Consulta: creatorFacets:"Leitao, Alexandra"
Registros recuperados: 27
Data/hora: 10/06/2024 01:24:13

A Microarray-Based Analysis of Gametogenesis in Two Portuguese Populations of the European Clam Ruditapes decussatus
Provedor de dados: 5
Autores: Sousa, Joana; Milan, Massimo; Bargelloni, Luca; Pauletto, Marianna; Matias, Domitilia; Joaquim, Sandra; Matias, Ana Margarete; Quillien, Virgile; Leitao, Alexandra; Huvet, Arnaud.
The European clam, Ruditapes decussatus is a species with a high commercial importance in Portugal and other Southern European countries. Its production is almost exclusively based on natural recruitment, which is subject to high annual fluctuations. Increased knowledge of the natural reproductive cycle of R. decussatus and its molecular mechanisms would be particularly important in providing new highly valuable genomic information for better understanding the regulation of reproduction in this economically important aquaculture species. In this study, the transcriptomic bases of R. decussatus reproduction have been analysed using a custom oligonucleotide microarray representing 51,678 assembled contigs. Microarray analyses were performed in four gonadal...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00188/29935/28623.pdf

Comparative karyological study of cupped oyster species
Provedor de dados: 5
Autores: Leitao, Alexandra; Boudry, Pierre; Labat, Jean-philippe; Thiriot-quievreux, Catherine.
Chromosomes of six cupped oyster species were studied using karyometric analysis alter conventional Giemsa staining, and silver staining, Karyotypes of Crassotrea angulata (nine metacentric and one submetacentric chromosome pairs), C. sikamea (nine metacentric and one submetacentric chromosome pairs), C. virginica (eight metacentric and two submetacentric chromosome pairs), C, ariakensis (eight metacentric and two submetacentric chromosome pairs), C, gasar (six metacentric and four submetacentric chromosome pairs), and Saccostrea commercialis (eight metacentric and two submetacentric chromosome pairs) are distinguishable by the number and position of the submetacentric chromosome pair and by the location of nucleolus organizer regions, Comparative...
Tipo: Text
Palavras-chave: Bivalvia; Cytotaxonomy; Karyotype; Chromosome; Cupped oyster.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/publication-2737.pdf

A microarray-based analysis of oocyte quality in the European clam Ruditapes decussatus
Provedor de dados: 5
Autores: De Sousa, Joana Teixeira; Milan, Massimo; Pauletto, Marianna; Bargelloni, Luca; Joaquim, Sandra; Matias, Domitilia; Matias, Ana Margarete; Quillien, Virgile; Leitao, Alexandra; Huvet, Arnaud.
A microarray-based analysis was performed with the objective of describing genomic features of oocytes and looking for potential markers of oocyte quality in the economically important European clam, Ruditapes decussatus. Oocytes of 25 females from Ria de Aveiro, Western coast of Portugal (40°42′N; 08°40′W) were selected for this study and oocyte quality was estimated by success of D-larval rate under controlled conditions, which appeared to vary from 0 to 95 %. By genome-wide expression profiling with a DNA microarray, 526 probes appeared differentially expressed between two groups representing the largest and smallest value of D larval rates, named good (represented by a mean D-larval yield of 57 ± 22%) and poor (9 ± 5%) quality oocytes. Enrichment...
Tipo: Text
Palavras-chave: Ruditapes decussatus; Oocyte; Developmental success; Gene expression; Marine bivalve; Transcriptomics.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00260/37147/35676.pdf

Impact of atrazine on somatic aneuploidy in cupped oysters, Crassostrea gigas
Provedor de dados: 5
Autores: Bouilly, Karine; Leitao, Alexandra; Mccombie, Helen; Chaves, R.; Guedes Pinto, H; Boudry, Pierre; Lapegue, Sylvie.
In the Pacific oyster, Crassostrea gigas hypodiploid aneuploid cells with 2n=19, 18 or 17 chromosomes have regularly been reported. There is a negative correlation between somatic aneuploidy and growth rate in oysters (Leitão et al., 2001a) as well as evidence for a genetic basis (Leitão et al., 2001b). Furthermore, non-random chromosome loss has been demonstrated in aneuploid karyotypes of C. gigas using the G-banding technique (Leitão et al., 2001c). This poster summarises different studies used to investigate the effects of the herbicide atrazine on the level of aneuploidy in this species
Tipo: Text
Palavras-chave: Genetic; Aneuploidy; Toxicology; Impact; Atrazine; Crassostrea gigas; Pacific oysters.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/acte-3489.pdf

Etude des anomalies chromosomiques chez Crassostrea gigas - Contrat de Plan Région Poitou-Charentes 2000-2006. Convention 2000
Provedor de dados: 5
Autores: Lapegue, Sylvie; Mccombie, Helen; Leitao, Alexandra; Bouilly, Karine; Sabatier, Sebastien; Heurtebise, Serge; Boudry, Pierre; Thiriot Quievreux, Catherine; Gerard, Andre.
Divers travaux menés depuis 1984 montrent qu’il existe, chez l’huître creuse Crassostrea gigas, des cellules montrant un nombre anormal de chromosomes (2n = 19, 18 ou même 17 au lieu de 2n = 20). Le niveau d’aneuploïdie est déterminé par le décompte des chromosomes à partir de suspensions cellulaires de tissu branchial. Le pourcentage de cellules aneuploïdes est toujours significativement supérieur dans les "lots de queue", c'est-à-dire les huîtres présentant des croissances plus faibles, et peut atteindre plus de 30 %. Récemment, une étude réalisée au sein du programme européen « Genephys » a démontré que plus de 50 % de la variance pour la vitesse de croissance était liée au taux d’aneuploïdie. Cependant, de nombreux points concernant ce phénomène...
Tipo: Text
Palavras-chave: Génétique; Chromosomes; Aneuploïdie; Huîtres creuses; Crassostrea gigas.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00043/15474/12853.pdf

Aneuploidy and its relationship with growth in different populations of the Pacific oyster (Crassostrea gigas, Thunberg)
Provedor de dados: 5
Autores: Boudry, Pierre; Leitao, Alexandra; Mccombie, Helen; Thiriot-quievreux, Catherine.
Cytogenetic abnormalities arising both in mitosis and meiosis are known to be common in bivalves. Here we review result obtained from the observations of somatic aneuploidy in different populations of the commercially important Pacific oyster, Crassostrea gigas. The oysters studied were either (1) produced in IFREMER hatcheries between 1986 and 1999, (some of these were part of the EU funded programme GENEPHYS); or (2) collected from wild populations along the French Atlantic coast. Chromosome numbers were scored from 30 mitotic metaphases in gill tissue per  individual studied. Aneuploid cells (2n - X) were observed in all the 13 populations studied. A highly significant negative correlation was observed between the level of aneuploidy and growth, i.e....
Tipo: Text
Palavras-chave: Growth; Genetic; Aneuploidy; Crassostrea gigas; Pacific oysters.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/acte-3446.pdf

Evidence of differential chromosome loss in aneuploid karyotypes of the Pacific oyster, Crassostrea gigas
Provedor de dados: 5
Autores: Leitao, Alexandra; Boudry, Pierre; Thiriot Quievreux, Catherine.
The G-banding technique was performed on aneuploid karyotypes from gill tissue of the Pacific oyster, Crassostrea gigas, to assess whether chromosome losses could be explained by differential chromosomal susceptibility and to clarify the negative correlation between aneuploidy and growth rate previously reported in different populations of this oyster. The study of 95 G-banded aneuploid karyotypes showed that only 4 of the 10 chromosome pairs (viz. 1, 5, 9, and 10) of C. gigas were affected by the loss of one homologous chromosome. Pairs 1, 9, and 10, which were lost in 56, 33, and 44% of cases, respectively, may be considered to be differentially affected. Hypotheses on this differential chromosomal susceptibility are discussed.
Tipo: Text
Palavras-chave: Oyster; Karyotype; G banding; Growth; Aneuploidy; Huître; Caryotype; Bandes G; Croissance; Aneuploïdie.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-742.pdf

Trans-Atlantic distribution of a mangrove oyster species revealed by 16S mtDNA and karyological analyses
Provedor de dados: 5
Autores: Lapegue, Sylvie; Boutet, Isabelle; Leitao, Alexandra; Heurtebise, Serge; Garcia, P; Thiriot Quievreux, C; Boudry, Pierre.
Three species of man.-rove oysters, Crassostrea rhizophorae, C. brasiliana, and C. gasar, have been described along the Atlantic shores of South America and Africa. Because the distribution of these molluscs is of great biological and commercial interest, their taxonomy and distribution deserve further clarification. Therefore, 15 populations were sampled from both continents. Their 16S mitochondrial polymorphism was studied by sequencing and PCR-RFLP analysis. Two haplotypes were identified. Haplotype a was the only one observed in Africa, but it was also observed in South America together with haplotype b. Because C. gasar is the only mangrove oyster identified on the west coast of Africa, haplotype a was attributed to this species, which has thus been...
Tipo: Text
Palavras-chave: Mangrove oyster; Crassostrea gasar; Karyotype; Phylogeography; 16S mitochondrial DNA.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/publication-2790.pdf

Endonuclease banding reveals that atrazine-induced aneuploidy resembles spontaneous chromosome loss in Crassostrea gigas
Provedor de dados: 5
Autores: Bouilly, Karine; Leitao, Alexandra; Chaves, Raquel; Guedes Pinto, Henrique; Boudry, Pierre; Lapegue, Sylvie.
Aneuploidy has previously been observed in the Pacific oyster, Crassostrea gigas, and shown to be negatively correlated with growth. Moreover, a significant impact of atrazine exposure has been described in C. gigas, and persistence of that effect has been observed between generations. Evidence of differential chromosome loss has been demonstrated in aneuploid karyotypes of C. gigas using the G-banding technique. Pairs 1, 5, 9, and 10 are characterized by the loss of 1 chromosome. As restriction enzyme (RE) digestion chromosome banding allows a better identification of chromosome pairs, we used this technique to identify which chromosomes are affected when aneuploidy is increased by exposure to atrazine. The progeny of oysters contaminated by atrazine were...
Tipo: Text
Palavras-chave: Crassostrea gigas; Pacific oyster; Restriction enzyme digestion chromosome banding; Atrazine; Aneuploidy; Crassostrea gigas; Huître creuse; Marquage chromosomique par digestion d'enzymes de restriction; Atrazine; Aneuploïdie.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/2005/publication-654.pdf

Impact of pollutants on aneuploidy in the Pacific oyster, Crassostrea gigas
Provedor de dados: 5
Autores: Bouilly, Karine; Leitao, Alexandra; Mccombie, Helen; Miramand, Pierre; Lapegue, Sylvie.
Aneuploidy is the alteration of the normal diploid chromosome number. In the Pacifie oyster, Crassastrea gigas, hypodiploid cells have regularly been reported as have a negative correlation between this phenomenon and growth and evidence for a genetic basis. We previously demonstrated a positive relationship between a pollutant, atrazine, and aneuploidy in Crassastrea gigas adults and juveniles. To evaluate the persistence of this impact, the present study focused on a sample of the same juveniles previously exposed to different atrazine treatments (0.0 1 mg/l which represents a peak value found in a polluted environment and 0.1 mg/l) for three and a half months. Then, we evaluated them for aneuploidy after another two and a half months in non polluted...
Tipo: Text
Palavras-chave: Cadmium; Atrazine; Pollutant; Pacific oyster; Aneuploidy.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-2852.pdf

Etude des anomalies chromosomiques chez Crassostrea gigas
Provedor de dados: 5
Autores: Lapegue, Sylvie; Mccombie, Helen; Leitao, Alexandra; Bouilly, Karine; Sabatier, Sebastien; Heurtebise, Serge; Boudry, Pierre; Thiriot, Catherine; Gerard, Andre.
Divers travaux menés depuis 1984 montrent qu'il existe, chez l'huître creuse Crassostrea gigas, des cellules montrant un nombre anormal de chromosomes (2n = 19, 18 ou même 17 au lieu de 2n = 20). Le niveau d'aneuploïdie est déterminé par le décompte des chromosomes à partir de suspensions cellulaires de tissu branchial. Le pourcentage de cellules aneuploïdes est toujours significativement supérieur dans les "lots de queue", c'est-à-dire les huîtres présentant des croissances plus faibles, et peut atteindre plus de 30 %. Récemment, une étude réalisée au sein du programme européen « Genephys » a démontré que plus de 50 % de la variance pour la vitesse de croissance était liée au taux d'aneuploïdie. Cependant, de nombreux points concernant ce phénomène...
Tipo: Text
Palavras-chave: Génétique; Chromosomes; Anomalies; Aneuploïdie; Atrazine; Huîtres creuses; Crassostrea gigas.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00199/31013/29417.pdf

Etude des anomalies chromosomiques chez Crassostrea gigas. Contrat Région Poitou-Charentes 2000-2006. Convention 99
Provedor de dados: 5
Autores: Lapegue, Sylvie; Mccombie, Helen; Leitao, Alexandra; Heurtebise, Serge; Boudry, Pierre; Thiriot Quievreux, Catherine; Gerard, Andre.
Divers travaux menés depuis 1984 montrent qu’il existe, chez l’huître creuse Crassostrea gigas, des cellules montrant un nombre anormal de chromosomes (2n = 19, 18 ou même 17 au lieu de 2n = 20). Le niveau d’aneuploïdie est déterminé par le décompte des chromosomes à partir de suspensions cellulaires de tissu branchial. Le pourcentage de cellules aneuploïdes est toujours significativement supérieur dans les "lots de queue", c'est-à-dire les huîtres présentant des croissances plus faibles, et peut atteindre plus de 30 %. Récemment, une étude réalisée au sein du programme européen « Genephys » a démontré que plus de 50 % de la variance pour la vitesse de croissance était liée au taux d’aneuploïdie. Cependant, de nombreux points concernant ce phénomène...
Tipo: Text
Palavras-chave: Génétique; Chromosomes; Aneuploïdie; Huîtres creuses; Crassostrea gigas.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00043/15473/12852.pdf

New insights about the introduction of the Portuguese oyster, Crassostrea angulata, into the North East Atlantic from Asia based on a highly polymorphic mitochondrial region
Provedor de dados: 5
Autores: Grade, Ana; Chairi, Hicham; Lallias, Delphine; Power, Deborah M.; Ruano, Francisco; Leitao, Alexandra; Drago, Teresa; King, Jonathan W.; Boudry, Pierre; Batista, Frederico M.
It is commonly presumed that the Portuguese oyster Crassostrea angulata was introduced into the North East (NE) Atlantic from Asia. The analysis of the nucleotide sequence of a highly polymorphic non-coding mitochondrial region (major noncoding region - MNR) of C. angulata samples collected in Europe (Portugal), Africa (Morocco) and Asia (Shantou and Taiwan) provided new insight into the introduction of this species into the NE Atlantic. Sixty haplotypes and a nucleotide diversity of 0.0077 were observed in 130 analyzed sequences. Higher nucleotide diversity levels were observed in NE Atlantic sites than in Asian sites and significant genetic differentiation was found between the two. Our results suggest that C. angulata might have been introduced to the...
Tipo: Text
Palavras-chave: Crassostrea angulata; Phylogeography; Genetic signature; Biological invasions.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00371/48200/48316.pdf

Etude des anomalies chromosomiques chez Crassostrea gigas - Contrat Région Poitou-Charentes 2000-2006. Convention 2002
Provedor de dados: 5
Autores: Bouilly, Karine; Mccombie, Helen; Leitao, Alexandra; Lapegue, Sylvie.
Divers travaux menés depuis 1984 montrent qu’il existe, chez l’huître creuse Crassostrea gigas, des cellules montrant un nombre anormal de chromosomes (2n = 19, 18 ou même 17 au lieu de 2n = 20). Le niveau d’aneuploïdie est déterminé par le décompte des chromosomes à partir de suspensions cellulaires de tissu branchial. Le pourcentage de cellules aneuploïdes est toujours significativement supérieur dans les "lots de queue", c'est-à-dire les huîtres présentant des croissances plus faibles, et peut atteindre plus de 30 %. Cette corrélation négative entre l’aneuploïdie somatique et le taux de croissance a été décrite à de nombreuses reprises (Thiriot-Quiévreux et al., 1988, 1992 ; Leitão et al., 2001a ; Zouros et al., 1996). Bien que les causes...
Tipo: Text
Palavras-chave: Génétique; Chromosomes; Aneuploïdie; Huîtres creuses; Crassostrea gigas.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00044/15475/12854.pdf

The taxonomic status and origin of the Portuguese oyster Crassostea angulata (Lamark, 1819)
Provedor de dados: 5
Autores: Batista, Frederico; Leitao, Alexandra; Huvet, Arnaud; Lapegue, Sylvie; Heurtebise, Serge; Boudry, Pierre.
The taxonomic status of the Portuguese oyster Crassostrea angulata and the Pacific oyster Crassostrea gigas has often been a matter of controversy. Based on larval shell morphology, experimental hybridisation and electrophoretic studies of enzyme polymorphism several authors have considered these two species as being synonymous. During the recent years, several genetic studies based on mitochondrial DNA and microsatellites data have provided evidences that the two taxa are genetically distinct although closely related. Furthermore, karyotype analyses have also highlighted the close genetic similarity of these taxa in comparison with other cupped oyster species. However, a comparative analysis of restriction enzymes ideograms revealed differences between...
Tipo: Text
Palavras-chave: Geographical origin; Phylogenetic; Genetic; Taxonomic status; Crassostrea angulata; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3433.pdf

Etude des ressources génétiques chez les huîtres creuses
Provedor de dados: 5
Autores: Boudry, Pierre; Heurtebise, Serge; Lapegue, Sylvie; Lam, Katherine; Mccombie, Helen; Leitao, Alexandra; Gerard, Andre.
L'étude de la variabilité génétique de l'huître creuse Crassostrea gigas est un point essentiel dans la mise en place de programmes de gestion des ressources génétiques et de sélection chez cette espèce. C. gigas, originaire du Japon, a été introduite dans de nombreuses régions du monde et représente aujourd'hui plus de 95 'ro de la production mondiale d'huîtres. Introduite en France au début des années 1970 pour remplacer l'huître portugaise Crassostrea angulata, c'est aujourd'hui une ressource de première importance pour notre région. Malgré la maîtrise du cycle de reproduction de l'espèce et son importance commerciale, elle n'a pas été génétiquement améliorée et on peut donc considérer les stocks comme « sauvages» ou « non domestiqués ». De plus, la...
Tipo: Text
Palavras-chave: Génétique; Huîtres creuses; Crassostrea gigas; Crassostrea gasar; Variabilité génétique.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00199/31008/29411.pdf

Le phénomène de l'anauploïdie et sa relation avec la croissance chez l'huître creuse Crassostrea gigas
Provedor de dados: 5
Autores: Leitao, Alexandra; Boudry, Pierre; Mccombie, Helen; Lapegue, Sylvie; Gerard, Andre; Thiriot-quievreux, Catherine.
Cytogenetic abnormalities have often been observed on bivalves on meiosis or mitosis. This is a review of various observations of somatic aneuploidy conducted on different populations of Crassastrea gigas.
Tipo: Text
Palavras-chave: Croissance; Aneuploïdie; Huîtres; Génétique; Crassostrea gigas; Cytogénétique.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3280.pdf

Persistence of atrazine impact on aneuploidy in the Pacific oyster, Crassostrea gigas
Provedor de dados: 5
Autores: Bouilly, Karine; Mccombie, Helen; Leitao, Alexandra; Lapegue, Sylvie.
Aneuploidy is the alteration of the normal diploid chromosome number. In the Pacific oyster, Crassostrea gigas, hypodiploid aneuploid cells have regularly been reported as has a negative correlation between this phenomenon and growth and evidence for a genetic basis. We previously demonstrated a positive relationship between a pollutant, atrazine, and aneuploidy in Crassostrea gigas adults and juveniles. To evaluate the persistence of this impact, the present study focused on a sample of the same juveniles exposed to different atrazine treatments (0.01 mg/l which represents a peak value found in a polluted environment and 0.1 mg/l) for three and a half months and evaluated them for aneuploidy after another two and a half months in non polluted conditions....
Tipo: Text
Palavras-chave: Crassostrea gigas; Genetic; Pollutant persistence; Oyster culture; Marine molluscs; Herbicides; Cultured organisms; Chromosomes.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-3344.pdf

Insights on the association between somatic aneuploidy and ostreid herpesvirus 1 detection in the oysters Crassostrea gigas, C. angulata and their F1 hybrids
Provedor de dados: 5
Autores: Batista, Frederico M.; Lopez-sanmartin, Monserrat; Boudry, Pierre; Navas, Jose I.; Ruano, Francisco; Renault, Tristan; Fonseca, Vera G.; Leitao, Alexandra.
Cytogenetic abnormalities associated with viral infections, including from viruses of the Herpesvirales order, have been reported in vertebrate species. Ostreid herpesvirus 1 (OsHV-1) has been detected worldwide during mortality outbreaks of the Pacific oyster Crassostrea gigas. On the other hand, a high proportion of aneuploid cells in somatic tissues have been observed in C. gigas. In this study, we analysed the putative association between aneuploidy levels and the detection of OsHV-1 in gills of C. gigas, the Portuguese oyster C. angulata and their F1 hybrids cultured in Ria Formosa (Portugal). OsHV-1 was detected by PCR in 5.4% of the total of oysters analysed (n = 111) namely in 11.1%, 8.0% and 1.7% of C. gigas, C. angulata and F1 hybrid...
Tipo: Text
Palavras-chave: Aneuploidy; Ostreid herpesvirus 1; Oyster; Crassostrea.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00215/32581/35759.pdf

Persistence of atrazine impact on aneuploidy in Pacific oysters, Crassostrea gigas
Provedor de dados: 5
Autores: Bouilly, Karine; Mccombie, Helen; Leitao, Alexandra; Lapegue, Sylvie.
Widespread use of the herbicide atrazine has incited much research on its toxicity in aquatic systems, where it is routinely detected due to runoff from cultivated fields. Moreover, the determination of the genotoxic effect of such pollutants in the marine environment has become a major requirement for ecosystem protection. In the Pacific oyster, Crassostrea gigas, hypodiploid aneuploid cells have regularly been reported. There is a negative correlation between this phenomenon and growth, as well as evidence for a genetic basis. A positive relationship between atrazine and aneuploidy has previously been demonstrated in C. gigas adults and juveniles. To evaluate the persistence of this impact, our study examined the offspring of the same adult population...
Tipo: Text
Palavras-chave: Aneuploidy; Crassostrea gigas; Atrazine; Toxicity; Pollutant persistence.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-580.pdf

Phylogeography of mangrove oysters from the Southern Atlantic ocean : Crassostrea gasar and Crassostre rhizophorae
Provedor de dados: 5
Autores: Lapegue, Sylvie; Boutet, Isabelle; Leitao, Alexandra; Thiriot-quievreux, Catherine; Heurtebise, Serge; Garcia, P.; Boudry, Pierre.
Mangrove oysters encompass several species and their taxomony is unclear. Among then, Crassostrea rhizophorae has been described along the Central and South American Atlantic coasts and Crassostrea gasar along African Atlantic coasts. Most taxonomic studies have so far been based on morphological criteria which are particularly susceptible to plasticity and new insight can be provided by molecular markers. The present work aims to provide information on the phylogeography of these two taxa.
Tipo: Text
Palavras-chave: Genetic; Phylogeography; Crassostrea rhizophorae; Crassostrea gasar; Mangrove oysters.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/acte-3496.pdf

Experimental evidence for a genetic basis to differences in aneuploidy in the Pacific oyster (Crassostrea gigas)
Provedor de dados: 5
Autores: Leitao, Alexandra; Boudry, Pierre; Mccombie, Helen; Gerard, Andre; Thiriot-quievreux, Catherine.
Aneuploidy has been previously reported in wild and cultivated Pacific oysters, Crassostrea gigas, and has been shown to be negatively correlated with growth. This is especially important since high variability of growth rate is one of the major problems in the aquacultural production of this species. The existence of a genetic basis for the observed differences in aneuploidy was first investigated through the comparative study of six full-sib families, with mean individual weights ranging from 0.59 to 1.49 g. The slowest growing family was found to have the highest level of aneuploidy. Significant differences in aneuploidy were also found among families when individuals with the same growth rate were sampled. This supports the hypothesis of the existence...
Tipo: Text
Palavras-chave: Oyster; Growth; Genetics; Full sib families; Crassostrea gigas; Aneuploidy; Huître; Croissance; Génétique; Famille de plein frères; Crassostrea gigas; Aneuploïdie.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/2001/publication-2700.pdf

Phylogéographie des huîtres de mangrove de l'Océan Atlantique Sud : C. gasar et C. rhisophorae
Provedor de dados: 5
Autores: Heurtebise, Serge; Boutet, Isabelle; Verden, B.; Lapegue, Sylvie; Leitao, Alexandra; Thiriot-quievreux, Catherine; Garica, P.; Boudry, Pierre.
Mangrove oysters include various species that are also present on different coasts. In the southern part of the Atlantic Ocean, Crassostrea rhizophorae has been observed along the southern coast of America and Crassostrea gasar along the western coast of Africa. Fifteen populations of these oysters were sampled from these two geographic areas. Their polymorphism was studied on the 16S mitochondrial fragment both by par sequencing and RFLP analysis. Some samples' caryotype were also analysed. Two haplotypes were identified: C. gasar was found in Africa, but also for the first time in South America, whereas C. rhizophorae was only found on the coasts of South America.
Tipo: Text
Palavras-chave: Crassostrea rhizophorae; Crassostrea gasar; Huîtres; Génétique; Phylogéographie.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/acte-3278.pdf

Cytogenetic study of Ostrea conchaphila (Mollusca : Bivalvia) and comparative karyological analysis within Ostreinae
Provedor de dados: 5
Autores: Leitao, Alexandra; Chaves, Raquel; Santos, Sara; Boudry, Pierre; Guedes Pinto, Henrique; Thiriot Quievreux, Catherine.
Chromosome preparations of the Olympia oyster Ostrea conchaphila Carpenter were studied using conventional Giemsa, silver staining, and C-banding techniques. The karyotype consists of six metacentric (1, 2, 4, 6, 8, and 10) and four submetacentric (3, 5, 7, 9) chromosome pairs. The silver-stained nucleolus organizer regions (Ag-NORs) were terminally located on the short arms of the submetacentric pair 5 (56% of cases) and on the long arms of submetacentric pair 7 (6% of cases). Constitutive heterochromatin was observed as telomeric C-bands on the short arm of the NOR-bearing chromosome pair 5 and as centromeric blocks of several chromosome pairs. Comparative analysis of patterns of karyotype, Ag-NORs, and C-bands of this species and of five other flat...
Tipo: Text
Palavras-chave: Ostreinae; Cytotaxonomy; Cytogenetics; Ostrea conchaphila.
Ano: 2002
URL: https://archimer.ifremer.fr/doc/2002/publication-2792.pdf

The reproductive cycle of the European clam Ruditapes decussatus (L., 1758) in two Portuguese populations: Implications for management and aquaculture programs
Provedor de dados: 5
Autores: Matias, Domitilia; Joaquim, Sandra; Matias, Ana Margarete; Moura, Paula; Sousa, Joana; Sobral, Paula; Leitao, Alexandra.
The reproductive cycle, as well as its nutrient storage and utilization, of two populations of Ruditapes decussatus from the main production areas of this species: Ria de Aveiro and Ria Formosa Lagoon (Portugal) were studied here over a 24 month period (May 2010-April 2012). The reproductive cycle of both populations of R. decussatus followed an annual cyclicality that comprised a ripe stage in spring followed by a spawning period that began in late spring and extended throughout summer until early autumn. This extended and continuous spawning period may be an advantageous strategy for this species by ensuring a continuous supply of gametes. Moreover, R. decussatus can adopt different reproductive strategies depending on the geographical origin. The...
Tipo: Text
Palavras-chave: European clam; Ruditapes decussatus; Reproductive cycle; Portuguese populations; Biochemical composition; Seasonal variations.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00152/26292/25461.pdf

Insights into Molecular Features of Venerupis decussata Oocytes: A Microarray-Based Study
Provedor de dados: 5
Autores: Pauletto, Marianna; Milan, Massimo; Teixeira De Sousa, Joana; Huvet, Arnaud; Joaquim, Sandra; Matias, Domitilia; Leitao, Alexandra; Patarnello, Tomaso; Bargelloni, Luca.
The production of Venerupis decussata relies on wild seed collection, which has been recently compromised due to recruitment failure and severe mortalities. To address this issue and provide an alternative source of seed, artificial spawning and larval rearing programs were developed. However, hatchery-based seed production is a relatively new industry and it is still underdeveloped. A major hurdle in the European clam seed production is the control of spawning and reproduction, which is further hindered by the impossibility of obtaining fertile gametes by gonadal "stripping'', as meiosis re-initiation is constrained to a maturation process along the genital ducts. In the present study, oocytes were collected from 15 females and microarray analyses was...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00254/36532/35059.pdf

A "G" chromosome banding study of three cupped oyster species : Crassostrea gigas, Crassostrea angulata and Crassostrea virginica (Mollusca : Bivalvia)
Provedor de dados: 5
Autores: Leitao, Alexandra; Thiriot-quievreux, Catherine; Malheiro, Isabel; Boudry, Pierre.
The G-banding technique was performed on chromosomes from gill tissue of three cupped oyster species : Crassostrea gigas, Crassostrea angulata and Crassostrea virginica. Identification of the ten individual chromosome pairs was obtained. Comparative analysis of G-banded karyotypes of the three species showed that their banding patterns generally resembled each other, with chromosome pair 3 being similar in all three species. However, differences from one species to another were also observed. The G-banding pattern highlighted greater similarities between C. gigas and C. angulata than between these two species and C. virginica, thus providing an additional argument for genetic divergence between, these two evolutionary lineages. C. gigas and C. angulata...
Tipo: Text
Palavras-chave: Crassostrea virginica; Crassostrea angulata; Crassostrea gigas; G banding; Chromosome.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/publication-2736.pdf