Genetic Localization and Action of Regulatory Genes and Elements for Tissue-Specific Expression of alpha-Amylase in DROSOPHILA MELANOGASTER.

Regulation of tissue-specific alpha-amylase (Amy) expression in Drosophila melanogaster was investigated with a newly developed method that detects the distribution of alpha-amylase allozymes in midguts of single adults or third-instar larvae. Trans regulation was found for alpha-amylase production in the posterior midgut (PMG) of adults, whereas cis regulation was demonstrated for the larval midgut. Independent regulation of components of the duplicated Amy locus was found in larvae. Recombination between the components of the Amy locus did not result in separation of the putative, very closely linked (less than 0.1 cM) cis-acting regulatory elements for alpha-amylase expression in the anterior midgut (AMG) of larvae. The expression of one of the components of the duplicated Amy locus in the AMG of larvae was influenced by a regulatory gene that was mapped at 2-79.1. alpha-Amylase expression in the adult PMG was controlled by a trans-acting regulatory gene localized at 2-79.0, in agreement with the data of Abraham and Doane.