ATF3 deficiency reduces MC numbers in vitro and in vivo. (A) BM cells were cultured at a starting density of 5 × 105 cells/mL in the presence of IL-3 (30 ng/mL). Total number of cells was counted every 7 days. (B) BM cells were cultured at a starting density of 5 × 105 cells/mL in the presence of SCF (50 ng/mL). Total number of cells was counted every 7 days. (C) BM cells were cultured at a starting density of 5 × 105 cells/mL in the presence of IL-3 (30 ng/mL) and SCF (50 ng/mL). (D) BM cells from WT and ATF3-null mice were cultured in IL-3/SCF for 5 weeks and examined for morphology by toluidine blue staining or (E) 2-color analysis of flow cytometry for IgE receptor (horizontal axis) and c-kit expression (vertical axis), percentages of positive cells are indicated. (F) Peritoneal lavage from WT or ATF3-null mice were spun onto cytospin slides and stained with Wright-Giemsa. Results are expressed as mean ± SE from counts of 3 separate experiments. (G) Sections from skin were stained with toluidine blue for MCs. Results are expressed as mean ± SE from counts of 3 separate experiments. *P < .05 by comparison to WT.
