Cloning and Expression Profiles of Myf5 Gene of Yak

To reveal the sequence characteristic and expression pattern of Myf5 gene in Jiulong yaks (Bos grunniens), a full-length cDNA of Myf5 was cloned from yak muscle tisssue by RT-PCR. The cDNA obtained was 821bp nucleotide (nt) long with an ORF of 768 bp which encoding 255 amino acids. Compared with cattle, sheep, pig, horse, human, pygmy chimpanzee, mouse, rat and dog, the homology of amino acid sequences were higher (89- 9%), but lower in Zebrafish (60%). SQ RT-PCR analysis showed that Myf5 gene expression was observed only in longissimus muscle, but not be detected in heart, liver, kidney, spleen and adipose tissues. The expression level of Myf5 gene in longissium muscle of 0.5 and over 9 years old yaks was significantly higher than those of 3.5-5.5 years old yaks (p<0.05). These results suggest that Myf5 may play an important role in the regulation of muscle growth and development of yak.