ROLES OF THE NOTCH GENE IN DROSOPHILA WING MORPHOGENESIS

The Notch gene encodes a transmembrane protein that functions as a rec eptor of intercellular signals in many developmental processes of Dros ophila. We study here the Notch function in wing morphogenesis and vei n patterning in genetic mosaics of both Notch null and Notch gain-of-f unction alleles. Cell proliferation and differentiation properties of mutant Notch cells define three different Notch requirements in the wi ng: in imaginal disc cell proliferation, in restriction of vein differ entiation and in margin formation. The study of Notch mosaics in diffe rent mutant backgrounds reveals that Notch activity during epidermal c ell proliferation and wing vein differentiation is exerted by its regu lation of a common group of genes involved in the specification and re striction of vein competent regions.