GENETIC INTERACTIONS AMONG VESTIGIAL, HAIRY, AND NOTCH SUGGEST A ROLEOF VESTIGIAL IN THE DIFFERENTIATION OF EPIDERMAL AND NEURAL CELLS OF THE WING AND HALTER OF DROSOPHILA-MELANOGASTER

In this paper we describe the results of genetic analysis of the vesti gial locus by studying its interactions with hairy and Notch loci in D rosophila melanogaster. Different vestigial alleles in homo- and heter ozygous combination with different hairy alleles show synergism in inc reasing both cell death and formation of ectopic bristles and produce ectopic veins. Interactions between Nand vg also show synergism in inc reasing cell death and formation of ectopic bristles. Only synergism i n cell death is seen between h and N. The interactions indicate that v g product plays a role in the differentiation of epidermal and neural cells of the wing disc by interacting with N and h products either dir ectly or indirectly. Mechanisms of molecular interactions among the th ree loci are discussed.