Analysis of TEL-AML1 expression in bone marrow B cells from mice receiving transplants. (A) CD19⁺ B cells were sorted from the bone marrow of MSCV-EGFP and MSCV-T/A mice 4 months after transplantation and a C57BL/10 control (B10). The purity of the sorted cells was in excess of 95%. (B) Western blot analysis was performed on protein extracted from the sorted CD19⁺ bone marrow cells. HA-tagged TEL-AML1 protein was detected using an anti-HA antibody. Anti–alpha tubulin was used to estimate protein loading. (C) Expression of EGFP by (R) CD19⁺IgD⁺ recirculating and (I) CD19⁺IgD^– immature bone marrow B cells from MSCV-EGFP, MSCV-T/A, and C57BL/10 mice.