B-lineage development in Eμ-A1 SCID mice.

(A) Flow cytometric analysis of bone marrow of SCID mice with and without the Eμ-A1 transgene. B-lineage cells were IgM⁻and CD43⁺ and were indistinguishable from nontransgenic SCID littermates. Results are representative of 7 mice analyzed for each genotype. (B) Analysis of IgHI DJ and V(D)J rearrangements in SCID and Eμ-A1 SCID bone marrow using PCR. A faint DJ rearrangement signal is seen in the Eμ-A1 SCID samples, but no V(D)J rearrangements were detected. Wild-type bone marrow and kidney are shown for comparison. The V(D)J signal in the kidney sample likely reflects low levels of lymphoid cells in the organ.