Analysis of B- and T-lymphoid development after irradiation of newborn SCID mice. Mice were analyzed 22 days after irradiation with 150 cGy shortly after birth.

(A) Flow cytometric analysis of bone marrow with markers indicated. No rescue of pre–B-cell development was observed. (B) Rescue of CD4⁺CD8⁺ thymocytes, in comparison with unirradiated SCID control. Plots show CD8⁺ cells (which also expressed CD4) in comparison with CD25⁺ prothymocytes, which were negative for both CD4 and CD8.