中文摘要：

水通道蛋白1（Aquaporin1,AQP1）是一类通过渗透梯度将水或一些小的中性分子快速穿过细胞膜的通道蛋白。通过RT-PCR和RACE技术克隆获得了香港牡蛎AQP1基因全长,并命名为Ch AQP1（Gen Bank登录号：KJ704847）。该基因全长1153bp,开放阅读框长度为888bp,编码295个氨基酸残基。Ch AQP1基因包括1个保守的MIP结构域、6个跨膜区、5个连接环、2个NPA（Asn-Pro-Ala）基序和选择性水孔构件ar/R（aromatic/arginine）。系统学分析表明Ch AQP1属于AQP1-like型水通道蛋白。m RNA组织分布结果显示,Ch AQP1在各个组织中均有表达,其中在闭壳肌和外套膜中表达量相对较高。利用实时定量PCR分析高、低盐胁迫下其在鳃中的表达模式,结果表明,Ch AQP1 m RNA表达量在低盐处理下基本没有太大变化;在高盐胁迫下,第1天（P〈0.01）、第3天和第5天（P〈0.05）显著下调;这说明Ch AQP1基因参与了香港牡蛎的渗透压平衡调节。

英文摘要：

Aquaporin1（AQP1） is one of water channel proteins that facilitate water and/or small solutes across cell membrane responding to osmotic gradients. We cloned the AQP1 gene by RT-PCR and RACE technology in mollusk Crassostrea hongkongensis and named Ch AQP1（Gen Bank accession number： KJ704847）. The full-length c DNA of Ch AQP1 is 1153 bp in length with ORF of 888 bp, encoding a peptide of 295 amino acids. Ch AQP1 includes a conserved MIP domain, six transmembrane regions, five loops, two NPA boxes, and an ar/R（aromatic/arginine） selectivity filter. Phylogenetic analysis showed that Ch AQP1 belongs to the AQP1-like subfamily. Tissue distribution of Ch AQP1 m RNA indicates that Ch AQP1 is constitutively expressed in all detected tissues, especially in adductor muscle and mantle. Furthermore, as shown in the expression pattern in gill under osmotic stress revealed in real-time PCR analysis, Ch AQP1 m RNA stayed almost unchanged in hypo-osmotic exposure, whereas its m RNA level was significantly down-regulated on Days1（P0.01）, 3, and 5（P0.05） upon hyper-osmotic exposure. Thus, the expression pattern of Ch AQP1 m RNA in gill is inducible under salinity stress, which strongly discloses the involvement of the gene in the regulation of osmotic homeostasis in C. hongkongensis. With these basic molecular findings, future works shall focus on the mechanism of euryhaline adaptation in C. hongkongensis.