目的:研究FOXO3a(forkhead box group O)转录因子是否参与调控哺乳动物卵巢中裸露卵母细胞和原始卵泡内卵母细胞的凋亡。方法:体外分离培养新生大鼠卵母细胞巢和原始卵泡内的卵母细胞,干细胞因子(stem cell factor,SCF)单独或与磷脂酰肌醇-3激酶(phosphoinositide 3-kinase,PI3K)抑制剂LY 294002联合作用于卵母细胞,TUNEL法凋亡染色观察卵母细胞凋亡状况;RT-PCR、Western blotting检测FOXO3a及其下游靶分子与卵母细胞凋亡的关系。结果:SCF不影响卵母细胞FOXO3a总蛋白表达水平,但使其磷酸化水平增加,从而抑制了卵母细胞凋亡;LY 294002可完全阻断上述效果。SCF使FOXO3a的靶基因Bim和p27kip1表达下调,此作用同样可被LY 294002逆转。结论:FOXO3a和其下游靶基因Bim及p27kip1可能参与了SCF信号通路对新生大鼠卵母细胞的凋亡调控。 OBJECTIVE: To investigate whether forkhead box group O (FOXO3a) transcription factors are involved in the regulation of oocyte oocysts in naked oocytes and oocytes in the primordial follicles. Methods: Oocytes were isolated and cultured in neonate oocytes and primordial follicles in vitro. Stem cell factor (SCF) alone or in combination with inhibitors of phosphoinositide 3-kinase (PI3K) LY 294002 in oocytes. The apoptotic status of oocytes was observed by TUNEL staining. The relationship between FOXO3a and its downstream target molecules and oocyte apoptosis was detected by RT-PCR and Western blotting. Results: SCF did not affect ovalbumin FOXO3a total protein expression, but increased its phosphorylation, which inhibited oocyte apoptosis; LY 294002 completely blocked the above effects. SCF down-regulated the expression of Bim and p27kip1, a target gene of FOXO3a, which was also reversed by LY294002. Conclusion: FOXO3a and its downstream target genes Bim and p27kip1 may be involved in the regulation of apoptosis of neonatal rat oocytes by SCF signaling pathway.