Hedgehog Signal Transduction in the Posterior Compartment of the Drosophila Wing Imaginal Disc

• Published in: Molecular cell 2000-08, Vol.6 (2), p.479-485
• Main Authors: Ramírez-Weber, F.-A., Casso, D.J., Aza-Blanc, P., Tabata, T., Kornberg, T.B.
• Format: Article
• Language: English
• Subjects: Animals; Drosophila; Drosophila melanogaster - genetics; Drosophila melanogaster - physiology; Drosophila Proteins; Fused protein; Gene Expression Regulation; Hedgehog protein; Hedgehog Proteins; Insect Proteins - genetics; Insect Proteins - physiology; Patched protein; Protein-Serine-Threonine Kinases - physiology; Sequence Deletion; Signal Transduction - physiology; Transcription, Genetic; Wings, Animal - cytology; Wings, Animal - growth & development
• ISSN: 1097-2765; 1097-4164
• DOI: 10.1016/S1097-2765(00)00046-0

Drosophila Hedgehog (Hh) is secreted by Posterior (P) compartment cells and induces Anterior (A) cells to create a developmental organizer at the AP compartment border. Hh signaling converts Fused (Fu) to a hyperphosphorylated form, Fu*. We show that A border cells of wing imaginal discs contain Fu*. Unexpectedly, P cells also produce Fu*, in a Hh-dependent and Ptc-independent manner. Increasing Ptc, the putative Hh receptor expressed specifically by A cells, reduced Fu*. These results are consistent with proposals that Ptc downregulates Hh signaling and suggest that a receptor other than Ptc mediates Hh signaling in P cells of imaginal discs. We conclude that Hh signals in these P cells and that the outputs of the pathway are blocked by transcriptional repression.