Fig. 2.

Effects of different concentrations of MT on nuclear maturity of GV oocytes and MI oocytes of human. a Effects of different concentrations of MT on GV oocytes. b Effects of different concentrations of MT on MI oocytes. Dotted line = significant increase of nuclear maturity rate between the two adjacent observing time points; Square frame = significant difference compared to the control group; Rectangular frame = significant difference compared to the controls and significant difference between the value of the upper frame and that of the lower frame; MT = melatonin