Mature B-cell subsets in the spleen of induced B-Indu-Rag1^fl/fl mice. (A) Flow cytometry of splenocytes from wild-type, control-treated, and tamoxifen-induced B-Indu-Rag1^fl/fl mice. Mice were induced 3 times with 4-day intervals and analyzed at day 35 after the first administration. Single-cell suspensions were prepared from spleen and stained for IgM, IgD, CD21, and CD23. Numbers indicate percentages of cells in the respective quadrants and gates. (B-C) Steady-state antibody production in induced B-Indu-Rag1^fl/fl mice. Sera from B-Indu-Rag1^fl/fl mice (age at first induction 8-12 weeks), either treated with tamoxifen or left untreated, and from Rag1^−/− and wild-type control mice (all n = 10) were collected 35 days after the first induction, and the amounts of total IgM (B) and total IgG (C) were determined by enzyme-linked immunosorbent assay.