ABSTRACT
Caenorhabditis elegans is one of the premier model organisms for research on aging, and discoveries from this tiny nematode have helped lay a solid foundation in understanding the molecular biology of aging. C. elegans produces one of the most highly unsaturated membranes in nature, especially at low temperatures, where up to one-third of total membrane fatty acids are eicosapentaenoic acid (EPA). Docosahexaenoic acid (DHA) is not produced, and when incorporated in the diet, DHA is mostly retroconverted to EPA. C. elegans has evolved a desaturase pathway for synthesis of EPA, and mutational and regulatory analysis has established each step of its biosynthesis. A cold-activated enzyme system has evolved that generates a hierarchy of di-unsaturated molecular species of phospholipids with 10, 9, 8, 6, 5, 4, 3, and 2 double bonds. Mitochondrial membranes of C. elegans contain almost twice the level of double bonds as human mitochondria.
