IL-7Rα expression in different thymic subsets of 3 founder mice. (A) Unfractionated thymocytes from wild-type and the indicated IL-7Rα Tg mice (D4, B1, and C10) were stained for IL-7Rα expression. (B) Thymocytes from 10-day-old mice were stained for CD4 and CD8. Representative profiles from wild-type, Tg low-expressor (D4), and Tg high-expressor (C10) lines are shown. (C) IL-7Rα expression is shown in thymocyte subpopulations (DN, DP, and SP) in wild-type (thin line), D4 (dashed line), and C10 mice (thick line); for clarity, the negative staining control is shown only in the first histogram (dotted line).