Epithelial organ shape is generated by patterned actomyosin contractility and maintained by the extracellular matrix
Fig 1
Cross-section of wing imaginal disc along the anterior-posterior axis.
(A) Imaginal wings discs in 3rd instar ap>GFP larvae. (B) Top view of a wing disc at 96 hours after wing disc in B stained for actin (phalloidin), P-Myosin II, and β-Integrin. (C, D) Patterns of Actin, P-Myosin II, and β-Integrin in the cross-section that follows the major axis of the wing disc pouch. (E) Multiple cell types within the wing disc. The wing disc is composed of squamous peripodial cells (top, blue), columnar pouch cells (bottom center, red), and cuboidal marginal cells (sides, grey). An aqueous lumen is enclosed by the apical surface of the two cell layers. The basal surface is constrained by the extracellular matrix (ECM). (F) Structural components of the Drosophila wing disc columnar cells (left). Schematic showing for actomyosin contractility (right, top). An actin mesh provides structural support to the cell membrane. Actin filaments are pulled together by phosphorylated non-muscle Myosin II (P-Myosin II) resulting in increased membrane tension. Actomyosin driven tension opposes the internal pressure in cells and acts to constrict the membrane (right, bottom).