Figure 2. .

RAG1 ubiquitin ligase promotes Igλ⁺ B cell development. (A) Numbers of pro-, pre-, and immature B cells in bone marrow from mice 4–6 wk of age. (B) Percentages of pro-, pre-, and immature B cells among live B220⁺ cells in the bone marrow. (C) Representative flow cytometry data showing the populations of B220⁺IgM⁺ B cells of the Igκ or Igλ lineage in bone marrow or spleen of WT and R1.PG mice. (D) Igκ:Igλ ratio in bone marrow and spleen. Calculated by taking exact number of IgM⁺ Igκ⁺ divided by exact number of IgM⁺ Igλ⁺ cells. All analyses were done from organs isolated from mice aged 4–6 wk. Each dot in B and D indicates data from an independent mouse, with data presented as mean ± SEM. (E and F) Graphed flow cytometry data depicting the frequency or number of B220⁺IgM⁺ bone marrow (E) or spleen (F) cells that express Igλ on their surface. Shown are individual data points collected from three mice from each genotype, with the average ± SEM. Statistical significance determined by two-tailed Welch’s t test (ns, P > 0.05; *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001; ****, P ≤ 0.0001).