The effect of forced IRF8 expression on basophil and mast cell differentiation. (A-B) Bone marrow Lin⁻ cells and Flt3⁻ GPs from WT and Irf8^−/− mice were transduced with empty MIG (MSCV-internal ribosome entry site-GFP) or MIG-IRF8 retrovirus in the presence of IL-3 on day 1. Retrovirally transduced (GFP⁺) cells were analyzed for basophil and mast cell generation on day 7. (C) Bone marrow Lin⁻ cells from Irf8^−/− mice were transduced with empty MICD8 (MSCV-internal ribosome entry site-human truncated CD8) vector (Ctrl), MICD8-IRF8, MICD8-IRF8^K79E, or MICD8-IRF8^R289E, and analyzed as described in (A). Retrovirally transduced (human CD8⁺) cells were analyzed. Values in the bar graphs are means ± standard deviations from triplicate samples. Similar results were obtained in 3 additional independent experiments (A) or 1 additional independent experiment (B-C). *P < .05; **P < .01; ***P < .001 (Student t test).