G: Rates of PB2 emission and normal spindle assembly in oocytes cultured with or without U0126. Fully grown GV oocytes were microinjected with mRNAs encoding CNOT6L, CNOT7 and/or BTG4 and are released from milrinone at 12 h after microinjection. Then the oocytes were further culture for 24 h with or without adding U0126 to the medium. Error bars, s.e.m. *P < 0.05; **P < 0.01; ***P < 0.001 by two-tailed Student"s t test. n.s.: non-significant. The numbers of analyzed oocytes were indicate 