The influence of cellular rosettes on epithelial tissue mechanics and the jamming transition.

Models for densely packed and confluent biological tissues often describe the network formed cells as a triple-junction network, similar to foams. However, higher order vertices or cellular Rosettes are prevalent in biology and is crucial in many important aspects of development, disease and physiology. In this work, we study the influence of cellular rosettes on the mechanics of a confluent tissue. We find that the existence of rosettes in a tissue can act to rigidify it. We characterize a new fluid-to-solid transition that is purely driven by the density of rosettes in a tissue. We propose a universal framework for the rigidity of a confluent tissue.