K129E expressed alone cannot support mitosis. (A) Cells were treated with control or survivin specific siRNA as described in Wheatley et al. , and cell number monitored by trypan blue exclusion. Fold difference between control treatment and survivin siRNA-specific treatment is plotted, and is representative of three independent experiments. (B) Immunofluorescence images of formaldeyde fixed cells in prometaphase, anaphase and cytokinesis 72 h after depletion of the endogenous protein showing WT or K129E (green), microtubules (red) and chromosomes (blue). Scale bar 5 μm. (C) Cells depleted of endogenous survivin were then arrested in mitosis by 3 h treatment with DMA and imaged in DIC (upper panels) and GFP (lower panels) to determine their fate post-release from mitotic arrest, as in Figure 2B. (D) Quantitation of cell fates post-release from DMA and depleted of endogenous survivin for 48 h or 72 h.