Immature erythroblasts with extensive ex vivo self-renewal capacity emerge from the early mammalian fetus

摘要: In the hematopoietic hierarchy, only stem cells are thought to be capable of long-term self-renewal. Erythroid progenitors derived from fetal or adult mammalian tissues short-term, restricted (102- 105-fold), ex vivo expansion in presence erythropoietin, cell factor, and dexamethasone. Here, we report that primary erythroid precursors early mouse embryos extensive (106- 1060-fold) proliferation. These morphologically, immunophenotypically, functionally resemble proerythroblasts, maintaining both cytokine dependence potential, despite prolonged culture, generate enucleated erythrocytes after 3-4 maturational divisions. This capacity for erythroblast self-renewal is temporally associated with emergence definitive erythropoiesis yolk sac its transition liver. contrast, cell-derived almost exclusively Primary primitive precursors, which lack significant expression Kit glucocorticoid receptors, capacity. Extensively self-renewing erythroblasts, their near complete maturity within may ultimately serve as a renewable source red transfusion therapy.