FIG. 9.

Radiation-induced cell death in the brains of DR5-null animals. (A) Western blot analysis shows that p53 protein levels are increased in the brain of wild-type mice (WT) 8 h following 5 Gy of gamma irradiation. Also, at this time point DR5 mRNA is upregulated in the brain of DR5^+/+ mice but not DR5^−/− mice. Comparative quantitative analysis of the upregulation was done with NIH Image 1.62 software and 18S RNA as a housekeeping gene. (B) Quantitation of radiation-induced cell death in the brain of DR5-null and wild-type animals by TUNEL staining.