Scientists at the University of Kentucky have brought human regeneration — a concept straight out of science fiction — one step closer to reality by assembling the genome of the axolotl, salamander which exclusively inhabits a lake near Mexico city. They also have remarkable regenerative abilities.
“It’s hard to find a body part they can’t regenerate: the limbs, the tail, the spinal cord, the eye, and in some species, the lens, even half of their brain has been shown to regenerate,” said Randal Voss, a professor in the UK Spinal Cord and Brain Injury Research Center and a co-PI on the project.
Humans actually share many of the same genes with the axolotl. However, their genome is 10 times larger, which poses a formidable barrier to genetic analyses.
A genome is like a puzzle. Until it is assembled in the correct order, scientists cannot attempt large scale analyses of genome structure and function for later application in humans. However, Voss along with his partner in the project Jeremiah Smith cleverly adapted a classical genetic approach called linkage mapping to put the axolotl genome together in the correct order. This is the first genome of this size to be assembled to date.
“Just a few years ago, no one thought it was possible to assemble a 30+GB genome,” said Smith. “We have now shown it is possible using a cost-effective and accessible method, which opens up the possibility of routinely sequencing other animals with large genomes.”
Voss and Smith also used the assembled data to rapidly identify a gene that causes a heart defect in an axolotl as proof of concept, thus providing a new model of human disease.
“Biomedical research is increasingly becoming a genetically-driven enterprise,” said Voss. “To understand human disease, you have to be able to study gene functions in other organisms like the axolotl.”
“Now that we have access to genomic information, we can really start to probe axolotl gene functions and learn how they are able to regenerate body parts. Hopefully someday we can translate this information to human therapy, with potential applications for spinal cord injury, stroke, joint-repair…the sky’s the limit, really.”