Some Salamanders Can Regrow Lost Body Parts. Could Humans One Day Do the Same?
by Amber Dance/Knowable Magazine/Smithsonianmag.com
As amphibians go, axolotls are pretty cute. These salamanders sport a Mona Lisa half-smile and red, frilly gills that make them look dressed up for a party. You might not want them at your soiree, though: They’re also cannibals. While rare now in the wild, axolotls used to hatch en masse, and it was a salamander-eat-salamander world. In such a harsh nursery, they evolved — or maybe kept — the ability to regrow severed limbs.
“Their regenerative powers are just incredible,” says Joshua Currie, a biologist at the Lunenfeld-Tanenbaum Research Institute in Toronto who’s been studying salamander regeneration since 2011. If an axolotl loses a limb, the appendage will grow back, at just the right size and orientation. Within weeks, the seam between old and new disappears completely.
And it’s not just legs: Axolotls can regenerate ovary and lung tissue, even parts of the brain and spinal cord.
The salamander’s exceptional comeback from injury has been known for more than a century, and scientists have unraveled some of its secrets. It seals the amputation site with a special type of skin called wound epithelium, then builds a bit of tissue called the blastema, from which sprouts the new body part…