Figure 6.

Down-regulation of WDHD1 leads to cell cycle progression deficiencies attributable to defective centromere. (A) Cell cycle profiles of the control (ctrl) and WDHD1 knockdown cells. Mock or WDHD1-knockdown 293T cells were subjected to FACS for measurement of DNA content. (B) Mitotic fidelity was assessed by scoring mitotic cells with chromosome bridges. Condensed mitotic chromosomes were visualized by phospho-histone H3 immunostaining. Representative immunofluorescence images are depicted on the left. Both anaphase and telophase nuclei are shown, as indicated. Panel on the right shows the percentages of mitotic cells with chromosome bridges in control (ctrl) versus knockdown cells (n = 250). The results represent averages of three independent experiments. (C) Nuclear morphology was altered in WDHD1-deficient cells. Control (ctrl) and knockdown HeLa cells were immunostained for WDHD1, and counterstained for F-actin (for demarcating cell membrane) and DNA (DAPI). Confocal microscopy was done as described before (scale bar is 10 µm). Percentages of cells with more than one nuclei staining, examples of which are indicated by arrowheads, are shown on the bottom (n = 1000) and represent averages of three independent experiments.