The remarkable ability to regenerate body parts is fairly common amongst invertebrates. If you chop up a flat worm (planarian) in several bits, they will each grow into a tiny worm (scientists have even been able to grow flat worms from single cells!). When spiders (and some insects) amputate their own limbs because of an injury or as a defence against predators, a new limb identical to the original one will grow back. But for vertebrates like us, it’s a whole different story.
|Lizards and geckos can regrow their tails, but the new tail |
isn't a perfect replica, and they can't regenerate limbs.
|Diagram showing the steps in limb regeneration (credit: Whited and Tabin, Journal of Biology 2009)|
|An ever so cute axolotl posing for the camera.|
Simon and colleagues used genetic tricks to label muscle cells with a fluorescent marker in two closely related salamander species (newts and axolotls) and then tracked them under the microscope at different time points during limb regeneration. They showed that in newt, all blastema cells that form muscle tissue come from dedifferentiated muscle cells, while in axolotl they originate exclusively from satellite cells.
A shorter version of this article was originally published in Lab Times on the 10-12-2013. You can read it here.