Platelets from Vav1-deficient mice have a normal shape change response.

(A) Platelets from wild-type and Vav1^−/− mice were stimulated with the indicated concentrations of CRP (i) or thrombin (ii) and the increase in optical density indicative of shape change monitored. One experiment representative of 3 is depicted. (B) Wild-type and Vav1^−/− mouse platelets under resting and CRP (1 μg/mL, 90 seconds)–  or thrombin (1 U/mL, 30 seconds)–activated conditions were studied by scanning electron microscopy. Original magnification, × 5200. Results are representative of 5 independently analyzed fields. Scanning electron micrographs were taken as described in “Materials and methods.”