Fic1 localizes to the contractile ring and plays a nonessential role in cytokinesis. (A and B) fic1-GFP cells were imaged live. In B, one 0.5-μm slice was taken through cell middles to allow imaging of fainter structures. BF, bright field. (C) cdc15-CFP fic1-YFP cells were imaged through one 0.5-μm plane. Bright field, CFP (green), YFP (red), and merged images are shown. Insets (boxed area) show colocalization of Cdc15 and Fic1 at cell tips (arrows). (D) Wild-type and fic1Δ cells were stained as in Fig. 1 A. Quantitation of cell phenotypes is shown in Fig. S3 E (available). (E) fic1Δ was crossed with several mutants or deletions in cytokinesis genes to determine synthetic interactions. Bars: (A–D) 5 μm; (C, inset) 2 μm.