Many jellyfish follow an predictable lifecycle from birth through reproduction and death; however, one species, Mnemiopsis leidyi comb jelly, appears to defy this linear principle.
Mnemiopsis leidyi can reverse its lifecycle in captivity by returning to polyp stage from any point during medusa phase, effectively living forever. This trick allows it to navigate ocean crossings by riding ballast water from ships.
The Immortal Jellyfish
Scientists have recently discovered an incredible hydrozoan known as the immortal jellyfish which defies biology and can actually reverse its own growth and development, going through reverse puberty from adult medusa back into an infant polyp. This allows it to repeat its lifecycle indefinitely – effectively living forever!
While most animals age in one direction, certain species such as Turritopsis dohrnii (the immortal jellyfish) and Mnemiopsis leidyi (comb jellyfish) have discovered ways to break this trend. These include immortal jellyfish such as Turritopsis dohrnii (Turritopsis dohrnii).
Jellyfish are one of the world’s most widespread invertebrates, comprising over 750 known species. Renowned for their mesmerizing bell-like bells, sting-filled tentacles, and transparent gelatinous bodies, jellyfish are beloved aquatic inhabitants known for their mesmerising bell-like bells, sting-filled tentacles, and clear gelatinous bodies. Most jellyfish begin life as tiny planula larvae that settle onto sea floors or ship hulls where colonies of polyps form colonies before sexual maturity occurs and then finally buds into mobile jellyfish-like medusae which may drift throughout the ocean until eventually the medusae die off leaving behind another polyp which continues its cycle – leaving another polyp that can continue the cycle anew.
Researchers from Norway’s University of Bergen were shocked to find a baby polyp in an aquarium meant to house adult comb jellyfish; upon closer examination they realized it had reverted back into its baby polyp stage despite having reached adulthood. This unexpected discovery published in Proceedings of the National Academy of Sciences suggests that certain species can cheat death by changing its biological clock and defying aging by going backward.
To test their theory, scientists exposed comb jellyfish to several stressors – prolonged starvation and physical injury via “lobectomy”, or cutting of adult lobes). After testing six individuals under both types of stressors, they discovered that each could revert back into its baby polyp stage using either treatment option.
Researchers aim to understand the cellular mechanisms behind this extraordinary phenomenon that has earned immortal jellyfish the title of “immortal”. Additionally, they would like to learn if similar processes can be applied to other jellyfish and species with an ultimate aim of increasing human lifespans.
Turritopsis dohrnii
Biology dictates that most organisms abide by a lifecycle consisting of birth, aging and death – yet some manage to defy this pattern. One such creature is Turritopsis dohrnii jellyfish; an immortal species capable of changing between its polyp and medusa stages through transdifferentiation; it’s like watching a butterfly transform back into its larval stage before changing back again into its butterfly form on an enormous scale!
Scientists have observed that this ability enables immortal jellyfish to avoid death and restart their lives when stressed, such as when starved or its temperature or salinity changes suddenly; when injured; or starving. When stressed, these animals drop to the ocean floor where their cells transform into cysts before eventually growing back into medusas or polyps and starting the cycle all over again.
Miglietta emphasizes that jellyfish with this unique ability make an excellent model for studying systemic senescence and regeneration, since their cysts serve not only as models of medusae stages but also the genetic processes involved in transitions between the medusa stage and polyp stage. Early data indicate that immortal jellyfish revert back into polyp form by expressing genes from sirtuin family linked with healthy longevity in humans as well as having active heat shock proteins known to counteract telomere shortening.
Turritopsis dohrnii’s ability to change back to its polyp stage when under stress is both fascinating and expected. Other species, including close relatives of Turritopsis dohrnii such as Mnemiopsis leidyi comb jelly species have shown that when stressed they can switch from their mature “lobate” state back into an earlier larval form reverting back into early larval stages revert back into this early state revert back into polyp formation reverting back from mature “lobate” state back into early larval stage!
Future learning from these two organisms on how to reverse aging could provide invaluable lessons. There have already been encouraging signs; immortal jellyfish have genes which may prevent telomere degradation while both organisms express numerous genes associated with anti-ageing properties of stress.
Mnemiopsis leidyi
Mnemiopsis leidyi, commonly known as the sea walnut, has proven to have devastating impacts on ecosystems it invades. Competing with native fish species for food sources and potentially leading to local ecosystem collapse. First observed in the Black Sea during the 1980s and now found throughout western Eurasia via ship ballast water transport, Mnemiopsis leidyi can now be found across much of western Eurasia.
Joan Soto-Angel of Norway’s University of Bergen and Pawel Burkhardt have discovered that Mnemiopsis leidyi is unique among aquatic organisms in that it can revert back to an earlier stage in its lifecycle after reaching adult status, providing flexibility not often seen within animal species. Under stressful conditions, this may prove especially helpful.
Researchers observed that Mnemiopsis leidyi could easily transform back to its larval form with two tentacles used to capture food. Mnemiopsis leidyi exposed to high levels of stress such as starvation developed more quickly into its larval state than non-stressed jellies.
Six Mnemiopsis leidyi injected with DiI dissolved in soybean oil underwent full reverse development within 15 days, while uninjected jellies took seven weeks. DiI injection stimulated their reverse development by increasing levels of the protein known as cyclin B which promotes cell division and growth.
Scientists believe Mnemiopsis leidyi’s ability to reverse its aging may be related to its production of cyclin B, an enzyme responsible for cell division regulation. By understanding what triggers its reverse cellular process, scientists hope they may be able to replicate this process in other marine organisms to increase survival rates and ensure continued aquatic ecosystem health.
This research expands our understanding of developmental flexibility in ctenophores and establishes Mnemiopsis leidyi as an invaluable model system to study its molecular mechanisms that regulate growth. It would be fascinating to witness if other organisms such as humans could replicate similar forms of development.
How it works
Researchers have solved the riddle behind an astonishing jellyfish species known as Mnemiopsis leidyi, which defies nature’s usual aging process by turning back time after sexual maturity. After sexual maturation, Mnemiopsis leidyi can skip its larval stage altogether and start life all over again as a polyp, similar to how butterflies often transition back from caterpillar to butterfly form after mating. This remarkable feat earned Mnemiopsis leidyi the moniker “Benjamin Button jelly,” yet researchers weren’t sure how this remarkable feat could work until now.
Other jellyfish species can morph back into polyp form once or twice after sexual reproduction, while T. dohrnii appears to do this time after time after sexual reproduction. To understand what sets T. dohrnii apart, scientists conducted comparisons between it and another similar jellyfish that normally ages; researchers discovered that immortal species has double the number of genes involved with DNA repair and protection, according to New Scientist; these may help the animal thwart death by switching into its polyp form again after death occurs.
Polyp stages, which reach full maturity when they reach smaller than your pinky nail when fully grown, can develop into adult medusae or umbrella-shaped jellyfish that swim around and mate to produce more eggs. But if one is injured or stressed during adulthood, its polyp stage could revert back into its butterfly form without going through another metamorphosis into caterpillar stage first – like butterflies can go back into butterfly mode without going through another transformation stage like caterpillar to butterfly transformation.
A polyp may revert back into an adult jellyfish as often as desired, though there may be risks involved in doing so. For instance, too long as an adult could expose itself to predators and diseases; fortunately the immortal jellyfish has other survival strategies at its disposal as well – sucking water from surrounding seas for replenishing nutrition or accepting an attack from another jellyfish to restore vitality and vitality.
Scientists hope that with their new knowledge, scientists could one day develop drugs to mimic the immortal jellyfish’s incredible regeneration capabilities; but for now, their team of researchers are focused on understanding more about how this incredible species reverses aging so as to better promote human health.
