Establishment of Global Patterns of Planar Polarity during Growth of the Drosophila Wing Epithelium

• Published in: Current biology Vol. 22; no. 14; pp. 1296 - 1301
• Main Authors: Sagner, Andreas, Merkel, Matthias, Aigouy, Benoit, Gaebel, Julia, Brankatschk, Marko, Jülicher, Frank, Eaton, Suzanne
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 24-07-2012
• Subjects: Animals; Cell Polarity; cilia; Drosophila; Drosophila melanogaster - cytology; Drosophila melanogaster - embryology; Drosophila melanogaster - growth & development; Drosophila melanogaster - metabolism; Drosophila Proteins - metabolism; Embryo, Nonmammalian - cytology; Embryo, Nonmammalian - embryology; Embryo, Nonmammalian - metabolism; epithelium; Epithelium - embryology; Epithelium - growth & development; Epithelium - metabolism; Gene Expression Regulation, Developmental; Genes, Developmental; hairs; image analysis; Larva - cytology; Larva - growth & development; Larva - metabolism; larval development; Morphogenesis; proteins; Pupa - cytology; Pupa - growth & development; Pupa - metabolism; Wings, Animal - cytology; Wings, Animal - embryology; Wings, Animal - growth & development; Wings, Animal - metabolism
• ISSN: 0960-9822; 1879-0445
• DOI: 10.1016/j.cub.2012.04.066

Epithelial tissues develop planar polarity that is reflected in the global alignment of hairs and cilia with respect to the tissue axes. The planar cell polarity (PCP) proteins form asymmetric and polarized domains across epithelial junctions that are aligned locally between cells and orient these external structures [1–3]. Although feedback mechanisms can polarize PCP proteins intracellularly and locally align polarity between cells, how global PCP patterns are specified is not understood. It has been proposed that the graded distribution of a biasing factor could guide long-range PCP [4, 5]. However, we recently identified epithelial morphogenesis as a mechanism that can reorganize global PCP patterns; in the Drosophila pupal wing, oriented cell divisions and rearrangements reorient PCP from a margin-oriented pattern to one that points distally [6]. Here, we use quantitative image analysis to study how PCP patterns first emerge in the wing. PCP appears during larval growth and is spatially oriented through the activities of three organizer regions that control disc growth and patterning. Flattening morphogen gradients emanating from these regions does not reduce intracellular polarity but distorts growth and alters specific features of the PCP pattern. Thus, PCP may be guided by morphogenesis rather than morphogen gradients.
[Display omitted]
► A global PCP pattern emerges during growth of the third-instar wing disc ► Ft/Ds signaling orients PCP near the hinge ► The AP and DV boundary organizers orient subsets of the global PCP pattern ► Vector direction of PCP domains is not specified by ligand gradients