Salamanders don’t regrow limbs from scratch

Given a chance to regrow a limb, salamanders don’t change a thing.

Since the 18th century, scientists have puzzled over how salamanders regenerate amputated limbs and have looked for clues to regrow human limbs. Researchers thought they knew part of the answer: Cells at the wound site would lose their identities as they turned back their developmental clocks to become pluripotent stem cells — capable of developing into many cell types in the body — and then recreate the lost limb.

But a new study published July 2 in Nature and led by Elly Tanaka, a developmental biologist at the Center for Regenerative Therapies at the Dresden University of Technology in Germany, shows that cells left behind after amputation retain memories of their identities and proliferate to form the same type of tissue in the replacement limb.