FIGURE 1. λ5 knockout mice show loss of c-kit^-, but not c-kit⁺ early pre-B cells in vivo.

(A) Representative dot plots of c-kit⁺ and c-kit^- precursors in wild-type (B6) (WT) and λ5 knockout (KO) mice. B220⁺CD43⁺ are pro-B/early pre-B cells and late pre-B cells are B220⁺CD43^- with percentages out of total bone marrow shown. Pro-B/early pre-B cells were further gated as surface IgM^-CD19⁺ with percent cells present in total bone marrow indicated. Surface IgM^-CD19⁺B220⁺CD43⁺ B cell precursors were gated based on c-kit and cytoplasmic μ (cμ) with proportion indicated for c-kit⁺cμ^- pro-B, c-kit⁺cμ⁺ early pre-B, and c-kit^-cμ⁺ early pre-B subsets. (B) Analysis of c-kit⁺ pro-B, c-kit⁺ and c-kit^- early pre-B, and late pre-B cell numbers for 7 pairs of WT and λ5 KO mice. *p<0.02.