Hedgehog and Resident Vascular Stem Cell Fate

Figure 3

Signalling cascade involved in determining arterial-venous identity in zebrafish. (a) Shh from the notochord induces vegf expression in somites, promoting arterial identity of endothelial cells in the aorta. The arterial ECs then stimulate Notch signalling in the surrounding cells resulting in an upregulation of gridlock and thus ephrin B2, conferring arterial identity of the aorta. (b) Impairment of the signalling hierarchy responsible for arterial-venous identity results in either loss of arterial identity in vessels or loss of arterial vessels entirely. (c) Overstimulation of one or more of the pathways in the signalling hierarchy responsible for arterial-venous identity results in either gain of arterial identity in venous vessels or loss of venous vessels entirely.