CEP290 recruits Rab8a to centrosomes. RPE-1 cells transfected with control or CEP290 siRNAs were (A, B) grown asynchronously in the presence of serum or (C, D) induced to quiescence, and stained with antibodies to gltuamylated tubulin (GT335, green), Rab8a (red), and with DAPI (blue). Bar: 10 μM; insets: 2 μM. (B, D) Histograms quantifying the fold increase in the percentage of cells with fewer than two Rab8a foci at centrosomes. About 100 cells were scored for each siRNA condition, and the histograms showed the averages of three independent experiments. Error bars represent +/- S.D. The average percentage of cells with fewer than two Rab8a foci after transfection with control siRNA was 16.5% in quiescent cells and 9.8% in growing cells.