Figure 7.
p21 gene dosage affects radiosensitivity of p537KR mice. (A) Kaplan-Meier radiation survival curves. Littermate p537KR;p21+/+ (n = 7) and p537KR;p21+/− (n = 10) mice were exposed to 6 Gy of whole-body irradiation. Losing one allele of p21 partially rescued the sensitivity of p537KR mice to 6 Gy irradiation. P = 0.06. (B) Analysis of gene expression in thymus and BM showed that p21 expression was reduced by half in p537KR;p21+/− mice (p21+/−), while puma expression was not affected. Error bars represent the SEM from three animals. (C) Western analysis showed reduced p21 levels in irradiated p537KR;p21+/− mice, while p53 levels were unchanged. (D) p537KR;p21+/− mice exhibited slight lower frequency of HSC-enriched SLAM cells when compared with p537KR;p21+/+ mice. Error bars represent the SEM from three animals.