title: An extracellular adhesion molecule complex patterns dendritic branching and morphogenesis.
abstract: Robust dendrite morphogenesis is a critical step in the development of reproducible neural circuits. However, little is known about the extracellular cues that pattern complex dendrite morphologies. In the model nematode Caenorhabditis elegans, the sensory neuron PVD establishes stereotypical, highly branched dendrite morphology. Here, we report the identification of a tripartite ligand-receptor complex of membrane adhesion molecules that is both necessary and sufficient to instruct spatially restricted growth and branching of PVD dendrites. The ligand complex SAX-7/L1CAM and MNR-1 function at defined locations in the surrounding hypodermal tissue, whereas DMA-1 acts as the cognate receptor on PVD. Mutations in this complex lead to dramatic defects in the formation, stabilization, and organization of the dendritic arbor. Ectopic expression of SAX-7 and MNR-1 generates a predictable, unnaturally patterned dendritic tree in a DMA-1-dependent manner. Both in vivo and in vitro experiments indicate that all three molecules are needed for interaction.
authors.affiliation: Howard Hughes Medical Institute, Department of Biology, Stanford University, 385 Serra Mall, Stanford, CA 94305, USA.
authors.forename: Xintong
authors.initials: X
authors.lastname: Dong
authors.forename: Oliver W
authors.initials: OW
authors.lastname: Liu
authors.forename: Audrey S
authors.initials: AS
authors.lastname: Howell
authors.forename: Kang
authors.initials: K
authors.lastname: Shen
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D019006:Neural Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D055495:Neurogenesis; D010802:Phylogeny
chemical_list: D029742:Caenorhabditis elegans Proteins; C569907:DMA-1 protein, C elegans; D005353:Fibronectins; C585068:MNR-1 protein, C elegans; D008565:Membrane Proteins; D019006:Neural Cell Adhesion Molecules; C501528:SAX-7 protein, C elegans