An anonymous reader quotes a report from Ars Technica: Nintendo's Satellaview, a Japan-only satellite add-on for the Super Famicom, is a rich target for preservationists because it was the home to some of the most ephemeral games ever released. That includes a host of content for Nintendo's own games, including F-Zero. That influential Super Nintendo (Super Famicom in Japan) racing title was the subject of eight weekly broadcasts sent to subscribing Japanese homes in 1996 and 1997, some with live "Soundlink" CD-quality music and voiceovers. When live game broadcasts were finished, the memory cartridges used to store game data would report themselves as empty, even though they technically were not. Keeping that same 1MB memory cartridge in the system when another broadcast started would overwrite that data, and there were no rebroadcasts.

As reported by Matthew Green at Press the Buttons (along with Did You Know Gaming's informative video), data from some untouched memory cartridges was found and used to re-create some of the content. Some courses, part of a multi-week "Grand Prix 2" event, have never been found, despite a $5,000 bounty offering and extensive effort. And yet, remarkably, the 10 courses in those later broadcasts were reverse-engineered, using a VHS recording, machine learning tools, and some manual pixel-by-pixel re-creation. The results are "north of 99.9% accurate," according to those who crafted it and exist now as a mod you can patch onto an existing F-Zero ROM. [...] Their work means that, 25 years later, a moment in gaming that was nearly lost to time and various corporate currents has been, if not entirely restored, brought as close as is humanly (and machine-ably) possible to what it once was.

Nvidia blog: Every country needs to own the production of their own intelligence, NVIDIA founder and CEO Jensen Huang told attendees Monday at the World Governments Summit in Dubai. Huang, who spoke as part of a fireside chat with the UAE's Minister of AI, His Excellency Omar Al Olama, described sovereign AI -- which emphasizes a country's ownership over its data and the intelligence it produces -- as an enormous opportunity for the world's leaders. "It codifies your culture, your society's intelligence, your common sense, your history -- you own your own data," Huang told Al Olama during their conversation, a highlight of an event attended by more than 4,000 delegates from 150 countries.

"We completely subscribe to that vision," Al Olama said. "That's why the UAE is moving aggressively on creating large language models and mobilizing compute." Huang's appearance in the UAE comes as the Gulf State is moving rapidly to transform itself from an energy powerhouse into a global information technology hub. Dubai is the latest stop for Huang in a global tour that has included meetings with leaders in Canada, France, India, Japan, Malaysia, Singapore and Vietnam over the past six months. The Middle East is poised to reap significant benefits from AI, with PwC projecting a $320 billion boost to the region's economy by 2030.

Taiwanese chipmaker TSMC announced plans to build a second chip factory in Japan by the end of 2027, bringing total investment in its Japan venture to more than $20 billion. "Taiwan Semiconductor Manufacturing Co announced plans in 2021 to build a $7 billion chip plant in Kumamoto in southern Japan's Kyushu," notes Reuters. From the report: In a statement, TSMC, the world's largest contract chipmaker, said its majority-owned unit Japan Advanced Semiconductor Manufacturing in Kumamoto would build a second fabrication plant, or fab, in response to rising customer demand. The second fab will begin construction by the end of this year and with both factories the site is expected to have total monthly capacity of more than 100,000 12-inch wafers to be used for automotive, industrial, consumer and high performance computing-related applications, TSMC said. The capacity plan may be further adjusted based upon customer demand, it added.

TSMC's expansion in Kyushu is central to the Japanese government's efforts to rebuild the country's position as a leading chip manufacturing centre and ensure the stable supply of chips amid trade tensions between the United States and China. The decision to build a second fab is a vote of confidence by TSMC in Japan where construction of the first fab has run smoothly and which, Reuters has reported, it sees as a source of diligent workers with a government that is easy to deal with.

"Japan's first moon mission has likely come to an end after a surprising late-game comeback," reports Mashable, "with the spacecraft taking one last photo of its surroundings before the deep-freeze of night... showing ominous shadows cast upon a slope of the Shioli crater, its landing site on the near side of the moon." Since Monday, the spacecraft has analyzed rocks around the crater with a multi-band spectral camera. JAXA picked the landing spot because of what it could tell scientists about the moon's formation... The special camera completed its planned observation, able to study more targets than originally expected, according to an English translation of a news release from the space agency... "Based on the large amount of data we have obtained, we are proceeding with (analyses) to identify rocks and estimate the chemical composition of minerals, which will help solve the mystery of the origin of the moon," JAXA said in a statement translated by Google...

The spacecraft has now entered a dormant state, prompted by nightfall on the moon. Because one rotation of the moon is about 27 Earth days, the so-called "lunar night," when the moon is no longer receiving sunlight, lasts about two weeks. Not much can survive the -270 degrees Fahrenheit brought on by darkness — not even robots. In this freezing temperature, soldered joints on hardware and mechanical parts break, and batteries die. But rest assured, the JAXA team will try to communicate with its scrappy moon lander when the sun rises again.
In mid-week Japan's space agency posted that "Although SLIM was not designed for the harsh lunar nights, we plan to try to operate again from mid-February, when the Sun will shine again on SLIM's solar cells."

Later they posted that they'd sent a command to turn on SLIM's communicator again "just in case, but with no response, we confirmed SLIM had entered a dormant state. This is the last scene of the Moon taken by SLIM before dusk."

Kyle Orland reports via Ars Technica: Even massive Sega fans would be forgiven for not being too familiar with the Sega AI Computer. After all, the usually obsessive documentation over at Sega Retro includes only the barest stub of an information page for the quixotic, education-focused 1986 hardware. Thankfully, the folks at the self-described "Sega 8-bit preservation and fanaticism" site SMS Power have been able to go a little deeper. The site's recently posted deep dive on the Sega AI Computer includes an incredible amount of well-documented information on this historical oddity, including ROMs for dozens of previously unpreserved pieces of software that can now be partially run on MAME. [...]

While the general existence of the Sega AI Computer has been known in certain circles for a while, detailed information about its workings and software was extremely hard to come by, especially in the English-speaking world. That began to change in 2014 when a rare Yahoo Auctions listing offered a boxed AI Computer along with 15 pieces of software. The site was able to crowdfund the winning bid on that auction (which reportedly ran the equivalent of $1,100) and later obtained a keyboard and more software from the winner of a 2022 auction. SMS Power notes that the majority of the software it has uncovered "had zero information about them on the Internet prior to us publishing them: no screenshots, no photos or scans of actual software." Now, the site's community has taken the trouble to preserve all those ROMs and create a new MAME driver that already allows for "partial emulation" of the system (which doesn't yet include a keyboard, tape drive, or speech emulation support).

That dumped software is all "educational and mostly aimed at kids," SMS Power notes, and is laden with Japanese text that will make it hard for many foreigners to even tinker with. That means this long-lost emulation release probably won't set the MAME world on fire as 2022's surprise dump of Marble Madness II did. Still, it's notable how much effort the community has put in to fill a formerly black hole in our understanding of this corner of Sega history. SMS Power's write-up of its findings is well worth a full look, as is the site's massive Google Drive, which is filled with documentation, screenshots, photos, contemporaneous articles and ads, and much more.

In an effort to boost tourism and innovation, Japan will launch a new visa program for digital nomads, allowing remote workers to work in the country for up to six months while enjoying sightseeing trips. Tech Times reports: Starting from the end of March, Japan will introduce a unique visa status aimed at IT engineers and remote workers employed by overseas companies. The program is designed to cater to the evolving work landscape, recognizing the surge in digital nomads-individuals who can seamlessly work from anywhere in the world. Nikkei Asia (paywalled) tells us that to be eligible for this digital nomad visa, applicants must boast an annual income of at least 10 million yen ($68,000).

Citizens from 50 countries and regions, including the U.S., Australia, and Singapore, which have existing visa waiver agreements with Japan, can apply. Private health insurance is a prerequisite, ensuring the well-being of the visa holders during their stay. Self-employed individuals engaged in overseas business can also benefit from this innovative program. Moreover, they have the option to bring their family members along, provided they are covered by private health insurance.

While the program offers the freedom to explore Japan, it has unique conditions. Digital nomads under this visa will not receive a residence card or certificate, limiting access to specific government benefits. The visa is non-renewable, requiring reapplication after a six-month interval, and applicants must spend that time outside the country. Japan joins the ranks of over 50 countries issuing digital nomad visas. Notably, South Korea allows up to two years, while Taiwan offers a three-year stay, with the possibility of permanent residency. The diverse offerings cater to digital nomads' varied needs and preferences, seeking a balance between work and exploration.

Shiftall, the Japan-based VR hardware creator, is no longer owned by Panasonic, as the company has been effectively sold off to the Tokyo-based company CREEK & RIVER. From a report: As first noted by tech analyst and YouTuber Brad Lynch, Panasonic today announced it has transferred all shares of Shiftall to the Tokyo-based company CREEK & RIVER Co., Ltd., which specializes in outsourcing, consulting, content management and distribution services. Acquired by Panasonic in 2018, Shiftall primarily focused on niche consumer devices, but shifted over the years to focusing on VR hardware, such as its MeganeX PC VR headset, HaritoraX wireless body trackers, FlipVR motion controllers, and mutalk soundproof microphones.

An anonymous reader quotes a report from The Guardian: The first lab-grown freshwater eel meat has been produced, potentially solving a diner's dilemma. Rampant overfishing has caused eel populations to plummet and prices to soar, but the cultivated eel could provide the delicacy guilt-free. The eel meat was produced by Forsea Foods in Israel from embryonic cells of a freshwater eel. The company collaborated with a Japanese chef to create unagi kabayaki, marinated grilled eel over rice, and unagi nigiri, a type of sushi.

The company aims to scale up its operation and have the cultivated eel on sale in about two years. Japan's prime minister, Fumio Kishida, last year backed the development of a cultivated meat industry. The restaurant price in Japan is about $250 a kilogram, and Forsea Foods expects the price of the cultivated eel to match that of the wild-caught eel. [...] Forsea Foods' strategy is to target species at risk of extinction in the wild that also command high prices in restaurants and shops, with eel meeting both criteria. The very complex life cycle of eels, involving long migrations from rivers to the ocean and several distinct life stages, means it is not possible to farm them like some fish.

The cultivated eel was produced using organoids, tiny bundles of tissue originally developed for use in medical research. The organoids are made of embryonic stem cells taken from fertilized eel eggs. These cells can develop into any kind of tissue and, as they grow, they self-organize into the structure of real meat. The final product also contains some plant-based ingredients. Other approaches to cultivated meat require greater use of expensive growth factor chemicals and scaffolds for cells to grow on [...]. The technique is particularly suited to fish and seafood, whose meat is fairly uniform unlike, for example, marbled beef, he said. Like other cultivated meat, the product is not produced using antibiotics or hormones. Forsea Foods is the only company known to be producing cultivated meat using this technology. The company has raised $5.2 million in investment, with more expected to be announced soon.

Japan is aiming to phase out floppy disks and CD-ROMs, which until now were forms of physical media required for submitting some official documents to the government. Engadget reports: Back in 2022, Minister of Digital Affairs Taro Kono urged various branches of the government to stop requiring businesses to submit information on outdated forms of physical media. The Ministry of Economy, Trade and Industry (METI) is one of the first to make the switch. "Under the current law, there are many provisions stipulating the use of specific recording media such as floppy disks regarding application and notification methods," METI said last week, according to The Register. After this calendar year, METI will no longer require businesses to submit data on floppy disks under 34 ordinances. The same goes for CD-ROMs when it comes to an unspecified number of procedures. There's still quite some way to go before businesses can stop using either format entirely, however.

Kono's staff identified some 1,900 protocols across several government departments that still require the likes of floppy disks, CD-ROMs and even MiniDiscs. The physical media requirements even applied to key industries such as utility suppliers, mining operations and aircraft and weapons manufacturers. There are a couple of main reasons why there's a push to stop using floppy disks, as SoraNews24 points out. One major factor is that floppy disks can be hard to come by. Sony, the last major manufacturer, stopped selling them in 2011. Another is that some data types just won't fit on a floppy disk. A single photo can easily be larger than the format's 1.4MB storage capacity.

Around three hours after its moon lander had touched down, Japan's space agency "decided to switch SLIM off with 12% power remaining to allow for a possible resumption when the sun's angle changed," reports Agence France-Presse.

Today there was good news: Japan's Moon lander has resumed operations, the country's space agency said on Monday, indicating that power had been restored after it was left upside down during a slightly haphazard landing. The probe, nicknamed the "moon sniper", had tumbled down a crater slope during its landing on 20 January, leaving its solar batteries facing in the wrong direction and unable to generate electricity...

The agency posted on X an image shot by Slim of "toy poodle", a rock observed near the lander.

"A photo of Japan's robotic moon lander shows that though the spacecraft did make the quarter-million-mile journey to the lunar surface, it landed upside down..." reports Mashable. Because of the lander's now-apparent inverted position, its solar panels weren't oriented correctly to generate power, according to the space agency. The team elected to conserve power by shutting down the spacecraft about 2.5 hours after landing.

What's perhaps as surprising as the photo of the lander is how it was taken. Two small rovers separated from the crewless mothership just prior to touchdown. It was one of these baseball-sized robots that was able to snap the image of the spacecraft with its head in the moondust. The rover, built with the help of Japanese toy maker Takara Tomy, is a sphere that splits in half to expose a pair of cameras that point front and back. The two hemispheres also become the rover wheels. "The company is perhaps most famous for originally creating the Transformers, the alien robots that can disguise themselves as machines," said Elizabeth Tasker, who provided commentary on the moon landing in English on Jan. 20.

The space agency still isn't entirely sure what went wrong. At about 55 yards above the ground, the spacecraft performed an obstacle avoidance maneuver, part of the pinpoint-landing demonstration. Just prior to this step, one of the two main engines stopped thrusting, throwing the lander's orientation off. JAXA is continuing to investigate what caused the engine problem... Despite the fact that the spacecraft is now sleeping, the SLIM team hasn't lost hope for a recovery. With solar panels facing west, the lander still has a chance of catching some rays and generating power. If the angle of sunlight changes, SLIM could still be awakened, mission officials said.

That would have to happen soon, though. Night will fall on the moon on Feb. 1, bringing about freezing temperatures. The spacecraft was not built to withstand those conditions.
NASA's Lunar Reconnaissance Orbiter spacecraft has now passed over the landing site at an altitude of about 50 miles (80 km) — and snapped their own photograph which they say shows "the slight change in reflectance around the lander due to engine exhaust sweeping the surface."

The Pokemon Company said Thursday it has not granted any permission to "another company," referring to viral new game Palworld-developer Pocketpair, to use Pokemon intellectual property or assets and "intends to investigate and take appropriate measures" against the fast-growing survival game operator. From a report: The statement is Pokemon Company's first acknowledgement of Palworld's fast-growing survival title, which has sold over 8 million copies in less than six days, exceeding the performance of even the most popular AAA titles. But as TechCrunch previously reported, Palworld is also attracting a growing number of fans of Japan's legendary firm over perceived plagiarism and uncanny resemblance. However, its fusion of monster collecting, automation, and survival/crafting mechanics has struck a chord with players nonetheless.

Japan has become the fifth country in the world to soft-land a spacecraft on the Moon, using precision technology that allowed it to touch down closer to its target landing site than any mission has before. However the spacecraft might have survived on the lunar surface for just a few hours due to power failure. Nature: Telemetry showed that the Smart Lander for Investigating Moon, or SLIM, touched down in its target area near Shioli crater, south of the lunar equator early Saturday morning, four months after lifting off from the Tanegashima Space Centre, off the south coast of Japan. [...] According to [Hitoshi] Kuninaka (VP of Kanegawa-based Japan Aerospace Exploration Agency), SLIM has very likely achieved its primary goal -- to land on the Moon with an unprecedented accuracy of 100 metres, which is a big leap from previous ranges of a few to dozens of kilometres. SLIM carried vision-based navigation technology, which was intended to image the surface as it flew over the Moon, and locate itself quickly by matching the images with onboard maps.

It remains unclear if the car-sized, 200-kilogram spacecraft actually touched down in the planned, two-step manner with its five legs. Unlike previous Moon landers, which used four legs to simultaneously reach a relatively flat area, SLIM was designed to hit a 15-degree slope outside Shioli crater first with one leg at the back, and then tip forward to stabilize on the four front legs. Observers suggest that SLIM might have rolled during its touch-down, preventing its solar cells from facing the Sun. Kuninaka said not enough data were available to establish the probe's posture or orientation. However, if some sunlight is able to reach the solar cells there is a chance that SLIM could come back to life.

"Would you pay $15 a month so Android doesn't track you and send all of that data back to Google?" asks Stuff South Africa: A new Swiss-based privacy company thinks $15 is a fair fee for that peace of mind. "A person's data is the original digital currency," argues Apostrophy, which has created its own operating system, called Apostrophy OS.

It's based on Android — don't panic — but the version that has already been stripped of Google's intrusiveness by another privacy project called GrapheneOS, which used to be known as CopperheadOS. Launched in 2014, it which was briefly known as the Android Hardening project, before being rebranded as GrapheneOS in 2019. Apostrophy OS is "focused on empowering our users, not leveraging them," it says and is "purposely Swiss-based, so we can be champions of data sovereignty".

What it does, they say, is separate the apps from the underlying architecture of the operating system and therefore prevent apps from accessing miscellaneous personal data, especially the all-important location data so beloved of surveillance capitalism... Apostrophy OS has its own app store, but also cleverly allows users to access the Google Play Store. If you think that is defeating the point, Apostrophy argues that those apps can't get to the vitals of your digital life. Apostrophy OS has "partitioned segments prioritising application integrity and personal data privacy".
The service is free for one year with the purchase of the new MC02 phone from Swiss manufacturer Punkt, according to PC Magazine. "The phone costs $749 and is available for preorder now. It will ship at the end of January." Additional features include a built-in VPN called Digital Nomad based on the open-source Wireguard framework to secure your activity against outside snooping, which includes "exit addresses" in the US, Germany, and Japan with the base subscription.

Geoffrey.landis writes: The Japan SLIM spacecraft has successfully landed on moon, but power problems mean it may be short mission. The good news is that the landing was successful, making Japan only the fifth nation to successfully make a lunar landing, and the ultra-miniature rover and the hopper both deployed. The bad news is that the solar arrays aren't producing power, and unless they can fix the problem in the next few hours, the batteries will be depleted and it will die. But, short mission or long, hurrah for Japan for being the fifth country to successfully land a mission on the surface of the moon (on their third try; two previous missions didn't make it). It's a rather amazing mission. I've never seen a spacecraft concept that lands under rocket power vertically but then rotates over to rest horizontally on the surface.

Japanese startup EX-Fusion plans to eliminate small pieces of space junk with laser beams fired from the ground. Nikkei Asia reports: EX-Fusion stands apart in that it is taking the ground-based approach, with the startup tapping its arsenal of laser technology originally developed in pursuit of fusion power. In October, EX-Fusion signed a memorandum of understanding with EOS Space Systems, an Australian contractor that possesses technology used to detect space debris. EX-Fusion plans to place a high-powered laser inside an observatory operated by EOS Space outside of Canberra. The first phase will be to set up laser technology to track debris measuring less than 10 cm. Pieces of this size have typically been difficult to target from the ground using lasers.

For the second phase, EX-Fusion and EOS Space will attempt to remove the space debris by boosting the power of the laser beams fired from the surface. The idea is to fire the laser intermittently against the debris from the opposing direction of its travel in order to slow it down. With a decreased orbiting speed, the debris will enter the Earth's atmosphere to burn up. High-powered lasers are often associated with weapons that blast objects into smithereens. Indeed, the EOS Space group supplies laser weapon systems used to destroy drones. But lasers designed to remove space debris are completely different from weapon-grade lasers, EOS Space's executive vice president James Bennett said during a visit to Japan in November.

Current laser weaponry often uses fiber lasers, which are capable of cutting and welding metal and can destroy targets like drones through heat created from continuous firing. Capturing and removing space junk instead involves diode-pumped solid-state (DPSS) lasers, which are pulsed to apply force to fast moving debris, stopping it like a brake. EX-Fusion's signature laser fusion process also involves DPSS lasers, which strike the surface of a hydrogen fuel pellet just millimeters in diameter, compressing it to trigger a fusion reaction. This makes space debris removal a useful test along the path to commercializing the fusion technology.

ScienceAlert reminds us that plants exude "a fine mist of airborne compounds that they use to communicate and protect themselves." And while they've been detected in over 80 plant species, now researchers have applied real-time imaging techniques "to reveal how plants receive and respond to these aerial alarms." Yuri Aratani and Takuya Uemura, molecular biologists at Saitama University in Japan, and colleagues rigged up a pump to transfer compounds emitted by injured and insect-riddled plants onto their undamaged neighbors, and a fluorescence microscope to watch what happened. Caterpillars (Spodoptera litura) were set upon leaves cut from tomato plants and Arabidopsis thaliana, a common weed in the mustard family, and the researchers imaged the responses of a second, intact, insect-free Arabidopsis plant to those danger cues.

These plants weren't any ordinary weeds: they had been genetically altered so their cells contained a biosensor that fluoresced green when an influx of calcium ions was detected... [T]he team visualized how plants responded to being bathed in volatile compounds, which plants release within seconds of wounding. It wasn't a natural set-up; the compounds were concentrated in a plastic bottle and pumped onto the recipient plant at a constant rate, but this allowed the researchers to analyze what compounds were in the pungent mix...

[T]he undamaged plants received the messages of their injured neighbors loud and clear, responding with bursts of calcium signaling that rippled across their outstretched leaves... [G]uard cells generated calcium signals within a minute or so, after which mesophyll cells picked up the message... "We have finally unveiled the intricate story of when, where, and how plants respond to airborne 'warning messages' from their threatened neighbors," says Masatsugu Toyota, a molecular biologist at Saitama University in Japan and senior author of the study.

Tuesday's launch was different. "SpaceX launched its first batch of Starlink satellites designed to connect directly to unmodified smartphones..." reports SpaceNews, "after getting a temporary experimental license to start testing the capability in the United States." Six of the 21 Starlink satellites that launched on a Falcon 9 rocket at 10:44 p.m. Eastern from Vandenberg Space Force Base, California, carry a payload that the company said could provide connectivity for most 4G LTE devices when in range. SpaceX plans to start enabling texting from space this year in partnership with cellular operators, with voice and data connectivity coming in 2025, although the company still needs regulatory permission to provide the services commercially. Initial direct-to-smartphone tests would use cellular spectrum from SpaceX's U.S. mobile partner T-Mobile. SpaceX has also partnered with mobile operators in Australia, Canada, Chile, Japan, New Zealand, and Switzerland....

Meanwhile, early-stage ventures AST SpaceMobile and Lynk Global are closing in on fundraising deals to expand their dedicated direct-to-device constellations. AST SpaceMobile said January 2 it is seeking to secure funds this month from "multiple parties" ahead of launching its first five commercial satellites early this year on a Falcon 9. Lynk Global, which is currently providing intermittent texting and other low-bandwidth services to phones outside cellular networks in parts of the Solomon Islands, Cook Islands, and Palau, plans to raise funds by merging with a shell company run by former professional baseball player Alex Rodriguez.

SpaceX launched a total of 21 satellites on Tuesday night, including "the first six Starlink satellites with Direct to Cell capabilities that enable mobile network operators around the world to provide seamless global access to texting, calling, and browsing wherever you may be on land, lakes, or coastal waters without changing hardware or firmware. The enhanced Starlink satellites have an advanced modem that acts as a cellphone tower in space, eliminating dead zones with network integration similar to a standard roaming partner," the company said. Ars Technica reports: Besides T-Mobile in the US, several carriers in other countries have signed up to use the direct-to-cell satellites. SpaceX said the other carriers are Rogers in Canada, KDDI in Japan, Optus in Australia, One NZ in New Zealand, Salt in Switzerland, and Entel in Chile and Peru. While SpaceX CEO Elon Musk wrote that the satellites will "allow for mobile phone connectivity anywhere on Earth," he also described a significant bandwidth limit. "Note, this only supports ~7Mb per beam and the beams are very big, so while this is a great solution for locations with no cellular connectivity, it is not meaningfully competitive with existing terrestrial cellular networks," Musk wrote.

Starlink's direct-to-cell website says the service will provide text messaging only when it becomes available in 2024, with voice and data service beginning sometime in 2025. Starlink's low Earth orbit satellites will work with standard LTE phones, unlike earlier services that required phones specifically built for satellite use. SpaceX's direct-to-cell satellites will also connect with Internet of Things (IoT) devices in 2025, the company says.

An anonymous reader quotes a report from Technology Networks: At about the size of a pinkie nail, the jellyfish species Cladonema can regenerate an amputated tentacle in two to three days -- but how? Regenerating functional tissue across species, including salamanders and insects, relies on the ability to form a blastema, a clump of undifferentiated cells that can repair damage and grow into the missing appendage. Jellyfish, along with other cnidarians such as corals and sea anemones, exhibit high regeneration abilities, but how they form the critical blastema has remained a mystery until now.

A research team based in Japan has revealed that stem-like proliferative cells -- which are actively growing and dividing but not yet differentiating into specific cell types -- appear at the site of injury and help form the blastema. "Importantly, these stem-like proliferative cells in blastema are different from the resident stem cells localized in the tentacle," said corresponding author Yuichiro Nakajima, lecturer in the Graduate School of Pharmaceutical Sciences at the University of Tokyo. "Repair-specific proliferative cells mainly contribute to the epithelium -- the thin outer layer -- of the newly formed tentacle."

The resident stem cells that exist in and near the tentacle are responsible for generating all cellular lineages during homeostasis and regeneration, meaning they maintain and repair whatever cells are needed during the jellyfish's lifetime, according to Nakajima. Repair-specific proliferative cells only appear at the time of injury. "Together, resident stem cells and repair-specific proliferative cells allow rapid regeneration of the functional tentacle within a few days," Nakajima said, noting that jellyfish use their tentacles to hunt and feed. [...] The cellular origins of the repair-specific proliferative cells observed in the blastema remain unclear, though, and the researchers say the currently available tools to investigate the origins are too limited to elucidate the source of those cells or to identify other, different stem-like cells. "It would be essential to introduce genetic tools that allow the tracing of specific cell lineages and the manipulation in Cladonema," Nakajima said. "Ultimately, understanding blastema formation mechanisms in regenerative animals, including jellyfish, may help us identify cellular and molecular components that improve our own regenerative abilities."

The findings were published in the journal PLOS Biology.