鲈鱼cxcr4 cDNA克隆和序列分析

cDNA cloning and sequence analysis of cxcr4 in Weever,Lateolabrax Japonicus

趋化因子受体(cxcr4)是一类重要的免疫调节因子受体,对原始生殖细胞的迁移和存活具有十分重要的作用。在对脊椎动物cxcr4进行初步生物信息学分析基础上设计引物,采用RT-PCR和RACE相结合的方法从鲈鱼卵巢克隆了cxcr4a全长和4b部分cDNAs序列,并预测其编码的氨基酸序列。结果表明,由于鱼类基因组经历一次特有的复制,cxcr4在鱼类存在两个复制基因。鲈鱼cxcr4a cDNA全长为1432 bp,编码311个氨基酸;cxcr4b部分cDNA片段长为905 bp,编码285个氨基酸。将鲈鱼cxcr4序列与所有已克隆的硬骨鱼类进行同源性比较,结果显示硬骨鱼类保守性较高,所有已经克隆的cxcr4按照进化地位的不同成簇聚类,表现出了较高的同源性。

Chemokine receptor 4（cxcr4） is a kind of important immune regulation factor receptor. It plays a very important role in migration and survival of the primordial germ cell. In this study, bioinformatics methods were adopted to make a preliminary analysis on vertebrate＇ s cxcr4. Two types ofcxcr4 encoded by two different genes were found in several fish genomes because of the fish specific genome duplication. Then we cloned the 1432-bp full length of cxcr4a and 905-bp partial sequence of4b cDNAs from weever using RT-PCR and RACE method, encoding 311 and 285 amino acids（ aa）, respectively. Alignment of all known excr4 sequences revealed that weever cxer4 exhibits high homology to its counterparts from other teleosts.