20 Mar 2009
Cavendish Laboratory of Physics, Cambridge, and
Department of Systems Biology, HMS
Adult stem cells are endowed with the capacity to self-renew while generating differentiated progeny. In many adult tissues these processes are delicately balanced: one cell is added for every differentiated cell lost. How is such a balance achieved? I will argue that all mechanisms of stem cell regulation lead to only three universal cell fate patterns. These patterns are analogous to neutral drift of alleles in proliferating populations. Using this analogy, I will harness the past efforts of population geneticists to show that stem cell self-renewal must lead to one of several distinct "scaling behaviours" in the size distributions of cell families within the tissue. By identifying these scaling behaviours in experiment, I will show that several tissues undergo different processes of stochastic self-renewal.
current theory lunch schedule