Figure 2. Expression of a 3′RR-deleted allele in bone marrow B cells.

(A) Flow cytometry analysis of IgM^a and IgM^b on B220⁺ bone marrow cells of heterozygous a^Δ3′RR/b^wt, a^wt/b^wt and a^ΔEμMARs/b^wt mice. One representative experiment out of ten is shown for a^Δ3′RR/b^wt and a^wt/b^wt mice. One representative experiment out of four is shown for a^ΔEμMARs/b^wt mice. Cells were gated on B220⁺ cells. (B) Percentages (left part) and numbers (right part) of B220⁺ bone marrow B cells expressing the a or b allele in a^Δ3′RR/b^wt, a^wt/b^wt and a^ΔEμMARs/b^wt mice. Mean ± SEM of ten a^Δ3′RR/b^wt mice, ten a^wt/b^wt and four a^ΔEμMARs/b^wt mice. Millions of bone marrow B cells are reported. *p < 0.05 (Mann-Whitney U-test). (C) IgM^a and IgM^b fluorescence intensity on B220⁺ B cells of a^Δ3′RR/b^wt and a^wt/b^wt mice. Mean ± SEM of ten mice. **p < 0.01 (Mann-Whitney U-test). (D) Percentages (left part) and numbers (right part) of B220⁺AA4.1⁺ bone marrow B cells in a^Δ3′RR/b^wt and a^wt/b^wt mice. Mean ± SEM of ten mice. **p < 0.01 (Mann-Whitney U-test). (E) IgM^a and IgM^b fluorescence intensity on B220⁺AA4.1⁺ bone marrow B cells in a^Δ3′RR/b^wt and a^wt/b^wt mice. Mean ± SEM of ten mice. **p < 0.01 (Mann-Whitney U-test). (F) Real time PCR analysis of μ membrane transcripts in sorted B220⁺AA4.1⁺ bone marrow B cells of a^Δ3′RR/b^wt and a^wt/b^wt mice. Values were normalized to GAPDH transcripts. Mean ± SEM of six mice. *p < 0.05 (Mann-Whitney U-test).