Crassostrea nippona is a commercially important oyster species in East Asia for it is edible during the summer when the other oyster species are unavailable. Salinity is one of the important limiting factors to the survival and distribution of this stenohaline species. In this study, 535 million reads (74G data) from C. nippona were produced and assembled into 66,742 transcripts. The number of 19,253 differentially expressed genes (DEGs) under salinity stress were identified as salinity stress-response genes. Through comparative evolutionary analysis in five Crassostrea species from East Asia, salinity stress-response genes were noticed to have higher adaptive evolution rates than other genes. This study presents the first de novo transcriptome of C. nippona. Furthermore, comparative evolutionary analysis implies that salinity plays an important role in speciation of Crassostrea species.

Crassostrea nippona是东亚一种具有重要商业价值的牡蛎品种，因为它可以在其他牡蛎品种不可用的夏季食用。盐度是该狭盐类物种生存和分布的重要限制因素之一。在这项研究中，产生了来自C. nippona 的5.35 亿个读数（74G 数据）并组装成 66,742 个转录本。19,253个在盐胁迫下差异表达的基因（DEGs）被鉴定为盐胁迫反应基因。通过对东亚五种牡蛎物种的比较进化分析，发现盐胁迫响应基因比其他基因具有更高的适应性进化率。本研究展示了日本C. nippona的第一个 de novo 转录组. 此外，比较进化分析表明，盐度在Crassostrea物种的物种形成中起着重要作用。