The deletion of GATA2 CF results in a loss of mast cell identity in mouse bone marrow-derived mast cells. (A) (Left) Representative FACS data for BMMCs prepared from Gata2^flox/flox::Rosa26CreER^T2 mice after 0, 3, 6, and 9 days of 4-OHT treatment (D0, D3, D6, and D9, respectively). (Right) Average percentages and SD of the DP cells within the gates examined on days 0, 3, 5, 7, and 9 of the 4-OHT treatment (D0, D3, D5, D7, and D9, respectively). N = 9. (B) Representative bright field (BF) phase contrast photomicrographs (left; original magnification, ×200) and cytospin preparations (center and right; original magnification, ×400) of BMMCs prepared from Gata2^+/+::Rosa26CreER^T2 (CreER^T2) and Gata2^flox/flox::Rosa26CreER^T2(ΔCF/ΔCF) mice treated with 0.5 μM of 4-OHT for 10 days. For cytospin preparations, the cells were stained with Wright-Giemsa stain (center, WG) and toluidine blue (right, TB). (C) The ratio of 4-OHT (+) relative to 4-OHT (−) BMMCs prepared from CreER^T2, ΔCF/+, and ΔCF/ΔCF mice. The cells were counted on days 3 and 6 of the 4-OHT treatment (D3 and D6, respectively). (D) The percentages of dead cells in the CreER^T2 and ΔCF/ΔCF BMMCs cultured in the absence (−) or presence (+) of 4-OHT for 3 and 6 days (D3 and D6, respectively). In C and D, no cells survived in the absence of IL-3 and SCF [cytokine(−)]. (E) (Left) Representative FACS data for the 5-bromo-2'-deoxyuridine and 7-amino-actinomycin D expression of ΔCF/ΔCF BMMCs on days 0, 4, and 8 of 4-OHT treatment (D0, D4, and D8, respectively). The lower right panel shows the gates displaying the cell cycle populations in the subG0/G1 (Sub), G0/G1, S, and G2/M phases. (Right) Average percentages and SD of the gated cells. *P < .05, **P < 0.01. N = 4. (F) The results of a FACS analysis of the presorted c-Kit/FcεRIα DP BMMCs from Gata2^flox/flox::Rosa26CreER^T2 mice after 0, 3, 6, and 9 days of 4-OHT treatment (D0, D3, D6, and D9, respectively). The average percentages and SD of the gated cells are indicated. N = 4.