Fig. 1.

Mouse LigI-deficient cells show endogenous LigIII and XRCC1 accumulation at PCNA- and BrdU-stained foci. a Endogenous LigI (red) was co-immunodetected with BrdU incorporation sites (green) in proliferating wild-type (LIGI ^+/+) and LIGI knockout (LIGI ^−/−) mouse cells. b Co-immunodetection of endogenous LigIII (red) and BrdU incorporation site or PCNA staining (green) in late-S phase LIGI ^+/+ and LIGI ^−/− cells. LigIII signal overlapping with BrdU or PCNA signal is observed in LIGI ^−/− cells with typical late-S phase BrdU or PCNA staining (enlarged images below showing examples of late-replication structures ring-shape or horseshoe staining). The thresholded images were obtained as described in “Materials and methods”. Scale bars 5 μm. c Percentages of nuclei with more than two late-replication structures in the depleted cells. For each double staining combination, more than 40 nuclei were analyzed per cell line. Representative images from cells co-immunostained for endogenous XRCC1 and BrdU or XRCC1 and PCNA are presented in ESM Fig. 1b, c