C. elegans slit acts in midline, dorsal-ventral, and anterior-posterior guidance via the SAX-3/Robo receptor

Neuron. 2001 Oct 11;32(1):25-38. doi: 10.1016/s0896-6273(01)00448-2.


Robo receptors interact with ligands of the Slit family. The nematode C. elegans has one Robo receptor (SAX-3) and one Slit protein (SLT-1), which direct ventral axon guidance and guidance at the midline. In larvae, slt-1 expression in dorsal muscles repels axons to promote ventral guidance. SLT-1 acts through the SAX-3 receptor, in parallel with the ventral attractant UNC-6 (Netrin). Removing both UNC-6 and SLT-1 eliminates all ventral guidance information for some axons, revealing an underlying longitudinal guidance pathway. In the embryo, slt-1 is expressed at high levels in anterior epidermis. Embryonic expression of SLT-1 provides anterior-posterior guidance information to migrating CAN neurons. Surprisingly, slt-1 mutants do not exhibit the nerve ring and epithelial defects of sax-3 mutants, suggesting that SAX-3 has both Slit-dependent and Slit-independent functions in development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / physiology*
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins*
  • Cell Movement
  • Gene Expression Regulation, Developmental
  • Green Fluorescent Proteins
  • Helminth Proteins / genetics
  • Helminth Proteins / metabolism
  • Indicators and Reagents / metabolism
  • Luminescent Proteins / genetics
  • Muscles / innervation
  • Muscles / physiology
  • Mutagenesis / physiology
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism*
  • Netrins
  • Neurons / physiology
  • Neurons / ultrastructure
  • Protein Structure, Tertiary
  • Receptors, Immunologic / genetics*
  • Receptors, Immunologic / metabolism*


  • Caenorhabditis elegans Proteins
  • Helminth Proteins
  • Indicators and Reagents
  • Luminescent Proteins
  • Nerve Tissue Proteins
  • Netrins
  • Receptors, Immunologic
  • UNC-6 protein, C elegans
  • roundabout protein
  • slt-1 protein, C elegans
  • Green Fluorescent Proteins