Fig. 7: RIF1-L promotes RAD51-dependent repair of broken replication forks.

A Representative images of RAD51 immunofluorescence in HeLa cells that are RIF1 KO, or express indicated RIF1 constructs. Nuclei outlines are drawn in white. RAD51 signal is shown in orange. unt: not treated with HU; HU: 4 mM 24 h. Scalebar: 10 µm. B Percentage of nuclei containing indicated number of RAD51 foci in cells from the experiment as (A). Means and standard errors of three independent experiments are plotted. p values calculated by chi-square tests. Source data are provided as a Source Data file. C Western blot analysis of BRCA1 depletion by siRNA in HeLa cells. D Representative images of RAD51 immunofluorescence in HeLa cells with indicated RIF1 expression and siRNA treatments. All samples were treated with 4 mM 24 h HU. Scalebar: 10 µm. E Percentage of nuclei containing indicated number of RAD51 foci in cells from the experiment as (D). Means and standard errors of two independent experiments are plotted. p values calculated by chi-square tests. Source data are provided as a Source Data file. F Schematic diagram of the reporter construct in HCT116 HR reporter cell lines to assess homologous recombination-mediated repair at Cas9n-induced broken forks. G Flow cytometry analysis of HR-mediated fork repair assessed by the reporter shown in (F), in HCT116 HR reporter cells expressing indicated RIF1 derivatives made at the endogenous RIF1 loci by CRISPR modification. (See Supplementary Fig. 7G for HCT116 HR reporter cell characterisation). Dots of the same colour represent data collected from the same experiment. Means and standard errors of three independent experiments are plotted. p values (two-tailed) calculated by paired Student’s t test. H Number of micronuclei per 100 cells in HeLa cells with indicated RIF1 expression and treatments. unt: not treated with HU; HU: 4 mM 24 h. Means and standard errors of three independent experiments are plotted. p values (one-tailed) calculated by paired Student’s t test.