title: Cell packing influences planar cell polarity signaling.
abstract: Some epithelial cells display asymmetry along an axis orthogonal to the apical-basal axis, referred to as planar cell polarity (PCP). A Frizzled-mediated feedback loop coordinates PCP between neighboring cells, and the cadherin Fat transduces a global directional cue that orients PCP with respect to the tissue axes. The feedback loop can propagate polarity across clones of cells that lack the global directional signal, although this polarity propagation is error prone. Here, we show that, in the Drosophila wing, a combination of cell geometry and nonautonomous signaling at clone boundaries determines the correct or incorrect polarity propagation in clones that lack Fat mediated global directional information. Pattern elements, such as veins, and sporadic occurrences of irregular geometry are obstacles to polarity propagation. Hence, in the wild type, broad distribution of the global directional cue combines with a local feedback mechanism to overcome irregularities in cell packing geometry during PCP signaling.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305-5324, USA.
authors.forename: Dali
authors.initials: D
authors.lastname: Ma
authors.forename: Keith
authors.initials: K
authors.lastname: Amonlirdviman
authors.forename: Robin L
authors.initials: RL
authors.lastname: Raffard
authors.forename: Alessandro
authors.initials: A
authors.lastname: Abate
authors.forename: Claire J
authors.initials: CJ
authors.lastname: Tomlin
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Axelrod
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D016764:Cell Polarity; D048430:Cell Shape; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D000072261:Dishevelled Proteins; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000502:physiology; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology; D051157:Frizzled Receptors / Q000235:genetics / Q000378:metabolism*; D060588:LIM Domain Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008962:Models, Theoretical; D010641:Phenotype; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D014921:Wings, Animal / Q000166:cytology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015815:Cell Adhesion Molecules; D004268:DNA-Binding Proteins; D000072261:Dishevelled Proteins; D029721:Drosophila Proteins; D051157:Frizzled Receptors; D060588:LIM Domain Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; C111638:Vang protein, Drosophila; C472307:ft protein, Drosophila; C121600:pk protein, Drosophila