Understanding hair follicle cycling: a systems approach

Continuous stem cell regeneration is essential for the repair and maintenance of many organs, rendering an understanding of the mechanisms underlying this phenomenon of prime importance. In this respect the hair follicle system provides an excellent test bed: mammalian skin contains thousands of hair follicles, each of which undergoes continuous regenerative cycling events that can be visualized via changing pigmentation patterns. Moreover, the system is inherently two-dimensional and reasonably easy to manipulate experimentally. Combined, the hair follicle system is an ideal candidate for an integrated theoretical and experimental approach that characterizes events occurring over multiple spatial and temporal scales. In this work we summarise recent developments in the field, and outline our hopes for future iterations of modelling and experiment.