Pericentrin and CDK5RAP2 are crucial for bipolar spindle formation of one-centrosome cells. (A–D) Mitotic spindle structures in siPCM-treated RPE1 (A) and A549 (C) cells. DMSO-treated control mitotic spindles (two centrosomes) and centrinone-treated mitotic spindles (one centrosome). After siRNA treatment with or without 100 nM centrinone, mitotic spindle structures were observed. Green, red, and blue represent GT335, α-tubulin, and DNA, respectively. Z-projections: 31 planes, 0.5 µm apart. Scale bar, 10 µm. Frequency of mitotic spindle structures in RPE1 (B) and A549 (D) cells. Values are mean percentages from two independent experiments (n > 20 for each experiment).