The receptor tyrosine kinase EphB4 and ephrin-B ligands restrict angiogenic growth of embryonic veins in Xenopus laevis.

摘要: The cues and signaling systems that guide the formation of embryonic blood vessels in tissues organs are poorly understood. Members Eph family receptor tyrosine kinases their cell membrane-anchored ligands, ephrins, have been assigned important roles control migration during embryogenesis, particularly axon guidance neural crest migration. Here we investigated role EphB receptors ligands vessel development Xenopus laevis. In a survey tadpole-stage embryos for expression, detected expression EphB4 posterior cardinal veins derivatives, intersomitic veins. Vascular other receptors, including EphB1, EphB2 or EphB3, could however not be observed, suggesting is principal early vasculature Xenopus. Furthermore, found ephrin-B expressed complementary to somites adjacent migratory pathways taken by angiogenic growth. We performed RNA injection experiments study function its vein development. Disruption dominant negative misexpression resulted growing abnormally into somitic tissue. Our findings demonstrate B-class ephrins act as regulators angiogenesis possibly mediating repulsive migrating endothelial cells.