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| Registros recuperados: 85 | |
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| Degremont, Lionel; Boudry, Pierre; Soletchnik, Patrick; Bedier, Edouard; Ropert, Michel; Samain, Jean-francois. |
| Three successive generations were produced between 2001 and 2003 to assess to what extent genetic variability exists for survival in juvenile oysters Crassostrea gigas. For each generation, two groups were selected for their high ("R" for resistant) and low ("S" for susceptible) survival. Significant differences in mortality were observed during the first year in Riviere d'Auray (RA) (Brittany-France). However, low and similar mortality were observed for both groups, with no significant difference between groups in the first and second generation in this site, where the first summer is the critical, sensitive period with a clear age effect. In Baie des Veys (BDV) (Normandie-France), where mortalities usually mainly affect adults, mortality between groups,... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Spat; Spatial variations; Survival; Rearing; Mollusc culture; Marine molluscs; Environmental factors; Nursery grounds; Mortality causes; Biological age; Aquaculture techniques. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3385.pdf |
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| Huvet, Arnaud; Degremont, Lionel; Labreuche, Yannick; Daniel, Jean-yves; Dubrunfaut, Thomas; Boudry, Pierre; Haure, Joel; Bedier, Edouard; Ropert, Michel; Herpin, Amaury; Cunningham, Charles; Moal, Jeanne; Samain, Jean-francois. |
| Summer mortality associated with juveniles of the oyster Crassostrea gigas is the result of a complex interaction between the host, pathogens and environment. Divergent selection based on summer survival have been applied to produce families with resistant and susceptible progeny. Here, we describe the use of suppression subtractive hybridization to generate 150 clones that were differentially regulated between resistant and susceptible F2 progeny. The nucleotide sequence of these 150 clones was determined. Among the 25 unique sequences that matched with the products of known genes, those putatively implicated in energy generation (12%) and immune function (16%), systems suspected to be implicated in summer mortality, were extended and analyzed by real... |
| Tipo: Text |
Palavras-chave: Selection; Gene; Genetic; Summer mortality; Crassostrea gigas; Pacific oysters. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3447.pdf |
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| Degremont, Lionel; Boudry, Pierre; Bedier, Edouard; Ropert, Michel; Soletchnik, Patrick; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| The French project "Morest", coordinated by IFREMER, aims to understand the causes of the summer mortalities in Crassostrea gigas. In 2001, three sets of families were bred following a nested half-sib mating design. 17 half-sib families (HSF) were obtained in this first generation (G1) and reared in 3 sites. Significant differences in survival were observed among HSF, and some HSF showed high levels of mortality in all sites, clearly indicating a genetic basis for survival. In 2002, a second generation (G2), including divergent selection and inbred lines, was constituted. Monitoring of survival and growth of G2s were the same as in 2001. Significant differences in survival were found between the offspring of the "high" and "low" selected groups and between... |
| Tipo: Text |
Palavras-chave: Summer; Oyster culture; Juveniles mortality; Genetics; Commercial species; Breeding. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3346.pdf |
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| Segarra, Amelie; Mauduit, Florian; Faury, Nicole; Trancart, Suzanne; Degremont, Lionel; Tourbiez, Delphine; Haffner, Philippe; Barbosa-solomieu, Valerie; Pepin, Jean-francois; Travers, Marie-agnes; Renault, Tristan. |
| Background: Massive mortality outbreaks affecting Pacific oyster (Crassostrea gigas) spat in various countries have been associated with the detection of a herpesvirus called ostreid herpesvirus type 1 (OsHV-1). However, few studies have been performed to understand and follow viral gene expression, as it has been done in vertebrate herpesviruses. In this work, experimental infection trials of C. gigas spat with OsHV-1 were conducted in order to test the susceptibility of several bi-parental oyster families to this virus and to analyze host-pathogen interactions using in vivo transcriptomic approaches. Results: The divergent response of these oyster families in terms of mortality confirmed that susceptibility to OsHV-1 infection has a significant... |
| Tipo: Text |
Palavras-chave: Interactions; Ostreid herpesvirus 1; Gene expression; Susceptibility; Crassostrea gigas. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00199/31029/29431.pdf |
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| Degremont, Lionel; Boudry, Pierre; Soletchnik, Patrick; Bedier, Edouard; Ropert, Michel; Samain, Jean-francois. |
| Three successive generations were produced between 2001 and 2003 to assess to what extent genetic variability exists for this trait in juvenile oysters Crassostrea gigas. For each generation, two groups were selected for their high ("R" for resistant) and low ("S" for susceptible) survival. Significant differences of mortality were observed during the first year in Rivière d'Auray (RA) (Brittany-France). However, low and similar mortality were observed for both groups, with no significant difference between groups in the first and second generation in this site, where the first summer is the critical sensitive period with a clear age effect. In Baie des Veys (BDV) (Normandie-France), where mortalities usually mainly affect adults, mortality between... |
| Tipo: Text |
Palavras-chave: Genetic variability; Genetic; Summer mortality; Crassostrea gigas; Pacific oysters. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3442.pdf |
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| Travers, Marie-agnes; Degremont, Lionel; De Lorgeril, Julien; Azema, Patrick; Montagnani, Caroline; Benabdelmouna, Abdellah; Nicolas, Jean-louis; Le Roux, Frederique. |
| En 2012, le nombre de cas de mortalités d’huîtres creuses adultes rapportés dans le cadre du réseau Repamo, et dans lesquels la bactérie Vibrio aestuarianus a été isolée, a fortement augmenté. Afin d’apporter de premiers éléments de réponse concernant cette augmentation, les objectifs de cette étude étaient de déterminer si l’émergence/la ré-émergence de V. aestuarianus était associée (i) à l’apparition d’un génotype bactérien particulier et/ou (ii) à une sensibilité accrue de certains animaux. L’Ifremer dispose d’une collection de souches bactériennes appartenant majoritairement au genre Vibrio et qui comporte différents isolats de V. aestuarianus, collectés depuis 2001 pendant ou hors épisodes de mortalité. La comparaison de ces isolats en termes de... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; Huître creuse; Crassostrea gigas; Bactérie; Ré-émergenece; Virulence; Génome; Statut immunitaire; Génétique. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00229/34037/32430.pdf |
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| Soletchnik, Patrick; Ropert, Michel; Bedier, Edouard; Costil, K. S.; Dubois, Brice; Degremont, Lionel; Bouget, Jean-francois; Martin, Jean-louis; Enriquez-diaz, M.; Faury, Nicole; Le Moine, Olivier; Renault, Tristan; Gagnaire, Beatrice; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| Field characterization of summer mortality was performed in France in the frame of the Morest project. Natural and hatchery spat were compared between three oyster production areas in France. Regardless of the natural or hatchery origin, oysters died during the reproduction period after temperature reaches 19 degree C. Thus, in southern areas, temperature accelerated gametogenesis of small spat (10mm) as well as adults, and mortality appeared for the two age classes. In contrast, sexual maturation proceeded more slowly in northern where spat mortality was lower compared to 18 months old oysters. However, critical gametogenesis and temperature were not sufficient to induce mortalities, as observed in examples with stable environment. Alternatively sediment... |
| Tipo: Text |
Palavras-chave: Seasonal variation; Oyster culture; Mortality causes; Hatcheries; Gametogenesis; Environmental factors; Crassostrea gigas; Oysters. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3348.pdf |
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| Degremont, Lionel; Maurouard, Elise; Nourry, Max; Seugnet, Jean-luc; Bedier, Edouard; Fleury, Elodie; Langlade, Aime; Pernet, Fabrice; Pouvreau, Stephane; Le Souchu, Pierrick; Normand, Julien; D'Amico, Florence; Rumebe, Myriam; Cantin, Christian; Barret, Jean; Le Gall, Patrik; Baud, Jean-pierre; Cochennec-laureau, Nathalie; Gervasoni, Erika; Pelissier, Pablo. |
| Ce rapport présente la comparaison des mortalités de deux lots de naissains de Crassostrea gigas dans plusieurs bassins conchylicoles et déterminer le gain de survie obtenu par la sélection pour des huîtres diploïdes |
| Tipo: Text |
Palavras-chave: Mortalités; Huître creuse; Crassostrea gigas; Sélection génétique; Naissain. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00065/17644/15180.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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| Lambert, Christophe; Soudant, Phillippe; Degremont, Lionel; Delaporte, Maryse; Moal, Jeanne; Boudry, Pierre; Jean, Frédéric; Huvet, Arnaud; Samain, Jean-francois. |
| High variability among individuals is often encountered when hemocyte characteristics are measured in bivalves. Such variability is suspected to result partly from genetic factors. In this study, hemocyte characteristics of six families of Crassostrea gigas were compared by flow cytometry at one sampling date in October 2001. These families were obtained from a nested, half-sibling cross design, and reared from July to October 2001 at three sites distributed along the French Atlantic coast from north to south: Baie des Veys (Normandy), Riviere d'Auray (Brittany) and Ronce (Marennes-oleron Basin, Poitou Charentes). Among the 15 measured hemocyte characteristics, production of reactive oxygen species (ROS) of untreated hemocytes (maintained in filtered... |
| Tipo: Text |
Palavras-chave: Genetic; Flow cytometry; Reactive oxygen species ROS; Adhesion; Hemocyte; Crassostrea gigas; Summer mortality. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3054.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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| Petton, Bruno; Destoumieux Garzon, Delphine; Pernet, Fabrice; Toulza, Eve; De Lorgeril, Julien; Degremont, Lionel; Mitta, Guillaume. |
| The Pacific oyster (Crassostreae gigas) has been introduced from Asia to numerous countries around the world during the 20th century. C. gigas is the main oyster species farmed worldwide and represents more than 98% of oyster production. The severity of disease outbreaks that affect C. gigas, which primarily impact juvenile oysters, has increased dramatically since 2008. The most prevalent disease, Pacific oyster mortality syndrome (POMS), has become panzootic and represents a threat to the oyster industry. Recently, major steps towards understanding POMS have been achieved through integrative molecular approaches. These studies demonstrated that infection by Ostreid herpesvirus type 1 µVar (OsHV-1 µvar) is the first critical step in the infectious process... |
| Tipo: Text |
Palavras-chave: Pacific oyster mortality syndrome; Polymicrobial disease; Multifactorial disease; Crassostrea gigas; OsHV-1; Opportunistic bacterial pathogens. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00679/79158/81669.pdf |
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| Parizadeh, Leila; Tourbiez, Delphine; Garcia, Celine; Haffner, Philippe; Degremont, Lionel; Le Roux, Frederique; Travers, Marie-agnes. |
| Although vibrios are frequently associated with marine organisms mortality outbreaks, knowledge on their ecology and pathogenicity is sparse, thus limiting disease management and prophylactic strategies. Here, we investigated V. aestuarianus infection onset and progression in the wild, taking advantage of a “claire” pond: a semi‐closed system with limited seawater renewal, theoretically more adapted to disease transmission. We showed a positive association of the bacteria with oysters, which can constitute a reservoir for the bacteria in the winter. Moreover, passage through oysters was found to be necessary for experimental disease reproduction as vibrios shedding from diseased oysters has higher infectivity than from in vitro grown. We next developed an... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00446/55761/57423.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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| Degremont, Lionel; Soletchnik, Patrick; Boudry, Pierre. |
| This study reports mortality under laboratory conditions in unselected controls and two lines of juvenile Pacific oysters Crassostrea gigas, previously selected for their high or low survival in the field during the summer period. Oysters were also deployed in field conditions and mortality between both conditions was then compared. In the laboratory, mortality was observed in all experiments and it always lasted for a week indicating that mortality under laboratory conditions was a short-term event. It was also shown that mortality could be repeated for a batch in several experiments using oysters which never experienced any abnormal mortality. This approach could facilitate further studies to investigate the causes of mortality by allowing repeated... |
| Tipo: Text |
Palavras-chave: Summer mortality; Crassostrea gigas; Laboratory; Field; Oyster; Juvenile. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12432/9228.pdf |
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| Degremont, Lionel; Bordeyne, Francois; Yonneau, Caroline; Maurouard, Elise; Nourry, Max. |
| Depuis 2008, les mortalités touchant le naissain Crassostrea gigas sont particulièrement élevées en France (>70%), fragilisant de nombreuses entreprises ostréicoles. Cependant, une voie de sortie de crise proposée dès 2001 est la mise en place de programmes de sélection pour l’amélioration de la survie suite à la mise en évidence de la forte héritabilité de ce caractère au stade naissain chez C. gigas (Dégremont et al., 2007 ; Dégremont et al., 2010a). Ainsi, des familles d’huîtres C. gigas présentant des survies contrastées au stade naissain ont été reproduites et maintenues depuis 2002 par le Laboratoire de Génétique et Pathologie à la station Ifremer de La Tremblade. Ces lots d’huîtres ont été nommés « R » et « S » respectivement pour leur meilleure... |
| Tipo: Text |
Palavras-chave: Génétique; Sélection génétique; Naissain; Huîtres creuses; Crassostrea gigas; Reproduction. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00065/17643/15179.pdf |
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| Degremont, Lionel; Soletchnik, Patrick; Doner, Anne. |
| 2001 shows how important the "R" and "S" biological families are for experimentation as well as the need to "preserve" these families from mortality during the first year. The "experimental nursing" conditions do not allow the conservation of dozens of families with many members for 6 to 8 months. Precocious characterisation at around 4-5 months enables a first selection of the biological material, as well as a first answer to the "in lab" genetical selection of the families. After the first results in 2001 (Céline de Ambroggi, LCPC, L. Degremont), two "precocious characterisation of mortality" experiments are carried out in 2002 on the divergent lineage of some genetical families (LGP production). Two 15 day long experiments are conducted in la Tremblade... |
| Tipo: Text |
Palavras-chave: Mortalités; Sélection; Physiologie; Genetique; Crassostrea gigas; Huîtres. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/acte-3406.pdf |
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| Registros recuperados: 85 | |
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