Oocyte cell death is a normal process in the mammalian ovary during follicular growth. Recent reports have demonstrated the presence of pro-apoptotic and pro-autophagic proteins during oocyte elimination. The goal of this study was to identify the interactions between proteins involved in different types of programmed cell death in the same oocyte during follicular atresia. We evaluated the presence of Beclin 1 and its interaction with the pro-apoptotic proteins active caspase-3, Bax, and Bak by means of histochemical observations, ultrastructural immunodetection, and immunoprecipitation techniques in ovaries from prepubertal (28- and 33-day-old), juvenile (40-day-old), and young adult (90-day-old) rats. In this study, we identified that oocyte elimination occurred with a high quantity of pro-autophagic protein Beclin 1 and increased the presence of the pro-apoptotic proteins active caspase-3, Bax, and Bak. Conversely, the antiapoptotic protein Bcl-2 was reduced in oocytes from atretic follicles. In addition, Beclin 1 was shown to interact with active caspase-3 and Bax. Our results suggest that the increase in Beclin 1 is directly related to the rise of pro-apoptotic proteins, which could promote the apoptotic process during oocyte elimination.

卵母细胞细胞死亡是卵泡生长期间哺乳动物卵巢中的正常过程。最近的报告表明在卵母细胞消除过程中存在促凋亡和促自噬蛋白。本研究的目的是确定卵泡闭锁期间同一卵母细胞中不同类型程序性细胞死亡所涉及的蛋白质之间的相互作用。我们通过组织化学观察、超微结构免疫检测和免疫沉淀技术评估了青春期前（28 天和 33 天）卵巢中 Beclin 1 的存在及其与促凋亡蛋白活性 caspase-3、Bax 和 Bak 的相互作用)、幼鼠（40 天大）和年轻的成年（90 天大）大鼠。在这项研究中，我们发现卵母细胞消除发生在大量促自噬蛋白 Beclin 1 的情况下，并增加了促凋亡蛋白活性 caspase-3、Bax 和 Bak 的存在。相反，抗凋亡蛋白 Bcl-2 在闭锁卵泡的卵母细胞中减少。此外，Beclin 1 显示与活性 caspase-3 和 Bax 相互作用。我们的结果表明，Beclin 1 的增加与促凋亡蛋白的增加直接相关，促凋亡蛋白可以促进卵母细胞消除过程中的细胞凋亡过程。