(C) B cells were purified from the spleens of Pacs1+/−;Bcl2TG and Pacs1−/−;Bcl2TG mice (CD45.2), labelled with CTFR and CTV proliferation dyes, respectively, and transplanted into unirradiated CD45.1 recipients. Donor B cells were measured in the spleen of recipient mice 7 days after B cell transfer based on CD45.2 expression and proliferation dye fluorescence. 