Figure 3. Effect of melatonin on histone methylation at H3K27me2 of prolonged-culture oocytes. Porcine oocytes matured in vitro were continuously cultured in medium supplemented with or without 10−3 M melatonin for 24 h. (A) Representative images of fresh, prolonged-culture and prolonged-culture + Mel oocytes stained with H3K27me2 antibody. (B) Quantitative analysis of H3K27me2 ﬂuorescence intensity. PC, prolonged-culture; Mel, melatonin, Scale bar=100 μm. The data are expressed as the mean ± SEM of at least three independent experiments, **** P<0.0001.