Fig. 3. Defect in anaphase cell elongation is observed when hepatocytes do not complete cytokinesis. (A) Hepatocytes were isolated from either 15- or 25-day-old rats. Mitosis of mononuclear 2n cells was monitored. Images are shown at selected time points (minutes). Complete cytokinesis: the cell divides successfully (supplementary material Movie 1, 15-day-old-rat, 100% of cytokinesis events). Incomplete cytokinesis: division leads to the genesis of a binucleated hepatocyte (supplementary material Movie 2, 25-day-old-rats, 28±3.6% of cytokinesis events). Movies are representative of 50 cells analyzed in four independent cultures. The outlines show cell shape. (B) Cell elongation from metaphase to telophase was determined using time-lapse sequences. Time 0 correspond to chromosome alignment along the metaphase plate. Data are presented as the mean±s.e. from 25 independent time-lapse sequences. (C) Chromosome-to-membrane distance was measured on the same time-lapse sequences presented in B. The histogram represents the average chromosome-to-membrane distance of complete/incomplete cytokinesis. Data are presented as the mean±s.e. from 25 independent time-lapse sequences, P<0.0001. Images shown are representative of anaphase cells that will complete or not complete cytokinesis. The outlines show cell shape; arrows represent chromosome-to-membrane distance. Bars, 5 µm.