The discovery of two species of Polypterus bichir fish found in Africa that can regenerate an amputated side (pectoral) fin with remarkable accuracy, in as little as a month, has the potential to provide insight into human limb regeneration.
Bichirs are ray-finned, which means their fins comprise skin-like webbing stretched between bony structures connected directly to the skeleton. They also share traits, such as paired lungs, with both modern amphibians and very early four-limbed vertebrates. The bichirs’ regeneration powers suggest that appendage regeneration was a common property of vertebrates during the fin-to-limb evolutionary transition, contend developmental biologist Luis Covarrubias, with the Department of Developmental Genetics and Molecular Physiology, Institute of Biotechnology, National Autonomous University of Mexico, Cuernavaca, Morelos, and his colleagues in a paper published online in the Proceedings of the National Academy of Sciences.
The researchers found that the fish can also regenerate their tails if lost, though this feature is not as noteworthy since the tail does not contain bones that are connected to the skeleton.
Because bichir fins grow considerable fleshy tissue as well as bones similar to the internal skeleton, their comeback fins may prove useful for comparing regeneration systems, Ken Poss, PhD, an associate professor, cell biology, at Duke University, Durham, North Carolina, told a Science News reporter. Discovering why some animals and fish can regenerate body parts while others cannot might lead scientists to discover a way to cause limb regeneration to happen when it’s needed, as in the case of amputation.