Retroviral-mediated gene transfer of the wild-type Baffr gene into A/WySnJ HSC-restored B cell development. Flow cytometry was performed on individual splenocyte samples gated according to their GFP expression. (A) The cells were stained with antibodies to IgM, CD21 and CD23, and gated for NF, MZ and FO B cell subsets. (B) The cells were stained with antibodies to IgM and to IgD; the IgM+IgD+ cells were gated as shown to evaluate B cell subsets. (C) The cells were stained with antibodies to IgM, C1qRp, and CD23; the IgM+ cells were gated for the C1qRp−CD23+ mature B cells [47]. (D) The cells were stained with antibodies to IgM, C1qRp, and CD23; the C1qRp+ cells were subdivided into T1, T2 and T3 B cells. The data shown are representative of five mice per strain.