Fig. 6.

FL promotes proliferation but not survival of Ly6D⁺CD135⁺CD127⁺CD19⁻ progenitors. (A) Numbers of EPLM (Upper Left), CLP (Lower Left), Ly6D⁺ EPLM (Upper Right), and Ly6D⁺ CLP (Lower Right) from WT (n = 14), Flt3l^−/− (n = 10) and Flt3ltg (n = 9) mice. Bars show mean ± SEM. (B) Cell cycle analysis of Ly6D⁺ EPLM from WT (n = 5), Flt3l^−/− (n = 3), and Flt3ltg (n = 9) mice. Graph shows percentages of Ki67⁻DAPI⁻, Ki67⁺DAPI⁻, and Ki67⁺DAPI⁺ Ly6D⁺ EPLM. Bars show mean ± SEM. (C) Numbers of EPLM (Upper Left), CLP (Lower Left), Ly6D⁺ EPLM (Upper Right), and Ly6D⁺ CLP (Lower Right) from WT and mutant mice, as indicated on the x axes. For each mouse genotype, mean ± SEM is shown. (D) In vitro limiting dilution analysis of Ly6D⁺ EPLM B-cell potential. Ly6D⁺ EPLM were sorted from WT, Flt3l^−/−, and Bcl2tg-Flt3l^−/− mice and plated at the indicated concentrations on OP9 stromal cells together with IL-7. (E) Numbers of CD19⁺CD117⁺ (Left), CD19⁺CD117⁻IgM⁻ (Middle), and CD19⁺IgM⁺ (Right) bone marrow cells from WT and mutant mice, as indicated on the x axes. For each mouse genotype, mean ± SEM is shown. *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001.