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W. Yoosukh - One of the best experts on this subject based on the ideXlab platform.
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Molecular taxonomy of cupped oysters (Crassostrea, Saccostrea, and Striostrea) in Thailand based on COI, 16S, and 18S rDNA polymorphism.
Marine Biotechnology, 2005Co-Authors: Sirawut Klinbunga, Bavornlak Khamnamtong, Narongsak Puanglarp, Padermsak Jarayabhand, W. Yoosukh, Piamsak MenasvetaAbstract:Genetic diversity of oysters Crassostrea belcheri (Sowerby, 1871), C. iredalei (Faustino, 1932), Saccostrea cucullata (Born, 1778), S. forskali (Gmelin, 1791), and Striostrea (Parastriostrea) mytiloides (Lamarck, 1819) (Ostreoida, Mollusca) was analyzed by polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) of 16S ribosomal DNA with AcsI, AluI, DdeI, DraI, RsaI, and TaqI, 18S ribosomal DNA with HinfI, and cytochrome oxidase subunit I with AcsI, DdeI and MboI. A total of 54 composite haplotypes were observed. Species-diagnostic markers were specifically found in C. belcheri, C. iredalei, and S. cucullata, but not in S. forskali and Striostrea mytiloides, which shared common composite haplotypes. Neighbor-joining trees constructed from genetic distances between pairs of composite haplotypes and species indicated large genetic differences between Crassostrea and Saccostrea (including Striostrea mytiloides), but closer relationships were observed within each genus. Four groups of unidentified oysters (Crassostrea sp. and Saccostrea sp. groups 1, 2, and 3) were also genetically analyzed. Fixed RFLP markers were found in Crassostrea sp. and Saccostrea sp. group 2, but not in Saccostrea sp. groups 1 and 3. Phylogenetic and genetic heterogeneity analyses indicated that Crassostrea sp. and Saccostrea sp. group 2 should be considered as newly unidentified oyster species in Thailand.
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Molecular Genetic Identification Tools for Three Commercially Cultured Oysters (Crassostrea belcheri, Crassostrea iredalei, and Saccostrea cucullata) in Thailand
Marine Biotechnology, 2003Co-Authors: Sirawut Klinbunga, Narongsak Puanglarp, Padermsak Jarayabhand, Anchalee Tassanakajon, N. Khamnamtong, W. YoosukhAbstract:Abstract Molecular genetic keys for identification of 3 commercially cultured oysters (Crassostrea belcheri, Crassostrea iredalei, and Saccostrea cucullata) in Thailand were developed based on restriction analysis of 18S ribosomal DNA and cytochrome oxidase subunit I (COI). Digestion of the amplified 18S rDNA with Hinf I unambiguously differentiated Crassostrea oysters from Saccostrea oysters and Striostrea (Parastriostrea) mytiloides. In addition, species-specific restriction fragment length polymorphism patterns of C. belcheri, C. iredalei, and S. cucullata were consistently observed when the gel-eluted COI was digested with Mbo I and Dde I. Thirty composite haplotypes were observed across all individuals. Species-specific composite haplotypes were found in C. belcheri (AAAA and AAAB), C. iredalei (AABC and AABU), and S. cucullata (BBCD and BBCE), respectively. The most common composite haplotype of COI in C. belcheri (AAAA), C. iredalei (AABC), and S. cucullata (BBCD) was amplified, cloned, and sequenced. Detection of C. belcheri and C. iredalei based on polymerase chain reaction was further developed using more specific primers (HCO2198 and R372) followed by digestion of a 372-bp product with Mbo I.
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Genetic diversity and molecular markers of cupped oysters (Genera Crassostrea, Saccostrea, and Striostrea) in Thailand revealed by randomly amplified polymorphic DNA analysis.
Marine Biotechnology, 2001Co-Authors: Sirawut Klinbunga, Padermsak Jarayabhand, P. Ampayup, Anchalee Tassanakajon, W. YoosukhAbstract:Genetic diversity and species-diagnostic markers of 5 oysters in Thailand, Crassostrea belcheri (Sowerby, 1871), Crassostrea iredalei (Faustino, 1932), Saccostrea cucullata (Born, 1778), Saccostrea forskali (Gmelin, 1791), and Striostrea (Parastriostrea) mytiloides (Lamarck, 1819), were investigated by randomly amplified polymorphic DNA (RAPD) analysis. In a total, 135, 127, and 108 genotypes were observed from primers OPA09, OPB01, and OPB08 (Operon Technologies Inc., kits A and B), and 131 and 122 genotypes from primers UBC210 and UBC220 (University of British Columbia), respectively. Two hundred fifty-four reproducible and polymorphic fragments (200–2500 bp in length) were generated across the 5 investigated species. The average number of bands per primer varied between 12.4 and 32.2. The percentage of polymorphic bands within Crassostrea (53.23%–77.67%) was lower than that within Saccostrea and Striostrea oysters (86.21%–99.36%). Nine, species-specific markers were found in C. belcheri, 4 in C. iredalei, and 2 in S. cucullata. The mean of a ratio between the number of genotypes generated by each primer and the number of investigated specimens of C. belcheri (0.58) was lower than that of the remaining species (0.90–1.00). Genetic distances between pairs of oyster samples were between 0.105 and 0.811. A neighbor-joining tree indicated distant relationships between Crassostrea and Saccostrea oysters, but closer relationships were observed between the latter and Striostrea mytiloides.
Sirawut Klinbunga - One of the best experts on this subject based on the ideXlab platform.
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Molecular taxonomy of cupped oysters (Crassostrea, Saccostrea, and Striostrea) in Thailand based on COI, 16S, and 18S rDNA polymorphism.
Marine Biotechnology, 2005Co-Authors: Sirawut Klinbunga, Bavornlak Khamnamtong, Narongsak Puanglarp, Padermsak Jarayabhand, W. Yoosukh, Piamsak MenasvetaAbstract:Genetic diversity of oysters Crassostrea belcheri (Sowerby, 1871), C. iredalei (Faustino, 1932), Saccostrea cucullata (Born, 1778), S. forskali (Gmelin, 1791), and Striostrea (Parastriostrea) mytiloides (Lamarck, 1819) (Ostreoida, Mollusca) was analyzed by polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) of 16S ribosomal DNA with AcsI, AluI, DdeI, DraI, RsaI, and TaqI, 18S ribosomal DNA with HinfI, and cytochrome oxidase subunit I with AcsI, DdeI and MboI. A total of 54 composite haplotypes were observed. Species-diagnostic markers were specifically found in C. belcheri, C. iredalei, and S. cucullata, but not in S. forskali and Striostrea mytiloides, which shared common composite haplotypes. Neighbor-joining trees constructed from genetic distances between pairs of composite haplotypes and species indicated large genetic differences between Crassostrea and Saccostrea (including Striostrea mytiloides), but closer relationships were observed within each genus. Four groups of unidentified oysters (Crassostrea sp. and Saccostrea sp. groups 1, 2, and 3) were also genetically analyzed. Fixed RFLP markers were found in Crassostrea sp. and Saccostrea sp. group 2, but not in Saccostrea sp. groups 1 and 3. Phylogenetic and genetic heterogeneity analyses indicated that Crassostrea sp. and Saccostrea sp. group 2 should be considered as newly unidentified oyster species in Thailand.
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Molecular Genetic Identification Tools for Three Commercially Cultured Oysters (Crassostrea belcheri, Crassostrea iredalei, and Saccostrea cucullata) in Thailand
Marine Biotechnology, 2003Co-Authors: Sirawut Klinbunga, Narongsak Puanglarp, Padermsak Jarayabhand, Anchalee Tassanakajon, N. Khamnamtong, W. YoosukhAbstract:Abstract Molecular genetic keys for identification of 3 commercially cultured oysters (Crassostrea belcheri, Crassostrea iredalei, and Saccostrea cucullata) in Thailand were developed based on restriction analysis of 18S ribosomal DNA and cytochrome oxidase subunit I (COI). Digestion of the amplified 18S rDNA with Hinf I unambiguously differentiated Crassostrea oysters from Saccostrea oysters and Striostrea (Parastriostrea) mytiloides. In addition, species-specific restriction fragment length polymorphism patterns of C. belcheri, C. iredalei, and S. cucullata were consistently observed when the gel-eluted COI was digested with Mbo I and Dde I. Thirty composite haplotypes were observed across all individuals. Species-specific composite haplotypes were found in C. belcheri (AAAA and AAAB), C. iredalei (AABC and AABU), and S. cucullata (BBCD and BBCE), respectively. The most common composite haplotype of COI in C. belcheri (AAAA), C. iredalei (AABC), and S. cucullata (BBCD) was amplified, cloned, and sequenced. Detection of C. belcheri and C. iredalei based on polymerase chain reaction was further developed using more specific primers (HCO2198 and R372) followed by digestion of a 372-bp product with Mbo I.
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Genetic diversity and molecular markers of cupped oysters (Genera Crassostrea, Saccostrea, and Striostrea) in Thailand revealed by randomly amplified polymorphic DNA analysis.
Marine Biotechnology, 2001Co-Authors: Sirawut Klinbunga, Padermsak Jarayabhand, P. Ampayup, Anchalee Tassanakajon, W. YoosukhAbstract:Genetic diversity and species-diagnostic markers of 5 oysters in Thailand, Crassostrea belcheri (Sowerby, 1871), Crassostrea iredalei (Faustino, 1932), Saccostrea cucullata (Born, 1778), Saccostrea forskali (Gmelin, 1791), and Striostrea (Parastriostrea) mytiloides (Lamarck, 1819), were investigated by randomly amplified polymorphic DNA (RAPD) analysis. In a total, 135, 127, and 108 genotypes were observed from primers OPA09, OPB01, and OPB08 (Operon Technologies Inc., kits A and B), and 131 and 122 genotypes from primers UBC210 and UBC220 (University of British Columbia), respectively. Two hundred fifty-four reproducible and polymorphic fragments (200–2500 bp in length) were generated across the 5 investigated species. The average number of bands per primer varied between 12.4 and 32.2. The percentage of polymorphic bands within Crassostrea (53.23%–77.67%) was lower than that within Saccostrea and Striostrea oysters (86.21%–99.36%). Nine, species-specific markers were found in C. belcheri, 4 in C. iredalei, and 2 in S. cucullata. The mean of a ratio between the number of genotypes generated by each primer and the number of investigated specimens of C. belcheri (0.58) was lower than that of the remaining species (0.90–1.00). Genetic distances between pairs of oyster samples were between 0.105 and 0.811. A neighbor-joining tree indicated distant relationships between Crassostrea and Saccostrea oysters, but closer relationships were observed between the latter and Striostrea mytiloides.
Standish K. Allen - One of the best experts on this subject based on the ideXlab platform.
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Performance of selectively-bred lines of eastern oyster, Crassostrea virginica, across eastern US estuaries
Aquaculture, 2016Co-Authors: Dina A. Proestou, Bryan T. Vinyard, Ryan J. Corbett, Jessica Piesz, Jessica M. Small, Standish K. Allen, Cui Li, Gregory DebrosseAbstract:Abstract Eastern oyster, Crassostrea virginica , aquaculture has expanded greatly in recent years, but further growth of the industry is constrained by disease-related losses. Oyster breeding programs supporting the oyster aquaculture industry along the east coast of the US have targeted resistance to three prominent diseases: MSX, Dermo, and ROD, caused by Haplosporidium nelsoni , Perkinsus marinus , and Roseovarius Crassostreae respectively. Consequently, selected oyster lines possess some level of resistance and/or tolerance but the extent to which these lines, derived from various programs, perform across diverse growing environments used by industry has not been tested. The performance of six selected eastern oyster lines was evaluated at five sites along the east coast of the US (Maine to Virginia) to 1) identify differences in performance among lines at each site, and 2) identify lines that perform well across all sites. Performance measures included growth, mortality, and yield over a 15-month evaluation period. During unusually high mortality events, subsets of oysters were processed for disease diagnosis. Growth trajectories were similar among lines within a site, but varied significantly across sites (78% of random variance explained). Oysters grown in Rhode Island were largest while oysters grown in Maine were smallest at the end of the study. Mortality varied greatly among lines at each site as well as among sites. Line × site interaction explained 61% of the total random variance in the mortality data. In Maine, extensive mortality was observed early in the year for all lines, coincident with increased ROD prevalence. In New Jersey and Virginia, unusually high mortality was evident in the UMFS, Clinton, and NEH-RI lines during the final months of the experiment when the prevalence of both Dermo and MSX were 100% and Statement of relevance First to evaluate multiple oyster lines across diverse sites.
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evaluation of cytochalasin b and 6 dimethylaminopurine for tetraploidy induction in the eastern oyster Crassostrea virginica
Aquaculture, 2016Co-Authors: Brittany L Peachey, Standish K. AllenAbstract:Abstract Cytochalasin B (CB) has been used to induce tetraploidy in oysters since the practice began in 1993. However, CB is toxic and presents health risks to hatchery workers who administer the treatment. 6-dimethylaminopurine (6-DMAP) is also an effective cytokinetic inhibitor, and does not carry the health risks of CB. We examined the relative effectiveness of 6-DMAP vs CB for producing tetraploids in the Eastern oyster ( Crassostrea virginica ). Survival and yield of tetraploids varied widely among the 15 experiments. Larvae resulting from 6-DMAP treatment had higher survival in 11 of the 14 trials on day two and day six/seven. For yield of tetraploids, 10 of 13 6-DMAP treatments had higher proportions of tetraploids on day two and at the second sampling – day six, seven, or nine – 7 of 10 had higher proportions of tetraploids. Tetraploid spat were obtained from the majority of surviving cultures. Based on these results, 6-DMAP can effectively replace CB for inducing polyploidy in C. virginica , and probably other Crassostrea spp. , due to the success of the treatment, the ease of application, and the reduction in health risk to hatchery workers. This study set the precedent for the use of 6-DMAP on C. virginica and established a new procedure for inducing tetraploids using triploid eggs. It might be possible to refine the treatment to further optimize yield of tetraploids. Statement of relevance In this manuscript we report a novel method of inducing tetraploid Crassostrea virginica from triploid eggs using 6-dimethylaminopurine. We compare the efficiency of cytochalasin B and 6-dimethylaminopurine for tetraploid induction. We also report the expected fecundity of triploid C. virginica females. The method of tetraploidy induction we report here will likely be useful for inducing tetraploidy in other Crassostrea spp.
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Genetic improvement for disease resistance in oysters: A review.
Journal of Invertebrate Pathology, 2015Co-Authors: Lionel Dégremont, Céline Garcia, Standish K. AllenAbstract:Oyster species suffer from numerous disease outbreaks, often causing high mortality. Because the environment cannot be controlled, genetic improvement for disease resistance to pathogens is an attractive option to reduce their impact on oyster production. We review the literature on selective breeding programs for disease resistance in oyster species, and the impact of triploidy on such resistance. Significant response to selection to improve disease resistance was observed in all studies after two to four generations of selection for Haplosporidium nelsoni and Roseovarius Crassostrea in Crassostrea virginica, OsHV-1 in Crassostrea gigas, and Martelia sydneyi in Saccostrea glomerata. Clearly, resistance in these cases was heritable, but most of the studies failed to provide estimates for heritability or genetic correlations with other traits, e.g., between resistance to one disease and another. Generally, it seems breeding for higher resistance to one disease does not confer higher resistance or susceptibility to another disease. For disease resistance in triploid oysters, several studies showed that triploidy confers neither advantage nor disadvantage in survival, e.g., OsHV-1 resistance in C. gigas. Other studies showed higher disease resistance of triploids over diploid as observed in C. virginica and S. glomerata. One indirect mechanism for triploids to avoid disease was to grow faster, thus limiting the span of time when oysters might be exposed to disease.
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Genetic confirmation of hybridization between Crassostrea gigas (Thunberg) and Crassostrea rivularis (Gould)
Aquaculture, 1993Co-Authors: Standish K. Allen, Patrick M. GaffneyAbstract:Abstract Of the numerous reports of hybridization attempts in the genus Crassostrea, none has been confirmed genetically. Three replicates of a 2×2 factorial mating of Crassostrea gigas×C. rivularis (C. arakiensis) were produced to examine the viability of this cross. Fertilization rate, yield of 48-h-old larvae, and survival of fertilized eggs was lower in the hybrids than pure crosses. All crosses showed similar larval growth rates, except C. rivularis×C. gigas, which grew more slowly. Genetic control of eyed larval size was indicated by the intermediate size of hybrids compared to pure crosses. Spat were obtained from most cultures and were shown by protein electrophoresis to be hybrids. Contaminants were also present, underscoring the need for genetic confirmation in studies on bivalve hybridization.
Padermsak Jarayabhand - One of the best experts on this subject based on the ideXlab platform.
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Molecular taxonomy of cupped oysters (Crassostrea, Saccostrea, and Striostrea) in Thailand based on COI, 16S, and 18S rDNA polymorphism.
Marine Biotechnology, 2005Co-Authors: Sirawut Klinbunga, Bavornlak Khamnamtong, Narongsak Puanglarp, Padermsak Jarayabhand, W. Yoosukh, Piamsak MenasvetaAbstract:Genetic diversity of oysters Crassostrea belcheri (Sowerby, 1871), C. iredalei (Faustino, 1932), Saccostrea cucullata (Born, 1778), S. forskali (Gmelin, 1791), and Striostrea (Parastriostrea) mytiloides (Lamarck, 1819) (Ostreoida, Mollusca) was analyzed by polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) of 16S ribosomal DNA with AcsI, AluI, DdeI, DraI, RsaI, and TaqI, 18S ribosomal DNA with HinfI, and cytochrome oxidase subunit I with AcsI, DdeI and MboI. A total of 54 composite haplotypes were observed. Species-diagnostic markers were specifically found in C. belcheri, C. iredalei, and S. cucullata, but not in S. forskali and Striostrea mytiloides, which shared common composite haplotypes. Neighbor-joining trees constructed from genetic distances between pairs of composite haplotypes and species indicated large genetic differences between Crassostrea and Saccostrea (including Striostrea mytiloides), but closer relationships were observed within each genus. Four groups of unidentified oysters (Crassostrea sp. and Saccostrea sp. groups 1, 2, and 3) were also genetically analyzed. Fixed RFLP markers were found in Crassostrea sp. and Saccostrea sp. group 2, but not in Saccostrea sp. groups 1 and 3. Phylogenetic and genetic heterogeneity analyses indicated that Crassostrea sp. and Saccostrea sp. group 2 should be considered as newly unidentified oyster species in Thailand.
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Molecular Genetic Identification Tools for Three Commercially Cultured Oysters (Crassostrea belcheri, Crassostrea iredalei, and Saccostrea cucullata) in Thailand
Marine Biotechnology, 2003Co-Authors: Sirawut Klinbunga, Narongsak Puanglarp, Padermsak Jarayabhand, Anchalee Tassanakajon, N. Khamnamtong, W. YoosukhAbstract:Abstract Molecular genetic keys for identification of 3 commercially cultured oysters (Crassostrea belcheri, Crassostrea iredalei, and Saccostrea cucullata) in Thailand were developed based on restriction analysis of 18S ribosomal DNA and cytochrome oxidase subunit I (COI). Digestion of the amplified 18S rDNA with Hinf I unambiguously differentiated Crassostrea oysters from Saccostrea oysters and Striostrea (Parastriostrea) mytiloides. In addition, species-specific restriction fragment length polymorphism patterns of C. belcheri, C. iredalei, and S. cucullata were consistently observed when the gel-eluted COI was digested with Mbo I and Dde I. Thirty composite haplotypes were observed across all individuals. Species-specific composite haplotypes were found in C. belcheri (AAAA and AAAB), C. iredalei (AABC and AABU), and S. cucullata (BBCD and BBCE), respectively. The most common composite haplotype of COI in C. belcheri (AAAA), C. iredalei (AABC), and S. cucullata (BBCD) was amplified, cloned, and sequenced. Detection of C. belcheri and C. iredalei based on polymerase chain reaction was further developed using more specific primers (HCO2198 and R372) followed by digestion of a 372-bp product with Mbo I.
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Genetic diversity and molecular markers of cupped oysters (Genera Crassostrea, Saccostrea, and Striostrea) in Thailand revealed by randomly amplified polymorphic DNA analysis.
Marine Biotechnology, 2001Co-Authors: Sirawut Klinbunga, Padermsak Jarayabhand, P. Ampayup, Anchalee Tassanakajon, W. YoosukhAbstract:Genetic diversity and species-diagnostic markers of 5 oysters in Thailand, Crassostrea belcheri (Sowerby, 1871), Crassostrea iredalei (Faustino, 1932), Saccostrea cucullata (Born, 1778), Saccostrea forskali (Gmelin, 1791), and Striostrea (Parastriostrea) mytiloides (Lamarck, 1819), were investigated by randomly amplified polymorphic DNA (RAPD) analysis. In a total, 135, 127, and 108 genotypes were observed from primers OPA09, OPB01, and OPB08 (Operon Technologies Inc., kits A and B), and 131 and 122 genotypes from primers UBC210 and UBC220 (University of British Columbia), respectively. Two hundred fifty-four reproducible and polymorphic fragments (200–2500 bp in length) were generated across the 5 investigated species. The average number of bands per primer varied between 12.4 and 32.2. The percentage of polymorphic bands within Crassostrea (53.23%–77.67%) was lower than that within Saccostrea and Striostrea oysters (86.21%–99.36%). Nine, species-specific markers were found in C. belcheri, 4 in C. iredalei, and 2 in S. cucullata. The mean of a ratio between the number of genotypes generated by each primer and the number of investigated specimens of C. belcheri (0.58) was lower than that of the remaining species (0.90–1.00). Genetic distances between pairs of oyster samples were between 0.105 and 0.811. A neighbor-joining tree indicated distant relationships between Crassostrea and Saccostrea oysters, but closer relationships were observed between the latter and Striostrea mytiloides.
Pierre Boudry - One of the best experts on this subject based on the ideXlab platform.
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Restriction enzyme digestion chromosome banding in Crassostrea and Ostrea species: comparative karyological analysis within Ostreidae.
Genome, 2004Co-Authors: Alexandra Leitão, Raquel Chaves, Sara Santos, Henrique Guedes-pinto, Pierre BoudryAbstract:Reliable banding techniques are a major necessity for genetic research in oysters. In this study, we carried out the cytogenetic characterization of four oyster species (family Ostreidae) using restriction endonuclease treatments. Chromosomes were treated with three different restriction enzymes, stained with Giemsa, and examined for banding patterns. The following species were studied: Crassostrea gigas (2n = 20; total number of bands with ApaI, 74; HaeIII, 61; PstI, 76), Crassostrea angulata (2n = 20; ApaI, 62; HaeIII, 61; PstI, 55) (subfamily Crassostreinae), Ostrea edulis (2n = 20; ApaI, 82; HaeIII, 59; PstI, 66), and Ostrea conchaphila (2n = 20; ApaI, 68; HaeIII, 62; PstI, 69) (subfamily Ostreinae). Treatment of samples with ApaI, HaeIII, and PstI produced specific banding patterns, which demonstrates the potential of these enzymes for chromosome banding in oysters. This is of special interest, since it has been recently shown in mammalian chromosomes that restriction enzyme banding is compatible with fluorescence in situ hybridiza- tion. This study therefore provides a fundamental step in genome mapping of oysters, since chromosome banding with restriction enzymes facilitates physical gene mapping in these important aquaculture species. The analysis of the banded karyotypes revealed a greater similarity within the genera of Crassostrea and Ostrea than between them. Resume : Des techniques fiables d'analyse caryotypique sont necessaires afin de pousser plus avant la recherche gene- tique chez les huitres. Dans ce travail, les auteurs ont realise une caracterisation cytogenetique de quatre especes d'huitres (famille des ostreides) a l'aide de traitements avec des enzymes de restriction. Les chromosomes ont ete trai- tes avec trois enzymes de restriction differentes, colores au Giemsa et examines pour la presence de bandes. Voici les resultats pour chacune des especes : Crassostrea gigas (2n = 20; nombre total de bandes avec ApaI, 74; HaeIII, 61; PstI, 76), Crassostrea angulata (2n = 20; ApaI, 62; HaeIII, 61; PstI, 55) (sous-famille des Crassostreinae) Ostrea edu- lis (2n = 20; ApaI, 82; HaeIII, 59; PstI, 66) et Ostrea conchaphila (2n = 20; ApaI, 68; HaeIII, 62; PstI, 69) (sous- famille des Ostreinae). Les traitements avec les enzymes de restriction ont produit des bandes specifiques, ce qui de- montre l'utilite potentielle de ces enzymes pour la revelation de bandes chromosomiques chez les huitres. Ceci est par - ticulierement interessant suite a la recente demonstration, sur des chromosomes de mammiferes, que la revelation des bandes resultant de ces traitements aux enzymes de restriction est compatible avec l'hybridation in situ en fluorescence. Cette etude fournit une assise importante en matiere de cartographie genomique chez les huitres puisque le marquage des chromosomes a l'aide d'enzymes de restriction facilitera la cartographie physique chez ces especes importantes en aquaculture. L'analyse des carytoypes ainsi marques a revele une plus grande similarite au sein des genres Crassostrea et Ostrea qu'entre eux. Mots cles : Ostreides, Crassostrea, Ostrea, marquage chromosomique, marquage in situ par digestion avec des enzymes de restriction.
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Phylogeography of mangrove oysters from the Southern Atlantic ocean : Crassostrea gasar and Crassostre rhizophorae
2000Co-Authors: Sylvie Lapegue, Serge Heurtebise, Alexandra Leitão, Catherine Thiriot-quiévreux, Isabelle Boutet, Pascale Garcia, Pierre BoudryAbstract: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.
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COMPARATIVE KARYOLOGICAL STUDY OF CUPPED OYSTER SPECIES
Malacologia, 1999Co-Authors: Alexandra Leitão, Pierre Boudry, Jean-philippe Labat, Catherine Thiriot-quiévreuxAbstract: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 nu cleolus organizer regions, Comparative karyological analysis of these six cupped oysters and of C. gigas was made using a Principal Component Analysis and a Hierarchical Clustering Analy sis, Crassostrea gasar appears isolated trom the other oyster species, Then, two c1usters are separated. The first one groups C. gigas, C. angulata and C. sikamea, in which C. gigas is ple siomorphic, The second one consists of C, ariakensis, C. virginica and S, commercialis. Results are discussed with regards to oyster species relationships based on other genetic characters and to hybridization possibilities.
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A 'G' chromosome banding study of three cupped oyster species: Crassostrea gigas, Crassostrea angulata and Crassostrea virginica (Mollusca: Bivalvia)
Genetics Selection Evolution, 1999Co-Authors: Alexandra Leitão, Catherine Thiriot-quiévreux, Pierre Boudry, Isabel MalheiroAbstract:The G-banding technique was performed on chromosomes from gill tissue of three cupped oyster species: Orassostrea gigas, Cmssostrea angulata and Cmssostrea virginiea. 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 ail three species. However, differences from one species to another were also observed. The G-banding pattern highlighted greater similarities between C. gigas and C. ang'l!lata than between these two species and C. virginiea, thus providing an additional argument for genetic divergence between these two evolutionary lineages. C. gigas and C. angulata showed a different G-banding patterns on the two arms of chromosome pair 7, which agrees with their taxonomic separation. The application of this banding technique offers a new approach to specifie problems in oyster taxonorny and genetics. © Inra/Elsevier, Paris chI'omosome / G-banding / Crassostrea gigas / Crassostrea angulata / Crassostrea virginica
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Comparative analysis of oxygen consumption rates between cupped oyster spat of Crassostrea gigas of French, japanese, Spanish and Taiwanese origins
Aquatic Living Resources, 1999Co-Authors: Philippe Goulletquer, Philippe Geairon, Maciej Wołowicz, Adam Latała, Arnaud Huvet, Pierre BoudryAbstract:Respiration rates of various geographical strains of Crassostrea gigas were compared to assess the respiratory expenditure as a physiological indicator of catabolism (cost of maintenance). Parental oysters, sampled in France (Marennes-Oleron), Japan (Hiroshima), Taiwan (Tunkang) and Spain (Cadix), were differentiated by both their geographic origin and by mitochondrial DNA markers, allowing the distinction between the two cIosely related taxa Crassostrea gigas and Crassostrea angulata. After reproduction of these parental oysters, respiration rates of spat of each strain, reared under common controlled conditions, were individually estimated at 20 oC by using a volumetric microrespirometer. Our results demonstrated that physiological variability existed among the Crassostrea gigas strains and is likely to be related to physiological differences between geographical regions and/or genetic adaptations. The French strain showed the highest rates (0.71 IlL·h-I), while the Japanese, Taiwanese and the hybrid between Spanish and French strains consumed less, 0.53, 0.43 and 0.40 IlL·h-l, respectively. Our results confirmed the discrepancies previously suggested between Crassostrea gigas and Crassostrea angulata. Comprehensive physiological assessments should be carried out over a wide temperature range to confirm our results and to further evaluate growth potential. Appropriate decision making based on these studies will help future shellfish management in shellfish rearing areas such as the overstocked Marennes-Oleron Bay. © 1999 Ifremer/CnrslInrallrd/CemagreflEditions scientifiques et medicales Elsevier SAS Respiration rates / metabolism / Crassostrea gigas / Crassostrea angulata / hybrids / oyster strains / NE Atlantic / Pacific Ocean