肌生成抑制素基因研究进展

肌生成抑制素是 1 997年发现的骨骼肌生长发育负调控因子 ,肌生成抑制素不仅在骨骼肌中表达 ,还可在心肌和浦肯野纤维等多种组织中表达。研究表明 ,大鼠骨骼肌在体内的再生 ,对 MSTN m RNA的表达表现出明显的时间依赖性 ,并且 m RNA的表达不必由功能性神经支配。通过对不同品种双肌表型牛 MSTN基因的研究 ,发现其骨胳肌增大的共同特点是肌生成抑制素基因发生了突变 ,如布鲁牛 MSTN基因在编码区外显子 3发生 1 1 bp的缺失 ,导致MSTN此位点后的阅读框架改变 ,并在此点后的 1 4个密码子处终止了阅读框架 ,从而使MSTN被截短 ,MSTN蛋白活性区域消失 ,活性丧失 ,结果肌肉大量增加。目前 ,已分别对人、牛和猪的 MSTN基因进行了定位研究 ,猪肌生成抑制素基因定位研究表明 ,猪 MSTN基因位于1 5号染色体上。

Progress of Study on Myostatin Gene

Myostatin(MSTN) negatively regulates mammalian skeletal muscle growth and development by inhibiting myoblast proliferation that was found in 1997. Myostatin not only expresses in skeletal muscle, but also can express in Purkinje fibers and cardiomyocytes in heart tissue. Research indicated,that in vivo regenerating rat skeletal muscles showed a characteristic time-dependent expression of myostatin mRNA, and in vitro experimentation suggested that functional innervation is no prerequisite for myostatin expression. At studying the bovine myostatin gene caused the double-muscled phenotype in cattles,found an 11-bp deletion in the coding sequence that results in a frame-shift mutation for the bioactive carboxy-terminal domain of the protein causing the muscular hypertrophy observed in Belgian Blue cattle. At present,it has beanstuded on the myostatin genes of people, cattle and pig separately yet, and the porcine myostatin gene is positioned within the chromosome 15.