-based adaptive immune system against the invading virus particles. Detection of mobile elements and genomic islands (GIs) in all bacterial members highlighted the role of horizontal gene transfer for the acquisition of novel genetic features, likely enhancing the bacterial ecological fitness. These findings are insightful to understand the role of genome diversity in Pseudovibrio as an evolutionary strategy to increase their colonizing success across a wide range of marine eukaryotic hosts.

  20. Distribution and diversity of cytotypes in Dianthus broteri as evidenced by genome size variations.

    Science.gov (United States)

    Balao, Francisco; Casimiro-Soriguer, Ramón; Talavera, María; Herrera, Javier; Talavera, Salvador

    2009-10-01

    Studying the spatial distribution of cytotypes and genome size in plants can provide valuable information about the evolution of polyploid complexes. Here, the spatial distribution of cytological races and the amount of DNA in Dianthus broteri, an Iberian carnation with several ploidy levels, is investigated. Sample chromosome counts and flow cytometry (using propidium iodide) were used to determine overall genome size (2C value) and ploidy level in 244 individuals of 25 populations. Both fresh and dried samples were investigated. Differences in 2C and 1Cx values among ploidy levels within biogeographical provinces were tested using ANOVA. Geographical correlations of genome size were also explored. Extensive variation in chromosomes numbers (2n = 2x = 30, 2n = 4x = 60, 2n = 6x = 90 and 2n = 12x =180) was detected, and the dodecaploid cytotype is reported for the first time in this genus. As regards cytotype distribution, six populations were diploid, 11 were tetraploid, three were hexaploid and five were dodecaploid. Except for one diploid population containing some triploid plants (2n = 45), the remaining populations showed a single cytotype. Diploids appeared in two disjunct areas (south-east and south-west), and so did tetraploids (although with a considerably wider geographic range). Dehydrated leaf samples provided reliable measurements of DNA content. Genome size varied significantly among some cytotypes, and also extensively within diploid (up to 1.17-fold) and tetraploid (1.22-fold) populations. Nevertheless, variations were not straightforwardly congruent with ecology and geographical distribution. Dianthus broteri shows the highest diversity of cytotypes known to date in the genus Dianthus. Moreover, some cytotypes present remarkable internal genome size variation. The evolution of the complex is discussed in terms of autopolyploidy, with primary and secondary contact zones.

  1. Assessing genetic diversity among Brettanomyces yeasts by DNA fingerprinting and whole-genome sequencing.

    Science.gov (United States)

    Crauwels, Sam; Zhu, Bo; Steensels, Jan; Busschaert, Pieter; De Samblanx, Gorik; Marchal, Kathleen; Willems, Kris A; Verstrepen, Kevin J; Lievens, Bart

    2014-07-01

    Brettanomyces yeasts, with the species Brettanomyces (Dekkera) bruxellensis being the most important one, are generally reported to be spoilage yeasts in the beer and wine industry due to the production of phenolic off flavors. However, B. bruxellensis is also known to be a beneficial contributor in certain fermentation processes, such as the production of certain specialty beers. Nevertheless, despite its economic importance, Brettanomyces yeasts remain poorly understood at the genetic and genomic levels. In this study, the genetic relationship between more than 50 Brettanomyces strains from all presently known species and from several sources was studied using a combination of DNA fingerprinting techniques. This revealed an intriguing correlation between the B. bruxellensis fingerprints and the respective isolation source. To further explore this relationship, we sequenced a (beneficial) beer isolate of B. bruxellensis (VIB X9085; ST05.12/22) and compared its genome sequence with the genome sequences of two wine spoilage strains (AWRI 1499 and CBS 2499). ST05.12/22 was found to be substantially different from both wine strains, especially at the level of single nucleotide polymorphisms (SNPs). In addition, there were major differences in the genome structures between the strains investigated, including the presence of large duplications and deletions. Gene content analysis revealed the presence of 20 genes which were present in both wine strains but absent in the beer strain, including many genes involved in carbon and nitrogen metabolism, and vice versa, no genes that were missing in both AWRI 1499 and CBS 2499 were found in ST05.12/22. Together, this study provides tools to discriminate Brettanomyces strains and provides a first glimpse at the genetic diversity and genome plasticity of B. bruxellensis. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  2. The analysis of APOL1 genetic variation and haplotype diversity provided by 1000 Genomes project.

    Science.gov (United States)

    Peng, Ting; Wang, Li; Li, Guisen

    2017-08-11

    The APOL1 gene variants has been shown to be associated with an increased risk of multiple kinds of diseases, particularly in African Americans, but not in Caucasians and Asians. In this study, we explored the single nucleotide polymorphism (SNP) and haplotype diversity of APOL1 gene in different races provided by 1000 Genomes project. Variants of APOL1 gene in 1000 Genome Project were obtained and SNPs located in the regulatory region or coding region were selected for genetic variation analysis. Total 2504 individuals from 26 populations were classified as four groups that included Africa, Europe, Asia and Admixed populations. Tag SNPs were selected to evaluate the haplotype diversities in the four populations by HaploStats software. APOL1 gene was surrounded by some of the most polymorphic genes in the human genome, variation of APOL1 gene was common, with up to 613 SNP (1000 Genome Project reported) and 99 of them (16.2%) with MAF ≥ 1%. There were 79 SNPs in the URR and 92 SNPs in 3'UTR. Total 12 SNPs in URR and 24 SNPs in 3'UTR were considered as common variants with MAF ≥ 1%. It is worth noting that URR-1 was presents lower frequencies in European populations, while other three haplotypes taken an opposite pattern; 3'UTR presents several high-frequency variation sites in a short segment, and the differences of its haplotypes among different population were significant (P < 0.01), UTR-1 and UTR-5 presented much higher frequency in African population, while UTR-2, UTR-3 and UTR-4 were much lower. APOL1 coding region showed that two SNP of G1 with higher frequency are actually pull down the haplotype H-1 frequency when considering all populations pooled together, and the diversity among the four populations be widen by the G1 two mutation (P 1  = 3.33E-4 vs P 2  = 3.61E-30). The distributions of APOL1 gene variants and haplotypes were significantly different among the different populations, in either regulatory or coding regions. It could provide

  3. Unlocking the diversity of genebanks: whole-genome marker analysis of Swiss bread wheat and spelt

    KAUST Repository

    Mü ller, Thomas; Schierscher-Viret, Beate; Fossati, Dario; Brabant, Cé cile; Schori, Arnold; Keller, Beat; Krattinger, Simon G.

    2017-01-01

    Genebanks play a pivotal role in preserving the genetic diversity present among old landraces and wild progenitors of modern crops and they represent sources of agriculturally important genes that were lost during domestication and in modern breeding. However, undesirable genes that negatively affect crop performance are often co-introduced when landraces and wild crop progenitors are crossed with elite cultivars, which often limit the use of genebank material in modern breeding programs. A detailed genetic characterization is an important prerequisite to solve this problem and to make genebank material more accessible to breeding. Here, we genotyped 502 bread wheat and 293 spelt accessions held in the Swiss National Genebank using a 15K wheat SNP array. The material included both spring and winter wheats and consisted of old landraces and modern cultivars. Genome- and sub-genome-wide analyses revealed that spelt and bread wheat form two distinct gene pools. In addition, we identified bread wheat landraces that were genetically distinct from modern cultivars. Such accessions were possibly missed in the early Swiss wheat breeding program and are promising targets for the identification of novel genes. The genetic information obtained in this study is appropriate to perform genome-wide association studies, which will facilitate the identification and transfer of agriculturally important genes from the genebank into modern cultivars through marker-assisted selection.

  4. Penicillium arizonense, a new, genome sequenced fungal species, reveals a high chemical diversity in secreted metabolites

    Science.gov (United States)

    Grijseels, Sietske; Nielsen, Jens Christian; Randelovic, Milica; Nielsen, Jens; Nielsen, Kristian Fog; Workman, Mhairi; Frisvad, Jens Christian

    2016-01-01

    A new soil-borne species belonging to the Penicillium section Canescentia is described, Penicillium arizonense sp. nov. (type strain CBS 141311T = IBT 12289T). The genome was sequenced and assembled into 33.7 Mb containing 12,502 predicted genes. A phylogenetic assessment based on marker genes confirmed the grouping of P. arizonense within section Canescentia. Compared to related species, P. arizonense proved to encode a high number of proteins involved in carbohydrate metabolism, in particular hemicellulases. Mining the genome for genes involved in secondary metabolite biosynthesis resulted in the identification of 62 putative biosynthetic gene clusters. Extracts of P. arizonense were analysed for secondary metabolites and austalides, pyripyropenes, tryptoquivalines, fumagillin, pseurotin A, curvulinic acid and xanthoepocin were detected. A comparative analysis against known pathways enabled the proposal of biosynthetic gene clusters in P. arizonense responsible for the synthesis of all detected compounds except curvulinic acid. The capacity to produce biomass degrading enzymes and the identification of a high chemical diversity in secreted bioactive secondary metabolites, offers a broad range of potential industrial applications for the new species P. arizonense. The description and availability of the genome sequence of P. arizonense, further provides the basis for biotechnological exploitation of this species. PMID:27739446

  5. Unlocking the diversity of genebanks: whole-genome marker analysis of Swiss bread wheat and spelt

    KAUST Repository

    Müller, Thomas

    2017-11-04

    Genebanks play a pivotal role in preserving the genetic diversity present among old landraces and wild progenitors of modern crops and they represent sources of agriculturally important genes that were lost during domestication and in modern breeding. However, undesirable genes that negatively affect crop performance are often co-introduced when landraces and wild crop progenitors are crossed with elite cultivars, which often limit the use of genebank material in modern breeding programs. A detailed genetic characterization is an important prerequisite to solve this problem and to make genebank material more accessible to breeding. Here, we genotyped 502 bread wheat and 293 spelt accessions held in the Swiss National Genebank using a 15K wheat SNP array. The material included both spring and winter wheats and consisted of old landraces and modern cultivars. Genome- and sub-genome-wide analyses revealed that spelt and bread wheat form two distinct gene pools. In addition, we identified bread wheat landraces that were genetically distinct from modern cultivars. Such accessions were possibly missed in the early Swiss wheat breeding program and are promising targets for the identification of novel genes. The genetic information obtained in this study is appropriate to perform genome-wide association studies, which will facilitate the identification and transfer of agriculturally important genes from the genebank into modern cultivars through marker-assisted selection.

  6. The highly heterogeneous methylated genomes and diverse restriction-modification systems of bloom-forming Microcystis.

    Science.gov (United States)

    Zhao, Liang; Song, Yulong; Li, Lin; Gan, Nanqin; Brand, Jerry J; Song, Lirong

    2018-05-01

    The occurrence of harmful Microcystis blooms is increasing in frequency in a myriad of freshwater ecosystems. Despite considerable research pertaining to the cause and nature of these blooms, the molecular mechanisms behind the cosmopolitan distribution and phenotypic diversity in Microcystis are still unclear. We compared the patterns and extent of DNA methylation in three strains of Microcystis, PCC 7806SL, NIES-2549 and FACHB-1757, using Single Molecule Real-Time (SMRT) sequencing technology. Intact restriction-modification (R-M) systems were identified from the genomes of these strains, and from two previously sequenced strains of Microcystis, NIES-843 and TAIHU98. A large number of methylation motifs and R-M genes were identified in these strains, which differ substantially among different strains. Of the 35 motifs identified, eighteen had not previously been reported. Strain NIES-843 contains a larger number of total putative methyltransferase genes than have been reported previously from any bacterial genome. Genomic comparisons reveal that methyltransferases (some partial) may have been acquired from the environment through horizontal gene transfer. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Genomic diversity among Beijing and non-Beijing Mycobacterium tuberculosis isolates from Myanmar.

    Directory of Open Access Journals (Sweden)

    Ruth Stavrum

    2008-04-01

    Full Text Available The Beijing family of Mycobacterium tuberculosis is dominant in countries in East Asia. Genomic polymorphisms are a source of diversity within the M. tuberculosis genome and may account for the variation of virulence among M. tuberculosis isolates. Till date there are no studies that have examined the genomic composition of M. tuberculosis isolates from the high TB-burden country, Myanmar.Twenty-two M. tuberculosis isolates from Myanmar were screened on whole-genome arrays containing genes from M. tuberculosis H37Rv, M. tuberculosis CDC1551 and M. bovis AF22197. Screening identified 198 deletions or extra regions in the clinical isolates compared to H37Rv. Twenty-two regions differentiated between Beijing and non-Beijing isolates and were verified by PCR on an additional 40 isolates. Six regions (Rv0071-0074 [RD105], Rv1572-1576c [RD149], Rv1585c-1587c [RD149], MT1798-Rv1755c [RD152], Rv1761c [RD152] and Rv0279c were deleted in Beijing isolates, of which 4 (Rv1572-1576c, Rv1585c-1587c, MT1798-Rv1755c and Rv1761c were variably deleted among ST42 isolates, indicating a closer relationship between the Beijing and ST42 lineages. The TbD1 region, Mb1582-Mb1583 was deleted in Beijing and ST42 isolates. One M. bovis gene of unknown function, Mb3184c was present in all isolates, except 11 of 13 ST42 isolates. The CDC1551 gene, MT1360 coding for a putative adenylate cyclase, was present in all Beijing and ST42 isolates (except 1. The pks15/1 gene, coding for a putative virulence factor, was intact in all Beijing and non-Beijing isolates, except in ST42 and ST53 isolates.This study describes previously unreported deletions/extra regions in Beijing and non-Beijing M. tuberculosis isolates. The modern and highly frequent ST42 lineage showed a closer relationship to the hypervirulent Beijing lineage than to the ancient non-Beijing lineages. The pks15/1 gene was disrupted only in modern non-Beijing isolates. This is the first report of an in-depth analysis on

  8. Genomic diversity guides conservation strategies among rare terrestrial orchid species when taxonomy remains uncertain.

    Science.gov (United States)

    Ahrens, Collin W; Supple, Megan A; Aitken, Nicola C; Cantrill, David J; Borevitz, Justin O; James, Elizabeth A

    2017-06-01

    Species are often used as the unit for conservation, but may not be suitable for species complexes where taxa are difficult to distinguish. Under such circumstances, it may be more appropriate to consider species groups or populations as evolutionarily significant units (ESUs). A population genomic approach was employed to investigate the diversity within and among closely related species to create a more robust, lineage-specific conservation strategy for a nationally endangered terrestrial orchid and its relatives from south-eastern Australia. Four putative species were sampled from a total of 16 populations in the Victorian Volcanic Plain (VVP) bioregion and one population of a sub-alpine outgroup in south-eastern Australia. Morphological measurements were taken in situ along with leaf material for genotyping by sequencing (GBS) and microsatellite analyses. Species could not be differentiated using morphological measurements. Microsatellite and GBS markers confirmed the outgroup as distinct, but only GBS markers provided resolution of population genetic structure. The nationally endangered Diuris basaltica was indistinguishable from two related species ( D. chryseopsis and D. behrii ), while the state-protected D. gregaria showed genomic differentiation. Genomic diversity identified among the four Diuris species suggests that conservation of this taxonomically complex group will be best served by considering them as one ESU rather than separately aligned with species as currently recognized. This approach will maximize evolutionary potential among all species during increased isolation and environmental change. The methods used here can be applied generally to conserve evolutionary processes for groups where taxonomic uncertainty hinders the use of species as conservation units. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  9. Ancient genomes reveal a high diversity of Mycobacterium leprae in medieval Europe.

    Science.gov (United States)

    Schuenemann, Verena J; Avanzi, Charlotte; Krause-Kyora, Ben; Seitz, Alexander; Herbig, Alexander; Inskip, Sarah; Bonazzi, Marion; Reiter, Ella; Urban, Christian; Dangvard Pedersen, Dorthe; Taylor, G Michael; Singh, Pushpendra; Stewart, Graham R; Velemínský, Petr; Likovsky, Jakub; Marcsik, Antónia; Molnár, Erika; Pálfi, György; Mariotti, Valentina; Riga, Alessandro; Belcastro, M Giovanna; Boldsen, Jesper L; Nebel, Almut; Mays, Simon; Donoghue, Helen D; Zakrzewski, Sonia; Benjak, Andrej; Nieselt, Kay; Cole, Stewart T; Krause, Johannes

    2018-05-01

    Studying ancient DNA allows us to retrace the evolutionary history of human pathogens, such as Mycobacterium leprae, the main causative agent of leprosy. Leprosy is one of the oldest recorded and most stigmatizing diseases in human history. The disease was prevalent in Europe until the 16th century and is still endemic in many countries with over 200,000 new cases reported annually. Previous worldwide studies on modern and European medieval M. leprae genomes revealed that they cluster into several distinct branches of which two were present in medieval Northwestern Europe. In this study, we analyzed 10 new medieval M. leprae genomes including the so far oldest M. leprae genome from one of the earliest known cases of leprosy in the United Kingdom-a skeleton from the Great Chesterford cemetery with a calibrated age of 415-545 C.E. This dataset provides a genetic time transect of M. leprae diversity in Europe over the past 1500 years. We find M. leprae strains from four distinct branches to be present in the Early Medieval Period, and strains from three different branches were detected within a single cemetery from the High Medieval Period. Altogether these findings suggest a higher genetic diversity of M. leprae strains in medieval Europe at various time points than previously assumed. The resulting more complex picture of the past phylogeography of leprosy in Europe impacts current phylogeographical models of M. leprae dissemination. It suggests alternative models for the past spread of leprosy such as a wide spread prevalence of strains from different branches in Eurasia already in Antiquity or maybe even an origin in Western Eurasia. Furthermore, these results highlight how studying ancient M. leprae strains improves understanding the history of leprosy worldwide.

  10. Ancient genomes reveal a high diversity of Mycobacterium leprae in medieval Europe.

    Directory of Open Access Journals (Sweden)

    Verena J Schuenemann

    2018-05-01

    Full Text Available Studying ancient DNA allows us to retrace the evolutionary history of human pathogens, such as Mycobacterium leprae, the main causative agent of leprosy. Leprosy is one of the oldest recorded and most stigmatizing diseases in human history. The disease was prevalent in Europe until the 16th century and is still endemic in many countries with over 200,000 new cases reported annually. Previous worldwide studies on modern and European medieval M. leprae genomes revealed that they cluster into several distinct branches of which two were present in medieval Northwestern Europe. In this study, we analyzed 10 new medieval M. leprae genomes including the so far oldest M. leprae genome from one of the earliest known cases of leprosy in the United Kingdom-a skeleton from the Great Chesterford cemetery with a calibrated age of 415-545 C.E. This dataset provides a genetic time transect of M. leprae diversity in Europe over the past 1500 years. We find M. leprae strains from four distinct branches to be present in the Early Medieval Period, and strains from three different branches were detected within a single cemetery from the High Medieval Period. Altogether these findings suggest a higher genetic diversity of M. leprae strains in medieval Europe at various time points than previously assumed. The resulting more complex picture of the past phylogeography of leprosy in Europe impacts current phylogeographical models of M. leprae dissemination. It suggests alternative models for the past spread of leprosy such as a wide spread prevalence of strains from different branches in Eurasia already in Antiquity or maybe even an origin in Western Eurasia. Furthermore, these results highlight how studying ancient M. leprae strains improves understanding the history of leprosy worldwide.

  11. Genome diversity of marine phages recovered from Mediterranean metagenomes: Size matters.

    Directory of Open Access Journals (Sweden)

    Mario López-Pérez

    2017-09-01

    Full Text Available Marine viruses play a critical role not only in the global geochemical cycles but also in the biology and evolution of their hosts. Despite their importance, viral diversity remains underexplored mostly due to sampling and cultivation challenges. Direct sequencing approaches such as viromics has provided new insights into the marine viral world. As a complementary approach, we analysed 24 microbial metagenomes (>0.2 μm size range obtained from six sites in the Mediterranean Sea that vary by depth, season and filter used to retrieve the fraction. Filter-size comparison showed a significant number of viral sequences that were retained on the larger-pore filters and were different from those found in the viral fraction from the same sample, indicating that some important viral information is missing using only assembly from viromes. Besides, we were able to describe 1,323 viral genomic fragments that were more than 10Kb in length, of which 36 represented complete viral genomes including some of them retrieved from a cross-assembly from different metagenomes. Host prediction based on sequence methods revealed new phage groups belonging to marine prokaryotes like SAR11, Cyanobacteria or SAR116. We also identified the first complete virophage from deep seawater and a new endemic clade of the recently discovered Marine group II Euryarchaeota virus. Furthermore, analysis of viral distribution using metagenomes and viromes indicated that most of the new phages were found exclusively in the Mediterranean Sea and some of them, mostly the ones recovered from deep metagenomes, do not recruit in any database probably indicating higher variability and endemicity in Mediterranean bathypelagic waters. Together these data provide the first detailed picture of genomic diversity, spatial and depth variations of viral communities within the Mediterranean Sea using metagenome assembly.

  12. Analysis of genotype diversity and evolution of Dengue virus serotype 2 using complete genomes

    Directory of Open Access Journals (Sweden)

    Vaishali P. Waman

    2016-08-01

    Full Text Available Background Dengue is one of the most common arboviral diseases prevalent worldwide and is caused by Dengue viruses (genus Flavivirus, family Flaviviridae. There are four serotypes of Dengue Virus (DENV-1 to DENV-4, each of which is further subdivided into distinct genotypes. DENV-2 is frequently associated with severe dengue infections and epidemics. DENV-2 consists of six genotypes such as Asian/American, Asian I, Asian II, Cosmopolitan, American and sylvatic. Comparative genomic study was carried out to infer population structure of DENV-2 and to analyze the role of evolutionary and spatiotemporal factors in emergence of diversifying lineages. Methods Complete genome sequences of 990 strains of DENV-2 were analyzed using Bayesian-based population genetics and phylogenetic approaches to infer genetically distinct lineages. The role of spatiotemporal factors, genetic recombination and selection pressure in the evolution of DENV-2 is examined using the sequence-based bioinformatics approaches. Results DENV-2 genetic structure is complex and consists of fifteen subpopulations/lineages. The Asian/American genotype is observed to be diversified into seven lineages. The Asian I, Cosmopolitan and sylvatic genotypes were found to be subdivided into two lineages, each. The populations of American and Asian II genotypes were observed to be homogeneous. Significant evidence of episodic positive selection was observed in all the genes, except NS4A. Positive selection operational on a few codons in envelope gene confers antigenic and lineage diversity in the American strains of Asian/American genotype. Selection on codons of non-structural genes was observed to impact diversification of lineages in Asian I, cosmopolitan and sylvatic genotypes. Evidence of intra/inter-genotype recombination was obtained and the uncertainty in classification of recombinant strains was resolved using the population genetics approach. Discussion Complete genome-based analysis

  13. Genomic diversity among drug sensitive and multidrug resistant isolates of Mycobacterium tuberculosis with identical DNA fingerprints.

    Directory of Open Access Journals (Sweden)

    Stefan Niemann

    2009-10-01

    Full Text Available Mycobacterium tuberculosis complex (MTBC, the causative agent of tuberculosis (TB, is characterized by low sequence diversity making this bacterium one of the classical examples of a genetically monomorphic pathogen. Because of this limited DNA sequence variation, routine genotyping of clinical MTBC isolates for epidemiological purposes relies on highly discriminatory DNA fingerprinting methods based on mobile and repetitive genetic elements. According to the standard view, isolates exhibiting the same fingerprinting pattern are considered direct progeny of the same bacterial clone, and most likely reflect ongoing transmission or disease relapse within individual patients.Here we further investigated this assumption and used massively parallel whole-genome sequencing to compare one drug-susceptible (K-1 and one multidrug resistant (MDR isolate (K-2 of a rapidly spreading M. tuberculosis Beijing genotype clone from a high incidence region (Karakalpakstan, Uzbekistan. Both isolates shared the same IS6110 RFLP pattern and the same allele at 23 out of 24 MIRU-VNTR loci. We generated 23.9 million (K-1 and 33.0 million (K-2 paired 50 bp purity filtered reads corresponding to a mean coverage of 483.5 fold and 656.1 fold respectively. Compared with the laboratory strain H37Rv both Beijing isolates shared 1,209 SNPs. The two Beijing isolates differed by 130 SNPs and one large deletion. The susceptible isolate had 55 specific SNPs, while the MDR variant had 75 specific SNPs, including the five known resistance-conferring mutations.Our results suggest that M. tuberculosis isolates exhibiting identical DNA fingerprinting patterns can harbour substantial genomic diversity. Because this heterogeneity is not captured by traditional genotyping of MTBC, some aspects of the transmission dynamics of tuberculosis could be missed or misinterpreted. Furthermore, a valid differentiation between disease relapse and exogenous reinfection might be impossible using

  14. Genomic diversity among drug sensitive and multidrug resistant isolates of Mycobacterium tuberculosis with identical DNA fingerprints.

    Science.gov (United States)

    Niemann, Stefan; Köser, Claudio U; Gagneux, Sebastien; Plinke, Claudia; Homolka, Susanne; Bignell, Helen; Carter, Richard J; Cheetham, R Keira; Cox, Anthony; Gormley, Niall A; Kokko-Gonzales, Paula; Murray, Lisa J; Rigatti, Roberto; Smith, Vincent P; Arends, Felix P M; Cox, Helen S; Smith, Geoff; Archer, John A C

    2009-10-12

    Mycobacterium tuberculosis complex (MTBC), the causative agent of tuberculosis (TB), is characterized by low sequence diversity making this bacterium one of the classical examples of a genetically monomorphic pathogen. Because of this limited DNA sequence variation, routine genotyping of clinical MTBC isolates for epidemiological purposes relies on highly discriminatory DNA fingerprinting methods based on mobile and repetitive genetic elements. According to the standard view, isolates exhibiting the same fingerprinting pattern are considered direct progeny of the same bacterial clone, and most likely reflect ongoing transmission or disease relapse within individual patients. Here we further investigated this assumption and used massively parallel whole-genome sequencing to compare one drug-susceptible (K-1) and one multidrug resistant (MDR) isolate (K-2) of a rapidly spreading M. tuberculosis Beijing genotype clone from a high incidence region (Karakalpakstan, Uzbekistan). Both isolates shared the same IS6110 RFLP pattern and the same allele at 23 out of 24 MIRU-VNTR loci. We generated 23.9 million (K-1) and 33.0 million (K-2) paired 50 bp purity filtered reads corresponding to a mean coverage of 483.5 fold and 656.1 fold respectively. Compared with the laboratory strain H37Rv both Beijing isolates shared 1,209 SNPs. The two Beijing isolates differed by 130 SNPs and one large deletion. The susceptible isolate had 55 specific SNPs, while the MDR variant had 75 specific SNPs, including the five known resistance-conferring mutations. Our results suggest that M. tuberculosis isolates exhibiting identical DNA fingerprinting patterns can harbour substantial genomic diversity. Because this heterogeneity is not captured by traditional genotyping of MTBC, some aspects of the transmission dynamics of tuberculosis could be missed or misinterpreted. Furthermore, a valid differentiation between disease relapse and exogenous reinfection might be impossible using standard

  15. Genome-wide analysis of the diversity and ancestry of Korean dogs.

    Science.gov (United States)

    Choi, Bong Hwan; Wijayananda, Hasini I; Lee, Soo Hyun; Lee, Doo Ho; Kim, Jong Seok; Oh, Seok Il; Park, Eung Woo; Lee, Cheul Koo; Lee, Seung Hwan

    2017-01-01

    There are various hypotheses on dog domestication based on archeological and genetic studies. Although many studies have been conducted on the origin of dogs, the existing literature about the ancestry, diversity, and population structure of Korean dogs is sparse. Therefore, this study is focused on the origin, diversity and population structure of Korean dogs. The study sample comprised four major categories, including non-dogs (coyotes and wolves), ancient, modern and Korean dogs. Selected samples were genotyped using an Illumina CanineHD array containing 173,662 single nucleotide polymorphisms. The genome-wide data were filtered using quality control parameters in PLINK 1.9. Only autosomal chromosomes were used for further analysis. The negative off-diagonal variance of the genetic relationship matrix analysis depicted, the variability of samples in each population. FIS (inbreeding rate within a population) values indicated, a low level of inbreeding within populations, and the patterns were in concordance with the results of Nei's genetic distance analysis. The lowest FST (inbreeding rate between populations) values among Korean and Chinese breeds, using a phylogenetic tree, multi-dimensional scaling, and a TreeMix likelihood tree showed Korean breeds are highly related to Chinese breeds. The Korean breeds possessed a unique and large diversity of admixtures compared with other breeds. The highest and lowest effective population sizes were observed in Korean Jindo Black (485) and Korean Donggyeong White (109), respectively. The historical effective population size of all Korean dogs showed declining trend from the past to present. It is important to take immediate action to protect the Korean dog population while conserving their diversity. Furthermore, this study suggests that Korean dogs have unique diversity and are one of the basal lineages of East Asian dogs, originating from China.

  16. Genome-wide analysis of the diversity and ancestry of Korean dogs.

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    Bong Hwan Choi

    Full Text Available There are various hypotheses on dog domestication based on archeological and genetic studies. Although many studies have been conducted on the origin of dogs, the existing literature about the ancestry, diversity, and population structure of Korean dogs is sparse. Therefore, this study is focused on the origin, diversity and population structure of Korean dogs. The study sample comprised four major categories, including non-dogs (coyotes and wolves, ancient, modern and Korean dogs. Selected samples were genotyped using an Illumina CanineHD array containing 173,662 single nucleotide polymorphisms. The genome-wide data were filtered using quality control parameters in PLINK 1.9. Only autosomal chromosomes were used for further analysis. The negative off-diagonal variance of the genetic relationship matrix analysis depicted, the variability of samples in each population. FIS (inbreeding rate within a population values indicated, a low level of inbreeding within populations, and the patterns were in concordance with the results of Nei's genetic distance analysis. The lowest FST (inbreeding rate between populations values among Korean and Chinese breeds, using a phylogenetic tree, multi-dimensional scaling, and a TreeMix likelihood tree showed Korean breeds are highly related to Chinese breeds. The Korean breeds possessed a unique and large diversity of admixtures compared with other breeds. The highest and lowest effective population sizes were observed in Korean Jindo Black (485 and Korean Donggyeong White (109, respectively. The historical effective population size of all Korean dogs showed declining trend from the past to present. It is important to take immediate action to protect the Korean dog population while conserving their diversity. Furthermore, this study suggests that Korean dogs have unique diversity and are one of the basal lineages of East Asian dogs, originating from China.

  17. Using Whole Genome Analysis to Examine Recombination across Diverse Sequence Types of Staphylococcus aureus.

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    Elizabeth M Driebe

    Full Text Available Staphylococcus aureus is an important clinical pathogen worldwide and understanding this organism's phylogeny and, in particular, the role of recombination, is important both to understand the overall spread of virulent lineages and to characterize outbreaks. To further elucidate the phylogeny of S. aureus, 35 diverse strains were sequenced using whole genome sequencing. In addition, 29 publicly available whole genome sequences were included to create a single nucleotide polymorphism (SNP-based phylogenetic tree encompassing 11 distinct lineages. All strains of a particular sequence type fell into the same clade with clear groupings of the major clonal complexes of CC8, CC5, CC30, CC45 and CC1. Using a novel analysis method, we plotted the homoplasy density and SNP density across the whole genome and found evidence of recombination throughout the entire chromosome, but when we examined individual clonal lineages we found very little recombination. However, when we analyzed three branches of multiple lineages, we saw intermediate and differing levels of recombination between them. These data demonstrate that in S. aureus, recombination occurs across major lineages that subsequently expand in a clonal manner. Estimated mutation rates for the CC8 and CC5 lineages were different from each other. While the CC8 lineage rate was similar to previous studies, the CC5 lineage was 100-fold greater. Fifty known virulence genes were screened in all genomes in silico to determine their distribution across major clades. Thirty-three genes were present variably across clades, most of which were not constrained by ancestry, indicating horizontal gene transfer or gene loss.

  18. Genome-wide detection of copy number variations among diverse horse breeds by array CGH.

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    Wei Wang

    Full Text Available Recent studies have found that copy number variations (CNVs are widespread in human and animal genomes. CNVs are a significant source of genetic variation, and have been shown to be associated with phenotypic diversity. However, the effect of CNVs on genetic variation in horses is not well understood. In the present study, CNVs in 6 different breeds of mare horses, Mongolia horse, Abaga horse, Hequ horse and Kazakh horse (all plateau breeds and Debao pony and Thoroughbred, were determined using aCGH. In total, seven hundred CNVs were identified ranging in size from 6.1 Kb to 0.57 Mb across all autosomes, with an average size of 43.08 Kb and a median size of 15.11 Kb. By merging overlapping CNVs, we found a total of three hundred and fifty-three CNV regions (CNVRs. The length of the CNVRs ranged from 6.1 Kb to 1.45 Mb with average and median sizes of 38.49 Kb and 13.1 Kb. Collectively, 13.59 Mb of copy number variation was identified among the horses investigated and accounted for approximately 0.61% of the horse genome sequence. Five hundred and eighteen annotated genes were affected by CNVs, which corresponded to about 2.26% of all horse genes. Through the gene ontology (GO, genetic pathway analysis and comparison of CNV genes among different breeds, we found evidence that CNVs involving 7 genes may be related to the adaptation to severe environment of these plateau horses. This study is the first report of copy number variations in Chinese horses, which indicates that CNVs are ubiquitous in the horse genome and influence many biological processes of the horse. These results will be helpful not only in mapping the horse whole-genome CNVs, but also to further research for the adaption to the high altitude severe environment for plateau horses.

  19. DNA variation of the mammalian major histocompatibility complex reflects genomic diversity and population history

    International Nuclear Information System (INIS)

    Yuhki, Naoya; O'Brien, S.J.

    1990-01-01

    The major histocompatibility complex (MHC) is a multigene complex of tightly linked homologous genes that encode cell surface antigens that play a key role in immune regulation and response to foreign antigens. In most species, MHC gene products display extreme antigenic polymorphism, and their variability has been interpreted to reflect an adaptive strategy for accommodating rapidly evolving infectious agents that periodically afflict natural populations. Determination of the extent of MHC variation has been limited to populations in which skin grafting is feasible or for which serological reagents have been developed. The authors present here a quantitative analysis of restriction fragment length polymorphism of MHC class I genes in several mammalian species (cats, rodents, humans) known to have very different levels of genetic diversity based on functional MHC assays and on allozyme surveys. When homologous class I probes were employed, a notable concordance was observed between the extent of MHC restriction fragment variation and functional MHC variation detected by skin grafts or genome-wide diversity estimated by allozyme screens. These results confirm the genetically depauperate character of the African cheetah, Acinonyx jubatus, and the Asiatic lion, Panthera leo persica; further, they support the use of class I MHC molecular reagents in estimating the extent and character of genetic diversity in natural populations

  20. DNA variation of the mammalian major histocompatibility complex reflects genomic diversity and population history

    Energy Technology Data Exchange (ETDEWEB)

    Yuhki, Naoya; O' Brien, S.J. (National Cancer Institute, Frederick, MD (USA))

    1990-01-01

    The major histocompatibility complex (MHC) is a multigene complex of tightly linked homologous genes that encode cell surface antigens that play a key role in immune regulation and response to foreign antigens. In most species, MHC gene products display extreme antigenic polymorphism, and their variability has been interpreted to reflect an adaptive strategy for accommodating rapidly evolving infectious agents that periodically afflict natural populations. Determination of the extent of MHC variation has been limited to populations in which skin grafting is feasible or for which serological reagents have been developed. The authors present here a quantitative analysis of restriction fragment length polymorphism of MHC class I genes in several mammalian species (cats, rodents, humans) known to have very different levels of genetic diversity based on functional MHC assays and on allozyme surveys. When homologous class I probes were employed, a notable concordance was observed between the extent of MHC restriction fragment variation and functional MHC variation detected by skin grafts or genome-wide diversity estimated by allozyme screens. These results confirm the genetically depauperate character of the African cheetah, Acinonyx jubatus, and the Asiatic lion, Panthera leo persica; further, they support the use of class I MHC molecular reagents in estimating the extent and character of genetic diversity in natural populations.

  1. Population diversity of Diaphorina citri (Hemiptera: Liviidae) in China based on whole mitochondrial genome sequences.

    Science.gov (United States)

    Wu, Fengnian; Jiang, Hongyan; Beattie, G Andrew C; Holford, Paul; Chen, Jianchi; Wallis, Christopher M; Zheng, Zheng; Deng, Xiaoling; Cen, Yijing

    2018-04-24

    Diaphorina citri (Asian citrus psyllid; ACP) transmits 'Candidatus Liberibacter asiaticus' associated with citrus Huanglongbing (HLB). ACP has been reported in 11 provinces/regions in China, yet its population diversity remains unclear. In this study, we evaluated ACP population diversity in China using representative whole mitochondrial genome (mitogenome) sequences. Additional mitogenome sequences outside China were also acquired and evaluated. The sizes of the 27 ACP mitogenome sequences ranged from 14 986 to 15 030 bp. Along with three previously published mitogenome sequences, the 30 sequences formed three major mitochondrial groups (MGs): MG1, present in southwestern China and occurring at elevations above 1000 m; MG2, present in southeastern China and Southeast Asia (Cambodia, Indonesia, Malaysia, and Vietnam) and occurring at elevations below 180 m; and MG3, present in the USA and Pakistan. Single nucleotide polymorphisms in five genes (cox2, atp8, nad3, nad1 and rrnL) contributed mostly in the ACP diversity. Among these genes, rrnL had the most variation. Mitogenome sequences analyses revealed two major phylogenetic groups of ACP present in China as well as a possible unique group present currently in Pakistan and the USA. The information could have significant implications for current ACP control and HLB management. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  2. MBGD update 2015: microbial genome database for flexible ortholog analysis utilizing a diverse set of genomic data.

    Science.gov (United States)

    Uchiyama, Ikuo; Mihara, Motohiro; Nishide, Hiroyo; Chiba, Hirokazu

    2015-01-01

    The microbial genome database for comparative analysis (MBGD) (available at http://mbgd.genome.ad.jp/) is a comprehensive ortholog database for flexible comparative analysis of microbial genomes, where the users are allowed to create an ortholog table among any specified set of organisms. Because of the rapid increase in microbial genome data owing to the next-generation sequencing technology, it becomes increasingly challenging to maintain high-quality orthology relationships while allowing the users to incorporate the latest genomic data available into an analysis. Because many of the recently accumulating genomic data are draft genome sequences for which some complete genome sequences of the same or closely related species are available, MBGD now stores draft genome data and allows the users to incorporate them into a user-specific ortholog database using the MyMBGD functionality. In this function, draft genome data are incorporated into an existing ortholog table created only from the complete genome data in an incremental manner to prevent low-quality draft data from affecting clustering results. In addition, to provide high-quality orthology relationships, the standard ortholog table containing all the representative genomes, which is first created by the rapid classification program DomClust, is now refined using DomRefine, a recently developed program for improving domain-level clustering using multiple sequence alignment information. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. Genome-Wide Diversity and Phylogeography of Mycobacterium avium subsp. paratuberculosis in Canadian Dairy Cattle.

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    Christina Ahlstrom

    Full Text Available Mycobacterium avium subsp. paratuberculosis (MAP is the causative bacterium of Johne's disease (JD in ruminants. The control of JD in the dairy industry is challenging, but can be improved with a better understanding of the diversity and distribution of MAP subtypes. Previously established molecular typing techniques used to differentiate MAP have not been sufficiently discriminatory and/or reliable to accurately assess the population structure. In this study, the genetic diversity of 182 MAP isolates representing all Canadian provinces was compared to the known global diversity, using single nucleotide polymorphisms identified through whole genome sequencing. MAP isolates from Canada represented a subset of the known global diversity, as there were global isolates intermingled with Canadian isolates, as well as multiple global subtypes that were not found in Canada. One Type III and six "Bison type" isolates were found in Canada as well as one Type II subtype that represented 86% of all Canadian isolates. Rarefaction estimated larger subtype richness in Québec than in other Canadian provinces using a strict definition of MAP subtypes and lower subtype richness in the Atlantic region using a relaxed definition. Significant phylogeographic clustering was observed at the inter-provincial but not at the intra-provincial level, although most major clades were found in all provinces. The large number of shared subtypes among provinces suggests that cattle movement is a major driver of MAP transmission at the herd level, which is further supported by the lack of spatial clustering on an intra-provincial scale.

  4. Genome-wide and paternal diversity reveal a recent origin of human populations in North Africa.

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    Karima Fadhlaoui-Zid

    Full Text Available The geostrategic location of North Africa as a crossroad between three continents and as a stepping-stone outside Africa has evoked anthropological and genetic interest in this region. Numerous studies have described the genetic landscape of the human population in North Africa employing paternal, maternal, and biparental molecular markers. However, information from these markers which have different inheritance patterns has been mostly assessed independently, resulting in an incomplete description of the region. In this study, we analyze uniparental and genome-wide markers examining similarities or contrasts in the results and consequently provide a comprehensive description of the evolutionary history of North Africa populations. Our results show that both males and females in North Africa underwent a similar admixture history with slight differences in the proportions of admixture components. Consequently, genome-wide diversity show similar patterns with admixture tests suggesting North Africans are a mixture of ancestral populations related to current Africans and Eurasians with more affinity towards the out-of-Africa populations than to sub-Saharan Africans. We estimate from the paternal lineages that most North Africans emerged ∼15,000 years ago during the last glacial warming and that population splits started after the desiccation of the Sahara. Although most North Africans share a common admixture history, the Tunisian Berbers show long periods of genetic isolation and appear to have diverged from surrounding populations without subsequent mixture. On the other hand, continuous gene flow from the Middle East made Egyptians genetically closer to Eurasians than to other North Africans. We show that genetic diversity of today's North Africans mostly captures patterns from migrations post Last Glacial Maximum and therefore may be insufficient to inform on the initial population of the region during the Middle Paleolithic period.

  5. Genome-wide and paternal diversity reveal a recent origin of human populations in North Africa.

    Science.gov (United States)

    Fadhlaoui-Zid, Karima; Haber, Marc; Martínez-Cruz, Begoña; Zalloua, Pierre; Benammar Elgaaied, Amel; Comas, David

    2013-01-01

    The geostrategic location of North Africa as a crossroad between three continents and as a stepping-stone outside Africa has evoked anthropological and genetic interest in this region. Numerous studies have described the genetic landscape of the human population in North Africa employing paternal, maternal, and biparental molecular markers. However, information from these markers which have different inheritance patterns has been mostly assessed independently, resulting in an incomplete description of the region. In this study, we analyze uniparental and genome-wide markers examining similarities or contrasts in the results and consequently provide a comprehensive description of the evolutionary history of North Africa populations. Our results show that both males and females in North Africa underwent a similar admixture history with slight differences in the proportions of admixture components. Consequently, genome-wide diversity show similar patterns with admixture tests suggesting North Africans are a mixture of ancestral populations related to current Africans and Eurasians with more affinity towards the out-of-Africa populations than to sub-Saharan Africans. We estimate from the paternal lineages that most North Africans emerged ∼15,000 years ago during the last glacial warming and that population splits started after the desiccation of the Sahara. Although most North Africans share a common admixture history, the Tunisian Berbers show long periods of genetic isolation and appear to have diverged from surrounding populations without subsequent mixture. On the other hand, continuous gene flow from the Middle East made Egyptians genetically closer to Eurasians than to other North Africans. We show that genetic diversity of today's North Africans mostly captures patterns from migrations post Last Glacial Maximum and therefore may be insufficient to inform on the initial population of the region during the Middle Paleolithic period.

  6. Comparative Genomics Reveals the Diversity of Restriction-Modification Systems and DNA Methylation Sites in Listeria monocytogenes.

    Science.gov (United States)

    Chen, Poyin; den Bakker, Henk C; Korlach, Jonas; Kong, Nguyet; Storey, Dylan B; Paxinos, Ellen E; Ashby, Meredith; Clark, Tyson; Luong, Khai; Wiedmann, Martin; Weimer, Bart C

    2017-02-01

    Listeria monocytogenes is a bacterial pathogen that is found in a wide variety of anthropogenic and natural environments. Genome sequencing technologies are rapidly becoming a powerful tool in facilitating our understanding of how genotype, classification phenotypes, and virulence phenotypes interact to predict the health risks of individual bacterial isolates. Currently, 57 closed L. monocytogenes genomes are publicly available, representing three of the four phylogenetic lineages, and they suggest that L. monocytogenes has high genomic synteny. This study contributes an additional 15 closed L. monocytogenes genomes that were used to determine the associations between the genome and methylome with host invasion magnitude. In contrast to previous findings, large chromosomal inversions and rearrangements were detected in five isolates at the chromosome terminus and within rRNA genes, including a previously undescribed inversion within rRNA-encoding regions. Each isolate's epigenome contained highly diverse methyltransferase recognition sites, even within the same serotype and methylation pattern. Eleven strains contained a single chromosomally encoded methyltransferase, one strain contained two methylation systems (one system on a plasmid), and three strains exhibited no methylation, despite the occurrence of methyltransferase genes. In three isolates a new, unknown DNA modification was observed in addition to diverse methylation patterns, accompanied by a novel methylation system. Neither chromosome rearrangement nor strain-specific patterns of epigenome modification observed within virulence genes were correlated with serotype designation, clonal complex, or in vitro infectivity. These data suggest that genome diversity is larger than previously considered in L. monocytogenes and that as more genomes are sequenced, additional structure and methylation novelty will be observed in this organism. Listeria monocytogenes is the causative agent of listeriosis, a disease

  7. Implementing sponge physiological and genomic information to enhance the diversity of its culturable associated bacteria.

    Science.gov (United States)

    Lavy, Adi; Keren, Ray; Haber, Markus; Schwartz, Inbar; Ilan, Micha

    2014-02-01

    In recent years new approaches have emerged for culturing marine environmental bacteria. They include the use of novel culture media, sometimes with very low-nutrient content, and a variety of growth conditions such as temperature, oxygen levels, and different atmospheric pressures. These approaches have largely been neglected when it came to the cultivation of sponge-associated bacteria. Here, we used physiological and environmental conditions to reflect the environment of sponge-associated bacteria along with genomic data of the prominent sponge symbiont Candidatus Poribacteria sp. WGA-4E, to cultivate bacteria from the Red Sea sponge Theonella swinhoei. Designing culturing conditions to fit the metabolic needs of major bacterial taxa present in the sponge, through a combined use of diverse culture media compositions with aerobic and microaerophilic states, and addition of antibiotics, yielded higher diversity of the cultured bacteria and led to the isolation of novel sponge-associated and sponge-specific bacteria. In this work, 59 OTUs of six phyla were isolated. Of these, 22 have no close type strains at the species level (< 97% similarity of 16S rRNA gene sequence), representing novel bacteria species, and some are probably new genera and even families. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  8. Assessment of genome origins and genetic diversity in the genus Eleusine with DNA markers.

    Science.gov (United States)

    Salimath, S S; de Oliveira, A C; Godwin, I D; Bennetzen, J L

    1995-08-01

    Finger millet (Eleusine coracana), an allotetraploid cereal, is widely cultivated in the arid and semiarid regions of the world. Three DNA marker techniques, restriction fragment length polymorphism (RFLP), randomly amplified polymorphic DNA (RAPD), and inter simple sequence repeat amplification (ISSR), were employed to analyze 22 accessions belonging to 5 species of Eleusine. An 8 probe--3 enzyme RFLP combination, 18 RAPD primers, and 6 ISSR primers, respectively, revealed 14, 10, and 26% polymorphism in 17 accessions of E. coracana from Africa and Asia. These results indicated a very low level of DNA sequence variability in the finger millets but did allow each line to be distinguished. The different Eleusine species could be easily identified by DNA marker technology and the 16% intraspecific polymorphism exhibited by the two analyzed accessions of E. floccifolia suggested a much higher level of diversity in this species than in E. coracana. Between species, E. coracana and E. indica shared the most markers, while E. indica and E. tristachya shared a considerable number of markers, indicating that these three species form a close genetic assemblage within the Eleusine. Eleusine floccifolia and E. compressa were found to be the most divergent among the species examined. Comparison of RFLP, RAPD, and ISSR technologies, in terms of the quantity and quality of data output, indicated that ISSRs are particularly promising for the analysis of plant genome diversity.

  9. Comparison of relative efficiency of genomic SSR and EST-SSR markers in estimating genetic diversity in sugarcane.

    Science.gov (United States)

    Parthiban, S; Govindaraj, P; Senthilkumar, S

    2018-03-01

    Twenty-five primer pairs developed from genomic simple sequence repeats (SSR) were compared with 25 expressed sequence tags (EST) SSRs to evaluate the efficiency of these two sets of primers using 59 sugarcane genetic stocks. The mean polymorphism information content (PIC) of genomic SSR was higher (0.72) compared to the PIC value recorded by EST-SSR marker (0.62). The relatively low level of polymorphism in EST-SSR markers may be due to the location of these markers in more conserved and expressed sequences compared to genomic sequences which are spread throughout the genome. Dendrogram based on the genomic SSR and EST-SSR marker data showed differences in grouping of genotypes. A total of 59 sugarcane accessions were grouped into 6 and 4 clusters using genomic SSR and EST-SSR, respectively. The highly efficient genomic SSR could subcluster the genotypes of some of the clusters formed by EST-SSR markers. The difference in dendrogram observed was probably due to the variation in number of markers produced by genomic SSR and EST-SSR and different portion of genome amplified by both the markers. The combined dendrogram (genomic SSR and EST-SSR) more clearly showed the genetic relationship among the sugarcane genotypes by forming four clusters. The mean genetic similarity (GS) value obtained using EST-SSR among 59 sugarcane accessions was 0.70, whereas the mean GS obtained using genomic SSR was 0.63. Although relatively lower level of polymorphism was displayed by the EST-SSR markers, genetic diversity shown by the EST-SSR was found to be promising as they were functional marker. High level of PIC and low genetic similarity values of genomic SSR may be more useful in DNA fingerprinting, selection of true hybrids, identification of variety specific markers and genetic diversity analysis. Identification of diverse parents based on cluster analysis can be effectively done with EST-SSR as the genetic similarity estimates are based on functional attributes related to

  10. Small RNA pathways and diversity in model legumes: lessons from genomics.

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    Pilar eBustos-Sanmamed

    2013-07-01

    Full Text Available Small non coding RNAs (smRNA participate in the regulation of development, cell differentiation, adaptation to environmental constraints and defense responses in plants. They negatively regulate gene expression by degrading specific mRNA targets, repressing their translation or modifying chromatin conformation through homologous interaction with target loci. MicroRNAs (miRNA and short-interfering RNAs (siRNA are generated from long double stranded RNA (dsRNA that are cleaved into 20- to 24-nucleotide dsRNAs by RNase III proteins called DICERs (DCL. One strand of the duplex is then loaded onto effective complexes containing different ARGONAUTE (AGO proteins. In this review, we explored smRNA diversity in model legumes and compiled available data from miRBAse, the miRNA database, and from 22 reports of smRNA deep sequencing or miRNA identification genome-wide in Medicago truncatula, Glycine max and Lotus japonicus. In addition to conserved miRNAs present in other plant species, 229, 179 and 35 novel miRNA families were identified respectively in these 3 legumes, among which several seems legume-specific. New potential functions of several miRNAs in the legume-specific nodulation process are discussed. Furthermore, a new category of siRNA, the phased siRNAs, which seems to mainly regulate disease-resistance genes, was recently discovered in legumes. Despite that the genome sequence of model legumes are not yet fully completed, further analysis was performed by database mining of gene families and protein characteristics of DCLs and AGOs in these genomes. Although most components of the smRNA pathways are conserved, identifiable homologs of key smRNA players from non-legumes could not yet be detected in M. truncatula available genomic and expressed sequence databases. In addition, an important gene diversification was observed in the three legumes. Functional significance of these variant isoforms may reflect peculiarities of smRNA biogenesis in

  11. Genome diversity and divergence in Drosophila mauritiana: multiple signatures of faster X evolution.

    Science.gov (United States)

    Garrigan, Daniel; Kingan, Sarah B; Geneva, Anthony J; Vedanayagam, Jeffrey P; Presgraves, Daven C

    2014-09-04

    Drosophila mauritiana is an Indian Ocean island endemic species that diverged from its two sister species, Drosophila simulans and Drosophila sechellia, approximately 240,000 years ago. Multiple forms of incomplete reproductive isolation have evolved among these species, including sexual, gametic, ecological, and intrinsic postzygotic barriers, with crosses among all three species conforming to Haldane's rule: F(1) hybrid males are sterile and F(1) hybrid females are fertile. Extensive genetic resources and the fertility of hybrid females have made D. mauritiana, in particular, an important model for speciation genetics. Analyses between D. mauritiana and both of its siblings have shown that the X chromosome makes a disproportionate contribution to hybrid male sterility. But why the X plays a special role in the evolution of hybrid sterility in these, and other, species remains an unsolved problem. To complement functional genetic analyses, we have investigated the population genomics of D. mauritiana, giving special attention to differences between the X and the autosomes. We present a de novo genome assembly of D. mauritiana annotated with RNAseq data and a whole-genome analysis of polymorphism and divergence from ten individuals. Our analyses show that, relative to the autosomes, the X chromosome has reduced nucleotide diversity but elevated nucleotide divergence; an excess of recurrent adaptive evolution at its protein-coding genes; an excess of recent, strong selective sweeps; and a large excess of satellite DNA. Interestingly, one of two centimorgan-scale selective sweeps on the D. mauritiana X chromosome spans a region containing two sex-ratio meiotic drive elements and a high concentration of satellite DNA. Furthermore, genes with roles in reproduction and chromosome biology are enriched among genes that have histories of recurrent adaptive protein evolution. Together, these genome-wide analyses suggest that genetic conflict and frequent positive natural

  12. Comparative Genomics Reveals the Origins and Diversity of Arthropod Immune Systems.

    Science.gov (United States)

    Palmer, William J; Jiggins, Francis M

    2015-08-01

    Insects are an important model for the study of innate immune systems, but remarkably little is known about the immune system of other arthropod groups despite their importance as disease vectors, pests, and components of biological diversity. Using comparative genomics, we have characterized the immune system of all the major groups of arthropods beyond insects for the first time--studying five chelicerates, a myriapod, and a crustacean. We found clear traces of an ancient origin of innate immunity, with some arthropods having Toll-like receptors and C3-complement factors that are more closely related in sequence or structure to vertebrates than other arthropods. Across the arthropods some components of the immune system, such as the Toll signaling pathway, are highly conserved. However, there is also remarkable diversity. The chelicerates apparently lack the Imd signaling pathway and beta-1,3 glucan binding proteins--a key class of pathogen recognition receptors. Many genes have large copy number variation across species, and this may sometimes be accompanied by changes in function. For example, we find that peptidoglycan recognition proteins have frequently lost their catalytic activity and switch between secreted and intracellular forms. We also find that there has been widespread and extensive duplication of the cellular immune receptor Dscam (Down syndrome cell adhesion molecule), which may be an alternative way to generate the high diversity produced by alternative splicing in insects. In the antiviral short interfering RNAi pathway Argonaute 2 evolves rapidly and is frequently duplicated, with a highly variable copy number. Our results provide a detailed analysis of the immune systems of several important groups of animals for the first time and lay the foundations for functional work on these groups. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  13. Comparative genome analysis of PHB gene family reveals deep evolutionary origins and diverse gene function.

    Science.gov (United States)

    Di, Chao; Xu, Wenying; Su, Zhen; Yuan, Joshua S

    2010-10-07

    PHB (Prohibitin) gene family is involved in a variety of functions important for different biological processes. PHB genes are ubiquitously present in divergent species from prokaryotes to eukaryotes. Human PHB genes have been found to be associated with various diseases. Recent studies by our group and others have shown diverse function of PHB genes in plants for development, senescence, defence, and others. Despite the importance of the PHB gene family, no comprehensive gene family analysis has been carried to evaluate the relatedness of PHB genes across different species. In order to better guide the gene function analysis and understand the evolution of the PHB gene family, we therefore carried out the comparative genome analysis of the PHB genes across different kingdoms. The relatedness, motif distribution, and intron/exon distribution all indicated that PHB genes is a relatively conserved gene family. The PHB genes can be classified into 5 classes and each class have a very deep evolutionary origin. The PHB genes within the class maintained the same motif patterns during the evolution. With Arabidopsis as the model species, we found that PHB gene intron/exon structure and domains are also conserved during the evolution. Despite being a conserved gene family, various gene duplication events led to the expansion of the PHB genes. Both segmental and tandem gene duplication were involved in Arabidopsis PHB gene family expansion. However, segmental duplication is predominant in Arabidopsis. Moreover, most of the duplicated genes experienced neofunctionalization. The results highlighted that PHB genes might be involved in important functions so that the duplicated genes are under the evolutionary pressure to derive new function. PHB gene family is a conserved gene family and accounts for diverse but important biological functions based on the similar molecular mechanisms. The highly diverse biological function indicated that more research needs to be carried out

  14. Exceptional diversity, non-random distribution, and rapid evolution of retroelements in the B73 maize genome.

    Directory of Open Access Journals (Sweden)

    Regina S Baucom

    2009-11-01

    Full Text Available Recent comprehensive sequence analysis of the maize genome now permits detailed discovery and description of all transposable elements (TEs in this complex nuclear environment. Reiteratively optimized structural and homology criteria were used in the computer-assisted search for retroelements, TEs that transpose by reverse transcription of an RNA intermediate, with the final results verified by manual inspection. Retroelements were found to occupy the majority (>75% of the nuclear genome in maize inbred B73. Unprecedented genetic diversity was discovered in the long terminal repeat (LTR retrotransposon class of retroelements, with >400 families (>350 newly discovered contributing >31,000 intact elements. The two other classes of retroelements, SINEs (four families and LINEs (at least 30 families, were observed to contribute 1,991 and approximately 35,000 copies, respectively, or a combined approximately 1% of the B73 nuclear genome. With regard to fully intact elements, median copy numbers for all retroelement families in maize was 2 because >250 LTR retrotransposon families contained only one or two intact members that could be detected in the B73 draft sequence. The majority, perhaps all, of the investigated retroelement families exhibited non-random dispersal across the maize genome, with LINEs, SINEs, and many low-copy-number LTR retrotransposons exhibiting a bias for accumulation in gene-rich regions. In contrast, most (but not all medium- and high-copy-number LTR retrotransposons were found to preferentially accumulate in gene-poor regions like pericentromeric heterochromatin, while a few high-copy-number families exhibited the opposite bias. Regions of the genome with the highest LTR retrotransposon density contained the lowest LTR retrotransposon diversity. These results indicate that the maize genome provides a great number of different niches for the survival and procreation of a great variety of retroelements that have evolved to

  15. Vast diversity of prokaryotic virus genomes encoding double jelly-roll major capsid proteins uncovered by genomic and metagenomic sequence analysis.

    Science.gov (United States)

    Yutin, Natalya; Bäckström, Disa; Ettema, Thijs J G; Krupovic, Mart; Koonin, Eugene V

    2018-04-10

    Analysis of metagenomic sequences has become the principal approach for the study of the diversity of viruses. Many recent, extensive metagenomic studies on several classes of viruses have dramatically expanded the visible part of the virosphere, showing that previously undetected viruses, or those that have been considered rare, actually are important components of the global virome. We investigated the provenance of viruses related to tail-less bacteriophages of the family Tectiviridae by searching genomic and metagenomics sequence databases for distant homologs of the tectivirus-like Double Jelly-Roll major capsid proteins (DJR MCP). These searches resulted in the identification of numerous genomes of virus-like elements that are similar in size to tectiviruses (10-15 kilobases) and have diverse gene compositions. By comparison of the gene repertoires, the DJR MCP-encoding genomes were classified into 6 distinct groups that can be predicted to differ in reproduction strategies and host ranges. Only the DJR MCP gene that is present by design is shared by all these genomes, and most also encode a predicted DNA-packaging ATPase; the rest of the genes are present only in subgroups of this unexpectedly diverse collection of DJR MCP-encoding genomes. Only a minority encode a DNA polymerase which is a hallmark of the family Tectiviridae and the putative family "Autolykiviridae". Notably, one of the identified putative DJR MCP viruses encodes a homolog of Cas1 endonuclease, the integrase involved in CRISPR-Cas adaptation and integration of transposon-like elements called casposons. This is the first detected occurrence of Cas1 in a virus. Many of the identified elements are individual contigs flanked by inverted or direct repeats and appear to represent complete, extrachromosomal viral genomes, whereas others are flanked by bacterial genes and thus can be considered as proviruses. These contigs come from metagenomes of widely different environments, some dominated by

  16. Genome mining of the genetic diversity in the Aspergillus genus - from a collection of more than 30 Aspergillus species

    DEFF Research Database (Denmark)

    Rasmussen, Jane Lind Nybo; Vesth, Tammi Camilla; Theobald, Sebastian

    In the era of high-throughput sequencing, comparative genomics can be applied for evaluating species diversity. In this project we aim to compare the genomes of 300 species of filamentous fungi from the Aspergillus genus, a complex task. To be able to define species, clade, and core features......, this project uses BLAST on the amino acid level to discover orthologs. With a potential of 300 Aspergillus species each having ~12,000 annotated genes, traditional clustering will demand supercomputing. Instead, our approach reduces the search space by identifying isoenzymes within each genome creating...... intragenomic protein families (iPFs), and then connecting iPFs across all genomes. The initial findings in a set of 31 species show that ~48% of the annotated genes are core genes (genes shared between all species) and 2-24% of the genes are defining the individual species. The methods presented here...

  17. Trait variation and genetic diversity in a banana genomic selection training population.

    Directory of Open Access Journals (Sweden)

    Moses Nyine

    Full Text Available Banana (Musa spp. is an important crop in the African Great Lakes region in terms of income and food security, with the highest per capita consumption worldwide. Pests, diseases and climate change hamper sustainable production of bananas. New breeding tools with increased crossbreeding efficiency are being investigated to breed for resistant, high yielding hybrids of East African Highland banana (EAHB. These include genomic selection (GS, which will benefit breeding through increased genetic gain per unit time. Understanding trait variation and the correlation among economically important traits is an essential first step in the development and selection of suitable GS models for banana. In this study, we tested the hypothesis that trait variations in bananas are not affected by cross combination, cycle, field management and their interaction with genotype. A training population created using EAHB breeding material and its progeny was phenotyped in two contrasting conditions. A high level of correlation among vegetative and yield related traits was observed. Therefore, genomic selection models could be developed for traits that are easily measured. It is likely that the predictive ability of traits that are difficult to phenotype will be similar to less difficult traits they are highly correlated with. Genotype response to cycle and field management practices varied greatly with respect to traits. Yield related traits accounted for 31-35% of principal component variation under low and high input field management conditions. Resistance to Black Sigatoka was stable across cycles but varied under different field management depending on the genotype. The best cross combination was 1201K-1xSH3217 based on selection response (R of hybrids. Genotyping using simple sequence repeat (SSR markers revealed that the training population was genetically diverse, reflecting a complex pedigree background, which was mostly influenced by the male parents.

  18. Trait variation and genetic diversity in a banana genomic selection training population.

    Science.gov (United States)

    Nyine, Moses; Uwimana, Brigitte; Swennen, Rony; Batte, Michael; Brown, Allan; Christelová, Pavla; Hřibová, Eva; Lorenzen, Jim; Doležel, Jaroslav

    2017-01-01

    Banana (Musa spp.) is an important crop in the African Great Lakes region in terms of income and food security, with the highest per capita consumption worldwide. Pests, diseases and climate change hamper sustainable production of bananas. New breeding tools with increased crossbreeding efficiency are being investigated to breed for resistant, high yielding hybrids of East African Highland banana (EAHB). These include genomic selection (GS), which will benefit breeding through increased genetic gain per unit time. Understanding trait variation and the correlation among economically important traits is an essential first step in the development and selection of suitable GS models for banana. In this study, we tested the hypothesis that trait variations in bananas are not affected by cross combination, cycle, field management and their interaction with genotype. A training population created using EAHB breeding material and its progeny was phenotyped in two contrasting conditions. A high level of correlation among vegetative and yield related traits was observed. Therefore, genomic selection models could be developed for traits that are easily measured. It is likely that the predictive ability of traits that are difficult to phenotype will be similar to less difficult traits they are highly correlated with. Genotype response to cycle and field management practices varied greatly with respect to traits. Yield related traits accounted for 31-35% of principal component variation under low and high input field management conditions. Resistance to Black Sigatoka was stable across cycles but varied under different field management depending on the genotype. The best cross combination was 1201K-1xSH3217 based on selection response (R) of hybrids. Genotyping using simple sequence repeat (SSR) markers revealed that the training population was genetically diverse, reflecting a complex pedigree background, which was mostly influenced by the male parents.

  19. Trait variation and genetic diversity in a banana genomic selection training population

    Science.gov (United States)

    Nyine, Moses; Uwimana, Brigitte; Swennen, Rony; Batte, Michael; Brown, Allan; Christelová, Pavla; Hřibová, Eva; Lorenzen, Jim

    2017-01-01

    Banana (Musa spp.) is an important crop in the African Great Lakes region in terms of income and food security, with the highest per capita consumption worldwide. Pests, diseases and climate change hamper sustainable production of bananas. New breeding tools with increased crossbreeding efficiency are being investigated to breed for resistant, high yielding hybrids of East African Highland banana (EAHB). These include genomic selection (GS), which will benefit breeding through increased genetic gain per unit time. Understanding trait variation and the correlation among economically important traits is an essential first step in the development and selection of suitable GS models for banana. In this study, we tested the hypothesis that trait variations in bananas are not affected by cross combination, cycle, field management and their interaction with genotype. A training population created using EAHB breeding material and its progeny was phenotyped in two contrasting conditions. A high level of correlation among vegetative and yield related traits was observed. Therefore, genomic selection models could be developed for traits that are easily measured. It is likely that the predictive ability of traits that are difficult to phenotype will be similar to less difficult traits they are highly correlated with. Genotype response to cycle and field management practices varied greatly with respect to traits. Yield related traits accounted for 31–35% of principal component variation under low and high input field management conditions. Resistance to Black Sigatoka was stable across cycles but varied under different field management depending on the genotype. The best cross combination was 1201K-1xSH3217 based on selection response (R) of hybrids. Genotyping using simple sequence repeat (SSR) markers revealed that the training population was genetically diverse, reflecting a complex pedigree background, which was mostly influenced by the male parents. PMID:28586365

  20. Comparative genomics of plant-associated Pseudomonas spp.: insights into diversity and inheritance of traits involved in multitrophic interactions.

    Directory of Open Access Journals (Sweden)

    Joyce E Loper

    2012-07-01

    Full Text Available We provide here a comparative genome analysis of ten strains within the Pseudomonas fluorescens group including seven new genomic sequences. These strains exhibit a diverse spectrum of traits involved in biological control and other multitrophic interactions with plants, microbes, and insects. Multilocus sequence analysis placed the strains in three sub-clades, which was reinforced by high levels of synteny, size of core genomes, and relatedness of orthologous genes between strains within a sub-clade. The heterogeneity of the P. fluorescens group was reflected in the large size of its pan-genome, which makes up approximately 54% of the pan-genome of the genus as a whole, and a core genome representing only 45-52% of the genome of any individual strain. We discovered genes for traits that were not known previously in the strains, including genes for the biosynthesis of the siderophores achromobactin and pseudomonine and the antibiotic 2-hexyl-5-propyl-alkylresorcinol; novel bacteriocins; type II, III, and VI secretion systems; and insect toxins. Certain gene clusters, such as those for two type III secretion systems, are present only in specific sub-clades, suggesting vertical inheritance. Almost all of the genes associated with multitrophic interactions map to genomic regions present in only a subset of the strains or unique to a specific strain. To explore the evolutionary origin of these genes, we mapped their distributions relative to the locations of mobile genetic elements and repetitive extragenic palindromic (REP elements in each genome. The mobile genetic elements and many strain-specific genes fall into regions devoid of REP elements (i.e., REP deserts and regions displaying atypical tri-nucleotide composition, possibly indicating relatively recent acquisition of these loci. Collectively, the results of this study highlight the enormous heterogeneity of the P. fluorescens group and the importance of the variable genome in tailoring

  1. Challenges and strategies for implementing genomic services in diverse settings: experiences from the Implementing GeNomics In pracTicE (IGNITE) network.

    Science.gov (United States)

    Sperber, Nina R; Carpenter, Janet S; Cavallari, Larisa H; J Damschroder, Laura; Cooper-DeHoff, Rhonda M; Denny, Joshua C; Ginsburg, Geoffrey S; Guan, Yue; Horowitz, Carol R; Levy, Kenneth D; Levy, Mia A; Madden, Ebony B; Matheny, Michael E; Pollin, Toni I; Pratt, Victoria M; Rosenman, Marc; Voils, Corrine I; W Weitzel, Kristen; Wilke, Russell A; Ryanne Wu, R; Orlando, Lori A

    2017-05-22

    To realize potential public health benefits from genetic and genomic innovations, understanding how best to implement the innovations into clinical care is important. The objective of this study was to synthesize data on challenges identified by six diverse projects that are part of a National Human Genome Research Institute (NHGRI)-funded network focused on implementing genomics into practice and strategies to overcome these challenges. We used a multiple-case study approach with each project considered as a case and qualitative methods to elicit and describe themes related to implementation challenges and strategies. We describe challenges and strategies in an implementation framework and typology to enable consistent definitions and cross-case comparisons. Strategies were linked to challenges based on expert review and shared themes. Three challenges were identified by all six projects, and strategies to address these challenges varied across the projects. One common challenge was to increase the relative priority of integrating genomics within the health system electronic health record (EHR). Four projects used data warehousing techniques to accomplish the integration. The second common challenge was to strengthen clinicians' knowledge and beliefs about genomic medicine. To overcome this challenge, all projects developed educational materials and conducted meetings and outreach focused on genomic education for clinicians. The third challenge was engaging patients in the genomic medicine projects. Strategies to overcome this challenge included use of mass media to spread the word, actively involving patients in implementation (e.g., a patient advisory board), and preparing patients to be active participants in their healthcare decisions. This is the first collaborative evaluation focusing on the description of genomic medicine innovations implemented in multiple real-world clinical settings. Findings suggest that strategies to facilitate integration of genomic

  2. Probing Genomic Aspects of the Multi-Host Pathogen Clostridium perfringens Reveals Significant Pangenome Diversity, and a Diverse Array of Virulence Factors

    Directory of Open Access Journals (Sweden)

    Raymond Kiu

    2017-12-01

    Full Text Available Clostridium perfringens is an important cause of animal and human infections, however information about the genetic makeup of this pathogenic bacterium is currently limited. In this study, we sought to understand and characterise the genomic variation, pangenomic diversity, and key virulence traits of 56 C. perfringens strains which included 51 public, and 5 newly sequenced and annotated genomes using Whole Genome Sequencing. Our investigation revealed that C. perfringens has an “open” pangenome comprising 11667 genes and 12.6% of core genes, identified as the most divergent single-species Gram-positive bacterial pangenome currently reported. Our computational analyses also defined C. perfringens phylogeny (16S rRNA gene in relation to some 25 Clostridium species, with C. baratii and C. sardiniense determined to be the closest relatives. Profiling virulence-associated factors confirmed presence of well-characterised C. perfringens-associated exotoxins genes including α-toxin (plc, enterotoxin (cpe, and Perfringolysin O (pfo or pfoA, although interestingly there did not appear to be a close correlation with encoded toxin type and disease phenotype. Furthermore, genomic analysis indicated significant horizontal gene transfer events as defined by presence of prophage genomes, and notably absence of CRISPR defence systems in >70% (40/56 of the strains. In relation to antimicrobial resistance mechanisms, tetracycline resistance genes (tet and anti-defensins genes (mprF were consistently detected in silico (tet: 75%; mprF: 100%. However, pre-antibiotic era strain genomes did not encode for tet, thus implying antimicrobial selective pressures in C. perfringens evolutionary history over the past 80 years. This study provides new genomic understanding of this genetically divergent multi-host bacterium, and further expands our knowledge on this medically and veterinary important pathogen.

  3. Probing Genomic Aspects of the Multi-Host Pathogen Clostridium perfringens Reveals Significant Pangenome Diversity, and a Diverse Array of Virulence Factors.

    Science.gov (United States)

    Kiu, Raymond; Caim, Shabhonam; Alexander, Sarah; Pachori, Purnima; Hall, Lindsay J

    2017-01-01

    Clostridium perfringens is an important cause of animal and human infections, however information about the genetic makeup of this pathogenic bacterium is currently limited. In this study, we sought to understand and characterise the genomic variation, pangenomic diversity, and key virulence traits of 56 C. perfringens strains which included 51 public, and 5 newly sequenced and annotated genomes using Whole Genome Sequencing. Our investigation revealed that C. perfringens has an "open" pangenome comprising 11667 genes and 12.6% of core genes, identified as the most divergent single-species Gram-positive bacterial pangenome currently reported. Our computational analyses also defined C. perfringens phylogeny (16S rRNA gene) in relation to some 25 Clostridium species, with C. baratii and C. sardiniense determined to be the closest relatives. Profiling virulence-associated factors confirmed presence of well-characterised C. perfringens -associated exotoxins genes including α-toxin ( plc ), enterotoxin ( cpe ), and Perfringolysin O ( pfo or pfoA ), although interestingly there did not appear to be a close correlation with encoded toxin type and disease phenotype. Furthermore, genomic analysis indicated significant horizontal gene transfer events as defined by presence of prophage genomes, and notably absence of CRISPR defence systems in >70% (40/56) of the strains. In relation to antimicrobial resistance mechanisms, tetracycline resistance genes ( tet ) and anti-defensins genes ( mprF ) were consistently detected in silico ( tet : 75%; mprF : 100%). However, pre-antibiotic era strain genomes did not encode for tet , thus implying antimicrobial selective pressures in C. perfringens evolutionary history over the past 80 years. This study provides new genomic understanding of this genetically divergent multi-host bacterium, and further expands our knowledge on this medically and veterinary important pathogen.

  4. Culture Phenotypes of Genomically and Geographically Diverse Mycobacterium avium subsp. paratuberculosis Isolates from Different Hosts▿

    Science.gov (United States)

    Whittington, Richard J.; Marsh, Ian B.; Saunders, Vanessa; Grant, Irene R.; Juste, Ramon; Sevilla, Iker A.; Manning, Elizabeth J. B.; Whitlock, Robert H.

    2011-01-01

    Mycobacterium avium subsp. paratuberculosis causes paratuberculosis (Johne's disease) in ruminants in most countries. Historical data suggest substantial differences in culturability of M. avium subsp. paratuberculosis isolates from small ruminants and cattle; however, a systematic comparison of culture media and isolates from different countries and hosts has not been undertaken. Here, 35 field isolates from the United States, Spain, Northern Ireland, and Australia were propagated in Bactec 12B medium and Middlebrook 7H10 agar, genomically characterized, and subcultured to Lowenstein-Jensen (LJ), Herrold's egg yolk (HEY), modified Middlebrook 7H10, Middlebrook 7H11, and Watson-Reid (WR) agars, all with and without mycobactin J and some with sodium pyruvate. Fourteen genotypes of M. avium subsp. paratuberculosis were represented as determined by BstEII IS900 and IS1311 restriction fragment length polymorphism analysis. There was no correlation between genotype and overall culturability, although most S strains tended to grow poorly on HEY agar. Pyruvate was inhibitory to some isolates. All strains grew on modified Middlebrook 7H10 agar but more slowly and less prolifically on LJ agar. Mycobactin J was required for growth on all media except 7H11 agar, but growth was improved by the addition of mycobactin J to 7H11 agar. WR agar supported the growth of few isolates. The differences in growth of M. avium subsp. paratuberculosis that have historically been reported in diverse settings have been strongly influenced by the type of culture medium used. When an optimal culture medium, such as modified Middlebrook 7H10 agar, is used, very little difference between the growth phenotypes of diverse strains of M. avium subsp. paratuberculosis was observed. This optimal medium is recommended to remove bias in the isolation and cultivation of M. avium subsp. paratuberculosis. PMID:21430104

  5. Diversity

    Science.gov (United States)

    Portraits In Courage Vol. VIII Portraits In Courage Vol. IX Portraits In Courage Vol. X AF Sites Social -Wide Initiative to Promote Diversity and Inclusion in the Federal Workforce Executive Order 13548 : Virtual Diversity Conference Air Force Diversity & Inclusion Air Force Diversity Graphic There is no

  6. Selection for silage yield and composition did not affect genomic diversity within the Wisconsin Quality Synthetic maize population.

    Science.gov (United States)

    Lorenz, Aaron J; Beissinger, Timothy M; Silva, Renato Rodrigues; de Leon, Natalia

    2015-02-02

    Maize silage is forage of high quality and yield, and represents the second most important use of maize in the United States. The Wisconsin Quality Synthetic (WQS) maize population has undergone five cycles of recurrent selection for silage yield and composition, resulting in a genetically improved population. The application of high-density molecular markers allows breeders and geneticists to identify important loci through association analysis and selection mapping, as well as to monitor changes in the distribution of genetic diversity across the genome. The objectives of this study were to identify loci controlling variation for maize silage traits through association analysis and the assessment of selection signatures and to describe changes in the genomic distribution of gene diversity through selection and genetic drift in the WQS recurrent selection program. We failed to find any significant marker-trait associations using the historical phenotypic data from WQS breeding trials combined with 17,719 high-quality, informative single nucleotide polymorphisms. Likewise, no strong genomic signatures were left by selection on silage yield and quality in the WQS despite genetic gain for these traits. These results could be due to the genetic complexity underlying these traits, or the role of selection on standing genetic variation. Variation in loss of diversity through drift was observed across the genome. Some large regions experienced much greater loss in diversity than what is expected, suggesting limited recombination combined with small populations in recurrent selection programs could easily lead to fixation of large swaths of the genome. Copyright © 2015 Lorenz et al.

  7. Genetic and genomic diversity studies of Acacia symbionts in Senegal reveal new species of Mesorhizobium with a putative geographical pattern.

    Directory of Open Access Journals (Sweden)

    Fatou Diouf

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

  8. Genetic and genomic diversity studies of Acacia symbionts in Senegal reveal new species of Mesorhizobium with a putative geographical pattern.

    Science.gov (United States)

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

    2015-01-01

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

  9. Population genomic analysis reveals differential evolutionary histories and patterns of diversity across subgenomes and subpopulations of Brassica napus L.

    Directory of Open Access Journals (Sweden)

    Elodie eGazave

    2016-04-01

    Full Text Available The allotetraploid species Brassica napus L. is a global crop of major economic importance, providing canola oil (seed and vegetables for human consumption and fodder and meal for livestock feed. Characterizing the genetic diversity present in the extant germplasm pool of B. napus is fundamental to better conserve, manage and utilize the genetic resources of this species. We used sequence-based genotyping to identify and genotype 30,881 SNPs in a diversity panel of 782 B. napus accessions, representing samples of winter and spring growth habits originating from 33 countries across Europe, Asia and America. We detected strong population structure broadly concordant with growth habit and geography, and identified three major genetic groups: spring (SP, winter Europe (WE, and winter Asia (WA. Subpopulation-specific polymorphism patterns suggest enriched genetic diversity within the WA group and a smaller effective breeding population for the SP group compared to WE. Interestingly, the two subgenomes of B. napus appear to have different geographic origins, with phylogenetic analysis placing WE and WA as basal clades for the other subpopulations in the C and A subgenomes, respectively. Finally, we identified 16 genomic regions where the patterns of diversity differed markedly from the genome-wide average, several of which are suggestive of genomic inversions. The results obtained in this study constitute a valuable resource for worldwide breeding efforts and the genetic dissection and prediction of complex B. napus traits.

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

    Science.gov (United States)

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

    2016-05-12

    In regions where malaria is endemic, individuals are often infected with multiple distinct parasite genotypes, a situation that may impact on evolution of parasite virulence and drug resistance. Most approaches to studying genotypic diversity have involved analysis of a modest number of polymorphic loci, although whole genome sequencing enables a broader characterisation of samples. PCR-based microsatellite typing of a panel of ten loci was performed on Plasmodium falciparum in 95 clinical isolates from a highly endemic area in the Republic of Guinea, to characterize within-isolate genetic diversity. Separately, single nucleotide polymorphism (SNP) data from genome-wide short-read sequences of the same samples were used to derive within-isolate fixation indices (F ws), an inverse measure of diversity within each isolate compared to overall local genetic diversity. The latter indices were compared with the microsatellite results, and also with indices derived by randomly sampling modest numbers of SNPs. As expected, the number of microsatellite loci with more than one allele in each isolate was highly significantly inversely correlated with the genome-wide F ws fixation index (r = -0.88, P 10 % had high correlation (r > 0.90) with the index derived using all SNPs. Different types of data give highly correlated indices of within-infection diversity, although PCR-based analysis detects low-level minority genotypes not apparent in bulk sequence analysis. When whole-genome data are not obtainable, quantitative assay of ten or more SNPs can yield a reasonably accurate estimate of the within-infection fixation index (F ws).

  11. Integrating Diverse Types of Genomic Data to Identify Genes that Underlie Adverse Pregnancy Phenotypes.

    Directory of Open Access Journals (Sweden)

    Jibril Hirbo

    Full Text Available Progress in understanding complex genetic diseases has been bolstered by synthetic approaches that overlay diverse data types and analyses to identify functionally important genes. Pre-term birth (PTB, a major complication of pregnancy, is a leading cause of infant mortality worldwide. A major obstacle in addressing PTB is that the mechanisms controlling parturition and birth timing remain poorly understood. Integrative approaches that overlay datasets derived from comparative genomics with function-derived ones have potential to advance our understanding of the genetics of birth timing, and thus provide insights into the genes that may contribute to PTB. We intersected data from fast evolving coding and non-coding gene regions in the human and primate lineage with data from genes expressed in the placenta, from genes that show enriched expression only in the placenta, as well as from genes that are differentially expressed in four distinct PTB clinical subtypes. A large fraction of genes that are expressed in placenta, and differentially expressed in PTB clinical subtypes (23-34% are fast evolving, and are associated with functions that include adhesion neurodevelopmental and immune processes. Functional categories of genes that express fast evolution in coding regions differ from those linked to fast evolution in non-coding regions. Finally, there is a surprising lack of overlap between fast evolving genes that are differentially expressed in four PTB clinical subtypes. Integrative approaches, especially those that incorporate evolutionary perspectives, can be successful in identifying potential genetic contributions to complex genetic diseases, such as PTB.

  12. Hunter-gatherer genomic diversity suggests a southern African origin for modern humans.

    Science.gov (United States)

    Henn, Brenna M; Gignoux, Christopher R; Jobin, Matthew; Granka, Julie M; Macpherson, J M; Kidd, Jeffrey M; Rodríguez-Botigué, Laura; Ramachandran, Sohini; Hon, Lawrence; Brisbin, Abra; Lin, Alice A; Underhill, Peter A; Comas, David; Kidd, Kenneth K; Norman, Paul J; Parham, Peter; Bustamante, Carlos D; Mountain, Joanna L; Feldman, Marcus W

    2011-03-29

    Africa is inferred to be the continent of origin for all modern human populations, but the details of human prehistory and evolution in Africa remain largely obscure owing to the complex histories of hundreds of distinct populations. We present data for more than 580,000 SNPs for several hunter-gatherer populations: the Hadza and Sandawe of Tanzania, and the ≠Khomani Bushmen of South Africa, including speakers of the nearly extinct N|u language. We find that African hunter-gatherer populations today remain highly differentiated, encompassing major components of variation that are not found in other African populations. Hunter-gatherer populations also tend to have the lowest levels of genome-wide linkage disequilibrium among 27 African populations. We analyzed geographic patterns of linkage disequilibrium and population differentiation, as measured by F(ST), in Africa. The observed patterns are consistent with an origin of modern humans in southern Africa rather than eastern Africa, as is generally assumed. Additionally, genetic variation in African hunter-gatherer populations has been significantly affected by interaction with farmers and herders over the past 5,000 y, through both severe population bottlenecks and sex-biased migration. However, African hunter-gatherer populations continue to maintain the highest levels of genetic diversity in the world.

  13. Human Genome Diversity Project. Summary of planning workshop 3(B): Ethical and human-rights implications

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    The third planning workshop of the Human Genome Diversity Project was held on the campus of the US National Institutes of Health in Bethesda, Maryland, from February 16 through February 18, 1993. The second day of the workshop was devoted to an exploration of the ethical and human-rights implications of the Project. This open meeting centered on three roundtables, involving 12 invited participants, and the resulting discussions among all those present. Attendees and their affiliations are listed in the attached Appendix A. The discussion was guided by a schedule and list of possible issues, distributed to all present and attached as Appendix B. This is a relatively complete, and thus lengthy, summary of the comments at the meeting. The beginning of the summary sets out as conclusions some issues on which there appeared to be widespread agreement, but those conclusions are not intended to serve as a set of detailed recommendations. The meeting organizer is distributing his recommendations in a separate memorandum; recommendations from others who attended the meeting are welcome and will be distributed by the meeting organizer to the participants and to the Project committee.

  14. Analysis of genetic diversity in Brown Swiss, Jersey and Holstein populations using genome-wide single nucleotide polymorphism markers

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    Melka Melkaye G

    2012-03-01

    Full Text Available Abstract Background Studies of genetic diversity are essential in understanding the extent of differentiation between breeds, and in designing successful diversity conservation strategies. The objective of this study was to evaluate the level of genetic diversity within and between North American Brown Swiss (BS, n = 900, Jersey (JE, n = 2,922 and Holstein (HO, n = 3,535 cattle, using genotyped bulls. GENEPOP and FSTAT software were used to evaluate the level of genetic diversity within each breed and between each pair of the three breeds based on genome-wide SNP markers (n = 50,972. Results Hardy-Weinberg equilibrium (HWE exact test within breeds showed a significant deviation from equilibrium within each population (P st indicated that the combination of BS and HO in an ideally amalgamated population had higher genetic diversity than the other pairs of breeds. Conclusion Results suggest that the three bull populations have substantially different gene pools. BS and HO show the largest gene differentiation and jointly the highest total expected gene diversity compared to when JE is considered. If the loss of genetic diversity within breeds worsens in the future, the use of crossbreeding might be an option to recover genetic diversity, especially for the breeds with small population size.

  15. The Pinus taeda genome is characterized by diverse and highly diverged repetitive sequences

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    Yandell Mark

    2010-07-01

    Full Text Available Abstract Background In today's age of genomic discovery, no attempt has been made to comprehensively sequence a gymnosperm genome. The largest genus in the coniferous family Pinaceae is Pinus, whose 110-120 species have extremely large genomes (c. 20-40 Gb, 2N = 24. The size and complexity of these genomes have prompted much speculation as to the feasibility of completing a conifer genome sequence. Conifer genomes are reputed to be highly repetitive, but there is little information available on the nature and identity of repetitive units in gymnosperms. The pines have extensive genetic resources, with approximately 329000 ESTs from eleven species and genetic maps in eight species, including a dense genetic map of the twelve linkage groups in Pinus taeda. Results We present here the Sanger sequence and annotation of ten P. taeda BAC clones and Genome Analyzer II whole genome shotgun (WGS sequences representing 7.5% of the genome. Computational annotation of ten BACs predicts three putative protein-coding genes and at least fifteen likely pseudogenes in nearly one megabase of sequence. We found three conifer-specific LTR retroelements in the BACs, and tentatively identified at least 15 others based on evidence from the distantly related angiosperms. Alignment of WGS sequences to the BACs indicates that 80% of BAC sequences have similar copies (≥ 75% nucleotide identity elsewhere in the genome, but only 23% have identical copies (99% identity. The three most common repetitive elements in the genome were identified and, when combined, represent less than 5% of the genome. Conclusions This study indicates that the majority of repeats in the P. taeda genome are 'novel' and will therefore require additional BAC or genomic sequencing for accurate characterization. The pine genome contains a very large number of diverged and probably defunct repetitive elements. This study also provides new evidence that sequencing a pine genome using a WGS approach is

  16. Study on the thermodynamics of the gadolinium-hydrogen binary system (H/Gd = 0.0–2.0) and implications to metallic gadolinium purification

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Kai; Li, Guoling [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Department of Materials Physics and Chemistry, University of Science and Technology Beijing, NO. 30, Xueyuan Road, Beijing 100083 (China); Li, Jigang [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Liu, Yang [Department of Food Science, College of Arts and Science, Beijing Union University, Beijing, 100101 (China); Tian, Wenhuai, E-mail: wenhuaitian@ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, NO. 30, Xueyuan Road, Beijing 100083 (China); Zheng, Jie [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Li, Xingguo, E-mail: xgli@pku.edu.cn [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2016-07-15

    The thermodynamics of the gadolinium-hydrogen (Gd–H) binary system (H/Gd = 0.0–2.0) between 650 and 900 °C is studied by pressure composition isotherm measurement. Significant H dissolution in Gd is observed, up to H/Gd = 0.34 at 650 °C and 0.55 at 900 °C. The metal-rich phase boundary of nonstoichiometric gadolinium dihydride was found to occur with nominal composition of GdH{sub 1.80} at 650 °C and GdH{sub 1.53} at 900 °C. The results are in fairly good agreement with previous experimental work but with improved accuracy. The binary phase diagram is obtained using the CALPHAD method. The thermodynamic study here assists the understanding on the efficient deoxygenation effect by the H in Gd for Gd purification. - Highlights: • PCI measurements with high accuracy has been carried out. • A first assessment of Gd–H system has been carried out by the CALPHAD method. • A set of self-consistent thermodynamic parameters was derived for this system.

  17. Large Diversity of Nonstandard Genes and Dynamic Evolution of Chloroplast Genomes in Siphonous Green Algae (Bryopsidales, Chlorophyta).

    Science.gov (United States)

    Cremen, Ma Chiela M; Leliaert, Frederik; Marcelino, Vanessa R; Verbruggen, Heroen

    2018-04-01

    Chloroplast genomes have undergone tremendous alterations through the evolutionary history of the green algae (Chloroplastida). This study focuses on the evolution of chloroplast genomes in the siphonous green algae (order Bryopsidales). We present five new chloroplast genomes, which along with existing sequences, yield a data set representing all but one families of the order. Using comparative phylogenetic methods, we investigated the evolutionary dynamics of genomic features in the order. Our results show extensive variation in chloroplast genome architecture and intron content. Variation in genome size is accounted for by the amount of intergenic space and freestanding open reading frames that do not show significant homology to standard plastid genes. We show the diversity of these nonstandard genes based on their conserved protein domains, which are often associated with mobile functions (reverse transcriptase/intron maturase, integrases, phage- or plasmid-DNA primases, transposases, integrases, ligases). Investigation of the introns showed proliferation of group II introns in the early evolution of the order and their subsequent loss in the core Halimedineae, possibly through RT-mediated intron loss.

  18. Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax.

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    Thais C de Oliveira

    2017-07-01

    Full Text Available The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax.We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences, Peru (PER, n = 23, Colombia (COL, n = 31, and Mexico (MEX, n = 19.We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10-4 and 6.2 × 10-4 as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092. Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between parasite lineages from geographically

  19. Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax.

    Science.gov (United States)

    de Oliveira, Thais C; Rodrigues, Priscila T; Menezes, Maria José; Gonçalves-Lopes, Raquel M; Bastos, Melissa S; Lima, Nathália F; Barbosa, Susana; Gerber, Alexandra L; Loss de Morais, Guilherme; Berná, Luisa; Phelan, Jody; Robello, Carlos; de Vasconcelos, Ana Tereza R; Alves, João Marcelo P; Ferreira, Marcelo U

    2017-07-01

    The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax. We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences), Peru (PER, n = 23), Colombia (COL, n = 31), and Mexico (MEX, n = 19). We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10-4 and 6.2 × 10-4) as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed) in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o) gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092). Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between parasite lineages from geographically diverse sites

  20. Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax

    Science.gov (United States)

    de Oliveira, Thais C.; Rodrigues, Priscila T.; Menezes, Maria José; Gonçalves-Lopes, Raquel M.; Bastos, Melissa S.; Lima, Nathália F.; Barbosa, Susana; Gerber, Alexandra L.; Loss de Morais, Guilherme; Berná, Luisa; Phelan, Jody; Robello, Carlos; de Vasconcelos, Ana Tereza R.

    2017-01-01

    Background The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax. Methods We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences), Peru (PER, n = 23), Colombia (COL, n = 31), and Mexico (MEX, n = 19). Principal findings/Conclusions We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10−4 and 6.2 × 10−4) as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed) in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o) gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092). Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between

  1. Genetic diversity and structure of elite cotton germplasm (Gossypium hirsutum L.) using genome-wide SNP data.

    Science.gov (United States)

    Ai, XianTao; Liang, YaJun; Wang, JunDuo; Zheng, JuYun; Gong, ZhaoLong; Guo, JiangPing; Li, XueYuan; Qu, YanYing

    2017-10-01

    Cotton (Gossypium spp.) is the most important natural textile fiber crop, and Gossypium hirsutum L. is responsible for 90% of the annual cotton crop in the world. Information on cotton genetic diversity and population structure is essential for new breeding lines. In this study, we analyzed population structure and genetic diversity of 288 elite Gossypium hirsutum cultivar accessions collected from around the world, and especially from China, using genome-wide single nucleotide polymorphisms (SNP) markers. The average polymorphsim information content (PIC) was 0.25, indicating a relatively low degree of genetic diversity. Population structure analysis revealed extensive admixture and identified three subgroups. Phylogenetic analysis supported the subgroups identified by STRUCTURE. The results from both population structure and phylogenetic analysis were, for the most part, in agreement with pedigree information. Analysis of molecular variance revealed a larger amount of variation was due to diversity within the groups. Establishment of genetic diversity and population structure from this study could be useful for genetic and genomic analysis and systematic utilization of the standing genetic variation in upland cotton.

  2. Pan-genome analysis of Aeromonas hydrophila, Aeromonas veronii and Aeromonas caviae indicates phylogenomic diversity and greater pathogenic potential for Aeromonas hydrophila.

    Science.gov (United States)

    Ghatak, Sandeep; Blom, Jochen; Das, Samir; Sanjukta, Rajkumari; Puro, Kekungu; Mawlong, Michael; Shakuntala, Ingudam; Sen, Arnab; Goesmann, Alexander; Kumar, Ashok; Ngachan, S V

    2016-07-01

    Aeromonas species are important pathogens of fishes and aquatic animals capable of infecting humans and other animals via food. Due to the paucity of pan-genomic studies on aeromonads, the present study was undertaken to analyse the pan-genome of three clinically important Aeromonas species (A. hydrophila, A. veronii, A. caviae). Results of pan-genome analysis revealed an open pan-genome for all three species with pan-genome sizes of 9181, 7214 and 6884 genes for A. hydrophila, A. veronii and A. caviae, respectively. Core-genome: pan-genome ratio (RCP) indicated greater genomic diversity for A. hydrophila and interestingly RCP emerged as an effective indicator to gauge genomic diversity which could possibly be extended to other organisms too. Phylogenomic network analysis highlighted the influence of homologous recombination and lateral gene transfer in the evolution of Aeromonas spp. Prediction of virulence factors indicated no significant difference among the three species though analysis of pathogenic potential and acquired antimicrobial resistance genes revealed greater hazards from A. hydrophila. In conclusion, the present study highlighted the usefulness of whole genome analyses to infer evolutionary cues for Aeromonas species which indicated considerable phylogenomic diversity for A. hydrophila and hitherto unknown genomic evidence for pathogenic potential of A. hydrophila compared to A. veronii and A. caviae.

  3. Genome sequence and genetic diversity of the common carp, Cyprinus carpio.

    Science.gov (United States)

    Xu, Peng; Zhang, Xiaofeng; Wang, Xumin; Li, Jiongtang; Liu, Guiming; Kuang, Youyi; Xu, Jian; Zheng, Xianhu; Ren, Lufeng; Wang, Guoliang; Zhang, Yan; Huo, Linhe; Zhao, Zixia; Cao, Dingchen; Lu, Cuiyun; Li, Chao; Zhou, Yi; Liu, Zhanjiang; Fan, Zhonghua; Shan, Guangle; Li, Xingang; Wu, Shuangxiu; Song, Lipu; Hou, Guangyuan; Jiang, Yanliang; Jeney, Zsigmond; Yu, Dan; Wang, Li; Shao, Changjun; Song, Lai; Sun, Jing; Ji, Peifeng; Wang, Jian; Li, Qiang; Xu, Liming; Sun, Fanyue; Feng, Jianxin; Wang, Chenghui; Wang, Shaolin; Wang, Baosen; Li, Yan; Zhu, Yaping; Xue, Wei; Zhao, Lan; Wang, Jintu; Gu, Ying; Lv, Weihua; Wu, Kejing; Xiao, Jingfa; Wu, Jiayan; Zhang, Zhang; Yu, Jun; Sun, Xiaowen

    2014-11-01

    The common carp, Cyprinus carpio, is one of the most important cyprinid species and globally accounts for 10% of freshwater aquaculture production. Here we present a draft genome of domesticated C. carpio (strain Songpu), whose current assembly contains 52,610 protein-coding genes and approximately 92.3% coverage of its paleotetraploidized genome (2n = 100). The latest round of whole-genome duplication has been estimated to have occurred approximately 8.2 million years ago. Genome resequencing of 33 representative individuals from worldwide populations demonstrates a single origin for C. carpio in 2 subspecies (C. carpio Haematopterus and C. carpio carpio). Integrative genomic and transcriptomic analyses were used to identify loci potentially associated with traits including scaling patterns and skin color. In combination with the high-resolution genetic map, the draft genome paves the way for better molecular studies and improved genome-assisted breeding of C. carpio and other closely related species.

  4. Comparative Genomic Analysis Reveals a Diverse Repertoire of Genes Involved in Prokaryote-Eukaryote Interactions within the Pseudovibrio Genus.

    Science.gov (United States)

    Romano, Stefano; Fernàndez-Guerra, Antonio; Reen, F Jerry; Glöckner, Frank O; Crowley, Susan P; O'Sullivan, Orla; Cotter, Paul D; Adams, Claire; Dobson, Alan D W; O'Gara, Fergal

    2016-01-01

    Strains of the Pseudovibrio genus have been detected worldwide, mainly as part of bacterial communities associated with marine invertebrates, particularly sponges. This recurrent association has been considered as an indication of a symbiotic relationship between these microbes and their host. Until recently, the availability of only two genomes, belonging to closely related strains, has limited the knowledge on the genomic and physiological features of the genus to a single phylogenetic lineage. Here we present 10 newly sequenced genomes of Pseudovibrio strains isolated from marine sponges from the west coast of Ireland, and including the other two publicly available genomes we performed an extensive comparative genomic analysis. Homogeneity was apparent in terms of both the orthologous genes and the metabolic features shared amongst the 12 strains. At the genomic level, a key physiological difference observed amongst the isolates was the presence only in strain P. axinellae AD2 of genes encoding proteins involved in assimilatory nitrate reduction, which was then proved experimentally. We then focused on studying those systems known to be involved in the interactions with eukaryotic and prokaryotic cells. This analysis revealed that the genus harbors a large diversity of toxin-like proteins, secretion systems and their potential effectors. Their distribution in the genus was not always consistent with the phylogenetic relationship of the strains. Finally, our analyses identified new genomic islands encoding potential toxin-immunity systems, previously unknown in the genus. Our analyses shed new light on the Pseudovibrio genus, indicating a large diversity of both metabolic features and systems for interacting with the host. The diversity in both distribution and abundance of these systems amongst the strains underlines how metabolically and phylogenetically similar bacteria may use different strategies to interact with the host and find a niche within its

  5. High-resolution genetic map for understanding the effect of genome-wide recombination rate on nucleotide diversity in watermelon.

    Science.gov (United States)

    Reddy, Umesh K; Nimmakayala, Padma; Levi, Amnon; Abburi, Venkata Lakshmi; Saminathan, Thangasamy; Tomason, Yan R; Vajja, Gopinath; Reddy, Rishi; Abburi, Lavanya; Wehner, Todd C; Ronin, Yefim; Karol, Abraham

    2014-09-15

    We used genotyping by sequencing to identify a set of 10,480 single nucleotide polymorphism (SNP) markers for constructing a high-resolution genetic map of 1096 cM for watermelon. We assessed the genome-wide variation in recombination rate (GWRR) across the map and found an association between GWRR and genome-wide nucleotide diversity. Collinearity between the map and the genome-wide reference sequence for watermelon was studied to identify inconsistency and chromosome rearrangements. We assessed genome-wide nucleotide diversity, linkage disequilibrium (LD), and selective sweep for wild, semi-wild, and domesticated accessions of Citrullus lanatus var. lanatus to track signals of domestication. Principal component analysis combined with chromosome-wide phylogenetic study based on 1563 SNPs obtained after LD pruning with minor allele frequency of 0.05 resolved the differences between semi-wild and wild accessions as well as relationships among worldwide sweet watermelon. Population structure analysis revealed predominant ancestries for wild, semi-wild, and domesticated watermelons as well as admixture of various ancestries that were important for domestication. Sliding window analysis of Tajima's D across various chromosomes was used to resolve selective sweep. LD decay was estimated for various chromosomes. We identified a strong selective sweep on chromosome 3 consisting of important genes that might have had a role in sweet watermelon domestication. Copyright © 2014 Reddy et al.

  6. Comparative genomic and functional analyses: unearthing the diversity and specificity of nematicidal factors in Pseudomonas putida strain 1A00316

    Science.gov (United States)

    Guo, Jing; Jing, Xueping; Peng, Wen-Lei; Nie, Qiyu; Zhai, Yile; Shao, Zongze; Zheng, Longyu; Cai, Minmin; Li, Guangyu; Zuo, Huaiyu; Zhang, Zhitao; Wang, Rui-Ru; Huang, Dian; Cheng, Wanli; Yu, Ziniu; Chen, Ling-Ling; Zhang, Jibin

    2016-01-01

    We isolated Pseudomonas putida (P. putida) strain 1A00316 from Antarctica. This bacterium has a high efficiency against Meloidogyne incognita (M. incognita) in vitro and under greenhouse conditions. The complete genome of P. putida 1A00316 was sequenced using PacBio single molecule real-time (SMRT) technology. A comparative genomic analysis of 16 Pseudomonas strains revealed that although P. putida 1A00316 belonged to P. putida, it was phenotypically more similar to nematicidal Pseudomonas fluorescens (P. fluorescens) strains. We characterized the diversity and specificity of nematicidal factors in P. putida 1A00316 with comparative genomics and functional analysis, and found that P. putida 1A00316 has diverse nematicidal factors including protein alkaline metalloproteinase AprA and two secondary metabolites, hydrogen cyanide and cyclo-(l-isoleucyl-l-proline). We show for the first time that cyclo-(l-isoleucyl-l-proline) exhibit nematicidal activity in P. putida. Interestingly, our study had not detected common nematicidal factors such as 2,4-diacetylphloroglucinol (2,4-DAPG) and pyrrolnitrin in P. putida 1A00316. The results of the present study reveal the diversity and specificity of nematicidal factors in P. putida strain 1A00316. PMID:27384076

  7. Intraspecies genomic diversity and natural population structure of the meat-borne lactic acid bacterium Lactobacillus sakei.

    Science.gov (United States)

    Chaillou, Stéphane; Daty, Marie; Baraige, Fabienne; Dudez, Anne-Marie; Anglade, Patricia; Jones, Rhys; Alpert, Carl-Alfred; Champomier-Vergès, Marie-Christine; Zagorec, Monique

    2009-02-01

    Lactobacillus sakei is a food-borne bacterium naturally found in meat and fish products. A study was performed to examine the intraspecies diversity among 73 isolates sourced from laboratory collections in several different countries. Pulsed-field gel electrophoresis analysis demonstrated a 25% variation in genome size between isolates, ranging from 1,815 kb to 2,310 kb. The relatedness between isolates was then determined using a PCR-based method that detects the possession of 60 chromosomal genes belonging to the flexible gene pool. Ten different strain clusters were identified that had noticeable differences in their average genome size reflecting the natural population structure. The results show that many different genotypes may be isolated from similar types of meat products, suggesting a complex ecological habitat in which intraspecies diversity may be required for successful adaptation. Finally, proteomic analysis revealed a slight difference between the migration patterns of highly abundant GapA isoforms of the two prevailing L. sakei subspecies (sakei and carnosus). This analysis was used to affiliate the genotypic clusters with the corresponding subspecies. These findings reveal for the first time the extent of intraspecies genomic diversity in L. sakei. Consequently, identification of molecular subtypes may in the future prove valuable for a better understanding of microbial ecosystems in food products.

  8. Comparative genomic analysis of 45 type strains of the genus Bifidobacterium: a snapshot of its genetic diversity and evolution.

    Directory of Open Access Journals (Sweden)

    Zhihong Sun

    Full Text Available Bifidobacteria are well known for their human health-promoting effects and are therefore widely applied in the food industry. Members of the Bifidobacterium genus were first identified from the human gastrointestinal tract and were then found to be widely distributed across various ecological niches. Although the genetic diversity of Bifidobacterium has been determined based on several marker genes or a few genomes, the global diversity and evolution scenario for the entire genus remain unresolved. The present study comparatively analyzed the genomes of 45 type strains. We built a robust genealogy for Bifidobacterium based on 402 core genes and defined its root according to the phylogeny of the tree of bacteria. Our results support that all human isolates are of younger lineages, and although species isolated from bees dominate the more ancient lineages, the bee was not necessarily the original host for bifidobacteria. Moreover, the species isolated from different hosts are enriched with specific gene sets, suggesting host-specific adaptation. Notably, bee-specific genes are strongly associated with respiratory metabolism and are potential in helping those bacteria adapt to the oxygen-rich gut environment in bees. This study provides a snapshot of the genetic diversity and evolution of Bifidobacterium, paving the way for future studies on the taxonomy and functional genomics of the genus.

  9. Genomic patterns of nucleotide diversity in divergent populations of U.S. weedy rice

    Directory of Open Access Journals (Sweden)

    Olsen Kenneth M

    2010-06-01

    Full Text Available Abstract Background Weedy rice (red rice, a conspecific weed of cultivated rice (Oryza sativa L., is a significant problem throughout the world and an emerging threat in regions where it was previously absent. Despite belonging to the same species complex as domesticated rice and its wild relatives, the evolutionary origins of weedy rice remain unclear. We use genome-wide patterns of single nucleotide polymorphism (SNP variation in a broad geographic sample of weedy, domesticated, and wild Oryza samples to infer the origin and demographic processes influencing U.S. weedy rice evolution. Results We find greater population structure than has been previously reported for U.S. weedy rice, and that the multiple, genetically divergent populations have separate origins. The two main U.S. weedy rice populations share genetic backgrounds with cultivated O. sativa varietal groups not grown commercially in the U.S., suggesting weed origins from domesticated ancestors. Hybridization between weedy groups and between weedy rice and local crops has also led to the evolution of distinct U.S. weedy rice populations. Demographic simulations indicate differences among the main weedy groups in the impact of bottlenecks on their establishment in the U.S., and in the timing of divergence from their cultivated relatives. Conclusions Unlike prior research, we did not find unambiguous evidence for U.S. weedy rice originating via hybridization between cultivated and wild Oryza species. Our results demonstrate the potential for weedy life-histories to evolve directly from within domesticated lineages. The diverse origins of U.S. weedy rice populations demonstrate the multiplicity of evolutionary forces that can influence the emergence of weeds from a single species complex.

  10. Genomic Analysis of Hospital Plumbing Reveals Diverse Reservoir of Bacterial Plasmids Conferring Carbapenem Resistance

    Directory of Open Access Journals (Sweden)

    Rebecca A. Weingarten

    2018-02-01

    Full Text Available The hospital environment is a potential reservoir of bacteria with plasmids conferring carbapenem resistance. Our Hospital Epidemiology Service routinely performs extensive sampling of high-touch surfaces, sinks, and other locations in the hospital. Over a 2-year period, additional sampling was conducted at a broader range of locations, including housekeeping closets, wastewater from hospital internal pipes, and external manholes. We compared these data with previously collected information from 5 years of patient clinical and surveillance isolates. Whole-genome sequencing and analysis of 108 isolates provided comprehensive characterization of blaKPC/blaNDM-positive isolates, enabling an in-depth genetic comparison. Strikingly, despite a very low prevalence of patient infections with blaKPC-positive organisms, all samples from the intensive care unit pipe wastewater and external manholes contained carbapenemase-producing organisms (CPOs, suggesting a vast, resilient reservoir. We observed a diverse set of species and plasmids, and we noted species and susceptibility profile differences between environmental and patient populations of CPOs. However, there were plasmid backbones common to both populations, highlighting a potential environmental reservoir of mobile elements that may contribute to the spread of resistance genes. Clear associations between patient and environmental isolates were uncommon based on sequence analysis and epidemiology, suggesting reasonable infection control compliance at our institution. Nonetheless, a probable nosocomial transmission of Leclercia sp. from the housekeeping environment to a patient was detected by this extensive surveillance. These data and analyses further our understanding of CPOs in the hospital environment and are broadly relevant to the design of infection control strategies in many infrastructure settings.

  11. Mitochondrial Genome Diversity of Native Americans Supports a Single Early Entry of Founder Populations into America

    Science.gov (United States)

    Silva Jr., Wilson A.; Bonatto, Sandro L.; Holanda, Adriano J.; Ribeiro-dos-Santos, Andrea K.; Paixão, Beatriz M.; Goldman, Gustavo H.; Abe-Sandes, Kiyoko; Rodriguez-Delfin, Luis; Barbosa, Marcela; Paçó-Larson, Maria Luiza; Petzl-Erler, Maria Luiza; Valente, Valeria; Santos, Sidney E. B.; Zago, Marco A.

    2002-01-01

    There is general agreement that the Native American founder populations migrated from Asia into America through Beringia sometime during the Pleistocene, but the hypotheses concerning the ages and the number of these migrations and the size of the ancestral populations are surrounded by controversy. DNA sequence variations of several regions of the genome of Native Americans, especially in the mitochondrial DNA (mtDNA) control region, have been studied as a tool to help answer these questions. However, the small number of nucleotides studied and the nonclocklike rate of mtDNA control-region evolution impose several limitations to these results. Here we provide the sequence analysis of a continuous region of 8.8 kb of the mtDNA outside the D-loop for 40 individuals, 30 of whom are Native Americans whose mtDNA belongs to the four founder haplogroups. Haplogroups A, B, and C form monophyletic clades, but the five haplogroup D sequences have unstable positions and usually do not group together. The high degree of similarity in the nucleotide diversity and time of differentiation (i.e., ∼21,000 years before present) of these four haplogroups support a common origin for these sequences and suggest that the populations who harbor them may also have a common history. Additional evidence supports the idea that this age of differentiation coincides with the process of colonization of the New World and supports the hypothesis of a single and early entry of the ancestral Asian population into the Americas. PMID:12022039

  12. Genome-wide analysis of gene expression in primate taste buds reveals links to diverse processes.

    Directory of Open Access Journals (Sweden)

    Peter Hevezi

    Full Text Available Efforts to unravel the mechanisms underlying taste sensation (gustation have largely focused on rodents. Here we present the first comprehensive characterization of gene expression in primate taste buds. Our findings reveal unique new insights into the biology of taste buds. We generated a taste bud gene expression database using laser capture microdissection (LCM procured fungiform (FG and circumvallate (CV taste buds from primates. We also used LCM to collect the top and bottom portions of CV taste buds. Affymetrix genome wide arrays were used to analyze gene expression in all samples. Known taste receptors are preferentially expressed in the top portion of taste buds. Genes associated with the cell cycle and stem cells are preferentially expressed in the bottom portion of taste buds, suggesting that precursor cells are located there. Several chemokines including CXCL14 and CXCL8 are among the highest expressed genes in taste buds, indicating that immune system related processes are active in taste buds. Several genes expressed specifically in endocrine glands including growth hormone releasing hormone and its receptor are also strongly expressed in taste buds, suggesting a link between metabolism and taste. Cell type-specific expression of transcription factors and signaling molecules involved in cell fate, including KIT, reveals the taste bud as an active site of cell regeneration, differentiation, and development. IKBKAP, a gene mutated in familial dysautonomia, a disease that results in loss of taste buds, is expressed in taste cells that communicate with afferent nerve fibers via synaptic transmission. This database highlights the power of LCM coupled with transcriptional profiling to dissect the molecular composition of normal tissues, represents the most comprehensive molecular analysis of primate taste buds to date, and provides a foundation for further studies in diverse aspects of taste biology.

  13. Genomic diversity in Mycobacterium leprae isolates from leprosy cases in South India.

    Science.gov (United States)

    Das, Madhusmita; Chaitanya, V Sundeep; Kanmani, K; Rajan, Lakshmi; Ebenezer, Mannam

    2016-11-01

    The Objective of this study was to identify the strain diversity of Mycobacterium leprae in terms of SNP types and subtypes stratified as per genomic single nucleotide polymorphisms, in clinical isolates of leprosy patients from a tertiary care leprosy center in South India. Further, the associations of SNP types with clinical outcomes in leprosy were also investigated. DNA was extracted from excisional skin biopsies of a total of 172 newly diagnosed untreated leprosy patients from a clinic in Tamil Nadu, in south India, that also serves patients from neighboring states. All the leprosy patients were those who voluntarily reported at the clinic during the study period of one year i.e., 2015. Clinical and histopathological details were collected at diagnosis and leprosy was confirmed through bacteriological smear examination and PCR for M. leprae specific RLEP region. SNP types and subtypes were determined by PCR amplification and Sanger sequencing of PCR products. M. leprae specific RLEP gene amplification was achieved in 160 out of 172 patients. Among 160 specimens 118(73.75%) were type 1 and 42 (26.25%) were type 2 and on subtyping it was noted that 88/160 (55.00%) were 1D, 25/160 (15.62%) 1C, 5/160 (3.12%) 1A, 33/160 (20.62%) 2G and 9/160 (5.62%) were 2H. Our results indicated that subtype 1D is predominant in the south Indian population. We also noted 2G, 1C and 1A in the patient sample tested. Additionally we identified subtype 2H for the first time in India. Copyright © 2016. Published by Elsevier B.V.

  14. Genome Structural Diversity among 31 Bordetella pertussis Isolates from Two Recent U.S. Whooping Cough Statewide Epidemics.

    Science.gov (United States)

    Bowden, Katherine E; Weigand, Michael R; Peng, Yanhui; Cassiday, Pamela K; Sammons, Scott; Knipe, Kristen; Rowe, Lori A; Loparev, Vladimir; Sheth, Mili; Weening, Keeley; Tondella, M Lucia; Williams, Margaret M

    2016-01-01

    During 2010 and 2012, California and Vermont, respectively, experienced statewide epidemics of pertussis with differences seen in the demographic affected, case clinical presentation, and molecular epidemiology of the circulating strains. To overcome limitations of the current molecular typing methods for pertussis, we utilized whole-genome sequencing to gain a broader understanding of how current circulating strains are causing large epidemics. Through the use of combined next-generation sequencing technologies, this study compared de novo, single-contig genome assemblies from 31 out of 33 Bordetella pertussis isolates collected during two separate pertussis statewide epidemics and 2 resequenced vaccine strains. Final genome architecture assemblies were verified with whole-genome optical mapping. Sixteen distinct genome rearrangement profiles were observed in epidemic isolate genomes, all of which were distinct from the genome structures of the two resequenced vaccine strains. These rearrangements appear to be mediated by repetitive sequence elements, such as high-copy-number mobile genetic elements and rRNA operons. Additionally, novel and previously identified single nucleotide polymorphisms were detected in 10 virulence-related genes in the epidemic isolates. Whole-genome variation analysis identified state-specific variants, and coding regions bearing nonsynonymous mutations were classified into functional annotated orthologous groups. Comprehensive studies on whole genomes are needed to understand the resurgence of pertussis and develop novel tools to better characterize the molecular epidemiology of evolving B. pertussis populations. IMPORTANCE Pertussis, or whooping cough, is the most poorly controlled vaccine-preventable bacterial disease in the United States, which has experienced a resurgence for more than a decade. Once viewed as a monomorphic pathogen, B. pertussis strains circulating during epidemics exhibit diversity visible on a genome structural

  15. Hidden diversity revealed by genome-resolved metagenomics of iron-oxidizing microbial mats from Lō'ihi Seamount, Hawai'i.

    Science.gov (United States)

    Fullerton, Heather; Hager, Kevin W; McAllister, Sean M; Moyer, Craig L

    2017-08-01

    The Zetaproteobacteria are ubiquitous in marine environments, yet this class of Proteobacteria is only represented by a few closely-related cultured isolates. In high-iron environments, such as diffuse hydrothermal vents, the Zetaproteobacteria are important members of the community driving its structure. Biogeography of Zetaproteobacteria has shown two ubiquitous operational taxonomic units (OTUs), yet much is unknown about their genomic diversity. Genome-resolved metagenomics allows for the specific binning of microbial genomes based on genomic signatures present in composite metagenome assemblies. This resulted in the recovery of 93 genome bins, of which 34 were classified as Zetaproteobacteria. Form II ribulose 1,5-bisphosphate carboxylase genes were recovered from nearly all the Zetaproteobacteria genome bins. In addition, the Zetaproteobacteria genome bins contain genes for uptake and utilization of bioavailable nitrogen, detoxification of arsenic, and a terminal electron acceptor adapted for low oxygen concentration. Our results also support the hypothesis of a Cyc2-like protein as the site for iron oxidation, now detected across a majority of the Zetaproteobacteria genome bins. Whole genome comparisons showed a high genomic diversity across the Zetaproteobacteria OTUs and genome bins that were previously unidentified by SSU rRNA gene analysis. A single lineage of cosmopolitan Zetaproteobacteria (zOTU 2) was found to be monophyletic, based on cluster analysis of average nucleotide identity and average amino acid identity comparisons. From these data, we can begin to pinpoint genomic adaptations of the more ecologically ubiquitous Zetaproteobacteria, and further understand their environmental constraints and metabolic potential.

  16. Estimating variation within the genes and inferring the phylogeny of 186 sequenced diverse Escherichia coli genomes

    DEFF Research Database (Denmark)

    Kaas, Rolf Sommer; Rundsten, Carsten Friis; Ussery, David

    2012-01-01

    Background Escherichia coli exists in commensal and pathogenic forms. By measuring the variation of individual genes across more than a hundred sequenced genomes, gene variation can be studied in detail, including the number of mutations found for any given gene. This knowledge will be useful...... for creating better phylogenies, for determination of molecular clocks and for improved typing techniques. Results We find 3,051 gene clusters/families present in at least 95% of the genomes and 1,702 gene clusters present in 100% of the genomes. The former 'soft core' of about 3,000 gene families is perhaps...... more biologically relevant, especially considering that many of these genome sequences are draft quality. The E. coli pan-genome for this set of isolates contains 16,373 gene clusters. A core-gene tree, based on alignment and a pan-genome tree based on gene presence/absence, maps the relatedness...

  17. Sifting through genomes with iterative-sequence clustering produces a large, phylogenetically diverse protein-family resource.

    Science.gov (United States)

    Sharpton, Thomas J; Jospin, Guillaume; Wu, Dongying; Langille, Morgan G I; Pollard, Katherine S; Eisen, Jonathan A

    2012-10-13

    New computational resources are needed to manage the increasing volume of biological data from genome sequencing projects. One fundamental challenge is the ability to maintain a complete and current catalog of protein diversity. We developed a new approach for the identification of protein families that focuses on the rapid discovery of homologous protein sequences. We implemented fully automated and high-throughput procedures to de novo cluster proteins into families based upon global alignment similarity. Our approach employs an iterative clustering strategy in which homologs of known families are sifted out of the search for new families. The resulting reduction in computational complexity enables us to rapidly identify novel protein families found in new genomes and to perform efficient, automated updates that keep pace with genome sequencing. We refer to protein families identified through this approach as "Sifting Families," or SFams. Our analysis of ~10.5 million protein sequences from 2,928 genomes identified 436,360 SFams, many of which are not represented in other protein family databases. We validated the quality of SFam clustering through statistical as well as network topology-based analyses. We describe the rapid identification of SFams and demonstrate how they can be used to annotate genomes and metagenomes. The SFam database catalogs protein-family quality metrics, multiple sequence alignments, hidden Markov models, and phylogenetic trees. Our source code and database are publicly available and will be subject to frequent updates (http://edhar.genomecenter.ucdavis.edu/sifting_families/).

  18. Selection on Optimal Haploid Value Increases Genetic Gain and Preserves More Genetic Diversity Relative to Genomic Selection.

    Science.gov (United States)

    Daetwyler, Hans D; Hayden, Matthew J; Spangenberg, German C; Hayes, Ben J

    2015-08-01

    Doubled haploids are routinely created and phenotypically selected in plant breeding programs to accelerate the breeding cycle. Genomic selection, which makes use of both phenotypes and genotypes, has been shown to further improve genetic gain through prediction of performance before or without phenotypic characterization of novel germplasm. Additional opportunities exist to combine genomic prediction methods with the creation of doubled haploids. Here we propose an extension to genomic selection, optimal haploid value (OHV) selection, which predicts the best doubled haploid that can be produced from a segregating plant. This method focuses selection on the haplotype and optimizes the breeding program toward its end goal of generating an elite fixed line. We rigorously tested OHV selection breeding programs, using computer simulation, and show that it results in up to 0.6 standard deviations more genetic gain than genomic selection. At the same time, OHV selection preserved a substantially greater amount of genetic diversity in the population than genomic selection, which is important to achieve long-term genetic gain in breeding populations. Copyright © 2015 by the Genetics Society of America.

  19. Development of novel InDel markers and genetic diversity in Chenopodium quinoa through whole-genome re-sequencing.

    Science.gov (United States)

    Zhang, Tifu; Gu, Minfeng; Liu, Yuhe; Lv, Yuanda; Zhou, Ling; Lu, Haiyan; Liang, Shuaiqiang; Bao, Huabin; Zhao, Han

    2017-09-05

    Quinoa (Chenopodium quinoa Willd.) is a balanced nutritional crop, but its breeding improvement has been limited by the lack of information on its genetics and genomics. Therefore, it is necessary to obtain knowledge on genomic variation, population structure, and genetic diversity and to develop novel Insertion/Deletion (InDel) markers for quinoa by whole-genome re-sequencing. We re-sequenced 11 quinoa accessions and obtained a coverage depth between approximately 7× to 23× the quinoa genome. Based on the 1453-megabase (Mb) assembly from the reference accession Riobamba, 8,441,022 filtered bi-allelic single nucleotide polymorphisms (SNPs) and 842,783 filtered InDels were identified, with an estimated SNP and InDel density of 5.81 and 0.58 per kilobase (kb). From the genomic InDel variations, 85 dimorphic InDel markers were newly developed and validated. Together with the 62 simple sequence repeat (SSR) markers reported, a total of 147 markers were used for genotyping the 129 quinoa accessions. Molecular grouping analysis showed classification into two major groups, the Andean highland (composed of the northern and southern highland subgroups) and Chilean coastal, based on combined STRUCTURE, phylogenetic tree and PCA (Principle Component Analysis) analyses. Further analysis of the genetic diversity exhibited a decreasing tendency from the Chilean coast group to the Andean highland group, and the gene flow between subgroups was more frequent than that between the two subgroups and the Chilean coastal group. The majority of the variations (approximately 70%) were found through an analysis of molecular variation (AMOVA) due to the diversity between the groups. This was congruent with the observation of a highly significant F ST value (0.705) between the groups, demonstrating significant genetic differentiation between the Andean highland type of quinoa and the Chilean coastal type. Moreover, a core set of 16 quinoa germplasms that capture all 362 alleles was

  20. Microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility

    Directory of Open Access Journals (Sweden)

    Nieto Pamela A

    2008-11-01

    uptake systems could reflect their obligatory occupation of extremely low pH environments where high concentrations of soluble iron may always be available and were oxidized sulfur species might not compromise iron speciation dynamics. Presence of bacterioferritin in the Acidithiobacilli, polyphosphate accumulation functions and variants of FieF-like diffusion facilitators in both Acidithiobacilli and Leptospirilla, indicate that they may remove or store iron under conditions of variable availability. In addition, the Fe(II-oxidizing capacity of both A. ferrooxidans and Leptospirilla could itself be a way to evade iron stress imposed by readily available Fe(II ions at low pH. Fur regulatory sites have been predicted for a number of gene clusters including iron related and non-iron related functions in both the Acidithiobacilli and Leptospirilla, laying the foundation for the future discovery of iron regulated and iron-phosphate coordinated regulatory control circuits. Conclusion In silico analyses of the genomes of acidophilic bacteria are beginning to tease apart the mechanisms that mediate iron uptake and homeostasis in low pH environments. Initial models pinpoint significant differences in abundance and diversity of iron management mechanisms between Leptospirilla and Acidithiobacilli, and begin to reveal how these two groups respond to iron cycling and iron fluctuations in naturally acidic environments and in industrial operations. Niche partitions and ecological successions between acidophilic microorganisms may be partially explained by these observed differences. Models derived from these analyses pave the way for improved hypothesis testing and well directed experimental investigation. In addition, aspects of these models should challenge investigators to evaluate alternative iron management strategies in non-acidophilic model organisms.

  1. Comparison of 26 sphingomonad genomes reveals diverse environmental adaptations and biodegradative capabilities

    DEFF Research Database (Denmark)

    Aylward, Frank O.; McDonald, Bradon R.; Adams, Sandra M.

    2013-01-01

    to the genus Sphingobium. Our pan-genomic analysis of sphingomonads reveals numerous species-specific open reading frames (ORFs) but few signatures of genus-specific cores. The organization and coding potential of the sphingomonad genomes appear to be highly variable, and plasmid-mediated gene transfer...... and chromosome-plasmid recombination, together with prophage- and transposon-mediated rearrangements, appear to play prominent roles in the genome evolution of this group. We find that many of the sphingomonad genomes encode numerous oxygenases and glycoside hydrolases, which are likely responsible...... a basis for understanding the ecological strategies employed by sphingomonads and their role in environmental nutrient cycling....

  2. Defining the diverse spectrum of inversions, complex structural variation, and chromothripsis in the morbid human genome.

    Science.gov (United States)

    Collins, Ryan L; Brand, Harrison; Redin, Claire E; Hanscom, Carrie; Antolik, Caroline; Stone, Matthew R; Glessner, Joseph T; Mason, Tamara; Pregno, Giulia; Dorrani, Naghmeh; Mandrile, Giorgia; Giachino, Daniela; Perrin, Danielle; Walsh, Cole; Cipicchio, Michelle; Costello, Maura; Stortchevoi, Alexei; An, Joon-Yong; Currall, Benjamin B; Seabra, Catarina M; Ragavendran, Ashok; Margolin, Lauren; Martinez-Agosto, Julian A; Lucente, Diane; Levy, Brynn; Sanders, Stephan J; Wapner, Ronald J; Quintero-Rivera, Fabiola; Kloosterman, Wigard; Talkowski, Michael E

    2017-03-06

    Structural variation (SV) influences genome organization and contributes to human disease. However, the complete mutational spectrum of SV has not been routinely captured in disease association studies. We sequenced 689 participants with autism spectrum disorder (ASD) and other developmental abnormalities to construct a genome-wide map of large SV. Using long-insert jumping libraries at 105X mean physical coverage and linked-read whole-genome sequencing from 10X Genomics, we document seven major SV classes at ~5 kb SV resolution. Our results encompass 11,735 distinct large SV sites, 38.1% of which are novel and 16.8% of which are balanced or complex. We characterize 16 recurrent subclasses of complex SV (cxSV), revealing that: (1) cxSV are larger and rarer than canonical SV; (2) each genome harbors 14 large cxSV on average; (3) 84.4% of large cxSVs involve inversion; and (4) most large cxSV (93.8%) have not been delineated in previous studies. Rare SVs are more likely to disrupt coding and regulatory non-coding loci, particularly when truncating constrained and disease-associated genes. We also identify multiple cases of catastrophic chromosomal rearrangements known as chromoanagenesis, including somatic chromoanasynthesis, and extreme balanced germline chromothripsis events involving up to 65 breakpoints and 60.6 Mb across four chromosomes, further defining rare categories of extreme cxSV. These data provide a foundational map of large SV in the morbid human genome and demonstrate a previously underappreciated abundance and diversity of cxSV that should be considered in genomic studies of human disease.

  3. A high-density Diversity Arrays Technology (DArT microarray for genome-wide genotyping in Eucalyptus

    Directory of Open Access Journals (Sweden)

    Myburg Alexander A

    2010-06-01

    Full Text Available Abstract Background A number of molecular marker technologies have allowed important advances in the understanding of the genetics and evolution of Eucalyptus, a genus that includes over 700 species, some of which are used worldwide in plantation forestry. Nevertheless, the average marker density achieved with current technologies remains at the level of a few hundred markers per population. Furthermore, the transferability of markers produced with most existing technology across species and pedigrees is usually very limited. High throughput, combined with wide genome coverage and high transferability are necessary to increase the resolution, speed and utility of molecular marker technology in eucalypts. We report the development of a high-density DArT genome profiling resource and demonstrate its potential for genome-wide diversity analysis and linkage mapping in several species of Eucalyptus. Findings After testing several genome complexity reduction methods we identified the PstI/TaqI method as the most effective for Eucalyptus and developed 18 genomic libraries from PstI/TaqI representations of 64 different Eucalyptus species. A total of 23,808 cloned DNA fragments were screened and 13,300 (56% were found to be polymorphic among 284 individuals. After a redundancy analysis, 6,528 markers were selected for the operational array and these were supplemented with 1,152 additional clones taken from a library made from the E. grandis tree whose genome has been sequenced. Performance validation for diversity studies revealed 4,752 polymorphic markers among 174 individuals. Additionally, 5,013 markers showed segregation when screened using six inter-specific mapping pedigrees, with an average of 2,211 polymorphic markers per pedigree and a minimum of 859 polymorphic markers that were shared between any two pedigrees. Conclusions This operational DArT array will deliver 1,000-2,000 polymorphic markers for linkage mapping in most eucalypt pedigrees

  4. The dnd operon for DNA phosphorothioation modification system in Escherichia coli is located in diverse genomic islands.

    Science.gov (United States)

    Ho, Wing Sze; Ou, Hong-Yu; Yeo, Chew Chieng; Thong, Kwai Lin

    2015-03-17

    Strains of Escherichia coli that are non-typeable by pulsed-field gel electrophoresis (PFGE) due to in-gel degradation can influence their molecular epidemiological data. The DNA degradation phenotype (Dnd(+)) is mediated by the dnd operon that encode enzymes catalyzing the phosphorothioation of DNA, rendering the modified DNA susceptible to oxidative cleavage during a PFGE run. In this study, a PCR assay was developed to detect the presence of the dnd operon in Dnd(+) E. coli strains and to improve their typeability. Investigations into the genetic environments of the dnd operon in various E. coli strains led to the discovery that the dnd operon is harboured in various diverse genomic islands. The dndBCDE genes (dnd operon) were detected in all Dnd(+) E. coli strains by PCR. The addition of thiourea improved the typeability of Dnd(+) E. coli strains to 100% using PFGE and the Dnd(+) phenotype can be observed in both clonal and genetically diverse E. coli strains. Genomic analysis of 101 dnd operons from genome sequences of Enterobacteriaceae revealed that the dnd operons of the same bacterial species were generally clustered together in the phylogenetic tree. Further analysis of dnd operons of 52 E. coli genomes together with their respective immediate genetic environments revealed a total of 7 types of genetic organizations, all of which were found to be associated with genomic islands designated dnd-encoding GIs. The dnd-encoding GIs displayed mosaic structure and the genomic context of the 7 islands (with 1 representative genome from each type of genetic organization) were also highly variable, suggesting multiple recombination events. This is also the first report where two dnd operons were found within a strain although the biological implication is unknown. Surprisingly, dnd operons were frequently found in pathogenic E. coli although their link with virulence has not been explored. Genomic islands likely play an important role in facilitating the horizontal

  5. Determination of Elizabethkingia Diversity by MALDI-TOF Mass Spectrometry and Whole-Genome Sequencing

    DEFF Research Database (Denmark)

    Eriksen, Helle Brander; Gumpert, Heidi; Faurholt, Cecilie Haase

    2017-01-01

    In a hospital-acquired infection with multidrug-resistant Elizabethkingia, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene analysis identified the pathogen as Elizabethkingia miricola. Whole-genome sequencing, genus-level core genome analysis, and in...

  6. Genome-wide distribution of genetic diversity and linkage disequilibrium in a mass-selected population of maritime pine

    Science.gov (United States)

    2014-01-01

    Background The accessibility of high-throughput genotyping technologies has contributed greatly to the development of genomic resources in non-model organisms. High-density genotyping arrays have only recently been developed for some economically important species such as conifers. The potential for using genomic technologies in association mapping and breeding depends largely on the genome wide patterns of diversity and linkage disequilibrium in current breeding populations. This study aims to deepen our knowledge regarding these issues in maritime pine, the first species used for reforestation in south western Europe. Results Using a new map merging algorithm, we first established a 1,712 cM composite linkage map (comprising 1,838 SNP markers in 12 linkage groups) by bringing together three already available genetic maps. Using rigorous statistical testing based on kernel density estimation and resampling we identified cold and hot spots of recombination. In parallel, 186 unrelated trees of a mass-selected population were genotyped using a 12k-SNP array. A total of 2,600 informative SNPs allowed to describe historical recombination, genetic diversity and genetic structure of this recently domesticated breeding pool that forms the basis of much of the current and future breeding of this species. We observe very low levels of population genetic structure and find no evidence that artificial selection has caused a reduction in genetic diversity. By combining these two pieces of information, we provided the map position of 1,671 SNPs corresponding to 1,192 different loci. This made it possible to analyze the spatial pattern of genetic diversity (H e ) and long distance linkage disequilibrium (LD) along the chromosomes. We found no particular pattern in the empirical variogram of H e across the 12 linkage groups and, as expected for an outcrossing species with large effective population size, we observed an almost complete lack of long distance LD. Conclusions These

  7. Genome-wide analysis of LTR-retrotransposon diversity and its impact on the evolution of the genus Helianthus (L.).

    Science.gov (United States)

    Mascagni, Flavia; Giordani, Tommaso; Ceccarelli, Marilena; Cavallini, Andrea; Natali, Lucia

    2017-08-18

    Genome divergence by mobile elements activity and recombination is a continuous process that plays a key role in the evolution of species. Nevertheless, knowledge on retrotransposon-related variability among species belonging to the same genus is still limited. Considering the importance of the genus Helianthus, a model system for studying the ecological genetics of speciation and adaptation, we performed a comparative analysis of the repetitive genome fraction across ten species and one subspecies of sunflower, focusing on long terminal repeat retrotransposons at superfamily, lineage and sublineage levels. After determining the relative genome size of each species, genomic DNA was isolated and subjected to Illumina sequencing. Then, different assembling and clustering approaches allowed exploring the repetitive component of all genomes. On average, repetitive DNA in Helianthus species represented more than 75% of the genome, being composed mostly by long terminal repeat retrotransposons. Also, the prevalence of Gypsy over Copia superfamily was observed and, among lineages, Chromovirus was by far the most represented. Although nearly all the same sublineages are present in all species, we found considerable variability in the abundance of diverse retrotransposon lineages and sublineages, especially between annual and perennial species. This large variability should indicate that different events of amplification or loss related to these elements occurred following species separation and should have been involved in species differentiation. Our data allowed us inferring on the extent of interspecific repetitive DNA variation related to LTR-RE abundance, investigating the relationship between changes of LTR-RE abundance and the evolution of the genus, and determining the degree of coevolution of different LTR-RE lineages or sublineages between and within species. Moreover, the data suggested that LTR-RE abundance in a species was affected by the annual or perennial

  8. Genomic and transcriptomic analyses reveal differential regulation of diverse terpenoid and polyketides secondary metabolites in Hericium erinaceus.

    Science.gov (United States)

    Chen, Juan; Zeng, Xu; Yang, Yan Long; Xing, Yong Mei; Zhang, Qi; Li, Jia Mei; Ma, Ke; Liu, Hong Wei; Guo, Shun Xing

    2017-08-31

    The lion's mane mushroom Hericium erinaceus is a famous traditional medicinal fungus credited with anti-dementia activity and a producer of cyathane diterpenoid natural products (erinacines) useful against nervous system diseases. To date, few studies have explored the biosynthesis of these compounds, although their chemical synthesis is known. Here, we report the first genome and tanscriptome sequence of the medicinal fungus H. erinaceus. The size of the genome is 39.35 Mb, containing 9895 gene models. The genome of H. erinaceus reveals diverse enzymes and a large family of cytochrome P450 (CYP) proteins involved in the biosynthesis of terpenoid backbones, diterpenoids, sesquiterpenes and polyketides. Three gene clusters related to terpene biosynthesis and one gene cluster for polyketides biosynthesis (PKS) were predicted. Genes involved in terpenoid biosynthesis were generally upregulated in mycelia, while the PKS gene was upregulated in the fruiting body. Comparative genome analysis of 42 fungal species of Basidiomycota revealed that most edible and medicinal mushroom show many more gene clusters involved in terpenoid and polyketide biosynthesis compared to the pathogenic fungi. None of the gene clusters for terpenoid or polyketide biosynthesis were predicted in the poisonous mushroom Amanita muscaria. Our findings may facilitate future discovery and biosynthesis of bioactive secondary metabolites from H. erinaceus and provide fundamental information for exploring the secondary metabolites in other Basidiomycetes.

  9. Defining the diverse spectrum of inversions, complex structural variation, and chromothripsis in the morbid human genome

    NARCIS (Netherlands)

    Collins, Ryan L; Brand, Harrison; Redin, Claire E.; Hanscom, Carrie; Antolik, Caroline; Stone, Matthew R; Glessner, Joseph T.; Mason, Tamara; Pregno, Giulia; Dorrani, Naghmeh; Mandrile, Giorgia; Giachino, Daniela; Perrin, Danielle; Walsh, Cole; Cipicchio, Michelle; Costello, Maura; Stortchevoi, Alexei; An, Joon Yong; Currall, Benjamin B; Seabra, Catarina M; Ragavendran, Ashok; Margolin, Lauren; Martinez-Agosto, Julian A.; Lucente, Diane; Levy, Brynn; Sanders, Jan-Stephan; Wapner, Ronald J.; Quintero-Rivera, Fabiola; Kloosterman, Wigard; Talkowski, Michael E.

    2017-01-01

    Background: Structural variation (SV) influences genome organization and contributes to human disease. However, the complete mutational spectrum of SV has not been routinely captured in disease association studies. Results: We sequenced 689 participants with autism spectrum disorder (ASD) and other

  10. DivStat: a user-friendly tool for single nucleotide polymorphism analysis of genomic diversity.

    Directory of Open Access Journals (Sweden)

    Inês Soares

    Full Text Available Recent developments have led to an enormous increase of publicly available large genomic data, including complete genomes. The 1000 Genomes Project was a major contributor, releasing the results of sequencing a large number of individual genomes, and allowing for a myriad of large scale studies on human genetic variation. However, the tools currently available are insufficient when the goal concerns some analyses of data sets encompassing more than hundreds of base pairs and when considering haplotype sequences of single nucleotide polymorphisms (SNPs. Here, we present a new and potent tool to deal with large data sets allowing the computation of a variety of summary statistics of population genetic data, increasing the speed of data analysis.

  11. Increasing genomic diversity and evidence of constrained lifestyle evolution due to insertion sequences in Aeromonas salmonicida.

    Science.gov (United States)

    Vincent, Antony T; Trudel, Mélanie V; Freschi, Luca; Nagar, Vandan; Gagné-Thivierge, Cynthia; Levesque, Roger C; Charette, Steve J

    2016-01-12

    Aeromonads make up a group of Gram-negative bacteria that includes human and fish pathogens. The Aeromonas salmonicida species has the peculiarity of including five known subspecies. However, few studies of the genomes of A. salmonicida subspecies have been reported to date. We sequenced the genomes of additional A. salmonicida isolates, including three from India, using next-generation sequencing in order to gain a better understanding of the genomic and phylogenetic links between A. salmonicida subspecies. Their relative phylogenetic positions were confirmed by a core genome phylogeny based on 1645 gene sequences. The Indian isolates, which formed a sub-group together with A. salmonicida subsp. pectinolytica, were able to grow at either at 18 °C and 37 °C, unlike the A. salmonicida psychrophilic isolates that did not grow at 37 °C. Amino acid frequencies, GC content, tRNA composition, loss and gain of genes during evolution, pseudogenes as well as genes under positive selection and the mobilome were studied to explain this intraspecies dichotomy. Insertion sequences appeared to be an important driving force that locked the psychrophilic strains into their particular lifestyle in order to conserve their genomic integrity. This observation, based on comparative genomics, is in agreement with previous results showing that insertion sequence mobility induced by heat in A. salmonicida subspecies causes genomic plasticity, resulting in a deleterious effect on the virulence of the bacterium. We provide a proof-of-concept that selfish DNAs play a major role in the evolution of bacterial species by modeling genomes.

  12. Which Individuals To Choose To Update the Reference Population? Minimizing the Loss of Genetic Diversity in Animal Genomic Selection Programs

    Directory of Open Access Journals (Sweden)

    Sonia E. Eynard

    2018-01-01

    Full Text Available Genomic selection (GS is commonly used in livestock and increasingly in plant breeding. Relying on phenotypes and genotypes of a reference population, GS allows performance prediction for young individuals having only genotypes. This is expected to achieve fast high genetic gain but with a potential loss of genetic diversity. Existing methods to conserve genetic diversity depend mostly on the choice of the breeding individuals. In this study, we propose a modification of the reference population composition to mitigate diversity loss. Since the high cost of phenotyping is the limiting factor for GS, our findings are of major economic interest. This study aims to answer the following questions: how would decisions on the reference population affect the breeding population, and how to best select individuals to update the reference population and balance maximizing genetic gain and minimizing loss of genetic diversity? We investigated three updating strategies for the reference population: random, truncation, and optimal contribution (OC strategies. OC maximizes genetic merit for a fixed loss of genetic diversity. A French Montbéliarde dairy cattle population with 50K SNP chip genotypes and simulations over 10 generations were used to compare these different strategies using milk production as the trait of interest. Candidates were selected to update the reference population. Prediction bias and both genetic merit and diversity were measured. Changes in the reference population composition slightly affected the breeding population. Optimal contribution strategy appeared to be an acceptable compromise to maintain both genetic gain and diversity in the reference and the breeding populations.

  13. Which Individuals To Choose To Update the Reference Population? Minimizing the Loss of Genetic Diversity in Animal Genomic Selection Programs.

    Science.gov (United States)

    Eynard, Sonia E; Croiseau, Pascal; Laloë, Denis; Fritz, Sebastien; Calus, Mario P L; Restoux, Gwendal

    2018-01-04

    Genomic selection (GS) is commonly used in livestock and increasingly in plant breeding. Relying on phenotypes and genotypes of a reference population, GS allows performance prediction for young individuals having only genotypes. This is expected to achieve fast high genetic gain but with a potential loss of genetic diversity. Existing methods to conserve genetic diversity depend mostly on the choice of the breeding individuals. In this study, we propose a modification of the reference population composition to mitigate diversity loss. Since the high cost of phenotyping is the limiting factor for GS, our findings are of major economic interest. This study aims to answer the following questions: how would decisions on the reference population affect the breeding population, and how to best select individuals to update the reference population and balance maximizing genetic gain and minimizing loss of genetic diversity? We investigated three updating strategies for the reference population: random, truncation, and optimal contribution (OC) strategies. OC maximizes genetic merit for a fixed loss of genetic diversity. A French Montbéliarde dairy cattle population with 50K SNP chip genotypes and simulations over 10 generations were used to compare these different strategies using milk production as the trait of interest. Candidates were selected to update the reference population. Prediction bias and both genetic merit and diversity were measured. Changes in the reference population composition slightly affected the breeding population. Optimal contribution strategy appeared to be an acceptable compromise to maintain both genetic gain and diversity in the reference and the breeding populations. Copyright © 2018 Eynard et al.

  14. Genome‐scale diversity and niche adaptation analysis of Lactococcus lactis by comparative genome hybridization using multi‐strain arrays

    Science.gov (United States)

    Siezen, Roland J.; Bayjanov, Jumamurat R.; Felis, Giovanna E.; van der Sijde, Marijke R.; Starrenburg, Marjo; Molenaar, Douwe; Wels, Michiel; van Hijum, Sacha A. F. T.; van Hylckama Vlieg, Johan E. T.

    2011-01-01

    Summary Lactococcus lactis produces lactic acid and is widely used in the manufacturing of various fermented dairy products. However, the species is also frequently isolated from non‐dairy niches, such as fermented plant material. Recently, these non‐dairy strains have gained increasing interest, as they have been described to possess flavour‐forming activities that are rarely found in dairy isolates and have diverse metabolic properties. We performed an extensive whole‐genome diversity analysis on 39 L. lactis strains, isolated from dairy and plant sources. Comparative genome hybridization analysis with multi‐strain microarrays was used to assess presence or absence of genes and gene clusters in these strains, relative to all L. lactis sequences in public databases, whereby chromosomal and plasmid‐encoded genes were computationally analysed separately. Nearly 3900 chromosomal orthologous groups (chrOGs) were defined on basis of four sequenced chromosomes of L. lactis strains (IL1403, KF147, SK11, MG1363). Of these, 1268 chrOGs are present in at least 35 strains and represent the presently known core genome of L. lactis, and 72 chrOGs appear to be unique for L. lactis. Nearly 600 and 400 chrOGs were found to be specific for either the subspecies lactis or subspecies cremoris respectively. Strain variability was found in presence or absence of gene clusters related to growth on plant substrates, such as genes involved in the consumption of arabinose, xylan, α‐galactosides and galacturonate. Further niche‐specific differences were found in gene clusters for exopolysaccharides biosynthesis, stress response (iron transport, osmotolerance) and bacterial defence mechanisms (nisin biosynthesis). Strain variability of functions encoded on known plasmids included proteolysis, lactose fermentation, citrate uptake, metal ion resistance and exopolysaccharides biosynthesis. The present study supports the view of L. lactis as a species with a very flexible

  15. Genomic patterns in Acropora cervicornis show extensive population structure and variable genetic diversity.

    Science.gov (United States)

    Drury, Crawford; Schopmeyer, Stephanie; Goergen, Elizabeth; Bartels, Erich; Nedimyer, Ken; Johnson, Meaghan; Maxwell, Kerry; Galvan, Victor; Manfrino, Carrie; Lirman, Diego

    2017-08-01

    Threatened Caribbean coral communities can benefit from high-resolution genetic data used to inform management and conservation action. We use Genotyping by Sequencing (GBS) to investigate genetic patterns in the threatened coral, Acropora cervicornis , across the Florida Reef Tract (FRT) and the western Caribbean. Results show extensive population structure at regional scales and resolve previously unknown structure within the FRT. Different regions also exhibit up to threefold differences in genetic diversity (He), suggesting targeted management based on the goals and resources of each population is needed. Patterns of genetic diversity have a strong spatial component, and our results show Broward and the Lower Keys are among the most diverse populations in Florida. The genetic diversity of Caribbean staghorn coral is concentrated within populations and within individual reefs (AMOVA), highlighting the complex mosaic of population structure. This variance structure is similar over regional and local scales, which suggests that in situ nurseries are adequately capturing natural patterns of diversity, representing a resource that can replicate the average diversity of wild assemblages, serving to increase intraspecific diversity and potentially leading to improved biodiversity and ecosystem function. Results presented here can be translated into specific goals for the recovery of A. cervicornis , including active focus on low diversity areas, protection of high diversity and connectivity, and practical thresholds for responsible restoration.

  16. A Near-Complete Haplotype-Phased Genome of the Dikaryotic Wheat Stripe Rust Fungus Puccinia striiformis f. sp. tritici Reveals High Interhaplotype Diversity.

    Science.gov (United States)

    Schwessinger, Benjamin; Sperschneider, Jana; Cuddy, William S; Garnica, Diana P; Miller, Marisa E; Taylor, Jennifer M; Dodds, Peter N; Figueroa, Melania; Park, Robert F; Rathjen, John P

    2018-02-20

    A long-standing biological question is how evolution has shaped the genomic architecture of dikaryotic fungi. To answer this, high-quality genomic resources that enable haplotype comparisons are essential. Short-read genome assemblies for dikaryotic fungi are highly fragmented and lack haplotype-specific information due to the high heterozygosity and repeat content of these genomes. Here, we present a diploid-aware assembly of the wheat stripe rust fungus Puccinia striiformis f. sp. tritici based on long reads using the FALCON-Unzip assembler. Transcriptome sequencing data sets were used to infer high-quality gene models and identify virulence genes involved in plant infection referred to as effectors. This represents the most complete Puccinia striiformis f. sp. tritici genome assembly to date (83 Mb, 156 contigs, N 50 of 1.5 Mb) and provides phased haplotype information for over 92% of the genome. Comparisons of the phase blocks revealed high interhaplotype diversity of over 6%. More than 25% of all genes lack a clear allelic counterpart. When we investigated genome features that potentially promote the rapid evolution of virulence, we found that candidate effector genes are spatially associated with conserved genes commonly found in basidiomycetes. Yet, candidate effectors that lack an allelic counterpart are more distant from conserved genes than allelic candidate effectors and are less likely to be evolutionarily conserved within the P. striiformis species complex and Pucciniales In summary, this haplotype-phased assembly enabled us to discover novel genome features of a dikaryotic plant-pathogenic fungus previously hidden in collapsed and fragmented genome assemblies. IMPORTANCE Current representations of eukaryotic microbial genomes are haploid, hiding the genomic diversity intrinsic to diploid and polyploid life forms. This hidden diversity contributes to the organism's evolutionary potential and ability to adapt to stress conditions. Yet, it is

  17. Use of SNP markers to conserve genome-wide genetic diversity in livestock

    NARCIS (Netherlands)

    Engelsma, K.A.

    2012-01-01

    Conservation of genetic diversity in livestock breeds is important since it is, both within and between breeds, under threat. The availability of large numbers of SNP markers has resulted in new opportunities to estimate genetic diversity in more detail, and to improve prioritization of animals

  18. Entropy and Information Approaches to Genetic Diversity and its Expression: Genomic Geography

    Directory of Open Access Journals (Sweden)

    William B. Sherwin

    2010-07-01

    Full Text Available This article highlights advantages of entropy-based genetic diversity measures, at levels from gene expression to landscapes. Shannon’s entropy-based diversity is the standard for ecological communities. The exponentials of Shannon’s and the related “mutual information” excel in their ability to express diversity intuitively, and provide a generalised method of considering microscopic behaviour to make macroscopic predictions, under given conditions. The hierarchical nature of entropy and information allows integrated modeling of diversity along one DNA sequence, and between different sequences within and among populations, species, etc. The aim is to identify the formal connections between genetic diversity and the flow of information to and from the environment.

  19. Sifting through genomes with iterative-sequence clustering produces a large, phylogenetically diverse protein-family resource

    Directory of Open Access Journals (Sweden)

    Sharpton Thomas J

    2012-10-01

    Full Text Available Abstract Background New computational resources are needed to manage the increasing volume of biological data from genome sequencing projects. One fundamental challenge is the ability to maintain a complete and current catalog of protein diversity. We developed a new approach for the identification of protein families that focuses on the rapid discovery of homologous protein sequences. Results We implemented fully automated and high-throughput procedures to de novo cluster proteins into families based upon global alignment similarity. Our approach employs an iterative clustering strategy in which homologs of known families are sifted out of the search for new families. The resulting reduction in computational complexity enables us to rapidly identify novel protein families found in new genomes and to perform efficient, automated updates that keep pace with genome sequencing. We refer to protein families identified through this approach as “Sifting Families,” or SFams. Our analysis of ~10.5 million protein sequences from 2,928 genomes identified 436,360 SFams, many of which are not represented in other protein family databases. We validated the quality of SFam clustering through statistical as well as network topology–based analyses. Conclusions We describe the rapid identification of SFams and demonstrate how they can be used to annotate genomes and metagenomes. The SFam database catalogs protein-family quality metrics, multiple sequence alignments, hidden Markov models, and phylogenetic trees. Our source code and database are publicly available and will be subject to frequent updates (http://edhar.genomecenter.ucdavis.edu/sifting_families/.

  20. House spider genome uncovers evolutionary shifts in the diversity and expression of black widow venom proteins associated with extreme toxicity.

    Science.gov (United States)

    Gendreau, Kerry L; Haney, Robert A; Schwager, Evelyn E; Wierschin, Torsten; Stanke, Mario; Richards, Stephen; Garb, Jessica E

    2017-02-16

    Black widow spiders are infamous for their neurotoxic venom, which can cause extreme and long-lasting pain. This unusual venom is dominated by latrotoxins and latrodectins, two protein families virtually unknown outside of the black widow genus Latrodectus, that are difficult to study given the paucity of spider genomes. Using tissue-, sex- and stage-specific expression data, we analyzed the recently sequenced genome of the house spider (Parasteatoda tepidariorum), a close relative of black widows, to investigate latrotoxin and latrodectin diversity, expression and evolution. We discovered at least 47 latrotoxin genes in the house spider genome, many of which are tandem-arrayed. Latrotoxins vary extensively in predicted structural domains and expression, implying their significant functional diversification. Phylogenetic analyses show latrotoxins have substantially duplicated after the Latrodectus/Parasteatoda split and that they are also related to proteins found in endosymbiotic bacteria. Latrodectin genes are less numerous than latrotoxins, but analyses show their recruitment for venom function from neuropeptide hormone genes following duplication, inversion and domain truncation. While latrodectins and other peptides are highly expressed in house spider and black widow venom glands, latrotoxins account for a far smaller percentage of house spider venom gland expression. The house spider genome sequence provides novel insights into the evolution of venom toxins once considered unique to black widows. Our results greatly expand the size of the latrotoxin gene family, reinforce its narrow phylogenetic distribution, and provide additional evidence for the lateral transfer of latrotoxins between spiders and bacterial endosymbionts. Moreover, we strengthen the evidence for the evolution of latrodectin venom genes from the ecdysozoan Ion Transport Peptide (ITP)/Crustacean Hyperglycemic Hormone (CHH) neuropeptide superfamily. The lower expression of latrotoxins in

  1. Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae, an urgent threat to public health

    Science.gov (United States)

    Holt, Kathryn E.; Wertheim, Heiman; Zadoks, Ruth N.; Baker, Stephen; Whitehouse, Chris A.; Dance, David; Jenney, Adam; Connor, Thomas R.; Hsu, Li Yang; Severin, Juliëtte; Brisse, Sylvain; Cao, Hanwei; Wilksch, Jonathan; Gorrie, Claire; Schultz, Mark B.; Edwards, David J.; Nguyen, Kinh Van; Nguyen, Trung Vu; Dao, Trinh Tuyet; Mensink, Martijn; Minh, Vien Le; Nhu, Nguyen Thi Khanh; Schultsz, Constance; Kuntaman, Kuntaman; Newton, Paul N.; Moore, Catrin E.; Strugnell, Richard A.; Thomson, Nicholas R.

    2015-01-01

    Klebsiella pneumoniae is now recognized as an urgent threat to human health because of the emergence of multidrug-resistant strains associated with hospital outbreaks and hypervirulent strains associated with severe community-acquired infections. K. pneumoniae is ubiquitous in the environment and can colonize and infect both plants and animals. However, little is known about the population structure of K. pneumoniae, so it is difficult to recognize or understand the emergence of clinically important clones within this highly genetically diverse species. Here we present a detailed genomic framework for K. pneumoniae based on whole-genome sequencing of more than 300 human and animal isolates spanning four continents. Our data provide genome-wide support for the splitting of K. pneumoniae into three distinct species, KpI (K. pneumoniae), KpII (K. quasipneumoniae), and KpIII (K. variicola). Further, for K. pneumoniae (KpI), the entity most frequently associated with human infection, we show the existence of >150 deeply branching lineages including numerous multidrug-resistant or hypervirulent clones. We show K. pneumoniae has a large accessory genome approaching 30,000 protein-coding genes, including a number of virulence functions that are significantly associated with invasive community-acquired disease in humans. In our dataset, antimicrobial resistance genes were common among human carriage isolates and hospital-acquired infections, which generally lacked the genes associated with invasive disease. The convergence of virulence and resistance genes potentially could lead to the emergence of untreatable invasive K. pneumoniae infections; our data provide the whole-genome framework against which to track the emergence of such threats. PMID:26100894

  2. Coping with genetic diversity: the contribution of pathogen and human genomics to modern vaccinology

    International Nuclear Information System (INIS)

    Lemaire, D.; Barbosa, T.; Rihet, P.

    2011-01-01

    Vaccine development faces major difficulties partly because of genetic variation in both infectious organisms and humans. This causes antigenic variation in infectious agents and a high interindividual variability in the human response to the vaccine. The exponential growth of genome sequence information has induced a shift from conventional culture-based to genome-based vaccinology, and allows the tackling of challenges in vaccine development due to pathogen genetic variability. Additionally, recent advances in immunogenetics and genomics should help in the understanding of the influence of genetic factors on the interindividual and interpopulation variations in immune responses to vaccines, and could be useful for developing new vaccine strategies. Accumulating results provide evidence for the existence of a number of genes involved in protective immune responses that are induced either by natural infections or vaccines. Variation in immune responses could be viewed as the result of a perturbation of gene networks; this should help in understanding how a particular polymorphism or a combination thereof could affect protective immune responses. Here we will present: i) the first genome-based vaccines that served as proof of concept, and that provided new critical insights into vaccine development strategies; ii) an overview of genetic predisposition in infectious diseases and genetic control in responses to vaccines; iii) population genetic differences that are a rationale behind group-targeted vaccines; iv) an outlook for genetic control in infectious diseases, with special emphasis on the concept of molecular networks that will provide a structure to the huge amount of genomic data

  3. Sequence capture by hybridization to explore modern and ancient genomic diversity in model and nonmodel organisms.

    Science.gov (United States)

    Gasc, Cyrielle; Peyretaillade, Eric; Peyret, Pierre

    2016-06-02

    The recent expansion of next-generation sequencing has significantly improved biological research. Nevertheless, deep exploration of genomes or metagenomic samples remains difficult because of the sequencing depth and the associated costs required. Therefore, different partitioning strategies have been developed to sequence informative subsets of studied genomes. Among these strategies, hybridization capture has proven to be an innovative and efficient tool for targeting and enriching specific biomarkers in complex DNA mixtures. It has been successfully applied in numerous areas of biology, such as exome resequencing for the identification of mutations underlying Mendelian or complex diseases and cancers, and its usefulness has been demonstrated in the agronomic field through the linking of genetic variants to agricultural phenotypic traits of interest. Moreover, hybridization capture has provided access to underexplored, but relevant fractions of genomes through its ability to enrich defined targets and their flanking regions. Finally, on the basis of restricted genomic information, this method has also allowed the expansion of knowledge of nonreference species and ancient genomes and provided a better understanding of metagenomic samples. In this review, we present the major advances and discoveries permitted by hybridization capture and highlight the potency of this approach in all areas of biology. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. Metabolic diversity and ecological niches of Achromatium populations revealed with single-cell genomic sequencing

    Directory of Open Access Journals (Sweden)

    Muammar eMansor

    2015-08-01

    Full Text Available Large, sulfur-cycling, calcite-precipitating bacteria in the genus Achromatium represent a significant proportion of bacterial communities near sediment-water interfaces throughout the world. Our understanding of their potentially crucial roles in calcium, carbon, sulfur, nitrogen, and iron cycling is limited because they have not been cultured or sequenced using environmental genomics approaches to date. We utilized single-cell genomic sequencing to obtain one incomplete and two nearly complete draft genomes for Achromatium collected at Warm Mineral Springs, FL. Based on 16S rRNA gene sequences, the three cells represent distinct and relatively distant Achromatium populations (91-92% identity. The draft genomes encode key genes involved in sulfur and hydrogen oxidation; oxygen, nitrogen and polysulfide respiration; carbon and nitrogen fixation; organic carbon assimilation and storage; chemotaxis; twitching motility; antibiotic resistance; and membrane transport. Known genes for iron and manganese energy metabolism were not detected. The presence of pyrophosphatase and vacuolar (V-type ATPases, which are generally rare in bacterial genomes, suggests a role for these enzymes in calcium transport, proton pumping, and/or energy generation in the membranes of calcite-containing inclusions.

  5. Short interspersed elements (SINEs) are a major source of canine genomic diversity.

    Science.gov (United States)

    Wang, Wei; Kirkness, Ewen F

    2005-12-01

    SINEs are retrotransposons that have enjoyed remarkable reproductive success during the course of mammalian evolution, and have played a major role in shaping mammalian genomes. Previously, an analysis of survey-sequence data from an individual dog (a poodle) indicated that canine genomes harbor a high frequency of alleles that differ only by the absence or presence of a SINEC_Cf repeat. Comparison of this survey-sequence data with a draft genome sequence of a distinct dog (a boxer) has confirmed this prediction, and revealed the chromosomal coordinates for >10,000 loci that are bimorphic for SINEC_Cf insertions. Analysis of SINE insertion sites from the genomes of nine additional dogs indicates that 3%-5% are absent from either the poodle or boxer genome sequences--suggesting that an additional 10,000 bimorphic loci could be readily identified in the general dog population. We describe a methodology that can be used to identify these loci, and could be adapted to exploit these bimorphic loci for genotyping purposes. Approximately half of all annotated canine genes contain SINEC_Cf repeats, and these elements are occasionally transcribed. When transcribed in the antisense orientation, they provide splice acceptor sites that can result in incorporation of novel exons. The high frequency of bimorphic SINE insertions in the dog population is predicted to provide numerous examples of allele-specific transcription patterns that will be valuable for the study of differential gene expression among multiple dog breeds.

  6. The humankind genome: from genetic diversity to the origin of human diseases.

    Science.gov (United States)

    Belizário, Jose E

    2013-12-01

    Genome-wide association studies have failed to establish common variant risk for the majority of common human diseases. The underlying reasons for this failure are explained by recent studies of resequencing and comparison of over 1200 human genomes and 10 000 exomes, together with the delineation of DNA methylation patterns (epigenome) and full characterization of coding and noncoding RNAs (transcriptome) being transcribed. These studies have provided the most comprehensive catalogues of functional elements and genetic variants that are now available for global integrative analysis and experimental validation in prospective cohort studies. With these datasets, researchers will have unparalleled opportunities for the alignment, mining, and testing of hypotheses for the roles of specific genetic variants, including copy number variations, single nucleotide polymorphisms, and indels as the cause of specific phenotypes and diseases. Through the use of next-generation sequencing technologies for genotyping and standardized ontological annotation to systematically analyze the effects of genomic variation on humans and model organism phenotypes, we will be able to find candidate genes and new clues for disease's etiology and treatment. This article describes essential concepts in genetics and genomic technologies as well as the emerging computational framework to comprehensively search websites and platforms available for the analysis and interpretation of genomic data.

  7. Probing genomic diversity and evolution of Streptococcus suis serotype 2 by NimbleGen tiling arrays

    Directory of Open Access Journals (Sweden)

    Liao Hui

    2011-05-01

    Full Text Available Abstract Background Our previous studies revealed that a new disease form of streptococcal toxic shock syndrome (STSS is associated with specific Streptococcus suis serotype 2 (SS2 strains. To achieve a better understanding of the pathogenicity and evolution of SS2 at the whole-genome level, comparative genomic analysis of 18 SS2 strains, selected on the basis of virulence and geographic origin, was performed using NimbleGen tiling arrays. Results Our results demonstrate that SS2 isolates have highly divergent genomes. The 89K pathogenicity island (PAI, which has been previously recognized as unique to the Chinese epidemic strains causing STSS, was partially included in some other virulent and avirulent strains. The ABC-type transport systems, encoded by 89K, were hypothesized to greatly contribute to the catastrophic features of STSS. Moreover, we identified many polymorphisms in genes encoding candidate or known virulence factors, such as PlcR, lipase, sortases, the pilus-associated proteins, and the response regulator RevS and CtsR. On the basis of analysis of regions of differences (RDs across the entire genome for the 18 selected SS2 strains, a model of microevolution for these strains is proposed, which provides clues into Streptococcus pathogenicity and evolution. Conclusions Our deep comparative genomic analysis of the 89K PAI present in the genome of SS2 strains revealed details into how some virulent strains acquired genes that may contribute to STSS, which may lead to better environmental monitoring of epidemic SS2 strains.

  8. Environmental Whole-Genome Amplification to Access Microbial Diversity in Contaminated Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Abulencia, C.B.; Wyborski, D.L.; Garcia, J.; Podar, M.; Chen, W.; Chang, S.H.; Chang, H.W.; Watson, D.; Brodie,E.I.; Hazen, T.C.; Keller, M.

    2005-12-10

    Low-biomass samples from nitrate and heavy metal contaminated soils yield DNA amounts that have limited use for direct, native analysis and screening. Multiple displacement amplification (MDA) using ?29 DNA polymerase was used to amplify whole genomes from environmental, contaminated, subsurface sediments. By first amplifying the genomic DNA (gDNA), biodiversity analysis and gDNA library construction of microbes found in contaminated soils were made possible. The MDA method was validated by analyzing amplified genome coverage from approximately five Escherichia coli cells, resulting in 99.2 percent genome coverage. The method was further validated by confirming overall representative species coverage and also an amplification bias when amplifying from a mix of eight known bacterial strains. We extracted DNA from samples with extremely low cell densities from a U.S. Department of Energy contaminated site. After amplification, small subunit rRNA analysis revealed relatively even distribution of species across several major phyla. Clone libraries were constructed from the amplified gDNA, and a small subset of clones was used for shotgun sequencing. BLAST analysis of the library clone sequences showed that 64.9 percent of the sequences had significant similarities to known proteins, and ''clusters of orthologous groups'' (COG) analysis revealed that more than half of the sequences from each library contained sequence similarity to known proteins. The libraries can be readily screened for native genes or any target of interest. Whole-genome amplification of metagenomic DNA from very minute microbial sources, while introducing an amplification bias, will allow access to genomic information that was not previously accessible.

  9. Comparative analysis of the Oenococcus oeni pan genome reveals genetic diversity in industrially-relevant pathways

    Directory of Open Access Journals (Sweden)

    Borneman Anthony R

    2012-08-01

    Full Text Available Abstract Background Oenococcus oeni, a member of the lactic acid bacteria, is one of a limited number of microorganisms that not only survive, but actively proliferate in wine. It is also unusual as, unlike the majority of bacteria present in wine, it is beneficial to wine quality rather than causing spoilage. These benefits are realised primarily through catalysing malolactic fermentation, but also through imparting other positive sensory properties. However, many of these industrially-important secondary attributes have been shown to be strain-dependent and their genetic basis it yet to be determined. Results In order to investigate the scale and scope of genetic variation in O. oeni, we have performed whole-genome sequencing on eleven strains of this bacterium, bringing the total number of strains for which genome sequences are available to fourteen. While any single strain of O. oeni was shown to contain around 1800 protein-coding genes, in-depth comparative annotation based on genomic synteny and protein orthology identified over 2800 orthologous open reading frames that comprise the pan genome of this species, and less than 1200 genes that make up the conserved genomic core present in all of the strains. The expansion of the pan genome relative to the coding potential of individual strains was shown to be due to the varied presence and location of multiple distinct bacteriophage sequences and also in various metabolic functions with potential impacts on the industrial performance of this species, including cell wall exopolysaccharide biosynthesis, sugar transport and utilisation and amino acid biosynthesis. Conclusions By providing a large cohort of sequenced strains, this study provides a broad insight into the genetic variation present within O. oeni. This data is vital to understanding and harnessing the phenotypic variation present in this economically-important species.

  10. Genetic diversity and population structure inferred from the partially duplicated genome of domesticated carp, Cyprinus carpio L.

    Directory of Open Access Journals (Sweden)

    Feldman Marcus W

    2007-04-01

    Full Text Available Abstract Genetic relationships among eight populations of domesticated carp (Cyprinus carpio L., a species with a partially duplicated genome, were studied using 12 microsatellites and 505 AFLP bands. The populations included three aquacultured carp strains and five ornamental carp (koi variants. Grass carp (Ctenopharyngodon idella was used as an outgroup. AFLP-based gene diversity varied from 5% (grass carp to 32% (koi and reflected the reasonably well understood histories and breeding practices of the populations. A large fraction of the molecular variance was due to differences between aquacultured and ornamental carps. Further analyses based on microsatellite data, including cluster analysis and neighbor-joining trees, supported the genetic distinctiveness of aquacultured and ornamental carps, despite the recent divergence of the two groups. In contrast to what was observed for AFLP-based diversity, the frequency of heterozygotes based on microsatellites was comparable among all populations. This discrepancy can potentially be explained by duplication of some loci in Cyprinus carpio L., and a model that shows how duplication can increase heterozygosity estimates for microsatellites but not for AFLP loci is discussed. Our analyses in carp can help in understanding the consequences of genotyping duplicated loci and in interpreting discrepancies between dominant and co-dominant markers in species with recent genome duplication.

  11. Genomes

    National Research Council Canada - National Science Library

    Brown, T. A. (Terence A.)

    2002-01-01

    ... of genome expression and replication processes, and transcriptomics and proteomics. This text is richly illustrated with clear, easy-to-follow, full color diagrams, which are downloadable from the book's website...

  12. Linking secondary metabolites to gene clusters through genome sequencing of six diverse Aspergillus species

    DEFF Research Database (Denmark)

    Kjærbølling, Inge; Vesth, Tammi C.; Frisvad, Jens C.

    2018-01-01

    The fungal genus of Aspergillus is highly interesting, containing everything from industrial cell factories, model organisms, and human pathogens. In particular, this group has a prolific production of bioactive secondary metabolites (SMs). In this work, four diverse Aspergillus species (A...

  13. Insight into the genomic diversity and relationship of Astragalus glycyphyllos symbionts by RAPD, ERIC-PCR, and AFLP fingerprinting.

    Science.gov (United States)

    Gnat, Sebastian; Małek, Wanda; Oleńska, Ewa; Trościańczyk, Aleksandra; Wdowiak-Wróbel, Sylwia; Kalita, Michał; Wójcik, Magdalena

    2015-11-01

    We assessed the genomic diversity and genomic relationship of 28 Astragalus glycyphyllos symbionts by three methodologies based on PCR reaction, i.e., RAPD, ERIC-PCR, and AFLP. The AFLP method with one PstI restriction enzyme and selective PstI-GC primer pair had a comparable discriminatory power as ERIC-PCR one and these fingerprinting techniques distinguished among the studied 28 A. glycyphyllos symbionts 18 and 17 genomotypes, respectively. RAPD method was less discriminatory in the genomotyping of rhizobia analyzed and it efficiently resolved nine genomotypes. The cluster analysis of RAPD, ERIC-PCR, and AFLP profiles resulted in a generally similar grouping of the test strains on generated dendrograms supporting a great potential of these DNA fingerprinting techniques for study of genomic polymorphism and evolutionary relationship of A. glycyphyllos nodulators. The RAPD, ERIC-PCR, and AFLP pattern similarity coefficients between A. glycyphyllos symbionts studied was in the ranges 8-100, 18-100, and 23-100%, respectively.

  14. Exploration of genetic diversity among medicinally important genus Epimedium species based on genomic and EST-SSR marker.

    Science.gov (United States)

    Yousaf, Zubaida; Hu, Weiming; Zhang, Yanjun; Zeng, Shaohua; Wang, Ying

    2015-01-01

    Epimedium species has gained prime importance due to their medicinal and economic values. Therefore, in this study, 26 genomic SSR and 10 EST-SSR markers were developed for 13 medicinal species of the Epimedium genus and one out-group species Vancouveria hexandra W. J. Hooker to explore the existing genetic diversity. A total of 100 alleles by genomic SSR and 65 by EST-SSR were detected. The genomic SSR markers were presented between 2-7 alleles per locus. The observed heterozygosity (Ho) and expected heterozygosity (He) ranged from 0.00 to 4.5 and 0.0254 to 2.8108, respectively. Similarly, for EST-SSR, these values were ranged from 3.00 to 4.00 and 1.9650 to 2.7142. The number of alleles for EST-SSR markers ranged from 3 to 10 with an average of 3.51 per loci. It has been concluded that medicinally important species of the genus Epimedium possesses lower intraspecific genetic variation.

  15. Genomic Characterization of Dairy Associated Leuconostoc Species and Diversity of Leuconostocs in Undefined Mixed Mesophilic Starter Cultures.

    Science.gov (United States)

    Frantzen, Cyril A; Kot, Witold; Pedersen, Thomas B; Ardö, Ylva M; Broadbent, Jeff R; Neve, Horst; Hansen, Lars H; Dal Bello, Fabio; Østlie, Hilde M; Kleppen, Hans P; Vogensen, Finn K; Holo, Helge

    2017-01-01

    Undefined mesophilic mixed (DL-type) starter cultures are composed of predominantly Lactococcus lactis subspecies and 1-10% Leuconostoc spp. The composition of the Leuconostoc population in the starter culture ultimately affects the characteristics and the quality of the final product. The scientific basis for the taxonomy of dairy relevant leuconostocs can be traced back 50 years, and no documentation on the genomic diversity of leuconostocs in starter cultures exists. We present data on the Leuconostoc population in five DL-type starter cultures commonly used by the dairy industry. The analyses were performed using traditional cultivation methods, and further augmented by next-generation DNA sequencing methods. Bacterial counts for starter cultures cultivated on two different media, MRS and MPCA, revealed large differences in the relative abundance of leuconostocs. Most of the leuconostocs in two of the starter cultures were unable to grow on MRS, emphasizing the limitations of culture-based methods and the importance of careful media selection or use of culture independent methods. Pan-genomic analysis of 59 Leuconostoc genomes enabled differentiation into twelve robust lineages. The genomic analyses show that the dairy-associated leuconostocs are highly adapted to their environment, characterized by the acquisition of genotype traits, such as the ability to metabolize citrate. In particular, Leuconostoc mesenteroides subsp. cremoris display telltale signs of a degenerative evolution, likely resulting from a long period of growth in milk in association with lactococci. Great differences in the metabolic potential between Leuconostoc species and subspecies were revealed. Using targeted amplicon sequencing, the composition of the Leuconostoc population in the five commercial starter cultures was shown to be significantly different. Three of the cultures were dominated by Ln. mesenteroides subspecies cremoris. Leuconostoc pseudomesenteroides dominated in two of the

  16. Wild emmer genome architecture and diversity elucidate wheat evolution and domestication

    Science.gov (United States)

    Wheat (Triticum spp.) is one of the founder crops that likely drove the Neolithic transition to sedentary agrarian societies in the Fertile Crescent over 10,000 years ago. Identifying genetic modifications underlying wheat's domestication requires knowledge of the genome of its allo-tetraploid proge...

  17. Genome sequence analysis with MonetDB - A case study on Ebola virus diversity

    NARCIS (Netherlands)

    Cijvat, R.; Manegold, S.; Kersten, M.; Klau, G.W.; Schönhuth, A.; Marschall, T.; Zhang, Y.

    2015-01-01

    Next-generation sequencing (NGS) technology has led the life sciences into the big data era. Today, sequencing genomes takes little time and cost, but yields terabytes of data to be stored and analyzed. Biologists are often exposed to excessively time consuming and error-prone data management and

  18. Novel Insights into the Diversity of Catabolic Metabolism from Ten Haloarchaeal Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain; Scheuner, Carmen; Goker, Markus; Mavromatis, Kostas; Hooper, Sean D.; Porat, Iris; Klenk, Hans-Peter; Ivanova, Natalia; Kyrpides, Nikos

    2011-05-03

    The extremely halophilic archaea are present worldwide in saline environments and have important biotechnological applications. Ten complete genomes of haloarchaea are now available, providing an opportunity for comparative analysis. We report here the comparative analysis of five newly sequenced haloarchaeal genomes with five previously published ones. Whole genome trees based on protein sequences provide strong support for deep relationships between the ten organisms. Using a soft clustering approach, we identified 887 protein clusters present in all halophiles. Of these core clusters, 112 are not found in any other archaea and therefore constitute the haloarchaeal signature. Four of the halophiles were isolated from water, and four were isolated from soil or sediment. Although there are few habitat-specific clusters, the soil/sediment halophiles tend to have greater capacity for polysaccharide degradation, siderophore synthesis, and cell wall modification. Halorhabdus utahensis and Haloterrigena turkmenica encode over forty glycosyl hydrolases each, and may be capable of breaking down naturally occurring complex carbohydrates. H. utahensis is specialized for growth on carbohydrates and has few amino acid degradation pathways. It uses the non-oxidative pentose phosphate pathway instead of the oxidative pathway, giving it more flexibility in the metabolism of pentoses. These new genomes expand our understanding of haloarchaeal catabolic pathways, providing a basis for further experimental analysis, especially with regard to carbohydrate metabolism. Halophilic glycosyl hydrolases for use in biofuel production are more likely to be found in halophiles isolated from soil or sediment.

  19. Diversity in non-repetitive human sequences not found in the reference genome.

    Science.gov (United States)

    Kehr, Birte; Helgadottir, Anna; Melsted, Pall; Jonsson, Hakon; Helgason, Hannes; Jonasdottir, Adalbjörg; Jonasdottir, Aslaug; Sigurdsson, Asgeir; Gylfason, Arnaldur; Halldorsson, Gisli H; Kristmundsdottir, Snaedis; Thorgeirsson, Gudmundur; Olafsson, Isleifur; Holm, Hilma; Thorsteinsdottir, Unnur; Sulem, Patrick; Helgason, Agnar; Gudbjartsson, Daniel F; Halldorsson, Bjarni V; Stefansson, Kari

    2017-04-01

    Genomes usually contain some non-repetitive sequences that are missing from the reference genome and occur only in a population subset. Such non-repetitive, non-reference (NRNR) sequences have remained largely unexplored in terms of their characterization and downstream analyses. Here we describe 3,791 breakpoint-resolved NRNR sequence variants called using PopIns from whole-genome sequence data of 15,219 Icelanders. We found that over 95% of the 244 NRNR sequences that are 200 bp or longer are present in chimpanzees, indicating that they are ancestral. Furthermore, 149 variant loci are in linkage disequilibrium (r 2 > 0.8) with a genome-wide association study (GWAS) catalog marker, suggesting disease relevance. Additionally, we report an association (P = 3.8 × 10 -8 , odds ratio (OR) = 0.92) with myocardial infarction (23,360 cases, 300,771 controls) for a 766-bp NRNR sequence variant. Our results underline the importance of including variation of all complexity levels when searching for variants that associate with disease.

  20. Genome wide association studies on yield components using a lentil genetic diversity panel

    Science.gov (United States)

    The cool season food legume research community are now at the threshold of deploying the cutting-edge molecular genetics and genomics tools that have led to significant and rapid expansion of gene discovery, knowledge of gene function (including tolerance to biotic and abiotic stresses) and genetic ...

  1. Genome-wide prediction methods in highly diverse and heterozygous species: proof-of-concept through simulation in grapevine.

    Directory of Open Access Journals (Sweden)

    Agota Fodor

    Full Text Available Nowadays, genome-wide association studies (GWAS and genomic selection (GS methods which use genome-wide marker data for phenotype prediction are of much potential interest in plant breeding. However, to our knowledge, no studies have been performed yet on the predictive ability of these methods for structured traits when using training populations with high levels of genetic diversity. Such an example of a highly heterozygous, perennial species is grapevine. The present study compares the accuracy of models based on GWAS or GS alone, or in combination, for predicting simple or complex traits, linked or not with population structure. In order to explore the relevance of these methods in this context, we performed simulations using approx 90,000 SNPs on a population of 3,000 individuals structured into three groups and corresponding to published diversity grapevine data. To estimate the parameters of the prediction models, we defined four training populations of 1,000 individuals, corresponding to these three groups and a core collection. Finally, to estimate the accuracy of the models, we also simulated four breeding populations of 200 individuals. Although prediction accuracy was low when breeding populations were too distant from the training populations, high accuracy levels were obtained using the sole core-collection as training population. The highest prediction accuracy was obtained (up to 0.9 using the combined GWAS-GS model. We thus recommend using the combined prediction model and a core-collection as training population for grapevine breeding or for other important economic crops with the same characteristics.

  2. A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

    Directory of Open Access Journals (Sweden)

    Emile R Chimusa

    2015-03-01

    Full Text Available We report a study of genome-wide, dense SNP (∼ 900K and copy number polymorphism data of indigenous southern Africans. We demonstrate the genetic contribution to southern and eastern African populations, which involved admixture between indigenous San, Niger-Congo-speaking and populations of Eurasian ancestry. This finding illustrates the need to account for stratification in genome-wide association studies, and that admixture mapping would likely be a successful approach in these populations. We developed a strategy to detect the signature of selection prior to and following putative admixture events. Several genomic regions show an unusual excess of Niger-Kordofanian, and unusual deficiency of both San and Eurasian ancestry, which were considered the footprints of selection after population admixture. Several SNPs with strong allele frequency differences were observed predominantly between the admixed indigenous southern African populations, and their ancestral Eurasian populations. Interestingly, many candidate genes, which were identified within the genomic regions showing signals for selection, were associated with southern African-specific high-risk, mostly communicable diseases, such as malaria, influenza, tuberculosis, and human immunodeficiency virus/AIDs. This observation suggests a potentially important role that these genes might have played in adapting to the environment. Additionally, our analyses of haplotype structure, linkage disequilibrium, recombination, copy number variation and genome-wide admixture highlight, and support the unique position of San relative to both African and non-African populations. This study contributes to a better understanding of population ancestry and selection in south-eastern African populations; and the data and results obtained will support research into the genetic contributions to infectious as well as non-communicable diseases in the region.

  3. A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

    Science.gov (United States)

    Chimusa, Emile R; Meintjies, Ayton; Tchanga, Milaine; Mulder, Nicola; Seoighe, Cathal; Seioghe, Cathal; Soodyall, Himla; Ramesar, Rajkumar

    2015-03-01

    We report a study of genome-wide, dense SNP (∼ 900K) and copy number polymorphism data of indigenous southern Africans. We demonstrate the genetic contribution to southern and eastern African populations, which involved admixture between indigenous San, Niger-Congo-speaking and populations of Eurasian ancestry. This finding illustrates the need to account for stratification in genome-wide association studies, and that admixture mapping would likely be a successful approach in these populations. We developed a strategy to detect the signature of selection prior to and following putative admixture events. Several genomic regions show an unusual excess of Niger-Kordofanian, and unusual deficiency of both San and Eurasian ancestry, which were considered the footprints of selection after population admixture. Several SNPs with strong allele frequency differences were observed predominantly between the admixed indigenous southern African populations, and their ancestral Eurasian populations. Interestingly, many candidate genes, which were identified within the genomic regions showing signals for selection, were associated with southern African-specific high-risk, mostly communicable diseases, such as malaria, influenza, tuberculosis, and human immunodeficiency virus/AIDs. This observation suggests a potentially important role that these genes might have played in adapting to the environment. Additionally, our analyses of haplotype structure, linkage disequilibrium, recombination, copy number variation and genome-wide admixture highlight, and support the unique position of San relative to both African and non-African populations. This study contributes to a better understanding of population ancestry and selection in south-eastern African populations; and the data and results obtained will support research into the genetic contributions to infectious as well as non-communicable diseases in the region.

  4. Insights into the genetic structure and diversity of 38 South Asian Indians from deep whole-genome sequencing.

    Directory of Open Access Journals (Sweden)

    Lai-Ping Wong

    2014-05-01

    Full Text Available South Asia possesses a significant amount of genetic diversity due to considerable intergroup differences in culture and language. There have been numerous reports on the genetic structure of Asian Indians, although these have mostly relied on genotyping microarrays or targeted sequencing of the mitochondria and Y chromosomes. Asian Indians in Singapore are primarily descendants of immigrants from Dravidian-language-speaking states in south India, and 38 individuals from the general population underwent deep whole-genome sequencing with a target coverage of 30X as part of the Singapore Sequencing Indian Project (SSIP. The genetic structure and diversity of these samples were compared against samples from the Singapore Sequencing Malay Project and populations in Phase 1 of the 1,000 Genomes Project (1 KGP. SSIP samples exhibited greater intra-population genetic diversity and possessed higher heterozygous-to-homozygous genotype ratio than other Asian populations. When compared against a panel of well-defined Asian Indians, the genetic makeup of the SSIP samples was closely related to South Indians. However, even though the SSIP samples clustered distinctly from the Europeans in the global population structure analysis with autosomal SNPs, eight samples were assigned to mitochondrial haplogroups that were predominantly present in Europeans and possessed higher European admixture than the remaining samples. An analysis of the relative relatedness between SSIP with two archaic hominins (Denisovan, Neanderthal identified higher ancient admixture in East Asian populations than in SSIP. The data resource for these samples is publicly available and is expected to serve as a valuable complement to the South Asian samples in Phase 3 of 1 KGP.

  5. Insights into the genetic structure and diversity of 38 South Asian Indians from deep whole-genome sequencing.

    Science.gov (United States)

    Wong, Lai-Ping; Lai, Jason Kuan-Han; Saw, Woei-Yuh; Ong, Rick Twee-Hee; Cheng, Anthony Youzhi; Pillai, Nisha Esakimuthu; Liu, Xuanyao; Xu, Wenting; Chen, Peng; Foo, Jia-Nee; Tan, Linda Wei-Lin; Koo, Seok-Hwee; Soong, Richie; Wenk, Markus Rene; Lim, Wei-Yen; Khor, Chiea-Chuen; Little, Peter; Chia, Kee-Seng; Teo, Yik-Ying

    2014-05-01

    South Asia possesses a significant amount of genetic diversity due to considerable intergroup differences in culture and language. There have been numerous reports on the genetic structure of Asian Indians, although these have mostly relied on genotyping microarrays or targeted sequencing of the mitochondria and Y chromosomes. Asian Indians in Singapore are primarily descendants of immigrants from Dravidian-language-speaking states in south India, and 38 individuals from the general population underwent deep whole-genome sequencing with a target coverage of 30X as part of the Singapore Sequencing Indian Project (SSIP). The genetic structure and diversity of these samples were compared against samples from the Singapore Sequencing Malay Project and populations in Phase 1 of the 1,000 Genomes Project (1 KGP). SSIP samples exhibited greater intra-population genetic diversity and possessed higher heterozygous-to-homozygous genotype ratio than other Asian populations. When compared against a panel of well-defined Asian Indians, the genetic makeup of the SSIP samples was closely related to South Indians. However, even though the SSIP samples clustered distinctly from the Europeans in the global population structure analysis with autosomal SNPs, eight samples were assigned to mitochondrial haplogroups that were predominantly present in Europeans and possessed higher European admixture than the remaining samples. An analysis of the relative relatedness between SSIP with two archaic hominins (Denisovan, Neanderthal) identified higher ancient admixture in East Asian populations than in SSIP. The data resource for these samples is publicly available and is expected to serve as a valuable complement to the South Asian samples in Phase 3 of 1 KGP.

  6. Phylogenetic diversity and genotypical complexity of H9N2 influenza A viruses revealed by genomic sequence analysis.

    Directory of Open Access Journals (Sweden)

    Guoying Dong

    Full Text Available H9N2 influenza A viruses have become established worldwide in terrestrial poultry and wild birds, and are occasionally transmitted to mammals including humans and pigs. To comprehensively elucidate the genetic and evolutionary characteristics of H9N2 influenza viruses, we performed a large-scale sequence analysis of 571 viral genomes from the NCBI Influenza Virus Resource Database, representing the spectrum of H9N2 influenza viruses isolated from 1966 to 2009. Our study provides a panoramic framework for better understanding the genesis and evolution of H9N2 influenza viruses, and for describing the history of H9N2 viruses circulating in diverse hosts. Panorama phylogenetic analysis of the eight viral gene segments revealed the complexity and diversity of H9N2 influenza viruses. The 571 H9N2 viral genomes were classified into 74 separate lineages, which had marked host and geographical differences in phylogeny. Panorama genotypical analysis also revealed that H9N2 viruses include at least 98 genotypes, which were further divided according to their HA lineages into seven series (A-G. Phylogenetic analysis of the internal genes showed that H9N2 viruses are closely related to H3, H4, H5, H7, H10, and H14 subtype influenza viruses. Our results indicate that H9N2 viruses have undergone extensive reassortments to generate multiple reassortants and genotypes, suggesting that the continued circulation of multiple genotypical H9N2 viruses throughout the world in diverse hosts has the potential to cause future influenza outbreaks in poultry and epidemics in humans. We propose a nomenclature system for identifying and unifying all lineages and genotypes of H9N2 influenza viruses in order to facilitate international communication on the evolution, ecology and epidemiology of H9N2 influenza viruses.

  7. Secondary uses and the governance of de-identified data: Lessons from the human genome diversity panel

    Directory of Open Access Journals (Sweden)

    Lee Sandra S-J

    2011-09-01

    Full Text Available Abstract Background Recent changes to regulatory guidance in the US and Europe have complicated oversight of secondary research by rendering most uses of de-identified data exempt from human subjects oversight. To identify the implications of such guidelines for harms to participants and communities, this paper explores the secondary uses of one de-identified DNA sample collection with limited oversight: the Human Genome Diversity Project (HGDP-Centre d'Etude du Polymorphisme Humain, Fondation Jean Dausset (CEPH Human Genome Diversity Panel. Methods Using a combination of keyword and cited reference search, we identified English-language scientific articles published between 2002 and 2009 that reported analysis of HGDP Diversity Panel samples and/or data. We then reviewed each article to identify the specific research use to which the samples and/or data was applied. Secondary uses were categorized according to the type and kind of research supported by the collection. Results A wide variety of secondary uses were identified from 148 peer-reviewed articles. While the vast majority of these uses were consistent with the original intent of the collection, a minority of published reports described research whose primary findings could be regarded as controversial, objectionable, or potentially stigmatizing in their interpretation. Conclusions We conclude that potential risks to participants and communities cannot be wholly eliminated by anonymization of individual data and suggest that explicit review of proposed secondary uses, by a Data Access Committee or similar internal oversight body with suitable stakeholder representation, should be a required component of the trustworthy governance of any repository of data or specimens.

  8. Genome-wide genetic diversity and differentially selected regions among Suffolk, Rambouillet, Columbia, Polypay, and Targhee sheep.

    Directory of Open Access Journals (Sweden)

    Lifan Zhang

    Full Text Available Sheep are among the major economically important livestock species worldwide because the animals produce milk, wool, skin, and meat. In the present study, the Illumina OvineSNP50 BeadChip was used to investigate genetic diversity and genome selection among Suffolk, Rambouillet, Columbia, Polypay, and Targhee sheep breeds from the United States. After quality-control filtering of SNPs (single nucleotide polymorphisms, we used 48,026 SNPs, including 46,850 SNPs on autosomes that were in Hardy-Weinberg equilibrium and 1,176 SNPs on chromosome × for analysis. Phylogenetic analysis based on all 46,850 SNPs clearly separated Suffolk from Rambouillet, Columbia, Polypay, and Targhee, which was not surprising as Rambouillet contributed to the synthesis of the later three breeds. Based on pair-wise estimates of F(ST, significant genetic differentiation appeared between Suffolk and Rambouillet (F(ST = 0.1621, while Rambouillet and Targhee had the closest relationship (F(ST = 0.0681. A scan of the genome revealed 45 and 41 differentially selected regions (DSRs between Suffolk and Rambouillet and among Rambouillet-related breed populations, respectively. Our data indicated that regions 13 and 24 between Suffolk and Rambouillet might be good candidates for evaluating breed differences. Furthermore, ovine genome v3.1 assembly was used as reference to link functionally known homologous genes to economically important traits covered by these differentially selected regions. In brief, our present study provides a comprehensive genome-wide view on within- and between-breed genetic differentiation, biodiversity, and evolution among Suffolk, Rambouillet, Columbia, Polypay, and Targhee sheep breeds. These results may provide new guidance for the synthesis of new breeds with different breeding objectives.

  9. Detecting exact breakpoints of deletions with diversity in hepatitis B viral genomic DNA from next-generation sequencing data.

    Science.gov (United States)

    Cheng, Ji-Hong; Liu, Wen-Chun; Chang, Ting-Tsung; Hsieh, Sun-Yuan; Tseng, Vincent S

    2017-10-01

    Many studies have suggested that deletions of Hepatitis B Viral (HBV) are associated with the development of progressive liver diseases, even ultimately resulting in hepatocellular carcinoma (HCC). Among the methods for detecting deletions from next-generation sequencing (NGS) data, few methods considered the characteristics of virus, such as high evolution rates and high divergence among the different HBV genomes. Sequencing high divergence HBV genome sequences using the NGS technology outputs millions of reads. Thus, detecting exact breakpoints of deletions from these big and complex data incurs very high computational cost. We proposed a novel analytical method named VirDelect (Virus Deletion Detect), which uses split read alignment base to detect exact breakpoint and diversity variable to consider high divergence in single-end reads data, such that the computational cost can be reduced without losing accuracy. We use four simulated reads datasets and two real pair-end reads datasets of HBV genome sequence to verify VirDelect accuracy by score functions. The experimental results show that VirDelect outperforms the state-of-the-art method Pindel in terms of accuracy score for all simulated datasets and VirDelect had only two base errors even in real datasets. VirDelect is also shown to deliver high accuracy in analyzing the single-end read data as well as pair-end data. VirDelect can serve as an effective and efficient bioinformatics tool for physiologists with high accuracy and efficient performance and applicable to further analysis with characteristics similar to HBV on genome length and high divergence. The software program of VirDelect can be downloaded at https://sourceforge.net/projects/virdelect/. Copyright © 2017. Published by Elsevier Inc.

  10. A tutorial of diverse genome analysis tools found in the CoGe web-platform using Plasmodium spp. as a model

    Science.gov (United States)

    Castillo, Andreina I; Nelson, Andrew D L; Haug-Baltzell, Asher K; Lyons, Eric

    2018-01-01

    Abstract Integrated platforms for storage, management, analysis and sharing of large quantities of omics data have become fundamental to comparative genomics. CoGe (https://genomevolution.org/coge/) is an online platform designed to manage and study genomic data, enabling both data- and hypothesis-driven comparative genomics. CoGe’s tools and resources can be used to organize and analyse both publicly available and private genomic data from any species. Here, we demonstrate the capabilities of CoGe through three example workflows using 17 Plasmodium genomes as a model. Plasmodium genomes present unique challenges for comparative genomics due to their rapidly evolving and highly variable genomic AT/GC content. These example workflows are intended to serve as templates to help guide researchers who would like to use CoGe to examine diverse aspects of genome evolution. In the first workflow, trends in genome composition and amino acid usage are explored. In the second, changes in genome structure and the distribution of synonymous (Ks) and non-synonymous (Kn) substitution values are evaluated across species with different levels of evolutionary relatedness. In the third workflow, microsyntenic analyses of multigene families’ genomic organization are conducted using two Plasmodium-specific gene families—serine repeat antigen, and cytoadherence-linked asexual gene—as models. In general, these example workflows show how to achieve quick, reproducible and shareable results using the CoGe platform. We were able to replicate previously published results, as well as leverage CoGe’s tools and resources to gain additional insight into various aspects of Plasmodium genome evolution. Our results highlight the usefulness of the CoGe platform, particularly in understanding complex features of genome evolution. Database URL: https://genomevolution.org/coge/

  11. Reconstruction of diverse verrucomicrobial genomes from metagenome datasets of freshwater reservoirs

    Czech Academy of Sciences Publication Activity Database

    Cabello-Yeves, P.J.; Ghai, Rohit; Mehrshad, Maliheh; Picazo, A.; Camacho, A.; Rodriguez-Valera, F.

    2017-01-01

    Roč. 8, Nov (2017), č. článku 2131. ISSN 1664-302X R&D Projects: GA ČR GA17-04828S Grant - others:AV ČR(CZ) L200961651 Institutional support: RVO:60077344 Keywords : freshwater Verrucomicrobia * metagenomics * rhodopsin * nitrogen fixation * genome streamlining Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.076, year: 2016

  12. Distinct patterns of mitochondrial genome diversity in bonobos (Pan paniscus and humans

    Directory of Open Access Journals (Sweden)

    Zsurka Gábor

    2010-09-01

    Full Text Available Abstract Background We have analyzed the complete mitochondrial genomes of 22 Pan paniscus (bonobo, pygmy chimpanzee individuals to assess the detailed mitochondrial DNA (mtDNA phylogeny of this close relative of Homo sapiens. Results We identified three major clades among bonobos that separated approximately 540,000 years ago, as suggested by Bayesian analysis. Incidentally, we discovered that the current reference sequence for bonobo likely is a hybrid of the mitochondrial genomes of two distant individuals. When comparing spectra of polymorphic mtDNA sites in bonobos and humans, we observed two major differences: (i Of all 31 bonobo mtDNA homoplasies, i.e. nucleotide changes that occurred independently on separate branches of the phylogenetic tree, 13 were not homoplasic in humans. This indicates that at least a part of the unstable sites of the mitochondrial genome is species-specific and difficult to be explained on the basis of a mutational hotspot concept. (ii A comparison of the ratios of non-synonymous to synonymous changes (dN/dS among polymorphic positions in bonobos and in 4902 Homo sapiens mitochondrial genomes revealed a remarkable difference in the strength of purifying selection in the mitochondrial genes of the F0F1-ATPase complex. While in bonobos this complex showed a similar low value as complexes I and IV, human haplogroups displayed 2.2 to 7.6 times increased dN/dS ratios when compared to bonobos. Conclusions Some variants of mitochondrially encoded subunits of the ATPase complex in humans very likely decrease the efficiency of energy conversion leading to production of extra heat. Thus, we hypothesize that the species-specific release of evolutionary constraints for the mitochondrial genes of the proton-translocating ATPase is a consequence of altered heat homeostasis in modern humans.

  13. Chitinase family GH18: evolutionary insights from the genomic history of a diverse protein family

    Directory of Open Access Journals (Sweden)

    Aronson Nathan N

    2007-06-01

    Full Text Available Abstract Background Chitinases (EC.3.2.1.14 hydrolyze the β-1,4-linkages in chitin, an abundant N-acetyl-β-D-glucosamine polysaccharide that is a structural component of protective biological matrices such as insect exoskeletons and fungal cell walls. The glycoside hydrolase 18 (GH18 family of chitinases is an ancient gene family widely expressed in archea, prokaryotes and eukaryotes. Mammals are not known to synthesize chitin or metabolize it as a nutrient, yet the human genome encodes eight GH18 family members. Some GH18 proteins lack an essential catalytic glutamic acid and are likely to act as lectins rather than as enzymes. This study used comparative genomic analysis to address the evolutionary history of the GH18 multiprotein family, from early eukaryotes to mammals, in an effort to understand the forces that shaped the human genome content of chitinase related proteins. Results Gene duplication and loss according to a birth-and-death model of evolution is a feature of the evolutionary history of the GH18 family. The current human family likely originated from ancient genes present at the time of the bilaterian expansion (approx. 550 mya. The family expanded in the chitinous protostomes C. elegans and D. melanogaster, declined in early deuterostomes as chitin synthesis disappeared, and expanded again in late deuterostomes with a significant increase in gene number after the avian/mammalian split. Conclusion This comprehensive genomic study of animal GH18 proteins reveals three major phylogenetic groups in the family: chitobiases, chitinases/chitolectins, and stabilin-1 interacting chitolectins. Only the chitinase/chitolectin group is associated with expansion in late deuterostomes. Finding that the human GH18 gene family is closely linked to the human major histocompatibility complex paralogon on chromosome 1, together with the recent association of GH18 chitinase activity with Th2 cell inflammation, suggests that its late expansion

  14. Horizontal Gene Transfer from Diverse Bacteria to an Insect Genome Enables a Tripartite Nested Mealybug Symbiosis

    Czech Academy of Sciences Publication Activity Database

    Husník, Filip; Nikoh, N.; Koga, R.; Ross, L.; Duncan, R.P.; Fuije, M.; Tanaka, M.; Satoh, N.; Bachtrog, D.; Wilson, A.C.C.; von Dohlen, C.D.; Fukatsu, T.; McCutcheon, J.P.

    2013-01-01

    Roč. 153, č. 7 (2013), s. 1567-1578 ISSN 0092-8674 Grant - others:GA ČR(CZ) GAP505/10/1401; GA ČR(CZ) GA13-01878S Program:GA Institutional support: RVO:60077344 Keywords : intracellular bacteria * beta-proteobacteria * reduced genomes * host cell * evolution * endosymbionts * Wolbachia Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 33.116, year: 2013

  15. Allelic recombination between distinct genomic locations generates copy number diversity in human β-defensins

    Science.gov (United States)

    Bakar, Suhaili Abu; Hollox, Edward J.; Armour, John A. L.

    2009-01-01

    β-Defensins are small secreted antimicrobial and signaling peptides involved in the innate immune response of vertebrates. In humans, a cluster of at least 7 of these genes shows extensive copy number variation, with a diploid copy number commonly ranging between 2 and 7. Using a genetic mapping approach, we show that this cluster is at not 1 but 2 distinct genomic loci ≈5 Mb apart on chromosome band 8p23.1, contradicting the most recent genome assembly. We also demonstrate that the predominant mechanism of change in β-defensin copy number is simple allelic recombination occurring in the interval between the 2 distinct genomic loci for these genes. In 416 meiotic transmissions, we observe 3 events creating a haplotype copy number not found in the parent, equivalent to a germ-line rate of copy number change of ≈0.7% per gamete. This places it among the fastest-changing copy number variants currently known. PMID:19131514

  16. Hidden diversity revealed by genome-resolved metagenomics of iron-oxidizing microbial mats from L??ihi Seamount, Hawai?i

    OpenAIRE

    Fullerton, Heather; Hager, Kevin W; McAllister, Sean M; Moyer, Craig L

    2017-01-01

    The Zetaproteobacteria are ubiquitous in marine environments, yet this class of Proteobacteria is only represented by a few closely-related cultured isolates. In high-iron environments, such as diffuse hydrothermal vents, the Zetaproteobacteria are important members of the community driving its structure. Biogeography of Zetaproteobacteria has shown two ubiquitous operational taxonomic units (OTUs), yet much is unknown about their genomic diversity. Genome-resolved metagenomics allows for the...

  17. Characterizing the population structure and genetic diversity of maize breeding germplasm in Southwest China using genome-wide SNP markers.

    Science.gov (United States)

    Zhang, Xiao; Zhang, Hua; Li, Lujiang; Lan, Hai; Ren, Zhiyong; Liu, Dan; Wu, Ling; Liu, Hailan; Jaqueth, Jennifer; Li, Bailin; Pan, Guangtang; Gao, Shibin

    2016-08-31

    Maize breeding germplasm used in Southwest China has high complexity because of the diverse ecological features of this area. In this study, the population structure, genetic diversity, and linkage disequilibrium decay distance of 362 important inbred lines collected from the breeding program of Southwest China were characterized using the MaizeSNP50 BeadChip with 56,110 single nucleotide polymorphisms (SNPs). With respect to population structure, two (Tropical and Temperate), three (Tropical, Stiff Stalk and non-Stiff Stalk), four [Tropical, group A germplasm derived from modern U.S. hybrids (PA), group B germplasm derived from modern U.S. hybrids (PB) and Reid] and six (Tropical, PB, Reid, Iowa Stiff Stalk Synthetic, PA and North) subgroups were identified. With increasing K value, the Temperate group showed pronounced hierarchical structure with division into further subgroups. The Genetic Diversity of each group was also estimated, and the Tropical group was more diverse than the Temperate group. Seven low-genetic-diversity and one high-genetic-diversity regions were collectively identified in the Temperate, Tropical groups, and the entire panel. SNPs with significant variation in allele frequency between the Tropical and Temperate groups were also evaluated. Among them, a region located at 130 Mb on Chromosome 2 showed the highest genetic diversity, including both number of SNPs with significant variation and the ratio of significant SNPs to total SNPs. Linkage disequilibrium decay distance in the Temperate group was greater (2.5-3 Mb) than that in the entire panel (0.5-0.75 Mb) and the Tropical group (0.25-0.5 Mb). A large region at 30-120 Mb of Chromosome 7 was concluded to be a region conserved during the breeding process by comparison between S37, which was considered a representative tropical line in Southwest China, and its 30 most similar derived lines. For the panel covered most of widely used inbred lines in Southwest China, this work

  18. Contrasting Patterns of Genomic Diversity Reveal Accelerated Genetic Drift but Reduced Directional Selection on X-Chromosome in Wild and Domestic Sheep Species.

    Science.gov (United States)

    Chen, Ze-Hui; Zhang, Min; Lv, Feng-Hua; Ren, Xue; Li, Wen-Rong; Liu, Ming-Jun; Nam, Kiwoong; Bruford, Michael W; Li, Meng-Hua

    2018-04-01

    Analyses of genomic diversity along the X chromosome and of its correlation with autosomal diversity can facilitate understanding of evolutionary forces in shaping sex-linked genomic architecture. Strong selective sweeps and accelerated genetic drift on the X-chromosome have been inferred in primates and other model species, but no such insight has yet been gained in domestic animals compared with their wild relatives. Here, we analyzed X-chromosome variability in a large ovine data set, including a BeadChip array for 943 ewes from the world's sheep populations and 110 whole genomes of wild and domestic sheep. Analyzing whole-genome sequences, we observed a substantially reduced X-to-autosome diversity ratio (∼0.6) compared with the value expected under a neutral model (0.75). In particular, one large X-linked segment (43.05-79.25 Mb) was found to show extremely low diversity, most likely due to a high density of coding genes, featuring highly conserved regions. In general, we observed higher nucleotide diversity on the autosomes, but a flat diversity gradient in X-linked segments, as a function of increasing distance from the nearest genes, leading to a decreased X: autosome (X/A) diversity ratio and contrasting to the positive correlation detected in primates and other model animals. Our evidence suggests that accelerated genetic drift but reduced directional selection on X chromosome, as well as sex-biased demographic events, explain low X-chromosome diversity in sheep species. The distinct patterns of X-linked and X/A diversity we observed between Middle Eastern and non-Middle Eastern sheep populations can be explained by multiple migrations, selection, and admixture during the domestic sheep's recent postdomestication demographic expansion, coupled with natural selection for adaptation to new environments. In addition, we identify important novel genes involved in abnormal behavioral phenotypes, metabolism, and immunity, under selection on the sheep X-chromosome.

  19. Population diversity of Diaphorina citri (Hemiptera: Liviidae) in China based on whole mitochondrial genome sequences

    Science.gov (United States)

    BACKGROUND: Diaphorina citri (Asian citrus psyllid, ACP) transmits “Candidatus Liberibacter asiaticus”, an unculturable alpha-proteobacterium associated with citrus Huanglongbing (HLB). ACP has been reported in 11 provinces/regions in China, yet its population diversity remains unclear. In this stud...

  20. Genome-wide diversity and association mapping for capsaicinoids and fruit weight in Capsicum annuum L

    Science.gov (United States)

    Accumulated capsaicinoid content and increased fruit size are traits resulting from Capsicum annuum domestication. In this study, we used a diverse collection of domesticated and wild C. annuum to generate 66,960 SNPs using genotyping by sequencing. Principal component analysis and identity by state...

  1. Retroelement insertional polymorphisms, diversity and phylogeography within diploid, D-genome Aegilops tauschii (Triticeae, Poaceae) sub-taxa in Iran.

    Science.gov (United States)

    Saeidi, Hojjatollah; Rahiminejad, Mohammad Reza; Heslop-Harrison, J S

    2008-04-01

    The diploid goat grass Aegilops tauschii (2n = 2x = 14) is native to the Middle East and is the D-genome donor to hexaploid bread wheat. The aim of this study was to measure the diversity of different subspecies and varieties of wild Ae. tauschii collected across the major areas where it grows in Iran and to examine patterns of diversity related to the taxa and geography. Inter-retroelement amplified polymorphism (IRAP) markers were used to analyse the biodiversity of DNA from 57 accessions of Ae. tauschii from northern and central Iran, and two hexaploid wheats. Key Results Eight IRAP primer combinations amplified a total of 171 distinct DNA fragments between 180 and 3200 bp long from the accessions, of which 169 were polymorphic. On average, about eight fragments were amplified with each primer combination, with more bands being amplified from accessions from the north-west of the country than from other accessions. The IRAP markers showed high levels of genetic diversity. Analysis of all accessions together did not allow the allocation of individuals to taxa based on morphology, but showed a tendency to put accessions from the north-west apart from others regions. It is speculated that this could be due to different activity of retroelements in the different regions. Within the two taxa with most accessions, there was a range of IRAP genotypes that could be correlated closely with geographical origin. This supports suggestions that the centre of origin of the species is towards the south-east of the Caspian Sea. IRAP is an appropriate marker system to evaluate genetic diversity and evolutionary relationships within the taxa, but it is too variable to define the taxa themselves, where more slowly evolving morphological, DNA sequence or chromosomal makers may be more appropriate.

  2. Genome analysis coupled with physiological studies reveals a diverse nitrogen metabolism in Methylocystis sp. strain SC2.

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    Bomba Dam

    Full Text Available BACKGROUND: Methylocystis sp. strain SC2 can adapt to a wide range of methane concentrations. This is due to the presence of two isozymes of particulate methane monooxygenase exhibiting different methane oxidation kinetics. To gain insight into the underlying genetic information, its genome was sequenced and found to comprise a 3.77 Mb chromosome and two large plasmids. PRINCIPAL FINDINGS: We report important features of the strain SC2 genome. Its sequence is compared with those of seven other methanotroph genomes, comprising members of the Alphaproteobacteria, Gammaproteobacteria, and Verrucomicrobia. While the pan-genome of all eight methanotroph genomes totals 19,358 CDS, only 154 CDS are shared. The number of core genes increased with phylogenetic relatedness: 328 CDS for proteobacterial methanotrophs and 1,853 CDS for the three alphaproteobacterial Methylocystaceae members, Methylocystis sp. strain SC2 and strain Rockwell, and Methylosinus trichosporium OB3b. The comparative study was coupled with physiological experiments to verify that strain SC2 has diverse nitrogen metabolism capabilities. In correspondence to a full complement of 34 genes involved in N2 fixation, strain SC2 was found to grow with atmospheric N2 as the sole nitrogen source, preferably at low oxygen concentrations. Denitrification-mediated accumulation of 0.7 nmol (30N2/hr/mg dry weight of cells under anoxic conditions was detected by tracer analysis. N2 production is related to the activities of plasmid-borne nitric oxide and nitrous oxide reductases. CONCLUSIONS/PERSPECTIVES: Presence of a complete denitrification pathway in strain SC2, including the plasmid-encoded nosRZDFYX operon, is unique among known methanotrophs. However, the exact ecophysiological role of this pathway still needs to be elucidated. Detoxification of toxic nitrogen compounds and energy conservation under oxygen-limiting conditions are among the possible roles. Relevant features that may stimulate

  3. Variation in the OC locus of Acinetobacter baumannii genomes predicts extensive structural diversity in the lipooligosaccharide.

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    Johanna J Kenyon

    Full Text Available Lipooligosaccharide (LOS is a complex surface structure that is linked to many pathogenic properties of Acinetobacter baumannii. In A. baumannii, the genes responsible for the synthesis of the outer core (OC component of the LOS are located between ilvE and aspS. The content of the OC locus is usually variable within a species, and examination of 6 complete and 227 draft A. baumannii genome sequences available in GenBank non-redundant and Whole Genome Shotgun databases revealed nine distinct new types, OCL4-OCL12, in addition to the three known ones. The twelve gene clusters fell into two distinct groups, designated Group A and Group B, based on similarities in the genes present. OCL6 (Group B was unique in that it included genes for the synthesis of L-Rhamnosep. Genetic exchange of the different configurations between strains has occurred as some OC forms were found in several different sequence types (STs. OCL1 (Group A was the most widely distributed being present in 18 STs, and OCL6 was found in 16 STs. Variation within clones was also observed, with more than one OC locus type found in the two globally disseminated clones, GC1 and GC2, that include the majority of multiply antibiotic resistant isolates. OCL1 was the most abundant gene cluster in both GC1 and GC2 genomes but GC1 isolates also carried OCL2, OCL3 or OCL5, and OCL3 was also present in GC2. As replacement of the OC locus in the major global clones indicates the presence of sub-lineages, a PCR typing scheme was developed to rapidly distinguish Group A and Group B types, and to distinguish the specific forms found in GC1 and GC2 isolates.

  4. Genomic analysis of globally diverse Mycobacterium tuberculosis strains provides insights into emergence and spread of multidrug resistance

    Science.gov (United States)

    Manson, Abigail L.; Cohen, Keira A.; Abeel, Thomas; Desjardins, Christopher A.; Armstrong, Derek T.; Barry, Clifton E.; Brand, Jeannette; Chapman, Sinéad B.; Cho, Sang-Nae; Gabrielian, Andrei; Gomez, James; Jodals, Andreea M.; Joloba, Moses; Jureen, Pontus; Lee, Jong Seok; Malinga, Lesibana; Maiga, Mamoudou; Nordenberg, Dale; Noroc, Ecaterina; Romancenco, Elena; Salazar, Alex; Ssengooba, Willy; Velayati, A. A.; Winglee, Kathryn; Zalutskaya, Aksana; Via, Laura E.; Cassell, Gail H.; Dorman, Susan E.; Ellner, Jerrold; Farnia, Parissa; Galagan, James E.; Rosenthal, Alex; Crudu, Valeriu; Homorodean, Daniela; Hsueh, Po-Ren; Narayanan, Sujatha; Pym, Alexander S.; Skrahina, Alena; Swaminathan, Soumya; Van der Walt, Martie; Alland, David; Bishai, William R.; Cohen, Ted; Hoffner, Sven; Birren, Bruce W.; Earl, Ashlee M.

    2017-01-01

    Multidrug-resistant tuberculosis (MDR-TB), caused by drug resistant strains of Mycobacterium tuberculosis, is an increasingly serious problem worldwide. In this study, we examined a dataset of 5,310 M. tuberculosis whole genome sequences from five continents. Despite great diversity with respect to geographic point of isolation, genetic background and drug resistance, patterns of drug resistance emergence were conserved globally. We have identified harbinger mutations that often precede MDR. In particular, the katG S315T mutation, conferring resistance to isoniazid, overwhelmingly arose before rifampicin resistance across all lineages, geographic regions, and time periods. Molecular diagnostics that include markers for rifampicin resistance alone will be insufficient to identify pre-MDR strains. Incorporating knowledge of pre-MDR polymorphisms, particularly katG S315, into molecular diagnostics will enable targeted treatment of patients with pre-MDR-TB to prevent further development of MDR-TB. PMID:28092681

  5. Genomic and Metagenomic Analysis of Diversity-Generating Retroelements Associated with Treponema denticola

    OpenAIRE

    Nimkulrat, Sutichot; Lee, Heewook; Doak, Thomas G.; Ye, Yuzhen

    2016-01-01

    Diversity-generating retroelements (DGRs) are genetic cassettes that can produce massive protein sequence variation in prokaryotes. Presumably DGRs confer selective advantages to their hosts (bacteria or viruses) by generating variants of target genes—typically resulting in target proteins with altered ligand-binding specificity—through a specialized error-prone reverse transcription process. The only extensively studied DGR system is from the Bordetella phage BPP-1, although DGRs are predict...

  6. Structural diversity and dynamics of genomic replication origins in Schizosaccharomyces pombe

    Science.gov (United States)

    Cotobal, Cristina; Segurado, Mónica; Antequera, Francisco

    2010-01-01

    DNA replication origins (ORI) in Schizosaccharomyces pombe colocalize with adenine and thymine (A+T)-rich regions, and earlier analyses have established a size from 0.5 to over 3 kb for a DNA fragment to drive replication in plasmid assays. We have asked what are the requirements for ORI function in the chromosomal context. By designing artificial ORIs, we have found that A+T-rich fragments as short as 100 bp without homology to S. pombe DNA are able to initiate replication in the genome. On the other hand, functional dissection of endogenous ORIs has revealed that some of them span a few kilobases and include several modules that may be as short as 25–30 contiguous A+Ts capable of initiating replication from ectopic chromosome positions. The search for elements with these characteristics across the genome has uncovered an earlier unnoticed class of low-efficiency ORIs that fire late during S phase. These results indicate that ORI specification and dynamics varies widely in S. pombe, ranging from very short elements to large regions reminiscent of replication initiation zones in mammals. PMID:20094030

  7. New Insights into the genetic diversity of Clostridium botulinum Group III through extensive genome exploration

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    Cédric eWoudstra

    2016-05-01

    Full Text Available Animal botulism is caused by group III Clostridium botulinum strains producing type C and D toxins, or their chimeric forms C/D and D/C. Animal botulism is considered an emerging disease in Europe, notably in poultry production. Before our study, 14 genomes from different countries were available in the public database, but none were from France. In order to investigate the genetic relationship of French strains with different geographical areas and find new potential typing targets, 17 strains of C. botulinum group III were sequenced (16 from France and one from New Caledonia. Fourteen were type C/D strains isolated from chickens, ducks, guinea fowl and turkeys and three were type D/C strains isolated from cattle. The New Caledonian strain was a type D/C strain. Whole genome sequence analysis showed the French strains to be closely related to European strains from C. botulinum group III lineages Ia and Ib. The investigation of CRISPR sequences as genetic targets for differentiating strains in group III proved to be irrelevant for type C/D due to a deficient CRISPR/Cas mechanism, but not for type D/C. Conversely, the extrachromosomal elements of type C/D strains could be used to generate a genetic ID card. The highest level of discrimination was achieved with SNP core phylogeny, which allowed differentiation up to strain level and provide the most relevant information for genetic epidemiology studies and discrimination.

  8. Genomic diversity and immunomodulatory activity of Lactobacillus plantarum isolated from dairy products.

    Science.gov (United States)

    Zago, M; Scaltriti, E; Bonvini, B; Fornasari, M E; Penna, G; Massimiliano, L; Carminati, D; Rescigno, M; Giraffa, G

    2017-08-24

    In this study, we aimed to investigate some functional characteristics and the immunomodulatory properties of three strains of Lactobacillus plantarum of dairy origin which, in a previous screening, showed to be candidate probiotics. Genome sequencing and comparative genomics, which confirmed the presence of genes involved in folate and riboflavin production and in the immune response of dendritic cells (DCs), prompted us to investigate the ability of the three strains to accumulate the two vitamins and their immunomodulation properties. The ability of the three strains to release antioxidant components in milk was also investigated. Small amounts of folate and riboflavin were produced by the three strains, while they showed a good antioxidant capacity in milk with FRAP method. The immune response experiments well correlated with the presence of candidate genes influencing in DCs cytokine response to L. plantarum. Specifically, the amounts of secreted cytokins by DCs after stimulation with cells of Lp790, Lp813 and Lp998 resulted pro-inflammatory whereas stimulation with culture supernatants (postbiotics) inhibited the release of interleukin (IL)-12p70 and increased the release of the anti-inflammatory IL-10 cytokine. This study adds further evidence on the importance of L. plantarum in human health. Understanding how probiotics (or postbiotics) work in preclinical models can allow a rational choice of the different strains for clinical and/or commercial use.

  9. A Genome-Wide Association Study Reveals Genes Associated with Fusarium Ear Rot Resistance in a Maize Core Diversity Panel

    Science.gov (United States)

    Zila, Charles T.; Samayoa, L. Fernando; Santiago, Rogelio; Butrón, Ana; Holland, James B.

    2013-01-01

    Fusarium ear rot is a common disease of maize that affects food and feed quality globally. Resistance to the disease is highly quantitative, and maize breeders have difficulty incorporating polygenic resistance alleles from unadapted donor sources into elite breeding populations without having a negative impact on agronomic performance. Identification of specific allele variants contributing to improved resistance may be useful to breeders by allowing selection of resistance alleles in coupling phase linkage with favorable agronomic characteristics. We report the results of a genome-wide association study to detect allele variants associated with increased resistance to Fusarium ear rot in a maize core diversity panel of 267 inbred lines evaluated in two sets of environments. We performed association tests with 47,445 single-nucleotide polymorphisms (SNPs) while controlling for background genomic relationships with a mixed model and identified three marker loci significantly associated with disease resistance in at least one subset of environments. Each associated SNP locus had relatively small additive effects on disease resistance (±1.1% on a 0–100% scale), but nevertheless were associated with 3 to 12% of the genotypic variation within or across environment subsets. Two of three identified SNPs colocalized with genes that have been implicated with programmed cell death. An analysis of associated allele frequencies within the major maize subpopulations revealed enrichment for resistance alleles in the tropical/subtropical and popcorn subpopulations compared with other temperate breeding pools. PMID:24048647

  10. Genome-wide analysis of SSR and ILP markers in trees: diversity profiling, alternate distribution, and applications in duplication.

    Science.gov (United States)

    Xia, Xinyao; Luan, Lin Lin; Qin, Guanghua; Yu, Li Fang; Wang, Zhi Wei; Dong, Wan Chen; Song, Yumin; Qiao, Yuling; Zhang, Xian Sheng; Sang, Ya Lin; Yang, Long

    2017-12-20

    Molecular markers are efficient tools for breeding and genetic studies. However, despite their ecological and economic importance, their development and application have long been hampered. In this study, we identified 524,170 simple sequence repeat (SSR), 267,636 intron length polymorphism (ILP), and 11,872 potential intron polymorphism (PIP) markers from 16 tree species based on recently available genome sequences. Larger motifs, including hexamers and heptamers, accounted for most of the seven different types of SSR loci. Within these loci, A/T bases comprised a significantly larger proportion of sequence than G/C. SSR and ILP markers exhibited an alternative distribution pattern. Most SSRs were monomorphic markers, and the proportions of polymorphic markers were positively correlated with genome size. By verifying with all 16 tree species, 54 SSR, 418 ILP, and four PIP universal markers were obtained, and their efficiency was examined by PCR. A combination of five SSR and six ILP markers were used for the phylogenetic analysis of 30 willow samples, revealing a positive correlation between genetic diversity and geographic distance. We also found that SSRs can be used as tools for duplication analysis. Our findings provide important foundations for the development of breeding and genetic studies in tree species.

  11. Diverse and Abundant Secondary Metabolism Biosynthetic Gene Clusters in the Genomes of Marine Sponge Derived Streptomyces spp. Isolates

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    Stephen A. Jackson

    2018-02-01

    Full Text Available The genus Streptomyces produces secondary metabolic compounds that are rich in biological activity. Many of these compounds are genetically encoded by large secondary metabolism biosynthetic gene clusters (smBGCs such as polyketide synthases (PKS and non-ribosomal peptide synthetases (NRPS which are modular and can be highly repetitive. Due to the repeats, these gene clusters can be difficult to resolve using short read next generation datasets and are often quite poorly predicted using standard approaches. We have sequenced the genomes of 13 Streptomyces spp. strains isolated from shallow water and deep-sea sponges that display antimicrobial activities against a number of clinically relevant bacterial and yeast species. Draft genomes have been assembled and smBGCs have been identified using the antiSMASH (antibiotics and Secondary Metabolite Analysis Shell web platform. We have compared the smBGCs amongst strains in the search for novel sequences conferring the potential to produce novel bioactive secondary metabolites. The strains in this study recruit to four distinct clades within the genus Streptomyces. The marine strains host abundant smBGCs which encode polyketides, NRPS, siderophores, bacteriocins and lantipeptides. The deep-sea strains appear to be enriched with gene clusters encoding NRPS. Marine adaptations are evident in the sponge-derived strains which are enriched for genes involved in the biosynthesis and transport of compatible solutes and for heat-shock proteins. Streptomyces spp. from marine environments are a promising source of novel bioactive secondary metabolites as the abundance and diversity of smBGCs show high degrees of novelty. Sponge derived Streptomyces spp. isolates appear to display genomic adaptations to marine living when compared to terrestrial strains.

  12. Genomic diversity of Saccharomyces cerevisiae yeasts associated with alcoholic fermentation of bacanora produced by artisanal methods.

    Science.gov (United States)

    Álvarez-Ainza, M L; Zamora-Quiñonez, K A; Moreno-Ibarra, G M; Acedo-Félix, E

    2015-03-01

    Bacanora is a spirituous beverage elaborated with Agave angustifolia Haw in an artisanal process. Natural fermentation is mostly performed with native yeasts and bacteria. In this study, 228 strains of yeast like Saccharomyces were isolated from the natural alcoholic fermentation on the production of bacanora. Restriction analysis of the amplified region ITS1-5.8S-ITS2 of the ribosomal DNA genes (RFLPr) were used to confirm the genus, and 182 strains were identified as Saccharomyces cerevisiae. These strains displayed high genomic variability in their chromosomes profiles by karyotyping. Electrophoretic profiles of the strains evaluated showed a large number of chromosomes the size of which ranged between 225 and 2200 kpb approximately.

  13. Genomic fingerprinting and serotyping of Salmonella from Galápagos iguanas demonstrates island differences in strain diversity.

    Science.gov (United States)

    Wheeler, Emily; Cann, Isaac K O; Mackie, Roderick I

    2011-04-01

    Salmonella carriage patterns in wild and captive reptiles suggest that both geographical proximity and host ecological differences may determine bacterial diversity among reptile populations. In this study, we explore the relative importance of these factors on Salmonella diversity in free-living Galápagos iguanas. We isolated Salmonella enterica from marine iguanas (Amblyrhynchus cristatus) and land iguanas (Conolophus subcristatus and C. pallidus) living on two islands (Plaza Sur and Santa Fe). We evaluated Salmonella population patterns using genomic fingerprints, sequence typing and serotyping. Rep-PCR fingerprinting revealed significant grouping of isolates by iguana population. Island residence had the strongest effect on isolate similarity, but a smaller divergence among Salmonella isolates from different iguana ecotypes (land versus marine) was detected within each island. In contrast, sequence typing detected a marginal difference in isolate genotypes between islands. Sequence types corresponded strongly to serotype identity, with both islands hosting a unique serovar pool. Our findings suggest that both geographical location and host ecotype differences (either from within host strain selection or from differences in habitat use) contribute to Salmonella population patterns in the Galápagos Islands. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  14. Genetic diversity and genomic resources available for the small millet crops to accelerate a New Green Revolution.

    Science.gov (United States)

    Goron, Travis L; Raizada, Manish N

    2015-01-01

    Small millets are nutrient-rich food sources traditionally grown and consumed by subsistence farmers in Asia and Africa. They include finger millet (Eleusine coracana), foxtail millet (Setaria italica), kodo millet (Paspalum scrobiculatum), proso millet (Panicum miliaceum), barnyard millet (Echinochloa spp.), and little millet (Panicum sumatrense). Local farmers value the small millets for their nutritional and health benefits, tolerance to extreme stress including drought, and ability to grow under low nutrient input conditions, ideal in an era of climate change and steadily depleting natural resources. Little scientific attention has been paid to these crops, hence they have been termed "orphan cereals." Despite this challenge, an advantageous quality of the small millets is that they continue to be grown in remote regions of the world which has preserved their biodiversity, providing breeders with unique alleles for crop improvement. The purpose of this review, first, is to highlight the diverse traits of each small millet species that are valued by farmers and consumers which hold potential for selection, improvement or mechanistic study. For each species, the germplasm, genetic and genomic resources available will then be described as potential tools to exploit this biodiversity. The review will conclude with noting current trends and gaps in the literature and make recommendations on how to better preserve and utilize diversity within these species to accelerate a New Green Revolution for subsistence farmers in Asia and Africa.

  15. Genetic diversity and genomic resources available for the small millet crops to accelerate a New Green Revolution

    Directory of Open Access Journals (Sweden)

    Travis Luc Goron

    2015-03-01

    Full Text Available Small millets are nutrient-rich food sources traditionally grown and consumed by subsistence farmers in Asia and Africa. They include finger millet (Eleusine coracana, foxtail millet (Setaria italica, kodo millet (Paspalum scrobiculatum, proso millet (Panicum miliaceum, barnyard millet (Echinochloa spp., and little millet (Panicum sumatrense. Local farmers value the small millets for their nutritional and health, tolerance to extreme stress including drought, and ability to grow under low nutrient input conditions, ideal in an era of climate change and steadily depleting natural resources. Little scientific attention has been paid to these crops, hence they have been termed orphan cereals. Despite this challenge, an advantageous quality of the small millets is that they continue to be grown in remote regions of the world which has preserved their biodiversity, providing breeders with unique alleles for crop improvement. The purpose of this review, first, is to highlight the diverse traits of each small millet species that are valued by farmers and consumers (e.g. nutritional quality which hold potential for selection, improvement or mechanistic study. For each species, the germplasm, genetic and genomic resources available will then be described as potential tools to exploit this biodiversity. The review will conclude with noting current trends and gaps in the literature and make recommendations on how to better preserve and utilize diversity within these species to accelerate a New Green Revolution for subsistence farmers in Asia and Africa.

  16. Mitochondrial genome diversity and population structure of two western honey bee subspecies in the Republic of South Africa.

    Science.gov (United States)

    Eimanifar, Amin; Kimball, Rebecca T; Braun, Edward L; Ellis, James D

    2018-01-22

    Apis mellifera capensis Eschscholtz and A.m. scutellata Lepeletier are subspecies of western honey bees that are indigenous to the Republic of South Africa (RSA). Both subspecies have invasive potential and are organisms of concern for areas outside their native range, though they are important bees to beekeepers, agriculture, and the environment where they are native. The aim of the present study was to examine genetic differentiation among these subspecies and estimate their phylogenetic relationships using complete mitochondrial genomes sequences. We used 25 individuals that were either assigned to one of the subspecies or designated hybrids using morphometric analyses. Phylogenetic analyses of mitogenome sequences by maximum likelihood (ML) and Bayesian inference identified a monophyletic RSA clade, subdivided into two clades. A haplotype network was consistent with the phylogenetic trees. However, members of both subspecies occurred in both clades, indicating that A.m. capensis and A.m. scutellata are neither reciprocally monophyletic nor do they exhibit paraphyly with one subspecies nested within the other subspecies. Furthermore, no mitogenomic features were diagnostic to either subspecies. All bees analyzed from the RSA expressed a substantial level of haplotype diversity (most samples had unique haplotypes) but limited nucleotide diversity. The number of variable codons across protein-coding genes (PCGs) differed among loci, with CO3 exhibiting the most variation and ATP6 the least.

  17. The little bacteria that can – diversity, genomics and ecophysiology of ‘Dehalococcoides’ spp. in contaminated environments

    Science.gov (United States)

    Taş, Neslihan; Van Eekert, Miriam H. A.; De Vos, Willem M.; Smidt, Hauke

    2010-01-01

    Summary The fate and persistence of chlorinated organics in the environment have been a concern for the past 50 years. Industrialization and extensive agricultural activities have led to the accumulation of these pollutants in the environment, while their adverse impact on various ecosystems and human health also became evident. This review provides an update on the current knowledge of specialized anaerobic bacteria, namely ‘Dehalococcoides’ spp., which are dedicated to the transformation of various chlorinated organic compounds via reductive dechlorination. Advances in microbiology and molecular techniques shed light into the diversity and functioning of Dehalococcoides spp. in several different locations. Recent genome sequencing projects revealed a large number of genes that are potentially involved in reductive dechlorination. Molecular approaches towards analysis of diversity and expression especially of reductive dehalogenase‐encoding genes are providing a growing body of knowledge on biodegradative pathways active in defined pure and mixed cultures as well as directly in the environment. Moreover, several successful field cases of bioremediation strengthen the notion of dedicated degraders such as Dehalococcoides spp. as key players in the restoration of contaminated environments. PMID:21255338

  18. An ancestry informative marker set for determining continental origin: validation and extension using human genome diversity panels

    Directory of Open Access Journals (Sweden)

    Gregersen Peter K

    2009-07-01

    Full Text Available Abstract Background Case-control genetic studies of complex human diseases can be confounded by population stratification. This issue can be addressed using panels of ancestry informative markers (AIMs that can provide substantial population substructure information. Previously, we described a panel of 128 SNP AIMs that were designed as a tool for ascertaining the origins of subjects from Europe, Sub-Saharan Africa, Americas, and East Asia. Results In this study, genotypes from Human Genome Diversity Panel populations were used to further evaluate a 93 SNP AIM panel, a subset of the 128 AIMS set, for distinguishing continental origins. Using both model-based and relatively model-independent methods, we here confirm the ability of this AIM set to distinguish diverse population groups that were not previously evaluated. This study included multiple population groups from Oceana, South Asia, East Asia, Sub-Saharan Africa, North and South America, and Europe. In addition, the 93 AIM set provides population substructure information that can, for example, distinguish Arab and Ashkenazi from Northern European population groups and Pygmy from other Sub-Saharan African population groups. Conclusion These data provide additional support for using the 93 AIM set to efficiently identify continental subject groups for genetic studies, to identify study population outliers, and to control for admixture in association studies.

  19. Mitochondrial genomes of Australian chicken Eimeria support the presence of ten species with low genetic diversity among strains.

    Science.gov (United States)

    Morgan, Jess A T; Godwin, Rosamond M

    2017-08-30

    Modern molecular approaches have vastly improved diagnostic capabilities for differentiating among species of chicken infecting Eimeria. Consolidating information from multiple genetic markers, adding additional poultry Eimeria species and increasing the size of available data-sets is improving the resolving power of the DNA, and consequently our understanding of the genus. This study adds information from 25 complete mitochondrial DNA genomes from Australian chicken Eimeria isolates representing all 10 species known to occur in Australia, including OTU-X, -Y and -Z. The resulting phylogeny provides a comprehensive view of species relatedness highlighting where the OTUs align with respect to others members of the genus. All three OTUs fall within the Eimeria clade that contains only chicken-infecting species with close affinities to E. maxima, E. brunetti and E. mitis. Mitochondrial genetic diversity was low among Australian isolates likely reflecting their recent introduction to the country post-European settlement. The lack of observed genetic diversity is a promising outcome as it suggests that the currently used live vaccines should continue to offer widespread protection against Eimeria outbreaks in all states and territories. Flocks were frequently found to host multiple strains of the same species, a factor that should be considered when studying disease epidemiology in the field. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  20. Brucella spp. of amphibians comprise genomically diverse motile strains competent for replication in macrophages and survival in mammalian hosts

    Science.gov (United States)

    Al Dahouk, Sascha; Köhler, Stephan; Occhialini, Alessandra; Jiménez de Bagüés, María Pilar; Hammerl, Jens Andre; Eisenberg, Tobias; Vergnaud, Gilles; Cloeckaert, Axel; Zygmunt, Michel S.; Whatmore, Adrian M.; Melzer, Falk; Drees, Kevin P.; Foster, Jeffrey T.; Wattam, Alice R.; Scholz, Holger C.

    2017-01-01

    Twenty-one small Gram-negative motile coccobacilli were isolated from 15 systemically diseased African bullfrogs (Pyxicephalus edulis), and were initially identified as Ochrobactrum anthropi by standard microbiological identification systems. Phylogenetic reconstructions using combined molecular analyses and comparative whole genome analysis of the most diverse of the bullfrog strains verified affiliation with the genus Brucella and placed the isolates in a cluster containing B. inopinata and the other non-classical Brucella species but also revealed significant genetic differences within the group. Four representative but molecularly and phenotypically diverse strains were used for in vitro and in vivo infection experiments. All readily multiplied in macrophage-like murine J774-cells, and their overall intramacrophagic growth rate was comparable to that of B. inopinata BO1 and slightly higher than that of B. microti CCM 4915. In the BALB/c murine model of infection these strains replicated in both spleen and liver, but were less efficient than B. suis 1330. Some strains survived in the mammalian host for up to 12 weeks. The heterogeneity of these novel strains hampers a single species description but their phenotypic and genetic features suggest that they represent an evolutionary link between a soil-associated ancestor and the mammalian host-adapted pathogenic Brucella species. PMID:28300153

  1. Genetic diversity of Streptococcus suis isolates as determined by comparative genome hybridization

    Directory of Open Access Journals (Sweden)

    Thi Hoa

    2011-07-01

    Full Text Available Abstract Background Streptococcus suis is a zoonotic pathogen that causes infections in young piglets. S. suis is a heterogeneous species. Thirty-three different capsular serotypes have been described, that differ in virulence between as well as within serotypes. Results In this study, the correlation between gene content, serotype, phenotype and virulence among 55 S. suis strains was studied using Comparative Genome Hybridization (CGH. Clustering of CGH data divided S. suis isolates into two clusters, A and B. Cluster A isolates could be discriminated from cluster B isolates based on the protein expression of extracellular factor (EF. Cluster A contained serotype 1 and 2 isolates that were correlated with virulence. Cluster B mainly contained serotype 7 and 9 isolates. Genetic similarity was observed between serotype 7 and serotype 2 isolates that do not express muramidase released protein (MRP and EF (MRP-EF-, suggesting these isolates originated from a common founder. Profiles of 25 putative virulence-associated genes of S. suis were determined among the 55 isolates. Presence of all 25 genes was shown for cluster A isolates, whereas cluster B isolates lacked one or more putative virulence genes. Divergence of S. suis isolates was further studied based on the presence of 39 regions of difference. Conservation of genes was evaluated by the definition of a core genome that contained 78% of all ORFs in P1/7. Conclusions In conclusion, we show that CGH is a valuable method to study distribution of genes or gene clusters among isolates in detail, yielding information on genetic similarity, and virulence traits of S. suis isolates.

  2. Chaperone-usher fimbriae in a diverse selection of Gallibacterium genomes

    DEFF Research Database (Denmark)

    Kudirkiene, Egle; Bager, Ragnhild Jørgensen; Johnson, Timothy J.

    2014-01-01

    Background Fimbriae are bacterial cell surface organelles involved in the pathogenesis of many bacterial species, including Gallibacterium anatis, in which a F17-like fimbriae of the chaperone-usher (CU) family was recently shown to be an important virulence factor and vaccine candidate. To reveal...... that their expression may require other in vitro or in vivo conditions. Conclusions This is the first approach establishing a systematic fimbria classification system within Gallibacterium spp., which indicates a species-wide distribution of γ4 CU fimbriae among a diverse collection of Gallibacterium isolates...

  3. Molecular diversity and phylogeny of Triticum-Aegilops species possessing D genome revealed by SSR and ISSR markers

    Directory of Open Access Journals (Sweden)

    Moradkhani Hoda

    2015-12-01

    Full Text Available The aim of this study is investigation the applicability of SSR and ISSR markers in evaluating the genetic relationships in twenty accessions of Aegilops and Triticum species with D genome in different ploidy levels. Totally, 119 bands and 46 alleles were detected using ten primers for ISSR and SSR markers, respectively. Polymorphism Information Content values for all primers ranged from 0.345 to 0.375 with an average of 0.367 for SSR, and varied from 0.29 to 0.44 with the average 0.37 for ISSR marker. Analysis of molecular variance (AMOVA revealed that 81% (ISSR and 84% (SSR of variability was partitioned among individuals within populations. Comparing the genetic diversity of Aegilops and Triticum accessions, based on genetic parameters, shows that genetic variation of Ae. crassa and Ae. tauschii species are higher than other species, especially in terms of Nei’s gene diversity. Cluster analysis, based on both markers, separated total accessions in three groups. However, classification based on SSR marker data was not conformed to classification according to ISSR marker data. Principal co-ordinate analysis (PCoA for SSR and ISSR data showed that, the first two components clarified 53.48% and 49.91% of the total variation, respectively. This analysis (PCoA, also, indicated consistent patterns of genetic relationships for ISSR data sets, however, the grouping of accessions was not completely accorded to their own geographical origins. Consequently, a high level of genetic diversity was revealed from the accessions sampled from different eco-geographical regions of Iran.

  4. New Insights on Water Buffalo Genomic Diversity and Post-Domestication Migration Routes From Medium Density SNP Chip Data

    Directory of Open Access Journals (Sweden)

    Licia Colli

    2018-03-01

    Full Text Available The domestic water buffalo is native to the Asian continent but through historical migrations and recent importations, nowadays has a worldwide distribution. The two types of water buffalo, i.e., river and swamp, display distinct morphological and behavioral traits, different karyotypes and also have different purposes and geographical distributions. River buffaloes from Pakistan, Iran, Turkey, Egypt, Romania, Bulgaria, Italy, Mozambique, Brazil and Colombia, and swamp buffaloes from China, Thailand, Philippines, Indonesia and Brazil were genotyped with a species-specific medium-density 90K SNP panel. We estimated the levels of molecular diversity and described population structure, which revealed historical relationships between populations and migration events. Three distinct gene pools were identified in pure river as well as in pure swamp buffalo populations. Genomic admixture was seen in the Philippines and in Brazil, resulting from importations of animals for breed improvement. Our results were largely consistent with previous archeological, historical and molecular-based evidence for two independent domestication events for river- and swamp-type buffaloes, which occurred in the Indo-Pakistani region and close to the China/Indochina border, respectively. Based on a geographical analysis of the distribution of diversity, our evidence also indicated that the water buffalo spread out of the domestication centers followed two major divergent migration directions: river buffaloes migrated west from the Indian sub-continent while swamp buffaloes migrated from northern Indochina via an east-south-eastern route. These data suggest that the current distribution of water buffalo diversity has been shaped by the combined effects of multiple migration events occurred at different stages of the post-domestication history of the species.

  5. Using diverse U.S. beef cattle genomes to identify missense mutations in EPAS1, a gene associated with pulmonary hypertension

    Science.gov (United States)

    The availability of whole genome sequence (WGS) data has made it possible to discover protein variants in silico. However, existing bovine WGS databases do not show data in a form conducive to protein variant analysis, and tend to under represent the breadth of genetic diversity in U.S. beef cattle...

  6. Using diverse U.S. beef cattle genomes to identify missense mutations in EPAS1, a gene associated with high-altitude pulmonary hypertension

    Science.gov (United States)

    The availability of whole genome sequence (WGS) data has made it possible to discover protein variants in silico. However, bovine WGS databases comprised of related influential sires from relatively few breeds tend to under represent the breadth of genetic diversity in U.S. beef cattle. Thus, our ...

  7. Characterization and Diversity of Novel PIF/Harbinger DNA Transposons in Brassica Genomes

    International Nuclear Information System (INIS)

    Nouroz, F.; Noreen, S.; Harrison, H.

    2016-01-01

    Among DNA transposons, PIF/Harbinger is most recently identified superfamily characterized by 3 bp target site duplications (TSDs), flanked by 14-45 bp terminal inverted repeats (TIRs) and displaying DDD or DDE domain displaying transposase. Their autonomous elements contain two open reading frames, ORF1 and ORF2 encoding superfamily specific transposase and DNA-binding domain. Harbinger DNA transposons are recently identified in few plants. In present study, computational and molecular approaches were used for the identification of 8 Harbinger transposons, of which only 2 were complete with putative trans posase, while rest 6 lack transposase and are considered as defective or non-autonomous elements. They ranged in size from 0.5-4 kb with 3 bp TSDs, 15-42 bp TIRs and internal AT richregions. The PCR amplification of Brassica Harbinger transposase revealed diversity and ancient nature of these elements. The amplification polymorphism of some non-autonomous Harbingers showed species specific distribution. Phylogenetic analyses of transposase clustered them into two clades (monocot and dicot) and five sub-clades. The Brassica, Arabidopsis and Malustransposase clustered into genera specific sub-clades; although a lot of homology in transposase was observed. The multiple sequence alignment of Brassica and related transposase showed homology in five conserved blocks. The DD/Sub 35/E triad and sequences showed similarity to already known Pong-like or Arabidopsis ATIS12 Harbinger transposase in contrast to other transposase having DD/Sub 47/E or DD/Sub 48/E motifs. The present study will be helpful in the characterization of Harbingers, their structural diversity in related genera and Harbinger based molecular markers for varietal/lines identifications. (author)

  8. Getting genetic access to natural adenovirus genomes to explore vector diversity.

    Science.gov (United States)

    Zhang, Wenli; Ehrhardt, Anja

    2017-10-01

    Recombinant vectors based on the human adenovirus type 5 (HAdV5) have been developed and extensively used in preclinical and clinical studies for over 30 years. However, certain restrictions of HAdV5-based vectors have limited their clinical applications because they are rather inefficient in specifically transducing cells of therapeutic interest that lack the coxsackievirus and adenovirus receptor (CAR). Moreover, enhanced vector-associated toxicity and widespread preexisting immunity have been shown to significantly hamper the effectiveness of HAdV-5-mediated gene transfer. However, evolution of adenoviruses in the natural host is driving the generation of novel types with altered virulence, enhanced transmission, and altered tissue tropism. As a consequence, an increasing number of alternative adenovirus types were identified, which may represent a valuable resource for the development of novel vector types. Thus, researchers are focusing on the other naturally occurring adenovirus types, which are structurally similar but functionally different from HAdV5. To this end, several strategies have been devised for getting genetic access to adenovirus genomes, resulting in a new panel of adenoviral vectors. Importantly, these vectors were shown to have a host range different from HAdV5 and to escape the anti-HAdV5 immune response, thus underlining the great potential of this approach. In summary, this review provides a state-of-the-art overview of one essential step in adenoviral vector development.

  9. A geographically-diverse collection of 418 human gut microbiome pathway genome databases

    KAUST Repository

    Hahn, Aria S.

    2017-04-11

    Advances in high-throughput sequencing are reshaping how we perceive microbial communities inhabiting the human body, with implications for therapeutic interventions. Several large-scale datasets derived from hundreds of human microbiome samples sourced from multiple studies are now publicly available. However, idiosyncratic data processing methods between studies introduce systematic differences that confound comparative analyses. To overcome these challenges, we developed GutCyc, a compendium of environmental pathway genome databases (ePGDBs) constructed from 418 assembled human microbiome datasets using MetaPathways, enabling reproducible functional metagenomic annotation. We also generated metabolic network reconstructions for each metagenome using the Pathway Tools software, empowering researchers and clinicians interested in visualizing and interpreting metabolic pathways encoded by the human gut microbiome. For the first time, GutCyc provides consistent annotations and metabolic pathway predictions, making possible comparative community analyses between health and disease states in inflammatory bowel disease, Crohn’s disease, and type 2 diabetes. GutCyc data products are searchable online, or may be downloaded and explored locally using MetaPathways and Pathway Tools.

  10. Integrated Genomic Analysis of Diverse Induced Pluripotent Stem Cells from the Progenitor Cell Biology Consortium.

    Science.gov (United States)

    Salomonis, Nathan; Dexheimer, Phillip J; Omberg, Larsson; Schroll, Robin; Bush, Stacy; Huo, Jeffrey; Schriml, Lynn; Ho Sui, Shannan; Keddache, Mehdi; Mayhew, Christopher; Shanmukhappa, Shiva Kumar; Wells, James; Daily, Kenneth; Hubler, Shane; Wang, Yuliang; Zambidis, Elias; Margolin, Adam; Hide, Winston; Hatzopoulos, Antonis K; Malik, Punam; Cancelas, Jose A; Aronow, Bruce J; Lutzko, Carolyn

    2016-07-12

    The rigorous characterization of distinct induced pluripotent stem cells (iPSC) derived from multiple reprogramming technologies, somatic sources, and donors is required to understand potential sources of variability and downstream potential. To achieve this goal, the Progenitor Cell Biology Consortium performed comprehensive experimental and genomic analyses of 58 iPSC from ten laboratories generated using a variety of reprogramming genes, vectors, and cells. Associated global molecular characterization studies identified functionally informative correlations in gene expression, DNA methylation, and/or copy-number variation among key developmental and oncogenic regulators as a result of donor, sex, line stability, reprogramming technology, and cell of origin. Furthermore, X-chromosome inactivation in PSC produced highly correlated differences in teratoma-lineage staining and regulator expression upon differentiation. All experimental results, and raw, processed, and metadata from these analyses, including powerful tools, are interactively accessible from a new online portal at https://www.synapse.org to serve as a reusable resource for the stem cell community. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Aboriginal Australian mitochondrial genome variation - an increased understanding of population antiquity and diversity

    Science.gov (United States)

    Nagle, Nano; van Oven, Mannis; Wilcox, Stephen; van Holst Pellekaan, Sheila; Tyler-Smith, Chris; Xue, Yali; Ballantyne, Kaye N.; Wilcox, Leah; Papac, Luka; Cooke, Karen; van Oorschot, Roland A. H.; McAllister, Peter; Williams, Lesley; Kayser, Manfred; Mitchell, R. John; Adhikarla, Syama; Adler, Christina J.; Balanovska, Elena; Balanovsky, Oleg; Bertranpetit, Jaume; Clarke, Andrew C.; Comas, David; Cooper, Alan; der Sarkissian, Clio S. I.; Dulik, Matthew C.; Gaieski, Jill B.; Ganeshprasad, Arunkumar; Haak, Wolfgang; Haber, Marc; Hobbs, Angela; Javed, Asif; Jin, Li; Kaplan, Matthew E.; Li, Shilin; Martínez-Cruz, Begoña; Matisoo-Smith, Elizabeth A.; Melé, Marta; Merchant, Nirav C.; Owings, Amanda C.; Parida, Laxmi; Pitchappan, Ramasamy; Platt, Daniel E.; Quintana-Murci, Lluis; Renfrew, Colin; Royyuru, Ajay K.; Santhakumari, Arun Varatharajan; Santos, Fabrício R.; Schurr, Theodore G.; Soodyall, Himla; Soria Hernanz, David F.; Swamikrishnan, Pandikumar; Vilar, Miguel G.; Wells, R. Spencer; Zalloua, Pierre A.; Ziegle, Janet S.

    2017-03-01

    Aboriginal Australians represent one of the oldest continuous cultures outside Africa, with evidence indicating that their ancestors arrived in the ancient landmass of Sahul (present-day New Guinea and Australia) ~55 thousand years ago. Genetic studies, though limited, have demonstrated both the uniqueness and antiquity of Aboriginal Australian genomes. We have further resolved known Aboriginal Australian mitochondrial haplogroups and discovered novel indigenous lineages by sequencing the mitogenomes of 127 contemporary Aboriginal Australians. In particular, the more common haplogroups observed in our dataset included M42a, M42c, S, P5 and P12, followed by rarer haplogroups M15, M16, N13, O, P3, P6 and P8. We propose some major phylogenetic rearrangements, such as in haplogroup P where we delinked P4a and P4b and redefined them as P4 (New Guinean) and P11 (Australian), respectively. Haplogroup P2b was identified as a novel clade potentially restricted to Torres Strait Islanders. Nearly all Aboriginal Australian mitochondrial haplogroups detected appear to be ancient, with no evidence of later introgression during the Holocene. Our findings greatly increase knowledge about the geographic distribution and phylogenetic structure of mitochondrial lineages that have survived in contemporary descendants of Australia’s first settlers.

  12. Comparative evolutionary genomics of Corynebacterium with special reference to codon and amino acid usage diversities.

    Science.gov (United States)

    Pal, Shilpee; Sarkar, Indrani; Roy, Ayan; Mohapatra, Pradeep K Das; Mondal, Keshab C; Sen, Arnab

    2018-02-01

    The present study has been aimed to the comparative analysis of high GC composition containing Corynebacterium genomes and their evolutionary study by exploring codon and amino acid usage patterns. Phylogenetic study by MLSA approach, indel analysis and BLAST matrix differentiated Corynebacterium species in pathogenic and non-pathogenic clusters. Correspondence analysis on synonymous codon usage reveals that, gene length, optimal codon frequencies and tRNA abundance affect the gene expression of Corynebacterium. Most of the optimal codons as well as translationally optimal codons are C ending i.e. RNY (R-purine, N-any nucleotide base, and Y-pyrimidine) and reveal translational selection pressure on codon bias of Corynebacterium. Amino acid usage is affected by hydrophobicity, aromaticity, protein energy cost, etc. Highly expressed genes followed the cost minimization hypothesis and are less diverged at their synonymous positions of codons. Functional analysis of core genes shows significant difference in pathogenic and non-pathogenic Corynebacterium. The study reveals close relationship between non-pathogenic and opportunistic pathogenic Corynebaterium as well as between molecular evolution and survival niches of the organism.

  13. Targeted genomic enrichment and sequencing of CyHV-3 from carp tissues confirms low nucleotide diversity and mixed genotype infections

    Directory of Open Access Journals (Sweden)

    Saliha Hammoumi

    2016-09-01

    Full Text Available Koi herpesvirus disease (KHVD is an emerging disease that causes mass mortality in koi and common carp, Cyprinus carpio L. Its causative agent is Cyprinid herpesvirus 3 (CyHV-3, also known as koi herpesvirus (KHV. Although data on the pathogenesis of this deadly virus is relatively abundant in the literature, still little is known about its genomic diversity and about the molecular mechanisms that lead to such a high virulence. In this context, we developed a new strategy for sequencing full-length CyHV-3 genomes directly from infected fish tissues. Total genomic DNA extracted from carp gill tissue was specifically enriched with CyHV-3 sequences through hybridization to a set of nearly 2 million overlapping probes designed to cover the entire genome length, using KHV-J sequence (GenBank accession number AP008984 as reference. Applied to 7 CyHV-3 specimens from Poland and Indonesia, this targeted genomic enrichment enabled recovery of the full genomes with >99.9% reference coverage. The enrichment rate was directly correlated to the estimated number of viral copies contained in the DNA extracts used for library preparation, which varied between ∼5000 and ∼2×107. The average sequencing depth was >200 for all samples, thus allowing the search for variants with high confidence. Sequence analyses highlighted a significant proportion of intra-specimen sequence heterogeneity, suggesting the presence of mixed infections in all investigated fish. They also showed that inter-specimen genetic diversity at the genome scale was very low (>99.95% of sequence identity. By enabling full genome comparisons directly from infected fish tissues, this new method will be valuable to trace outbreaks rapidly and at a reasonable cost, and in turn to understand the transmission routes of CyHV-3.

  14. Genetic determinants of lipid traits in diverse populations from the population architecture using genomics and epidemiology (PAGE study.

    Directory of Open Access Journals (Sweden)

    Logan Dumitrescu

    2011-06-01

    Full Text Available For the past five years, genome-wide association studies (GWAS have identified hundreds of common variants associated with human diseases and traits, including high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C, and triglyceride (TG levels. Approximately 95 loci associated with lipid levels have been identified primarily among populations of European ancestry. The Population Architecture using Genomics and Epidemiology (PAGE study was established in 2008 to characterize GWAS-identified variants in diverse population-based studies. We genotyped 49 GWAS-identified SNPs associated with one or more lipid traits in at least two PAGE studies and across six racial/ethnic groups. We performed a meta-analysis testing for SNP associations with fasting HDL-C, LDL-C, and ln(TG levels in self-identified European American (~20,000, African American (~9,000, American Indian (~6,000, Mexican American/Hispanic (~2,500, Japanese/East Asian (~690, and Pacific Islander/Native Hawaiian (~175 adults, regardless of lipid-lowering medication use. We replicated 55 of 60 (92% SNP associations tested in European Americans at p<0.05. Despite sufficient power, we were unable to replicate ABCA1 rs4149268 and rs1883025, CETP rs1864163, and TTC39B rs471364 previously associated with HDL-C and MAFB rs6102059 previously associated with LDL-C. Based on significance (p<0.05 and consistent direction of effect, a majority of replicated genotype-phentoype associations for HDL-C, LDL-C, and ln(TG in European Americans generalized to African Americans (48%, 61%, and 57%, American Indians (45%, 64%, and 77%, and Mexican Americans/Hispanics (57%, 56%, and 86%. Overall, 16 associations generalized across all three populations. For the associations that did not generalize, differences in effect sizes, allele frequencies, and linkage disequilibrium offer clues to the next generation of association studies for these traits.

  15. Whole genome analysis of porcine astroviruses detected in Japanese pigs reveals genetic diversity and possible intra-genotypic recombination.

    Science.gov (United States)

    Ito, Mika; Kuroda, Moegi; Masuda, Tsuneyuki; Akagami, Masataka; Haga, Kei; Tsuchiaka, Shinobu; Kishimoto, Mai; Naoi, Yuki; Sano, Kaori; Omatsu, Tsutomu; Katayama, Yukie; Oba, Mami; Aoki, Hiroshi; Ichimaru, Toru; Mukono, Itsuro; Ouchi, Yoshinao; Yamasato, Hiroshi; Shirai, Junsuke; Katayama, Kazuhiko; Mizutani, Tetsuya; Nagai, Makoto

    2017-06-01

    Porcine astroviruses (PoAstVs) are ubiquitous enteric virus of pigs that are distributed in several countries throughout the world. Since PoAstVs are detected in apparent healthy pigs, the clinical significance of infection is unknown. However, AstVs have recently been associated with a severe neurological disorder in animals, including humans, and zoonotic potential has been suggested. To date, little is known about the epidemiology of PoAstVs among the pig population in Japan. In this report, we present an analysis of nearly complete genomes of 36 PoAstVs detected by a metagenomics approach in the feces of Japanese pigs. Based on a phylogenetic analysis and pairwise sequence comparison, 10, 5, 15, and 6 sequences were classified as PoAstV2, PoAstV3, PoAstV4, and PoAstV5, respectively. Co-infection with two or three strains was found in individual fecal samples from eight pigs. The phylogenetic trees of ORF1a, ORF1b, and ORF2 of PoAstV2 and PoAstV4 showed differences in their topologies. The PoAstV3 and PoAstV5 strains shared high sequence identities within each genotype in all ORFs; however, one PoAstV3 strain and one PoAstV5 strain showed considerable sequence divergence from the other PoAstV3 and PoAstV5 strains, respectively, in ORF2. Recombination analysis using whole genomes revealed evidence of multiple possible intra-genotype recombination events in PoAstV2 and PoAstV4, suggesting that recombination might have contributed to the genetic diversity and played an important role in the evolution of Japanese PoAstVs. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Whole-Genome Sequencing and Comparative Genome Analysis Provided Insight into the Predatory Features and Genetic Diversity of Two Bdellovibrio Species Isolated from Soil

    Directory of Open Access Journals (Sweden)

    Omotayo Opemipo Oyedara

    2018-01-01

    Full Text Available Bdellovibrio spp. are predatory bacteria with great potential as antimicrobial agents. Studies have shown that members of the genus Bdellovibrio exhibit peculiar characteristics that influence their ecological adaptations. In this study, whole genomes of two different Bdellovibrio spp. designated SKB1291214 and SSB218315 isolated from soil were sequenced. The core genes shared by all the Bdellovibrio spp. considered for the pangenome analysis including the epibiotic B. exovorus were 795. The number of unique genes identified in Bdellovibrio spp. SKB1291214, SSB218315, W, and B. exovorus JJS was 1343, 113, 857, and 1572, respectively. These unique genes encode hydrolytic, chemotaxis, and transporter proteins which might be useful for predation in the Bdellovibrio strains. Furthermore, the two Bdellovibrio strains exhibited differences based on the % GC content, amino acid identity, and 16S rRNA gene sequence. The 16S rRNA gene sequence of Bdellovibrio sp. SKB1291214 shared 99% identity with that of an uncultured Bdellovibrio sp. clone 12L 106 (a pairwise distance of 0.008 and 95–97% identity (a pairwise distance of 0.043 with that of other culturable terrestrial Bdellovibrio spp., including strain SSB218315. In Bdellovibrio sp. SKB1291214, 174 bp sequence was inserted at the host interaction (hit locus region usually attributed to prey attachment, invasion, and development of host independent Bdellovibrio phenotypes. Also, a gene equivalent to Bd0108 in B. bacteriovorus HD100 was not conserved in Bdellovibrio sp. SKB1291214. The results of this study provided information on the genetic characteristics and diversity of the genus Bdellovibrio that can contribute to their successful applications as a biocontrol agent.

  17. FANCG knockout CHO cells display sensitivity to diverse DNA damaging agents and possible genomic instability

    International Nuclear Information System (INIS)

    Hinz, J.M.; Tebbs, R.S.; Yamada, N.A.; Salazar, E.P.; Kopf, V.L.; Thompson, L.H.

    2003-01-01

    Full text: The function of the proteins encoded by the genes responsible for the disease Fanconi anemia (FA) have not been elucidated. Several of these proteins (FancA, C, E, F, and G) form a complex in the nucleus, and cells deficient in any one of these proteins are sensitive to crosslinking agents, suggesting a possible role for these proteins in some aspect of DNA repair, chromosomal maintenance, or replication. We constructed a FancG knockout mutant (FGKO40) in CHO AA8 cells, as well as FancG-corrected FGKO40 cells (KO40BP6, which is a pool of six BAC-clone transformants). FGKO40 cells are sensitive to a wide variety of DNA damaging agents. Sensitivity to the cross-linking agents MMC (3x) and chloroethyl-nitrosourea (3x) does not exceed that of methyl methanesulfonate (MMS) (4x), methyl-nitrosourea (4x), or ethyl-nitrosourea (3x), or the purine analog 6-thioguanine (5x). Other agents show mild sensitivity in FGKO40 cells: ionizing radiation (1.2x), UV-C (1.5x), hydroxyurea (1.2x), camptothecin (1.2x), and excess thymidine (normal). The length of S phase was carefully measured by monitoring the progression of highly synchronous G1 cells obtained by centrifugal elutriation. FGKO40 cells traversed S phase normally but had a slightly longer G2 phase than parental cells. Treatment of synchronized G1 cells with MMS did not increase S phase in parental or mutant cells, but again G2 was slightly longer for FGKO40. Mutation rates were measured at the hrpt and aprt loci, where gene inactivation confers resistance to 6-thioguanine or 8-azaadenine, respectively. FGKO40 had a slightly reduced mutation rate for hprt mutants, suggesting reduced recovery of large deletions at this locus. Moreover, the rate of methotrexate resistance was elevated 2.5-fold in mutant cells compared to controls. Resistance to this drug is generally associated with amplification of the dhfr locus, suggesting FancG plays a role in this aspect of genome stability. We suggest that the defect in FGKO

  18. Genome-wide-analyses of Listeria monocytogenes from food-processing plants reveal clonal diversity and date the emergence of persisting sequence types.

    Science.gov (United States)

    Knudsen, Gitte M; Nielsen, Jesper Boye; Marvig, Rasmus L; Ng, Yin; Worning, Peder; Westh, Henrik; Gram, Lone

    2017-08-01

    Whole genome sequencing is increasing used in epidemiology, e.g. for tracing outbreaks of food-borne diseases. This requires in-depth understanding of pathogen emergence, persistence and genomic diversity along the food production chain including in food processing plants. We sequenced the genomes of 80 isolates of Listeria monocytogenes sampled from Danish food processing plants over a time-period of 20 years, and analysed the sequences together with 10 public available reference genomes to advance our understanding of interplant and intraplant genomic diversity of L. monocytogenes. Except for three persisting sequence types (ST) based on Multi Locus Sequence Typing being ST7, ST8 and ST121, long-term persistence of clonal groups was limited, and new clones were introduced continuously, potentially from raw materials. No particular gene could be linked to the persistence phenotype. Using time-based phylogenetic analyses of the persistent STs, we estimate the L. monocytogenes evolutionary rate to be 0.18-0.35 single nucleotide polymorphisms/year, suggesting that the persistent STs emerged approximately 100 years ago, which correlates with the onset of industrialization and globalization of the food market. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Trends in genome-wide and region-specific genetic diversity in the Dutch-Flemish Holstein-Friesian breeding program from 1986 to 2015.

    Science.gov (United States)

    Doekes, Harmen P; Veerkamp, Roel F; Bijma, Piter; Hiemstra, Sipke J; Windig, Jack J

    2018-04-11

    In recent decades, Holstein-Friesian (HF) selection schemes have undergone profound changes, including the introduction of optimal contribution selection (OCS; around 2000), a major shift in breeding goal composition (around 2000) and the implementation of genomic selection (GS; around 2010). These changes are expected to have influenced genetic diversity trends. Our aim was to evaluate genome-wide and region-specific diversity in HF artificial insemination (AI) bulls in the Dutch-Flemish breeding program from 1986 to 2015. Pedigree and genotype data (~ 75.5 k) of 6280 AI-bulls were used to estimate rates of genome-wide inbreeding and kinship and corresponding effective population sizes. Region-specific inbreeding trends were evaluated using regions of homozygosity (ROH). Changes in observed allele frequencies were compared to those expected under pure drift to identify putative regions under selection. We also investigated the direction of changes in allele frequency over time. Effective population size estimates for the 1986-2015 period ranged from 69 to 102. Two major breakpoints were observed in genome-wide inbreeding and kinship trends. Around 2000, inbreeding and kinship levels temporarily dropped. From 2010 onwards, they steeply increased, with pedigree-based, ROH-based and marker-based inbreeding rates as high as 1.8, 2.1 and 2.8% per generation, respectively. Accumulation of inbreeding varied substantially across the genome. A considerable fraction of markers showed changes in allele frequency that were greater than expected under pure drift. Putative selected regions harboured many quantitative trait loci (QTL) associated to a wide range of traits. In consecutive 5-year periods, allele frequencies changed more often in the same direction than in opposite directions, except when comparing the 1996-2000 and 2001-2005 periods. Genome-wide and region-specific diversity trends reflect major changes in the Dutch-Flemish HF breeding program. Introduction of

  20. Comparative Genomics Revealed Genetic Diversity and Species/Strain-Level Differences in Carbohydrate Metabolism of Three Probiotic Bifidobacterial Species

    Directory of Open Access Journals (Sweden)

    Toshitaka Odamaki

    2015-01-01

    Full Text Available Strains of Bifidobacterium longum, Bifidobacterium breve, and Bifidobacterium animalis are widely used as probiotics in the food industry. Although numerous studies have revealed the properties and functionality of these strains, it is uncertain whether these characteristics are species common or strain specific. To address this issue, we performed a comparative genomic analysis of 49 strains belonging to these three bifidobacterial species to describe their genetic diversity and to evaluate species-level differences. There were 166 common clusters between strains of B. breve and B. longum, whereas there were nine common clusters between strains of B. animalis and B. longum and four common clusters between strains of B. animalis and B. breve. Further analysis focused on carbohydrate metabolism revealed the existence of certain strain-dependent genes, such as those encoding enzymes for host glycan utilisation or certain membrane transporters, and many genes commonly distributed at the species level, as was previously reported in studies with limited strains. As B. longum and B. breve are human-residential bifidobacteria (HRB, whereas B. animalis is a non-HRB species, several of the differences in these species’ gene distributions might be the result of their adaptations to the nutrient environment. This information may aid both in selecting probiotic candidates and in understanding their potential function as probiotics.

  1. A Near-Complete Haplotype-Phased Genome of the Dikaryotic Wheat Stripe Rust Fungus Puccinia striiformis f. sp. tritici Reveals High Interhaplotype Diversity

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    Benjamin Schwessinger

    2018-02-01

    Full Text Available A long-standing biological question is how evolution has shaped the genomic architecture of dikaryotic fungi. To answer this, high-quality genomic resources that enable haplotype comparisons are essential. Short-read genome assemblies for dikaryotic fungi are highly fragmented and lack haplotype-specific information due to the high heterozygosity and repeat content of these genomes. Here, we present a diploid-aware assembly of the wheat stripe rust fungus Puccinia striiformis f. sp. tritici based on long reads using the FALCON-Unzip assembler. Transcriptome sequencing data sets were used to infer high-quality gene models and identify virulence genes involved in plant infection referred to as effectors. This represents the most complete Puccinia striiformis f. sp. tritici genome assembly to date (83 Mb, 156 contigs, N50 of 1.5 Mb and provides phased haplotype information for over 92% of the genome. Comparisons of the phase blocks revealed high interhaplotype diversity of over 6%. More than 25% of all genes lack a clear allelic counterpart. When we investigated genome features that potentially promote the rapid evolution of virulence, we found that candidate effector genes are spatially associated with conserved genes commonly found in basidiomycetes. Yet, candidate effectors that lack an allelic counterpart are more distant from conserved genes than allelic candidate effectors and are less likely to be evolutionarily conserved within the P. striiformis species complex and Pucciniales. In summary, this haplotype-phased assembly enabled us to discover novel genome features of a dikaryotic plant-pathogenic fungus previously hidden in collapsed and fragmented genome assemblies.

  2. Genetic Determinants of Lipid Traits in Diverse Populations from the Population Architecture using Genomics and Epidemiology (PAGE) Study

    Science.gov (United States)

    Dumitrescu, Logan; Carty, Cara L.; Taylor, Kira; Schumacher, Fredrick R.; Hindorff, Lucia A.; Ambite, José L.; Anderson, Garnet; Best, Lyle G.; Brown-Gentry, Kristin; Bůžková, Petra; Carlson, Christopher S.; Cochran, Barbara; Cole, Shelley A.; Devereux, Richard B.; Duggan, Dave; Eaton, Charles B.; Fornage, Myriam; Franceschini, Nora; Haessler, Jeff; Howard, Barbara V.; Johnson, Karen C.; Laston, Sandra; Kolonel, Laurence N.; Lee, Elisa T.; MacCluer, Jean W.; Manolio, Teri A.; Pendergrass, Sarah A.; Quibrera, Miguel; Shohet, Ralph V.; Wilkens, Lynne R.; Haiman, Christopher A.; Le Marchand, Loïc; Buyske, Steven; Kooperberg, Charles; North, Kari E.; Crawford, Dana C.

    2011-01-01

    For the past five years, genome-wide association studies (GWAS) have identified hundreds of common variants associated with human diseases and traits, including high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) levels. Approximately 95 loci associated with lipid levels have been identified primarily among populations of European ancestry. The Population Architecture using Genomics and Epidemiology (PAGE) study was established in 2008 to characterize GWAS–identified variants in diverse population-based studies. We genotyped 49 GWAS–identified SNPs associated with one or more lipid traits in at least two PAGE studies and across six racial/ethnic groups. We performed a meta-analysis testing for SNP associations with fasting HDL-C, LDL-C, and ln(TG) levels in self-identified European American (∼20,000), African American (∼9,000), American Indian (∼6,000), Mexican American/Hispanic (∼2,500), Japanese/East Asian (∼690), and Pacific Islander/Native Hawaiian (∼175) adults, regardless of lipid-lowering medication use. We replicated 55 of 60 (92%) SNP associations tested in European Americans at p<0.05. Despite sufficient power, we were unable to replicate ABCA1 rs4149268 and rs1883025, CETP rs1864163, and TTC39B rs471364 previously associated with HDL-C and MAFB rs6102059 previously associated with LDL-C. Based on significance (p<0.05) and consistent direction of effect, a majority of replicated genotype-phentoype associations for HDL-C, LDL-C, and ln(TG) in European Americans generalized to African Americans (48%, 61%, and 57%), American Indians (45%, 64%, and 77%), and Mexican Americans/Hispanics (57%, 56%, and 86%). Overall, 16 associations generalized across all three populations. For the associations that did not generalize, differences in effect sizes, allele frequencies, and linkage disequilibrium offer clues to the next generation of association studies for these traits. PMID:21738485

  3. As Clear as Mud? Determining the Diversity and Prevalence of Prophages in the Draft Genomes of Estuarine Isolates of Clostridium difficile.

    Science.gov (United States)

    Hargreaves, Katherine R; Otieno, James R; Thanki, Anisha; Blades, Matthew J; Millard, Andrew D; Browne, Hilary P; Lawley, Trevor D; Clokie, Martha R J

    2015-05-27

    The bacterium Clostridium difficile is a significant cause of nosocomial infections worldwide. The pathogenic success of this organism can be attributed to its flexible genome which is characterized by the exchange of mobile genetic elements, and by ongoing genome evolution. Despite its pathogenic status, C. difficile can also be carried asymptomatically, and has been isolated from natural environments such as water and sediments where multiple strain types (ribotypes) are found in close proximity. These include ribotypes which are associated with disease, as well as those that are less commonly isolated from patients. Little is known about the genomic content of strains in such reservoirs in the natural environment. In this study, draft genomes have been generated for 13 C. difficile isolates from estuarine sediments including clinically relevant and environmental associated types. To identify the genetic diversity within this strain collection, whole-genome comparisons were performed using the assemblies. The strains are highly genetically diverse with regards to the C. difficile "mobilome," which includes transposons and prophage elements. We identified a novel transposon-like element in two R078 isolates. Multiple, related and unrelated, prophages were detected in isolates across ribotype groups, including two novel prophage elements and those related to the transducing phage φC2. The susceptibility of these isolates to lytic phage infection was tested using a panel of characterized phages found from the same locality. In conclusion, estuarine sediments are a source of genetically diverse C. difficile strains with a complex network of prophages, which could contribute to the emergence of new strains in clinics. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  4. Development, characterization and use of genomic SSR markers for assessment of genetic diversity in some Saudi date palm (Phoenix dactylifera L. cultivars

    Directory of Open Access Journals (Sweden)

    Sulieman A. Al-Faifi

    2016-05-01

    Conclusions: The developed microsatellite markers are additional values to date palm characterization tools that can be used by researchers in population genetics, cultivar identification as well as genetic resource exploration and management. The tested cultivars exhibited a significant amount of genetic diversity and could be suitable for successful breeding program. Genomic sequences generated from this study are available at the National Center for Biotechnology Information (NCBI, Sequence Read Archive (Accession numbers. LIBGSS_039019.

  5. The genome of the endophytic bacterium H. frisingense GSF30T identifies diverse strategies in the Herbaspirillum genus to interact with plants

    Directory of Open Access Journals (Sweden)

    Daniel eStraub

    2013-06-01

    Full Text Available The diazotrophic, bacterial endophyte Herbaspirillum frisingense GSF30T has been identified in biomass grasses grown in temperate climate, including the highly nitrogen-efficient grass Miscanthus. Its genome was annotated and compared with related Herbaspirillum species from diverse habitats, including H. seropedicae, and further well-characterized endophytes. The analysis revealed that Herbaspirillum frisingense lacks a type III secretion system that is present in some related Herbaspirillum grass endophytes. Together with the lack of components of the type II secretion system, the genomic inventory indicates distinct interaction scenarios of endophytic Herbaspirillum strains with plants. Differences in respiration, carbon, nitrogen and cell wall metabolism among Herbaspirillum isolates partially correlate with their different habitats. Herbaspirillum frisingense is closely related to strains isolated from the rhizosphere of phragmites and from well water, but these lack nitrogen fixation and metabolism genes. Within grass endophytes, the high diversity in their genomic inventory suggests that even individual plant species provide distinct, highly diverse metabolic niches for successful endophyte-plant associations.

  6. The genome of the endophytic bacterium H. frisingense GSF30(T) identifies diverse strategies in the Herbaspirillum genus to interact with plants.

    Science.gov (United States)

    Straub, Daniel; Rothballer, Michael; Hartmann, Anton; Ludewig, Uwe

    2013-01-01

    The diazotrophic, bacterial endophyte Herbaspirillum frisingense GSF30(T) has been identified in biomass grasses grown in temperate climate, including the highly nitrogen-efficient grass Miscanthus. Its genome was annotated and compared with related Herbaspirillum species from diverse habitats, including H. seropedicae, and further well-characterized endophytes. The analysis revealed that Herbaspirillum frisingense lacks a type III secretion system that is present in some related Herbaspirillum grass endophytes. Together with the lack of components of the type II secretion system, the genomic inventory indicates distinct interaction scenarios of endophytic Herbaspirillum strains with plants. Differences in respiration, carbon, nitrogen and cell wall metabolism among Herbaspirillum isolates partially correlate with their different habitats. Herbaspirillum frisingense is closely related to strains isolated from the rhizosphere of phragmites and from well water, but these lack nitrogen fixation and metabolism genes. Within grass endophytes, the high diversity in their genomic inventory suggests that even individual plant species provide distinct, highly diverse metabolic niches for successful endophyte-plant associations.

  7. The genome of the endophytic bacterium H. frisingense GSF30T identifies diverse strategies in the Herbaspirillum genus to interact with plants

    Science.gov (United States)

    Straub, Daniel; Rothballer, Michael; Hartmann, Anton; Ludewig, Uwe

    2013-01-01

    The diazotrophic, bacterial endophyte Herbaspirillum frisingense GSF30T has been identified in biomass grasses grown in temperate climate, including the highly nitrogen-efficient grass Miscanthus. Its genome was annotated and compared with related Herbaspirillum species from diverse habitats, including H. seropedicae, and further well-characterized endophytes. The analysis revealed that Herbaspirillum frisingense lacks a type III secretion system that is present in some related Herbaspirillum grass endophytes. Together with the lack of components of the type II secretion system, the genomic inventory indicates distinct interaction scenarios of endophytic Herbaspirillum strains with plants. Differences in respiration, carbon, nitrogen and cell wall metabolism among Herbaspirillum isolates partially correlate with their different habitats. Herbaspirillum frisingense is closely related to strains isolated from the rhizosphere of phragmites and from well water, but these lack nitrogen fixation and metabolism genes. Within grass endophytes, the high diversity in their genomic inventory suggests that even individual plant species provide distinct, highly diverse metabolic niches for successful endophyte-plant associations. PMID:23825472

  8. Analysis of the a genome genetic diversity among brassica napus, b. rapa and b. juncea accessions using specific simple sequence repeat markers

    International Nuclear Information System (INIS)

    Tian, H.; Yan, J.; Zhang, R.; Guo, Y.; Hu, S.; Channa, S.A.

    2017-01-01

    This investigation was aimed at evaluating the genetic diversity of 127 accessions among Brassica napus, B. rapa, and B. juncea by using 15 pairs of the A genome specific simple sequence repeat primers. These 127 accessions could be clearly separated into three groups by cluster analysis, principal component analysis, and population structure analysis separately, and the results analyzed by the three methods were very similar. Group I comprised of mainly B. napus accessions and the most of B. juncea accessions formed Group II, Group III included nearly all of the B. rapa accessions. The result showed that 36.86% of the variance was due to significant differences among populations of species, indicated that abundance genetic diversity existed among the A genome of B. napus, B. rapa, and B. juncea accessions. B. napus, B. rapa, and B. juncea have the abundant genetic diversity in the A genome, and some elite genes can be used to broaden the genetic base of them, especially for B. napus, in future rapeseed breeding program. (author)

  9. Genome survey of pistachio (Pistacia vera L.) by next generation sequencing: Development of novel SSR markers and genetic diversity in Pistacia species.

    Science.gov (United States)

    Ziya Motalebipour, Elmira; Kafkas, Salih; Khodaeiaminjan, Mortaza; Çoban, Nergiz; Gözel, Hatice

    2016-12-07

    Pistachio (Pistacia vera L.) is one of the most important nut crops in the world. There are about 11 wild species in the genus Pistacia, and they have importance as rootstock seed sources for cultivated P. vera and forest trees. Published information on the pistachio genome is limited. Therefore, a genome survey is necessary to obtain knowledge on the genome structure of pistachio by next generation sequencing. Simple sequence repeat (SSR) markers are useful tools for germplasm characterization, genetic diversity analysis, and genetic linkage mapping, and may help to elucidate genetic relationships among pistachio cultivars and species. To explore the genome structure of pistachio, a genome survey was performed using the Illumina platform at approximately 40× coverage depth in the P. vera cv. Siirt. The K-mer analysis indicated that pistachio has a genome that is about 600 Mb in size and is highly heterozygous. The assembly of 26.77 Gb Illumina data produced 27,069 scaffolds at N50 = 3.4 kb with a total of 513.5 Mb. A total of 59,280 SSR motifs were detected with a frequency of 8.67 kb. A total of 206 SSRs were used to characterize 24 P. vera cultivars and 20 wild Pistacia genotypes (four genotypes from each five wild Pistacia species) belonging to P. atlantica, P. integerrima, P. chinenesis, P. terebinthus, and P. lentiscus genotypes. Overall 135 SSR loci amplified in all 44 cultivars and genotypes, 41 were polymorphic in six Pistacia species. The novel SSR loci developed from cultivated pistachio were highly transferable to wild Pistacia species. The results from a genome survey of pistachio suggest that the genome size of pistachio is about 600 Mb with a high heterozygosity rate. This information will help to design whole genome sequencing strategies for pistachio. The newly developed novel polymorphic SSRs in this study may help germplasm characterization, genetic diversity, and genetic linkage mapping studies in the genus Pistacia.

  10. Diversity and Composition of Sulfate-Reducing Microbial Communities Based on Genomic DNA and RNA Transcription in Production Water of High Temperature and Corrosive Oil Reservoir

    Directory of Open Access Journals (Sweden)

    Xiao-Xiao Li

    2017-06-01

    Full Text Available Deep subsurface petroleum reservoir ecosystems harbor a high diversity of microorganisms, and microbial influenced corrosion is a major problem for the petroleum industry. Here, we used high-throughput sequencing to explore the microbial communities based on genomic 16S rDNA and metabolically active 16S rRNA analyses of production water samples with different extents of corrosion from a high-temperature oil reservoir. Results showed that Desulfotignum and Roseovarius were the most abundant genera in both genomic and active bacterial communities of all the samples. Both genomic and active archaeal communities were mainly composed of Archaeoglobus and Methanolobus. Within both bacteria and archaea, the active and genomic communities were compositionally distinct from one another across the different oil wells (bacteria p = 0.002; archaea p = 0.01. In addition, the sulfate-reducing microorganisms (SRMs were specifically assessed by Sanger sequencing of functional genes aprA and dsrA encoding the enzymes adenosine-5′-phosphosulfate reductase and dissimilatory sulfite reductase, respectively. Functional gene analysis indicated that potentially active Archaeoglobus, Desulfotignum, Desulfovibrio, and Thermodesulforhabdus were frequently detected, with Archaeoglobus as the most abundant and active sulfate-reducing group. Canonical correspondence analysis revealed that the SRM communities in petroleum reservoir system were closely related to pH of the production water and sulfate concentration. This study highlights the importance of distinguishing the metabolically active microorganisms from the genomic community and extends our knowledge on the active SRM communities in corrosive petroleum reservoirs.

  11. Diversity and Composition of Sulfate-Reducing Microbial Communities Based on Genomic DNA and RNA Transcription in Production Water of High Temperature and Corrosive Oil Reservoir

    Science.gov (United States)

    Li, Xiao-Xiao; Liu, Jin-Feng; Zhou, Lei; Mbadinga, Serge M.; Yang, Shi-Zhong; Gu, Ji-Dong; Mu, Bo-Zhong

    2017-01-01

    Deep subsurface petroleum reservoir ecosystems harbor a high diversity of microorganisms, and microbial influenced corrosion is a major problem for the petroleum industry. Here, we used high-throughput sequencing to explore the microbial communities based on genomic 16S rDNA and metabolically active 16S rRNA analyses of production water samples with different extents of corrosion from a high-temperature oil reservoir. Results showed that Desulfotignum and Roseovarius were the most abundant genera in both genomic and active bacterial communities of all the samples. Both genomic and active archaeal communities were mainly composed of Archaeoglobus and Methanolobus. Within both bacteria and archaea, the active and genomic communities were compositionally distinct from one another across the different oil wells (bacteria p = 0.002; archaea p = 0.01). In addition, the sulfate-reducing microorganisms (SRMs) were specifically assessed by Sanger sequencing of functional genes aprA and dsrA encoding the enzymes adenosine-5′-phosphosulfate reductase and dissimilatory sulfite reductase, respectively. Functional gene analysis indicated that potentially active Archaeoglobus, Desulfotignum, Desulfovibrio, and Thermodesulforhabdus were frequently detected, with Archaeoglobus as the most abundant and active sulfate-reducing group. Canonical correspondence analysis revealed that the SRM communities in petroleum reservoir system were closely related to pH of the production water and sulfate concentration. This study highlights the importance of distinguishing the metabolically active microorganisms from the genomic community and extends our knowledge on the active SRM communities in corrosive petroleum reservoirs. PMID:28638372

  12. The genome of the Erwinia amylovora phage PhiEaH1 reveals greater diversity and broadens the applicability of phages for the treatment of fire blight.

    Science.gov (United States)

    Meczker, Katalin; Dömötör, Dóra; Vass, János; Rákhely, Gábor; Schneider, György; Kovács, Tamás

    2014-01-01

    The enterobacterium Erwinia amylovora is the causal agent of fire blight. This study presents the analysis of the complete genome of phage PhiEaH1, isolated from the soil surrounding an E. amylovora-infected apple tree in Hungary. Its genome is 218 kb in size, containing 244 ORFs. PhiEaH1 is the second E. amylovora infecting phage from the Siphoviridae family whose complete genome sequence was determined. Beside PhiEaH2, PhiEaH1 is the other active component of Erwiphage, the first bacteriophage-based pesticide on the market against E. amylovora. Comparative genome analysis in this study has revealed that PhiEaH1 not only differs from the 10 formerly sequenced E. amylovora bacteriophages belonging to other phage families, but also from PhiEaH2. Sequencing of more Siphoviridae phage genomes might reveal further diversity, providing opportunities for the development of even more effective biological control agents, phage cocktails against Erwinia fire blight disease of commercial fruit crops.

  13. Genome-wide signatures of flowering adaptation to climate temperature: Regional analyses in a highly diverse native range of Arabidopsis thaliana.

    Science.gov (United States)

    Tabas-Madrid, Daniel; Méndez-Vigo, Belén; Arteaga, Noelia; Marcer, Arnald; Pascual-Montano, Alberto; Weigel, Detlef; Xavier Picó, F; Alonso-Blanco, Carlos

    2018-03-08

    Current global change is fueling an interest to understand the genetic and molecular mechanisms of plant adaptation to climate. In particular, altered flowering time is a common strategy for escape from unfavourable climate temperature. In order to determine the genomic bases underlying flowering time adaptation to this climatic factor, we have systematically analysed a collection of 174 highly diverse Arabidopsis thaliana accessions from the Iberian Peninsula. Analyses of 1.88 million single nucleotide polymorphisms provide evidence for a spatially heterogeneous contribution of demographic and adaptive processes to geographic patterns of genetic variation. Mountains appear to be allele dispersal barriers, whereas the relationship between flowering time and temperature depended on the precise temperature range. Environmental genome-wide associations supported an overall genome adaptation to temperature, with 9.4% of the genes showing significant associations. Furthermore, phenotypic genome-wide associations provided a catalogue of candidate genes underlying flowering time variation. Finally, comparison of environmental and phenotypic genome-wide associations identified known (Twin Sister of FT, FRIGIDA-like 1, and Casein Kinase II Beta chain 1) and new (Epithiospecifer Modifier 1 and Voltage-Dependent Anion Channel 5) genes as candidates for adaptation to climate temperature by altered flowering time. Thus, this regional collection provides an excellent resource to address the spatial complexity of climate adaptation in annual plants. © 2018 John Wiley & Sons Ltd.

  14. Novel genetic diversity of the alien D-genome synthetic hexaploid wheat (2n=6x=42, Aabbdd) germplasm for various phenology traits

    International Nuclear Information System (INIS)

    Masood, R.M.; Bibi, K.; Jamil, M.

    2016-01-01

    The current study evaluates genetic penetrance and expressivity of an alien genome introgression in a set of 117 primary synthetic hexaploid wheat (SHW) accessions. These SHW have originated from durum wheat /accessions with three sets of durum wheat cultivars ALTAR 84, D67.2 and CERCETA as the female and diverse Ae. tauschii accessions as the pollen parents. Diversity of the 12 important traits (Growth habit, pigmentation, chlorophyll content, leaf area index, crop digital ground cover, awn size, awn length, and several seed digital imaging parameters)revealed significant variation for the respective traits, leading to the conclusion that Ae. tauschii accessions have tremendous diversity than the durum controls. Further, the value deviations within each attribute had a range of being lower or higher than their durum wheat female parents and these observations allowed us to use the variations as selective sieves and narrow down the desirable SHW that would be advantageous to exploit for wheat breeding and cultivar improvement programs. Selections were made and a group of 41SHW accessions were identified that will after an intermediate DNA diversity evaluation form a crisper final set for user friendly utilization. The range of selections shows multiple trait advantages for exploitation in both irrigated and rain-fed conditions. This pivotal study sets the foundation to better define the D genome SHW for efficient utilization in future research investigations. Our results have implications in widening the genetic base of hexaploid bread wheat and may facilitate the development of agronomically desirable wheat cultivars. (author)

  15. Selection on Optimal Haploid Value Increases Genetic Gain and Preserves More Genetic Diversity Relative to Genomic Selection

    OpenAIRE

    Daetwyler, Hans D.; Hayden, Matthew J.; Spangenberg, German C.; Hayes, Ben J.

    2015-01-01

    Doubled haploids are routinely created and phenotypically selected in plant breeding programs to accelerate the breeding cycle. Genomic selection, which makes use of both phenotypes and genotypes, has been shown to further improve genetic gain through prediction of performance before or without phenotypic characterization of novel germplasm. Additional opportunities exist to combine genomic prediction methods with the creation of doubled haploids. Here we propose an extension to genomic selec...

  16. Adaptation of maize to temperate climates: mid-density genome-wide association genetics and diversity patterns reveal key genomic regions, with a major contribution of the Vgt2 (ZCN8 locus.

    Directory of Open Access Journals (Sweden)

    Sophie Bouchet

    Full Text Available The migration of maize from tropical to temperate climates was accompanied by a dramatic evolution in flowering time. To gain insight into the genetic architecture of this adaptive trait, we conducted a 50K SNP-based genome-wide association and diversity investigation on a panel of tropical and temperate American and European representatives. Eighteen genomic regions were associated with flowering time. The number of early alleles cumulated along these regions was highly correlated with flowering time. Polymorphism in the vicinity of the ZCN8 gene, which is the closest maize homologue to Arabidopsis major flowering time (FT gene, had the strongest effect. This polymorphism is in the vicinity of the causal factor of Vgt2 QTL. Diversity was lower, whereas differentiation and LD were higher for associated loci compared to the rest of the genome, which is consistent with selection acting on flowering time during maize migration. Selection tests also revealed supplementary loci that were highly differentiated among groups and not associated with flowering time in our panel, whereas they were in other linkage-based studies. This suggests that allele fixation led to a lack of statistical power when structure and relatedness were taken into account in a linear mixed model. Complementary designs and analysis methods are necessary to unravel the architecture of complex traits. Based on linkage disequilibrium (LD estimates corrected for population structure, we concluded that the number of SNPs genotyped should be at least doubled to capture all QTLs contributing to the genetic architecture of polygenic traits in this panel. These results show that maize flowering time is controlled by numerous QTLs of small additive effect and that strong polygenic selection occurred under cool climatic conditions. They should contribute to more efficient genomic predictions of flowering time and facilitate the dissemination of diverse maize genetic resources under a wide

  17. Cyanobacterial life at low O(2): community genomics and function reveal metabolic versatility and extremely low diversity in a Great Lakes sinkhole mat.

    Science.gov (United States)

    Voorhies, A A; Biddanda, B A; Kendall, S T; Jain, S; Marcus, D N; Nold, S C; Sheldon, N D; Dick, G J

    2012-05-01

    Cyanobacteria are renowned as the mediators of Earth's oxygenation. However, little is known about the cyanobacterial communities that flourished under the low-O(2) conditions that characterized most of their evolutionary history. Microbial mats in the submerged Middle Island Sinkhole of Lake Huron provide opportunities to investigate cyanobacteria under such persistent low-O(2) conditions. Here, venting groundwater rich in sulfate and low in O(2) supports a unique benthic ecosystem of purple-colored cyanobacterial mats. Beneath the mat is a layer of carbonate that is enriched in calcite and to a lesser extent dolomite. In situ benthic metabolism chambers revealed that the mats are net sinks for O(2), suggesting primary production mechanisms other than oxygenic photosynthesis. Indeed, (14)C-bicarbonate uptake studies of autotrophic production show variable contributions from oxygenic and anoxygenic photosynthesis and chemosynthesis, presumably because of supply of sulfide. These results suggest the presence of either facultatively anoxygenic cyanobacteria or a mix of oxygenic/anoxygenic types of cyanobacteria. Shotgun metagenomic sequencing revealed a remarkably low-diversity mat community dominated by just one genotype most closely related to the cyanobacterium Phormidium autumnale, for which an essentially complete genome was reconstructed. Also recovered were partial genomes from a second genotype of Phormidium and several Oscillatoria. Despite the taxonomic simplicity, diverse cyanobacterial genes putatively involved in sulfur oxidation were identified, suggesting a diversity of sulfide physiologies. The dominant Phormidium genome reflects versatile metabolism and physiology that is specialized for a communal lifestyle under fluctuating redox conditions and light availability. Overall, this study provides genomic and physiologic insights into low-O(2) cyanobacterial mat ecosystems that played crucial geobiological roles over long stretches of Earth history.

  18. Untangling nucleotide diversity and evolution of the H genome in polyploid Hordeum and Elymus species based on the single copy of nuclear gene DMC1.

    Directory of Open Access Journals (Sweden)

    Dongfa Sun

    Full Text Available Numerous hybrid and polypoid species are found within the Triticeae. It has been suggested that the H subgenome of allopolyploid Elymus (wheatgrass species originated from diploid Hordeum (barley species, but the role of hybridization between polyploid Elymus and Hordeum has not been studied. It is not clear whether gene flow across polyploid Hordeum and Elymus species has occurred following polyploid speciation. Answering these questions will provide new insights into the formation of these polyploid species, and the potential role of gene flow among polyploid species during polyploid evolution. In order to address these questions, disrupted meiotic cDNA1 (DMC1 data from the allopolyploid StH Elymus are analyzed together with diploid and polyploid Hordeum species. Phylogenetic analysis revealed that the H copies of DMC1 sequence in some Elymus are very close to the H copies of DMC1 sequence in some polyploid Hordeum species, indicating either that the H genome in theses Elymus and polyploid Hordeum species originated from same diploid donor or that gene flow has occurred among them. Our analysis also suggested that the H genomes in Elymus species originated from limited gene pool, while H genomes in Hordeum polyploids have originated from broad gene pools. Nucleotide diversity (π of the DMC1 sequences on H genome from polyploid species (π = 0.02083 in Elymus, π = 0.01680 in polyploid Hordeum is higher than that in diploid Hordeum (π = 0.01488. The estimates of Tajima's D were significantly departure from the equilibrium neutral model at this locus in diploid Hordeum species (P<0.05, suggesting an excess of rare variants in diploid species which may not contribute to the origination of polyploids. Nucleotide diversity (π of the DMC1 sequences in Elymus polyploid species (π = 0.02083 is higher than that in polyploid Hordeum (π = 0.01680, suggesting that the degree of relationships between two parents of a polyploid might be a factor

  19. The Genomics Education Partnership: Successful Integration of Research into Laboratory Classes at a Diverse Group of Undergraduate Institutions

    Science.gov (United States)

    Shaffer, Christopher D.; Alvarez, Consuelo; Bailey, Cheryl; Barnard, Daron; Bhalla, Satish; Chandrasekaran, Chitra; Chandrasekaran, Vidya; Chung, Hui-Min; Dorer, Douglas R.; Du, Chunguang; Eckdahl, Todd T.; Poet, Jeff L.; Frohlich, Donald; Goodman, Anya L.; Gosser, Yuying; Hauser, Charles; Hoopes, Laura L.M.; Johnson, Diana; Jones, Christopher J.; Kaehler, Marian; Kokan, Nighat; Kopp, Olga R.; Kuleck, Gary A.; McNeil, Gerard; Moss, Robert; Myka, Jennifer L.; Nagengast, Alexis; Morris, Robert; Overvoorde, Paul J.; Shoop, Elizabeth; Parrish, Susan; Reed, Kelynne; Regisford, E. Gloria; Revie, Dennis; Rosenwald, Anne G.; Saville, Ken; Schroeder, Stephanie; Shaw, Mary; Skuse, Gary; Smith, Christopher; Smith, Mary; Spana, Eric P.; Spratt, Mary; Stamm, Joyce; Thompson, Jeff S.; Wawersik, Matthew; Wilson, Barbara A.; Youngblom, Jim; Leung, Wilson; Buhler, Jeremy; Mardis, Elaine R.; Lopatto, David

    2010-01-01

    Genomics is not only essential for students to understand biology but also provides unprecedented opportunities for undergraduate research. The goal of the Genomics Education Partnership (GEP), a collaboration between a growing number of colleges and universities around the country and the Department of Biology and Genome Center of Washington University in St. Louis, is to provide such research opportunities. Using a versatile curriculum that has been adapted to many different class settings, GEP undergraduates undertake projects to bring draft-quality genomic sequence up to high quality and/or participate in the annotation of these sequences. GEP undergraduates have improved more than 2 million bases of draft genomic sequence from several species of Drosophila and have produced hundreds of gene models using evidence-based manual annotation. Students appreciate their ability to make a contribution to ongoing research, and report increased independence and a more active learning approach after participation in GEP projects. They show knowledge gains on pre- and postcourse quizzes about genes and genomes and in bioinformatic analysis. Participating faculty also report professional gains, increased access to genomics-related technology, and an overall positive experience. We have found that using a genomics research project as the core of a laboratory course is rewarding for both faculty and students. PMID:20194808

  20. Genome characterization and genetic diversity of sweet potato symptomless virus 1: a mastrevirus with an unusual nonanucleotide

    Science.gov (United States)

    Complete genomic sequences of nine isolates of sweet potato symptomless virus 1 (SPSMV-1), a virus of genus Mastrevirus in the family Geminiviridae, was determined to be 2,559-2,602 nucleotides from sweet potato accessions from different countries. These isolates shared genomic sequence identities o...

  1. Using sheep genomes from diverse U.S. breeds to identify missense variants in genes affecting fecundity

    Science.gov (United States)

    Background: Access to sheep genome sequences significantly improves the chances of identifying genes that may influence the health, welfare, and productivity of these animals. Methods: A public, searchable DNA sequence resource for U.S. sheep was created with whole genome sequence (WGS) of 96 rams. ...

  2. The draft genome of watermelon (Citrullus lanatus) and resequencing of 20 diverse accessions

    DEFF Research Database (Denmark)

    Guo, Shaogui; Zhang, Jianguo; Sun, Honghe

    2013-01-01

    Watermelon, Citrullus lanatus, is an important cucurbit crop grown throughout the world. Here we report a high-quality draft genome sequence of the east Asia watermelon cultivar 97103 (2n = 2× = 22) containing 23,440 predicted protein-coding genes. Comparative genomics analysis provided an evolut...

  3. Lactococcus lactis Diversity in Undefined Mixed Dairy Starter Cultures as Revealed by Comparative Genome Analyses and Targeted Amplicon Sequencing of epsD.

    Science.gov (United States)

    Frantzen, Cyril A; Kleppen, Hans Petter; Holo, Helge

    2018-02-01

    Undefined mesophilic mixed (DL) starter cultures are used in the production of continental cheeses and contain unknown strain mixtures of Lactococcus lactis and leuconostocs. The choice of starter culture affects the taste, aroma, and quality of the final product. To gain insight into the diversity of Lactococcus lactis strains in starter cultures, we whole-genome sequenced 95 isolates from three different starter cultures. Pan-genomic analyses, which included 30 publically available complete genomes, grouped the strains into 21 L. lactis subsp . lactis and 28 L. lactis subsp. cremoris lineages. Only one of the 95 isolates grouped with previously sequenced strains, and the three starter cultures showed no overlap in lineage distributions. The culture diversity was assessed by targeted amplicon sequencing using purR , a core gene, and epsD , present in 93 of the 95 starter culture isolates but absent in most of the reference strains. This enabled an unprecedented discrimination of starter culture Lactococcus lactis and revealed substantial differences between the three starter cultures and compositional shifts during the cultivation of cultures in milk. IMPORTANCE In contemporary cheese production, standardized frozen seed stock starter cultures are used to ensure production stability, reproducibility, and quality control of the product. The dairy industry experiences significant disruptions of cheese production due to phage attacks, and one commonly used countermeasure to phage attack is to employ a starter rotation strategy, in which two or more starters with minimal overlap in phage sensitivity are used alternately. A culture-independent analysis of the lactococcal diversity in complex undefined starter cultures revealed large differences between the three starter cultures and temporal shifts in lactococcal composition during the production of bulk starters. A better understanding of the lactococcal diversity in starter cultures will enable the development of

  4. Annotated Draft Genome Assemblies for the Northern Bobwhite (Colinus virginianus and the Scaled Quail (Callipepla squamata Reveal Disparate Estimates of Modern Genome Diversity and Historic Effective Population Size

    Directory of Open Access Journals (Sweden)

    David L. Oldeschulte

    2017-09-01

    Full Text Available Northern bobwhite (Colinus virginianus; hereafter bobwhite and scaled quail (Callipepla squamata populations have suffered precipitous declines across most of their US ranges. Illumina-based first- (v1.0 and second- (v2.0 generation draft genome assemblies for the scaled quail and the bobwhite produced N50 scaffold sizes of 1.035 and 2.042 Mb, thereby producing a 45-fold improvement in contiguity over the existing bobwhite assembly, and ≥90% of the assembled genomes were captured within 1313 and 8990 scaffolds, respectively. The scaled quail assembly (v1.0 = 1.045 Gb was ∼20% smaller than the bobwhite (v2.0 = 1.254 Gb, which was supported by kmer-based estimates of genome size. Nevertheless, estimates of GC content (41.72%; 42.66%, genome-wide repetitive content (10.40%; 10.43%, and MAKER-predicted protein coding genes (17,131; 17,165 were similar for the scaled quail (v1.0 and bobwhite (v2.0 assemblies, respectively. BUSCO analyses utilizing 3023 single-copy orthologs revealed a high level of assembly completeness for the scaled quail (v1.0; 84.8% and the bobwhite (v2.0; 82.5%, as verified by comparison with well-established avian genomes. We also detected 273 putative segmental duplications in the scaled quail genome (v1.0, and 711 in the bobwhite genome (v2.0, including some that were shared among both species. Autosomal variant prediction revealed ∼2.48 and 4.17 heterozygous variants per kilobase within the scaled quail (v1.0 and bobwhite (v2.0 genomes, respectively, and estimates of historic effective population size were uniformly higher for the bobwhite across all time points in a coalescent model. However, large-scale declines were predicted for both species beginning ∼15–20 KYA.

  5. Annotated Draft Genome Assemblies for the Northern Bobwhite (Colinus virginianus) and the Scaled Quail (Callipepla squamata) Reveal Disparate Estimates of Modern Genome Diversity and Historic Effective Population Size.

    Science.gov (United States)

    Oldeschulte, David L; Halley, Yvette A; Wilson, Miranda L; Bhattarai, Eric K; Brashear, Wesley; Hill, Joshua; Metz, Richard P; Johnson, Charles D; Rollins, Dale; Peterson, Markus J; Bickhart, Derek M; Decker, Jared E; Sewell, John F; Seabury, Christopher M

    2017-09-07

    Northern bobwhite ( Colinus virginianus ; hereafter bobwhite) and scaled quail ( Callipepla squamata ) populations have suffered precipitous declines across most of their US ranges. Illumina-based first- (v1.0) and second- (v2.0) generation draft genome assemblies for the scaled quail and the bobwhite produced N50 scaffold sizes of 1.035 and 2.042 Mb, thereby producing a 45-fold improvement in contiguity over the existing bobwhite assembly, and ≥90% of the assembled genomes were captured within 1313 and 8990 scaffolds, respectively. The scaled quail assembly (v1.0 = 1.045 Gb) was ∼20% smaller than the bobwhite (v2.0 = 1.254 Gb), which was supported by kmer-based estimates of genome size. Nevertheless, estimates of GC content (41.72%; 42.66%), genome-wide repetitive content (10.40%; 10.43%), and MAKER-predicted protein coding genes (17,131; 17,165) were similar for the scaled quail (v1.0) and bobwhite (v2.0) assemblies, respectively. BUSCO analyses utilizing 3023 single-copy orthologs revealed a high level of assembly completeness for the scaled quail (v1.0; 84.8%) and the bobwhite (v2.0; 82.5%), as verified by comparison with well-established avian genomes. We also detected 273 putative segmental duplications in the scaled quail genome (v1.0), and 711 in the bobwhite genome (v2.0), including some that were shared among both species. Autosomal variant prediction revealed ∼2.48 and 4.17 heterozygous variants per kilobase within the scaled quail (v1.0) and bobwhite (v2.0) genomes, respectively, and estimates of historic effective population size were uniformly higher for the bobwhite across all time points in a coalescent model. However, large-scale declines were predicted for both species beginning ∼15-20 KYA. Copyright © 2017 Oldeschulte et al.

  6. Chromosome-level genome map provides insights into diverse defense mechanisms in the medicinal fungus Ganoderma sinense

    Science.gov (United States)

    Zhu, Yingjie; Xu, Jiang; Sun, Chao; Zhou, Shiguo; Xu, Haibin; Nelson, David R.; Qian, Jun; Song, Jingyuan; Luo, Hongmei; Xiang, Li; Li, Ying; Xu, Zhichao; Ji, Aijia; Wang, Lizhi; Lu, Shanfa; Hayward, Alice; Sun, Wei; Li, Xiwen; Schwartz, David C.; Wang, Yitao; Chen, Shilin

    2015-01-01

    Fungi have evolved powerful genomic and chemical defense systems to protect themselves against genetic destabilization and other organisms. However, the precise molecular basis involved in fungal defense remain largely unknown in Basidiomycetes. Here the complete genome sequence, as well as DNA methylation patterns and small RNA transcriptomes, was analyzed to provide a holistic overview of secondary metabolism and defense processes in the model medicinal fungus, Ganoderma sinense. We reported the 48.96 Mb genome sequence of G. sinense, consisting of 12 chromosomes and encoding 15,688 genes. More than thirty gene clusters involved in the biosynthesis of secondary metabolites, as well as a large array of genes responsible for their transport and regulation were highlighted. In addition, components of genome defense mechanisms, namely repeat-induced point mutation (RIP), DNA methylation and small RNA-mediated gene silencing, were revealed in G. sinense. Systematic bioinformatic investigation of the genome and methylome suggested that RIP and DNA methylation combinatorially maintain G. sinense genome stability by inactivating invasive genetic material and transposable elements. The elucidation of the G. sinense genome and epigenome provides an unparalleled opportunity to advance our understanding of secondary metabolism and fungal defense mechanisms. PMID:26046933

  7. Characterization of genomic sequence showing strong association with polyembryony among diverse Citrus species and cultivars, and its synteny with Vitis and Populus.

    Science.gov (United States)

    Nakano, Michiharu; Shimada, Takehiko; Endo, Tomoko; Fujii, Hiroshi; Nesumi, Hirohisa; Kita, Masayuki; Ebina, Masumi; Shimizu, Tokurou; Omura, Mitsuo

    2012-02-01

    Polyembryony, in which multiple somatic nucellar cell-derived embryos develop in addition to the zygotic embryo in a seed, is common in the genus Citrus. Previous genetic studies indicated polyembryony is mainly determined by a single locus, but the underlying molecular mechanism is still unclear. As a step towards identification and characterization of the gene or genes responsible for nucellar embryogenesis in Citrus, haplotype-specific physical maps around the polyembryony locus were constructed. By sequencing three BAC clones aligned on the polyembryony haplotype, a single contiguous draft sequence consisting of 380 kb containing 70 predicted open reading frames (ORFs) was reconstructed. Single nucleotide polymorphism genotypes detected in the sequenced genomic region showed strong association with embryo type in Citrus, indicating a common polyembryony locus is shared among widely diverse Citrus cultivars and species. The arrangement of the predicted ORFs in the characterized genomic region showed high collinearity to the genomic sequence of chromosome 4 of Vitis vinifera and linkage group VI of Populus trichocarpa, suggesting that the syntenic relationship among these species is conserved even though V. vinifera and P. trichocarpa are non-apomictic species. This is the first study to characterize in detail the genomic structure of an apomixis locus determining adventitious embryony. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Specific regions of genome plasticity and genetic diversity of the commensal Escherichia coli A0 34/86

    Czech Academy of Sciences Publication Activity Database

    Hejnová, Jana; Pages, Delphine; Rusniok, Ch.; Glaser, P.; Šebo, Peter; Buchrieser, C.

    2006-01-01

    Roč. 296, - (2006), s. 541-546 ISSN 1438-4221 Institutional research plan: CEZ:AV0Z50200510 Keywords : escherichia coli * commensal * genome comparison Subject RIV: EE - Microbiology, Virology Impact factor: 2.760, year: 2006

  9. Use of Comparative Genomics To Characterize the Diversity of Acinetobacter baumannii Surveillance Isolates in a Health Care Institution

    Science.gov (United States)

    Wallace, Lalena; Daugherty, Sean C.; Nagaraj, Sushma; Johnson, J. Kristie; Harris, Anthony D.

    2016-01-01

    Despite the increasing prevalence of the nosocomial pathogen Acinetobacter baumannii, little is known about which genomic components contribute to clinical presentation of this important pathogen. Most whole-genome comparisons of A. baumannii have focused on specific genomic regions associated with phenotypes in a limited number of genomes. In this work, we describe the results of a whole-genome comparative analysis of 254 surveillance isolates of Acinetobacter species, 203 of which were A. baumannii, isolated from perianal swabs and sputum samples collected as part of an infection control active surveillance program at the University of Maryland Medical Center. The collection of surveillance isolates includes both carbapenem-susceptible and -resistant isolates. Based on the whole-genome phylogeny, the A. baumannii isolates collected belong to two major phylogenomic lineages. Results from multilocus sequence typing indicated that one of the major phylogenetic groups of A. baumannii was comprised solely of strains from the international clonal lineage 2. The genomic content of the A. baumannii isolates was examined using large-scale BLAST score ratio analysis to identify genes that are associated with carbapenem-susceptible and -resistant isolates, as well as genes potentially associated with the source of isolation. This analysis revealed a number of genes that were exclusive or at greater frequency in each of these classifications. This study is the most comprehensive genomic comparison of Acinetobacter isolates from a surveillance study to date and provides important information that will contribute to our understanding of the success of A. baumannii as a human pathogen. PMID:27458211

  10. Genomic diversity in two related plant species with and without sex chromosomes--Silene latifolia and S. vulgaris.

    Directory of Open Access Journals (Sweden)

    Radim Cegan

    Full Text Available Genome size evolution is a complex process influenced by polyploidization, satellite DNA accumulation, and expansion of retroelements. How this process could be affected by different reproductive strategies is still poorly understood.We analyzed differences in the number and distribution of major repetitive DNA elements in two closely related species, Silene latifolia and S. vulgaris. Both species are diploid and possess the same chromosome number (2n = 24, but differ in their genome size and mode of reproduction. The dioecious S. latifolia (1C = 2.70 pg DNA possesses sex chromosomes and its genome is 2.5× larger than that of the gynodioecious S. vulgaris (1C = 1.13 pg DNA, which does not possess sex chromosomes. We discovered that the genome of S. latifolia is larger mainly due to the expansion of Ogre retrotransposons. Surprisingly, the centromeric STAR-C and TR1 tandem repeats were found to be more abundant in S. vulgaris, the species with the smaller genome. We further examined the distribution of major repetitive sequences in related species in the Caryophyllaceae family. The results of FISH (fluorescence in situ hybridization on mitotic chromosomes with the Retand element indicate that large rearrangements occurred during the evolution of the Caryophyllaceae family.Our data demonstrate that the evolution of genome size in the genus Silene is accompanied by the expansion of different repetitive elements with specific patterns in the dioecious species possessing the sex chromosomes.

  11. Novel viral genomes identified from six metagenomes reveal wide distribution of archaeal viruses and high viral diversity in terrestrial hot springs

    DEFF Research Database (Denmark)

    Islin, Sóley Ruth; Menzel, Peter; Krogh, Anders

    2016-01-01

    Limited by culture-dependent methods the number of viruses identified from thermophilic Archaea and Bacteria is still very small. In this study we retrieved viral sequences from six hot spring metagenomes isolated worldwide, revealing a wide distribution of four archaeal viral families....... Among the novel genomes, one belongs to a putative thermophilic virus infecting the bacterium Hydrogenobaculum, for which no virus has been reported in the literature. Moreover, a high viral diversity was observed in the metagenomes, especially among the Lipothrixviridae, as indicated by the large...

  12. Transcriptional Slippage and RNA Editing Increase the Diversity of Transcripts in Chloroplasts: Insight from Deep Sequencing of Vigna radiata Genome and Transcriptome.

    Directory of Open Access Journals (Sweden)

    Ching-Ping Lin

    Full Text Available We performed deep sequencing of the nuclear and organellar genomes of three mungbean genotypes: Vigna radiata ssp. sublobata TC1966, V. radiata var. radiata NM92 and the recombinant inbred line RIL59 derived from a cross between TC1966 and NM92. Moreover, we performed deep sequencing of the RIL59 transcriptome to investigate transcript variability. The mungbean chloroplast genome has a quadripartite structure including a pair of inverted repeats separated by two single copy regions. A total of 213 simple sequence repeats were identified in the chloroplast genomes of NM92 and RIL59; 78 single nucleotide variants and nine indels were discovered in comparing the chloroplast genomes of TC1966 and NM92. Analysis of the mungbean chloroplast transcriptome revealed mRNAs that were affected by transcriptional slippage and RNA editing. Transcriptional slippage frequency was positively correlated with the length of simple sequence repeats of the mungbean chloroplast genome (R2=0.9911. In total, 41 C-to-U editing sites were found in 23 chloroplast genes and in one intergenic spacer. No editing site that swapped U to C was found. A combination of bioinformatics and experimental methods revealed that the plastid-encoded RNA polymerase-transcribed genes psbF and ndhA are affected by transcriptional slippage in mungbean and in main lineages of land plants, including three dicots (Glycine max, Brassica rapa, and Nicotiana tabacum, two monocots (Oryza sativa and Zea mays, two gymnosperms (Pinus taeda and Ginkgo biloba and one moss (Physcomitrella patens. Transcript analysis of the rps2 gene showed that transcriptional slippage could affect transcripts at single sequence repeat regions with poly-A runs. It showed that transcriptional slippage together with incomplete RNA editing may cause sequence diversity of transcripts in chloroplasts of land plants.

  13. Genome-wide association study and genetic diversity analysis on nitrogen use efficiency in a Central European winter wheat (Triticum aestivum L. collection.

    Directory of Open Access Journals (Sweden)

    István Monostori

    Full Text Available To satisfy future demands, the increase of wheat (Triticum aestivum L. yield is inevitable. Simultaneously, maintaining high crop productivity and efficient use of nutrients, especially nitrogen use efficiency (NUE, are essential for sustainable agriculture. NUE and its components are inherently complex and highly influenced by environmental factors, nitrogen management practices and genotypic variation. Therefore, a better understanding of their genetic basis and regulation is fundamental. To investigate NUE-related traits and their genetic and environmental regulation, field trials were evaluated in a Central European wheat collection of 93 cultivars at two nitrogen input levels across three seasons. This elite germplasm collection was genotyped on DArTseq® genotypic platform to identify loci affecting N-related complex agronomic traits. To conduct robust genome-wide association mapping, the genetic diversity, population structure and linkage disequilibrium were examined. Population structure was investigated by various methods and two subpopulations were identified. Their separation is based on the breeding history of the cultivars, while analysis of linkage disequilibrium suggested that selective pressures had acted on genomic regions bearing loci with remarkable agronomic importance. Besides NUE, genetic basis for variation in agronomic traits indirectly affecting NUE and its components, moreover genetic loci underlying response to nitrogen fertilisation were also determined. Altogether, 183 marker-trait associations (MTA were identified spreading over almost the entire genome. We found that most of the MTAs were environmental-dependent. The present study identified several associated markers in those genomic regions where previous reports had found genes or quantitative trait loci influencing the same traits, while most of the MTAs revealed new genomic regions. Our data provides an overview of the allele composition of bread wheat

  14. Genetic diversity, molecular phylogeny and selection evidence of the silkworm mitochondria implicated by complete resequencing of 41 genomes

    Directory of Open Access Journals (Sweden)

    Tellier Laurent C

    2010-03-01

    Full Text Available Abstract Background Mitochondria are a valuable resource for studying the evolutionary process and deducing phylogeny. A few mitochondria genomes have been sequenced, but a comprehensive picture of the domestication event for silkworm mitochondria remains to be established. In this study, we integrate the extant data, and perform a whole genome resequencing of Japanese wild silkworm to obtain breakthrough results in silkworm mitochondrial (mt population, and finally use these to deduce a more comprehensive phylogeny of the Bombycidae. Results We identified 347 single nucleotide polymorphisms (SNPs in the mt genome, but found no past recombination event to have occurred in the silkworm progenitor. A phylogeny inferred from these whole genome SNPs resulted in a well-classified tree, confirming that the domesticated silkworm, Bombyx mori, most recently diverged from the Chinese wild silkworm, rather than from the Japanese wild silkworm. We showed that the population sizes of the domesticated and Chinese wild silkworms both experience neither expansion nor contraction. We also discovered that one mt gene, named cytochrome b, shows a strong signal of positive selection in the domesticated clade. This gene is related to energy metabolism, and may have played an important role during silkworm domestication. Conclusions We present a comparative analysis on 41 mt genomes of B. mori and B. mandarina from China and Japan. With these, we obtain a much clearer picture of the evolution history of the silkworm. The data and analyses presented here aid our understanding of the silkworm in general, and provide a crucial insight into silkworm phylogeny.

  15. Comparative genomic analysis of the MHC: the evolution of class I duplication blocks, diversity and complexity from shark to man.

    Science.gov (United States)

    Kulski, Jerzy K; Shiina, Takashi; Anzai, Tatsuya; Kohara, Sakae; Inoko, Hidetoshi

    2002-12-01

    The major histocompatibility complex (MHC) genomic region is composed of a group of linked genes involved functionally with the adaptive and innate immune systems. The class I and class II genes are intrinsic features of the MHC and have been found in all the jawed vertebrates studied so far. The MHC genomic regions of the human and the chicken (B locus) have been fully sequenced and mapped, and the mouse MHC sequence is almost finished. Information on the MHC genomic structures (size, complexity, genic and intergenic composition and organization, gene order and number) of other vertebrates is largely limited or nonexistent. Therefore, we are mapping, sequencing and analyzing the MHC genomic regions of different human haplotypes and at least eight nonhuman species. Here, we review our progress with these sequences and compare the human MHC structure with that of the nonhuman primates (chimpanzee and rhesus macaque), other mammals (pigs, mice and rats) and nonmammalian vertebrates such as birds (chicken and quail), bony fish (medaka, pufferfish and zebrafish) and cartilaginous fish (nurse shark). This comparison reveals a complex MHC structure for mammals and a relatively simpler design for nonmammalian animals with a hypothetical prototypic structure for the shark. In the mammalian MHC, there are two to five different class I duplication blocks embedded within a framework of conserved nonclass I and/or nonclass II genes. With a few exceptions, the class I framework genes are absent from the MHC of birds, bony fish and sharks. Comparative genomics of the MHC reveal a highly plastic region with major structural differences between the mammalian and nonmammalian vertebrates. Additional genomic data are needed on animals of the reptilia, crocodilia and marsupial classes to find the origins of the class I framework genes and examples of structures that may be intermediate between the simple and complex MHC organizations of birds and mammals, respectively.

  16. Genetic Diversity of Infectious Laryngotracheitis Virus during In Vivo Coinfection Parallels Viral Replication and Arises from Recombination Hot Spots within the Genome.

    Science.gov (United States)

    Loncoman, Carlos A; Hartley, Carol A; Coppo, Mauricio J C; Vaz, Paola K; Diaz-Méndez, Andrés; Browning, Glenn F; García, Maricarmen; Spatz, Stephen; Devlin, Joanne M

    2017-12-01

    Recombination is a feature of many alphaherpesviruses that infect people and animals. Infectious laryngotracheitis virus (ILTV; Gallid alphaherpesvirus 1 ) causes respiratory disease in chickens, resulting in significant production losses in poultry industries worldwide. Natural (field) ILTV recombination is widespread, particularly recombination between attenuated ILTV vaccine strains to create virulent viruses. These virulent recombinants have had a major impact on animal health. Recently, the development of a single nucleotide polymorphism (SNP) genotyping assay for ILTV has helped to understand ILTV recombination in laboratory settings. In this study, we applied this SNP genotyping assay to further examine ILTV recombination in the natural host. Following coinoculation of specific-pathogen-free chickens, we examined the resultant progeny for evidence of viral recombination and characterized the diversity of the recombinants over time. The results showed that ILTV replication and recombination are closely related and that the recombinant viral progeny are most diverse 4 days after coinoculation, which is the peak of viral replication. Further, the locations of recombination breakpoints in a selection of the recombinant progeny, and in field isolates of ILTV from different geographical regions, were examined following full-genome sequencing and used to identify recombination hot spots in the ILTV genome. IMPORTANCE Alphaherpesviruses are common causes of disease in people and animals. Recombination enables genome diversification in many different species of alphaherpesviruses, which can lead to the evolution of higher levels of viral virulence. Using the alphaherpesvirus infectious laryngotracheitis virus (ILTV), we performed coinfections in the natural host (chickens) to demonstrate high levels of virus recombination. Higher levels of diversity in the recombinant progeny coincided with the highest levels of virus replication. In the recombinant progeny, and in

  17. The Arsenic Resistance-Associated Listeria Genomic Island LGI2 Exhibits Sequence and Integration Site Diversity and a Propensity for Three Listeria monocytogenes Clones with Enhanced Virulence.

    Science.gov (United States)

    Lee, Sangmi; Ward, Todd J; Jima, Dereje D; Parsons, Cameron; Kathariou, Sophia

    2017-11-01

    In the foodborne pathogen Listeria monocytogenes , arsenic resistance is encountered primarily in serotype 4b clones considered to have enhanced virulence and is associated with an arsenic resistance gene cluster within a 35-kb chromosomal region, Listeria genomic island 2 (LGI2). LGI2 was first identified in strain Scott A and includes genes putatively involved in arsenic and cadmium resistance, DNA integration, conjugation, and pathogenicity. However, the genomic localization and sequence content of LGI2 remain poorly characterized. Here we investigated 85 arsenic-resistant L. monocytogenes strains, mostly of serotype 4b. All but one of the 70 serotype 4b strains belonged to clonal complex 1 (CC1), CC2, and CC4, three major clones associated with enhanced virulence. PCR analysis suggested that 53 strains (62.4%) harbored an island highly similar to LGI2 of Scott A, frequently (42/53) in the same location as Scott A ( LMOf2365_2257 homolog). Random-primed PCR and whole-genome sequencing revealed seven novel insertion sites, mostly internal to chromosomal coding sequences, among strains harboring LGI2 outside the LMOf2365_2257 homolog. Interestingly, many CC1 strains harbored a noticeably diversified LGI2 (LGI2-1) in a unique location ( LMOf2365_0902 homolog) and with a novel additional gene. With few exceptions, the tested LGI2 genes were not detected in arsenic-resistant strains of serogroup 1/2, which instead often harbored a Tn 554 -associated arsenic resistance determinant not encountered in serotype 4b. These findings indicate that in L. monocytogenes , LGI2 has a propensity for certain serotype 4b clones, exhibits content diversity, and is highly promiscuous, suggesting an ability to mobilize various accessory genes into diverse chromosomal loci. IMPORTANCE Listeria monocytogenes is widely distributed in the environment and causes listeriosis, a foodborne disease with high mortality and morbidity. Arsenic and other heavy metals can powerfully shape the

  18. Salmonella strains isolated from Galápagos iguanas show spatial structuring of serovar and genomic diversity.

    Directory of Open Access Journals (Sweden)

    Emily W Lankau

    Full Text Available It is thought that dispersal limitation primarily structures host-associated bacterial populations because host distributions inherently limit transmission opportunities. However, enteric bacteria may disperse great distances during food-borne outbreaks. It is unclear if such rapid long-distance dispersal events happen regularly in natural systems or if these events represent an anthropogenic exception. We characterized Salmonella enterica isolates from the feces of free-living Galápagos land and marine iguanas from five sites on four islands using serotyping and genomic fingerprinting. Each site hosted unique and nearly exclusive serovar assemblages. Genomic fingerprint analysis offered a more complex model of S. enterica biogeography, with evidence of both unique strain pools and of spatial population structuring along a geographic gradient. These findings suggest that even relatively generalist enteric bacteria may be strongly dispersal limited in a natural system with strong barriers, such as oceanic divides. Yet, these differing results seen on two typing methods also suggests that genomic variation is less dispersal limited, allowing for different ecological processes to shape biogeographical patterns of the core and flexible portions of this bacterial species' genome.

  19. Salmonella strains isolated from Galápagos iguanas show spatial structuring of serovar and genomic diversity.

    Science.gov (United States)

    Lankau, Emily W; Cruz Bedon, Lenin; Mackie, Roderick I

    2012-01-01

    It is thought that dispersal limitation primarily structures host-associated bacterial populations because host distributions inherently limit transmission opportunities. However, enteric bacteria may disperse great distances during food-borne outbreaks. It is unclear if such rapid long-distance dispersal events happen regularly in natural systems or if these events represent an anthropogenic exception. We characterized Salmonella enterica isolates from the feces of free-living Galápagos land and marine iguanas from five sites on four islands using serotyping and genomic fingerprinting. Each site hosted unique and nearly exclusive serovar assemblages. Genomic fingerprint analysis offered a more complex model of S. enterica biogeography, with evidence of both unique strain pools and of spatial population structuring along a geographic gradient. These findings suggest that even relatively generalist enteric bacteria may be strongly dispersal limited in a natural system with strong barriers, such as oceanic divides. Yet, these differing results seen on two typing methods also suggests that genomic variation is less dispersal limited, allowing for different ecological processes to shape biogeographical patterns of the core and flexible portions of this bacterial species' genome.

  20. Comparative genomics reveals high biological diversity and specific adaptations in the industrially and medically important fungal genus Aspergillus

    DEFF Research Database (Denmark)

    de Vries, Ronald P.; Riley, Robert; Wiebenga, Ad

    2017-01-01

    Background:  The fungal genus Aspergillus is of critical importance to humankind. Species include those with industrial applications, important pathogens of humans, animals and crops, a source of potent carcinogenic contaminants of food, and an important genetic model. The genome sequences of eig...

  1. Salmonella Strains Isolated from Galápagos Iguanas Show Spatial Structuring of Serovar and Genomic Diversity

    Science.gov (United States)

    Lankau, Emily W.; Cruz Bedon, Lenin; Mackie, Roderick I.

    2012-01-01

    It is thought that dispersal limitation primarily structures host-associated bacterial populations because host distributions inherently limit transmission opportunities. However, enteric bacteria may disperse great distances during food-borne outbreaks. It is unclear if such rapid long-distance dispersal events happen regularly in natural systems or if these events represent an anthropogenic exception. We characterized Salmonella enterica isolates from the feces of free-living Galápagos land and marine iguanas from five sites on four islands using serotyping and genomic fingerprinting. Each site hosted unique and nearly exclusive serovar assemblages. Genomic fingerprint analysis offered a more complex model of S. enterica biogeography, with evidence of both unique strain pools and of spatial population structuring along a geographic gradient. These findings suggest that even relatively generalist enteric bacteria may be strongly dispersal limited in a natural system with strong barriers, such as oceanic divides. Yet, these differing results seen on two typing methods also suggests that genomic variation is less dispersal limited, allowing for different ecological processes to shape biogeographical patterns of the core and flexible portions of this bacterial species' genome. PMID:22615968

  2. The nuclear genome of Rhazya stricta and the evolution of alkaloid diversity in a medically relevant clade of Apocynaceae.

    Science.gov (United States)

    Sabir, Jamal S M; Jansen, Robert K; Arasappan, Dhivya; Calderon, Virginie; Noutahi, Emmanuel; Zheng, Chunfang; Park, Seongjun; Sabir, Meshaal J; Baeshen, Mohammed N; Hajrah, Nahid H; Khiyami, Mohammad A; Baeshen, Nabih A; Obaid, Abdullah Y; Al-Malki, Abdulrahman L; Sankoff, David; El-Mabrouk, Nadia; Ruhlman, Tracey A

    2016-09-22

    Alkaloid accumulation in plants is activated in response to stress, is limited in distribution and specific alkaloid repertoires are variable across taxa. Rauvolfioideae (Apocynaceae, Gentianales) represents a major center of structural expansion in the monoterpenoid indole alkaloids (MIAs) yielding thousands of unique molecules including highly valuable chemotherapeutics. The paucity of genome-level data for Apocynaceae precludes a deeper understanding of MIA pathway evolution hindering the elucidation of remaining pathway enzymes and the improvement of MIA availability in planta or in vitro. We sequenced the nuclear genome of Rhazya stricta (Apocynaceae, Rauvolfioideae) and present this high quality assembly in comparison with that of coffee (Rubiaceae, Coffea canephora, Gentianales) and others to investigate the evolution of genome-scale features. The annotated Rhazya genome was used to develop the community resource, RhaCyc, a metabolic pathway database. Gene family trees were constructed to identify homologs of MIA pathway genes and to examine their evolutionary history. We found that, unlike Coffea, the Rhazya lineage has experienced many structural rearrangements. Gene tree analyses suggest recent, lineage-specific expansion and diversification among homologs encoding MIA pathway genes in Gentianales and provide candidate sequences with the potential to close gaps in characterized pathways and support prospecting for new MIA production avenues.

  3. Which individuals to choose to update the reference population? Minimizing the loss of genetic diversity in animal genomic selection programs

    NARCIS (Netherlands)

    Eynard, Sonia E.; Croiseau, Pascal; Laloë, Denis; Fritz, Sebastien; Calus, Mario P.L.; Restoux, Gwendal

    2018-01-01

    Genomic selection (GS) is commonly used in livestock and increasingly in plant breeding. Relying on phenotypes and genotypes of a reference population, GS allows performance prediction for young individuals having only genotypes. This is expected to achieve fast high genetic gain but with a

  4. Unlocking Diversity in Germplasm Collections via Genomic Selection: A Case Study Based on Quantitative Adult Plant Resistance to Stripe Rust in Spring Wheat.

    Science.gov (United States)

    Muleta, Kebede T; Bulli, Peter; Zhang, Zhiwu; Chen, Xianming; Pumphrey, Michael

    2017-11-01

    Harnessing diversity from germplasm collections is more feasible today because of the development of lower-cost and higher-throughput genotyping methods. However, the cost of phenotyping is still generally high, so efficient methods of sampling and exploiting useful diversity are needed. Genomic selection (GS) has the potential to enhance the use of desirable genetic variation in germplasm collections through predicting the genomic estimated breeding values (GEBVs) for all traits that have been measured. Here, we evaluated the effects of various scenarios of population genetic properties and marker density on the accuracy of GEBVs in the context of applying GS for wheat ( L.) germplasm use. Empirical data for adult plant resistance to stripe rust ( f. sp. ) collected on 1163 spring wheat accessions and genotypic data based on the wheat 9K single nucleotide polymorphism (SNP) iSelect assay were used for various genomic prediction tests. Unsurprisingly, the results of the cross-validation tests demonstrated that prediction accuracy increased with an increase in training population size and marker density. It was evident that using all the available markers (5619) was unnecessary for capturing the trait variation in the germplasm collection, with no further gain in prediction accuracy beyond 1 SNP per 3.2 cM (∼1850 markers), which is close to the linkage disequilibrium decay rate in this population. Collectively, our results suggest that larger germplasm collections may be efficiently sampled via lower-density genotyping methods, whereas genetic relationships between the training and validation populations remain critical when exploiting GS to select from germplasm collections. Copyright © 2017 Crop Science Society of America.

  5. Full genome analysis of rotavirus G9P[8] strains identified in acute gastroenteritis cases reveals genetic diversity: Pune, western India.

    Science.gov (United States)

    Tatte, Vaishali S; Chaphekar, Deepa; Gopalkrishna, Varanasi

    2017-08-01

    Group A rotaviruses (RVA) are the major enteric etiological agents of severe acute gastroenteritis among children globally. As G9 RVA now represents as one of the major human RVA genotypes, studies on full genome of this particular genotype are being carried out worldwide. So far, no such studies on G9P[8] RVAs have been reported from Pune, western part of India. Keeping in view of this, the study was undertaken to understand the degree of genetic diversity of the commonly circulating G9P[8] RVA strains. Rotavirus surveillance studies carried out earlier during the years 2009-2011 showed increase in the prevalence of G9P[8] RVAs. Representative G9P[8] RVA strains from the years 2009, 2010, and 2011 were selected for the study. In general, all the G9 RVA strains showed clustering in the globally circulating sublineage of the VP7 gene and showed nucleotide/amino acid identities of 96.8-99.7%/96.9-99.8% with global G9 RV strains. Full genome analysis, of all three RVAs in this study indicated Wa-like genotype constellation G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. Within the strains nucleotide/amino acid divergence of 0.1-3.4%/0.0-4.1% was noted in all the RVA structural and non-structural genes. In conclusion, the present study highlights intra-genotypic variations throughout the RVA genome. The study further emphasizes the need for surveillance and analysis of the whole genomic constellation of the commonly circulating RVA strains of other regions in the country for understanding to a greater degree of the impact of rotavirus vaccination recently introduced in India. © 2017 Wiley Periodicals, Inc.

  6. Genetic diversity and population structure among six cattle breeds in South Africa using a whole genome SNP panel

    Directory of Open Access Journals (Sweden)

    Sithembile Olga Makina

    2014-09-01

    Full Text Available Information about genetic diversity and population structure among cattle breeds is essential for genetic improvement, understanding of environmental adaptation as well as utilization and conservation of cattle breeds. This study investigated genetic diversity and the population structure among six cattle breeds in South African (SA including Afrikaner (n=44, Nguni (n=54, Drakensberger (n=47, Bonsmara (n=44, Angus (n=31 and Holstein (n=29. Genetic diversity within cattle breeds was analyzed using three measures of genetic diversity namely allelic richness (AR, expected heterozygosity (He and inbreeding coefficient (f. Genetic distances between breed pairs were evaluated using Nei’s genetic distance. Population structure was assessed using model-based clustering (ADMIXTURE. Results of this study revealed that the allelic richness ranged from 1.88 (Afrikaner to 1.73 (Nguni. Afrikaner cattle had the lowest level of genetic diversity (He=0.24 and the Drakensberger cattle (He=0.30 had the highest level of genetic variation among indigenous and locally-developed cattle breeds. The level of inbreeding was lower across the studied cattle breeds. As expected the average genetic distance was the greatest between indigenous cattle breeds and Bos taurus cattle breeds but the lowest among indigenous and locally-developed breeds. Model-based clustering revealed some level of admixture among indigenous and locally-developed breeds and supported the clustering of the breeds according to their history of origin. The results of this study provided useful insight regarding genetic structure of South African cattle breeds.

  7. Genome-wide indel markers shared by diverse Asian rice cultivars compared to Japanese rice cultivar ?Koshihikari?

    OpenAIRE

    Yonemaru, Jun-ichi; Choi, Sun Hee; Sakai, Hiroaki; Ando, Tsuyu; Shomura, Ayahiko; Yano, Masahiro; Wu, Jianzhong; Fukuoka, Shuichi

    2015-01-01

    Insertion-deletion (indel) polymorphisms, such as simple sequence repeats, have been widely used as DNA markers to identify QTLs and genes and to facilitate rice breeding. Recently, next-generation sequencing has produced deep sequences that allow genome-wide detection of indels. These polymorphisms can potentially be used to develop high-accuracy polymerase chain reaction (PCR)-based markers. Here, re-sequencing of 5 indica, 2 aus, and 3 tropical japonica cultivars and Japanese elite cultiva...

  8. Comparative genome and methylome analysis reveals restriction/modification system diversity in the gut commensal Bifidobacterium breve

    Science.gov (United States)

    Bottacini, Francesca; Morrissey, Ruth; Roberts, Richard John; James, Kieran; van Breen, Justin; Egan, Muireann; Lambert, Jolanda; van Limpt, Kees; Knol, Jan; Motherway, Mary O’Connell; van Sinderen, Douwe

    2018-01-01

    Abstract Bifidobacterium breve represents one of the most abundant bifidobacterial species in the gastro-intestinal tract of breast-fed infants, where their presence is believed to exert beneficial effects. In the present study whole genome sequencing, employing the PacBio Single Molecule, Real-Time (SMRT) sequencing platform, combined with comparative genome analysis allowed the most extensive genetic investigation of this taxon. Our findings demonstrate that genes encoding Restriction/Modification (R/M) systems constitute a substantial part of the B. breve variable gene content (or variome). Using the methylome data generated by SMRT sequencing, combined with targeted Illumina bisulfite sequencing (BS-seq) and comparative genome analysis, we were able to detect methylation recognition motifs and assign these to identified B. breve R/M systems, where in several cases such assignments were confirmed by restriction analysis. Furthermore, we show that R/M systems typically impose a very significant barrier to genetic accessibility of B. breve strains, and that cloning of a methyltransferase-encoding gene may overcome such a barrier, thus allowing future functional investigations of members of this species. PMID:29294107

  9. Diversity and strain specificity of plant cell wall degrading enzymes revealed by the draft genome of Ruminococcus flavefaciens FD-1.

    Directory of Open Access Journals (Sweden)

    Margret E Berg Miller

    Full Text Available BACKGROUND: Ruminococcus flavefaciens is a predominant cellulolytic rumen bacterium, which forms a multi-enzyme cellulosome complex that could play an integral role in the ability of this bacterium to degrade plant cell wall polysaccharides. Identifying the major enzyme types involved in plant cell wall degradation is essential for gaining a better understanding of the cellulolytic capabilities of this organism as well as highlighting potential enzymes for application in improvement of livestock nutrition and for conversion of cellulosic biomass to liquid fuels. METHODOLOGY/PRINCIPAL FINDINGS: The R. flavefaciens FD-1 genome was sequenced to 29x-coverage, based on pulsed-field gel electrophoresis estimates (4.4 Mb, and assembled into 119 contigs providing 4,576,399 bp of unique sequence. As much as 87.1% of the genome encodes ORFs, tRNA, rRNAs, or repeats. The GC content was calculated at 45%. A total of 4,339 ORFs was detected with an average gene length of 918 bp. The cellulosome model for R. flavefaciens was further refined by sequence analysis, with at least 225 dockerin-containing ORFs, including previously characterized cohesin-containing scaffoldin molecules. These dockerin-containing ORFs encode a variety of catalytic modules including glycoside hydrolases (GHs, polysaccharide lyases, and carbohydrate esterases. Additionally, 56 ORFs encode proteins that contain carbohydrate-binding modules (CBMs. Functional microarray analysis of the genome revealed that 56 of the cellulosome-associated ORFs were up-regulated, 14 were down-regulated, 135 were unaffected, when R. flavefaciens FD-1 was grown on cellulose versus cellobiose. Three multi-modular xylanases (ORF01222, ORF03896, and ORF01315 exhibited the highest levels of up-regulation. CONCLUSIONS/SIGNIFICANCE: The genomic evidence indicates that R. flavefaciens FD-1 has the largest known number of fiber-degrading enzymes likely to be arranged in a cellulosome architecture. Functional

  10. Assessment of genetic diversity, population structure and relationships in Indian and non-Indian genotypes of finger millet (Eleusine coracana (L.) Gaertn) using genomic SSR markers.

    Science.gov (United States)

    Ramakrishnan, M; Antony Ceasar, S; Duraipandiyan, V; Al-Dhabi, N A; Ignacimuthu, S

    2016-01-01

    We evaluated the genetic variation and population structure in Indian and non-Indian genotypes of finger millet using 87 genomic SSR primers. The 128 finger millet genotypes were collected and genomic DNA was isolated. Eighty-seven genomic SSR primers with 60-70 % GC contents were used for PCR analysis of 128 finger millet genotypes. The PCR products were separated and visualized on a 6 % polyacrylamide gel followed by silver staining. The data were used to estimate major allele frequency using Power Marker v3.0. Dendrograms were constructed based on the Jaccard's similarity coefficient. Statistical fitness and population structure analyses were performed to find the genetic diversity. The mean major allele frequency was 0.92; the means of polymorphic alleles were 2.13 per primer and 1.45 per genotype; the average polymorphism was 59.94 % per primer and average PIC value was 0.44 per primer. Indian genotypes produced an additional 0.21 allele than non-Indian genotypes. Gene diversity was in the range from 0.02 to 0.35. The average heterozygosity was 0.11, close to 100 % homozygosity. The highest inbreeding coefficient was observed with SSR marker UGEP67. The Jaccard's similarity coefficient value ranged from 0.011 to 0.836. The highest similarity value was 0.836 between genotypes DPI009-04 and GPU-45. Indian genotypes were placed in Eleusine coracana major cluster (EcMC) 1 along with 6 non-Indian genotypes. AMOVA showed that molecular variance in genotypes from various geographical regions was 4 %; among populations it was 3 % and within populations it was 93 %. PCA scatter plot analysis showed that GPU-28, GPU-45 and DPI009-04 were closely dispersed in first component axis. In structural analysis, the genotypes were divided into three subpopulations (SP1, SP2 and SP3). All the three subpopulations had an admixture of alleles and no pure line was observed. These analyses confirmed that all the genotypes were genetically diverse and had been grouped based on

  11. Proportioning whole-genome single-nucleotide-polymorphism diversity for the identification of geographic population structure and genetic ancestry

    NARCIS (Netherlands)

    O. Lao Grueso (Oscar); K. van Duijn (Kate); P. Kersbergen (Paula); P. de Knijff (Peter); M.H. Kayser (Manfred)

    2006-01-01

    textabstractThe identification of geographic population structure and genetic ancestry on the basis of a minimal set of genetic markers is desirable for a wide range of applications in medical and forensic sciences. However, the absence of sharp discontinuities in the neutral genetic diversity among

  12. Genetic diversity and structure of core collection of winter mushroom (Flammulina velutipes) developed by genomic SSR markers.

    Science.gov (United States)

    Liu, Xiao Bin; Li, Jing; Yang, Zhu L

    2018-01-01

    A core collection is a subset of an entire collection that represents as much of the genetic diversity of the entire collection as possible. The establishment of a core collection for crops is practical for efficient management and use of germplasm. However, the establishment of a core collection of mushrooms is still in its infancy, and no established core collection of the economically important species Flammulina velutipes has been reported. We established the first core collection of F. velutipes , containing 32 strains based on 81 genetically different F. veltuipes strains. The allele retention proportion of the core collection for the entire collection was 100%. Moreover, the genetic diversity parameters (the effective number of alleles, Nei's expected heterozygosity, the number of observed heterozygosity, and Shannon's information index) of the core collection showed no significant differences from the entire collection ( p  > 0.01). Thus, the core collection is representative of the genetic diversity of the entire collection. Genetic structure analyses of the core collection revealed that the 32 strains could be clustered into 6 groups, among which groups 1 to 3 were cultivars and groups 4 to 6 were wild strains. The wild strains from different locations harbor their own specific alleles, and were clustered stringently in accordance with their geographic origins. Genetic diversity analyses of the core collection revealed that the wild strains possessed greater genetic diversity than the cultivars. We established the first core collection of F. velutipes in China, which is an important platform for efficient breeding of this mushroom in the future. In addition, the wild strains in the core collection possess favorable agronomic characters and produce unique bioactive compounds, adding value to the platform. More attention should be paid to wild strains in further strain breeding.

  13. Gene-trait matching across the Bifidobacterium longum pan-genome reveals considerable diversity in carbohydrate catabolism among human infant strains.

    LENUS (Irish Health Repository)

    Arboleya, Silvia

    2018-01-08

    Bifidobacterium longum is a common member of the human gut microbiota and is frequently present at high numbers in the gut microbiota of humans throughout life, thus indicative of a close symbiotic host-microbe relationship. Different mechanisms may be responsible for the high competitiveness of this taxon in its human host to allow stable establishment in the complex and dynamic intestinal microbiota environment. The objective of this study was to assess the genetic and metabolic diversity in a set of 20 B. longum strains, most of which had previously been isolated from infants, by performing whole genome sequencing and comparative analysis, and to analyse their carbohydrate utilization abilities using a gene-trait matching approach.

  14. Microbial Culturomics Broadens Human Vaginal Flora Diversity: Genome Sequence and Description of Prevotella lascolaii sp. nov. Isolated from a Patient with Bacterial Vaginosis.

    Science.gov (United States)

    Diop, Khoudia; Diop, Awa; Levasseur, Anthony; Mediannikov, Oleg; Robert, Catherine; Armstrong, Nicholas; Couderc, Carine; Bretelle, Florence; Raoult, Didier; Fournier, Pierre-Edouard; Fenollar, Florence

    2018-03-01

    Microbial culturomics is a new subfield of postgenomic medicine and omics biotechnology application that has broadened our awareness on bacterial diversity of the human microbiome, including the human vaginal flora bacterial diversity. Using culturomics, a new obligate anaerobic Gram-stain-negative rod-shaped bacterium designated strain khD1 T was isolated in the vagina of a patient with bacterial vaginosis and characterized using taxonogenomics. The most abundant cellular fatty acids were C 15:0 anteiso (36%), C 16:0 (19%), and C 15:0 iso (10%). Based on an analysis of the full-length 16S rRNA gene sequences, phylogenetic analysis showed that the strain khD1 T exhibited 90% sequence similarity with Prevotella loescheii, the phylogenetically closest validated Prevotella species. With 3,763,057 bp length, the genome of strain khD1 T contained (mol%) 48.7 G + C and 3248 predicted genes, including 3194 protein-coding and 54 RNA genes. Given the phenotypical and biochemical characteristic results as well as genome sequencing, strain khD1 T is considered to represent a novel species within the genus Prevotella, for which the name Prevotella lascolaii sp. nov. is proposed. The type strain is khD1 T ( = CSUR P0109, = DSM 101754). These results show that microbial culturomics greatly improves the characterization of the human microbiome repertoire by isolating potential putative new species. Further studies will certainly clarify the microbial mechanisms of pathogenesis of these new microbes and their role in health and disease. Microbial culturomics is an important new addition to the diagnostic medicine toolbox and warrants attention in future medical, global health, and integrative biology postgraduate teaching curricula.

  15. Molecular evolution of avian reovirus: evidence for genetic diversity and reassortment of the S-class genome segments and multiple cocirculating lineages

    International Nuclear Information System (INIS)

    Liu, Hung J.; Lee, Long H.; Hsu, Hsiao W.; Kuo, Liam C.; Liao, Ming H.

    2003-01-01

    Nucleotide sequences of the S-class genome segments of 17 field-isolates and vaccine strains of avian reovirus (ARV) isolated over a 23-year period from different hosts, pathotypes, and geographic locations were examined and analyzed to define phylogenetic profiles and evolutionary mechanism. The S1 genome segment showed noticeably higher divergence than the other S-class genes. The σC-encoding gene has evolved into six distinct lineages. In contrast, the other S-class genes showed less divergence than that of the σC-encoding gene and have evolved into two to three major distinct lineages, respectively. Comparative sequence analysis provided evidence indicating extensive sequence divergence between ARV and other orthoreoviruses. The evolutionary trees of each gene were distinct, suggesting that these genes evolve in an independent manner. Furthermore, variable topologies were the result of frequent genetic reassortment among multiple cocirculating lineages. Results showed genetic diversity correlated more closely with date of isolation and geographic sites than with host species and pathotypes. This is the first evidence demonstrating genetic variability among circulating ARVs through a combination of evolutionary mechanisms involving multiple cocirculating lineages and genetic reassortment. The evolutionary rates and patterns of base substitutions were examined. The evolutionary rate for the σC-encoding gene and σC protein was higher than for the other S-class genes and other family of viruses. With the exception of the σC-encoding gene, which nonsynonymous substitutions predominate over synonymous, the evolutionary process of the other S-class genes can be explained by the neutral theory of molecular evolution. Results revealed that synonymous substitutions predominate over nonsynonymous in the S-class genes, even though genetic diversity and substitution rates vary among the viruses

  16. Diversity and dynamics of plant genome size: an example of polysomaty from a cytogenetic study of Tahitian vanilla (Vanilla xtahitensis, Orchidaceae).

    Science.gov (United States)

    Lepers-Andrzejewski, Sandra; Siljak-Yakovlev, Sonja; Brown, Spencer C; Wong, Maurice; Dron, Michel

    2011-06-01

    Abnormal mitotic behavior with somatic aneuploidy and partial endoreplication were previously reported for the first time in the plant kingdom in Vanilla planifolia. Because vanilla plants are vegetatively propagated, such abnormalities have been transmitted. This study aimed to determine whether mitotic abnormalities also occur in Vanilla hybrid or are suppressed by sexual reproduction. Twenty-eight accessions of Vanilla ×tahitensis, one V. planifolia, and hybrid V. planifolia × V. ×tahitensis were analyzed by chromosome counts, cytometry, and fluorescent in situ hybridization of 18S-5.8S-26S rDNA. In a single root meristem of V. ×tahitensis, chromosome number varied from 22 to 31 in diploids (mean 2C = 5.23 pg), 31 to 41 in triploids (2C = 7.82 pg) and 43 to 60 in tetraploids (2C = 10.27 pg). Morphological diversity is apparently related to ploidy changes. Aneuploidy and partial (asymmetrical) endoreduplication were observed in root meristems of both V. ×tahitensis and the hybrid V. planifolia × V. ×tahitensis, but pollen grains had the euploid chromosome number (n = 15 in diploids). Genome irregularities may be transmitted not only during vegetative propagation but also by sexual reproduction in Vanilla. However, there must be a complex regulation of genome size and organization between the aneuploidy in somatic tissues and subsequently euploid gametic tissue. This is a novel example of polysomaty with developmentally regulated partial endoreplication.

  17. The Environmental Acinetobacter baumannii Isolate DSM30011 Reveals Clues into the Preantibiotic Era Genome Diversity, Virulence Potential, and Niche Range of a Predominant Nosocomial Pathogen

    Science.gov (United States)

    Viale, Alejandro M.; Borges, Vítor; Cameranesi, María M.; Taib, Najwa; Espariz, Martín; Brochier-Armanet, Céline; Gomes, João Paulo; Salcedo, Suzana P.

    2017-01-01

    Abstract Acinetobacter baumannii represents nowadays an important nosocomial opportunistic pathogen whose reservoirs outside the clinical setting are obscure. Here, we traced the origins of the collection strain A. baumannii DSM30011 to an isolate first reported in 1944, obtained from the enriched microbiota responsible of the aerobic decomposition of the resinous desert shrub guayule. Whole-genome sequencing and phylogenetic analysis based on core genes confirmed DSM30011 affiliation to A. baumannii. Comparative studies with 32 complete A. baumannii genomes revealed the presence of 12 unique accessory chromosomal regions in DSM30011 including five encompassing phage-related genes, five containing toxin genes of the type-6 secretion system, and one with an atypical CRISPRs/cas cluster. No antimicrobial resistance islands were identified in DSM30011 agreeing with a general antimicrobial susceptibility phenotype including folate synthesis inhibitors. The marginal ampicillin resistance of DSM30011 most likely derived from chromosomal ADC-type ampC and blaOXA-51-type genes. Searching for catabolic pathways genes revealed several clusters involved in the degradation of plant defenses including woody tissues and a previously unreported atu locus responsible of aliphatic terpenes degradation, thus suggesting that resinous plants may provide an effective niche for this organism. DSM30011 also harbored most genes and regulatory mechanisms linked to persistence and virulence in pathogenic Acinetobacter species. This strain thus revealed important clues into the genomic diversity, virulence potential, and niche ranges of the preantibiotic era A. baumannii population, and may provide an useful tool for our understanding of the processes that led to the recent evolution of this species toward an opportunistic pathogen of humans. PMID:28934377

  18. Genomic diversity in two related plant species with and without sex chromosomes - Silene latifolia and S. vulgaris

    Czech Academy of Sciences Publication Activity Database

    Čegan, Radim; Vyskot, Boris; Kejnovský, Eduard; Kubát, Zdeněk; Blavet, Hana; Šafář, Jan; Doležel, Jaroslav; Blavet, N.; Hobza, Roman

    2012-01-01

    Roč. 7, č. 2 (2012), e31898 E-ISSN 1932-6203 R&D Projects: GA AV ČR(CZ) KJB600040901; GA ČR(CZ) GPP501/10/P483; GA ČR(CZ) GAP501/10/0102; GA ČR(CZ) GD204/09/H002; GA ČR(CZ) GAP305/10/0930; GA ČR(CZ) GA522/09/0083 Institutional research plan: CEZ:AV0Z50040702; CEZ:AV0Z50040507; CEZ:AV0Z50380511 Keywords : Silene * repetitive DNA * genome size Subject RIV: BO - Biophysics Impact factor: 3.730, year: 2012

  19. Growth and Its Relationship to Individual Genetic Diversity of Mountain Hemlock (Tsuga mertensiana at Alpine Treeline in Alaska: Combining Dendrochronology and Genomics

    Directory of Open Access Journals (Sweden)

    Jeremy S. Johnson

    2017-11-01

    Full Text Available Globally, alpine treelines are characterized as temperature-limited environments with strong controls on tree growth. However, at local scales spatially heterogeneous environments generally have more variable impacts on individual patterns of tree growth. In addition to the landscape spatial heterogeneity there is local variability in individual tree genetic diversity (level of individual heterozygosity. It has been hypothesized that higher individual heterozygosity will result in more consistent patterns of growth. In this article, we combine genomics and dendrochronology to explore the relationship between individual genetic diversity and tree growth at a mountain hemlock (Tsuga mertensiana Bong. Carr alpine treeline on the Kenai Peninsula, Alaska, USA. We correlated average observed individual heterozygosity with average tree-ring width and variance in tree-ring width within individuals to test the hypothesis that trees with higher individual heterozygosity will also have more consistent growth patterns, suggesting that they may be more resilient to climate and environmental fluctuations at the alpine treeline. Our results showed that there was no significant relationship between tree growth and individual heterozygosity. However, there was a significant positive relationship between average tree-ring width and variance in tree-ring width implying that overall, fast growing trees in stressful environments, such as the alpine treeline, grow unstably regardless of the level of individual heterozygosity.

  20. From prediction to function using evolutionary genomics: human-specific ecotypes of Lactobacillus reuteri have diverse probiotic functions.

    Science.gov (United States)

    Spinler, Jennifer K; Sontakke, Amrita; Hollister, Emily B; Venable, Susan F; Oh, Phaik Lyn; Balderas, Miriam A; Saulnier, Delphine M A; Mistretta, Toni-Ann; Devaraj, Sridevi; Walter, Jens; Versalovic, James; Highlander, Sarah K

    2014-06-19

    The vertebrate gut symbiont Lactobacillus reuteri has diversified into separate clades reflecting host origin. Strains show evidence of host adaptation, but how host-microbe coevolution influences microbial-derived effects on hosts is poorly understood. Emphasizing human-derived strains of L. reuteri, we combined comparative genomic analyses with functional assays to examine variations in host interaction among genetically distinct ecotypes. Within clade II or VI, the genomes of human-derived L. reuteri strains are highly conserved in gene content and at the nucleotide level. Nevertheless, they share only 70-90% of total gene content, indicating differences in functional capacity. Human-associated lineages are distinguished by genes related to bacteriophages, vitamin biosynthesis, antimicrobial production, and immunomodulation. Differential production of reuterin, histamine, and folate by 23 clade II and VI strains was demonstrated. These strains also differed with respect to their ability to modulate human cytokine production (tumor necrosis factor, monocyte chemoattractant protein-1, interleukin [IL]-1β, IL-5, IL-7, IL-12, and IL-13) by myeloid cells. Microarray analysis of representative clade II and clade VI strains revealed global regulation of genes within the reuterin, vitamin B12, folate, and arginine catabolism gene clusters by the AraC family transcriptional regulator, PocR. Thus, human-derived L. reuteri clade II and VI strains are genetically distinct and their differences affect their functional repertoires and probiotic features. These findings highlight the biological impact of microbe:host coevolution and illustrate the functional significance of subspecies differences in the human microbiome. Consideration of host origin and functional differences at the subspecies level may have major impacts on probiotic strain selection and considerations of microbial ecology in mammalian species. © The Author(s) 2014. Published by Oxford University Press on

  1. GENETIC DIVERSITY OF WILD AND FARMED KALIBAUS (Labeo calbasu, Hamilton, 1822 BY RAPD ANALYSIS OF THE GENOMIC DNA

    Directory of Open Access Journals (Sweden)

    M.G. Mostafa

    2009-04-01

    Full Text Available Genetic diversity of two wild Kalibaus, Labeo calbasu populations and one hatchery stock was studied using random amplified polymorphic DNA (RAPD method. The three 10–mer random primers (OPA01, OPB02 and OPC03 yielded a total of 26 reproducible and consistently scorable RAPD bands of which 15 (57.69% were considered as polymorphic (P95 indicating a high level of genetic variation in all the studied populations. Among the three populations, Padma population shows low level of genetic diversity (0.1238 compared to other two and it might be caused by habitat degradation in many ways which ultimately affects the genetic variation of Kalibaus. The UPGMA dendrogram based on Nei’s (1972 original measures of genetic distance (D indicated the segregation of two wild and hatchery populations of L. calbasu into two distinct clusters: the Hatchery and Padma populations produced one cluster whereas the Jamuna population belonged to another cluster. This indicates that hatchery brood stock is derived from Padma River. Nevertheless, the preliminary study revealed that RAPD technique could be an effective tool in the assessment of population genetic structure of Kalibaus.

  2. De novo assembly of mitochondrial genomes provides insights into genetic diversity and molecular evolution in wild boars and domestic pigs.

    Science.gov (United States)

    Ni, Pan; Bhuiyan, Ali Akbar; Chen, Jian-Hai; Li, Jingjin; Zhang, Cheng; Zhao, Shuhong; Du, Xiaoyong; Li, Hua; Yu, Hui; Liu, Xiangdong; Li, Kui

    2018-05-10

    Up to date, the scarcity of publicly available complete mitochondrial sequences for European wild pigs hampers deeper understanding about the genetic changes following domestication. Here, we have assembled 26 de novo mtDNA sequences of European wild boars from next generation sequencing (NGS) data and downloaded 174 complete mtDNA sequences to assess the genetic relationship, nucleotide diversity, and selection. The Bayesian consensus tree reveals the clear divergence between the European and Asian clade and a very small portion (10 out of 200 samples) of maternal introgression. The overall nucleotides diversities of the mtDNA sequences have been reduced following domestication. Interestingly, the selection efficiencies in both European and Asian domestic pigs are reduced, probably caused by changes in both selection constraints and maternal population size following domestication. This study suggests that de novo assembled mitogenomes can be a great boon to uncover the genetic turnover following domestication. Further investigation is warranted to include more samples from the ever-increasing amounts of NGS data to help us to better understand the process of domestication.

  3. Analysis of genetic diversity and genome relationships of four eggplant species (Solanum melongena L) using RAPD markers

    Science.gov (United States)

    Susilo; Setyaningsih, M.

    2018-01-01

    Solanum melongena (eggplant) is one of the diversity of the Solanum family which is grown and widely spread in Indonesia and widely used by the community. This research explored the genetic diversity of four local Indonesian eggplant species namely leuca, tekokak, gelatik and kopek by using RAPD (Random Amplified Polymorphic DNA). The samples were obtained from Agricultural Technology Assessment Institute (BPTP) Bogor, Indonesia. The result of data observation was in the form of Solanum melongena plant’s DNA profile analyzed descriptively and quantitatively. 30 DNA bands (28 polymorphic and 2 monomorphic) were successfully scored by using four primers (OPF-01, OPF-02, OPF-03, and OPF-04). The Primers were used able to amplify all of the four eggplant samples. The result of PCR-RAPD visualization produces bands of 300-1500 bp. The result of cluster analysis showed the existence of three clusters (A, B, and C). Cluster A (coefficient of equal to 49%) consisted of a gelatik, cluster B (coefficient of 65% equilibrium) consisted of TPU (Kopek) and TK (Tekokak), and cluster C (55% equilibrium coefficient) consisted of LC (Leunca). These results indicated that the closest proximity is found in samples of TK (Tekokak) and TPU (Kopek).

  4. Genetic mapping using the Diversity Arrays Technology (DArT) : application and validation using the whole-genome sequences of Arabidopsis thaliana and the fungal wheat pathogen Mycosphaerella graminicola

    NARCIS (Netherlands)

    Wittenberg, A.H.J.

    2007-01-01

    Diversity Arrays Technology (DArT) is a microarray-based DNA marker technique for genome-wide discovery and genotyping of genetic variation. DArT allows simultaneous scoring of hundreds- to thousands of restriction site based polymorphisms between genotypes and does not require DNA sequence

  5. A TALE of shrimps: Genome-wide survey of homeobox genes in 120 species from diverse crustacean taxa.

    Science.gov (United States)

    Chang, Wai Hoong; Lai, Alvina G

    2018-01-01

    The homeodomain-containing proteins are an important group of transcription factors found in most eukaryotes including animals, plants and fungi. Homeobox genes are responsible for a wide range of critical developmental and physiological processes, ranging from embryonic development, innate immune homeostasis to whole-body regeneration. With continued fascination on this key class of proteins by developmental and evolutionary biologists, multiple efforts have thus far focused on the identification and characterization of homeobox orthologs from key model organisms in attempts to infer their evolutionary origin and how this underpins the evolution of complex body plans. Despite their importance, the genetic complement of homeobox genes has yet been described in one of the most valuable groups of animals representing economically important food crops. With crustacean aquaculture being a growing industry worldwide, it is clear that systematic and cross-species identification of crustacean homeobox orthologs is necessary in order to harness this genetic circuitry for the improvement of aquaculture sustainability. Using publicly available transcriptome data sets, we identified a total of 4183 putative homeobox genes from 120 crustacean species that include food crop species, such as lobsters, shrimps, crayfish and crabs. Additionally, we identified 717 homeobox orthologs from 6 other non-crustacean arthropods, which include the scorpion, deer tick, mosquitoes and centipede. This high confidence set of homeobox genes will now serve as a key resource to the broader community for future functional and comparative genomics studies.

  6. High diversity of beta-lactamases in the General Hospital Vienna verified by whole genome sequencing and statistical analysis.

    Science.gov (United States)

    Barišić, Ivan; Mitteregger, Dieter; Hirschl, Alexander M; Noehammer, Christa; Wiesinger-Mayr, Herbert

    2014-10-01

    The detailed analysis of antibiotic resistance mechanisms is essential for understanding the underlying evolutionary processes, the implementation of appropriate intervention strategies and to guarantee efficient treatment options. In the present study, 110 β-lactam-resistant, clinical isolates of Enterobacteriaceae sampled in 2011 in one of Europe's largest hospitals, the General Hospital Vienna, were screened for the presence of 31 β-lactamase genes. Twenty of those isolates were selected for whole genome sequencing (WGS). In addition, the number of β-lactamase genes was estimated using biostatistical models. The carbapenemase genes blaKPC-2, blaKPC-3, and blaVIM-4 were identified in carbapenem-resistant and intermediate susceptible isolates, blaOXA-72 in an extended-spectrum β-lactamase (ESBL)-positive one. Furthermore, the observed high prevalence of the acquired blaDHA-1 and blaCMY AmpC β-lactamase genes (70%) in phenotypically AmpC-positive isolates is alarming due to their capability to become carbapenem-resistant upon changes in membrane permeability. The statistical anal