let-60, a gene that specifies cell fates during C. elegans vulval induction, encodes a ras protein

Cell. 1990 Nov 30;63(5):921-31. doi: 10.1016/0092-8674(90)90495-z.


Genetic analysis previously suggested that the let-60 gene controls the switch between vulval and hypodermal cell fates during C. elegans vulval induction. We have cloned the let-60 gene, and shown that it encodes a gene product identical in 84% of its first 164 amino acids to ras gene products from other vertebrate and invertebrate species. This conservation suggests that the let-60 product contains all the biochemical functions of ras proteins. Extrachromosomal arrays of let-60 ras DNA cause cell-type misspecification (extra vulval fates) phenotypically opposite to that caused by let-60 ras loss-of-function mutations (no vulval fates), and suppress the vulvaless phenotype of mutations in two other genes necessary for vulval induction. Thus, the level and pattern of let-60 ras expression may be under strict regulation; increase in let-60 ras activity bypasses or reduces the need for upstream genes in the vulval induction pathway.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Caenorhabditis / embryology
  • Caenorhabditis / genetics*
  • Caenorhabditis elegans Proteins*
  • Cloning, Molecular
  • Cosmids
  • DNA / genetics
  • DNA / isolation & purification
  • Disorders of Sex Development
  • Embryo, Nonmammalian
  • Female
  • Genes, ras*
  • Helminth Proteins / genetics*
  • Models, Biological
  • Molecular Sequence Data
  • Plasmids
  • Restriction Mapping
  • Sequence Homology, Nucleic Acid
  • Signal Transduction
  • Transcription, Genetic
  • Vulva / embryology
  • ras Proteins*


  • Caenorhabditis elegans Proteins
  • Helminth Proteins
  • let-60 protein, C elegans
  • DNA
  • ras Proteins

Associated data

  • GENBANK/M5535
  • GENBANK/M55535