Hedgehog signal transduction in the posterior compartment of the Drosophila wing imaginal disc.
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.
Ramírez-Weber
F A
FA
Department of Biochemistry and Biophysics, University of California, San Francisco 94143, USA.
Casso
D J
DJ
Aza-Blanc
P
P
Tabata
T
T
Kornberg
T B
TB
D000818:Animals; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation; D053823:Hedgehog Proteins; D019476:Insect Proteins / Q000235:genetics / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D017384:Sequence Deletion; D015398:Signal Transduction / Q000502:physiology*; D014158:Transcription, Genetic; D014921:Wings, Animal / Q000166:cytology / Q000254:growth & development
D029721:Drosophila Proteins; D053823:Hedgehog Proteins; D019476:Insect Proteins; C077245:hh protein, Drosophila; C085770:fu protein, Drosophila; D017346:Protein Serine-Threonine Kinases