Cell–cell contact landscapes in <i>Xenopus</i> gastrula tissues
Debanjan Barua, Martina Nagel, Rudolf Winklbauer
Abstract
Significance Distinct cell contacts like adherens junctions or desmosomes are well studied. Understanding the seemingly amorphous structures of cell–cell adhesion in many tissues still poses a challenge. Here, we explore the landscape of adhesive contacts in Xenopus gastrula tissues. Prompted by the continuous, nondiscrete variation of contact morphology, we use contact width spectra to analyze the roles of adhesion molecules. Currently, it is understood that cadherins are the main mediators of adhesion in these tissues. However, we find abundant contacts with intercellular distances far too wide for cadherin–cadherin binding. We show that alongside cadherins, glycocalyx-like structures and associated factors like heparan sulfate proteoglycans, fibronectin, and hyaluronic acid control contacts, and glycocalyx-mediated adhesion is essential for gastrula tissue architecture.