Introduction of p53^−/− mutation restores the defect of αβ T-cell development in lck/SPA-1 Tg mice. (A) The thymocytes from lck/SPA-1 Tg mice of p53^+/+, p53^+/−, or p53^−/− backgrounds at 5 weeks of age (4 mice per group) were stained with the combinations of indicated antibodies; the representative FACS profiles are indicated (left). The mean numbers and SE (parentheses) of the total thymocytes as well as the subsets are also indicated (bottom); DN (□), DP (■), CD4 SP () and CD8 SP () cells. (B) Thymocytes from p53^−/− lck/SPA-1 Tg and control SPA-1^flox mice were lysed, immunoprecipitated with anti-FLAG, and blotted with anti–SPA-1 antibody. (C) Spleen cells were 2-color stained with anti-TCRβ and anti-TCRδ antibodies, and the mean numbers and SE of αβ T cells (□) and γδ T cells (■) were determined.