Fig. 1

The rates of GVBD and MII stages in different culture systems. The different culture systems include maturation medium (MM) as control, co-culture with granulosa cells for 24 h (CG) and co-culture with granulosa cells plus 12 h further culture in MM (CG + 12hMM). ** Statistically different from the respective controls, p < 0.01. Bars represent mean ± SEM. Numbers of oocytes in each treatment: MM (n = 456), CG (n = 530), CG + 12hMM (n = 526)