Cell junctions play central roles in regulating cell-cell interactions, tissue architecture and collective cellular behaviors during tissue and organ development and disease progression. As dynamic structures, junctions can be more or less stable and interact with different cytoskeletal networks and signaling pathways depending on their molecular composition and cellular context. While much research has focused on Adherens Junctions due to their critical roles in cell-cell adhesion and mechanotransduction, other types of junctional complexes, such as occluding junctions and desmosomes, have received less attention.

This Research Topic brings together a collection of review, methods, and research articles that offer new insights into the roles of different types of cell-cell contacts and cell adhesions, from occluding junctions and desmosomes to atypical cadherin adhesions and integrin-based contacts, during tissue remodeling. Importantly, this Research Topic includes studies covering diverse tissue contexts and cell types, ranging from cell migration and tissue patterning during development to the pathogenesis of genetic diseases. This diversity of research is made possible by taking advantage of established model organisms-including flies, frogs, and mice-and emerging systems, such as echinoderms. Below is a brief overview of the articles included in this Research Topic:

Two articles delve into the role of atypical cadherins in tissue polarity, patterning, and growth. Gridnev and Misra provide a review of the recent literature on the role the Dachsous-Fat signaling pathway in tissue planar cell polarity and growth and how these two facets of morphogenesis are coordinated. They discuss the key components of this pathway in Drosophila, namely, the atypical cadherins Dachsous and Fat, and their interplay with other signaling pathways, such as the Hippo pathway. Furthermore, this review summarizes the limited yet significant recent findings regarding Dachsous and Fat in mammalian systems. Regarding also atypical cadherins in mammals, Basta et al. investigate the role of two additional proteins, Celsr1 and Celsr2, in establishing planar cell polarity in the mammalian skin. Their study reveals that Celsr1 plays a more critical role than Celsr2 in the establishment of hair follicle polarization in the mouse epidermis. By comparing the phenotypes of single and double mutant mice for Celsr1 and Celsr2, the authors propose