TY - JOUR T1 - Frizzled-dependent Planar Cell Polarity without Wnt Ligands JF - bioRxiv DO - 10.1101/2020.05.23.108977 SP - 2020.05.23.108977 AU - Joyce J.S. Yu AU - Aude Maugarny-Calès AU - Stéphane Pelletier AU - Cyrille Alexandre AU - Yohanns Bellaiche AU - Jean-Paul Vincent AU - Ian J. McGough Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/05/24/2020.05.23.108977.abstract N2 - Planar cell polarity (PCP) organizes the orientation of cellular protrusions and migratory activity within the tissue plane. PCP establishment involves the subcellular polarization of core PCP components. It has been suggested Wnt gradients could provide a global cue that coordinates local PCP with tissue axes. Here we dissect the role of Wnt ligands in the orientation of hairs of Drosophila wings, an established system for study of PCP. We found that PCP was normal in quintuple mutant wings that rely solely on membrane-tethered Wingless for Wnt signaling, suggesting that a Wnt gradient is not required. We then used a nanobody-based approach to trap Wntless in the endoplasmic reticulum, and hence prevent all Wnt secretion, specifically during the period of PCP establishment. PCP was still established. We conclude that, even though Wnt ligands could contribute to PCP, they are not essential, and another global cue must exist for tissue-wide polarization.Competing Interest StatementThe authors have declared no competing interest. ER -