GSE104790
Hemogenic endothelial fate mapping reveals dual developmental origin of mast cells.
Hematopoiesis occurs in distinct waves. 'Definitive' hematopoietic stem cells (HSC) with the potential for all blood lineages emerge in the aorta-gonado-mesonephros (AGM), while 'primitive' progenitors, whose potential is thought to be limited to erythrocytes, megakaryocytes and macrophages (MF), arise earlier in the yolk sac (YS). Here, we questioned whether other YS lineages exist that have not been identified, partially owing to limitations of current lineage tracing models. We established the use of Cdh5CreERT2 for hematopoietic fate mapping, which revealed the YS origin of mast cells (MC). YS derived MC are replaced by definitive MC, which maintain themselves independently from the BM in the adult. Replacement occurs with tissue specific kinetics. MC in the skin, but not other organs, remain largely YS derived prenatally and are phenotypically and transcriptomically distinct from definite adult MC. We conclude that dual hematopoietic origin is not MF specific, but shared between these two myeloid lineages. Overall design: RNAsequencing of YS HE derived embryonic (E16.5) and definitive adult skin MC. 3 replicates for each population.