CYP51在小鼠胚胎卵母细胞第一次减数分裂前期转换的作用机制

羊毛甾醇代谢产物在卵母细胞后期减数分裂恢复中具有重要作用。CYP51是羊毛甾醇代谢通路中的关键合成酶。已有实验表明，CYP51在小鼠胚胎卵巢中大量表达，并随着生殖细胞减数分裂进程逐步下降，但其在此过程中发挥的具体作用尚不清楚。本课题以本实验室研究成果和国内外最新进展为依据，利用小鼠胚胎卵巢体外培养模型，主要研究CYP51 蛋白在小鼠胚胎期生殖细胞减数分裂启动中的作用,及其与减数分裂关键信号视黄酸(RA)之间的关系，进一步探索CYP51蛋白在卵母细胞第一次减数分裂前期进程中的功能与作用机理。研究结果将有助于加深人们对哺乳动物减数分裂启动和阻滞机制的理解；减数分裂进程关系着原始卵泡库的建立，其直接决定了雌性生殖力。此外，减数分裂的异常常导致生殖疾病的发生，因此，本研究也为妇女因生殖细胞异常造成的生殖障碍的发病机理提供理论支持，为提高人类生殖健康提供新的思路与方法。

Lanosterol 14α-demethylase (CYP51) is a crucial enzyme in cholesterol biosynthesis, producing meiosis-activating sterol (MAS). It can cause resumption of the later stage of meiosis in oocytes in vitro. Previously, we observed strong CYP51 expression in the foetal ovary in which germ cells are under the progression of Meiotic Prophase I, but the role of CYP51 remains unknown.We use the fetal ovary in vitro culture model to pursue the posssible role of CYP51 during Meiotic Prophase I and the relationship with Retinoic Acid (RA), the key signal to initiate meiosis. The study will help better understanding the mechanism of meiosis initiation and meiotic arrest in female mammals. Since the progression of Meiotic Prophase I is coincident with the establishment of primordial follicle pool which serves as a resting population of oocytes available during the female reproductive life span, this study also help better understangding of the possible pathogenesis of female sterility, provides new methods to improve human reproduction quality and livestock reprodutive production.