Embryonic hematopoiesis involves successive waves of progenitors from distinct anatomical sites, but the origins and contributions of early hematopoietic stem and progenitor cells (HSPCs) remain incompletely defined. Here we use genetic fate mapping in mice to temporally label hemogenic endothelium (HE) subsets and track their progeny. We show that a wave of fetal-restricted HSPCs arises from HE in the vitelline and umbilical arteries between embryonic days 8.5 and 9.5, preceding the emergence of definitive hematopoietic stem cells. Lineage tracing, single-cell transcriptomic analyses and functional assays revealed that these progenitors are transient and distinct from erythro-myeloid progenitors, contribute extensively to fetal lympho-myelopoiesis but decline postnatally. Our findings reveal a previously unrecognized early HE wave as a key source of fetal-restricted HSPCs, refining the spatial-temporal understanding of layered hematopoiesis and informing developmental origins of blood cell diversity.
Journal article
2026-04-01T00:00:00+00:00
5
308 - 327
19
Animals, Hematopoietic Stem Cells, Hemangioblasts, Umbilical Arteries, Cell Lineage, Hematopoiesis, Female, Gene Expression Regulation, Developmental, Mice, Inbred C57BL, Mice, Vitelline Duct, Single-Cell Analysis