Regenerating damaged or diseased tissue requires specific activation of a variety of specific precursors with a coordinated set of instructions. Lee et al. demonstrate that the regeneration of an amputated zebrafish fin causes Ras activation in a subset of precursor cells. Cells expand and migrate to form a new striped fin, similar to the original. Ras stimulates necessary melanocyte expansion and regeneration, and activated Ras leads to hyperpigmentation. Ras is a central regulator of pigmentation and pattern formation in the regenerating fin.
2010
