Regeneration is a trick that many animals, including lizards, starfish and octopus, have mastered. The axolotls, a kind of salamander from Mexico, can push almost everything, cut limbs, in the eyes and parts of the brain with spinal cord. Mammals, however, have mainly lost this capacity somewhere along their scalable path. Regeneration has persisted, in a limited number of tissues, in some species of mammals such as rabbits or goats.
“We were trying to learn how some animals lost their capacity for regeneration during evolution, then to put the gene or the responsible path to reactivate the regeneration program,” explains Wei Wang, researcher at the National Institute of Biological Sciences in Beijing. The Wang team found one of these inactive regeneration genes, activated it and brought back a limited regeneration capacity to mice that had not previously had it.
Mouse and rabbits
The idea that Wang and his colleagues had was a comparative study of how the wound healing process works in regenerative and non -regenerative mammals. They chose rabbits like their regenerating mammals and mice as non -regenerative species. As a reference body, the team chose the pinna of the ear. “We wanted a relatively simple structure that was easy to observe and yet composed many types of different cells,” explains Wang. The test consisted in perceiving holes in the pina of the rabbits and mouse ear and following the process of repairing wounds.
The healing process started in the same way in rabbits and mice. During the first days that followed the injury, a blastem – a mass of heterogeneous cells – was formed on the wound site. “Rabbits and mice will heal the injuries after a few days,” said Wang. “But between the 10th and 15th day, you will see the main difference.” Within this delay, the ear hole in rabbits began to become smaller. There were growths above the blastem – animals produced more fabrics. In mice, on the other hand, the healing process has stopped completely, leaving a hole in the ear.
