Research Paper Volume 10, Issue 12 pp 3897—3909

Melatonin prevents deterioration in quality by preserving epigenetic modifications of porcine oocytes after prolonged culture

Figure 5. The effect of melatonin on DNA methylation on the NNAT promoter 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) Primer and CpG loci examined at the NNAT differentially methylated region (DMR) are shown. DNA methylation was examined by bisulfite sequencing in fresh (B), prolonged-culture (C) and prolonged-culture + Mel oocytes (D). Each line presents an individually cloned allele, with an open circle for a non-methylated CpG site and filled circles for methylated CpG. Ten clones successfully sequenced for each group are presented. Methylation level (%) = (Methylated CpG/Total CpG) × 100. PC, prolonged-culture; Mel, melatonin.