• 75% of mutants exhibit a strong elevation of platelets but with normal or slightly increased counts of white blood and red blood cells, resembling essential thrombocythemia

• 25% of mutants show abnormally high levels of red blood cells and white blood cells as well as platelets, resembling polycythemia vera

• bone marrow and spleen give rise to an increase in hematopoietic colonies, indicating the presence of a larger percentage of progenitor cells

• bone marrow cells produce an increased number of granulocyte-macrophage colony-forming cell colonies compared to controls in the absence of growth factors

• mutants exhibit autonomous formation of erythrocyte colony-forming unit colonies with cells from bone marrow

• erythroid hyperplasia in the spleen and bone marrow

• mutants exhibit many smaller red blood cells

• mutants exhibit increased number of platelets with the occasional presence of giant platelets

• mutants exhibit an increase in the number of megakaryocytic progenitor cells in the bone marrow

• megakaryocytic hyperplasia in the spleen and bone marrow

• spleens weigh 2-8 times more than those of controls

• 10 of 26 mutants develop various degrees of fibrosis in the bone marrow and spleen

• plasma thyroid peroxidase levels are decreased

• spleens weigh 2-8 times more than those of controls

• 10 of 26 mutants develop various degrees of fibrosis in the bone marrow and spleen

• 10 of 26 mutants develop various degrees of fibrosis in the bone marrow and spleen