Zonal endothelial cell heterogeneity underlies murine renal vascular development

The renal vasculature consists of highly specialized blood vessels that carry out distinct physiological functions. Defining their transcriptional signatures and tracing their developmental ontogeny has thus far been challenging due to a lack of regionally specific endothelial biomarkers. Here, we performed single nuclear RNA sequencing (snucRNA-Seq) to interrogate embryonic renal endothelial cells. We identified nine different endothelial cell types, and validated expression of novel candidates using multiplex RNAScope. We interrogate biological characteristics, including cell cycle stage, of developmental blood vessels with a variety of in vivo tools. Using genetic tools based on expression of tip cell marker Esm1 , we performed detailed lineage tracing, demonstrating multi-clonal and multi-directional endothelial contribution to glomerular vasculature. Together, this study provides the first validated, tool-focused developmental atlas of the murine renal vasculature and elucidates several novel cellular mechanisms of nephron vascularization.