Genetic regulation of amylase activity in Drosophila virilis.

I. Activity variation among laboratory strains

Abstract

Extensive variation of amylase activity in adults and 3rd instar larvae was found among D. virilis strains homozygous for both Amy^F allele and Amy^S allele. The activity in adult is not correlated with that in larva, suggesting that the amylase activity is differently regulated between the two stages, although the same amylase locus is expressed. Cross experiments between the strain with the highest activity and the strain with the lowest activity reveal that amylase activity in adult is an additive character and that amylase activity co-segregates with amylase genotype. Electrophoretic zymogram of the F₁ progeny and the mixture of the parents suggested that the genetic factors for amylase activity are probably not identical to the Amy and that they are likely to operate on the activity determination in a trans-active manner.