A hierarchy of regulatory genes controls a larva-to-adult developmental switch in C. elegans

Cell. 1989 Apr 7;57(1):49-57. doi: 10.1016/0092-8674(89)90171-2.


The heterochronic genes lin-4, lin-14, lin-28, and lin-29 control the timing of specific postembryonic developmental events in C. elegans. The experiments described here examine how these four genes interact to control a particular stage-specific event of the lateral hypodermal cell lineages. This event, termed the "larva-to-adult switch" (L/A switch), involves several coordinate changes in the behavior of hypodermal cells at the fourth molt: cessation of cell division, formation of adult (instead of larval) cuticle, cell fusion, and cessation of the molting cycle. The phenotypes of multiply mutant strains suggest a model wherein the L/A switch is controlled by the stage-specific activity of a regulatory hierarchy: At early stages of wild-type development, lin-14 and lin-28 inhibit lin-29 and thus prevent switching. Later, lin-4 inhibits lin-14 and lin-28, allowing activation of lin-29, which in turn triggers the switch in the L4 stage. lin-29 may activate the L/A switch by regulating genes that control cell division, differentiation, and stage-specific gene expression in hypodermal cells.

Publication types

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

MeSH terms

  • Animals
  • Caenorhabditis / genetics*
  • Gene Expression Regulation
  • Genes, Regulator*
  • Metamorphosis, Biological / drug effects
  • Transcription Factors / pharmacology


  • Transcription Factors