A few of millions of germ cells existed in mamallian ovaries can catch an opportunity to grow to embryonic stage and reproductive achievement. Most of them are eliminated by diffrent ways. Two of these ways are "apoptosis and autophagic action. These major events play a ciritical role in germ cells elimination from mamallian ovaries. Apoptosis is described as programmed cell death and can be performed by follicular atresia. Therefore, these major events should be prevented in endangered species in order to keep the generations.Good luck