Changes in basophil numbers after S venezuelensis infection or IL-3 injection in Runx1^P1N/P1N versus WT mice. (A) WT or Runx1^P1N/P1N mice were infected with 10 000 S venezuelensis larvae and basophils (mIgE⁺DX5⁺) in the BM and spleen were analyzed 8 days after infection. Data shown are from 1 of 3 independent experiments, each of which gave similar results. (B) Recombinant IL-3 (200 ng/mouse/d) was injected into WT or Runx1^P1N/P1N mice for 7 consecutive days. Basophils in the BM and spleen from each mouse were stained the day after the 7th injection. Data shown in panels B and D are means + SEM.