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| Registros recuperados: 85 | |
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| Agnew, M. Victoria; Friedman, Carolyn S.; Langdon, Christopher; Divilov, Konstantin; Schoolfield, Blaine; Morga, Benjamin; Degremont, Lionel; Dhar, Arun K.; Kirkland, Peter; Dumbauld, Brett; Burge, Colleen A.. |
| Pacific oysters, Crassostrea gigas, are one of the most productive aquaculture species in the world. However, they are threatened by the spread of Ostreid herpesvirus-1 (OsHV-1) and its microvariants (collectively “µvars”), which cause mass mortalities in all life stages of Pacific oysters globally. Breeding programs have been successful in reducing mortality due to OsHV-1 variants following viral outbreaks; however, an OsHV-1-resistant oyster line does not yet exist in the United States (US), and it is unknown how OsHV-1 µvars will affect US oyster populations compared to the current variant, which is similar to the OsHV-1 reference, found in Tomales Bay, CA. The goals of this study were to investigate the resistance of C. gigas juveniles produced by the... |
| Tipo: Text |
Palavras-chave: OsHV-1; Mu vars; Oyster; Virus; Tolerance; Virulence; QPCR. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00665/77739/79862.pdf |
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| Azema, Patrick; Lamy, Jean-baptiste; Boudry, Pierre; Renault, Tristan; Travers, Marie-agnes; Degremont, Lionel. |
| Background In France, two main diseases threaten Pacific oyster production. Since 2008, Crassostrea gigas spat have suffered massive losses due to the ostreid herpesvirus OsHV-1, and since 2012, significant mortalities in commercial-size adults have been related to infection by the bacterium Vibrio aestuarianus. The genetic basis for resistance to V. aestuarianus and OsHV-1 and the nature of the genetic correlation between these two traits were investigated by using 20 half-sib sire families, each containing two full-sib families. For each disease, controlled infectious challenges were conducted using naïve oysters that were 3 to 26 months old. In addition, siblings were tested under field, pond and raceway conditions to determine whether laboratory... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00372/48350/48518.pdf |
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| Azema, Patrick; Maurouard, Elise; Lamy, Jean-baptiste; Degremont, Lionel. |
| Mortality associated with ostreid herpesvirus 1 (OsHV-1) has significantly impacted Crassostrea gigas farmers all around the world. Although selective breeding programs to improve OsHV-1 resistance can significantly reduce the mortality rate below 20%, husbandry practices have also been one way to limit or decrease mortality. The main objectives of this study were to describe the influence of two husbandry practices on OsHV-1-induced mortality in C. gigas spat and how different family lines respond to husbandry practices to gain a better understanding of the potential benefits of breeding management as a tool to adapt to improved practices. The first analysis investigated the importance of the size of C. gigas when challenged with OsHV-1 for the first... |
| Tipo: Text |
Palavras-chave: Mortality; Crassostrea gigas; Size; OsHV-1; Growing height. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00366/47717/47758.pdf |
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| Azema, Patrick; Travers, Marie-agnes; Benabdelmouna, Abdellah; Degremont, Lionel. |
| French production of the Pacific cupped oyster, Crassostrea gigas, is currently threatened by two pathogens, OsHV-1 and V. aestuarianus. While oysters selected for their higher resistance to OsHV-1 are now available for the industry, the impact of V. aestuarianus on such oysters is unknown, especially for triploids. In addition, experimental infection has used the virus or the bacteria alone, but there have been no investigations of dual exposure to these pathogens. This study is the first report of single or dual exposure in spat (Spat1 and Spat2), juvenile and adult naïve oysters. For each of the two stocks evaluated, unselected oysters and oysters selected for their higher resistance to OsHV-1 infection were tested, as well as their triploid siblings of... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; OsHV-1; Dual exposure; Ploidy; Selection; Crassostrea gigas. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45835/45918.pdf |
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| Azema, Patrick; Travers, Marie-agnes; De Lorgeril, Julien; Tourbiez, Delphine; Degremont, Lionel. |
| Since 2008, the emergent virus OsHV 1μvar has provoked massive mortality events in Crassostrea gigas spat and juveniles in France. Since 2012, mortality driven by the pathogenic bacteria Vibrio aestuarianus has stricken market sized adults. A hypothesis to explain the sudden increase in mortality observed in France since 2012 is that selective pressure due to recurrent viral infections could have led to a higher susceptibility of adults to Vibrio infection. In our study, two OsHV-1-resistant lines (AS and BS) and their respective controls (AC and BC) were experimentally challenged in the laboratory to determine their level of susceptibility to V. aestuarianus infection. At the juvenile stage, the selected lines exhibited lower mortality (14 and 33%) than... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00299/41054/40215.pdf |
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| Barranger, Audrey; Benabdelmouna, Abdellah; Degremont, Lionel; Burgeot, Thierry; Akcha, Farida. |
| Changes in normal chromosome numbers (i.e. aneuploidy) due to abnormal chromosome segregation may arise either spontaneously or as a result of chemical/radiation exposure, particularly during cell division. Coastal ecosystems are continuously subjected to various contaminants originating from urban, industrial and agricultural activities. Genotoxicity is common to several families of major environmental pollutants, including pesticides, which therefore represent a potential important environmental hazard for marine organisms. A previous study demonstrated the vertical transmission of DNA damage by subjecting oyster genitors to short-term exposure to the herbicide diuron at environmental concentrations during gametogenesis. In this paper, Fluorescent in... |
| Tipo: Text |
Palavras-chave: Aneuploidy; FISH; Diuron; Crassostrea gigas. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00238/34911/33216.pdf |
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| Benabdelmouna, Abdellah; Guyader, Tanguy; Ledu, Christophe; Laporte, Philippe; Degremont, Lionel. |
| Depuis son introduction en France, l’huître creuse du Pacifique Crassostrea gigas subit des épisodes répétés de mortalité estivale touchant principalement les juvéniles. A partir de 2008, un nouveau pallier a été franchi et ces épisodes de mortalité estivale se sont accrus en intensité, touchant jusqu’à 90% des lots. Actuellement, ces mortalités touchent l’ensemble des façades maritimes ainsi que plusieurs pays utilisant des naissains d’origine Française. L’ostréiculture Française est basée sur l’utilisation majoritaire de naissains sauvages issus d’un captage naturel (75 à 80%) réalisé au niveau des bassins d’Arcachon et de Marennes Oléron en complément avec l’utilisation de naissains, principalement triploïdes, produits par diverses écloseries privées... |
| Tipo: Text |
Palavras-chave: Huître creuse; Crassostrea gigas; Mortalité; Condition d'élevage; Historique des lots. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00063/17405/14910.pdf |
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| Bernard, Ismael; Lapegue, Sylvie; Dumas, Franck; Talarmain, Eric; Cornette, Florence; Degremont, Lionel; Chavanne, Herve; Pouvreau, Stephane; Auby, Isabelle; Maurer, Daniele; Plus, Martin; Le Moine, Olivier; Boudry, Pierre. |
| La forte augmentation des mortalités de juvéniles d’huître creuse depuis 2008 a relancé la problématique de l’approvisionnement en naissains de l’ostréiculture française. Dans ce contexte, cette étude a pour objectif d’étudier la faisabilité d’opérations de repeuplement en huîtres génétiquement plus résistantes, afin d’améliorer les performances de survie du naissain capté dans le milieu naturel. Cette étude s’est ainsi focalisée sur les deux bassins naisseurs historiques, Marennes-Oléron et Arcachon. Nous avons donc cherché à établir (1) une hiérarchie des bancs en fonction de l’expulsion de larves d’huître dans le bassin d’Arcachon, (2) une cartographie des liens en termes de connectivité entre les bancs des pertuis charentais et (3) la faisabilité du... |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00083/19410/17013.pdf |
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| Bigot, L.; Dubos, M. P.; Dheilly, N.; Favrel, P.; Kellner, K.; Lelong, C.; Martinez, A. S.; Riviere, G.; Santerre, C.; Sourdaine, P.; Degremont, Lionel; Flahauw, Emilie; Hatt, Philippe-jacques; Heurtebise, Serge; Lapegue, Sylvie; Azzouzi, N.; Galibert, F.; Boudry, Pierre; Corporeau, Charlotte; Fabioux, Caroline; Guevelou, Eric; Huvet, Arnaud; Sussarellu, Rossana. |
| Le projet GAMETOGENES vise à améliorer les connaissances des bases physiologiques et génétiques de la reproduction et des métabolismes associés chez un mollusque d'importance économique l'huître creuse, Crassostrea gigas. Il a pour objectifs (1) la définition de marqueurs clés de la gamétogenèse, de l'investissement reproducteur et du déterminisme du sexe chez une espèce hermaphrodite à protandrie irrégulière (2) la recherche de QTL de survie aux mortalités estivales ou à l'effort de reproduction dont le succès repose sur l'augmentation de la densité de marqueurs sur les cartes génétiques existantes (SNP en particulier) et sur les liens qui pourront être établis entre ces cartes de liaison et une carte physique (3) le développement d'outils pour valider la... |
| Tipo: Text |
Palavras-chave: Génétique; Huître creuse; Crassostrea gigas; Gamétogenèse; QTL; Marqueur; Physiologie. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00107/21781/19355.pdf |
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| Boudry, Pierre; Degremont, Lionel; Bedier, Edouard; Pouvreau, Stephane; Normand, Julien; Ernande, Bruno. |
| To date, the most significant method to genetically reduce reproductive effort in the Pacific oyster (Crassostrea gigas) has been through the production of triploids, especially since the development of tetraploid lines allowing the breeding of 'natural' triploids. Gametogenesis of triploid oysters is strongly reduced compared with diploids, although they are not fully sterile and can produce viable gametes and some progenies when crossed with diploids. Reduced reproductive allocation and higher heterozygocity are commonly proposed as the main reasons why triploids often present superior yield compared with diploids. Temperature and food availability are known to favour gametogenesis in triploids, but the existence of genetic variation for this trait... |
| Tipo: Text |
Palavras-chave: Selective breeding; Reproduction; Genetic variation; Crassostrea gigas; Pacific oyster; Genetic. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-3445.pdf |
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| Boudry, Pierre; Degremont, Lionel; Taris, Nicolas; Mccombie, Helen; Haffray, Pierrick; Ernande, Bruno. |
| The most significant genetic improvement for production of Pacific oyster (Crassastrea gigas) has been obtained through the breeding of triploids, especially since the development of tetraploids. Quantitative genetics studies suggest that significant gains, for disease resistance or for other traits of aquacultural interest, could be obtained using this approach. However, the limited extent of hatchery-propagation (versus natural recruitment) and/or various technical difficulties and biological characteristics of the species have slowed the development of selective breeding programs. Recently, in the USA, Australia and New Zealand, family-based selective breeding programs have been initiated to improve growth and yield. In Europe, where both natural and... |
| Tipo: Text |
Palavras-chave: Microsatellites; Quantitative genetic; Genetic variability; Crassostrea gigas; Oysters. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-2861.pdf |
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| Boudry, Pierre; Degremont, Lionel; Taris, Nicolas; Mccombie, Helen; Haffray, Pierrick; Ernande, Bruno. |
| To date, the most significant genetic improvement for the production of Pacific oyster (Crassostrea gigas) has been obtained through the breeding of triploids, especially since the development of tetraploids. Quantitative genetics studies suggest that significant gains, for disease resistance or for other traits of aquacultural interest, could be obtained in diploids using this approach. However, the limited extent of hatchery-propagation (versus natural recruitment) and/or various technical difficulties and biological characteristics of the species have retarded the development of selective breeding programs. Recently, in the U.S.A., Australia and New Zealand, countries where hatcheries are a major source of C. gigas juveniles, family-based selective... |
| Tipo: Text |
Palavras-chave: Microsatellite markers; Selective breeding; Genetic; Genetic variability; Crassostrea gigas; Pacific oysters. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/acte-3449.pdf |
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| Burge, Colleen A.; Reecez, Kimberly S.; Dhar, Arun K.; Kirkland, Peter; Morga, Benjamin; Degremont, Lionel; Faury, Nicole; Wippel, Bryanda J. T.; Macintyre, Alanna; Friedman, Carolyn S.. |
| Economically devastating mortality events of farmed and wild shellfish due to infectious disease have been reported globally. Currently, one of the most significant disease threats to Pacific oyster Crassostrea gigas culture is the ostreid herpesvirus 1 (OsHV-1), in particular the emerging OsHV-1 microvariant genotypes. OsHV-1 microvariants (OsHV-1 mu vars) are spreading globally, and concern is high among growers in areas unaffected by OsHV-1. No study to date has compared the relative virulence among variants. We provide the first challenge study comparing survival of naive juvenile Pacific oysters exposed to OsHV-1 mu vars from Australia (AUS mu var) and France (FRA mu var). Oysters challenged with OsHV-1 mu vars had low survival (2.5%a exposed to AUS... |
| Tipo: Text |
Palavras-chave: Ostreid herpesvirus 1; Microvariant; OsHV-1 mu vars; POMS; Pacific oyster; Crassostrea gigas; Viral disease; QPCR; Alkalinity; Emerging infectious diseases. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00631/74277/73889.pdf |
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| Chavanne, Herve; Maurouard, Elise; Yonneau, Caroline; Heroin, Debora; Ledu, Christophe; Degremont, Lionel; Benabdelmouna, Abdellah. |
| Afin de permettre l’approvisionnement partiel des établissements ostréicoles en naissain « à survie améliorée », un protocole d’approvisionnement partiel de sauvegarde (PSI) a été mis en place en 2010 entre le CNC, les CRCs, les écloseurs et l’Ifremer afin de fournir aux ostréiculteurs du naissain présentant les meilleures chances de survie face aux mortalités estivales. Il avait ainsi été décidé que des écloseries privées produiraient du naissain triploïde « à survie améliorée » en 2010 à partir de géniteurs, femelles diploïdes et mâles tétraploïdes, sélectionnés et fournis par Ifremer. Sur la base notamment des recommandations des Assises de la Conchyliculture, l’opération a été reconduite en 2011 (PSII) et 2012 (PSIII). Suite aux productions réalisées... |
| Tipo: Text |
Palavras-chave: Mortalités; Crassostrea gigas; Huîtres creuses; Triploïde R; Sélection Génétique. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00143/25412/23563.pdf |
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| Cochennec-laureau, Nathalie; Baud, Jean-pierre; Pepin, Jean-francois; Benabdelmouna, Abdellah; Soletchnik, Patrick; Lupo, Coralie; Garcia, Celine; Arzul, Isabelle; Boudry, Pierre; Huvet, Arnaud; Pernet, Fabrice; Bachere, Evelyne; Bedier, Edouard; Petton, Bruno; Gaussem, Florian; Stanisiere, Jean-yves; Degremont, Lionel. |
| Depuis 2008, la filière ostréicole française doit faire face à des surmortalités exceptionnelles des naissains d’huîtres creuses, Crassostrea gigas, (huîtres de moins d’un an) comprises entre 60 et 90% dans tous les sites d’élevage. Des cas de mortalité similaires ont été décrits en Irlande, dans les îles anglo-normandes, au Portugal en 2009 et au Royaume-Uni en 2010. Récemment deux épisodes de mortalité, associés à la présence d’un virus OsHV1 μvar (ou un variant très proche) ont été également décrits en Nouvelle Zélande (décembre 2010) et en Australie (janvier 2011) soulignant la vulnérabilité de la filière ostréicole dans le monde. L’objectif de ce document est de faire un point sur les recherches menées depuis l’apparition de ce phénomène et de... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00033/14423/11719.pdf |
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| David, Elise; Boudry, Pierre; Degremont, Lionel; Tanguy, Amelie; Quere, N; Samain, Jean-francois; Moraga, D. |
| Large-scale mortality events have been observed in Pacific oyster Crassostrea gigas on the west coast of France since the early 1980s, particularly during summer. In order to understand the causes of this mortality, two generations of oysters from single-pair matings were studied in three sites on the French Atlantic coast (Baie-des-Veys, Auray and Ronce-les-Bains). The present paper examines the role of two candidate genes in the susceptibility of oysters to summer mortality, and the selective pressure exerted by such mortality on their polymorphism. Glutamine synthetase (amino-acid metabolism) and delta-9 desaturase (lipid metabolism) genes were studied in the successive generations, using polymerase chain reaction single-strand conformation polymorphism... |
| Tipo: Text |
Palavras-chave: SSCP; Mortality; Glutamine synthetase; Delta 9 desaturase; Crassostrea gigas. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3040.pdf |
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| Registros recuperados: 85 | |
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