Splenic and pLN Bcl2 transgenic GC B cells are dispersed in the absence of FDCs. ROSA^DTR+CD21Cre⁺ mice that had been reconstituted with Bcl2 transgenic BM were immunized with SRBCs and then control (Ctrl) or DTx treated at day 6 and analyzed at day 8. (A) Flow cytometric analysis of GC B cells (IgD^lowFas⁺GL7⁺) in pLNs. Bar graphs show total cell numbers for pLNs, spleen (spl), and mLNs (bars indicate means, and dots represent individual mice). Statistical analysis was performed with the two-tailed unpaired Student’s t test. n.s., not significant. (B) Sections of pLNs, spleen, and mLNs stained to detect GL7 (blue) and IgD (brown). Two examples of each type are shown at different magnifications. Data are representative of at least four experiments (more than six mice of each type). Bars: (white) 400 µm; (black) 100 µm.