Fig. 2.

The formation of late-onset DSBs in the presence of APOBEC3B requires ATR. (A, B) HeLa cells were treated as depicted in the upper box. The numbers of γH2AX and 53BP1 foci in HeLa cells were quantified via immunofluorescence at late (A) and early (B) time-points after γ-irradiation. Where indicated, the cells were treated with KU55933, VE-822, or NU7441. Bars show means ± s.d. The numbers of cells counted in each condition are inserted in the graphs. Scale bars, 10 µm.