A, B, C, D. siRNA-treated U2OS cells (PCM1 for A and B; Plk4 for C and D) were transfected with plasmids producing various EGFP-PCM1 constructs (WT*, S372A*, S372D* or S372E*), fixed and stained with the indicated antibodies (arrowheads point to the centrosome) (A and C). Quantification data are shown in B and D. >200 cells were counted and classified into three categories: normal (around and away from the centrosome), aggregated or dispersed. Data represent the mean + SD (n=3). Statistical analysis was performed using two-tailed unpaired student's t-tests. ***p<0.001, **p<0.01, *p<0.05, n.s. (not significant). Note that the percentage of cells displaying "dispersed" is analysed. Scale bars, 5 μm (A and C). 