Development of erythropoiesis in the mouse

Hematopoiesis consists of a small number of stem cells which rise to a progeny of several distinct lineages. Among these, cells of the erythroid lineage emerge early in the mammalian embryo and provide indispensable functions throughout gestation and postnatal life. Knowledge of the existence of two distinct erythroid lineages, traditionally known as primitive and definitive, has more than a century. In the last decade, it has become evident that the ontogeny of erythropoiesis is more complex than a simple two-steps model. This review summarizes the development and differentiation of the erythroid lineage cells during gestation, and also the characteristics of erythropoiesis during the infant stage, discussing which issues remain open and which need further research.