title: Infrared laser-induced gene expression for tracking development and function of single C. elegans embryonic neurons.
abstract: Visualizing neural-circuit assembly in vivo requires tracking growth of optically resolvable neurites. The Caenorhabditis elegans embryonic nervous system, comprising 222 neurons and 56 glia, is attractive for comprehensive studies of development; however, embryonic reporters are broadly expressed, making single-neurite tracking/manipulation challenging. We present a method, using an infrared laser, for reproducible heat-dependent gene expression in small sublineages (one to four cells) without radiation damage. We go beyond proof-of-principle, and use our system to label and track single neurons during early nervous-system assembly. We uncover a retrograde extension mechanism for axon growth, and reveal the aetiology of axon-guidance defects in sax-3/Robo and vab-1/EphR mutants. We also perform cell-specific rescues, determining DAF-6/patched-related site of action during sensory-organ development. Simultaneous ablation and labelling of cells using our system reveals roles for glia in dendrite extension. Our method can be applied to other optically/IR-transparent organisms, and opens the door to high-resolution systematic analyses of C. elegans morphogenesis.
authors.affiliation: Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, New York 10065, USA.
authors.forename: Anupriya
authors.initials: A
authors.lastname: Singhal
authors.affiliation: Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, New York 10065, USA.
authors.forename: Shai
authors.initials: S
authors.lastname: Shaham
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D006358:Hot Temperature; D007259:Infrared Rays; D007834:Lasers; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism; D000097905:Roundabout Proteins
chemical_list: D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D009419:Nerve Tissue Proteins; D020794:Receptor Protein-Tyrosine Kinases; D011971:Receptors, Immunologic; D000097905:Roundabout Proteins; C502788:DAF-6 protein, C elegans; C111040:vab-1 protein, C elegans