Genetic regulation of unsaturated fatty acid composition in C. elegans

PLoS Genet. 2006 Jul;2(7):e108. doi: 10.1371/journal.pgen.0020108. Epub 2006 Jun 5.


Delta-9 desaturases, also known as stearoyl-CoA desaturases, are lipogenic enzymes responsible for the generation of vital components of membranes and energy storage molecules. We have identified a novel nuclear hormone receptor, NHR-80, that regulates delta-9 desaturase gene expression in Caenorhabditis elegans. Here we describe fatty acid compositions, lifespans, and gene expression studies of strains carrying mutations in nhr-80 and in the three genes encoding delta-9 desaturases, fat-5, fat-6, and fat-7. The delta-9 desaturase single mutants display only subtle changes in fatty acid composition and no other visible phenotypes, yet the fat-5;fat-6;fat-7 triple mutant is lethal, revealing that endogenous production of monounsaturated fatty acids is essential for survival. In the absence of FAT-6 or FAT-7, the expression of the remaining desaturases increases, and this ability to compensate depends on NHR-80. We conclude that, like mammals, C. elegans requires adequate synthesis of unsaturated fatty acids and maintains complex regulation of the delta-9 desaturases to achieve optimal fatty acid composition.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans
  • Fatty Acids, Unsaturated / metabolism*
  • Gene Expression Regulation*
  • Green Fluorescent Proteins / chemistry
  • Mutation
  • Stearoyl-CoA Desaturase / metabolism
  • Substrate Specificity


  • Fatty Acids, Unsaturated
  • Green Fluorescent Proteins
  • Stearoyl-CoA Desaturase