BioProject

Most resident macrophages (MF) populations in adult tissues arise from MF progenitors populations that emerge during ontogeny, either from haematopoietic stem cells (HSC), or from Yolk Sac (YS) progenitors produced prior to HSC development. More...

Most resident macrophages (MF) populations in adult tissues arise from MF progenitors populations that emerge during ontogeny, either from haematopoietic stem cells (HSC), or from Yolk Sac (YS) progenitors produced prior to HSC development. The YS generates two populations of MF progenitors. In the earliest one, called primitive, MF progenitors arise from monopotent/uni-lineage progenitors, while in the second one they derive from multipotent erythro-myeloid progenitors. These two populations soon mix in the blood circulation, and as they are highly similar in phenotype, the specific features and function of the two MF progenitors populations are still unclear. When investigating the function of the bHLH transcription factor Lyl-1 during the development of blood cells in mouse embryos, we observed that Lyl-1 expression marks YS primitive MF progenitors. Lyl-1 bHLH disruption leads to an increased production and a defective differentiation of primitive MF progenitors. To gain a better insight into primitive MF progenitors specificity and function, we performed a RNA-seq analysis of these progenitors sorted from the YS at embryonic day (E) 9, when the YS only contains primitive MF progenitors, and at E10, when it contains both primitive MF progenitors and those produced by erythro-myeloid progenitors. At both stages, MF progenitors were collected from the YS of either wild-type or Lyl-1-deficient embryos, to better understand the role of Lyl-1 in the development of Lyl-1-expressing resident macrophage populations. Less...