Image of the Day: Transgenic Axolotl

The regrown limb of an axolotl bears various cell types labeled by fluorescent proteins. Scale bar is 300 micrometers.

 IMP / W. MASSELINK

Axolotls (Ambystoma mexicanum) have the remarkable ability to regrow missing body parts. In a study reported in Science last week (September 27), investigators traced cells that form the regenerative tissue once a limb is amputated, finding that they de-differentiate themselves during the repair process to a multipotent state to become like a limb bud typical of embryonic development.