cDNA cloning and expression analysis of MSTN gene from Schizopygopsis pylzovi

Myostatin (MSTN) is a member of the TGF-β superfamily that acts as a negative regulator of skeletal muscle growth. A full-length, 2 180 bp, cDNA sequence of the myostatin gene from Schizopygopisis pylzovi was cloned with RT-PCR,5'-RACE and 3'-RACE and the cDNA clone included a 1 128 bp ORF, encoding a 375 amino acid peptide. Using PCR, we obtained the sequences of two introns of the MSTN gene and found that its structure in Schizopygopsis pylzovi was similar to that of other vertebrates, including three exons and two introns. Likewise, the putative MSTN peptide of Schizopygopsis pylzovi contains a conserved RXXR proteolytic cleavage domain, and 8 conserved cysteine residues in the C terminal of the protein, similar to other vertebrates. Phylogenetic analysis showed that the MSTN of Schizopygopsis pylzovi has high homology with other cyprinid fishes, but a low homology with mammals and birds. In the 9 examined tissues, the MSTN gene was highly expressed in heart, kidney, intestine and spermary, while weakly expressed in muscle, brain, fat, gill and hepatopancreas. Quantitative real-time PCR analysis showed that the expression of MSTN gene was different during embryo development, suggesting that the fish MSTN may not only play roles in muscle development but also contribute to other biological functions.