Fig. 7. Epithelial organization in pim mutants. Embryos before mitosis 15 (A,B) or before mitosis 16 (C,D) were labeled with a DNA stain (red) and anti--spectrin (green). Single confocal sections through the nuclear layer of the epidermal epithelium do not reveal differences between pim¹ mutant (B,D) and pim⁺ sibling embryos (A,C) before mitosis 15 (compare A and B). In contrast, a relatively disorganized epidermal epithelium is observed in pim¹ mutants before mitosis 16 (compare C and D). Bar, 10 µm.