Regulation of cytokinesis initiation by Polo-like kinase, CIF1, and Aurora B kinase in trypanosomes and the activation of a backup cytokinesis pathway by inhibiting normal cytokinesis. Depicted are trypanosome cells at different cell cycle stages and the dynamic localizations of T. brucei Polo-like kinase homolog TbPLK, Aurora B kinase homolog TbAUK1, and CIF1. A, anterior; P, posterior.