Ephrin-A5 exerts positive or inhibitory effects on distinct subsets of EphA4-positive motor neurons
| Autor: | Sinead O'Connell, Elena B. Pasquale, Alleda E. Flagg, Johann K. Eberhart, Kathryn W. Tosney, Catherine E. Krull, Karina S. Cramer, Jason Barr, Mary E. Swartz |
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| Rok vydání: | 2004 |
| Předmět: |
Mesoderm
animal structures Cellular differentiation Development/Plasticity/Repair Neural Inhibition Chick Embryo Biology Ligands medicine Ephrin Animals Axon Cells Cultured Motor Neurons General Neuroscience Erythropoietin-producing hepatocellular (Eph) receptor Cell Differentiation Ephrin-A5 biological factors Axons Ephrin-A4 Hindlimb Somite medicine.anatomical_structure Electroporation nervous system embryonic structures Ephrin A5 sense organs Neuroscience Signal Transduction |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience. 24(5) |
| ISSN: | 1529-2401 |
| Popis: | Eph receptor tyrosine kinases and ephrins are required for axon patterning and plasticity in the developing nervous system. Typically, Eph–ephrin interactions promote inhibitory events; for example, prohibiting the entry of neural cells into certain embryonic territories. Here, we show that distinct subsets of motor neurons that express EphA4 respond differently to ephrin-A5. EphA4-positive LMC(l) axons avoid entering ephrin-A5-positive hindlimb mesoderm. In contrast, EphA4-positive MMC(m) axons extend through ephrin-A5-positive rostral half-sclerotome. Blocking EphA4 activation in MMC(m) neurons or expanding the domain of ephrin-A5 expression in the somite results in the aberrant growth of MMC(m) axons into the caudal half-sclerotome. Moreover, premature expression of EphA4 in MMC(m) neurons leads to a portion of their axons growing into novel ephrin-A5-positive territories. Together, these results indicate that EphA4-ephrin-A5 signaling acts in a positive manner to constrain MMC(m) axons to the rostral half-sclerotome. Furthermore, we show that Eph activation localizes to distinct subcellular compartments of LMC(l) and MMC(m) neurons, consistent with distinct EphA4 signaling cascades in these neuronal subpopulations. |
| Databáze: | OpenAIRE |
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