Distribution of FV activity in mice that received transplants. One mouse each of unirradiated controls (left panel; Table 1, mouse A), Fv-wild-type (Fv+/+) FLC recipients (middle panel; Table 1, mouse F), and Fv-null (Fv–/–) FLC recipients (right panel; Table 1, mouse J) are shown. Total FV activity per fraction (dark gray) and the pellet-associated component of the total FV activity (light gray) both measured with the one-stage assay (“Materials and methods”) are plotted for each fraction. The platelet count for each fraction is also plotted (black line). Little or no platelet-associated FV activity is seen in fractions from the Fv-null FLC recipient.