The number of peritoneal mast cells is decreased in γ_c⁻ and Jak3⁻ mice.

(A) Peritoneal mast cells were recovered by lavage and counted in 8- to 12-week-old wild-type (WT), γ_c-deficient (γ_c⁻), and Jak3-deficient (Jak3⁻) mice. Peritoneal mast cells were identified morphologically on cytospin cell preparations stained with Wright-Giemsa solution. Data are means ± SD for 6 to 8 mice in each group. The mean values for γ_c⁻ mice and Jak3⁻ mice are significantly different from the mean value for WT mice, *P < .01. (B) Expression of IgE receptors on c-kit⁺ peritoneal cells. IgE receptors on peritoneal mast cells were quantified by first incubating the cells recovered by peritoneal lavage with mouse IgE, then labeling with anti-IgE FITC, and analyzing by FACS gating on c-kit⁺ cells. Shown are representative FACS profiles of IgE receptor staining and control staining (dashed lines) on c-kit⁺ peritoneal cells from WT, γ_c⁻, and Jak3⁻ mice (n = 6-8 mice in each group).