Tolerance to 1-pentene-3-ol and to 1-pentene-3-one in relation to alcohol dehydrogenase (ADH) and aldo keto reductase (AKR) activities inDrosophila melanogaster

Abstract

The detoxification of 1-pentene-3-ol (pentenol) and 1-pentene-3-one (pentenone) byDrosophila melanogaster adult flies has been studied in two homozygous lines for theAdh ^F andAdh ^S alleles (LRC lines), in their respective lines selected for tolerance to ethanol (LRSe lines) and in a homozygous strain for theAdh ⁿ⁴ null allele. For each line, the genotype and sex LDs₅₀ of both compounds were estimated. Then, in order to explain the differences in LD₅₀, both alcohol dehydrogenase (ADH) and aldo keto reductase (AKR) activities were assayed. In addition, the effects of pentenone on AKR activity were also studied. Our results show that ADH-positive flies exhibit a much higher sensitivity to pentenol than ADH-null flies. However, both ADH-positive and ADH-null flies show a similar tolerance to pentenone. Our results show that flies selected for improving tolerance to ethanol also have increased tolerance to pentenol (FF andSS flies) and pentenone (SS flies). However, this improved ability to tolerate pentenol and/or pentenone cannot be explained by changes in ADH or AKR activities. On the other hand, we have observed a beneficial effect of pentenol, but not of pentenone, in n⁴ flies. We also show that AKR activity is not modified by the administration of pentenone. These results suggest that, in the absence of ADH activity, pentenol may be transformed into a compound that is less toxic than pentenone and that pentenone itself might also be transformed into a less toxic compound.