Nathan Rich of the New York Times has put together an article about the apparent "immortal" jellyfish, Turritopsis dohrnii, and how insights into its lifecycle could eventually lead to powerful rejuvenation therapies for humans. Not only is this article a must-read from the perspective of radical life extension, it's also a beautifully written pean to scientists and the impassioned dreams that often drive their research.
Intrigued by the work being done by marine biologist Shin Kubota, Rich decided to pay him a visit in Japan. Kubota, who grew up on science fiction, makes no bones about the ultimate purpose of his work: He wants to cure human aging — and to that end he's studying the inner workings of Turritopsis to find out how the species performs its remarkable trick.
"Turritopsis application for human beings is the most wonderful dream of mankind," he told Rich. "Once we determine how the jellyfish rejuvenates itself, we should achieve very great things. My opinion is that we will evolve and become immortal ourselves."
And indeed, Turritopsis is a good place to start. Like other jellyfish, it goes through two main stages of life, polyp and medusa. During the medusa phase, it produces eggs or sperm, which combine to create larvae that form new polyps. In most jellyfish species, the medusa dies after it spawns — but not the Turritopsis. Rich explains:
A Turritopsis medusa, however, sinks to the bottom of the ocean floor, where its body folds in on itself — assuming the jellyfish equivalent of the fetal position. The bell reabsorbs the tentacles, and then it degenerates further until it becomes a gelatinous blob. Over the course of several days, this blob forms an outer shell. Next it shoots out stolons, which resemble roots. The stolons lengthen and become a polyp. The new polyp produces new medusas, and the process begins again.
It's this endless cycle that gives scientists reason to believe Turritopsis is immortal — or infinitely capable of regenerating itself at the very least. And surprisingly, as Kevin J. Peterson told the NYT, "There's a shocking amount of genetic similarity between jellyfish and human beings."
Further insights into Turritopsis could have profound implications for medicine, particularly the fields of cancer and longevity. To that end, scientists are studying its microRNA, what are tiny strands of genetic material that regulate gene expression and serve a crucial role in stem cell function.
And as for Kubota, it's clear that Rich was in the presence of a special character — a scientist unmoved by criticism and driven by his vision of a higher goal. Rich recounts the time Kubota demonstrated the jellyfish's special skill:
"Watch," he said. "I will make this medusa rejuvenate."
The most reliable way to make the immortal jellyfish age in reverse, Kubota explained to me, is to mutilate it. With two fine metal picks, he began to perforate the medusa's mesoglea, the gelatinous tissue that composes the bell. After Kubota poked it six times, the medusa behaved like any stabbing victim - it lay on its side and began twitching spasmodically. Its tentacles stopped undulating, and its bell slightly puckered. But Kubota, in what appeared a misdirected act of sadism, didn't stop there. He stabbed it 50 times in all. The medusa had long since stopped moving. It lay limp, crippled, its mesoglea torn, the bell deflated. Kubota looked satisfied.
"You rejuvenate!" he yelled at the jellyfish. Then he started laughing.
We checked on the stab victim every day that week to watch its transformation. On the second day, the depleted, gelatinous mess had attached itself to the floor of the petri dish; its tentacles were bent in on themselves. "It's transdifferentiating," Kubota said. "Dynamic changes are occurring." By the fourth day the tentacles were gone, and the organism ceased to resemble a medusa entirely; it looked instead like an amoeba. Kubota called this a "meatball." By the end of the week, stolons had begun to shoot out of the meatball.
This method is, in a certain sense, cheating, as physical distress induces rejuvenation. But the process also occurs naturally when the medusa grows old or sick. In Kubota's most recent paper on Turritopsis, he documented the natural rejuvenation of a single colony in his lab between 2009 and 2011. The idea was to see how quickly the species would regenerate itself when left to its own devices. During the two-year period, the colony rebirthed itself 10 times, in intervals as brief as one month. In his paper's conclusion, published in the journal Biogeography, Kubota wrote, "Turritopsis will be kept forever by the present method and will...contribute to any study for everyone in the future."
Over the course of his investigation and interview, Rich was also treated to several songs written by Kubota in tribute to the jellyfish. In one song he sang:
My name is Shin Kubota
Associate professor of Kyoto University
At Shirahama, Wakayama Prefecture
I live next to an aquarium
Enjoying marine-biology research
Every day, I walk on the beach
Scooping up with a plankton net
Searching for wondrous creatures
Searching for unknown jellyfish.
Dedicate my life to small creatures
Patrolling the beaches every day
Hot spring sandals are always on
Necessary item to get in the sea
Scarlet medusa rejuvenates
Scarlet medusa is immortal
And it's not just Kubota who has become enamoured by this species; this simple jellyfish has taken on epic proportions in Japan on account of its preternatural powers.
Do yourself a favor and read the entire thing — this summary just scratches the surface.
Images: Takashi Murai/NYT.