You're only young... twice? Comb jellyfish are now reverse aging
Comb jellyfish continue to fascinate scientists having now shown the "unprecedented ability" to reverse age and revert from adult to larva "as if going back in time."
Benjamin Button, Professor Brian Cox, and now – it would appear – the comb jellyfish. There are few things on this planet blessed enough with the ability to reverse the aging process, so when a new example pops its baby-faced head into the corridors of science, you can bet your last dollar researchers are going to find out how.
The secret behind this much-envied process has now been revealed in a new article published in Proceedings of the National Academy of Sciences, which details the unprecedented ability for ‘reverse development’ in the ctenophore – otherwise known as the comb jelly.
What the findings reveal is quite astonishing, indicating that ‘life cycle plasticity’ in animals may just be more common than we previously thought.
Only a few species have been found to possess such a super power and deviate from the general – linear – principle of being born, growing, reproducing, and dying, the most famous example to date being the ‘immortal jellyfish’ Turritopsis dohrnii – a species with the ability to revert from an adult medusa to a polyp.
However, research led by the postdoctoral fellow at the Department of Natural History and University Museum of Bergen, Joan J. Soto-Angel, now adds the comb jelly Mnemiopsis leidyi to this exclusive group of age-defying organisms.
“We showed that mature lobate stages of M. leidyi are able to reverse to a cydippid larval stage after a period of stress,” explained Soto-Angel. “The fact we have found a new species that uses this peculiar “time-travel machine” raises fascinating questions about how spread this capacity is across the animal tree of life.”
Ctenophores have long-fascinated scientists with their regeneration capacities. Earlier this month, reports that two comb jellies could fuse to form one as a mechanism for surviving injury caught the world’s imagination when its discovery made global headlines. It would appear this was just the tip of the iceberg.
In other news
It was once their ability to reproduce sexually at the larval stage that baffled and fascinated scientists. With this latest revelation, comb jellies appear to be blurring the lines between adulthood and immature youth even further.
Previous experiments had concluded that the larva-to-adult transition was irreversible, but when Soto-Angel noticed that an adult ctenophore had vanished from a tank, seemingly replaced by a larva, he became curious to find out if they could be one and the same individual. Working alongside the Michael Sars Centre group leader, Pawel Burkhardt, he went about designing experiments to reproduce this potential reversion under controlled conditions.
“Witnessing how they slowly transition to a typical cydippid larva as if they were going back in time, was simply fascinating,” he said. “Over several weeks, they not only reshaped their morphological features, but also had a completely different feeding behaviour, typical of a cydippid larva.”
Now, before we all start reaching for whatever elixir of life the comb jellyfish seems to carry, the circumstances under which the ctenophore can perform its miracles are a little less than desirable. It was, fundamentally, when exposed to the stress of starvation and physical injury that the Mnemiopsis leidyi demonstrated its extraordinary ability to shift from adult lobate back to a cydippid larval stage – evident of yet another tool in the jellyfish toolbox for survival.
The findings do, however, position the comb jellyfish as a ‘valuable model’ for future research in developmental biology and aging. And, since comb jellies are among the earliest animal lineages, the findings suggest that reverse development may represent an ancient feature in the animal kingdom.
While it’s unlikely we’ll unlock the secrets to eternal youth anytime soon, Burkhardt admits this is a “very exciting time for us” opening the door to “many important discoveries” to come.
“It will be interesting to reveal the molecular mechanism driving reverse development, and what happens to the animal’s nerve net during this process,” he said.
Click here for more from the Oceanographic Newsroom.
Printed editions
Current issue
Back issues
Current Issue
Issue 39 Special Edition: OPY2024
Back Issues
Issue 37 Wild Alaska: River & Ocean
Enjoy so much more from Oceanographic Magazine by becoming a subscriber.
A range of subscription options are available.
