Epithelial polarization by the core planar cell polarity complex is exclusively non-autonomous

For cells to polarize collectively along a tissue plane, asymmetrically localized planar cell polarity (PCP) complexes must form intercellular contacts between neighboring cells. Yet, it is unknown whether asymmetric segregation of PCP complexes requires cell-cell contact, or if cell- autonomous, antagonistic interactions are sufficient for polarization. To test this, we generated mouse chimeras consisting of dual PCP-reporter cells mixed with unlabeled cells that cannot form PCP bridges. In the absence of intercellular interactions, PCP proteins failed to polarize cell autonomously. Rather, PCP-mediated contacts along single cell-cell interfaces were sufficient to sort PCP components to opposite sides of the junction, independent of junction orientation. Thus, intercellular binding of PCP complexes is the critical step that initiates sorting of opposing PCP complexes to generate asymmetry., , , # Epithelial polarization by the core planar cell polarity complex is exclusively non-autonomous [https://doi.org/10.5061/dryad.bvq83bkkb](https://doi.org/10.5061/dryad.bvq83bkkb) ## Description of the data and file structure This dataset contains all data crucial to the key findings of this study, including original raw images of chimeric embryonic skin (ads5704_RawImages.zip), data analysis (*ads5704_Data.xlsx), and scripts (ads5704_MATLAB scripts.zip). Using embryo aggregation, we generated mouse chimeras to test the hypothesis of whether planar cell polarity (PCP) can arise cell autonomously in the absence of intercelullar PCP interactions. The raw data is uploaded in original format allowing for replication of presented analyses and further analysis or interpretation. ### Files and variables #### File: ads5704\_Data.xlsx **Description:** Excel file containing all quantification of analyses presented in the publication. Each tab in the excel sheet corresponds with a figure a...,