Mycn Facilitates Hematopoietic Stem and Progenitor Cell Generation from Endothelial Cells by Inhibiting Adhesion Signaling

As a signature gene of hematopoietic stem cell-primed HECs, Mycn is highly expressed in these cells alongside its paralog, Myc. However, their roles and underlying mechanisms in EHT remain unclear.

Here, we demonstrate that endothelial-specific deletion of Mycn, but not Myc, impairs HSPC formation in mouse embryos. Single-cell transcriptomics and functional assays reveal that Mycn deficiency specifically attenuates the HEC-to-HSPC transition but not thereafter. We also establish a mosaic analysis strategy to distinguish Mycn deletion states in mutant embryos, enabling precise characterization.