Effect of a single intravenous injection of rmMGDF on average size of polyploid megakaryocytes. The mean megakaryocyte size of 8N-128N cells was significantly increased from days 2 to 4 in mice treated with 25 μg/kg of MGDF, and on days 2 and 3 in mice treated with 250 μg/kg of MGDF. Each data point represents the mean ± SEM of megakaryocyte size (8N-128N cells); for the 25-μg/kg dose, n = 4-10 mice per MGDF group and n = 13 for controls and for the 250-μg/kg dose, n = 5-9 mice per MGDF group and n = 20 for controls. Data from control mice were pooled to represent the day 0 data point.