Fig. 1: RPA marks heritable DNA lesions distinct from 53BP1 nuclear bodies.
From: RPA shields inherited DNA lesions for post-mitotic DNA synthesis
a Asynchronously growing U-2 OS cells were treated with aphidicolin (APH, 0.2 μM), ATR inhibitor (ATRi, 1μM), or APH + ATRi for 24h as indicated. 5-Ethynyl-2′-deoxyuridine (EdU) was added 20 min before fixation. Cells were stained for 53BP1 and RPA70, and cell cycle staging was performed based on DAPI and EdU by QIBC (see Supplementary Fig. 1a and Methods section for details). Depicted are cell cycle-resolved scatter plots, in which G1 cells are labeled in blue, S phase cells in light red, and G2/M cells in dark red. Nuclear 53BP1 foci are on the y-axis, DNA content is on the x-axis. Each dot represents a single cell with its foci count. A rescaled version is shown on the right with a focus on cells in G1. Color-code as indicated. At least 1000 cells per condition were analyzed. b For the same cell populations depicted in (a) RPA foci were quantified and are shown in a cell cycle-resolved manner. c Average RPA foci counts in G1 in the different treatment conditions from n = 3 independent samples with n1 = 499, n2 = 495, n3 = 476 (Control), n1 = 367, n2 = 345, n3 = 278 (APH), n1 = 944, n2 = 1046, n3 = 968 (ATRi), n1 = 959, n2 = 1042, n3 = 1044 (APH + ATRi) cells in G1 per sample. Individual average values and means ± SD are shown. P-values were determined by two-tailed unpaired t-test; *p < 0.05 (exact p-values are p = 0.0291 and p = 0.0392, respectively), **p < 0.01 (exact p-value is p = 0.0074). d Representative images of individual cells in G1 are shown. The upper row shows the EdU and DAPI signals used by QIBC to identify G1 cells (see Supplementary Fig. 1a). The lower rows show G1 cells with 53BP1 and RPA foci. Scale bar: 10 μm. A. U., arbitrary units. Source data are provided as a Source Data file.
