Jonathan the Tortoise's Genes Offer Clues to Longevity

Jonathan, a giant tortoise approaching his 195th birthday, may offer insights into human longevity. Researchers have analyzed his genome and found that certain biological processes within his cells appear remarkably youthful, despite his advanced age.

Born around 1832, before Queen Victoria's reign, Jonathan resides on the remote South Atlantic island of St Helena. Scientists sequenced his DNA from a cheek swab collected by his veterinarian, Dr. Joe Hollins. The findings, published in Science Advances, revealed genetic variants associated with DNA repair, metabolism regulation, and cancer protection.

One of the most significant discoveries pertained to Jonathan's mitochondria, the powerhouses of cells, whose declining function is typically linked to aging and age-related diseases. By examining chemical tags on his DNA, researchers found that the patterns related to mitochondrial function in Jonathan more closely resembled those of much younger tortoises than older ones. This suggests his mitochondria might be exceptionally stable, a key factor in longevity.

"His mitochondria must be especially stable and that's an insight into longevity in general. It's important that the mitochondria are kept as pristine as possible," stated Stephen Clark, a researcher at the Kallel Foundation, to The Guardian.

Further analysis identified differences in DNA repair mechanisms and telomere maintenance. DNA damage and telomere shortening are processes generally thought to contribute to aging. Jonathan also shares genetic similarities with other long-lived species, such as naked mole rats, known for their extended lifespan and resistance to cancer.

"We almost never get to study an animal this old while it is still alive," said Steve Horvath, a biologist studying aging at UCLA and an author of the study, to The New York Times.

Obtaining Jonathan's DNA was a delicate procedure. Dr. Hollins used a welding glove to manage the tortoise's head and prop open his beak for the swab, as blood samples were not permitted due to infection risk. A previous attempt yielded a sample mixed with half-chewed carrot, one of Jonathan's favorite foods. The saliva sample had to be transported off the island by boat.

Jonathan lives on the grounds of Plantation House, the official residence of St Helena's governor. While his exact birth date is unknown, he was already fully grown when he arrived on the island in 1882, suggesting he was at least 50 years old at the time. This estimation places his birth year around 1832.

Earlier this year, a fake account on X falsely announced Jonathan's death, reportedly to solicit cryptocurrency donations. The deception was exposed by his vet, and the governor of St Helena confirmed Jonathan was alive and well, found sleeping under a tree.

Despite developing cataracts and losing his sense of smell, Jonathan maintains excellent hearing and a strong libido. Since Dr. Hollins took over his care in 2009, Jonathan's health has improved, with regular hand-feeding helping him regain weight and develop a stronger beak.

Scientists acknowledge that Jonathan's protected environment, diet, and veterinary care likely contribute to his exceptional age. However, his unique biology presents promising avenues for further research into the mechanisms of aging. "Each of these long-lived species has some kind of special trick. And some of those may turn out to be relevant to human aging," noted Steve Austad, a biologist at the University of Alabama at Birmingham, to The New York Times.