It’s long been documented that humans share the vast majority of our genes with most of the animals on Earth. Despite this genetic overlap, many animals possess traits or abilities far beyond what our puny human bodies can do. One such trait found throughout the animal kingdom is the superpower-like ability to regrow lost limbs or tissue. This peculiar animal capacity has baffled scientists for thousands of years, but now new research might have shone light on the mechanism behind it.
According to a recent study published in PLOS ONE, genetic researchers have discovered a common genetic regulator in three very different animals: the zebrafish, the axolotl salamander, and the bichir fish from Africa. These three animals last had a common ancestor over 400 million years ago, implying that these genetic regulators have been selected for and maintained throughout evolutionary history.
To make this discovery, scientists examined any genetic changes that occurred during the regeneration process the three animals underwent. In each case, a particular microRNA marker was activated when a new set of cells called a blastema began to form. According to the research, this marker is believed to be one of the genetic triggers for regrowing lost tissue:
Although there are fundamental differences in tissue composition and complexity among zebrafish caudal fins, bichir pectoral fins and axolotl forelimbs, our study suggests that natural cellular reprogramming of differentiated cells during regeneration is guided by a core group of shared, differentially controlled miRNAs.
Dr. Voot P. Yin, one of the researchers in this study, believes this same genetic marker could one day be inserted into a human genome, allowing for possible limb regeneration in humans:
Limb regeneration in humans may sound like science fiction, but it's within the realm of possibility. The fact that we've identified a genetic signature for limb regeneration in three different species with three different types of appendages suggests that nature has created a common genetic instruction manual governing regeneration that may be shared by all forms of animal life, including humans.
Aside from potentially regrowing human limbs, this genetic marker might be able to speed up the human body’s healing mechanisms, or even allow for new prosthetic devices which can be incorporated directly into existing tissues and nerve networks. While perfect cyborg prosthetics sound cool and all, I’m holding out for that new third arm to keep my back nice and itch-free.