Flicking the Switch
The ability to regenerate limbs sounds like a superpower (and it is), but it's also a pretty normal occurrence for lizards. If their tail is pulled off while outrunning a predator, they simply grow a new one. Until now, the science behind this has been a mystery.
And as it turns out, it may be as simple as flicking a switch. Well, kind of.
Researchers at the Translational Genomics Research Institute (TGen) and Arizona State University (ASU) have identified three tiny RNA switches, known as microRNAs, which may hold the keys to regenerating muscles, cartilage, and spinal columns. These switches are able to turn genes on and off, and are associated with the regeneration of tails in the green anole lizard.
"Since microRNAs are able to control a large number of genes at the same time, like an orchestra conductor leading the musicians, we hypothesized that they had to play a role in regeneration," said senior author Dr. Kenro Kusumi, a Professor in ASU's School of Life Sciences and Associate Dean in the College of Liberal Arts and Sciences, and an adjunct faculty member at TGen. "Our earlier work found that hundreds of genes are involved in regeneration, and we are very excited to study these three new microRNAs."
From Lizards to Humans
After nearly 6 years of research, the team of scientists hopes that their research will help lead to discoveries of new therapeutic approaches to switch on regeneration genes in humans.
Dr. Elizabeth Hutchins, a Post-Doctoral Fellow in TGen's Neurogenomics Division, and co-lead author of the study, said she hopes this investigation eventually enables such things as regenerating cartilage in knees, repairing spinal cords in accident victims, and reproducing the muscles of injured war veterans.
"This work highlights the importance of tiny RNA molecules in the tissue regeneration process, and showed for the first time an asymmetric microRNA distribution in different portions of the regenerating lizard tails," said Dr. Marco Mangone, a co-author and Assistant Professor with ASU's School of Life Sciences and Biodesign Institute. "It seems like microRNAs may play an active role in this process, and are potentially able to shape the regenerating lizard tail like playdough."
Of course, it should go out without saying that such advancements in humans will be a long way in coming; however, it is a remarkable new beginning.