title: A global pattern of mechanical stress polarizes cell divisions and cell shape in the growing Drosophila wing disc.
abstract: Organismal development is under genetic control. Ultimately, mechanical forces shape embryos. If we want to understand the precise regulation of size and shape in animals, we must dissect how forces are distributed in developing tissues, and how they drive cell behavior to shape organs. This has not been addressed fully in the context of growing tissues. As cells grow and divide, they exert a pressure on their neighbors. How these local stresses add up or dissipate as the tissue grows is an unanswered question. We address this issue in the growing wing imaginal disc of Drosophila larvae, the precursor of the adult wing. We used a quantitative approach to analyze the strains and stresses of cells of the wing pouch, and found a global pattern of stress whereby cells in the periphery of the tissue are mechanically stretched and cells in the center are compressed. This pattern has important consequences on cell shape in the wing pouch: cells respond to it by polarizing their acto-myosin cortex, and aligning their divisions with the main axis of cell stretch, thereby polarizing tissue growth. Ectopic perturbations of tissue growth by the Hippo signaling pathway reorganize this pattern in a non-autonomous manner, suggesting a synergy between tissue mechanics and growth control during wing disc morphogenesis.
authors.affiliation: IBDML, UMR7288 CNRS-Université d'Aix-Marseille. Campus de Luminy, case 907, 13288 Marseille Cedex 09, France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Legoff
authors.forename: Hervé
authors.initials: H
authors.lastname: Rouault
authors.forename: Thomas
authors.initials: T
authors.lastname: Lecuit
mesh_terms: D000818:Animals; D002455:Cell Division / Q000235:genetics / Q000502:physiology*; D048430:Cell Shape / Q000235:genetics / Q000502:physiology*; D004330:Drosophila / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D013314:Stress, Mechanical; D014921:Wings, Animal / Q000166:cytology* / Q000196:embryology* / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins
keywords: Drosophila; Hippo signaling; Tissue growth; Tissue mechanics; Wing imaginal disc