Figure 3. SIRT2 knockdown abolishes the effects of melatonin on meiotic phenotypes in aged oocytes. (A) Schematic illustration of the experimental protocol to check whether SIRT2 mediates the effects of melatonin on aged oocyte. (B) The efficiency of SIRT2 knockdown was verified by Western blot. Actin served as a loading control. Band intensity was calculated using ImageJ software. (C) Representative images of spindle/chromosome organization in young, old, old+Mel and old+Mel+siSirt2 oocytes are shown. Arrows indicate the disorganized spindle and arrowheads indicate the misaligned chromosomes. (D) Quantification of young, old, old+Mel and old+Mel+siSirt2 oocytes with abnormal spindle/chromosomes. Error bars indicate ± SD. *P<0.05 vs. controls. Scale bars: 50 μm.