Morphologic abnormalities of V205GR megakaryocytes. (A) (B) Histologic examination of E17.5 liver with hematoxylin and eosin staining. Megakaryocytes in the liver of V205GR embryo (B, arrowheads) are increased in number and larger in size compared with those of wild-type littermate (A arrowhead). Scale bar corresponds to 40 μm. (C)–(H) Histologic examination of wild-type (C, D), V205GR (panels E, F), and G1R (G, H) mouse spleens. Spleen sections with hematoxylin-eosin staining (C, E, G) or AChE staining (D, F, H) are shown. Scale bars correspond to 40 μm (C, E, G) and 300 μm (D, F, H), respectively. (I,J) Electron microscopic analysis of megakaryocytes. Megakaryocytes were prepared from bone marrow of wild-type (I; original magnification, ×3000) and V205GR (J; original magnification, ×2000) mice.