XB-ART-6736Neuron August 1, 2002; 35 (3): 461-73.
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Topographic mapping in dorsoventral axis of the Xenopus retinotectal system depends on signaling through ephrin-B ligands.
Ephrin-B and EphB are distributed in matching dorsoventral gradients in the embryonic Xenopus visual system with retinal axons bearing high levels of ligand (dorsal) projecting to tectal regions with high receptor expression (ventral). In vitro stripe assays show that dorsal retinal axons prefer to grow on EphB receptor stripes supporting an attractive guidance mechanism. In vivo disruption of EphB/ephrin-B function by application of exogenous EphB or expression of dominant-negative ephrin-B ligand in dorsal retinal axons causes these axons to shift dorsally in the tectum, while misexpression of wild-type ephrin-B in ventral axons causes them to shift ventrally. These dorsoventral targeting errors are consistent with the hypothesis that an attractive mechanism that requires ephrin-B cytoplasmic domain is critical for retinotectal mapping in this axis.
PubMed ID: 12165469
Article link: Neuron
Species referenced: Xenopus laevis
Genes referenced: efnb1 efnb2 efnb3 epha2 epha5 ephb1 ephb2 ephb3 ephb4 vax2
Article Images: [+] show captions
Pittman, Understanding dorsoventral topography: backwards and forwards. 2002, Pubmed