Project description:Here we reported 226 sperm proteins from the Hong Kong oyster Crassostrea hongkongensis. Proteins extracted from three sperm samples were separated by SDS-PAGE, analyzed by LC-MS/MS and identified using Mascot.
Project description:Thermal exposure of sessile marine animals inhabiting estuarine intertidal regions is a matter of serious concern. The Hong Kong oyster, Crassostrea hongkongensis is one of the dominant sessile inhabitants of marine intertidal region which undergoes large seasonal temperature fluctuations every year. The oyster has developed several adaptation mechanisms to cope with acute thermal stress. However, the genetic basis of these mechanisms remain largely unclear. To better understand how acute thermal exposure affects the biology of the oyster, two cDNA libraries obtained from the gill of oysters exposed to thermal stress and ambient temperature were sequenced using the Digital Gene Expression (DGE) tag profiling strategy. In total, 5.9 and 6.2 million reads were obtained for thermal stress and control libraries respectively, with approximately 74.25% and 75.02 % of the reads mapping to the C. hongkongensis reference sequence. A total of 605 differentially expressed transcripts could be detected in the thermal stress group as compared to the control group, of which 378 are up-regulated and 227 are down-regulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these Differentially Expressed Genes (DEGs) were enriched with a broad spectrum of biological processes and pathways, including those associated with chaperones, antioxidants, immunity, apoptosis and cytoskeletal reorganization. Among these significantly enriched pathways, protein processing in the endoplasmic reticulum was the most affected metabolic pathway, which plays an important role in the unfolded protein response (UPR) and ER-associated degradation (ERAD) processes. Our results demonstrate the complex multi-modal cellular response to thermal stress in C. hongkongensis.
Project description:Method development for protein extraction from microscopic biominerals. The method was developed using Hong Kong oyster larval shells
Project description:The aim of this study was to gain insight into the molecular mechanisms of intraspecies difference of copper accumulation in Crassostrea angulata. In this attempt, we have performed a comprehensive analysis of the transcriptome of oyster (gill and mantle). Digital gene expression (DGE) technology was applied to analyze the relationships between gene expression and differential Cu body burden.
Project description:The aim of this study was to gain insight into the molecular mechanisms of intraspecies difference of copper accumulation in Crassostrea angulata. In this attempt, we have performed a comprehensive analysis of the transcriptome of oyster (gill and mantle). Digital gene expression (DGE) technology was applied to analyze the relationships between gene expression and differential Cu body burden. Digital gene expression (DGE) technology was applied to analyze the relationships between gene expression and differential Cu body burden
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: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.