Fig. 4. Centrosome separation is blocked by depolymerization of actin-filaments in HeLa cells. (A) HeLa cells that had been through two rounds of thymidine synchronization were released in the presence of cytochalasin B (+cyto B), nocodazole (+noco) or both (+nono & ctyo B). At indicated times (4 hours, 6 hours, 8 hours and 10 hours), control cells and regeant-treated cells were harvested for flow cytometry and immunofluorescence staining with anti--tubulin (T) and DAPI. Scale bars: 10 µm. (B) Measurements of the distance between (d) two centrosomes and (D) the corresponding nuclear diameter. (C) Average distance of two centrosomes and nuclear diameter of 200 cells. Measurements were conducted using fluorescence images similar to those shown in A. (D) Plotting of the centrosome-separation ratio (distance between two centrosomes per nuclear diameter, d/D). In each experiment, 200 cells were plotted.