Impaired GATA-1 expression and myelofibrosis in an animal model.

The genetic lesion(s) underlying chronic idiopathic myelofibrosis, as well as the mechanisms leading to the typical fibro-osteosclerotic changes of the bone marrow microenvironment, are still undefined. Recently, animal models of the disease have been described. We will briefly review the characteristics of these models, the thrombopoietin-overexpressing mice and the GATA-1(low) mice (mice deficient for GATA-1 expression in megakaryocytes), and illustrate how they provided insights into pathogenetic mechanisms of myelofibrosis, with special regard to the role of abnormal megakaryocyte proliferation and maturation.