Svep1 stabilizes developmental vascular anastomosis in reduced flow conditions

We report the discovery that flow and Svep1 are modulator of vessel anastomosis during developmental angiogenesis in zebrafish embryos. We show that loss of Svep1 and blood flow reduction both contribute to defective anastomosis of intersegmental vessels. We show that this defect in primary angiogenic sprouts is associated with an expansion of Apelin-positive tip cells and with reduced formation and lumenisation of the dorsal longitudinal anastomotic vessel. Mechanistically, our results suggest that flow and Svep1 act synergistically to modulate vascular network formation in the zebrafish trunk. ### Competing Interest Statement The authors have declared no competing interest. * DLAV : dorsal longitudinal anastomotic vessel hpf : hours post-fertilization ISVs : intersegmental vessels DA : Dorsal Aorta PCV : Posterior Cardinal Vein VEGFR-2 : vascular endothelial growth factor receptor-2 Kdr : Kinase insert domain receptor Kdrl : Kinase insert domain receptor like VEGFA : vascular endothelial growth factor A MO : Morpholino