Project description:Hox and ParaHox genes encode transcription factors with conserved similar expression patterns in divergent animals. The Pdx (Xlox) homeobox gene, for example, is expressed in a sharp spatial domain in the endodermal cell layer of the gut in chordates, echinoderms, annelids and molluscs. The significance of comparable gene expression patterns is unclear because it is not known if downstream transcriptional targets are also conserved. We thus conducted experiments to show that a classic transcriptional target of Pdx1 in vertebrates, the insulin gene, is also a direct target of Pdx in the Pacific oyster. We report that oyster has a diversity of insulin-related genes including one co-expressed with Pdx in the endodermal layer of oyster digestive tissue. Transcriptome analysis reveals functional similarity of this tissue to vertebrate pancreas. Using ATAC-seq we identify a Pdx homeodomain binding site upstream of the endodermally-expressed oyster insulin-related gene and using cell culture demonstrate that oyster Pdx acts as a transcriptional activator through this site. These data argue that a classic homeodomain-target gene interaction dates back to the base of Bilateria.
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 systematic deep sequencing analysis provided a comprehensive understanding of the transcriptome complexity of 2n and 3n Fujian oyster. This information broadens our understanding of the mechanisms of C.angulata polyploidization and contributes to molecular and genetic research by enriching the oyster database. This is the first report on genome-wide transcriptional analysis of adductor muscle of diploid and triploid Fujian oyster and has demonstrated triploid oysters are morphologically almost identical to their diploid counterparts, but have faster growth, due to the reorientation of energetic allocation from gametogenesis to somatic investment. This study provides a foundation for further analysis of the gene expression patterns and signaling pathways which regulate the molecular mechanisms of diploid and triploid oyster.
Project description:The Pacific oyster (Crassostrea gigas) is a kind of marine bivalve of great economic and ecological importance and is among the animals possessing the highest level of genome DNA variations. Despite large efforts made for the discovery of Pacific oyster SNPs in many research groups, challenge still remains as how to utilize SNPs in a high-throughput, transferable and economical manner. In the study, we constructed an oyster 190K SNP array with Affymetrix Axiom genotyping technology. A total of 190,420 SNPs were designed on the chip, which were selected from 54 M SNPs identified by re-sequencing of more than 400 Pacific oysters. Genotyping results from 96 wild oysters indicated that 133,984 (70.4%) SNPs were polymorphic and successfully converted on the chip. Carrying 133K polymorphic SNPs, the oyster 190K SNP array is the first high density SNP chip with the largest throughput currently in mollusc and is commercially available to the worldwide research community.
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. A common garden experiment was performed in order to compare progenies from two populations of Pacific oyster sampled in France and Denmark and their hybrids. Progenies were reared under standard hatchery and nursery conditions until gonadal maturation. The employed arrays were Agilent 60-mer 4x44K custom microarrays, containing 31,918 C. gigas ESTs, designed by Dheilly et al. (2011).
Project description:To elucidate the modulatory participation of miRNAs in mollusk biomineralization, we have employed high-throughput sequencing to identify miRNAs of pearl oyster, Pinctada fucata. Our study focused on the miRNA expression profile of the mantle, an organ responsible for shell formation of the oyster. The pearl oysters were cultured in the tank with the maintaining conditions of temperature 19 ℃, PH 8.1 and salinity 33‰ in recirculating seawater.
Project description:The systematic deep sequencing analysis provided a comprehensive understanding of the transcriptome complexity of 2n and 3n Fujian oyster. This information broadens our understanding of the mechanisms of C.angulata polyploidization and contributes to molecular and genetic research by enriching the oyster database. This is the first report on genome-wide transcriptional analysis of adductor muscle of diploid and triploid Fujian oyster and has demonstrated triploid oysters are morphologically almost identical to their diploid counterparts, but have faster growth, due to the reorientation of energetic allocation from gametogenesis to somatic investment. This study provides a foundation for further analysis of the gene expression patterns and signaling pathways which regulate the molecular mechanisms of diploid and triploid oyster. Examination of 3 different samples, including diploid (DF and DM) and triplod(T) oyster.