Figure 9: Schematic representation of neurovascular communication involving neuronal sFlt1-Vegfaa and sprouting from intersegmental veins.

(a) Spinal cord neurons produce both sFlt1 and Vegfaa in close proximity to the dorsal aspect of intersegmental arteries and veins. (b) Schematic representation of vascularization around the neural tube in WT (top left), flt1^ka601 single mutant or vhl^hu2114 single mutant (top right), and flt1^ka601;vhl^hu2114 double mutant (bottom). Loss of flt1 or vhl induces the formation of a peri-neural tube network, and combining both mutants in addition promotes sprouting into the neural tube. NT, neural tube; ISV, intersegmental vessel (a-arterial, v-venous); DA, dorsal aorta; PCV, posterior cardinal vein; DLAV, dorsal longitudinal anastomotic vessel; hpf, hours post fertilization.