Genetic regulation of the Achaete-scute complex of Drosophila melanogaster

Abstract

Mutants in two loci, hairy (h+) and extramacrochaetae (emc+), produce phenotypes corresponding to an excess of function of the achaete-scute complex (AS-C), that is, they cause the appearance of extra chaetae. These mutants, although recessive in normal flies, become dominant in the presence of extra doses of AS-C. Here we study the interactions between these three genes, in an attempt to elucidate their relationships. The results show that the insufficiency produced by h or emc mutants can be titrated by altering the number of copies of AS-C. Moreover, excess of function of AS-C produced by derepression mutants within the complex (Hairy-wing) can also be titrated by altering the number of wild type copies of+ or emc+. These specific interactions indicate that both h+ and emc+ code for "repressors" of AS-C that interact with the achaete and scute region of the complex respectively. © 1984 Springer-Verlag.