Fig. 6. Prolonged CycE expression during the terminal division cycles restores mitosis 16 in CycA mutants. (A-H) The prd-Gal4 transgene was used to drive UAS-CycE expression in alternating segments of CycA^C8LR1 (CycA^- prd>CycE) or sibling control (CycA⁺ prd>CycE) embryos. Embryos were immunolabeled with anti-Cyclin B3 (A,B; CycB3), or with anti-tubulin (C,E,G; Tub) and a DNA stain (D,F,H; DNA). Premature Cyclin B3 degradation before mitosis 16 is prevented in the UAS-CycE-expressing segments of CycA^C8LR1 mutants (white arrowheads in A, right side in B). Mitosis 16 is restored in the UAS-CycE- expressing segments of CycA^C8LR1 mutants (white arrows in E,F), resulting in a twofold higher cell density in the UAS-CycE-expressing segments of CycA^C8LR1 mutants after the stage of mitosis 16 (compare left and right side in G,H).