肌抑素(Myostatin)基因突变体活性区的克隆、表达及活性的研究

肌抑素Myostatin是肌肉发育的重要抑制因子，肌抑素的突变，使其抑制功能的全部或几乎全部丧失，表现为肌肉细胞的增大和肌纤维束的增加。采用PCR技术，从肌抑素天然突变的双肌牛皮尔蒙特（Piedmontese）的基因组中扩增得到肌抑素突变体的活性区，并将其亚克隆到pMD18T载体上，利用基因重组技术，构建原核表达质粒pET30a(+)/action/Myostatin，在大肠杆菌中高效表达，采用亲和层析法纯化表达产物，并将其共孵育于离体培养的绵羊肌肉细胞，检测肌抑素突变体的生化活性，结果显示肌抑素的突变体具有促进肌肉细胞增生和增殖的功能。

Molecular Cloning, Expression Mutation of Myostatin and Study on Biochemical Activity of Its C-terminal Peptide

Myostatin, a member of the TGF-beta family, negatively regulates skeletal muscle development. Mutation of myostatin activity leads to increases muscle growth and carcass lean yield. The bovine myostatin mutation cDNA was amplified by polymerase chain reaction, and then sub-cloned into the expression vector pET-30a( + ) to form the expression plasmid pET30a (+)-action/ Myostatin. The recombinant plasmid was transformed into E. coli BL21. The overexpression product of pET30a (+)-action/ Myostatin was been showed in vitro. Sheep skeletal muscle cell were cultured with the purified myostatin mutation C-terminal peptide. The results of this study suggest that had a powerful activity to stimulate the hyperplasia and proliferation of sheep muscle cells and shows high biochemical activity.