Results of FACS analyses. (A) Panel i shows 2 populations of GFP⁺ cells (CD41^low and CD41^high representing 0.81% and 0.79% of WKM, respectively) that are detected in the kidney. CD41^low cells (ii) are predominantly large prothrombocytic cells and CD41^high cells (iii) are differentiated thrombocytes as demonstrated by the corresponding Wright-Giemsa staining of flow-sorted cells shown in panels iv and v (see “Flow sorting of GFP⁺ thrombocytes”). A representative erythrocyte is placed at the top right corner for comparison. By contrast, the vast majority of cells isolated from peripheral blood (B) and spleen (C) are CD41^high (0.64% and 4.21%, respectively) and display the mature thrombocyte morphology.