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Registros recuperados: 33 | |
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Bierne, Nicolas; Bezuart, Ivan; Vonau, Vincent; Bonhomme, François; Bedier, Edouard. |
Correlation between DNA microsatellite heterozygosity and growth rate was investigated in two hatchery-propagated stocks of the shrimp Penaeus stylirostris, which had been genetically isolated from wild founders for 17 generations, and from each other for five more generations. presumed demographic history of these populations suggested that they were maintained at small effective population sizes. and this was confirmed by significant changes in allelic frequencies between the two stocks. Despite a small sample size (n = 60) and a small number of loci screened, a significant positive correlation was detected between microsatellite tri-locus heterozygosity and growth rate in one of the two stocks (r = 0.3, P = 0.02). In the other stock (n = 48), the... |
Tipo: Text |
Palavras-chave: Penaeus stylirostris; Heterozygosity; Marker associated heterosis; Inbreeding depression; Microsatellites. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-753.pdf |
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Bierne, Nicolas; David, Pierre; Langlade, Aime; Bonhomme, F. |
Maintaining the integrity of differentiated genomes in marine organisms needs efficient isolation mechanisms, because planktonic larval dispersion provides contacts between taxa. Habitat specialisation is interesting in this respect, because it can both prevent interspecific crosses (each taxon reproduces in its own habitat) and eliminate hybrids (typically less fit than a parental taxon in each habitat). The contact zone between smooth-shelled mussels Mytilus edulis and M. galloprovincialis in Europe is a good example, as allozyme genotypes typical of both taxa seem to segregate into different habitats. However, allozymes may be selected directly and it is not known whether the same pattern can be extended to the whole genome. Here, we used 6 presumably... |
Tipo: Text |
Palavras-chave: Habitat specialisation; Hybrid zone; Introgression; Mytilus edulis; Mytilus galloprovincialis. |
Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00000/10228/7597.pdf |
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Bierne, Nicolas; Eyre Walker, A. |
A strong negative correlation between the rate of amino-acid substitution and codon usage bias in Drosophila has been attributed to interference between positive selection at nonsynonymous sites and weak selection on codon usage. To further explore this possibility we have investigated polymorphism and divergence at three kinds of sites: synonymous, nonsynonymous and intronic in relation to codon bias in D. melanogaster and D. simulans. We confirmed that protein evolution is one of the main explicative parameters for interlocus codon bias variation (r(2) similar to 40%). However, intron or synonymous diversities, which could have been expected to be good indicators of local interference [here defined as the additional increase of drift due to selection on... |
Tipo: Text |
Palavras-chave: Substitution rate; Selective constraints; Linkage; Hill Robertson interference; GC content; Drosophila; Diversity; Codon usage. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-4221.pdf |
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Bierne, Nicolas; Boudry, Pierre; Lapegue, Sylvie; Bonhomme, Francois; Faure, M; Sauvage, Christopher; Moraga, D; Boutet, Isabelle; David, Elise; Jollivet, Didier; Tanguy, Arnaud; Faure, Baptiste; David, Patrice. |
For a long time, population geneticists have had to content themselves with analysing neutral markers to infer selection processes indirectly. The recent improvement of sequencing tools now enables them to analyse the variations of a large number of genes and therefore to spot the genes, or the amino acids, which are under the direct influence of the selection (Yang & Bielawski, 2000). In order to analyse the selection processes acting on the mutations and discriminate the different factors acting on their evolution (genetic selection or drift), it is essential to compare polymorphism data between genomes of the same species/population and divergence data between species/populations (Kimura, 1983). Recently, polymorphism data has become available for a... |
Tipo: Text |
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Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/rapport-6489.pdf |
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Sauvage, Christopher; Lapegue, Sylvie; Bierne, Nicolas; Boudry, Pierre. |
Summer mortalities of the Pacific cupped oyster Crassostrea gigas have been described in the literature for decades. One solution to overcome this problem would be to select animals more tolerant to summer mortalities, as this trait was shown to be highly heritable (Degrémont, 2003). The identification of markers associated to the resistance would allow to better understand this complex phenomenon and, eventually to establish markers assisted selection. Recently, two moderately dense genetic linkage maps have been established in the Pacific oyster based on microsatellites and AFLP markers (Hubert and Hedgecock, 2004; Li and Guo, 2004). In this context, the development and mapping of SNPs will increase the density of the linkage map and consequently the... |
Tipo: Text |
Palavras-chave: QTLs analyses; Summer mortaliy; Genetic; SNPs; Crassostrea gigas; Oyster. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-3351.pdf |
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Masseret, Estelle; Bierne, Nicolas; Chevret, Pascale; Roumagnac, Marie; Bec, Béatrice; Laugier, Thierry; Collos, Yves; Vaquer, Andre. |
Coastal lagoons are morphologically and ecologically complex ecosystems, subject to constantly changing environmental conditions generally of much greater magnitude than it is recorded in the open sea. Due to their transitional nature, they usually display a number of specific features (ie. high nutrient concentrations, light spectral quality, salinity range) which are potentially influencing strategies of adaptation of photosynthetic microorganisms. The unicellular cyanobacteria Synechococcus is a major component of marine and freshwater picophytoplankton. Its genetic diversity is well documented for these ecosystems, but knowledge about biodiversity and distribution of this genus in transitional waters remains scarce. The phylogenetic analysis of a... |
Tipo: Text |
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Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00011/12198/8960.pdf |
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Bierne, Nicolas; Tanguy, A; Faure, Michel; Faure, B; David, E; Boutet, I; Boon, E; Quere, N; Plouviez, S; Kemppainen, P; Jollivet, D; Moraga, D; Boudry, Pierre; David, P. |
We describe a simple protocol to reduce the number of cloning reactions of nuclear DNA sequences in population genetic studies of diploid organisms. Cloning is a necessary step to obtain correct haplotypes in such organisms, and, while traditional methods are efficient at cloning together many genes of a single individual, population geneticists rather need to clone the same locus in many individuals. Our method consists of marking individual sequences during the polymerase chain reaction (PCR) using 5'-tailed primers with small polynucleotide tags. PCR products are mixed together before the cloning reaction and clones are sequenced with universal plasmid primers. The individual from which a sequence comes from is identified by the tag sequences upstream... |
Tipo: Text |
Palavras-chave: Sequence; Population genetics; High throughput allele recognition; DNA polymorphism. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-4222.pdf |
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Rohfritsch, Audrey; Bierne, Nicolas; Boudry, Pierre; Heurtebise, Serge; Lapegue, Sylvie. |
Originating from the north eastern Asia, Crassostrea gigas has been introduced and translocated, mainly for aquaculture purpose, into several European countries (from Norway to Portugal and in the Mediterranean Sea) (1). Although highly variable, the invasiveness pattern of C. gigas has been demonstrated in several countries and therefore considered as a pest or a noxious species in those areas (2 and 3). Our project aims at identifying the characteristics of such a flourishing species: can its success be explained by chance and/or global warming only or does it exhibit a more important potential of adaptation than other species? Therefore we developed a population genomics approach, known as "genome scan". It corresponds to the study of numerous loci... |
Tipo: Text |
Palavras-chave: Pacific oyster; Invasive; AFLP; Genome scan; Crassostrea gigas. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/acte-4542.pdf |
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Rohfritsch, Audrey; Bierne, Nicolas; Boudry, Pierre; Heurtebise, Serge; Lapegue, Sylvie. |
Originating from the north eastern Asia, Crassostrea gigas has been introduced and translocated, mainly for aquaculture purpose, into several European countries (from Norway to Portugal and in the Mediterranean Sea) (1). Although highly variable, the invasiveness pattern of C. gigas has been demonstrated in several countries and therefore considered as a pest or a noxious species in those areas (2 and 3).Our project aims at identifying the characteristics of such a flourishing species: can its success be explained by chance and/or global warming only or does it exhibit a more important potential of adaptation than other species? Therefore we developed a population genomics approach, known as "genome scan". It corresponds to the study of numerous loci... |
Tipo: Text |
Palavras-chave: Invasive; AFLP; Genome scan; Crassotrea gigas; Pacific oyster. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/acte-4805.pdf |
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Harrang, Estelle; Bierne, Nicolas; Heurtebise, Serge; Morga, Benjamin; Lapegue, Sylvie. |
L'huître plate européenne Ostrea edulis a connu une période faste dans l'aquaculture jusqu'à la fin des années 1960, lorsque deux parasites, Marteilia refringens (1969) et Bonamia ostreae (1979), ont successivement décimé les bancs naturels de cette espèce endémique, déjà affaiblis par la sur-exploitation de ses gisements. Historiquement présente sur toute la côte européenne, de la Mer du Nord à la Mer Méditerranée, en passant par l'Océan Atlantique, la Mer Adriatique et la Mer Noire, les bancs naturels de cette espèce sont devenus très localisés, laissant penser à des phénomènes d'adaptation locale de l'huître vis à vis de son environnement biotique et abiotique. La diversité et la structuration génétique de plusieurs populations de l'espèce, à l'échelle... |
Tipo: Text |
Palavras-chave: Huître plate; Ostrea edulis; Génétique des populations; Sélection Génétique. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12547/9417.pdf |
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Rohfritsch, Audrey; Bierne, Nicolas; Boudry, Pierre; Heurtebise, Serge; Cornette, Florence; Lapegue, Sylvie. |
Originaire du nord de l’Asie, l'huître creuse, Crassostrea gigas, a été introduite et transférée, principalement pour l’aquaculture, dans plusieurs pays européens depuis le début des années 1970. Le caractère invasif de cette espèce a été observé au cours de la dernière décennie dans plusieurs pays et elle a même été considérée comme une espèce nuisible dans certaines régions, telles que la mer de Wadden. Dans le cadre du projet HiFlo, soutenu par l’ANR, nous avons pour objectif d'identifier les caractéristiques d'une telle espèce florissante: son succès peut-il être expliqué par le hasard des opportunités (expansion de leur niche écologique) ou est-il lié à des processus évolutifs, ce qui impliquerait une adaptation génétique de l'espèce à de nouvelles... |
Tipo: Text |
Palavras-chave: Huîtres; Crassostrea gigas; Génétique; Génétique des populations. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12552/9418.pdf |
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Harrang, Estelle; Lapegue, Sylvie; Morga, Benjamin; Bierne, Nicolas. |
Marine bivalves show among the greatest allozyme diversity ever reported in Eukaryotes, putting them historically at the heart of the neutralist-selectionist controversy on the maintenance of genetic variation. Although it is now acknowledged that this high diversity is most probably a simple consequence of a large population size, convincing support for this explanation would require a rigorous assessment of the silent nucleotide diversity in natural populations of marine bivalves, which has not yet been done. This study investigated DNA sequence polymorphism in a set of 37 nuclear loci in wild samples of the flat oyster Ostrea edulis. Silent diversity was found to be only moderate (0.7%), and there was no departure from demographic equilibrium under the... |
Tipo: Text |
Palavras-chave: Nucleotide; Polymorphism; Marine bivalve; Deleterious; Mutations; Genetic load; Ostrea edulis. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00125/23610/21444.pdf |
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Rohfritsch, Audrey; Bierne, Nicolas; Boudry, Pierre; Heurtebise, Serge; Cornette, Florence; Lapegue, Sylvie. |
Crassostrea gigas originated from the Pacific coast of Asia, but was introduced into several European countries in the early 1970s. Natural populations have now spread across the length of the western seaboard of Europe. To elucidate the demographic and selective processes at play during this rapid expansion, genome-scan analysis was performed on different populations. High diversities and low differentiation were observed overall, but significant genetic differentiation was found among newly established populations and between the newly established northern group and a nearly panmictic group composed of southern European populations and a population from Japan. Loss of genetic diversity was also seen in the north, likely caused by founder events during... |
Tipo: Text |
Palavras-chave: AFLPs; Crassostrea gigas; Genome scan; Invasive species; Microsatellites; SNPs. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00149/25977/24070.pdf |
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Sussarellu, Rossana; Huvet, Arnaud; Lelong, Christophe; Pernet, Fabrice; Quillen, Virgile; Lapegue, Sylvie; Cornette, Florence; Jensen, Lasse Fast; Bierne, Nicolas; Boudry, Pierre. |
Originating from north-eastern Asia, the Pacific oyster Crassostrea gigas has been introduced, mainly for aquaculture purpose, into a large number of countries. Although highly variable, its invasive nature has been reported in an increasing number of coastal areas, notably. Northern Europe. We set up a common garden experiment based on the comparison of progenies of Pacific oysters sampled in France, where populations settled since the introduction of the species in the 70’s, and Denmark, where established populations were observed since the beginning of 90s. Pure and hybrid progenies, resulting from crosses within and between adults sampled in both populations, were studied for their sex-ratio, condition index, transcriptomics, and biochemical parameters |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00167/27815/26008.pdf |
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Gagnaire, Pierre-alexandre; Cornette, Florence; Heurtebise, Serge; Auge, M. T.; Bierne, Nicolas; Lapegue, Sylvie. |
The cupped oysters Crassostrea angulata and Crassostrea gigas have been sequentially introduced in Europe from their native Pacific area for aquaculture purposes. Ongoing viral epidemic disease is responsible for large losses in oyster aquaculture production throughout Europe. In parallel with current efforts in developing selection programs for disease resistance, it becomes critically important to characterize genetic diversity patterns in both native and introduced areas. With the advent of next generation sequencing techniques, the power to resolve the fine-scale genetic structure at a genome-wide scale opens to new perspectives towards genetic resource management. Here, we present a genome-wide screen of genetic variation that combines SNP genotyping... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00167/27816/26009.pdf |
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Plouviez, Sophie; Faure, Baptiste; Le Guen, Dominique; Lallier, Francois; Bierne, Nicolas; Jollivet, Didier. |
Comparative phylogeography of deep-sea hydrothermal vent species has uncovered several genetic breaks between populations inhabiting northern and southern latitudes of the East Pacific Rise. However, the geographic width and position of genetic clines are variable among species. In this report, we further characterize the position and strength of barriers to gene flow between populations of the deep-sea vent mussel Bathymodiolus thermophilus. Eight allozyme loci and DNA sequences of four nuclear genes were added to previously published sequences of the cytochrome c oxidase subunit I gene. Our data confirm the presence of two barriers to gene flow, one located at the Easter Microplate (between 21 degrees 33'S and 31 degrees S) recently described as a hybrid... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00185/29622/28006.pdf |
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Registros recuperados: 33 | |
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