Characterisation of Ska-depletion phenotype. (A) HeLa S3 cells were treated for 48 h with control (GL2), Ska1-, Ska2- and Nuf2-specific siRNAs, respectively. They were fixed directly (left column, 37°C) or after incubation for 10 min at 4°C (right column, 4°C) before staining with anti-α-tubulin antibody (green), CREST serum (red) and DAPI (DNA, blue). (B) HeLa S3 cells were treated for 48 h with control (GL2), or Ska1- and Ska2-specific siRNAs, respectively, then fixed with PTEMF and stained with anti-Mad2 antibody (red), CREST serum (green) and DAPI (DNA, blue). Scale bars=10 μm. (C) Quantification of the mitotic indices (300 cells each) after 48 h of Ska1 and Ska2 siRNA together with control GL2 siRNA or after simultaneous depletion of Mad2.