Abstract: The yak MSTN gene was amplified using paRticulaR pRimeRs， then cloned and sequenced． It was obtained by sequence splicing using moleculaR biology softwaRe． The Results showed that yak MSTN gene( GenBank Accession No: EU926670) had 3 exons and 2 intRons． The size of CDS( GenBank Accession No: EU926671) sequence of the yak MSTN gene，encoding 375 amino acid，was 1 128 bp． The size of exonⅠ，exonⅡand exon Ⅲ was 373，3 74， 374 bp， Respectively; while the size of intRon Ⅰ and intRonⅡwas 1 843，2 024 bp， Respectively． A single base conveRsion( C→T) located 417 base was found in Yak MSTN gene coding Region compaRed to oRdinaRy cattle， which did not cause changes in amino acids． The nucleotide sequence of the coding Region and deduced amino acid sequences among diffeRent species weRe quitely conseRvative． The homology Rates of nucleotide sequences of the coding Region of MSTN gene between the yak and cattle， sheep，pig，human，dog，mouse，house， Rabbit，chick and chimpanzee weRe 99． 9%， 96． 4%， 94． 6%，92． 2%，91． 8%，91． 8%，92． 8%，95． 3%，84． 4%，84． 9%， Respectively， while the homology Rates of amino acid sequences weRe 100%， 93． 3%， 95． 5%， 92． 5%，94． 1%， 93． 3%， 94. 9%， 94． 4%，88． 0% and 94． 4%， Respectively． Biological softwaRe analysis showed that the theoRetical moleculaR weight of Yak MSTN gene was 42． 6 kDa and PI was 6． 14． Leu was the highest( 9． 9%) ， followed by Lys( 7. 2%) ． The secondaRy stRuctuRe of Yak MSTN pRotein was mainly β-folding and it had chaRacteRistics of tRansmembRane pRotein stRuctuRe． And the tRansmembRane domain located between AA6 and AA23 ． MoReoveR， it had a secRetion signal peptide stRuctuRe，MQKLQICVYIYLFMLIVA，which pRobably Related well with TGF-β pRotein family．

Key words: Yak, MSTN gene, Cloning, Sequence analysis

CLC Number: 

• Q78

• S858．23