Fig. 1.

Primary B cell development in Fas-deficient HKI65 and HKIR mice. (A) Splenocytes were isolated from Fas-sufficient and Fas-deficient HKI65 and HKIR hemizygous mice as well as B6 mice and were stained with anti-B220 and anti-IgM^a and anti-IgM^b allotypic mAbs and analyzed by flow cytometry. HKI knock-in loci encode the IgM^a allotype. The data shown are from pooled cells from two mice of each genotype. (B) Splenocytes from mice of the indicated genotypes were stained with anti-B220, anti-CD21 and anti-CD23 and analyzed by flow cytometry. Follicular (CD23^high CD21^low) and marginal zone (CD23^low CD21^high) sub-populations are gated. The data shown are representative of at least three independent experiments. (C) Splenocytes from mice of the indicated genotypes were stained with anti-B220, anti-IgD and anti-clonotypic E4 mAbs and analyzed by flow cytometry. All data shown in this figure are from cells in the B220⁺ gate. The results are representative of at least three independent experiments.