Long-chain fatty acids and ethanol affect the properties of membranes in Drosophila melanogaster larvae.
The larval fatty acid composition of neutral lipids and membrane lipids was determined in three ethanol-tolerant strains of Drosophila melanogaster. Dietary ethanol promoted a decrease in long-chain fatty acids in neutral lipids along with enhanced alcohol dehydrogenase (EC 1.1.1.1) activity in all of the strains. Dietary ethanol also increased the incorporation of 14C-ethanol into fatty acid ethyl esters (FAEE) by two- to threefold and decreased the incorporation of 14C-ethanol into free fatty acids (FFA). When cultured on sterile, defined media with stearic acid at 0 to 5 mM, stearic acid decreased ADH activity up to 33%. In strains not selected for superior tolerance to ethanol, dietary ethanol promoted a loss of long-chain fatty acids in membrane lipids. The loss of long-chain fatty acids in membranes was strongly correlated with increased fluidity in hydrophobic domains of mitochondrial membranes as determined by electron spin resonance and correlated with a loss of ethanol tolerance. In the ethanol-tolerant E2 strain, which had been exposed to ethanol for many generations, dietary ethanol failed to promote a loss of long-chain fatty acids in membrane lipids.
Department of Biology, Knox College, Gatesburg, Illinois 61401-4999.
R R
RR
Miller
A O
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Dare
M L
ML
Moore
R G
RG
Kooser
B W
BW
Geer
D000426:Alcohol Dehydrogenase / Q000378:metabolism; D000818:Animals; D004032:Diet; D004331:Drosophila melanogaster; D004361:Drug Tolerance; D004578:Electron Spin Resonance Spectroscopy; D000431:Ethanol / Q000494:pharmacology*; D005227:Fatty Acids / Q000378:metabolism*; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D007814:Larva; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D013045:Species Specificity; D013229:Stearic Acids / Q000494:pharmacology
D005227:Fatty Acids; D008563:Membrane Lipids; D013229:Stearic Acids; D000431:Ethanol; D000426:Alcohol Dehydrogenase