Mechanical heterogeneity along single cell-cell junctions is driven by lateral clustering of cadherins during vertebrate axis elongation

Morphogenesis is governed by the interplay of molecular signals and mechanical forces across multiple length scales.  The last decade has seen tremendous advances in our understanding of the dynamics of protein localization and turnover at sub-cellular length scales, and at the other end of the spectrum, of mechanics at tissue-level length scales.  Integrating the two remains a challenge, however, because we lack a detailed understanding of the subcellular patterns of mechanical properties of cells within tissues.  Here, in the context of the elongating body axis of Xenopus embryos, we combine tools from cell biology and physics to demonstrate that individual cell-cell junctions display finely-patterned local mechanical heterogeneity along their length. We show that such local mechanical patterning is essential for the cell movements of convergent extension and is imparted by locally patterned clustering of a classical cadherin.  Finally, the patterning of cadherins and thus local mechanics along cell-cell junctions are controlled by Planar Cell Polarity signaling, a key genetic module for CE that is mutated in diverse human birth defects.

Methods
This dataset contains raw time-lapse microscopy movies of cell-cell junctions in the Xenopus Laevis dorsal mesoderm. Data was collected using instant structured illumination microscopy (BioVision Technologies) with a 100x Plan Apo silicone emersion lens. Image acquisition parameters are described in the methods section of the associated manuscript. This dataset also contains processed versions of each time-lapse movie. Movies were processed as described in the methods section of the associated manuscript. The processed movies were used to measure cadherin3-GFP intensity at cell junctions and to measure junction movements over time. The regions of interest used to collect these measurements and the raw measurement values are also included in this dataset.