Figure 5.

Abnormal chromosome segregation in topoIIα-depleted cells. (A) Frequency of abnormal cytokineses after addition of doxycycline. The samples were the same as those analyzed in Figure 3A: no further treatment (circles; green) or 7-h treatments with nocodazole (triangles; blue), caffeine (diamonds; brown), or nocodazole and caffeine (squares; black). (B) Fluorescence and immunofluorescence confocal microscopy of DNA (DAPI; blue) and phosphorylated Histone H3 (green), respectively, in normal (a) and abnormal (b–d) cytokinesis in cultures treated with doxycycline for 1 (a and b), 2 (c), or 3 (d) d. (C) Confocal fluorescence microscopy of an abnormal cytokinesis in HTETOP/H2B-GFP cells treated with doxycycine for 3 d. (D) Time-lapse confocal microscopy showing an abnormal cytokinesis arising from an abnormal anaphase in HTETOP/H2B-GFP cells treated with doxycycline for 1 d. (E) Time-lapse confocal microscopy showing normal anaphase in HTETOP/H2B-GFP cells not treated with doxycycline. (F) Time-lapse confocal microscopy showing abortive anaphase in HTETOP/H2B-GFP cells treated with doxycycline for 2 d. All bars, 10 μm. Images in D, E, and F were taken from videos (Fig 5video1.mov, Fig 5video2.mov and Fig 5video3.mov, respectively) that can been seen as online Supplementary Material.