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Sample records for evolutionary genomics revealed

  1. Genomic Mining Reveals Deep Evolutionary Relationships between Bornaviruses and Bats

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    Jie Cui

    2015-11-01

    Full Text Available Bats globally harbor viruses in order Mononegavirales, such as lyssaviruses and henipaviruses; however, little is known about their relationships with bornaviruses. Previous studies showed that viral fossils of bornaviral origin are embedded in the genomes of several mammalian species such as primates, indicative of an ancient origin of exogenous bornaviruses. In this study, we mined the available 10 bat genomes and recreated a clear evolutionary relationship of endogenous bornaviral elements and bats. Comparative genomics showed that endogenization of bornaviral elements frequently occurred in vesper bats, harboring EBLLs (endogenous bornavirus-like L elements in their genomes. Molecular dating uncovered a continuous bornavirus-bat interaction spanning 70 million years. We conclude that better understanding of modern exogenous bornaviral circulation in bat populations is warranted.

  2. Gorilla genome structural variation reveals evolutionary parallelisms with chimpanzee

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    Ventura, Mario; Catacchio, Claudia R.; Alkan, Can; Marques-Bonet, Tomas; Sajjadian, Saba; Graves, Tina A.; Hormozdiari, Fereydoun; Navarro, Arcadi; Malig, Maika; Baker, Carl; Lee, Choli; Turner, Emily H.; Chen, Lin; Kidd, Jeffrey M.; Archidiacono, Nicoletta; Shendure, Jay; Wilson, Richard K.; Eichler, Evan E.

    2011-01-01

    Structural variation has played an important role in the evolutionary restructuring of human and great ape genomes. Recent analyses have suggested that the genomes of chimpanzee and human have been particularly enriched for this form of genetic variation. Here, we set out to assess the extent of structural variation in the gorilla lineage by generating 10-fold genomic sequence coverage from a western lowland gorilla and integrating these data into a physical and cytogenetic framework of structural variation. We discovered and validated over 7665 structural changes within the gorilla lineage, including sequence resolution of inversions, deletions, duplications, and mobile element insertions. A comparison with human and other ape genomes shows that the gorilla genome has been subjected to the highest rate of segmental duplication. We show that both the gorilla and chimpanzee genomes have experienced independent yet convergent patterns of structural mutation that have not occurred in humans, including the formation of subtelomeric heterochromatic caps, the hyperexpansion of segmental duplications, and bursts of retroviral integrations. Our analysis suggests that the chimpanzee and gorilla genomes are structurally more derived than either orangutan or human genomes. PMID:21685127

  3. Algal genomes reveal evolutionary mosaicism and the fate of nucleomorphs

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    Curtis, Bruce A.; Tanifuji, Goro; Burki, Fabien; Gruber, Ansgar; Irimia, Manuuel; Maruyama, Shinichiro; Arias, Maria C.; Ball, Steven G.; Gile, Gillian H.; Hirakawa, Yoshihisa; Hopkins, Julia F.; Kuo, Alan; Rensing, Stefan A.; Schmutz, Jeremy; Symeonidi, Aikaterini; Elias, Marek; Eveleigh, Robert J. M.; Herman, Emily K.; Klute, Mary J.; Nakayama, Takuro; Obornik, Miroslav; Reyes-Prieto, Adrian; Armbrust, E. Virginia; Aves, Stephen J.; Beiko, Robert G.; Coutinho, Pedro; Dacks, Joel B.; Durnford, Dion G.; Fast, Naomi M.; Green, Beverley R.; Grisdale, Cameron J.; Hempel, Franziska; Henrissat, Bernard; Hoppner, Marc P.; Ishida, Ken-Ichiro; Kim, Eunsoo; Koreny, Ludek; Kroth, Peter G.; Liu, Yuan; Malik, Shehre-Banoo; Maier, Uwe G.; McRose, Darcy; Mock, Thomas; Neilson, Jonathan A. D.; Onodera, Naoko T.; Poole, Anthony M.; Pritham, Ellen J.; Richards, Thomas A.; Rocap, Gabrielle; Roy, Scott W.; Sarai, Chihiro; Schaack, Sarah; Shirato, Shu; Slamovits, Claudio H.; Spencer, Davie F.; Suzuki, Shigekatsu; Worden, Alexandra Z.; Zauner, Stefan; Barry, Kerrie; Bell, Callum; Bharti, Arvind K.; Crow, John A.; Grimwood, Jane; Kramer, Robin; Lindquist, Erika; Lucas, Susan; Salamov, Asaf; McFadden, Geoffrey I.; Lane, Christopher E.; Keeling, Patrick J.; Gray, Michael W.; Grigoriev, Igor V.; Archibald, John M.

    2012-08-10

    Cryptophyte and chlorarachniophyte algae are transitional forms in the widespread secondary endosymbiotic acquisition of photosynthesis by engulfment of eukaryotic algae. Unlike most secondary plastid-bearing algae, miniaturized versions of the endosymbiont nuclei (nucleomorphs) persist in cryptophytes and chlorarachniophytes. To determine why, and to address other fundamental questions about eukaryote eukaryote endosymbiosis, we sequenced the nuclear genomes of the cryptophyte Guillardia theta and the chlorarachniophyte Bigelowiella natans. Both genomes have 21,000 protein genes and are intron rich, and B. natans exhibits unprecedented alternative splicing for a single-celled organism. Phylogenomic analyses and subcellular targeting predictions reveal extensive genetic and biochemical mosaicism, with both host- and endosymbiont-derived genes servicing the mitochondrion, the host cell cytosol, the plastid and the remnant endosymbiont cytosol of both algae. Mitochondrion-to-nucleus gene transfer still occurs in both organisms but plastid-to-nucleus and nucleomorph-to-nucleus transfers do not, which explains why a small residue of essential genes remains locked in each nucleomorph.

  4. The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants

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    Rensing, Stefan A.; Lang, Daniel; Zimmer, Andreas D.; Terry, Astrid; Salamov, Asaf; Shapiro, Harris; Nishiyama, Tomaoki; Perroud, Pierre-Francois; Lindquist, Erika A.; Kamisugi, Yasuko; Tanahashi, Takako; Sakakibara, Keiko; Fujita, Tomomichi; Oishi, Kazuko; Shin, Tadasu; Kuroki, Yoko; Toyoda, Atsushi; Suzuki, Yutaka; Hashimoto, Shin-ichi; Yamaguchi, Kazuo; Sugano, Sumio; Kohara, Yuji; Fujiyama, Asao; Anterola, Aldwin; Aoki, Setsuyuki; Ashton, Neil; Barbazuk, W. Brad; Barker, Elizabeth; Bennetzen, Jeffrey L.; Blankenship, Robert; Cho, Sung Hyun; Dutcher, Susan K.; Estelle, Mark; Fawcett, Jeffrey A.; Gundlach, Heidrum; Hanada, Kousuke; Melkozernov, Alexander; Murata, Takashi; Nelson, David R.; Pils, Birgit; Prigge, Michael; Reiss, Bernd; Renner, Tanya; Rombauts, Stephane; Rushton, Paul J.; Sanderfoot, Anton; Schween, Gabriele; Shiu, Shin-Han; Stueber, Kurt; Theodoulou, Frederica L.; Tu, Hank; Van de Peer, Yves; Verrier, Paul J.; Waters, Elizabeth; Wood, Andrew; Yang, Lixing; Cove, David; Cuming, Andrew C.; Hasebe, Mitsayasu; Lucas, Susan; Mishler, Brent D.; Reski, Ralf; Grigoriev, Igor V.; Quatrano, Rakph S.; Boore, Jeffrey L.

    2007-09-18

    We report the draft genome sequence of the model moss Physcomitrella patens and compare its features with those of flowering plants, from which it is separated by more than 400 million years, and unicellular aquatic algae. This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments (e.g., flagellar arms); acquisition of genes for tolerating terrestrial stresses (e.g., variation in temperature and water availability); and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response. The Physcomitrella genome provides a resource for phylogenetic inferences about gene function and for experimental analysis of plant processes through this plant's unique facility for reverse genetics.

  5. Evolutionary genomics of Entamoeba

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    Weedall, Gareth D.; Hall, Neil

    2011-01-01

    Entamoeba histolytica is a human pathogen that causes amoebic dysentery and leads to significant morbidity and mortality worldwide. Understanding the genome and evolution of the parasite will help explain how, when and why it causes disease. Here we review current knowledge about the evolutionary genomics of Entamoeba: how differences between the genomes of different species may help explain different phenotypes, and how variation among E. histolytica parasites reveals patterns of population structure. The imminent expansion of the amount genome data will greatly improve our knowledge of the genus and of pathogenic species within it. PMID:21288488

  6. Transcriptome sequencing reveals genome-wide variation in molecular evolutionary rate among ferns.

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    Grusz, Amanda L; Rothfels, Carl J; Schuettpelz, Eric

    2016-08-30

    Transcriptomics in non-model plant systems has recently reached a point where the examination of nuclear genome-wide patterns in understudied groups is an achievable reality. This progress is especially notable in evolutionary studies of ferns, for which molecular resources to date have been derived primarily from the plastid genome. Here, we utilize transcriptome data in the first genome-wide comparative study of molecular evolutionary rate in ferns. We focus on the ecologically diverse family Pteridaceae, which comprises about 10 % of fern diversity and includes the enigmatic vittarioid ferns-an epiphytic, tropical lineage known for dramatically reduced morphologies and radically elongated phylogenetic branch lengths. Using expressed sequence data for 2091 loci, we perform pairwise comparisons of molecular evolutionary rate among 12 species spanning the three largest clades in the family and ask whether previously documented heterogeneity in plastid substitution rates is reflected in their nuclear genomes. We then inquire whether variation in evolutionary rate is being shaped by genes belonging to specific functional categories and test for differential patterns of selection. We find significant, genome-wide differences in evolutionary rate for vittarioid ferns relative to all other lineages within the Pteridaceae, but we recover few significant correlations between faster/slower vittarioid loci and known functional gene categories. We demonstrate that the faster rates characteristic of the vittarioid ferns are likely not driven by positive selection, nor are they unique to any particular type of nucleotide substitution. Our results reinforce recently reviewed mechanisms hypothesized to shape molecular evolutionary rates in vittarioid ferns and provide novel insight into substitution rate variation both within and among fern nuclear genomes.

  7. Genome-wide investigation reveals high evolutionary rates in annual model plants

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    Araki Hitoshi

    2010-11-01

    Full Text Available Abstract Background Rates of molecular evolution vary widely among species. While significant deviations from molecular clock have been found in many taxa, effects of life histories on molecular evolution are not fully understood. In plants, annual/perennial life history traits have long been suspected to influence the evolutionary rates at the molecular level. To date, however, the number of genes investigated on this subject is limited and the conclusions are mixed. To evaluate the possible heterogeneity in evolutionary rates between annual and perennial plants at the genomic level, we investigated 85 nuclear housekeeping genes, 10 non-housekeeping families, and 34 chloroplast genes using the genomic data from model plants including Arabidopsis thaliana and Medicago truncatula for annuals and grape (Vitis vinifera and popular (Populus trichocarpa for perennials. Results According to the cross-comparisons among the four species, 74-82% of the nuclear genes and 71-97% of the chloroplast genes suggested higher rates of molecular evolution in the two annuals than those in the two perennials. The significant heterogeneity in evolutionary rate between annuals and perennials was consistently found both in nonsynonymous sites and synonymous sites. While a linear correlation of evolutionary rates in orthologous genes between species was observed in nonsynonymous sites, the correlation was weak or invisible in synonymous sites. This tendency was clearer in nuclear genes than in chloroplast genes, in which the overall evolutionary rate was small. The slope of the regression line was consistently lower than unity, further confirming the higher evolutionary rate in annuals at the genomic level. Conclusions The higher evolutionary rate in annuals than in perennials appears to be a universal phenomenon both in nuclear and chloroplast genomes in the four dicot model plants we investigated. Therefore, such heterogeneity in evolutionary rate should result from

  8. Comparative genomics of eukaryotic small nucleolar RNAs reveals deep evolutionary ancestry amidst ongoing intragenomic mobility

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    Hoeppner Marc P

    2012-09-01

    Full Text Available Abstract Background Small nucleolar (snoRNAs are required for posttranscriptional processing and modification of ribosomal, spliceosomal and messenger RNAs. Their presence in both eukaryotes and archaea indicates that snoRNAs are evolutionarily ancient. The location of some snoRNAs within the introns of ribosomal protein genes has been suggested to belie an RNA world origin, with the exons of the earliest protein-coding genes having evolved around snoRNAs after the advent of templated protein synthesis. Alternatively, this intronic location may reflect more recent selection for coexpression of snoRNAs and ribosomal components, ensuring rRNA modification by snoRNAs during ribosome synthesis. To gain insight into the evolutionary origins of this genetic organization, we examined the antiquity of snoRNA families and the stability of their genomic location across 44 eukaryote genomes. Results We report that dozens of snoRNA families are traceable to the Last Eukaryotic Common Ancestor (LECA, but find only weak similarities between the oldest eukaryotic snoRNAs and archaeal snoRNA-like genes. Moreover, many of these LECA snoRNAs are located within the introns of host genes independently traceable to the LECA. Comparative genomic analyses reveal the intronic location of LECA snoRNAs is not ancestral however, suggesting the pattern we observe is the result of ongoing intragenomic mobility. Analysis of human transcriptome data indicates that the primary requirement for hosting intronic snoRNAs is a broad expression profile. Consistent with ongoing mobility across broadly-expressed genes, we report a case of recent migration of a non-LECA snoRNA from the intron of a ubiquitously expressed non-LECA host gene into the introns of two LECA genes during the evolution of primates. Conclusions Our analyses show that snoRNAs were a well-established family of RNAs at the time when eukaryotes began to diversify. While many are intronic, this association is not

  9. Genomic Analysis of Hepatitis B Virus Reveals Antigen State and Genotype as Sources of Evolutionary Rate Variation

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    Harrison, Abby; Lemey, Philippe; Hurles, Matthew; Moyes, Chris; Horn, Susanne; Pryor, Jan; Malani, Joji; Supuri, Mathias; Masta, Andrew; Teriboriki, Burentau; Toatu, Tebuka; Penny, David; Rambaut, Andrew; Shapiro, Beth

    2011-01-01

    Hepatitis B virus (HBV) genomes are small, semi-double-stranded DNA circular genomes that contain alternating overlapping reading frames and replicate through an RNA intermediary phase. This complex biology has presented a challenge to estimating an evolutionary rate for HBV, leading to difficulties resolving the evolutionary and epidemiological history of the virus. Here, we re-examine rates of HBV evolution using a novel data set of 112 within-host, transmission history (pedigree) and among-host genomes isolated over 20 years from the indigenous peoples of the South Pacific, combined with 313 previously published HBV genomes. We employ Bayesian phylogenetic approaches to examine several potential causes and consequences of evolutionary rate variation in HBV. Our results reveal rate variation both between genotypes and across the genome, as well as strikingly slower rates when genomes are sampled in the Hepatitis B e antigen positive state, compared to the e antigen negative state. This Hepatitis B e antigen rate variation was found to be largely attributable to changes during the course of infection in the preCore and Core genes and their regulatory elements. PMID:21765983

  10. Comparative mitochondrial genome analysis reveals the evolutionary rearrangement mechanism in Brassica.

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    Yang, J; Liu, G; Zhao, N; Chen, S; Liu, D; Ma, W; Hu, Z; Zhang, M

    2016-05-01

    The genus Brassica has many species that are important for oil, vegetable and other food products. Three mitochondrial genome types (mitotype) originated from its common ancestor. In this paper, a B. nigra mitochondrial main circle genome with 232,407 bp was generated through de novo assembly. Synteny analysis showed that the mitochondrial genomes of B. rapa and B. oleracea had a better syntenic relationship than B. nigra. Principal components analysis and development of a phylogenetic tree indicated maternal ancestors of three allotetraploid species in Us triangle of Brassica. Diversified mitotypes were found in allotetraploid B. napus, in which napus-type B. napus was derived from B. oleracea, while polima-type B. napus was inherited from B. rapa. In addition, the mitochondrial genome of napus-type B. napus was closer to botrytis-type than capitata-type B. oleracea. The sub-stoichiometric shifting of several mitochondrial genes suggested that mitochondrial genome rearrangement underwent evolutionary selection during domestication and/or plant breeding. Our findings clarify the role of diploid species in the maternal origin of allotetraploid species in Brassica and suggest the possibility of breeding selection of the mitochondrial genome. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. Phylogenetic and evolutionary patterns in microbial carotenoid biosynthesis are revealed by comparative genomics.

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    Jonathan L Klassen

    Full Text Available BACKGROUND: Carotenoids are multifunctional, taxonomically widespread and biotechnologically important pigments. Their biosynthesis serves as a model system for understanding the evolution of secondary metabolism. Microbial carotenoid diversity and evolution has hitherto been analyzed primarily from structural and biosynthetic perspectives, with the few phylogenetic analyses of microbial carotenoid biosynthetic proteins using either used limited datasets or lacking methodological rigor. Given the recent accumulation of microbial genome sequences, a reappraisal of microbial carotenoid biosynthetic diversity and evolution from the perspective of comparative genomics is warranted to validate and complement models of microbial carotenoid diversity and evolution based upon structural and biosynthetic data. METHODOLOGY/PRINCIPAL FINDINGS: Comparative genomics were used to identify and analyze in silico microbial carotenoid biosynthetic pathways. Four major phylogenetic lineages of carotenoid biosynthesis are suggested composed of: (i Proteobacteria; (ii Firmicutes; (iii Chlorobi, Cyanobacteria and photosynthetic eukaryotes; and (iv Archaea, Bacteroidetes and two separate sub-lineages of Actinobacteria. Using this phylogenetic framework, specific evolutionary mechanisms are proposed for carotenoid desaturase CrtI-family enzymes and carotenoid cyclases. Several phylogenetic lineage-specific evolutionary mechanisms are also suggested, including: (i horizontal gene transfer; (ii gene acquisition followed by differential gene loss; (iii co-evolution with other biochemical structures such as proteorhodopsins; and (iv positive selection. CONCLUSIONS/SIGNIFICANCE: Comparative genomics analyses of microbial carotenoid biosynthetic proteins indicate a much greater taxonomic diversity then that identified based on structural and biosynthetic data, and divides microbial carotenoid biosynthesis into several, well-supported phylogenetic lineages not evident

  12. Phylogenetic and evolutionary patterns in microbial carotenoid biosynthesis are revealed by comparative genomics.

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    Klassen, Jonathan L

    2010-06-22

    Carotenoids are multifunctional, taxonomically widespread and biotechnologically important pigments. Their biosynthesis serves as a model system for understanding the evolution of secondary metabolism. Microbial carotenoid diversity and evolution has hitherto been analyzed primarily from structural and biosynthetic perspectives, with the few phylogenetic analyses of microbial carotenoid biosynthetic proteins using either used limited datasets or lacking methodological rigor. Given the recent accumulation of microbial genome sequences, a reappraisal of microbial carotenoid biosynthetic diversity and evolution from the perspective of comparative genomics is warranted to validate and complement models of microbial carotenoid diversity and evolution based upon structural and biosynthetic data. Comparative genomics were used to identify and analyze in silico microbial carotenoid biosynthetic pathways. Four major phylogenetic lineages of carotenoid biosynthesis are suggested composed of: (i) Proteobacteria; (ii) Firmicutes; (iii) Chlorobi, Cyanobacteria and photosynthetic eukaryotes; and (iv) Archaea, Bacteroidetes and two separate sub-lineages of Actinobacteria. Using this phylogenetic framework, specific evolutionary mechanisms are proposed for carotenoid desaturase CrtI-family enzymes and carotenoid cyclases. Several phylogenetic lineage-specific evolutionary mechanisms are also suggested, including: (i) horizontal gene transfer; (ii) gene acquisition followed by differential gene loss; (iii) co-evolution with other biochemical structures such as proteorhodopsins; and (iv) positive selection. Comparative genomics analyses of microbial carotenoid biosynthetic proteins indicate a much greater taxonomic diversity then that identified based on structural and biosynthetic data, and divides microbial carotenoid biosynthesis into several, well-supported phylogenetic lineages not evident previously. This phylogenetic framework is applicable to understanding the evolution of

  13. Genomes of three tomato pathogens within the Ralstonia solanacearum species complex reveal significant evolutionary divergence.

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    Remenant, Benoît; Coupat-Goutaland, Bénédicte; Guidot, Alice; Cellier, Gilles; Wicker, Emmanuel; Allen, Caitilyn; Fegan, Mark; Pruvost, Olivier; Elbaz, Mounira; Calteau, Alexandra; Salvignol, Gregory; Mornico, Damien; Mangenot, Sophie; Barbe, Valérie; Médigue, Claudine; Prior, Philippe

    2010-06-15

    The Ralstonia solanacearum species complex includes thousands of strains pathogenic to an unusually wide range of plant species. These globally dispersed and heterogeneous strains cause bacterial wilt diseases, which have major socio-economic impacts. Pathogenicity is an ancestral trait in R. solanacearum and strains with high genetic variation can be subdivided into four phylotypes, correlating to isolates from Asia (phylotype I), the Americas (phylotype IIA and IIB), Africa (phylotype III) and Indonesia (phylotype IV). Comparison of genome sequences strains representative of this phylogenetic diversity can help determine which traits allow this bacterium to be such a pathogen of so many different plant species and how the bacteria survive in many different habitats. The genomes of three tomato bacterial wilt pathogens, CFBP2957 (phy. IIA), CMR15 (phy. III) and PSI07 (phy. IV) were sequenced and manually annotated. These genomes were compared with those of three previously sequenced R. solanacearum strains: GMI1000 (tomato, phy. I), IPO1609 (potato, phy. IIB), and Molk2 (banana, phy. IIB). The major genomic features (size, G+C content, number of genes) were conserved across all of the six sequenced strains. Despite relatively high genetic distances (calculated from average nucleotide identity) and many genomic rearrangements, more than 60% of the genes of the megaplasmid and 70% of those on the chromosome are syntenic. The three new genomic sequences revealed the presence of several previously unknown traits, probably acquired by horizontal transfers, within the genomes of R. solanacearum, including a type IV secretion system, a rhi-type anti-mitotic toxin and two small plasmids. Genes involved in virulence appear to be evolving at a faster rate than the genome as a whole. Comparative analysis of genome sequences and gene content confirmed the differentiation of R. solanacearum species complex strains into four phylotypes. Genetic distances between strains, in

  14. Genomes of three tomato pathogens within the Ralstonia solanacearum species complex reveal significant evolutionary divergence

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    Barbe Valérie

    2010-06-01

    Full Text Available Abstract Background The Ralstonia solanacearum species complex includes thousands of strains pathogenic to an unusually wide range of plant species. These globally dispersed and heterogeneous strains cause bacterial wilt diseases, which have major socio-economic impacts. Pathogenicity is an ancestral trait in R. solanacearum and strains with high genetic variation can be subdivided into four phylotypes, correlating to isolates from Asia (phylotype I, the Americas (phylotype IIA and IIB, Africa (phylotype III and Indonesia (phylotype IV. Comparison of genome sequences strains representative of this phylogenetic diversity can help determine which traits allow this bacterium to be such a pathogen of so many different plant species and how the bacteria survive in many different habitats. Results The genomes of three tomato bacterial wilt pathogens, CFBP2957 (phy. IIA, CMR15 (phy. III and PSI07 (phy. IV were sequenced and manually annotated. These genomes were compared with those of three previously sequenced R. solanacearum strains: GMI1000 (tomato, phy. I, IPO1609 (potato, phy. IIB, and Molk2 (banana, phy. IIB. The major genomic features (size, G+C content, number of genes were conserved across all of the six sequenced strains. Despite relatively high genetic distances (calculated from average nucleotide identity and many genomic rearrangements, more than 60% of the genes of the megaplasmid and 70% of those on the chromosome are syntenic. The three new genomic sequences revealed the presence of several previously unknown traits, probably acquired by horizontal transfers, within the genomes of R. solanacearum, including a type IV secretion system, a rhi-type anti-mitotic toxin and two small plasmids. Genes involved in virulence appear to be evolving at a faster rate than the genome as a whole. Conclusions Comparative analysis of genome sequences and gene content confirmed the differentiation of R. solanacearum species complex strains into four

  15. Genome wide evolutionary analyses reveal serotype specific patterns of positive selection in selected Salmonella serotypes

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    Sun Qi

    2009-11-01

    Full Text Available Abstract Background The bacterium Salmonella enterica includes a diversity of serotypes that cause disease in humans and different animal species. Some Salmonella serotypes show a broad host range, some are host restricted and exclusively associated with one particular host, and some are associated with one particular host species, but able to cause disease in other host species and are thus considered "host adapted". Five Salmonella genome sequences, representing a broad host range serotype (Typhimurium, two host restricted serotypes (Typhi [two genomes] and Paratyphi and one host adapted serotype (Choleraesuis were used to identify core genome genes that show evidence for recombination and positive selection. Results Overall, 3323 orthologous genes were identified in all 5 Salmonella genomes analyzed. Use of four different methods to assess homologous recombination identified 270 genes that showed evidence for recombination with at least one of these methods (false discovery rate [FDR] ompC, a gene encoding an outer membrane protein, which has also been found to be under positive selection in other bacteria. A total of 8, 16, 7, and 5 genes showed evidence for positive selection in Choleraesuis, Typhi, Typhimurium, and Paratyphi branch analyses, respectively. Sequencing and evolutionary analyses of four genes in an additional 42 isolates representing 23 serotypes confirmed branch specific positive selection and recombination patterns. Conclusion Our data show that, among the four serotypes analyzed, (i less than 10% of Salmonella genes in the core genome show evidence for homologous recombination, (ii a number of Salmonella genes are under positive selection, including genes that appear to contribute to virulence, and (iii branch specific positive selection contributes to the evolution of host restricted Salmonella serotypes.

  16. Comparative genomic analysis of clinical and environmental Vibrio vulnificus isolates revealed biotype 3 evolutionary relationships.

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    Koton, Yael; Gordon, Michal; Chalifa-Caspi, Vered; Bisharat, Naiel

    2014-01-01

    In 1996 a common-source outbreak of severe soft tissue and bloodstream infections erupted among Israeli fish farmers and fish consumers due to changes in fish marketing policies. The causative pathogen was a new strain of Vibrio vulnificus, named biotype 3, which displayed a unique biochemical and genotypic profile. Initial observations suggested that the pathogen erupted as a result of genetic recombination between two distinct populations. We applied a whole genome shotgun sequencing approach using several V. vulnificus strains from Israel in order to study the pan genome of V. vulnificus and determine the phylogenetic relationship of biotype 3 with existing populations. The core genome of V. vulnificus based on 16 draft and complete genomes consisted of 3068 genes, representing between 59 and 78% of the whole genome of 16 strains. The accessory genome varied in size from 781 to 2044 kbp. Phylogenetic analysis based on whole, core, and accessory genomes displayed similar clustering patterns with two main clusters, clinical (C) and environmental (E), all biotype 3 strains formed a distinct group within the E cluster. Annotation of accessory genomic regions found in biotype 3 strains and absent from the core genome yielded 1732 genes, of which the vast majority encoded hypothetical proteins, phage-related proteins, and mobile element proteins. A total of 1916 proteins (including 713 hypothetical proteins) were present in all human pathogenic strains (both biotype 3 and non-biotype 3) and absent from the environmental strains. Clustering analysis of the non-hypothetical proteins revealed 148 protein clusters shared by all human pathogenic strains; these included transcriptional regulators, arylsulfatases, methyl-accepting chemotaxis proteins, acetyltransferases, GGDEF family proteins, transposases, type IV secretory system (T4SS) proteins, and integrases. Our study showed that V. vulnificus biotype 3 evolved from environmental populations and formed a genetically

  17. Comparative Genomic Analysis of Clinical and Environmental Vibrio Vulnificus Isolates Revealed Biotype 3 Evolutionary Relationships

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    Yael eKotton

    2015-01-01

    Full Text Available In 1996 a common-source outbreak of severe soft tissue and bloodstream infections erupted among Israeli fish farmers and fish consumers due to changes in fish marketing policies. The causative pathogen was a new strain of Vibrio vulnificus, named biotype 3, which displayed a unique biochemical and genotypic profile. Initial observations suggested that the pathogen erupted as a result of genetic recombination between two distinct populations. We applied a whole genome shotgun sequencing approach using several V. vulnificus strains from Israel in order to study the pan genome of V. vulnificus and determine the phylogenetic relationship of biotype 3 with existing populations. The core genome of V. vulnificus based on 16 draft and complete genomes consisted of 3068 genes, representing between 59% and 78% of the whole genome of 16 strains. The accessory genome varied in size from 781 kbp to 2044 kbp. Phylogenetic analysis based on whole, core, and accessory genomes displayed similar clustering patterns with two main clusters, clinical (C and environmental (E, all biotype 3 strains formed a distinct group within the E cluster. Annotation of accessory genomic regions found in biotype 3 strains and absent from the core genome yielded 1732 genes, of which the vast majority encoded hypothetical proteins, phage-related proteins, and mobile element proteins. A total of 1916 proteins (including 713 hypothetical proteins were present in all human pathogenic strains (both biotype 3 and non-biotype 3 and absent from the environmental strains. Clustering analysis of the non-hypothetical proteins revealed 148 protein clusters shared by all human pathogenic strains; these included transcriptional regulators, arylsulfatases, methyl-accepting chemotaxis proteins, acetyltransferases, GGDEF family proteins, transposases, type IV secretory system (T4SS proteins, and integrases. Our study showed that V. vulnificus biotype 3 evolved from environmental populations and

  18. Conservation genomics reveals multiple evolutionary units within Bell’s Vireo (Vireo bellii).

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    Klicka, Luke B.; Kus, Barbara E.; Title, Pascal O.; Burns, Kevin J.

    2016-01-01

    The Bell’s Vireo (Vireo bellii) is a widespread North American species of bird that has declined since the mid-1960s primarily due to habitat modification. Throughout its range, Bell’s Vireo populations are regulated under varying degrees of protection; however, the species has never been characterized genetically. Therefore, the current taxonomy used to guide management decisions may misrepresent the true evolutionary history for the species. We sequenced 86 individuals for ND2 and genotyped 48 individuals for genome-wide SNPs to identify distinct lineages within Bell’s Vireo. Phylogenetic analyses uncovered two distinct clades that are separated in the arid southwestern United States, near the border of the Chihuahuan and Sonoran Deserts. These clades diverged from each other approximately 1.11–2.04 mya. The timing of diversification, geographic location, and niche modeling of the east/west divergence suggest vicariance as a mode of diversification for these two lineages. Analyses of the SNP dataset provided additional resolution and indicated the Least Bell’s Vireo populations are a distinct evolutionary lineage. Our genetic evidence, together with information from morphology and behavior, suggests that the Bell’s Vireo complex involves two species, each containing two separate subspecies. This new information has implications for the federal, state and other listing status of Bell’s Vireo throughout its range.

  19. Complete mitochondrial genomes reveal phylogeny relationship and evolutionary history of the family Felidae.

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    Zhang, W Q; Zhang, M H

    2013-09-03

    Many mitochondrial DNA sequences are used to estimate phylogenetic relationships among animal taxa and perform molecular phylogenetic evolution analysis. With the continuous development of sequencing technology, numerous mitochondrial sequences have been released in public databases, especially complete mitochondrial DNA sequences. Using multiple sequences is better than using single sequences for phylogenetic analysis of animals because multiple sequences have sufficient information for evolutionary process reconstruction. Therefore, we performed phylogenetic analyses of 14 species of Felidae based on complete mitochondrial genome sequences, with Canis familiaris as an outgroup, using neighbor joining, maximum likelihood, maximum parsimony, and Bayesian inference methods. The consensus phylogenetic trees supported the monophyly of Felidae, and the family could be divided into 2 subfamilies, Felinae and Pantherinae. The genus Panthera and species tigris were also studied in detail. Meanwhile, the divergence of this family was estimated by phylogenetic analysis using the Bayesian method with a relaxed molecular clock, and the results shown were consistent with previous studies. In summary, the evolution of Felidae was reconstructed by phylogenetic analysis based on mitochondrial genome sequences. The described method may be broadly applicable for phylogenetic analyses of anima taxa.

  20. Population genomics reveal recent speciation and rapid evolutionary adaptation in polar bears

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    Liu, Shiping; Lorenzen, Eline D.; Fumagalli, Matteo

    2014-01-01

    Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyperlipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show...

  1. Molluscan Evolutionary Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Simison, W. Brian; Boore, Jeffrey L.

    2005-12-01

    In the last 20 years there have been dramatic advances in techniques of high-throughput DNA sequencing, most recently accelerated by the Human Genome Project, a program that has determined the three billion base pair code on which we are based. Now this tremendous capability is being directed at other genome targets that are being sampled across the broad range of life. This opens up opportunities as never before for evolutionary and organismal biologists to address questions of both processes and patterns of organismal change. We stand at the dawn of a new 'modern synthesis' period, paralleling that of the early 20th century when the fledgling field of genetics first identified the underlying basis for Darwin's theory. We must now unite the efforts of systematists, paleontologists, mathematicians, computer programmers, molecular biologists, developmental biologists, and others in the pursuit of discovering what genomics can teach us about the diversity of life. Genome-level sampling for mollusks to date has mostly been limited to mitochondrial genomes and it is likely that these will continue to provide the best targets for broad phylogenetic sampling in the near future. However, we are just beginning to see an inroad into complete nuclear genome sequencing, with several mollusks and other eutrochozoans having been selected for work about to begin. Here, we provide an overview of the state of molluscan mitochondrial genomics, highlight a few of the discoveries from this research, outline the promise of broadening this dataset, describe upcoming projects to sequence whole mollusk nuclear genomes, and challenge the community to prepare for making the best use of these data.

  2. Population Genomics Reveal Recent Speciation and Rapid Evolutionary Adaptation in Polar Bears

    OpenAIRE

    Liu, Shiping; Lorenzen, Eline D.; Fumagalli, Matteo; Li, Bo; Harris, Kelley; Xiong, Zijun; ZHOU, Long; Korneliussen, Thorfinn Sand; Somel, Mehmet; Babbitt, Courtney; Wray, Greg; Li, Jianwen; He, Weiming; Wang, Zhuo; Fu, Wenjing

    2014-01-01

    Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyperlipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show that the species diverged only 479–343 thousand years BP. We find that genes on the polar bear lineage have been under stronger positive selection than in brown bears; nine of the top 16 genes under...

  3. POPULATION GENOMICS REVEAL RECENT SPECIATION AND RAPID EVOLUTIONARY ADAPTATION IN POLAR BEARS

    Science.gov (United States)

    Liu, Shiping; Lorenzen, Eline D.; Fumagalli, Matteo; Li, Bo; Harris, Kelley; Xiong, Zijun; Zhou, Long; Korneliussen, Thorfinn Sand; Somel, Mehmet; Babbitt, Courtney; Wray, Greg; Li, Jianwen; He, Weiming; Wang, Zhuo; Fu, Wenjing; Xiang, Xueyan; Morgan, Claire C.; Doherty, Aoife; O’Connell, Mary J.; McInerney, James O.; Born, Erik W.; Dalén, Love; Dietz, Rune; Orlando, Ludovic; Sonne, Christian; Zhang, Guojie; Nielsen, Rasmus; Willerslev, Eske; Wang, Jun

    2014-01-01

    SUMMARY Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyperlipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show that the species diverged only 479–343 thousand years BP. We find that genes on the polar bear lineage have been under stronger positive selection than in brown bears; nine of the top 16 genes under strong positive selection are associated with cardiomyopathy and vascular disease, implying important reorganization of the cardio-vascular system. One of the genes showing the strongest evidence of selection, APOB, encodes the primary lipoprotein component of low-density lipoprotein (LDL); functional mutations in APOB may explain how polar bears are able to cope with life-long elevated LDL levels that are associated with high risk of heart disease in humans. PMID:24813606

  4. Population genomics reveal recent speciation and rapid evolutionary adaptation in polar bears.

    Science.gov (United States)

    Liu, Shiping; Lorenzen, Eline D; Fumagalli, Matteo; Li, Bo; Harris, Kelley; Xiong, Zijun; Zhou, Long; Korneliussen, Thorfinn Sand; Somel, Mehmet; Babbitt, Courtney; Wray, Greg; Li, Jianwen; He, Weiming; Wang, Zhuo; Fu, Wenjing; Xiang, Xueyan; Morgan, Claire C; Doherty, Aoife; O'Connell, Mary J; McInerney, James O; Born, Erik W; Dalén, Love; Dietz, Rune; Orlando, Ludovic; Sonne, Christian; Zhang, Guojie; Nielsen, Rasmus; Willerslev, Eske; Wang, Jun

    2014-05-08

    Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyper-lipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show that the species diverged only 479-343 thousand years BP. We find that genes on the polar bear lineage have been under stronger positive selection than in brown bears; nine of the top 16 genes under strong positive selection are associated with cardiomyopathy and vascular disease, implying important reorganization of the cardiovascular system. One of the genes showing the strongest evidence of selection, APOB, encodes the primary lipoprotein component of low-density lipoprotein (LDL); functional mutations in APOB may explain how polar bears are able to cope with life-long elevated LDL levels that are associated with high risk of heart disease in humans. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites

    KAUST Repository

    Woo, Yong

    2015-07-15

    The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga. © Woo et al.

  6. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites.

    Science.gov (United States)

    Woo, Yong H; Ansari, Hifzur; Otto, Thomas D; Klinger, Christen M; Kolisko, Martin; Michálek, Jan; Saxena, Alka; Shanmugam, Dhanasekaran; Tayyrov, Annageldi; Veluchamy, Alaguraj; Ali, Shahjahan; Bernal, Axel; del Campo, Javier; Cihlář, Jaromír; Flegontov, Pavel; Gornik, Sebastian G; Hajdušková, Eva; Horák, Aleš; Janouškovec, Jan; Katris, Nicholas J; Mast, Fred D; Miranda-Saavedra, Diego; Mourier, Tobias; Naeem, Raeece; Nair, Mridul; Panigrahi, Aswini K; Rawlings, Neil D; Padron-Regalado, Eriko; Ramaprasad, Abhinay; Samad, Nadira; Tomčala, Aleš; Wilkes, Jon; Neafsey, Daniel E; Doerig, Christian; Bowler, Chris; Keeling, Patrick J; Roos, David S; Dacks, Joel B; Templeton, Thomas J; Waller, Ross F; Lukeš, Julius; Oborník, Miroslav; Pain, Arnab

    2015-07-15

    The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga.

  7. Genome analysis of a transmissible lineage of pseudomonas aeruginosa reveals pathoadaptive mutations and distinct evolutionary paths of hypermutators.

    Directory of Open Access Journals (Sweden)

    Rasmus Lykke Marvig

    Full Text Available Genome sequencing of bacterial pathogens has advanced our understanding of their evolution, epidemiology, and response to antibiotic therapy. However, we still have only a limited knowledge of the molecular changes in in vivo evolving bacterial populations in relation to long-term, chronic infections. For example, it remains unclear what genes are mutated to facilitate the establishment of long-term existence in the human host environment, and in which way acquisition of a hypermutator phenotype with enhanced rates of spontaneous mutations influences the evolutionary trajectory of the pathogen. Here we perform a retrospective study of the DK2 clone type of P. aeruginosa isolated from Danish patients suffering from cystic fibrosis (CF, and analyze the genomes of 55 bacterial isolates collected from 21 infected individuals over 38 years. Our phylogenetic analysis of 8,530 mutations in the DK2 genomes shows that the ancestral DK2 clone type spread among CF patients through several independent transmission events. Subsequent to transmission, sub-lineages evolved independently for years in separate hosts, creating a unique possibility to study parallel evolution and identification of genes targeted by mutations to optimize pathogen fitness (pathoadaptive mutations. These genes were related to antibiotic resistance, the cell envelope, or regulatory functions, and we find that the prevalence of pathoadaptive mutations correlates with evolutionary success of co-evolving sub-lineages. The long-term co-existence of both normal and hypermutator populations enabled comparative investigations of the mutation dynamics in homopolymeric sequences in which hypermutators are particularly prone to mutations. We find a positive exponential correlation between the length of the homopolymer and its likelihood to acquire mutations and identify two homopolymer-containing genes preferentially mutated in hypermutators. This homopolymer facilitated differential

  8. Comparative genomics and evolutionary biology.

    Science.gov (United States)

    Kondrashov, A S

    1999-12-01

    Data of large-scale DNA sequencing are relevant to some of the most fundamental issues in evolutionary biology: suboptimality, homology, hierarchy, ancestry, novelties, the role of natural selection, and the relative importance of directional versus stabilizing selection. Already, these data provided the best available evidence for some evolutionary phenomena, and in several cases led to refinement of old concepts. Still, the Darwinian evolutionary paradigm will successfully accommodate comparative genomics.

  9. Evolutionary genomics of animal personality.

    Science.gov (United States)

    van Oers, Kees; Mueller, Jakob C

    2010-12-27

    Research on animal personality can be approached from both a phenotypic and a genetic perspective. While using a phenotypic approach one can measure present selection on personality traits and their combinations. However, this approach cannot reconstruct the historical trajectory that was taken by evolution. Therefore, it is essential for our understanding of the causes and consequences of personality diversity to link phenotypic variation in personality traits with polymorphisms in genomic regions that code for this trait variation. Identifying genes or genome regions that underlie personality traits will open exciting possibilities to study natural selection at the molecular level, gene-gene and gene-environment interactions, pleiotropic effects and how gene expression shapes personality phenotypes. In this paper, we will discuss how genome information revealed by already established approaches and some more recent techniques such as high-throughput sequencing of genomic regions in a large number of individuals can be used to infer micro-evolutionary processes, historical selection and finally the maintenance of personality trait variation. We will do this by reviewing recent advances in molecular genetics of animal personality, but will also use advanced human personality studies as case studies of how molecular information may be used in animal personality research in the near future.

  10. Genome characterisation of the genus Francisella reveals insight into similar evolutionary paths in pathogens of mammals and fish

    Directory of Open Access Journals (Sweden)

    Sjödin Andreas

    2012-06-01

    Full Text Available Abstract Background Prior to this study, relatively few strains of Francisella had been genome-sequenced. Previously published Francisella genome sequences were largely restricted to the zoonotic agent F. tularensis. Only limited data were available for other members of the Francisella genus, including F. philomiragia, an opportunistic pathogen of humans, F. noatunensis, a serious pathogen of farmed fish, and other less well described endosymbiotic species. Results We determined the phylogenetic relationships of all known Francisella species, including some for which the phylogenetic positions were previously uncertain. The genus Francisella could be divided into two main genetic clades: one included F. tularensis, F. novicida, F. hispaniensis and Wolbachia persica, and another included F. philomiragia and F. noatunensis. Some Francisella species were found to have significant recombination frequencies. However, the fish pathogen F. noatunensis subsp. noatunensis was an exception due to it exhibiting a highly clonal population structure similar to the human pathogen F. tularensis. Conclusions The genus Francisella can be divided into two main genetic clades occupying both terrestrial and marine habitats. However, our analyses suggest that the ancestral Francisella species originated in a marine habitat. The observed genome to genome variation in gene content and IS elements of different species supports the view that similar evolutionary paths of host adaptation developed independently in F. tularensis (infecting mammals and F. noatunensis subsp. noatunensis (infecting fish.

  11. Integrating genomics into evolutionary medicine.

    Science.gov (United States)

    Rodríguez, Juan Antonio; Marigorta, Urko M; Navarro, Arcadi

    2014-12-01

    The application of the principles of evolutionary biology into medicine was suggested long ago and is already providing insight into the ultimate causes of disease. However, a full systematic integration of medical genomics and evolutionary medicine is still missing. Here, we briefly review some cases where the combination of the two fields has proven profitable and highlight two of the main issues hindering the development of evolutionary genomic medicine as a mature field, namely the dissociation between fitness and health and the still considerable difficulties in predicting phenotypes from genotypes. We use publicly available data to illustrate both problems and conclude that new approaches are needed for evolutionary genomic medicine to overcome these obstacles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Evolutionary genomics of environmental pollution.

    Science.gov (United States)

    Whitehead, Andrew

    2014-01-01

    Chemical toxins have been a persistent source of evolutionary challenges throughout the history of life, and deep within the genomic storehouse of evolutionary history lay ancient adaptations to diverse chemical poisons. However, the rate of change of contemporary environments mediated by human-introduced pollutants is rapidly screening this storehouse and severely testing the adaptive potential of many species. In this chapter, we briefly review the deep history of evolutionary adaptation to environmental toxins, and then proceed to describe the attributes of stressors and populations that may facilitate contemporary adaptation to pollutants introduced by humans. We highlight that phenotypes derived to enable persistence in polluted habitats may be multi-dimensional, requiring global genome-scale tools and approaches to uncover their mechanistic basis, and include examples of recent progress in the field. The modern tools of genomics offer promise for discovering how pollutants interact with genomes on physiological timescales, and also for discovering what genomic attributes of populations may enable resistance to pollutants over evolutionary timescales. Through integration of these sophisticated genomics tools and approaches with an understanding of the deep historical forces that shaped current populations, a more mature understanding of the mechanistic basis of contemporary ecological-evolutionary dynamics should emerge.

  13. The evolutionary fate of the chloroplast and nuclear rps16 genes as revealed through the sequencing and comparative analyses of four novel legume chloroplast genomes from Lupinus.

    Science.gov (United States)

    Keller, J; Rousseau-Gueutin, M; Martin, G E; Morice, J; Boutte, J; Coissac, E; Ourari, M; Aïnouche, M; Salmon, A; Cabello-Hurtado, F; Aïnouche, A

    2017-08-01

    The Fabaceae family is considered as a model system for understanding chloroplast genome evolution due to the presence of extensive structural rearrangements, gene losses and localized hypermutable regions. Here, we provide sequences of four chloroplast genomes from the Lupinus genus, belonging to the underinvestigated Genistoid clade. Notably, we found in Lupinus species the functional loss of the essential rps16 gene, which was most likely replaced by the nuclear rps16 gene that encodes chloroplast and mitochondrion targeted RPS16 proteins. To study the evolutionary fate of the rps16 gene, we explored all available plant chloroplast, mitochondrial and nuclear genomes. Whereas no plant mitochondrial genomes carry an rps16 gene, many plants still have a functional nuclear and chloroplast rps16 gene. Ka/Ks ratios revealed that both chloroplast and nuclear rps16 copies were under purifying selection. However, due to the dual targeting of the nuclear rps16 gene product and the absence of a mitochondrial copy, the chloroplast gene may be lost. We also performed comparative analyses of lupine plastomes (SNPs, indels and repeat elements), identified the most variable regions and examined their phylogenetic utility. The markers identified here will help to reveal the evolutionary history of lupines, Genistoids and closely related clades. © The Author 2017. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  14. Evolutionary genomics reveals lineage-specific gene loss and rapid evolution of a sperm-specific ion channel complex: CatSpers and CatSperbeta.

    Directory of Open Access Journals (Sweden)

    Xinjiang Cai

    Full Text Available The mammalian CatSper ion channel family consists of four sperm-specific voltage-gated Ca2+ channels that are crucial for sperm hyperactivation and male fertility. All four CatSper subunits are believed to assemble into a heteromultimeric channel complex, together with an auxiliary subunit, CatSperbeta. Here, we report a comprehensive comparative genomics study and evolutionary analysis of CatSpers and CatSperbeta, with important correlation to physiological significance of molecular evolution of the CatSper channel complex. The development of the CatSper channel complex with four CatSpers and CatSperbeta originated as early as primitive metazoans such as the Cnidarian Nematostella vectensis. Comparative genomics revealed extensive lineage-specific gene loss of all four CatSpers and CatSperbeta through metazoan evolution, especially in vertebrates. The CatSper channel complex underwent rapid evolution and functional divergence, while distinct evolutionary constraints appear to have acted on different domains and specific sites of the four CatSper genes. These results reveal unique evolutionary characteristics of sperm-specific Ca2+ channels and their adaptation to sperm biology through metazoan evolution.

  15. Evolutionary genomics revealed interkingdom distribution of Tcn1-like chromodomain-containing Gypsy LTR retrotransposons among fungi and plants

    Directory of Open Access Journals (Sweden)

    Blinov Alexander

    2010-04-01

    Full Text Available Abstract Background Chromodomain-containing Gypsy LTR retrotransposons or chromoviruses are widely distributed among eukaryotes and have been found in plants, fungi and vertebrates. The previous comprehensive survey of chromoviruses from mosses (Bryophyta suggested that genomes of non-seed plants contain the clade which is closely related to the retrotransposons from fungi. The origin, distribution and evolutionary history of this clade remained unclear mainly due to the absence of information concerning the diversity and distribution of LTR retrotransposons in other groups of non-seed plants as well as in fungal genomes. Results In present study we preformed in silico analysis of chromodomain-containing LTR retrotransposons in 25 diverse fungi and a number of plant species including spikemoss Selaginella moellendorffii (Lycopodiophyta coupled with an experimental survey of chromodomain-containing Gypsy LTR retrotransposons from diverse non-seed vascular plants (lycophytes, ferns, and horsetails. Our mining of Gypsy LTR retrotransposons in genomic sequences allowed identification of numerous families which have not been described previously in fungi. Two new well-supported clades, Galahad and Mordred, as well as several other previously unknown lineages of chromodomain-containing Gypsy LTR retrotransposons were described based on the results of PCR-mediated survey of LTR retrotransposon fragments from ferns, horsetails and lycophytes. It appeared that one of the clades, namely Tcn1 clade, was present in basidiomycetes and non-seed plants including mosses (Bryophyta and lycophytes (genus Selaginella. Conclusions The interkingdom distribution is not typical for chromodomain-containing LTR retrotransposons clades which are usually very specific for a particular taxonomic group. Tcn1-like LTR retrotransposons from fungi and non-seed plants demonstrated high similarity to each other which can be explained by strong selective constraints and the

  16. Genomic and phenotypic characterization of myxoma virus from Great Britain reveals multiple evolutionary pathways distinct from those in Australia.

    Directory of Open Access Journals (Sweden)

    Peter J Kerr

    2017-03-01

    Full Text Available The co-evolution of myxoma virus (MYXV and the European rabbit occurred independently in Australia and Europe from different progenitor viruses. Although this is the canonical study of the evolution of virulence, whether the genomic and phenotypic outcomes of MYXV evolution in Europe mirror those observed in Australia is unknown. We addressed this question using viruses isolated in the United Kingdom early in the MYXV epizootic (1954-1955 and between 2008-2013. The later UK viruses fell into three distinct lineages indicative of a long period of separation and independent evolution. Although rates of evolutionary change were almost identical to those previously described for MYXV in Australia and strongly clock-like, genome evolution in the UK and Australia showed little convergence. The phenotypes of eight UK viruses from three lineages were characterized in laboratory rabbits and compared to the progenitor (release Lausanne strain. Inferred virulence ranged from highly virulent (grade 1 to highly attenuated (grade 5. Two broad disease types were seen: cutaneous nodular myxomatosis characterized by multiple raised secondary cutaneous lesions, or an amyxomatous phenotype with few or no secondary lesions. A novel clinical outcome was acute death with pulmonary oedema and haemorrhage, often associated with bacteria in many tissues but an absence of inflammatory cells. Notably, reading frame disruptions in genes defined as essential for virulence in the progenitor Lausanne strain were compatible with the acquisition of high virulence. Combined, these data support a model of ongoing host-pathogen co-evolution in which multiple genetic pathways can produce successful outcomes in the field that involve both different virulence grades and disease phenotypes, with alterations in tissue tropism and disease mechanisms.

  17. Genomic and phenotypic characterization of myxoma virus from Great Britain reveals multiple evolutionary pathways distinct from those in Australia.

    Science.gov (United States)

    Kerr, Peter J; Cattadori, Isabella M; Rogers, Matthew B; Fitch, Adam; Geber, Adam; Liu, June; Sim, Derek G; Boag, Brian; Eden, John-Sebastian; Ghedin, Elodie; Read, Andrew F; Holmes, Edward C

    2017-03-01

    The co-evolution of myxoma virus (MYXV) and the European rabbit occurred independently in Australia and Europe from different progenitor viruses. Although this is the canonical study of the evolution of virulence, whether the genomic and phenotypic outcomes of MYXV evolution in Europe mirror those observed in Australia is unknown. We addressed this question using viruses isolated in the United Kingdom early in the MYXV epizootic (1954-1955) and between 2008-2013. The later UK viruses fell into three distinct lineages indicative of a long period of separation and independent evolution. Although rates of evolutionary change were almost identical to those previously described for MYXV in Australia and strongly clock-like, genome evolution in the UK and Australia showed little convergence. The phenotypes of eight UK viruses from three lineages were characterized in laboratory rabbits and compared to the progenitor (release) Lausanne strain. Inferred virulence ranged from highly virulent (grade 1) to highly attenuated (grade 5). Two broad disease types were seen: cutaneous nodular myxomatosis characterized by multiple raised secondary cutaneous lesions, or an amyxomatous phenotype with few or no secondary lesions. A novel clinical outcome was acute death with pulmonary oedema and haemorrhage, often associated with bacteria in many tissues but an absence of inflammatory cells. Notably, reading frame disruptions in genes defined as essential for virulence in the progenitor Lausanne strain were compatible with the acquisition of high virulence. Combined, these data support a model of ongoing host-pathogen co-evolution in which multiple genetic pathways can produce successful outcomes in the field that involve both different virulence grades and disease phenotypes, with alterations in tissue tropism and disease mechanisms.

  18. Genomic and phenotypic characterization of myxoma virus from Great Britain reveals multiple evolutionary pathways distinct from those in Australia

    Science.gov (United States)

    Kerr, Peter J.; Cattadori, Isabella M.; Fitch, Adam; Geber, Adam; Liu, June; Sim, Derek G.; Boag, Brian; Ghedin, Elodie

    2017-01-01

    The co-evolution of myxoma virus (MYXV) and the European rabbit occurred independently in Australia and Europe from different progenitor viruses. Although this is the canonical study of the evolution of virulence, whether the genomic and phenotypic outcomes of MYXV evolution in Europe mirror those observed in Australia is unknown. We addressed this question using viruses isolated in the United Kingdom early in the MYXV epizootic (1954–1955) and between 2008–2013. The later UK viruses fell into three distinct lineages indicative of a long period of separation and independent evolution. Although rates of evolutionary change were almost identical to those previously described for MYXV in Australia and strongly clock-like, genome evolution in the UK and Australia showed little convergence. The phenotypes of eight UK viruses from three lineages were characterized in laboratory rabbits and compared to the progenitor (release) Lausanne strain. Inferred virulence ranged from highly virulent (grade 1) to highly attenuated (grade 5). Two broad disease types were seen: cutaneous nodular myxomatosis characterized by multiple raised secondary cutaneous lesions, or an amyxomatous phenotype with few or no secondary lesions. A novel clinical outcome was acute death with pulmonary oedema and haemorrhage, often associated with bacteria in many tissues but an absence of inflammatory cells. Notably, reading frame disruptions in genes defined as essential for virulence in the progenitor Lausanne strain were compatible with the acquisition of high virulence. Combined, these data support a model of ongoing host-pathogen co-evolution in which multiple genetic pathways can produce successful outcomes in the field that involve both different virulence grades and disease phenotypes, with alterations in tissue tropism and disease mechanisms. PMID:28253375

  19. The evolutionary dynamics of variant antigen genes in Babesia reveal a history of genomic innovation underlying host-parasite interaction

    KAUST Repository

    Jackson, Andrew P.

    2014-05-05

    Babesia spp. are tick-borne, intraerythrocytic hemoparasites that use antigenic variation to resist host immunity, through sequential modification of the parasite-derived variant erythrocyte surface antigen (VESA) expressed on the infected red blood cell surface. We identified the genomic processes driving antigenic diversity in genes encoding VESA (ves1) through comparative analysis within and between three Babesia species, (B. bigemina, B. divergens and B. bovis). Ves1 structure diverges rapidly after speciation, notably through the evolution of shortened forms (ves2) from 5? ends of canonical ves1 genes. Phylogenetic analyses show that ves1 genes are transposed between loci routinely, whereas ves2 genes are not. Similarly, analysis of sequence mosaicism shows that recombination drives variation in ves1 sequences, but less so for ves2, indicating the adoption of different mechanisms for variation of the two families. Proteomic analysis of the B. bigemina PR isolate shows that two dominant VESA1 proteins are expressed in the population, whereas numerous VESA2 proteins are co-expressed, consistent with differential transcriptional regulation of each family. Hence, VESA2 proteins are abundant and previously unrecognized elements of Babesia biology, with evolutionary dynamics consistently different to those of VESA1, suggesting that their functions are distinct. 2014 The Author(s) 2014.

  20. Comparative Genomics of a Bacterivorous Green Alga Reveals Evolutionary Causalities and Consequences of Phago-Mixotrophic Mode of Nutrition.

    Science.gov (United States)

    Burns, John A; Paasch, Amber; Narechania, Apurva; Kim, Eunsoo

    2015-07-29

    Cymbomonas tetramitiformis-a marine prasinophyte-is one of only a few green algae that still retain an ancestral particulate-feeding mechanism while harvesting energy through photosynthesis. The genome of the alga is estimated to be 850 Mb-1.2 Gb in size-the bulk of which is filled with repetitive sequences-and is annotated with 37,366 protein-coding gene models. A number of unusual metabolic pathways (for the Chloroplastida) are predicted for C. tetramitiformis, including pathways for Lipid-A and peptidoglycan metabolism. Comparative analyses of the predicted peptides of C. tetramitiformis to sets of other eukaryotes revealed that nonphagocytes are depleted in a number of genes, a proportion of which have known function in feeding. In addition, our analysis suggests that obligatory phagotrophy is associated with the loss of genes that function in biosynthesis of small molecules (e.g., amino acids). Further, C. tetramitiformis and at least one other phago-mixotrophic alga are thus unique, compared with obligatory heterotrophs and nonphagocytes, in that both feeding and small molecule synthesis-related genes are retained in their genomes. These results suggest that early, ancestral host eukaryotes that gave rise to phototrophs had the capacity to assimilate building block molecules from inorganic substances (i.e., prototrophy). The loss of biosynthesis genes, thus, may at least partially explain the apparent lack of instances of permanent incorporation of photosynthetic endosymbionts in later-divergent, auxotrophic eukaryotic lineages, such as metazoans and ciliates. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. Evolutionary genomics of mycovirus-related dsRNA viruses reveals cross-family horizontal gene transfer and evolution of diverse viral lineages.

    Science.gov (United States)

    Liu, Huiquan; Fu, Yanping; Xie, Jiatao; Cheng, Jiasen; Ghabrial, Said A; Li, Guoqing; Peng, Youliang; Yi, Xianhong; Jiang, Daohong

    2012-06-20

    Double-stranded (ds) RNA fungal viruses are typically isometric single-shelled particles that are classified into three families, Totiviridae, Partitiviridae and Chrysoviridae, the members of which possess monopartite, bipartite and quadripartite genomes, respectively. Recent findings revealed that mycovirus-related dsRNA viruses are more diverse than previously recognized. Although an increasing number of viral complete genomic sequences have become available, the evolution of these diverse dsRNA viruses remains to be clarified. This is particularly so since there is little evidence for horizontal gene transfer (HGT) among dsRNA viruses. In this study, we report the molecular properties of two novel dsRNA mycoviruses that were isolated from a field strain of Sclerotinia sclerotiorum, Sunf-M: one is a large monopartite virus representing a distinct evolutionary lineage of dsRNA viruses; the other is a new member of the family Partitiviridae. Comprehensive phylogenetic analysis and genome comparison revealed that there are at least ten monopartite, three bipartite, one tripartite and three quadripartite lineages in the known dsRNA mycoviruses and that the multipartite lineages have possibly evolved from different monopartite dsRNA viruses. Moreover, we found that homologs of the S7 Domain, characteristic of members of the genus phytoreovirus in family Reoviridae are widely distributed in diverse dsRNA viral lineages, including chrysoviruses, endornaviruses and some unclassified dsRNA mycoviruses. We further provided evidence that multiple HGT events may have occurred among these dsRNA viruses from different families. Our study provides an insight into the phylogeny and evolution of mycovirus-related dsRNA viruses and reveals that the occurrence of HGT between different virus species and the development of multipartite genomes during evolution are important macroevolutionary mechanisms in dsRNA viruses.

  2. Evolutionary genomics of mycovirus-related dsRNA viruses reveals cross-family horizontal gene transfer and evolution of diverse viral lineages

    Directory of Open Access Journals (Sweden)

    Liu Huiquan

    2012-06-01

    Full Text Available Abstract Background Double-stranded (ds RNA fungal viruses are typically isometric single-shelled particles that are classified into three families, Totiviridae, Partitiviridae and Chrysoviridae, the members of which possess monopartite, bipartite and quadripartite genomes, respectively. Recent findings revealed that mycovirus-related dsRNA viruses are more diverse than previously recognized. Although an increasing number of viral complete genomic sequences have become available, the evolution of these diverse dsRNA viruses remains to be clarified. This is particularly so since there is little evidence for horizontal gene transfer (HGT among dsRNA viruses. Results In this study, we report the molecular properties of two novel dsRNA mycoviruses that were isolated from a field strain of Sclerotinia sclerotiorum, Sunf-M: one is a large monopartite virus representing a distinct evolutionary lineage of dsRNA viruses; the other is a new member of the family Partitiviridae. Comprehensive phylogenetic analysis and genome comparison revealed that there are at least ten monopartite, three bipartite, one tripartite and three quadripartite lineages in the known dsRNA mycoviruses and that the multipartite lineages have possibly evolved from different monopartite dsRNA viruses. Moreover, we found that homologs of the S7 Domain, characteristic of members of the genus phytoreovirus in family Reoviridae are widely distributed in diverse dsRNA viral lineages, including chrysoviruses, endornaviruses and some unclassified dsRNA mycoviruses. We further provided evidence that multiple HGT events may have occurred among these dsRNA viruses from different families. Conclusions Our study provides an insight into the phylogeny and evolution of mycovirus-related dsRNA viruses and reveals that the occurrence of HGT between different virus species and the development of multipartite genomes during evolution are important macroevolutionary mechanisms in dsRNA viruses.

  3. Genome-wide analysis of UDP-glycosyltransferase super family in Brassica rapa and Brassica oleracea reveals its evolutionary history and functional characterization.

    Science.gov (United States)

    Yu, Jingyin; Hu, Fan; Dossa, Komivi; Wang, Zhaokai; Ke, Tao

    2017-06-23

    Glycosyltransferases comprise a highly divergent and polyphyletic multigene family that is involved in widespread modification of plant secondary metabolites in a process called glycosylation. According to conserved domains identified in their amino acid sequences, these glycosyltransferases can be classified into a single UDP-glycosyltransferase (UGT) 1 superfamily. We performed genome-wide comparative analysis of UGT genes to trace evolutionary history in algae, bryophytes, pteridophytes, and angiosperms; then, we further investigated the expansion mechanisms and function characterization of UGT gene families in Brassica rapa and Brassica oleracea. Using Hidden Markov Model search, we identified 3, 21, 140, 200, 115, 147, and 147 UGTs in Chlamydomonas reinhardtii, Physcomitrella patens, Selaginella moellendorffii, Oryza sativa, Arabidopsis thaliana, B. rapa, and B. oleracea, respectively. Phylogenetic analysis revealed that UGT80 gene family is an ancient gene family, which is shared by all plants and UGT74 gene family is shared by ferns and angiosperms, but the remaining UGT gene families were shared by angiosperms. In dicot lineage, UGTs among three species were classified into three subgroups containing 3, 6, and 12 UGT gene families. Analysis of chromosomal distribution indicates that 98.6 and 71.4% of UGTs were located on B. rapa and B. oleracea pseudo-molecules, respectively. Expansion mechanism analyses uncovered that whole genome duplication event exerted larger influence than tandem duplication on expansion of UGT gene families in B. rapa, and B. oleracea. Analysis of selection forces of UGT orthologous gene pairs in B. rapa, and B. oleracea compared to A. thaliana suggested that orthologous genes in B. rapa, and B. oleracea have undergone negative selection, but there were no significant differences between A. thaliana -B. rapa and A. thaliana -B. oleracea lineages. Our comparisons of expression profiling illustrated that UGTs in B. rapa performed more

  4. Comparative genomics study of polyhydroxyalkanoates (PHA) and ectoine relevant genes from Halomonas sp. TD01 revealed extensive horizontal gene transfer events and co-evolutionary relationships.

    Science.gov (United States)

    Cai, Lei; Tan, Dan; Aibaidula, Gulsimay; Dong, Xin-Ran; Chen, Jin-Chun; Tian, Wei-Dong; Chen, Guo-Qiang

    2011-11-01

    Halophilic bacteria have shown their significance in industrial production of polyhydroxyalkanoates (PHA) and are gaining more attention for genetic engineering modification. Yet, little information on the genomics and PHA related genes from halophilic bacteria have been disclosed so far. The draft genome of moderately halophilic bacterium, Halomonas sp. TD01, a strain of great potential for industrial production of short-chain-length polyhydroxyalkanoates (PHA), was analyzed through computational methods to reveal the osmoregulation mechanism and the evolutionary relationship of the enzymes relevant to PHA and ectoine syntheses. Genes involved in the metabolism of PHA and osmolytes were annotated and studied in silico. Although PHA synthase, depolymerase, regulator/repressor and phasin were all involved in PHA metabolic pathways, they demonstrated different horizontal gene transfer (HGT) events between the genomes of different strains. In contrast, co-occurrence of ectoine genes in the same genome was more frequently observed, and ectoine genes were more likely under coincidental horizontal gene transfer than PHA related genes. In addition, the adjacent organization of the homologues of PHA synthase phaC1 and PHA granule binding protein phaP was conserved in the strain TD01, which was also observed in some halophiles and non-halophiles exclusively from γ-proteobacteria. In contrast to haloarchaea, the proteome of Halomonas sp. TD01 did not show obvious inclination towards acidity relative to non-halophilic Escherichia coli MG1655, which signified that Halomonas sp. TD01 preferred the accumulation of organic osmolytes to ions in order to balance the intracellular osmotic pressure with the environment. The accessibility of genome information would facilitate research on the genetic engineering of halophilic bacteria including Halomonas sp. TD01.

  5. Comparative genomics study of polyhydroxyalkanoates (PHA and ectoine relevant genes from Halomonas sp. TD01 revealed extensive horizontal gene transfer events and co-evolutionary relationships

    Directory of Open Access Journals (Sweden)

    Cai Lei

    2011-11-01

    Full Text Available Abstract Background Halophilic bacteria have shown their significance in industrial production of polyhydroxyalkanoates (PHA and are gaining more attention for genetic engineering modification. Yet, little information on the genomics and PHA related genes from halophilic bacteria have been disclosed so far. Results The draft genome of moderately halophilic bacterium, Halomonas sp. TD01, a strain of great potential for industrial production of short-chain-length polyhydroxyalkanoates (PHA, was analyzed through computational methods to reveal the osmoregulation mechanism and the evolutionary relationship of the enzymes relevant to PHA and ectoine syntheses. Genes involved in the metabolism of PHA and osmolytes were annotated and studied in silico. Although PHA synthase, depolymerase, regulator/repressor and phasin were all involved in PHA metabolic pathways, they demonstrated different horizontal gene transfer (HGT events between the genomes of different strains. In contrast, co-occurrence of ectoine genes in the same genome was more frequently observed, and ectoine genes were more likely under coincidental horizontal gene transfer than PHA related genes. In addition, the adjacent organization of the homologues of PHA synthase phaC1 and PHA granule binding protein phaP was conserved in the strain TD01, which was also observed in some halophiles and non-halophiles exclusively from γ-proteobacteria. In contrast to haloarchaea, the proteome of Halomonas sp. TD01 did not show obvious inclination towards acidity relative to non-halophilic Escherichia coli MG1655, which signified that Halomonas sp. TD01 preferred the accumulation of organic osmolytes to ions in order to balance the intracellular osmotic pressure with the environment. Conclusions The accessibility of genome information would facilitate research on the genetic engineering of halophilic bacteria including Halomonas sp. TD01.

  6. Partial sequencing reveals the transposable element composition of Coffea genomes and provides evidence for distinct evolutionary stories.

    Science.gov (United States)

    Guyot, Romain; Darré, Thibaud; Dupeyron, Mathilde; de Kochko, Alexandre; Hamon, Serge; Couturon, Emmanuel; Crouzillat, Dominique; Rigoreau, Michel; Rakotomalala, Jean-Jacques; Raharimalala, Nathalie E; Akaffou, Sélastique Doffou; Hamon, Perla

    2016-10-01

    The Coffea genus, 124 described species, has a natural distribution spreading from inter-tropical Africa, to Western Indian Ocean Islands, India, Asia and up to Australasia. Two cultivated species, C. arabica and C. canephora, are intensively studied while, the breeding potential and the genome composition of all the wild species remained poorly uncharacterized. Here, we report the characterization and comparison of the highly repeated transposable elements content of 11 Coffea species representatives of the natural biogeographic distribution. A total of 994 Mb from 454 reads were produced with a genome coverage ranging between 3.2 and 15.7 %. The analyses showed that highly repeated transposable elements, mainly LTR retrotransposons (LTR-RT), represent between 32 and 53 % of Coffea genomes depending on their biogeographic location and genome size. Species from West and Central Africa (Eucoffea) contained the highest LTR-RT content but with no strong variation relative to their genome size. At the opposite, for the insular species (Mascarocoffea), a strong variation of LTR-RT was observed suggesting differential dynamics of these elements in this group. Two LTR-RT lineages, SIRE and Del were clearly differentially accumulated between African and insular species, suggesting these lineages were associated to the genome divergence of Coffea species in Africa. Altogether, the information obtained in this study improves our knowledge and brings new data on the composition, the evolution and the divergence of wild Coffea genomes.

  7. Genome Analysis of a Transmissible Lineage of Pseudomonas aeruginosa Reveals Pathoadaptive Mutations and Distinct Evolutionary Paths of Hypermutators

    DEFF Research Database (Denmark)

    Marvig, Rasmus Lykke; Johansen, Helle Krogh; Molin, Søren

    2013-01-01

    genomes shows that the ancestral DK2 clone type spread among CF patients through several independent transmission events. Subsequent to transmission, sub-lineages evolved independently for years in separate hosts, creating a unique possibility to study parallel evolution and identification of genes...

  8. Evolutionary genomics of dog domestication.

    Science.gov (United States)

    Wayne, Robert K; vonHoldt, Bridgett M

    2012-02-01

    We review the underlying principles and tools used in genomic studies of domestic dogs aimed at understanding the genetic changes that have occurred during domestication. We show that there are two principle modes of evolution within dogs. One primary mode that accounts for much of the remarkable diversity of dog breeds is the fixation of discrete mutations of large effect in individual lineages that are then crossed to various breed groupings. This transfer of mutations across the dog evolutionary tree leads to the appearance of high phenotypic diversity that in actuality reflects a small number of major genes. A second mechanism causing diversification involves the selective breeding of dogs within distinct phenotypic or functional groups, which enhances specific group attributes such as heading or tracking. Such progressive selection leads to a distinct genetic structure in evolutionary trees such that functional and phenotypic groups cluster genetically. We trace the origin of the nuclear genome in dogs based on haplotype-sharing analyses between dogs and gray wolves and show that contrary to previous mtDNA analyses, the nuclear genome of dogs derives primarily from Middle Eastern or European wolves, a result more consistent with the archeological record. Sequencing analysis of the IGF1 gene, which has been the target of size selection in small breeds, further supports this conclusion. Finally, we discuss how a black coat color mutation that evolved in dogs has transformed North American gray wolf populations, providing a first example of a mutation that appeared under domestication and selectively swept through a wild relative.

  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. 2004 Structural, Function and Evolutionary Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Douglas L. Brutlag Nancy Ryan Gray

    2005-03-23

    This Gordon conference will cover the areas of structural, functional and evolutionary genomics. It will take a systematic approach to genomics, examining the evolution of proteins, protein functional sites, protein-protein interactions, regulatory networks, and metabolic networks. Emphasis will be placed on what we can learn from comparative genomics and entire genomes and proteomes.

  11. Evolutionary Dynamics of Cryptophyte Plastid Genomes.

    Science.gov (United States)

    Kim, Jong Im; Moore, Christa E; Archibald, John M; Bhattacharya, Debashish; Yi, Gangman; Yoon, Hwan Su; Shin, Woongghi

    2017-07-01

    Cryptophytes are an ecologically important group of largely photosynthetic unicellular eukaryotes. This lineage is of great interest to evolutionary biologists because their plastids are of red algal secondary endosymbiotic origin and the host cell retains four different genomes (host nuclear, mitochondrial, plastid, and red algal nucleomorph). Here, we report a comparative analysis of plastid genomes from six representative cryptophyte genera. Four newly sequenced cryptophyte plastid genomes of Chroomonas mesostigmatica, Ch. placoidea, Cryptomonas curvata, and Storeatula sp. CCMP1868 share a number of features including synteny and gene content with the previously sequenced genomes of Cryptomonas paramecium, Rhodomonas salina, Teleaulax amphioxeia, and Guillardia theta. Our analysis of these plastid genomes reveals examples of gene loss and intron insertion. In particular, the chlB/chlL/chlN genes, which encode light-independent (dark active) protochlorophyllide oxidoreductase (LIPOR) proteins have undergone recent gene loss and pseudogenization in cryptophytes. Comparison of phylogenetic trees based on plastid and nuclear genome data sets show the introduction, via secondary endosymbiosis, of a red algal derived plastid in a lineage of chlorophyll-c containing algae. This event was followed by additional rounds of eukaryotic endosymbioses that spread the red lineage plastid to diverse groups such as haptophytes and stramenopiles. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  12. Evolutionary engineering by genome shuffling.

    Science.gov (United States)

    Biot-Pelletier, Damien; Martin, Vincent J J

    2014-05-01

    An upsurge in the bioeconomy drives the need for engineering microorganisms with increasingly complex phenotypes. Gains in productivity of industrial microbes depend on the development of improved strains. Classical strain improvement programmes for the generation, screening and isolation of such mutant strains have existed for several decades. An alternative to traditional strain improvement methods, genome shuffling, allows the directed evolution of whole organisms via recursive recombination at the genome level. This review deals chiefly with the technical aspects of genome shuffling. It first presents the diversity of organisms and phenotypes typically evolved using this technology and then reviews available sources of genetic diversity and recombination methodologies. Analysis of the literature reveals that genome shuffling has so far been restricted to microorganisms, both prokaryotes and eukaryotes, with an overepresentation of antibiotics- and biofuel-producing microbes. Mutagenesis is the main source of genetic diversity, with few studies adopting alternative strategies. Recombination is usually done by protoplast fusion or sexual recombination, again with few exceptions. For both diversity and recombination, prospective methods that have not yet been used are also presented. Finally, the potential of genome shuffling for gaining insight into the genetic basis of complex phenotypes is also discussed.

  13. The Use of Evolutionary Approaches to Understand Single Cell Genomes

    Directory of Open Access Journals (Sweden)

    Haiwei eLuo

    2015-03-01

    Full Text Available The vast majority of environmental bacteria and archaea remain uncultivated, yet their genome sequences are rapidly becoming available through single cell sequencing technologies. Reconstructing metabolism is one common way to make use of genome sequences of ecologically important bacteria, but molecular evolutionary analysis is another approach that, while currently underused, can reveal important insights into the function of these uncultivated microbes in nature. Because genome sequences from single cells are often incomplete, metabolic reconstruction based on genome content can be compromised. However, this problem does not necessarily impede the use of phylogenomic and population genomic approaches that are based on patterns of polymorphisms and substitutions at nucleotide and amino acid sites. These approaches explore how various evolutionary forces act to assemble genetic diversity within and between lineages. In this mini-review, I present examples illustrating the benefits of analyzing single cell genomes using evolutionary approaches.

  14. Scalable computing for evolutionary genomics.

    Science.gov (United States)

    Prins, Pjotr; Belhachemi, Dominique; Möller, Steffen; Smant, Geert

    2012-01-01

    Genomic data analysis in evolutionary biology is becoming so computationally intensive that analysis of multiple hypotheses and scenarios takes too long on a single desktop computer. In this chapter, we discuss techniques for scaling computations through parallelization of calculations, after giving a quick overview of advanced programming techniques. Unfortunately, parallel programming is difficult and requires special software design. The alternative, especially attractive for legacy software, is to introduce poor man's parallelization by running whole programs in parallel as separate processes, using job schedulers. Such pipelines are often deployed on bioinformatics computer clusters. Recent advances in PC virtualization have made it possible to run a full computer operating system, with all of its installed software, on top of another operating system, inside a "box," or virtual machine (VM). Such a VM can flexibly be deployed on multiple computers, in a local network, e.g., on existing desktop PCs, and even in the Cloud, to create a "virtual" computer cluster. Many bioinformatics applications in evolutionary biology can be run in parallel, running processes in one or more VMs. Here, we show how a ready-made bioinformatics VM image, named BioNode, effectively creates a computing cluster, and pipeline, in a few steps. This allows researchers to scale-up computations from their desktop, using available hardware, anytime it is required. BioNode is based on Debian Linux and can run on networked PCs and in the Cloud. Over 200 bioinformatics and statistical software packages, of interest to evolutionary biology, are included, such as PAML, Muscle, MAFFT, MrBayes, and BLAST. Most of these software packages are maintained through the Debian Med project. In addition, BioNode contains convenient configuration scripts for parallelizing bioinformatics software. Where Debian Med encourages packaging free and open source bioinformatics software through one central project

  15. Contrasting population-level responses to Pleistocene climatic oscillations in an alpine bat revealed by complete mitochondrial genomes and evolutionary history inference

    DEFF Research Database (Denmark)

    Alberdi, Antton; Gilbert, M. Thomas P; Razgour, Orly

    2015-01-01

    Aim: We used an integrative approach to reconstruct the evolutionary history of the alpine long-eared bat, Plecotus macrobullaris, to test whether the variable effects of Pleistocene climatic oscillations across geographical regions led to contrasting population-level demographic histories within...... a single species. Location: The Western Palaearctic. Methods: We sequenced the complete mitochondrial genomes of 57 individuals from across the distribution of the species. The analysis integrated ecological niche modelling (ENM), approximate Bayesian computation (ABC), measures of genetic diversity...

  16. Slow but not low: genomic comparisons reveal slower evolutionary rate and higher dN/dS in conifers compared to angiosperms

    Directory of Open Access Journals (Sweden)

    Buschiazzo Emmanuel

    2012-01-01

    Full Text Available Background Comparative genomics can inform us about the processes of mutation and selection across diverse taxa. Among seed plants, gymnosperms have been lacking in genomic comparisons. Recent EST and full-length cDNA collections for two conifers, Sitka spruce (Picea sitchensis and loblolly pine (Pinus taeda, together with full genome sequences for two angiosperms, Arabidopsis thaliana and poplar (Populus trichocarpa, offer an opportunity to infer the evolutionary processes underlying thousands of orthologous protein-coding genes in gymnosperms compared with an angiosperm orthologue set. Results Based upon pairwise comparisons of 3,723 spruce and pine orthologues, we found an average synonymous genetic distance (dS of 0.191, and an average dN/dS ratio of 0.314. Using a fossil-established divergence time of 140 million years between spruce and pine, we extrapolated a nucleotide substitution rate of 0.68 × 10-9 synonymous substitutions per site per year. When compared to angiosperms, this indicates a dramatically slower rate of nucleotide substitution rates in conifers: on average 15-fold. Coincidentally, we found a three-fold higher dN/dS for the spruce-pine lineage compared to the poplar-Arabidopsis lineage. This joint occurrence of a slower evolutionary rate in conifers with higher dN/dS, and possibly positive selection, showcases the uniqueness of conifer genome evolution. Conclusions Our results are in line with documented reduced nucleotide diversity, conservative genome evolution and low rates of diversification in conifers on the one hand and numerous examples of local adaptation in conifers on the other hand. We propose that reduced levels of nucleotide mutation in large and long-lived conifer trees, coupled with large effective population size, were the main factors leading to slow substitution rates but retention of beneficial mutations.

  17. Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle-plant interface.

    Science.gov (United States)

    McKenna, Duane D; Scully, Erin D; Pauchet, Yannick; Hoover, Kelli; Kirsch, Roy; Geib, Scott M; Mitchell, Robert F; Waterhouse, Robert M; Ahn, Seung-Joon; Arsala, Deanna; Benoit, Joshua B; Blackmon, Heath; Bledsoe, Tiffany; Bowsher, Julia H; Busch, André; Calla, Bernarda; Chao, Hsu; Childers, Anna K; Childers, Christopher; Clarke, Dave J; Cohen, Lorna; Demuth, Jeffery P; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dolan, Amanda; Duan, Jian J; Dugan, Shannon; Friedrich, Markus; Glastad, Karl M; Goodisman, Michael A D; Haddad, Stephanie; Han, Yi; Hughes, Daniel S T; Ioannidis, Panagiotis; Johnston, J Spencer; Jones, Jeffery W; Kuhn, Leslie A; Lance, David R; Lee, Chien-Yueh; Lee, Sandra L; Lin, Han; Lynch, Jeremy A; Moczek, Armin P; Murali, Shwetha C; Muzny, Donna M; Nelson, David R; Palli, Subba R; Panfilio, Kristen A; Pers, Dan; Poelchau, Monica F; Quan, Honghu; Qu, Jiaxin; Ray, Ann M; Rinehart, Joseph P; Robertson, Hugh M; Roehrdanz, Richard; Rosendale, Andrew J; Shin, Seunggwan; Silva, Christian; Torson, Alex S; Jentzsch, Iris M Vargas; Werren, John H; Worley, Kim C; Yocum, George; Zdobnov, Evgeny M; Gibbs, Richard A; Richards, Stephen

    2016-11-11

    Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle. The Asian longhorned beetle genome encodes a uniquely diverse arsenal of enzymes that can degrade the main polysaccharide networks in plant cell walls, detoxify plant allelochemicals, and otherwise facilitate feeding on woody plants. It has the metabolic plasticity needed to feed on diverse plant species, contributing to its highly invasive nature. Large expansions of chemosensory genes involved in the reception of pheromones and plant kairomones are consistent with the complexity of chemical cues it uses to find host plants and mates. Amplification and functional divergence of genes associated with specialized feeding on plants, including genes originally obtained via horizontal gene transfer from fungi and bacteria, contributed to the addition, expansion, and enhancement of the metabolic repertoire of the Asian longhorned beetle, certain other phytophagous beetles, and to a lesser degree, other phytophagous insects. Our results thus begin to establish a genomic basis for the evolutionary success of beetles on plants.

  18. Comparative genomics reveals insights into avian genome evolution and adaptation

    Science.gov (United States)

    Zhang, Guojie; Li, Cai; Li, Qiye; Li, Bo; Larkin, Denis M.; Lee, Chul; Storz, Jay F.; Antunes, Agostinho; Greenwold, Matthew J.; Meredith, Robert W.; Ödeen, Anders; Cui, Jie; Zhou, Qi; Xu, Luohao; Pan, Hailin; Wang, Zongji; Jin, Lijun; Zhang, Pei; Hu, Haofu; Yang, Wei; Hu, Jiang; Xiao, Jin; Yang, Zhikai; Liu, Yang; Xie, Qiaolin; Yu, Hao; Lian, Jinmin; Wen, Ping; Zhang, Fang; Li, Hui; Zeng, Yongli; Xiong, Zijun; Liu, Shiping; Zhou, Long; Huang, Zhiyong; An, Na; Wang, Jie; Zheng, Qiumei; Xiong, Yingqi; Wang, Guangbiao; Wang, Bo; Wang, Jingjing; Fan, Yu; da Fonseca, Rute R.; Alfaro-Núñez, Alonzo; Schubert, Mikkel; Orlando, Ludovic; Mourier, Tobias; Howard, Jason T.; Ganapathy, Ganeshkumar; Pfenning, Andreas; Whitney, Osceola; Rivas, Miriam V.; Hara, Erina; Smith, Julia; Farré, Marta; Narayan, Jitendra; Slavov, Gancho; Romanov, Michael N; Borges, Rui; Machado, João Paulo; Khan, Imran; Springer, Mark S.; Gatesy, John; Hoffmann, Federico G.; Opazo, Juan C.; Håstad, Olle; Sawyer, Roger H.; Kim, Heebal; Kim, Kyu-Won; Kim, Hyeon Jeong; Cho, Seoae; Li, Ning; Huang, Yinhua; Bruford, Michael W.; Zhan, Xiangjiang; Dixon, Andrew; Bertelsen, Mads F.; Derryberry, Elizabeth; Warren, Wesley; Wilson, Richard K; Li, Shengbin; Ray, David A.; Green, Richard E.; O’Brien, Stephen J.; Griffin, Darren; Johnson, Warren E.; Haussler, David; Ryder, Oliver A.; Willerslev, Eske; Graves, Gary R.; Alström, Per; Fjeldså, Jon; Mindell, David P.; Edwards, Scott V.; Braun, Edward L.; Rahbek, Carsten; Burt, David W.; Houde, Peter; Zhang, Yong; Yang, Huanming; Wang, Jian; Jarvis, Erich D.; Gilbert, M. Thomas P.; Wang, Jun

    2015-01-01

    Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific erosion of repetitive elements, large segmental deletions, and gene loss. Avian genomes furthermore show a remarkably high degree of evolutionary stasis at the levels of nucleotide sequence, gene synteny, and chromosomal structure. Despite this pattern of conservation, we detected many non-neutral evolutionary changes in protein-coding genes and noncoding regions. These analyses reveal that pan-avian genomic diversity covaries with adaptations to different lifestyles and convergent evolution of traits. PMID:25504712

  19. Genomes, Phylogeny, and Evolutionary Systems Biology

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Monica

    2005-03-25

    With the completion of the human genome and the growing number of diverse genomes being sequenced, a new age of evolutionary research is currently taking shape. The myriad of technological breakthroughs in biology that are leading to the unification of broad scientific fields such as molecular biology, biochemistry, physics, mathematics and computer science are now known as systems biology. Here I present an overview, with an emphasis on eukaryotes, of how the postgenomics era is adopting comparative approaches that go beyond comparisons among model organisms to shape the nascent field of evolutionary systems biology.

  20. Genome-scale rates of evolutionary change in bacteria.

    Science.gov (United States)

    Duchêne, Sebastian; Holt, Kathryn E; Weill, François-Xavier; Le Hello, Simon; Hawkey, Jane; Edwards, David J; Fourment, Mathieu; Holmes, Edward C

    2016-11-01

    Estimating the rates at which bacterial genomes evolve is critical to understanding major evolutionary and ecological processes such as disease emergence, long-term host-pathogen associations and short-term transmission patterns. The surge in bacterial genomic data sets provides a new opportunity to estimate these rates and reveal the factors that shape bacterial evolutionary dynamics. For many organisms estimates of evolutionary rate display an inverse association with the time-scale over which the data are sampled. However, this relationship remains unexplored in bacteria due to the difficulty in estimating genome-wide evolutionary rates, which are impacted by the extent of temporal structure in the data and the prevalence of recombination. We collected 36 whole genome sequence data sets from 16 species of bacterial pathogens to systematically estimate and compare their evolutionary rates and assess the extent of temporal structure in the absence of recombination. The majority (28/36) of data sets possessed sufficient clock-like structure to robustly estimate evolutionary rates. However, in some species reliable estimates were not possible even with 'ancient DNA' data sampled over many centuries, suggesting that they evolve very slowly or that they display extensive rate variation among lineages. The robustly estimated evolutionary rates spanned several orders of magnitude, from approximately 10-5 to 10-8 nucleotide substitutions per site year-1. This variation was negatively associated with sampling time, with this relationship best described by an exponential decay curve. To avoid potential estimation biases, such time-dependency should be considered when inferring evolutionary time-scales in bacteria.

  1. Evolutionary genomics of animal personality

    OpenAIRE

    van Oers, Kees; Mueller, Jakob C.

    2010-01-01

    Research on animal personality can be approached from both a phenotypic and a genetic perspective. While using a phenotypic approach one can measure present selection on personality traits and their combinations. However, this approach cannot reconstruct the historical trajectory that was taken by evolution. Therefore, it is essential for our understanding of the causes and consequences of personality diversity to link phenotypic variation in personality traits with polymorphisms in genomic r...

  2. Evolutionary genomics and population structure of Entamoeba histolytica

    Science.gov (United States)

    Das, Koushik; Ganguly, Sandipan

    2014-01-01

    Amoebiasis caused by the gastrointestinal parasite Entamoeba histolytica has diverse disease outcomes. Study of genome and evolution of this fascinating parasite will help us to understand the basis of its virulence and explain why, when and how it causes diseases. In this review, we have summarized current knowledge regarding evolutionary genomics of E. histolytica and discussed their association with parasite phenotypes and its differential pathogenic behavior. How genetic diversity reveals parasite population structure has also been discussed. Queries concerning their evolution and population structure which were required to be addressed have also been highlighted. This significantly large amount of genomic data will improve our knowledge about this pathogenic species of Entamoeba. PMID:25505504

  3. Genomic Resources of Three Pulsatilla Species Reveal Evolutionary Hotspots, Species-Specific Sites and Variable Plastid Structure in the Family Ranunculaceae

    Directory of Open Access Journals (Sweden)

    Monika Szczecińska

    2015-09-01

    Full Text Available Background: The European continent is presently colonized by nine species of the genus Pulsatilla, five of which are encountered only in mountainous regions of southwest and south-central Europe. The remaining four species inhabit lowlands in the north-central and eastern parts of the continent. Most plants of the genus Pulsatilla are rare and endangered, which is why most research efforts focused on their biology, ecology and hybridization. The objective of this study was to develop genomic resources, including complete plastid genomes and nuclear rRNA clusters, for three sympatric Pulsatilla species that are most commonly found in Central Europe. The results will supply valuable information about genetic variation, which can be used in the process of designing primers for population studies and conservation genetics research. The complete plastid genomes together with the nuclear rRNA cluster can serve as a useful tool in hybridization studies. Methodology/principal findings: Six complete plastid genomes and nuclear rRNA clusters were sequenced from three species of Pulsatilla using the Illumina sequencing technology. Four junctions between single copy regions and inverted repeats and junctions between the identified locally-collinear blocks (LCB were confirmed by Sanger sequencing. Pulsatilla genomes of 120 unique genes had a total length of approximately 161–162 kb, and 21 were duplicated in the inverted repeats (IR region. Comparative plastid genomes of newly-sequenced Pulsatilla and the previously-identified plastomes of Aconitum and Ranunculus species belonging to the family Ranunculaceae revealed several variations in the structure of the genome, but the gene content remained constant. The nuclear rRNA cluster (18S-ITS1-5.8S-ITS2-26S of studied Pulsatilla species is 5795 bp long. Among five analyzed regions of the rRNA cluster, only Internal Transcribed Spacer 2 (ITS2 enabled the molecular delimitation of closely-related Pulsatilla

  4. The origin of snakes: revealing the ecology, behavior, and evolutionary history of early snakes using genomics, phenomics, and the fossil record.

    Science.gov (United States)

    Hsiang, Allison Y; Field, Daniel J; Webster, Timothy H; Behlke, Adam D B; Davis, Matthew B; Racicot, Rachel A; Gauthier, Jacques A

    2015-05-20

    The highly derived morphology and astounding diversity of snakes has long inspired debate regarding the ecological and evolutionary origin of both the snake total-group (Pan-Serpentes) and crown snakes (Serpentes). Although speculation abounds on the ecology, behavior, and provenance of the earliest snakes, a rigorous, clade-wide analysis of snake origins has yet to be attempted, in part due to a dearth of adequate paleontological data on early stem snakes. Here, we present the first comprehensive analytical reconstruction of the ancestor of crown snakes and the ancestor of the snake total-group, as inferred using multiple methods of ancestral state reconstruction. We use a combined-data approach that includes new information from the fossil record on extinct crown snakes, new data on the anatomy of the stem snakes Najash rionegrina, Dinilysia patagonica, and Coniophis precedens, and a deeper understanding of the distribution of phenotypic apomorphies among the major clades of fossil and Recent snakes. Additionally, we infer time-calibrated phylogenies using both new 'tip-dating' and traditional node-based approaches, providing new insights on temporal patterns in the early evolutionary history of snakes. Comprehensive ancestral state reconstructions reveal that both the ancestor of crown snakes and the ancestor of total-group snakes were nocturnal, widely foraging, non-constricting stealth hunters. They likely consumed soft-bodied vertebrate and invertebrate prey that was subequal to head size, and occupied terrestrial settings in warm, well-watered, and well-vegetated environments. The snake total-group - approximated by the Coniophis node - is inferred to have originated on land during the middle Early Cretaceous (~128.5 Ma), with the crown-group following about 20 million years later, during the Albian stage. Our inferred divergence dates provide strong evidence for a major radiation of henophidian snake diversity in the wake of the Cretaceous-Paleogene (K

  5. The Genome as an Evolutionary Timepiece.

    Science.gov (United States)

    Ho, Simon Y W; Chen, Amanda X Y; Lins, Luana S F; Duchêne, David A; Lo, Nathan

    2016-10-05

    The molecular clock is a valuable and widely used tool for estimating evolutionary rates and timescales in biological research. There has been considerable progress in the theory and practice of molecular clocks over the past five decades. Although the idea of a molecular clock was originally put forward in the context of protein evolution and advanced using various biochemical techniques, it is now primarily applied to analyses of DNA sequences. An interesting but very underappreciated aspect of molecular clocks is that they can be based on genetic data other than DNA or protein sequences. For example, evolutionary timescales can be estimated using microsatellites, protein folds, and even the extent of recombination. These genome features hold great potential for molecular dating, particularly in cases where nucleotide sequences might be uninformative or unreliable. Here we present an outline of the different genetic data types that have been used for molecular dating, and we describe the features that good molecular clocks should possess. We hope that our article inspires further work on the genome as an evolutionary timepiece. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. Evolutionary genomics of yeast pathogens in the Saccharomycotina

    Science.gov (United States)

    Naranjo-Ortíz, Miguel A.; Marcet-Houben, Marina

    2016-01-01

    Saccharomycotina comprises a diverse group of yeasts that includes numerous species of industrial or clinical relevance. Opportunistic pathogens within this clade are often assigned to the genus Candida but belong to phylogenetically distant lineages that also comprise non-pathogenic species. This indicates that the ability to infect humans has evolved independently several times among Saccharomycotina. Although the mechanisms of infection of the main groups of Candida pathogens are starting to be unveiled, we still lack sufficient understanding of the evolutionary paths that led to a virulent phenotype in each of the pathogenic lineages. Deciphering what genomic changes underlie the evolutionary emergence of a virulence trait will not only aid the discovery of novel virulence mechanisms but it will also provide valuable information to understand how new pathogens emerge, and what clades may pose a future danger. Here we review recent comparative genomics efforts that have revealed possible evolutionary paths to pathogenesis in different lineages, focusing on the main three agents of candidiasis worldwide: Candida albicans, C. parapsilosis and C. glabrata. We will discuss what genomic traits may facilitate the emergence of virulence, and focus on two different genome evolution mechanisms able to generate drastic phenotypic changes and which have been associated to the emergence of virulence: gene family expansion and interspecies hybridization. PMID:27493146

  7. Genome of the Asian longhorned beetle, Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle-plant interface

    Science.gov (United States)

    The Asian longhorned beetle (Anoplophora glabripennis; AGLAB) is a globally significant invasive species capable of inflicting severe feeding damage on many important orchard, ornamental and forest trees. Genome sequencing, annotation, gene expression assays, and functional and comparative genomic s...

  8. Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle–plant interface

    National Research Council Canada - National Science Library

    McKenna, Duane D; Scully, Erin D; Pauchet, Yannick; Hoover, Kelli; Kirsch, Roy; Geib, Scott M; Mitchell, Robert F; Waterhouse, Robert M; Ahn, Seung-Joon; Arsala, Deanna; Benoit, Joshua B; Blackmon, Heath; Bledsoe, Tiffany; Bowsher, Julia H; Busch, André; Calla, Bernarda; Chao, Hsu; Childers, Anna K; Childers, Christopher; Clarke, Dave J; Cohen, Lorna; Demuth, Jeffery P; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dolan, Amanda; Duan, Jian J; Dugan, Shannon; Friedrich, Markus; Glastad, Karl M; Goodisman, Michael A. D; Haddad, Stephanie; Han, Yi; Hughes, Daniel S. T; Ioannidis, Panagiotis; Johnston, J. Spencer; Jones, Jeffery W; Kuhn, Leslie A; Lance, David R; Lee, Chien-Yueh; Lee, Sandra L; Lin, Han; Lynch, Jeremy A; Moczek, Armin P; Murali, Shwetha C; Muzny, Donna M; Nelson, David R; Palli, Subba R; Panfilio, Kristen A; Pers, Dan; Poelchau, Monica F; Quan, Honghu; Qu, Jiaxin; Ray, Ann M; Rinehart, Joseph P; Robertson, Hugh M; Roehrdanz, Richard; Rosendale, Andrew J; Shin, Seunggwan; Silva, Christian; Torson, Alex S; Jentzsch, Iris M. Vargas; Werren, John H; Worley, Kim C; Yocum, George; Zdobnov, Evgeny M; Gibbs, Richard A; Richards, Stephen

    2016-01-01

    .... We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle...

  9. Comparative Analysis of the Mitochondrial Genomes of Callitettixini Spittlebugs (Hemiptera: Cercopidae) Confirms the Overall High Evolutionary Speed of the AT-Rich Region but Reveals the Presence of Short Conservative Elements at the Tribal Level

    Science.gov (United States)

    Liu, Jie; Bu, Cuiping; Wipfler, Benjamin; Liang, Aiping

    2014-01-01

    The present study compares the mitochondrial genomes of five species of the spittlebug tribe Callitettixini (Hemiptera: Cercopoidea: Cercopidae) from eastern Asia. All genomes of the five species sequenced are circular double-stranded DNA molecules and range from 15,222 to 15,637 bp in length. They contain 22 tRNA genes, 13 protein coding genes (PCGs) and 2 rRNA genes and share the putative ancestral gene arrangement of insects. The PCGs show an extreme bias of nucleotide and amino acid composition. Significant differences of the substitution rates among the different genes as well as the different codon position of each PCG are revealed by the comparative evolutionary analyses. The substitution speeds of the first and second codon position of different PCGs are negatively correlated with their GC content. Among the five species, the AT-rich region features great differences in length and pattern and generally shows a 2–5 times higher substitution rate than the fastest PCG in the mitochondrial genome, atp8. Despite the significant variability in length, short conservative segments were identified in the AT-rich region within Callitettixini, although absent from the other groups of the spittlebug superfamily Cercopoidea. PMID:25285442

  10. The genomic landscape of rapid repeated evolutionary ...

    Science.gov (United States)

    Atlantic killifish populations have rapidly adapted to normally lethal levels of pollution in four urban estuaries. Through analysis of 384 whole killifish genome sequences and comparative transcriptomics in four pairs of sensitive and tolerant populations, we identify the aryl hydrocarbon receptor–based signaling pathway as a shared target of selection. This suggests evolutionary constraint on adaptive solutions to complex toxicant mixtures at each site. However, distinct molecular variants apparently contribute to adaptive pathway modification among tolerant populations. Selection also targets other toxicity-mediatinggenes and genes of connected signaling pathways; this indicates complex tolerance phenotypes and potentially compensatory adaptations. Molecular changes are consistent with selection on standing genetic variation. In killifish, high nucleotide diversityhas likely been a crucial substrate for selective sweeps to propel rapid adaptation. This manuscript describes genomic evaluations that contribute to our understanding of the ecological and evolutionary risks associated with chronic contaminant exposures to wildlife populations. Here, we assessed genetic patterns associated with long-term response to an important class of highly toxic environmental pollutants. Specifically, chemical-specific tolerance has rapidly and repeatedly evolved in an estuarine fish species resident to estuaries of the Atlantic U.S. coast. We used laboratory studies to ch

  11. Evolutionary genomics and population structure of Entamoeba histolytica

    Directory of Open Access Journals (Sweden)

    Koushik Das

    2014-11-01

    Full Text Available Amoebiasis caused by the gastrointestinal parasite Entamoeba histolytica has diverse disease outcomes. Study of genome and evolution of this fascinating parasite will help us to understand the basis of its virulence and explain why, when and how it causes diseases. In this review, we have summarized current knowledge regarding evolutionary genomics of E. histolytica and discussed their association with parasite phenotypes and its differential pathogenic behavior. How genetic diversity reveals parasite population structure has also been discussed. Queries concerning their evolution and population structure which were required to be addressed have also been highlighted. This significantly large amount of genomic data will improve our knowledge about this pathogenic species of Entamoeba.

  12. Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle?plant interface

    OpenAIRE

    McKenna, Duane D.; Scully, Erin D.; Pauchet, Yannick; Hoover, Kelli; Kirsch, Roy; Geib, Scott M.; Mitchell, Robert F.; Waterhouse, Robert; Ahn, Seung-Joon; Arsala, Deanna; Benoit, Joshua B.; Blackmon, Heath; Bledsoe, Tiffany; Bowsher, Julia H.; Busch, André

    2016-01-01

    Background Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved ...

  13. Salmo salar and Esox lucius full-length cDNA sequences reveal changes in evolutionary pressures on a post-tetraploidization genome

    Directory of Open Access Journals (Sweden)

    Holt Robert A

    2010-04-01

    Full Text Available Abstract Background Salmonids are one of the most intensely studied fish, in part due to their economic and environmental importance, and in part due to a recent whole genome duplication in the common ancestor of salmonids. This duplication greatly impacts species diversification, functional specialization, and adaptation. Extensive new genomic resources have recently become available for Atlantic salmon (Salmo salar, but documentation of allelic versus duplicate reference genes remains a major uncertainty in the complete characterization of its genome and its evolution. Results From existing expressed sequence tag (EST resources and three new full-length cDNA libraries, 9,057 reference quality full-length gene insert clones were identified for Atlantic salmon. A further 1,365 reference full-length clones were annotated from 29,221 northern pike (Esox lucius ESTs. Pairwise dN/dS comparisons within each of 408 sets of duplicated salmon genes using northern pike as a diploid out-group show asymmetric relaxation of selection on salmon duplicates. Conclusions 9,057 full-length reference genes were characterized in S. salar and can be used to identify alleles and gene family members. Comparisons of duplicated genes show that while purifying selection is the predominant force acting on both duplicates, consistent with retention of functionality in both copies, some relaxation of pressure on gene duplicates can be identified. In addition, there is evidence that evolution has acted asymmetrically on paralogs, allowing one of the pair to diverge at a faster rate.

  14. Genome landscape and evolutionary plasticity of chromosomes in malaria mosquitoes.

    Science.gov (United States)

    Xia, Ai; Sharakhova, Maria V; Leman, Scotland C; Tu, Zhijian; Bailey, Jeffrey A; Smith, Christopher D; Sharakhov, Igor V

    2010-05-12

    Nonrandom distribution of rearrangements is a common feature of eukaryotic chromosomes that is not well understood in terms of genome organization and evolution. In the major African malaria vector Anopheles gambiae, polymorphic inversions are highly nonuniformly distributed among five chromosomal arms and are associated with epidemiologically important adaptations. However, it is not clear whether the genomic content of the chromosomal arms is associated with inversion polymorphism and fixation rates. To better understand the evolutionary dynamics of chromosomal inversions, we created a physical map for an Asian malaria mosquito, Anopheles stephensi, and compared it with the genome of An. gambiae. We also developed and deployed novel Bayesian statistical models to analyze genome landscapes in individual chromosomal arms An. gambiae. Here, we demonstrate that, despite the paucity of inversion polymorphisms on the X chromosome, this chromosome has the fastest rate of inversion fixation and the highest density of transposable elements, simple DNA repeats, and GC content. The highly polymorphic and rapidly evolving autosomal 2R arm had overrepresentation of genes involved in cellular response to stress supporting the role of natural selection in maintaining adaptive polymorphic inversions. In addition, the 2R arm had the highest density of regions involved in segmental duplications that clustered in the breakpoint-rich zone of the arm. In contrast, the slower evolving 2L, 3R, and 3L, arms were enriched with matrix-attachment regions that potentially contribute to chromosome stability in the cell nucleus. These results highlight fundamental differences in evolutionary dynamics of the sex chromosome and autosomes and revealed the strong association between characteristics of the genome landscape and rates of chromosomal evolution. We conclude that a unique combination of various classes of genes and repetitive DNA in each arm, rather than a single type of repetitive

  15. Genome landscape and evolutionary plasticity of chromosomes in malaria mosquitoes.

    Directory of Open Access Journals (Sweden)

    Ai Xia

    2010-05-01

    Full Text Available Nonrandom distribution of rearrangements is a common feature of eukaryotic chromosomes that is not well understood in terms of genome organization and evolution. In the major African malaria vector Anopheles gambiae, polymorphic inversions are highly nonuniformly distributed among five chromosomal arms and are associated with epidemiologically important adaptations. However, it is not clear whether the genomic content of the chromosomal arms is associated with inversion polymorphism and fixation rates.To better understand the evolutionary dynamics of chromosomal inversions, we created a physical map for an Asian malaria mosquito, Anopheles stephensi, and compared it with the genome of An. gambiae. We also developed and deployed novel Bayesian statistical models to analyze genome landscapes in individual chromosomal arms An. gambiae. Here, we demonstrate that, despite the paucity of inversion polymorphisms on the X chromosome, this chromosome has the fastest rate of inversion fixation and the highest density of transposable elements, simple DNA repeats, and GC content. The highly polymorphic and rapidly evolving autosomal 2R arm had overrepresentation of genes involved in cellular response to stress supporting the role of natural selection in maintaining adaptive polymorphic inversions. In addition, the 2R arm had the highest density of regions involved in segmental duplications that clustered in the breakpoint-rich zone of the arm. In contrast, the slower evolving 2L, 3R, and 3L, arms were enriched with matrix-attachment regions that potentially contribute to chromosome stability in the cell nucleus.These results highlight fundamental differences in evolutionary dynamics of the sex chromosome and autosomes and revealed the strong association between characteristics of the genome landscape and rates of chromosomal evolution. We conclude that a unique combination of various classes of genes and repetitive DNA in each arm, rather than a single type

  16. The genomic basis of eco-evolutionary dynamics.

    Science.gov (United States)

    Rodríguez-Verdugo, Alejandra; Buckley, James; Stapley, Jessica

    2017-03-01

    Recent recognition that ecological and evolutionary processes can operate on similar timescales has led to a rapid increase in theoretical and empirical studies on eco-evolutionary dynamics. Progress in the fields of evolutionary biology, genomics and ecology is greatly enhancing our understanding of rapid adaptive processes, the predictability of adaptation and the genetics of ecologically important traits. However, progress in these fields has proceeded largely independently of one another. In an attempt to better integrate these fields, the centre for 'Adaptation to a Changing Environment' organized a conference entitled 'The genomic basis of eco-evolutionary change' and brought together experts in ecological genomics and eco-evolutionary dynamics. In this review, we use the work of the invited speakers to summarize eco-evolutionary dynamics and discuss how they are relevant for understanding and predicting responses to contemporary environmental change. Then, we show how recent advances in genomics are contributing to our understanding of eco-evolutionary dynamics. Finally, we highlight the gaps in our understanding of eco-evolutionary dynamics and recommend future avenues of research in eco-evolutionary dynamics. © 2017 John Wiley & Sons Ltd.

  17. Evolutionary Quantitative Genomics of Populus trichocarpa.

    Directory of Open Access Journals (Sweden)

    Ilga Porth

    Full Text Available Forest trees generally show high levels of local adaptation and efforts focusing on understanding adaptation to climate will be crucial for species survival and management. Here, we address fundamental questions regarding the molecular basis of adaptation in undomesticated forest tree populations to past climatic environments by employing an integrative quantitative genetics and landscape genomics approach. Using this comprehensive approach, we studied the molecular basis of climate adaptation in 433 Populus trichocarpa (black cottonwood genotypes originating across western North America. Variation in 74 field-assessed traits (growth, ecophysiology, phenology, leaf stomata, wood, and disease resistance was investigated for signatures of selection (comparing QST-FST using clustering of individuals by climate of origin (temperature and precipitation. 29,354 SNPs were investigated employing three different outlier detection methods and marker-inferred relatedness was estimated to obtain the narrow-sense estimate of population differentiation in wild populations. In addition, we compared our results with previously assessed selection of candidate SNPs using the 25 topographical units (drainages across the P. trichocarpa sampling range as population groupings. Narrow-sense QST for 53% of distinct field traits was significantly divergent from expectations of neutrality (indicating adaptive trait variation; 2,855 SNPs showed signals of diversifying selection and of these, 118 SNPs (within 81 genes were associated with adaptive traits (based on significant QST. Many SNPs were putatively pleiotropic for functionally uncorrelated adaptive traits, such as autumn phenology, height, and disease resistance. Evolutionary quantitative genomics in P. trichocarpa provides an enhanced understanding regarding the molecular basis of climate-driven selection in forest trees and we highlight that important loci underlying adaptive trait variation also show

  18. Complete genomic sequence analyses of the first group A giraffe rotavirus reveals close evolutionary relationship with rotaviruses infecting other members of the Artiodactyla.

    Science.gov (United States)

    O'Shea, Helen; Mulherin, Emily; Matthijnssens, Jelle; McCusker, Matthew P; Collins, P J; Cashman, Olivia; Gunn, Lynda; Beltman, Marijke E; Fanning, Séamus

    2014-05-14

    Group A Rotaviruses (RVA) have been established as significant contributory agents of acute gastroenteritis in young children and many animal species. In 2008, we described the first RVA strain detected in a giraffe calf (RVA/Giraffe-wt/IRL/GirRV/2008/G10P[11]), presenting with acute diarrhoea. Molecular characterisation of the VP7 and VP4 genes revealed the bovine-like genotypes G10 and P[11], respectively. To further investigate the origin of this giraffe RVA strain, the 9 remaining gene segments were sequenced and analysed, revealing the following genotype constellation: G10-P[11]-I2-R2-C2-M2-A3-N2-T6-E2-H3. This genotype constellation is very similar to RVA strains isolated from cattle or other members of the artiodactyls. Phylogenetic analyses confirmed the close relationship between GirRV and RVA strains with a bovine-like genotype constellation detected from several host species, including humans. These results suggest that RVA strain GirRV was the result of an interspecies transmission from a bovine host to the giraffe calf. However, we cannot rule out completely that this bovine-like RVA genotype constellation may be enzootic in giraffes. Future RVA surveillance in giraffes may answer this intriguing question. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. GB virus C (GBV-C) evolutionary patterns revealed by analyses of reference genomes, E2 and NS5B sequences amplified from viral strains circulating in the Lisbon area (Portugal).

    Science.gov (United States)

    Parreira, Ricardo; Branco, Cristina; Piedade, João; Esteves, Aida

    2012-01-01

    GBV-C is a non-pathogenic virus that is largely dispersed in different human populations. The phylogenetic analysis of the 5'-untranslated region (5'UTR) of the GBV-C genome has led to the segregation of viral strains into six genotypes, but incongruent results are frequently obtained depending on the genome region analyzed. In this report, different phylogenetic approaches and multivariate statistics were combined to disclose evolutionary patterns that contribute to shape GBV-C evolution. The data here presented indicate: (i) that the phylogenetic noise was mostly determined by the size of the analyzed sequence, rather than by its position on the viral genome; (ii) that most genomic segments in the coding sequence seemed to evolve under a similar evolution model, which was different from that which best fits the 5'UTR, with overall large heterogeneity of rate change across the sequence; (iii) that due to saturation of transversions occurring in the 5'UTR at genetic distances GBV-C evolution extensively, this being shown for both reference genomes and NS5B GBV-C sequences amplified from Portuguese residents. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. The genome of Tetranychus urticae reveals herbivorous pest adaptations

    Science.gov (United States)

    Grbić, Miodrag; Van Leeuwen, Thomas; Clark, Richard M.; Rombauts, Stephane; Rouzé, Pierre; Grbić, Vojislava; Osborne, Edward J.; Dermauw, Wannes; Ngoc, Phuong Cao Thi; Ortego, Félix; Hernández-Crespo, Pedro; Diaz, Isabel; Martinez, Manuel; Navajas, Maria; Sucena, Élio; Magalhães, Sara; Nagy, Lisa; Pace, Ryan M.; Djuranović, Sergej; Smagghe, Guy; Iga, Masatoshi; Christiaens, Olivier; Veenstra, Jan A.; Ewer, John; Villalobos, Rodrigo Mancilla; Hutter, Jeffrey L.; Hudson, Stephen D.; Velez, Marisela; Yi, Soojin V.; Zeng, Jia; Pires-daSilva, Andre; Roch, Fernando; Cazaux, Marc; Navarro, Marie; Zhurov, Vladimir; Acevedo, Gustavo; Bjelica, Anica; Fawcett, Jeffrey A.; Bonnet, Eric; Martens, Cindy; Baele, Guy; Wissler, Lothar; Sanchez-Rodriguez, Aminael; Tirry, Luc; Blais, Catherine; Demeestere, Kristof; Henz, Stefan R.; Gregory, T. Ryan; Mathieu, Johannes; Verdon, Lou; Farinelli, Laurent; Schmutz, Jeremy; Lindquist, Erika; Feyereisen, René; Van de Peer, Yves

    2016-01-01

    The spider mite Tetranychus urticae is a cosmopolitan agricultural pest with an extensive host plant range and an extreme record of pesticide resistance. Here we present the completely sequenced and annotated spider mite genome, representing the first complete chelicerate genome. At 90 megabases T. urticae has the smallest sequenced arthropod genome. Compared with other arthropods, the spider mite genome shows unique changes in the hormonal environment and organization of the Hox complex, and also reveals evolutionary innovation of silk production. We find strong signatures of polyphagy and detoxification in gene families associated with feeding on different hosts and in new gene families acquired by lateral gene transfer. Deep transcriptome analysis of mites feeding on different plants shows how this pest responds to a changing host environment. The T. urticae genome thus offers new insights into arthropod evolution and plant–herbivore interactions, and provides unique opportunities for developing novel plant protection strategies. PMID:22113690

  1. Genome-wide detection of selection and other evolutionary forces

    DEFF Research Database (Denmark)

    Xu, Zhuofei; Zhou, Rui

    2015-01-01

    As is well known, pathogenic microbes evolve rapidly to escape from the host immune system and antibiotics. Genetic variations among microbial populations occur frequently during the long-term pathogen–host evolutionary arms race, and individual mutation beneficial for the fitness can be fixed...... of an animal pathogen. The evolutionary analysis of the protein-coding part of the genomes will provide a wide spectrum oof genetic variations that play potential roles in adaptive evolution of bacteria....

  2. Human genomic disease variants: a neutral evolutionary explanation.

    Science.gov (United States)

    Dudley, Joel T; Kim, Yuseob; Liu, Li; Markov, Glenn J; Gerold, Kristyn; Chen, Rong; Butte, Atul J; Kumar, Sudhir

    2012-08-01

    Many perspectives on the role of evolution in human health include nonempirical assumptions concerning the adaptive evolutionary origins of human diseases. Evolutionary analyses of the increasing wealth of clinical and population genomic data have begun to challenge these presumptions. In order to systematically evaluate such claims, the time has come to build a common framework for an empirical and intellectual unification of evolution and modern medicine. We review the emerging evidence and provide a supporting conceptual framework that establishes the classical neutral theory of molecular evolution (NTME) as the basis for evaluating disease- associated genomic variations in health and medicine. For over a decade, the NTME has already explained the origins and distribution of variants implicated in diseases and has illuminated the power of evolutionary thinking in genomic medicine. We suggest that a majority of disease variants in modern populations will have neutral evolutionary origins (previously neutral), with a relatively smaller fraction exhibiting adaptive evolutionary origins (previously adaptive). This pattern is expected to hold true for common as well as rare disease variants. Ultimately, a neutral evolutionary perspective will provide medicine with an informative and actionable framework that enables objective clinical assessment beyond convenient tendencies to invoke past adaptive events in human history as a root cause of human disease.

  3. Human genomic disease variants: A neutral evolutionary explanation

    Science.gov (United States)

    Dudley, Joel T.; Kim, Yuseob; Liu, Li; Markov, Glenn J.; Gerold, Kristyn; Chen, Rong; Butte, Atul J.; Kumar, Sudhir

    2012-01-01

    Many perspectives on the role of evolution in human health include nonempirical assumptions concerning the adaptive evolutionary origins of human diseases. Evolutionary analyses of the increasing wealth of clinical and population genomic data have begun to challenge these presumptions. In order to systematically evaluate such claims, the time has come to build a common framework for an empirical and intellectual unification of evolution and modern medicine. We review the emerging evidence and provide a supporting conceptual framework that establishes the classical neutral theory of molecular evolution (NTME) as the basis for evaluating disease- associated genomic variations in health and medicine. For over a decade, the NTME has already explained the origins and distribution of variants implicated in diseases and has illuminated the power of evolutionary thinking in genomic medicine. We suggest that a majority of disease variants in modern populations will have neutral evolutionary origins (previously neutral), with a relatively smaller fraction exhibiting adaptive evolutionary origins (previously adaptive). This pattern is expected to hold true for common as well as rare disease variants. Ultimately, a neutral evolutionary perspective will provide medicine with an informative and actionable framework that enables objective clinical assessment beyond convenient tendencies to invoke past adaptive events in human history as a root cause of human disease. PMID:22665443

  4. Evolutionary maintenance of filovirus-like genes in bat genomes

    Directory of Open Access Journals (Sweden)

    Taylor Derek J

    2011-11-01

    Full Text Available Abstract Background Little is known of the biological significance and evolutionary maintenance of integrated non-retroviral RNA virus genes in eukaryotic host genomes. Here, we isolated novel filovirus-like genes from bat genomes and tested for evolutionary maintenance. We also estimated the age of filovirus VP35-like gene integrations and tested the phylogenetic hypotheses that there is a eutherian mammal clade and a marsupial/ebolavirus/Marburgvirus dichotomy for filoviruses. Results We detected homologous copies of VP35-like and NP-like gene integrations in both Old World and New World species of Myotis (bats. We also detected previously unknown VP35-like genes in rodents that are positionally homologous. Comprehensive phylogenetic estimates for filovirus NP-like and VP35-like loci support two main clades with a marsupial and a rodent grouping within the ebolavirus/Lloviu virus/Marburgvirus clade. The concordance of VP35-like, NP-like and mitochondrial gene trees with the expected species tree supports the notion that the copies we examined are orthologs that predate the global spread and radiation of the genus Myotis. Parametric simulations were consistent with selective maintenance for the open reading frame (ORF of VP35-like genes in Myotis. The ORF of the filovirus-like VP35 gene has been maintained in bat genomes for an estimated 13. 4 MY. ORFs were disrupted for the NP-like genes in Myotis. Likelihood ratio tests revealed that a model that accommodates positive selection is a significantly better fit to the data than a model that does not allow for positive selection for VP35-like sequences. Moreover, site-by-site analysis of selection using two methods indicated at least 25 sites in the VP35-like alignment are under positive selection in Myotis. Conclusions Our results indicate that filovirus-like elements have significance beyond genomic imprints of prior infection. That is, there appears to be, or have been, functionally maintained

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

    DEFF Research Database (Denmark)

    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...

  6. Evolutionary Meta-Analysis of Association Studies Reveals Ancient Constraints Affecting Disease Marker Discovery

    Science.gov (United States)

    Dudley, Joel T.; Chen, Rong; Sanderford, Maxwell; Butte, Atul J.; Kumar, Sudhir

    2012-01-01

    Genome-wide disease association studies contrast genetic variation between disease cohorts and healthy populations to discover single nucleotide polymorphisms (SNPs) and other genetic markers revealing underlying genetic architectures of human diseases. Despite scores of efforts over the past decade, many reproducible genetic variants that explain substantial proportions of the heritable risk of common human diseases remain undiscovered. We have conducted a multispecies genomic analysis of 5,831 putative human risk variants for more than 230 disease phenotypes reported in 2,021 studies. We find that the current approaches show a propensity for discovering disease-associated SNPs (dSNPs) at conserved genomic positions because the effect size (odds ratio) and allelic P value of genetic association of an SNP relates strongly to the evolutionary conservation of their genomic position. We propose a new measure for ranking SNPs that integrates evolutionary conservation scores and the P value (E-rank). Using published data from a large case-control study, we demonstrate that E-rank method prioritizes SNPs with a greater likelihood of bona fide and reproducible genetic disease associations, many of which may explain greater proportions of genetic variance. Therefore, long-term evolutionary histories of genomic positions offer key practical utility in reassessing data from existing disease association studies, and in the design and analysis of future studies aimed at revealing the genetic basis of common human diseases. PMID:22389448

  7. Use of genome-scale metabolic models in evolutionary systems biology.

    Science.gov (United States)

    Papp, Balázs; Szappanos, Balázs; Notebaart, Richard A

    2011-01-01

    One of the major aims of the nascent field of evolutionary systems biology is to test evolutionary hypotheses that are not only realistic from a population genetic point of view but also detailed in terms of molecular biology mechanisms. By providing a mapping between genotype and phenotype for hundreds of genes, genome-scale systems biology models of metabolic networks have already provided valuable insights into the evolution of metabolic gene contents and phenotypes of yeast and other microbial species. Here we review the recent use of these computational models to predict the fitness effect of mutations, genetic interactions, evolutionary outcomes, and to decipher the mechanisms of mutational robustness. While these studies have demonstrated that even simplified models of biochemical reaction networks can be highly informative for evolutionary analyses, they have also revealed the weakness of this modeling framework to quantitatively predict mutational effects, a challenge that needs to be addressed for future progress in evolutionary systems biology.

  8. A novel evolutionary strategy revealed in the phaeoviruses.

    Directory of Open Access Journals (Sweden)

    Kim Stevens

    Full Text Available Phaeoviruses infect the brown algae, which are major contributors to primary production of coastal waters and estuaries. They exploit a Persistent evolutionary strategy akin to a K- selected life strategy via genome integration and are the only known representatives to do so within the giant algal viruses that are typified by r- selected Acute lytic viruses. In screening the genomes of five species within the filamentous brown algal lineage, here we show an unprecedented diversity of viral gene sequence variants especially amongst the smaller phaeoviral genomes. Moreover, one variant shares features from both the two major sub-groups within the phaeoviruses. These phaeoviruses have exploited the reduction of their giant dsDNA genomes and accompanying loss of DNA proofreading capability, typical of an Acute life strategist, but uniquely retain a Persistent life strategy.

  9. Evolutionary and Ecological Genomics of Non-Model Plants

    OpenAIRE

    Song, Bao-Hua; Mitchell-Olds, Thomas

    2011-01-01

    Dissecting evolutionary dynamics of ecologically important traits is a long-term challenge for biologists. Attempts to understand natural variation and molecular mechanisms have motivated a move from laboratory model systems to non-model systems in diverse natural environments. Next generation sequencing methods, along with an expansion of genomic resources and tools, have fostered new links between diverse disciplines, including molecular biology, evolution, and ecology, and genomics. Great ...

  10. Evolutionary Genomics of Life in (and from) the Sea

    Energy Technology Data Exchange (ETDEWEB)

    Boore, Jeffrey L.; Dehal, Paramvir; Fuerstenberg, Susan I.

    2006-01-09

    High throughput genome sequencing centers that were originally built for the Human Genome Project (Lander et al., 2001; Venter et al., 2001) have now become an engine for comparative genomics. The six largest centers alone are now producing over 150 billion nucleotides per year, more than 50 times the amount of DNA in the human genome, and nearly all of this is directed at projects that promise great insights into the pattern and processes of evolution. Unfortunately, this data is being produced at a pace far exceeding the capacity of the scientific community to provide insightful analysis, and few scientists with training and experience in evolutionary biology have played prominent roles to date. One of the consequences is that poor quality analyses are typical; for example, orthology among genes is generally determined by simple measures of sequence similarity, when this has been discredited by molecular evolutionary biologists decades ago. Here we discuss the how genomes are chosen for sequencing and how the scientific community can have input. We describe the PhIGs database and web tools (Dehal and Boore 2005a; http://PhIGs.org), which provide phylogenetic analysis of all gene families for all completely sequenced genomes and the associated 'Synteny Viewer', which allows comparisons of the relative positions of orthologous genes. This is the best tool available for inferring gene function across multiple genomes. We also describe how we have used the PhIGs methods with the whole genome sequences of a tunicate, fish, mouse, and human to conclusively demonstrate that two rounds of whole genome duplication occurred at the base of vertebrates (Dehal and Boore 2005b). This evidence is found in the large scale structure of the positions of paralogous genes that arose from duplications inferred by evolutionary analysis to have occurred at the base of vertebrates.

  11. Evolutionary and Ecological Genomics of Non-Model Plants

    Science.gov (United States)

    Song, Bao-Hua; Mitchell-Olds, Thomas

    2011-01-01

    Dissecting evolutionary dynamics of ecologically important traits is a long-term challenge for biologists. Attempts to understand natural variation and molecular mechanisms have motivated a move from laboratory model systems to non-model systems in diverse natural environments. Next generation sequencing methods, along with an expansion of genomic resources and tools, have fostered new links between diverse disciplines, including molecular biology, evolution, and ecology, and genomics. Great progress has been made in a few non-model wild plants, such as Arabidopsis relatives, monkey flowers, and wild sunflowers. Until recently, the lack of comprehensive genomic information has limited evolutionary and ecological studies to larger QTL regions rather than single gene resolution, and has hindered recognition of general patterns of natural variation and local adaptation. Further efforts in accumulating genomic data and developing bioinformatic and biostatistical tools are now poised to move this field forward. Integrative national and international collaborations and research communities are needed to facilitate development in the field of evolutionary and ecological genomics. PMID:21394233

  12. The dynamic evolutionary history of genome size in North American woodland salamanders.

    Science.gov (United States)

    Newman, Catherine E; Gregory, T Ryan; Austin, Christopher C

    2017-04-01

    The genus Plethodon is the most species-rich salamander genus in North America, and nearly half of its species face an uncertain future. It is also one of the most diverse families in terms of genome sizes, which range from 1C = 18.2 to 69.3 pg, or 5-20 times larger than the human genome. Large genome size in salamanders results in part from accumulation of transposable elements and is associated with various developmental and physiological traits. However, genome sizes have been reported for only 25% of the species of Plethodon (14 of 55). We collected genome size data for Plethodon serratus to supplement an ongoing phylogeographic study, reconstructed the evolutionary history of genome size in Plethodontidae, and inferred probable genome sizes for the 41 species missing empirical data. Results revealed multiple genome size changes in Plethodon: genomes of western Plethodon increased, whereas genomes of eastern Plethodon decreased, followed by additional decreases or subsequent increases. The estimated genome size of P. serratus was 21 pg. New understanding of variation in genome size evolution, along with genome size inferences for previously unstudied taxa, provide a foundation for future studies on the biology of plethodontid salamanders.

  13. The evolutionary value of recombination is constrained by genome modularity.

    Directory of Open Access Journals (Sweden)

    Darren P Martin

    2005-10-01

    Full Text Available Genetic recombination is a fundamental evolutionary mechanism promoting biological adaptation. Using engineered recombinants of the small single-stranded DNA plant virus, Maize streak virus (MSV, we experimentally demonstrate that fragments of genetic material only function optimally if they reside within genomes similar to those in which they evolved. The degree of similarity necessary for optimal functionality is correlated with the complexity of intragenomic interaction networks within which genome fragments must function. There is a striking correlation between our experimental results and the types of MSV recombinants that are detectable in nature, indicating that obligatory maintenance of intragenome interaction networks strongly constrains the evolutionary value of recombination for this virus and probably for genomes in general.

  14. Ecological and evolutionary genomics of marine photosynthetic organisms.

    Science.gov (United States)

    Coelho, Susana M; Simon, Nathalie; Ahmed, Sophia; Cock, J Mark; Partensky, Frédéric

    2013-02-01

    Environmental (ecological) genomics aims to understand the genetic basis of relationships between organisms and their abiotic and biotic environments. It is a rapidly progressing field of research largely due to recent advances in the speed and volume of genomic data being produced by next generation sequencing (NGS) technologies. Building on information generated by NGS-based approaches, functional genomic methodologies are being applied to identify and characterize genes and gene systems of both environmental and evolutionary relevance. Marine photosynthetic organisms (MPOs) were poorly represented amongst the early genomic models, but this situation is changing rapidly. Here we provide an overview of the recent advances in the application of ecological genomic approaches to both prokaryotic and eukaryotic MPOs. We describe how these approaches are being used to explore the biology and ecology of marine cyanobacteria and algae, particularly with regard to their functions in a broad range of marine ecosystems. Specifically, we review the ecological and evolutionary insights gained from whole genome and transcriptome sequencing projects applied to MPOs and illustrate how their genomes are yielding information on the specific features of these organisms. © 2012 Blackwell Publishing Ltd.

  15. Genomes as documents of evolutionary history: a probabilistic macrosynteny model for the reconstruction of ancestral genomes.

    Science.gov (United States)

    Nakatani, Yoichiro; McLysaght, Aoife

    2017-07-15

    It has been argued that whole-genome duplication (WGD) exerted a profound influence on the course of evolution. For the purpose of fully understanding the impact of WGD, several formal algorithms have been developed for reconstructing pre-WGD gene order in yeast and plant. However, to the best of our knowledge, those algorithms have never been successfully applied to WGD events in teleost and vertebrate, impeded by extensive gene shuffling and gene losses. Here, we present a probabilistic model of macrosynteny (i.e. conserved linkage or chromosome-scale distribution of orthologs), develop a variational Bayes algorithm for inferring the structure of pre-WGD genomes, and study estimation accuracy by simulation. Then, by applying the method to the teleost WGD, we demonstrate effectiveness of the algorithm in a situation where gene-order reconstruction algorithms perform relatively poorly due to a high rate of rearrangement and extensive gene losses. Our high-resolution reconstruction reveals previously overlooked small-scale rearrangements, necessitating a revision to previous views on genome structure evolution in teleost and vertebrate. We have reconstructed the structure of a pre-WGD genome by employing a variational Bayes approach that was originally developed for inferring topics from millions of text documents. Interestingly, comparison of the macrosynteny and topic model algorithms suggests that macrosynteny can be regarded as documents on ancestral genome structure. From this perspective, the present study would seem to provide a textbook example of the prevalent metaphor that genomes are documents of evolutionary history. The analysis data are available for download at http://www.gen.tcd.ie/molevol/supp_data/MacrosyntenyTGD.zip , and the software written in Java is available upon request. yoichiro.nakatani@tcd.ie or aoife.mclysaght@tcd.ie. Supplementary data are available at Bioinformatics online.

  16. Integrated assessment of genomic correlates of protein evolutionary rate.

    Directory of Open Access Journals (Sweden)

    Yu Xia

    2009-06-01

    Full Text Available Rates of evolution differ widely among proteins, but the causes and consequences of such differences remain under debate. With the advent of high-throughput functional genomics, it is now possible to rigorously assess the genomic correlates of protein evolutionary rate. However, dissecting the correlations among evolutionary rate and these genomic features remains a major challenge. Here, we use an integrated probabilistic modeling approach to study genomic correlates of protein evolutionary rate in Saccharomyces cerevisiae. We measure and rank degrees of association between (i an approximate measure of protein evolutionary rate with high genome coverage, and (ii a diverse list of protein properties (sequence, structural, functional, network, and phenotypic. We observe, among many statistically significant correlations, that slowly evolving proteins tend to be regulated by more transcription factors, deficient in predicted structural disorder, involved in characteristic biological functions (such as translation, biased in amino acid composition, and are generally more abundant, more essential, and enriched for interaction partners. Many of these results are in agreement with recent studies. In addition, we assess information contribution of different subsets of these protein properties in the task of predicting slowly evolving proteins. We employ a logistic regression model on binned data that is able to account for intercorrelation, non-linearity, and heterogeneity within features. Our model considers features both individually and in natural ensembles ("meta-features" in order to assess joint information contribution and degree of contribution independence. Meta-features based on protein abundance and amino acid composition make strong, partially independent contributions to the task of predicting slowly evolving proteins; other meta-features make additional minor contributions. The combination of all meta-features yields predictions

  17. phyloXML: XML for evolutionary biology and comparative genomics.

    Science.gov (United States)

    Han, Mira V; Zmasek, Christian M

    2009-10-27

    Evolutionary trees are central to a wide range of biological studies. In many of these studies, tree nodes and branches need to be associated (or annotated) with various attributes. For example, in studies concerned with organismal relationships, tree nodes are associated with taxonomic names, whereas tree branches have lengths and oftentimes support values. Gene trees used in comparative genomics or phylogenomics are usually annotated with taxonomic information, genome-related data, such as gene names and functional annotations, as well as events such as gene duplications, speciations, or exon shufflings, combined with information related to the evolutionary tree itself. The data standards currently used for evolutionary trees have limited capacities to incorporate such annotations of different data types. We developed a XML language, named phyloXML, for describing evolutionary trees, as well as various associated data items. PhyloXML provides elements for commonly used items, such as branch lengths, support values, taxonomic names, and gene names and identifiers. By using "property" elements, phyloXML can be adapted to novel and unforeseen use cases. We also developed various software tools for reading, writing, conversion, and visualization of phyloXML formatted data. PhyloXML is an XML language defined by a complete schema in XSD that allows storing and exchanging the structures of evolutionary trees as well as associated data. More information about phyloXML itself, the XSD schema, as well as tools implementing and supporting phyloXML, is available at http://www.phyloxml.org.

  18. Comparative genomics reveals mobile pathogenicity chromosomes in Fusarium

    Science.gov (United States)

    Ma, Li-Jun; van der Does, H. Charlotte; Borkovich, Katherine A.; Coleman, Jeffrey J.; Daboussi, Marie-Josée; Di Pietro, Antonio; Dufresne, Marie; Freitag, Michael; Grabherr, Manfred; Henrissat, Bernard; Houterman, Petra M.; Kang, Seogchan; Shim, Won-Bo; Woloshuk, Charles; Xie, Xiaohui; Xu, Jin-Rong; Antoniw, John; Baker, Scott E.; Bluhm, Burton H.; Breakspear, Andrew; Brown, Daren W.; Butchko, Robert A. E.; Chapman, Sinead; Coulson, Richard; Coutinho, Pedro M.; Danchin, Etienne G. J.; Diener, Andrew; Gale, Liane R.; Gardiner, Donald M.; Goff, Stephen; Hammond-Kosack, Kim E.; Hilburn, Karen; Hua-Van, Aurélie; Jonkers, Wilfried; Kazan, Kemal; Kodira, Chinnappa D.; Koehrsen, Michael; Kumar, Lokesh; Lee, Yong-Hwan; Li, Liande; Manners, John M.; Miranda-Saavedra, Diego; Mukherjee, Mala; Park, Gyungsoon; Park, Jongsun; Park, Sook-Young; Proctor, Robert H.; Regev, Aviv; Ruiz-Roldan, M. Carmen; Sain, Divya; Sakthikumar, Sharadha; Sykes, Sean; Schwartz, David C.; Turgeon, B. Gillian; Wapinski, Ilan; Yoder, Olen; Young, Sarah; Zeng, Qiandong; Zhou, Shiguo; Galagan, James; Cuomo, Christina A.; Kistler, H. Corby; Rep, Martijn

    2011-01-01

    Fusarium species are among the most important phytopathogenic and toxigenic fungi. To understand the molecular underpinnings of pathogenicity in the genus Fusarium, we compared the genomes of three phenotypically diverse species: Fusarium graminearum, Fusarium verticillioides and Fusarium oxysporum f. sp. lycopersici. Our analysis revealed lineage-specific (LS) genomic regions in F. oxysporum that include four entire chromosomes and account for more than one-quarter of the genome. LS regions are rich in transposons and genes with distinct evolutionary profiles but related to pathogenicity, indicative of horizontal acquisition. Experimentally, we demonstrate the transfer of two LS chromosomes between strains of F. oxysporum, converting a non-pathogenic strain into a pathogen. Transfer of LS chromosomes between otherwise genetically isolated strains explains the polyphyletic origin of host specificity and the emergence of new pathogenic lineages in F. oxysporum. These findings put the evolution of fungal pathogenicity into a new perspective. PMID:20237561

  19. Evolutionary biology through the lens of budding yeast comparative genomics.

    Science.gov (United States)

    Marsit, Souhir; Leducq, Jean-Baptiste; Durand, Éléonore; Marchant, Axelle; Filteau, Marie; Landry, Christian R

    2017-10-01

    The budding yeast Saccharomyces cerevisiae is a highly advanced model system for studying genetics, cell biology and systems biology. Over the past decade, the application of high-throughput sequencing technologies to this species has contributed to this yeast also becoming an important model for evolutionary genomics. Indeed, comparative genomic analyses of laboratory, wild and domesticated yeast populations are providing unprecedented detail about many of the processes that govern evolution, including long-term processes, such as reproductive isolation and speciation, and short-term processes, such as adaptation to natural and domestication-related environments.

  20. Evolutionary genomics of LysM genes in land plants

    Directory of Open Access Journals (Sweden)

    Stacey Gary

    2009-08-01

    Full Text Available Abstract Background The ubiquitous LysM motif recognizes peptidoglycan, chitooligosaccharides (chitin and, presumably, other structurally-related oligosaccharides. LysM-containing proteins were first shown to be involved in bacterial cell wall degradation and, more recently, were implicated in perceiving chitin (one of the established pathogen-associated molecular patterns and lipo-chitin (nodulation factors in flowering plants. However, the majority of LysM genes in plants remain functionally uncharacterized and the evolutionary history of complex LysM genes remains elusive. Results We show that LysM-containing proteins display a wide range of complex domain architectures. However, only a simple core architecture is conserved across kingdoms. Each individual kingdom appears to have evolved a distinct array of domain architectures. We show that early plant lineages acquired four characteristic architectures and progressively lost several primitive architectures. We report plant LysM phylogenies and associated gene, protein and genomic features, and infer the relative timing of duplications of LYK genes. Conclusion We report a domain architecture catalogue of LysM proteins across all kingdoms. The unique pattern of LysM protein domain architectures indicates the presence of distinctive evolutionary paths in individual kingdoms. We describe a comparative and evolutionary genomics study of LysM genes in plant kingdom. One of the two groups of tandemly arrayed plant LYK genes likely resulted from an ancient genome duplication followed by local genomic rearrangement, while the origin of the other groups of tandemly arrayed LYK genes remains obscure. Given the fact that no animal LysM motif-containing genes have been functionally characterized, this study provides clues to functional characterization of plant LysM genes and is also informative with regard to evolutionary and functional studies of animal LysM genes.

  1. Genome size analyses of Pucciniales reveal the largest fungal genomes

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    Silvia eTavares

    2014-08-01

    Full Text Available Rust fungi (Basidiomycota, Pucciniales are biotrophic plant pathogens which exhibit diverse complexities in their life cycles and host ranges. The completion of genome sequencing of a few rust fungi has revealed the occurrence of large genomes. Sequencing efforts for other rust fungi have been hampered by uncertainty concerning their genome sizes. Flow cytometry was recently applied to estimate the genome size of a few rust fungi, and confirmed the occurrence of large genomes in this order (averaging 151.5 Mbp, while the average for Basidiomycota was 49.9 Mbp and was 37.7 Mbp for all fungi. In this work, we have used an innovative and simple approach to simultaneously isolate nuclei from the rust and its host plant in order to estimate the genome size of 30 rust species by flow cytometry. Genome sizes varied over 10-fold, from 70 to 893 Mbp, with an average genome size value of 380.2 Mbp. Compared to the genome sizes of over 1,800 fungi, Gymnosporangium confusum possesses the largest fungal genome ever reported (893.2 Mbp. Moreover, even the smallest rust genome determined in this study is larger than the vast majority of fungal genomes (94 %. The average genome size of the Pucciniales is now of 305.5 Mbp, while the average Basidiomycota genome size has shifted to 70.4 Mbp and the average for all fungi reached 44.2 Mbp. Despite the fact that no correlation could be drawn between the genome sizes, the phylogenomics or the life cycle of rust fungi, it is interesting to note that rusts with Fabaceae hosts present genomes clearly larger than those with Poaceae hosts. Although this study comprises only a small fraction of the more than 7,000 rust species described, it seems already evident that the Pucciniales represent a group where genome size expansion could be a common characteristic. This is in sharp contrast to sister taxa, placing this order in a relevant position in fungal genomics research.

  2. Application of resequencing to rice genomics, functional genomics and evolutionary analysis

    Science.gov (United States)

    2014-01-01

    Rice is a model system used for crop genomics studies. The completion of the rice genome draft sequences in 2002 not only accelerated functional genome studies, but also initiated a new era of resequencing rice genomes. Based on the reference genome in rice, next-generation sequencing (NGS) using the high-throughput sequencing system can efficiently accomplish whole genome resequencing of various genetic populations and diverse germplasm resources. Resequencing technology has been effectively utilized in evolutionary analysis, rice genomics and functional genomics studies. This technique is beneficial for both bridging the knowledge gap between genotype and phenotype and facilitating molecular breeding via gene design in rice. Here, we also discuss the limitation, application and future prospects of rice resequencing. PMID:25006357

  3. Comparative genomics reveals novel biochemical pathways.

    Science.gov (United States)

    Piskur, Jure; Schnackerz, Klaus D; Andersen, Gorm; Björnberg, Olof

    2007-08-01

    How well do we understand which enzymes are involved in the primary metabolism of the cell? A recent study using comparative genomics and postgenomics approaches revealed a novel pathway in the most studied organism, Escherichia coli. The analysis of a new operon consisting of seven previously uncharacterized genes thought to be involved in the degradation of nucleic acid precursors shows the impact of comparative genomics on the discovery of novel pathways and enzymes.

  4. Mitochondrial genome sequencing helps show the evolutionary mechanism of mitochondrial genome formation in Brassica

    Science.gov (United States)

    2011-01-01

    Background Angiosperm mitochondrial genomes are more complex than those of other organisms. Analyses of the mitochondrial genome sequences of at least 11 angiosperm species have showed several common properties; these cannot easily explain, however, how the diverse mitotypes evolved within each genus or species. We analyzed the evolutionary relationships of Brassica mitotypes by sequencing. Results We sequenced the mitotypes of cam (Brassica rapa), ole (B. oleracea), jun (B. juncea), and car (B. carinata) and analyzed them together with two previously sequenced mitotypes of B. napus (pol and nap). The sizes of whole single circular genomes of cam, jun, ole, and car are 219,747 bp, 219,766 bp, 360,271 bp, and 232,241 bp, respectively. The mitochondrial genome of ole is largest as a resulting of the duplication of a 141.8 kb segment. The jun mitotype is the result of an inherited cam mitotype, and pol is also derived from the cam mitotype with evolutionary modifications. Genes with known functions are conserved in all mitotypes, but clear variation in open reading frames (ORFs) with unknown functions among the six mitotypes was observed. Sequence relationship analysis showed that there has been genome compaction and inheritance in the course of Brassica mitotype evolution. Conclusions We have sequenced four Brassica mitotypes, compared six Brassica mitotypes and suggested a mechanism for mitochondrial genome formation in Brassica, including evolutionary events such as inheritance, duplication, rearrangement, genome compaction, and mutation. PMID:21988783

  5. Cross-species genome-wide identification of evolutionary conserved microproteins

    DEFF Research Database (Denmark)

    Straub, Daniel; Wenkel, Stephan

    2017-01-01

    Protein concept beyond transcription factors to other protein families. Here, we reveal potential microProtein candidates in several plant and animal reference genomes. A large number of these microProteins are species-specific while others evolved early and are evolutionary highly conserved. Most known micro......MicroProteins are small single-domain proteins that act by engaging their targets into different, sometimes nonproductive protein complexes. In order to identify novel microProteins in any sequenced genome of interest, we have developed miPFinder, a program that identifies and classifies potential...

  6. Mitochondrial genome sequences effectively reveal the phylogeny of Hylobates gibbons.

    Directory of Open Access Journals (Sweden)

    Yi-Chiao Chan

    Full Text Available BACKGROUND: Uniquely among hominoids, gibbons exist as multiple geographically contiguous taxa exhibiting distinctive behavioral, morphological, and karyotypic characteristics. However, our understanding of the evolutionary relationships of the various gibbons, especially among Hylobates species, is still limited because previous studies used limited taxon sampling or short mitochondrial DNA (mtDNA sequences. Here we use mtDNA genome sequences to reconstruct gibbon phylogenetic relationships and reveal the pattern and timing of divergence events in gibbon evolutionary history. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced the mitochondrial genomes of 51 individuals representing 11 species belonging to three genera (Hylobates, Nomascus and Symphalangus using the high-throughput 454 sequencing system with the parallel tagged sequencing approach. Three phylogenetic analyses (maximum likelihood, Bayesian analysis and neighbor-joining depicted the gibbon phylogenetic relationships congruently and with strong support values. Most notably, we recover a well-supported phylogeny of the Hylobates gibbons. The estimation of divergence times using Bayesian analysis with relaxed clock model suggests a much more rapid speciation process in Hylobates than in Nomascus. CONCLUSIONS/SIGNIFICANCE: Use of more than 15 kb sequences of the mitochondrial genome provided more informative and robust data than previous studies of short mitochondrial segments (e.g., control region or cytochrome b as shown by the reliable reconstruction of divergence patterns among Hylobates gibbons. Moreover, molecular dating of the mitogenomic divergence times implied that biogeographic change during the last five million years may be a factor promoting the speciation of Sundaland animals, including Hylobates species.

  7. Comparative Genomics of the Bacterial Genus Streptococcus Illuminates Evolutionary Implications of Species Groups

    Science.gov (United States)

    Gao, Xiao-Yang; Zhi, Xiao-Yang; Li, Hong-Wei; Klenk, Hans-Peter; Li, Wen-Jun

    2014-01-01

    Members of the genus Streptococcus within the phylum Firmicutes are among the most diverse and significant zoonotic pathogens. This genus has gone through considerable taxonomic revision due to increasing improvements of chemotaxonomic approaches, DNA hybridization and 16S rRNA gene sequencing. It is proposed to place the majority of streptococci into “species groups”. However, the evolutionary implications of species groups are not clear presently. We use comparative genomic approaches to yield a better understanding of the evolution of Streptococcus through genome dynamics, population structure, phylogenies and virulence factor distribution of species groups. Genome dynamics analyses indicate that the pan-genome size increases with the addition of newly sequenced strains, while the core genome size decreases with sequential addition at the genus level and species group level. Population structure analysis reveals two distinct lineages, one including Pyogenic, Bovis, Mutans and Salivarius groups, and the other including Mitis, Anginosus and Unknown groups. Phylogenetic dendrograms show that species within the same species group cluster together, and infer two main clades in accordance with population structure analysis. Distribution of streptococcal virulence factors has no obvious patterns among the species groups; however, the evolution of some common virulence factors is congruous with the evolution of species groups, according to phylogenetic inference. We suggest that the proposed streptococcal species groups are reasonable from the viewpoints of comparative genomics; evolution of the genus is congruent with the individual evolutionary trajectories of different species groups. PMID:24977706

  8. A phylogenomic study of birds reveals their evolutionary history.

    Science.gov (United States)

    Hackett, Shannon J; Kimball, Rebecca T; Reddy, Sushma; Bowie, Rauri C K; Braun, Edward L; Braun, Michael J; Chojnowski, Jena L; Cox, W Andrew; Han, Kin-Lan; Harshman, John; Huddleston, Christopher J; Marks, Ben D; Miglia, Kathleen J; Moore, William S; Sheldon, Frederick H; Steadman, David W; Witt, Christopher C; Yuri, Tamaki

    2008-06-27

    Deep avian evolutionary relationships have been difficult to resolve as a result of a putative explosive radiation. Our study examined approximately 32 kilobases of aligned nuclear DNA sequences from 19 independent loci for 169 species, representing all major extant groups, and recovered a robust phylogeny from a genome-wide signal supported by multiple analytical methods. We documented well-supported, previously unrecognized interordinal relationships (such as a sister relationship between passerines and parrots) and corroborated previously contentious groupings (such as flamingos and grebes). Our conclusions challenge current classifications and alter our understanding of trait evolution; for example, some diurnal birds evolved from nocturnal ancestors. Our results provide a valuable resource for phylogenetic and comparative studies in birds.

  9. Late replication domains are evolutionary conserved in the Drosophila genome.

    Directory of Open Access Journals (Sweden)

    Natalya G Andreyenkova

    Full Text Available Drosophila chromosomes are organized into distinct domains differing in their predominant chromatin composition, replication timing and evolutionary conservation. We show on a genome-wide level that genes whose order has remained unaltered across 9 Drosophila species display late replication timing and frequently map to the regions of repressive chromatin. This observation is consistent with the existence of extensive domains of repressive chromatin that replicate extremely late and have conserved gene order in the Drosophila genome. We suggest that such repressive chromatin domains correspond to a handful of regions that complete replication at the very end of S phase. We further demonstrate that the order of genes in these regions is rarely altered in evolution. Substantial proportion of such regions significantly coincide with large synteny blocks. This indicates that there are evolutionary mechanisms maintaining the integrity of these late-replicating chromatin domains. The synteny blocks corresponding to the extremely late-replicating regions in the D. melanogaster genome consistently display two-fold lower gene density across different Drosophila species.

  10. Open chromatin reveals the functional maize genome

    Science.gov (United States)

    Every cellular process mediated through nuclear DNA must contend with chromatin. As results from ENCODE show, open chromatin assays can efficiently integrate across diverse regulatory elements, revealing functional non-coding genome. In this study, we use a MNase hypersensitivity assay to discover o...

  11. Characterization of evolutionary rates and constraints in three mammalian genomes

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Gregory M.; Brudno, Michael; Stone, Eric A.; Dubchak, Inna; Batzoglou, Serafim; Sidow, Arend

    2004-02-15

    We present an analysis of rates and patterns of microevolutionary phenomena that have shaped the human, mouse, and rat genomes since their last common ancestor. We find evidence for a shift in the mutational spectrum between the mouse and rat lineages, with the net effect being a relative increase in GC content in the rat genome. Our estimate for the neutral point substitution rate separating the two rodents is 0.196 substitutions per site, and 0.65 substitutions per site for the tree relating all three mammals. Small insertions and deletions of 1-10 bp in length (''microindels'') occur at approximately 5 percent of the point substitution rate. Inferred regional correlations in evolutionary rates between lineages and between types of sites support the idea that rates of evolution are influenced by local genomic or cell biological context. No substantial correlations between rates of point substitutions and rates of microindels are found, however, implying that the influences that affect these processes are distinct. Finally, we have identified those regions in the human genome that are evolving slowly, which are likely to include functional elements important to human biology. At least 5 percent of the human genome is under substantial constraint, most of which is noncoding.

  12. An Evolutionary Genomic Perspective on the Breeding of Dwarf Chickens.

    Science.gov (United States)

    Wang, Ming-Shan; Otecko, Newton O; Wang, Sheng; Wu, Dong-Dong; Yang, Min-Min; Xu, Yi-Long; Murphy, Robert W; Peng, Min-Sheng; Zhang, Ya-Ping

    2017-12-01

    The evolutionary history for dwarfism in chickens remains an enigma. Herein, we explore the evolution of the Serama, the smallest breed of chicken. Leveraging comparative population genomics, analyses identify several genes that are potentially associated with the growth and development of bones and muscles. These genes, and in particular both POU1F1 and IGF1, are under strong positive selection. Three allopatric dwarf bantams (Serama, Yuanbao, and Daweishan) with different breeding-histories, form distinct clusters and exhibit unique population structures. Parallel genetic mechanisms underlay their variation in body size. These findings provide insights into the multiple and complex pathways, depending on genomic variation, that chicken can take in response to aviculture selection for dwarfism. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. The evolutionary dynamics of operon distributions in eukaryote genomes.

    Science.gov (United States)

    Cutter, Asher D; Agrawal, Aneil F

    2010-06-01

    Genes in nematode and ascidian genomes frequently occur in operons--multiple genes sharing a common promoter to generate a polycistronic primary transcript--and such genes comprise 15-20% of the coding genome for Caenorhabditis elegans and Ciona intestinalis. Recent work in nematodes has demonstrated that the identity of genes within operons is highly conserved among species and that the unifying feature of genes within operons is that they are expressed in germline tissue. However, it is generally unknown what processes are responsible for generating the distribution of operon sizes across the genome, which are composed of up to eight genes per operon. Here we investigate several models for operon evolution to better understand their abundance, distribution of sizes, and evolutionary dynamics over time. We find that birth-death models of operon evolution reasonably describe the relative abundance of operons of different sizes in the C. elegans and Ciona genomes and generate predictions about the number of monocistronic, nonoperon genes that likely participate in the birth-death process. This theory, and applications to C. elegans and Ciona, motivates several new and testable hypotheses about eukaryote operon evolution.

  14. Sequencing of seven haloarchaeal genomes reveals patterns of genomic flux.

    Directory of Open Access Journals (Sweden)

    Erin A Lynch

    Full Text Available We report the sequencing of seven genomes from two haloarchaeal genera, Haloferax and Haloarcula. Ease of cultivation and the existence of well-developed genetic and biochemical tools for several diverse haloarchaeal species make haloarchaea a model group for the study of archaeal biology. The unique physiological properties of these organisms also make them good candidates for novel enzyme discovery for biotechnological applications. Seven genomes were sequenced to ∼20×coverage and assembled to an average of 50 contigs (range 5 scaffolds-168 contigs. Comparisons of protein-coding gene compliments revealed large-scale differences in COG functional group enrichment between these genera. Analysis of genes encoding machinery for DNA metabolism reveals genera-specific expansions of the general transcription factor TATA binding protein as well as a history of extensive duplication and horizontal transfer of the proliferating cell nuclear antigen. Insights gained from this study emphasize the importance of haloarchaea for investigation of archaeal biology.

  15. Evolutionary Origins and Dynamics of Octoploid Strawberry Subgenomes Revealed by Dense Targeted Capture Linkage Maps

    Science.gov (United States)

    Tennessen, Jacob A.; Govindarajulu, Rajanikanth; Ashman, Tia-Lynn; Liston, Aaron

    2014-01-01

    Whole-genome duplications are radical evolutionary events that have driven speciation and adaptation in many taxa. Higher-order polyploids have complex histories often including interspecific hybridization and dynamic genomic changes. This chromosomal reshuffling is poorly understood for most polyploid species, despite their evolutionary and agricultural importance, due to the challenge of distinguishing homologous sequences from each other. Here, we use dense linkage maps generated with targeted sequence capture to improve the diploid strawberry (Fragaria vesca) reference genome and to disentangle the subgenomes of the wild octoploid progenitors of cultivated strawberry, Fragaria virginiana and Fragaria chiloensis. Our novel approach, POLiMAPS (Phylogenetics Of Linkage-Map-Anchored Polyploid Subgenomes), leverages sequence reads to associate informative interhomeolog phylogenetic markers with linkage groups and reference genome positions. In contrast to a widely accepted model, we find that one of the four subgenomes originates with the diploid cytoplasm donor F. vesca, one with the diploid Fragaria iinumae, and two with an unknown ancestor close to F. iinumae. Extensive unidirectional introgression has converted F. iinumae-like subgenomes to be more F. vesca-like, but never the reverse, due either to homoploid hybridization in the F. iinumae-like diploid ancestors or else strong selection spreading F. vesca-like sequence among subgenomes through homeologous exchange. In addition, divergence between homeologous chromosomes has been substantially augmented by interchromosomal rearrangements. Our phylogenetic approach reveals novel aspects of the complicated web of genetic exchanges that occur during polyploid evolution and suggests a path forward for unraveling other agriculturally and ecologically important polyploid genomes. PMID:25477420

  16. Comparative evolutionary histories of kisspeptins and kisspeptin receptors in vertebrates reveal both parallel and divergent features

    Directory of Open Access Journals (Sweden)

    Jérémy ePasquier

    2012-12-01

    Full Text Available During the past decade, the kisspeptin system has been identified in various vertebrates, leading to the discovery of multiple genes encoding both peptides (Kiss and receptors (Kissr. The investigation of recently published genomes from species of phylogenetic interest, such as a chondrichthyan, the elephant shark, an early sarcopterygian, the coelacanth, a non-teleost actinopterygian, the spotted gar, and an early teleost, the European eel, allowed us to get new insights into the molecular diversity and evolution of both Kiss and Kissr families. We identified four Kissr in the spotted gar and coelacanth genomes, providing the first evidence of four Kissr genes in vertebrates. We also found three Kiss in the coelacanth and elephant shark genomes revealing two new species, in addition to Xenopus, presenting three Kiss genes. Considering the increasing diversity of kisspeptin system, phylogenetic and synteny analyses enabled us to clarify both Kiss and Kissr classifications. We also could trace back the evolution of both gene families from the early steps of vertebrate history. Four Kissr and four Kiss paralogs may have arisen via the two whole genome duplication rounds (1R & 2R in early vertebrates. This would have been followed by multiple independent Kiss and Kissr gene losses in the sarcopterygian and actinopterygian lineages. In particular, no impact of the teleost-specific 3R could be recorded on the numbers of teleost Kissr or Kiss paralogs. The origin of their diversity via 1R & 2R, as well as the subsequent occurrence of multiple gene losses, represent common features of the evolutionary histories of Kiss and Kissr families in vertebrates. In contrast, comparisons also revealed un-matching numbers of Kiss and Kissr genes in some species, as well as a large variability of Kiss/Kissr couples according to species. These discrepancies support independent features of the Kiss and Kissr evolutionary histories across vertebrate radiation.

  17. Clusters of orthologous genes for 41 archaeal genomes and implications for evolutionary genomics of archaea

    Science.gov (United States)

    Makarova, Kira S; Sorokin, Alexander V; Novichkov, Pavel S; Wolf, Yuri I; Koonin, Eugene V

    2007-01-01

    Background An evolutionary classification of genes from sequenced genomes that distinguishes between orthologs and paralogs is indispensable for genome annotation and evolutionary reconstruction. Shortly after multiple genome sequences of bacteria, archaea, and unicellular eukaryotes became available, an attempt on such a classification was implemented in Clusters of Orthologous Groups of proteins (COGs). Rapid accumulation of genome sequences creates opportunities for refining COGs but also represents a challenge because of error amplification. One of the practical strategies involves construction of refined COGs for phylogenetically compact subsets of genomes. Results New Archaeal Clusters of Orthologous Genes (arCOGs) were constructed for 41 archaeal genomes (13 Crenarchaeota, 27 Euryarchaeota and one Nanoarchaeon) using an improved procedure that employs a similarity tree between smaller, group-specific clusters, semi-automatically partitions orthology domains in multidomain proteins, and uses profile searches for identification of remote orthologs. The annotation of arCOGs is a consensus between three assignments based on the COGs, the CDD database, and the annotations of homologs in the NR database. The 7538 arCOGs, on average, cover ~88% of the genes in a genome compared to a ~76% coverage in COGs. The finer granularity of ortholog identification in the arCOGs is apparent from the fact that 4538 arCOGs correspond to 2362 COGs; ~40% of the arCOGs are new. The archaeal gene core (protein-coding genes found in all 41 genome) consists of 166 arCOGs. The arCOGs were used to reconstruct gene loss and gene gain events during archaeal evolution and gene sets of ancestral forms. The Last Archaeal Common Ancestor (LACA) is conservatively estimated to possess 996 genes compared to 1245 and 1335 genes for the last common ancestors of Crenarchaeota and Euryarchaeota, respectively. It is inferred that LACA was a chemoautotrophic hyperthermophile that, in addition to the

  18. Clusters of orthologous genes for 41 archaeal genomes and implications for evolutionary genomics of archaea

    Directory of Open Access Journals (Sweden)

    Wolf Yuri I

    2007-11-01

    Full Text Available Abstract Background An evolutionary classification of genes from sequenced genomes that distinguishes between orthologs and paralogs is indispensable for genome annotation and evolutionary reconstruction. Shortly after multiple genome sequences of bacteria, archaea, and unicellular eukaryotes became available, an attempt on such a classification was implemented in Clusters of Orthologous Groups of proteins (COGs. Rapid accumulation of genome sequences creates opportunities for refining COGs but also represents a challenge because of error amplification. One of the practical strategies involves construction of refined COGs for phylogenetically compact subsets of genomes. Results New Archaeal Clusters of Orthologous Genes (arCOGs were constructed for 41 archaeal genomes (13 Crenarchaeota, 27 Euryarchaeota and one Nanoarchaeon using an improved procedure that employs a similarity tree between smaller, group-specific clusters, semi-automatically partitions orthology domains in multidomain proteins, and uses profile searches for identification of remote orthologs. The annotation of arCOGs is a consensus between three assignments based on the COGs, the CDD database, and the annotations of homologs in the NR database. The 7538 arCOGs, on average, cover ~88% of the genes in a genome compared to a ~76% coverage in COGs. The finer granularity of ortholog identification in the arCOGs is apparent from the fact that 4538 arCOGs correspond to 2362 COGs; ~40% of the arCOGs are new. The archaeal gene core (protein-coding genes found in all 41 genome consists of 166 arCOGs. The arCOGs were used to reconstruct gene loss and gene gain events during archaeal evolution and gene sets of ancestral forms. The Last Archaeal Common Ancestor (LACA is conservatively estimated to possess 996 genes compared to 1245 and 1335 genes for the last common ancestors of Crenarchaeota and Euryarchaeota, respectively. It is inferred that LACA was a chemoautotrophic hyperthermophile

  19. Whole genome sequencing and analysis reveal insights into the genetic structure, diversity and evolutionary relatedness of luxI and luxR homologs in bacteria belonging to the Sphingomonadaceae family.

    Science.gov (United States)

    Gan, Han Ming; Gan, Huan You; Ahmad, Nurul H; Aziz, Nazrin A; Hudson, André O; Savka, Michael A

    2014-01-01

    Here we report the draft genomes and annotation of four N-acyl homoserine lactone (AHL)-producing members from the family Sphingomonadaceae. Comparative genomic analyses of 62 Sphingomonadaceae genomes were performed to gain insights into the distribution of the canonical luxI/R-type quorum sensing (QS) network within this family. Forty genomes contained at least one luxR homolog while the genome of Sphingobium yanoikuyae B1 contained seven Open Reading Frames (ORFs) that have significant homology to that of luxR. Thirty-three genomes contained at least one luxI homolog while the genomes of Sphingobium sp. SYK6, Sphingobium japonicum, and Sphingobium lactosutens contained four luxI. Using phylogenetic analysis, the sphingomonad LuxR homologs formed five distinct clades with two minor clades located near the plant associated bacteria (PAB) LuxR solo clade. This work for the first time shows that 13 Sphingobium and one Sphingomonas genome(s) contain three convergently oriented genes composed of two tandem luxR genes proximal to one luxI (luxR-luxR-luxI). Interestingly, luxI solos were identified in two Sphingobium species and may represent species that contribute to AHL-based QS system by contributing AHL molecules but are unable to perceive AHLs as signals. This work provides the most comprehensive description of the luxI/R circuitry and genome-based taxonomical description of the available sphingomonad genomes to date indicating that the presence of luxR solos and luxI solos are not an uncommon feature in members of the Sphingomonadaceae family.

  20. Genomic affinities revealed by GISH suggests intergenomic restructuring between parental genomes of the paleopolyploid genus Zea.

    Science.gov (United States)

    González, Graciela Esther; Poggio, Lidia

    2015-10-01

    The present work compares the molecular affinities, revealed by GISH, with the analysis of meiotic pairing in intra- and interspecific hybrids between species of Zea obtained in previous works. The joint analysis of these data provided evidence about the evolutionary relationships among the species from the paleopolyploid genus Zea (maize and teosintes). GISH and meiotic pairing of intraspecific hybrids revealed high genomic affinity between maize (Zea mays subsp. mays) and both Zea mays subsp. parviglumis and Zea mays subsp. mexicana. On the other hand, when Zea mays subsp. huehuetenanguensis DNA was probed on maize chromosomes, a lower affinity was detected, and the pattern of hybridization suggested intergenomical restructuring between the parental genomes of maize. When DNA from Zea luxurians was used as probe, homogeneous hybridization signals were observed through all maize chromosomes. Lower genomic affinity was observed when DNA from Zea diploperennis was probed on maize chromosomes, especially at knob regions. Maize chromosomes hybridized with Zea perennis DNA showed hybridization signals on four chromosome pairs: two chromosome pairs presented hybridization signal in only one chromosomal arm, whereas four chromosome pairs did not show any hybridization. These results are in agreement with previous GISH studies, which have identified the genomic source of the chromosomes involved in the meiotic configurations of Z. perennis × maize hybrids. These findings allow postulating that maize has a parental genome not shared with Z. perennis, and the existence of intergenomic restructuring between the parental genomes of maize. Moreover, the absence of hybridization signals in all maize knobs indicate that these heterochromatic regions were lost during the Z. perennis genome evolution.

  1. Genetic variation architecture of mitochondrial genome reveals the differentiation in Korean landrace and weedy rice

    OpenAIRE

    Wei Tong; Qiang He; Yong-Jin Park

    2017-01-01

    Mitochondrial genome variations have been detected despite the overall conservation of this gene content, which has been valuable for plant population genetics and evolutionary studies. Here, we describe mitochondrial variation architecture and our performance of a phylogenetic dissection of Korean landrace and weedy rice. A total of 4,717 variations across the mitochondrial genome were identified adjunct with 10 wild rice. Genetic diversity assessment revealed that wild rice has higher nucle...

  2. Evolutionary dynamics of the accessory genome of Listeria monocytogenes.

    Directory of Open Access Journals (Sweden)

    Henk C den Bakker

    Full Text Available Listeria monocytogenes, a foodborne bacterial pathogen, is comprised of four phylogenetic lineages that vary with regard to their serotypes and distribution among sources. In order to characterize lineage-specific genomic diversity within L. monocytogenes, we sequenced the genomes of eight strains from several lineages and serotypes, and characterized the accessory genome, which was hypothesized to contribute to phenotypic differences across lineages. The eight L. monocytogenes genomes sequenced range in size from 2.85-3.14 Mb, encode 2,822-3,187 genes, and include the first publicly available sequenced representatives of serotypes 1/2c, 3a and 4c. Mapping of the distribution of accessory genes revealed two distinct regions of the L. monocytogenes chromosome: an accessory-rich region in the first 65° adjacent to the origin of replication and a more stable region in the remaining 295°. This pattern of genome organization is distinct from that of related bacteria Staphylococcus aureus and Bacillus cereus. The accessory genome of all lineages is enriched for cell surface-related genes and phosphotransferase systems, and transcriptional regulators, highlighting the selective pressures faced by contemporary strains from their hosts, other microbes, and their environment. Phylogenetic analysis of O-antigen genes and gene clusters predicts that serotype 4 was ancestral in L. monocytogenes and serotype 1/2 associated gene clusters were putatively introduced through horizontal gene transfer in the ancestral population of L. monocytogenes lineage I and II.

  3. Integrating cytogenetics and genomics in comparative evolutionary studies of cichlid fish

    Directory of Open Access Journals (Sweden)

    Mazzuchelli Juliana

    2012-09-01

    Full Text Available Abstract Background The availability of a large number of recently sequenced vertebrate genomes opens new avenues to integrate cytogenetics and genomics in comparative and evolutionary studies. Cytogenetic mapping can offer alternative means to identify conserved synteny shared by distinct genomes and also to define genome regions that are still not fine characterized even after wide-ranging nucleotide sequence efforts. An efficient way to perform comparative cytogenetic mapping is based on BAC clones mapping by fluorescence in situ hybridization. In this report, to address the knowledge gap on the genome evolution in cichlid fishes, BAC clones of an Oreochromis niloticus library covering the linkage groups (LG 1, 3, 5, and 7 were mapped onto the chromosomes of 9 African cichlid species. The cytogenetic mapping data were also integrated with BAC-end sequences information of O. niloticus and comparatively analyzed against the genome of other fish species and vertebrates. Results The location of BACs from LG1, 3, 5, and 7 revealed a strong chromosomal conservation among the analyzed cichlid species genomes, which evidenced a synteny of the markers of each LG. Comparative in silico analysis also identified large genomic blocks that were conserved in distantly related fish groups and also in other vertebrates. Conclusions Although it has been suggested that fishes contain plastic genomes with high rates of chromosomal rearrangements and probably low rates of synteny conservation, our results evidence that large syntenic chromosome segments have been maintained conserved during evolution, at least for the considered markers. Additionally, our current cytogenetic mapping efforts integrated with genomic approaches conduct to a new perspective to address important questions involving chromosome evolution in fishes.

  4. Phytophthora Genome Sequences Uncover Evolutionary Origins and Mechanisms of Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Brett M.; Tripathy, Sucheta; Zhang, Xuemin; Dehal, Paramvir; Jiang, Rays H. Y.; Aerts, Andrea; Arredondo, Felipe D.; Baxter, Laura; Bensasson, Douda; Beynon, JIm L.; Chapman, Jarrod; Damasceno, Cynthia M. B.; Dorrance, Anne E.; Dou, Daolong; Dickerman, Allan W.; Dubchak, Inna L.; Garbelotto, Matteo; Gijzen, Mark; Gordon, Stuart G.; Govers, Francine; Grunwald, NIklaus J.; Huang, Wayne; Ivors, Kelly L.; Jones, Richard W.; Kamoun, Sophien; Krampis, Konstantinos; Lamour, Kurt H.; Lee, Mi-Kyung; McDonald, W. Hayes; Medina, Monica; Meijer, Harold J. G.; Nordberg, Erik K.; Maclean, Donald J.; Ospina-Giraldo, Manuel D.; Morris, Paul F.; Phuntumart, Vipaporn; Putnam, Nicholas J.; Rash, Sam; Rose, Jocelyn K. C.; Sakihama, Yasuko; Salamov, Asaf A.; Savidor, Alon; Scheuring, Chantel F.; Smith, Brian M.; Sobral, Bruno W. S.; Terry, Astrid; Torto-Alalibo, Trudy A.; Win, Joe; Xu, Zhanyou; Zhang, Hongbin; Grigoriev, Igor V.; Rokhsar, Daniel S.; Boore, Jeffrey L.

    2006-04-17

    Draft genome sequences have been determined for the soybean pathogen Phytophthora sojae and the sudden oak death pathogen Phytophthora ramorum. Oömycetes such as these Phytophthora species share the kingdom Stramenopila with photosynthetic algae such as diatoms, and the presence of many Phytophthora genes of probable phototroph origin supports a photosynthetic ancestry for the stramenopiles. Comparison of the two species' genomes reveals a rapid expansion and diversification of many protein families associated with plant infection such as hydrolases, ABC transporters, protein toxins, proteinase inhibitors, and, in particular, a superfamily of 700 proteins with similarity to known oömycete avirulence genes.

  5. Evolutionary pets: offspring numbers reveal speciation process in domesticated chickens.

    Directory of Open Access Journals (Sweden)

    Inga Tiemann

    Full Text Available Since Darwin, the nature of the relationship between evolution and domestication has been debated. Evolution offers different mechanisms of selection that lead to adaptation and may end in the origin of new species as defined by the biological species concept. Domestication has given rise to numerous breeds in almost every domesticated species, including chickens. At the same time, so-called artificial selection seems to exclude mechanisms of sexual selection by the animals themselves. We want to forward the question to the animal itself: With whom do you reproduce successfully? This study focused on the sexual behavior of the domestic chicken Gallus gallus f.dom., particularly the White Crested Polish breed. Experiments on mate choice and the observation of fertilization and hatching rates of mixed-breeding groups revealed breed-specific preferences. In breeding groups containing White Crested Polish and a comparative breed, more purebred chicks hatched than hybrids (number of eggs collected: 1059. Mating was possible in equal shares, but in relation to the number of eggs collected, purebred offspring (62.75% ± 7.10%, M ± SE hatched to a greater extend compared to hybrid offspring (28.75% ± 15.32%, M ± SE. These data demonstrate that the mechanism of sexual selection is still present in domestic chicken breeds, which includes the alteration of gene frequencies typical for domestication and evolutionary speciation. Due to selection and mate choice we state that breeding in principle can generate new species. Therefore, we see domestication as an evolutionary process that integrates human interests of animal breeding with innate mate choice by the animal.

  6. Comparative genomics reveals mobile pathogenicity chromosomes in Fusarium

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Li Jun; van der Does, H. C.; Borkovich, Katherine A.; Coleman, Jeffrey J.; Daboussi, Marie-Jose; Di Pietro, Antonio; Dufresne, Marie; Freitag, Michael; Grabherr, Manfred; Henrissat, Bernard; Houterman, Petra M.; Kang, Seogchan; Shim, Won-Bo; Wolochuk, Charles; Xie, Xiaohui; Xu, Jin Rong; Antoniw, John; Baker, Scott E.; Bluhm, Burton H.; Breakspear, Andrew; Brown, Daren W.; Butchko, Robert A.; Chapman, Sinead; Coulson, Richard; Coutinho, Pedro M.; Danchin, Etienne G.; Diener, Andrew; Gale, Liane R.; Gardiner, Donald; Goff, Steven; Hammond-Kossack, Kim; Hilburn, Karen; Hua-Van, Aurelie; Jonkers, Wilfried; Kazan, Kemal; Kodira, Chinnappa D.; Koehrsen, Michael; Kumar, Lokesh; Lee, Yong Hwan; Li, Liande; Manners, John M.; Miranda-Saavedra, Diego; Mukherjee, Mala; Park, Gyungsoon; Park, Jongsun; Park, Sook Young; Proctor, Robert H.; Regev, Aviv; Ruiz-Roldan, M. C.; Sain, Divya; Sakthikumar, Sharadha; Sykes, Sean; Schwartz, David C.; Turgeon, Barbara G.; Wapinski, Ilan; Yoder, Olen; Young, Sarah; Zeng, Qiandong; Zhou, Shiguo; Galagan, James; Cuomo, Christina A.; Kistler, H. Corby; Rep, Martijn

    2010-03-18

    Fusarium species are among the most important phytopathogenic and toxigenic fungi, having significant impact on crop production and animal health. Distinctively, members of the F. oxysporum species complex exhibit wide host range but discontinuously distributed host specificity, reflecting remarkable genetic adaptability. To understand the molecular underpinnings of diverse phenotypic traits and their evolution in Fusarium, we compared the genomes of three economically important and phylogenetically related, yet phenotypically diverse plant-pathogenic species, F. graminearum, F. verticillioides and F. oxysporum f. sp. lycopersici. Our analysis revealed greatly expanded lineage-specific (LS) genomic regions in F. oxysporum that include four entire chromosomes, accounting for more than one-quarter of the genome. LS regions are rich in transposons and genes with distinct evolutionary profiles but related to pathogenicity. Experimentally, we demonstrate for the first time the transfer of two LS chromosomes between strains of F. oxysporum, resulting in the conversion of a non-pathogenic strain into a pathogen. Transfer of LS chromosomes between otherwise genetically isolated strains explains the polyphyletic origin of host specificity and the emergence of new pathogenic lineages in the F. oxysporum species complex, putting the evolution of fungal pathogenicity into a new perspective.

  7. Comparative genomics explains the evolutionary success of reef-forming corals.

    Science.gov (United States)

    Bhattacharya, Debashish; Agrawal, Shobhit; Aranda, Manuel; Baumgarten, Sebastian; Belcaid, Mahdi; Drake, Jeana L; Erwin, Douglas; Foret, Sylvian; Gates, Ruth D; Gruber, David F; Kamel, Bishoy; Lesser, Michael P; Levy, Oren; Liew, Yi Jin; MacManes, Matthew; Mass, Tali; Medina, Monica; Mehr, Shaadi; Meyer, Eli; Price, Dana C; Putnam, Hollie M; Qiu, Huan; Shinzato, Chuya; Shoguchi, Eiichi; Stokes, Alexander J; Tambutté, Sylvie; Tchernov, Dan; Voolstra, Christian R; Wagner, Nicole; Walker, Charles W; Weber, Andreas Pm; Weis, Virginia; Zelzion, Ehud; Zoccola, Didier; Falkowski, Paul G

    2016-05-24

    Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years.

  8. Comparative genomics explains the evolutionary success of reef-forming corals

    KAUST Repository

    Bhattacharya, Debashish

    2016-05-24

    Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years.

  9. How Single-Cell Genomics Is Changing Evolutionary and Developmental Biology.

    Science.gov (United States)

    Marioni, John C; Arendt, Detlev

    2017-10-06

    The recent flood of single-cell data not only boosts our knowledge of cells and cell types, but also provides new insight into development and evolution from a cellular perspective. For example, assaying the genomes of multiple cells during development reveals developmental lineage trees-the kinship lineage-whereas cellular transcriptomes inform us about the regulatory state of cells and their gradual restriction in potency-the Waddington lineage. Beyond that, the comparison of single-cell data across species allows evolutionary changes to be tracked at all stages of development from the zygote, via different kinds of stem cells, to the differentiating cells. We discuss recent insights into the evolution of stem cells and initial attempts to reconstruct the evolutionary cell type tree of the mammalian forebrain, for example, by the comparative analysis of neuron types in the mesencephalic floor. These studies illustrate the immense potential of single-cell genomics to open up a new era in developmental and evolutionary research.

  10. The 3D organization of chromatin explains evolutionary fragile genomic regions.

    Science.gov (United States)

    Berthelot, Camille; Muffato, Matthieu; Abecassis, Judith; Roest Crollius, Hugues

    2015-03-24

    Genomic rearrangements are a major source of evolutionary divergence in eukaryotic genomes, a cause of genetic diseases and a hallmark of tumor cell progression, yet the mechanisms underlying their occurrence and evolutionary fixation are poorly understood. Statistical associations between breakpoints and specific genomic features suggest that genomes may contain elusive “fragile regions” with a higher propensity for breakage. Here, we use ancestral genome reconstructions to demonstrate a near-perfect correlation between gene density and evolutionary rearrangement breakpoints. Simulations based on functional features in the human genome show that this pattern is best explained as the outcome of DNA breaks that occur in open chromatin regions coming into 3D contact in the nucleus. Our model explains how rearrangements reorganize the order of genes in an evolutionary neutral fashion and provides a basis for understanding the susceptibility of “fragile regions” to breakage.

  11. The 3D Organization of Chromatin Explains Evolutionary Fragile Genomic Regions

    Directory of Open Access Journals (Sweden)

    Camille Berthelot

    2015-03-01

    Full Text Available Genomic rearrangements are a major source of evolutionary divergence in eukaryotic genomes, a cause of genetic diseases and a hallmark of tumor cell progression, yet the mechanisms underlying their occurrence and evolutionary fixation are poorly understood. Statistical associations between breakpoints and specific genomic features suggest that genomes may contain elusive “fragile regions” with a higher propensity for breakage. Here, we use ancestral genome reconstructions to demonstrate a near-perfect correlation between gene density and evolutionary rearrangement breakpoints. Simulations based on functional features in the human genome show that this pattern is best explained as the outcome of DNA breaks that occur in open chromatin regions coming into 3D contact in the nucleus. Our model explains how rearrangements reorganize the order of genes in an evolutionary neutral fashion and provides a basis for understanding the susceptibility of “fragile regions” to breakage.

  12. Genomic investigation reveals evolution and lifestyle adaptation of endophytic Staphylococcus epidermidis.

    Science.gov (United States)

    Chaudhry, Vasvi; Patil, Prabhu B

    2016-01-13

    Staphylococcus epidermidis is a major human associated bacterium and also an emerging nosocomial pathogen. There are reports of its association to rodents, sheep and plants. However, comparative and evolutionary studies of ecologically diverse strains of S. epidermidis are lacking. Here, we report the whole genome sequences of four S. epidermidis strains isolated from surface sterilized rice seeds along with genome sequence of type strain. Phylogenomic analysis of rice endophytic S. epidermidis (RESE) with "type strain" unequivocally established their species identity. Whole genome based tree of 93 strains of S. epidermidis revealed RESE as distinct sub-lineage which is more related to rodent sub-lineage than to majority of human lineage strains. Furthermore, comparative genomics revealed 20% variable gene-pool in S. epidermidis, suggesting that genomes of ecologically diverse strains are under flux. Interestingly, we were also able to map several genomic regions that are under flux and gave rise to RESE strains. The largest of these genomic regions encodes a cluster of genes unique to RESE that are known to be required for survival and stress tolerance, apart from those required for adaptation to plant habitat. The genomes and genes of RESE represent distinct ecological resource/sequences and provided first evolutionary insights into adaptation of S. epidermidis to plants.

  13. Whole Genome Sequencing Allows Better Understanding of the Evolutionary History of Leptospira interrogans Serovar Hardjo.

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    Alejandro Llanes

    Full Text Available The genome of a laboratory-adapted strain of Leptospira interrogans serovar Hardjo was sequenced and analyzed. Comparison of the sequenced genome with that recently published for a field isolate of the same serovar revealed relatively high sequence conservation at the nucleotide level, despite the different biological background of both samples. Conversely, comparison of both serovar Hardjo genomes with those of L. borgpetersenii serovar Hardjo showed extensive differences between the corresponding chromosomes, except for the region occupied by their rfb loci. Additionally, comparison of the serovar Hardjo genomes with those of different L. interrogans serovars allowed us to detect several genomic features that may confer an adaptive advantage to L. interrogans serovar Hardjo, including a possible integrated plasmid and an additional copy of a cluster encoding a membrane transport system known to be involved in drug resistance. A phylogenomic strategy was used to better understand the evolutionary position of the Hardjo serovar among L. interrogans serovars and other Leptospira species. The proposed phylogeny supports the hypothesis that the presence of similar rfb loci in two different species may be the result of a lateral gene transfer event.

  14. Genome-wide evolutionary dynamics of influenza B viruses on a global scale.

    Directory of Open Access Journals (Sweden)

    Pinky Langat

    2017-12-01

    Full Text Available The global-scale epidemiology and genome-wide evolutionary dynamics of influenza B remain poorly understood compared with influenza A viruses. We compiled a spatio-temporally comprehensive dataset of influenza B viruses, comprising over 2,500 genomes sampled worldwide between 1987 and 2015, including 382 newly-sequenced genomes that fill substantial gaps in previous molecular surveillance studies. Our contributed data increase the number of available influenza B virus genomes in Europe, Africa and Central Asia, improving the global context to study influenza B viruses. We reveal Yamagata-lineage diversity results from co-circulation of two antigenically-distinct groups that also segregate genetically across the entire genome, without evidence of intra-lineage reassortment. In contrast, Victoria-lineage diversity stems from geographic segregation of different genetic clades, with variability in the degree of geographic spread among clades. Differences between the lineages are reflected in their antigenic dynamics, as Yamagata-lineage viruses show alternating dominance between antigenic groups, while Victoria-lineage viruses show antigenic drift of a single lineage. Structural mapping of amino acid substitutions on trunk branches of influenza B gene phylogenies further supports these antigenic differences and highlights two potential mechanisms of adaptation for polymerase activity. Our study provides new insights into the epidemiological and molecular processes shaping influenza B virus evolution globally.

  15. Distinct evolutionary trajectories of primary high-grade serous ovarian cancers revealed through spatial mutational profiling.

    Science.gov (United States)

    Bashashati, Ali; Ha, Gavin; Tone, Alicia; Ding, Jiarui; Prentice, Leah M; Roth, Andrew; Rosner, Jamie; Shumansky, Karey; Kalloger, Steve; Senz, Janine; Yang, Winnie; McConechy, Melissa; Melnyk, Nataliya; Anglesio, Michael; Luk, Margaret T Y; Tse, Kane; Zeng, Thomas; Moore, Richard; Zhao, Yongjun; Marra, Marco A; Gilks, Blake; Yip, Stephen; Huntsman, David G; McAlpine, Jessica N; Shah, Sohrab P

    2013-09-01

    High-grade serous ovarian cancer (HGSC) is characterized by poor outcome, often attributed to the emergence of treatment-resistant subclones. We sought to measure the degree of genomic diversity within primary, untreated HGSCs to examine the natural state of tumour evolution prior to therapy. We performed exome sequencing, copy number analysis, targeted amplicon deep sequencing and gene expression profiling on 31 spatially and temporally separated HGSC tumour specimens (six patients), including ovarian masses, distant metastases and fallopian tube lesions. We found widespread intratumoural variation in mutation, copy number and gene expression profiles, with key driver alterations in genes present in only a subset of samples (eg PIK3CA, CTNNB1, NF1). On average, only 51.5% of mutations were present in every sample of a given case (range 10.2-91.4%), with TP53 as the only somatic mutation consistently present in all samples. Complex segmental aneuploidies, such as whole-genome doubling, were present in a subset of samples from the same individual, with divergent copy number changes segregating independently of point mutation acquisition. Reconstruction of evolutionary histories showed one patient with mixed HGSC and endometrioid histology, with common aetiologic origin in the fallopian tube and subsequent selection of different driver mutations in the histologically distinct samples. In this patient, we observed mixed cell populations in the early fallopian tube lesion, indicating that diversity arises at early stages of tumourigenesis. Our results revealed that HGSCs exhibit highly individual evolutionary trajectories and diverse genomic tapestries prior to therapy, exposing an essential biological characteristic to inform future design of personalized therapeutic solutions and investigation of drug-resistance mechanisms. © 2013 The Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

  16. Evolutionary insights into scleractinian corals using comparative genomic hybridizations

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    Aranda Manuel

    2012-09-01

    Full Text Available Abstract Background Coral reefs belong to the most ecologically and economically important ecosystems on our planet. Yet, they are under steady decline worldwide due to rising sea surface temperatures, disease, and pollution. Understanding the molecular impact of these stressors on different coral species is imperative in order to predict how coral populations will respond to this continued disturbance. The use of molecular tools such as microarrays has provided deep insight into the molecular stress response of corals. Here, we have performed comparative genomic hybridizations (CGH with different coral species to an Acropora palmata microarray platform containing 13,546 cDNA clones in order to identify potentially rapidly evolving genes and to determine the suitability of existing microarray platforms for use in gene expression studies (via heterologous hybridization. Results Our results showed that the current microarray platform for A. palmata is able to provide biological relevant information for a wide variety of coral species covering both the complex clade as well the robust clade. Analysis of the fraction of highly diverged genes showed a significantly higher amount of genes without annotation corroborating previous findings that point towards a higher rate of divergence for taxonomically restricted genes. Among the genes with annotation, we found many mitochondrial genes to be highly diverged in M. faveolata when compared to A. palmata, while the majority of nuclear encoded genes maintained an average divergence rate. Conclusions The use of present microarray platforms for transcriptional analyses in different coral species will greatly enhance the understanding of the molecular basis of stress and health and highlight evolutionary differences between scleractinian coral species. On a genomic basis, we show that cDNA arrays can be used to identify patterns of divergence. Mitochondrion-encoded genes seem to have diverged faster than

  17. Genome sequence of the basal haplorrhine primate Tarsius syrichta reveals unusual insertions

    Science.gov (United States)

    Schmitz, Jürgen; Noll, Angela; Raabe, Carsten A.; Churakov, Gennady; Voss, Reinhard; Kiefmann, Martin; Rozhdestvensky, Timofey; Brosius, Jürgen; Baertsch, Robert; Clawson, Hiram; Roos, Christian; Zimin, Aleksey; Minx, Patrick; Montague, Michael J.; Wilson, Richard K.; Warren, Wesley C.

    2016-01-01

    Tarsiers are phylogenetically located between the most basal strepsirrhines and the most derived anthropoid primates. While they share morphological features with both groups, they also possess uncommon primate characteristics, rendering their evolutionary history somewhat obscure. To investigate the molecular basis of such attributes, we present here a new genome assembly of the Philippine tarsier (Tarsius syrichta), and provide extended analyses of the genome and detailed history of transposable element insertion events. We describe the silencing of Alu monomers on the lineage leading to anthropoids, and recognize an unexpected abundance of long terminal repeat-derived and LINE1-mobilized transposed elements (Tarsius interspersed elements; TINEs). For the first time in mammals, we identify a complete mitochondrial genome insertion within the nuclear genome, then reveal tarsier-specific, positive gene selection and posit population size changes over time. The genomic resources and analyses presented here will aid efforts to more fully understand the ancient characteristics of primate genomes. PMID:27708261

  18. Annelids in evolutionary developmental biology and comparative genomics.

    Science.gov (United States)

    McDougall, C; Hui, J H L; Monteiro, A; Takahashi, T; Ferrier, D E K

    2008-09-01

    Annelids have had a long history in comparative embryology and morphology, which has helped to establish them in zoology textbooks as an ideal system to understand the evolution of the typical triploblastic, coelomate, protostome condition. In recent years there has been a relative upsurge in embryological data, particularly with regard to the expression and function of developmental control genes. Polychaetes, as well as other annelids such as the parasitic leech, are now also entering the age of comparative genomics. All of this comparative data has had an important impact on our views of the ancestral conditions at various levels of the animal phylogeny, including the bilaterian ancestor and the nature of the annelid ancestor. Here we review some of the recent advances made in annelid comparative development and genomics, revealing a hitherto unsuspected level of complexity in these ancestors. It is also apparent that the transition to a parasitic lifestyle leads to, or requires, extensive modifications and derivations at both the genomic and embryological levels.

  19. Annelids in evolutionary developmental biology and comparative genomics

    Directory of Open Access Journals (Sweden)

    Mcdougall C.

    2008-09-01

    Full Text Available Annelids have had a long history in comparative embryology and morphology, which has helped to establish them in zoology textbooks as an ideal system to understand the evolution of the typical triploblastic, coelomate, protostome condition. In recent years there has been a relative upsurge in embryological data, particularly with regard to the expression and function of developmental control genes. Polychaetes, as well as other annelids such as the parasitic leech, are now also entering the age of comparative genomics. All of this comparative data has had an important impact on our views of the ancestral conditions at various levels of the animal phylogeny, including the bilaterian ancestor and the nature of the annelid ancestor. Here we review some of the recent advances made in annelid comparative development and genomics, revealing a hitherto unsuspected level of complexity in these ancestors. It is also apparent that the transition to a parasitic lifestyle leads to, or requires, extensive modifications and derivations at both the genomic and embryological levels.

  20. Fungal plant cell wall-degrading enzyme database: a platform for comparative and evolutionary genomics in fungi and Oomycetes.

    Science.gov (United States)

    Choi, Jaeyoung; Kim, Ki-Tae; Jeon, Jongbum; Lee, Yong-Hwan

    2013-01-01

    Plant cell wall-degrading enzymes (PCWDEs) play significant roles throughout the fungal life including acquisition of nutrients and decomposition of plant cell walls. In addition, many of PCWDEs are also utilized by biofuel and pulp industries. In order to develop a comparative genomics platform focused in fungal PCWDEs and provide a resource for evolutionary studies, Fungal PCWDE Database (FPDB) is constructed (http://pcwde.riceblast.snu.ac.kr/). In order to archive fungal PCWDEs, 22 sequence profiles were constructed and searched on 328 genomes of fungi, Oomycetes, plants and animals. A total of 6,682 putative genes encoding PCWDEs were predicted, showing differential distribution by their life styles, host ranges and taxonomy. Genes known to be involved in fungal pathogenicity, including polygalacturonase (PG) and pectin lyase, were enriched in plant pathogens. Furthermore, crop pathogens had more PCWDEs than those of rot fungi, implying that the PCWDEs analysed in this study are more needed for invading plant hosts than wood-decaying processes. Evolutionary analysis of PGs in 34 selected genomes revealed that gene duplication and loss events were mainly driven by taxonomic divergence and partly contributed by those events in species-level, especially in plant pathogens. The FPDB would provide a fungi-specialized genomics platform, a resource for evolutionary studies of PCWDE gene families and extended analysis option by implementing Favorite, which is a data exchange and analysis hub built in Comparative Fungal Genomics Platform (CFGP 2.0; http://cfgp.snu.ac.kr/).

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

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    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

  2. Grand challenges in evolutionary and population genetics: The importance of integrating epigenetics, genomics, modeling, and experimentation

    Science.gov (United States)

    Samuel A. Cushman

    2014-01-01

    This is a time of explosive growth in the fields of evolutionary and population genetics, with whole genome sequencing and bioinformatics driving a transformative paradigm shift (Morozova and Marra, 2008). At the same time, advances in epigenetics are thoroughly transforming our understanding of evolutionary processes and their implications for populations, species and...

  3. Array Comparative Genomic Hybridizations: Assessing the ability to recapture evolutionary relationships using an in silico approach

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    Kasuga Takao

    2011-09-01

    Full Text Available Abstract Background Comparative Genomic Hybridization (CGH with DNA microarrays has many biological applications including surveys of copy number changes in tumorogenesis, species detection and identification, and functional genomics studies among related organisms. Array CGH has also been used to infer phylogenetic relatedness among species or strains. Although the use of the entire genome can be seen as a considerable advantage for use in phylogenetic analysis, few such studies have questioned the reliability of array CGH to correctly determine evolutionary relationships. A potential flaw in this application lies in the fact that all comparisons are made to a single reference species. This situation differs from traditional DNA sequence, distance-based phylogenetic analyses where all possible pairwise comparisons are made for the isolates in question. By simulating array data based on the Neurospora crassa genome, we address this potential flaw and other questions regarding array CGH phylogeny. Results Our simulation data indicates that having a single reference can, in some cases, be a serious limitation when using this technique. Additionally, the tree building process with a single reference is sensitive to many factors including tree topology, choice of tree reconstruction method, and the distance metric used. Conclusions Without prior knowledge of the topology and placement of the reference taxon in the topology, the outcome is likely to be wrong and the error undetected. Given these limitations, using CGH to reveal phylogeny based on sequence divergence does not offer a robust alternative to traditional phylogenetic analysis.

  4. Array Comparative Genomic Hybridizations: assessing the ability to recapture evolutionary relationships using an in silico approach.

    Science.gov (United States)

    Gilbert, Luz B; Chae, Lee; Kasuga, Takao; Taylor, John W

    2011-09-21

    Comparative Genomic Hybridization (CGH) with DNA microarrays has many biological applications including surveys of copy number changes in tumorogenesis, species detection and identification, and functional genomics studies among related organisms. Array CGH has also been used to infer phylogenetic relatedness among species or strains. Although the use of the entire genome can be seen as a considerable advantage for use in phylogenetic analysis, few such studies have questioned the reliability of array CGH to correctly determine evolutionary relationships. A potential flaw in this application lies in the fact that all comparisons are made to a single reference species. This situation differs from traditional DNA sequence, distance-based phylogenetic analyses where all possible pairwise comparisons are made for the isolates in question. By simulating array data based on the Neurospora crassa genome, we address this potential flaw and other questions regarding array CGH phylogeny. Our simulation data indicates that having a single reference can, in some cases, be a serious limitation when using this technique. Additionally, the tree building process with a single reference is sensitive to many factors including tree topology, choice of tree reconstruction method, and the distance metric used. Without prior knowledge of the topology and placement of the reference taxon in the topology, the outcome is likely to be wrong and the error undetected. Given these limitations, using CGH to reveal phylogeny based on sequence divergence does not offer a robust alternative to traditional phylogenetic analysis.

  5. Genome-Wide Identification, Evolutionary, and Expression Analyses of Histone H3 Variants in Plants

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    Jinteng Cui

    2015-01-01

    Full Text Available Histone variants alter the nucleosome structure and play important roles in chromosome segregation, transcription, DNA repair, and sperm compaction. Histone H3 is encoded by many genes in most eukaryotic species and is the histone that contains the largest variety of posttranslational modifications. Compared with the metazoan H3 variants, little is known about the complex evolutionary history of H3 variants proteins in plants. Here, we study the identification, evolutionary, and expression analyses of histone H3 variants from genomes in major branches in the plant tree of life. Firstly we identified all the histone three related (HTR genes from the examined genomes, then we classified the four groups variants: centromeric H3, H3.1, H3.3 and H3-like, by phylogenetic analysis, intron information, and alignment. We further demonstrated that the H3 variants have evolved under strong purifying selection, indicating the conservation of HTR proteins. Expression analysis revealed that the HTR has a wide expression profile in maize and rice development and plays important roles in development.

  6. Ruler arrays reveal haploid genomic structural variation.

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    P Alexander Rolfe

    Full Text Available Despite the known relevance of genomic structural variants to pathogen behavior, cancer, development, and evolution, certain repeat based structural variants may evade detection by existing high-throughput techniques. Here, we present ruler arrays, a technique to detect genomic structural variants including insertions and deletions (indels, duplications, and translocations. A ruler array exploits DNA polymerase's processivity to detect physical distances between defined genomic sequences regardless of the intervening sequence. The method combines a sample preparation protocol, tiling genomic microarrays, and a new computational analysis. The analysis of ruler array data from two genomic samples enables the identification of structural variation between the samples. In an empirical test between two closely related haploid strains of yeast ruler arrays detected 78% of the structural variants larger than 100 bp.

  7. Comparative genomics reveals insights into avian genome evolution and adaptation

    DEFF Research Database (Denmark)

    Zhang, Guojie; Li, Cai; Li, Qiye

    2014-01-01

    Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, ...

  8. The dynamic evolutionary history of the bananaquit (Coereba flaveola) in the Caribbean revealed by a multigene analysis

    Science.gov (United States)

    2008-01-01

    Background The bananaquit (Coereba flaveola) is a small nectivorous and frugivorous emberizine bird (order Passeriformes) that is an abundant resident throughout the Caribbean region. We used multi-gene analyses to investigate the evolutionary history of this species throughout its distribution in the West Indies and in South and Middle America. We sequenced six mitochondrial genes (3744 base pairs) and three nuclear genes (2049 base pairs) for forty-four bananaquits and three outgroup species. We infer the ancestral area of the present-day bananaquit populations, report on the species' phylogenetic, biogeographic and evolutionary history, and propose scenarios for its diversification and range expansion. Results Phylogenetic concordance between mitochondrial and nuclear genes at the base of the bananaquit phylogeny supported a West Indian origin for continental populations. Multi-gene analysis showing genetic remnants of successive colonization events in the Lesser Antilles reinforced earlier research demonstrating that bananaquits alternate periods of invasiveness and colonization with biogeographic quiescence. Although nuclear genes provided insufficient information at the tips of the tree to further evaluate relationships of closely allied but strongly supported mitochondrial DNA clades, the discrepancy between mitochondrial and nuclear data in the population of Dominican Republic suggested that the mitochondrial genome was recently acquired by introgression from Jamaica. Conclusion This study represents one of the most complete phylogeographic analyses of its kind and reveals three patterns that are not commonly appreciated in birds: (1) island to mainland colonization, (2) multiple expansion phases, and (3) mitochondrial genome replacement. The detail revealed by this analysis will guide evolutionary analyses of populations in archipelagos such as the West Indies, which include islands varying in size, age, and geological history. Our results suggest that

  9. The dynamic evolutionary history of the bananaquit (Coereba flaveola in the Caribbean revealed by a multigene analysis

    Directory of Open Access Journals (Sweden)

    Ricklefs Robert E

    2008-08-01

    Full Text Available Abstract Background The bananaquit (Coereba flaveola is a small nectivorous and frugivorous emberizine bird (order Passeriformes that is an abundant resident throughout the Caribbean region. We used multi-gene analyses to investigate the evolutionary history of this species throughout its distribution in the West Indies and in South and Middle America. We sequenced six mitochondrial genes (3744 base pairs and three nuclear genes (2049 base pairs for forty-four bananaquits and three outgroup species. We infer the ancestral area of the present-day bananaquit populations, report on the species' phylogenetic, biogeographic and evolutionary history, and propose scenarios for its diversification and range expansion. Results Phylogenetic concordance between mitochondrial and nuclear genes at the base of the bananaquit phylogeny supported a West Indian origin for continental populations. Multi-gene analysis showing genetic remnants of successive colonization events in the Lesser Antilles reinforced earlier research demonstrating that bananaquits alternate periods of invasiveness and colonization with biogeographic quiescence. Although nuclear genes provided insufficient information at the tips of the tree to further evaluate relationships of closely allied but strongly supported mitochondrial DNA clades, the discrepancy between mitochondrial and nuclear data in the population of Dominican Republic suggested that the mitochondrial genome was recently acquired by introgression from Jamaica. Conclusion This study represents one of the most complete phylogeographic analyses of its kind and reveals three patterns that are not commonly appreciated in birds: (1 island to mainland colonization, (2 multiple expansion phases, and (3 mitochondrial genome replacement. The detail revealed by this analysis will guide evolutionary analyses of populations in archipelagos such as the West Indies, which include islands varying in size, age, and geological history. Our

  10. Genomic changes associated with the evolutionary transition of an insect gut symbiont into a blood-borne pathogen.

    Science.gov (United States)

    Segers, Francisca Hid; Kešnerová, Lucie; Kosoy, Michael; Engel, Philipp

    2017-05-01

    The genus Bartonella comprises facultative intracellular bacteria with a unique lifestyle. After transmission by blood-sucking arthropods they colonize the erythrocytes of mammalian hosts causing acute and chronic infectious diseases. Although the pathogen-host interaction is well understood, little is known about the evolutionary origin of the infection strategy manifested by Bartonella species. Here we analyzed six genomes of Bartonella apis, a honey bee gut symbiont that to date represents the closest relative of pathogenic Bartonella species. Comparative genomics revealed that B. apis encodes a large set of vertically inherited genes for amino acid and cofactor biosynthesis and nitrogen metabolism. Most pathogenic bartonellae have lost these ancestral functions, but acquired specific virulence factors and expanded a vertically inherited gene family for harvesting cofactors from the blood. However, the deeply rooted pathogen Bartonella tamiae has retained many of the ancestral genome characteristics reflecting an evolutionary intermediate state toward a host-restricted intraerythrocytic lifestyle. Our findings suggest that the ancestor of the pathogen Bartonella was a gut symbiont of insects and that the adaptation to blood-feeding insects facilitated colonization of the mammalian bloodstream. This study highlights the importance of comparative genomics among pathogens and non-pathogenic relatives to understand disease emergence within an evolutionary-ecological framework.

  11. Comparative genomics reveals evidence of marine adaptation in Salinispora species

    Science.gov (United States)

    2012-01-01

    Background Actinobacteria represent a consistent component of most marine bacterial communities yet little is known about the mechanisms by which these Gram-positive bacteria adapt to life in the marine environment. Here we employed a phylogenomic approach to identify marine adaptation genes in marine Actinobacteria. The focus was on the obligate marine actinomycete genus Salinispora and the identification of marine adaptation genes that have been acquired from other marine bacteria. Results Functional annotation, comparative genomics, and evidence of a shared evolutionary history with bacteria from hyperosmotic environments were used to identify a pool of more than 50 marine adaptation genes. An Actinobacterial species tree was used to infer the likelihood of gene gain or loss in accounting for the distribution of each gene. Acquired marine adaptation genes were associated with electron transport, sodium and ABC transporters, and channels and pores. In addition, the loss of a mechanosensitive channel gene appears to have played a major role in the inability of Salinispora strains to grow following transfer to low osmotic strength media. Conclusions The marine Actinobacteria for which genome sequences are available are broadly distributed throughout the Actinobacterial phylogenetic tree and closely related to non-marine forms suggesting they have been independently introduced relatively recently into the marine environment. It appears that the acquisition of transporters in Salinispora spp. represents a major marine adaptation while gene loss is proposed to play a role in the inability of this genus to survive outside of the marine environment. This study reveals fundamental differences between marine adaptations in Gram-positive and Gram-negative bacteria and no common genetic basis for marine adaptation among the Actinobacteria analyzed. PMID:22401625

  12. Genome-wide identification, characterization, and evolutionary analysis of flowering genes in radish (Raphanus sativus L.).

    Science.gov (United States)

    Wang, Jinglei; Qiu, Yang; Cheng, Feng; Chen, Xiaohua; Zhang, Xiaohui; Wang, Haiping; Song, Jiangping; Duan, Mengmeng; Yang, Haohui; Li, Xixiang

    2017-12-19

    Radish (Raphanus sativus L.) belongs to the family Brassicaceae, and is an economically important root crop grown worldwide. Flowering is necessary for plant propagation, but it is also an important agronomic trait influencing R. sativus fleshy taproot yield and quality in the case of an imbalance between vegetative and reproductive growth. There is currently a lack of detailed information regarding the pathways regulating the flowering genes or their evolution in R. sativus. The release of the R. sativus genome sequence provides an opportunity to identify and characterize the flowering genes using a comparative genomics approach. We identified 254 R. sativus flowering genes based on sequence similarities and analyses of syntenic regions. The genes were unevenly distributed on the various chromosomes. Furthermore, we discovered the existence of R. sativus core function genes in the flowering regulatory network, which revealed that basic flowering pathways are relatively conserved between Arabidopsis thaliana and R. sativus. Additional comparisons with Brassica oleracea and Brassica rapa indicated that the retained flowering genes differed among species after genome triplication events. The R. sativus flowering genes were preferentially retained, especially those associated with gibberellin signaling and metabolism. Moreover, analyses of selection pressures suggested that the genes in vernalization and autonomous pathways were more variable than the genes in other R. sativus flowering pathways. Our results revealed that the core flowering genes are conserved between R. sativus and A. thaliana to a certain extent. Moreover, the copy number variation and functional differentiation of the homologous genes in R. sativus increased the complexity of the flowering regulatory networks after genome polyploidization. Our study provides an integrated framework for the R. sativus flowering pathways and insights into the evolutionary relationships between R. sativus flowering

  13. Genomic signatures of evolutionary transitions from solitary to group living

    DEFF Research Database (Denmark)

    Kapheim, Karen M.; Pan, Hailin; Li, Cai

    2015-01-01

    . First, many important genes show evidence of neutral evolution as a consequence of relaxed selection with increasing social complexity. Second, there is no single road map to eusociality; independent evolutionary transitions in sociality have independent genetic underpinnings. Third, though clearly...

  14. Microsatellite landscape evolutionary dynamics across 450 million years of vertebrate genome evolution.

    Science.gov (United States)

    Adams, Richard H; Blackmon, Heath; Reyes-Velasco, Jacobo; Schield, Drew R; Card, Daren C; Andrew, Audra L; Waynewood, Nyimah; Castoe, Todd A

    2016-05-01

    The evolutionary dynamics of simple sequence repeats (SSRs or microsatellites) across the vertebrate tree of life remain largely undocumented and poorly understood. In this study, we analyzed patterns of genomic microsatellite abundance and evolution across 71 vertebrate genomes. The highest abundances of microsatellites exist in the genomes of ray-finned fishes, squamate reptiles, and mammals, while crocodilian, turtle, and avian genomes exhibit reduced microsatellite landscapes. We used comparative methods to infer evolutionary rates of change in microsatellite abundance across vertebrates and to highlight particular lineages that have experienced unusually high or low rates of change in genomic microsatellite abundance. Overall, most variation in microsatellite content, abundance, and evolutionary rate is observed among major lineages of reptiles, yet we found that several deeply divergent clades (i.e., squamate reptiles and mammals) contained relatively similar genomic microsatellite compositions. Archosauromorph reptiles (turtles, crocodilians, and birds) exhibit reduced genomic microsatellite content and the slowest rates of microsatellite evolution, in contrast to squamate reptile genomes that have among the highest rates of microsatellite evolution. Substantial branch-specific shifts in SSR content in primates, monotremes, rodents, snakes, and fish are also evident. Collectively, our results support multiple major shifts in microsatellite genomic landscapes among vertebrates.

  15. Evolutionary genomics of archaeal viruses: unique viral genomes in the third domain of life

    DEFF Research Database (Denmark)

    Prangishvili, D.; Garrett, R. A.; Koonin, E.

    2006-01-01

    . In accord with this distinction, the sequenced genomes of euryarchaeal viruses encode many proteins homologous to bacteriophage capsid proteins. In contrast, initial analysis of the crenarchaeal viral genomes revealed no relationships with bacteriophages and, generally, very few proteins with detectable...... homologs. Here we describe a re-analysis of the proteins encoded by archaeal viruses, with an emphasis on comparative genomics of the unique viruses of Crenarchaeota. Detailed examination of conserved domains and motifs uncovered a significant number of previously unnoticed homologous relationships among...... the proteins of crenarchaeal viruses and between viral proteins and those from cellular life forms and allowed functional predictions for some of these conserved genes. A small pool of genes is shared by overlapping subsets of crenarchaeal viruses, in a general analogy with the metagenome structure...

  16. Population genomics reveals chromosome-scale heterogeneous evolution in a protoploid yeast.

    Science.gov (United States)

    Friedrich, Anne; Jung, Paul; Reisser, Cyrielle; Fischer, Gilles; Schacherer, Joseph

    2015-01-01

    Yeast species represent an ideal model system for population genomic studies but large-scale polymorphism surveys have only been reported for species of the Saccharomyces genus so far. Hence, little is known about intraspecific diversity and evolution in yeast. To obtain a new insight into the evolutionary forces shaping natural populations, we sequenced the genomes of an expansive worldwide collection of isolates from a species distantly related to Saccharomyces cerevisiae: Lachancea kluyveri (formerly S. kluyveri). We identified 6.5 million single nucleotide polymorphisms and showed that a large introgression event of 1 Mb of GC-rich sequence in the chromosomal arm probably occurred in the last common ancestor of all L. kluyveri strains. Our population genomic data clearly revealed that this 1-Mb region underwent a molecular evolution pattern very different from the rest of the genome. It is characterized by a higher recombination rate, with a dramatically elevated A:T → G:C substitution rate, which is the signature of an increased GC-biased gene conversion. In addition, the predicted base composition at equilibrium demonstrates that the chromosome-scale compositional heterogeneity will persist after the genome has reached mutational equilibrium. Altogether, the data presented herein clearly show that distinct recombination and substitution regimes can coexist and lead to different evolutionary patterns within a single genome. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  17. gmos: Rapid Detection of Genome Mosaicism over Short Evolutionary Distances.

    Science.gov (United States)

    Domazet-Lošo, Mirjana; Domazet-Lošo, Tomislav

    2016-01-01

    Prokaryotic and viral genomes are often altered by recombination and horizontal gene transfer. The existing methods for detecting recombination are primarily aimed at viral genomes or sets of loci, since the expensive computation of underlying statistical models often hinders the comparison of complete prokaryotic genomes. As an alternative, alignment-free solutions are more efficient, but cannot map (align) a query to subject genomes. To address this problem, we have developed gmos (Genome MOsaic Structure), a new program that determines the mosaic structure of query genomes when compared to a set of closely related subject genomes. The program first computes local alignments between query and subject genomes and then reconstructs the query mosaic structure by choosing the best local alignment for each query region. To accomplish the analysis quickly, the program mostly relies on pairwise alignments and constructs multiple sequence alignments over short overlapping subject regions only when necessary. This fine-tuned implementation achieves an efficiency comparable to an alignment-free tool. The program performs well for simulated and real data sets of closely related genomes and can be used for fast recombination detection; for instance, when a new prokaryotic pathogen is discovered. As an example, gmos was used to detect genome mosaicism in a pathogenic Enterococcus faecium strain compared to seven closely related genomes. The analysis took less than two minutes on a single 2.1 GHz processor. The output is available in fasta format and can be visualized using an accessory program, gmosDraw (freely available with gmos).

  18. The ancient evolutionary origins of Scleractinia revealed by azooxanthellate corals

    Science.gov (United States)

    2011-01-01

    Background Scleractinian corals are currently a focus of major interest because of their ecological importance and the uncertain fate of coral reefs in the face of increasing anthropogenic pressure. Despite this, remarkably little is known about the evolutionary origins of corals. The Scleractinia suddenly appear in the fossil record about 240 Ma, but the range of morphological variation seen in these Middle Triassic fossils is comparable to that of modern scleractinians, implying much earlier origins that have so far remained elusive. A significant weakness in reconstruction(s) of early coral evolution is that deep-sea corals have been poorly represented in molecular phylogenetic analyses. Results By adding new data from a large and representative range of deep-water species to existing molecular datasets and applying a relaxed molecular clock, we show that two exclusively deep-sea families, the Gardineriidae and Micrabaciidae, diverged prior to the Complexa/Robusta coral split around 425 Ma, thereby pushing the evolutionary origin of scleractinian corals deep into the Paleozoic. Conclusions The early divergence and distinctive morphologies of the extant gardineriid and micrabaciid corals suggest a link with Ordovician "scleractiniamorph" fossils that were previously assumed to represent extinct anthozoan skeletonized lineages. Therefore, scleractinian corals most likely evolved from Paleozoic soft-bodied ancestors. Modern shallow-water Scleractinia, which are dependent on symbionts, appear to have had several independent origins from solitary, non-symbiotic precursors. The Scleractinia have survived periods of massive climate change in the past, suggesting that as a lineage they may be less vulnerable to future changes than often assumed. PMID:22034946

  19. The ancient evolutionary origins of Scleractinia revealed by azooxanthellate corals.

    Science.gov (United States)

    Stolarski, Jarosław; Kitahara, Marcelo V; Miller, David J; Cairns, Stephen D; Mazur, Maciej; Meibom, Anders

    2011-10-28

    Scleractinian corals are currently a focus of major interest because of their ecological importance and the uncertain fate of coral reefs in the face of increasing anthropogenic pressure. Despite this, remarkably little is known about the evolutionary origins of corals. The Scleractinia suddenly appear in the fossil record about 240 Ma, but the range of morphological variation seen in these Middle Triassic fossils is comparable to that of modern scleractinians, implying much earlier origins that have so far remained elusive. A significant weakness in reconstruction(s) of early coral evolution is that deep-sea corals have been poorly represented in molecular phylogenetic analyses. By adding new data from a large and representative range of deep-water species to existing molecular datasets and applying a relaxed molecular clock, we show that two exclusively deep-sea families, the Gardineriidae and Micrabaciidae, diverged prior to the Complexa/Robusta coral split around 425 Ma, thereby pushing the evolutionary origin of scleractinian corals deep into the Paleozoic. The early divergence and distinctive morphologies of the extant gardineriid and micrabaciid corals suggest a link with Ordovician "scleractiniamorph" fossils that were previously assumed to represent extinct anthozoan skeletonized lineages. Therefore, scleractinian corals most likely evolved from Paleozoic soft-bodied ancestors. Modern shallow-water Scleractinia, which are dependent on symbionts, appear to have had several independent origins from solitary, non-symbiotic precursors. The Scleractinia have survived periods of massive climate change in the past, suggesting that as a lineage they may be less vulnerable to future changes than often assumed.

  20. The ancient evolutionary origins of Scleractinia revealed by azooxanthellate corals

    Directory of Open Access Journals (Sweden)

    Stolarski Jarosław

    2011-10-01

    Full Text Available Abstract Background Scleractinian corals are currently a focus of major interest because of their ecological importance and the uncertain fate of coral reefs in the face of increasing anthropogenic pressure. Despite this, remarkably little is known about the evolutionary origins of corals. The Scleractinia suddenly appear in the fossil record about 240 Ma, but the range of morphological variation seen in these Middle Triassic fossils is comparable to that of modern scleractinians, implying much earlier origins that have so far remained elusive. A significant weakness in reconstruction(s of early coral evolution is that deep-sea corals have been poorly represented in molecular phylogenetic analyses. Results By adding new data from a large and representative range of deep-water species to existing molecular datasets and applying a relaxed molecular clock, we show that two exclusively deep-sea families, the Gardineriidae and Micrabaciidae, diverged prior to the Complexa/Robusta coral split around 425 Ma, thereby pushing the evolutionary origin of scleractinian corals deep into the Paleozoic. Conclusions The early divergence and distinctive morphologies of the extant gardineriid and micrabaciid corals suggest a link with Ordovician "scleractiniamorph" fossils that were previously assumed to represent extinct anthozoan skeletonized lineages. Therefore, scleractinian corals most likely evolved from Paleozoic soft-bodied ancestors. Modern shallow-water Scleractinia, which are dependent on symbionts, appear to have had several independent origins from solitary, non-symbiotic precursors. The Scleractinia have survived periods of massive climate change in the past, suggesting that as a lineage they may be less vulnerable to future changes than often assumed.

  1. The Complete Plastid Genome Sequence of the Secondarily Nonphotosynthetic Alga Cryptomonas paramecium: Reduction, Compaction, and Accelerated Evolutionary Rate

    Science.gov (United States)

    Donaher, Natalie; Tanifuji, Goro; Onodera, Naoko T.; Malfatti, Stephanie A.; Chain, Patrick S. G.; Hara, Yoshiaki

    2009-01-01

    The cryptomonads are a group of unicellular algae that acquired photosynthesis through the engulfment of a red algal cell, a process called secondary endosymbiosis. Here, we present the complete plastid genome sequence of the secondarily nonphotosynthetic species Cryptomonas paramecium CCAP977/2a. The ∼78 kilobase pair (Kbp) C. paramecium genome contains 82 predicted protein genes, 29 transfer RNA genes, and a single pseudogene (atpF). The C. paramecium plastid genome is approximately 50 Kbp smaller than those of the photosynthetic cryptomonads Guillardia theta and Rhodomonas salina; 71 genes present in the G. theta and/or R. salina plastid genomes are missing in C. paramecium. The pet, psa, and psb photosynthetic gene families are almost entirely absent. Interestingly, the ribosomal RNA operon, present as inverted repeats in most plastid genomes (including G. theta and R. salina), exists as a single copy in C. paramecium. The G + C content (38%) is higher in C. paramecium than in other cryptomonad plastid genomes, and C. paramecium plastid genes are characterized by significantly different codon usage patterns and increased evolutionary rates. The content and structure of the C. paramecium plastid genome provides insight into the changes associated with recent loss of photosynthesis in a predominantly photosynthetic group of algae and reveals features shared with the plastid genomes of other secondarily nonphotosynthetic eukaryotes. PMID:20333213

  2. ECRbase: Database of Evolutionary Conserved Regions, Promoters, and Transcription Factor Binding Sites in Vertebrate Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Loots, G; Ovcharenko, I

    2006-08-08

    Evolutionary conservation of DNA sequences provides a tool for the identification of functional elements in genomes. We have created a database of evolutionary conserved regions (ECRs) in vertebrate genomes entitled ECRbase that is constructed from a collection of pairwise vertebrate genome alignments produced by the ECR Browser database. ECRbase features a database of syntenic blocks that recapitulate the evolution of rearrangements in vertebrates and a collection of promoters in all vertebrate genomes presented in the database. The database also contains a collection of annotated transcription factor binding sites (TFBS) in all ECRs and promoter elements. ECRbase currently includes human, rhesus macaque, dog, opossum, rat, mouse, chicken, frog, zebrafish, and two pufferfish genomes. It is freely accessible at http://ECRbase.dcode.org.

  3. Integrating phylogenetics, phylogeography and population genetics through genomes and evolutionary theory.

    Science.gov (United States)

    Cutter, Asher D

    2013-12-01

    Evolutionary theory is primed to synthesize microevolutionary processes with macroevolutionary divergence by taking advantage of multilocus multispecies genomic data in the molecular evolutionary analysis of biodiversity. While coalescent theory bridges across timescales to facilitate this integration, it is important to appreciate the assumptions, caveats, and recent theoretical advances so as to most effectively exploit genomic analysis. Here I outline the connections between population processes and phylogeny, with special attention to how genomic features play into underlying predictions. I discuss empirical and theoretical complications, and solutions, relating to recombination and multifurcating genealogical processes, predictions about how genome structure affects gene tree heterogeneity, and practical choices in genome sequencing and analysis. I illustrate the conceptual implications and practical benefits of how genomic features generate predictable patterns of discordance of gene trees and species trees along genomes, for example, as a consequence of how regions of low recombination and sex linkage interact with natural selection and with the accumulation of reproductive incompatibilities in speciation. Moreover, treating population genetic parameters as characters to be mapped onto phylogenies offers a new way to understand the evolutionary drivers of diversity within and differentiation between populations. Despite a number of challenges conferred by genomic information, the melding of phylogenetics, phylogeography and population genetics into integrative molecular evolution is poised to improve our understanding of biodiversity at all levels. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Characterization and evolutionary landscape of AmnSINE1 in Amniota genomes.

    Science.gov (United States)

    Hirakawa, Mika; Nishihara, Hidenori; Kanehisa, Minoru; Okada, Norihiro

    2009-07-15

    Discovery of a large number of conserved non-coding elements (CNEs) in vertebrate genomes provides a cornerstone to elucidate molecular mechanisms of macroevolution. Extensive comparative genomics has proven that transposons such as short interspersed elements (SINEs) were an important source of CNEs. We recently characterized AmnSINE1, a SINE family in Amniota genomes, some of which are present in CNEs, and demonstrated that two AmnSINE1 loci play an important role in mammalian-specific brain development by functioning as an enhancer (Sasaki et al. Proc. Natl. Acad. Sci. USA 2008). To get more information about AmnSINE1s, we here performed a multi-species search for AmnSINE1, and revealed the distribution and evolutionary history of these SINEs in amniote genomes. The number of AmnSINE1 regions in amniotes ranged from 160 to 1200; the number in the eutherians were under 500 and the largest was that in chicken. Phylogenetic analysis established that each AmnSINE1 locus has evolved uniquely, primarily since the divergence of mammals from reptiles. These results support the notion that AmnSINE1s were amplified as an ancient retroposon in a common ancestor of Amniota and subsequently have survived for 300 Myr because of functions acquired by mutation-coupled exaptation prior mammalian radiation. On the basis of sequence homology and conserved synteny, we detected the orthologs of AmnSINE1 for candidates of further enhancer analysis, which are more conserved than two loci that were shown to have been involved in mammalian brain development. The present work provides a comprehensive data set to test the role of AmnSINE1s, many of which were exapted and contributed to mammalian macroevolution.

  5. Single-Molecule FISH Reveals Non-selective Packaging of Rift Valley Fever Virus Genome Segments

    NARCIS (Netherlands)

    Wichgers Schreur, Paul J.; Kortekaas, Jeroen

    2016-01-01

    The bunyavirus genome comprises a small (S), medium (M), and large (L) RNA segment of negative polarity. Although genome segmentation confers evolutionary advantages by enabling genome reassortment events with related viruses, genome segmentation also complicates genome replication and packaging.

  6. gmos: Rapid Detection of Genome Mosaicism over Short Evolutionary Distances.

    Directory of Open Access Journals (Sweden)

    Mirjana Domazet-Lošo

    Full Text Available Prokaryotic and viral genomes are often altered by recombination and horizontal gene transfer. The existing methods for detecting recombination are primarily aimed at viral genomes or sets of loci, since the expensive computation of underlying statistical models often hinders the comparison of complete prokaryotic genomes. As an alternative, alignment-free solutions are more efficient, but cannot map (align a query to subject genomes. To address this problem, we have developed gmos (Genome MOsaic Structure, a new program that determines the mosaic structure of query genomes when compared to a set of closely related subject genomes. The program first computes local alignments between query and subject genomes and then reconstructs the query mosaic structure by choosing the best local alignment for each query region. To accomplish the analysis quickly, the program mostly relies on pairwise alignments and constructs multiple sequence alignments over short overlapping subject regions only when necessary. This fine-tuned implementation achieves an efficiency comparable to an alignment-free tool. The program performs well for simulated and real data sets of closely related genomes and can be used for fast recombination detection; for instance, when a new prokaryotic pathogen is discovered. As an example, gmos was used to detect genome mosaicism in a pathogenic Enterococcus faecium strain compared to seven closely related genomes. The analysis took less than two minutes on a single 2.1 GHz processor. The output is available in fasta format and can be visualized using an accessory program, gmosDraw (freely available with gmos.

  7. Genome fluctuations in cyanobacteria reflect evolutionary, developmental and adaptive traits

    Science.gov (United States)

    2011-01-01

    Background Cyanobacteria belong to an ancient group of photosynthetic prokaryotes with pronounced variations in their cellular differentiation strategies, physiological capacities and choice of habitat. Sequencing efforts have shown that genomes within this phylum are equally diverse in terms of size and protein-coding capacity. To increase our understanding of genomic changes in the lineage, the genomes of 58 contemporary cyanobacteria were analysed for shared and unique orthologs. Results A total of 404 protein families, present in all cyanobacterial genomes, were identified. Two of these are unique to the phylum, corresponding to an AbrB family transcriptional regulator and a gene that escapes functional annotation although its genomic neighbourhood is conserved among the organisms examined. The evolution of cyanobacterial genome sizes involves a mix of gains and losses in the clade encompassing complex cyanobacteria, while a single event of reduction is evident in a clade dominated by unicellular cyanobacteria. Genome sizes and gene family copy numbers evolve at a higher rate in the former clade, and multi-copy genes were predominant in large genomes. Orthologs unique to cyanobacteria exhibiting specific characteristics, such as filament formation, heterocyst differentiation, diazotrophy and symbiotic competence, were also identified. An ancestral character reconstruction suggests that the most recent common ancestor of cyanobacteria had a genome size of approx. 4.5 Mbp and 1678 to 3291 protein-coding genes, 4%-6% of which are unique to cyanobacteria today. Conclusions The different rates of genome-size evolution and multi-copy gene abundance suggest two routes of genome development in the history of cyanobacteria. The expansion strategy is driven by gene-family enlargment and generates a broad adaptive potential; while the genome streamlining strategy imposes adaptations to highly specific niches, also reflected in their different functional capacities. A few

  8. A replicated climate change field experiment reveals rapid evolutionary response in an ecologically important soil invertebrate

    DEFF Research Database (Denmark)

    Bataillon, Thomas; Galtier, Nicolas; Bernard, Aurelien

    2016-01-01

    associated to changes in soil temperature and soil moisture. This shows an evolutionaryresponse to realistic climate change happening over short-time scale, and calls for incorporating evolution into modelspredicting future response of species to climate change. It also shows that designed climate change...... experiments coupled with genome sequencing offer great potential to test for the occurrence (or lack) of an evolutionary response.......Whether species can respond evolutionarily to current climate change is crucial for the persistence of many species. Yet, very few studies have examined genetic responses to climate change in manipulated experiments carried out innatural field conditions. We examined the evolutionary response...

  9. Genome-driven evolutionary game theory helps understand the rise of metabolic interdependencies in microbial communities.

    Science.gov (United States)

    Zomorrodi, Ali R; Segrè, Daniel

    2017-11-16

    Metabolite exchanges in microbial communities give rise to ecological interactions that govern ecosystem diversity and stability. It is unclear, however, how the rise of these interactions varies across metabolites and organisms. Here we address this question by integrating genome-scale models of metabolism with evolutionary game theory. Specifically, we use microbial fitness values estimated by metabolic models to infer evolutionarily stable interactions in multi-species microbial "games". We first validate our approach using a well-characterized yeast cheater-cooperator system. We next perform over 80,000 in silico experiments to infer how metabolic interdependencies mediated by amino acid leakage in Escherichia coli vary across 189 amino acid pairs. While most pairs display shared patterns of inter-species interactions, multiple deviations are caused by pleiotropy and epistasis in metabolism. Furthermore, simulated invasion experiments reveal possible paths to obligate cross-feeding. Our study provides genomically driven insight into the rise of ecological interactions, with implications for microbiome research and synthetic ecology.

  10. 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.

  11. Genome-Wide Motif Statistics are Shaped by DNA Binding Proteins over Evolutionary Time Scales

    Directory of Open Access Journals (Sweden)

    Long Qian

    2016-10-01

    Full Text Available The composition of a genome with respect to all possible short DNA motifs impacts the ability of DNA binding proteins to locate and bind their target sites. Since nonfunctional DNA binding can be detrimental to cellular functions and ultimately to organismal fitness, organisms could benefit from reducing the number of nonfunctional DNA binding sites genome wide. Using in vitro measurements of binding affinities for a large collection of DNA binding proteins, in multiple species, we detect a significant global avoidance of weak binding sites in genomes. We demonstrate that the underlying evolutionary process leaves a distinct genomic hallmark in that similar words have correlated frequencies, a signal that we detect in all species across domains of life. We consider the possibility that natural selection against weak binding sites contributes to this process, and using an evolutionary model we show that the strength of selection needed to maintain global word compositions is on the order of point mutation rates. Likewise, we show that evolutionary mechanisms based on interference of protein-DNA binding with replication and mutational repair processes could yield similar results and operate with similar rates. On the basis of these modeling and bioinformatic results, we conclude that genome-wide word compositions have been molded by DNA binding proteins acting through tiny evolutionary steps over time scales spanning millions of generations.

  12. Genes but not genomes reveal bacterial domestication of Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Delphine Passerini

    Full Text Available BACKGROUND: The population structure and diversity of Lactococcus lactis subsp. lactis, a major industrial bacterium involved in milk fermentation, was determined at both gene and genome level. Seventy-six lactococcal isolates of various origins were studied by different genotyping methods and thirty-six strains displaying unique macrorestriction fingerprints were analyzed by a new multilocus sequence typing (MLST scheme. This gene-based analysis was compared to genomic characteristics determined by pulsed-field gel electrophoresis (PFGE. METHODOLOGY/PRINCIPAL FINDINGS: The MLST analysis revealed that L. lactis subsp. lactis is essentially clonal with infrequent intra- and intergenic recombination; also, despite its taxonomical classification as a subspecies, it displays a genetic diversity as substantial as that within several other bacterial species. Genome-based analysis revealed a genome size variability of 20%, a value typical of bacteria inhabiting different ecological niches, and that suggests a large pan-genome for this subspecies. However, the genomic characteristics (macrorestriction pattern, genome or chromosome size, plasmid content did not correlate to the MLST-based phylogeny, with strains from the same sequence type (ST differing by up to 230 kb in genome size. CONCLUSION/SIGNIFICANCE: The gene-based phylogeny was not fully consistent with the traditional classification into dairy and non-dairy strains but supported a new classification based on ecological separation between "environmental" strains, the main contributors to the genetic diversity within the subspecies, and "domesticated" strains, subject to recent genetic bottlenecks. Comparison between gene- and genome-based analyses revealed little relationship between core and dispensable genome phylogenies, indicating that clonal diversification and phenotypic variability of the "domesticated" strains essentially arose through substantial genomic flux within the dispensable

  13. Landscape community genomics: understanding eco-evolutionary processes in complex environments

    Science.gov (United States)

    Hand, Brian K.; Lowe, Winsor H.; Kovach, Ryan P.; Muhlfeld, Clint C.; Luikart, Gordon

    2015-01-01

    Extrinsic factors influencing evolutionary processes are often categorically lumped into interactions that are environmentally (e.g., climate, landscape) or community-driven, with little consideration of the overlap or influence of one on the other. However, genomic variation is strongly influenced by complex and dynamic interactions between environmental and community effects. Failure to consider both effects on evolutionary dynamics simultaneously can lead to incomplete, spurious, or erroneous conclusions about the mechanisms driving genomic variation. We highlight the need for a landscape community genomics (LCG) framework to help to motivate and challenge scientists in diverse fields to consider a more holistic, interdisciplinary perspective on the genomic evolution of multi-species communities in complex environments.

  14. Novel genomic rearrangements mediated by multiple genetic elements in Streptococcus pyogenes M23ND confer potential for evolutionary persistence.

    Science.gov (United States)

    Bao, Yun-Juan; Liang, Zhong; Mayfield, Jeffrey A; McShan, William M; Lee, Shaun W; Ploplis, Victoria A; Castellino, Francis J

    2016-08-01

    Symmetric genomic rearrangements around replication axes in genomes are commonly observed in prokaryotic genomes, including Group A Streptococcus (GAS). However, asymmetric rearrangements are rare. Our previous studies showed that the hypervirulent invasive GAS strain, M23ND, containing an inactivated transcriptional regulator system, covRS, exhibits unique extensive asymmetric rearrangements, which reconstructed a genomic structure distinct from other GAS genomes. In the current investigation, we identified the rearrangement events and examined the genetic consequences and evolutionary implications underlying the rearrangements. By comparison with a close phylogenetic relative, M18-MGAS8232, we propose a molecular model wherein a series of asymmetric rearrangements have occurred in M23ND, involving translocations, inversions and integrations mediated by multiple factors, viz., rRNA-comX (factor for late competence), transposons and phage-encoded gene segments. Assessments of the cumulative gene orientations and GC skews reveal that the asymmetric genomic rearrangements did not affect the general genomic integrity of the organism. However, functional distributions reveal re-clustering of a broad set of CovRS-regulated actively transcribed genes, including virulence factors and metabolic genes, to the same leading strand, with high confidence (p-value ~10-10). The re-clustering of the genes suggests a potential selection advantage for the spatial proximity to the transcription complexes, which may contain the global transcriptional regulator, CovRS, and other RNA polymerases. Their proximities allow for efficient transcription of the genes required for growth, virulence and persistence. A new paradigm of survival strategies of GAS strains is provided through multiple genomic rearrangements, while, at the same time, maintaining genomic integrity.

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

    Directory of Open Access Journals (Sweden)

    Steven E. Massey

    2015-04-01

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

  16. Evolutionary forces shaping genomic islands of population differentiation in humans

    Directory of Open Access Journals (Sweden)

    Hofer Tamara

    2012-03-01

    Full Text Available Abstract Background Levels of differentiation among populations depend both on demographic and selective factors: genetic drift and local adaptation increase population differentiation, which is eroded by gene flow and balancing selection. We describe here the genomic distribution and the properties of genomic regions with unusually high and low levels of population differentiation in humans to assess the influence of selective and neutral processes on human genetic structure. Methods Individual SNPs of the Human Genome Diversity Panel (HGDP showing significantly high or low levels of population differentiation were detected under a hierarchical-island model (HIM. A Hidden Markov Model allowed us to detect genomic regions or islands of high or low population differentiation. Results Under the HIM, only 1.5% of all SNPs are significant at the 1% level, but their genomic spatial distribution is significantly non-random. We find evidence that local adaptation shaped high-differentiation islands, as they are enriched for non-synonymous SNPs and overlap with previously identified candidate regions for positive selection. Moreover there is a negative relationship between the size of islands and recombination rate, which is stronger for islands overlapping with genes. Gene ontology analysis supports the role of diet as a major selective pressure in those highly differentiated islands. Low-differentiation islands are also enriched for non-synonymous SNPs, and contain an overly high proportion of genes belonging to the 'Oncogenesis' biological process. Conclusions Even though selection seems to be acting in shaping islands of high population differentiation, neutral demographic processes might have promoted the appearance of some genomic islands since i as much as 20% of islands are in non-genic regions ii these non-genic islands are on average two times shorter than genic islands, suggesting a more rapid erosion by recombination, and iii most loci are

  17. Signatures of selection in tilapia revealed by whole genome resequencing.

    Science.gov (United States)

    Xia, Jun Hong; Bai, Zhiyi; Meng, Zining; Zhang, Yong; Wang, Le; Liu, Feng; Jing, Wu; Wan, Zi Yi; Li, Jiale; Lin, Haoran; Yue, Gen Hua

    2015-09-16

    Natural selection and selective breeding for genetic improvement have left detectable signatures within the genome of a species. Identification of selection signatures is important in evolutionary biology and for detecting genes that facilitate to accelerate genetic improvement. However, selection signatures, including artificial selection and natural selection, have only been identified at the whole genome level in several genetically improved fish species. Tilapia is one of the most important genetically improved fish species in the world. Using next-generation sequencing, we sequenced the genomes of 47 tilapia individuals. We identified a total of 1.43 million high-quality SNPs and found that the LD block sizes ranged from 10-100 kb in tilapia. We detected over a hundred putative selective sweep regions in each line of tilapia. Most selection signatures were located in non-coding regions of the tilapia genome. The Wnt signaling, gonadotropin-releasing hormone receptor and integrin signaling pathways were under positive selection in all improved tilapia lines. Our study provides a genome-wide map of genetic variation and selection footprints in tilapia, which could be important for genetic studies and accelerating genetic improvement of tilapia.

  18. Complete genome of the cellulolytic thermophile Acidothermus cellulolyticus 11B provides insights into its ecophysiological and evolutionary adaptations

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Gary [Los Alamos National Laboratory; Detter, John C [Los Alamos National Laboratory; Bruce, David C [Los Alamos National Laboratory; Challacombe, Jean F [Los Alamos National Laboratory; Brettin, Thomas S [Los Alamos National Laboratory; Necsulea, Anamaria [UNIV LYON; Daubin, Vincent [UNIV LYON; Medigue, Claudine [GENOSCOPE; Adney, William S [NREL; Xu, Xin C [UC DAVIS; Lapidus, Alla [JGI; Pujic, Pierre [UNIV LYON; Berry, Alison M [UC DAVIS; Barabote, Ravi D [UC DAVIS; Leu, David [UC DAVIS; Normand, Phillipe [UNIV LYON

    2009-01-01

    We present here the complete 2.4 MB genome of the actinobacterial thermophile, Acidothermus cellulolyticus 11B, that surprisingly reveals thermophilic amino acid usage in only the cytosolic subproteome rather than its whole proteome. Thermophilic amino acid usage in the partial proteome implies a recent, ongoing evolution of the A. cellulolyticus genome since its divergence about 200-250 million years ago from its closest phylogenetic neighbor Frankia, a mesophilic plant symbiont. Differential amino acid usage in the predicted subproteomes of A. cellulolyticus likely reflects a stepwise evolutionary process of modern thermophiles in general. An unusual occurrence of higher G+C in the non-coding DNA than in the transcribed genome reinforces a late evolution from a higher G+C common ancestor. Comparative analyses of the A. cellulolyticus genome with those of Frankia and other closely-related actinobacteria revealed that A. cellulolyticus genes exhibit reciprocal purine preferences at the first and third codon positions, perhaps reflecting a subtle preference for the dinucleotide AG in its mRNAs, a possible adaptation to a thermophilic environment. Other interesting features in the genome of this cellulolytic, hot-springs dwelling prokaryote reveal streamlining for adaptation to its specialized ecological niche. These include a low occurrence of pseudo genes or mobile genetic elements, a flagellar gene complement previously unknown in this organism, and presence of laterally-acquired genomic islands of likely ecophysiological value. New glycoside hydrolases relevant for lignocellulosic biomass deconstruction were identified in the genome, indicating a diverse biomass-degrading enzyme repertoire several-fold greater than previously characterized, and significantly elevating the industrial value of this organism.

  19. Complete genome of the cellulolytic thermophile Acidothermus cellulolyticus 11B provides insights into its ecophysiological and evolutionary adaptations

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Gary [Los Alamos National Laboratory; Detter, Chris [Los Alamos National Laboratory; Bruce, David [Los Alamos National Laboratory; Challacome, Jean F [Los Alamos National Laboratory; Brettin, Thomas S [Los Alamos National Laboratory; Barabote, Ravi D [UC DAVIS; Leu, David [UC DAVIS; Normand, Philippe [CNRS, UNIV LYON; Necsula, Anamaria [CNRS, UNIV LYON; Daubin, Vincent [CNRS, UNIV LYON; Medigue, Claudine [CNRS/GENOSCOPE; Adney, William S [NREL; Xu, Xin C [UC DAVIS; Lapidus, Alla [DOE JOINT GENOME INST.; Pujic, Pierre [CNRS, UNIV LYON; Richardson, Paul [DOE JOINT GENOME INST; Berry, Alison M [UC DAVIS

    2008-01-01

    We present here the complete 2.4 MB genome of the actinobacterial thermophile, Acidothermus cellulolyticus lIB, that surprisingly reveals thermophilic amino acid usage in only the cytosolic subproteome rather than its whole proteome. Thermophilic amino acid usage in the partial proteome implies a recent, ongoing evolution of the A. cellulolyticus genome since its divergence about 200-250 million years ago from its closest phylogenetic neighbor Frankia, a mesophilic plant symbiont. Differential amino acid usage in the predicted subproteomes of A. cellulolyticus likely reflects a stepwise evolutionary process of modern thermophiles in general. An unusual occurrence of higher G+C in the non-coding DNA than in the transcribed genome reinforces a late evolution from a higher G+C common ancestor. Comparative analyses of the A. cellulolyticus genome with those of Frankia and other closely-related actinobacteria revealed that A. cellulolyticus genes exhibit reciprocal purine preferences at the first and third codon positions, perhaps reflecting a subtle preference for the dinucleotide AG in its mRNAs, a possible adaptation to a thermophilic environment. Other interesting features in the genome of this cellulolytic, hot-springs dwelling prokaryote reveal streamlining for adaptation to its specialized ecological niche. These include a low occurrence of pseudogenes or mobile genetic elements, a flagellar gene complement previously unknown in this organism, and presence of laterally-acquired genomic islands of likely ecophysiological value. New glycoside hydrolases relevant for lignocellulosic biomass deconstruction were identified in the genome, indicating a diverse biomass-degrading enzyme repertoire several-fold greater than previously characterized, and significantly elevating the industrial value of this organism.

  20. Evolutionary insights from suffix array-based genome sequence ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    2007-08-06

    Aug 6, 2007 ... matching and searching algorithms. With recent advances in sequencing technology, several genomes have been sequenced in the last few years, leading to an unprecedented growth of the sequence databases. Availability of information of such large magnitude has given rise to a new tide in biology ...

  1. Evolutionary Nephrology.

    Science.gov (United States)

    Chevalier, Robert L

    2017-05-01

    Progressive kidney disease follows nephron loss, hyperfiltration, and incomplete repair, a process described as "maladaptive." In the past 20 years, a new discipline has emerged that expands research horizons: evolutionary medicine. In contrast to physiologic (homeostatic) adaptation, evolutionary adaptation is the result of reproductive success that reflects natural selection. Evolutionary explanations for physiologically maladaptive responses can emerge from mismatch of the phenotype with environment or evolutionary tradeoffs. Evolutionary adaptation to a terrestrial environment resulted in a vulnerable energy-consuming renal tubule and a hypoxic, hyperosmolar microenvironment. Natural selection favors successful energy investment strategy: energy is allocated to maintenance of nephron integrity through reproductive years, but this declines with increasing senescence after ~40 years of age. Risk factors for chronic kidney disease include restricted fetal growth or preterm birth (life history tradeoff resulting in fewer nephrons), evolutionary selection for APOL1 mutations (that provide resistance to trypanosome infection, a tradeoff), and modern life experience (Western diet mismatch leading to diabetes and hypertension). Current advances in genomics, epigenetics, and developmental biology have revealed proximate causes of kidney disease, but attempts to slow kidney disease remain elusive. Evolutionary medicine provides a complementary approach by addressing ultimate causes of kidney disease. Marked variation in nephron number at birth, nephron heterogeneity, and changing susceptibility to kidney injury throughout life history are the result of evolutionary processes. Combined application of molecular genetics, evolutionary developmental biology (evo-devo), developmental programming and life history theory may yield new strategies for prevention and treatment of chronic kidney disease.

  2. Application of resequencing to rice genomics, functional genomics and evolutionary analysis

    OpenAIRE

    Guo, Longbiao; Gao, Zhenyu; Qian, Qian

    2014-01-01

    Rice is a model system used for crop genomics studies. The completion of the rice genome draft sequences in 2002 not only accelerated functional genome studies, but also initiated a new era of resequencing rice genomes. Based on the reference genome in rice, next-generation sequencing (NGS) using the high-throughput sequencing system can efficiently accomplish whole genome resequencing of various genetic populations and diverse germplasm resources. Resequencing technology has been effectively...

  3. Evolutionary profiling reveals the heterogeneous origins of classes of human disease genes: implications for modeling disease genetics in animals.

    Science.gov (United States)

    Maxwell, Evan K; Schnitzler, Christine E; Havlak, Paul; Putnam, Nicholas H; Nguyen, Anh-Dao; Moreland, R Travis; Baxevanis, Andreas D

    2014-10-04

    The recent expansion of whole-genome sequence data available from diverse animal lineages provides an opportunity to investigate the evolutionary origins of specific classes of human disease genes. Previous studies have observed that human disease genes are of particularly ancient origin. While this suggests that many animal species have the potential to serve as feasible models for research on genes responsible for human disease, it is unclear whether this pattern has meaningful implications and whether it prevails for every class of human disease. We used a comparative genomics approach encompassing a broad phylogenetic range of animals with sequenced genomes to determine the evolutionary patterns exhibited by human genes associated with different classes of disease. Our results support previous claims that most human disease genes are of ancient origin but, more importantly, we also demonstrate that several specific disease classes have a significantly large proportion of genes that emerged relatively recently within the metazoans and/or vertebrates. An independent assessment of the synonymous to non-synonymous substitution rates of human disease genes found in mammals reveals that disease classes that arose more recently also display unexpected rates of purifying selection between their mammalian and human counterparts. Our results reveal the heterogeneity underlying the evolutionary origins of (and selective pressures on) different classes of human disease genes. For example, some disease gene classes appear to be of uncommonly recent (i.e., vertebrate-specific) origin and, as a whole, have been evolving at a faster rate within mammals than the majority of disease classes having more ancient origins. The novel patterns that we have identified may provide new insight into cases where studies using traditional animal models were unable to produce results that translated to humans. Conversely, we note that the larger set of disease classes do have ancient origins

  4. Virulent clones of Klebsiella pneumoniae: identification and evolutionary scenario based on genomic and phenotypic characterization.

    Directory of Open Access Journals (Sweden)

    Sylvain Brisse

    Full Text Available Klebsiella pneumoniae is found in the environment and as a harmless commensal, but is also a frequent nosocomial pathogen (causing urinary, respiratory and blood infections and the agent of specific human infections including Friedländer's pneumonia, rhinoscleroma and the emerging disease pyogenic liver abscess (PLA. The identification and precise definition of virulent clones, i.e. groups of strains with a single ancestor that are associated with particular infections, is critical to understand the evolution of pathogenicity from commensalism and for a better control of infections. We analyzed 235 K. pneumoniae isolates of diverse environmental and clinical origins by multilocus sequence typing, virulence gene content, biochemical and capsular profiling and virulence to mice. Phylogenetic analysis of housekeeping genes clearly defined clones that differ sharply by their clinical source and biological features. First, two clones comprising isolates of capsular type K1, clone CC23(K1 and clone CC82(K1, were strongly associated with PLA and respiratory infection, respectively. Second, only one of the two major disclosed K2 clones was highly virulent to mice. Third, strains associated with the human infections ozena and rhinoscleroma each corresponded to one monomorphic clone. Therefore, K. pneumoniae subsp. ozaenae and K. pneumoniae subsp. rhinoscleromatis should be regarded as virulent clones derived from K. pneumoniae. The lack of strict association of virulent capsular types with clones was explained by horizontal transfer of the cps operon, responsible for the synthesis of the capsular polysaccharide. Finally, the reduction of metabolic versatility observed in clones Rhinoscleromatis, Ozaenae and CC82(K1 indicates an evolutionary process of specialization to a pathogenic lifestyle. In contrast, clone CC23(K1 remains metabolically versatile, suggesting recent acquisition of invasive potential. In conclusion, our results reveal the existence of

  5. Evolutionary changes of multiple visual pigment genes in the complete genome of Pacific bluefin tuna.

    Science.gov (United States)

    Nakamura, Yoji; Mori, Kazuki; Saitoh, Kenji; Oshima, Kenshiro; Mekuchi, Miyuki; Sugaya, Takuma; Shigenobu, Yuya; Ojima, Nobuhiko; Muta, Shigeru; Fujiwara, Atushi; Yasuike, Motoshige; Oohara, Ichiro; Hirakawa, Hideki; Chowdhury, Vishwajit Sur; Kobayashi, Takanori; Nakajima, Kazuhiro; Sano, Motohiko; Wada, Tokio; Tashiro, Kosuke; Ikeo, Kazuho; Hattori, Masahira; Kuhara, Satoru; Gojobori, Takashi; Inouye, Kiyoshi

    2013-07-02

    Tunas are migratory fishes in offshore habitats and top predators with unique features. Despite their ecological importance and high market values, the open-ocean lifestyle of tuna, in which effective sensing systems such as color vision are required for capture of prey, has been poorly understood. To elucidate the genetic and evolutionary basis of optic adaptation of tuna, we determined the genome sequence of the Pacific bluefin tuna (Thunnus orientalis), using next-generation sequencing technology. A total of 26,433 protein-coding genes were predicted from 16,802 assembled scaffolds. From these, we identified five common fish visual pigment genes: red-sensitive (middle/long-wavelength sensitive; M/LWS), UV-sensitive (short-wavelength sensitive 1; SWS1), blue-sensitive (SWS2), rhodopsin (RH1), and green-sensitive (RH2) opsin genes. Sequence comparison revealed that tuna's RH1 gene has an amino acid substitution that causes a short-wave shift in the absorption spectrum (i.e., blue shift). Pacific bluefin tuna has at least five RH2 paralogs, the most among studied fishes; four of the proteins encoded may be tuned to blue light at the amino acid level. Moreover, phylogenetic analysis suggested that gene conversions have occurred in each of the SWS2 and RH2 loci in a short period. Thus, Pacific bluefin tuna has undergone evolutionary changes in three genes (RH1, RH2, and SWS2), which may have contributed to detecting blue-green contrast and measuring the distance to prey in the blue-pelagic ocean. These findings provide basic information on behavioral traits of predatory fish and, thereby, could help to improve the technology to culture such fish in captivity for resource management.

  6. Ancient Ethiopian genome reveals extensive Eurasian admixture in Eastern Africa

    KAUST Repository

    Gallego Llorente, M.

    2015-10-09

    Characterizing genetic diversity in Africa is a crucial step for most analyses reconstructing the evolutionary history of anatomically modern humans. However, historic migrations from Eurasia into Africa have affected many contemporary populations, confounding inferences. Here, we present a 12.5×coverage ancient genome of an Ethiopian male ("Mota") who lived approximately 4500 years ago. We use this genome to demonstrate that the Eurasian backflow into Africa came from a population closely related to Early Neolithic farmers, who had colonized Europe 4000 years earlier. The extent of this backflow was much greater than previously reported, reaching all the way to Central, West, and Southern Africa, affecting even populations such as Yoruba and Mbuti, previously thought to be relatively unadmixed, who harbor 6 to 7% Eurasian ancestry.

  7. Evolutionary genomics of the cold-adapted diatom Fragilariopsis cylindrus

    KAUST Repository

    Mock, Thomas

    2017-01-17

    The Southern Ocean houses a diverse and productive community of organisms. Unicellular eukaryotic diatoms are the main primary producers in this environment, where photosynthesis is limited by low concentrations of dissolved iron and large seasonal fluctuations in light, temperature and the extent of sea ice. How diatoms have adapted to this extreme environment is largely unknown. Here we present insights into the genome evolution of a cold-adapted diatom from the Southern Ocean, Fragilariopsis cylindrus, based on a comparison with temperate diatoms. We find that approximately 24.7 per cent of the diploid F. cylindrus genome consists of genetic loci with alleles that are highly divergent (15.1 megabases of the total genome size of 61.1 megabases). These divergent alleles were differentially expressed across environmental conditions, including darkness, low iron, freezing, elevated temperature and increased CO2. Alleles with the largest ratio of non-synonymous to synonymous nucleotide substitutions also show the most pronounced condition-dependent expression, suggesting a correlation between diversifying selection and allelic differentiation. Divergent alleles may be involved in adaptation to environmental fluctuations in the Southern Ocean.

  8. Next generation sequencing reveals genome downsizing in allotetraploid Nicotiana tabacum, predominantly through the elimination of paternally derived repetitive DNAs.

    Science.gov (United States)

    Renny-Byfield, Simon; Chester, Michael; Kovařík, Ales; Le Comber, Steven C; Grandbastien, Marie-Angèle; Deloger, Marc; Nichols, Richard A; Macas, Jiri; Novák, Petr; Chase, Mark W; Leitch, Andrew R

    2011-10-01

    We used next generation sequencing to characterize and compare the genomes of the recently derived allotetraploid, Nicotiana tabacum (downsizing and sequences loss across most repeat types. This is particularly evident amongst the Ty3-gypsy retroelements in which all families identified are underrepresented in N. tabacum, as is 35S ribosomal DNA. Analysis of all repetitive DNA sequences indicates the T-genome of N. tabacum has experienced greater sequence loss than the S-genome, revealing preferential loss of paternally derived repetitive DNAs at a genome-wide level. Thus, the three genomes of N. sylvestris, N. tomentosiformis, and N. tabacum have experienced different evolutionary trajectories, with genomes that are dynamic, stable, and downsized, respectively.

  9. The Douglas-Fir Genome Sequence Reveals Specialization of the Photosynthetic Apparatus in Pinaceae

    Directory of Open Access Journals (Sweden)

    David B. Neale

    2017-09-01

    Full Text Available A reference genome sequence for Pseudotsuga menziesii var. menziesii (Mirb. Franco (Coastal Douglas-fir is reported, thus providing a reference sequence for a third genus of the family Pinaceae. The contiguity and quality of the genome assembly far exceeds that of other conifer reference genome sequences (contig N50 = 44,136 bp and scaffold N50 = 340,704 bp. Incremental improvements in sequencing and assembly technologies are in part responsible for the higher quality reference genome, but it may also be due to a slightly lower exact repeat content in Douglas-fir vs. pine and spruce. Comparative genome annotation with angiosperm species reveals gene-family expansion and contraction in Douglas-fir and other conifers which may account for some of the major morphological and physiological differences between the two major plant groups. Notable differences in the size of the NDH-complex gene family and genes underlying the functional basis of shade tolerance/intolerance were observed. This reference genome sequence not only provides an important resource for Douglas-fir breeders and geneticists but also sheds additional light on the evolutionary processes that have led to the divergence of modern angiosperms from the more ancient gymnosperms.

  10. Screening of duplicated loci reveals hidden divergence patterns in a complex salmonid genome

    Science.gov (United States)

    Limborg, Morten T.; Larson, Wesley; Seeb, Lisa W.; Seeb, James E.

    2017-01-01

    A whole-genome duplication (WGD) doubles the entire genomic content of a species and is thought to have catalysed adaptive radiation in some polyploid-origin lineages. However, little is known about general consequences of a WGD because gene duplicates (i.e., paralogs) are commonly filtered in genomic studies; such filtering may remove substantial portions of the genome in data sets from polyploid-origin species. We demonstrate a new method that enables genome-wide scans for signatures of selection at both nonduplicated and duplicated loci by taking locus-specific copy number into account. We apply this method to RAD sequence data from different ecotypes of a polyploid-origin salmonid (Oncorhynchus nerka) and reveal signatures of divergent selection that would have been missed if duplicated loci were filtered. We also find conserved signatures of elevated divergence at pairs of homeologous chromosomes with residual tetrasomic inheritance, suggesting that joint evolution of some nondiverged gene duplicates may affect the adaptive potential of these genes. These findings illustrate that including duplicated loci in genomic analyses enables novel insights into the evolutionary consequences of WGDs and local segmental gene duplications.

  11. Correlated evolutionary rates across genomic compartments in Annonaceae.

    Science.gov (United States)

    Hoekstra, Paul H; Wieringa, Jan J; Smets, Erik; Brandão, Rita D; Lopes, Jenifer de Carvalho; Erkens, Roy H J; Chatrou, Lars W

    2017-09-01

    The molecular clock hypothesis is an important concept in biology. Deviations from a constant rate of nucleotide substitution have been found widely among lineages, genomes, genes and individual sites. Phylogenetic research can accommodate for these differences in applying specific models of evolution. Lineage-specific rate heterogeneity however can generate bi- or multimodal distributions of substitution rates across the branches of a tree and this may mislead phylogenetic inferences with currently available models. The plant family Annonaceae is an excellent case to study lineage-specific rate heterogeneity. The two major sister subfamilies, Annonoideae and Malmeoideae, have shown great discrepancies in branch lengths. We used high-throughput sequencing data of 72 genes, 99 spacers and 16 introns from 24 chloroplast genomes and nuclear ribosomal DNA of 23 species to study the molecular rate of evolution in Annonaceae. In all analyses, longer branch lengths and/or higher substitution rates were found for the Annonoideae compared to the Malmeoideae. The Annonaceae had wide variability in chloroplast length, ranging from minimal 175,684bp to 201,723 for Annonoideae and minimal 152,357 to 170,985bp in Malmeoideae, mostly reflecting variation in inverted-repeat length. The Annonoideae showed a higher GC-content in the conserved parts of the chloroplast genome and higher omega (dN/dS)-ratios than the Malmeoideae, which could indicate less stringent purifying selection, a pattern that has been found in groups with small population sizes. This study generates new insights into the processes causing lineage-specific rate heterogeneity, which could lead to improved phylogenetic methods. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Whole-genome sequencing of Oryza brachyantha reveals mechanisms underlying Oryza genome evolution.

    Science.gov (United States)

    Chen, Jinfeng; Huang, Quanfei; Gao, Dongying; Wang, Junyi; Lang, Yongshan; Liu, Tieyan; Li, Bo; Bai, Zetao; Luis Goicoechea, Jose; Liang, Chengzhi; Chen, Chengbin; Zhang, Wenli; Sun, Shouhong; Liao, Yi; Zhang, Xuemei; Yang, Lu; Song, Chengli; Wang, Meijiao; Shi, Jinfeng; Liu, Geng; Liu, Junjie; Zhou, Heling; Zhou, Weili; Yu, Qiulin; An, Na; Chen, Yan; Cai, Qingle; Wang, Bo; Liu, Binghang; Min, Jiumeng; Huang, Ying; Wu, Honglong; Li, Zhenyu; Zhang, Yong; Yin, Ye; Song, Wenqin; Jiang, Jiming; Jackson, Scott A; Wing, Rod A; Wang, Jun; Chen, Mingsheng

    2013-01-01

    The wild species of the genus Oryza contain a largely untapped reservoir of agronomically important genes for rice improvement. Here we report the 261-Mb de novo assembled genome sequence of Oryza brachyantha. Low activity of long-terminal repeat retrotransposons and massive internal deletions of ancient long-terminal repeat elements lead to the compact genome of Oryza brachyantha. We model 32,038 protein-coding genes in the Oryza brachyantha genome, of which only 70% are located in collinear positions in comparison with the rice genome. Analysing breakpoints of non-collinear genes suggests that double-strand break repair through non-homologous end joining has an important role in gene movement and erosion of collinearity in the Oryza genomes. Transition of euchromatin to heterochromatin in the rice genome is accompanied by segmental and tandem duplications, further expanded by transposable element insertions. The high-quality reference genome sequence of Oryza brachyantha provides an important resource for functional and evolutionary studies in the genus Oryza.

  13. Comparative and Evolutionary Analyses of Meloidogyne spp. Based on Mitochondrial Genome Sequences

    Science.gov (United States)

    García, Laura Evangelina; Sánchez-Puerta, M. Virginia

    2015-01-01

    Molecular taxonomy and evolution of nematodes have been recently the focus of several studies. Mitochondrial sequences were proposed as an alternative for precise identification of Meloidogyne species, to study intraspecific variability and to follow maternal lineages. We characterized the mitochondrial genomes (mtDNAs) of the root knot nematodes M. floridensis, M. hapla and M. incognita. These were AT rich (81–83%) and highly compact, encoding 12 proteins, 2 rRNAs, and 22 tRNAs. Comparisons with published mtDNAs of M. chitwoodi, M. incognita (another strain) and M. graminicola revealed that they share protein and rRNA gene order but differ in the order of tRNAs. The mtDNAs of M. floridensis and M. incognita were strikingly similar (97–100% identity for all coding regions). In contrast, M. floridensis, M. chitwoodi, M. hapla and M. graminicola showed 65–84% nucleotide identity for coding regions. Variable mitochondrial sequences are potentially useful for evolutionary and taxonomic studies. We developed a molecular taxonomic marker by sequencing a highly-variable ~2 kb mitochondrial region, nad5-cox1, from 36 populations of root-knot nematodes to elucidate relationships within the genus Meloidogyne. Isolates of five species formed monophyletic groups and showed little intraspecific variability. We also present a thorough analysis of the mitochondrial region cox2-rrnS. Phylogenies based on either mitochondrial region had good discrimination power but could not discriminate between M. arenaria, M. incognita and M. floridensis. PMID:25799071

  14. Inference and Evolutionary Analysis of Genome-Scale Regulatory Networks in Large Phylogenies.

    Science.gov (United States)

    Koch, Christopher; Konieczka, Jay; Delorey, Toni; Lyons, Ana; Socha, Amanda; Davis, Kathleen; Knaack, Sara A; Thompson, Dawn; O'Shea, Erin K; Regev, Aviv; Roy, Sushmita

    2017-05-24

    Changes in transcriptional regulatory networks can significantly contribute to species evolution and adaptation. However, identification of genome-scale regulatory networks is an open challenge, especially in non-model organisms. Here, we introduce multi-species regulatory network learning (MRTLE), a computational approach that uses phylogenetic structure, sequence-specific motifs, and transcriptomic data, to infer the regulatory networks in different species. Using simulated data from known networks and transcriptomic data from six divergent yeasts, we demonstrate that MRTLE predicts networks with greater accuracy than existing methods because it incorporates phylogenetic information. We used MRTLE to infer the structure of the transcriptional networks that control the osmotic stress responses of divergent, non-model yeast species and then validated our predictions experimentally. Interrogating these networks reveals that gene duplication promotes network divergence across evolution. Taken together, our approach facilitates study of regulatory network evolutionary dynamics across multiple poorly studied species. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  15. Deep Sequencing of Norovirus Genomes Defines Evolutionary Patterns in an Urban Tropical Setting

    Science.gov (United States)

    Cotten, Matthew; Petrova, Velislava; Phan, My V. T.; Rabaa, Maia A.; Watson, Simon J.; Ong, Swee Hoe; Baker, Stephen

    2014-01-01

    ABSTRACT Norovirus is a highly transmissible infectious agent that causes epidemic gastroenteritis in susceptible children and adults. Norovirus infections can be severe and can be initiated from an exceptionally small number of viral particles. Detailed genome sequence data are useful for tracking norovirus transmission and evolution. To address this need, we have developed a whole-genome deep-sequencing method that generates entire genome sequences from small amounts of clinical specimens. This novel approach employs an algorithm for reverse transcription and PCR amplification primer design using all of the publically available norovirus sequence data. Deep sequencing and de novo assembly were used to generate norovirus genomes from a large set of diarrheal patients attending three hospitals in Ho Chi Minh City, Vietnam, over a 2.5-year period. Positive-selection analysis and direct examination of protein changes in the virus over time identified codons in the regions encoding proteins VP1, p48 (NS1-2), and p22 (NS4) under positive selection and expands the known targets of norovirus evolutionary pressure. IMPORTANCE The high transmissibility and rapid evolutionary rate of norovirus, combined with a short-lived host immune responses, are thought to be the reasons why the virus causes the majority of pediatric viral diarrhea cases. The evolutionary patterns of this RNA virus have been described in detail for only a portion of the virus genome and never for a virus from a detailed urban tropical setting. We provide a detailed sequence description of the noroviruses circulating in three Ho Chi Minh City hospitals over a 2.5-year period. This study identified patterns of virus change in known sites of host immune response and identified three additional regions of the virus genome under selection that were not previously recognized. In addition, the method described here provides a robust full-genome sequencing platform for community-based virus surveillance. PMID

  16. The ctenophore genome and the evolutionary origins of neural systems.

    Science.gov (United States)

    Moroz, Leonid L; Kocot, Kevin M; Citarella, Mathew R; Dosung, Sohn; Norekian, Tigran P; Povolotskaya, Inna S; Grigorenko, Anastasia P; Dailey, Christopher; Berezikov, Eugene; Buckley, Katherine M; Ptitsyn, Andrey; Reshetov, Denis; Mukherjee, Krishanu; Moroz, Tatiana P; Bobkova, Yelena; Yu, Fahong; Kapitonov, Vladimir V; Jurka, Jerzy; Bobkov, Yuri V; Swore, Joshua J; Girardo, David O; Fodor, Alexander; Gusev, Fedor; Sanford, Rachel; Bruders, Rebecca; Kittler, Ellen; Mills, Claudia E; Rast, Jonathan P; Derelle, Romain; Solovyev, Victor V; Kondrashov, Fyodor A; Swalla, Billie J; Sweedler, Jonathan V; Rogaev, Evgeny I; Halanych, Kenneth M; Kohn, Andrea B

    2014-06-05

    The origins of neural systems remain unresolved. In contrast to other basal metazoans, ctenophores (comb jellies) have both complex nervous and mesoderm-derived muscular systems. These holoplanktonic predators also have sophisticated ciliated locomotion, behaviour and distinct development. Here we present the draft genome of Pleurobrachia bachei, Pacific sea gooseberry, together with ten other ctenophore transcriptomes, and show that they are remarkably distinct from other animal genomes in their content of neurogenic, immune and developmental genes. Our integrative analyses place Ctenophora as the earliest lineage within Metazoa. This hypothesis is supported by comparative analysis of multiple gene families, including the apparent absence of HOX genes, canonical microRNA machinery, and reduced immune complement in ctenophores. Although two distinct nervous systems are well recognized in ctenophores, many bilaterian neuron-specific genes and genes of 'classical' neurotransmitter pathways either are absent or, if present, are not expressed in neurons. Our metabolomic and physiological data are consistent with the hypothesis that ctenophore neural systems, and possibly muscle specification, evolved independently from those in other animals.

  17. Evolutionary Growth of Genome Representations on Artificial Cellular Organisms with Indirect Encodings.

    Science.gov (United States)

    Nichele, Stefano; Giskeødegård, Andreas; Tufte, Gunnar

    2016-01-01

    Evolutionary design targets systems of continuously increasing complexity. Thus, indirect developmental mappings are often a necessity. Varying the amount of genotype information changes the cardinality of the mapping, which in turn affects the developmental process. An open question is how to find the genotype size and representation in which a developmental solution would fit. A restricted pool of genes may not be large enough to encode a solution or may need complex heuristics to find a realistic size. On the other hand, using the whole set of possible regulatory combinations may be intractable. In nature, the genomes of biological organisms are not fixed in size; they slowly evolve and acquire new genes by random gene duplications. Such incremental growth of genome information can be beneficial also in the artificial domain. For an evolutionary and developmental (evo-devo) system based on cellular automata, we investigate an incremental evolutionary growth of genomes without any a priori knowledge on the necessary genotype size. Evolution starts with simple solutions in a low-dimensional space and incrementally increases the genotype complexity by means of gene duplication, allowing the evolution of scalable genomes that are able to adapt genetic information content while compactness and efficiency are retained. The results are consistent when the target phenotypic complexity, the geometry size, and the number of cell states are scaled up.

  18. Metagenomic and whole-genome analysis reveals new lineages of gokushoviruses and biogeographic separation in the sea

    Directory of Open Access Journals (Sweden)

    Jessica Myriam Labonté

    2013-12-01

    Full Text Available Much remains to be learned about single-stranded (ss DNA viruses in natural systems, and the evolutionary relationships among them. One of the eight recognized families of ssDNA viruses is the Microviridae, a group of viruses infecting bacteria. In this study we used metagenomic analysis, genome assembly and amplicon sequencing of purified ssDNA to show that bacteriophages belonging to the subfamily Gokushovirinae within the Microviridae are genetically diverse and widespread members of marine microbial communities. Metagenomic analysis of coastal samples from the Gulf of Mexico and British Columbia, Canada, revealed numerous sequences belonging to gokushoviruses and allowed the assembly of five putative genomes with an organization similar to chlamydiamicroviruses. Fragment recruitment to these genomes from different metagenomic data sets is consistent with gokushovirus genotypes being restricted to specific oceanic regions. Conservation among the assembled genomes allowed the design of degenerate primers that target an 800 bp fragment from the gene encoding the major capsid protein. Sequences could be amplified from coastal temperate and subtropical waters, but not from samples collected from the Arctic Ocean, or freshwater lakes. Phylogenetic analysis revealed that most sequences were distantly related to those from cultured representatives. Moreover, the sequences fell into at least seven distinct evolutionary groups, most of which were represented by one of the assembled metagenomes. Our results greatly expand the known sequence space for gokushoviruses, and reveal biogeographic separation and new evolutionary lineages of gokushoviruses in the oceans.

  19. Evolutionary insights into scleractinian corals using comparative genomic hybridizations.

    KAUST Repository

    Aranda, Manuel

    2012-09-21

    Coral reefs belong to the most ecologically and economically important ecosystems on our planet. Yet, they are under steady decline worldwide due to rising sea surface temperatures, disease, and pollution. Understanding the molecular impact of these stressors on different coral species is imperative in order to predict how coral populations will respond to this continued disturbance. The use of molecular tools such as microarrays has provided deep insight into the molecular stress response of corals. Here, we have performed comparative genomic hybridizations (CGH) with different coral species to an Acropora palmata microarray platform containing 13,546 cDNA clones in order to identify potentially rapidly evolving genes and to determine the suitability of existing microarray platforms for use in gene expression studies (via heterologous hybridization).

  20. Genomic imprinting and the evolutionary psychology of human kinship.

    Science.gov (United States)

    Haig, David

    2011-06-28

    Genomic imprinting is predicted to influence behaviors that affect individuals to whom an actor has different degrees of matrilineal and patrilineal kinship (asymmetric kin). Effects of imprinted genes are not predicted in interactions with nonrelatives or with individuals who are equally related to the actor's maternally and paternally derived genes (unless a gene also has pleiotropic effects on fitness of asymmetric kin). Long-term mating bonds are common in most human populations, but dissolution of marriage has always affected a significant proportion of mated pairs. Children born in a new union are asymmetric kin of children born in a previous union. Therefore, the innate dispositions of children toward parents and sibs are expected to be sensitive to cues of marital stability, and these dispositions may be subject to effects of imprinted genes.

  1. Evolutionary genomics of grape (Vitis vinifera ssp. vinifera) domestication.

    Science.gov (United States)

    Zhou, Yongfeng; Massonnet, Mélanie; Sanjak, Jaleal S; Cantu, Dario; Gaut, Brandon S

    2017-10-31

    We gathered genomic data from grapes (Vitis vinifera ssp. vinifera), a clonally propagated perennial crop, to address three ongoing mysteries about plant domestication. The first is the duration of domestication; archaeological evidence suggests that domestication occurs over millennia, but genetic evidence indicates that it can occur rapidly. We estimated that our wild and cultivated grape samples diverged ∼22,000 years ago and that the cultivated lineage experienced a steady decline in population size (Ne ) thereafter. The long decline may reflect low-intensity management by humans before domestication. The second mystery is the identification of genes that contribute to domestication phenotypes. In cultivated grapes, we identified candidate-selected genes that function in sugar metabolism, flower development, and stress responses. In contrast, candidate-selected genes in the wild sample were limited to abiotic and biotic stress responses. A genomic region of high divergence corresponded to the sex determination region and included a candidate male sterility factor and additional genes with sex-specific expression. The third mystery concerns the cost of domestication. Annual crops accumulate putatively deleterious variants, in part due to strong domestication bottlenecks. The domestication of perennial crops differs from that of annuals in several ways, including the intensity of bottlenecks, and it is not yet clear if they accumulate deleterious variants. We found that grape accessions contained 5.2% more deleterious variants than wild individuals, and these were more often in a heterozygous state. Using forward simulations, we confirm that clonal propagation leads to the accumulation of recessive deleterious mutations but without decreasing fitness. Copyright © 2017 the Author(s). Published by PNAS.

  2. Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMcahon, Katherine D.; Mamlstrom, Rex R.

    2014-05-12

    Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ecotype model? of diversification, but not previously observed in natural populations.

  3. Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMahon, Katherine D.; Malmstrom, Rex R.

    2014-06-18

    Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ‘ecotype model’ of diversification, but not previously observed in natural populations.

  4. Structural genomics reveals EVE as a new ASCH/PUA-related domain.

    Science.gov (United States)

    Bertonati, Claudia; Punta, Marco; Fischer, Markus; Yachdav, Guy; Forouhar, Farhad; Zhou, Weihong; Kuzin, Alexander P; Seetharaman, Jayaraman; Abashidze, Mariam; Ramelot, Theresa A; Kennedy, Michael A; Cort, John R; Belachew, Adam; Hunt, John F; Tong, Liang; Montelione, Gaetano T; Rost, Burkhard

    2009-05-15

    We report on several proteins recently solved by structural genomics consortia, in particular by the Northeast Structural Genomics consortium (NESG). The proteins considered in this study differ substantially in their sequences but they share a similar structural core, characterized by a pseudobarrel five-stranded beta sheet. This core corresponds to the PUA domain-like architecture in the SCOP database. By connecting sequence information with structural knowledge, we characterize a new subgroup of these proteins that we propose to be distinctly different from previously described PUA domain-like domains such as PUA proper or ASCH. We refer to these newly defined domains as EVE. Although EVE may have retained the ability of PUA domains to bind RNA, the available experimental and computational data suggests that both the details of its molecular function and its cellular function differ from those of other PUA domain-like domains. This study of EVE and its relatives illustrates how the combination of structure and genomics creates new insights by connecting a cornucopia of structures that map to the same evolutionary potential. Primary sequence information alone would have not been sufficient to reveal these evolutionary links.

  5. Structural genomics reveals EVE as a new ASCH/PUA-related domain

    Science.gov (United States)

    Bertonati, Claudia; Punta, Marco; Fischer, Markus; Yachdav, Guy; Forouhar, Farhad; Zhou, Weihong; Kuzin, Alexander P.; Seetharaman, Jayaraman; Abashidze, Mariam; Ramelot, Theresa A.; Kennedy, Michael A.; Cort, John R.; Belachew, Adam; Hunt, John F.; Tong, Liang; Montelione, Gaetano T.; Rost, Burkhard

    2014-01-01

    Summary We report on several proteins recently solved by structural genomics consortia, in particular by the Northeast Structural Genomics consortium (NESG). The proteins considered in this study differ substantially in their sequences but they share a similar structural core, characterized by a pseudobarrel five-stranded beta sheet. This core corresponds to the PUA domain-like architecture in the SCOP database. By connecting sequence information with structural knowledge, we characterize a new subgroup of these proteins that we propose to be distinctly different from previously described PUA domain-like domains such as PUA proper or ASCH. We refer to these newly defined domains as EVE. Although EVE may have retained the ability of PUA domains to bind RNA, the available experimental and computational data suggests that both the details of its molecular function and its cellular function differ from those of other PUA domain-like domains. This study of EVE and its relatives illustrates how the combination of structure and genomics creates new insights by connecting a cornucopia of structures that map to the same evolutionary potential. Primary sequence information alone would have not been sufficient to reveal these evolutionary links. PMID:19191354

  6. Diversity arrays technology (DArT for pan-genomic evolutionary studies of non-model organisms.

    Directory of Open Access Journals (Sweden)

    Karen E James

    Full Text Available BACKGROUND: High-throughput tools for pan-genomic study, especially the DNA microarray platform, have sparked a remarkable increase in data production and enabled a shift in the scale at which biological investigation is possible. The use of microarrays to examine evolutionary relationships and processes, however, is predominantly restricted to model or near-model organisms. METHODOLOGY/PRINCIPAL FINDINGS: This study explores the utility of Diversity Arrays Technology (DArT in evolutionary studies of non-model organisms. DArT is a hybridization-based genotyping method that uses microarray technology to identify and type DNA polymorphism. Theoretically applicable to any organism (even one for which no prior genetic data are available, DArT has not yet been explored in exclusively wild sample sets, nor extensively examined in a phylogenetic framework. DArT recovered 1349 markers of largely low copy-number loci in two lineages of seed-free land plants: the diploid fern Asplenium viride and the haploid moss Garovaglia elegans. Direct sequencing of 148 of these DArT markers identified 30 putative loci including four routinely sequenced for evolutionary studies in plants. Phylogenetic analyses of DArT genotypes reveal phylogeographic and substrate specificity patterns in A. viride, a lack of phylogeographic pattern in Australian G. elegans, and additive variation in hybrid or mixed samples. CONCLUSIONS/SIGNIFICANCE: These results enable methodological recommendations including procedures for detecting and analysing DArT markers tailored specifically to evolutionary investigations and practical factors informing the decision to use DArT, and raise evolutionary hypotheses concerning substrate specificity and biogeographic patterns. Thus DArT is a demonstrably valuable addition to the set of existing molecular approaches used to infer biological phenomena such as adaptive radiations, population dynamics, hybridization, introgression, ecological

  7. Genomes of coral dinoflagellate symbionts highlight evolutionary adaptations conducive to a symbiotic lifestyle

    KAUST Repository

    Aranda, Manuel

    2016-12-22

    Despite half a century of research, the biology of dinoflagellates remains enigmatic: they defy many functional and genetic traits attributed to typical eukaryotic cells. Genomic approaches to study dinoflagellates are often stymied due to their large, multi-gigabase genomes. Members of the genus Symbiodinium are photosynthetic endosymbionts of stony corals that provide the foundation of coral reef ecosystems. Their smaller genome sizes provide an opportunity to interrogate evolution and functionality of dinoflagellate genomes and endosymbiosis. We sequenced the genome of the ancestral Symbiodinium microadriaticum and compared it to the genomes of the more derived Symbiodinium minutum and Symbiodinium kawagutii and eukaryote model systems as well as transcriptomes from other dinoflagellates. Comparative analyses of genome and transcriptome protein sets show that all dinoflagellates, not only Symbiodinium, possess significantly more transmembrane transporters involved in the exchange of amino acids, lipids, and glycerol than other eukaryotes. Importantly, we find that only Symbiodinium harbor an extensive transporter repertoire associated with the provisioning of carbon and nitrogen. Analyses of these transporters show species-specific expansions, which provides a genomic basis to explain differential compatibilities to an array of hosts and environments, and highlights the putative importance of gene duplications as an evolutionary mechanism in dinoflagellates and Symbiodinium.

  8. Evolutionary genomics and adaptive evolution of the hedgehog gene family (Shh, Ihh and Dhh) in vertebrates

    DEFF Research Database (Denmark)

    Pereira, Joana; Johnson, Warren E.; O'Brien, Stephen J.

    2014-01-01

    . In this study, we used comparative genomic and adaptive evolutionary analyses to characterize the evolution of the Hh genes in vertebrates following the two major whole genome duplication (WGD) events. To overcome the lack of Hh-coding sequences on avian publicly available databases, we used an extensive...... the catalytic domain. The structural regions around the ion-binding site were identified to be under positive selection in the signaling domain. These findings contrast with those observed in invertebrates, where different lineages that experienced gene duplication retained similar selective constraints...

  9. CGAT: a comparative genome analysis tool for visualizing alignments in the analysis of complex evolutionary changes between closely related genomes

    Directory of Open Access Journals (Sweden)

    Kobayashi Ichizo

    2006-10-01

    Full Text Available Abstract Background The recent accumulation of closely related genomic sequences provides a valuable resource for the elucidation of the evolutionary histories of various organisms. However, although numerous alignment calculation and visualization tools have been developed to date, the analysis of complex genomic changes, such as large insertions, deletions, inversions, translocations and duplications, still presents certain difficulties. Results We have developed a comparative genome analysis tool, named CGAT, which allows detailed comparisons of closely related bacteria-sized genomes mainly through visualizing middle-to-large-scale changes to infer underlying mechanisms. CGAT displays precomputed pairwise genome alignments on both dotplot and alignment viewers with scrolling and zooming functions, and allows users to move along the pre-identified orthologous alignments. Users can place several types of information on this alignment, such as the presence of tandem repeats or interspersed repetitive sequences and changes in G+C contents or codon usage bias, thereby facilitating the interpretation of the observed genomic changes. In addition to displaying precomputed alignments, the viewer can dynamically calculate the alignments between specified regions; this feature is especially useful for examining the alignment boundaries, as these boundaries are often obscure and can vary between programs. Besides the alignment browser functionalities, CGAT also contains an alignment data construction module, which contains various procedures that are commonly used for pre- and post-processing for large-scale alignment calculation, such as the split-and-merge protocol for calculating long alignments, chaining adjacent alignments, and ortholog identification. Indeed, CGAT provides a general framework for the calculation of genome-scale alignments using various existing programs as alignment engines, which allows users to compare the outputs of different

  10. Evolutionary changes of multiple visual pigment genes in the complete genome of Pacific bluefin tuna

    OpenAIRE

    Nakamura, Yoji; Mori, Kazuki; Saitoh, Kenji; Oshima, Kenshiro; Mekuchi, Miyuki; Sugaya, Takuma; Shigenobu, Yuya; Ojima, Nobuhiko; Muta, Shigeru; Fujiwara, Atushi; Yasuike, Motoshige; Oohara, Ichiro; Hirakawa, Hideki; Chowdhury, Vishwajit Sur; Kobayashi, Takanori

    2013-01-01

    Tunas are migratory fishes in offshore habitats and top predators with unique features. Despite their ecological importance and high market values, the open-ocean lifestyle of tuna, in which effective sensing systems such as color vision are required for capture of prey, has been poorly understood. To elucidate the genetic and evolutionary basis of optic adaptation of tuna, we determined the genome sequence of the Pacific bluefin tuna (Thunnus orientalis), using next-generation sequencing tec...

  11. Bioinformatic analysis of the neprilysin (M13 family of peptidases reveals complex evolutionary and functional relationships

    Directory of Open Access Journals (Sweden)

    Pinney John W

    2008-01-01

    Full Text Available Abstract Background The neprilysin (M13 family of endopeptidases are zinc-metalloenzymes, the majority of which are type II integral membrane proteins. The best characterised of this family is neprilysin, which has important roles in inactivating signalling peptides involved in modulating neuronal activity, blood pressure and the immune system. Other family members include the endothelin converting enzymes (ECE-1 and ECE-2, which are responsible for the final step in the synthesis of potent vasoconstrictor endothelins. The ECEs, as well as neprilysin, are considered valuable therapeutic targets for treating cardiovascular disease. Other members of the M13 family have not been functionally characterised, but are also likely to have biological roles regulating peptide signalling. The recent sequencing of animal genomes has greatly increased the number of M13 family members in protein databases, information which can be used to reveal evolutionary relationships and to gain insight into conserved biological roles. Results The phylogenetic analysis successfully resolved vertebrate M13 peptidases into seven classes, one of which appears to be specific to mammals, and insect genes into five functional classes and a series of expansions, which may include inactive peptidases. Nematode genes primarily resolved into groups containing no other taxa, bar the two nematode genes associated with Drosophila DmeNEP1 and DmeNEP4. This analysis reconstructed only one relationship between chordate and invertebrate clusters, that of the ECE sub-group and the DmeNEP3 related genes. Analysis of amino acid utilisation in the active site of M13 peptidases reveals a basis for their biochemical properties. A relatively invariant S1' subsite gives the majority of M13 peptidases their strong preference for hydrophobic residues in P1' position. The greater variation in the S2' subsite may be instrumental in determining the specificity of M13 peptidases for their substrates

  12. Targeted sequencing for high-resolution evolutionary analyses following genome duplication in salmonid fish: Proof of concept for key components of the insulin-like growth factor axis.

    Science.gov (United States)

    Lappin, Fiona M; Shaw, Rebecca L; Macqueen, Daniel J

    2016-12-01

    High-throughput sequencing has revolutionised comparative and evolutionary genome biology. It has now become relatively commonplace to generate multiple genomes and/or transcriptomes to characterize the evolution of large taxonomic groups of interest. Nevertheless, such efforts may be unsuited to some research questions or remain beyond the scope of some research groups. Here we show that targeted high-throughput sequencing offers a viable alternative to study genome evolution across a vertebrate family of great scientific interest. Specifically, we exploited sequence capture and Illumina sequencing to characterize the evolution of key components from the insulin-like growth (IGF) signalling axis of salmonid fish at unprecedented phylogenetic resolution. The IGF axis represents a central governor of vertebrate growth and its core components were expanded by whole genome duplication in the salmonid ancestor ~95Ma. Using RNA baits synthesised to genes encoding the complete family of IGF binding proteins (IGFBP) and an IGF hormone (IGF2), we captured, sequenced and assembled orthologous and paralogous exons from species representing all ten salmonid genera. This approach generated 299 novel sequences, most as complete or near-complete protein-coding sequences. Phylogenetic analyses confirmed congruent evolutionary histories for all nineteen recognized salmonid IGFBP family members and identified novel salmonid-specific IGF2 paralogues. Moreover, we reconstructed the evolution of duplicated IGF axis paralogues across a replete salmonid phylogeny, revealing complex historic selection regimes - both ancestral to salmonids and lineage-restricted - that frequently involved asymmetric paralogue divergence under positive and/or relaxed purifying selection. Our findings add to an emerging literature highlighting diverse applications for targeted sequencing in comparative-evolutionary genomics. We also set out a viable approach to obtain large sets of nuclear genes for any

  13. Fish lateral line innovation: insights into the evolutionary genomic dynamics of a unique mechanosensory organ.

    Science.gov (United States)

    Philip, Siby; Machado, João Paulo; Maldonado, Emanuel; Vasconcelos, Vítor; O'Brien, Stephen J; Johnson, Warren E; Antunes, Agostinho

    2012-12-01

    The mechanosensory lateral line, found only in fishes and amphibians, is an important sense organ associated with aquatic life. Lateral line patterns differ among teleost, the most diverse vertebrate taxa, hypothetically in response to selective pressures from different aquatic habitats. In this article, we conduct evolutionary genomic analyses of 34 genes associated with lateral line system development in teleosts to elucidate the significance of contrasting evolutionary rates and changes in the protein coding sequences. We find that duplicated copies of these genes are preferentially retained in the teleost genomes and that episodic events of positive selection have occurred in 22 of the 30 postduplication branches. In general, teleost genes evolved at a faster rate relative to their tetrapod counterparts, and the mutation rates of 26 of the 34 genes differed among teleosts and tetrapods. We conclude that following whole genome duplication, evolutionary rates and episodic events of positive selection on the lateral line system development genes might have been one of the factors favoring the subsequent adaptive radiation of teleosts into diverse habitats. These results provide the foundation for further detailed explorations into lateral line system genes and the evolution of diverse phenotypes and adaptations.

  14. Tools for Accurate and Efficient Analysis of Complex Evolutionary Mechanisms in Microbial Genomes. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Nakhleh, Luay

    2014-03-12

    I proposed to develop computationally efficient tools for accurate detection and reconstruction of microbes' complex evolutionary mechanisms, thus enabling rapid and accurate annotation, analysis and understanding of their genomes. To achieve this goal, I proposed to address three aspects. (1) Mathematical modeling. A major challenge facing the accurate detection of HGT is that of distinguishing between these two events on the one hand and other events that have similar "effects." I proposed to develop a novel mathematical approach for distinguishing among these events. Further, I proposed to develop a set of novel optimization criteria for the evolutionary analysis of microbial genomes in the presence of these complex evolutionary events. (2) Algorithm design. In this aspect of the project, I proposed to develop an array of e cient and accurate algorithms for analyzing microbial genomes based on the formulated optimization criteria. Further, I proposed to test the viability of the criteria and the accuracy of the algorithms in an experimental setting using both synthetic as well as biological data. (3) Software development. I proposed the nal outcome to be a suite of software tools which implements the mathematical models as well as the algorithms developed.

  15. When COI barcodes deceive: complete genomes reveal introgression in hairstreaks.

    Science.gov (United States)

    Cong, Qian; Shen, Jinhui; Borek, Dominika; Robbins, Robert K; Opler, Paul A; Otwinowski, Zbyszek; Grishin, Nick V

    2017-02-08

    Two species of hairstreak butterflies from the genus Calycopis are known in the United States: C. cecrops and C. isobeon Analysis of mitochondrial COI barcodes of Calycopis revealed cecrops-like specimens from the eastern US with atypical barcodes that were 2.6% different from either USA species, but similar to Central American Calycopis species. To address the possibility that the specimens with atypical barcodes represent an undescribed cryptic species, we sequenced complete genomes of 27 Calycopis specimens of four species: C. cecrops, C. isobeon, C. quintana and C. bactra Some of these specimens were collected up to 60 years ago and preserved dry in museum collections, but nonetheless produced genomes as complete as fresh samples. Phylogenetic trees reconstructed using the whole mitochondrial and nuclear genomes were incongruent. While USA Calycopis with atypical barcodes grouped with Central American species C. quintana by mitochondria, nuclear genome trees placed them within typical USA C. cecrops in agreement with morphology, suggesting mitochondrial introgression. Nuclear genomes also show introgression, especially between C. cecrops and C. isobeon About 2.3% of each C. cecrops genome has probably (p-value COI barcodes and mitochondrial DNA for species identification or discovery. © 2017 The Author(s).

  16. Chromosomal instability in Afrotheria: fragile sites, evolutionary breakpoints and phylogenetic inference from genome sequence assemblies

    Directory of Open Access Journals (Sweden)

    Ruiz-Herrera Aurora

    2007-10-01

    Full Text Available Abstract Background Extant placental mammals are divided into four major clades (Laurasiatheria, Supraprimates, Xenarthra and Afrotheria. Given that Afrotheria is generally thought to root the eutherian tree in phylogenetic analysis of large nuclear gene data sets, the study of the organization of the genomes of afrotherian species provides new insights into the dynamics of mammalian chromosomal evolution. Here we test if there are chromosomal bands with a high tendency to break and reorganize in Afrotheria, and by analyzing the expression of aphidicolin-induced common fragile sites in three afrotherian species, whether these are coincidental with recognized evolutionary breakpoints. Results We described 29 fragile sites in the aardvark (OAF genome, 27 in the golden mole (CAS, and 35 in the elephant-shrew (EED genome. We show that fragile sites are conserved among afrotherian species and these are correlated with evolutionary breakpoints when compared to the human (HSA genome. Inddition, by computationally scanning the newly released opossum (Monodelphis domestica and chicken sequence assemblies for use as outgroups to Placentalia, we validate the HSA 3/21/5 chromosomal synteny as a rare genomic change that defines the monophyly of this ancient African clade of mammals. On the other hand, support for HSA 1/19p, which is also thought to underpin Afrotheria, is currently ambiguous. Conclusion We provide evidence that (i the evolutionary breakpoints that characterise human syntenies detected in the basal Afrotheria correspond at the chromosomal band level with fragile sites, (ii that HSA 3p/21 was in the amniote ancestor (i.e., common to turtles, lepidosaurs, crocodilians, birds and mammals and was subsequently disrupted in the lineage leading to marsupials. Its expansion to include HSA 5 in Afrotheria is unique and (iii that its fragmentation to HSA 3p/21 + HSA 5/21 in elephant and manatee was due to a fission within HSA 21 that is probably shared

  17. Editing site analysis in a gymnosperm mitochondrial genome reveals similarities with angiosperm mitochondrial genomes.

    Science.gov (United States)

    Salmans, Michael Lee; Chaw, Shu-Miaw; Lin, Ching-Ping; Shih, Arthur Chun-Chieh; Wu, Yu-Wei; Mulligan, R Michael

    2010-10-01

    Sequence analysis of organelle genomes and comprehensive analysis of C-to-U editing sites from flowering and non-flowering plants have provided extensive sequence information from diverse taxa. This study includes the first comprehensive analysis of RNA editing sites from a gymnosperm mitochondrial genome, and utilizes informatics analyses to determine conserved features in the RNA sequence context around editing sites. We have identified 565 editing sites in 21 full-length and 4 partial cDNAs of the 39 protein-coding genes identified from the mitochondrial genome of Cycas taitungensis. The information profiles and RNA sequence context of C-to-U editing sites in the Cycas genome exhibit similarity in the immediate flanking nucleotides. Relative entropy analyses indicate that similar regions in the 5' flanking 20 nucleotides have information content compared to angiosperm mitochondrial genomes. These results suggest that evolutionary constraints exist on the nucleotide sequences immediately adjacent to C-to-U editing sites, and similar regions are utilized in editing site recognition.

  18. Evolutionary genomics of miniature inverted-repeat transposable elements (MITEs) in Brassica.

    Science.gov (United States)

    Nouroz, Faisal; Noreen, Shumaila; Heslop-Harrison, J S

    2015-12-01

    Miniature inverted-repeat transposable elements (MITEs) are truncated derivatives of autonomous DNA transposons, and are dispersed abundantly in most eukaryotic genomes. We aimed to characterize various MITEs families in Brassica in terms of their presence, sequence characteristics and evolutionary activity. Dot plot analyses involving comparison of homoeologous bacterial artificial chromosome (BAC) sequences allowed identification of 15 novel families of mobile MITEs. Of which, 5 were Stowaway-like with TA Target Site Duplications (TSDs), 4 Tourist-like with TAA/TTA TSDs, 5 Mutator-like with 9-10 bp TSDs and 1 novel MITE (BoXMITE1) flanked by 3 bp TSDs. Our data suggested that there are about 30,000 MITE-related sequences in Brassica rapa and B. oleracea genomes. In situ hybridization showed one abundant family was dispersed in the A-genome, while another was located near 45S rDNA sites. PCR analysis using primers flanking sequences of MITE elements detected MITE insertion polymorphisms between and within the three Brassica (AA, BB, CC) genomes, with many insertions being specific to single genomes and others showing evidence of more recent evolutionary insertions. Our BAC sequence comparison strategy enables identification of evolutionarily active MITEs with no prior knowledge of MITE sequences. The details of MITE families reported in Brassica enable their identification, characterization and annotation. Insertion polymorphisms of MITEs and their transposition activity indicated important mechanism of genome evolution and diversification. MITE families derived from known Mariner, Harbinger and Mutator DNA transposons were discovered, as well as some novel structures. The identification of Brassica MITEs will have broad applications in Brassica genomics, breeding, hybridization and phylogeny through their use as DNA markers.

  19. History of plastid DNA insertions reveals weak deletion and at mutation biases in angiosperm mitochondrial genomes.

    Science.gov (United States)

    Sloan, Daniel B; Wu, Zhiqiang

    2014-11-21

    Angiosperm mitochondrial genomes exhibit many unusual properties, including heterogeneous nucleotide composition and exceptionally large and variable genome sizes. Determining the role of nonadaptive mechanisms such as mutation bias in shaping the molecular evolution of these unique genomes has proven challenging because their dynamic structures generally prevent identification of homologous intergenic sequences for comparative analyses. Here, we report an analysis of angiosperm mitochondrial DNA sequences that are derived from inserted plastid DNA (mtpts). The availability of numerous completely sequenced plastid genomes allows us to infer the evolutionary history of these insertions, including the specific nucleotide substitutions and indels that have occurred because their incorporation into the mitochondrial genome. Our analysis confirmed that many mtpts have a complex history, including frequent gene conversion and multiple examples of horizontal transfer between divergent angiosperm lineages. Nevertheless, it is clear that the majority of extant mtpt sequence in angiosperms is the product of recent transfer (or gene conversion) and is subject to rapid loss/deterioration, suggesting that most mtpts are evolving relatively free from functional constraint. The evolution of mtpt sequences reveals a pattern of biased mutational input in angiosperm mitochondrial genomes, including an excess of small deletions over insertions and a skew toward nucleotide substitutions that increase AT content. However, these mutation biases are far weaker than have been observed in many other cellular genomes, providing insight into some of the notable features of angiosperm mitochondrial architecture, including the retention of large intergenic regions and the relatively neutral GC content found in these regions. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  20. The Brassica oleracea genome reveals the asymmetrical evolution of polyploid genomes

    Science.gov (United States)

    Liu, Shengyi; Liu, Yumei; Yang, Xinhua; Tong, Chaobo; Edwards, David; Parkin, Isobel A. P.; Zhao, Meixia; Ma, Jianxin; Yu, Jingyin; Huang, Shunmou; Wang, Xiyin; Wang, Junyi; Lu, Kun; Fang, Zhiyuan; Bancroft, Ian; Yang, Tae-Jin; Hu, Qiong; Wang, Xinfa; Yue, Zhen; Li, Haojie; Yang, Linfeng; Wu, Jian; Zhou, Qing; Wang, Wanxin; King, Graham J; Pires, J. Chris; Lu, Changxin; Wu, Zhangyan; Sampath, Perumal; Wang, Zhuo; Guo, Hui; Pan, Shengkai; Yang, Limei; Min, Jiumeng; Zhang, Dong; Jin, Dianchuan; Li, Wanshun; Belcram, Harry; Tu, Jinxing; Guan, Mei; Qi, Cunkou; Du, Dezhi; Li, Jiana; Jiang, Liangcai; Batley, Jacqueline; Sharpe, Andrew G; Park, Beom-Seok; Ruperao, Pradeep; Cheng, Feng; Waminal, Nomar Espinosa; Huang, Yin; Dong, Caihua; Wang, Li; Li, Jingping; Hu, Zhiyong; Zhuang, Mu; Huang, Yi; Huang, Junyan; Shi, Jiaqin; Mei, Desheng; Liu, Jing; Lee, Tae-Ho; Wang, Jinpeng; Jin, Huizhe; Li, Zaiyun; Li, Xun; Zhang, Jiefu; Xiao, Lu; Zhou, Yongming; Liu, Zhongsong; Liu, Xuequn; Qin, Rui; Tang, Xu; Liu, Wenbin; Wang, Yupeng; Zhang, Yangyong; Lee, Jonghoon; Kim, Hyun Hee; Denoeud, France; Xu, Xun; Liang, Xinming; Hua, Wei; Wang, Xiaowu; Wang, Jun; Chalhoub, Boulos; Paterson, Andrew H

    2014-01-01

    Polyploidization has provided much genetic variation for plant adaptive evolution, but the mechanisms by which the molecular evolution of polyploid genomes establishes genetic architecture underlying species differentiation are unclear. Brassica is an ideal model to increase knowledge of polyploid evolution. Here we describe a draft genome sequence of Brassica oleracea, comparing it with that of its sister species B. rapa to reveal numerous chromosome rearrangements and asymmetrical gene loss in duplicated genomic blocks, asymmetrical amplification of transposable elements, differential gene co-retention for specific pathways and variation in gene expression, including alternative splicing, among a large number of paralogous and orthologous genes. Genes related to the production of anticancer phytochemicals and morphological variations illustrate consequences of genome duplication and gene divergence, imparting biochemical and morphological variation to B. oleracea. This study provides insights into Brassica genome evolution and will underpin research into the many important crops in this genus. PMID:24852848

  1. Genome-wide analysis of HPV integration in human cancers reveals recurrent, focal genomic instability

    Science.gov (United States)

    Akagi, Keiko; Li, Jingfeng; Broutian, Tatevik R.; Padilla-Nash, Hesed; Xiao, Weihong; Jiang, Bo; Rocco, James W.; Teknos, Theodoros N.; Kumar, Bhavna; Wangsa, Danny; He, Dandan; Ried, Thomas; Symer, David E.; Gillison, Maura L.

    2014-01-01

    Genomic instability is a hallmark of human cancers, including the 5% caused by human papillomavirus (HPV). Here we report a striking association between HPV integration and adjacent host genomic structural variation in human cancer cell lines and primary tumors. Whole-genome sequencing revealed HPV integrants flanking and bridging extensive host genomic amplifications and rearrangements, including deletions, inversions, and chromosomal translocations. We present a model of “looping” by which HPV integrant-mediated DNA replication and recombination may result in viral–host DNA concatemers, frequently disrupting genes involved in oncogenesis and amplifying HPV oncogenes E6 and E7. Our high-resolution results shed new light on a catastrophic process, distinct from chromothripsis and other mutational processes, by which HPV directly promotes genomic instability. PMID:24201445

  2. Comparative genomics of four closely related Clostridium perfringens bacteriophages reveals variable evolution among core genes with therapeutic potential

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    Siragusa Gregory R

    2011-06-01

    Full Text Available Abstract Background Because biotechnological uses of bacteriophage gene products as alternatives to conventional antibiotics will require a thorough understanding of their genomic context, we sequenced and analyzed the genomes of four closely related phages isolated from Clostridium perfringens, an important agricultural and human pathogen. Results Phage whole-genome tetra-nucleotide signatures and proteomic tree topologies correlated closely with host phylogeny. Comparisons of our phage genomes to 26 others revealed three shared COGs; of particular interest within this core genome was an endolysin (PF01520, an N-acetylmuramoyl-L-alanine amidase and a holin (PF04531. Comparative analyses of the evolutionary history and genomic context of these common phage proteins revealed two important results: 1 strongly significant host-specific sequence variation within the endolysin, and 2 a protein domain architecture apparently unique to our phage genomes in which the endolysin is located upstream of its associated holin. Endolysin sequences from our phages were one of two very distinct genotypes distinguished by variability within the putative enzymatically-active domain. The shared or core genome was comprised of genes with multiple sequence types belonging to five pfam families, and genes belonging to 12 pfam families, including the holin genes, which were nearly identical. Conclusions Significant genomic diversity exists even among closely-related bacteriophages. Holins and endolysins represent conserved functions across divergent phage genomes and, as we demonstrate here, endolysins can have significant variability and host-specificity even among closely-related genomes. Endolysins in our phage genomes may be subject to different selective pressures than the rest of the genome. These findings may have important implications for potential biotechnological applications of phage gene products.

  3. Genomic Analysis of Two Phylogenetically DistinctNitrospiraSpecies Reveals Their Genomic Plasticity and Functional Diversity.

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    Ushiki, Norisuke; Fujitani, Hirotsugu; Shimada, Yu; Morohoshi, Tomohiro; Sekiguchi, Yuji; Tsuneda, Satoshi

    2017-01-01

    The genus Nitrospira represents a dominant group of nitrite-oxidizing bacteria in natural and engineered ecosystems. This genus is phylogenetically divided into six lineages, for which vast phylogenetic and functional diversity has been revealed by recent molecular ecophysiological analyses. However, the genetic basis underlying these phenotypic differences remains largely unknown because of the lack of genome sequences representing their diversity. To gain a more comprehensive understanding of Nitrospira , we performed genomic comparisons between two Nitrospira strains (ND1 and NJ1 belonging to lineages I and II, respectively) previously isolated from activated sludge. In addition, the genomes of these strains were systematically compared with previously reported six Nitrospira genomes to reveal their similarity and presence/absence of several functional genes/operons. Comparisons of Nitrospira genomes indicated that their genomic diversity reflects phenotypic differences and versatile nitrogen metabolisms. Although most genes involved in key metabolic pathways were conserved between strains ND1 and NJ1, assimilatory nitrite reduction pathways of the two Nitrospira strains were different. In addition, the genomes of both strains contain a phylogenetically different urease locus and we confirmed their ureolytic activity. During gene annotation of strain NJ1, we found a gene cluster encoding a quorum-sensing system. From the enriched supernatant of strain NJ1, we successfully identified seven types of acyl-homoserine lactones with a range of C10-C14. In addition, the genome of strain NJ1 lacks genes relevant to flagella and the clustered regularly interspaced short palindromic repeat (CRISPR)-Cas (CRISPR-associated genes) systems, whereas most nitrifying bacteria including strain ND1 possess these genomic elements. These findings enhance our understanding of genomic plasticity and functional diversity among members of the genus Nitrospira .

  4. Evolutionary interrogation of human biology in well-annotated genomic framework of rhesus macaque.

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    Zhang, Shi-Jian; Liu, Chu-Jun; Yu, Peng; Zhong, Xiaoming; Chen, Jia-Yu; Yang, Xinzhuang; Peng, Jiguang; Yan, Shouyu; Wang, Chenqu; Zhu, Xiaotong; Xiong, Jingwei; Zhang, Yong E; Tan, Bertrand Chin-Ming; Li, Chuan-Yun

    2014-05-01

    With genome sequence and composition highly analogous to human, rhesus macaque represents a unique reference for evolutionary studies of human biology. Here, we developed a comprehensive genomic framework of rhesus macaque, the RhesusBase2, for evolutionary interrogation of human genes and the associated regulations. A total of 1,667 next-generation sequencing (NGS) data sets were processed, integrated, and evaluated, generating 51.2 million new functional annotation records. With extensive NGS annotations, RhesusBase2 refined the fine-scale structures in 30% of the macaque Ensembl transcripts, reporting an accurate, up-to-date set of macaque gene models. On the basis of these annotations and accurate macaque gene models, we further developed an NGS-oriented Molecular Evolution Gateway to access and visualize macaque annotations in reference to human orthologous genes and associated regulations (www.rhesusbase.org/molEvo). We highlighted the application of this well-annotated genomic framework in generating hypothetical link of human-biased regulations to human-specific traits, by using mechanistic characterization of the DIEXF gene as an example that provides novel clues to the understanding of digestive system reduction in human evolution. On a global scale, we also identified a catalog of 9,295 human-biased regulatory events, which may represent novel elements that have a substantial impact on shaping human transcriptome and possibly underpin recent human phenotypic evolution. Taken together, we provide an NGS data-driven, information-rich framework that will broadly benefit genomics research in general and serves as an important resource for in-depth evolutionary studies of human biology.

  5. Evaluating the Impact of Genomic Data and Priors on Bayesian Estimates of the Angiosperm Evolutionary Timescale.

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    Foster, Charles S P; Sauquet, Hervê; van der Merwe, Marlien; McPherson, Hannah; Rossetto, Maurizio; Ho, Simon Y W

    2017-05-01

    The evolutionary timescale of angiosperms has long been a key question in biology. Molecular estimates of this timescale have shown considerable variation, being influenced by differences in taxon sampling, gene sampling, fossil calibrations, evolutionary models, and choices of priors. Here, we analyze a data set comprising 76 protein-coding genes from the chloroplast genomes of 195 taxa spanning 86 families, including novel genome sequences for 11 taxa, to evaluate the impact of models, priors, and gene sampling on Bayesian estimates of the angiosperm evolutionary timescale. Using a Bayesian relaxed molecular-clock method, with a core set of 35 minimum and two maximum fossil constraints, we estimated that crown angiosperms arose 221 (251-192) Ma during the Triassic. Based on a range of additional sensitivity and subsampling analyses, we found that our date estimates were generally robust to large changes in the parameters of the birth-death tree prior and of the model of rate variation across branches. We found an exception to this when we implemented fossil calibrations in the form of highly informative gamma priors rather than as uniform priors on node ages. Under all other calibration schemes, including trials of seven maximum age constraints, we consistently found that the earliest divergences of angiosperm clades substantially predate the oldest fossils that can be assigned unequivocally to their crown group. Overall, our results and experiments with genome-scale data suggest that reliable estimates of the angiosperm crown age will require increased taxon sampling, significant methodological changes, and new information from the fossil record. [Angiospermae, chloroplast, genome, molecular dating, Triassic.]. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Genome size as a key to evolutionary complex aquatic plants: polyploidy and hybridization in Callitriche (Plantaginaceae.

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    Jan Prančl

    Full Text Available Despite their complex evolutionary histories, aquatic plants are highly underrepresented in contemporary biosystematic studies. Of them, the genus Callitriche is particularly interesting because of such evolutionary features as wide variation in chromosome numbers and pollination systems. However, taxonomic difficulties have prevented broader investigation of this genus. In this study we applied flow cytometry to Callitriche for the first time in order to gain an insight into evolutionary processes and genome size differentiation in the genus. Flow cytometry complemented by confirmation of chromosome counts was applied to an extensive dataset of 1077 Callitriche individuals from 495 localities in 11 European countries and the USA. Genome size was determined for 12 taxa. The results suggest that many important processes have interacted in the evolution of the genus, including polyploidization and hybridization. Incongruence between genome size and ploidy level, intraspecific variation in genome size, formation of autotriploid and hybridization between species with different pollination systems were also detected. Hybridization takes place particularly in the diploid-tetraploid complex C. cophocarpa-C. platycarpa, for which the triploid hybrids were frequently recorded in the area of co-occurrence of its parents. A hitherto unknown hybrid (probably C. hamulata × C. cophocarpa with a unique chromosome number was discovered in the Czech Republic. However, hybridization occurs very rarely among most of the studied species. The main ecological preferences were also compared among the taxa collected. Although Callitriche taxa often grow in mixed populations, the ecological preferences of individual species are distinctly different in some cases. Anyway, flow cytometry is a very efficient method for taxonomic delimitation, determination and investigation of Callitriche species, and is even able to distinguish homoploid taxa and identify introduced

  7. Evolutionary genomics and adaptive evolution of the Hedgehog gene family (Shh, Ihh and Dhh in vertebrates.

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    Joana Pereira

    Full Text Available The Hedgehog (Hh gene family codes for a class of secreted proteins composed of two active domains that act as signalling molecules during embryo development, namely for the development of the nervous and skeletal systems and the formation of the testis cord. While only one Hh gene is found typically in invertebrate genomes, most vertebrates species have three (Sonic hedgehog--Shh; Indian hedgehog--Ihh; and Desert hedgehog--Dhh, each with different expression patterns and functions, which likely helped promote the increasing complexity of vertebrates and their successful diversification. In this study, we used comparative genomic and adaptive evolutionary analyses to characterize the evolution of the Hh genes in vertebrates following the two major whole genome duplication (WGD events. To overcome the lack of Hh-coding sequences on avian publicly available databases, we used an extensive dataset of 45 avian and three non-avian reptilian genomes to show that birds have all three Hh paralogs. We find suggestions that following the WGD events, vertebrate Hh paralogous genes evolved independently within similar linkage groups and under different evolutionary rates, especially within the catalytic domain. The structural regions around the ion-binding site were identified to be under positive selection in the signaling domain. These findings contrast with those observed in invertebrates, where different lineages that experienced gene duplication retained similar selective constraints in the Hh orthologs. Our results provide new insights on the evolutionary history of the Hh gene family, the functional roles of these paralogs in vertebrate species, and on the location of mutational hotspots.

  8. The Schistosoma mansoni phylome: using evolutionary genomics to gain insight into a parasite’s biology

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    Silva Larissa

    2012-11-01

    Full Text Available Abstract Background Schistosoma mansoni is one of the causative agents of schistosomiasis, a neglected tropical disease that affects about 237 million people worldwide. Despite recent efforts, we still lack a general understanding of the relevant host-parasite interactions, and the possible treatments are limited by the emergence of resistant strains and the absence of a vaccine. The S. mansoni genome was completely sequenced and still under continuous annotation. Nevertheless, more than 45% of the encoded proteins remain without experimental characterization or even functional prediction. To improve our knowledge regarding the biology of this parasite, we conducted a proteome-wide evolutionary analysis to provide a broad view of the S. mansoni’s proteome evolution and to improve its functional annotation. Results Using a phylogenomic approach, we reconstructed the S. mansoni phylome, which comprises the evolutionary histories of all parasite proteins and their homologs across 12 other organisms. The analysis of a total of 7,964 phylogenies allowed a deeper understanding of genomic complexity and evolutionary adaptations to a parasitic lifestyle. In particular, the identification of lineage-specific gene duplications pointed to the diversification of several protein families that are relevant for host-parasite interaction, including proteases, tetraspanins, fucosyltransferases, venom allergen-like proteins, and tegumental-allergen-like proteins. In addition to the evolutionary knowledge, the phylome data enabled us to automatically re-annotate 3,451 proteins through a phylogenetic-based approach rather than solely sequence similarity searches. To allow further exploitation of this valuable data, all information has been made available at PhylomeDB (http://www.phylomedb.org. Conclusions In this study, we used an evolutionary approach to assess S. mansoni parasite biology, improve genome/proteome functional annotation, and provide insights into

  9. The Schistosoma mansoni phylome: using evolutionary genomics to gain insight into a parasite's biology.

    Science.gov (United States)

    Silva, Larissa Lopes; Marcet-Houben, Marina; Nahum, Laila Alves; Zerlotini, Adhemar; Gabaldón, Toni; Oliveira, Guilherme

    2012-11-13

    Schistosoma mansoni is one of the causative agents of schistosomiasis, a neglected tropical disease that affects about 237 million people worldwide. Despite recent efforts, we still lack a general understanding of the relevant host-parasite interactions, and the possible treatments are limited by the emergence of resistant strains and the absence of a vaccine. The S. mansoni genome was completely sequenced and still under continuous annotation. Nevertheless, more than 45% of the encoded proteins remain without experimental characterization or even functional prediction. To improve our knowledge regarding the biology of this parasite, we conducted a proteome-wide evolutionary analysis to provide a broad view of the S. mansoni's proteome evolution and to improve its functional annotation. Using a phylogenomic approach, we reconstructed the S. mansoni phylome, which comprises the evolutionary histories of all parasite proteins and their homologs across 12 other organisms. The analysis of a total of 7,964 phylogenies allowed a deeper understanding of genomic complexity and evolutionary adaptations to a parasitic lifestyle. In particular, the identification of lineage-specific gene duplications pointed to the diversification of several protein families that are relevant for host-parasite interaction, including proteases, tetraspanins, fucosyltransferases, venom allergen-like proteins, and tegumental-allergen-like proteins. In addition to the evolutionary knowledge, the phylome data enabled us to automatically re-annotate 3,451 proteins through a phylogenetic-based approach rather than solely sequence similarity searches. To allow further exploitation of this valuable data, all information has been made available at PhylomeDB (http://www.phylomedb.org). In this study, we used an evolutionary approach to assess S. mansoni parasite biology, improve genome/proteome functional annotation, and provide insights into host-parasite interactions. Taking advantage of a proteome

  10. Comparative genomics of Coniophora olivacea reveals different patterns of genome expansion in Boletales.

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    Castanera, Raúl; Pérez, Gúmer; López-Varas, Leticia; Amselem, Joëlle; LaButti, Kurt; Singan, Vasanth; Lipzen, Anna; Haridas, Sajeet; Barry, Kerrie; Grigoriev, Igor V; Pisabarro, Antonio G; Ramírez, Lucía

    2017-11-16

    Coniophora olivacea is a basidiomycete fungus belonging to the order Boletales that produces brown-rot decay on dead wood of conifers. The Boletales order comprises a diverse group of species including saprotrophs and ectomycorrhizal fungi that show important differences in genome size. In this study we report the 39.07-megabase (Mb) draft genome assembly and annotation of C. olivacea. A total of 14,928 genes were annotated, including 470 putatively secreted proteins enriched in functions involved in lignocellulose degradation. Using similarity clustering and protein structure prediction we identified a new family of 10 putative lytic polysaccharide monooxygenase genes. This family is conserved in basidiomycota and lacks of previous functional annotation. Further analyses showed that C. olivacea has a low repetitive genome, with 2.91% of repeats and a restrained content of transposable elements (TEs). The annotation of TEs in four related Boletales yielded important differences in repeat content, ranging from 3.94 to 41.17% of the genome size. The distribution of insertion ages of LTR-retrotransposons showed that differential expansions of these repetitive elements have shaped the genome architecture of Boletales over the last 60 million years. Coniophora olivacea has a small, compact genome that shows macrosynteny with Coniophora puteana. The functional annotation revealed the enzymatic signature of a canonical brown-rot. The annotation and comparative genomics of transposable elements uncovered their particular contraction in the Coniophora genera, highlighting their role in the differential genome expansions found in Boletales species.

  11. Mitogenomes from The 1000 Genome Project Reveal New Near Eastern Features in Present-Day Tuscans

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    Pardo-Seco, Jacobo; Amigo, Jorge; Martinón-Torres, Federico

    2015-01-01

    Background Genetic analyses have recently been carried out on present-day Tuscans (Central Italy) in order to investigate their presumable recent Near East ancestry in connection with the long-standing debate on the origins of the Etruscan civilization. We retrieved mitogenomes and genome-wide SNP data from 110 Tuscans analyzed within the context of The 1000 Genome Project. For phylogeographic and evolutionary analysis we made use of a large worldwide database of entire mitogenomes (>26,000) and partial control region sequences (>180,000). Results Different analyses reveal the presence of typical Near East haplotypes in Tuscans representing isolated members of various mtDNA phylogenetic branches. As a whole, the Near East component in Tuscan mitogenomes can be estimated at about 8%; a proportion that is comparable to previous estimates but significantly lower than admixture estimates obtained from autosomal SNP data (21%). Phylogeographic and evolutionary inter-population comparisons indicate that the main signal of Near Eastern Tuscan mitogenomes comes from Iran. Conclusions Mitogenomes of recent Near East origin in present-day Tuscans do not show local or regional variation. This points to a demographic scenario that is compatible with a recent arrival of Near Easterners to this region in Italy with no founder events or bottlenecks. PMID:25786119

  12. Fast turnover of genome transcription across evolutionary time exposes entire non-coding DNA to de novo gene emergence.

    Science.gov (United States)

    Neme, Rafik; Tautz, Diethard

    2016-02-02

    Deep sequencing analyses have shown that a large fraction of genomes is transcribed, but the significance of this transcription is much debated. Here, we characterize the phylogenetic turnover of poly-adenylated transcripts in a comprehensive sampling of taxa of the mouse (genus Mus), spanning a phylogenetic distance of 10 Myr. Using deep RNA sequencing we find that at a given sequencing depth transcriptome coverage becomes saturated within a taxon, but keeps extending when compared between taxa, even at this very shallow phylogenetic level. Our data show a high turnover of transcriptional states between taxa and that no major transcript-free islands exist across evolutionary time. This suggests that the entire genome can be transcribed into poly-adenylated RNA when viewed at an evolutionary time scale. We conclude that any part of the non-coding genome can potentially become subject to evolutionary functionalization via de novo gene evolution within relatively short evolutionary time spans.

  13. Comparative genomic analysis reveals a distant liver enhancer upstream of the COUP-TFII gene

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    Baroukh, Nadine; Ahituv, Nadav; Chang, Jessie; Shoukry, Malak; Afzal, Veena; Rubin, Edward M.; Pennacchio, Len A.

    2004-08-20

    COUP-TFII is a central nuclear hormone receptor that tightly regulates the expression of numerous target lipid metabolism genes in vertebrates. However, it remains unclear how COUP-TFII itself is transcriptionally controlled since studies with its promoter and upstream region fail to recapitulate the genes liver expression. In an attempt to identify liver enhancers in the vicinity of COUP-TFII, we employed a comparative genomic approach. Initial comparisons between humans and mice of the 3,470kb gene poor region surrounding COUP-TFII revealed 2,023 conserved non-coding elements. To prioritize a subset of these elements for functional studies, we performed further genomic comparisons with the orthologous pufferfish (Fugu rubripes) locus and uncovered two anciently conserved non-coding sequences (CNS) upstream of COUP-TFII (CNS-62kb and CNS-66kb). Testing these two elements using reporter constructs in liver (HepG2) cells revealed that CNS-66kb, but not CNS-62kb, yielded robust in vitro enhancer activity. In addition, an in vivo reporter assay using naked DNA transfer with CNS-66kb linked to luciferase displayed strong reproducible liver expression in adult mice, further supporting its role as a liver enhancer. Together, these studies further support the utility of comparative genomics to uncover gene regulatory sequences based on evolutionary conservation and provide the substrates to better understand the regulation and expression of COUP-TFII.

  14. Population Genomics Reveals Speciation and Introgression between Brown Norway Rats and Their Sibling Species.

    Science.gov (United States)

    Teng, Huajing; Zhang, Yaohua; Shi, Chengmin; Mao, Fengbiao; Cai, Wanshi; Lu, Liang; Zhao, Fangqing; Sun, Zhongsheng; Zhang, Jianxu

    2017-09-01

    Murine rodents are excellent models for study of adaptive radiations and speciation. Brown Norway rats (Rattus norvegicus) are successful global colonizers and the contributions of their domesticated laboratory strains to biomedical research are well established. To identify nucleotide-based speciation timing of the rat and genomic information contributing to its colonization capabilities, we analyzed 51 whole-genome sequences of wild-derived Brown Norway rats and their sibling species, R. nitidus, and identified over 20 million genetic variants in the wild Brown Norway rats that were absent in the laboratory strains, which substantially expand the reservoir of rat genetic diversity. We showed that divergence of the rat and its siblings coincided with drastic climatic changes that occurred during the Middle Pleistocene. Further, we revealed that there was a geographically widespread influx of genes between Brown Norway rats and the sibling species following the divergence, resulting in numerous introgressed regions in the genomes of admixed Brown Norway rats. Intriguing, genes related to chemical communications among these introgressed regions appeared to contribute to the population-specific adaptations of the admixed Brown Norway rats. Our data reveals evolutionary history of the Brown Norway rat, and offers new insights into the role of climatic changes in speciation of animals and the effect of interspecies introgression on animal adaptation. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  15. Comparative genomics of grass EST libraries reveals previously uncharacterized splicing events in crop plants.

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    Chuang, Trees-Juen; Yang, Min-Yu; Lin, Chuang-Chieh; Hsieh, Ping-Hung; Hung, Li-Yuan

    2015-02-05

    Crop plants such as rice, maize and sorghum play economically-important roles as main sources of food, fuel, and animal feed. However, current genome annotations of crop plants still suffer false-positive predictions; a more comprehensive registry of alternative splicing (AS) events is also in demand. Comparative genomics of crop plants is largely unexplored. We performed a large-scale comparative analysis (ExonFinder) of the expressed sequence tag (EST) library from nine grass plants against three crop genomes (rice, maize, and sorghum) and identified 2,879 previously-unannotated exons (i.e., novel exons) in the three crops. We validated 81% of the tested exons by RT-PCR-sequencing, supporting the effectiveness of our in silico strategy. Evolutionary analysis reveals that the novel exons, comparing with their flanking annotated ones, are generally under weaker selection pressure at the protein level, but under stronger pressure at the RNA level, suggesting that most of the novel exons also represent novel alternatively spliced variants (ASVs). However, we also observed the consistency of evolutionary rates between certain novel exons and their flanking exons, which provided further evidence of their co-occurrence in the transcripts, suggesting that previously-annotated isoforms might be subject to erroneous predictions. Our validation showed that 54% of the tested genes expressed the newly-identified isoforms that contained the novel exons, rather than the previously-annotated isoforms that excluded them. The consistent results were steadily observed across cultivated (Oryza sativa and O. glaberrima) and wild (O. rufipogon and O. nivara) rice species, asserting the necessity of our curation of the crop genome annotations. Our comparative analyses also inferred the common ancestral transcriptome of grass plants and gain- and loss-of-ASV events. We have reannotated the rice, maize, and sorghum genomes, and showed that evolutionary rates might serve as an indicator

  16. Sequence analysis reveals mosaic genome of Aichi virus

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    Han Xiaohong

    2011-08-01

    Full Text Available Abstract Aichi virus is a positive-sense and single-stranded RNA virus, which demonstrated to be related to diarrhea of Children. In the present study, phylogenetic and recombination analysis based on the Aichi virus complete genomes available in GenBank reveal a mosaic genome sequence [GenBank: FJ890523], of which the nt 261-852 region (the nt position was based on the aligned sequence file shows close relationship with AB010145/Japan with 97.9% sequence identity, while the other genomic regions show close relationship with AY747174/German with 90.1% sequence identity. Our results will provide valuable hints for future research on Aichi virus diversity. Aichi virus is a member of the Kobuvirus genus of the Picornaviridae family 12 and belongs to a positive-sense and single-stranded RNA virus. Its presence in fecal specimens of children suffering from diarrhea has been demonstrated in several Asian countries 3456, in Brazil and German 7, in France 8 and in Tunisia 9. Some reports showed the high level of seroprevalence in adults 710, suggesting the widespread exposure to Aichi virus during childhood. The genome of Aichi virus contains 8,280 nucleotides and a poly(A tail. The single large open reading frame (nt 713-8014 according to the strain AB010145 encodes a polyprotein of 2,432 amino acids that is cleaved into the typical picornavirus structural proteins VP0, VP3, VP1, and nonstructural proteins 2A, 2B, 2C, 3A, 3B, 3C and 3D 211. Based on the phylogenetic analysis of 519-bp sequences at the 3C-3D (3CD junction, Aichi viruses can be divided into two genotypes A and B with approximately 90% sequence homology 12. Although only six complete genomes of Aichi virus were deposited in GenBank at present, mosaic genomes can be found in strains from different countries.

  17. Sequence analysis reveals mosaic genome of Aichi virus.

    Science.gov (United States)

    Han, Xiaohong; Zhang, Wen; Xue, Yanjun; Shao, Shihe

    2011-08-05

    Aichi virus is a positive-sense and single-stranded RNA virus, which demonstrated to be related to diarrhea of Children. In the present study, phylogenetic and recombination analysis based on the Aichi virus complete genomes available in GenBank reveal a mosaic genome sequence [GenBank: FJ890523], of which the nt 261-852 region (the nt position was based on the aligned sequence file) shows close relationship with AB010145/Japan with 97.9% sequence identity, while the other genomic regions show close relationship with AY747174/German with 90.1% sequence identity. Our results will provide valuable hints for future research on Aichi virus diversity.Aichi virus is a member of the Kobuvirus genus of the Picornaviridae family 12 and belongs to a positive-sense and single-stranded RNA virus. Its presence in fecal specimens of children suffering from diarrhea has been demonstrated in several Asian countries 3456, in Brazil and German 7, in France 8 and in Tunisia 9. Some reports showed the high level of seroprevalence in adults 710, suggesting the widespread exposure to Aichi virus during childhood.The genome of Aichi virus contains 8,280 nucleotides and a poly(A) tail. The single large open reading frame (nt 713-8014 according to the strain AB010145) encodes a polyprotein of 2,432 amino acids that is cleaved into the typical picornavirus structural proteins VP0, VP3, VP1, and nonstructural proteins 2A, 2B, 2C, 3A, 3B, 3C and 3D 211. Based on the phylogenetic analysis of 519-bp sequences at the 3C-3D (3CD) junction, Aichi viruses can be divided into two genotypes A and B with approximately 90% sequence homology 12. Although only six complete genomes of Aichi virus were deposited in GenBank at present, mosaic genomes can be found in strains from different countries.

  18. Functional and evolutionary correlates of gene constellations in the Drosophila melanogaster genome that deviate from the stereotypical gene architecture

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    Kohn Michael H

    2010-05-01

    Full Text Available Abstract Background The biological dimensions of genes are manifold. These include genomic properties, (e.g., X/autosomal linkage, recombination and functional properties (e.g., expression level, tissue specificity. Multiple properties, each generally of subtle influence individually, may affect the evolution of genes or merely be (auto-correlates. Results of multidimensional analyses may reveal the relative importance of these properties on the evolution of genes, and therefore help evaluate whether these properties should be considered during analyses. While numerous properties are now considered during studies, most work still assumes the stereotypical solitary gene as commonly depicted in textbooks. Here, we investigate the Drosophila melanogaster genome to determine whether deviations from the stereotypical gene architecture correlate with other properties of genes. Results Deviations from the stereotypical gene architecture were classified as the following gene constellations: Overlapping genes were defined as those that overlap in the 5-prime, exonic, or intronic regions. Chromatin co-clustering genes were defined as genes that co-clustered within 20 kb of transcriptional territories. If this scheme is applied the stereotypical gene emerges as a rare occurrence (7.5%, slightly varied schemes yielded between ~1%-50%. Moreover, when following our scheme, paired-overlapping genes and chromatin co-clustering genes accounted for 50.1 and 42.4% of the genes analyzed, respectively. Gene constellation was a correlate of a number of functional and evolutionary properties of genes, but its statistical effect was ~1-2 orders of magnitude lower than the effects of recombination, chromosome linkage and protein function. Analysis of datasets on male reproductive proteins showed these were biased in their representation of gene constellations and evolutionary rate Ka/Ks estimates, but these biases did not overwhelm the biologically meaningful

  19. Genomes of Gardnerella Strains Reveal an Abundance of Prophages within the Bladder Microbiome.

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    Kema Malki

    Full Text Available Bacterial surveys of the vaginal and bladder human microbiota have revealed an abundance of many similar bacterial taxa. As the bladder was once thought to be sterile, the complex interactions between microbes within the bladder have yet to be characterized. To initiate this process, we have begun sequencing isolates, including the clinically relevant genus Gardnerella. Herein, we present the genomic sequences of four Gardnerella strains isolated from the bladders of women with symptoms of urgency urinary incontinence; these are the first Gardnerella genomes produced from this niche. Congruent to genomic characterization of Gardnerella isolates from the reproductive tract, isolates from the bladder reveal a large pangenome, as well as evidence of high frequency horizontal gene transfer. Prophage gene sequences were found to be abundant amongst the strains isolated from the bladder, as well as amongst publicly available Gardnerella genomes from the vagina and endometrium, motivating an in depth examination of these sequences. Amongst the 39 Gardnerella strains examined here, there were more than 400 annotated prophage gene sequences that we could cluster into 95 homologous groups; 49 of these groups were unique to a single strain. While many of these prophages exhibited no sequence similarity to any lytic phage genome, estimation of the rate of phage acquisition suggests both vertical and horizontal acquisition. Furthermore, bioinformatic evidence indicates that prophage acquisition is ongoing within both vaginal and bladder Gardnerella populations. The abundance of prophage sequences within the strains examined here suggests that phages could play an important role in the species' evolutionary history and in its interactions within the complex communities found in the female urinary and reproductive tracts.

  20. Preliminary comparative genomics revealed pathogenic potential and international spread of Staphylococcus argenteus.

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    Zhang, Dao-Feng; Zhi, Xiao-Yang; Zhang, Jing; Paoli, George C; Cui, Yan; Shi, Chunlei; Shi, Xianming

    2017-10-23

    Staphylococcus argenteus and S. schweitzeri, were recently proposed as novel species within S. aureus complex (SAC). S. argenteus has been reported in many countries and can threaten human health. S. schweitzeri has not been associated with human infections, but has been isolated from non-human primates. Questions regarding the evolution of pathogenicity of these two species will remain elusive until an exploratory evolutionary framework is established. We present genomic comparison analysis among members of SAC based on a pan-genome definition, which included 15 S. argenteus genomes (five newly sequenced), six S. schweitzeri genomes and 30 divergent S. aureus genomes. The three species had divergent core genomes and rare interspecific recombination was observed among the core genes. However, some subtypes of staphylococcal cassette chromosome mec (SCCmec) elements and prophages were present in different species. Of 111 tested virulence genes of S. aureus, 85 and 86 homologous genes were found in S. argenteus and S. schweitzeri, respectively. There was no difference in virulence gene content among the three species, but the sequence of most core virulence genes was divergent. Analysis of the agr locus and the genes in the capsular polysaccharides biosynthetic operon revealed that they both diverged before the speciation of SAC members. Furthermore, the widespread geographic distribution of S. argenteus, sequence type 2250, showed ambiguous biogeographical structure among geographically isolated populations, demonstrating an international spread of this pathogen. S. argenteus has spread among several countries, and invasive infections and persistent carriage may be not limited to currently reported regions. S. argenteus probably had undergone a recent host adaption and can cause human infections with a similar pathogenic potential.

  1. Intraspecific comparative genomics of Candida albicans mitochondria reveals non-coding regions under neutral evolution.

    Science.gov (United States)

    Bartelli, Thais F; Ferreira, Renata C; Colombo, Arnaldo L; Briones, Marcelo R S

    2013-03-01

    The opportunistic fungal pathogen Candida albicans causes serious hematogenic hospital acquired candidiasis with worldwide impact on public health. Because of its importance as a nosocomial etiologic agent, C. albicans genome has been largely studied to identify intraspecific variation and several typing methods have been developed to distinguish closely related strains. Mitochondrial DNA can be useful for this purpose because, as compared to nuclear DNA, its higher mutational load and evolutionary rate readily reveals microvariants. Accordingly, we sequenced and assembled, with 8-fold coverage, the mitochondrial genomes of two C. albicans clinical isolates (L296 and L757) and compared these sequences with the genome sequence of reference strain SC5314. The genome alignment of 33,928 positions revealed 372 polymorphic sites being 230 in coding and 142 in non-coding regions. Three intergenic regions located between genes tRNAGly/COX1, NAD3/COB and ssurRNA/NAD4L, named IG1, IG2 and IG3, respectively, which showed high number of neutral substitutions, were amplified and sequenced from 18 clinical isolates from different locations in Latin America and 2 ATCC standard C. albicans strains. High variability of sequence and size were observed, ranging up to 56bp size difference and phylogenies based on IG1, IG2 and IG3 revealed three groups. Insertions of up to 49bp were observed exclusively in Argentinean strains relative to the other sequences which could suggest clustering by geographical polymorphism. Because of neutral evolution, high variability, easy isolation by PCR and full length sequencing these mitochondrial intergenic regions can contribute with a novel perspective in molecular studies of C. albicans isolates, complementing well established multilocus sequence typing methods. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Evolutionary Nephrology

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    Robert L. Chevalier

    2017-05-01

    Full Text Available Progressive kidney disease follows nephron loss, hyperfiltration, and incomplete repair, a process described as “maladaptive.” In the past 20 years, a new discipline has emerged that expands research horizons: evolutionary medicine. In contrast to physiologic (homeostatic adaptation, evolutionary adaptation is the result of reproductive success that reflects natural selection. Evolutionary explanations for physiologically maladaptive responses can emerge from mismatch of the phenotype with environment or from evolutionary tradeoffs. Evolutionary adaptation to a terrestrial environment resulted in a vulnerable energy-consuming renal tubule and a hypoxic, hyperosmolar microenvironment. Natural selection favors successful energy investment strategy: energy is allocated to maintenance of nephron integrity through reproductive years, but this declines with increasing senescence after ∼40 years of age. Risk factors for chronic kidney disease include restricted fetal growth or preterm birth (life history tradeoff resulting in fewer nephrons, evolutionary selection for APOL1 mutations (which provide resistance to trypanosome infection, a tradeoff, and modern life experience (Western diet mismatch leading to diabetes and hypertension. Current advances in genomics, epigenetics, and developmental biology have revealed proximate causes of kidney disease, but attempts to slow kidney disease remain elusive. Evolutionary medicine provides a complementary approach by addressing ultimate causes of kidney disease. Marked variation in nephron number at birth, nephron heterogeneity, and changing susceptibility to kidney injury throughout the life history are the result of evolutionary processes. Combined application of molecular genetics, evolutionary developmental biology (evo-devo, developmental programming, and life history theory may yield new strategies for prevention and treatment of chronic kidney disease.

  3. Advances in genome editing technology and its promising application in evolutionary and ecological studies.

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    Chen, Lei; Tang, Linyi; Xiang, Hui; Jin, Lijun; Li, Qiye; Dong, Yang; Wang, Wen; Zhang, Guojie

    2014-01-01

    Genetic modification has long provided an approach for "reverse genetics", analyzing gene function and linking DNA sequence to phenotype. However, traditional genome editing technologies have not kept pace with the soaring progress of the genome sequencing era, as a result of their inefficiency, time-consuming and labor-intensive methods. Recently, invented genome modification technologies, such as ZFN (Zinc Finger Nuclease), TALEN (Transcription Activator-Like Effector Nuclease), and CRISPR/Cas9 nuclease (Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 nuclease) can initiate genome editing easily, precisely and with no limitations by organism. These new tools have also offered intriguing possibilities for conducting functional large-scale experiments. In this review, we begin with a brief introduction of ZFN, TALEN, and CRISPR/Cas9 technologies, then generate an extensive prediction of effective TALEN and CRISPR/Cas9 target sites in the genomes of a broad range of taxonomic species. Based on the evidence, we highlight the potential and practicalities of TALEN and CRISPR/Cas9 editing in non-model organisms, and also compare the technologies and test interesting issues such as the functions of candidate domesticated, as well as candidate genes in life-environment interactions. When accompanied with a high-throughput sequencing platform, we forecast their potential revolutionary impacts on evolutionary and ecological research, which may offer an exciting prospect for connecting the gap between DNA sequence and phenotype in the near future.

  4. From mouse to human: evolutionary genomics analysis of human orthologs of essential genes.

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    Benjamin Georgi

    2013-05-01

    Full Text Available Understanding the core set of genes that are necessary for basic developmental functions is one of the central goals in biology. Studies in model organisms identified a significant fraction of essential genes through the analysis of null-mutations that lead to lethality. Recent large-scale next-generation sequencing efforts have provided unprecedented data on genetic variation in human. However, evolutionary and genomic characteristics of human essential genes have never been directly studied on a genome-wide scale. Here we use detailed phenotypic resources available for the mouse and deep genomics sequencing data from human populations to characterize patterns of genetic variation and mutational burden in a set of 2,472 human orthologs of known essential genes in the mouse. Consistent with the action of strong, purifying selection, these genes exhibit comparatively reduced levels of sequence variation, skew in allele frequency towards more rare, and exhibit increased conservation across the primate and rodent lineages relative to the remainder of genes in the genome. In individual genomes we observed ~12 rare mutations within essential genes predicted to be damaging. Consistent with the hypothesis that mutations in essential genes are risk factors for neurodevelopmental disease, we show that de novo variants in patients with Autism Spectrum Disorder are more likely to occur in this collection of genes. While incomplete, our set of human orthologs shows characteristics fully consistent with essential function in human and thus provides a resource to inform and facilitate interpretation of sequence data in studies of human disease.

  5. The effect of multiple evolutionary selections on synonymous codon usage of genes in the Mycoplasma bovis genome.

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    Jian-hua Zhou

    Full Text Available Mycoplasma bovis is a major pathogen causing arthritis, respiratory disease and mastitis in cattle. A better understanding of its genetic features and evolution might represent evidences of surviving host environments. In this study, multiple factors influencing synonymous codon usage patterns in M. bovis (three strains' genomes were analyzed. The overall nucleotide content of genes in the M. bovis genome is AT-rich. Although the G and C contents at the third codon position of genes in the leading strand differ from those in the lagging strand (p<0.05, the 59 synonymous codon usage patterns of genes in the leading strand are highly similar to those in the lagging strand. The over-represented codons and the under-represented codons were identified. A comparison of the synonymous codon usage pattern of M. bovis and cattle (susceptible host indicated the independent formation of synonymous codon usage of M. bovis. Principal component analysis revealed that (i strand-specific mutational bias fails to affect the synonymous codon usage pattern in the leading and lagging strands, (ii mutation pressure from nucleotide content plays a role in shaping the overall codon usage, and (iii the major trend of synonymous codon usage has a significant correlation with the gene expression level that is estimated by the codon adaptation index. The plot of the effective number of codons against the G+C content at the third codon position also reveals that mutation pressure undoubtedly contributes to the synonymous codon usage pattern of M. bovis. Additionally, the formation of the overall codon usage is determined by certain evolutionary selections for gene function classification (30S protein, 50S protein, transposase, membrane protein, and lipoprotein and translation elongation region of genes in M. bovis. The information could be helpful in further investigations of evolutionary mechanisms of the Mycoplasma family and heterologous expression of its functionally

  6. The Effect of Multiple Evolutionary Selections on Synonymous Codon Usage of Genes in the Mycoplasma bovis Genome

    Science.gov (United States)

    Zhou, Jian-hua; Ding, Yao-zhong; He, Ying; Chu, Yue-feng; Zhao, Ping; Ma, Li-ya; Wang, Xin-jun; Li, Xue-rui; Liu, Yong-sheng

    2014-01-01

    Mycoplasma bovis is a major pathogen causing arthritis, respiratory disease and mastitis in cattle. A better understanding of its genetic features and evolution might represent evidences of surviving host environments. In this study, multiple factors influencing synonymous codon usage patterns in M. bovis (three strains’ genomes) were analyzed. The overall nucleotide content of genes in the M. bovis genome is AT-rich. Although the G and C contents at the third codon position of genes in the leading strand differ from those in the lagging strand (p<0.05), the 59 synonymous codon usage patterns of genes in the leading strand are highly similar to those in the lagging strand. The over-represented codons and the under-represented codons were identified. A comparison of the synonymous codon usage pattern of M. bovis and cattle (susceptible host) indicated the independent formation of synonymous codon usage of M. bovis. Principal component analysis revealed that (i) strand-specific mutational bias fails to affect the synonymous codon usage pattern in the leading and lagging strands, (ii) mutation pressure from nucleotide content plays a role in shaping the overall codon usage, and (iii) the major trend of synonymous codon usage has a significant correlation with the gene expression level that is estimated by the codon adaptation index. The plot of the effective number of codons against the G+C content at the third codon position also reveals that mutation pressure undoubtedly contributes to the synonymous codon usage pattern of M. bovis. Additionally, the formation of the overall codon usage is determined by certain evolutionary selections for gene function classification (30S protein, 50S protein, transposase, membrane protein, and lipoprotein) and translation elongation region of genes in M. bovis. The information could be helpful in further investigations of evolutionary mechanisms of the Mycoplasma family and heterologous expression of its functionally important

  7. The complete chloroplast genome sequence of Podocarpus lambertii: genome structure, evolutionary aspects, gene content and SSR detection.

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    Leila do Nascimento Vieira

    Full Text Available BACKGROUND: Podocarpus lambertii (Podocarpaceae is a native conifer from the Brazilian Atlantic Forest Biome, which is considered one of the 25 biodiversity hotspots in the world. The advancement of next-generation sequencing technologies has enabled the rapid acquisition of whole chloroplast (cp genome sequences at low cost. Several studies have proven the potential of cp genomes as tools to understand enigmatic and basal phylogenetic relationships at different taxonomic levels, as well as further probe the structural and functional evolution of plants. In this work, we present the complete cp genome sequence of P. lambertii. METHODOLOGY/PRINCIPAL FINDINGS: The P. lambertii cp genome is 133,734 bp in length, and similar to other sequenced cupressophytes, it lacks one of the large inverted repeat regions (IR. It contains 118 unique genes and one duplicated tRNA (trnN-GUU, which occurs as an inverted repeat sequence. The rps16 gene was not found, which was previously reported for the plastid genome of another Podocarpaceae (Nageia nagi and Araucariaceae (Agathis dammara. Structurally, P. lambertii shows 4 inversions of a large DNA fragment ∼20,000 bp compared to the Podocarpus totara cp genome. These unexpected characteristics may be attributed to geographical distance and different adaptive needs. The P. lambertii cp genome presents a total of 28 tandem repeats and 156 SSRs, with homo- and dipolymers being the most common and tri-, tetra-, penta-, and hexapolymers occurring with less frequency. CONCLUSION: The complete cp genome sequence of P. lambertii revealed significant structural changes, even in species from the same genus. These results reinforce the apparently loss of rps16 gene in Podocarpaceae cp genome. In addition, several SSRs in the P. lambertii cp genome are likely intraspecific polymorphism sites, which may allow highly sensitive phylogeographic and population structure studies, as well as phylogenetic studies of species of

  8. Analyses of Evolutionary Characteristics of the Hemagglutinin-Esterase Gene of Influenza C Virus during a Period of 68 Years Reveals Evolutionary Patterns Different from Influenza A and B Viruses

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    Yuki Furuse

    2016-11-01

    Full Text Available Infections with the influenza C virus causing respiratory symptoms are common, particularly among children. Since isolation and detection of the virus are rarely performed, compared with influenza A and B viruses, the small number of available sequences of the virus makes it difficult to analyze its evolutionary dynamics. Recently, we reported the full genome sequence of 102 strains of the virus. Here, we exploited the data to elucidate the evolutionary characteristics and phylodynamics of the virus compared with influenza A and B viruses. Along with our data, we obtained public sequence data of the hemagglutinin-esterase gene of the virus; the dataset consists of 218 unique sequences of the virus collected from 14 countries between 1947 and 2014. Informatics analyses revealed that (1 multiple lineages have been circulating globally; (2 there have been weak and infrequent selective bottlenecks; (3 the evolutionary rate is low because of weak positive selection and a low capability to induce mutations; and (4 there is no significant positive selection although a few mutations affecting its antigenicity have been induced. The unique evolutionary dynamics of the influenza C virus must be shaped by multiple factors, including virological, immunological, and epidemiological characteristics.

  9. Genomic Resources for Gene Discovery, Functional Genome Annotation, and Evolutionary Studies of Maize and Its Close Relatives

    Science.gov (United States)

    Wang, Chao; Shi, Xue; Liu, Lin; Li, Haiyan; Ammiraju, Jetty S.S.; Kudrna, David A.; Xiong, Wentao; Wang, Hao; Dai, Zhaozhao; Zheng, Yonglian; Lai, Jinsheng; Jin, Weiwei; Messing, Joachim; Bennetzen, Jeffrey L; Wing, Rod A.; Luo, Meizhong

    2013-01-01

    Maize is one of the most important food crops and a key model for genetics and developmental biology. A genetically anchored and high-quality draft genome sequence of maize inbred B73 has been obtained to serve as a reference sequence. To facilitate evolutionary studies in maize and its close relatives, much like the Oryza Map Alignment Project (OMAP) (www.OMAP.org) bacterial artificial chromosome (BAC) resource did for the rice community, we constructed BAC libraries for maize inbred lines Zheng58, Chang7-2, and Mo17 and maize wild relatives Zea mays ssp. parviglumis and Tripsacum dactyloides. Furthermore, to extend functional genomic studies to maize and sorghum, we also constructed binary BAC (BIBAC) libraries for the maize inbred B73 and the sorghum landrace Nengsi-1. The BAC/BIBAC vectors facilitate transfer of large intact DNA inserts from BAC clones to the BIBAC vector and functional complementation of large DNA fragments. These seven Zea Map Alignment Project (ZMAP) BAC/BIBAC libraries have average insert sizes ranging from 92 to 148 kb, organellar DNA from 0.17 to 2.3%, empty vector rates between 0.35 and 5.56%, and genome equivalents of 4.7- to 8.4-fold. The usefulness of the Parviglumis and Tripsacum BAC libraries was demonstrated by mapping clones to the reference genome. Novel genes and alleles present in these ZMAP libraries can now be used for functional complementation studies and positional or homology-based cloning of genes for translational genomics. PMID:24037269

  10. Social evolution. Genomic signatures of evolutionary transitions from solitary to group living.

    Science.gov (United States)

    Kapheim, Karen M; Pan, Hailin; Li, Cai; Salzberg, Steven L; Puiu, Daniela; Magoc, Tanja; Robertson, Hugh M; Hudson, Matthew E; Venkat, Aarti; Fischman, Brielle J; Hernandez, Alvaro; Yandell, Mark; Ence, Daniel; Holt, Carson; Yocum, George D; Kemp, William P; Bosch, Jordi; Waterhouse, Robert M; Zdobnov, Evgeny M; Stolle, Eckart; Kraus, F Bernhard; Helbing, Sophie; Moritz, Robin F A; Glastad, Karl M; Hunt, Brendan G; Goodisman, Michael A D; Hauser, Frank; Grimmelikhuijzen, Cornelis J P; Pinheiro, Daniel Guariz; Nunes, Francis Morais Franco; Soares, Michelle Prioli Miranda; Tanaka, Érica Donato; Simões, Zilá Luz Paulino; Hartfelder, Klaus; Evans, Jay D; Barribeau, Seth M; Johnson, Reed M; Massey, Jonathan H; Southey, Bruce R; Hasselmann, Martin; Hamacher, Daniel; Biewer, Matthias; Kent, Clement F; Zayed, Amro; Blatti, Charles; Sinha, Saurabh; Johnston, J Spencer; Hanrahan, Shawn J; Kocher, Sarah D; Wang, Jun; Robinson, Gene E; Zhang, Guojie

    2015-06-05

    The evolution of eusociality is one of the major transitions in evolution, but the underlying genomic changes are unknown. We compared the genomes of 10 bee species that vary in social complexity, representing multiple independent transitions in social evolution, and report three major findings. First, many important genes show evidence of neutral evolution as a consequence of relaxed selection with increasing social complexity. Second, there is no single road map to eusociality; independent evolutionary transitions in sociality have independent genetic underpinnings. Third, though clearly independent in detail, these transitions do have similar general features, including an increase in constrained protein evolution accompanied by increases in the potential for gene regulation and decreases in diversity and abundance of transposable elements. Eusociality may arise through different mechanisms each time, but would likely always involve an increase in the complexity of gene networks. Copyright © 2015, American Association for the Advancement of Science.

  11. 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

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

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    Koebnik Ralf

    2011-03-01

    Full Text Available 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

  13. CpGislandEVO: A Database and Genome Browser for Comparative Evolutionary Genomics of CpG Islands

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    Guillermo Barturen

    2013-01-01

    Full Text Available Hypomethylated, CpG-rich DNA segments (CpG islands, CGIs are epigenome markers involved in key biological processes. Aberrant methylation is implicated in the appearance of several disorders as cancer, immunodeficiency, or centromere instability. Furthermore, methylation differences at promoter regions between human and chimpanzee strongly associate with genes involved in neurological/psychological disorders and cancers. Therefore, the evolutionary comparative analyses of CGIs can provide insights on the functional role of these epigenome markers in both health and disease. Given the lack of specific tools, we developed CpGislandEVO. Briefly, we first compile a database of statistically significant CGIs for the best assembled mammalian genome sequences available to date. Second, by means of a coupled browser front-end, we focus on the CGIs overlapping orthologous genes extracted from OrthoDB, thus ensuring the comparison between CGIs located on truly homologous genome segments. This allows comparing the main compositional features between homologous CGIs. Finally, to facilitate nucleotide comparisons, we lifted genome coordinates between assemblies from different species, which enables the analysis of sequence divergence by direct count of nucleotide substitutions and indels occurring between homologous CGIs. The resulting CpGislandEVO database, linking together CGIs and single-cytosine DNA methylation data from several mammalian species, is freely available at our website.

  14. Comparative genomics reveals adaptive evolution of Asian tapeworm in switching to a new intermediate host.

    Science.gov (United States)

    Wang, Shuai; Wang, Sen; Luo, Yingfeng; Xiao, Lihua; Luo, Xuenong; Gao, Shenghan; Dou, Yongxi; Zhang, Huangkai; Guo, Aijiang; Meng, Qingshu; Hou, Junling; Zhang, Bing; Zhang, Shaohua; Yang, Meng; Meng, Xuelian; Mei, Hailiang; Li, Hui; He, Zilong; Zhu, Xueliang; Tan, Xinyu; Zhu, Xing-Quan; Yu, Jun; Cai, Jianping; Zhu, Guan; Hu, Songnian; Cai, Xuepeng

    2016-09-22

    Taenia saginata, Taenia solium and Taenia asiatica (beef, pork and Asian tapeworms, respectively) are parasitic flatworms of major public health and food safety importance. Among them, T. asiatica is a newly recognized species that split from T. saginata via an intermediate host switch ∼1.14 Myr ago. Here we report the 169- and 168-Mb draft genomes of T. saginata and T. asiatica. Comparative analysis reveals that high rates of gene duplications and functional diversifications might have partially driven the divergence between T. asiatica and T. saginata. We observe accelerated evolutionary rates, adaptive evolutions in homeostasis regulation, tegument maintenance and lipid uptakes, and differential/specialized gene family expansions in T. asiatica that may favour its hepatotropism in the new intermediate host. We also identify potential targets for developing diagnostic or intervention tools against human tapeworms. These data provide new insights into the evolution of Taenia parasites, particularly the recent speciation of T. asiatica.

  15. Comparative genomics reveals adaptive evolution of Asian tapeworm in switching to a new intermediate host

    Science.gov (United States)

    Wang, Shuai; Wang, Sen; Luo, Yingfeng; Xiao, Lihua; Luo, Xuenong; Gao, Shenghan; Dou, Yongxi; Zhang, Huangkai; Guo, Aijiang; Meng, Qingshu; Hou, Junling; Zhang, Bing; Zhang, Shaohua; Yang, Meng; Meng, Xuelian; Mei, Hailiang; Li, Hui; He, Zilong; Zhu, Xueliang; Tan, Xinyu; Zhu, Xing-quan; Yu, Jun; Cai, Jianping; Zhu, Guan; Hu, Songnian; Cai, Xuepeng

    2016-01-01

    Taenia saginata, Taenia solium and Taenia asiatica (beef, pork and Asian tapeworms, respectively) are parasitic flatworms of major public health and food safety importance. Among them, T. asiatica is a newly recognized species that split from T. saginata via an intermediate host switch ∼1.14 Myr ago. Here we report the 169- and 168-Mb draft genomes of T. saginata and T. asiatica. Comparative analysis reveals that high rates of gene duplications and functional diversifications might have partially driven the divergence between T. asiatica and T. saginata. We observe accelerated evolutionary rates, adaptive evolutions in homeostasis regulation, tegument maintenance and lipid uptakes, and differential/specialized gene family expansions in T. asiatica that may favour its hepatotropism in the new intermediate host. We also identify potential targets for developing diagnostic or intervention tools against human tapeworms. These data provide new insights into the evolution of Taenia parasites, particularly the recent speciation of T. asiatica. PMID:27653464

  16. Calculation of evolutionary correlation between individual genes and full-length genome: a method useful for choosing phylogenetic markers for molecular epidemiology.

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    Shuai Wang

    Full Text Available Individual genes or regions are still commonly used to estimate the phylogenetic relationships among viral isolates. The genomic regions that can faithfully provide assessments consistent with those predicted with full-length genome sequences would be preferable to serve as good candidates of the phylogenetic markers for molecular epidemiological studies of many viruses. Here we employed a statistical method to evaluate the evolutionary relationships between individual viral genes and full-length genomes without tree construction as a way to determine which gene can match the genome well in phylogenetic analyses. This method was performed by calculation of linear correlations between the genetic distance matrices of aligned individual gene sequences and aligned genome sequences. We applied this method to the phylogenetic analyses of porcine circovirus 2 (PCV2, measles virus (MV, hepatitis E virus (HEV and Japanese encephalitis virus (JEV. Phylogenetic trees were constructed for comparisons and the possible factors affecting the method accuracy were also discussed in the calculations. The results revealed that this method could produce results consistent with those of previous studies about the proper consensus sequences that could be successfully used as phylogenetic markers. And our results also suggested that these evolutionary correlations could provide useful information for identifying genes that could be used effectively to infer the genetic relationships.

  17. Controlling for Phylogenetic Relatedness and Evolutionary Rates Improves the Discovery of Associations Between Species' Phenotypic and Genomic Differences.

    Science.gov (United States)

    Prudent, Xavier; Parra, Genis; Schwede, Peter; Roscito, Juliana G; Hiller, Michael

    2016-08-01

    The growing number of sequenced genomes allows us now to address a key question in genetics and evolutionary biology: which genomic changes underlie particular phenotypic changes between species? Previously, we developed a computational framework called Forward Genomics that associates phenotypic to genomic differences by focusing on phenotypes that are independently lost in different lineages. However, our previous implementation had three main limitations. Here, we present two new Forward Genomics methods that overcome these limitations by (1) directly controlling for phylogenetic relatedness, (2) controlling for differences in evolutionary rates, and (3) computing a statistical significance. We demonstrate on large-scale simulated data and on real data that both new methods substantially improve the sensitivity to detect associations between phenotypic and genomic differences. We applied these new methods to detect genomic differences involved in the loss of vision in the blind mole rat and the cape golden mole, two independent subterranean mammals. Forward Genomics identified several genes that are enriched in functions related to eye development and the perception of light, as well as genes involved in the circadian rhythm. These new Forward Genomics methods represent a significant advance in our ability to discover the genomic basis underlying phenotypic differences between species. Source code: https://github.com/hillerlab/ForwardGenomics/. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Dynamic evolution of pathogenicity revealed by sequencing and comparative genomics of 19 Pseudomonas syringae isolates.

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    David A Baltrus

    2011-07-01

    Full Text Available Closely related pathogens may differ dramatically in host range, but the molecular, genetic, and evolutionary basis for these differences remains unclear. In many Gram- negative bacteria, including the phytopathogen Pseudomonas syringae, type III effectors (TTEs are essential for pathogenicity, instrumental in structuring host range, and exhibit wide diversity between strains. To capture the dynamic nature of virulence gene repertoires across P. syringae, we screened 11 diverse strains for novel TTE families and coupled this nearly saturating screen with the sequencing and assembly of 14 phylogenetically diverse isolates from a broad collection of diseased host plants. TTE repertoires vary dramatically in size and content across all P. syringae clades; surprisingly few TTEs are conserved and present in all strains. Those that are likely provide basal requirements for pathogenicity. We demonstrate that functional divergence within one conserved locus, hopM1, leads to dramatic differences in pathogenicity, and we demonstrate that phylogenetics-informed mutagenesis can be used to identify functionally critical residues of TTEs. The dynamism of the TTE repertoire is mirrored by diversity in pathways affecting the synthesis of secreted phytotoxins, highlighting the likely role of both types of virulence factors in determination of host range. We used these 14 draft genome sequences, plus five additional genome sequences previously reported, to identify the core genome for P. syringae and we compared this core to that of two closely related non-pathogenic pseudomonad species. These data revealed the recent acquisition of a 1 Mb megaplasmid by a sub-clade of cucumber pathogens. This megaplasmid encodes a type IV secretion system and a diverse set of unknown proteins, which dramatically increases both the genomic content of these strains and the pan-genome of the species.

  19. Dynamic evolution of pathogenicity revealed by sequencing and comparative genomics of 19 Pseudomonas syringae isolates.

    Science.gov (United States)

    Baltrus, David A; Nishimura, Marc T; Romanchuk, Artur; Chang, Jeff H; Mukhtar, M Shahid; Cherkis, Karen; Roach, Jeff; Grant, Sarah R; Jones, Corbin D; Dangl, Jeffery L

    2011-07-01

    Closely related pathogens may differ dramatically in host range, but the molecular, genetic, and evolutionary basis for these differences remains unclear. In many Gram- negative bacteria, including the phytopathogen Pseudomonas syringae, type III effectors (TTEs) are essential for pathogenicity, instrumental in structuring host range, and exhibit wide diversity between strains. To capture the dynamic nature of virulence gene repertoires across P. syringae, we screened 11 diverse strains for novel TTE families and coupled this nearly saturating screen with the sequencing and assembly of 14 phylogenetically diverse isolates from a broad collection of diseased host plants. TTE repertoires vary dramatically in size and content across all P. syringae clades; surprisingly few TTEs are conserved and present in all strains. Those that are likely provide basal requirements for pathogenicity. We demonstrate that functional divergence within one conserved locus, hopM1, leads to dramatic differences in pathogenicity, and we demonstrate that phylogenetics-informed mutagenesis can be used to identify functionally critical residues of TTEs. The dynamism of the TTE repertoire is mirrored by diversity in pathways affecting the synthesis of secreted phytotoxins, highlighting the likely role of both types of virulence factors in determination of host range. We used these 14 draft genome sequences, plus five additional genome sequences previously reported, to identify the core genome for P. syringae and we compared this core to that of two closely related non-pathogenic pseudomonad species. These data revealed the recent acquisition of a 1 Mb megaplasmid by a sub-clade of cucumber pathogens. This megaplasmid encodes a type IV secretion system and a diverse set of unknown proteins, which dramatically increases both the genomic content of these strains and the pan-genome of the species. © 2011 Baltrus et al.

  20. Preferential duplication of intermodular hub genes: an evolutionary signature in eukaryotes genome networks.

    Directory of Open Access Journals (Sweden)

    Ricardo M Ferreira

    Full Text Available Whole genome protein-protein association networks are not random and their topological properties stem from genome evolution mechanisms. In fact, more connected, but less clustered proteins are related to genes that, in general, present more paralogs as compared to other genes, indicating frequent previous gene duplication episodes. On the other hand, genes related to conserved biological functions present few or no paralogs and yield proteins that are highly connected and clustered. These general network characteristics must have an evolutionary explanation. Considering data from STRING database, we present here experimental evidence that, more than not being scale free, protein degree distributions of organisms present an increased probability for high degree nodes. Furthermore, based on this experimental evidence, we propose a simulation model for genome evolution, where genes in a network are either acquired de novo using a preferential attachment rule, or duplicated with a probability that linearly grows with gene degree and decreases with its clustering coefficient. For the first time a model yields results that simultaneously describe different topological distributions. Also, this model correctly predicts that, to produce protein-protein association networks with number of links and number of nodes in the observed range for Eukaryotes, it is necessary 90% of gene duplication and 10% of de novo gene acquisition. This scenario implies a universal mechanism for genome evolution.

  1. Conflicting Evolutionary Histories of the Mitochondrial and Nuclear Genomes in New World Myotis Bats.

    Science.gov (United States)

    Platt, Roy N; Faircloth, Brant C; Sullivan, Kevin A M; Kieran, Troy J; Glenn, Travis C; Vandewege, Michael W; Lee, Thomas E; Baker, Robert J; Stevens, Richard D; Ray, David A

    2018-03-01

    The rapid diversification of Myotis bats into more than 100 species is one of the most extensive mammalian radiations available for study. Efforts to understand relationships within Myotis have primarily utilized mitochondrial markers and trees inferred from nuclear markers lacked resolution. Our current understanding of relationships within Myotis is therefore biased towards a set of phylogenetic markers that may not reflect the history of the nuclear genome. To resolve this, we sequenced the full mitochondrial genomes of 37 representative Myotis, primarily from the New World, in conjunction with targeted sequencing of 3648 ultraconserved elements (UCEs). We inferred the phylogeny and explored the effects of concatenation and summary phylogenetic methods, as well as combinations of markers based on informativeness or levels of missing data, on our results. Of the 294 phylogenies generated from the nuclear UCE data, all are significantly different from phylogenies inferred using mitochondrial genomes. Even within the nuclear data, quartet frequencies indicate that around half of all UCE loci conflict with the estimated species tree. Several factors can drive such conflict, including incomplete lineage sorting, introgressive hybridization, or even phylogenetic error. Despite the degree of discordance between nuclear UCE loci and the mitochondrial genome and among UCE loci themselves, the most common nuclear topology is recovered in one quarter of all analyses with strong nodal support. Based on these results, we re-examine the evolutionary history of Myotis to better understand the phenomena driving their unique nuclear, mitochondrial, and biogeographic histories.

  2. Genomic Data from Extinct North American Camelops Revise Camel Evolutionary History.

    Science.gov (United States)

    Heintzman, Peter D; Zazula, Grant D; Cahill, James A; Reyes, Alberto V; MacPhee, Ross D E; Shapiro, Beth

    2015-09-01

    Recent advances in paleogenomic technologies have enabled an increasingly detailed understanding of the evolutionary relationships of now-extinct mammalian taxa. However, a number of enigmatic Quaternary species have never been characterized with molecular data, often because available fossils are rare or are found in environments that are not optimal for DNA preservation. Here, we analyze paleogenomic data extracted from bones attributed to the late Pleistocene western camel, Camelops cf. hesternus, a species that was distributed across central and western North America until its extinction approximately 13,000 years ago. Despite a modal sequence length of only around 35 base pairs, we reconstructed high-coverage complete mitochondrial genomes and low-coverage partial nuclear genomes for each specimen. We find that Camelops is sister to African and Asian bactrian and dromedary camels, to the exclusion of South American camelids (llamas, guanacos, alpacas, and vicuñas). These results contradict previous morphology-based phylogenetic models for Camelops, which suggest instead a closer relationship between Camelops and the South American camelids. The molecular data imply a Late Miocene divergence of the Camelops clade from lineages that separately gave rise to the extant camels of Eurasia. Our results demonstrate the increasing capacity of modern paleogenomic methods to resolve evolutionary relationships among distantly related lineages. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Genome-wide comparative analysis reveals similar types of NBS genes in hybrid Citrus sinensis genome and original Citrus clementine genome and provides new insights into non-TIR NBS genes.

    Science.gov (United States)

    Wang, Yunsheng; Zhou, Lijuan; Li, Dazhi; Dai, Liangying; Lawton-Rauh, Amy; Srimani, Pradip K; Duan, Yongping; Luo, Feng

    2015-01-01

    In this study, we identified and compared nucleotide-binding site (NBS) domain-containing genes from three Citrus genomes (C. clementina, C. sinensis from USA and C. sinensis from China). Phylogenetic analysis of all Citrus NBS genes across these three genomes revealed that there are three approximately evenly numbered groups: one group contains the Toll-Interleukin receptor (TIR) domain and two different Non-TIR groups in which most of proteins contain the Coiled Coil (CC) domain. Motif analysis confirmed that the two groups of CC-containing NBS genes are from different evolutionary origins. We partitioned NBS genes into clades using NBS domain sequence distances and found most clades include NBS genes from all three Citrus genomes. This suggests that three Citrus genomes have similar numbers and types of NBS genes. We also mapped the re-sequenced reads of three pomelo and three mandarin genomes onto the C. sinensis genome. We found that most NBS genes of the hybrid C. sinensis genome have corresponding homologous genes in both pomelo and mandarin genomes. The homologous NBS genes in pomelo and mandarin suggest that the parental species of C. sinensis may contain similar types of NBS genes. This explains why the hybrid C. sinensis and original C. clementina have similar types of NBS genes in this study. Furthermore, we found that sequence variation amongst Citrus NBS genes were shaped by multiple independent and shared accelerated mutation accumulation events among different groups of NBS genes and in different Citrus genomes. Our comparative analyses yield valuable insight into the structure, organization and evolution of NBS genes in Citrus genomes. Furthermore, our comprehensive analysis showed that the non-TIR NBS genes can be divided into two groups that come from different evolutionary origins. This provides new insights into non-TIR genes, which have not received much attention.

  4. Genome-wide comparative analysis reveals similar types of NBS genes in hybrid Citrus sinensis genome and original Citrus clementine genome and provides new insights into non-TIR NBS genes.

    Directory of Open Access Journals (Sweden)

    Yunsheng Wang

    Full Text Available In this study, we identified and compared nucleotide-binding site (NBS domain-containing genes from three Citrus genomes (C. clementina, C. sinensis from USA and C. sinensis from China. Phylogenetic analysis of all Citrus NBS genes across these three genomes revealed that there are three approximately evenly numbered groups: one group contains the Toll-Interleukin receptor (TIR domain and two different Non-TIR groups in which most of proteins contain the Coiled Coil (CC domain. Motif analysis confirmed that the two groups of CC-containing NBS genes are from different evolutionary origins. We partitioned NBS genes into clades using NBS domain sequence distances and found most clades include NBS genes from all three Citrus genomes. This suggests that three Citrus genomes have similar numbers and types of NBS genes. We also mapped the re-sequenced reads of three pomelo and three mandarin genomes onto the C. sinensis genome. We found that most NBS genes of the hybrid C. sinensis genome have corresponding homologous genes in both pomelo and mandarin genomes. The homologous NBS genes in pomelo and mandarin suggest that the parental species of C. sinensis may contain similar types of NBS genes. This explains why the hybrid C. sinensis and original C. clementina have similar types of NBS genes in this study. Furthermore, we found that sequence variation amongst Citrus NBS genes were shaped by multiple independent and shared accelerated mutation accumulation events among different groups of NBS genes and in different Citrus genomes. Our comparative analyses yield valuable insight into the structure, organization and evolution of NBS genes in Citrus genomes. Furthermore, our comprehensive analysis showed that the non-TIR NBS genes can be divided into two groups that come from different evolutionary origins. This provides new insights into non-TIR genes, which have not received much attention.

  5. Genome-scale transcriptional analyses of first-generation interspecific sunflower hybrids reveals broad regulatory compatibility

    OpenAIRE

    Rowe, Heather C.; Rieseberg, Loren H.

    2013-01-01

    Background Interspecific hybridization creates individuals harboring diverged genomes. The interaction of these genomes can generate successful evolutionary novelty or disadvantageous genomic conflict. Annual sunflowers Helianthus annuus and H. petiolaris have a rich history of hybridization in natural populations. Although first-generation hybrids generally have low fertility, hybrid swarms that include later generation and fully fertile backcross plants have been identified, as well as at l...

  6. Mountain gorilla genomes reveal the impact of long-term population decline and inbreeding

    DEFF Research Database (Denmark)

    Xue, Yali; Prado-Martinez, Javier; Sudmant, Peter H

    2015-01-01

    Mountain gorillas are an endangered great ape subspecies and a prominent focus for conservation, yet we know little about their genomic diversity and evolutionary past. We sequenced whole genomes from multiple wild individuals and compared the genomes of all four Gorilla subspecies. We found that......, such that individuals are typically homozygous at 34% of their sequence, leading to the purging of severely deleterious recessive mutations from the population. We discuss the causes of their decline and the consequences for their future survival....

  7. Sequencing the CHO DXB11 genome reveals regional variations in genomic stability and haploidy

    DEFF Research Database (Denmark)

    Kaas, Christian Schrøder; Kristensen, Claus; Betenbaugh, Michael J.

    2015-01-01

    depths of 0x, 16x, 33x and 49x coverage corresponding to a copy number in the genome of 0, 1, 2 and 3 copies. This indicate that 17% of the genes are haploid revealing a large number of genes which can be knocked out with relative ease. This tendency of haploidy was furthermore shown to be present...... in eight additional analyzed CHO genomes (15-20% haploidy) but not in the genome of the Chinese hamster. The dhfr gene is confirmed to be haploid in CHO DXB11; transcriptionally active and the remaining allele contains a G410C point mutation causing a Thr137Arg missense mutation. We find similar to 2...

  8. Evolution and phylogeny of the mud shrimps (Crustacea: Decapoda) revealed from complete mitochondrial genomes.

    Science.gov (United States)

    Lin, Feng-Jiau; Liu, Yuan; Sha, Zhongli; Tsang, Ling Ming; Chu, Ka Hou; Chan, Tin-Yam; Liu, Ruiyu; Cui, Zhaoxia

    2012-11-16

    The evolutionary history and relationships of the mud shrimps (Crustacea: Decapoda: Gebiidea and Axiidea) are contentious, with previous attempts revealing mixed results. The mud shrimps were once classified in the infraorder Thalassinidea. Recent molecular phylogenetic analyses, however, suggest separation of the group into two individual infraorders, Gebiidea and Axiidea. Mitochondrial (mt) genome sequence and structure can be especially powerful in resolving higher systematic relationships that may offer new insights into the phylogeny of the mud shrimps and the other decapod infraorders, and test the hypothesis of dividing the mud shrimps into two infraorders. We present the complete mitochondrial genome sequences of five mud shrimps, Austinogebia edulis, Upogebia major, Thalassina kelanang (Gebiidea), Nihonotrypaea thermophilus and Neaxius glyptocercus (Axiidea). All five genomes encode a standard set of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a putative control region. Except for T. kelanang, mud shrimp mitochondrial genomes exhibited rearrangements and novel patterns compared to the pancrustacean ground pattern. Each of the two Gebiidea species (A. edulis and U. major) and two Axiidea species (N. glyptocercus and N. thermophiles) share unique gene order specific to their infraorders and analyses further suggest these two derived gene orders have evolved independently. Phylogenetic analyses based on the concatenated nucleotide and amino acid sequences of 13 protein-coding genes indicate the possible polyphyly of mud shrimps, supporting the division of the group into two infraorders. However, the infraordinal relationships among the Gebiidea and Axiidea, and other reptants are poorly resolved. The inclusion of mt genome from more taxa, in particular the reptant infraorders Polychelida and Glypheidea is required in further analysis. Phylogenetic analyses on the mt genome sequences and the distinct gene orders provide further

  9. Evolution and phylogeny of the mud shrimps (Crustacea: Decapoda) revealed from complete mitochondrial genomes

    Science.gov (United States)

    2012-01-01

    Background The evolutionary history and relationships of the mud shrimps (Crustacea: Decapoda: Gebiidea and Axiidea) are contentious, with previous attempts revealing mixed results. The mud shrimps were once classified in the infraorder Thalassinidea. Recent molecular phylogenetic analyses, however, suggest separation of the group into two individual infraorders, Gebiidea and Axiidea. Mitochondrial (mt) genome sequence and structure can be especially powerful in resolving higher systematic relationships that may offer new insights into the phylogeny of the mud shrimps and the other decapod infraorders, and test the hypothesis of dividing the mud shrimps into two infraorders. Results We present the complete mitochondrial genome sequences of five mud shrimps, Austinogebia edulis, Upogebia major, Thalassina kelanang (Gebiidea), Nihonotrypaea thermophilus and Neaxius glyptocercus (Axiidea). All five genomes encode a standard set of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a putative control region. Except for T. kelanang, mud shrimp mitochondrial genomes exhibited rearrangements and novel patterns compared to the pancrustacean ground pattern. Each of the two Gebiidea species (A. edulis and U. major) and two Axiidea species (N. glyptocercus and N. thermophiles) share unique gene order specific to their infraorders and analyses further suggest these two derived gene orders have evolved independently. Phylogenetic analyses based on the concatenated nucleotide and amino acid sequences of 13 protein-coding genes indicate the possible polyphyly of mud shrimps, supporting the division of the group into two infraorders. However, the infraordinal relationships among the Gebiidea and Axiidea, and other reptants are poorly resolved. The inclusion of mt genome from more taxa, in particular the reptant infraorders Polychelida and Glypheidea is required in further analysis. Conclusions Phylogenetic analyses on the mt genome sequences and the

  10. Evolutionary relationships of Fusobacterium nucleatum based on phylogenetic analysis and comparative genomics

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    Moreira David

    2004-11-01

    Full Text Available Abstract Background The phylogenetic position and evolutionary relationships of Fusobacteria remain uncertain. Especially intriguing is their relatedness to low G+C Gram positive bacteria (Firmicutes by ribosomal molecular phylogenies, but their possession of a typical gram negative outer membrane. Taking advantage of the recent completion of the Fusobacterium nucleatum genome sequence we have examined the evolutionary relationships of Fusobacterium genes by phylogenetic analysis and comparative genomics tools. Results The data indicate that Fusobacterium has a core genome of a very different nature to other bacterial lineages, and branches out at the base of Firmicutes. However, depending on the method used, 35–56% of Fusobacterium genes appear to have a xenologous origin from bacteroidetes, proteobacteria, spirochaetes and the Firmicutes themselves. A high number of hypothetical ORFs with unusual codon usage and short lengths were found and hypothesized to be remnants of transferred genes that were discarded. Some proteins and operons are also hypothesized to be of mixed ancestry. A large portion of the Gram-negative cell wall-related genes seems to have been transferred from proteobacteria. Conclusions Many instances of similarity to other inhabitants of the dental plaque that have been sequenced were found. This suggests that the close physical contact found in this environment might facilitate horizontal gene transfer, supporting the idea of niche-specific gene pools. We hypothesize that at a point in time, probably associated to the rise of mammals, a strong selective pressure might have existed for a cell with a Clostridia-like metabolic apparatus but with the adhesive and immune camouflage features of Proteobacteria.

  11. Evolutionary Dynamics of Small RNAs in 27 Escherichia coli and Shigella Genomes

    Science.gov (United States)

    Skippington, Elizabeth; Ragan, Mark A.

    2012-01-01

    Small RNAs (sRNAs) are widespread in bacteria and play critical roles in regulating physiological processes. They are best characterized in Escherichia coli K-12 MG1655, where 83 sRNAs constitute nearly 2% of the gene complement. Most sRNAs act by base pairing with a target mRNA, modulating its translation and/or stability; many of these RNAs share only limited complementarity to their mRNA target, and require the chaperone Hfq to facilitate base pairing. Little is known about the evolutionary dynamics of bacterial sRNAs. Here, we apply phylogenetic and network analyses to investigate the evolutionary processes and principles that govern sRNA gene distribution in 27 E. coli and Shigella genomes. We identify core (encoded in all 27 genomes) and variable sRNAs; more than two-thirds of the E. coli K-12 MG1655 sRNAs are core, whereas the others show patterns of presence and absence that are principally due to genetic loss, not duplication or lateral genetic transfer. We present evidence that variable sRNAs are less tightly integrated into cellular genetic regulatory networks than are the core sRNAs, and that Hfq facilitates posttranscriptional cross talk between the E. coli–Shigella core and variable genomes. Finally, we present evidence that more than 80% of genes targeted by Hfq-associated core sRNAs have been transferred within the E. coli–Shigella clade, and that most of these genes have been transferred intact. These results suggest that Hfq and sRNAs help integrate laterally acquired genes into established regulatory networks. PMID:22223756

  12. Comparative analysis of the peanut witches'-broom phytoplasma genome reveals horizontal transfer of potential mobile units and effectors.

    Science.gov (United States)

    Chung, Wan-Chia; Chen, Ling-Ling; Lo, Wen-Sui; Lin, Chan-Pin; Kuo, Chih-Horng

    2013-01-01

    Phytoplasmas are a group of bacteria that are associated with hundreds of plant diseases. Due to their economical importance and the difficulties involved in the experimental study of these obligate pathogens, genome sequencing and comparative analysis have been utilized as powerful tools to understand phytoplasma biology. To date four complete phytoplasma genome sequences have been published. However, these four strains represent limited phylogenetic diversity. In this study, we report the shotgun sequencing and evolutionary analysis of a peanut witches'-broom (PnWB) phytoplasma genome. The availability of this genome provides the first representative of the 16SrII group and substantially improves the taxon sampling to investigate genome evolution. The draft genome assembly contains 13 chromosomal contigs with a total size of 562,473 bp, covering ∼90% of the chromosome. Additionally, a complete plasmid sequence is included. Comparisons among the five available phytoplasma genomes reveal the differentiations in gene content and metabolic capacity. Notably, phylogenetic inferences of the potential mobile units (PMUs) in these genomes indicate that horizontal transfer may have occurred between divergent phytoplasma lineages. Because many effectors are associated with PMUs, the horizontal transfer of these transposon-like elements can contribute to the adaptation and diversification of these pathogens. In summary, the findings from this study highlight the importance of improving taxon sampling when investigating genome evolution. Moreover, the currently available sequences are inadequate to fully characterize the pan-genome of phytoplasmas. Future genome sequencing efforts to expand phylogenetic diversity are essential in improving our understanding of phytoplasma evolution.

  13. Evolutionary Genomics and Conservation of the Endangered Przewalski’s Horse

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Ermini, Luca; Schubert, Mikkel

    2015-01-01

    and short legs, they are phenotypically and behaviorally distinct from domesticated horses (DHs, Equus caballus). Here, we sequenced the complete genomes of 11 PHs, representing all founding lineages, and five historical specimens dated to 1878–1929 CE, including the Holotype. These were compared...... to the hitherto-most-extensive genome dataset characterized for horses, comprising 21 new genomes. We found that loci showing the most genetic differentiation with DHs were enriched in genes involved in metabolism, cardiac disorders, muscle contraction, reproduction, behavior, and signaling pathways. We also show...... that DH and PH populations split ∼45,000 years ago and have remained connected by gene-flow thereafter. Finally, we monitor the genomic impact of ∼110 years of captivity, revealing reduced heterozygosity, increased inbreeding, and variable introgression of domestic alleles, ranging from non...

  14. Evolutionary history of barley cultivation in Europe revealed by genetic analysis of extant landraces

    Directory of Open Access Journals (Sweden)

    Jones Huw

    2011-11-01

    Full Text Available Abstract Background Understanding the evolution of cultivated barley is important for two reasons. First, the evolutionary relationships between different landraces might provide information on the spread and subsequent development of barley cultivation, including the adaptation of the crop to new environments and its response to human selection. Second, evolutionary information would enable landraces with similar traits but different genetic backgrounds to be identified, providing alternative strategies for the introduction of these traits into modern germplasm. Results The evolutionary relationships between 651 barley landraces were inferred from the genotypes for 24 microsatellites. The landraces could be divided into nine populations, each with a different geographical distribution. Comparisons with ear row number, caryopsis structure, seasonal growth habit and flowering time revealed a degree of association between population structure and phenotype, and analysis of climate variables indicated that the landraces are adapted, at least to some extent, to their environment. Human selection and/or environmental adaptation may therefore have played a role in the origin and/or maintenance of one or more of the barley landrace populations. There was also evidence that at least some of the population structure derived from geographical partitioning set up during the initial spread of barley cultivation into Europe, or reflected the later introduction of novel varieties. In particular, three closely-related populations were made up almost entirely of plants with the daylength nonresponsive version of the photoperiod response gene PPD-H1, conferring adaptation to the long annual growth season of northern Europe. These three populations probably originated in the eastern Fertile Crescent and entered Europe after the initial spread of agriculture. Conclusions The discovery of population structure, combined with knowledge of associated phenotypes and

  15. The repetitive component of the A genome of peanut (Arachis hypogaea) and its role in remodelling intergenic sequence space since its evolutionary divergence from the B genome

    Science.gov (United States)

    Bertioli, David J.; Vidigal, Bruna; Nielen, Stephan; Ratnaparkhe, Milind B.; Lee, Tae-Ho; Leal-Bertioli, Soraya C. M.; Kim, Changsoo; Guimarães, Patricia M.; Seijo, Guillermo; Schwarzacher, Trude; Paterson, Andrew H.; Heslop-Harrison, Pat; Araujo, Ana C. G.

    2013-01-01

    Background and Aims Peanut (Arachis hypogaea) is an allotetraploid (AABB-type genome) of recent origin, with a genome of about 2·8 Gb and a high repetitive content. This study reports an analysis of the repetitive component of the peanut A genome using bacterial artificial chromosome (BAC) clones from A. duranensis, the most probable A genome donor, and the probable consequences of the activity of these elements since the divergence of the peanut A and B genomes. Methods The repetitive content of the A genome was analysed by using A. duranensis BAC clones as probes for fluorescence in situ hybridization (BAC-FISH), and by sequencing and characterization of 12 genomic regions. For the analysis of the evolutionary dynamics, two A genome regions are compared with their B genome homeologues. Key Results BAC-FISH using 27 A. duranensis BAC clones as probes gave dispersed and repetitive DNA characteristic signals, predominantly in interstitial regions of the peanut A chromosomes. The sequences of 14 BAC clones showed complete and truncated copies of ten abundant long terminal repeat (LTR) retrotransposons, characterized here. Almost all dateable transposition events occurred genomes. The most abundant retrotransposon is Feral, apparently parasitic on the retrotransposon FIDEL, followed by Pipa, also non-autonomous and probably parasitic on a retrotransposon we named Pipoka. The comparison of the A and B genome homeologous regions showed conserved segments of high sequence identity, punctuated by predominantly indel regions without significant similarity. Conclusions A substantial proportion of the highly repetitive component of the peanut A genome appears to be accounted for by relatively few LTR retrotransposons and their truncated copies or solo LTRs. The most abundant of the retrotransposons are non-autonomous. The activity of these retrotransposons has been a very significant driver of genome evolution since the evolutionary divergence of the A and B genomes. PMID

  16. The Population Genomics of Sunflowers and Genomic Determinants of Protein Evolution Revealed by RNAseq

    Directory of Open Access Journals (Sweden)

    Loren H. Rieseberg

    2012-10-01

    Full Text Available Few studies have investigated the causes of evolutionary rate variation among plant nuclear genes, especially in recently diverged species still capable of hybridizing in the wild. The recent advent of Next Generation Sequencing (NGS permits investigation of genome wide rates of protein evolution and the role of selection in generating and maintaining divergence. Here, we use individual whole-transcriptome sequencing (RNAseq to refine our understanding of the population genomics of wild species of sunflowers (Helianthus spp. and the factors that affect rates of protein evolution. We aligned 35 GB of transcriptome sequencing data and identified 433,257 polymorphic sites (SNPs in a reference transcriptome comprising 16,312 genes. Using SNP markers, we identified strong population clustering largely corresponding to the three species analyzed here (Helianthus annuus, H. petiolaris, H. debilis, with one distinct early generation hybrid. Then, we calculated the proportions of adaptive substitution fixed by selection (alpha and identified gene ontology categories with elevated values of alpha. The “response to biotic stimulus” category had the highest mean alpha across the three interspecific comparisons, implying that natural selection imposed by other organisms plays an important role in driving protein evolution in wild sunflowers. Finally, we examined the relationship between protein evolution (dN/dS ratio and several genomic factors predicted to co-vary with protein evolution (gene expression level, divergence and specificity, genetic divergence [FST], and nucleotide diversity pi. We find that variation in rates of protein divergence was correlated with gene expression level and specificity, consistent with results from a broad range of taxa and timescales. This would in turn imply that these factors govern protein evolution both at a microevolutionary and macroevolutionary timescale. Our results contribute to a general understanding of the

  17. Characterization of the avian Trojan gene family reveals contrasting evolutionary constraints.

    Directory of Open Access Journals (Sweden)

    Petar Petrov

    Full Text Available "Trojan" is a leukocyte-specific, cell surface protein originally identified in the chicken. Its molecular function has been hypothesized to be related to anti-apoptosis and the proliferation of immune cells. The Trojan gene has been localized onto the Z sex chromosome. The adjacent two genes also show significant homology to Trojan, suggesting the existence of a novel gene/protein family. Here, we characterize this Trojan family, identify homologues in other species and predict evolutionary constraints on these genes. The two Trojan-related proteins in chicken were predicted as a receptor-type tyrosine phosphatase and a transmembrane protein, bearing a cytoplasmic immuno-receptor tyrosine-based activation motif. We identified the Trojan gene family in ten other bird species and found related genes in three reptiles and a fish species. The phylogenetic analysis of the homologues revealed a gradual diversification among the family members. Evolutionary analyzes of the avian genes predicted that the extracellular regions of the proteins have been subjected to positive selection. Such selection was possibly a response to evolving interacting partners or to pathogen challenges. We also observed an almost complete lack of intracellular positively selected sites, suggesting a conserved signaling mechanism of the molecules. Therefore, the contrasting patterns of selection likely correlate with the interaction and signaling potential of the molecules.

  18. Characterization of the avian Trojan gene family reveals contrasting evolutionary constraints.

    Science.gov (United States)

    Petrov, Petar; Syrjänen, Riikka; Smith, Jacqueline; Gutowska, Maria Weronika; Uchida, Tatsuya; Vainio, Olli; Burt, David W

    2015-01-01

    "Trojan" is a leukocyte-specific, cell surface protein originally identified in the chicken. Its molecular function has been hypothesized to be related to anti-apoptosis and the proliferation of immune cells. The Trojan gene has been localized onto the Z sex chromosome. The adjacent two genes also show significant homology to Trojan, suggesting the existence of a novel gene/protein family. Here, we characterize this Trojan family, identify homologues in other species and predict evolutionary constraints on these genes. The two Trojan-related proteins in chicken were predicted as a receptor-type tyrosine phosphatase and a transmembrane protein, bearing a cytoplasmic immuno-receptor tyrosine-based activation motif. We identified the Trojan gene family in ten other bird species and found related genes in three reptiles and a fish species. The phylogenetic analysis of the homologues revealed a gradual diversification among the family members. Evolutionary analyzes of the avian genes predicted that the extracellular regions of the proteins have been subjected to positive selection. Such selection was possibly a response to evolving interacting partners or to pathogen challenges. We also observed an almost complete lack of intracellular positively selected sites, suggesting a conserved signaling mechanism of the molecules. Therefore, the contrasting patterns of selection likely correlate with the interaction and signaling potential of the molecules.

  19. Evolutionary and Functional Relationships of the dha Regulon by Genomic Context Analysis.

    Directory of Open Access Journals (Sweden)

    Marinalva Martins-Pinheiro

    Full Text Available 3-hydroxypropionaldehyde (3-HPA and 1,3-propanediol (1,3-PD are subproducts of glycerol degradation and of economical interest as they are used for polymers synthesis, such as polyesters and polyurethanes. Some few characterized bacterial species (mostly from Firmicutes and Gamma-proteobacteria groups are able to catabolize these monomers from glycerol using the gene products from the dha regulon. To expand our knowledge and direct further experimental studies on the regulon and related genes for the anaerobic glycerol metabolism, an extensive genomic screening was performed to identify the presence of the dha genes in fully sequenced prokaryotic genomes. Interestingly, this work shows that although only few bacteria species are known to produce 3-HPA or 1,3-PD, the incomplete regulon is found in more than 100 prokaryotic genomes. However, the complete pathway is found only in a few dozen species belonging to five different taxonomic groups, including one Archaea species, Halalkalicoccus jeotgali. Phylogenetic analysis and conservation of both gene synteny and primary sequence similarity reinforce the idea that these genes have a common origin and were possibly acquired by lateral gene transfer (LGT. Besides the evolutionary aspect, the identification of homologs from several different organisms may predict potential alternative targets for faster or more efficient biological synthesis of 3-HPA or 1,3-PD.

  20. Identification of putative regulatory upstream ORFs in the yeast genome using heuristics and evolutionary conservation

    Directory of Open Access Journals (Sweden)

    Bilsland Elizabeth

    2007-08-01

    Full Text Available Abstract Background The translational efficiency of an mRNA can be modulated by upstream open reading frames (uORFs present in certain genes. A uORF can attenuate translation of the main ORF by interfering with translational reinitiation at the main start codon. uORFs also occur by chance in the genome, in which case they do not have a regulatory role. Since the sequence determinants for functional uORFs are not understood, it is difficult to discriminate functional from spurious uORFs by sequence analysis. Results We have used comparative genomics to identify novel uORFs in yeast with a high likelihood of having a translational regulatory role. We examined uORFs, previously shown to play a role in regulation of translation in Saccharomyces cerevisiae, for evolutionary conservation within seven Saccharomyces species. Inspection of the set of conserved uORFs yielded the following three characteristics useful for discrimination of functional from spurious uORFs: a length between 4 and 6 codons, a distance from the start of the main ORF between 50 and 150 nucleotides, and finally a lack of overlap with, and clear separation from, neighbouring uORFs. These derived rules are inherently associated with uORFs with properties similar to the GCN4 locus, and may not detect most uORFs of other types. uORFs with high scores based on these rules showed a much higher evolutionary conservation than randomly selected uORFs. In a genome-wide scan in S. cerevisiae, we found 34 conserved uORFs from 32 genes that we predict to be functional; subsequent analysis showed the majority of these to be located within transcripts. A total of 252 genes were found containing conserved uORFs with properties indicative of a functional role; all but 7 are novel. Functional content analysis of this set identified an overrepresentation of genes involved in transcriptional control and development. Conclusion Evolutionary conservation of uORFs in yeasts can be traced up to 100

  1. Single-Cell (Meta-Genomics of a Dimorphic Candidatus Thiomargarita nelsonii Reveals Genomic Plasticity

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    Beverly E. Flood

    2016-05-01

    Full Text Available The genus Thiomargarita includes the world’s largest bacteria. But as uncultured organisms, their physiology, metabolism, and basis for their gigantism are not well understood. Thus a genomics approach, applied to a single Candidatus Thiomargarita nelsonii cell was employed to explore the genetic potential of one of these enigmatic giant bacteria. The Thiomargarita cell was obtained from an assemblage of budding Ca. T. nelsonii attached to a provannid gastropod shell from Hydrate Ridge, a methane seep offshore of Oregon, USA. Here we present a manually curated genome of Bud S10 resulting from a hybrid assembly of long Pacific Biosciences and short Illumina sequencing reads. With respect to inorganic carbon fixation and sulfur oxidation pathways, the Ca. T. nelsonii Hydrate Ridge Bud S10 genome was similar to marine sister taxa within the family Beggiatoaceae. However, the Bud S10 genome contains genes suggestive of the genetic potential for lithotrophic growth on arsenite and perhaps hydrogen. The genome also revealed that Bud S10 likely respires nitrate via two pathways: a complete denitrification pathway and a dissimilatory nitrate reduction to ammonia pathway. Both pathways have been predicted, but not previously fully elucidated, in the genomes of other large, vacuolated, sulfur-oxidizing bacteria.Surprisingly, the genome also had a high number of unusual features for a bacterium to include the largest number of metacaspases and introns ever reported in a bacterium. Also present, are a large number of other mobile genetic elements, such as insertion sequence transposable elements and miniature inverted-repeat transposable elements (MITEs. In some cases, mobile genetic elements disrupted key genes in metabolic pathways. For example, a MITE interrupts hupL, which encodes the large subunit of the hydrogenase in hydrogen oxidation. Moreover, we detected a group I intron in one of the most critical genes in the sulfur oxidation pathway, dsr

  2. Transcriptome profiling reveals mosaic genomic origins of modern cultivated barley

    Science.gov (United States)

    Dai, Fei; Chen, Zhong-Hua; Wang, Xiaolei; Li, Zefeng; Jin, Gulei; Wu, Dezhi; Cai, Shengguan; Wang, Ning; Wu, Feibo; Nevo, Eviatar; Zhang, Guoping

    2014-01-01

    The domestication of cultivated barley has been used as a model system for studying the origins and early spread of agrarian culture. Our previous results indicated that the Tibetan Plateau and its vicinity is one of the centers of domestication of cultivated barley. Here we reveal multiple origins of domesticated barley using transcriptome profiling of cultivated and wild-barley genotypes. Approximately 48-Gb of clean transcript sequences in 12 Hordeum spontaneum and 9 Hordeum vulgare accessions were generated. We reported 12,530 de novo assembled transcripts in all of the 21 samples. Population structure analysis showed that Tibetan hulless barley (qingke) might have existed in the early stage of domestication. Based on the large number of unique genomic regions showing the similarity between cultivated and wild-barley groups, we propose that the genomic origin of modern cultivated barley is derived from wild-barley genotypes in the Fertile Crescent (mainly in chromosomes 1H, 2H, and 3H) and Tibet (mainly in chromosomes 4H, 5H, 6H, and 7H). This study indicates that the domestication of barley may have occurred over time in geographically distinct regions. PMID:25197090

  3. Genomic Perturbations Reveal Distinct Regulatory Networks in Intrahepatic Cholangiocarcinoma

    DEFF Research Database (Denmark)

    Nepal, Chirag; O'Rourke, Colm J; Oliveira, Douglas Vnp

    2018-01-01

    -exome sequencing, targeted exome sequencing) and epigenomic data from 496 patients, and used the three most recurrently mutated genes to stratify patients (IDH, KRAS, TP53, 'undetermined'). Using this molecular dissection approach, each subgroup was determined to possess unique mutational signature preferences, co...... all 3 mutations ('undetermined') harbored the most extensive structural alterations while IDH mutant tumors displayed the most extensive DNA methylome dysregulation, consistent with previous findings. CONCLUSION: Stratification of iCCA patients based on occurrence of mutations in three classifier...... genes (IDH, KRAS, TP53) revealed unique oncogenic programs (mutational, structural, epi-mutational) that influence pharmacologic response in drug repositioning protocols. This genome dissection approach highlights the potential of individual mutations to induce extensive molecular heterogeneity...

  4. Trends in genome dynamics among major orders of insects revealed through variations in protein families.

    Science.gov (United States)

    Rappoport, Nadav; Linial, Michal

    2015-08-07

    Insects belong to a class that accounts for the majority of animals on earth. With over one million identified species, insects display a huge diversity and occupy extreme environments. At present, there are dozens of fully sequenced insect genomes that cover a range of habitats, social behavior and morphologies. In view of such diverse collection of genomes, revealing evolutionary trends and charting functional relationships of proteins remain challenging. We analyzed the relatedness of 17 complete proteomes representative of proteomes from insects including louse, bee, beetle, ants, flies and mosquitoes, as well as an out-group from the crustaceans. The analyzed proteomes mostly represented the orders of Hymenoptera and Diptera. The 287,405 protein sequences from the 18 proteomes were automatically clustered into 20,933 families, including 799 singletons. A comprehensive analysis based on statistical considerations identified the families that were significantly expanded or reduced in any of the studied organisms. Among all the tested species, ants are characterized by an exceptionally high rate of family gain and loss. By assigning annotations to hundreds of species-specific families, the functional diversity among species and between the major clades (Diptera and Hymenoptera) is revealed. We found that many species-specific families are associated with receptor signaling, stress-related functions and proteases. The highest variability among insects associates with the function of transposition and nucleic acids processes (collectively coined TNAP). Specifically, the wasp and ants have an order of magnitude more TNAP families and proteins relative to species that belong to Diptera (mosquitoes and flies). An unsupervised clustering methodology combined with a comparative functional analysis unveiled proteomic signatures in the major clades of winged insects. We propose that the expansion of TNAP families in Hymenoptera potentially contributes to the accelerated

  5. Evolutionary strategies of viruses, bacteria and archaea in hydrothermal vent ecosystems revealed through metagenomics.

    Directory of Open Access Journals (Sweden)

    Rika E Anderson

    Full Text Available The deep-sea hydrothermal vent habitat hosts a diverse community of archaea and bacteria that withstand extreme fluctuations in environmental conditions. Abundant viruses in these systems, a high proportion of which are lysogenic, must also withstand these environmental extremes. Here, we explore the evolutionary strategies of both microorganisms and viruses in hydrothermal systems through comparative analysis of a cellular and viral metagenome, collected by size fractionation of high temperature fluids from a diffuse flow hydrothermal vent. We detected a high enrichment of mobile elements and proviruses in the cellular fraction relative to microorganisms in other environments. We observed a relatively high abundance of genes related to energy metabolism as well as cofactors and vitamins in the viral fraction compared to the cellular fraction, which suggest encoding of auxiliary metabolic genes on viral genomes. Moreover, the observation of stronger purifying selection in the viral versus cellular gene pool suggests viral strategies that promote prolonged host integration. Our results demonstrate that there is great potential for hydrothermal vent viruses to integrate into hosts, facilitate horizontal gene transfer, and express or transfer genes that manipulate the hosts' functional capabilities.

  6. Assessing the evolutionary impact of amino acid mutations in the human genome

    DEFF Research Database (Denmark)

    Boyko, Adam R; Williamson, Scott H; Indap, Amit R

    2008-01-01

    with non-stationary demographic history (such as that of modern humans). Application of our method to 47,576 coding SNPs found by direct resequencing of 11,404 protein coding-genes in 35 individuals (20 European Americans and 15 African Americans) allows us to assess the relative contribution......Quantifying the distribution of fitness effects among newly arising mutations in the human genome is key to resolving important debates in medical and evolutionary genetics. Here, we present a method for inferring this distribution using Single Nucleotide Polymorphism (SNP) data from a population...... genetic variation affecting disease phenotype may be missed by this widely used approach for mapping genes underlying complex traits....

  7. Genomics and evolutionary aspect of calcium signaling event in calmodulin and calmodulin-like proteins in plants.

    Science.gov (United States)

    Mohanta, Tapan Kumar; Kumar, Pradeep; Bae, Hanhong

    2017-02-03

    Ca2+ ion is a versatile second messenger that operate in a wide ranges of cellular processes that impact nearly every aspect of life. Ca2+ regulates gene expression and biotic and abiotic stress responses in organisms ranging from unicellular algae to multi-cellular higher plants through the cascades of calcium signaling processes. In this study, we deciphered the genomics and evolutionary aspects of calcium signaling event of calmodulin (CaM) and calmodulin like- (CML) proteins. We studied the CaM and CML gene family of 41 different species across the plant lineages. Genomic analysis showed that plant encodes more calmodulin like-protein than calmodulins. Further analyses showed, the majority of CMLs were intronless, while CaMs were intron rich. Multiple sequence alignment showed, the EF-hand domain of CaM contains four conserved D-x-D motifs, one in each EF-hand while CMLs contain only one D-x-D-x-D motif in the fourth EF-hand. Phylogenetic analysis revealed that, the CMLs were evolved earlier than CaM and later diversified. Gene expression analysis demonstrated that different CaM and CMLs genes were express differentially in different tissues in a spatio-temporal manner. In this study we provided in detailed genome-wide identifications and characterization of CaM and CML protein family, phylogenetic relationships, and domain structure. Expression study of CaM and CML genes were conducted in Glycine max and Phaseolus vulgaris. Our study provides a strong foundation for future functional research in CaM and CML gene family in plant kingdom.

  8. LRR-RLK family from two Citrus species: genome-wide identification and evolutionary aspects.

    Science.gov (United States)

    Magalhães, Diogo M; Scholte, Larissa L S; Silva, Nicholas V; Oliveira, Guilherme C; Zipfel, Cyril; Takita, Marco A; De Souza, Alessandra A

    2016-08-12

    Leucine-rich repeat receptor-like kinases (LRR-RLKs) represent the largest subfamily of plant RLKs. The functions of most LRR-RLKs have remained undiscovered, and a few that have been experimentally characterized have been shown to have important roles in growth and development as well as in defense responses. Although RLK subfamilies have been previously studied in many plants, no comprehensive study has been performed on this gene family in Citrus species, which have high economic importance and are frequent targets for emerging pathogens. In this study, we performed in silico analysis to identify and classify LRR-RLK homologues in the predicted proteomes of Citrus clementina (clementine) and Citrus sinensis (sweet orange). In addition, we used large-scale phylogenetic approaches to elucidate the evolutionary relationships of the LRR-RLKs and further narrowed the analysis to the LRR-XII group, which contains several previously described cell surface immune receptors. We built integrative protein signature databases for Citrus clementina and Citrus sinensis using all predicted protein sequences obtained from whole genomes. A total of 300 and 297 proteins were identified as LRR-RLKs in C. clementina and C. sinensis, respectively. Maximum-likelihood phylogenetic trees were estimated using Arabidopsis LRR-RLK as a template and they allowed us to classify Citrus LRR-RLKs into 16 groups. The LRR-XII group showed a remarkable expansion, containing approximately 150 paralogs encoded in each Citrus genome. Phylogenetic analysis also demonstrated the existence of two distinct LRR-XII clades, each one constituted mainly by RD and non-RD kinases. We identified 68 orthologous pairs from the C. clementina and C. sinensis LRR-XII genes. In addition, among the paralogs, we identified a subset of 78 and 62 clustered genes probably derived from tandem duplication events in the genomes of C. clementina and C. sinensis, respectively. This work provided the first comprehensive

  9. Conserved Units of Co-Expression in Bacterial Genomes: An Evolutionary Insight into Transcriptional Regulation

    Science.gov (United States)

    Junier, Ivan; Rivoire, Olivier

    2016-01-01

    Genome-wide measurements of transcriptional activity in bacteria indicate that the transcription of successive genes is strongly correlated beyond the scale of operons. Here, we analyze hundreds of bacterial genomes to identify supra-operonic segments of genes that are proximal in a large number of genomes. We show that these synteny segments correspond to genomic units of strong transcriptional co-expression. Structurally, the segments contain operons with specific relative orientations (co-directional or divergent) and nucleoid-associated proteins are found to bind at their boundaries. Functionally, operons inside a same segment are highly co-expressed even in the apparent absence of regulatory factors at their promoter regions. Remote operons along DNA can also be co-expressed if their corresponding segments share a transcriptional or sigma factor, without requiring these factors to bind directly to the promoters of the operons. As evidence that these results apply across the bacterial kingdom, we demonstrate them both in the Gram-negative bacterium Escherichia coli and in the Gram-positive bacterium Bacillus subtilis. The underlying process that we propose involves only RNA-polymerases and DNA: it implies that the transcription of an operon mechanically enhances the transcription of adjacent operons. In support of a primary role of this regulation by facilitated co-transcription, we show that the transcription en bloc of successive operons as a result of transcriptional read-through is strongly and specifically enhanced in synteny segments. Finally, our analysis indicates that facilitated co-transcription may be evolutionary primitive and may apply beyond bacteria. PMID:27195891

  10. Evolutionary genomic remodelling of the human 4q subtelomere (4q35.2

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    Riva Paola

    2007-03-01

    Full Text Available Abstract Background In order to obtain insights into the functionality of the human 4q35.2 domain harbouring the facioscapulohumeral muscular dystrophy (FSHD locus, we investigated in African apes genomic and chromatin organisations, and the nuclear topology of orthologous regions. Results A basic block consisting of short D4Z4 arrays (10–15 repeats, 4q35.2 specific sequences, and approximately 35 kb of interspersed repeats from different LINE subfamilies was repeated at least twice in the gorilla 4qter. This genomic organisation has undergone evolutionary remodelling, leading to the single representation of both the D4Z4 array and LINE block in chimpanzee, and the loss of the LINE block in humans. The genomic remodelling has had an impact on 4qter chromatin organisation, but not its interphase nuclear topology. In comparison with humans, African apes show very low or undetectable levels of FRG1 and FRG2 histone 4 acetylation and gene transcription, although histone deacetylase inhibition restores gene transcription to levels comparable with those of human cells, thus indicating that the 4qter region is capable of acquiring a more open chromatin structure. Conversely, as in humans, the 4qter region in African apes has a very peripheral nuclear localisation. Conclusion The 4q subtelomere has undergone substantial genomic changes during evolution that have had an impact on chromatin condensation and the region's transcriptional regulation. Consequently, the 4qter genes in African apes and humans seem to be subjected to a different strategy of regulation in which LINE and D4Z4 sequences may play a pivotal role. However, the effect of peripheral nuclear anchoring of 4qter on these regulation mechanisms is still unclear. The observed differences in the regulation of 4qter gene expression between African apes and humans suggest that the human 4q35.2 locus has acquired a novel functional relevance.

  11. PLAZA 4.0: an integrative resource for functional, evolutionary and comparative plant genomics.

    Science.gov (United States)

    Van Bel, Michiel; Diels, Tim; Vancaester, Emmelien; Kreft, Lukasz; Botzki, Alexander; Van de Peer, Yves; Coppens, Frederik; Vandepoele, Klaas

    2017-10-23

    PLAZA ( https://bioinformatics.psb.ugent.be/plaza ) is a plant-oriented online resource for comparative, evolutionary and functional genomics. The PLAZA platform consists of multiple independent instances focusing on different plant clades, while also providing access to a consistent set of reference species. Each PLAZA instance contains structural and functional gene annotations, gene family data and phylogenetic trees and detailed gene colinearity information. A user-friendly web interface makes the necessary tools and visualizations accessible, specific for each data type. Here we present PLAZA 4.0, the latest iteration of the PLAZA framework. This version consists of two new instances (Dicots 4.0 and Monocots 4.0) providing a large increase in newly available species, and offers access to updated and newly implemented tools and visualizations, helping users with the ever-increasing demands for complex and in-depth analyzes. The total number of species across both instances nearly doubles from 37 species in PLAZA 3.0 to 71 species in PLAZA 4.0, with a much broader coverage of crop species (e.g. wheat, palm oil) and species of evolutionary interest (e.g. spruce, Marchantia ). The new PLAZA instances can also be accessed by a programming interface through a RESTful web service, thus allowing bioinformaticians to optimally leverage the power of the PLAZA platform. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  12. Resolving Evolutionary Relationships in Closely Related Species with Whole-Genome Sequencing Data.

    Science.gov (United States)

    Nater, Alexander; Burri, Reto; Kawakami, Takeshi; Smeds, Linnéa; Ellegren, Hans

    2015-11-01

    Using genetic data to resolve the evolutionary relationships of species is of major interest in evolutionary and systematic biology. However, reconstructing the sequence of speciation events, the so-called species tree, in closely related and potentially hybridizing species is very challenging. Processes such as incomplete lineage sorting and interspecific gene flow result in local gene genealogies that differ in their topology from the species tree, and analyses of few loci with a single sequence per species are likely to produce conflicting or even misleading results. To study these phenomena on a full phylogenomic scale, we use whole-genome sequence data from 200 individuals of four black-and-white flycatcher species with so far unresolved phylogenetic relationships to infer gene tree topologies and visualize genome-wide patterns of gene tree incongruence. Using phylogenetic analysis in nonoverlapping 10-kb windows, we show that gene tree topologies are extremely diverse and change on a very small physical scale. Moreover, we find strong evidence for gene flow among flycatcher species, with distinct patterns of reduced introgression on the Z chromosome. To resolve species relationships on the background of widespread gene tree incongruence, we used four complementary coalescent-based methods for species tree reconstruction, including complex modeling approaches that incorporate post-divergence gene flow among species. This allowed us to infer the most likely species tree with high confidence. Based on this finding, we show that regions of reduced effective population size, which have been suggested as particularly useful for species tree inference, can produce positively misleading species tree topologies. Our findings disclose the pitfalls of using loci potentially under selection as phylogenetic markers and highlight the potential of modeling approaches to disentangle species relationships in systems with large effective population sizes and post

  13. Genome sequence of Thermofilum pendens reveals an exceptional loss of biosynthetic pathways without genome reduction

    Energy Technology Data Exchange (ETDEWEB)

    Kyrpides, Nikos; Anderson, Iain; Rodriguez, Jason; Susanti, Dwi; Porat, Iris; Reich, Claudia; Ulrich, Luke E.; Elkins, James G.; Mavromatis, Kostas; Lykidis, Athanasios; Kim, Edwin; Thompson, Linda S.; Nolan, Matt; Land, Miriam; Copeland, Alex; Lapidus, Alla; Lucas, Susan; Detter, Chris; Zhulin, Igor B.; Olsen, Gary J.; Whitman, William; Mukhopadhyay, Biswarup; Bristow, James; Kyrpides, Nikos

    2008-01-01

    We report the complete genome of Thermofilum pendens, a deep-branching, hyperthermophilic member of the order Thermoproteales within the archaeal kingdom Crenarchaeota. T. pendens is a sulfur-dependent, anaerobic heterotroph isolated from a solfatara in Iceland. It is an extracellular commensal, requiring an extract of Thermoproteus tenax for growth, and the genome sequence reveals that biosynthetic pathways for purines, most amino acids, and most cofactors are absent. In fact T. pendens has fewer biosynthetic enzymes than obligate intracellular parasites, although it does not display other features common among obligate parasites and thus does not appear to be in the process of becoming a parasite. It appears that T. pendens has adapted to life in an environment rich in nutrients. T. pendens was known to utilize peptides as an energy source, but the genome reveals substantial ability to grow on carbohydrates. T. pendens is the first crenarchaeote and only the second archaeon found to have a transporter of the phosphotransferase system. In addition to fermentation, T. pendens may gain energy from sulfur reduction with hydrogen and formate as electron donors. It may also be capable of sulfur-independent growth on formate with formate hydrogenlyase. Additional novel features are the presence of a monomethylamine:corrinoid methyltransferase, the first time this enzyme has been found outside of Methanosarcinales, and a presenilin-related protein. Predicted highly expressed proteins do not include housekeeping genes, and instead include ABC transporters for carbohydrates and peptides, and CRISPR-associated proteins.

  14. Genome Sequence of Thermofilum pendens Reveals an Exceptional Loss of Biosynthetic Pathways without Genome Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain [U.S. Department of Energy, Joint Genome Institute; Rodriquez, Jason [Virginia Polytechnic Institute and State University (Virginia Tech); Susanti, Dwi [Virginia Polytechnic Institute and State University (Virginia Tech); Porat, I. [University of Georgia, Athens, GA; Reich, Claudia [University of Illinois, Urbana-Champaign; Ulrich, Luke [ORNL; Elkins, James G [ORNL; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Lykidis, A [U.S. Department of Energy, Joint Genome Institute; Kim, Edwin [U.S. Department of Energy, Joint Genome Institute; Thompson, Linda S [Los Alamos National Laboratory (LANL); Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Detter, J C [U.S. Department of Energy, Joint Genome Institute; Zhulin, Igor B [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Olsen, Gary [ORNL; Whitman, W. B. [University of Georgia, Athens, GA; Mukhopadhyay, Biswarup [Virginia Polytechnic Institute and State University (Virginia Tech); Bristow, James [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute

    2008-01-01

    We report the complete genome of Thermofilum pendens, a deep-branching member of class Thermoproteales of Crenarchaeota. T. pendens is a sulfur-dependent, anaerobic heterotroph isolated from a solfatara in Iceland. It was known to utilize peptides as an energy source, but the genome reveals substantial ability to grow on carbohydrates. T. pendens is the first Crenarchaeote and only the second archaeon found to have transporters of the phosphotransferase system. T. pendens is known to require an extract of Thermoproteus tenax for growth, and the genome sequence reveals that biosynthetic pathways for purines, most amino acids, and most cofactors are absent. T. pendens has fewer biosynthetic enzymes than any other free-living organism. In addition to heterotrophy, T. pendens may gain energy from sulfur reduction with hydrogen and formate as electron donors. It may also be capable of sulfur-independent growth on formate with formate hydrogenlyase. Additional novel features are the presence of a monomethylamine:corrinoid methyltransferase, the first time this enzyme has been found outside of Methanosarcinales, and a presenilin-related protein from a new subfamily. Predicted highly expressed proteins include ABC transporters for carbohydrates and peptides, and CRISPR-associated proteins, suggesting that defense against viruses is a high priority.

  15. Comparative Genomics Including the Early-Diverging Smut Fungus Ceraceosorus bombacis Reveals Signatures of Parallel Evolution within Plant and Animal Pathogens of Fungi and Oomycetes.

    Science.gov (United States)

    Sharma, Rahul; Xia, Xiaojuan; Riess, Kai; Bauer, Robert; Thines, Marco

    2015-08-27

    Ceraceosorus bombacis is an early-diverging lineage of smut fungi and a pathogen of cotton trees (Bombax ceiba). To study the evolutionary genomics of smut fungi in comparison with other fungal and oomycete pathogens, the genome of C. bombacis was sequenced and comparative genomic analyses were performed. The genome of 26.09 Mb encodes for 8,024 proteins, of which 576 are putative-secreted effector proteins (PSEPs). Orthology analysis revealed 30 ortholog PSEPs among six Ustilaginomycotina genomes, the largest groups of which are lytic enzymes, such as aspartic peptidase and glycoside hydrolase. Positive selection analyses revealed the highest percentage of positively selected PSEPs in C. bombacis compared with other Ustilaginomycotina genomes. Metabolic pathway analyses revealed the absence of genes encoding for nitrite and nitrate reductase in the genome of the human skin pathogen Malassezia globosa, but these enzymes are present in the sequenced plant pathogens in smut fungi. Interestingly, these genes are also absent in cultivable oomycete animal pathogens, while nitrate reductase has been lost in cultivable oomycete plant pathogens. Similar patterns were also observed for obligate biotrophic and hemi-biotrophic fungal and oomycete pathogens. Furthermore, it was found that both fungal and oomycete animal pathogen genomes are lacking cutinases and pectinesterases. Overall, these findings highlight the parallel evolution of certain genomic traits, revealing potential common evolutionary trajectories among fungal and oomycete pathogens, shaping the pathogen genomes according to their lifestyle. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  16. Genomic analysis of the basal lineage fungus Rhizopus oryzae reveals a whole-genome duplication.

    Directory of Open Access Journals (Sweden)

    Li-Jun Ma

    2009-07-01

    Full Text Available Rhizopus oryzae is the primary cause of mucormycosis, an emerging, life-threatening infection characterized by rapid angioinvasive growth with an overall mortality rate that exceeds 50%. As a representative of the paraphyletic basal group of the fungal kingdom called "zygomycetes," R. oryzae is also used as a model to study fungal evolution. Here we report the genome sequence of R. oryzae strain 99-880, isolated from a fatal case of mucormycosis. The highly repetitive 45.3 Mb genome assembly contains abundant transposable elements (TEs, comprising approximately 20% of the genome. We predicted 13,895 protein-coding genes not overlapping TEs, many of which are paralogous gene pairs. The order and genomic arrangement of the duplicated gene pairs and their common phylogenetic origin provide evidence for an ancestral whole-genome duplication (WGD event. The WGD resulted in the duplication of nearly all subunits of the protein complexes associated with respiratory electron transport chains, the V-ATPase, and the ubiquitin-proteasome systems. The WGD, together with recent gene duplications, resulted in the expansion of multiple gene families related to cell growth and signal transduction, as well as secreted aspartic protease and subtilase protein families, which are known fungal virulence factors. The duplication of the ergosterol biosynthetic pathway, especially the major azole target, lanosterol 14alpha-demethylase (ERG11, could contribute to the variable responses of R. oryzae to different azole drugs, including voriconazole and posaconazole. Expanded families of cell-wall synthesis enzymes, essential for fungal cell integrity but absent in mammalian hosts, reveal potential targets for novel and R. oryzae-specific diagnostic and therapeutic treatments.

  17. Genomic Analysis of the Basal Lineage Fungus Rhizopus oryzae Reveals a Whole-Genome Duplication

    Science.gov (United States)

    Ma, Li-Jun; Ibrahim, Ashraf S.; Skory, Christopher; Grabherr, Manfred G.; Burger, Gertraud; Butler, Margi; Elias, Marek; Idnurm, Alexander; Lang, B. Franz; Sone, Teruo; Abe, Ayumi; Calvo, Sarah E.; Corrochano, Luis M.; Engels, Reinhard; Fu, Jianmin; Hansberg, Wilhelm; Kim, Jung-Mi; Kodira, Chinnappa D.; Koehrsen, Michael J.; Liu, Bo; Miranda-Saavedra, Diego; O'Leary, Sinead; Ortiz-Castellanos, Lucila; Poulter, Russell; Rodriguez-Romero, Julio; Ruiz-Herrera, José; Shen, Yao-Qing; Zeng, Qiandong; Galagan, James; Birren, Bruce W.

    2009-01-01

    Rhizopus oryzae is the primary cause of mucormycosis, an emerging, life-threatening infection characterized by rapid angioinvasive growth with an overall mortality rate that exceeds 50%. As a representative of the paraphyletic basal group of the fungal kingdom called “zygomycetes,” R. oryzae is also used as a model to study fungal evolution. Here we report the genome sequence of R. oryzae strain 99–880, isolated from a fatal case of mucormycosis. The highly repetitive 45.3 Mb genome assembly contains abundant transposable elements (TEs), comprising approximately 20% of the genome. We predicted 13,895 protein-coding genes not overlapping TEs, many of which are paralogous gene pairs. The order and genomic arrangement of the duplicated gene pairs and their common phylogenetic origin provide evidence for an ancestral whole-genome duplication (WGD) event. The WGD resulted in the duplication of nearly all subunits of the protein complexes associated with respiratory electron transport chains, the V-ATPase, and the ubiquitin–proteasome systems. The WGD, together with recent gene duplications, resulted in the expansion of multiple gene families related to cell growth and signal transduction, as well as secreted aspartic protease and subtilase protein families, which are known fungal virulence factors. The duplication of the ergosterol biosynthetic pathway, especially the major azole target, lanosterol 14α-demethylase (ERG11), could contribute to the variable responses of R. oryzae to different azole drugs, including voriconazole and posaconazole. Expanded families of cell-wall synthesis enzymes, essential for fungal cell integrity but absent in mammalian hosts, reveal potential targets for novel and R. oryzae-specific diagnostic and therapeutic treatments. PMID:19578406

  18. Genome Sequence, Comparative Analysis, and Evolutionary Insights into Chitinases of Entomopathogenic Fungus Hirsutella thompsonii

    Science.gov (United States)

    Agrawal, Yamini; Khatri, Indu; Subramanian, Srikrishna; Shenoy, Belle Damodara

    2015-01-01

    Hirsutella thompsonii (Ht) is a fungal pathogen of acarines and the primary cause of epizootics among mites. The draft genomes of two isolates of Ht (MTCC 3556: Ht3, 34.6 Mb and MTCC 6686: Ht6, 34.7 Mb) are presented and compared with the genomes of Beauveria bassiana (Bb) ARSEF 2860 and Ophiocordyceps sinensis (Os) CO18. Comparative analysis of carbohydrate active enzymes, pathogen–host interaction genes, metabolism-associated genes, and genes involved in biosynthesis of secondary metabolites in the four genomes was carried out. Reduction in gene family sizes in Ht3 and Os as compared with Ht6 and Bb is observed. Analysis of the mating type genes in Ht reveals the presence of MAT idiomorphs which is suggestive of cryptic sexual traits in Ht. We further identify and classify putative chitinases that may function as virulence factors in fungal entomopathogens due to their role in degradation of arthropod cuticle. PMID:25716828

  19. Spt-Ada-Gcn5-Acetyltransferase (SAGA Complex in Plants: Genome Wide Identification, Evolutionary Conservation and Functional Determination.

    Directory of Open Access Journals (Sweden)

    Rakesh Srivastava

    Full Text Available The recruitment of RNA polymerase II on a promoter is assisted by the assembly of basal transcriptional machinery in eukaryotes. The Spt-Ada-Gcn5-Acetyltransferase (SAGA complex plays an important role in transcription regulation in eukaryotes. However, even in the advent of genome sequencing of various plants, SAGA complex has been poorly defined for their components and roles in plant development and physiological functions. Computational analysis of Arabidopsis thaliana and Oryza sativa genomes for SAGA complex resulted in the identification of 17 to 18 potential candidates for SAGA subunits. We have further classified the SAGA complex based on the conserved domains. Phylogenetic analysis revealed that the SAGA complex proteins are evolutionary conserved between plants, yeast and mammals. Functional annotation showed that they participate not only in chromatin remodeling and gene regulation, but also in different biological processes, which could be indirect and possibly mediated via the regulation of gene expression. The in silico expression analysis of the SAGA components in Arabidopsis and O. sativa clearly indicates that its components have a distinct expression profile at different developmental stages. The co-expression analysis of the SAGA components suggests that many of these subunits co-express at different developmental stages, during hormonal interaction and in response to stress conditions. Quantitative real-time PCR analysis of SAGA component genes further confirmed their expression in different plant tissues and stresses. The expression of representative salt, heat and light inducible genes were affected in mutant lines of SAGA subunits in Arabidopsis. Altogether, the present study reveals expedient evidences of involvement of the SAGA complex in plant gene regulation and stress responses.

  20. A parts list for fungal cellulosomes revealed by comparative genomics

    Energy Technology Data Exchange (ETDEWEB)

    Haitjema, Charles H.; Gilmore, Sean P.; Henske, John K.; Solomon, Kevin V.; de Groot, Randall; Kuo, Alan; Mondo, Stephen J.; Salamov, Asaf A.; LaButti, Kurt; Zhao, Zhiying; Chiniquy, Jennifer; Barry, Kerrie; Brewer, Heather M.; Purvine, Samuel O.; Wright, Aaron T.; Hainaut, Matthieu; Boxma, Brigitte; van Alen, Theo; Hackstein, Johannes H. P.; Henrissat, Bernard; Baker, Scott E.; Grigoriev, Igor V.; O' Malley, Michelle A.

    2017-05-26

    Cellulosomes are large, multi-protein complexes that tether plant biomass degrading enzymes together for improved hydrolysis1. These complexes were first described in anaerobic bacteria where species specific dockerin domains mediate assembly of enzymes onto complementary cohesin motifs interspersed within non-catalytic protein scaffolds1. The versatile protein assembly mechanism conferred by the bacterial cohesin-dockerin interaction is now a standard design principle for synthetic protein-scale pathways2,3. For decades, analogous structures have been reported in the early branching anaerobic fungi, which are known to assemble by sequence divergent non-catalytic dockerin domains (NCDD)4. However, the enzyme components, modular assembly mechanism, and functional role of fungal cellulosomes remain unknown5,6. Here, we describe the comprehensive set of proteins critical to fungal cellulosome assembly, including novel, conserved scaffolding proteins unique to the Neocallimastigomycota. High quality genomes of the anaerobic fungi Anaeromyces robustus, Neocallimastix californiae and Piromyces finnis were assembled with long-read, single molecule technology to overcome their repeat-richness and extremely low GC content. Genomic analysis coupled with proteomic validation revealed an average 320 NCDD-containing proteins per fungal strain that were overwhelmingly carbohydrate active enzymes (CAZymes), with 95 large fungal scaffoldins identified across 4 genera that contain a conserved amino acid sequence repeat that binds to NCDDs. Fungal dockerin and scaffoldin domains have no similarity to their bacterial counterparts, yet several catalytic domains originated via horizontal gene transfer with gut bacteria. Though many catalytic domains are shared with bacteria, the biocatalytic activity of anaerobic fungi is expanded by the inclusion of GH3, GH6, and GH45 enzymes in the enzyme complexes. Collectively, these findings suggest that the fungal cellulosome is an evolutionarily

  1. Complex evolutionary history of the Aeromonas veronii group revealed by host interaction and DNA sequence data.

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    Adam C Silver

    Full Text Available Aeromonas veronii biovar sobria, Aeromonas veronii biovar veronii, and Aeromonas allosaccharophila are a closely related group of organisms, the Aeromonas veronii Group, that inhabit a wide range of host animals as a symbiont or pathogen. In this study, the ability of various strains to colonize the medicinal leech as a model for beneficial symbiosis and to kill wax worm larvae as a model for virulence was determined. Isolates cultured from the leech out-competed other strains in the leech model, while most strains were virulent in the wax worms. Three housekeeping genes, recA, dnaJ and gyrB, the gene encoding chitinase, chiA, and four loci associated with the type three secretion system, ascV, ascFG, aexT, and aexU were sequenced. The phylogenetic reconstruction failed to produce one consensus tree that was compatible with most of the individual genes. The Approximately Unbiased test and the Genetic Algorithm for Recombination Detection both provided further support for differing evolutionary histories among this group of genes. Two contrasting tests detected recombination within aexU, ascFG, ascV, dnaJ, and gyrB but not in aexT or chiA. Quartet decomposition analysis indicated a complex recent evolutionary history for these strains with a high frequency of horizontal gene transfer between several but not among all strains. In this study we demonstrate that at least for some strains, horizontal gene transfer occurs at a sufficient frequency to blur the signal from vertically inherited genes, despite strains being adapted to distinct niches. Simply increasing the number of genes included in the analysis is unlikely to overcome this challenge in organisms that occupy multiple niches and can exchange DNA between strains specialized to different niches. Instead, the detection of genes critical in the adaptation to specific niches may help to reveal the physiological specialization of these strains.

  2. The genetics of loneliness: linking evolutionary theory to genome-wide genetics, epigenetics, and social science.

    Science.gov (United States)

    Goossens, Luc; van Roekel, Eeske; Verhagen, Maaike; Cacioppo, John T; Cacioppo, Stephanie; Maes, Marlies; Boomsma, Dorret I

    2015-03-01

    As a complex trait, loneliness is likely to be influenced by the interplay of numerous genetic and environmental factors. Studies in behavioral genetics indicate that loneliness has a sizable degree of heritability. Candidate-gene and gene-expression studies have pointed to several genes related to neurotransmitters and the immune system. The notion that these genes are related to loneliness is compatible with the basic tenets of the evolutionary theory of loneliness. Research on gene-environment interactions indicates that social-environmental factors (e.g., low social support) may have a more pronounced effect and lead to higher levels of loneliness if individuals carry the sensitive variant of these candidate genes. Currently, there is no extant research on loneliness based on genome-wide association studies, gene-environment-interaction studies, or studies in epigenetics. Such studies would allow researchers to identify networks of genes that contribute to loneliness. The contribution of genetics to loneliness research will become stronger when genome-wide genetics and epigenetics are integrated and used along with well-established methods in psychology to analyze the complex process of gene-environment interplay. © The Author(s) 2015.

  3. Exploiting genomic knowledge in optimising molecular breeding programmes: algorithms from evolutionary computing.

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    Steve O'Hagan

    Full Text Available Comparatively few studies have addressed directly the question of quantifying the benefits to be had from using molecular genetic markers in experimental breeding programmes (e.g. for improved crops and livestock, nor the question of which organisms should be mated with each other to best effect. We argue that this requires in silico modelling, an approach for which there is a large literature in the field of evolutionary computation (EC, but which has not really been applied in this way to experimental breeding programmes. EC seeks to optimise measurable outcomes (phenotypic fitnesses by optimising in silico the mutation, recombination and selection regimes that are used. We review some of the approaches from EC, and compare experimentally, using a biologically relevant in silico landscape, some algorithms that have knowledge of where they are in the (genotypic search space (G-algorithms with some (albeit well-tuned ones that do not (F-algorithms. For the present kinds of landscapes, F- and G-algorithms were broadly comparable in quality and effectiveness, although we recognise that the G-algorithms were not equipped with any 'prior knowledge' of epistatic pathway interactions. This use of algorithms based on machine learning has important implications for the optimisation of experimental breeding programmes in the post-genomic era when we shall potentially have access to the full genome sequence of every organism in a breeding population. The non-proprietary code that we have used is made freely available (via Supplementary information.

  4. Genomic Insights into the Evolutionary Origin of Xanthomonas axonopodis pv. citri and Its Ecological Relatives

    Science.gov (United States)

    Midha, Samriti

    2014-01-01

    Xanthomonas axonopodis pv. citri (Xac) is the causal agent of citrus bacterial canker (CBC) and is a serious problem worldwide. Like CBC, several important diseases in other fruits, such as mango, pomegranate, and grape, are also caused by Xanthomonas pathovars that display remarkable specificity toward their hosts. While citrus and mango diseases were documented more than 100 years ago, the pomegranate and grape diseases have been known only since the 1950s and 1970s, respectively. Interestingly, diseases caused by all these pathovars were noted first in India. Our genome-based phylogenetic studies suggest that these diverse pathogens belong to a single species and these pathovars may be just a group of rapidly evolving strains. Furthermore, the recently reported pathovars, such as those infecting grape and pomegranate, form independent clonal lineages, while the citrus and mango pathovars that have been known for a long time form one clonal lineage. Such an understanding of their phylogenomic relationship has further allowed us to understand major and unique variations in the lineages that give rise to these pathovars. Whole-genome sequencing studies including ecological relatives from their putative country of origin has allowed us to understand the evolutionary history of Xac and other pathovars that infect fruits. PMID:25085494

  5. Expression Profiling of Mitogen-Activated Protein Kinase Genes Reveals Their Evolutionary and Functional Diversity in Different Rubber Tree (Hevea brasiliensis) Cultivars.

    Science.gov (United States)

    Jin, Xiang; Zhu, Liping; Yao, Qi; Meng, Xueru; Ding, Guohua; Wang, Dan; Xie, Quanliang; Tong, Zheng; Tao, Chengcheng; Yu, Li; Li, Hongbin; Wang, Xuchu

    2017-10-06

    Rubber tree (Heveabrasiliensis) is the only commercially cultivated plant for producing natural rubber, one of the most essential industrial raw materials. Knowledge of the evolutionary and functional characteristics of kinases in H. brasiliensis is limited because of the long growth period and lack of well annotated genome information. Here, we reported mitogen-activated protein kinases in H.brasiliensis (HbMPKs) by manually checking and correcting the rubber tree genome. Of the 20 identified HbMPKs, four members were validated by proteomic data. Protein motif and phylogenetic analyses classified these members into four known groups comprising Thr-Glu-Tyr (TEY) and Thr-Asp-Tyr (TDY) domains, respectively. Evolutionary and syntenic analyses suggested four duplication events: HbMPK3/HbMPK6, HbMPK8/HbMPK9/HbMPK15, HbMPK10/HbMPK12 and HbMPK11/HbMPK16/HbMPK19. Expression profiling of the identified HbMPKs in roots, stems, leaves and latex obtained from three cultivars with different latex yield ability revealed tissue- and variety-expression specificity of HbMPK paralogues. Gene expression patterns under osmotic, oxidative, salt and cold stresses, combined with cis-element distribution analyses, indicated different regulation patterns of HbMPK paralogues. Further, Ka/Ks and Tajima analyses suggested an accelerated evolutionary rate in paralogues HbMPK10/12. These results revealed HbMPKs have diverse functions in natural rubber biosynthesis, and highlighted the potential possibility of using MPKs to improve stress tolerance in future rubber tree breeding.

  6. Expression Profiling of Mitogen-Activated Protein Kinase Genes Reveals Their Evolutionary and Functional Diversity in Different Rubber Tree (Hevea brasiliensis Cultivars

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    Xiang Jin

    2017-10-01

    Full Text Available Rubber tree (Hevea brasiliensis is the only commercially cultivated plant for producing natural rubber, one of the most essential industrial raw materials. Knowledge of the evolutionary and functional characteristics of kinases in H. brasiliensis is limited because of the long growth period and lack of well annotated genome information. Here, we reported mitogen-activated protein kinases in H. brasiliensis (HbMPKs by manually checking and correcting the rubber tree genome. Of the 20 identified HbMPKs, four members were validated by proteomic data. Protein motif and phylogenetic analyses classified these members into four known groups comprising Thr-Glu-Tyr (TEY and Thr-Asp-Tyr (TDY domains, respectively. Evolutionary and syntenic analyses suggested four duplication events: HbMPK3/HbMPK6, HbMPK8/HbMPK9/HbMPK15, HbMPK10/HbMPK12 and HbMPK11/HbMPK16/HbMPK19. Expression profiling of the identified HbMPKs in roots, stems, leaves and latex obtained from three cultivars with different latex yield ability revealed tissue- and variety-expression specificity of HbMPK paralogues. Gene expression patterns under osmotic, oxidative, salt and cold stresses, combined with cis-element distribution analyses, indicated different regulation patterns of HbMPK paralogues. Further, Ka/Ks and Tajima analyses suggested an accelerated evolutionary rate in paralogues HbMPK10/12. These results revealed HbMPKs have diverse functions in natural rubber biosynthesis, and highlighted the potential possibility of using MPKs to improve stress tolerance in future rubber tree breeding.

  7. Large-Scale Phylogenomic Analysis Reveals the Complex Evolutionary History of Rabies Virus in Multiple Carnivore Hosts.

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    Cécile Troupin

    2016-12-01

    Full Text Available The natural evolution of rabies virus (RABV provides a potent example of multiple host shifts and an important opportunity to determine the mechanisms that underpin viral emergence. Using 321 genome sequences spanning an unprecedented diversity of RABV, we compared evolutionary rates and selection pressures in viruses sampled from multiple primary host shifts that occurred on various continents. Two major phylogenetic groups, bat-related RABV and dog-related RABV, experiencing markedly different evolutionary dynamics were identified. While no correlation between time and genetic divergence was found in bat-related RABV, the evolution of dog-related RABV followed a generally clock-like structure, although with a relatively low evolutionary rate. Subsequent molecular clock dating indicated that dog-related RABV likely underwent a rapid global spread following the intensification of intercontinental trade starting in the 15th century. Strikingly, although dog RABV has jumped to various wildlife species from the order Carnivora, we found no clear evidence that these host-jumping events involved adaptive evolution, with RABV instead characterized by strong purifying selection, suggesting that ecological processes also play an important role in shaping patterns of emergence. However, specific amino acid changes were associated with the parallel emergence of RABV in ferret-badgers in Asia, and some host shifts were associated with increases in evolutionary rate, particularly in the ferret-badger and mongoose, implying that changes in host species can have important impacts on evolutionary dynamics.

  8. Large-Scale Phylogenomic Analysis Reveals the Complex Evolutionary History of Rabies Virus in Multiple Carnivore Hosts.

    Science.gov (United States)

    Troupin, Cécile; Dacheux, Laurent; Tanguy, Marion; Sabeta, Claude; Blanc, Hervé; Bouchier, Christiane; Vignuzzi, Marco; Duchene, Sebastián; Holmes, Edward C; Bourhy, Hervé

    2016-12-01

    The natural evolution of rabies virus (RABV) provides a potent example of multiple host shifts and an important opportunity to determine the mechanisms that underpin viral emergence. Using 321 genome sequences spanning an unprecedented diversity of RABV, we compared evolutionary rates and selection pressures in viruses sampled from multiple primary host shifts that occurred on various continents. Two major phylogenetic groups, bat-related RABV and dog-related RABV, experiencing markedly different evolutionary dynamics were identified. While no correlation between time and genetic divergence was found in bat-related RABV, the evolution of dog-related RABV followed a generally clock-like structure, although with a relatively low evolutionary rate. Subsequent molecular clock dating indicated that dog-related RABV likely underwent a rapid global spread following the intensification of intercontinental trade starting in the 15th century. Strikingly, although dog RABV has jumped to various wildlife species from the order Carnivora, we found no clear evidence that these host-jumping events involved adaptive evolution, with RABV instead characterized by strong purifying selection, suggesting that ecological processes also play an important role in shaping patterns of emergence. However, specific amino acid changes were associated with the parallel emergence of RABV in ferret-badgers in Asia, and some host shifts were associated with increases in evolutionary rate, particularly in the ferret-badger and mongoose, implying that changes in host species can have important impacts on evolutionary dynamics.

  9. The mitochondrial genome of the terrestrial carnivorous plant Utricularia reniformis (Lentibulariaceae: Structure, comparative analysis and evolutionary landmarks.

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    Saura R Silva

    Full Text Available The carnivorous plants of the family Lentibulariaceae have attained recent attention not only because of their interesting lifestyle, but also because of their dynamic nuclear genome size. Lentibulariaceae genomes span an order of magnitude and include species with the smallest genomes in angiosperms, making them a powerful system to study the mechanisms of genome expansion and contraction. However, little is known about mitochondrial DNA (mtDNA sequences of this family, and the evolutionary forces that shape this organellar genome. Here we report the sequencing and assembly of the complete mtDNA from the endemic terrestrial Brazilian species Utricularia reniformis. The 857,234bp master circle mitochondrial genome encodes 70 transcriptionaly active genes (42 protein-coding, 25 tRNAs and 3 rRNAs, covering up to 7% of the mtDNA. A ltrA-like protein related to splicing and mobility and a LAGLIDADG homing endonuclease have been identified in intronic regions, suggesting particular mechanisms of genome maintenance. RNA-seq analysis identified properties with putative diverse and important roles in genome regulation and evolution: 1 672kbp (78% of the mtDNA is covered by full-length reads; 2 most of the 243kbp intergenic regions exhibit transcripts; and 3 at least 69 novel RNA editing sites in the protein-coding genes. Additional genomic features are hypothetical ORFs (48%, chloroplast insertions, including truncated plastid genes that have been lost from the chloroplast DNA (5%, repeats (5%, relics of transposable elements mostly related to LTR retrotransposons (5%, and truncated mitovirus sequences (0.4%. Phylogenetic analysis based on 32 different Lamiales mitochondrial genomes corroborate that Lentibulariaceae is a monophyletic group. In summary, the U. reniformis mtDNA represents the eighth largest plant mtDNA described to date, shedding light on the genomic trends and evolutionary characteristics and phylogenetic history of the family

  10. The mitochondrial genome of the terrestrial carnivorous plant Utricularia reniformis (Lentibulariaceae): Structure, comparative analysis and evolutionary landmarks.

    Science.gov (United States)

    Silva, Saura R; Alvarenga, Danillo O; Aranguren, Yani; Penha, Helen A; Fernandes, Camila C; Pinheiro, Daniel G; Oliveira, Marcos T; Michael, Todd P; Miranda, Vitor F O; Varani, Alessandro M

    2017-01-01

    The carnivorous plants of the family Lentibulariaceae have attained recent attention not only because of their interesting lifestyle, but also because of their dynamic nuclear genome size. Lentibulariaceae genomes span an order of magnitude and include species with the smallest genomes in angiosperms, making them a powerful system to study the mechanisms of genome expansion and contraction. However, little is known about mitochondrial DNA (mtDNA) sequences of this family, and the evolutionary forces that shape this organellar genome. Here we report the sequencing and assembly of the complete mtDNA from the endemic terrestrial Brazilian species Utricularia reniformis. The 857,234bp master circle mitochondrial genome encodes 70 transcriptionaly active genes (42 protein-coding, 25 tRNAs and 3 rRNAs), covering up to 7% of the mtDNA. A ltrA-like protein related to splicing and mobility and a LAGLIDADG homing endonuclease have been identified in intronic regions, suggesting particular mechanisms of genome maintenance. RNA-seq analysis identified properties with putative diverse and important roles in genome regulation and evolution: 1) 672kbp (78%) of the mtDNA is covered by full-length reads; 2) most of the 243kbp intergenic regions exhibit transcripts; and 3) at least 69 novel RNA editing sites in the protein-coding genes. Additional genomic features are hypothetical ORFs (48%), chloroplast insertions, including truncated plastid genes that have been lost from the chloroplast DNA (5%), repeats (5%), relics of transposable elements mostly related to LTR retrotransposons (5%), and truncated mitovirus sequences (0.4%). Phylogenetic analysis based on 32 different Lamiales mitochondrial genomes corroborate that Lentibulariaceae is a monophyletic group. In summary, the U. reniformis mtDNA represents the eighth largest plant mtDNA described to date, shedding light on the genomic trends and evolutionary characteristics and phylogenetic history of the family Lentibulariaceae.

  11. Comparative genome analysis reveals a conserved family of actin-like proteins in apicomplexan parasites

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    Sibley L David

    2005-12-01

    Full Text Available Abstract Background The phylum Apicomplexa is an early-branching eukaryotic lineage that contains a number of important human and animal pathogens. Their complex life cycles and unique cytoskeletal features distinguish them from other model eukaryotes. Apicomplexans rely on actin-based motility for cell invasion, yet the regulation of this system remains largely unknown. Consequently, we focused our efforts on identifying actin-related proteins in the recently completed genomes of Toxoplasma gondii, Plasmodium spp., Cryptosporidium spp., and Theileria spp. Results Comparative genomic and phylogenetic studies of apicomplexan genomes reveals that most contain only a single conventional actin and yet they each have 8–10 additional actin-related proteins. Among these are a highly conserved Arp1 protein (likely part of a conserved dynactin complex, and Arp4 and Arp6 homologues (subunits of the chromatin-remodeling machinery. In contrast, apicomplexans lack canonical Arp2 or Arp3 proteins, suggesting they lost the Arp2/3 actin polymerization complex on their evolutionary path towards intracellular parasitism. Seven of these actin-like proteins (ALPs are novel to apicomplexans. They show no phylogenetic associations to the known Arp groups and likely serve functions specific to this important group of intracellular parasites. Conclusion The large diversity of actin-like proteins in apicomplexans suggests that the actin protein family has diverged to fulfill various roles in the unique biology of intracellular parasites. Conserved Arps likely participate in vesicular transport and gene expression, while apicomplexan-specific ALPs may control unique biological traits such as actin-based gliding motility.

  12. Genome-Wide Analyses Reveal Genes Subject to Positive Selection in Pasteurella multocida

    Science.gov (United States)

    Cao, Peili; Guo, Dongchun; Liu, Jiasen; Jiang, Qian; Xu, Zhuofei; Qu, Liandong

    2017-01-01

    Pasteurella multocida, a Gram-negative opportunistic pathogen, has led to a broad range of diseases in mammals and birds, including fowl cholera in poultry, pneumonia and atrophic rhinitis in swine and rabbit, hemorrhagic septicemia in cattle, and bite infections in humans. In order to better interpret the genetic diversity and adaptation evolution of this pathogen, seven genomes of P. multocida strains isolated from fowls, rabbit and pigs were determined by using high-throughput sequencing approach. Together with publicly available P. multocida genomes, evolutionary features were systematically analyzed in this study. Clustering of 70,565 protein-coding genes showed that the pangenome of 33 P. multocida strains was composed of 1,602 core genes, 1,364 dispensable genes, and 1,070 strain-specific genes. Of these, we identified a full spectrum of genes related to virulence factors and revealed genetic diversity of these potential virulence markers across P. multocida strains, e.g., bcbAB, fcbC, lipA, bexDCA, ctrCD, lgtA, lgtC, lic2A involved in biogenesis of surface polysaccharides, hsf encoding autotransporter adhesin, and fhaB encoding filamentous haemagglutinin. Furthermore, based on genome-wide positive selection scanning, a total of 35 genes were subject to strong selection pressure. Extensive analyses of protein subcellular location indicated that membrane-associated genes were highly abundant among all positively selected genes. The detected amino acid sites undergoing adaptive selection were preferably located in extracellular space, perhaps associated with bacterial evasion of host immune responses. Our findings shed more light on conservation and distribution of virulence-associated genes across P. multocida strains. Meanwhile, this study provides a genetic context for future researches on the mechanism of adaptive evolution in P. multocida. PMID:28611758

  13. Genome-Wide Analyses Reveal Genes Subject to Positive Selection in Pasteurella multocida

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    Peili Cao

    2017-05-01

    Full Text Available Pasteurella multocida, a Gram-negative opportunistic pathogen, has led to a broad range of diseases in mammals and birds, including fowl cholera in poultry, pneumonia and atrophic rhinitis in swine and rabbit, hemorrhagic septicemia in cattle, and bite infections in humans. In order to better interpret the genetic diversity and adaptation evolution of this pathogen, seven genomes of P. multocida strains isolated from fowls, rabbit and pigs were determined by using high-throughput sequencing approach. Together with publicly available P. multocida genomes, evolutionary features were systematically analyzed in this study. Clustering of 70,565 protein-coding genes showed that the pangenome of 33 P. multocida strains was composed of 1,602 core genes, 1,364 dispensable genes, and 1,070 strain-specific genes. Of these, we identified a full spectrum of genes related to virulence factors and revealed genetic diversity of these potential virulence markers across P. multocida strains, e.g., bcbAB, fcbC, lipA, bexDCA, ctrCD, lgtA, lgtC, lic2A involved in biogenesis of surface polysaccharides, hsf encoding autotransporter adhesin, and fhaB encoding filamentous haemagglutinin. Furthermore, based on genome-wide positive selection scanning, a total of 35 genes were subject to strong selection pressure. Extensive analyses of protein subcellular location indicated that membrane-associated genes were highly abundant among all positively selected genes. The detected amino acid sites undergoing adaptive selection were preferably located in extracellular space, perhaps associated with bacterial evasion of host immune responses. Our findings shed more light on conservation and distribution of virulence-associated genes across P. multocida strains. Meanwhile, this study provides a genetic context for future researches on the mechanism of adaptive evolution in P. multocida.

  14. Genome-Wide Analyses Reveal Genes Subject to Positive Selection in Pasteurella multocida.

    Science.gov (United States)

    Cao, Peili; Guo, Dongchun; Liu, Jiasen; Jiang, Qian; Xu, Zhuofei; Qu, Liandong

    2017-01-01

    Pasteurella multocida, a Gram-negative opportunistic pathogen, has led to a broad range of diseases in mammals and birds, including fowl cholera in poultry, pneumonia and atrophic rhinitis in swine and rabbit, hemorrhagic septicemia in cattle, and bite infections in humans. In order to better interpret the genetic diversity and adaptation evolution of this pathogen, seven genomes of P. multocida strains isolated from fowls, rabbit and pigs were determined by using high-throughput sequencing approach. Together with publicly available P. multocida genomes, evolutionary features were systematically analyzed in this study. Clustering of 70,565 protein-coding genes showed that the pangenome of 33 P. multocida strains was composed of 1,602 core genes, 1,364 dispensable genes, and 1,070 strain-specific genes. Of these, we identified a full spectrum of genes related to virulence factors and revealed genetic diversity of these potential virulence markers across P. multocida strains, e.g., bcbAB, fcbC, lipA, bexDCA, ctrCD, lgtA, lgtC, lic2A involved in biogenesis of surface polysaccharides, hsf encoding autotransporter adhesin, and fhaB encoding filamentous haemagglutinin. Furthermore, based on genome-wide positive selection scanning, a total of 35 genes were subject to strong selection pressure. Extensive analyses of protein subcellular location indicated that membrane-associated genes were highly abundant among all positively selected genes. The detected amino acid sites undergoing adaptive selection were preferably located in extracellular space, perhaps associated with bacterial evasion of host immune responses. Our findings shed more light on conservation and distribution of virulence-associated genes across P. multocida strains. Meanwhile, this study provides a genetic context for future researches on the mechanism of adaptive evolution in P. multocida.

  15. Genomic and evolutionary comparisons of diazotrophic and pathogenic bacteria of the order Rhizobiales

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    Vasconcelos Ana

    2010-02-01

    Full Text Available Abstract Background Species belonging to the Rhizobiales are intriguing and extensively researched for including both bacteria with the ability to fix nitrogen when in symbiosis with leguminous plants and pathogenic bacteria to animals and plants. Similarities between the strategies adopted by pathogenic and symbiotic Rhizobiales have been described, as well as high variability related to events of horizontal gene transfer. Although it is well known that chromosomal rearrangements, mutations and horizontal gene transfer influence the dynamics of bacterial genomes, in Rhizobiales, the scenario that determine pathogenic or symbiotic lifestyle are not clear and there are very few studies of comparative genomic between these classes of prokaryotic microorganisms trying to delineate the evolutionary characterization of symbiosis and pathogenesis. Results Non-symbiotic nitrogen-fixing bacteria and bacteria involved in bioremediation closer to symbionts and pathogens in study may assist in the origin and ancestry genes and the gene flow occurring in Rhizobiales. The genomic comparisons of 19 species of Rhizobiales, including nitrogen-fixing, bioremediators and pathogens resulted in 33 common clusters to biological nitrogen fixation and pathogenesis, 15 clusters exclusive to all nitrogen-fixing bacteria and bacteria involved in bioremediation, 13 clusters found in only some nitrogen-fixing and bioremediation bacteria, 01 cluster exclusive to some symbionts, and 01 cluster found only in some pathogens analyzed. In BBH performed to all strains studied, 77 common genes were obtained, 17 of which were related to biological nitrogen fixation and pathogenesis. Phylogenetic reconstructions for Fix, Nif, Nod, Vir, and Trb showed possible horizontal gene transfer events, grouping species of different phenotypes. Conclusions The presence of symbiotic and virulence genes in both pathogens and symbionts does not seem to be the only determinant factor for lifestyle

  16. Genomic and evolutionary comparisons of diazotrophic and pathogenic bacteria of the order Rhizobiales.

    Science.gov (United States)

    Carvalho, Fabíola M; Souza, Rangel C; Barcellos, Fernando G; Hungria, Mariangela; Vasconcelos, Ana Tereza R

    2010-02-08

    Species belonging to the Rhizobiales are intriguing and extensively researched for including both bacteria with the ability to fix nitrogen when in symbiosis with leguminous plants and pathogenic bacteria to animals and plants. Similarities between the strategies adopted by pathogenic and symbiotic Rhizobiales have been described, as well as high variability related to events of horizontal gene transfer. Although it is well known that chromosomal rearrangements, mutations and horizontal gene transfer influence the dynamics of bacterial genomes, in Rhizobiales, the scenario that determine pathogenic or symbiotic lifestyle are not clear and there are very few studies of comparative genomic between these classes of prokaryotic microorganisms trying to delineate the evolutionary characterization of symbiosis and pathogenesis. Non-symbiotic nitrogen-fixing bacteria and bacteria involved in bioremediation closer to symbionts and pathogens in study may assist in the origin and ancestry genes and the gene flow occurring in Rhizobiales. The genomic comparisons of 19 species of Rhizobiales, including nitrogen-fixing, bioremediators and pathogens resulted in 33 common clusters to biological nitrogen fixation and pathogenesis, 15 clusters exclusive to all nitrogen-fixing bacteria and bacteria involved in bioremediation, 13 clusters found in only some nitrogen-fixing and bioremediation bacteria, 01 cluster exclusive to some symbionts, and 01 cluster found only in some pathogens analyzed. In BBH performed to all strains studied, 77 common genes were obtained, 17 of which were related to biological nitrogen fixation and pathogenesis. Phylogenetic reconstructions for Fix, Nif, Nod, Vir, and Trb showed possible horizontal gene transfer events, grouping species of different phenotypes. The presence of symbiotic and virulence genes in both pathogens and symbionts does not seem to be the only determinant factor for lifestyle evolution in these microorganisms, although they may act in

  17. Classification, naming and evolutionary history of glycosyltransferases from sequenced green and red algal genomes.

    Directory of Open Access Journals (Sweden)

    Peter Ulvskov

    Full Text Available The Archaeplastida consists of three lineages, Rhodophyta, Virideplantae and Glaucophyta. The extracellular matrix of most members of the Rhodophyta and Viridiplantae consists of carbohydrate-based or a highly glycosylated protein-based cell wall while the Glaucophyte covering is poorly resolved. In order to elucidate possible evolutionary links between the three advanced lineages in Archaeplastida, a genomic analysis was initiated. Fully sequenced genomes from the Rhodophyta and Virideplantae and the well-defined CAZy database on glycosyltransferases were included in the analysis. The number of glycosyltransferases found in the Rhodophyta and Chlorophyta are generally much lower then in land plants (Embryophyta. Three specific features exhibited by land plants increase the number of glycosyltransferases in their genomes: (1 cell wall biosynthesis, the more complex land plant cell walls require a larger number of glycosyltransferases for biosynthesis, (2 a richer set of protein glycosylation, and (3 glycosylation of secondary metabolites, demonstrated by a large proportion of family GT1 being involved in secondary metabolite biosynthesis. In a comparative analysis of polysaccharide biosynthesis amongst the taxa of this study, clear distinctions or similarities were observed in (1 N-linked protein glycosylation, i.e., Chlorophyta has different mannosylation and glucosylation patterns, (2 GPI anchor biosynthesis, which is apparently missing in the Rhodophyta and truncated in the Chlorophyta, (3 cell wall biosynthesis, where the land plants have unique cell wall related polymers not found in green and red algae, and (4 O-linked glycosylation where comprehensive orthology was observed in glycosylation between the Chlorophyta and land plants but not between the target proteins.

  18. Evolutionary dynamics of olfactory receptor genes in chordates: interaction between environments and genomic contents

    OpenAIRE

    Niimura, Yoshihito

    2009-01-01

    Abstract Olfaction is essential for the survival of animals. Versatile odour molecules in the environment are received by olfactory receptors (ORs), which form the largest multigene family in vertebrates. Identification of the entire repertories of OR genes using bioinformatics methods from the whole-genome sequences of diverse organisms revealed that the numbers of OR genes vary enormously, ranging from ~1,200 in rats and ~400 in humans to ~150 in zebrafish and ~15 in pufferfish. Most specie...

  19. Novel Genomic and Evolutionary Insight of WRKY Transcription Factors in Plant Lineage

    OpenAIRE

    Tapan Kumar Mohanta; Yong-Hwan Park; Hanhong Bae

    2016-01-01

    The evolutionarily conserved WRKY transcription factor (TF) regulates different aspects of gene expression in plants, and modulates growth, development, as well as biotic and abiotic stress responses. Therefore, understanding the details regarding WRKY TFs is very important. In this study, large-scale genomic analyses of the WRKY TF gene family from 43 plant species were conducted. The results of our study revealed that WRKY TFs could be grouped and specifically classified as those belonging ...

  20. Analysis of fine-scale mammalian evolutionary breakpoints provides new insight into their relation to genome organisation

    Directory of Open Access Journals (Sweden)

    Zaghloul Lamia

    2009-07-01

    Full Text Available Abstract Background The Intergenic Breakage Model, which is the current model of structural genome evolution, considers that evolutionary rearrangement breakages happen with a uniform propensity along the genome but are selected against in genes, their regulatory regions and in-between. However, a growing body of evidence shows that there exists regions along mammalian genomes that present a high susceptibility to breakage. We reconsidered this question taking advantage of a recently published methodology for the precise detection of rearrangement breakpoints based on pairwise genome comparisons. Results We applied this methodology between the genome of human and those of five sequenced eutherian mammals which allowed us to delineate evolutionary breakpoint regions along the human genome with a finer resolution (median size 26.6 kb than obtained before. We investigated the distribution of these breakpoints with respect to genome organisation into domains of different activity. In agreement with the Intergenic Breakage Model, we observed that breakpoints are under-represented in genes. Surprisingly however, the density of breakpoints in small intergenes (1 per Mb appears significantly higher than in gene deserts (0.1 per Mb. More generally, we found a heterogeneous distribution of breakpoints that follows the organisation of the genome into isochores (breakpoints are more frequent in GC-rich regions. We then discuss the hypothesis that regions with an enhanced susceptibility to breakage correspond to regions of high transcriptional activity and replication initiation. Conclusion We propose a model to describe the heterogeneous distribution of evolutionary breakpoints along human chromosomes that combines natural selection and a mutational bias linked to local open chromatin state.

  1. Genomic view of bipolar disorder revealed by whole genome sequencing in a genetic isolate.

    Directory of Open Access Journals (Sweden)

    Benjamin Georgi

    2014-03-01

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

  2. A diversity study of Saccharomycopsis fibuligera in rice wine starter nuruk, reveals the evolutionary process associated with its interspecies hybrid.

    Science.gov (United States)

    Farh, Mohamed El-Agamy; Cho, Yunjoo; Lim, Jae Yun; Seo, Jeong-Ah

    2017-05-01

    The amylolytic yeast Saccharomycopsis fibuligera is the predominant yeast in the starter product, nuruk, which is utilized for rice wine production in South Korea. Latest molecular studies explore a recently developed interspecific hybridization among stains of S. fibuligera with a unique genetic feature. However, the origin of the natural hybridization occurrence is still unclear. Thus, to respectively distinguish parental and hybrid strains, specific primer sets were applied on 141 yeast strains isolated from different nuruk samples fermented in different provinces. Sixty-seven strains were defined accordingly as parental species with genome A while 8 strains were defined as hybrid strains. Unexpectedly, another parental species with genome B could not be found among the strain pools yet. Furthermore, it was observed that hybrid strains are phenotypically different from A genome strains; asci containing tetrad ascospores were observed in A genome strains more frequent than in hybrid strains. Nevertheless, hybrid strains were slightly more thermotolerant than A genome strains. Interestingly, all hybrid strains were located only in Jeju province. Based on these sets of data, we speculated that the unique climate of Jeju province might play an evolutionary role in the interspecific hybridization between A genome strains, as well as the unculturable allopatric B genome strains.

  3. Perspectives provided by leopard and other cat genomes: how diet determined the evolutionary history of carnivores, omnivores, and herbivores.

    Science.gov (United States)

    Kim, Soonok; Cho, Yun Sung; Bhak, Jong; O'Brian, Stephen J; Yeo, Joo-Hong

    2017-01-01

    Recent advances in genome sequencing technologies have enabled humans to generate and investigate the genomes of wild species. This includes the big cat family, such as tigers, lions, and leopards. Adding the first high quality leopard genome, we have performed an in-depth comparative analysis to identify the genomic signatures in the evolution of felid to become the top predators on land. Our study focused on how the carnivore genomes, as compared to the omnivore or herbivore genomes, shared evolutionary adaptations in genes associated with nutrient metabolism, muscle strength, agility, and other traits responsible for hunting and meat digestion. We found genetic evidence that genomes represent what animals eat through modifying genes. Highly conserved genetically relevant regions were discovered in genomes at the family level. Also, the Felidae family genomes exhibited low levels of genetic diversity associated with decreased population sizes, presumably because of their strict diet, suggesting their vulnerability and critical conservation status. Our findings can be used for human health enhancement, since we share the same genes as cats with some variation. This is an example how wildlife genomes can be a critical resource for human evolution, providing key genetic marker information for disease treatment. [BMB Reports 2017; 50(1): 3-4].

  4. Genome sequencing reveals loci under artificial selection that underlie disease phenotypes in the laboratory rat

    NARCIS (Netherlands)

    Atanur, S.S.; Diaz, A.G.; Maratou, K.; Sarkis, A.; Rotival, M.; Game, L.; Tschannen, M.R.; Kaisaki, P.J.; Otto, G.W.; Ma, M.C.; Keane, T.M.; Hummel, O.; Saar, K.; Chen, W.; Guryev, V.; Gopalakrishnan, K.; Garrett, M.R.; Joe, B.; Citterio, L.; Bianchi, G.; McBride, M.; Dominiczak, A.; Adams, D.J.; Serikawa, T.; Flicek, P.; Cuppen, E.; Hubner, N.; Petretto, E.; Gauguier, D.; Kwitek, A.; Jacob, H.; Aitman, T.J.

    2013-01-01

    Large numbers of inbred laboratory rat strains have been developed for a range of complex disease phenotypes. To gain insights into the evolutionary pressures underlying selection for these phenotypes, we sequenced the genomes of 27 rat strains, including 11 models of hypertension, diabetes, and

  5. Genome Sequencing Reveals Loci under Artificial Selection that Underlie Disease Phenotypes in the Laboratory Rat

    NARCIS (Netherlands)

    Atanur, Santosh S.; Diaz, Ana Garcia; Maratou, Klio; Sarkis, Allison; Rotival, Maxime; Game, Laurence; Tschannen, Michael R.; Kaisaki, Pamela J.; Otto, Georg W.; Ma, Man Chun John; Keane, Thomas M.; Hummel, Oliver; Saar, Kathrin; Chen, Wei; Guryev, Victor; Gopalakrishnan, Kathirvel; Garrett, Michael R.; Joe, Bina; Citterio, Lorena; Bianchi, Giuseppe; McBride, Martin; Dominiczak, Anna; Adams, David J.; Serikawa, Tadao; Flicek, Paul; Cuppen, Edwin; Hubner, Norbert; Petretto, Enrico; Gauguier, Dominique; Kwitek, Anne; Jacob, Howard; Aitman, Timothy J.

    2013-01-01

    Large numbers of inbred laboratory rat strains have been developed for a range of complex disease phenotypes. To gain insights into the evolutionary pressures underlying selection for these phenotypes, we sequenced the genomes of 27 rat strains, including 11 models of hypertension, diabetes, and

  6. Symbiodinium genomes reveal adaptive evolution of functions related to symbiosis

    KAUST Repository

    Liu, Huanle

    2017-10-06

    Symbiosis between dinoflagellates of the genus Symbiodinium and reef-building corals forms the trophic foundation of the world\\'s coral reef ecosystems. Here we present the first draft genome of Symbiodinium goreaui (Clade C, type C1: 1.03 Gbp), one of the most ubiquitous endosymbionts associated with corals, and an improved draft genome of Symbiodinium kawagutii (Clade F, strain CS-156: 1.05 Gbp), previously sequenced as strain CCMP2468, to further elucidate genomic signatures of this symbiosis. Comparative analysis of four available Symbiodinium genomes against other dinoflagellate genomes led to the identification of 2460 nuclear gene families that show evidence of positive selection, including genes involved in photosynthesis, transmembrane ion transport, synthesis and modification of amino acids and glycoproteins, and stress response. Further, we identified extensive sets of genes for meiosis and response to light stress. These draft genomes provide a foundational resource for advancing our understanding Symbiodinium biology and the coral-algal symbiosis.

  7. Genomics of the Genus Bifidobacterium Reveals Species-Specific Adaptation to the Glycan-Rich Gut Environment

    Science.gov (United States)

    Milani, Christian; Turroni, Francesca; Duranti, Sabrina; Lugli, Gabriele Andrea; Mancabelli, Leonardo; Ferrario, Chiara; van Sinderen, Douwe

    2015-01-01

    Bifidobacteria represent one of the dominant microbial groups that occur in the gut of various animals, being particularly prevalent during the suckling period of humans and other mammals. Their ability to compete with other gut bacteria is largely attributed to their saccharolytic features. Comparative and functional genomic as well as transcriptomic analyses have revealed the genetic background that underpins the overall saccharolytic phenotype for each of the 47 bifidobacterial (sub)species representing the genus Bifidobacterium, while also generating insightful information regarding carbohydrate resource sharing and cross-feeding among bifidobacteria. The abundance of bifidobacterial saccharolytic features in human microbiomes supports the notion that metabolic accessibility to dietary and/or host-derived glycans is a potent evolutionary force that has shaped the bifidobacterial genome. PMID:26590291

  8. Seventeen new complete mtDNA sequences reveal extensive mitochondrial genome evolution within the Demospongiae.

    Directory of Open Access Journals (Sweden)

    Xiujuan Wang

    Full Text Available Two major transitions in animal evolution--the origins of multicellularity and bilaterality--correlate with major changes in mitochondrial DNA (mtDNA organization. Demosponges, the largest class in the phylum Porifera, underwent only the first of these transitions and their mitochondrial genomes display a peculiar combination of ancestral and animal-specific features. To get an insight into the evolution of mitochondrial genomes within the Demospongiae, we determined 17 new mtDNA sequences from this group and analyzing them with five previously published sequences. Our analysis revealed that all demosponge mtDNAs are 16- to 25-kbp circular molecules, containing 13-15 protein genes, 2 rRNA genes, and 2-27 tRNA genes. All but four pairs of sampled genomes had unique gene orders, with the number of shared gene boundaries ranging from 1 to 41. Although most demosponge species displayed low rates of mitochondrial sequence evolution, a significant acceleration in evolutionary rates occurred in the G1 group (orders Dendroceratida, Dictyoceratida, and Verticillitida. Large variation in mtDNA organization was also observed within the G0 group (order Homosclerophorida including gene rearrangements, loss of tRNA genes, and the presence of two introns in Plakortis angulospiculatus. While introns are rare in modern-day demosponge mtDNA, we inferred that at least one intron was present in cox1 of the common ancestor of all demosponges. Our study uncovered an extensive mitochondrial genomic diversity within the Demospongiae. Although all sampled mitochondrial genomes retained some ancestral features, including a minimally modified genetic code, conserved structures of tRNA genes, and presence of multiple non-coding regions, they vary considerably in their size, gene content, gene order, and the rates of sequence evolution. Some of the changes in demosponge mtDNA, such as the loss of tRNA genes and the appearance of hairpin-containing repetitive elements

  9. Phylogeny of Banana Streak Virus reveals recent and repetitive endogenization in the genome of its banana host (Musa sp.).

    Science.gov (United States)

    Gayral, Philippe; Iskra-Caruana, Marie-Line

    2009-07-01

    Banana streak virus (BSV) is a plant dsDNA pararetrovirus (family Caulimoviridae, genus badnavirus). Although integration is not an essential step in the BSV replication cycle, the nuclear genome of banana (Musa sp.) contains BSV endogenous pararetrovirus sequences (BSV EPRVs). Some BSV EPRVs are infectious by reconstituting a functional viral genome. Recent studies revealed a large molecular diversity of episomal BSV viruses (i.e., nonintegrated) while others focused on BSV EPRV sequences only. In this study, the evolutionary history of badnavirus integration in banana was inferred from phylogenetic relationships between BSV and BSV EPRVs. The relative evolution rates and selective pressures (d(N)/d(S) ratio) were also compared between endogenous and episomal viral sequences. At least 27 recent independent integration events occurred after the divergence of three banana species, indicating that viral integration is a recent and frequent phenomenon. Relaxation of selective pressure on badnaviral sequences that experienced neutral evolution after integration in the plant genome was recorded. Additionally, a significant decrease (35%) in the EPRV evolution rate was observed compared to BSV, reflecting the difference in the evolution rate between episomal dsDNA viruses and plant genome. The comparison of our results with the evolution rate of the Musa genome and other reverse-transcribing viruses suggests that EPRVs play an active role in episomal BSV diversity and evolution.

  10. Comparative transcriptome analysis reveals whole-genome duplications and gene selection patterns in cultivated and wild Chrysanthemum species.

    Science.gov (United States)

    Won, So Youn; Kwon, Soo-Jin; Lee, Tae-Ho; Jung, Jae-A; Kim, Jung Sun; Kang, Sang-Ho; Sohn, Seong-Han

    2017-11-01

    Comparative transcriptome analysis of wild and cultivated chrysanthemums provides valuable genomic resources and helps uncover common and divergent patterns of genome and gene evolution in these species. Plants are unique in that they employ polyploidy (or whole-genome duplication, WGD) as a key process for speciation and evolution. The Chrysanthemum genus is closely associated with hybridization and polyploidization, with Chrysanthemum species exhibiting diverse ploidy levels. The commercially important species, C. morifolium is an allohexaploid plant that is thought to have originated via the hybridization of several Chrysanthemum species, but the genomic and molecular evolutionary mechanisms remain poorly understood. In the present study, we sequenced and compared the transcriptomes of C. morifolium and the wild Korean diploid species, C. boreale. De novo transcriptome assembly revealed 11,318 genes in C. morifolium and 10,961 genes in C. boreale, whose functions were annotated by homology searches. An analysis of synonymous substitution rates (Ks) of paralogous and orthologous genes suggested that the two Chrysanthemum species commonly experienced the Asteraceae paleopolyploidization and recent genome duplication or triplication before the divergence of these species. Intriguingly, C. boreale probably underwent rapid diploidization, with a reduction in chromosome number, whereas C. morifolium maintained the original chromosome number. Analysis of the ratios of non-synonymous to synonymous nucleotide substitutions (Ka/Ks) between orthologous gene pairs indicated that 107 genes experienced positive selection, which may have been crucial for the adaptation, domestication, and speciation of Chrysanthemum.

  11. Comparative genomics of enterohemorrhagic Escherichia coli O145:H28 demonstrates a common evolutionary lineage with Escherichia coli O157:H7.

    Science.gov (United States)

    Cooper, Kerry K; Mandrell, Robert E; Louie, Jacqueline W; Korlach, Jonas; Clark, Tyson A; Parker, Craig T; Huynh, Steven; Chain, Patrick S; Ahmed, Sanaa; Carter, Michelle Qiu

    2014-01-10

    Although serotype O157:H7 is the predominant enterohemorrhagic Escherichia coli (EHEC), outbreaks of non-O157 EHEC that cause severe foodborne illness, including hemolytic uremic syndrome have increased worldwide. In fact, non-O157 serotypes are now estimated to cause over half of all the Shiga toxin-producing Escherichia coli (STEC) cases, and outbreaks of non-O157 EHEC infections are frequently associated with serotypes O26, O45, O103, O111, O121, and O145. Currently, there are no complete genomes for O145 in public databases. We determined the complete genome sequences of two O145 strains (EcO145), one linked to a US lettuce-associated outbreak (RM13514) and one to a Belgium ice-cream-associated outbreak (RM13516). Both strains contain one chromosome and two large plasmids, with genome sizes of 5,737,294 bp for RM13514 and 5,559,008 bp for RM13516. Comparative analysis of the two EcO145 genomes revealed a large core (5,173 genes) and a considerable amount of strain-specific genes. Additionally, the two EcO145 genomes display distinct chromosomal architecture, virulence gene profile, phylogenetic origin of Stx2a prophage, and methylation profile (methylome). Comparative analysis of EcO145 genomes to other completely sequenced STEC and other E. coli and Shigella genomes revealed that, unlike any other known non-O157 EHEC strain, EcO145 ascended from a common lineage with EcO157/EcO55. This evolutionary relationship was further supported by the pangenome analysis of the 10 EHEC str ains. Of the 4,192 EHEC core genes, EcO145 shares more genes with EcO157 than with the any other non-O157 EHEC strains. Our data provide evidence that EcO145 and EcO157 evolved from a common lineage, but ultimately each serotype evolves via a lineage-independent nature to EHEC by acquisition of the core set of EHEC virulence factors, including the genes encoding Shiga toxin and the large virulence plasmid. The large variation between the two EcO145 genomes suggests a distinctive

  12. dbCRY: a Web-based comparative and evolutionary genomics platform for blue-light receptors.

    Science.gov (United States)

    Kim, Yong-Min; Choi, Jaeyoung; Lee, Hye-Young; Lee, Gir-Won; Lee, Yong-Hwan; Choi, Doil

    2014-01-01

    Cryptochromes are flavoproteins that play a central role in the circadian oscillations of all living organisms except archaea. Cryptochromes are clustered into three subfamilies: plant-type cryptochromes, animal-type cryptochromes and cryptochrome-DASH proteins. These subfamilies are composed of photolyase/cryptochrome superfamily with 6-4 photolyase and cyclobutane pyrimidine dimer photolyase. Cryptochromes have conserved domain architectures with two distinct domains, an N-terminal photolyase-related domain and a C-terminal domain. Although the molecular function and domain architecture of cryptochromes are conserved, their molecular mechanisms differ between plants and animals. Thus, cryptochromes are one of the best candidates for comparative and evolutionary studies. Here, we have developed a Web-based platform for comparative and evolutionary studies of cryptochromes, dbCRY (http://www.dbcryptochrome.org/). A pipeline built upon the consensus domain profile was applied to 1438 genomes and identified 1309 genes. To support comparative and evolutionary genomics studies, the Web interface provides diverse functions such as (i) browsing by species, (ii) protein domain analysis, (iii) multiple sequence alignment, (iv) homology search and (v) extended analysis opportunities through the implementation of 'Favorite Browser' powered by the Comparative Fungal Genomics Platform 2.0 (CFGP 2.0; http://cfgp.snu.ac.kr/). dbCRY would serve as a standardized and systematic solution for cryptochrome genomics studies. Database URL: http://www.dbcryptochrome.org/

  13. Evolutionary analysis revealed the horizontal transfer of the Cyt b gene from Fungi to Chromista.

    Science.gov (United States)

    Yin, Liang-Fen; Wang, Fei; Zhang, Yu; Kuang, Hanhui; Schnabel, Guido; Li, Guo-Qing; Luo, Chao-Xi

    2014-07-01

    In this study, the cytochrome b (Cyt b) amino acid sequences were analyzed in 50 organisms covering all 5 kingdoms of eukaryotes. Six conserved domains, i.e., heme bL binding sites, heme bH binding sites, Qo binding sites, Qi binding sites, the interchain domain interface, and the intrachain domain interface were found in all investigated sequences. The topology of the phylogenetic trees was largely consistent with the well recognized taxonomic relationships, indicating that the Cyt b genes originated from a common ancestral gene before the divergence of eukaryotic kingdoms. The eukaryotic Cyt b genes likely originated from an ancient prokaryotic gene in Alphaproteobacteria based on shared conserved domains. We provide evidence that the Cyt b gene of oomycete Pseudoperonospora cubensis was horizontally transferred from a fungus in the order Hypocreales. To our knowledge, this is the first reported evidence of Horizontal gene transfer (HGT) from Fungi to Chromista involving an essential house-keeping gene. Our data suggest that HGT events must be considered when evolutionary trees are constructed only based on Cyt b genes. Additional analysis of thousands of Cyt b sequences from Genbank revealed that introns in mitochondrial Cyt b genes were acquired after the endosymbiosis of alphaproteobacteria in eukaryotic cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Growth behaviors of bacteria reveal the evolutionary significance of energy-efficiency

    Science.gov (United States)

    Maitra, Arijit; Dill, Ken

    2015-03-01

    Microorganisms have evolved a mosaic of gene expression changes to adapt their growth behaviors to changing environmental conditions. The subset of genes coding for the protein translation machineries, the ribosomes, however display robust linear activities with growth rates. Such patterns are considered to be the source of growth itself. There is another robust growth law, observed by Monod in the 1940s, in which bacteria are able to scale their growth with food concentration before plateauing off to a constant value. To interlink these observed growth laws we derive an analytical network model that leverages metabolic data to capture how the cell manages its exchange of energy to support costly gene expression. The model explores the limits of energy allocation for function and reveals evolutionary principles. Among others, we find, in glucose medium the fastest growing E. coli operate close to their maximum energy-efficiency. Optimization of energy efficiency provides a quantitative limit to how much energy is allocated for protein synthesis and it is determined by evolutionarily selected structural and biophysical constants. We conclude that energy efficiency has played a key role in bacterial evolution. Supported by the Laufer Center for Physical and Quantitative Biology, SBU.

  15. Evolutionary history of human disease genes reveals phenotypic connections and comorbidity among genetic diseases

    Science.gov (United States)

    Park, Solip; Yang, Jae-Seong; Kim, Jinho; Shin, Young-Eun; Hwang, Jihye; Park, Juyong; Jang, Sung Key; Kim, Sanguk

    2012-10-01

    The extent to which evolutionary changes have impacted the phenotypic relationships among human diseases remains unclear. In this work, we report that phenotypically similar diseases are connected by the evolutionary constraints on human disease genes. Human disease groups can be classified into slowly or rapidly evolving classes, where the diseases in the slowly evolving class are enriched with morphological phenotypes and those in the rapidly evolving class are enriched with physiological phenotypes. Our findings establish a clear evolutionary connection between disease classes and disease phenotypes for the first time. Furthermore, the high comorbidity found between diseases connected by similar evolutionary constraints enables us to improve the predictability of the relative risk of human diseases. We find the evolutionary constraints on disease genes are a new layer of molecular connection in the network-based exploration of human diseases.

  16. Genomic and Evolutionary Perspectives on Sulfur Metabolism in Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A.

    2008-01-01

    Green sulfur bacteria (GSB) are anaerobic photoautotrophs that oxidize sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for growth. We present here an analysis of the distribution and evolution of enzymes involved in oxidation of sulfur compounds in GSB based on genome sequence......, in combination with phylogenetic analyses, suggests that the Dsr system in GSB could be a recent acquisition, which was obtained by lateral gene transfer in part from sulfideoxidizing bacteria and in part from sulfate-reducing bacteria. All thiosulfate-utilizing GSB strains have an identical sox gene cluster...... in some, but not all sulfide-utilizing strains. Even though different GSB strains superficially exhibit a similar sulfur oxidation phenotype, this may be caused by different combinations of enzymes. Thus, genome analyses have revealed that GSB have greater diversity in sulfur metabolism than previously...

  17. Mitochondrial Genome Analysis Reveals Historical Lineages in Yellowstone Bison.

    Directory of Open Access Journals (Sweden)

    David Forgacs

    Full Text Available Yellowstone National Park is home to one of the only plains bison populations that have continuously existed on their present landscape since prehistoric times without evidence of domestic cattle introgression. Previous studies characterized the relatively high levels of nuclear genetic diversity in these bison, but little is known about their mitochondrial haplotype diversity. This study assessed mitochondrial genomes from 25 randomly selected Yellowstone bison and found 10 different mitochondrial haplotypes with a haplotype diversity of 0.78 (± 0.06. Spatial analysis of these mitochondrial DNA (mtDNA haplotypes did not detect geographic population subdivision (FST = -0.06, p = 0.76. However, we identified two independent and historically important lineages in Yellowstone bison by combining data from 65 bison (defined by 120 polymorphic sites from across North America representing a total of 30 different mitochondrial DNA haplotypes. Mitochondrial DNA haplotypes from one of the Yellowstone lineages represent descendants of the 22 indigenous bison remaining in central Yellowstone in 1902. The other mitochondrial DNA lineage represents descendants of the 18 females introduced from northern Montana in 1902 to supplement the indigenous bison population and develop a new breeding herd in the northern region of the park. Comparing modern and historical mitochondrial DNA diversity in Yellowstone bison helps uncover a historical context of park restoration efforts during the early 1900s, provides evidence against a hypothesized mitochondrial disease in bison, and reveals the signature of recent hybridization between American plains bison (Bison bison bison and Canadian wood bison (B. b. athabascae. Our study demonstrates how mitochondrial DNA can be applied to delineate the history of wildlife species and inform future conservation actions.

  18. Mitochondrial Genome Analysis Reveals Historical Lineages in Yellowstone Bison

    Science.gov (United States)

    Derr, James N.

    2016-01-01

    Yellowstone National Park is home to one of the only plains bison populations that have continuously existed on their present landscape since prehistoric times without evidence of domestic cattle introgression. Previous studies characterized the relatively high levels of nuclear genetic diversity in these bison, but little is known about their mitochondrial haplotype diversity. This study assessed mitochondrial genomes from 25 randomly selected Yellowstone bison and found 10 different mitochondrial haplotypes with a haplotype diversity of 0.78 (± 0.06). Spatial analysis of these mitochondrial DNA (mtDNA) haplotypes did not detect geographic population subdivision (FST = -0.06, p = 0.76). However, we identified two independent and historically important lineages in Yellowstone bison by combining data from 65 bison (defined by 120 polymorphic sites) from across North America representing a total of 30 different mitochondrial DNA haplotypes. Mitochondrial DNA haplotypes from one of the Yellowstone lineages represent descendants of the 22 indigenous bison remaining in central Yellowstone in 1902. The other mitochondrial DNA lineage represents descendants of the 18 females introduced from northern Montana in 1902 to supplement the indigenous bison population and develop a new breeding herd in the northern region of the park. Comparing modern and historical mitochondrial DNA diversity in Yellowstone bison helps uncover a historical context of park restoration efforts during the early 1900s, provides evidence against a hypothesized mitochondrial disease in bison, and reveals the signature of recent hybridization between American plains bison (Bison bison bison) and Canadian wood bison (B. b. athabascae). Our study demonstrates how mitochondrial DNA can be applied to delineate the history of wildlife species and inform future conservation actions. PMID:27880780

  19. Comparative sex chromosome genomics in snakes: differentiation, evolutionary strata, and lack of global dosage compensation.

    Science.gov (United States)

    Vicoso, Beatriz; Emerson, J J; Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

    2013-01-01

    Snakes exhibit genetic sex determination, with female heterogametic sex chromosomes (ZZ males, ZW females). Extensive cytogenetic work has suggested that the level of sex chromosome heteromorphism varies among species, with Boidae having entirely homomorphic sex chromosomes, Viperidae having completely heteromorphic sex chromosomes, and Colubridae showing partial differentiation. Here, we take a genomic approach to compare sex chromosome differentiation in these three snake families. We identify homomorphic sex chromosomes in boas (Boidae), but completely heteromorphic sex chromosomes in both garter snakes (Colubridae) and pygmy rattlesnake (Viperidae). Detection of W-linked gametologs enables us to establish the presence of evolutionary strata on garter and pygmy rattlesnake sex chromosomes where recombination was abolished at different time points. Sequence analysis shows that all strata are shared between pygmy rattlesnake and garter snake, i.e., recombination was abolished between the sex chromosomes before the two lineages diverged. The sex-biased transmission of the Z and its hemizygosity in females can impact patterns of molecular evolution, and we show that rates of evolution for Z-linked genes are increased relative to their pseudoautosomal homologs, both at synonymous and amino acid sites (even after controlling for mutational biases). This demonstrates that mutation rates are male-biased in snakes (male-driven evolution), but also supports faster-Z evolution due to differential selective effects on the Z. Finally, we perform a transcriptome analysis in boa and pygmy rattlesnake to establish baseline levels of sex-biased expression in homomorphic sex chromosomes, and show that heteromorphic ZW chromosomes in rattlesnakes lack chromosome-wide dosage compensation. Our study provides the first full scale overview of the evolution of snake sex chromosomes at the genomic level, thus greatly expanding our knowledge of reptilian and vertebrate sex chromosomes

  20. Distinct evolutionary mechanisms for genomic imbalances in high-risk and low-risk neuroblastomas

    Directory of Open Access Journals (Sweden)

    Øra Ingrid

    2007-01-01

    Full Text Available Abstract Background Neuroblastoma (NB is the most common extracranial solid tumour of childhood. Several genomic imbalances correlate to prognosis in NB, with structural rearrangements, including gene amplification, in a near-diploid setting typically signifying high-risk tumours and numerical changes in a near-triploid setting signifying low-risk tumours. Little is known about the temporal sequence in which these imbalances occur during the carcinogenic process. Methods We have reconstructed the appearance of cytogenetic imbalances in 270 NBs by first grouping tumours and imbalances through principal component analysis and then using the number of imbalances in each tumour as an indicator of evolutionary progression. Results Tumours clustered in four sub-groups, dominated respectively by (1 gene amplification in double minute chromosomes and few other aberrations, (2 gene amplification and loss of 1p sequences, (3 loss of 1p and other structural aberrations including gain of 17q, and (4 whole-chromosome gains and losses. Temporal analysis showed that the structural changes in groups 1–3 were acquired in a step-wise fashion, with loss of 1p sequences and the emergence of double minute chromosomes as the earliest cytogenetic events. In contrast, the gains and losses of whole chromosomes in group 4 occurred through multiple simultaneous events leading to a near-triploid chromosome number. Conclusion The finding of different temporal patterns for the acquisition of genomic imbalances in high-risk and low-risk NBs lends strong support to the hypothesis that these tumours are biologically diverse entities, evolving through distinct genetic mechanisms.

  1. Evolutionary dynamics of the Ty3/gypsy LTR retrotransposons in the genome of Anopheles gambiae.

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    Jose Manuel C Tubio

    Full Text Available Ty3/gypsy elements represent one of the most abundant and diverse LTR-retrotransposon (LTRr groups in the Anopheles gambiae genome, but their evolutionary dynamics have not been explored in detail. Here, we conduct an in silico analysis of the distribution and abundance of the full complement of 1045 copies in the updated AgamP3 assembly. Chromosomal distribution of Ty3/gypsy elements is inversely related to arm length, with densities being greatest on the X, and greater on the short versus long arms of both autosomes. Taking into account the different heterochromatic and euchromatic compartments of the genome, our data suggest that the relative abundance of Ty3/gypsy LTRrs along each chromosome arm is determined mainly by the different proportions of heterochromatin, particularly pericentric heterochromatin, relative to total arm length. Additionally, the breakpoint regions of chromosomal inversion 2La appears to be a haven for LTRrs. These elements are underrepresented more than 7-fold in euchromatin, where 33% of the Ty3/gypsy copies are associated with genes. The euchromatin on chromosome 3R shows a faster turnover rate of Ty3/gypsy elements, characterized by a deficit of proviral sequences and the lowest average sequence divergence of any autosomal region analyzed in this study. This probably reflects a principal role of purifying selection against insertion for the preservation of longer conserved syntenyc blocks with adaptive importance located in 3R. Although some Ty3/gypsy LTRrs show evidence of recent activity, an important fraction are inactive remnants of relatively ancient insertions apparently subject to genetic drift. Consistent with these computational predictions, an analysis of the occupancy rate of putatively older insertions in natural populations suggested that the degenerate copies have been fixed across the species range in this mosquito, and also are shared with the sibling species Anopheles arabiensis.

  2. Comparative sex chromosome genomics in snakes: differentiation, evolutionary strata, and lack of global dosage compensation.

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    Beatriz Vicoso

    Full Text Available Snakes exhibit genetic sex determination, with female heterogametic sex chromosomes (ZZ males, ZW females. Extensive cytogenetic work has suggested that the level of sex chromosome heteromorphism varies among species, with Boidae having entirely homomorphic sex chromosomes, Viperidae having completely heteromorphic sex chromosomes, and Colubridae showing partial differentiation. Here, we take a genomic approach to compare sex chromosome differentiation in these three snake families. We identify homomorphic sex chromosomes in boas (Boidae, but completely heteromorphic sex chromosomes in both garter snakes (Colubridae and pygmy rattlesnake (Viperidae. Detection of W-linked gametologs enables us to establish the presence of evolutionary strata on garter and pygmy rattlesnake sex chromosomes where recombination was abolished at different time points. Sequence analysis shows that all strata are shared between pygmy rattlesnake and garter snake, i.e., recombination was abolished between the sex chromosomes before the two lineages diverged. The sex-biased transmission of the Z and its hemizygosity in females can impact patterns of molecular evolution, and we show that rates of evolution for Z-linked genes are increased relative to their pseudoautosomal homologs, both at synonymous and amino acid sites (even after controlling for mutational biases. This demonstrates that mutation rates are male-biased in snakes (male-driven evolution, but also supports faster-Z evolution due to differential selective effects on the Z. Finally, we perform a transcriptome analysis in boa and pygmy rattlesnake to establish baseline levels of sex-biased expression in homomorphic sex chromosomes, and show that heteromorphic ZW chromosomes in rattlesnakes lack chromosome-wide dosage compensation. Our study provides the first full scale overview of the evolution of snake sex chromosomes at the genomic level, thus greatly expanding our knowledge of reptilian and vertebrate sex

  3. Comparative Sex Chromosome Genomics in Snakes: Differentiation, Evolutionary Strata, and Lack of Global Dosage Compensation

    Science.gov (United States)

    Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

    2013-01-01

    Snakes exhibit genetic sex determination, with female heterogametic sex chromosomes (ZZ males, ZW females). Extensive cytogenetic work has suggested that the level of sex chromosome heteromorphism varies among species, with Boidae having entirely homomorphic sex chromosomes, Viperidae having completely heteromorphic sex chromosomes, and Colubridae showing partial differentiation. Here, we take a genomic approach to compare sex chromosome differentiation in these three snake families. We identify homomorphic sex chromosomes in boas (Boidae), but completely heteromorphic sex chromosomes in both garter snakes (Colubridae) and pygmy rattlesnake (Viperidae). Detection of W-linked gametologs enables us to establish the presence of evolutionary strata on garter and pygmy rattlesnake sex chromosomes where recombination was abolished at different time points. Sequence analysis shows that all strata are shared between pygmy rattlesnake and garter snake, i.e., recombination was abolished between the sex chromosomes before the two lineages diverged. The sex-biased transmission of the Z and its hemizygosity in females can impact patterns of molecular evolution, and we show that rates of evolution for Z-linked genes are increased relative to their pseudoautosomal homologs, both at synonymous and amino acid sites (even after controlling for mutational biases). This demonstrates that mutation rates are male-biased in snakes (male-driven evolution), but also supports faster-Z evolution due to differential selective effects on the Z. Finally, we perform a transcriptome analysis in boa and pygmy rattlesnake to establish baseline levels of sex-biased expression in homomorphic sex chromosomes, and show that heteromorphic ZW chromosomes in rattlesnakes lack chromosome-wide dosage compensation. Our study provides the first full scale overview of the evolution of snake sex chromosomes at the genomic level, thus greatly expanding our knowledge of reptilian and vertebrate sex chromosomes

  4. Evolutionary allometry reveals a shift in selection pressure on male horn size.

    Science.gov (United States)

    Tidière, M; Lemaître, J-F; Pélabon, C; Gimenez, O; Gaillard, J-M

    2017-10-01

    How selection pressures acting within species interact with developmental constraints to shape macro-evolutionary patterns of species divergence is still poorly understood. In particular, whether or not sexual selection affects evolutionary allometry, the increase in trait size with body size across species, of secondary sexual characters, remains largely unknown. In this context, bovid horn size is an especially relevant trait to study because horns are present in both sexes, but the intensity of sexual selection acting on them is expected to vary both among species and between sexes. Using a unique data set of sex-specific horn size and body mass including 91 species of bovids, we compared the evolutionary allometry between horn size and body mass between sexes while accounting for both the intensity of sexual selection and phylogenetic relationship among species. We found a nonlinear evolutionary allometry where the allometric slope decreased with increasing species body mass. This pattern, much more pronounced in males than in females, suggests either that horn size is limited by some constraints in the largest bovids or is no longer the direct target of sexual selection in very large species. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  5. Nannochloropsis genomes reveal evolution of microalgal oleaginous traits.

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    Dongmei Wang

    2014-01-01

    Full Text Available Oleaginous microalgae are promising feedstock for biofuels, yet the genetic diversity, origin and evolution of oleaginous traits remain largely unknown. Here we present a detailed phylogenomic analysis of five oleaginous Nannochloropsis species (a total of six strains and one time-series transcriptome dataset for triacylglycerol (TAG synthesis on one representative strain. Despite small genome sizes, high coding potential and relative paucity of mobile elements, the genomes feature small cores of ca. 2,700 protein-coding genes and a large pan-genome of >38,000 genes. The six genomes share key oleaginous traits, such as the enrichment of selected lipid biosynthesis genes and certain glycoside hydrolase genes that potentially shift carbon flux from chrysolaminaran to TAG synthesis. The eleven type II diacylglycerol acyltransferase genes (DGAT-2 in every strain, each expressed during TAG synthesis, likely originated from three ancient genomes, including the secondary endosymbiosis host and the engulfed green and red algae. Horizontal gene transfers were inferred in most lipid synthesis nodes with expanded gene doses and many glycoside hydrolase genes. Thus multiple genome pooling and horizontal genetic exchange, together with selective inheritance of lipid synthesis genes and species-specific gene loss, have led to the enormous genetic apparatus for oleaginousness and the wide genomic divergence among present-day Nannochloropsis. These findings have important implications in the screening and genetic engineering of microalgae for biofuels.

  6. Nannochloropsis Genomes Reveal Evolution of Microalgal Oleaginous Traits

    Science.gov (United States)

    Hu, Jianqiang; Han, Danxiang; Wang, Hui; Zeng, Xiaowei; Jing, Xiaoyan; Zhou, Qian; Su, Xiaoquan; Chang, Xingzhi; Wang, Anhui; Wang, Wei; Jia, Jing; Wei, Li; Xin, Yi; Qiao, Yinghe; Huang, Ranran; Chen, Jie; Han, Bo; Yoon, Kangsup; Hill, Russell T.; Zohar, Yonathan; Chen, Feng; Hu, Qiang; Xu, Jian

    2014-01-01

    Oleaginous microalgae are promising feedstock for biofuels, yet the genetic diversity, origin and evolution of oleaginous traits remain largely unknown. Here we present a detailed phylogenomic analysis of five oleaginous Nannochloropsis species (a total of six strains) and one time-series transcriptome dataset for triacylglycerol (TAG) synthesis on one representative strain. Despite small genome sizes, high coding potential and relative paucity of mobile elements, the genomes feature small cores of ca. 2,700 protein-coding genes and a large pan-genome of >38,000 genes. The six genomes share key oleaginous traits, such as the enrichment of selected lipid biosynthesis genes and certain glycoside hydrolase genes that potentially shift carbon flux from chrysolaminaran to TAG synthesis. The eleven type II diacylglycerol acyltransferase genes (DGAT-2) in every strain, each expressed during TAG synthesis, likely originated from three ancient genomes, including the secondary endosymbiosis host and the engulfed green and red algae. Horizontal gene transfers were inferred in most lipid synthesis nodes with expanded gene doses and many glycoside hydrolase genes. Thus multiple genome pooling and horizontal genetic exchange, together with selective inheritance of lipid synthesis genes and species-specific gene loss, have led to the enormous genetic apparatus for oleaginousness and the wide genomic divergence among present-day Nannochloropsis. These findings have important implications in the screening and genetic engineering of microalgae for biofuels. PMID:24415958

  7. Complete genome sequencing and evolutionary analysis of Indian isolates of Dengue virus type 2

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    Dash, Paban Kumar, E-mail: pabandash@rediffmail.com; Sharma, Shashi; Soni, Manisha; Agarwal, Ankita; Parida, Manmohan; Rao, P.V.Lakshmana

    2013-07-05

    Highlights: •Complete genome of Indian DENV-2 was deciphered for the first time in this study. •The recent Indian DENV-2 revealed presence of many unique amino acid residues. •Genotype shift (American to Cosmopolitan) characterizes evolution of DENV-2 in India. •Circulation of a unique clade of DENV-2 in South Asia was identified. -- Abstract: Dengue is the most important arboviral infection of global public health significance. It is now endemic in most parts of the South East Asia including India. Though Dengue virus type 2 (DENV-2) is predominantly associated with major outbreaks in India, complete genome information of Indian DENV-2 is not available. In this study, the full-length genome of five DENV-2 isolates (four from 2001 to 2011 and one from 1960), from different parts of India was determined. The complete genome of the Indian DENV-2 was found to be 10,670 bases long with an open reading frame coding for 3391 amino acids. The recent Indian DENV-2 (2001–2011) revealed a nucleotide sequence identity of around 90% and 97% with an older Indian DENV-2 (1960) and closely related Sri Lankan and Chinese DENV-2 respectively. Presence of unique amino acid residues and non-conservative substitutions in critical amino acid residues of major structural and non-structural proteins was observed in recent Indian DENV-2. Selection pressure analysis revealed positive selection in few amino acid sites of the genes encoding for structural and non-structural proteins. The molecular phylogenetic analysis based on comparison of both complete coding region and envelope protein gene with globally diverse DENV-2 viruses classified the recent Indian isolates into a unique South Asian clade within Cosmopolitan genotype. A shift of genotype from American to Cosmopolitan in 1970s characterized the evolution of DENV-2 in India. Present study is the first report on complete genome characterization of emerging DENV-2 isolates from India and highlights the circulation of a

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

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    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.

  9. Genome-scale modeling of the evolutionary path to C4 photosynthesis

    Science.gov (United States)

    Myers, Christopher R.; Bogart, Eli

    In C4 photosynthesis, plants maintain a high carbon dioxide level in specialized bundle sheath cells surrounding leaf veins and restrict CO2 assimilation to those cells, favoring CO2 over O2 in competition for Rubisco active sites. In C3 plants, which do not possess such a carbon concentrating mechanism, CO2 fixation is reduced due to this competition. Despite the complexity of the C4 system, it has evolved convergently from more than 60 independent origins in diverse families of plants around the world over the last 30 million years. We study the evolution of the C4 system in a genome-scale model of plant metabolism that describes interacting mesophyll and bundle sheath cells and enforces key nonlinear kinetic relationships. Adapting the zero-temperature string method for simulating transition paths in physics and chemistry, we find the highest-fitness paths connecting C3 and C4 positions in the model's high-dimensional parameter space, and show that they reproduce known aspects of the C3-C4 transition while making additional predictions about metabolic changes along the path. We explore the relationship between evolutionary history and C4 biochemical subtype, and the effects of atmospheric carbon dioxide levels.

  10. A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids

    Science.gov (United States)

    vonHoldt, Bridgett M.; Pollinger, John P.; Earl, Dent A.; Knowles, James C.; Boyko, Adam R.; Parker, Heidi; Geffen, Eli; Pilot, Malgorzata; Jedrzejewski, Wlodzimierz; Jedrzejewska, Bogumila; Sidorovich, Vadim; Greco, Claudia; Randi, Ettore; Musiani, Marco; Kays, Roland; Bustamante, Carlos D.; Ostrander, Elaine A.; Novembre, John; Wayne, Robert K.

    2011-01-01

    High-throughput genotyping technologies developed for model species can potentially increase the resolution of demographic history and ancestry in wild relatives. We use a SNP genotyping microarray developed for the domestic dog to assay variation in over 48K loci in wolf-like species worldwide. Despite the high mobility of these large carnivores, we find distinct hierarchical population units within gray wolves and coyotes that correspond with geographic and ecologic differences among populations. Further, we test controversial theories about the ancestry of the Great Lakes wolf and red wolf using an analysis of haplotype blocks across all 38 canid autosomes. We find that these enigmatic canids are highly admixed varieties derived from gray wolves and coyotes, respectively. This divergent genomic history suggests that they do not have a shared recent ancestry as proposed by previous researchers. Interspecific hybridization, as well as the process of evolutionary divergence, may be responsible for the observed phenotypic distinction of both forms. Such admixture complicates decisions regarding endangered species restoration and protection. PMID:21566151

  11. Deciphering the cryptic genome: genome-wide analyses of the rice pathogen Fusarium fujikuroi reveal complex regulation of secondary metabolism and novel metabolites.

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    Philipp Wiemann

    Full Text Available The fungus Fusarium fujikuroi causes "bakanae" disease of rice due to its ability to produce gibberellins (GAs, but it is also known for producing harmful mycotoxins. However, the genetic capacity for the whole arsenal of natural compounds and their role in the fungus' interaction with rice remained unknown. Here, we present a high-quality genome sequence of F. fujikuroi that was assembled into 12 scaffolds corresponding to the 12 chromosomes described for the fungus. We used the genome sequence along with ChIP-seq, transcriptome, proteome, and HPLC-FTMS-based metabolome analyses to identify the potential secondary metabolite biosynthetic gene clusters and to examine their regulation in response to nitrogen availability and plant signals. The results indicate that expression of most but not all gene clusters correlate with proteome and ChIP-seq data. Comparison of the F. fujikuroi genome to those of six other fusaria revealed that only a small number of gene clusters are conserved among these species, thus providing new insights into the divergence of secondary metabolism in the genus Fusarium. Noteworthy, GA biosynthetic genes are present in some related species, but GA biosynthesis is limited to F. fujikuroi, suggesting that this provides a selective advantage during infection of the preferred host plant rice. Among the genome sequences analyzed, one cluster that includes a polyketide synthase gene (PKS19 and another that includes a non-ribosomal peptide synthetase gene (NRPS31 are unique to F. fujikuroi. The metabolites derived from these clusters were identified by HPLC-FTMS-based analyses of engineered F. fujikuroi strains overexpressing cluster genes. In planta expression studies suggest a specific role for the PKS19-derived product during rice infection. Thus, our results indicate that combined comparative genomics and genome-wide experimental analyses identified novel genes and secondary metabolites that contribute to the evolutionary

  12. Comparative Genomic Analyses of the Human NPHP1 Locus Reveal Complex Genomic Architecture and Its Regional Evolution in Primates.

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    Bo Yuan

    2015-12-01

    Full Text Available Many loci in the human genome harbor complex genomic structures that can result in susceptibility to genomic rearrangements leading to various genomic disorders. Nephronophthisis 1 (NPHP1, MIM# 256100 is an autosomal recessive disorder that can be caused by defects of NPHP1; the gene maps within the human 2q13 region where low copy repeats (LCRs are abundant. Loss of function of NPHP1 is responsible for approximately 85% of the NPHP1 cases-about 80% of such individuals carry a large recurrent homozygous NPHP1 deletion that occurs via nonallelic homologous recombination (NAHR between two flanking directly oriented ~45 kb LCRs. Published data revealed a non-pathogenic inversion polymorphism involving the NPHP1 gene flanked by two inverted ~358 kb LCRs. Using optical mapping and array-comparative genomic hybridization, we identified three potential novel structural variant (SV haplotypes at the NPHP1 locus that may protect a haploid genome from the NPHP1 deletion. Inter-species comparative genomic analyses among primate genomes revealed massive genomic changes during evolution. The aggregated data suggest that dynamic genomic rearrangements occurred historically within the NPHP1 locus and generated SV haplotypes observed in the human population today, which may confer differential susceptibility to genomic instability and the NPHP1 deletion within a personal genome. Our study documents diverse SV haplotypes at a complex LCR-laden human genomic region. Comparative analyses provide a model for how this complex region arose during primate evolution, and studies among humans suggest that intra-species polymorphism may potentially modulate an individual's susceptibility to acquiring disease-associated alleles.

  13. Ceratocystis cacaofunesta genome analysis reveals a large expansion of extracellular phosphatidylinositol-specific phospholipase-C genes (PI-PLC).

    Science.gov (United States)

    Molano, Eddy Patricia Lopez; Cabrera, Odalys García; Jose, Juliana; do Nascimento, Leandro Costa; Carazzolle, Marcelo Falsarella; Teixeira, Paulo José Pereira Lima; Alvarez, Javier Correa; Tiburcio, Ricardo Augusto; Tokimatu Filho, Paulo Massanari; de Lima, Gustavo Machado Alvares; Guido, Rafael Victório Carvalho; Corrêa, Thamy Lívia Ribeiro; Leme, Adriana Franco Paes; Mieczkowski, Piotr; Pereira, Gonçalo Amarante Guimarães

    2018-01-17

    The Ceratocystis genus harbors a large number of phytopathogenic fungi that cause xylem parenchyma degradation and vascular destruction on a broad range of economically important plants. Ceratocystis cacaofunesta is a necrotrophic fungus responsible for lethal wilt disease in cacao. The aim of this work is to analyze the genome of C. cacaofunesta through a comparative approach with genomes of other Sordariomycetes in order to better understand the molecular basis of pathogenicity in the Ceratocystis genus. We present an analysis of the C. cacaofunesta genome focusing on secreted proteins that might constitute pathogenicity factors. Comparative genome analyses among five Ceratocystidaceae species and 23 other Sordariomycetes fungi showed a strong reduction in gene content of the Ceratocystis genus. However, some gene families displayed a remarkable expansion, in particular, the Phosphatidylinositol specific phospholipases-C (PI-PLC) family. Also, evolutionary rate calculations suggest that the evolution process of this family was guided by positive selection. Interestingly, among the 82 PI-PLCs genes identified in the C. cacaofunesta genome, 70 genes encoding extracellular PI-PLCs are grouped in eight small scaffolds surrounded by transposon fragments and scars that could be involved in the rapid evolution of the PI-PLC family. Experimental secretome using LC-MS/MS validated 24% (86 proteins) of the total predicted secretome (342 proteins), including four PI-PLCs and other important pathogenicity factors. Analysis of the Ceratocystis cacaofunesta genome provides evidence that PI-PLCs may play a role in pathogenicity. Subsequent functional studies will be aimed at evaluating this hypothesis. The observed genetic arsenals, together with the analysis of the PI-PLC family shown in this work, reveal significant differences in the Ceratocystis genome compared to the classical vascular fungi, Verticillium and Fusarium. Altogether, our analyses provide new insights into the

  14. Genome-Wide Search Identifies 1.9 Mb from the Polar Bear Y Chromosome for Evolutionary Analyses.

    Science.gov (United States)

    Bidon, Tobias; Schreck, Nancy; Hailer, Frank; Nilsson, Maria A; Janke, Axel

    2015-05-27

    The male-inherited Y chromosome is the major haploid fraction of the mammalian genome, rendering Y-linked sequences an indispensable resource for evolutionary research. However, despite recent large-scale genome sequencing approaches, only a handful of Y chromosome sequences have been characterized to date, mainly in model organisms. Using polar bear (Ursus maritimus) genomes, we compare two different in silico approaches to identify Y-linked sequences: 1) Similarity to known Y-linked genes and 2) difference in the average read depth of autosomal versus sex chromosomal scaffolds. Specifically, we mapped available genomic sequencing short reads from a male and a female polar bear against the reference genome and identify 112 Y-chromosomal scaffolds with a combined length of 1.9 Mb. We verified the in silico findings for the longer polar bear scaffolds by male-specific in vitro amplification, demonstrating the reliability of the average read depth approach. The obtained Y chromosome sequences contain protein-coding sequences, single nucleotide polymorphisms, microsatellites, and transposable elements that are useful for evolutionary studies. A high-resolution phylogeny of the polar bear patriline shows two highly divergent Y chromosome lineages, obtained from analysis of the identified Y scaffolds in 12 previously published male polar bear genomes. Moreover, we find evidence of gene conversion among ZFX and ZFY sequences in the giant panda lineage and in the ancestor of ursine and tremarctine bears. Thus, the identification of Y-linked scaffold sequences from unordered genome sequences yields valuable data to infer phylogenomic and population-genomic patterns in bears. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  15. An Angiotensin II type 1 receptor activation switch patch revealed through Evolutionary Trace analysis

    DEFF Research Database (Denmark)

    Bonde, Marie Mi; Yao, Rong; Ma, Jian-Nong

    2010-01-01

    ) displayed phenotypes associated with changed activation state, such as increased agonist affinity or basal activity, promiscuous activation, or constitutive internalization highlighting the importance of testing different signaling pathways. We conclude that this evolutionary important patch mediates...

  16. An angiotensin II type 1 receptor activation switch patch revealed through evolutionary trace analysis

    DEFF Research Database (Denmark)

    Bonde, Marie Mi; Yao, Rong; Ma, Jian-Nong

    2010-01-01

    ) displayed phenotypes associated with changed activation state, such as increased agonist affinity or basal activity, promiscuous activation, or constitutive internalization highlighting the importance of testing different signaling pathways. We conclude that this evolutionary important patch mediates...

  17. Stepwise Evolution of Coral Biomineralization Revealed with Genome-Wide Proteomics and Transcriptomics

    Science.gov (United States)

    Sawada, Hitoshi; Satoh, Noriyuki

    2016-01-01

    Despite the importance of stony corals in many research fields related to global issues, such as marine ecology, climate change, paleoclimatogy, and metazoan evolution, very little is known about the evolutionary origin of coral skeleton formation. In order to investigate the evolution of coral biomineralization, we have identified skeletal organic matrix proteins (SOMPs) in the skeletal proteome of the scleractinian coral, Acropora digitifera, for which large genomic and transcriptomic datasets are available. Scrupulous gene annotation was conducted based on comparisons of functional domain structures among metazoans. We found that SOMPs include not only coral-specific proteins, but also protein families that are widely conserved among cnidarians and other metazoans. We also identified several conserved transmembrane proteins in the skeletal proteome. Gene expression analysis revealed that expression of these conserved genes continues throughout development. Therefore, these genes are involved not only skeleton formation, but also in basic cellular functions, such as cell-cell interaction and signaling. On the other hand, genes encoding coral-specific proteins, including extracellular matrix domain-containing proteins, galaxins, and acidic proteins, were prominently expressed in post-settlement stages, indicating their role in skeleton formation. Taken together, the process of coral skeleton formation is hypothesized as: 1) formation of initial extracellular matrix between epithelial cells and substrate, employing pre-existing transmembrane proteins; 2) additional extracellular matrix formation using novel proteins that have emerged by domain shuffling and rapid molecular evolution and; 3) calcification controlled by coral-specific SOMPs. PMID:27253604

  18. Genomic data mining reveals a rich repertoire of transport proteins in Streptomyces.

    Science.gov (United States)

    Zhou, Zhan; Sun, Ning; Wu, Shanshan; Li, Yong-Quan; Wang, Yufeng

    2016-08-22

    Streptomycetes are soil-dwelling Gram-positive bacteria that are best known as the major producers of antibiotics used in the pharmaceutical industry. The evolution of exceptionally powerful transporter systems in streptomycetes has enabled their adaptation to the complex soil environment. Our comparative genomic analyses revealed that each of the eleven Streptomyces species examined possesses a rich repertoire of from 761-1258 transport proteins, accounting for 10.2 to 13.7 % of each respective proteome. These transporters can be divided into seven functional classes and 171 transporter families. Among them, the ATP-binding Cassette (ABC) superfamily and the Major Facilitator Superfamily (MFS) represent more than 40 % of all the transport proteins in Streptomyces. They play important roles in both nutrient uptake and substrate secretion, especially in the efflux of drugs and toxicants. The evolutionary flexibility across eleven Streptomyces species is seen in the lineage-specific distribution of transport proteins in two major protein translocation pathways: the general secretory (Sec) pathway and the twin-arginine translocation (Tat) pathway. Our results present a catalog of transport systems in eleven Streptomyces species. These expansive transport systems are important mediators of the complex processes including nutrient uptake, concentration balance of elements, efflux of drugs and toxins, and the timely and orderly secretion of proteins. A better understanding of transport systems will allow enhanced optimization of production processes for both pharmaceutical and industrial applications of Streptomyces, which are widely used in antibiotic production and heterologous expression of recombinant proteins.

  19. Mitochondrial genome sequences reveal deep divergences among Anopheles punctulatus sibling species in Papua New Guinea

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    Logue Kyle

    2013-02-01

    Full Text Available Abstract Background Members of the Anopheles punctulatus group (AP group are the primary vectors of human malaria in Papua New Guinea. The AP group includes 13 sibling species, most of them morphologically indistinguishable. Understanding why only certain species are able to transmit malaria requires a better comprehension of their evolutionary history. In particular, understanding relationships and divergence times among Anopheles species may enable assessing how malaria-related traits (e.g. blood feeding behaviours, vector competence have evolved. Methods DNA sequences of 14 mitochondrial (mt genomes from five AP sibling species and two species of the Anopheles dirus complex of Southeast Asia were sequenced. DNA sequences from all concatenated protein coding genes (10,770 bp were then analysed using a Bayesian approach to reconstruct phylogenetic relationships and date the divergence of the AP sibling species. Results Phylogenetic reconstruction using the concatenated DNA sequence of all mitochondrial protein coding genes indicates that the ancestors of the AP group arrived in Papua New Guinea 25 to 54 million years ago and rapidly diverged to form the current sibling species. Conclusion Through evaluation of newly described mt genome sequences, this study has revealed a divergence among members of the AP group in Papua New Guinea that would significantly predate the arrival of humans in this region, 50 thousand years ago. The divergence observed among the mtDNA sequences studied here may have resulted from reproductive isolation during historical changes in sea-level through glacial minima and maxima. This leads to a hypothesis that the AP sibling species have evolved independently for potentially thousands of generations. This suggests that the evolution of many phenotypes, such as insecticide resistance will arise independently in each of the AP sibling species studied here.

  20. Genome-wide identification, functional prediction, and evolutionary analysis of the R2R3-MYB superfamily in Brassica napus.

    Science.gov (United States)

    Hajiebrahimi, Ali; Owji, Hajar; Hemmati, Shiva

    2017-10-01

    R2R3-MYB transcription factors (TFs) have been shown to play important roles in plants, including in development and in various stress conditions. Phylogenetic analysis showed the presence of 249 R2R3-MYB TFs in Brassica napus, called BnaR2R3-MYB TFs, clustered into 38 clades. BnaR2R3-MYB TFs were distributed on 19 chromosomes of B. napus. Sixteen gene clusters were identified. BnaR2R3-MYB TFs were characterized by motif prediction, gene structure analysis, and gene ontology. Evolutionary analysis revealed that BnaR2R3-MYB TFs are mainly formed as a result of whole-genome duplication. Orthologs and paralogs of BnaR2R3-MYB TFs were identified in B. napus, B. rapa, B. oleracea, and Arabidopsis thaliana using synteny-based methods. Purifying selection was pervasive within R2R3-MYB TFs. Kn/Ks values lower than 0.3 indicated that BnaR2R3-MYB TFs are being functionally converged. The role of gene conversion in the formation of BnaR2R3-MYB TFs was significant. Cis-regulatory elements in the upstream regions of BnaR2R3-MYB genes, miRNA targeting BnaR2R3MYB TFs, and post translational modifications were identified. Digital expression data revealed that BnaR2R3-MYB genes were highly expressed in the roots and under high salinity treatment after 24 h. BnaMYB21, BnaMYB141, and BnaMYB148 have been suggested for improving salt-tolerant B. napus. BnaR2R3-MYB genes were mostly up regulated on the 14th day post inoculation with Leptosphaeria biglobosa and L. maculan. BnaMYB150 is a candidate for increased tolerance to Leptospheria in B. napus.

  1. Evolutionary history of barley cultivation in Europe revealed by genetic analysis of extant landraces

    OpenAIRE

    Jones, H; Civan, P.; Cockram, J.; Leigh, F.J.; Smith, L. M. J.; Jones, M. K.; Charles, M. P.; Molina-Cano, J. L.; Powell, W.; Jones, G.; Brown, T A

    2011-01-01

    Abstract Background Understanding the evolution of cultivated barley is important for two reasons. First, the evolutionary relationships between different landraces might provide information on the spread and subsequent development of barley cultivation, including the adaptation of the crop to new environments and its response to human selection. Second, evolutionary information would enable landraces with similar traits but different genetic backgrounds to be identified, providing alternativ...

  2. Comparative Genomics of Methanopyrus sp. SNP6 and KOL6 Revealing Genomic Regions of Plasticity Implicated in Extremely Thermophilic Profiles

    Directory of Open Access Journals (Sweden)

    Zhiliang Yu

    2017-07-01

    Full Text Available Methanopyrus spp. are usually isolated from harsh niches, such as high osmotic pressure and extreme temperature. However, the molecular mechanisms for their environmental adaption are poorly understood. Archaeal species is commonly considered as primitive organism. The evolutional placement of archaea is a fundamental and intriguing scientific question. We sequenced the genomes of Methanopyrus strains SNP6 and KOL6 isolated from the Atlantic and Iceland, respectively. Comparative genomic analysis revealed genetic diversity and instability implicated in niche adaption, including a number of transporter- and integrase/transposase-related genes. Pan-genome analysis also defined the gene pool of Methanopyrus spp., in addition of ~120-Kb genomic region of plasticity impacting cognate genomic architecture. We believe that Methanopyrus genomics could facilitate efficient investigation/recognition of archaeal phylogenetic diverse patterns, as well as improve understanding of biological roles and significance of these versatile microbes.

  3. Evolutionary rates of mitochondrial genomes correspond to diversification rates and to contemporary species richness in birds and reptiles

    Science.gov (United States)

    Eo, Soo Hyung; DeWoody, J. Andrew

    2010-01-01

    Rates of biological diversification should ultimately correspond to rates of genome evolution. Recent studies have compared diversification rates with phylogenetic branch lengths, but incomplete phylogenies hamper such analyses for many taxa. Herein, we use pairwise comparisons of confamilial sauropsid (bird and reptile) mitochondrial DNA (mtDNA) genome sequences to estimate substitution rates. These molecular evolutionary rates are considered in light of the age and species richness of each taxonomic family, using a random-walk speciation–extinction process to estimate rates of diversification. We find the molecular clock ticks at disparate rates in different families and at different genes. For example, evolutionary rates are relatively fast in snakes and lizards, intermediate in crocodilians and slow in turtles and birds. There was also rate variation across genes, where non-synonymous substitution rates were fastest at ATP8 and slowest at CO3. Family-by-gene interactions were significant, indicating that local clocks vary substantially among sauropsids. Most importantly, we find evidence that mitochondrial genome evolutionary rates are positively correlated with speciation rates and with contemporary species richness. Nuclear sequences are poorly represented among reptiles, but the correlation between rates of molecular evolution and species diversification also extends to 18 avian nuclear genes we tested. Thus, the nuclear data buttress our mtDNA findings. PMID:20610427

  4. Evolutionary gradient of predicted nuclear localization signals (NLS)-bearing proteins in genomes of family Planctomycetaceae.

    Science.gov (United States)

    Guo, Min; Yang, Ruifu; Huang, Chen; Liao, Qiwen; Fan, Guangyi; Sun, Chenghang; Lee, Simon Ming-Yuen

    2017-04-04

    The nuclear envelope is considered a key classification marker that distinguishes prokaryotes from eukaryotes. However, this marker does not apply to the family Planctomycetaceae, which has intracellular spaces divided by lipidic intracytoplasmic membranes (ICMs). Nuclear localization signal (NLS), a short stretch of amino acid sequence, destines to transport proteins from cytoplasm into nucleus, and is also associated with the development of nuclear envelope. We attempted to investigate the NLS motifs in Planctomycetaceae genomes to demonstrate the potential molecular transition in the development of intracellular membrane system. In this study, we identified NLS-like motifs that have the same amino acid compositions as experimentally identified NLSs in genomes of 11 representative species of family Planctomycetaceae. A total of 15 NLS types and 170 NLS-bearing proteins were detected in the 11 strains. To determine the molecular transformation, we compared NLS-bearing protein abundances in the 11 representative Planctomycetaceae genomes with them in genomes of 16 taxonomically varied microorganisms: nine bacteria, two archaea and five fungi. In the 27 strains, 29 NLS types and 1101 NLS-bearing proteins were identified, principal component analysis showed a significant transitional gradient from bacteria to Planctomycetaceae to fungi on their NLS-bearing protein abundance profiles. Then, we clustered the 993 non-redundant NLS-bearing proteins into 181 families and annotated their involved metabolic pathways. Afterwards, we aligned the ten types of NLS motifs from the 13 families containing NLS-bearing proteins among bacteria, Planctomycetaceae or fungi, considering their diversity, length and origin. A transition towards increased complexity from non-planctomycete bacteria to Planctomycetaceae to archaea and fungi was detected based on the complexity of the 10 types of NLS-like motifs in the 13 NLS-bearing proteins families. The results of this study reveal that

  5. Single-virus genomics reveals hidden cosmopolitan and abundant viruses

    Science.gov (United States)

    Martinez-Hernandez, Francisco; Fornas, Oscar; Lluesma Gomez, Monica; Bolduc, Benjamin; de la Cruz Peña, Maria Jose; Martínez, Joaquín Martínez; Anton, Josefa; Gasol, Josep M.; Rosselli, Riccardo; Rodriguez-Valera, Francisco; Sullivan, Matthew B.; Acinas, Silvia G.; Martinez-Garcia, Manuel

    2017-01-01

    Microbes drive ecosystems under constraints imposed by viruses. However, a lack of virus genome information hinders our ability to answer fundamental, biological questions concerning microbial communities. Here we apply single-virus genomics (SVGs) to assess whether portions of marine viral communities are missed by current techniques. The majority of the here-identified 44 viral single-amplified genomes (vSAGs) are more abundant in global ocean virome data sets than published metagenome-assembled viral genomes or isolates. This indicates that vSAGs likely best represent the dsDNA viral populations dominating the oceans. Species-specific recruitment patterns and virome simulation data suggest that vSAGs are highly microdiverse and that microdiversity hinders the metagenomic assembly, which could explain why their genomes have not been identified before. Altogether, SVGs enable the discovery of some of the likely most abundant and ecologically relevant marine viral species, such as vSAG 37-F6, which were overlooked by other methodologies. PMID:28643787

  6. Rapid evolutionary change of common bean (Phaseolus vulgaris L plastome, and the genomic diversification of legume chloroplasts

    Directory of Open Access Journals (Sweden)

    Dávila Guillermo

    2007-07-01

    Full Text Available Abstract Background Fabaceae (legumes is one of the largest families of flowering plants, and some members are important crops. In contrast to what we know about their great diversity or economic importance, our knowledge at the genomic level of chloroplast genomes (cpDNAs or plastomes for these crops is limited. Results We sequenced the complete genome of the common bean (Phaseolus vulgaris cv. Negro Jamapa chloroplast. The plastome of P. vulgaris is a 150,285 bp circular molecule. It has gene content similar to that of other legume plastomes, but contains two pseudogenes, rpl33 and rps16. A distinct inversion occurred at the junction points of trnH-GUG/rpl14 and rps19/rps8, as in adzuki bean 1. These two pseudogenes and the inversion were confirmed in 10 varieties representing the two domestication centers of the bean. Genomic comparative analysis indicated that inversions generally occur in legume plastomes and the magnitude and localization of insertions/deletions (indels also vary. The analysis of repeat sequences demonstrated that patterns and sequences of tandem repeats had an important impact on sequence diversification between legume plastomes and tandem repeats did not belong to dispersed repeats. Interestingly, P. vulgaris plastome had higher evolutionary rates of change on both genomic and gene levels than G. max, which could be the consequence of pressure from both mutation and natural selection. Conclusion Legume chloroplast genomes are widely diversified in gene content, gene order, indel structure, abundance and localization of repetitive sequences, intracellular sequence exchange and evolutionary rates. The P. vulgaris plastome is a rapidly evolving genome.

  7. Rapid evolutionary change of common bean (Phaseolus vulgaris L) plastome, and the genomic diversification of legume chloroplasts

    Science.gov (United States)

    Guo, Xianwu; Castillo-Ramírez, Santiago; González, Víctor; Bustos, Patricia; Luís Fernández-Vázquez, José; Santamaría, Rosa Isela; Arellano, Jesús; Cevallos, Miguel A; Dávila, Guillermo

    2007-01-01

    Background Fabaceae (legumes) is one of the largest families of flowering plants, and some members are important crops. In contrast to what we know about their great diversity or economic importance, our knowledge at the genomic level of chloroplast genomes (cpDNAs or plastomes) for these crops is limited. Results We sequenced the complete genome of the common bean (Phaseolus vulgaris cv. Negro Jamapa) chloroplast. The plastome of P. vulgaris is a 150,285 bp circular molecule. It has gene content similar to that of other legume plastomes, but contains two pseudogenes, rpl33 and rps16. A distinct inversion occurred at the junction points of trnH-GUG/rpl14 and rps19/rps8, as in adzuki bean [1]. These two pseudogenes and the inversion were confirmed in 10 varieties representing the two domestication centers of the bean. Genomic comparative analysis indicated that inversions generally occur in legume plastomes and the magnitude and localization of insertions/deletions (indels) also vary. The analysis of repeat sequences demonstrated that patterns and sequences of tandem repeats had an important impact on sequence diversification between legume plastomes and tandem repeats did not belong to dispersed repeats. Interestingly, P. vulgaris plastome had higher evolutionary rates of change on both genomic and gene levels than G. max, which could be the consequence of pressure from both mutation and natural selection. Conclusion Legume chloroplast genomes are widely diversified in gene content, gene order, indel structure, abundance and localization of repetitive sequences, intracellular sequence exchange and evolutionary rates. The P. vulgaris plastome is a rapidly evolving genome. PMID:17623083

  8. The genomes of four tapeworm species reveal adaptations to parasitism.

    Science.gov (United States)

    Tsai, Isheng J; Zarowiecki, Magdalena; Holroyd, Nancy; Garciarrubio, Alejandro; Sánchez-Flores, Alejandro; Brooks, Karen L; Tracey, Alan; Bobes, Raúl J; Fragoso, Gladis; Sciutto, Edda; Aslett, Martin; Beasley, Helen; Bennett, Hayley M; Cai, Xuepeng; Camicia, Federico; Clark, Richard; Cucher, Marcela; De Silva, Nishadi; Day, Tim A; Deplazes, Peter; Estrada, Karel; Fernández, Cecilia; Holland, Peter W H; Hou, Junling; Hu, Songnian; Huckvale, Thomas; Hung, Stacy S; Kamenetzky, Laura; Keane, Jacqueline A; Kiss, Ferenc; Koziol, Uriel; Lambert, Olivia; Liu, Kan; Luo, Xuenong; Luo, Yingfeng; Macchiaroli, Natalia; Nichol, Sarah; Paps, Jordi; Parkinson, John; Pouchkina-Stantcheva, Natasha; Riddiford, Nick; Rosenzvit, Mara; Salinas, Gustavo; Wasmuth, James D; Zamanian, Mostafa; Zheng, Yadong; Cai, Jianping; Soberón, Xavier; Olson, Peter D; Laclette, Juan P; Brehm, Klaus; Berriman, Matthew

    2013-04-04

    Tapeworms (Cestoda) cause neglected diseases that can be fatal and are difficult to treat, owing to inefficient drugs. Here we present an analysis of tapeworm genome sequences using the human-infective species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma as examples. The 115- to 141-megabase genomes offer insights into the evolution of parasitism. Synteny is maintained with distantly related blood flukes but we find extreme losses of genes and pathways that are ubiquitous in other animals, including 34 homeobox families and several determinants of stem cell fate. Tapeworms have specialized detoxification pathways, metabolism that is finely tuned to rely on nutrients scavenged from their hosts, and species-specific expansions of non-canonical heat shock proteins and families of known antigens. We identify new potential drug targets, including some on which existing pharmaceuticals may act. The genomes provide a rich resource to underpin the development of urgently needed treatments and control.

  9. Genome analysis of the platypus reveals unique signatures of evolution

    Science.gov (United States)

    Warren, Wesley C.; Hillier, LaDeana W.; Marshall Graves, Jennifer A.; Birney, Ewan; Ponting, Chris P.; Grützner, Frank; Belov, Katherine; Miller, Webb; Clarke, Laura; Chinwalla, Asif T.; Yang, Shiaw-Pyng; Heger, Andreas; Locke, Devin P.; Miethke, Pat; Waters, Paul D.; Veyrunes, Frédéric; Fulton, Lucinda; Fulton, Bob; Graves, Tina; Wallis, John; Puente, Xose S.; López-Otín, Carlos; Ordóñez, Gonzalo R.; Eichler, Evan E.; Chen, Lin; Cheng, Ze; Deakin, Janine E.; Alsop, Amber; Thompson, Katherine; Kirby, Patrick; Papenfuss, Anthony T.; Wakefield, Matthew J.; Olender, Tsviya; Lancet, Doron; Huttley, Gavin A.; Smit, Arian F. A.; Pask, Andrew; Temple-Smith, Peter; Batzer, Mark A.; Walker, Jerilyn A.; Konkel, Miriam K.; Harris, Robert S.; Whittington, Camilla M.; Wong, Emily S. W.; Gemmell, Neil J.; Buschiazzo, Emmanuel; Vargas Jentzsch, Iris M.; Merkel, Angelika; Schmitz, Juergen; Zemann, Anja; Churakov, Gennady; Kriegs, Jan Ole; Brosius, Juergen; Murchison, Elizabeth P.; Sachidanandam, Ravi; Smith, Carly; Hannon, Gregory J.; Tsend-Ayush, Enkhjargal; McMillan, Daniel; Attenborough, Rosalind; Rens, Willem; Ferguson-Smith, Malcolm; Lefèvre, Christophe M.; Sharp, Julie A.; Nicholas, Kevin R.; Ray, David A.; Kube, Michael; Reinhardt, Richard; Pringle, Thomas H.; Taylor, James; Jones, Russell C.; Nixon, Brett; Dacheux, Jean-Louis; Niwa, Hitoshi; Sekita, Yoko; Huang, Xiaoqiu; Stark, Alexander; Kheradpour, Pouya; Kellis, Manolis; Flicek, Paul; Chen, Yuan; Webber, Caleb; Hardison, Ross; Nelson, Joanne; Hallsworth-Pepin, Kym; Delehaunty, Kim; Markovic, Chris; Minx, Pat; Feng, Yucheng; Kremitzki, Colin; Mitreva, Makedonka; Glasscock, Jarret; Wylie, Todd; Wohldmann, Patricia; Thiru, Prathapan; Nhan, Michael N.; Pohl, Craig S.; Smith, Scott M.; Hou, Shunfeng; Renfree, Marilyn B.; Mardis, Elaine R.; Wilson, Richard K.

    2009-01-01

    We present a draft genome sequence of the platypus, Ornithorhynchus anatinus. This monotreme exhibits a fascinating combination of reptilian and mammalian characters. For example, platypuses have a coat of fur adapted to an aquatic lifestyle; platypus females lactate, yet lay eggs; and males are equipped with venom similar to that of reptiles. Analysis of the first monotreme genome aligned these features with genetic innovations. We find that reptile and platypus venom proteins have been co-opted independently from the same gene families; milk protein genes are conserved despite platypuses laying eggs; and immune gene family expansions are directly related to platypus biology. Expansions of protein, non-protein-coding RNA and microRNA families, as well as repeat elements, are identified. Sequencing of this genome now provides a valuable resource for deep mammalian comparative analyses, as well as for monotreme biology and conservation. PMID:18464734

  10. Global analysis of human duplicated genes reveals the relative importance of whole-genome duplicates originated in the early vertebrate evolution.

    Science.gov (United States)

    Acharya, Debarun; Ghosh, Tapash C

    2016-01-22

    Gene duplication is a genetic mutation that creates functionally redundant gene copies that are initially relieved from selective pressures and may adapt themselves to new functions with time. The levels of gene duplication may vary from small-scale duplication (SSD) to whole genome duplication (WGD). Studies with yeast revealed ample differences between these duplicates: Yeast WGD pairs were functionally more similar, less divergent in subcellular localization and contained a lesser proportion of essential genes. In this study, we explored the differences in evolutionary genomic properties of human SSD and WGD genes, with the identifiable human duplicates coming from the two rounds of whole genome duplication occurred early in vertebrate evolution. We observed that these two groups of duplicates were also dissimilar in terms of their evolutionary and genomic properties. But interestingly, this is not like the same observed in yeast. The human WGDs were found to be functionally less similar, diverge more in subcellular level and contain a higher proportion of essential genes than the SSDs, all of which are opposite from yeast. Additionally, we explored that human WGDs were more divergent in their gene expression profile, have higher multifunctionality and are more often associated with disease, and are evolutionarily more conserved than human SSDs. Our study suggests that human WGD duplicates are more divergent and entails the adaptation of WGDs to novel and important functions that consequently lead to their evolutionary conservation in the course of evolution.

  11. Excess of Deleterious Mutations around HLA Genes Reveals Evolutionary Cost of Balancing Selection.

    Science.gov (United States)

    Lenz, Tobias L; Spirin, Victor; Jordan, Daniel M; Sunyaev, Shamil R

    2016-10-01

    Deleterious mutations are expected to evolve under negative selection and are usually purged from the population. However, deleterious alleles segregate in the human population and some disease-associated variants are maintained at considerable frequencies. Here, we test the hypothesis that balancing selection may counteract purifying selection in neighboring regions and thus maintain deleterious variants at higher frequency than expected from their detrimental fitness effect. We first show in realistic simulations that balancing selection reduces the density of polymorphic sites surrounding a locus under balancing selection, but at the same time markedly increases the population frequency of the remaining variants, including even substantially deleterious alleles. To test the predictions of our simulations empirically, we then use whole-exome sequencing data from 6,500 human individuals and focus on the most established example for balancing selection in the human genome, the major histocompatibility complex (MHC). Our analysis shows an elevated frequency of putatively deleterious coding variants in nonhuman leukocyte antigen (non-HLA) genes localized in the MHC region. The mean frequency of these variants declined with physical distance from the classical HLA genes, indicating dependency on genetic linkage. These results reveal an indirect cost of the genetic diversity maintained by balancing selection, which has hitherto been perceived as mostly advantageous, and have implications both for the evolution of recombination and also for the epidemiology of various MHC-associated diseases. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  12. Genome differentiation between Lycopersicon esculentum and L. pennellii as revealed by genomic in situ hybridization

    NARCIS (Netherlands)

    Haider, S.N.; Ramanna, M.S.; Jacobsen, E.; Visser, R.G.F.

    2002-01-01

    Using an F1 hybrid between Lycopersicon esculentum and L. pennellii (2n = 2x = 24) and its BC1 progeny, an attempt was made to cytologically differentiate the genomes through genomic in situ hybridisation (GISH). When total genomic DNA of L. pennellii was used as a probe with a concentration of 2

  13. An Aboriginal Australian Genome Reveals Separate Human Dispersals into Asia

    DEFF Research Database (Denmark)

    Rasmussen, Morten; Guo, Xiaosen; Wang, Yong

    2011-01-01

    We present an Aboriginal Australian genomic sequence obtained from a 100-year-old lock of hair donated by an Aboriginal man from southern Western Australia in the early 20th century. We detect no evidence of European admixture and estimate contamination levels to be below 0.5%. We show that Abori......We present an Aboriginal Australian genomic sequence obtained from a 100-year-old lock of hair donated by an Aboriginal man from southern Western Australia in the early 20th century. We detect no evidence of European admixture and estimate contamination levels to be below 0.5%. We show...

  14. Revealing the genomic differences between two subgroups in Lactobacillus gasseri.

    Science.gov (United States)

    Tada, Ipputa; Tanizawa, Yasuhiro; Endo, Akihito; Tohno, Masanori; Arita, Masanori

    2017-01-01

    Being an autochthonous species in humans, Lactobacillus gasseri is widely used as a probiotic for fermented products. We thoroughly compared the gene contents of 75 L. gasseri genomes and identified two intraspecific groups by the average nucleotide identity (ANI) threshold of 94%. Group I, with 48 strains, possessed 53 group-specific genes including the gassericin T cluster (9 genes) and N-acyl homoserine lactone lactonase. Group II, with 27 strains, including the type strain ATCC 33323, possessed group-specific genes with plasmid- or phage-related annotations. The genomic differences provide evidences for demarcating a new probiotic group within L. gasseri.

  15. Genome engineering reveals large dispensable regions in Bacillus subtilis

    NARCIS (Netherlands)

    Westers, Helga; Dorenbos, Ronald; Dijl, Jan Maarten van; Kabel, Jorrit; Flanagan, Tony; Devine, Kevin M.; Jude, Florence; Séror, Simone J.; Beekman, Aäron C.; Darmon, Elise; Eschevins, Caroline; Jong, Anne de; Bron, Sierd; Kuipers, Oscar P.; Albertini, Alessandra M.; Antelmann, Haike; Hecker, Michael; Zamboni, Nicola; Sauer, Uwe; Bruand, Claude; Ehrlich, Dusko S.; Alonso, Juan C.; Salas, Margarita; Quax, Wim J.

    2003-01-01

    Bacterial genomes contain 250 to 500 essential genes, as suggested by single gene disruptions and theoretical considerations. If this view is correct, the remaining nonessential genes of an organism, such as Bacillus subtilis, have been acquired during evolution in its perpetually changing

  16. Genome-wide screening reveals the emergence and divergence of ...

    Indian Academy of Sciences (India)

    domain-based screening using Hidden Markov Models (HMMs) for RTKs in Genomescan predicted gene models of the Hydra magnipapillata genome .... its speed and minimal errors in tree topologies. A bootstrap test for all trees was ... according to the classification in RTKdb (Grassot et al. 2003). Another analysis along ...

  17. Extensive Pyrosequencing Reveals Frequent Intra-Genomic Variations of Internal Transcribed Spacer Regions of Nuclear Ribosomal DNA

    Science.gov (United States)

    Li, Dezhu; Sun, Yongzhen; Niu, Yunyun; Chen, Zhiduan; Luo, Hongmei; Pang, Xiaohui; Sun, Zhiying; Liu, Chang; Lv, Aiping; Deng, Youping; Larson-Rabin, Zachary; Wilkinson, Mike; Chen, Shilin

    2012-01-01

    Background Internal transcribed spacer of nuclear ribosomal DNA (nrDNA) is already one of the most popular phylogenetic and DNA barcoding markers. However, the existence of its multiple copies has complicated such usage and a detailed characterization of intra-genomic variations is critical to address such concerns. Methodology/Principal Findings In this study, we used sequence-tagged pyrosequencing and genome-wide analyses to characterize intra-genomic variations of internal transcribed spacer 2 (ITS2) regions from 178 plant species. We discovered that mutation of ITS2 is frequent, with a mean of 35 variants per species. And on average, three of the most abundant variants make up 91% of all ITS2 copies. Moreover, we found different congeneric species share identical variants in 13 genera. Interestingly, different species across different genera also share identical variants. In particular, one minor variant of ITS2 in Eleutherococcus giraldii was found identical to the ITS2 major variant of Panax ginseng, both from Araliaceae family. In addition, DNA barcoding gap analysis showed that the intra-genomic distances were markedly smaller than those of the intra-specific or inter-specific variants. When each of 5543 variants were examined for its species discrimination efficiency, a 97% success rate was obtained at the species level. Conclusions Identification of identical ITS2 variants across intra-generic or inter-generic species revealed complex species evolutionary history, possibly, horizontal gene transfer and ancestral hybridization. Although intra-genomic multiple variants are frequently found within each genome, the usage of the major variants alone is sufficient for phylogeny construction and species determination in most cases. Furthermore, the inclusion of minor variants further improves the resolution of species identification. PMID:22952830

  18. Preliminary comparative genomics revealed pathogenic potential and international spread of Staphylococcus argenteus

    OpenAIRE

    Zhang, Dao-Feng; Zhi, Xiao-Yang; Zhang, Jing; Paoli, George C.; Cui, Yan; Shi, Chunlei; Shi, Xianming

    2017-01-01

    Background Staphylococcus argenteus and S. schweitzeri, were recently proposed as novel species within S. aureus complex (SAC). S. argenteus has been reported in many countries and can threaten human health. S. schweitzeri has not been associated with human infections, but has been isolated from non-human primates. Questions regarding the evolution of pathogenicity of these two species will remain elusive until an exploratory evolutionary framework is established. Results We present genomic c...

  19. Genome-wide analysis reveals selection for important traits in domestic horse breeds

    OpenAIRE

    Mickelson, James R.; Aaron K Rendahl; Valberg, Stephanie J; Andersson, Lisa S.; Axelsson, Jeanette; Bailey, Ernie; Bannasch, Danika; Binns, Matthew M; Alexandre S. Borges; Brama, Pieter; da Câmara Machado, Artur; Capomaccio, Stefano; Cappelli, Katia; Cothran, E Gus; Distl, Ottmar

    2013-01-01

    Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an F(ST)-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of sel...

  20. Genome-wide analysis reveals selection for important traits in domestic horse breeds.

    OpenAIRE

    Petersen, Jessica L.; Mickelson, James R.; Aaron K Rendahl; Valberg, Stephanie J; Andersson, Lisa S.; Axelsson, Jeanette; Bailey, Ernie; Bannasch, Danika; Binns, Matthew M; Alexandre S. Borges; Brama, Pieter; da Câmara Machado, Artur; Capomaccio, Stefano; Cappelli, Katia; Cothran, E Gus

    2013-01-01

    Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an F(ST)-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of sel...

  1. Genome-Wide Analysis Reveals Selection for Important Traits in Domestic Horse Breeds

    OpenAIRE

    Petersen, Jessica L.; Mickelson, James R.; Aaron K Rendahl; Valberg, Stephanie J; Andersson, Lisa S.; Axelsson, Jeanette; Bailey, Ernie; Bannasch, Danika; Binns, Matthew M; Borges, Alexandre Secorun; Brama, Pieter; da Câmara Machado, Artur; Capomaccio, Stefano; Cappelli, Katia; Cothran, E Gus

    2013-01-01

    Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an FST-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of selec...

  2. Genome structure and reproductive behaviour influence the evolutionary potential of a fungal phytopathogen.

    Directory of Open Access Journals (Sweden)

    Guillaume Daverdin

    Full Text Available Modern agriculture favours the selection and spread of novel plant diseases. Furthermore, crop genetic resistance against pathogens is often rendered ineffective within a few years of its commercial deployment. Leptosphaeria maculans, the cause of phoma stem canker of oilseed rape, develops gene-for-gene interactions with its host plant, and has a high evolutionary potential to render ineffective novel sources of resistance in crops. Here, we established a four-year field experiment to monitor the evolution of populations confronted with the newly released Rlm7 resistance and to investigate the nature of the mutations responsible for virulence against Rlm7. A total of 2551 fungal isolates were collected from experimental crops of a Rlm7 cultivar or a cultivar without Rlm7. All isolates were phenotyped for virulence and a subset was genotyped with neutral genetic markers. Virulent isolates were investigated for molecular events at the AvrLm4-7 locus. Whilst virulent isolates were not found in neighbouring crops, their frequency had reached 36% in the experimental field after four years. An extreme diversity of independent molecular events leading to virulence was identified in populations, with large-scale Repeat Induced Point mutations or complete deletion of AvrLm4-7 being the most frequent. Our data suggest that increased mutability of fungal genes involved in the interactions with plants is directly related to their genomic environment and reproductive system. Thus, rapid allelic diversification of avirulence genes can be generated in L. maculans populations in a single field provided that large population sizes and sexual reproduction are favoured by agricultural practices.

  3. Sister Dehalobacter Genomes Reveal Specialization in Organohalide Respiration and Recent Strain Differentiation Likely Driven by Chlorinated Substrates

    Directory of Open Access Journals (Sweden)

    Shuiquan eTang

    2016-02-01

    , a complete heme biosynthesis pathway is present in the five Dehalobacter genomes. This pathway corresponds to a newly described alternative heme biosynthesis route first identified in Archaea. This analysis of organohalide-respiring Firmicutes and Chloroflexi reveals profound evolutionary differences despite very similar niche-specific metabolism and function.

  4. Sister Dehalobacter Genomes Reveal Specialization in Organohalide Respiration and Recent Strain Differentiation Likely Driven by Chlorinated Substrates.

    Science.gov (United States)

    Tang, Shuiquan; Wang, Po Hsiang; Higgins, Steven A; Löffler, Frank E; Edwards, Elizabeth A

    2016-01-01

    pathway is present in the five Dehalobacter genomes. This pathway corresponds to a newly described alternative heme biosynthesis route first identified in Archaea. This analysis of organohalide-respiring Firmicutes and Chloroflexi reveals profound evolutionary differences despite very similar niche-specific metabolism and function.

  5. Comparative analyses of coding and noncoding DNA regions indicate that Acropora (Anthozoa: Scleractina) possesses a similar evolutionary tempo of nuclear vs. mitochondrial genomes as in plants.

    Science.gov (United States)

    Chen, I-Ping; Tang, Chung-Yu; Chiou, Chih-Yung; Hsu, Jia-Ho; Wei, Nuwei Vivian; Wallace, Carden C; Muir, Paul; Wu, Henry; Chen, Chaolun Allen

    2009-01-01

    Evidence suggests that the mitochondrial (mt)DNA of anthozoans is evolving at a slower tempo than their nuclear DNA; however, parallel surveys of nuclear and mitochondrial variations and calibrated rates of both synonymous and nonsynonymous substitutions across taxa are needed in order to support this scenario. We examined species of the scleractinian coral genus Acropora, including previously unstudied species, for molecular variations in protein-coding genes and noncoding regions of both nuclear and mt genomes. DNA sequences of a calmodulin (CaM)-encoding gene region containing three exons, two introns and a 411-bp mt intergenic spacer (IGS) spanning the cytochrome b (cytb) and NADH 2 genes, were obtained from 49 Acropora species. The molecular evolutionary rates of coding and noncoding regions in nuclear and mt genomes were compared in conjunction with published data, including mt cytochrome b, the control region, and nuclear Pax-C introns. Direct sequencing of the mtIGS revealed an average interspecific variation comparable to that seen in published data for mt cytb. The average interspecific variation of the nuclear genome was two to five times greater than that of the mt genome. Based on the calibration of the closure of Panama Isthmus (3.0 mya) and closure of the Tethy Seaway (12 mya), synonymous substitution rates ranged from 0.367% to 1.467% Ma(-1) for nuclear CaM, which is about 4.8 times faster than those of mt cytb (0.076-0.303% Ma(-1)). This is similar to the findings in plant genomes that the nuclear genome is evolving at least five times faster than those of mitochondrial counterparts.

  6. Genetic variability among complete human respiratory syncytial virus subgroup A genomes: bridging molecular evolutionary dynamics and epidemiology.

    Directory of Open Access Journals (Sweden)

    Lydia Tan

    Full Text Available Human respiratory syncytial virus (RSV is an important cause of severe lower respiratory tract infections in infants and the elderly. In the vast majority of cases, however, RSV infections run mild and symptoms resemble those of a common cold. The immunological, clinical, and epidemiological profile of severe RSV infections suggests a disease caused by a virus with typical seasonal transmission behavior, lacking clear-cut virulence factors, but instead causing disease by modifying the host's immune response in a way that stimulates pathogenesis. Yet, the interplay between RSV-evoked immune responses and epidemic behavior, and how this affects the genomic evolutionary dynamics of the virus, remains poorly understood. Here, we present a comprehensive collection of 33 novel RSV subgroup A genomes from strains sampled over the last decade, and provide the first measurement of RSV-A genomic diversity through time in a phylodynamic framework. In addition, we map amino acid substitutions per protein to determine mutational hotspots in specific domains. Using Bayesian genealogical inference, we estimated the genomic evolutionary rate to be 6.47 × 10(-4 (credible interval: 5.56 × 10(-4, 7.38 × 10(-4 substitutions/site/year, considerably slower than previous estimates based on G gene sequences only. The G gene is however marked by elevated substitution rates compared to other RSV genes, which can be attributed to relaxed selective constraints. In line with this, site-specific selection analyses identify the G gene as the major target of diversifying selection. Importantly, statistical analysis demonstrates that the immune driven positive selection does not leave a measurable imprint on the genome phylogeny, implying that RSV lineage replacement mainly follows nonselective epidemiological processes. The roughly 50 years of RSV-A genomic evolution are characterized by a constant population size through time and general co-circulation of lineages over

  7. Genome-wide analysis of ruminant Staphylococcus aureus reveals diversification of the core genome.

    Science.gov (United States)

    Ben Zakour, Nouri L; Sturdevant, Daniel E; Even, Sergine; Guinane, Caitriona M; Barbey, Corinne; Alves, Priscila D; Cochet, Marie-Françoise; Gautier, Michel; Otto, Michael; Fitzgerald, J Ross; Le Loir, Yves

    2008-10-01

    Staphylococcus aureus causes disease in humans and a wide array of animals. Of note, S. aureus mastitis of ruminants, including cows, sheep, and goats, results in major economic losses worldwide. Extensive variation in genome content exists among S. aureus pathogenic clones. However, the genomic variation among S. aureus strains infecting different animal species has not been well examined. To investigate variation in the genome content of human and ruminant S. aureus, we carried out whole-genome PCR scanning (WGPS), comparative genomic hybridizations (CGH), and the directed DNA sequence analysis of strains of human, bovine, ovine, and caprine origin. Extensive variation in genome content was discovered, including host- and ruminant-specific genetic loci. Ovine and caprine strains were genetically allied, whereas bovine strains were heterogeneous in gene content. As expected, mobile genetic elements such as pathogenicity islands and bacteriophages contributed to the variation in genome content between strains. However, differences specific for ruminant strains were restricted to regions of the conserved core genome, which contained allelic variation in genes encoding proteins of known and unknown function. Many of these proteins are predicted to be exported and could play a role in host-pathogen interactions. The genomic regions of difference identified by the whole-genome approaches adopted in the current study represent excellent targets for studies of the molecular basis of S. aureus host adaptation.

  8. Comparative genomic paleontology across plant kingdom reveals the dynamics of TE-driven genome evolution.

    Science.gov (United States)

    El Baidouri, Moaine; Panaud, Olivier

    2013-01-01

    Long terminal repeat-retrotransposons (LTR-RTs) are the most abundant class of transposable elements (TEs) in plants. They strongly impact the structure, function, and evolution of their host genome, and, in particular, their role in genome size variation has been clearly established. However, the dynamics of the process through which LTR-RTs have differentially shaped plant genomes is still poorly understood because of a lack of comparative studies. Using a new robust and automated family classification procedure, we exhaustively characterized the LTR-RTs in eight plant genomes for which a high-quality sequence is available (i.e., Arabidopsis thaliana, A. lyrata, grapevine, soybean, rice, Brachypodium dystachion, sorghum, and maize). This allowed us to perform a comparative genome-wide study of the retrotranspositional landscape in these eight plant lineages from both monocots and dicots. We show that retrotransposition has recurrently occurred in all plant genomes investigated, regardless their size, and through bursts, rather than a continuous process. Moreover, in each genome, only one or few LTR-RT families have been active in the recent past, and the difference in genome size among the species studied could thus mostly be accounted for by the extent of the latest transpositional burst(s). Following these bursts, LTR-RTs are efficiently eliminated from their host genomes through recombination and deletion, but we show that the removal rate is not lineage specific. These new findings lead us to propose a new model of TE-driven genome evolution in plants.

  9. 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...... of geographic origin at country and regional scales. Multiple lines of evidence suggest that gene flow occurred from bonobos into the ancestors of central and eastern chimpanzees between 200,000 and 550,000 years ago, probably with subsequent spread into Nigeria-Cameroon chimpanzees. Together with another......, possibly more recent contact (after 200,000 years ago), bonobos contributed less than 1% to the central chimpanzee genomes. Admixture thus appears to have been widespread during hominid evolution....

  10. Novel Genomic and Evolutionary Insight of WRKY Transcription Factors in Plant Lineage.

    Science.gov (United States)

    Mohanta, Tapan Kumar; Park, Yong-Hwan; Bae, Hanhong

    2016-11-17

    The evolutionarily conserved WRKY transcription factor (TF) regulates different aspects of gene expression in plants, and modulates growth, development, as well as biotic and abiotic stress responses. Therefore, understanding the details regarding WRKY TFs is very important. In this study, large-scale genomic analyses of the WRKY TF gene family from 43 plant species were conducted. The results of our study revealed that WRKY TFs could be grouped and specifically classified as those belonging to the monocot or dicot plant lineage. In this study, we identified several novel WRKY TFs. To our knowledge, this is the first report on a revised grouping system of the WRKY TF gene family in plants. The different forms of novel chimeric forms of WRKY TFs in the plant genome might play a crucial role in their evolution. Tissue-specific gene expression analyses in Glycine max and Phaseolus vulgaris showed that WRKY11-1, WRKY11-2 and WRKY11-3 were ubiquitously expressed in all tissue types, and WRKY15-2 was highly expressed in the stem, root, nodule and pod tissues in G. max and P. vulgaris.

  11. Increased genome sampling reveals novel insights into vertebrate molecular evolution

    OpenAIRE

    Doherty, Aoife

    2012-01-01

    In this thesis, increased vertebrate genome sampling and recent methodological advancements were combined to address three distinct questions pertaining to vertebrate molecular evolution. Gene duplicability is the tendency to retain multiple gene copies after a duplication event. Various factors correlate with gene duplicability, such as protein function and timing of expression during development. The position of a gene’s encoded product in the protein-protein interaction n...

  12. Upper Palaeolithic genomes reveal deep roots of modern Eurasians

    KAUST Repository

    Jones, Eppie R.

    2015-11-16

    We extend the scope of European palaeogenomics by sequencing the genomes of Late Upper Palaeolithic (13,300 years old, 1.4-fold coverage) and Mesolithic (9,700 years old, 15.4-fold) males from western Georgia in the Caucasus and a Late Upper Palaeolithic (13,700 years old, 9.5-fold) male from Switzerland. While we detect Late Palaeolithic–Mesolithic genomic continuity in both regions, we find that Caucasus hunter-gatherers (CHG) belong to a distinct ancient clade that split from western hunter-gatherers ~45 kya, shortly after the expansion of anatomically modern humans into Europe and from the ancestors of Neolithic farmers ~25 kya, around the Last Glacial Maximum. CHG genomes significantly contributed to the Yamnaya steppe herders who migrated into Europe ~3,000 BC, supporting a formative Caucasus influence on this important Early Bronze age culture. CHG left their imprint on modern populations from the Caucasus and also central and south Asia possibly marking the arrival of Indo-Aryan languages.

  13. Use of genome-scale metabolic models in evolutionary systems biology.

    NARCIS (Netherlands)

    Papp, B.; Szappanos, B.; Notebaart, R.A.

    2011-01-01

    One of the major aims of the nascent field of evolutionary systems biology is to test evolutionary hypotheses that are not only realistic from a population genetic point of view but also detailed in terms of molecular biology mechanisms. By providing a mapping between genotype and phenotype for

  14. Transcriptomics and molecular evolutionary rate analysis of the bladderwort (Utricularia, a carnivorous plant with a minimal genome

    Directory of Open Access Journals (Sweden)

    Herrera-Estrella Alfredo

    2011-06-01

    Full Text Available Abstract Background The carnivorous plant Utricularia gibba (bladderwort is remarkable in having a minute genome, which at ca. 80 megabases is approximately half that of Arabidopsis. Bladderworts show an incredible diversity of forms surrounding a defined theme: tiny, bladder-like suction traps on terrestrial, epiphytic, or aquatic plants with a diversity of unusual vegetative forms. Utricularia plants, which are rootless, are also anomalous in physiological features (respiration and carbon distribution, and highly enhanced molecular evolutionary rates in chloroplast, mitochondrial and nuclear ribosomal sequences. Despite great interest in the genus, no genomic resources exist for Utricularia, and the substitution rate increase has received limited study. Results Here we describe the sequencing and analysis of the Utricularia gibba transcriptome. Three different organs were surveyed, the traps, the vegetative shoot bodies, and the inflorescence stems. We also examined the bladderwort transcriptome under diverse stress conditions. We detail aspects of functional classification, tissue similarity, nitrogen and phosphorus metabolism, respiration, DNA repair, and detoxification of reactive oxygen species (ROS. Long contigs of plastid and mitochondrial genomes, as well as sequences for 100 individual nuclear genes, were compared with those of other plants to better establish information on molecular evolutionary rates. Conclusion The Utricularia transcriptome provides a detailed genomic window into processes occurring in a carnivorous plant. It contains a deep representation of the complex metabolic pathways that characterize a putative minimal plant genome, permitting its use as a source of genomic information to explore the structural, functional, and evolutionary diversity of the genus. Vegetative shoots and traps are the most similar organs by functional classification of their transcriptome, the traps expressing hydrolytic enzymes for prey

  15. Comparative genomics of Eucalyptus and Corymbia reveals low rates of genome structural rearrangement.

    Science.gov (United States)

    Butler, J B; Vaillancourt, R E; Potts, B M; Lee, D J; King, G J; Baten, A; Shepherd, M; Freeman, J S

    2017-05-22

    Previous studies suggest genome structure is largely conserved between Eucalyptus species. However, it is unknown if this conservation extends to more divergent eucalypt taxa. We performed comparative genomics between the eucalypt genera Eucalyptus and Corymbia. Our results will facilitate transfer of genomic information between these important taxa and provide further insights into the rate of structural change in tree genomes. We constructed three high density linkage maps for two Corymbia species (Corymbia citriodora subsp. variegata and Corymbia torelliana) which were used to compare genome structure between both species and Eucalyptus grandis. Genome structure was highly conserved between the Corymbia species. However, the comparison of Corymbia and E. grandis suggests large (from 1-13 MB) intra-chromosomal rearrangements have occurred on seven of the 11 chromosomes. Most rearrangements were supported through comparisons of the three independent Corymbia maps to the E. grandis genome sequence, and to other independently constructed Eucalyptus linkage maps. These are the first large scale chromosomal rearrangements discovered between eucalypts. Nonetheless, in the general context of plants, the genomic structure of the two genera was remarkably conserved; adding to a growing body of evidence that conservation of genome structure is common amongst woody angiosperms.

  16. The Slow:Fast substitution ratio reveals changing patterns of natural selection in gamma-proteobacterial genomes

    Energy Technology Data Exchange (ETDEWEB)

    Alm, Eric; Shapiro, B. Jesse

    2009-04-15

    Different microbial species are thought to occupy distinct ecological niches, subjecting each species to unique selective constraints, which may leave a recognizable signal in their genomes. Thus, it may be possible to extract insight into the genetic basis of ecological differences among lineages by identifying unusual patterns of substitutions in orthologous gene or protein sequences. We use the ratio of substitutions in slow versus fast-evolving sites (nucleotides in DNA, or amino acids in protein sequence) to quantify deviations from the typical pattern of selective constraint observed across bacterial lineages. We propose that elevated S:F in one branch (an excess of slow-site substitutions) can indicate a functionally-relevant change, due to either positive selection or relaxed evolutionary constraint. In a genome-wide comparative study of gamma-proteobacterial proteins, we find that cell-surface proteins involved with motility and secretion functions often have high S:F ratios, while information-processing genes do not. Change in evolutionary constraints in some species is evidenced by increased S:F ratios within functionally-related sets of genes (e.g., energy production in Pseudomonas fluorescens), while other species apparently evolve mostly by drift (e.g., uniformly elevated S:F across most genes in Buchnera spp.). Overall, S:F reveals several species-specific, protein-level changes with potential functional/ecological importance. As microbial genome projects yield more species-rich gene-trees, the S:F ratio will become an increasingly powerful tool for uncovering functional genetic differences among species.

  17. Wild tobacco genomes reveal the evolution of nicotine biosynthesis.

    Science.gov (United States)

    Xu, Shuqing; Brockmöller, Thomas; Navarro-Quezada, Aura; Kuhl, Heiner; Gase, Klaus; Ling, Zhihao; Zhou, Wenwu; Kreitzer, Christoph; Stanke, Mario; Tang, Haibao; Lyons, Eric; Pandey, Priyanka; Pandey, Shree P; Timmermann, Bernd; Gaquerel, Emmanuel; Baldwin, Ian T

    2017-06-06

    Nicotine, the signature alkaloid of Nicotiana species responsible for the addictive properties of human tobacco smoking, functions as a defensive neurotoxin against attacking herbivores. However, the evolution of the genetic features that contributed to the assembly of the nicotine biosynthetic pathway remains unknown. We sequenced and assembled genomes of two wild tobaccos, Nicotiana attenuata (2.5 Gb) and Nicotiana obtusifolia (1.5 Gb), two ecological models for investigating adaptive traits in nature. We show that after the Solanaceae whole-genome triplication event, a repertoire of rapidly expanding transposable elements (TEs) bloated these Nicotiana genomes, promoted expression divergences among duplicated genes, and contributed to the evolution of herbivory-induced signaling and defenses, including nicotine biosynthesis. The biosynthetic machinery that allows for nicotine synthesis in the roots evolved from the stepwise duplications of two ancient primary metabolic pathways: the polyamine and nicotinamide adenine dinucleotide (NAD) pathways. In contrast to the duplication of the polyamine pathway that is shared among several solanaceous genera producing polyamine-derived tropane alkaloids, we found that lineage-specific duplications within the NAD pathway and the evolution of root-specific expression of the duplicated Solanaceae-specific ethylene response factor that activates the expression of all nicotine biosynthetic genes resulted in the innovative and efficient production of nicotine in the genus Nicotiana Transcription factor binding motifs derived from TEs may have contributed to the coexpression of nicotine biosynthetic pathway genes and coordinated the metabolic flux. Together, these results provide evidence that TEs and gene duplications facilitated the emergence of a key metabolic innovation relevant to plant fitness.

  18. Evolutionary and Comparative Genomics to Drive Rational Drug Design, with Particular Focus on Neuropeptide Seven-Transmembrane Receptors.

    Science.gov (United States)

    Furlong, Michael; Seong, Jae Young

    2017-01-01

    Seven transmembrane receptors (7TMRs), also known as G protein-coupled receptors, are popular targets of drug development, particularly 7TMR systems that are activated by peptide ligands. Although many pharmaceutical drugs have been discovered via conventional bulk analysis techniques the increasing availability of structural and evolutionary data are facilitating change to rational, targeted drug design. This article discusses the appeal of neuropeptide-7TMR systems as drug targets and provides an overview of concepts in the evolution of vertebrate genomes and gene families. Subsequently, methods that use evolutionary concepts and comparative analysis techniques to aid in gene discovery, gene function identification, and novel drug design are provided along with case study examples.

  19. Comparative genomic analysis reveals ecological differentiation in the genus Carnobacterium

    DEFF Research Database (Denmark)

    Iskandar, Christelle F.; Borges, Frédéric; Taminiau, Bernard

    2017-01-01

    was used as a model genus to elucidate the genetic basis of these colonization differences. Analyses of 16S rRNA gene meta-barcoding data showed that C. maltaromaticum followed by C. divergens are the most prevalent species in foods derived from animals (meat, fish, dairy products), and in the gut...... also exhibit genes for gut adaptation and respiration. In contrast, Carnobacterium species belonging to the second lineage encode a poorly diversified cell-surface proteome, lack genes for gut adaptation and are unable to respire. These results shed light on the important genomics traits required...

  20. The evolutionary history of Saccharomyces species inferred from completed mitochondrial genomes and revision in the 'yeast mitochondrial genetic code'.

    Science.gov (United States)

    Sulo, Pavol; Szabóová, Dana; Bielik, Peter; Poláková, Silvia; Šoltys, Katarína; Jatzová, Katarína; Szemes, Tomáš

    2017-12-01

    The yeast Saccharomyces are widely used to test ecological and evolutionary hypotheses. A large number of nuclear genomic DNA sequences are available, but mitochondrial genomic data are insufficient. We completed mitochondrial DNA (mtDNA) sequencing from Illumina MiSeq reads for all Saccharomyces species. All are circularly mapped molecules decreasing in size with phylogenetic distance from Saccharomyces cerevisiae but with similar gene content including regulatory and selfish elements like origins of replication, introns, free-standing open reading frames or GC clusters. Their most profound feature is species-specific alteration in gene order. The genetic code slightly differs from well-established yeast mitochondrial code as GUG is used rarely as the translation start and CGA and CGC code for arginine. The multilocus phylogeny, inferred from mtDNA, does not correlate with the trees derived from nuclear genes. mtDNA data demonstrate that Saccharomyces cariocanus should be assigned as a separate species and Saccharomyces bayanus CBS 380T should not be considered as a distinct species due to mtDNA nearly identical to Saccharomyces uvarum mtDNA. Apparently, comparison of mtDNAs should not be neglected in genomic studies as it is an important tool to understand the origin and evolutionary history of some yeast species. © The Author 2017. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

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

    Directory of Open Access Journals (Sweden)

    Xue-Feng Ma

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

  2. Evolutionary genetics of immunological supertypes reveals two faces of the Red Queen

    OpenAIRE

    Lighten, Jackie; Papadopulos, Alexander S. T.; Mohammed, Ryan S.; Ward, Ben J.; G. Paterson, Ian; Baillie, Lyndsey; Bradbury, Ian R.; Hendry, Andrew P.; Bentzen, Paul; van Oosterhout, Cock

    2017-01-01

    Red Queen host-parasite co-evolution can drive adaptations of immune-genes by positive selection that erodes genetic variation (Red Queen Arms Race), or result in a balanced polymorphism (Red Queen Dynamics) and the long-term preservation of genetic variation (trans-species polymorphism). These two Red Queen processes are opposite extremes of the co-evolutionary spectrum. Here we show that both Red Queen processes can operate simultaneously, analyzing the Major Histocompatibility Complex (MHC...

  3. Citizen science reveals unexpected continental-scale evolutionary change in a model organism.

    Directory of Open Access Journals (Sweden)

    Jonathan Silvertown

    Full Text Available Organisms provide some of the most sensitive indicators of climate change and evolutionary responses are becoming apparent in species with short generation times. Large datasets on genetic polymorphism that can provide an historical benchmark against which to test for recent evolutionary responses are very rare, but an exception is found in the brown-lipped banded snail (Cepaea nemoralis. This species is sensitive to its thermal environment and exhibits several polymorphisms of shell colour and banding pattern affecting shell albedo in the majority of populations within its native range in Europe. We tested for evolutionary changes in shell albedo that might have been driven by the warming of the climate in Europe over the last half century by compiling an historical dataset for 6,515 native populations of C. nemoralis and comparing this with new data on nearly 3,000 populations. The new data were sampled mainly in 2009 through the Evolution MegaLab, a citizen science project that engaged thousands of volunteers in 15 countries throughout Europe in the biggest such exercise ever undertaken. A known geographic cline in the frequency of the colour phenotype with the highest albedo (yellow was shown to have persisted and a difference in colour frequency between woodland and more open habitats was confirmed, but there was no general increase in the frequency of yellow shells. This may have been because snails adapted to a warming climate through behavioural thermoregulation. By contrast, we detected an unexpected decrease in the frequency of Unbanded shells and an increase in the Mid-banded morph. Neither of these evolutionary changes appears to be a direct response to climate change, indicating that the influence of other selective agents, possibly related to changing predation pressure and habitat change with effects on micro-climate.

  4. Citizen Science Reveals Unexpected Continental-Scale Evolutionary Change in a Model Organism

    Science.gov (United States)

    Silvertown, Jonathan; Cook, Laurence; Cameron, Robert; Dodd, Mike; McConway, Kevin; Worthington, Jenny; Skelton, Peter; Anton, Christian; Bossdorf, Oliver; Baur, Bruno; Schilthuizen, Menno; Fontaine, Benoît; Sattmann, Helmut; Bertorelle, Giorgio; Correia, Maria; Oliveira, Cristina; Pokryszko, Beata; Ożgo, Małgorzata; Stalažs, Arturs; Gill, Eoin; Rammul, Üllar; Sólymos, Péter; Féher, Zoltan; Juan, Xavier

    2011-01-01

    Organisms provide some of the most sensitive indicators of climate change and evolutionary responses are becoming apparent in species with short generation times. Large datasets on genetic polymorphism that can provide an historical benchmark against which to test for recent evolutionary responses are very rare, but an exception is found in the brown-lipped banded snail (Cepaea nemoralis). This species is sensitive to its thermal environment and exhibits several polymorphisms of shell colour and banding pattern affecting shell albedo in the majority of populations within its native range in Europe. We tested for evolutionary changes in shell albedo that might have been driven by the warming of the climate in Europe over the last half century by compiling an historical dataset for 6,515 native populations of C. nemoralis and comparing this with new data on nearly 3,000 populations. The new data were sampled mainly in 2009 through the Evolution MegaLab, a citizen science project that engaged thousands of volunteers in 15 countries throughout Europe in the biggest such exercise ever undertaken. A known geographic cline in the frequency of the colour phenotype with the highest albedo (yellow) was shown to have persisted and a difference in colour frequency between woodland and more open habitats was confirmed, but there was no general increase in the frequency of yellow shells. This may have been because snails adapted to a warming climate through behavioural thermoregulation. By contrast, we detected an unexpected decrease in the frequency of Unbanded shells and an increase in the Mid-banded morph. Neither of these evolutionary changes appears to be a direct response to climate change, indicating that the influence of other selective agents, possibly related to changing predation pressure and habitat change with effects on micro-climate. PMID:21556137

  5. Mountain gorilla genomes reveal the impact of long-term population decline and inbreeding.

    Science.gov (United States)

    Xue, Yali; Prado-Martinez, Javier; Sudmant, Peter H; Narasimhan, Vagheesh; Ayub, Qasim; Szpak, Michal; Frandsen, Peter; Chen, Yuan; Yngvadottir, Bryndis; Cooper, David N; de Manuel, Marc; Hernandez-Rodriguez, Jessica; Lobon, Irene; Siegismund, Hans R; Pagani, Luca; Quail, Michael A; Hvilsom, Christina; Mudakikwa, Antoine; Eichler, Evan E; Cranfield, Michael R; Marques-Bonet, Tomas; Tyler-Smith, Chris; Scally, Aylwyn

    2015-04-10

    Mountain gorillas are an endangered great ape subspecies and a prominent focus for conservation, yet we know little about their genomic diversity and evolutionary past. We sequenced whole genomes from multiple wild individuals and compared the genomes of all four Gorilla subspecies. We found that the two eastern subspecies have experienced a prolonged population decline over the past 100,000 years, resulting in very low genetic diversity and an increased overall burden of deleterious variation. A further recent decline in the mountain gorilla population has led to extensive inbreeding, such that individuals are typically homozygous at 34% of their sequence, leading to the purging of severely deleterious recessive mutations from the population. We discuss the causes of their decline and the consequences for their future survival. Copyright © 2015, American Association for the Advancement of Science.

  6. Genome sequencing of Ewing sarcoma patients reveals genetic predisposition | Center for Cancer Research

    Science.gov (United States)

    The largest and most comprehensive genomic analysis of individuals with Ewing sarcoma performed to date reveals that some patients are genetically predisposed to developing the cancer.  Learn more...

  7. The Laccaria and Tuber Genomes Reveal Unique Signatures of Mycorrhizal Symbiosis Evolution (2010 JGI User Meeting)

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Steve

    2010-03-24

    Francis Martin from the French agricultural research institute INRA talks on how "The Laccaria and Tuber genomes reveal unique signatures of mycorrhizal symbiosis evolution" on March 24, 2010 at the 5th Annual DOE JGI User Meeting

  8. The complete mitochondrial genome of Pauropus longiramus (Myriapoda: Pauropoda): implications on early diversification of the myriapods revealed from comparative analysis.

    Science.gov (United States)

    Dong, Yan; Sun, Hongying; Guo, Hua; Pan, Da; Qian, Changyuan; Hao, Sijing; Zhou, Kaiya

    2012-08-15

    Myriapods are among the earliest arthropods and may have evolved to become part of the terrestrial biota more than 400 million years ago. A noticeable lack of mitochondrial genome data from Pauropoda hampers phylogenetic and evolutionary studies within the subphylum Myriapoda. We sequenced the first complete mitochondrial genome of a microscopic pauropod, Pauropus longiramus (Arthropoda: Myriapoda), and conducted comprehensive mitogenomic analyses across the Myriapoda. The pauropod mitochondrial genome is a circular molecule of 14,487 bp long and contains the entire set of thirty-seven genes. Frequent intergenic overlaps occurred between adjacent tRNAs, and between tRNA and protein-coding genes. This is the first example of a mitochondrial genome with multiple intergenic overlaps and reveals a strategy for arthropods to effectively compact the mitochondrial genome by overlapping and truncating tRNA genes with neighbor genes, instead of only truncating tRNAs. Phylogenetic analyses based on protein-coding genes provide strong evidence that the sister group of Pauropoda is Symphyla. Additionally, approximately unbiased (AU) tests strongly support the Progoneata and confirm the basal position of Chilopoda in Myriapoda. This study provides an estimation of myriapod origins around 555 Ma (95% CI: 444-704 Ma) and this date is comparable with that of the Cambrian explosion and candidate myriapod-like fossils. A new time-scale suggests that deep radiations during early myriapod diversification occurred at least three times, not once as previously proposed. A Carboniferous origin of pauropods is congruent with the idea that these taxa are derived, rather than basal, progoneatans. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Comparative genomics reveals mechanism for short-term and long-term clonal transitions in pandemic Vibrio cholerae

    Science.gov (United States)

    Chun, Jongsik; Grim, Christopher J.; Hasan, Nur A.; Lee, Je Hee; Choi, Seon Young; Haley, Bradd J.; Taviani, Elisa; Jeon, Yoon-Seong; Kim, Dong Wook; Lee, Jae-Hak; Brettin, Thomas S.; Bruce, David C.; Challacombe, Jean F.; Detter, J. Chris; Han, Cliff S.; Munk, A. Christine; Chertkov, Olga; Meincke, Linda; Saunders, Elizabeth; Walters, Ronald A.; Huq, Anwar; Nair, G. Balakrish; Colwell, Rita R.

    2009-01-01

    Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the sixth and the current seventh pandemics, respectively. Cholera researchers continually face newly emerging and reemerging pathogenic clones carrying diverse combinations of phenotypic and genotypic properties, which significantly hampered control of the disease. To elucidate evolutionary mechanisms governing genetic diversity of pandemic V. cholerae, we compared the genome sequences of 23 V. cholerae strains isolated from a variety of sources over the past 98 years. The genome-based phylogeny revealed 12 distinct V. cholerae lineages, of which one comprises both O1 classical and El Tor biotypes. All seventh pandemic clones share nearly identical gene content. Using analogy to influenza virology, we define the transition from sixth to seventh pandemic strains as a “shift” between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages. In contrast, transition among clones during the present pandemic period is characterized as a “drift” between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V. cholerae O139 and V. cholerae O1 El Tor hybrid clones. Based on the comparative genomics it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to define pathogenic V. cholerae clones. PMID:19720995

  10. Genomic characterization of methanomicrobiales reveals three classes of methanogens.

    Directory of Open Access Journals (Sweden)

    Iain Anderson

    2009-06-01

    Full Text Available Methanomicrobiales is the least studied order of methanogens. While these organisms appear to be more closely related to the Methanosarcinales in ribosomal-based phylogenetic analyses, they are metabolically more similar to Class I methanogens.In order to improve our understanding of this lineage, we have completely sequenced the genomes of two members of this order, Methanocorpusculum labreanum Z and Methanoculleus marisnigri JR1, and compared them with the genome of a third, Methanospirillum hungatei JF-1. Similar to Class I methanogens, Methanomicrobiales use a partial reductive citric acid cycle for 2-oxoglutarate biosynthesis, and they have the Eha energy-converting hydrogenase. In common with Methanosarcinales, Methanomicrobiales possess the Ech hydrogenase and at least some of them may couple formylmethanofuran formation and heterodisulfide reduction to transmembrane ion gradients. Uniquely, M. labreanum and M. hungatei contain hydrogenases similar to the Pyrococcus furiosus Mbh hydrogenase, and all three Methanomicrobiales have anti-sigma factor and anti-anti-sigma factor regulatory proteins not found in other methanogens. Phylogenetic analysis based on seven core proteins of methanogenesis and cofactor biosynthesis places the Methanomicrobiales equidistant from Class I methanogens and Methanosarcinales.Our results indicate that Methanomicrobiales, rather than being similar to Class I methanogens or Methanomicrobiales, share some features of both and have some unique properties. We find that there are three distinct classes of methanogens: the Class I methanogens, the Methanomicrobiales (Class II, and the Methanosarcinales (Class III.

  11. Genomic Characterization of Methanomicrobiales Reveals Three Classes of Methanogens

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain [U.S. Department of Energy, Joint Genome Institute; Ulrich, Luke [ORNL; Lupa, Boguslaw [University of Georgia, Athens, GA; Susanti, Dwi [Virginia Polytechnic Institute and State University (Virginia Tech); Porat, I. [University of Georgia, Athens, GA; Hooper, Sean [U.S. Department of Energy, Joint Genome Institute; Lykidis, A [U.S. Department of Energy, Joint Genome Institute; Sieprawska-Lupa, Magdalena [University of Georgia, Athens, GA; Dharmarajan, Lakshmi [Virginia Polytechnic Institute and State University (Virginia Tech); Goltsman, Eugene [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Saunders, Elizabeth H [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Mukhopadhyay, Biswarup [Virginia Polytechnic Institute and State University (Virginia Tech); Whitman, William [ORNL; Woese, Carl [University of Illinois, Urbana-Champaign; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute

    2009-01-01

    Background Methanomicrobiales is the least studied order of methanogens. While these organisms appear to be more closely related to the Methanosarcinales in ribosomal-based phylogenetic analyses, they are metabolically more similar to Class I methanogens. Methodology/Principal Findings In order to improve our understanding of this lineage, we have completely sequenced the genomes of two members of this order, Methanocorpusculum labreanum Z and Methanoculleus marisnigri JR1, and compared them with the genome of a third, Methanospirillum hungatei JF-1. Similar to Class I methanogens, Methanomicrobiales use a partial reductive citric acid cycle for 2-oxoglutarate biosynthesis, and they have the Eha energy-converting hydrogenase. In common with Methanosarcinales, Methanomicrobiales possess the Ech hydrogenase and at least some of them may couple formylmethanofuran formation and heterodisulfide reduction to transmembrane ion gradients. Uniquely, M. labreanum and M. hungatei contain hydrogenases similar to the Pyrococcus furiosus Mbh hydrogenase, and all three Methanomicrobiales have anti-sigma factor and anti-anti-sigma factor regulatory proteins not found in other methanogens. Phylogenetic analysis based on seven core proteins of methanogenesis and cofactor biosynthesis places the Methanomicrobiales equidistant from Class I methanogens and Methanosarcinales. Conclusions/Significance Our results indicate that Methanomicrobiales, rather than being similar to Class I methanogens or Methanomicrobiales, share some features of both and have some unique properties. We find that there are three distinct classes of methanogens: the Class I methanogens, the Methanomicrobiales (Class II), and the Methanosarcinales (Class III).

  12. Genomic Characterization of Methanomicrobiales Reveals Three Classes of Methanogens

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain; Ulrich, Luke E.; Lupa, Boguslaw; Susanti, Dwi; Porat, Iris; Hooper, Sean D.; Lykidis, Athanasios; Sieprawska-Lupa, Magdalena; Dharmarajan, Lakshmi; Goltsman, Eugene; Lapidus, Alla; Saunders, Elizabeth; Han, Cliff; Land, Miriam; Lucas, Susan; Mukhopadhyay, Biswarup; Whitman, William B.; Woese, Carl; Bristow, James; Kyrpides, Nikos

    2009-05-01

    Methanomicrobiales is the least studied order of methanogens. While these organisms appear to be more closely related to the Methanosarcinales in ribosomal-based phylogenetic analyses, they are metabolically more similar to Class I methanogens. In order to improve our understanding of this lineage, we have completely sequenced the genomes of two members of this order, Methanocorpusculum labreanum Z and Methanoculleus marisnigri JR1, and compared them with the genome of a third, Methanospirillum hungatei JF-1. Similar to Class I methanogens, Methanomicrobiales use a partial reductive citric acid cycle for 2-oxoglutarate biosynthesis, and they have the Eha energy-converting hydrogenase. In common with Methanosarcinales, Methanomicrobiales possess the Ech hydrogenase and at least some of them may couple formylmethanofuran formation and heterodisulfide reduction to transmembrane ion gradients. Uniquely, M. labreanum and M. hungatei contain hydrogenases similar to the Pyrococcus furiosus Mbh hydrogenase, and all three Methanomicrobiales have anti-sigma factor and anti-anti-sigma factor regulatory proteins not found in other methanogens. Phylogenetic analysis based on seven core proteins of methanogenesis and cofactor biosynthesis places the Methanomicrobiales equidistant from Class I methanogens and Methanosarcinales. Our results indicate that Methanomicrobiales, rather than being similar to Class I methanogens or Methanomicrobiales, share some features of both and have some unique properties. We find that there are three distinct classes of methanogens: the Class I methanogens, the Methanomicrobiales (Class II), and the Methanosarcinales (Class III).

  13. Comparative phylogeography and population genetics within Buteo lineatus reveals evidence of distinct evolutionary lineages

    Science.gov (United States)

    Hull, J.M.; Strobel, Bradley N.; Boal, C.W.; Hull, A.C.; Dykstra, C.R.; Irish, A.M.; Fish, A.M.; Ernest, H.B.

    2008-01-01

    Traditional subspecies classifications may suggest phylogenetic relationships that are discordant with evolutionary history and mislead evolutionary inference. To more accurately describe evolutionary relationships and inform conservation efforts, we investigated the genetic relationships and demographic histories of Buteo lineatus subspecies in eastern and western North America using 21 nuclear microsatellite loci and 375-base pairs of mitochondrial control region sequence. Frequency based analyses of mitochondrial sequence data support significant population distinction between eastern (B. l. lineatus/alleni/texanus) and western (B. l. elegans) subspecies of B. lineatus. This distinction was further supported by frequency and Bayesian analyses of the microsatellite data. We found evidence of differing demographic histories between regions; among eastern sites, mitochondrial data suggested that rapid population expansion occurred following the end of the last glacial maximum, with B. l. texanus population expansion preceding that of B. l. lineatus/alleni. No evidence of post-glacial population expansion was detected among western samples (B. l. elegans). Rather, microsatellite data suggest that the western population has experienced a recent bottleneck, presumably associated with extensive anthropogenic habitat loss during the 19th and 20th centuries. Our data indicate that eastern and western populations of B. lineatus are genetically distinct lineages, have experienced very different demographic histories, and suggest management as separate conservation units may be warranted. ?? 2008 Elsevier Inc. All rights reserved.

  14. Genomic Identification of Founding Haplotypes Reveals the History of the Selfing Species Capsella rubella

    Science.gov (United States)

    Brandvain, Yaniv; Slotte, Tanja; Hazzouri, Khaled M.; Wright, Stephen I.; Coop, Graham

    2013-01-01

    The shift from outcrossing to self-fertilization is among the most common evolutionary transitions in flowering plants. Until recently, however, a genome-wide view of this transition has been obscured by both a dearth of appropriate data and the lack of appropriate population genomic methods to interpret such data. Here, we present a novel population genomic analysis detailing the origin of the selfing species, Capsella rubella, which recently split from its outcrossing sister, Capsella grandiflora. Due to the recency of the split, much of the variation within C. rubella is also found within C. grandiflora. We can therefore identify genomic regions where two C. rubella individuals have inherited the same or different segments of ancestral diversity (i.e. founding haplotypes) present in C. rubella's founder(s). Based on this analysis, we show that C. rubella was founded by multiple individuals drawn from a diverse ancestral population closely related to extant C. grandiflora, that drift and selection have rapidly homogenized most of this ancestral variation since C. rubella's founding, and that little novel variation has accumulated within this time. Despite the extensive loss of ancestral variation, the approximately 25% of the genome for which two C. rubella individuals have inherited different founding haplotypes makes up roughly 90% of the genetic variation between them. To extend these findings, we develop a coalescent model that utilizes the inferred frequency of founding haplotypes and variation within founding haplotypes to estimate that C. rubella was founded by a potentially large number of individuals between 50 and 100 kya, and has subsequently experienced a twenty-fold reduction in its effective population size. As population genomic data from an increasing number of outcrossing/selfing pairs are generated, analyses like the one developed here will facilitate a fine-scaled view of the evolutionary and demographic impact of the transition to self

  15. The Awesome Power of Yeast Evolutionary Genetics: New Genome Sequences and Strain Resources for the Saccharomyces sensu stricto Genus.

    Science.gov (United States)

    Scannell, Devin R; Zill, Oliver A; Rokas, Antonis; Payen, Celia; Dunham, Maitreya J; Eisen, Michael B; Rine, Jasper; Johnston, Mark; Hittinger, Chris Todd

    2011-06-01

    High-quality, well-annotated genome sequences and standardized laboratory strains fuel experimental and evolutionary research. We present improved genome sequences of three species of Saccharomyces sensu stricto yeasts: S. bayanus var. uvarum (CBS 7001), S. kudriavzevii (IFO 1802(T) and ZP 591), and S. mikatae (IFO 1815(T)), and describe their comparison to the genomes of S. cerevisiae and S. paradoxus. The new sequences, derived by assembling millions of short DNA sequence reads together with previously published Sanger shotgun reads, have vastly greater long-range continuity and far fewer gaps than the previously available genome sequences. New gene predictions defined a set of 5261 protein-coding orthologs across the five most commonly studied Saccharomyces yeasts, enabling a re-examination of the tempo and mode of yeast gene evolution and improved inferences of species-specific gains and losses. To facilitate experimental investigations, we generated genetically marked, stable haploid strains for all three of these Saccharomyces species. These nearly complete genome sequences and the collection of genetically marked strains provide a valuable toolset for comparative studies of gene function, metabolism, and evolution, and render Saccharomyces sensu stricto the most experimentally tractable model genus. These resources are freely available and accessible through www.SaccharomycesSensuStricto.org.

  16. Integrating networks and comparative genomics reveals retroelement proliferation dynamics in hominid genomes

    Science.gov (United States)

    Levy, Orr; Knisbacher, Binyamin A.; Levanon, Erez Y.; Havlin, Shlomo

    2017-01-01

    Retroelements (REs) are mobile DNA sequences that multiply and spread throughout genomes by a copy-and-paste mechanism. These parasitic elements are active in diverse genomes, from yeast to humans, where they promote diversity, cause disease, and accelerate evolution. Because of their high copy number and sequence similarity, studying their activity and tracking their proliferation dynamics is a challenge. It is particularly difficult to pinpoint the few REs in a genome that are still active in the haystack of degenerate and suppressed elements. We develop a computational framework based on network theory that tracks the path of RE proliferation throughout evolution. We analyze SVA (SINE-VNTR-Alu), the youngest RE family in human genomes, to understand RE dynamics across hominids. Integrating comparative genomics and network tools enables us to track the course of SVA proliferation, identify yet unknown active communities, and detect tentative “master REs” that played key roles in SVA propagation, providing strong support for the fundamental “master gene” model of RE proliferation. The method is generic and thus can be applied to REs of any of the thousands of available genomes to identify active RE communities and master REs that were pivotal in the evolution of their host genomes. PMID:29043294

  17. Novel Insights into Tree Biology and Genome Evolution as Revealed Through Genomics.

    Science.gov (United States)

    Neale, David B; Martínez-García, Pedro J; De La Torre, Amanda R; Montanari, Sara; Wei, Xiao-Xin

    2017-04-28

    Reference genome sequences are the key to the discovery of genes and gene families that determine traits of interest. Recent progress in sequencing technologies has enabled a rapid increase in genome sequencing of tree species, allowing the dissection of complex characters of economic importance, such as fruit and wood quality and resistance to biotic and abiotic stresses. Although the number of reference genome sequences for trees lags behind those for other plant species, it is not too early to gain insight into the unique features that distinguish trees from nontree plants. Our review of the published data suggests that, although many gene families are conserved among herbaceous and tree species, some gene families, such as those involved in resistance to biotic and abiotic stresses and in the synthesis and transport of sugars, are often expanded in tree genomes. As the genomes of more tree species are sequenced, comparative genomics will further elucidate the complexity of tree genomes and how this relates to traits unique to trees.

  18. Genome sequencing and comparative genomics reveal a repertoire of putative pathogenicity genes in chilli anthracnose fungus Colletotrichum truncatum.

    Science.gov (United States)

    Rao, Soumya; Nandineni, Madhusudan R

    2017-01-01

    Colletotrichum truncatum, a major fungal phytopathogen, causes the anthracnose disease on an economically important spice crop chilli (Capsicum annuum), resulting in huge economic losses in tropical and sub-tropical countries. It follows a subcuticular intramural infection strategy on chilli with a short, asymptomatic, endophytic phase, which contrasts with the intracellular hemibiotrophic lifestyle adopted by most of the Colletotrichum species. However, little is known about the molecular determinants and the mechanism of pathogenicity in this fungus. A high quality whole genome sequence and gene annotation based on transcriptome data of an Indian isolate of C. truncatum from chilli has been obtained. Analysis of the genome sequence revealed a rich repertoire of pathogenicity genes in C. truncatum encoding secreted proteins, effectors, plant cell wall degrading enzymes, secondary metabolism associated proteins, with potential roles in the host-specific infection strategy, placing it next only to the Fusarium species. The size of genome assembly, number of predicted genes and some of the functional categories were similar to other sequenced Colletotrichum species. The comparative genomic analyses with other species and related fungi identified some unique genes and certain highly expanded gene families of CAZymes, proteases and secondary metabolism associated genes in the genome of C. truncatum. The draft genome assembly and functional annotation of potential pathogenicity genes of C. truncatum provide an important genomic resource for understanding the biology and lifestyle of this important phytopathogen and will pave the way for designing efficient disease control regimens.

  19. Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americans

    DEFF Research Database (Denmark)

    Raghavan, Maanasa; Skoglund, Pontus; Graf, Kelly E.

    2014-01-01

    The origins of the First Americans remain contentious. Although Native Americans seem to be genetically most closely related to east Asians, there is no consensus with regard to which specific Old World populations they are closest to. Here we sequence the draft genome of an approximately 24...... and Mesolithic European hunter-gatherers, and the Y chromosome of MA-1 is basal to modern-day western Eurasians and near the root of most Native American lineages. Similarly, we find autosomal evidence that MA-1 is basal to modern-day western Eurasians and genetically closely related to modern-day Native...... Americans, with no close affinity to east Asians. This suggests that populations related to contemporary western Eurasians had a more north-easterly distribution 24,000 years ago than commonly thought. Furthermore, we estimate that 14 to 38% of Native American ancestry may originate through gene flow from...

  20. Ancient European dog genomes reveal continuity since the Early Neolithic

    Science.gov (United States)

    Botigué, Laura R.; Song, Shiya; Scheu, Amelie; Gopalan, Shyamalika; Pendleton, Amanda L.; Oetjens, Matthew; Taravella, Angela M.; Seregély, Timo; Zeeb-Lanz, Andrea; Arbogast, Rose-Marie; Bobo, Dean; Daly, Kevin; Unterländer, Martina; Burger, Joachim; Kidd, Jeffrey M.; Veeramah, Krishna R.

    2017-01-01

    Europe has played a major role in dog evolution, harbouring the oldest uncontested Palaeolithic remains and having been the centre of modern dog breed creation. Here we sequence the genomes of an Early and End Neolithic dog from Germany, including a sample associated with an early European farming community. Both dogs demonstrate continuity with each other and predominantly share ancestry with modern European dogs, contradicting a previously suggested Late Neolithic population replacement. We find no genetic evidence to support the recent hypothesis proposing dual origins of dog domestication. By calibrating the mutation rate using our oldest dog, we narrow the timing of dog domestication to 20,000–40,000 years ago. Interestingly, we do not observe the extreme copy number expansion of the AMY2B gene characteristic of modern dogs that has previously been proposed as an adaptation to a starch-rich diet driven by the widespread adoption of agriculture in the Neolithic. PMID:28719574

  1. Ancient European dog genomes reveal continuity since the Early Neolithic.

    Science.gov (United States)

    Botigué, Laura R; Song, Shiya; Scheu, Amelie; Gopalan, Shyamalika; Pendleton, Amanda L; Oetjens, Matthew; Taravella, Angela M; Seregély, Timo; Zeeb-Lanz, Andrea; Arbogast, Rose-Marie; Bobo, Dean; Daly, Kevin; Unterländer, Martina; Burger, Joachim; Kidd, Jeffrey M; Veeramah, Krishna R

    2017-07-18

    Europe has played a major role in dog evolution, harbouring the oldest uncontested Palaeolithic remains and having been the centre of modern dog breed creation. Here we sequence the genomes of an Early and End Neolithic dog from Germany, including a sample associated with an early European farming community. Both dogs demonstrate continuity with each other and predominantly share ancestry with modern European dogs, contradicting a previously suggested Late Neolithic population replacement. We find no genetic evidence to support the recent hypothesis proposing dual origins of dog domestication. By calibrating the mutation rate using our oldest dog, we narrow the timing of dog domestication to 20,000-40,000 years ago. Interestingly, we do not observe the extreme copy number expansion of the AMY2B gene characteristic of modern dogs that has previously been proposed as an adaptation to a starch-rich diet driven by the widespread adoption of agriculture in the Neolithic.

  2. An Aboriginal Australian genome reveals separate human dispersals into Asia.

    Science.gov (United States)

    Rasmussen, Morten; Guo, Xiaosen; Wang, Yong; Lohmueller, Kirk E; Rasmussen, Simon; Albrechtsen, Anders; Skotte, Line; Lindgreen, Stinus; Metspalu, Mait; Jombart, Thibaut; Kivisild, Toomas; Zhai, Weiwei; Eriksson, Anders; Manica, Andrea; Orlando, Ludovic; De La Vega, Francisco M; Tridico, Silvana; Metspalu, Ene; Nielsen, Kasper; Ávila-Arcos, María C; Moreno-Mayar, J Víctor; Muller, Craig; Dortch, Joe; Gilbert, M Thomas P; Lund, Ole; Wesolowska, Agata; Karmin, Monika; Weinert, Lucy A; Wang, Bo; Li, Jun; Tai, Shuaishuai; Xiao, Fei; Hanihara, Tsunehiko; van Driem, George; Jha, Aashish R; Ricaut, François-Xavier; de Knijff, Peter; Migliano, Andrea B; Gallego Romero, Irene; Kristiansen, Karsten; Lambert, David M; Brunak, Søren; Forster, Peter; Brinkmann, Bernd; Nehlich, Olaf; Bunce, Michael; Richards, Michael; Gupta, Ramneek; Bustamante, Carlos D; Krogh, Anders; Foley, Robert A; Lahr, Marta M; Balloux, Francois; Sicheritz-Pontén, Thomas; Villems, Richard; Nielsen, Rasmus; Wang, Jun; Willerslev, Eske

    2011-10-07

    We present an Aboriginal Australian genomic sequence obtained from a 100-year-old lock of hair donated by an Aboriginal man from southern Western Australia in the early 20th century. We detect no evidence of European admixture and estimate contamination levels to be below 0.5%. We show that Aboriginal Australians are descendants of an early human dispersal into eastern Asia, possibly 62,000 to 75,000 years ago. This dispersal is separate from the one that gave rise to modern Asians 25,000 to 38,000 years ago. We also find evidence of gene flow between populations of the two dispersal waves prior to the divergence of Native Americans from modern Asian ancestors. Our findings support the hypothesis that present-day Aboriginal Australians descend from the earliest humans to occupy Australia, likely representing one of the oldest continuous populations outside Africa.

  3. The complete mitochondrial genome of dhole Cuon alpinus: phylogenetic analysis and dating evolutionary divergence within Canidae.

    Science.gov (United States)

    Zhang, Honghai; Chen, Lei

    2011-03-01

    The dhole (Cuon alpinus) is the only existent species in the genus Cuon (Carnivora: Canidae). In the present study, the complete mitochon