(A) Foci formation of γH2AX, MDC1, 53BP1, RNF8, RAD51, BRCA1 and RPA in RNF138 deficient cells or control cells. Hela cells transfected with RNF138 siRNA exposed to 8Gy IR, Immunofluorescence staining was performed use γH2AX, MDC1, 53BP1, RNF8, RAD51, BRCA1 and RPA antibody as shown. (B) Relative quantification of the blots of Foci formation.The percentage of cells with Foci plotted and statistical analysed using GraphPad Prism 5. 50 cells were analysed for each experiment. Scale bar = 10 μm. Error bars represent the SD, n = 3. (C) HR efficiency was measured by HR-mediated gene conversion assay. DR-GFP U2OS cells were transfected with RNF138 siRNA and infected with adenovirus expressing I-SceI. Approximately 10,000 cells were evaluated by flow cytometry in each experiment. Error bars represent the SD n = 3.