Sterol Metabolism in the Nematodes Panagrellus Redivivus, Turbatrix Acet1 and Caenorhabditis Elegans

-1. Panagrellus redivivus, Turbatrix aceti and Caenorhabditis elegans were sterilely propagated in semidefined media containing sitosterol or cholesterol, and sterols were isolated and identified by capillary gas-liquid chromatography-mass spectrometry. 2. Each species was capable of removal of the C-24 ethyl substituent of sitosterol and production of 4x -methylsterols. 3. Other modifications of the sterol nucleus varied among the species, as only T. aceti and C. elegans introduced AT-and A~14)-bonds significantly. 4. P. redivivus and, to a much lesser extent, 7". aceti reduced AS-bonds to produce substantial quantities of cholestanol and 4~-methylcholestanol.