Figure 3

Cytokinesis failure does not significantly delay the exit frommitosis. (A) Images from time-lapse series of HDF cells at the indicated times after release from nocodazole-mediated mitotic arrest. "Control" cells were not treated with blebbistatin; "Blebbistatin" cells were treated with blebbistatin beginning at 30 min after release from nocodazole. (B) MPM-2 immunofluorescence as a marker for mitotic exit. Fluorescence image of a mitotic cell with condensed DNA and intense MPM-2 staining (top) and a cytokinetic cell with decondensed DNA and diminished MPM-2 staining (bottom). DNA, blue; MPM-2, green. Scale bar represents 10 μm. (C) Mitotic index of control and blebbistatin-treated cells after mitotic release. "Control" cells were not treated with blebbistatin; "Blebbistatin" cells were treated with blebbistatin beginning at 30 min after release from nocodazole. Mitotic index was determined by MPM-2 staining and DNA morphology, as in (B). For each point n = 100 cells.