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Genetic Evidence for a Contribution of EphA:EphrinA Reverse Signaling to Motor Axon Guidance

Authors :
Artur Kania
Tzu Jen Kao
Julia E. Herrmann
Binhai Zheng
Irina Dudanova
RĂ¼diger Klein
Source :
Journal of Neuroscience; Vol 32, Journal of Neuroscience
Publication Year :
2012
Publisher :
Society for Neuroscience, 2012.

Abstract

Repulsive Eph forward signaling from limb-derived ephrins guides the axons of lateral motor column (LMC) motor neurons. LMC axons also express ephrinAs, while their EphA receptors are expressed in the limb mesenchyme.In vitrostudies have suggested that reverse signaling from limb-derived EphA4 to axonal ephrinAs might result in attraction of LMC axons. However, genetic evidence for this function is lacking. Here we use the Dunn chamber turning assay to show that EphA proteins are chemoattractants and elicit fast turning responses in LMC neuronsin vitro. Moreover, ectopic expression of EphA4 in chick hindlimb changes the limb trajectory of LMC axons. Nervous system-specific deletion of EphA4 in mice resulted in fewer LMC axon projection errors than the ubiquitous deletion of EphA4. Additionally, a signaling-incompetent EphA4 mutant partially rescued guidance errors in the hindlimb, suggesting that limb-derived EphA4 contributes to the establishment of LMC projections. In summary, we provide evidence for a role of EphA:ephrinA attractive reverse signaling in motor axon guidance andin vivoevidence of in-parallel forward Eph and reverse ephrin signaling function in the same neuronal population.

Details

ISSN :
15292401 and 02706474
Volume :
32
Database :
OpenAIRE
Journal :
The Journal of Neuroscience
Accession number :
edsair.doi.dedup.....97e16c5b7399b58c2c1a4f26375b9156
Full Text :
https://doi.org/10.1523/jneurosci.5707-11.2012