Consulta: creatorFacets:"Launey, Sophie"
Registros recuperados: 14
Data/hora: 06/06/2024 07:48:33

Recherche de marqueurs génétiques et évaluation de la variabilité génétique dans le cadre d'un programme de sélection de l'huître plate Ostrea edulis au parasite Bonamia ostrea
Provedor de dados: 5
Autores: Launey, Sophie.
Dans le cadre du projet de relance de l'huître plate en France, projet mené par l'IFREMER et soutenu par les régions Bretagne et Poitou-Charentes, un programme de sélection pour la recherche de résistance au Bonamia ostreae, protozoaire parasite ayant entraîné une diminution importante des stocks cultivés, a été engagé à partir de 1985. Deux populations ont ainsi été sélectionnées et présentent maintenant des signes de résistance (ou de tolérance) accrue par rapport aux témoins du milieu naturel. Dans le cadre de ce programme, l'identification de marqueurs moléculaires a été initiée à partir d'octobre 1993 (Naciri et al, 1995). Mon sujet de thèse s'inscrit dans cette continuité. Mon travail s'articule en 2 parties: -  Dans un premier temps, la recherche de...
Tipo: Text
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00411/52206/52930.pdf

Influence of parentage upon growth in Ostrea edulis: evidence for inbreeding depression
Provedor de dados: 5
Autores: Naciri-graven, Y; Launey, Sophie; Lebayon, N; Gerard, Andre; Baud, Jean-pierre.
Genetic variability for growth was analysed in three populations of Ostrea edulis, selected for resistance to the protozoan parasite Bonamia ostreae. This study was undertaken first to determine the potential for selection for growth in populations that have never been selected for this character, and second to estimate heterosis versus inbreeding depression. Growth was monitored in culture for 10 months. The selected populations (namely S85-G3, S89I-G2 and S89W-G2), their crossbred population and a control population were composed of full-sib families whose parents were already genotyped using five microsatellite markers. This genotyping allowed the estimation of genetic relatedness among pairs of parents. The parents' relatedness was then correlated with...
Tipo: Text
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-2719.pdf

Approche comparative de la variabilité et de la structuration génétique chez deux espèces d'huîtres cultivées (Crassostrea gigas et Ostrea edulis) présentant des stratégies reproductives et des histoires contrastées
Provedor de dados: 5
Autores: Boudry, Pierre; Launey, Sophie; Huvet, Arnaud.
The two common oyster species cultivated in Europe are the flat oyster Ostrea edulis and the cupped oyster Crassostrea gigas. These species have two really different reproduction strategies (oviparity versus larviparity) and histories (natural distribution versus introductions linked to oyster culture). We used microsatellite markers to compare the observed variabilities Europe wide. O. edulis presents a lower rate of alleles per locus than C. gigas. The observed structuration levels (global Fst and by pairs values) are similar for both species, but the spatial organisation of the diversity is different. In O. edulis, appears a differentiation based on the distance (concordance of the results with those obtained with the allozymes) whereas in C. gigas,...
Tipo: Text
Palavras-chave: Différenciation génétique; Variabilité; Génétique; Crassostrea gigas; Ostrea edulis; Huîtres.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/acte-3455.pdf

Population bottleneck and effective size in Bonamia ostreae-resistant populations of Ostrea edulis as inferred by microsatellite markers
Provedor de dados: 5
Autores: Launey, Sophie; Barre, Marc; Gerard, Andre; Naciri, Yamama.
Genetic variability at five microsatellite loci was analysed in three hatchery-propagated populations of the flat oyster, Ostrea edulis. These populations were part of a selection programme for resistance to the protozoan parasite Bonamia ostreae and were produced by mass spawns, without control of the genealogy. Evidence for population bottlenecks and inbreeding was sought. A reduction in the number of alleles, mainly due to the loss of rare alleles, was observed in all selected populations, relative to the natural population from which they were derived. Heterozygote excesses were observed in two populations, and were attributed to substructuring of the population into a small number of families. Pedigree reconstruction showed that these two populations...
Tipo: Text
Palavras-chave: Inbreeding; Effective population size; Bonamia ostreae; Ostrea edulis; European flat oyster.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-2703.pdf

Acclimatation de nouvelles espèces d'huîtres creuses du genre Crassostrea: hybridation et conservatoire de souches. Contrat Région Poitou-Charentes 1994-1998 - 1ère partie : rapport année 1994
Provedor de dados: 5
Autores: 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

Small effective number of parents (N-b) inferred for a naturally spawned cohort of juvenile European flat oysters Ostrea edulis
Provedor de dados: 5
Autores: Hedgecock, Denis; Launey, Sophie; Pudovkin, A. I.; Naciri, Yamama; Lapegue, Sylvie; Bonhomme, Francois.
The great fecundity and very high larval mortality of most marine invertebrates and fish make possible substantial variance in the number of offspring contributed by adults to subsequent generations. The reproductive success of such organisms may thus resemble a sweepstakes lottery, in which a minority of progenitors succeeds in replacing an entire population, while the majority fails to procreate. One specific prediction of this hypothesis, that genetic diversity of newly settled cohorts should be less than that of the adult population, is tested in the present study. Microsatellite DNA markers were examined in naturally spawned juvenile European flat oysters Ostrea edulis (L.), collected over a 12-day period in 1993 from the western Mediterranean Sea,...
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2616.pdf

Historique, expériences en cours et perspectives du programme de sélection de l'huître plate Ostrea edulis pour la résistance à la bonamiose
Provedor de dados: 5
Autores: Barre, Marc; Naciri, Yamama; Boudry, Pierre; Goyard, Emmanuel; Launey, Sophie; Cochennec, Nathalie; Heurtebise, Serge; Ledu, Christophe; Phelipot, Pascal; Gerard, Andre.
The Aquaculture and Pathological Genetics (GAP) laboratory at La Tremblade has been monitoring three populations of European flat oyster since 1985 or 1989 under selection for higher survival rates in the presence of the parasite Bonamia ostrea. One selection cycle (1985 population) or two (1989 populations) were carried out by mass selection by placing the oysters for several years in a highly infested zone, and then harvesting spawns from survivors.
Tipo: Text
Palavras-chave: Huîtres plates; Génétique; Selection génétique; Ostrea edulis.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/1997/acte-3244.pdf

Population genetics of the European flat oyster (Ostrea edulis) : from larvae to populations
Provedor de dados: 5
Autores: Boudry, Pierre; Launey, Sophie; Diaz-almela, E.; Naciri-graven, Yamama; Ledu, Christophe; Mira, Sara; Taris, Nicolas; Bonhomme, Francois; Lapegue, Sylvie.
Nowadays, PCR-based DNA markers allow the study of diversity and differentiation of marine organisms at different stages of their life cycle. Our study of European flat oyster (Ostrea edulis) populations has 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. Results were congruent between allozymes, microsatellites and mitochondrial DNA and  support an isolation by distance model. High variability was observed in the breadth of diversity between populations using a mitochondrial marker, this highlights the small effective population sizes in some locations. A 10-fold quantitative difference was observed in Fst...
Tipo: Text
Palavras-chave: Larvae; Reproduction; Genetic; Ostrea edulis; European flat oyster; Population genetics.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/acte-3493.pdf

Marqueurs microsatellites chez l'huître plate Ostrea edulis l. : caractérisation et applications à un programme de sélection pour une résistance au parasite Bonamia ostreae et à l'etude de populations naturelles
Provedor de dados: 5
Autores: Launey, Sophie.
The flat oyster Ostrea edulis L. is the indigenous oyster of the Atlantic as well as the Mediterranean coasts of Europe.  Its commercial exploitation dates back to Antiquity but its breeding is now threatened by two parasitic protozoa, among which Bonamia ostreae. Various aspects of the genetics of this species' natural and farmed populations have been studied with the aid of microsatellite markers.  At first, the implementation and the screening of two partial genomic libraries made it possible to identify 28 new microsatellite loci. Analysis of the segregation of 12 of these loci and of two enzymatic loci shows that most microsatellite loci are transmitted in a Mendelian way, but some loci have significant segregation distortions. Moreover, seven linkage...
Tipo: Text
Palavras-chave: Microsatellites markers; Parasite; Bonamia ostreae; Oyster; Ostrea edulis; Marqueurs microsatellites; Parasite; Bonamia ostreae; Huître; Ostrea edulis.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/these-1919.pdf

Reduced female gene flow in the European flat oyster Ostrea edulis
Provedor de dados: 5
Autores: Diaz Almela, F; Boudry, Pierre; Launey, Sophie; Bonhomme, Francois; Lapegue, Sylvie.
The geographical structure of 15 natural populations of the flat oyster (Ostrea edulis L.) was assessed by single-strand conformation polymorphism (SSCP) of a 313-base-pair (bp) fragment of the mitochondrial 12S-rRNA gene. Fourteen haplotypes were observed, with one being dominant in the Mediterranean samples and another one in the Atlantic populations. The geographically extreme populations sampled in Norway and the Black Sea appeared differentiated by exhibiting the dominance of a third group of haplotypes. The results were compared to available microsatellite data at five loci. The Atlantic/Mediterranean differentiation pattern was qualitatively the same with both types of markers, confirming an isolation-by-distance pattern. The average mitochondrial...
Tipo: Text
Palavras-chave: Ostrea edulis; Polymorphism; Flat oyster; Population; Gene.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-680.pdf

Différenciation génétique des populations d'huître plate européenne, Ostrea edulis, à l'aide de marqueurs des génomes mitochondrial et nucléaire
Provedor de dados: 5
Autores: 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

Mitochondrial and microsatellite genetic differentiation of the flat oyster Ostrea edulis along the european coasts, and comparison with allozyme data
Provedor de dados: 5
Autores: Lapegue, Sylvie; Diaz-almela, E.; Launey, Sophie; Ledu, Christophe; Boudry, Pierre; Naciri-graven, Yamama; Bonhomme, Francois.
Natural populations of the European flat oyster, Ostrea edulis, have been harvested since Roman times. This species is distributed along the European Atlantic coasts, from Norway to Morocco, as well as the Mediterranean Sea and Black sea coasts. Previous studies, based on allozymes, have concluded that isolation by distance is taking place in  the Mediterranean sea and the Atlantic ocean. Because of the presumed non neutrality of these markers, another approach was made to examine the genetic differentiation of this species using nuclear microsatellite and mitochondrial markers, both considered as neutral, and to compare the results to those observed with allozymes.
Tipo: Text
Palavras-chave: Microsatellite markers; Ostrea edulis; Flat oyster; Genetic.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/acte-3497.pdf

Diversité et différentiation génétique chez l'huître plate européenne : de la population à l'individu (Actes)
Provedor de dados: 5
Autores: 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

Contrôle de la gamétogénèse des huîtres creuses et plates. Relations "reproduction" et "génétique"
Provedor de dados: 5
Autores: 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