Study finds youthful cellular patterns in 194-year-old tortoise

Jonathan, the world’s oldest known land animal at 194, has cellular patterns associated with younger giant tortoises, a new study has found. The findings, reported by ERR, suggest that protecting mitochondrial function may help explain the tortoise’s longevity.

An international research team mapped Jonathan’s genome and studied how its activity is regulated. The scientists analysed samples from the tortoise’s oral lining and compared his DNA with that of younger and other elderly giant tortoises. Jonathan lives on the South Atlantic island of Saint Helena.

Although chemical markers that regulate gene activity broadly resembled those in other old tortoises, regions controlling mitochondrial function were more like those found in younger animals. Jonathan’s genome also contained distinctive variants in genes involved in DNA repair, metabolism and defence against cancer cells.

The researchers said Jonathan appears to maintain more orderly patterns in gene regions linked to cellular energy production and RNA processing. As animals age, changes in DNA methylation can make the process of reading genetic information less precise. The team suggested that efficient energy production may give cells the resources to repair DNA errors, while repaired DNA helps keep energy production stable.

Jonathan has cataracts that have affected his vision and has lost his sense of smell, but he remains active. He was recently found mating with Emma, another tortoise in his enclosure. The study was published in the journal Science Advances.