Memory of fate and position, colorized.

Many of our ideas about cellular memory of fate and position come from regeneration studies in salamanders. A popular notion is that cells of the blastema transdifferentiate to different fates during limb regeneration. In a recent issue of Nature, Tanaka and colleagues challenge this notion. Using transplant experiments with GFP-expressing axolotl, they show vividly which cells of the blastema remember their fate and position of origin.