(G-H) Immunofluorescent staining of γ-H2AX, 53BP1 and Cleaved Caspase-3 in the intestinal epithelium of KLF4 loxp/loxp mice with injection of AAV7-mCherry or AAV7-Cre-mCherry followed by treatment of γ-irradiation. Tissues were collected from sham mice and mice at different time after exposure to γ-irradiation and then staining with indicated antibodies. (G) Quantification of γ-H2AX, 53BP1 and active Caspase-3 -positive cells based on the Immunofluorescent staining results presented in H. Data are mean ± SEM; n=4 per group; p = 0.0023 (r-H2AX), p = 7.9x10-4 (53BP1) p = 5.5x10-3 (Active Caspase-3). one-way ANOVA was used for the statistical analysis. Scale bars, 60 μm. 