Galapagos giant tortoises are some of the longest-living animals on Earth, but how do they pull off the feat? A new study has examined the genome of the species and found that they pack plenty of duplicate genes, which may protect them from aging-related diseases like cancer.
Galapagos tortoises have a long association with biological science, ever since Charles Darwin noticed that tortoises on different islands had different physical characteristics, which influenced his theory of evolution. They routinely live for over a century, with some specimens thought to live up to around 175 years.
But exactly how they manage this is unclear. In most animals, cancer is the price to pay for a long lifespan, and larger animals should have the highest cancer rates, for the very simple reason that they have more cells that could potentially go rogue.
To investigate the tortoises’ secret, the researchers on the new study examined its genome.
The team found that compared to other tortoise and turtle species, the Galapagos giant tortoise had extra copies of several genes, specifically those linked to longevity and tumor suppression. The latter works by having damaged cells destroy themselves before they become cancerous – a process that slows down as an organism ages. Or at least, it slows down in organisms other than Galapagos tortoises.
“In the lab, we can stress the cells out in ways that are associated with aging and see how well they resist that distress,” says Vincent Lynch, lead author of the study. “And it turns out that the Galápagos tortoise cells are really, really good at killing themselves before that stress has a chance to cause diseases like cancer.”
Improving our understanding of the biological mechanisms of cancer and aging is a worthwhile endeavor just for science’s sake, but there is the potential that some of the secrets hiding in the tortoise genome could one day inform developments for human health too.
“If you can identify the way nature has done something — the way certain species have evolved protections — maybe you can find a way to translate those discoveries into something that benefits human health and disease,” says Lynch. “We’re not going to go treating humans with Galápagos tortoise genes, but maybe we can find a drug that mimics certain important functions.”
The research was published in the journal Genome Biology and Evolution.
Source: University at Buffalo