Axial patterning of C. elegans male sensilla identities by selector genes

Dev Biol. 2004 May 1;269(1):137-51. doi: 10.1016/j.ydbio.2004.01.021.


The fan and rays of the C. elegans male tail constitute a compound sensory organ essential for mating. Within this organ, the individual sensilla, known as rays, have unique identities. We show that ray identities are patterned by a selector gene mechanism in a manner similar to other serially homologous axial structures. One selector gene that promotes the identities of a subset of the rays is the Hox gene egl-5. Within EGL-5-expressing rays, further patterning is provided by a Pax-6 homolog and a signal of the TGFbeta family. These genes and pathway coordinately specify multiple ray properties affecting all three terminal ray cell types. These properties include complex patterns of FMRFamide-like (FaRP) neuropeptides, serotonin (5HT) and dopamine expression, and ray morphology. Differences in these differentiated characteristics give each sensillum a unique identity and potentially endow the compound ray organ with a higher-order information gathering capacity.

Publication types

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

MeSH terms

  • Animals
  • Body Patterning / genetics*
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Eye Proteins
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Male
  • Neurons / metabolism
  • Neuropeptides / genetics
  • Neuropeptides / metabolism
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Repressor Proteins
  • Serotonin / biosynthesis
  • Tail / embryology*
  • Tail / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transforming Growth Factor beta / genetics
  • Transforming Growth Factor beta / metabolism


  • Caenorhabditis elegans Proteins
  • Dbl-1 protein, C elegans
  • Egl-5 protein, C elegans
  • Eye Proteins
  • Homeodomain Proteins
  • Neuropeptides
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Repressor Proteins
  • Transcription Factors
  • Transforming Growth Factor beta
  • Serotonin