title: LIN-44/Wnt directs dendrite outgrowth through LIN-17/Frizzled in C. elegans Neurons.
abstract: Nervous system function requires proper development of two functional and morphological domains of neurons, axons and dendrites. Although both these domains are equally important for signal transmission, our understanding of dendrite development remains relatively poor. Here, we show that in C. elegans the Wnt ligand, LIN-44, and its Frizzled receptor, LIN-17, regulate dendrite development of the PQR oxygen sensory neuron. In lin-44 and lin-17 mutants, PQR dendrites fail to form, display stunted growth, or are misrouted. Manipulation of temporal and spatial expression of LIN-44, combined with cell-ablation experiments, indicates that this molecule is patterned during embryogenesis and acts as an attractive cue to define the site from which the dendrite emerges. Genetic interaction between lin-44 and lin-17 suggests that the LIN-44 signal is transmitted through the LIN-17 receptor, which acts cell autonomously in PQR. Furthermore, we provide evidence that LIN-17 interacts with another Wnt molecule, EGL-20, and functions in parallel to MIG-1/Frizzled in this process. Taken together, our results reveal a crucial role for Wnt and Frizzled molecules in regulating dendrite development in vivo.
authors.affiliation: Queensland Brain Institute, The University of Queensland, Brisbane, Australia.
authors.forename: Leonie
authors.initials: L
authors.lastname: Kirszenblat
authors.forename: Divya
authors.initials: D
authors.lastname: Pattabiraman
authors.forename: Massimo A
authors.initials: MA
authors.lastname: Hilliard
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D019521:Body Patterning / Q000235:genetics; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D003712:Dendrites / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D051157:Frizzled Receptors / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D023281:Genomics; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009154:Mutation; D055495:Neurogenesis / Q000235:genetics; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D010100:Oxygen; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
chemical_list: D029742:Caenorhabditis elegans Proteins; D051157:Frizzled Receptors; D006023:Glycoproteins; C101684:LIN-17 protein, C elegans; C095991:LIN-44 protein, C elegans; D020033:Protein Isoforms; D043562:Receptors, G-Protein-Coupled; D010100:Oxygen