Figure 4. RSV promotes mitophagy in aged oocytes. (A) Electron microscopy results showed the effect of RSV on mitochondrial morphology. Bar = 1 μm. (B) With the treatment of RSV, the autophagy level was detected by counterstaining with LC3 (red), Tom20 (green) and DAPI (blue). Bar = 50 μm. (C) Quantitative analysis of autophagosome numbers in (B). (D) After RSV treatment, the LC3 (including LC3-1 and LC3-2), PINK and Parkin protein expressions were measured by western blot. α-Tubulin was used as a loading control. (E) Quantitative analysis of protein level of PINK1 in (D) and the relative LC3-2/1 level was calculated. Data are presented as means ± S.E.M of three independent experiments. Different lowercase letters represent the difference of expression levels that are significant (P < 0.05).