Cloning and structure analysis of sheep fertilin β coding region

Abstract

Fertilin beta may play an important role in sperm-egg plasma membrane adhesion and fusion. To explore the effects of fertilin beta, 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) of fertilin beta. The coding region was 2, 217 bp, which consists of 738 amino acids. The fertilin beta 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 the fertilin beta gene family indicated the fertilin beta 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 beta 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 beta is TDECE.