Bias of MP development in IRF8^−/− mice. (A) BM cells from IRF8^−/− and IRF8^+/+ littermate mice (n = 8) were stained with antibodies against Lineage panel (Lin), IL-7Rα, c-Kit, and Sca-1. The numbers represent percentage of total events. (B) The frequency (left panel) and absolute cell numbers (right panel) of HSCs, CLPs, and MPs in IRF8^+/+ and IRF8^−/− mice. Data are mean plus or minus SEM of 5 mice per group. *P < .05; **P < .001 compared with controls. (C) Sorted HSCs from IRF8^+/+ and IRF8^−/− mice were injected into lethally irradiated CD45.2⁻ B6 mice. Two months later, BM cells were analyzed by FACS and the donor cells (CD45.2⁺) were identified by an anti-CD45.2 antibody. The frequency (left panel) and absolute cell numbers (right panel) of donor HSCs, CLPs, and MPs were shown as mean plus or minus SEM of 6 mice per group. *P < .05 compared with controls.