The effect of dietary ethanol on the composition of lipids of Drosophila melanogaster larvae

Abstract

At a moderate concentration (2.5%, v/v) dietary ethanol reduced the chain length of total fatty acids (FA) and increased the desaturation of short-chain FA in Drosophila melanogaster larvae with a functional alcohol dehydrogenase (ADH). The changes in length in total FA were postulated to be due to the modulation of the termination specificity of fatty acid synthetase. Because the ethanol-stimulated reduction in the length of unsaturated FA was blocked by linoleic acid, it was thought to reflect the properties of FA 9-desaturase. Although the ethanol-stimulated reduction in chain length of unsaturated FA was also observed in ADH-null larvae, ethanol promoted an increase in the length of total FA of the mutant larvae. Thus, the ethanol-stimulated change in FA length was ADH dependent but the ethanol effect on FA desaturation was not. Ethanol also stimulated a decrease in the relative amount of phosphatidylcholine and an increase in phosphatidylethanolamine. Because similar ethanol-induced changes have been found in membrane lipids of other animals, ethanol may alter the properties of membranes in larvae. It is proposed that ethanol tolerance in D. melanogaster may be dependent on genes that specify lipids that are resistant to the detrimental effects of ethanol.

Chromosome inversion polymorphisms inDrosophila melanogaster IV. Inversion and Adh allele frequency changes under selection for different development times

“…This concurs with the increased frequencies of the high activity ADH F and GPDH S allozymes associated with rapid development in the studies of van Delden andKamping (1979), Cavener (1983) and ourselves. ADH, GPDH and 6PGH activity levels all affect in vivo rates of fatty acid synthesis (Cavener and Clegg, 1981;Geer et a!., 1983Geer et a!., , 1985Geer et a!., , 1986 and such a central metabolic pathway may well be relevant to variation in development time.…”

Effect of Gibberellin and Heat Shock on the Lipid Composition of Endoplasmic Reticulum in Barley Aleurone Layers

“…TLC-purified PC, eluted from the silica with chloroform: methanol (2:1, v/v), was hydrolyzed and methylated according to the procedures of Geer et al (1986). The resulting fatty acid methyl esters were analyzed by GC (model 5890, series II, Hewlett-Packard) using a column of 10% SP-2330 on 100/120 Supelcoport (Supelco, Bellefonte, PA).…”

Long-chain fatty acids and ethanol affect the properties of membranes inDrosophila melanogaster larvae

“…In Drosophila melanogaster larvae, dietary ethanol caused a two-to threefold reduction in the levels of phosphatidylcholine (PC) and increased phosphatidylethanolamine (PE) levels (Geer et al, 1986;Miller et al, 1992a, b). These phospholipid alterations were observed in ethanol-tolerant and -intolerant strains of D. melanogaster and correlated to ethanol toxicity (Miller et al, 1993a).…”

“…In wild-type strains olD. melanogaster, dietary ethanol promoted the accumulation of short-chain, unsaturated fatty acids within total lipid extracts (Geer et al, 1986). The larvae used in these studies were fed sterile, defined media, which lacked all lipids except cholesterol.…”