Migration and differentiation of hematopoietic stem cells

The hematopoietic system aims at producing mature blood cells from a small contingent of multipotent, self renewing cells called hematopoietic stem cells (HSC). 

The first HSCs emerge autonomously and in small numbers during embryonic development in the aorta from specialized endothelial cells qualified as hemogenic. HSCs then massively amplify in the placenta and the fetal liver before reaching their final destination in the bone marrow where they are maintained throughout adult life. During these steps, HSCs are in close contact with microenvironments that control the stem cell properties (stemness). 

The mechanism of HSC generation from hemogenic endothelium, the characterization and genetic identity card of HSC populations present simultaneously or sequentially in the embryo and of their microenvironments are the issues adressed by our team through avian, murine and human models using embryological approaches, functional tests and systems biology methods. We are also questioning the ascidian model and the control of migration of primordial germ cells.