From super-resolution imaging to theory: cadherin clustering drives asymmetric glassy dynamics during vertebrate embryo elongation*

Convergent extension is a mode of collective cell movement driven by cell intercalation, underlying tissue elongation in nematodes, arthropods and vertebrates. Defective convergent extension is implicated in catastrophic neural tube birth defects. By combining theoretical modeling and analysis of super-resolution imaging of Xenopus laevis embryos, we show that intracellular C-cadherin (Cdh3) cis-clustering regulates the local vertex viscoelasticity at subcellular length scales. We uncover that spatially heterogenous cadherin clustering drives asymmetric vertex dynamics in convergent extension, exhibiting features of glassy dynamics observed in non-equilibrium materials such as colloidal glasses and gels. Even as defective clustering of C-cadherin can facilitate tissue coherence in vivo, we discover that clustering of C-cadherin is crucial in the more mechanically challenging context of convergent extension.