FIG 4.
Compound heterozygous Recql4 mutants tolerate a sublethal dose of ionizing radiation and do not develop osteosarcoma. (A) Breeding data from 26 litters of Recql4G522/K525A and 25 litters of Recql4R347X/K525A intercrosses. Observed and expected Mendelian rates of the indicated genotypes are shown. No statistical significance was achieved. (B) Kaplan-Meier tumor-free survival plots of the indicated genotypes. +/+, n = 17; K/+, n = 39; G/K, n = 21; R/K, n = 14. (C) Schematic representation of the experimental setup. Compound heterozygous mutants received a single dose of 5-Gy gamma irradiation, peripheral blood was assessed, and the animals were monitored for tumor formation. Mice were euthanized at the last time point. (D to I) Peripheral blood cell counts following irradiation: leukocytes (D), red blood cells (E), platelets (F), B cells (G), CD4 T cells (H), and CD8 T cells (I). (J) Kaplan-Meier tumor-free survival plots of the irradiated mice. K/+, n = 5; G/K, n = 3; R/K, n = 6. Data expressed as mean ± SEM; ordinary one-way ANOVA. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. TBI, total body irradiation; K, K525A; G, G522Efs; R, R347X.