Cell autonomous induction of MZ B-cell development by KLF3. (A) FACS analysis of lethally irradiated B6.Rag-2^−/− mice that had been reconstituted with FL cells from B6.IgH^a (blue) and either normal B6.Ly-5.1 (purple) or CD19:KLF3 Ly-5.1 (red) embryos. Mice were analyzed 2 months after reconstitution by staining splenocytes for B220, CD21/35, CD23, and Ly-5.1. The proportion of Ly-5.1⁻ T cells was 33.1% and 39.9% in chimeras reconstituted with KLF3 transgenic and nontransgenic FL cells, respectively. (B) The ratio of cells derived either from normal or from KLF3 transgenic Ly-5.1⁺ FL cells divided by the proportion derived from control IgH^a FL cells as calculated for the indicated subset for chimeras as shown in panel A. (C) FACS analysis of cells from the peritoneal cavity of the chimeras as presented in panel A. Cells were stained for CD19, CD5, and Ly-5.1 as indicated. Data are representative of more than 5 mice of each group.