Fig. 9. Immunofluorescence analysis of conventional cytokinesis. (A) Mitotic domain, wild-type embryo. Anillin and Peanut colocalize in cleavage furrows (^*) and intracellular bridges (arrowheads). Intracellular bridges are long lasting, and were frequently observed in mitotic domains. (B) Mitotic domain, anillin^PQ/RS-derived embryo. Mutant Anillin, but not Peanut, is localized to cleavage furrows (arrowhead) and to an apparently regressed cleavage furrow in a bi-nucleate cell (^*). (C) Genotype as in B. Example of a rare intracellular bridge enriched in Anillin but not septins (arrowhead). Intracellular bridges were very rare, indicating that most attempts at cytokinesis fail. (D) Imaginal disc rudiment from 3rd instar larvae, genotype anillin⁷/anillin^PQ stained for F-actin (red) and DNA (blue). Large binucleate cells (arrowheads) are present. Scale bar: 5 µm.