Fig. 5. Overexpression of IFT88/polaris induces an arrest in the cell cycle before S phase and an apoptotic death. (A) HeLa cells were transfected for 36 hours to express either GFP-IFT88/polaris or GFP–C-Nap1 and these cells were treated or not with nocodazole for 12 hours. Cell-cycle-phase distribution of GFP-positive cells was assessed using propidium iodide. Proportions were estimated by triplicate measurements using FACS analysis and the software Wincycle^TM. (B) HeLa cells were transfected for 36 hours to express GFP-IFT88/polaris, GFP–C-Nap1 or GFP. BrdU staining was analyzed on GFP-positive cells after labeling with anti-BrdU monoclonal antibody (n=150). (C) HeLa cells were transfected for 36 hours to express GFP-IFT88/polaris, GFP–C-Nap1. These cells were synchronized by thymidine block for 12 hours and released for 6 hours. Cell-cycle-phase distribution of GFP-positive cells was assessed using iodide propidium and FACS analysis. (D) Caspase-3-like activity was measured 48 hours after transfection in GFP-positive cells (n=150). Data are from three independent experiments and presented as the mean ± s.d.