If you enjoy action movies, you can probably think of a superhero—maybe Wolverine?—who can lose a limb in battle, yet grow it right back and keep on going. But could regenerating a lost limb ever happen in real life? Some scientists are working hard to understand how other organisms do this.
As shown in this video of a regenerating fish fin, biology can sometimes be stranger than fiction. The zebrafish (Danio rerio), which is a species of tropical freshwater fish that’s an increasingly popular model organism for biological research, is among the few vertebrates that can regrow body parts after they’ve been badly damaged or even lost. Using time-lapse photography over a period of about 12 hours, NIH grantee Sandra Rieger, now at MDI Biological Laboratory, Bar Harbor, ME, used a fluorescent marker (green) to track a nerve fiber spreading through the skin of a zebrafish tail fin (gray). The nerve regeneration was occurring in tissue being spontaneously formed to replace a section of a young zebrafish’s tail fin that had been lopped off 3 days earlier.
Along with other tools, Rieger is using such imaging to explore how the processes of nerve regeneration and wound healing are coordinated. The researcher started out by using a laser to sever nerves in a zebrafish’s original tail fin, assuming that the nerves would regenerate—but they did not! So, she went back to the drawing board and discovered that if she also used the laser to damage some skin cells in the tail fin, the nerves regenerated. Rieger suspects the answer to the differing outcomes lies in the fact that the fish’s damaged skin cells release hydrogen peroxide, which may serve as a critical prompt for the regenerative process .
The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.