title: Axons break in animals lacking beta-spectrin.
abstract: Axons and dendrites can withstand acute mechanical strain despite their small diameter. In this study, we demonstrate that beta-spectrin is required for the physical integrity of neuronal processes in the nematode Caenorhabditis elegans. Axons in beta-spectrin mutants spontaneously break. Breakage is caused by acute strain generated by movement because breakage can be prevented by paralyzing the mutant animals. After breaking, the neuron attempts to regenerate by initiating a new growth cone; this second round of axon extension is error prone compared with initial outgrowth. Because spectrin is a major target of calpain proteolysis, it is possible that some neurodegenerative disorders may involve the cleavage of spectrin followed by the breakage of neural processes.
authors.affiliation: Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Hammarlund
authors.forename: Erik M
authors.initials: EM
authors.lastname: Jorgensen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bastiani
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology* / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000502:physiology; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D004548:Elasticity; D009068:Movement; D009154:Mutation; D009422:Nervous System Diseases / Q000235:genetics* / Q000473:pathology; D009474:Neurons / Q000473:pathology / Q000502:physiology / Q000648:ultrastructure; D010641:Phenotype; D013049:Spectrin / Q000235:genetics*; D013314:Stress, Mechanical
chemical_list: D029742:Caenorhabditis elegans Proteins; C409166:unc-70 protein, C elegans; D013049:Spectrin