Taurine has been reported high amounts in marine animals to maintain osmotic balance between osmoformers and sea water. Approximately 80% of the total amino-acid content is taurine in Pacific oyster Crassostrea gigas, an intertidal and euryhaline species. In this study, we cloned the two copies of cysteine sulfinate decarboxylase (CSAD), the key enzyme in taurine biosynthesis pathway, screened in oyster genome data. Sequentially, we compared the expression patterns of CgCSAD1 and CgCSAD2 under low salinity treatment (8‰ and 15‰) using different families from two populations. There was no correlation between the expression of CSAD and the different population. Notably, CgCSAD1 increased significantly in treated groups for 24 h, but CgCSAD2 had no significant differentiation. Moreover, the results of CgCSAD1 interference provided the evidence of the positive correlation between CgCSAD1 expressions and taurine contents. The zinc finger domain showed in multi-alignment results may be the important character of CgCSAD1 as the key enzyme in taurine biosynthesis to regulate taurine pool in response to low salinity. This study provides a new evidence for the important role of taurine in adaptation to low salinity in oyster. In addition, it is a good model to discuss the function and evolution of the duplication in mollusks.

中文翻译：

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半胱氨酸亚磺酸脱羧酶的鉴定和表达，可能对低盐度响应的鳄梨（Crassostrea gigas）牛磺酸生物合成的调控。

据报道，牛磺酸在海洋动物中含量很高，以维持渗透压剂和海水之间的渗透平衡。太平洋牡蛎Crassostrea gigas（一种潮间和鱼腥藻类）中的牛磺酸占氨基酸总量的大约80％。在这项研究中，我们克隆了两个拷贝的半胱氨酸亚磺酸脱羧酶（CSAD），这是牛磺酸生物合成途径中的关键酶，在牡蛎基因组数据中进行了筛选。随后，我们使用来自两个人群的不同家族，比较了在低盐度处理（8‰和15‰）下CgCSAD1和CgCSAD2的表达模式。CSAD的表达与不同人群之间没有相关性。值得注意的是，在治疗后的24小时内，CgCSAD1显着增加，但CgCSAD2没有明显的分化。而且，CgCSAD1干扰的结果提供了CgCSAD1表达与牛磺酸含量之间正相关的证据。多对齐结果显示的锌指结构域可能是CgCSAD1的重要特性，它是牛磺酸生物合成中调节低盐度响应牛磺酸池的关键酶。这项研究为牛磺酸在适应牡蛎低盐度中的重要作用提供了新的证据。此外，这是讨论在软体动物中复制的功能和演变的一个很好的模型。这项研究为牛磺酸在适应牡蛎低盐度中的重要作用提供了新的证据。此外，这是讨论在软体动物中复制的功能和演变的一个很好的模型。这项研究为牛磺酸在适应牡蛎低盐度中的重要作用提供了新的证据。此外，这是讨论在软体动物中复制的功能和演变的一个很好的模型。