Abstract
Dendrites from a single neuron may be highly branched but typically do not overlap. Self-avoidance behavior has been shown to depend on cell-specific membrane proteins that trigger mutual repulsion. Here we report the unexpected discovery that a diffusible cue, the axon guidance protein UNC-6 (Netrin), is required for self-avoidance of sister dendrites from the PVD nociceptive neuron in Caenorhabditis elegans. We used time-lapse imaging to show that dendrites fail to withdraw upon mutual contact in the absence of UNC-6 signaling. We propose a model in which the UNC-40 (Deleted in Colorectal Cancer; DCC) receptor captures UNC-6 at the tips of growing dendrites for interaction with UNC-5 on the apposing branch to induce mutual repulsion. UNC-40 also responds to dendritic contact through another pathway that is independent of UNC-6. Our findings offer a new model for how an evolutionarily conserved morphogenic cue and its cognate receptors can pattern a fundamental feature of dendritic architecture.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Animals, Genetically Modified
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Caenorhabditis elegans
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Caenorhabditis elegans Proteins / genetics
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Caenorhabditis elegans Proteins / metabolism*
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Cell Adhesion Molecules / genetics
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Cell Adhesion Molecules / metabolism
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Cell Movement / genetics
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Cell Movement / physiology*
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Cloning, Molecular
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Dendrites / genetics
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Dendrites / physiology*
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Hot Temperature
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Luminescent Proteins / genetics
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Luminescent Proteins / metabolism
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Microscopy, Confocal
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Models, Molecular
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Mutation / genetics
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism*
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Netrins
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Nociceptors / cytology*
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Signal Transduction / genetics
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Signal Transduction / physiology
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Time Factors
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Time-Lapse Imaging
Substances
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Caenorhabditis elegans Proteins
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Cell Adhesion Molecules
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Luminescent Proteins
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Membrane Proteins
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Nerve Tissue Proteins
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Netrins
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UNC-40 protein, C elegans
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UNC-6 protein, C elegans