Fig. 6. Bub3 is required to promote accumulation of cyclin A during G2. (A) Cyclin A accumulation during G1/S and G2 in control and Bub3-depleted cells. -tubulin staining (red) was used to classify G1/S and G2 cells. Cyclin A is shown in green and DNA in white. Bub3-depleted cells fail to accumulate cyclin A in G2. (B) Quantification of cyclin A levels for control and RNAi-treated cells. Image analysis was performed as described for cyclin B and the mean pixel intensity per cell at the different stages of cell cycle was determined (see also supplementary material Table S6); ***P<0.0005 when compared to intensity in control cells. Bar, 5 µm.