Fig. 6

Relocated early replication initiation induces DNA damage. a Schematic showing DRB treatment of G1 or early-S phase K562 cells; a detailed description is given in the “Methods” section. The blue arrows show the samples that are presented in b and c. b Detection of nuclei-resident γ-H2AX foci in G1-arrested or early S phase K562 cells following transcription re-initiation via withdrawal of DRB. c Intensity of nuclei-resident γ-H2AX foci following transcription re-initiation via withdrawal of DRB in G1-arrested or early S phase K562 cells. Representative images are shown in b. t-test; ***, p < 0.001. d Detection of γ-H2AX foci induced by DRB withdrawal with or without RNase H1 (GFP-RNH1) overexpression. The white triangle indicates early S phase cells with GFP or GFP-RNH1 overexpression at 3.5 h after DRB withdrawal. Of note, the antibody against γ-H2AX is different from the one in b. e The number of nuclei-resident γ-H2AX foci with or without RNase H1 overexpression in the G1 or early S phase before or after withdrawal of DRB. t-test; n.s., no significance; *, p < 0.05; **, p < 0.01; ***, p < 0.001