Bleeding time and clot retraction. (A) MYH9Δ mice had an increased bleeding time. Points indicate the time required for the arrest of bleeding, and when necessary bleeding was stopped manually after 10 minutes (control wt mice, , n = 13; heterozygous mice, □, n = 14; MYH9Δ mice, ▾, n = 21; wt mice treated with busulfan to achieve thrombocytopenia comparable to that of MYH9Δ mice, , n = 20). (B) Clot retraction was totally abolished in PRP from MYH9Δ mice, whereas it was delayed in heterozygous mice. The photograph corresponds to a 2- and 5-hour reaction in cPRP adjusted to 300 × 10⁹ platelets/L and treated with 10 U/mL thrombin and is representative of 3 experiments.