Meeting Abstract
Epithelial tissues usually provide support to organs and embryos, but during development, epithelial tissues can also exhibit a dynamic fluid-like behavior. During morphogenesis, epithelial tissues undergo both elastic and plastic shape changes. These shape changes are often accompanied by local cell rearrangement mechanisms such as intercalation, which are primarily orchestrated by genetic programs (e.g. drosophila). Here, we have discovered a novel fracture-based mechanism by which epithelial tissues can exhibit extreme plastic shape changes in a simple, early divergent animal – Trichoplax adhaerens. These animals continuously glide on substrates using ciliary traction to generate mechanical forces and induce internal strain in the tissue. The epithelium is surprisingly able to sustain local physiological fracture holes which can either enlarge or heal, resulting in plastic shape change and cell rearrangement. We employ novel bead-based tagging, live microscopy, and computational analysis to quantitatively demonstrate motility-induced tissue fractures in these animals. We also reveal how tissue dynamics plays a critical role in the life cycle of these animals during their asexual reproduction process.
