本试验旨在探讨肌肉生长抑制素（myostatin，MSTN）、细胞周期蛋白依赖性蛋白激酶2（cyclin-dependent-kinase 2，CDK2）、胰岛素样生长因子2（insulin-like growth factor 2，IGF2）和激素敏感脂肪酶（hormone sensitive lipase，HSL）对地方猪品种骨骼肌细胞生长及脂肪代谢的调节作用。选用贵州省地方优良品种糯谷猪为试验材料，外二元杂交猪（长×大）为对照，应用RT-PCR和免疫组织化学方法研究骨骼肌MSTN、IGF2及HSL基因的表达，及其蛋白在肌细胞中的定位和分布，并测定肌细胞中CDK2的活性。结果表明：糯谷猪骨骼肌MSTN mRNA的表达量略高于外二元杂交猪（P>0.05），IGF2基因表达量极显著高于对照（P<0.01），HSL基因表达量低于对照（P<0.05）。骨骼肌细胞中MSTN、IGF2、HSL阳性信号均定位于细胞质，与外二元杂交猪相比，糯谷猪骨骼肌细胞中MSTN和IGF2的表达量较高（P<0.05），HSL的表达量较低（P<0.01），CDK2的活性较低（P<0.01）。相关性分析结果提示，MSTN和IGF2基因的高表达、CDK2的低活性使糯谷猪骨骼肌细胞的数量减少，MSTN和IGF2协作使糯谷猪肌细胞出现一定的增生效应，HSL和IGF2共同促进糯谷猪的脂肪沉积，这些因子综合作用导致糯谷猪的瘦肉率较低。

The aim of this study was to explore the regulation of myostatin (MSTN), cyclin-dependent-kinase 2 (CDK2), insulin-like growth factor 2 (IGF2) and hormore sensitive lipase (HSL) genes on skeletal muscle cells growth and fat metabolism in local pig breeds. Taking Yorkshire×Landrace crossbreed pig as control, local varieties Nuogu pig from Guizhou province was chosen for the experiment, and the expression of MSTN, IGF2, HSL and activity of CDK2 were detected in the skeletal muscle cells by RT-PCR and immunohistochemistry methods. The results showed that the expression of MSTN mRNA in Nuogu pig tended to be higher than that in the crossbreed pig (P>0.05) and the expression of IGF2 mRNA in Nuogu pig was higher than that in the crossbreed pig (P<0.01), but the expression of HSL mRNA was lower (P<0.05). Brown granules of MSTN, IGF2 and HSL were detected in the cytoplasm of muscle cells from Nuogu and the crossbreed pig. Compared with the crossbreed pig, signal of MSTN and IGF2 proteins was much more intensive (P<0.05), but HSL expression and CDK2 activity were weaker in Nuogu pig (P<0.01). These results of correlation analysis indicated that the higher expression of MSTN and IGF2 together with the lower CDK2 activity decreased the number of muscle cells. Higher MSTN and IGF2 expression enlarged the fiber size of muscle cells in Nuogu pig breed. Furthermore, lower HSL and higher IGF2 made the fat deposition much easier in Nuogu pig than that in the Yorkshire×Landrace crossbreed pig. Altogether, 4 factors, MSTN, CDK2, IGF2 and HSL, cooperated with each other and resulted in the lower lean percentage in the native Nuogu pig breed in Guizhou province.［Chinese Journal of Animal Nutrition, 2010，22（2）:444-451］