NOTCH IS REQUIRED FOR WINGLESS SIGNALING IN THE EPIDERMIS OF DROSOPHILA

Mutations in the Notch (N) gene affect many processes during the devel opment of Drosophila. Some alleles of Notch affect only particular pro cesses, suggesting that the Notch protein (N) has more than one functi onal domain. We have found a series of N mutant phenotypes that are si milar to those produced by the loss of function of the segment polarit y gene wingless (wg) in the embryo and the adult. In addition, we obse rve that mutations in N behave as dominant enhancers of wg and that th ere exist allele-specific interactions between the two loci. Our resul ts suggest that the product of wg is a ligand for N.