title: Conserved and divergent elements in Torso RTK activation in Drosophila development.
abstract: The repeated use of signalling pathways is a common phenomenon but little is known about how they become co-opted in different contexts. Here we examined this issue by analysing the activation of Drosophila Torso receptor in embryogenesis and in pupariation. While its putative ligand differs in each case, we show that Torso-like, but not other proteins required for Torso activation in embryogenesis, is also required for Torso activation in pupariation. In addition, we demonstrate that distinct enhancers control torso-like expression in both scenarios. We conclude that repeated Torso activation is linked to a duplication and differential expression of a ligand-encoding gene, the acquisition of distinct enhancers in the torso-like promoter and the recruitment of proteins independently required for embryogenesis. A combination of these mechanisms is likely to allow the repeated activation of a single receptor in different contexts.
authors.affiliation: Institut de Biologia Molecular-CSIC and Institut de Recerca Biomèdica de Barcelona, C/Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain.
authors.forename: Marco
authors.initials: M
authors.lastname: Grillo
authors.forename: Marc
authors.initials: M
authors.lastname: Furriols
authors.forename: Cristina
authors.initials: C
authors.lastname: de Miguel
authors.forename: Xavier
authors.initials: X
authors.lastname: Franch-Marro
authors.forename: Jordi
authors.initials: J
authors.lastname: Casanova
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D004330:Drosophila / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D004789:Enzyme Activation; D005260:Female; D020440:Gene Duplication; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D017344:Genes, Insect; D007301:Insect Hormones / Q000235:genetics / Q000378:metabolism; D008024:Ligands; D009866:Oogenesis / Q000235:genetics / Q000502:physiology; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism*; D015398:Signal Transduction; D014231:Tribolium / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D007301:Insect Hormones; D008024:Ligands; C096356:trk protein, Drosophila; C085211:tsl protein, Drosophila; C009089:prothoracicotropic hormone; D020794:Receptor Protein-Tyrosine Kinases; C080148:tor protein, Drosophila