Figure 3.

Heterozygous bumble mice have normal frequencies of the major B cell subsets. Total B cells, marginal zone B cells (MZB), and transitional B cells were stained by FACS in wild-type (wt), heterozygous (hets), and bumble (bmb) mice. (A) Left panel: representative staining of marginal zone B cells (MZB, B220⁺, CD23⁻, and CD21^hi) and follicular B cells (B220⁺, CD23⁺, and CD21⁺). Right panel: total B cell (B220⁺) and MZB cell numbers. (B) Representative staining of surface IgM (sIgM) on wt (black), heterozygous (blue), and bumble (blue) follicular B cells. (C) Splenic transitional B cells (B220⁺ and CD93⁺), further subdivided into T1 (CD23⁻IgM⁺), T2 (CD23⁺IgM⁺), and T3 (CD23⁺IgM^lo). (D) Bone marrow B cell progenitors, pro B (B220⁺CD43⁺CD19⁺CD93⁺), pre B (B220⁺CD43⁻IgM⁻CD93⁺), immature B (B220⁺CD43⁻IgM⁺CD93⁺), and mature B cells (B220⁺CD43⁻IgM⁺CD93⁻). For transitional and progenitor B cell gating strategy, see Figure S1 in Supplementary Material. Figures represent 8- to 16-week-old mice with four to seven mice per group, and results are representative of at least two independent experiments. Graphs display mean + SD. Statistically significant differences between bumble, bumble heterozygotes, and wt mice are indicated by *p < 0.05 by Mann–Whitney test.