title: Differential biosynthesis of polyunsaturated fatty acids by Tetrahymena supplemented with ergosterol.
abstract: Tetrahymena grown with foreign sterols such as ergosterol incorporate them into cellular membranes at the expense of the native compound, tetrahymanol. It is shown that cells grown with ergosterol have a lessened capacity to produce the polyunsaturated linoleic and gamma-linolenic acids from [14C]oleic acid. However, the same cells have normal capacities to introduce double bonds at C-6 into linoleate, alpha-linolenate, or cis-vaccenate. Thus, a presumed 12-desaturase is inhibited in the presence of ergosterol, while desaturation at C-6 is unaffected.
mesh_terms: D004875:Ergosterol / Q000378:metabolism / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D008041:Linoleic Acids / Q000096:biosynthesis; D008042:Linolenic Acids / Q000096:biosynthesis; D013769:Tetrahymena pyriformis / Q000187:drug effects / Q000378:metabolism*
chemical_list: D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids; D008042:Linolenic Acids; D004875:Ergosterol