Jennifer Ouellette in WIRED:
IN 1961, OSAMU SHIMOMURA AND Frank Johnson isolated a protein from jellyfish that glow green under UV light. Corals, too, can fluoresce in a wide range of hues, thanks to similar proteins. Now scientists at Harvard University have genetically modified the three-banded panther worm to enable the creature to emit a similar green glow, according to a new paper published in the journal Developmental Cell. Their hope is to uncover the secrets to regeneration.
Most animals exhibit some form of regeneration: regrowing hair, for instance, or knitting a fractured bone back together. But some creatures are capable of particularly amazing regenerative feats, and studying the mechanisms by which they accomplish these could have important implications for human aging. If a salamander loses a leg, the limb will grow back, for example, while some geckos can detach their tails as a distraction to evade predators and then regrow them later. The zebra fish can regrow a lost or damaged fin, as well as repairing a damaged heart, retina, pancreas, brain, or spinal cord. Cut a planarian flatworm, a jellyfish, or a sea anemone in half, and it will regenerate its entire body.
And then there is the three-banded panther worm (Hofstenia miamia), a tiny creature that looks a bit like a plump grain of rice, so named because of its trademark trio of cream-colored stripes across its body. If a panther worm is cut into three parts, each part will generate into a fully formed worm within eight weeks or so.