Consulta: creatorFacets:"Sauvage, Christopher"
Registros recuperados: 22
Data/hora: 13/06/2024 05:58:02

Generation and analysis of a 29,745 unique Expressed Sequence Tags from the Pacific oyster (Crassostrea gigas) assembled into a publicly accessible database: the GigasDatabase
Provedor de dados: 5
Autores: Fleury, Elodie; Huvet, Arnaud; Lelong, Christophe; De Lorgeril, Julien; Boulo, Viviane; Gueguen, Yannick; Bachere, Evelyne; Tanguy, Arnaud; Moraga, Dario; Fabioux, Caroline; Lindeque, Penelope; Shaw, Jenny; Reinhardt, Richard; Prunet, Patrick; Davey, Grace; Lapegue, Sylvie; Sauvage, Christopher; Corporeau, Charlotte; Moal, Jeanne; Gavory, Frederick; Wincker, Patrick; Moreews, Francois; Klopp, Christophe; Mathieu, Michel; Boudry, Pierre; Favrel, Pascal.
Background: Although bivalves are among the most-studied marine organisms because of their ecological role and economic importance, very little information is available on the genome sequences of oyster species. This report documents three large-scale cDNA sequencing projects for the Pacific oyster Crassostrea gigas initiated to provide a large number of expressed sequence tags that were subsequently compiled in a publicly accessible database. This resource allowed for the identification of a large number of transcripts and provides valuable information for ongoing investigations of tissue-specific and stimulus-dependant gene expression patterns. These data are crucial for constructing comprehensive DNA microarrays, identifying single nucleotide...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6770.pdf

Conséquences génétiques de la production de larves d'huîtres en écloserie : étude des processus de dérive et de sélection
Provedor de dados: 5
Autores: Taris, Nicolas; Sauvage, Christopher; Batista, Frederico; Baron, Sophie; Ernande, Bruno; Haffray, Pierrick; Boudry, Pierre.
Previous studies have shown heritable variation in larval developmental traits in the Pacific oyster Crassostrea gigas. In order to study the genetic consequences of production of oyster larvae in hatcheries, two factors, specific to hatcheries, were examined: the effect of discarding the smallest larvae (i.e. culling) and the effect of temperature (20°C versus 26°C). A mixed-family approach was used in order to infer the genetic composition of larval populations and family assignment, limiting possible environmental bias and allowing the study of a relatively large number of families using a limited number of larval tanks. Our results show that three multiplexed highly polymorphic microsatellite markers are a powerful tool for family assignment and,...
Tipo: Text
Palavras-chave: Hatchery; Genetic diversity; Selection domestication; Larvae; Crassostrea gigas; Ecloserie; Diversité génétique; Sélection domestication; Larve; Crassostrea gigas.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-1505.pdf

A combined microsatellite multiplexing and boiling DNA extraction method for high-throughput parentage analyses in the Pacific oyster (Crassostrea gigas)
Provedor de dados: 5
Autores: Taris, Nicolas; Baron, S; Sharbel, Tim; Sauvage, Christopher; Boudry, Pierre.
The analysis of parentage using microsatellite markers is of increasing importance, notably in aquaculture genetic research where communal rearing of mixed families can be used to reduce unwanted environmental variance. We present here an optimization of parental genotype assessment for larvae or adults of the Pacific oyster, Crassostrea gigas, using a multiplex system of three microsatellite loci. In conjunction with a simple DNA extraction protocol, this method enables high throughput analyses of parentage in C. gigas. Using this method, we successfully determined the parentage of 93% (1224 out of 1318) of the progeny in a factorial cross between 3 females and 10 males. The inability to genotype the remaining 7% was due to DNA degradation of larvae...
Tipo: Text
Palavras-chave: Oysters; Aquaculture; Parental assignment; High throughput; Larval DNA extraction; Multiplex.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-1814.pdf

Domestication en phase larvaire chez l'huître creuse Crassostrea gigas. Effets sélectifs des conditions environnementales appliquées en écloseries sur la diversité génétique
Provedor de dados: 5
Autores: Sauvage, Christopher.
L'huître creuse Crassostrea gigas est, aujourd'hui, la première espèce ostréicole française avec une production de 140000 tonnes par an. Parallèlement au recrutement naturel, les écloseries produisent aujourd'hui 20% du naissain mis en élevage. Cette production est réalisée dans des conditions assurant une productivité maximale (température supérieure à 25°C, ration alimentaire optimale et tamisage sélectif). Peu de travaux se sont intéressés à l'impact génétique de ces pratiques d'élevage intensif au stade larvaire. Notre étude porte sur l'effet de la température appliquée lors de l'élevage larvaire sur la croissance et la survie et leurs composantes génétiques. Un croisement factoriel de 4 femelles et 12 mâles a été réalisé, en choisissant les géniteurs...
Tipo: Text
Palavras-chave: Crassostrea gigas; Ecloseries; Croissance; Survie; Température; Microsatellites; Larves; Sélection.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/00033/14418/11713.pdf

Ostreid herpes virus 1 infection in families of the Pacific oyster, Crassostrea gigas, during a summer mortality outbreak: Differences in viral DNA detection and quantification using real-time PCR
Provedor de dados: 5
Autores: Sauvage, Christopher; Pepin, Jean-francois; Lapegue, Sylvie; Boudry, Pierre; Renault, Tristan.
Ostreid herpes virus 1 (OsHV-1) infections, notably reported in Europe and the USA, are closely associated with significant mortalities of the Pacific oyster, Crassostrea gigas, especially during its early stages of life. In summer 2006, we monitored mortality by strict daily verification of three full-sib families of oysters reared under common conditions. We quantified OsHV-1 using real-time PCR in dead and living individuals during and after a mortality event. Mortality events were severe and brief, but significantly different between tested families (cumulative mortality ranging from 1.2 to 49%). Real-time PCR assays revealed different viral DNA loads in dead individuals from different families (P &lt; 0.001). Moreover, the mean level of infection...
Tipo: Text
Palavras-chave: Viral DNA quantification; Real time PCR; OsHV 1; Mortality; Crassostrea gigas.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6265.pdf

Mapping QTL for resistance to summer mortality in the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Sauvage, Christopher; Heurtebise, Serge; De Koning, D.; Haley, Chris; Boudry, Pierre; Lapegue, Sylvie.
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). Such selective breeding would strongly benefit from the identification of markers associated to the resistance to allow the development of markers assisted selection. Recently, a set of a new kinds of markers (SNPs) have been developed in the Pacific oyster. These markers were identified and characterized in several genes involved in the immune response and energetic pathways (Sauvage, 2007). In this context, the mapping of SNPs, of 16 new EST-SSR based markers and of...
Tipo: Text
Palavras-chave: Mortality; Genetic; Crassostrea gigas; Pacific oyster; Mapping QTL.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/acte-3504.pdf

Single Nucleotide polymorphisms and their relationship to codon usage bias in the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Sauvage, Christopher; Bierne, N; Lapegue, Sylvie; Boudry, Pierre.
DNA sequence polymorphism and codon usage bias were investigated in a set of 41 nuclear loci in the Pacific oyster Crassostrea gigas. Our results revealed a very high level of DNA polymorphism in oysters, in the order of magnitude of the highest levels reported in animals to date. A total of 290 single nucleotide polymorphisms (SNPs) were detected, 76 of which being localised in exons and 214 in non-coding regions. Average density of SNPs was estimated to be one SNP every 60 bp in coding regions and one every 40 bp in non-coding regions. Non-synonymous substitutions contributed substantially to the polymorphism observed in coding regions. The non-synonymous to silent diversity ratio was 0.16 on average, which is fairly higher to the ratio reported in other...
Tipo: Text
Palavras-chave: Crassostrea gigas; Codon bias; Genetic diversity; SNP.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3417.pdf

Development of a new diagnostic tool (Mini-Array) for ostreid Herpesvrus 1 (OsHV-1) detection in the Pacific oyster Crassostre gigas
Provedor de dados: 5
Autores: Varsamos, S.; Pepin, Jean-francois; Sauvage, Christopher; Renault, Tristan.
OsHV-1 was the first herpesvirus to be identified in an invertebrate host and is associated to mortalities in the Pacific oyster (Crassostrea gigas) and other economically important bivalve species. Infections due to OsHV-1 are frequently reported and cause high mortality rates in larvae and spat of C. gigas. Detection of this pathogen is usually performed by PCR and/or in situ hybridization. This presentation will focus on the development of a new molecular diagnostic tool for OsHV-1 (and OsHV-1 variant 1) detection: the mini-array. This detection system, which allows multiple pathogens detection, combines viral DNA amplification by PCR and a specific hybridisation on a nylon membrane, revealed by a colorimetric reaction (DNA chip). Multiplex PCR involves...
Tipo: Text
Palavras-chave: Diagnostic; Crassotrea gigas; Oyster; Detection; Herpesviridae; OsHV 1.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3652.pdf

Impact génétique de la production intensive d'huîtres en écloserie : processus de dérive et de sélection liés aux pratiques d'élevage larvaire
Provedor de dados: 5
Autores: Taris, Nicolas; Sauvage, Christopher; Boudry, Pierre.
Oysters, like many other marine bivalves, are characterized by high fertility and low survival rates during the precocious stages. Hatchery reproduction, realised in very different conditions than in their natural habitat (density, food, temperature, etc.), tends to optimize the production of larvae and juveniles. As a consequence, slow growing larvae are systematically culled. Previous results suggest the existence of a genetic variability linked to precocious development. Our approach consists in studying the evolutionary process (genetic drift and selection) linked with hatchery reproduction. Thanks to microsatellite markers enabling us to analyse the relatedness in "mixed" cultivated families, we studied the variability of breeding success in...
Tipo: Text
Palavras-chave: Crassostrea gigas; Huîtres; Marqueurs microsatellites; Reproduction; Sélection; Dérive génétique; Variabilité génétique; Génétique.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/acte-3481.pdf

QTL for resistance to summer mortality and OsHV-1 load in the Pacific oyster (Crassostrea gigas)
Provedor de dados: 5
Autores: Sauvage, Christopher; Boudry, Pierre; De Koning, D. -j.; Haley, C. S.; Heurtebise, Serge; Lapegue, Sylvie.
P&gt;Summer mortality is a phenomenon severely affecting the aquaculture production of the Pacific oyster (Crassostrea gigas). Although its causal factors are complex, resistance to mortality has been described as a highly heritable trait, and several pathogens including the virus Ostreid Herpes virus type 1 (OsHV-1) have been associated with this phenomenon. A QTL analysis for survival of summer mortality and OsHV-1 load, estimated using real-time PCR, was performed using five F-2 full-sib families resulting from a divergent selection experiment for resistance to summer mortality. A consensus linkage map was built using 29 SNPs and 51 microsatellite markers. Five significant QTL were identified and assigned to linkage groups V, VI, VII and IX. Analysis of...
Tipo: Text
Palavras-chave: Crassostrea gigas; Herpes virus; Pacific oyster; QTL mapping; Summer mortality.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00011/12241/9063.pdf

Identification and characterization of 18 novel polymorphic microsatellite makers derived from expressed sequence tags in the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Sauvage, Christopher; Boudry, Pierre; Lapegue, Sylvie.
We report the development of 18 new polymorphic microsatellite DNA markers derived from Crassostrea gigas expressed sequences tags. Genotyping of 48 wild adult oysters sampled from Marennes-OlEron bay (France) revealed 12 to 48 alleles per locus. Observed and expected heterozygosity levels ranged from 0.64 to 1 and from 0.77 to 0.97, respectively. The development of these new markers creates a useful complementary tool for population genetics studies, parentage analysis and mapping in Pacific oyster, a species of major aquacultural and ecological importance.
Tipo: Text
Palavras-chave: Pacific oyster; Null alleles; EST SSR markers; Crassostrea gigas.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6419.pdf

Développement de marqueurs moléculaires liés à la résistance à la mortalité estivale chez l'huître creuse Crassostrea gigas - Approche QTL
Provedor de dados: 5
Autores: Sauvage, Christopher.
The Pacific oyster Crassostrea gigas is the most cultivated marine species in the world (4.2 million tonnes for a turnover of 3.5 billion US dollars according to the FAO 2005). Flat oyster culture is one of the components of the French economic activity. However, for more than 15 years, farms have had to face some summer mortality episodes (30 %-60 %), that could jeopardize European mollusc culture competitivity. More than the economical importance of C. gigas, which justifies a great research effort, oysters constitute a study model of the complex physiological and genetic basis (i.e. growth, reproduction, and survival) strongly correlated to the oyster's response to different environmental conditions. One of the considered solutions is the selection of...
Tipo: Text
Palavras-chave: Crassostrea gigas; Huître; Microsatellite; SNP (Single Nucleotide Polymorphism); QTL (Quantitative Trait Locus); Phénotype; Génotype; Cartographie; Marqueurs moléculaires; Sélection Génétique; Génétique.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-4544.pdf

Recent advances in EST sequencing in Crassostrea gigas: towards the sequencing of the Pacific oyster genome
Provedor de dados: 5
Autores: Boudry, Pierre; Huvet, Arnaud; Lapegue, Sylvie; Sauvage, Christopher; Tanguy, A.; Moraga, D.; Goostrey, A.; Prunet, P.; Boulo, Viviane; Gueguen, Y.; Moal, Jeanne; Fleury, Elodie; Samain, Jean-francois; Mathieu, M.; Favrel, P.
Rationale for EST and genome sequencing of the Pacific oyster: • its membership of the Lophotrochozoa, an little studied branch of the Eukaryotes, • its worldwide aquacultural importance (4.2 million metric tons, worth 3.5 billion US dollars), • its high fecundity, with concomitantly high DNA polymorphism, • its use as a biosensor of coastal pollution. In 2004, an international community of biologists, the Oyster Genome Consortium (OGC) led by D. Hedgecock (University of Southern California) and uniting 70 participants from 10 countries, first presented the Pacific oyster Crassostrea gigas as a genome-sequencing candidate to Joint Genome Institute (JGI, USA) (Hedgecock et al., 2005). Besides this project (that remains to be accepted), several EST...
Tipo: Text
Palavras-chave: Characteristics; Genome size; Genome; Crassostrea gigas; Oyster; Genetic.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3414.pdf

Impact of intensive larval rearing practices in oyster hatcheries : selective processes and loss of genetic variability (Poster)
Provedor de dados: 5
Autores: Taris, Nicolas; Sauvage, Christopher; Boudry, Pierre.
Early-life history of oysters, like in most marine bivalves, is characterized by high fecundity and low survival rate. In hatcheries, which are ecoming more and more important for the production of juveniles for aquaculture production, rearing conditions are optimised (density, feeding, temperature...), and contrast with those observed in the wild. Additionally, slow growing larvae are culled by sieving.
Tipo: Text
Palavras-chave: Crassostrea gigas; Juvenile; Genetic variability; Selection; Genetic; Hatcheries; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3444.pdf

Microsatellite-based parentage analysis of factorial crosses in Pacific oyster (Crassostrea gigas) larvae and spat
Provedor de dados: 5
Autores: Taris, Nicolas; Sauvage, Christopher; Ernande, Bruno; Boudry, Pierre.
Several studies have suggested that significant genetic variability might exist for some early developmental traits in the Pacific oyster, C. gigas. However, most studies have examined only limited numbers of families.  More critically, these families were rarely replicated, leading to possible bias due to heterogeneous larval rearing conditions among families. To overcome these potential problems, we used a mixed-family approach with subsequent parentage analysis. A recently developed set of three multiplexed microsatellite markers was used to determine parentage in a complete factorial cross between 12 males and 4 females. Larvae were reared at two different temperatures (20 and 26°C) to provide a contrast resembling wild versus hatchery conditions....
Tipo: Text
Palavras-chave: Selection; Genetic variability; Microsatellites; Crassostrea gigas; Pacific oysters.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3440.pdf

Etude des effets de la sélection sur les gènes de l'amylase chez une population d'huître creuse Crassostrea gigas en fonction des conditions trophiques précoces
Provedor de dados: 5
Autores: Sauvage, Christopher.
In natural population of the Pacific cupped oyster, there are differences between allelic and genotypic frequencies for the A and B amylase genes. Set up a synthetical population of C. gigas, in which whole alleles and genotypes are better represented than in wild population, was done. An investigation links between trophic conditions applied during larvae developpment (in nursery), allelic frequencies for both amylase genes, oyster's individual waight and by the selectivity of summer mortalities during their exposition on the estran has been done. As a result, following facts have been observed :  - On one side, an influence of the trophic condition applied during the larvae development on genotypic frequencies of the gene B of the amylase - On the other...
Tipo: Text
Palavras-chave: Crassostrea gigas; Amylase; Polymorphisme; Condition trophique; Crassostre gigas; Amylase; Polymorphim; Trophic condition.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00371/48185/48300.pdf

"Bivalvomix" : génomique évolutive des bivalves marins
Provedor de dados: 5
Autores: 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 &amp; 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
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/rapport-6489.pdf

The use of SNPs in characterizing oysters genomes and their resistance to pathogens
Provedor de dados: 5
Autores: Lapegue, Sylvie; Heurtebise, Serge; Harrang, Estelle; Morga, Benjamin; Flahauw, Emilie; Sauvage, Christopher; Boudry, Pierre.
During the last five years, a great effort has been made to develop genomic tools in oyster species all over the world. In Europe, the Pacific cupped oyster, Crassostrea gigas, and the European flat oyster, Ostrea edulis received a special attention as they are the key species for local aquaculture. In particular, the Pacific oyster is a marine bivalve of major economical and ecological importance worldwide. Better knowledge of its physiology and its genetics contributes to optimize its aquaculture production using selective breeding or to understand its invasive behavior in some coastal areas. Current international developments of genomic resources include EST databases, BAC libraries, genome mapping and sequencing. The Genoscope (Evry, France) and the...
Tipo: Text
Palavras-chave: Oysters; Crassostrea gigas; Ostrea edulis; Resistance pathogens; QTLs; Single Nucleotide Polymorphism.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00015/12584/9454.pdf

Development of SNPs and their use for the identification of summer mortality resistance QTLs in the Pacific oyster (Crassotrea gigas)
Provedor de dados: 5
Autores: 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

Effects of genetic drift and selection at larval stage resulting from hatchery practices in the Pacific oyster (Crassostrea gigas)
Provedor de dados: 5
Autores: Taris, Nicolas; Sauvage, Christopher; Ernande, Bruno; Batista, Frederico; Boudry, Pierre.
Hatchery techniques are now well handled in an increasing number of aquaculture species. However, unintentional effects of domestication often remain poorly documented. In this context, we studied how current hatchery practices may genetically influence larval traits for which significant genetic variation had previously been reported in the Pacific oyster. Two main factors were studied: culling (i.e. discarding the smallest larvae) and rearing temperature (26°C versus 20°C). In parallel, we estimated genetic diversity of broodstock populations sampled in French hatcheries. Finally, we compared larval development and settlement success in the progeny of one of these hatchery broodstock, which had been selected for seven generations, with those of wild...
Tipo: Text
Palavras-chave: Genetic drift; Selection; Genetic; Crassostrea gigas; Oysters; Hatchery techniques.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-3362.pdf

Impact of intensive larval rearing practices in oyster hatcheries : selective processes and loss of genetic variability (slides)
Provedor de dados: 5
Autores: Taris, Nicolas; Sauvage, Christopher; Boudry, Pierre.
Oysters, like many marine bivalves, are characterized by very high fecundity and low survival rate at early stages of life. Rearing conditions in hatcheries (i.e. density, feeding, temperature...) are different from those observed in the wild. Additionally, slow growing larvae are culled by sieving. As previous studies have shown that genetic variability exists for several early development traits, we aimed to assess if common hatchery rearing practices exert specific selective processes at the larval stage. In order to avoid possible bias and to increase the number of families studied, we used a mixed-family approach with subsequent parentage analysis using a recently developed set of three multiplexed microsatellite markers. We studied the variance in...
Tipo: Text
Palavras-chave: Hatcheries; Selection; Genetic drift; Genetic; Crassotrea gigas; Pacific oysters.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/acte-3483.pdf

Genetic effect of domestication selective pressures on Pacific oyster at larval stage
Provedor de dados: 5
Autores: Taris, Nicolas; Sauvage, Christopher; Ernande, Bruno; Boudry, Pierre.
Among bivalve species, the Pacific oyster, Crassostrea gigas, is the most economically important bivalve production over the world. Today, C. gigas is subject to an important production effort that leads to an intensive artificial selection. Larval stage is relatively unknown, specifically in a domestication context. Genetic consequence of artificial selection is still at a preliminary study. We aimed to tackle the consequence of inconscient domestication on the variance reproductive success focusing on larval stage, keystone of the life cycle. We studied two kinds of specific selective processes that common hatchery rearing practices exert : the effect of discarding the smallest larvae on genetic diversity and the artificial environment rearing effect via...
Tipo: Text
Palavras-chave: Selection; Genetic correlations; Genetic variability; Genetic; Domestication selective; Crassostrea gigas; Pacific oysters.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3441.pdf