Decreased irradiation-induced γH2AX in UHRF1-depleted cells. UHRF1 and control shRNA-expressing cells were exposed to either 1 Gy (A) or 5 Gy (B) γ-irradiation and harvested following 0, 1, 3, 6, 12 or 24 h. Representative histograms plot γH2AX expression as measured by γH2AX-FITC intensity/cell (y-axis) vs. DNA content (x-axis) (left hand side of panel). Numbers indicate the percentage of cells showing elevated γH2AX levels. The percentage of cells with elevated γH2AX expression plotted is the mean ± S.D. of three independent experiments (right hand side of panel). (C) The decreased accumulation of γH2AX in UHRF1-depleted cells was confirmed by indirect immunofluorescence 12 h after 5 Gy γ-irradiation.