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Peudenier, Isabelle. |
La gynogenèse est le développement d'un oeuf activé par un spermatozoïde, mais sans participation du génome paternel. Sur le plan génétique, elle est équivelente à la parthénogénèse mais elle est déclenchée par d'autres facteurs. Chez l'huître creuse, Crassostrea gigas, l'inactiviation génétique du sperme par les UV est plus difficile à obtenir que chez les poissons, principalement du fait d'une grande variabilité inter-indivuelle de la motilité avant irradiation. Par ailleurs, l'absence constatée d'effet Hetwig rend plus délicate la définition d'un temps optimal d'exposition aux UV. Les haploïdes obtenus sont anormaux et n'atteignent pas le stade de larve D. La diploïdie peut être efficacement restaurée en retenant un globule polaire grâce au traitement... |
Tipo: Text |
Palavras-chave: Gynogenèse; Mollusuqe; Crassostrea gias; 6-DMAP; Cytochalasine B; Imagerie numérique. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00410/52161/52877.pdf |
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Gay, Melanie; Berthe, Franck; Leroux, Frederique. |
In an attempt to develop a reproducible experimental model of bacterial infection in Crassostrea gigas, oysters taken from very localised sub-populations suffering natural mortality outbreaks were used in cohabitation trials under laboratory conditions. From these trials, a collection of Vibrio strains was isolated from moribund and healthy oysters. In a second step, strains were experimentally tested for virulence by means of injection into healthy oysters. This screening revealed a span of virulence among isolated strains from none to medium. When pooling injected strains, results suggest increased virulence. Vibrio strains may have additive/synergistic action leading to higher C, gigas mortality rates in experimental challenges. Although the study... |
Tipo: Text |
Palavras-chave: Crassostrea gias; Antagonism; Agonism; Virulence; Vibrio splendidus. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-3174.pdf |
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Collet, Bertrand; Boudry, Pierre; Bougrier, Serge; Heurtebise, Serge; Phelipot, Pascal; Ledu, Christophe; Morand, Berenice; Heral, Maurice; Gerard, Andre. |
A European programme (GENEPHYS) was launched in 1996 to study the genetic basis and variability of physiological characters involved in growth in Crassostrea gigas. This research programme was a prerequisite for any genetic selection programme on physiological functions. Research groups from Ireland, England, Greece and France are involved in this project and participate in genetic analyses (allozymes and microsatellites) and physiological analyses (ecophysiology, enzymology, stress proteins). Ifremer at La Tremblade was responsible for producing the biological material while Ifremer-CREMA (human-influenced marine ecosystems research centre) was responsible for carrying out non-destructive physiological analyses. |
Tipo: Text |
Palavras-chave: Sélection génétique; Croissance; Crassostrea gias; Génétique. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/1997/acte-3243.pdf |
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