title: Sterol content and enzyme defects of nystatin-resistant mutants of Neurospora crassa.
abstract: Non-saponifiable cell extracts of wild type and sterol mutants of N. crassa were analysed by means of gas-liquid chromatography. The wild-type contained ergosterol and episertol in a 10:1 ratio. None of the mutants was able to synthesize ergosterol. Three of the mutants carry single recessive gene mutations cauisng blocks in the terminal steps of ergosterol biosynthesis: erg-1 has an inactive delta 8 leads to delta 7 isomerase erg-2 has an inactive 24(28) hydrogenase, and erg-4 has an inactive C-24 methyl transferase. Some of the mutants accumulated novel sterols as a result of their enzyme defects. The genes erg-1 and erg-2 were mapped close to inl on the right arm of chromosome V.
mesh_terms: D004352:Drug Resistance, Microbial; D004875:Ergosterol / Q000378:metabolism*; D009154:Mutation; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000235:genetics* / Q000378:metabolism; D009761:Nystatin / Q000494:pharmacology*; D010641:Phenotype; D013261:Sterols / Q000378:metabolism*
chemical_list: D013261:Sterols; D009761:Nystatin; D004875:Ergosterol