Single-cell transcriptomic analysis of embryonic vasculogenesis identifies the conversion of Etv2-deficient vascular progenitors into skeletal muscle

An ETS transcription factor Etv2 functions as an evolutionarily conserved master regulator of vasculogenesis. Here we performed single-cell transcriptomic analysis of hematovascular development in wild-type and etv2 mutant zebrafish embryos. Distinct transcriptional signatures of different types of hematopoietic and vascular progenitors were identified using an etv2ci32Gt gene trap line, in which the Gal4 transcriptional activator is integrated into the etv2 gene locus. Unexpectedly, a cell population with a skeletal muscle signature was observed in etv2-deficient embryos. We demonstrate that multiple etv2ci32Gt; UAS:GFP cells migrate into the somites, elongate and differentiate as skeletal muscle cells instead of contributing to vasculature in etv2-deficient embryos. Overall design: GFP+ cells FACS sorted from etv2^ci32Gt; UAS:GFP embryos at 20ss were analyzed using 10X single-cell RNA-seq