The genetic control of alcohol dehydrogenase and octanol dehydrogenase isozymes in Drosophila.

HE detection, by agar gel electrophoresis, of as many as ten alcohol dehydrogenase isozymes in Drosophila melanogaster (URSPRUNG and LEONE 1965) presents a problem in the interpretation of genetic and epigenetic control of synthesis and function of multiple forms of enzymes. The observation that the three slowest cathodalIy migrating isozymes show a more intensive formazan staining when primary octanol rather than ethanol is used as substrate suggested that these isozymes belong to a separate enzyme system. Support for this assumption comes from the finding that there are D. melanogaster stocks which are different with regard to electrophoretic mobility of those isozymes that stain with a wide spectrum of alcohols (ADH) , but are equal with regard to the mobility of the hexanol, heptanol, and octanol-specific enzyme (ODH) o r vice versa (COURTRIGHT 1966a). Strong support for the distinction between ADH and ODH comes from the map locations. The locus for ODH is on the third chromosome, in contrast to the locus for ADH which according to GRELL, JACOBSON and MURPHY (1965) maps on the second chromosome. Finally, the two isozyme systems, ADH and ODH, elute differentially from diethylaminoethyl cellulose (DEAE-cellulose) columns.