Figure 6. The effect of melatonin on NNAT expression and the glucose uptake 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) NNAT mRNA levels in the fresh, prolonged-culture, and prolonged-culture + Mel oocytes. (B) Representative images of fresh, prolonged-culture and prolonged-culture + Mel oocytes stained with NNAT antibody. (C) Quantification of the NNAT protein level. (D) Representative images of fresh, prolonged-culture and prolonged-culture + Mel oocytes stained with 2-NBDG. (E) Quantification of the 2-NBDG level. PC, prolonged-culture; Mel, melatonin; Scale bar=100 μm. The data are presented as the mean ± SEM of at least three independent experiments. *P<0.05, **** P<0.0001.