The PCM pole is formed by splitting PCM from the centriolar pole or by accumulation of PCM components. (A–D) HeLa cells expressing EGFP-centrin1 and pericentrin-mCherry were observed with a 60× objective. Magenta and green represent pericentrin-mCherry and EGFP-centrin1, respectively. Z-projections: 20 planes, 1.2 µm apart. Scale bars, 10 µm. Time zero corresponds to the beginning of mitotic cell rounding. (A) Splitting of the PCM components from the centriolar pole in one-centrosome cells. Arrowheads indicate the PCM at the acentriolar spindle pole. (B) PCM accumulation in one-centrosome cells. Arrowheads indicate the accumulation of PCM at acentriolar spindle poles. (C) Cell division in zero-centrosome cells without accumulation of PCM. (D) Quantification of patterns of PCM dynamics in A–C. Values are percentages of the total cells from 52 (for one-centrosome cells) or 24 (for zero-centrosome cells) cells from two independent experiments. (E) Averaged time courses of pericentrin-mCherry or CDK5RAP2-mCherry signals at the centriolar spindle pole and PCM pole of 10 cells. Time course data were aligned at PCM pole formation (0 h). Error bars represent SD; AU, arbitrary units. (F) Schematic illustration of PCM pole formation by splitting PCM from the centriolar spindle pole or by accumulation of PCM components.