IFT-81 and IFT-74 are required for intraflagellar transport in C. elegans

Genes Cells. 2007 May;12(5):593-602. doi: 10.1111/j.1365-2443.2007.01076.x.


Intraflagellar transport (IFT) is essential machinery for biogenesis and maintenance of cilia in many eukaryotic and prokaryotic cells. A large number of polypeptides are known to be involved in IFT, but the physiological role of each component is not fully elucidated. Here, we identified a C. elegans orthologue of a Chlamydomonas reinhardtii IFT component, IFT-81, and found that its loss-of-function mutants show an unusual behavioral property and small body size. IFT-81 is expressed in sensory neurons, and localized at the base of cilia. The similar phenotypes with ift-81 mutants were also observed in several IFT mutants, suggesting these defects are caused by inability of IFT. We also demonstrated that IFT-81 interacts and co-localizes with IFT-74, which is another putative component of IFT. The ift-74 loss-of-function mutants showed phenocopies with ift-81 mutants, suggesting IFT-81 and IFT-74 play comparable functions. Moreover, ift-81 and ift-74 mutants similarly exhibited weak anomalies in cilia formation and obvious disruptions of transport in mature cilia. Thus, we conclude that IFT-81 and IFT-74 coordinately act in IFT in C. elegans sensory cilia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Biological Transport, Active
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / physiology*
  • Carrier Proteins / genetics
  • Carrier Proteins / physiology*
  • Chemotaxis
  • Cilia / physiology
  • Flagella / physiology*
  • Genes, Helminth
  • Mutation
  • Neurons, Afferent / physiology
  • Phenotype


  • Caenorhabditis elegans Proteins
  • Carrier Proteins