Distribution of centrosomal factors in centriolar and acentriolar spindle poles. (A–D) Distribution of centrosomal factors in centriolar and acentriolar spindle poles. (A) DMSO-treated control mitotic spindles (two centrosomes) and centrinone-treated spindles (one or zero centrosomes) of HeLa cells. Green, red, and blue represent GT335, protein of interest (γ-tubulin, CEP152, or CPAP), and DNA, respectively. Z-projections: 21 planes, 1 µm apart. Scale bar, 10 µm. (B) PCM poles were observed in various cells. Green, red, and blue represent GT335, CEP192 and DNA, respectively. Z-projections: 40 planes, 0.3 µm apart. Scale bar, 10 µm. (C) PCM poles were observed in one-centrosome spindles induced by SAS6 depletion. Green, red and blue represent centrin, pericentrin, and DNA, respectively. Scale bar, 5 µm. Arrowheads indicate the PCM at the acentriolar spindle pole. (D) Quantification of pole patterns in C. Values are presented as mean percentages from three independent experiments (n = 20 for each experiment). Error bars represent SD. (E) Microtubule nucleation from the PCM pole. Following treatment with ice, microtubule nucleation (5 min at 25°C) was observed in one-centrosome cells. Gray, red, green, and blue in the merged image represent EB1, RFP (pericentrin), GFP (centrin), and DNA, respectively. Z-projections: 21 planes, 1 µm apart. Scale bar, 5 µm. MT, microtubule. Arrowheads indicate the PCM at the acentriolar spindle pole.