Biosynthesis of lipids during embryogenesis of Ascaris lumbricoides eggs.

Alteration in lipid metabolism of Ascaris lumbricoides eggs during development in either air or nitrogen gas was studied using acetate-1-14C and labeled fatty acids. It is thought that formation of 14C-lipids and 14C-palmitoleate from acetate-1-14C and palmitate-1-14C in developing eggs may be influenced by the concentration of molecular oxygen in the medium. Acetate-1-14C was incorporated into palmitate, palmitoleate and unsaturated 18-carbon acid of fatty acids in the eggs, but the incorporation into saturated 18-carbon acid was slight. Radioactive fatty acid methyl esters were major lipid component of the radioactive lipid classes in the first and second stage larvae incubated with palmitate-1-14C. Isopentadecanoic acid, which is a small component of fatty acids in Ascaris eggs, contains a high percentage of the total radioactivity in the second stage larvae incubated with acetate-1-14C under both air and nitrogen. It appears that a conversion of the fatty acid biosynthesis system may occur during development in to the second stage larvae.