title: ENU-3 functions in an UNC-6/netrin dependent pathway parallel to UNC-40/DCC/frazzled for outgrowth and guidance of the touch receptor neurons in C. elegans.
abstract: BACKGROUND
  UNC-6 and SLT-1 guide the migrations of the ventrally directed processes of the AVM and PVM touch receptor neurons and UNC-6 guides the axons of the DA and DB classes of motor neurons in C. elegans. The UNC-6 receptors are UNC-5 and UNC-40. The axon outgrowth defects of a subset of the DB motor neurons in the absence of UNC-5 are enhanced by mutations in enu-3.
  
  
  RESULTS
  An enu-3 mutation enhances defects in ventral guidance of the processes of the AVM and PVM touch receptor neurons, the dorsal guidance of the distal tip cell and causes additional architectural defects in axons in unc-40 mutant strains in an UNC-6 dependent manner. These observations suggest that ENU-3 and UNC-40 function in parallel pathways dependent on UNC-6. ENU-3 depends on the presence of UNC-40 for its full effect on motor neuron axon outgrowth.
  
  
  CONCLUSIONS
  ENU-3 works in an UNC-6 dependent pathway parallel to UNC-40 in ventral guidance of AVM and PVM and in dorsal guidance of the distal tip cells. Motor neuron axon outgrowth defects are caused by the presence of UNC-40 and the absence of functional UNC-5 or UNC-6 and defects are enhanced by the absence of functional ENU-3.
authors.affiliation: Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada M5B 2K3.
authors.forename: Callista
authors.initials: C
authors.lastname: Yee
authors.forename: Roxana
authors.initials: R
authors.lastname: Florica
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Fillingham
authors.forename: Marie T
authors.initials: MT
authors.lastname: Killeen
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D000075385:Netrins
chemical_list: D029742:Caenorhabditis elegans Proteins; D015815:Cell Adhesion Molecules; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D000075385:Netrins; C102174:UNC-40 protein, C elegans; C078146:UNC-6 protein, C elegans; C558393:enu-3 protein, C elegans
keywords: AVM; DA and DB motor neuron axon outgrowth; ENU-3; UNC-40/DCC; UNC-5; UNC-6/Netrin