Adaptive significance of amylase polymorphism in Drosophila. Analysis of the association between tissue-specific expression and specific activity in Amy(S) or Amy(F) genotypes of Drosophila subobscura

Abstract

The phenotypic variability at the level of the specific activity of α- amylases and their tissue-specific expression in the midgut of adult Drosophila subobscura flies, homozygous for the Amy(S) or Amy(F) allele, was analysed. The results indicate a homogeneous distribution of the phenotypes with a different numbers of α-amylase activity regions in the adult midgut between the lines homozygous for Amy(S) and Amy(F) alleles. The mean number of α-amylase midgut activity differs significantly only between the groups of lines homozygous for Amy(S), with the specific activity Of the enzyme above the average, and the groups of Amy(F) homozygote with a significantly lower mean specific activity of amylase. The analysis suggests the existence of compensation between the number of active regions and the specific activity of α-amylase within Amy(S) and Amy(F) lines.