Role of the EGF receptor pathway in growth and patterning of the Drosophila wing through the regulation of vestigial

Growth and patterning of the Drosophila wing disc depends on the coordinate d expression of the key regulatory gene vestigial both in the Dorsal-Ventra l (D/V) boundary cells and in the wing pouch. We propose that a short-range signal originating from the core of the D/V boundary cells is responsible for activating EGFR in a zone of organizing cells on the edges of the D/V b oundary. Using loss-of-function mutations and ectopic expression studies, w e show that EGFR signaling is essential for vestigial transcription in thes e cells and for making them competent to undergo subsequent vestigial-media ted proliferation within the wing pouch.