Homologs of vascular endothelial growth factor and receptor, VEGF and VEGFR, in the jellyfish Podocoryne carnea.

Vascular endothelial growth factors (VEGF) are the major inducers of vasculogenesis and angiogenesis in vertebrates. Their effects are mediated by receptor tyrosine kinases of the VEGF receptor (VEGFR) family located on endothelial cells and include stimulation of cell survival, proliferation, migration, and tube formation as well as regulation of vascular permeability. Here, we report the presence of VEGF and VEGFR homologous genes in a basal invertebrate of the phylum Cnidaria. The marine jellyfish Podocoryne carnea features a gastrovascular system consisting of the feeding organ, or manubrium, the radial and ring canals, and the tentacle bulbs. Expression analysis indicates that both genes are involved in tentacle and gastrovascular canal formation, indicating an early recruitment of the VEGF signalling pathway for morphogenetic processes leading to tube formation in metazoans. The evolutionary origin of the VEGF signalling pathway resides in the common ancestor of the Cnidaria and Bilateria.