BCR/ABL-induced DSBs are repaired by HRR and NHEJ. (A) HRR-dependent restoration of a functional GFP protein (GFP-positive cells) after I-SceI-mediated induction of a DSB in Draa-40 parental (P), BCR/ABL-Draa-40 (B/A), and BCR/ABL_(kin-)-Draa-40 (B/A(kin-)) cells (bars represent mean plus or minus standard deviation; ^*P < .05 compared with other experimental groups). (B) NHEJ-mediated end ligation of the XhoI + XbaI-digested plasmid substrate (monomers) by the lysis buffer (C) or cell lysates from 32Dcl3 parental (P), BCR/ABL-32Dcl3 (B/A), and BCR/ABL_(kin-)-32Dcl3 (B/A_(kin-)) cells, generating multiplasmid products (dimers, trimers). Mean ± SD percentages of end-joined substrate are shown below (P < .05, B/A compared with BCR/ABL_(kin-); P < .01 B/A compared with P). (C) Colocalization (yellow) of γ-H2AX (red) with Rad51 or Ku70 (both green) in the representative 32Dcl3 parental (P) and BCR/ABL-32Dcl3 (B/A) nuclei, whose borders are outlined in blue. Numbers indicate mean ± SD percentages of colocalization.