Developmental timing in C. elegans is regulated by kin-20 and tim-1, homologs of core circadian clock genes

Dev Cell. 2005 Feb;8(2):287-95. doi: 10.1016/j.devcel.2004.12.006.


In Caenorhabditis elegans, heterochronic genes constitute a developmental timer that specifies temporal cell fate selection. The heterochronic gene lin-42 is the C. elegans homolog of Drosophila and mammalian period, key regulators of circadian rhythms, which specify changes in behavior and physiology over a 24 hr day/night cycle. We show a role for two other circadian gene homologs, tim-1 and kin-20, in the developmental timer. Along with lin-42, tim-1 and kin-20, the C. elegans homologs of the Drosophila circadian clock genes timeless and doubletime, respectively, are required to maintain late-larval identity and prevent premature expression of adult cell fates. The molecular parallels between circadian and developmental timing pathways suggest the existence of a conserved molecular mechanism that may be used for different types of biological timing.

Publication types

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

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / growth & development*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / metabolism
  • Casein Kinase Idelta / genetics*
  • Casein Kinase Idelta / metabolism
  • Circadian Rhythm / genetics*
  • Gene Expression Regulation, Developmental
  • Genes, Helminth*
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • MicroRNAs
  • Models, Biological
  • Molecular Sequence Data
  • Mutation
  • Phenotype
  • Phylogeny
  • RNA Interference


  • Caenorhabditis elegans Proteins
  • Isoenzymes
  • MicroRNAs
  • TIM-1 protein, C elegans
  • let-7 microRNA, C elegans
  • Casein Kinase Idelta

Associated data

  • GENBANK/AY836556
  • GENBANK/AY836557
  • GENBANK/AY836558