Fig. 5. Chromosome alignment and segregation defects in HeLa cells with reduced levels of cohesin or Pds5 proteins. HeLa cells that had been mock-transfected (control) or transfected with siRNAs specific for Scc1, Pds5A or Pds5B were fixed and labeled with antibodies against -tubulin (green) and CENP-E (red). DNA was stained with DAPI (blue). Representative examples of a normal metaphase cell (a), and of the different types of abnormalities found among the cells treated with siRNA (b-e). The frequency of the defects among the population of prometaphase/metaphase cells in the different cultures is shown in the graph below the images. The number of cells scored was 284 (control), 461 (Scc1 siRNA), 269 (Pds5A siRNA) and 242 (Pds5B siRNA). Bar, 5 µm.