The conserved immunoglobulin superfamily member SAX-3/Robo directs multiple aspects of axon guidance in C. elegans

Cell. 1998 Jan 23;92(2):217-27. doi: 10.1016/s0092-8674(00)80916-2.


The C. elegans sax-3 gene encodes a predicted transmembrane protein with five immunoglobulin domains and three fibronectin type III repeats that is closely related to Drosophila Robo. Mutations in sax-3 lead to repeated midline crossing by ventral cord axons that normally do not cross the midline after they join the ventral cord, a phenotype similar to that of robo mutants. sax-3 is also required for guidance of some axons to the ventral cord, implicating this gene in two different types of guidance events. A sax-3::GFP fusion gene is expressed in developing neurons during axon outgrowth, and sax-3 function is required at the time of axon guidance, suggesting that this gene mediates cell interactions during guidance decisions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Axons / physiology*
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics
  • Central Nervous System / embryology
  • Central Nervous System / growth & development
  • Conserved Sequence / genetics*
  • Fibronectins / genetics
  • Gene Expression Regulation, Developmental
  • Genes, Helminth / genetics
  • Immunoglobulins / genetics*
  • Molecular Sequence Data
  • Motor Neurons / chemistry
  • Mutation
  • Nerve Tissue Proteins
  • Receptors, Immunologic / chemistry
  • Receptors, Immunologic / genetics*
  • Receptors, Immunologic / physiology
  • Recombinant Fusion Proteins


  • Fibronectins
  • Immunoglobulins
  • Nerve Tissue Proteins
  • Receptors, Immunologic
  • Recombinant Fusion Proteins
  • roundabout protein

Associated data

  • GENBANK/AF041053