Bone marrow transplantation experiments. (A) Representative slides of platelet spreading on collagen after phalloidin staining of cytoskeletal actin from mice that had Bdkrb2^+/+ bone marrow transplanted in Bdkrb2^+/+ hosts (WT to WT), Bdkrb2^−/− bone marrow transplanted in Bdkrb2^−/− hosts (KO to KO), Bdkrb2^+/+ bone marrow transplanted in Bdkrb2^−/− hosts (WT to KO), or Bdkrb2^−/− bone marrow transplanted in Bdkrb2^+/+ hosts (KO to WT). The white line is a 5-μm marker. (B) Quantification of spreading among the 4 groups of transplanted mice described in (A). Data were quantified from 4 separate experiments on multiple days including 1 or 2 transplanted mice per experiment (n ≥ 20 random fields). (C) The time to carotid artery thrombosis was determined in the 4 groups of transplanted mice characterized in (A). Each dot represents a single transplanted animal. The horizontal bar in each group represents the mean of the group. (B-C) Data are analyzed by 1-way analysis of variance and found to be significant between host WT and KO. Comparisons between 2 groups are indicated. A.U., arbitrary units; KO, knockout; WT, wild-type.