Figure 6

DAPI-dense blocks in BAZ1B -/- are present in G1, S and G2 phase and do not disrupt the cell cycle. (a) Examples of DAPI-dense blocks in BAZ1B -/- cells at different stages of the cell cycle as indicated by the appropriate markers; CDT1 for G1 (green, top), PCNA for S-phase (red, middle) and H3S10ph for G2 (green, bottom). H3S10ph accumulates first at heterochromatic regions before spreading throughout the nucleus [68], accounting for the elevated levels observed at the heterochromatin blocks in the example shown. The percentages given in brackets to the left of the DAPI image indicate the number of cells positive for the cell cycle stage marker in the population of cells examined (CTD1, n = 83; PCNA, n = 105; H3S10ph, n = 115). Note that the numbers are greater than 100%. This is because some H3S10ph positive cells are in late S-phase in RPE1 [15], and CDT1, while present throughout the cell cycle, is most abundant during G1 [64]. Consequently some cells from other stages of the cell cycle are inadvertently included in these numbers. (b) Representative FACS profile for RPE1 and BAZ1B -/-.