Patterned Anchorage to the Apical Extracellular Matrix Defines Tissue Shape in the Developing Appendages of Drosophila.
Bottom Line: Here, we describe a genetic pathway that shapes appendages in Drosophila by defining the pattern of global tensile forces in the tissue.Altering Dp expression in the developing wing results in predictable changes in wing shape that can be simulated by a computational model that incorporates only tissue contraction and localized anchorage.Three other wing shape genes, narrow, tapered, and lanceolate, encode components of a pathway that modulates Dp distribution in the wing to refine the global force pattern and thus wing shape.
Affiliation: School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK; The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's Inn Fields, London WC2A 3PX, UK. Electronic address: email@example.com.Show MeSH
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Mentions: The molecular characterization of nw, ta, and ll, and the mutant phenotype they produce, suggest that they might be involved in defining the localization of Dp in the developing wing. Consistent with this idea, the shape defect associated with nw mutants arises during hinge contraction (Figures 6Aâ€“6D), as we have observed for the dp mutations (cf. Figures 3C and 3D). In addition, the expression of a Nw-GFP fusion driven by the nub-Gal4 driver precisely follows the pattern of Dp expression throughout wing development, despite the fact that fusion protein is expressed in all cells of the wing blade. In the wing disc, Nw is localized apically, in the pupal wing at 18Â hr APF, it is localized to the wing margin and subsequently it accumulates uniformly in a fibrous network over the entire epithelium (Figures 6Fâ€“6J). Moreover, Nw-GFP does not localize to the aECM in dp mutant wings, in which the aECM fails to form properly (FigureÂ S4). Finally, nw and dp interact genetically, with transheterozygotes producing wings that are either acutely tapered or retracted toward the hinge, similar to dp mutants (Figures 7Aâ€“7G). These results suggest that nw mutants affect wing shape by influencing the pattern of anchorage of the wing epithelium to the overlying cuticle.
Affiliation: School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK; The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's Inn Fields, London WC2A 3PX, UK. Electronic address: firstname.lastname@example.org.