The mechanism that cells use to signal over long distances in developmental fields is important to understood. Our studies have focused on the wing imaginal disc where we identified the genetic network responsible for its principal signaling center. This network is controlled by the posterior compartment-specific engrailed gene, and it deploys hedgehog (hh) in the posterior compartment and cubitis interrptus (ci) and decapentaplegic (dpp) in the anterior compartment. Hh and Dpp proteins function as morphogens to regulate growth and development. Key findings are that post-translational processing of the Ci protein is a pivotal aspect of Hh signal transduction and that imaginal disc cells have extensions (cytonemes) that project to the signaling center and whose distribution is consistent with a role in transporting the key signals that direct the growth and patterning of the disc.

We also study the processes that lead to the development of the Drosophila equivalent of the lung. We found that growth of this organ is initiated by FGF and we are exploring the mechanisms that regulate subsequent growth and patterning of this organ.