Amazing stuff! This tortoise also survived European discoverers, explorers and seafarers stopping by at Saint Helena since 1502 AD.
"Current theory suggests that Aldabra tortoises dispersed “out of Africa,” first from the eastern African coast to Madagascar, then to Granitic Seychelles, and lastly to the Aldabra atoll, a UNESCO World Heritage Site now harboring around 100,000 tortoises ..."
"On an island in the South Atlantic Ocean, the world’s oldest known land animal spends his days munching on fresh fruit and veggies, sunbathing, napping, and getting frisky with the other members of his bisexual throuple.
At the ripe age of 194 years old, with an estimated hatching date of 1832, an Aldabra giant tortoise named Jonathan ... Old age has not come without challenges, however. Today, Jonathan is blind from cataracts and has lost his sense of smell. But the years do not appear to have diminished his libido: He still regularly mates with Emma and Frederik, two other, much younger, giant tortoises that reside with him on the island of Saint Helena.
What on Earth is Jonathan’s secret?
To find out, scientists decided to take a look at the old tortoise’s genome, as well as his epigenome—the collection of chemical changes on DNA that act like “on/off” switches for genes. ..."
From the abstract:
"Aldabra giant tortoises (Aldabrachelys gigantea) are exceptionally long-lived. We sequenced the genome and methylome of Jonathan, a 194-year-old Aldabra, to explore the molecular basis of his longevity.
Relative to other giant tortoises (A. gigantea and Chelonoidis abingdonii), Jonathan has unique gene variants in most aging pathways.
Moreover, Jonathan has substantial DNA methylation and methylation entropy changes compared to four other Aldabras ranging in age from a 5-year-old juvenile to older adults.
Notably, we found that lower-entropy regions in Jonathan’s methylome were enriched for the promoters of genes involved in the mitochondrial electron transport chain, and RNA metabolism. This suggests that high-fidelity transcription of the genes in these pathways may be crucial for long-lived species.
Our findings support a model for aging wherein the maintenance of low methylation entropy in gene promoters is coupled to efficient mitochondrial energy production, efficient RNA processing, and efficient genomic repair."
Jonathan, the tortoise
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