Fig. 5: Impact of light on ROS-induced DNA damage repair.

a Violin plot quantification of immunofluorescence assays of γ-H2AX levels in medaka WT cells transiently treated with 400 µM H₂O₂ and subsequently left to recover under light-dark cycle (LD) or constant darkness (DD) conditions. Cells were fixed at various timepoints indicated on the x-axis. Mean values of γ-H2AX fluorescence intensity are indicated by black horizontal lines and individual data points (n = 9 biologically independent samples) are shown as black hollow circles. b Cell viability assay of medaka WT cells exposed transiently to H₂O₂ concentrations from 200 µM to 3000 µM and subsequently left to recover under LD or DD conditions. Mean percentage ± SEM (n = 8 biologically independent samples) of cell viability with respect to untreated cells are indicated on the y-axis, while H₂O₂ concentrations are denoted on the x-axis. c, d Results of AHM assays of 3T3 and 3T3 CPD cells exposed transiently to a range of H₂O₂ concentrations from 10 µM to 50 µM, and then allowed to recover under LD or DD conditions. Total numbers of dead and viable cells are plotted as means ± SEM (n = 4 biologically independent samples) normalized in relation to untreated cells (Ctrl) on the y-axis, while H₂O₂ concentrations are indicated on the x-axis. e, f Cell viability assay of 3T3 and 3T3 CPD cells transiently exposed to a range of H₂O₂ concentrations from 200 to 3000 µM followed by recovery under LD or DD conditions. Mean percentage ± SEM (n = 8 biologically independent samples) of cell viability with respect to untreated cells is plotted on the y-axis, with H₂O₂ concentrations on the x-axis. g Cell viability assay of various 3T3 cell clones (3T3, 3T3 CPD, 3T3 CPD W310F, 3T3 CPD W400F) transiently exposed to a range of H₂O₂ concentrations, from 200 to 3000 µM and subsequently left to recover under DD conditions. Mean percentage ± SEM (n = 8 biologically independent samples) of cell viability with respect to untreated cells is plotted on the y-axis, while H₂O₂ concentrations are indicated on the x-axis. All assays were performed at least 3 times, independently. For the cell viability assays (b–g), representative data is shown. The statistical test used for (a) is student’s t-test, while the analysis for (b–g) is two-way ANOVA analysis. Statistical differences (P values) are annotated in each panel. Source data are provided as a Source Data file.