Fig. 1: Polygenic Brca2^Δ27/Δ27 + Rad51c^dah/dah mutant mice show congenital deformations.

a Exome sequencing of 37 confirmed FA patient serum filtered for additional passenger mutations defined as non-synonymous FANC mutations in additional FANC genes other than the primary, diagnostic biallelic FANC mutation. b Schematic of murine Brca2. Depicted are the BRCA2/FANCD1 mutation identified in the FANCD1 patient (c.9672dupA), which results in a truncation of exon 27 (p.Tyr3225fs*30). The Brca2^Δ27/Δ27 mouse bears an exon 27 deletion likewise truncating Brca2 similar to the human FANCD1 truncation. AA, amino acids; BRC, Rad51 binding motifs; TR2, Rad51 stabilization domain; DNA, DNA binding folds/motifs; NLS, nuclear localization sequence. c, Schematic of murine Rad51c. Depicted in orange is the α-helix that contains the RAD51C/FANCO mutation identified in the FANCO patient (human R258H, murine R268), and the adjacent site for the two-amino acid deletion in the Rad51c^dah/dah mouse. “dah” denotes “deletions within a-helix”; AA, amino acids; A,B, Walker A and B motifs; NLS, nuclear localization sequence. d PCR genotyping of ear biopsies showing the six base pair (bp) deletion. PCR genotyping were performed >100 times with similar results. e Western blot of wild-type (WT) and Rad51c^dah/dah mouse testis cell extracts showing similar protein expression. Experiment was performed once. f Representative image of wild-type and Brca2^Δ27/Δ27 + Rad51c^dah/dah mice at 12 weeks exhibiting noticeable growth defect. g Box-whisker plot of weight of mice with indicated genotypes at 12 weeks. Box centers indicate median, boundaries represent 25th and 75th percentiles, and error bars represent maximum and minimum values. Data represent biologically independent samples from wild-type (n = 18), Brca2^Δ27/Δ27(n = 20), Rad51c^dah/dah (n = 7), and Brca2^Δ27/Δ27 + Rad51c^dah/dah (n = 8) mice. Brca2^Δ27/Δ27 + Rad51c^dah/dah against WT and Rad51c^dah/dah: p < 0.0001; Brca2^Δ27/Δ27 + Rad51c^dah/dah against Brca2^Δ27/Δ27: p = 0.0005; WT against Brca2^Δ27/Δ2: p = 0.018; Brca2^Δ27/Δ27 against Rad51c^dah/dah: p = 0.0181. h Representative image of Brca2^Δ27/Δ27 + Rad51c^dah/dah mouse with kinked tail (arrow). i Box plot of frequency of mice with kinked tails with indicated genotypes (n = 10 mice). j Representative X-ray image of tails of WT and Brca2^Δ27/Δ27 + Rad51c^dah/dah mice indicating skeletal abnormalities (arrows). k Representative image of testis of mice with indicated genotypes at 12 weeks. l Bar graph of weight of testis with indicated genotypes at 12 weeks. Data represent biologically independent samples from wild-type (n = 6), Brca2^Δ27/Δ27(n = 4), Rad51c^dah/dah (n = 8) and Brca2^Δ27/Δ27 + Rad51c^dah/dah (n = 3) mice. Brca2^Δ27/Δ27 + Rad51c^dah/dah against WT and Rad51c^dah/dah: p < 0.0001; Brca2^Δ27/Δ27 + Rad51c^dah/dah against Brca2^Δ27/Δ2: p = 0.0194; WT against Brca2^Δ27/Δ27: p < 0.0001; Brca2^Δ27/Δ27 against Rad51c^dah/dah: p < 0.0001. m Representative images of hematoxylin and eosin (H&E)-stained tissue cross-sections of testis and ovary, respectively, from animals with indicated genotypes at 12 weeks. Scale bars indicate 100 μm. Similar results were obtained by analyzing three independent tissues of each genotype. Error bars represent the standard error of the mean. p-values are derived using the one-way ANOVA test. *p < 0.05, ***p < 0.001, ****p < 0.0001.