Runx1^P1N/P1N mice have markedly reduced numbers of basophils. (A) BM, spleen, and blood were isolated from WT and Runx1^P1N/P1N mice and stained with anti-IgE and anti-DX5 mAbs. Data shown are representative of 5 independent experiments, each of which gave similar results. (B) The numbers of basophils are shown as means + SEM. ***P < .0001; no asterisks, P > .05. (C) Semiquantitative RT-PCR analysis for Mcpt8, which encodes mMCP-8, was performed using RNA prepared from total BM cells from WT or Runx1^P1N/P1N mice. cDNA was diluted 3-fold. Data shown are from 1 of 3 independent experiments, each of which gave similar results.