二花脸猪和大白猪背最长肌中肌肉生长抑制素和生肌调节因子基因的表达及其性别特点

用相对定量RT—PCR方法研究大白猪和二花脸猪背最长肌中肌肉生长抑制素（Myostatin）和生肌调节因子（Myo—genin）基因表达的发育性变化并进行品种及性别间比较。研究结果表明：大白猪公猪Myostatin mRNA表达水平在20日龄时达到高峰且显著高于相同日龄二花脸公猪（P〈0．05），而二花脸公猪在45日龄时才显著升高，其他日龄品种间差异不显著。二花脸公猪和母猪出生后Myostatin mRNA表达水平均表现为上升，45日龄时达到高峰，120日龄时公母猪间差异显著（P〈0．05）。二花脸公猪与大白猪公猪Myogenin mRNA的表达发育模式基本相同，均在20日龄达到最高值，品种问差异不显著。90日龄二花脸母猪Myogenin mRNA表达水平较公猪显著下调（P〈0．05）。结果提示，猪背最长肌中Myostatin和Myogenin基因表达水平在猪出生后早期均较高，但没有出现随着日龄的增加而一直升高或降低的趋势；两种基因的表达在20日龄出现品种间差异；性成熟前后二花脸公母猪间表达有差异。

Developmental changes of Myostatin and Myogenin genes expression in longissimus dorsi muscle of Erhualian and Large White pigs

In present study,developmental patterns of Myostatin and Myogenin genes expression in longissimus dorsi(LD)muscle were compared between Erhualian and Large White pigs with semi-quantitative RT-PCR.The results indicated that:(1)the Myostatin mRNA expression in Large White pigs reached a peak at D 20 which was higher than that in Erhualian pigs significantly(P<0.05),and Myostatin mRNA expression increased significantly until D_45,no difference between breeds was observed at other ages;(2)the expression of Myostatin increased in both Erhualian gilts and boars after birth,then reached a peak at D 45,and the sexual difference was observed at D_120(P<0.05);(3)the development pattern of the expression of Myogenin mRNA was the same in two breeds,the expression of Myogenin mRNA was high at 20 dayold(D_20),then declined gradually;(4)compared with Erhualian boars,the Myogenin expression in Erhualian gilts exhibited remarkable down-regulation at D_90(P<0.05).The results suggest that the high level of Myostatin and Myogenin genes expression might play a role in regulating the metabolic and contractile maturation of myofibers during the early postnatal growth;there is strain difference at D_20;around the sex maturation,the sexual difference was found in two genes expression.