title: Sequoia establishes tip-cell number in Drosophila trachea by regulating FGF levels.
abstract: Competition and determination of leading and trailing cells during collective cell migration is a widespread phenomenon in development, wound healing and tumour invasion. Here, we analyse this issue during in vivo ganglionic branch cell migration in the Drosophila tracheal system. We identify Sequoia (Seq) as a negative transcriptional regulator of Branchless (Bnl), a Drosophila FGF homologue, and observe that modulation of Bnl levels determines how many cells will lead this migrating cluster, regardless of Notch lateral inhibition. Our results show that becoming a tip cell does not prevent others in the branch taking the same position, suggesting that leader choice does not depend only on sensing relative amounts of FGF receptor activity.
authors.affiliation: Institut de Biologia Molecular de Barcelona, Parc Cientific de Barcelona, C Baldiri Reixac 10, 08028 Barcelona, Spain.
authors.forename: Sofia J
authors.initials: SJ
authors.lastname: Araújo
authors.forename: Jordi
authors.initials: J
authors.lastname: Casanova
mesh_terms: D000818:Animals; D002450:Cell Communication / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism*; D032487:Sequoia / Q000378:metabolism*; D015398:Signal Transduction; D014132:Trachea / Q000166:cytology* / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D017468:Receptors, Fibroblast Growth Factor