Basophils do not affect progenitor B cell numbers and λ light chain usage <i>in vivo</i>.

<p>(A-E) Basoph8 mice were crossed to the ROSA-DTA strain and bone marrow cell numbers and B cell populations were enumerated by flow cytometry. Age and sex matched ROSA-DTA mice were used as controls. (B) Total bone marrow cellularity was calculated by trypan blue staining and counting with a hemocytometer. (A, C) Representative bone marrow flow cytometry plots are shown. (D) B cell populations were calculated with pro-B and pre-B defined as CD19⁺CD93⁺IgM^-IgD^-, immature-B as CD19⁺CD93⁺IgM⁺IgD^-, transitional as CD19⁺CD93⁺IgM⁺IgD⁺, and mature as CD19⁺CD93^-IgM⁺IgD⁺. (E) Bone marrow was stained for λ light chain. Data shown (D, E) as median + quartile box-and-whisker plots and is pooled from three individual experiments using mice aged 10-16 weeks; n = 9 ROSA-DTA, n = 10 Basoph8 X DTA. All groups are non-significant.