Re-growing Limbs, Organs on Horizon


Amphibians have a unique trait: the ability to grow back limbs and even organs. When a salamander loses a limb, a blood clot appears in the damaged area. Then with surprising speed, newly formed skin cells cover the wound. Underneath this skin-capped area, a structure called a blastema containing a complex array of new cells forms. Then tissues begin to develop and the structures necessary to form the missing limb.

A juvenile salamander can reform the limb with muscle, bones, and nerves in an astonishing forty to fifty days. Terrestrial forms can take up to half a year, but it's still an amazing trait that no other animals have.

New research is giving us clues about how they do this. It's focused on how quickly cells at the injury make proteins which is the opposite in humans where cells reduce protein production to conserve energy.

Salamanders can also "store" a large amount of mRNA at four times the amount normally needed. mRNA is the template that directs the proteins being made. Having premade mRNA gives the cells at the injury a "rapid start" to make the proteins necessary for tissue repair and grow new limbs.

There's also a specific signal built into the mRNA sequence unique to salamanders that accelerates protein production. When scientists blocked this mechanism, these salamanders couldn't grow back their missing limbs.

If only we had this ability. How amazing would it be to grow back a missing limb or damaged organ!

You can now hear additional episodes on many of your favorite podcast providers - visit Buzzsprout to subscribe.

More Information

How an ultra-sensitive on-off switch helps axolotls regrow limbs
It's one of the mysteries of nature: How does the axolotl, a small salamander, boast a superhero-like ability to regrow nearly any part of its body? For years, scientists have studied the amazing regenerative properties of the axolotl to inform wound healing in humans...

Evolutionarily divergent mTOR remodels translatome for tissue regeneration
An outstanding mystery in biology is why some species, such as the axolotl, can regenerate tissues whereas mammals cannot1. Here, we demonstrate that rapid activation of protein synthesis is a unique feature of the injury response critical for limb regeneration in the axolotl (Ambystoma mexicanum)...