A screen identifying genes responsive to Dpp and Wg signaling in the Drosophila developing wing.

Morphogens control developmental decisions by regulating the expression of different sets of target genes in specific regions. The products of these genes drive the region specific developmental program and lead to the formation of different adult structures. Therefore, identification of the morphogens downstream target effectors is an essential step in deciphering the mechanisms underlying organ development. In the Drosophila developing wing, signaling by the morphogens Decapentaplegic (Dpp) and Wingless (Wg) plays global roles in controlling differentiation, growth, and survival. However, only a handful of their downstream target genes have been identified. Here, we describe a screening method designed to quickly search through large collections of P-Gal4 enhancer-traps for candidate genes that are transcriptionally regulated by Dpp or Wg signaling. Using this screening method, we screened a small collection of lethal P-Gal4 insertion lines that are expressed in the wing disc. We identified 10 novel putative Dpp and/or Wg target genes in the developing wing. Further study of the roles of the genes recognized in this screen should shed light on how morphogens control various processes in organ development.