Fig. 6. Unequal cleavages in MO-injected 16-cell embryos. (A) In control embryo, B4.1 blastomeres divide into larger B5.1 and smaller B5.2 blastomeres, as indicated by red bar. (B) Normal CAB in extracted embryo. (C) In most cases, POPK-1 MO-injected embryos also showed normal cleavage pattern. (D) Occasionally, unequal cleavage failed. (E) Unequally cleaved POPK-1 MO-injected embryo had small CAB. (F) Even if POPK-1 MO-injected embryos failed to divide unequally, there was always a small CAB. The shape and size of the CAB was indistinguishable from those in embryos showing unequal cleavage. Scale bar: 100 µm.