Fig. 5. Dominant negative aPKC changes cleavage orientations and leads to cells `falling' from the outside cell layer into the inside part of the embryo (A',B'). Examples of the conservative (A') and differentiative (B') divisions in embryos followed by time-lapse microscopy through five focal planes after injection of a single 4-cell-stage blastomere with mRNA for DsRed and dominant negative aPKC. Images A-D represent stages of development of a single embryo at a central focal plane. The parental cells being followed are outlined with red and the daughter cells with blue and yellow dashed lines. (C') Example of the internalization of a cell followed by time-lapse microscopy through five focal planes in a pre-cavitation embryo injected with mRNA for DsRed and dominant negative aPKC into a single 4-cell-stage blastomere. Images A-D represent stages of development of a single embryo at a central focal plane. Bar, 10 µm.