Both authors contributed equally to this work.
Eph receptor–ligand interactions are necessary for guidance of retinal ganglion cell axons in vitro
Article first published online: 25 DEC 2001
European Journal of Neuroscience
Volume 10, Issue 5, pages 1574–1580, May 1998
How to Cite
Ciossek, T., Monschau, B., Kremoser, C., Löschinger, J., Lang, S., Müller, B. K., Bonhoeffer, F. and Drescher, U. (1998), Eph receptor–ligand interactions are necessary for guidance of retinal ganglion cell axons in vitro. European Journal of Neuroscience, 10: 1574–1580. doi: 10.1046/j.1460-9568.1998.00180.x
- Issue published online: 25 DEC 2001
- Article first published online: 25 DEC 2001
- Received 3 March 1997, revised 5 December 1997, accepted 5 January 1998
- retinotectal projection;
- stripe assay
Previous results of an in vitro guidance test, the stripe assay, have demonstrated the presence of a repulsive axon guidance activity for temporal retinal axons in the posterior part of the vertebrate optic tectum. Ephrin-A5 and Ephrin-A2 are ligands for the EphA subfamily of Eph receptor tyrosine kinases, which are expressed in overlapping gradients in the posterior part of the tectum. When recombinantly expressed, both proteins have been shown to guide retinal ganglion cell axons in the stripe assay. While these results suggest that Ephrin-A5 and Ephrin-A2 form part of the posterior repulsive guidance activity, they do not elucidate whether they are necessary components. Here we report that soluble forms of the ligands at nanomolar concentrations completely abolish this repulsive activity. Similar results were obtained with the soluble extracellular domain of EphA3, which is a receptor for Ephrin-A2 and Ephrin-A5, but not with the corresponding domain of EphB3, a receptor for the transmembrane class of Eph ligands. These experiments show that the repulsive axon guidance activity seen in the stripe assay is mediated by Ephrin-A ligands.