The roles of an ephrin and a semaphorin in patterning cell-cell contacts in C. elegans sensory organ development

Andrew C. Hahn, Scott W. Emmons

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Ephrins and semaphorins regulate a wide variety of developmental processes, including axon guidance and cell migration. We have studied the roles of the ephrin EFN-4 and the semaphorin MAB-20 in patterning cell-cell contacts among the cells that give rise to the ray sensory organs of Caenorhabditis elegans. In wild-type, contacts at adherens junctions form only between cells belonging to the same ray. In efn-4 and mab-20 mutants, ectopic contacts form between cells belonging to different rays. Ectopic contacts also occur in mutants in regulatory genes that specify ray morphological identity. We used efn-4 and mab-20 reporters to investigate whether these ray identity genes function through activating expression of efn-4 or mab-20 in ray cells. mab-20 reporter expression in ray cells was unaffected by mutants in the Pax6 homolog mab-18 and the Hox genes egl-5 and mab-5, suggesting that these genes do not regulate mab-20 expression. We find that mab-18 is necessary for activating efn-4 reporter expression, but this activity alone is not sufficient to account for mab-18 function in controlling cell-cell contact formation. In egl-5 mutants, efn-4 reporter expression in certain ray cells was increased, inconsistent with a simple repulsion model for efn-4 action. The evidence indicates that ray identity genes primarily regulate ray morphogenesis by pathways other than through regulation of expression of semaphorin and ephrin.

Original languageEnglish (US)
Pages (from-to)379-388
Number of pages10
JournalDevelopmental Biology
Issue number2
StatePublished - Apr 15 2003


  • Adherens junctions
  • C. elegans
  • Epidermis
  • Neurogenesis
  • Organ assembly
  • Sensory neurons

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology
  • Cell Biology


Dive into the research topics of 'The roles of an ephrin and a semaphorin in patterning cell-cell contacts in C. elegans sensory organ development'. Together they form a unique fingerprint.

Cite this