中文摘要：

为阐明泌乳奶牛乳腺中甲硫氨酸与乳蛋白生物合成之间的调控关系，本研究利用体外培养的泌乳期奶牛乳腺上皮细胞，采用Western blotting方法检测了甲硫氨酸对奶牛乳腺上皮细胞中酪蛋白生物合成以及mTOR4信号通路分子表达的影响。结果表明：甲硫氨酸可以诱导奶牛乳腺上皮细胞中的酪蛋白的表达．同时激活磷酸化的mTOR、p70SK6以及4E—BP1。这些结果表明甲硫氨酸对酪蛋白的合成和分泌具有正向调节作用，甲硫氨酸通过激活mTOR信号通路调节泌乳奶牛乳腺中酪蛋白的生物合成。

英文摘要：

To investigate the underlying relationship between methionine and milk protein synthesis, western blotting was used to detect the effect of methionine on casein expression, as well as on the expression of translation signal molecules in dairy cow mammary epithelial cells. The results showed that casein expression was induced by methionine. The expression of phospho-roTOR, phospho-4E-BP1 and phospho-p70S6K were also induced simultaneously. All these results revealed that methionine regulated casein synthesis by activatingmTOR signal pathway in dairy cow mammary gland.