Splenic B cells from reconstituted Rag2° and Rag2°γ_c° mice. Mice were analyzed 10 weeks after bone marrow transplantation with 10⁴ sorted Lin^–cKit⁺Sca1⁺ cells of wild-type C57Bl/6Ly5.1 mice. Age-matched C57Bl/6Ly5.1 mice were used as control. (A) Splenic B cells from these mice were stained for CD45.1, CD19, IgM, and IgD. Data represent profiles of IgM and IgD expression on gated CD45.1⁺CD19⁺ PI^– cells. The dotted line separates the flow cytometric results from unmanipulated C57Bl/6Ly5.1 mice and those from the reconstituted recipient mice. Absolute cell numbers are given in panel 3B. (B) Absolute cell numbers of CD45.1⁺CD19⁺IgM^loIgD^hi cells (i) and CD45.1⁺CD19⁺IgM^hiIgD^lo (ii) cells found in the respective recipient mice.