Figure 9. Schematic representation of how ubiquinol-10 delays oocyte ovulatory aging by defending against oxidative stress and controlling mitochondrial quality. Aging induced GSH depletion, ROS accumulation, mitochondrial biogenesis and mitophagy downregulation, followed by increases in autophagy and apoptosis. While supplementation with ubiquinol-10 prevented GSH depletion and ROS accumulation, it also enhanced mitochondrial biogenesis and mitophagy to control mitochondrial quality. Thus, ubiquinol-10 prevented postovulatory oocyte aging and promoted subsequent embryonic development in pigs. The black arrow indicates the aging-induced impairments in the oocytes. The red arrow indicates the beneficial effects of ubiquinol-10 on the aging oocytes.