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| Registros recuperados: 48 | |
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| Mccombie, Helen; Ledu, Christophe; Phelipot, Pascal; Lapegue, Sylvie; Boudry, Pierre; Gerard, Andre. |
| We present a new method to produce tetraploid Crassostrea gigas by cytochalasin B inhibition of polar body 2 expulsion in diploid females crossed with tetraploid males. This offers a means of direct introgression of genetic characters from selected diploid to tetraploid lines, avoiding a triploid step. Offspring larval ploidy shifted over time and depended on size, with tetraploids more frequent among the smaller larvae and triploids among the large. Viable tetraploids were found at 4 and 6 months, indicating the technique was successful. The possibility that gynogenesis occurred was tested by microsatellite analysis to confirm the presence of paternally inherited alleles. These were present in all animals of the 2n x 4n + CB (female first) cross. However,... |
| Tipo: Text |
Palavras-chave: Oyster breeding; Gynogenesis; Polar body; Cytochalasin B; Polyploidy; Crassostrea gigas. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-632.pdf |
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| Boudry, Pierre; Naciri, Yamama; Collet, Bertrand; Cornette, Florence; Heurtebise, Serge; Ledu, Christophe; Chollet, Bruno; Phelipot, Pascal; Gerard, Andre. |
| Les objectifs pour l'année 1996 étaient les suivants: Poursuivre les premières reproductions des espèces pour lesquelles nous disposons de géniteurs GO. L'objectif est toujours de limiter le stockage d'animaux importés en produisant une descendance simultanément à des témoins C. gigas qui serviront de comparaison. Tenter des hybridations inter-spécifiques des différents taxons présents au sein du conservatoire en fonction des connaissances disponibles dans la littérature sur ce sujet (voir pour revue Gaffney et Allen, 1993). • Importer de nouvelles souches ou espèces. Élargir la gamme des espèces présentes au sein du conservatoire de souches (les capacités d'accueil de la salle de quarantaine étant Limitée). |
| Tipo: Text |
Palavras-chave: Génétique; Acclimatation; Hybridation; Crassostrea; Sélection génétique; Saccostrea commercialis. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00044/15516/12903.pdf |
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| Boudry, Pierre; Naciri, Yamama; Launey, Sophie; Ledu, Christophe; Phelipot, Pascal; Heurtebise, Serge; Gerard, Andre. |
| Le laboratoire IFREMER "Génétique Aquaculture et Pathologie" (GAP) (La Tremblade et Bouin) a entrepris des actions de recherche sur ces différents points. L'Unité de Recherche en Génétique, en collaboration avec tous Ies membres du Réseau Génétique Mollusques (REGEMO) a axé une partie de ses travaux sur l'acclimatation et l'hybridation de différentes espèces du genre Crassostrea. Ces recherches ont débuté avec le soutien du Conseil Général de Charente-Maritime depuis 1992 sur des essais d'acclimatation de C. virginica, l'huître creuse américaine. En prolongement de cette étude, l'URGE a proposé à la région Poitou Charentes un programme de recherche plus vaste sur l'ensemble des espèces d'huîtres creuses. Le contrat de plan Etat-Région a été signé en... |
| Tipo: Text |
Palavras-chave: Génétique; Acclimatation; Hybridation; Crassostrea; Saccostrea; Génétique population. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00044/15517/12904.pdf |
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| Boudry, Pierre; Heurtebise, Serge; Lapegue, Sylvie; Ledu, Christophe; Phelipot, Pascal; Gerard, Andre. |
| Dans le cadre du plan Etat-Région 1994-1998, un programme de conservatoire de souches a été initié au Laboratoire IFREMER de La Tremblade. Ce conservatoire a pour objectif d'acclimater différentes espèces ou souches d'huîtres creuses (genres Crassostrea et Saccostrea) afin d'acquérir des connaissances sur ces espèces et d'évaluer l'intérêt qu'elles pourraient présenter pour l'ostréiculture locale. L'importation d'espèces étrangères sur les côtes françaises est désormais strictement réglementée: la dissémination d'une nouvelle espèce peut se révéler néfaste d'un point de vue écologique et nuire aux productions existantes. De plus, ces huîtres peuvent être porteuses de pathogènes qui, s'il venaient à se répandre dans le milieu, pourraient toucher les stocks... |
| Tipo: Text |
Palavras-chave: Génétique; Acclimatation; Croisement; Crassostrea gigas; Crassostrea ariakensis; Crassostrea sikamea; Hybridation. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00044/15514/12901.pdf |
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| Boudry, Pierre; Naciri, Yamama; Heurtebise, Serge; Delsert, Claude; Ledu, Christophe; Phelipot, Pascal; Chollet, Bruno; Cochennec, Nathalie; Gerard, Andre. |
| Le laboratoire IFREMER "Génétique Aquaculture et Pathologie" (GAP) (La Tremblade et Bouin) a entrepris des actions de recherche sur ces différents points. L'Unité de Recherche en Génétique, en collaboration avec tous les membres du Réseau Génétique Mollusques (REGEMO), a axé une partie de ses travaux sur l'acclimatation et l'hybridation de différentes espèces du genre Crassostrea. Ces recherches ont débuté avec le soutien du Conseil Général de Charente-Maritime depuis 1992 sur des essais d'acclimatation de C. virginica, l'huître creuse américaine. En prolongement de cette étude, l'URGE a proposé à la région Poitou-Charentes un programme de recherche plus vaste sur l'ensemble des espèces d'huîtres creuses. |
| Tipo: Text |
Palavras-chave: Génétique; Acclimatation; Hybridation; Crassostrea virgnica. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00044/15515/12902.pdf |
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| Boudry, Pierre; Naciri, Yamama; Heral, Maurice; Collet, Bertrand; Bougrier, Serge; Geffard, Olivier; Ledu, Christophe; Phelipot, Pascal; Heurtebise, Serge; Gerard, Andre. |
| Le programme de recherche présenté ci-dessous est le fruit d'une réflexion conjointe entre généticiens et physiologistes afin de mettre sur pied un ensemble d'expériences permettant d'étudier les bases génétiques de la variabilité des caractères impliqués dans la croissance chez l'huître creuse, Crassostrea gigas. |
| Tipo: Text |
Palavras-chave: Génétique; Sélection génétique; Génétique des populations; Croissance; Crassostrea gigas. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00044/15518/12905.pdf |
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| Benabdelmouna, Abdellah; Ledu, Christophe. |
| We describe two methods of producing viable and fertile autotetraploid Pacific oyster (Crassostrea gigas Thunberg) based on the use of normal-sized oocytes produced by normal diploid females. Our methods showed that the oocyte size is not a limiting factor for the success of the induction to autotetraploidy. These methods offer means of direct introgression of genetic progress from elite diploid lines to tetraploids used as broodstock, avoiding a triploid step with the risk of transferring undesirable traits from highly fecund triploids. High variability in the level of cytogenetic stability was found among the different tetraploid oysters tested showing that induction method has an important impact on the long-term cytogenetic stability of the... |
| Tipo: Text |
Palavras-chave: Oyster; Tetraploid induction; Mosaicism; Aneuploidy; Cytogenetic stability. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00278/38924/37464.pdf |
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| Benabdelmouna, Abdellah; Ledu, Christophe. |
| Since 2014, blue mussel industry in France has been facing heavy mortality outbreaks (90–100%) affecting both juveniles and adults. This report presents evidence of heavy genomic abnormalities associated with mortality outbreaks in blue mussels from the Atlantic coast of France. Ploidy characteristics of hemic cells were investigated using Flow CytoMetry (FCM), revealing an unusual, broad continuum of ploidy distribution from hypodiploidy to tetraploidy. FCM was additionally used to evaluate, at individual and populations levels, different thresholds of genomic abnormality (GA%)using the percentage of non-diploid nuclei. Individual mussels were considered to be abnormal when more than 10% of hemocytes in S–G2/M phase were present. At the population level,... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00356/46720/46591.pdf |
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| Mccombie, Helen; Lapegue, Sylvie; Cornette, Florence; Ledu, Christophe; Boudry, Pierre. |
| Alterations of chromosome number have been observed in the somatic tissue of Crassostrea gigas diploids and artificial polyploids bred in this species. Tetraploid animals with lower chromosome counts in some or all of their somatic tissue are considered undesirable as parents either for commercial triploids (produced via a cross with diploids) or for tetraploid breeding because (1) they may confer the tendency to lose chromosomes and revert to lower ploidy levels to their offspring or (2) their offspring could have a lower ploidy directly because of potential links between somatic and gametic chromosome loss. The present study evaluated the phenomenon in bi-parental tetraploid families bred from parents of differing ploidy quality, including a... |
| Tipo: Text |
Palavras-chave: Tetraploid; Chromosome; Genetic; Crassostrea gigas; Oyster. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3435.pdf |
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| Gerard, Andre; Naciri-graven, Yamama; Boudry, Pierre; Launey, Sophie; Heurtebise, Serge; Ledu, Christophe; Phelipot, Pascal. |
| At the end of the 1980s, after two decades of aquaculture research in molluscs, Ifremer initiated its first genetic studies. These new studies quickly revealed the limits of knowledge in aquaculture, particularly in terms of controlling oyster reproduction. This presentation attempts to summarize the available information on genetics in aquaculture. In particular, breeding practices in the 1980s involved populations of broodstock, while genetics requires modern techniques where individuals, not just populations, can be identified. Controlling reproduction at the individual level in oysters raises new questions that existing protocols cannot address, especially in terms of controlling sex determination, individual maturity, spawning synchrony, chemical... |
| Tipo: Text |
Palavras-chave: Gamètes; Fécondation; Induction ponte; Reproducteur; Conditionnement; Gamétogénèse; Génétique; Reproduction; Crassostrea gigas; Huîtres. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/1995/acte-3210.pdf |
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| Lapegue, Sylvie; Diaz-almela, E.; Launey, Sophie; Ledu, Christophe; Boudry, Pierre; Naciri-graven, Yamama; Bonhomme, Francois. |
| Two oyster species are cultivated on the French coasts: the Pacific cupped oyster (Crassostrea gigas), which has been introduced from Japan in the 1970's after the disappearance of the Portuguese oyster Crassostrea angulala, and the European flat oyster (Ostrea edulis). During the second half of the 1960's, the latter suffered successively from two diseases caused by protozoan parasites: marteiliosis (also called "maladie des Abers") and bonamiosis. In France, its production dropped from 20,000 tian in the 1960's to 2,000 today. The impact of these two pathogens as well as the exploitation of the remaining stocks show the importance of the conservation of this species, the only natural European species, whose population is more and more fragmented. |
| Tipo: Text |
Palavras-chave: Marqueurs; Génétique population; Génétique; Ostrea edulis; Crassostrea gigas. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/acte-3273.pdf |
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| Boudry, Pierre; Launey, Sophie; Diaz-almela, A.; Naciri-graven, Yamama; Ledu, Christophe; Mira, S.; Taris, Nicolas; Bonhomme, Francois; Lapegue, Sylvie. |
| PCR-based DNA markers enable the study of diversity and differentiation of marine organisms at different stages of their life cycle. Our study of European fiat oyster (Ostrea edulis) populations aimed to describe their spatial and temporal dynamics. First, we analyzed adults sampled over the natural range of the species. An Atlantic/Mediterranean differentiation pattern was observed. Similar patterns of variation were found using allozymes, microsatellites and mitochondrial DNA, aIl which support an isolation by distance model. High variability was observed in the range of diversity between populations using a mitochondrial marker, a reflection of small effective population sizes in sorne locations. A 10fold quantitative difference was observed in Fst,... |
| Tipo: Text |
Palavras-chave: Recruitment; Diversity; Molecular markers; Population genetics; Ostrea edulis; Flat oyster; Dynamique de recrutement; Diversité génétique; Microsatellites; Marqueurs moléculaires; Génétique des populations; Ostrea edulis; Huître plate. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-2851.pdf |
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| Degremont, Lionel; Ledu, Christophe; Maurouard, Elise; Nourry, Max; Benabdelmouna, Abdellah. |
| The effect of ploidy on the mortality of Crassostrea gigas spat caused by the ostreid herpesvirus (OsHV-1) genotype μVar was investigated at five sites along the Atlantic coast in France in 2011. Sibling diploids and triploids were produced using either unselected or selected OsHV-1-resistant oysters. No significant interactions were found between the factors of environment, genotype and ploidy at the endpoint dates. The mean mortality rates at the sites were 62 and 59% for diploids and triploids, respectively, and the two rates were not significantly different. The mean mortality rates were 33 and 32% for sibling diploids and triploids, respectively, when OsHV-1-resistant parents were used, and 91 and 85%, respectively, when unselected parents were used.... |
| Tipo: Text |
Palavras-chave: Diploid; Triploid; Mortality; Crassostrea gigas; Ostreid herpesvirus OsHV-1. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00199/31028/29427.pdf |
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| Ledu, Christophe; Mccombie, Helen. |
| The effects of cytochalasin B on fertilization and ploidy in Crassostrea gigas were examined in a controlled experiment. This enabled us to better understand why variable ploidy results have been found with the retention of polar bodies in previous studies on bivalve mollusks, and what the interaction with fertilization may be. By looking at the early development of Crassostrea gigas embryos with sequential samples stained using Hoechst 33258, a fluorescent DNA-specific dye, we compared normal evolution of fertilized eggs with that obtained with cytochalasin B treatment. In treated eggs, embryos with both three and four pronuclei were found after the second meiotic division. When embryos had three pronuclei, these were identified as the female pronucleus... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Fertilization; Cytochalasin B; Polar body; Polyploidy. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-2845.pdf |
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| Gerard, Andre; Naciri, Yamama; Peignon, Jean-marie; Ledu, Christophe; Phelipot, Pascal; Baud, Jean-pierre; Nourry, Max; Renault, Tristan; Cochennec, Nathalie. |
| Premier volet du programme d'essai d'acclimatation de l'huître américaine Crassostrea virginica, ce rapport présente les actions et les résultats de l'année 1992 qui a été consacrée à : • l'importation selon les normes du CIEM d'un lot de 50 huîtres en provenance d'Angleterre, • leur élevage en salle de quarantaine et leur conditionnement en vue d'une accélération de la maturation sexuelle, • l'obtention d'une première génération, ainsi que son suivi en élevage larvaire et en micronurserie à l'URGE-La Tremblade, • au contrôle des performances comparées des deux populations de C. virginica et de C. gigas en nurserie de prégrossissement à l'URRA-Bouin pendant toute la période automnale et hivernale. Au terme de cette première année d'étude il apparait que la... |
| Tipo: Text |
Palavras-chave: Mollusques; Acclimatation; Crassostrea virginica; Crassostrea gigas; Génétique; Pathologie. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00077/18843/16417.pdf |
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| Registros recuperados: 48 | |
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