Chmp4c-depletion induces chromosome misalignment and missegregation. (A and B) Time-lapse fluorescence images of HeLa cells stably expressing H2B:RFP and transfected with negative (control) or Chmp4c siRNA (siChmp4c). Time is from the start of chromatin condensation. Arrows indicate misaligned or missegregated chromosomes (magnified in insets). Related to Videos 1 and 2. (C) Time from NEBD to anaphase onset or in a metaphase-like state (“metaphase”), calculated from time-lapse movies as in Fig. S1. Control: n = 137; siChmp4c: n = 173. (D) Chromosome misalignment. Cells were transfected as in A and treated with MG132 for 1 h. (E and F) Chromosome missegregation and frequency of interphase cells with micronuclei. Arrows indicate misaligned, missegregated chromosomes or micronuclei. n = 300 cells (D–F) from three independent experiments. (G and H) Cells expressing GFP or Chmp4c:GFP resistant to degradation by Chmp4c-2 siRNA (siChmp4c-2) were transfected with negative siRNA (control) or siChmp4c-2 in the presence of MG132 for 1 h (G) or without MG132 (H). n = 90 cells from three independent experiments. Error bars show the SD. ***, P < 0.001 compared with the control. Student’s t test was used. Bars, 5 µm.