Histologic sections of tissues from MPZenTPO reconstituted mice studied 2 or 7 months posttransplant. (A) Myeloid hyperplasia in the femur from a mouse 2 months after transplantation. Note the elevated cell concentration in the center of the bone cavity (hematoxylin-eosin staining; original magnification × 40). (B and C) Myelofibrosis demonstrated by deposition of reticulin fibers and osteosclerosis in the femur 7 months posttransplant (Gordon-Sweet and hematoxylin-eosin stainings, respectively; original magnification × 100 and × 40, respectively). (D) Megakaryocytic hyperplasia in the spleen 2 months posttransplant (hematoxylin-eosin staining, original magnification × 400). (E) Fibrosis (Gordon-Sweet staining, original magnification × 400) and (F) accumulation of collagen fibers (hematoxylin-eosin staining, original magnification × 400) in spleen 7 months posttransplant. Extramedullary hematopoiesis seen in liver (G), kidney (H), and lymph node (I) 7 months posttransplant (hematoxylin-eosin, hematoxylin-eosin and Periodic Acid Schiff stainings, respectively; original magnification × 400, × 400, and × 250, respectively).