In Aztec mythology, the god Xolotl was a symbol of many things: fire and lightning, but also dogs, diseases and more. A melange of a divinity, in essence – and the strange salamander that takes its name is, rightly, also an unusual hybrid. Axolotls (Ambystoma mexicanum), sometimes known as Mexican walking fish, are actually not fish at all, but amphibians, those with a surprising trait that borders on being a superpower. the ability to regenerate entire parts of the body if they disappear . Other salamanders may replace lost limbs, but axolotl’s talents for regrowth may be unique. It can regenerate the limbs, but also the tail, eyes, ovary, lung tissue and spinal cord. Even whole sections of his brain and heart will conveniently reappear if they disappear. “It regenerates almost everything after almost any injury that doesn’t kill it, says Yale University molecular biologist Grant Parker Flowers. In a new study, Flowers and other researchers investigated the genetic basis for this wonderful ability a mystery that has intrigued scientists for years, but which could potentially lead to radical treatments for injury and human disease, if only we could unravel how axolotl does its what.
It is not, however, an easy puzzle to solve. In part this is due to the immense genetic complexity of axolotl. Don’t be fooled by that cute face and any good natured cooperation it might suggest. In 2018, the axolotl genome was sequenced in its entirety for the first time, revealing an enormous chain of code. the largest of any animal ever sequenced, and about 10 times larger than the human genome. Despite the challenges presented, scientists opened a new path last year by identifying and mapping the structures within this giant genome. Just a few years ago, nobody thought it was possible to assemble a genome of over 30 GB, said one of the team members, computational biologist Jeramiah Smith of the University of Kentucky. Now, in Flowers and colleagues new work, researchers have identified the genes they claim are involved in the regeneration of axolotl tissues. Based on methods developed by the same team in 2017, in which researchers quantified the mutations generated by CRISPR / Cas9 in the limbs of engineered axolotls, the team developed markers to trace 25 genes suspected of being linked to limb regeneration.
In doing so, they identified two genes in the axaste blastema . the mass of cells involved in tissue regeneration which appear to contribute to the regrowth of the tail. Here, we provide a new screening platform that couples targeted mutagenesis and lineage tracking to identify new regeneration regulators, the authors write in their article. Using this approach, we discover that catalase and fetuin-b are necessary for cells to participate in limb regeneration and for proper tail regeneration. Sure, it’s still starting out in this type of research and the team recognizes that many other genes are likely involved in regeneration but nonetheless it’s a promising avenue for future research, which one day could allow humans to replicate some of the axolotl tricks. impressive. The sad irony of it all is that for an animal whose characteristic move is its ability to regenerate, the wild axolotl populations are on the verge of extinction in their native Mexican habitat, with an endangered status for the IUCN Red List, largely due to human causes. In addition to borrowing all the genetic secrets we can from this strange little creature, we hope that conservation efforts can give them something equally valuable in return.