雷帕霉素靶在小鼠受精卵早期发育中的作用研究

The Role of Mammalian Target of Rapamycin in the Early Development of Mouse Zygotes

哺乳动物雷帕霉素靶(mTOR)是细胞生长的中心调控因子,应用RT-PCR、免疫印迹、放射性同位素体外测定酶活性等方法,研究mTOR在小鼠受精卵第一次有丝分裂过程中在卵中的表达、活性变化以及对卵裂的影响.研究发现mTOR在小鼠卵母细胞和受精卵中都有表达,在mRNA水平,mTOR从G2期开始降解,在蛋白水平,则各期没有明显变化;mTOR的激酶活性在受精后明显升高,并且在整个1-细胞期保持较高活性;mTOR的特异性抑制剂雷帕霉素能抑制卵裂,并且能抑制成熟促进因子MPF的调节亚基cyclin B的表达,从而抑制了MPF的活性.结果表明mTOR可能通过促进MPF的激活而促进小鼠受精卵的分裂.

MTOR is a central regulatory factor to the cell growth.RT-PCR,inmmunoblotting,kinase assay by isotope radioactive in vitro,etc.were used to study mTOR’s expression,activities in the mouse zygotes,and its effects to the cleavage.It was found that mTOR was expressed both in the mouse oocytes and in the zygotes,mTOR’s mRNA began to degrade since phase G2 stage,while it’s protein did not change obviously in the first mitosis of the mouse zygotes;the kinase activity of mTOR increased after fertilization,and kept in a high level during the whole 1-cell stage;rapamycin,the specific inhibitor of mTOR,could inhibit cleavage of the zygote,and inhibit the expression of cyclin B,the regulatory submit of maturation promote factor（MPF）,and therefore inhibited the activity of MPF.The results suggested that mTOR promote cleavage of the mouse zygote by promoting the activation of MPF.