Billy W. Geer

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Dietary sucrose and ethanol are potent modulators of sn-glycerol-3-phosphate dehydrogenase (GPDH) in the third instar larvae of Drosophila melanogaster. When added to modified Sang's medium C, 428 mM ethanol and 146 mM sucrose each increased the GPDH tissue activity more than 90% and GPDH cross-reacting material (CRM) more than 50% over the levels found in(More)
The tissue activities of the oxidative pentose shunt enzymes, glucose-6-phosphate dehydrogenase (E.C. and 6-phosphogluconate dehydrogenase (E.C., in the larvae of Drosophila melanogaster are not dependent on the amount of flux through the oxidative pentose shunt pathway. An oxidative pentose shunt deficiency effects about a 40% reduction(More)
When cultured on a defined diet, ethanol was an efficient substrate for lipid synthesis in wild-type Drosophila melanogaster larvae. At certain dietary levels both ethanol and sucrose could displace the other as a lipid substrate. In wild-type larvae more than 90% of the flux from ethanol to lipid was metabolized via the alcohol dehydrogenase (ADH) system.(More)
NADP-malic enzyme (NADP-ME) (E.C. is situated in the cytosol of Drosophila melanogaster. Both the tissue activity and CRM level of NADP-ME parallel changes in the dosage of a gene, Men +, located in region 87C2-3 to 87D1-2 of the third chromosome. The tissue activity of NADP-ME is very high in early third instar larvae, providing about 33% of the(More)
The genes encoding glycolytic enzymes inDrosophila form a group of functionally related genes that may be coordinately regulated and thus controlled by common factors. We have examined the effect of dietary carbohydrates and ethanol on expression of the genes encoding glycerol-3-phosphate dehydrogenase (GPDH), aldolase (ALD), and phosphoglycerate kinase(More)
When Drosophila melanogaster larvae were fed a defined fat-free, low sucrose medium, alcohol dehydrogenase (ADH) was increased to a higher activity with a moderate, nontoxic level of ethanol (2.5% vol/vol) within 5 h. Ethanol-stimulated increases in ADH activity and cross-reacting material in late third-instar larvae were paralleled by increases in the(More)
Both aldehyde dehydrogenase (ALDH, EC and the aldehyde dehydrogenase activity of alcohol dehydrogenase (ADH, EC were found to coexist in Drosophila melanogaster larvae. The enzymes, however, showed different inhibition patterns with respect to pyrazole, cyanamide and disulphiram. ALDH-1 and ALDH-2 isoenzymes were detected in larvae by(More)
In Drosophila melanogaster aldehyde oxidase occurs in at least two forms that can be separated electrophoretically. The mutant allele lao (low aldehyde oxidase activity) causes a deficiency of the major form of this enzyme. Immunoelectrophoretic analyses suggest that lao homozygotes produce aldehyde oxidase cross-reacting-material in nearly wild-type(More)