绵羊fertilin β基因编码区的钓取与结构分析

Cloning and structure analysis of sheep fertilin β coding region

Fertilin β与精卵的结合和融合有密切关系。为探讨fertilin β蛋白在绵羊受精过程中的作用机理,采用RACE技术,首次钓取了该基因的编码区。结果绵羊fertilin β基因的编码区cDNA全长为2,217bp。同源性分析显示,绵羊的fertilin β氨基酸序列与牛、猪和人的fertilin β具有79.4%、66.7%和58.1%的同源性。系统发育分析表明,绵羊fertilin β与牛属于同一分支,并且也显示了绵羊和牛分类地位最近,这和传统的分类一致。Fertilin β蛋白结构域分析显示,绵羊fertilin β去整合素识别序列为TDE,与牛的序列相同。除了上述三肽序列外,紧随X-D/E-E的ECD保守序列,从而形成了X-D/E-ECD五肽保守序列,在绵羊fertilin β中该五肽序列为TDECE。

Fertilinβ may play an important role in sperm-egg plasma membrane adhesion and fusion. To explore the effects of fertilin β, the sperm membrane protein subunit, in the sheep fertilization process, we used RACE technique for cloning the full length cDNA of the coding region （CDS） offertilin ft. The coding region was 2, 217 bp, which consists of 738 amino acids. The fertihn β in the sperm membrane of sheep shares 79.4%, 66.7%, and 58.1% sequence identity with that in bovine, pig and human, respectively. The phylogenetic analysis of thefertilin fl gene family indicated thefertilin β was clustered with bovine, and is closest to the one of bovine. This result is consistent with the result of the traditional classification. The protein structure analysis showed the disintegrin domain of sheep fertilin β contains a TDE. Besides the above tripeptide sequence, the family member of ADAM （A Disintegrin and A Metalloprotease） follow the conserved sequence of ECD of X-D/E-E, and formed the conserved sequence of X-D/E-ECD. The pentapeptide sequence of the sheep fertilin β is TDECE.