Mesoderm-Derived PDGFRA⁺ Cells Regulate the Emergence of Hematopoietic Stem Cells in the Dorsal Aorta

The authors investigated whether mesenchymal stem cells, which provide an essential niche for long-term HSCs in the bone marrow, reside in the aorta–gonad–mesonephros and contribute to the development of the dorsal aorta and endothelial-to-hematopoietic transition.