Project description:Method development for protein extraction from microscopic biominerals. The method was developed using Hong Kong oyster larval shells
Project description:We produced differentially sensitive-temperature phenotypes using genetically defined larval families of the bivalve Crassostrea gigas. Larval growth rates varied ~5-fold and reciprocal hybrids showed different genotype-dependent responses over a 15-25°C temperature range. Whole-genome expression analysis of ~24 million cDNAs from larvae identified 22,250 unique transcripts. Of these, ~15% showed a significant interaction between genotype and temperature and are associated with genotype-dependent differences in response to temperature. Examination of 2 genotypes of Pacific oyster larvae, grown at 3 temperatures
Project description:Acidification of seawater due to anthropogenic CO2, called as ocean acidification (OA), makes most coastal environments unfavorable for oysters. This is a serious socio-economical issue for China which is accounting for >70% of the world’s edible oyster supply. Understanding of OA effects at proteome level could lead to a better aquaculture management. Here, we present an iTRAQ based protein profiling analysis for the detection and quantification of proteome change under OA in one of the early life stages of a commercially important oyster species, Crassostrea hongkongensis. The completion of the genome sequence for oysters enabled us to confidently quantify over 1500 proteins in the larval oyster. Over 10% of proteome was altered in response to OA process at pH 7.6. Analysis of differentially expressed proteins and their associated pathways indicated that up-regulation of calcification, metabolic processes, cytoskeletal functions, oxidative stress and cell signaling processes might have been used by larvae to acclimate under OA. Although the expressions of cytoskeletal and signal transduction proteins were down-regulated in response to OA, there was no marked alternation in developmental processes such as metamorphic success. This study suggests that the estuarine edible oyster possess an adequate short-term adaptability or acclimation mechanism at proteome level to tolerate near-future OA scenario.
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.