Fig. 5. Molecular control of intersomitic vein development. (A) EphB4/ephrin-B signaling controls angiogenic growth of intersomitic veins in Xenopus. The panel depicts schematically the growth of an intersomitic vein (red) by sprouting angiogenesis from the posterior cardinal vein (blue). Ephrin-B1 and ephrin-B2 are expressed in the somites (yellow), whereas EphB4 receptors are present on the posterior cardinal vein and intersomitic veins. Interactions between EphB4 receptors and ephrin-B ligands restrict intersomitic veins from inappropriate growth into adjacent somitic tissues. Disruption of EphB4 signaling or ectopic expression of ephrin-B ligands leads to aberrant projection of intersomitic veins. (B) Tentative hierarchy of genes regulating intersomitic vein development in vertebrates. Key steps in intersomitic vein formation are shown together with the developmental block observed in Xenopus or mouse embryos that are disrupted for the indicated gene functions. EphB2/EphB3 refers to double mutant mice. Ephrin-B1 is also implicated based on its somitic expression and the phenotype observed in overexpression experiments.
Image published in: Helbling PM et al. (2000)
Copyright © 2000. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License.
Permanent Image Page
Printer Friendly View
XB-IMG-131250