The genes that enable a fish to re-grow limbs have been found to be present in humans, new research has found. This insight could help develop regenerative treatments in humans.

Many species can regenerate limbs after amputation including fish, salamanders and geckos. This can be used as a mechanism to escape predators and heal from injury. Scientists suspect that this ability was held by the last common ancestor of fish and the four-legged vertebrates that eventually evolved into humans. However, the ability to regrow limbs was lost along the evolutionary tree by mammals whilst being conserved by fish.

The scientists studied both the genes and the regulatory mechanisms that were needed in garfish to regrow their fins. They focused on the endochondral bones within the fins, which are the equivalents to human arms and legs. They then studied the human genome to identify if the same genes were present. They found that all the genes required by the fish to regrow limbs were present in humans, but the genetic mechanisms to activate these genes were not.

However, research advances in CRISPR and epigenetics could enable these genes to be activated in humans. This would enable a new generation of regenerative treatments in humans and the eventual possibility of re-growing limbs in humans.