Project description:Deep sequencing of mRNA from Pacific oyster Crassostrea gigas Competent larvae of Crassostrea gigas were treated with epinephrine solution, and then sampled at different time intervals. For shell damage experiment, shell were broken and then tissues were sampled at different time intervals.
Project description:Deep sequencing of samples from different development stages, different adult organs and different stress treatments of Pacific oyster Crassostrea gigas
Project description:Marine intertidal organisms commonly face hypoxic stress during low tide emersion; moreover, eutrophic conditions and sediment nearness could lead to hypoxic phenomena; it is indeed important to understand the molecular processes involved in the response to hypoxia. In this study the molecular response of the Pacific oyster Crassostrea gigas to prolonged hypoxia (2 mg O2 L-1 for 20 d) was investigated under experimental conditions. A transcriptomic approach was employed using a cDNA microarray of 9058 C. gigas clones to highlight the genetic expression patterns of the Pacific oyster under hypoxic conditions. Lines of oysters resistant (R) and susceptible (S) to summer mortality were used in this study. This is the first study employing microarrays to characterize the genetic markers and metabolic pathways responding to hypoxic stress in C. gigas.
Project description:miRNA sequencing of Pacific oyster Crassostrea gigas for different organs and developmental stages. Two RNA pools were created and sequenced by mixing the samples before and after the developmental stage "D shaped larvae". Then ten developmental samples and eleven samples from 7 organs were sequenced.
Project description:The Pacific oyster Crassostrea gigas, a commercially important species inhabiting the intertidal zone, can tolerate temperature fluctuations. Heat shock transcription factor 1 (HSF1) plays an important role in the process of resistance of thermal stress. However, HSF1 has not been fully characterized in the Pacific oyster. C. gigas with an expansion of heat shock protein (HSP) 70. In this study, we analyzed genes regulated by HSF1 in response to heat shock by Chromatin immunoprecipitation followed sequencing (ChIP-seq), determined the expression patterns of target genes by qRT-PCR, and validated the regulatory relationship between one HSP70 and HSF1. We found 916 peaks corresponding to specific binding sites of HSF1, and peaks were annotated to nearest genes. In Gene Ontology analysis, HSF1 target genes was related to signal transduction, energy production, and response to biotic stimulus. Four HSP70 genes, two HSP40 genes, and one small HSP gene exhibited binding to HSF1. One HSP70 with a binding site in the promoter region was validated to be regulated by HSF1 under heat shock. These results provide a basis for future studies aimed at determining the mechanisms underlying thermal tolerance and provide insights into gene regulation in the Pacific oyster.
Project description:Low salinity is one of the main factors limiting the distribution and survival of marine species. As a euryhaline species, the Pacific oyster Crassostrea gigas can be tolerant to relative low salinity. Through Illumina sequencing, we generated two transcriptomes with samples taken from gills of oysters exposed to the low salinity seawater versus the optimal seawater. By RNAseq technology, we found 1665 up-regulation genes and 1815 down-regulation genes that may regulate osmotic stress in C. gigas. As blasted by GO annotation and KEGG pathway mapping, functional annotation of the genes recovered diverse biological functions and processes. The genes regulated significantly were dominated in cellular process and regulation of biological process, intracellular and cell, binding and protein binding according to GO annotation. The results highlight genes related to osmoregulation and signaling and interactions of osmotic stress response, anti-apoptotic reactions as well as immune response, cell adhesion and communication, cytosqueleton and cell cycle. The study aimed to compare the expression data of the two transcriptomes to provide some useful insights into signal transduction pathways in oysters and offer a number of candidate genes as potential markers of tolerance to hypoosmotic stress for oysters. In addition, the characterization of C. gigas transcriptome will facilitate research into biological processes underlying physiological adaptations to hypoosmotic shock for marine invertebrates.
Project description:Low salinity is one of the main factors limiting the distribution and survival of marine species. As a euryhaline species, the Pacific oyster Crassostrea gigas can be tolerant to relative low salinity. Through Illumina sequencing, we generated two transcriptomes with samples taken from gills of oysters exposed to the low salinity seawater versus the optimal seawater. By RNAseq technology, we found 1665 up-regulation genes and 1815 down-regulation genes that may regulate osmotic stress in C. gigas. As blasted by GO annotation and KEGG pathway mapping, functional annotation of the genes recovered diverse biological functions and processes. The genes regulated significantly were dominated in cellular process and regulation of biological process, intracellular and cell, binding and protein binding according to GO annotation. The results highlight genes related to osmoregulation and signaling and interactions of osmotic stress response, anti-apoptotic reactions as well as immune response, cell adhesion and communication, cytosqueleton and cell cycle. The study aimed to compare the expression data of the two transcriptomes to provide some useful insights into signal transduction pathways in oysters and offer a number of candidate genes as potential markers of tolerance to hypoosmotic stress for oysters. In addition, the characterization of C. gigas transcriptome will facilitate research into biological processes underlying physiological adaptations to hypoosmotic shock for marine invertebrates. Twelve Pacific oysters were exposed in low salinity (8‰) seawater and in optimal salinity (25‰) seawater, respectively. Gills from six oysters in each condition were balanced mixed respectively. The transcriptomes of two samples were generated by deep sequencing, using Illumina HiSeq2000.
Project description:Originating from Northeast Asia, the Pacific oyster Crassostrea gigas has been introduced into a large number of countries for aquaculture purpose. Following introduction, the Pacific oyster has turned into an invasive species in an increasing number of coastal areas, notably in Northern Europe. To explore adaptation on reproductive traits of population considered as invasive, we set up a common garden experiment based on the comparison of progenies from two populations of Pacific oyster sampled in France and Denmark. A female-biased sex-ratio and a higher condition index were observed in the Danish progeny, possibly reflecting an evolutionary reproductive strategy to increase the potential success of natural recruitment in recently settled population. Using multifarious statistical approaches and accounting for sex differences we identified several genes differentially expressed between the Danish and French progenies, and with an intermediate expression level in hybrids (additive behavior). Candidate transcripts included mRNA coding for sperm quality and insulin metabolism known to be implicated in coordinated control of reproduction. Our results suggest adaptation of invasive populations during expansion acting on reproductive traits, and in particular on a female-biased sex-ratio, fertility and gamete quality.