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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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| Pepin, Jean-francois; Benabdelmouna, Abdellah; Degremont, Lionel; Guesdon, Stephane; Le Moine, Olivier; Morga, Benjamin; Bierne, Nicolas; Travers, Marie-agnes; Robert, Stephane; Soletchnik, Patrick. |
| Depuis 2014, des épisodes de mortalité anormale affectent les cheptels mytilicoles tant adultes que juvéniles. Dès l’année 2015, une première année d’étude a été réalisée au travers de l’action MORBLEU (Mortalité des moules Bleues). Elle a été menée dans les Pertuis charentais et la baie de Bourgneuf. Dans ce même contexte, elle a été reconduite en 2016 afin de poursuivre l’analyse des données collectées en 2015, renouveler une campagne d’étude et d’observation in situ, formuler des hypothèses autour de facteurs favorisants ces épisodes de mortalité de moules, développer des essais permettant de tester ces hypothèses dans le futur et produire des lots de moules pour ces essais et pour caractériser le potentiel adaptatif des animaux face aux épisodes de... |
| Tipo: Text |
Palavras-chave: Moules; Mytilus edulis; Facteurs environnementaux; Mortalité; Equilibre microbien; Populations; Qualité cytogénétique; Anomalies hémocytaires; Expression de gènes; Physiologie. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00391/50288/50978.pdf |
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| Pepin, Jean-francois; Benabdelmouna, Abdellah; Bierne, Nicolas; Costes, Louis; Degremont, Lionel; Garcia, Celine; Guesdon, Stephane; Lamy, Jean-baptiste; Le Moine, Olivier; Morga, Benjamin; Normand, Julien; Robert, Stephane; Saunier, Alice; Soletchnik, Patrick; Travers, Marie-agnes. |
| Depuis 2014, des épisodes de mortalité anormale affectent les cheptels mytilicoles tant adultes que juvéniles. Dès l’année 2015, une étude spécifique cofinancée par la DPMA et réalisée par l’Ifremer a été initiée, l’action de recherche MORBLEU (Mortalité des moules Bleues). Les années 2015 et 2016 ont permis de dégager des éléments de connaissance et des pistes relatifs aux facteurs biotiques et abiotiques qui semblent intervenir dans le phénomène de hausse de mortalité des moules depuis 2014. Pour l’année 2017, les trois objectifs principaux étaient de : i) poursuivre la description du phénomène de mortalité ainsi que le contexte environnemental associé en effectuant une nouvelle campagne d’études et d’observations in situ, ii) tester des hypothèses... |
| Tipo: Text |
Palavras-chave: Moules; Mytilus edulis; Mortalité; Statut cytogénétique; Anomalies génomiques; Populations; Facteurs environnementaux; Ecologie microbienne. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00503/61503/65337.pdf |
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| Pepin, Jean-francois; Benabdelmouna, Abdellah; Bierne, Nicolas; Chasselin, Leo; Degremont, Lionel; Guesdon, Stephane; Lamy, Jean-baptiste; Le Moine, Olivier; Normand, Julien; Robert, Stephane; Soletchnik, Patrick. |
| Depuis 2014, des épisodes de mortalité anormale affectent les cheptels mytilicoles tant adultes que juvéniles. Dès l’année 2015, une étude spécifique cofinancée par la DPMA et réalisée par l’Ifremer a été initiée, l’action de recherche MORBLEU (Mortalité des moules Bleues). Les années 2015- 2017 ont permis de dégager des éléments de connaissance et des pistes relatifs aux facteurs biotiques et abiotiques qui semblent intervenir dans le phénomène de hausse de mortalité des moules depuis 2014. Pour l’année 2018, les actions d’observation et de suivis du milieu et des moules ont été fortement réduites et trois axes principaux ont été poursuivis : i) l’étude de la relation entre l’évolution des équilibres microbiens planctoniques et l’apparition de mortalités... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70056/67999.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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| 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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| Simon, Alexis; Arbiol, Christine; Nielsen, Einar Eg; Couteau, Jérôme; Sussarellu, Rossana; Burgeot, Thierry; Bernard, Ismaël; Coolen, Joop W. P.; Lamy, Jean-baptiste; Robert, Stephane; Skazina, Maria; Strelkov, Petr; Queiroga, Henrique; Cancio, Ibon; Welch, John J.; Viard, Frédérique; Bierne, Nicolas. |
| Human‐mediated transport creates secondary contacts between genetically differentiated lineages, bringing new opportunities for gene exchange. When similar introductions occur in different places, they provide informally replicated experiments for studying hybridisation. We here examined 4,279 Mytilus mussels, sampled in Europe and genotyped with 77 ancestry‐informative markers. We identified a type of introduced mussels, called “dock mussels,” associated with port habitats and displaying a particular genetic signal of admixture between M. edulis and the Mediterranean lineage of M. galloprovincialis. These mussels exhibit similarities in their ancestry compositions, regardless of the local native genetic backgrounds and the distance separating colonised... |
| Tipo: Text |
Palavras-chave: Admixture; Bentho-pelagic species; Biological introductions; Clines; Ports; Secondary contact. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00594/70600/68791.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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| Duranton, Maud; Allal, Francois; Fraisse, Christelle; Bierne, Nicolas; Bonhomme, Francois; Gagnaire, Pierre-alexandre. |
| Speciation is a complex process that leads to the progressive establishment of reproductive isolation barriers between diverging populations. Genome-wide comparisons between closely related species have revealed the existence of heterogeneous divergence patterns, dominated by genomic islands of increased divergence supposed to contain reproductive isolation loci. However, this divergence landscape only provides a static picture of the dynamic process of speciation, during which confounding mechanisms unrelated to speciation can interfere. Here we use haplotype-resolved whole-genome sequences to identify the mechanisms responsible for the formation of genomic islands between Atlantic and Mediterranean sea bass lineages. Local ancestry patterns show that... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00446/55750/57409.pdf |
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| Gagnaire, Pierre-alexandre; Broquet, Thomas; Aurelle, Didier; Viard, Frederique; Souissi, Ahmed; Bonhomme, Francois; Arnaud-haond, Sophie; Bierne, Nicolas. |
| Estimating the rate of exchange of individuals among populations is a central concern to evolutionary ecology and its applications to conservation and management. For instance, the efficiency of protected areas in sustaining locally endangered populations and ecosystems depends on reserve network connectivity. The population genetics theory offers a powerful framework for estimating dispersal distances and migration rates from molecular data. In the marine realm, however, decades of molecular studies have met limited success in inferring genetic connectivity, due to the frequent lack of spatial genetic structure in species exhibiting high fecundity and dispersal capabilities. This is especially true within biogeographic regions bounded by well-known... |
| Tipo: Text |
Palavras-chave: Connectivity; Gene flow; Marine conservation; Population genomics; Population structure. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38592/37120.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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| Rey, Carine; Darnaude, Audrey; Ferraton, Franck; Guinand, Bruno; Bonhomme, François; Bierne, Nicolas; Gagnaire, Pierre-alexandre. |
| Understanding the genetic underpinnings of fitness trade-o s across spatially variable environments remains a major challenge in evolutionary biology. In Mediterranean gilthead sea bream, first-year juveniles use various marine and brackish lagoon nursery habitats characterized by a trade-o between food availability and environmental disturbance. Phenotypic di erences among juveniles foraging in di erent habitats rapidly appear after larval settlement, but the relative role of local selection and plasticity in phenotypic variation remains unclear. Here, we combine phenotypic and genetic data to address this question. We first report correlations of opposite signs between growth and condition depending on juvenile habitat type. Then, we use single... |
| Tipo: Text |
Palavras-chave: Antagonistic pleiotropy; Habitat association; Fitness trade-off; Juvenile growth; Polygenic scores; RAD-sequencing; Spatially varying selection. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00622/73370/72560.pdf |
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| Registros recuperados: 33 | |
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