OPA1 deficiency induces mitophagy through PINK1/Parkin pathway during bovine oocytes maturation.

In vitro embryo production (IVP) technology has been increasingly applied to beef cattle breeding. In vitro maturation (IVM) technology is the basis of IVP. However, the quality of in vitro-generated mature oocytes is still poor. Mitochondria are the energy factories of oocytes, so they are crucial for oocyte quality. OPA1 is a protein located on the mitochondrial inner membrane, and its main function is to mediate mitochondrial inner membrane fusion. This work demonstrated that OPA1 is expressed at different stages of meiosis in bovine oocytes. The inhibition of OPA1 activity resulted in a reduced rate of first polar body excretion from bovine oocytes and disruption of the spindle structure. OPA1 deficiency impacted mitochondria by leading to mitochondrial dysfunction, promoting mitochondrial fission, and inducing mitophagy through the PINK1/Parkin pathway. Taken together, our findings suggest that OPA1 is essential for bovine oocyte maturation and that OPA1 deficiency leads to mitochondrial dysfunction and promotes mitochondrial fission as well as mitophagy.