Fig. 4.

Cops5 KO leads to DDR defects in ESCs. (A) iC5; C5 KO ESCs cultured with (P0) or without Dox for the indicated time (P1, P2) were subjected to GGR assay. Representative images are shown on the Left. Triangles indicate non–S-phase cells. (Scale bar, 10 μm.) Relative fluorescence intensities of 50 non–S-phase cells were quantified and plotted (Right). (B) iC5; C5 KO ESCs were cultured with or without Dox and exposed to 3 μg/mL illudin S for two passages. The surviving fraction was defined as the ratio of live cells with illudin S treatment to live cells without illudin S treatment. (C and D) iC5; C5 KO ESCs containing NHEJ (C) or HR (D) reporter were cultured with or without Dox for 24 h and then transfected with I-SceI–expressing plasmid. Forty-eight hours after transfection, the percentage of GFP⁺ cells was analyzed by flow cytometry. (Left three panels) The result of a representative experiment. (Right) The quantification result of three independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001.