A: Live cell imaging results showing in vitro meiotic division of WT and Cnot6l-/- oocytes. Abbreviations: PM, prometaphase; MI, metaphase I; AI, anaphase I; TI, anaphase I-metaphase II transition; MII, metaphase II; PB1: polar body-1. Hours after released from GV arrest were indicated. Scale bar, 20 μm 