Endothelial Mekk3 alters fates of embryonic arterial endothelial cells

To examine how endothelial Mekk3 affects the cell and molecular transitions between endothelial (E), hemogenic endothelial (HE), and intra-aortic hematopoietic clusters (IAHC) cells, we profiled ~6,700 cells from wildtype embryos and ~3,200 cells from endothelial Mekk3 deleted embryos by single-cell RNA sequencing (scRNA-Seq). The cells were sorted from the caudal arteries (dorsal aorta, umbilical, vitelline arteries) of embryonic day (E) 9.5 mouse embryos. We identified a developmental alteration in endothelial to hematopoietic transition (EHT) and production of HE and IAHC in endothelial Mekk3 deleted embryos. Single cell RNA-Seq profiles of cells involved in endothelial to hematopoietic transition (EHT) from wildtype and endothelial Mekk3 deleted mouse embryos at embryonic day 9.5.