Researchers in the US have discovered that genes regulating cell energy production in a 194-year-old giant tortoise had fewer epigenetic signs of ageing than others, suggesting that protecting these processes may extend longevity.

One of the hallmarks of ageing is dysfunction of the cell organelles responsible for energy production – mitochondria – caused by alterations in chemical on-and-off signals that regulate mitochondrial processes. Studies have suggested an anti-ageing effect of rapamycin, a drug that increases mitochondria efficiency, but there is low incentive to conduct clinical trials using this drug because it no longer has patent protection.

Researchers at Vanderbilt Health and the Kallel Foundation, a nonprofit organisation focused on longevity research, in Tennessee, obtained a small tissue sample from the inside of the cheek of Jonathan, an Aldabra giant tortoise that hatched in about 1832 and was taken to St. Helena island in 1882. 

The researchers sequenced Jonathan’s epigenome, the group of chemical on-and-off signals that regulate gene expression without altering the DNA, and found that the regions of the DNA that had accumulated fewer alterations with ageing were in the activation regions of genes (promoters) associated with mitochondria and RNA metabolism.

“As a nonprofit, we want to do clinical trials that no drug company wants to do,” said Stephen Clark President and Chief Scientist of the Kallel Foundation and leader of the study published in Science Advances.

Future work will include studies into other long-lived species and using blood samples, which are necessary for more thorough sequencing.

Jonathan. CREDITS: St. Helena Government Communication Hub