Variation in activity and thermostability of alcohol dehydrogenase in Drosophila melanogaster

Abstract

The activity and thermostability of alcohol dehydrogenase (ADH) from 247 strains of Drosophila melanogaster were studied by spectrophotometric assay. The strains, in which second chromosomes had been made homozygous in a standard genetic background, were derived from five natural populations from diverse geographical and ecological sites. Evidence is presented that the majority of variation in ADH activity is attributable to the presence, in all five populations, of two electromorphs of the enzyme. However, some variation does exist between strains carrying the same electromorph, to some extent associated with variation hi body weight. Two strains showed atypical ADH activities. Variation in ADH thermostability was almost wholly attributable to the presence of two electromorphs; only two strains had enzymes with thermostabilities atypical of their electromorph. In the four strains with abnormal ADH properties the locus (loci) responsible map in the region of the Adh locus. Therelatively low level of heterogeneity within electrophoretic classes at this locus is discussed in view of recent findings at other enzyme loci in Drosophila. © 1981, Cambridge University Press. All rights reserved.