Abstract:

Oocyte aging is mainly manifested by the gradual decline of oocyte quantity and quality. Mitochondria are important cellular organelles in oocytes and are involved in a series of important physiological processes, including oocyte maturation, fertilization and embryo development. In recent years, increasing evidence supports that mitochondrial dysfunction regulates the process of ovarian aging. With increasing age, reactive oxygen species(ROS) accumulate in oocytes, the expression of key genes in the mitochondrial respiratory chain of oocytes decreases, the body′s protective mechanism against oxidative stress is weakened, and mitochondrial dynamics are altered, shifting to fission in the aging process. As the mitochondrial DNA(mtDNA) is close to the respiratory chain and lacks protective histones and effective repair mechanism, the mutation rate of mtDNA increases and the copy number of mtDNA decreases, which ultimately leads to an increase in apoptosis of oocytes and granulosa cells, an abnormal meiotic process, and a decrease in the quality of oocytes, which accelerates ovarian aging.

Key words: Ovary, Aging, Oxidative stress, Mitochondrial dynamics, DNA, mitochondrial