Cloning of the Encoding Region of Sex-determining Region on Y Chromosome Gene(SRY) in Tianzhu White Yak and Its Prokaryotic Expression

The encoding region of sex-determining region on Y chromosome(SRY) was amplified from genome in Tianzhu White Yak(Bos grunneins).The product was cloned to pGEM-T easy vector and sequenced.The total coding region of yak's SRY gene was 687 bp,encoding a peptide with 229 amino acid residues(GenBank:FJ373272).Sequence alignment showed that there were two mutations in the coding region compared with cow(B.taurus),causing one amino acid mutation in LF protein.The coding region of yak's SRY gene was cloned to EcoRⅠand Sal Ⅰ sites of pET-28a(+) vector to construct an expression plasmid pET-28a/SRY,which was then transformed into Escherichia coli BL21(DE3),and the SRY protein was highly expressed under 30 ℃ 200 r/min induced by IPTG.Western blotting results showed that the protein obtained could bind with anti-His tag,indicating that the SRY protein of yak was expressed.