Speaker
Description
Cell collective motion underlies many biological processes such as embryogenesis, morphogenesis, and cancer invasion. Cells can organize into diverse patterns across various spatiotemporal scales through the interplay of self-propulsion and mutual coupling. Topological defects, where the orientational order is undefined, are reported to govern many biological functions. In particular, integer defects are found to coincide with the presence of heads and feet in regenerating Hydra. However, past studies have mainly focused on the impact of half defects on cell dynamics and to a lesser extent on integer defects. In this work, we experimentally address this question by seeding undifferentiated myoblasts on a vortex microstructure. It is found that myoblasts initially migrate along the defect structure due to contact guidance at confluency. With increasing time, cells spontaneously extrude near the defect center, which initiates inward radial flows toward the center across the monolayer, leading to layering behaviors. At the defect core, cells gradually form a 3D cellular mound composed of stacks of ordered cell layers with different orientations.
