Notch2 is not required for peritoneal mast cell development. (A) Bone marrow cells from N2-MxcKO-Ly5.1 mice or control Notch2^flox/flox-Ly5.1 mice were transplanted into lethally irradiated W^sh/W^sh mice. Peritoneal mast cells were stained with anti–c-Kit–APC, IgE, and biotinylated anti-Notch2 antibody (HMN2-35), followed by anti-IgE–FITC and streptavidin-PE, or they were stained with anti–c-Kit–APC, IgE, and anti-Ly 5.1–PE, followed by anti-IgE–FITC; they were then analyzed by FACSCalibur (BD Biosciences). (B) The proportion (left) and the absolute number (right) of peritoneal mast cells were not significantly different between W^sh/W^sh mice transplanted with Notch2-WT bone marrow cells and those transplanted with Notch2-null bone marrow cells. P = .210642 (mast cell proportion) and P = .196045 (mast cell number).