Scientists have revealed that it is possible for frogs to regrow their legs if stimulated by a cocktail of drugs.
On Wednesday, January 26, researchers from Harvard University's Wyss Institute and Tufts University announced that African clawed frogs, also known as Xenopus laevis, can regrow an amputated leg when triggered by a mix of five different drugs.
The development has since been deemed a 'step closer to the goal of regenerative medicine'.
The 100 test frogs were placed in a small silicone dome for the experiment, where the scientists applied the concoction of drugs to their amputated stumps, CNN reports.
Despite it taking the limb 18 months to grow back and become fully functional, the mixture of drugs was only applied to the frogs for the first 24 hours of the experiment.
After 18 months, the animals were left able to respond to touch, swim, and even live fully in water once again.
However, the webbing in between the frogs' toes did not regrow.
An associate professor in the biological department at Northeastern University, James Monaghan, called the latest developments of the research 'impressive' and 'exciting'.
He said, 'Xenopus frogs are somewhere in between a salamander that regrows a limb nearly perfectly and a mammal that generates a scar after amputation. Adult Xenopus frogs regenerate a spike after amputation, but the spike lacks any pattern like a limb.'
The professor concluded by noting how 'significant' the study was because of it showing 'that patterning, albeit not perfect, can be induced in a limb that typically regenerates only a spike'.
The latest discovery also poses exciting possibilities for regeneration of limbs in other organisms with dormant regenerative capabilities that can be stimulated by drugs.
However, Monaghan noted that an 'immediate translation of this strategy into human is unlikely because a regenerative spike does not occur in humans as it does in Xenopus frogs. Yet, this work is exciting because it shows that endogenous regenerative processes can be enhanced by a short application of a drug cocktail'.
Instead of trying to 'micromanage its growth', scientists instead used drugs to stimulate mechanisms which were already dormant in the frogs, according to author of the study Mike Levin.
Levin, who is a professor of Biology at Vannevar Bush and director of the Allen Discovery Center at Tufts, explained that he feels the 'way to really achieve regenerative medicine is to exploit the collective intelligence of the body's cells'.
'They already know how to build all of these organs. They did it during embryonic development. All that information is still there,' he noted.
Levin stated that while the frogs were 'not perfect in every case', the goal for him is to be able to 'identify triggers, very simple kinds of stimuli, that will kick-start the cells and convince them to build whatever it is that you want them to build'.
The research marks the first-ever mixture of drugs to have been tested on frogs.
Further experimentation is needed to ascertain the best concoction of drugs to use, and the growth factor, with Levin noting how the frogs didn't quite yet have the 'correct terminal structure' because of the lack of 'long toes' or 'webbing'.
The next step of the experiment is to test the findings on other mammals, such as mice.
Ashely Seifert, associate professor of biology at the University of Kentucky, who studies animal regeneration, explained that while it was probable that one day it will be possible to 'regenerate a human digit or even a limb' that 'how long we need to wait is impossible to predict'.
She concluded, 'One step in that direction will be when regenerative biology fully embraces new regenerative models, particularly certain species of mammals. This and comparative studies will help us understand how and why regeneration fails in some contexts and succeeds in others.'
The research is published in Science Advances.
If you have a story you want to tell, send it to UNILAD via [email protected]
Featured Image Credit: AlamyTopics: Animals
Poppy Bilderbeck