Effect of down-regulation of Wee1 kinases on mouse oocyte meiotic arrest. (A and B) WT (A) or pde3a^−/− (B) oocytes were injected with MO corresponding to Wee1A, Wee1B, or Myt1. Scrambled MO (Ctrl) was used as a negative control. Error bars indicate SEM. Numbers above the bars indicate the number of oocytes in the GVBD stage and number of total oocytes, respectively, as well as the number of experiments performed. *, P < 0.005; and **, P < 0.0001 compared with control. ***, P = 0.0192.