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Pierre Boudry - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Genome-Wide Differentiation between Native and Introduced Populations of the Cupped Oysters Crassostrea gigas and Crassostrea angulata
    Genome Biology and Evolution, 2018
    Co-Authors: Pierre-alexandre Gagnaire, Serge Heurtebise, Pierre Boudry, Florence Cornette, Nicolas Bierne, Jean-baptiste Lamy, Lionel Degremont, Emilie Flahauw, Sylvie Lapègue
    Abstract:

    The Pacific cupped oyster is genetically subdivided into two sister taxa, Crassostrea gigas and Crassostrea angulata, which are in contact in the northwestern Pacific. The nature and origin of their genetic and taxonomic differentiation remains controversial due the lack of known reproductive barriers and the high degree of morphologic similarity. In particular, whether the presence of ecological and/or intrinsic isolating mechanisms contributes to species divergence is unknown. The recent co-introduction of both taxa into Europe offers a unique opportunity to test how genetic differentiation is maintained under new environmental and demographic conditions. We generated a pseudochromosome assembly of the Pacific oyster genome using a combination of BAC-end sequencing and scaffold anchoring to a new high-density linkage map. We characterized genome-wide differentiation between C. angulata and C. gigas in both their native and introduced ranges, and showed that gene flow between species has been facilitated by their recent co-introductions in Europe. Nevertheless, patterns of genomic divergence between species remain highly similar in Asia and Europe, suggesting that the environmental transition caused by the co-introduction of the two species did not affect the genomic architecture of their partial reproductive isolation. Increased genetic differentiation was preferentially found in regions of low recombination. Using historical demographic inference, we show that the hetero-geneity of differentiation across the genome is well explained by a scenario whereby recent gene flow has eroded past differentiation at different rates across the genome after a period of geographical isolation. Our results thus support the view that low-recombining regions help in maintaining intrinsic genetic differences between the two species.

  • Asynchrony in settlement time between the closely related oysters Crassostrea angulata and C. gigas in Ria Formosa lagoon (Portugal)
    Marine Biology, 2017
    Co-Authors: Frederico M Batista, Vera G. Fonseca, Francisco Ruano, Pierre Boudry
    Abstract:

    The Portuguese oyster Crassostrea angulata and the Pacific oyster Crassostrea gigas are very closely related species originating from Asia that were introduced in Europe. The objectives of the present study were to determine if there is asynchrony in settlement time of C. angulata and C. gigas larvae in an area where both taxa coexist and if hybridization between the two species occurs throughout the breeding season. Oyster collectors were deployed every two weeks during one year in two different sites in Ria Formosa lagoon (Portugal) and the oysters that settled were genotyped with nuclear and mitochondrial markers. Settlement of Crassostrea sp. was observed from April to November 2004 (n = 694), with two distinct periods. In the first period (April), when 19% of the oysters settled, the haplotypes and alleles characteristic of C. gigas were mainly observed. In the following settlement period (July to November), the frequency of haplotypes and alleles of C. gigas decreased over time while those characteristics of C. angulata reached high frequencies by the end of the settlement period. Our results suggest that C. gigas was able to reproduce at lower temperatures than C. angulata in spring. However, the non-significant allelic disequilibrium observed during almost all settlement periods suggests that hybridization is widespread in time. The results obtained in the present study show that there are differences in the reproductive behavior between C. angulata and C. gigas that may limit gene flow between the two species.

  • Infestation of the cupped oysters Crassostrea angulata, C. gigas and their first-generation hybrids by the copepod Myicola ostreae: differences in susceptibility and host response.
    Parasitology, 2009
    Co-Authors: Frederico M Batista, Pierre Boudry, A. Dos Santos, Tristan Renault, Francisco Ruano
    Abstract:

    We studied the prevalence and intensity of the parasitic copepod Myicola ostreae in 2 closely related oysters Crassostrea angulata and C. gigas and their F1 hybrids. The effects on host and host reaction were also analysed to better understand host-parasite relationships between copepods and bivalve molluscs. Full reciprocal crosses were carried out between C. angulata and C. gigas and the progenies were reared in the wild in Ria Formosa Lagoon (Portugal), allowing natural infestation by M. ostreae. Prevalence and intensity were significantly higher in C. angulata than in C. gigas. The parasite level of F1 hybrids was similar to C. angulata and significantly higher than in C. gigas. The results of our study support a hypothesis of dominantly inherited susceptibility to M. ostreae infestation. Moreover, copepods were observed on the gill surface of C. gigas engulfed by a capsulelike structure. Histological analyses revealed that the copepods were surrounded by a massive agglomerate of haemocyte-like cells encircled by a thin layer of fibroblast-like cells. This encapsulation response was not observed in C. angulata or in F1 hybrids. These results suggest that the differential susceptibility to M. ostreae between C. angulata and C. gigas may be ascribed to host defence factors.

  • interspecific hybridization in oysters restriction enzyme digestion chromosome banding confirms Crassostrea angulata Crassostrea gigas f1 hybrids
    Journal of Experimental Marine Biology and Ecology, 2007
    Co-Authors: Raquel Chaves, Alexandra Leitão, Sara Santos, Henrique Guedespinto, Pierre Boudry
    Abstract:

    The taxonomic status of the two commercially important cupped oysters, Crassostrea angulata, the Portuguese oyster (Lamarck, 1819) and Crassostrea gigas, the Japanese oyster (Thunberg, 1793) has long been in question. The recent observation of the hybridization between C. gigas and C. angulata and the production of fertile F1s led us to search for cytogenetic evidence of both parental genomes in the interspecific hybrids. The cytogenetic characterization of the hybrids was performed by the use of restriction endonuclease treatments. This technique has recently shown the potential for individual chromosome identification by banding in oysters. Chromosomes of C. gigas, C. angulata and their hybrids were treated with two different restriction enzymes (ApaI and HaeIII), stained with Giemsa, and examined for banding patterns. These chromosome markers allowed the parental haploid sets to be identified in the hybrids. The analysis of the banded karyotypes of the interspecific hybrids showed that for each chromosome pair, one of the homologues presented a banding pattern consistent with that of C. gigas and the other homologue presented a banding pattern consistent with that of C. angulata. These cytogenetic results substantiate the reported interspecific hybridization between C. gigas and C. angulata. In view of these results and taking into account the present expansion of C. gigas aquaculture in southern Europe, the question of the need for preservation of pure C. angulata stocks should be raised as only a few populations remain in the south of Spain and Portugal. Recently, changes in the genetic composition of populations in southern Portugal have indeed been observed, showing that human activities have created contact zones between the two taxa while no natural sympatric zones exist in Europe.

  • Individual relationship between aneuploidy of gill cells and growth rate in the cupped oysters Crassostrea angulata, C. gigas and their reciprocal hybrids
    Journal of Experimental Marine Biology and Ecology, 2007
    Co-Authors: Frederico M Batista, Alexandra Leitão, Vera G. Fonseca, Radhouan Ben-hamadou, Francisco Ruano, Maria Armanda-reis Henriques, Henrique Guedes-pinto, Pierre Boudry
    Abstract:

    The Portuguese oyster, Crassostrea angulata, is taxonomically close to the Pacific oyster, C. gigas, but there are clear genetic and phenotypic differences between these taxa. Among those differences, the faster growth of C. gigas compared with C. angulata has often been observed in the field. Crosses between C. angulata and C. gigas were performed to investigate the relationship between growth variation and somatic aneuploidy at the individual level in the two taxa and their reciprocal hybrids. The different progenies were reared in Ria Formosa (Portugal) under standard farming conditions. Growth rate and survival were significantly higher in C. gigas than in C. angulata, and the hybrids showed intermediate performances. Significant differences were also observed in the proportion of aneuploid cells (PAC) and of missing chromosomes (PMC) between the two taxa, C. angulata showing the highest values. Intermediate values of PAC and PMC were observed in the hybrids, supporting additive genetic bases of these parameters. Our results also confirm the negative correlation between somatic aneuploidy and growth rate at the individual level, as previously reported in C. gigas.

Weiwei You - One of the best experts on this subject based on the ideXlab platform.

  • The role of copper and zinc accumulation in defense against bacterial pathogen in the fujian oyster (Crassostrea angulata).
    Fish & shellfish immunology, 2019
    Co-Authors: Bo Shi, Long Zhou, Zhen Zeng, Tian Wang, Weiwei You
    Abstract:

    Abstract Cu and Zn are hyper-accumulated in oysters, and the accumulation of these metals increases host resistance to pathogens. However, the role of Cu/Zn in oyster immune defense remains unclear. In this study, Crassostrea angulata with different levels of Cu and Zn were obtained through metal exposure or selective breeding. Both in vivo and in vitro experiments showed that oysters accumulating more Cu/Zn exhibited stronger antibacterial abilities. Vibrio harveyi infection significantly promoted the metal redistribution in oysters: Cu and Zn concentrations decreased in the mantle, but increased in the plasma and hemocytes. This redistribution was accompanied by changes in the expression levels of Cu and Zn transporter genes (CTR1, ATP7A, ZIP1, and ZNT2), suggesting that the Cu/Zn burst observed in the hemocytes was likely due to the transfer of heavy metals from plasma (mediated by the metal importer proteins) or released from intracellular stores. The degree to which Cu/Zn concentration increased in the plasma and hemocytes was more dramatic in oysters with high levels of Cu/Zn accumulation. In vitro, Cu and Zn both inhibited the growth of V. harveyi, while Cu plus H2O2 was lethal to the bacteria. The strength of the growth-inhibition and lethal effects depended on the metal dose. In addition to these effects, increases in Cu concentration increased the activity levels of PO in the oyster plasma and hemocytes in vivo and in vitro. However, SOD activity was not affected by Cu or Zn accumulation. Thus, our results suggested that the Cu/Zn burst in the hemolymph was an important factor in the oyster immune reaction, creating a toxic internal environment for the pathogen, as well as catalyzing inorganic or enzymatic reactions to strengthen bacteriostasis. By determining the extent of Cu/Zn burst in the immune response, Cu/Zn accumulated levels could affect the resistance of oysters to pathogens.

  • heritability estimates for copper zinc accumulation capabilities and correlation with growth quality traits in the fujian oyster Crassostrea angulata
    Aquaculture, 2019
    Co-Authors: Bo Shi, Long Zhou, Chenyu Dong, Weiwei You
    Abstract:

    Abstract Oysters are hyper-accumulators of copper (Cu) and zinc (Zn) and are a good food source for trace element supplements. However, increasing heavy metal pollution in estuaries and coastal areas has posed a critical threat to oysters and thus led to food safety issues. Here, we assessed if it is possible to obtain oyster varieties with differential metal-accumulated properties through genetic improvement. The narrow-sense heritabilities of Cu and Zn accumulation capabilities and growth traits in Fujian oyster (Crassostrea angulata) were estimated to determine the degree to which Cu and Zn accumulation is under genetic control. In addition, we investigated the trade-offs between Cu/Zn accumulation and some farming performances, including growth-related traits, and the contents of glycogen and eight free amino acids. Moderate estimates were observed for narrow-sense heritability of Cu (0.189 ± 0.061) and Zn (0.373 ± 0.091) accumulation capability, while growth-related traits showed moderate-high heritability (0.168 ± 0.059–0.595 ± 0.116). High-level genetic (0.802 ± 0.080) and phenotypic (0.853 ± 0.012) correlations were detected between Cu and Zn accumulation capability, while correlations between metal accumulation and growth traits were low (−0.023 ± 0.042–0.491 ± 0.200). Moreover, Cu and Zn accumulation in Fujian oyster exhibited no significant influence on the quality traits measured, except for Taurine (Tau). Tau contents in high Cu/Zn accumulated oysters were significantly higher than in low-accumulated oysters, suggesting an important role of Tau in Cu/Zn accumulation. Our results provide important information to guide effective selective breeding of Fujian oysters with specific Cu/Zn accumulation capabilities.

  • Heritability estimates for copper/zinc accumulation capabilities and correlation with growth/quality traits in the Fujian oyster, Crassostrea angulata
    Aquaculture, 2019
    Co-Authors: Bo Shi, Long Zhou, Chenyu Dong, Weiwei You
    Abstract:

    Abstract Oysters are hyper-accumulators of copper (Cu) and zinc (Zn) and are a good food source for trace element supplements. However, increasing heavy metal pollution in estuaries and coastal areas has posed a critical threat to oysters and thus led to food safety issues. Here, we assessed if it is possible to obtain oyster varieties with differential metal-accumulated properties through genetic improvement. The narrow-sense heritabilities of Cu and Zn accumulation capabilities and growth traits in Fujian oyster (Crassostrea angulata) were estimated to determine the degree to which Cu and Zn accumulation is under genetic control. In addition, we investigated the trade-offs between Cu/Zn accumulation and some farming performances, including growth-related traits, and the contents of glycogen and eight free amino acids. Moderate estimates were observed for narrow-sense heritability of Cu (0.189 ± 0.061) and Zn (0.373 ± 0.091) accumulation capability, while growth-related traits showed moderate-high heritability (0.168 ± 0.059–0.595 ± 0.116). High-level genetic (0.802 ± 0.080) and phenotypic (0.853 ± 0.012) correlations were detected between Cu and Zn accumulation capability, while correlations between metal accumulation and growth traits were low (−0.023 ± 0.042–0.491 ± 0.200). Moreover, Cu and Zn accumulation in Fujian oyster exhibited no significant influence on the quality traits measured, except for Taurine (Tau). Tau contents in high Cu/Zn accumulated oysters were significantly higher than in low-accumulated oysters, suggesting an important role of Tau in Cu/Zn accumulation. Our results provide important information to guide effective selective breeding of Fujian oysters with specific Cu/Zn accumulation capabilities.

  • Differential effects of zinc exposure on male and female oysters (Crassostrea angulata) as revealed by label-free quantitative proteomics.
    Environmental toxicology and chemistry, 2017
    Co-Authors: Lianzhong Luo, Heqing Huang, Qinghong Zhang, Xue Kong, Weiwei You
    Abstract:

    Oysters accumulate Zn as an adaptation to Zn exposure; however, it is not known whether male and female oysters respond differently to Zn exposure. Proteomic and real-time polymerase chain reaction analyses were used to investigate differential responses of male and female oysters (Crassostrea angulata) to Zn exposure. After exposure to 50 μg L-1 or 500 μg L-1 Zn for 30 d, gonads of female oysters accumulated more Zn than those of males, and gonadal development was accelerated in females but was abnormal in males. Differentially expressed proteins after exposure to Zn were identified and shown to function in Zn transport, Ca transport, phosphate metabolism, energy metabolism, immune regulation, oxidative stress responses, gene expression regulation, and fat metabolism. Proteins with functions in Zn transportation and storage, and multifunctional proteins, such as hemicentin-1 and histidinol dehydrogenase, were expressed at significantly higher levels in the gonads of female than male oysters after Zn exposure. Environ Toxicol Chem 2017;36:2602-2613. © 2017 SETAC.

  • Molecular cloning of two molluscan caspases and gene functional analysis during Crassostrea angulata (Fujian oyster) larval metamorphosis
    Molecular biology reports, 2014
    Co-Authors: Bingye Yang, Weiwei You, Heqing Huang
    Abstract:

    Caspases have been demonstrated to possess important functions in apoptosis and immune system in vertebrate. But there is less information reported on the oyster larval development. In the present work, two full-length molluscan caspase genes, named Cacaspase-2 and Cacaspase-3, were characterized for the first time from Fujian oyster, Crassostrea angulata. Which respectively encode two predicted proteins both containing two caspase domains of p20 and p10 including the cysteine active site pentapeptide “QACRG” and the histidine active site signature. Otherwise Cacaspase-2 also contains a caspase recruitment domain. Homology and phylogenetic analysis showed that Cacaspase-2 shared high similarity with initiator caspase-2 groups, but Cacaspase-3 clustered together with executioner caspase-3 groups. Cacaspase-2 and Cacaspase-3 mRNA were both highly expressed in gills and labial palp and were significantly expressed highly in larvae during settlement and metamorphosis. Through the whole mount in situ hybridization, the location of Cacaspase-2 is in the foot of the oyster larvae and the location of Cacaspase-3 is in both the foot and velum tissues. These results implied that Cacaspase-2 and Cacaspase-3 genes play a key role in the loss of foot and Cacaspase-3 gene has an important function in the loss of velum during larvae metamorphosis in C. angulata.

Frederico M Batista - One of the best experts on this subject based on the ideXlab platform.

  • Asynchrony in settlement time between the closely related oysters Crassostrea angulata and C. gigas in Ria Formosa lagoon (Portugal)
    Marine Biology, 2017
    Co-Authors: Frederico M Batista, Vera G. Fonseca, Francisco Ruano, Pierre Boudry
    Abstract:

    The Portuguese oyster Crassostrea angulata and the Pacific oyster Crassostrea gigas are very closely related species originating from Asia that were introduced in Europe. The objectives of the present study were to determine if there is asynchrony in settlement time of C. angulata and C. gigas larvae in an area where both taxa coexist and if hybridization between the two species occurs throughout the breeding season. Oyster collectors were deployed every two weeks during one year in two different sites in Ria Formosa lagoon (Portugal) and the oysters that settled were genotyped with nuclear and mitochondrial markers. Settlement of Crassostrea sp. was observed from April to November 2004 (n = 694), with two distinct periods. In the first period (April), when 19% of the oysters settled, the haplotypes and alleles characteristic of C. gigas were mainly observed. In the following settlement period (July to November), the frequency of haplotypes and alleles of C. gigas decreased over time while those characteristics of C. angulata reached high frequencies by the end of the settlement period. Our results suggest that C. gigas was able to reproduce at lower temperatures than C. angulata in spring. However, the non-significant allelic disequilibrium observed during almost all settlement periods suggests that hybridization is widespread in time. The results obtained in the present study show that there are differences in the reproductive behavior between C. angulata and C. gigas that may limit gene flow between the two species.

  • 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
    Aquatic Living Resources, 2016
    Co-Authors: Deborah M. Power, Frederico M Batista, Alexandra Leitão, Francisco Ruano, Jonathan W. King, Ana Grade, Hicham Chairi, Delphine Lallias, Deborah Power, Teresa Drago
    Abstract:

    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 NE Atlantic by multiple introductory events, though the exact origins remain unknown since none of the analyzed Asian sites seemed to have been a source of introduction. The nucleotide diversity of C. angulata was higher than that previously reported for Pacific oyster C. gigas in Europe and Asia for the same mitochondrial region. The results obtained in the present study suggest that NE Atlantic C. angulata stocks are a unique genetic resource, which highlights the importance of their conservation.

  • evidence of vertical transmission of ostreid herpesvirus 1 in the portuguese oyster Crassostrea angulata
    Journal of Invertebrate Pathology, 2016
    Co-Authors: Monserrat Lopez Sanmartin, Jose I Navas, Frederico M Batista, Roberto Herrán, Deborah M. Power
    Abstract:

    Abstract In order to determine if ostreid herpesvirus 1 (OsHV-1) can be vertically transmitted, 9 full-sib families of the Portuguese oyster Crassostrea angulata were produced using a factorial mating design with 3 males and 3 females. The parents were survivors from an OsHV-1 mortality outbreak. OsHV-1 DNA was not detected by conventional PCR in the mantle of parents, gametes or 3 day-old larvae. However, viral DNA was detected by real-time PCR in all gametes and larvae samples. These results show that C. angulata that have survived an OsHV-1 mortality outbreak can carry the virus and vertically transmit it to their offspring.

  • Infestation of the cupped oysters Crassostrea angulata, C. gigas and their first-generation hybrids by the copepod Myicola ostreae: differences in susceptibility and host response.
    Parasitology, 2009
    Co-Authors: Frederico M Batista, Pierre Boudry, A. Dos Santos, Tristan Renault, Francisco Ruano
    Abstract:

    We studied the prevalence and intensity of the parasitic copepod Myicola ostreae in 2 closely related oysters Crassostrea angulata and C. gigas and their F1 hybrids. The effects on host and host reaction were also analysed to better understand host-parasite relationships between copepods and bivalve molluscs. Full reciprocal crosses were carried out between C. angulata and C. gigas and the progenies were reared in the wild in Ria Formosa Lagoon (Portugal), allowing natural infestation by M. ostreae. Prevalence and intensity were significantly higher in C. angulata than in C. gigas. The parasite level of F1 hybrids was similar to C. angulata and significantly higher than in C. gigas. The results of our study support a hypothesis of dominantly inherited susceptibility to M. ostreae infestation. Moreover, copepods were observed on the gill surface of C. gigas engulfed by a capsulelike structure. Histological analyses revealed that the copepods were surrounded by a massive agglomerate of haemocyte-like cells encircled by a thin layer of fibroblast-like cells. This encapsulation response was not observed in C. angulata or in F1 hybrids. These results suggest that the differential susceptibility to M. ostreae between C. angulata and C. gigas may be ascribed to host defence factors.

  • Individual relationship between aneuploidy of gill cells and growth rate in the cupped oysters Crassostrea angulata, C. gigas and their reciprocal hybrids
    Journal of Experimental Marine Biology and Ecology, 2007
    Co-Authors: Frederico M Batista, Alexandra Leitão, Vera G. Fonseca, Radhouan Ben-hamadou, Francisco Ruano, Maria Armanda-reis Henriques, Henrique Guedes-pinto, Pierre Boudry
    Abstract:

    The Portuguese oyster, Crassostrea angulata, is taxonomically close to the Pacific oyster, C. gigas, but there are clear genetic and phenotypic differences between these taxa. Among those differences, the faster growth of C. gigas compared with C. angulata has often been observed in the field. Crosses between C. angulata and C. gigas were performed to investigate the relationship between growth variation and somatic aneuploidy at the individual level in the two taxa and their reciprocal hybrids. The different progenies were reared in Ria Formosa (Portugal) under standard farming conditions. Growth rate and survival were significantly higher in C. gigas than in C. angulata, and the hybrids showed intermediate performances. Significant differences were also observed in the proportion of aneuploid cells (PAC) and of missing chromosomes (PMC) between the two taxa, C. angulata showing the highest values. Intermediate values of PAC and PMC were observed in the hybrids, supporting additive genetic bases of these parameters. Our results also confirm the negative correlation between somatic aneuploidy and growth rate at the individual level, as previously reported in C. gigas.

Bo Shi - One of the best experts on this subject based on the ideXlab platform.

  • Differential Gene expression related to morphological variation in the adductor muscle tissues of diploid and triploid fujian oysters, Crassostrea angulata
    Aquaculture Research, 2019
    Co-Authors: Zhen Zeng, Zixia Huang, Qianglai Tan, Bo Shi
    Abstract:

    The Fujian oyster, Crassostrea angulata, accounts for approximately 50% of the total oyster production in China and is one of the most economically important marine products. In this study, we investigated differential gene expression profiles between diploid (n = 2) and triploid (n = 3) oysters that may indicate the specific adaptation associated with ploidy. A total of 14,626,126 and 15,492,551 reads were generated from diploid and triploid oyster muscle transcriptomes using Illumina RNA‐Seq respectively. Gene expression analysis revealed a total of 2,045 differentially expressed genes between 2n and 3n individuals, from which 814 genes were significantly up‐regulated in the 2n transcriptome while 1,231 were down‐regulated. In addition, 24 differentially expressed genes (DEGs) were uniquely expressed in 2n individuals while 28 DEGs were uniquely expressed in 3n individuals. Furthermore, our pathway analysis suggested that the DEGs up‐regulated in 2n oysters were enriched in the pathways related to normal growth, development and reproduction, whereas DEGs up‐regulated in 3n individuals may be involved in faster growth and metabolism. Finally, we validated the expression levels of 15 genes using quantitative real‐time PCR (qRT‐PCR), and 14 out of 15 genes showed consistent expression patterns with RNA‐Seq data. This study provides an important foundation for further investigations on distinct gene expression patterns and signalling pathways that differ between diploid and triploid oysters.

  • The role of copper and zinc accumulation in defense against bacterial pathogen in the fujian oyster (Crassostrea angulata).
    Fish & shellfish immunology, 2019
    Co-Authors: Bo Shi, Long Zhou, Zhen Zeng, Tian Wang, Weiwei You
    Abstract:

    Abstract Cu and Zn are hyper-accumulated in oysters, and the accumulation of these metals increases host resistance to pathogens. However, the role of Cu/Zn in oyster immune defense remains unclear. In this study, Crassostrea angulata with different levels of Cu and Zn were obtained through metal exposure or selective breeding. Both in vivo and in vitro experiments showed that oysters accumulating more Cu/Zn exhibited stronger antibacterial abilities. Vibrio harveyi infection significantly promoted the metal redistribution in oysters: Cu and Zn concentrations decreased in the mantle, but increased in the plasma and hemocytes. This redistribution was accompanied by changes in the expression levels of Cu and Zn transporter genes (CTR1, ATP7A, ZIP1, and ZNT2), suggesting that the Cu/Zn burst observed in the hemocytes was likely due to the transfer of heavy metals from plasma (mediated by the metal importer proteins) or released from intracellular stores. The degree to which Cu/Zn concentration increased in the plasma and hemocytes was more dramatic in oysters with high levels of Cu/Zn accumulation. In vitro, Cu and Zn both inhibited the growth of V. harveyi, while Cu plus H2O2 was lethal to the bacteria. The strength of the growth-inhibition and lethal effects depended on the metal dose. In addition to these effects, increases in Cu concentration increased the activity levels of PO in the oyster plasma and hemocytes in vivo and in vitro. However, SOD activity was not affected by Cu or Zn accumulation. Thus, our results suggested that the Cu/Zn burst in the hemolymph was an important factor in the oyster immune reaction, creating a toxic internal environment for the pathogen, as well as catalyzing inorganic or enzymatic reactions to strengthen bacteriostasis. By determining the extent of Cu/Zn burst in the immune response, Cu/Zn accumulated levels could affect the resistance of oysters to pathogens.

  • heritability estimates for copper zinc accumulation capabilities and correlation with growth quality traits in the fujian oyster Crassostrea angulata
    Aquaculture, 2019
    Co-Authors: Bo Shi, Long Zhou, Chenyu Dong, Weiwei You
    Abstract:

    Abstract Oysters are hyper-accumulators of copper (Cu) and zinc (Zn) and are a good food source for trace element supplements. However, increasing heavy metal pollution in estuaries and coastal areas has posed a critical threat to oysters and thus led to food safety issues. Here, we assessed if it is possible to obtain oyster varieties with differential metal-accumulated properties through genetic improvement. The narrow-sense heritabilities of Cu and Zn accumulation capabilities and growth traits in Fujian oyster (Crassostrea angulata) were estimated to determine the degree to which Cu and Zn accumulation is under genetic control. In addition, we investigated the trade-offs between Cu/Zn accumulation and some farming performances, including growth-related traits, and the contents of glycogen and eight free amino acids. Moderate estimates were observed for narrow-sense heritability of Cu (0.189 ± 0.061) and Zn (0.373 ± 0.091) accumulation capability, while growth-related traits showed moderate-high heritability (0.168 ± 0.059–0.595 ± 0.116). High-level genetic (0.802 ± 0.080) and phenotypic (0.853 ± 0.012) correlations were detected between Cu and Zn accumulation capability, while correlations between metal accumulation and growth traits were low (−0.023 ± 0.042–0.491 ± 0.200). Moreover, Cu and Zn accumulation in Fujian oyster exhibited no significant influence on the quality traits measured, except for Taurine (Tau). Tau contents in high Cu/Zn accumulated oysters were significantly higher than in low-accumulated oysters, suggesting an important role of Tau in Cu/Zn accumulation. Our results provide important information to guide effective selective breeding of Fujian oysters with specific Cu/Zn accumulation capabilities.

  • Heritability estimates for copper/zinc accumulation capabilities and correlation with growth/quality traits in the Fujian oyster, Crassostrea angulata
    Aquaculture, 2019
    Co-Authors: Bo Shi, Long Zhou, Chenyu Dong, Weiwei You
    Abstract:

    Abstract Oysters are hyper-accumulators of copper (Cu) and zinc (Zn) and are a good food source for trace element supplements. However, increasing heavy metal pollution in estuaries and coastal areas has posed a critical threat to oysters and thus led to food safety issues. Here, we assessed if it is possible to obtain oyster varieties with differential metal-accumulated properties through genetic improvement. The narrow-sense heritabilities of Cu and Zn accumulation capabilities and growth traits in Fujian oyster (Crassostrea angulata) were estimated to determine the degree to which Cu and Zn accumulation is under genetic control. In addition, we investigated the trade-offs between Cu/Zn accumulation and some farming performances, including growth-related traits, and the contents of glycogen and eight free amino acids. Moderate estimates were observed for narrow-sense heritability of Cu (0.189 ± 0.061) and Zn (0.373 ± 0.091) accumulation capability, while growth-related traits showed moderate-high heritability (0.168 ± 0.059–0.595 ± 0.116). High-level genetic (0.802 ± 0.080) and phenotypic (0.853 ± 0.012) correlations were detected between Cu and Zn accumulation capability, while correlations between metal accumulation and growth traits were low (−0.023 ± 0.042–0.491 ± 0.200). Moreover, Cu and Zn accumulation in Fujian oyster exhibited no significant influence on the quality traits measured, except for Taurine (Tau). Tau contents in high Cu/Zn accumulated oysters were significantly higher than in low-accumulated oysters, suggesting an important role of Tau in Cu/Zn accumulation. Our results provide important information to guide effective selective breeding of Fujian oysters with specific Cu/Zn accumulation capabilities.

  • Transcriptome analysis of the key role of GAT2 gene in the hyper-accumulation of copper in the oyster Crassostrea angulata
    Scientific reports, 2015
    Co-Authors: Bo Shi, Miaoqin Huang, Zekun Huang, Xu Xiang, Wen-xiong Wang
    Abstract:

    One paradigm of oysters as the hyper-accumulators of many toxic metals is the inter-individual variation of metals, but the molecular mechanisms remain very elusive. A comprehensive analysis of the transcriptome of Crassostrea angulata was conducted to reveal the relationship between gene expression and differential Cu body burden in oysters. Gene ontology analysis for the differentially expressed genes showed that the neurotransmitter transporter might affect the oyster behavior, which in turn led to difference in Cu accumulation. The ATP-binding cassette transporters superfamily played an important role in the maintenance of cell Cu homeostasis, vitellogenin and apolipophorin transport, and elimination of excess Cu. Gill and mantle Cu concentrations were significantly reduced after silencing the GABA transporter 2 (GAT2) gene, but increased after the injection of GABA receptor antagonists, suggesting that the function of GABA transporter 2 gene was strongly related to Cu accumulation. These findings demonstrated that GABA transporter can control the action of transmitter GABA in the nervous system, thereby affecting the Cu accumulation in the gills and mantles.

Sylvie Lapègue - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Genome-Wide Differentiation between Native and Introduced Populations of the Cupped Oysters Crassostrea gigas and Crassostrea angulata
    Genome Biology and Evolution, 2018
    Co-Authors: Pierre-alexandre Gagnaire, Serge Heurtebise, Pierre Boudry, Florence Cornette, Nicolas Bierne, Jean-baptiste Lamy, Lionel Degremont, Emilie Flahauw, Sylvie Lapègue
    Abstract:

    The Pacific cupped oyster is genetically subdivided into two sister taxa, Crassostrea gigas and Crassostrea angulata, which are in contact in the northwestern Pacific. The nature and origin of their genetic and taxonomic differentiation remains controversial due the lack of known reproductive barriers and the high degree of morphologic similarity. In particular, whether the presence of ecological and/or intrinsic isolating mechanisms contributes to species divergence is unknown. The recent co-introduction of both taxa into Europe offers a unique opportunity to test how genetic differentiation is maintained under new environmental and demographic conditions. We generated a pseudochromosome assembly of the Pacific oyster genome using a combination of BAC-end sequencing and scaffold anchoring to a new high-density linkage map. We characterized genome-wide differentiation between C. angulata and C. gigas in both their native and introduced ranges, and showed that gene flow between species has been facilitated by their recent co-introductions in Europe. Nevertheless, patterns of genomic divergence between species remain highly similar in Asia and Europe, suggesting that the environmental transition caused by the co-introduction of the two species did not affect the genomic architecture of their partial reproductive isolation. Increased genetic differentiation was preferentially found in regions of low recombination. Using historical demographic inference, we show that the hetero-geneity of differentiation across the genome is well explained by a scenario whereby recent gene flow has eroded past differentiation at different rates across the genome after a period of geographical isolation. Our results thus support the view that low-recombining regions help in maintaining intrinsic genetic differences between the two species.

  • Application of high-throughput sequencing to population differentiation in the cupped oysters Crassostrea angulata/C. gigas
    2013
    Co-Authors: Pierre-alexandre Gagnaire, Serge Heurtebise, Florence Cornette, M. T. Auge, Nicolas Bierne, Sylvie Lapègue
    Abstract:

    The cupped oysters Crassostrea angulata and Crassostrea gigas have been sequentially introduced in Europe from their native Pacific area for aquaculture purposes. Ongoing viral epidemic disease is responsible for large losses in oyster aquaculture production throughout Europe. In parallel with current efforts in developing selection programs for disease resistance, it becomes critically important to characterize genetic diversity patterns in both native and introduced areas. With the advent of next generation sequencing techniques, the power to resolve the fine-scale genetic structure at a genome-wide scale opens to new perspectives towards genetic resource management. Here, we present a genome-wide screen of genetic variation that combines SNP genotyping and RADsequencing approaches. Our results, based on more than 18,000 SNP markers, improve our comprehension of the population structure and provide a powerful subset of highly informative markers for stock assignment. As these markers were also used in QTL mapping approaches, these new genomic resources will orientate the choice of breeders in selection programs in order to maximize the natural genetic variance involved in pathogen resistance.

  • application of high throughput sequencing to population differentiation in the cupped oysters Crassostrea angulata c gigas
    Workshop AQUAGENET 28 Novembre 2013 Cadix Spain, 2013
    Co-Authors: Pierre-alexandre Gagnaire, Serge Heurtebise, Florence Cornette, M. T. Auge, Nicolas Bierne, Sylvie Lapègue
    Abstract:

    The cupped oysters Crassostrea angulata and Crassostrea gigas have been sequentially introduced in Europe from their native Pacific area for aquaculture purposes. Ongoing viral epidemic disease is responsible for large losses in oyster aquaculture production throughout Europe. In parallel with current efforts in developing selection programs for disease resistance, it becomes critically important to characterize genetic diversity patterns in both native and introduced areas. With the advent of next generation sequencing techniques, the power to resolve the fine-scale genetic structure at a genome-wide scale opens to new perspectives towards genetic resource management. Here, we present a genome-wide screen of genetic variation that combines SNP genotyping and RADsequencing approaches. Our results, based on more than 18,000 SNP markers, improve our comprehension of the population structure and provide a powerful subset of highly informative markers for stock assignment. As these markers were also used in QTL mapping approaches, these new genomic resources will orientate the choice of breeders in selection programs in order to maximize the natural genetic variance involved in pathogen resistance.

  • Is the Portuguese oyster Crassostrea angulata in Southern Europe endangered by the expansion of the Pacific oyster C. gigas
    2005
    Co-Authors: Frederico M Batista, Serge Heurtebise, Pierre Boudry, Sylvie Lapègue, C. C. Monteiro
    Abstract:

    The Portuguese oyster, Crassostrea angulata, was introduced from Portugal to the French Atlantic Coast in the 1860s. C. angulata quickly settled and expanded and leaded to the development of a new aquacultural industry in France. In the late 1960s, mortality associated with the detection of an iridovirus, led to the wipe out of C. angulata from French Atlantic waters and to the massive introduction of C. gigas to sustain production. In Southern Europe, similar symptoms were also observed in natural stocks of C. angulata from Sado River (Portugal) and from the area of Cadiz (Spain). Nowadays, only very few «pure» populations of C. angulata remain in southern Europe. These populations are potentially endangered by the current expansion of C. gigas aquaculture, as well as the pollution of their habitats. In October 2002, cupped oysters from Sado and Mira estuaries (Portugal) were sampled and analysed using a mitochondrial DNA marker previously shown to be diagnostic for C. angulata and C. gigas. All oysters analyzed revealed haplotypes characteristic of C. angulata. We also analyzed wild cupped oysters from Ria Formosa (Southern Portugal), an area where C. gigas is known to be farmed. These samples were analysed with a «pseudospecific» nuclear DNA marker previously developed to differentiate populations of C. angulata and C. gigas. In addition, a new mitochondrial marker was developed that also allows the identification of other oyster species that exist in the area, namely the European oyster Ostrea edulis and the rock oyster Ostreola stentina. Despite the sympatric occurrence of C. angulata and C. gigas in Ria Formosa our results suggest that there is minimal hybridization between the two taxa. Furthermore, despite very limited natural beds, C. angulata seems to recrute much more than farmed C. gigas, indicating a differential ability to settle of these two taxa in Ria Formosa.

  • Mitochondrial and nuclear DNA sequence variation of presumed Crassostrea gigas and Crassostrea angulata specimens: a new oyster species in Hong Kong?
    Aquaculture, 2003
    Co-Authors: Pierre Boudry, Serge Heurtebise, Sylvie Lapègue
    Abstract:

    Abstract In several cases, oyster taxa have been misidentified owing to their high morphological plasticity, uncertain geographical range and undocumented introductions. Recently though, molecular techniques have been efficiently applied to discriminate between oysters and to quantify genetic divergence within and among species. In the present paper, we report mitochondrial (16S and COI) and nuclear (28S) DNA sequences of presumed Crassostrea gigas and Crassostrea angulata , two taxa of aquacultural importance. Mitochondrial DNA sequences are compared with previously published sequences and PCR-RFLP haplotypes. Within C. gigas , divergence was less than 0.5% for COI, and less than 0.2% for 16S. Within C. angulata , divergence was less than 1.1% for COI and 0.2% for 16S. Our results also confirm the close genetic relationship between C. gigas and C. angulata and further document their level of divergence: 2–3% for COI and 0.5–1% for 16S. However, the initially presumed C. gigas oysters farmed in Hong Kong (Pearl River delta), presented DNA sequences strongly divergent from both C. gigas and C. angulata : 13–14% for COI, 3–4% for 16S and 1.2–1.6% for 28S. The closest related species are C. gigas and Crassostrea nippona with a divergence of 12–13% for COI, 3–4% for 16S and 1.2–1.6% for 28S. Comparisons with existing DNA sequence data available in the nucleotide sequence databases shows that this is either a new species or that it corresponds to a species for which no DNA sequence is yet available. Further studies are required to document morphological characteristics and geographical range of this putative new species.