The hunt for a literal or figurative Fountain of Youth has been explored for ages, with longevity being one of the most coveted goals by humans in mythology and reality alike. While many investigations have yielded results, the secret to long life still evades scientists. Perhaps the focus should shift away from lab mice, and towards the weird and wonderful creatures of the sea.
Recently, a team led by Joao Pedro de Magalhaes at the University of Liverpool succeeded in sequencing the genome of the bowhead whale, a species capable of living for up to 200 years. With such large bodies and therefore a huge quantity of cells, these whales should be as affected by cellular mutation and disease as humans are. However, that is often not the case, sparking an investigation as to why. The first of the large whales to be sequenced, their findings established several genetic sequences in the bowheads that may reveal the reason for their long life. These genes contribute to the repair of DNA and the multiplication of cells. The next step would be to modify human genes according to these findings, and test the longevity of these new cells.
Another long-living marine creature is the Turritopsis dohrnii, also known as the immortal jellyfish. It does not react to age, trauma, or illness by dying like a normal mortal. Instead, it reverts back to its early, sexually immature stage, and essentially gets reborn. Because of this, the lifespan of this species is unknown, but it is likely to be biologically immortal. Shin Kubota, with Kyoto University’s Seto Marine Biological Laboratory, is currently the only scientist in the world conducting research on these tiny animals.
Jellyfish are simple creatures, thought to be a relic of ancient, more primitive life on Earth. However, they are genetically more similar to humans than many other creatures, such as the worm. For this reason, further study on the immortal jellyfish could possibly help to extend the human lifespan, or at least improve the quality of human life in the later years. Originally from the Caribbean, the Turritopsis dohrnii has since spread across the world’s oceans. Their numbers are likely increasing very rapidly because, apart from being victims of predation, they do not naturally die.
The creature has two main stages. The first is the polyp stage, in which it reproduces asexually by anchoring to the ocean floor and creating stolons, interconnected colonies of identical clones of itself. When matured, these polyps break off, grow tentacles, and enter the medusa (jellyfish) stage, which is a stage of sexual reproduction. An adult specimen can grow to be 4.5 mm in diameter. Tests have shown that they can revert back to the polyp stage from any level of maturity in the medusa stage, a feat that is quite possibly unique within the animal kingdom. When severely damaged or after a time of aging, the tentacles retract, and the body becomes of blob of cells that Benjamin Buttons into a polyp once more, generating a new colony of polyps. It must be noted that their cells are also re-purposed (transdifferentiated) and may take on different roles after the transformation. This process could potentially go on for thousands of years.
The quest for the extension of human life has led us down many paths. Perhaps the answer lies with the creatures of the deep. For many of us, however, the thought of living forever might be just as alarming as the thought of dying.
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