Embryos relying on one maternal dose of CycB exhibit timely but abortive mitosis. (A) Embryos expressing histone-GFP and containing either one or two maternal doses of CycB were injected with CycA and CycB3 dsRNA (represented as 1× CycB or 2× CycB, respectively). Mean cell cycle times during cycle 12 are presented. Embryos injected with control LacI dsRNA are presented for reference. (B) Behavior of mitosis 12 in different regions of a 1× CycB embryo after CycA and CycB3 dsRNA injection at one pole (left). (C) Embryos as in B were imaged at a higher resolution during cycle 12 near the injection site. (D) Single z sections from C during the atypical interphase (12:31).