Project

Erythromyeloid progenitors (EMPs) originate from the yolk sac during early mouse development and migrate to the fetal liver via the circulation where they undergo massive expansion and differentiation into hematopoietic lineages. These events occur prior to the intraembryonic emergence of hematopoietic stem cells (HSCs). Unlike HSCs, EMPs cannot give rise to lymphoid lineages, nor can they provide long-term repopulation. As such, they are considered a transient fetal population, yet it is EMP-derived hematopoiesis that supports the growth and survival of the embryo independently of HSCs. HSC differentiation respects a hierarchy of progenitors with either lymphoid or myeloid fates and has been well documented in adult hematopoiesis. However, fetal hematopoiesis ensues from erythroid and myeloid progenitors with dual origins from either EMPs or HSCs. Using a genetic pulse chase labeling approach to distinguish these two ontogenies, we would like to explore heterogeneity on the single cell level and to build the differentiation tree among fetal liver myeloid progenitors using MARS-Seq.