Events in Physics
Ben Simons, Cavendish
Theory of epidermal maintenance: of mice and men
One of the main challenges in biology is to understand how stem cells and their progeny function to maintain adult tissue. Recent developments in genetic labelling provide access to a wealth of clone fate data at single cell resolution over time scales long enough to address reliably the kinetics of cell fate in mouse epidermis. Drawing on these results, we show that epidermal maintenance conforms to a remarkably simple dynamics involving a critical (Galton-Watson) birth-death process, overturning a paradigm long-held in the scientific literature. Motivated by these findings, we argue that the mouse model can be straightforwardly incorporated into a generalised theory which provides a role for a quiescent stem cell population, and identifies the mechanism of pattern formation seen in human epidermis as an arrested spinodal decomposition. We discuss the implications of these results on the general mechanism of tissue maintenance, repair, and tumour formation