Complex Cellular Flows Shape Feather Follicle Topology

This study investigates the role of collective cellular flows and chemo-mechanical circuits in the development of chicken skin, specifically during feather bud formation. The research reveals that cell migration and adhesion lead to the formation of dermal condensates, which protrude through the epidermis to form feather buds. This process involves vertical cell flow that stretches and stiffens surrounding epidermal cells, causing invagination and the establishment of feather follicle bases. The study highlights how mechano-chemical morphogenetic events convert physical forces into transcriptional changes, transforming a 2D skin plane into 3D follicles. Functional experiments demonstrate that manipulating tissue mechanics can induce feather buds on stiff surfaces, providing insights into tissue patterning and phase transitions.