Oxidative damage and the repair of mitochondrial DNA in oocyte

Abstract

With the increase of infertility, there is growing concern about the decreased oocyte quality, as the essential reason to induce dysembryoplasia even female infertility. How to predict and improve oocyte quality also receives more attention. Researches has shown that the quantity and quality of mitochondria within oocyte can reduce developmental potentiality, including mitochondrial DNA (mtDNA) damage. The mtDNA is peculiarly susceptible to oxidative damage. And it tends to cause gene mutation and DNA strand break, which causes mitochondrial function to be injured in different degrees, then reduce the quality of oocyte. This paper describes the importance of mtDNA to oocyte, and mainly demonstrates a series of repair mechanisms after oxidative damage, such as base excision repair or mismatch repair. However, self-pair of mtDNA is limited. So, the new approach is vital to repair mtDNA. First, different antioxidants can decrease oxidative stress damage to a certain extent. Furthermore, mitochondrial transplantation and mitochondrial replacement straightly enhance and substitute within mitochondria, which improves fertilization rate and the quality of embryo. This paper may provide a useful reference for future research. Key words: Oocytes; DNA, mitochondrial; Oxidative stress; DNA repair