DENOVO BIOSYNTHESIS OF LINOLEIC-ACID IN INSECTS

The de novo biosynthesis of linoleic acid was demonstrated in 8 of the 32 insect species examined, which include members of three orders and encompass both holometabolous and hemimetabolous species. The incorporation of [1-14C]acetate into linoleate was demonstrated by radio-GLC, and in selected species by radio-HPLC, silver nitrate thin-layer chromatography, radio-GLC and GLC linked to mass epectrometry of ozonolysis products. In most of the species which synthesized linoleate, there was a time-dependent increase in the incorporation of [1-14C]acetate into linoleate from 2 to 24 h, and most of the labeled linoleate was recovered in the phospholipid fraction. There was no readily discernable evolutionary, physiological or nutritional pattern in the ability of certain species to synthesize linoleate.