Fig. 3. Chromosome condensation is delayed in abdominal histoblasts that are mutant for Dm myb. Abdominal epidermal samples from females were doubly stained with DAPI to visualize nuclei (blue in merged panels) and with the PH3 antibody to identify mitotic cells (red in merged panels, but appearing as magenta because of superimposition on blue). Scale bars: in A, 0.01 mm for A-C; in E, 0.01 mm for D,E. (A,D) w/Df(1)sd^72a controls at 36 hours APF; (B) myb² at 36-42 hours APF; (C,E) myb²/Df(1)sd^72a at 42-47 hours APF. Asterisks in (B,C) indicate examples of ‘pre-prophase’ cells. For comparison, examples of prophase (D) and ‘pre-prophase’ (E) cells are shown at higher magnification.