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These tiny animals (http://www.dogonews.com/2014/4/5/the-virtually-indestructible-water-bear) are really interesting, and some might even say a bit charismatic.  ;)


A recent study has apparently shown that tardigrades are in a way mostly head, with very little (if any) body: "Tardigrades Are One Giant Head" | Discover (http://blogs.discovermagazine.com/inkfish/2016/01/26/tardigrades-are-one-giant-head/#.VrJhmHn2bq4)

QuoteNo one would argue that tardigrades got stiffed in the weirdness department. These teensy animals, also called water bears, look roly-poly under a microscope. Less than a millimeter long, they can survive extremes of heat, cold, pressure, and radiation that are deadly to most other lifeforms. Under duress, a tardigrade may curl itself into a dried-up ball called a tun, then stay in a state of suspended animation for years before returning to life. Now, researchers poring over the animal's genes have found another oddity. The tardigrade, they say, is essentially one giant head.

Frank Smith, who's a postdoc in Bob Goldstein's lab at the University of North Carolina, Chapel Hill, and their colleagues studied the evolution of tardigrades by looking at their genes. Specifically, they looked at bits of DNA called "Hox genes." These are master controllers that organize an animal's body. During development, Hox genes make sure all the parts end up where they're supposed to be. Mutations in Hox genes can cause unsettling problems like, say, legs growing out of the head.

[. . .]

What emerged was a kind of whodunnit. The researchers saw that as tardigrades evolved from the ancestors they shared with arthropods, four or five of their Hox genes had simply disappeared.

Next, Smith and his colleagues asked what exactly the surviving Hox genes were doing in the tardigrade. Looking at where those genes switch on during the tardigrade's development, they saw a pattern "nearly identical" to how those genes are turned on in an arthropod's head, Smith says. In other words, most of a tardigrade's body is equivalent to just the head of an arthropod.

[Continues . . . (http://blogs.discovermagazine.com/inkfish/2016/01/26/tardigrades-are-one-giant-head/#.VrJhmHn2bq4)]

In the cladogram below, there's a hint that the tardigrades may be fairly closely related to Facivermis, which had all its legs at or near its head.

(https://i.imgur.com/NE50PcW.gif)

That is one strange looking creature bug thing.  Reminds me of some of the strange fossils in the Burgess shale. 

The day, in Genesis, when god made all the earths life forms, near the end, he was obviously becoming fatigued, or maybe high on some snort. Obviously a little bit confused when he got around to building the tartigrade, dinimichus, nectocarus, opabinia, and a shitload of other mysterious objects.

Fascinating.

Apparently their DNA is radiation-proof, to an extent.


These little creatures never cease to amaze me.  8)

Thanks, xSilverphinx--that's a cool video. Nature (http://www.nature.com/news/tardigrade-protein-helps-human-dna-withstand-radiation-1.20648) has a brief write-up about this, and the BBC has one that goes into a bit more detail (http://www.bbc.com/news/science-environment-37384466).

Aliens!!!
(and fascinating)

I;ve heard about those things from the new cosmos series. They can survive space!

Yes, a really amazing group of animals.

In Japan, a researcher has discovered new species of tardigrade that will reproduce sexually in a lab environment, which is unusual.

"A Totally New Species of Tardigrade Was Just Discovered in a Japanese Carpark" | Science Alert (https://www.sciencealert.com/brand-new-species-tardigrade-discovered-rock-japan-carpark-macrobiotus-shonaicus-hufelandi)

QuoteThey're the weirdest organisms known to science: unkillable critters (https://www.sciencealert.com/new-study-finally-reveals-how-water-bears-have-become-so-damn-indestructible) that can turn into glass (https://www.sciencealert.com/water-bears-turn-into-glass-when-they-dry-out) and survive the cold vacuum of space (https://www.sciencealert.com/the-tardigrade-genome-has-been-sequenced-and-it-has-the-most-foreign-dna-of-any-animal).

But sometimes tardigrades just want to take a breather, you know? Chill for a bit in more comfortable surroundings. Which is how scientists discovered a whole new species of them living in moss on the concrete surface of a Japanese carpark.

Bioscientist Kazuharu Arakawa from Keio University was renting an apartment in the city of Tsuruoka when he scooped up a sample of moss from the building's parking lot for later analysis.

It's not as crazy as it sounds.

Tardigrades – aka water bears and moss piglets (https://www.sciencealert.com/we-can-now-harness-the-tardigrade-s-strangest-superpower-and-give-it-to-other-organisms) – commonly dwell in mosses, lichens, and leaf litter, so there was a chance he could get lucky.

And he did, with examination in the lab revealing 10 of the microscopic metazoans living in the sample, who were extracted and transferred into culture in five separate pairs.

One of these pairs proliferated in their dish, with subsequent microscopic and genomic analysis revealing a new species of tardigrade – Macrobiotus shonaicus – belonging to the group Macrobiotus hufelandi.

What differentiates M. shonaicus is its eggs, which have a solid surface and flexible filaments protruding outwards, similar to those of two other recently described species, M. paulinae from Africa and M. polypiformis from South America.

[. . .]

Something else that sets M. shonaicus apart is its diet. To cultivate their cultures, the researchers fed the organisms algae, but most Macrobiotidae species are carnivorous, feeding on rotifers.

There's also the question of sex.

"M. shonaicus has two sexes, where other tardigrades that are culturable in labs have been mostly parthenogenetic (females reproduce by themselves without male population)," Arakawa says.

"So it is an ideal model to study the sexual reproduction machinery and behaviours of tardigrades."

[Continues . . . (https://www.sciencealert.com/brand-new-species-tardigrade-discovered-rock-japan-carpark-macrobiotus-shonaicus-hufelandi)]

Trials and tribulation for some water bears. I'll just say that I'm in favor of the practice of test to destruction (https://en.wikipedia.org/wiki/Destructive_testing) in the field of engineering. I look askance at its use in biology despite the fact that it may be necessary in at least some cases.  :sherlock3:


"High temperatures due to global warming will be dramatic even for tardigrades" | ScienceDaily (https://www.sciencedaily.com/releases/2020/01/200113104203.htm)

QuoteGlobal warming, a major aspect of climate change, is already causing a wide range of negative impacts on many habitats of our planet. It is thus of the utmost importance to understand how rising temperatures may affect animal health and welfare.

A research group from Department of Biology, University of Copenhagen has just shown that tardigrades are very vulnerable to long-term high temperature exposures. The tiny animals, in their desiccated state, are best known for their extraordinary tolerance to extreme environments.

In a study published recently in Scientific Reports, Ricardo Neves and Nadja Møbjerg and colleagues at Department of Biology, University of Copenhagen present results on the tolerance to high temperatures of a tardigrade species.

[. . .]

"The specimens used in this study were obtained from roof gutters of a house located in Nivå, Denmark. We evaluated the effect of exposures to high temperature in active and desiccated tardigrades, and we also investigated the effect of a brief acclimation period on active animals," explains postdoc Ricardo Neves.

Rather surprisingly the researchers estimated that for non-acclimated active tardigrades the median lethal temperature is 37.1°C, though a short acclimation periods leads to a small but significant increase of the median lethal temperature to 37.6°C. Interestingly, this temperature is not far from the currently measured maximum temperature in Denmark, i.e. 36.4°C. As for the desiccated specimens, the authors observed that the estimated 50% mortality temperature is 82.7°C following 1 hour exposures, though a significant decrease to 63.1°C following 24 hour exposures was registered.

[. . .]

"From this study, we can conclude that active tardigrades are vulnerable to high temperatures, though it seems that these critters would be able to acclimatize to increasing temperatures in their natural habitat. Desiccated tardigrades are much more resilient and can endure temperatures much higher than those endured by active tardigrades. However, exposure-time is clearly a limiting factor that constrains their tolerance to high temperatures," says Ricardo Neves.

Indeed, although tardigrades are able to tolerate a diverse set of severe environmental conditions, their endurance to high temperatures is noticeably limited and this might actually be the Achilles heel of these otherwise super-resistant animals.

[Link to full article. (https://www.sciencedaily.com/releases/2020/01/200113104203.htm)]

Further discoveries about these intriguing animals. . . .

"Scientists finally figure out why the water bear is nearly indestructible" | Big Think (https://bigthink.com/surprising-science/scientists-finally-figure-out-why-the-water-bear-is-nearly-unstoppable/)

QuoteThe tardigrade, also known as the moss piglet or water bear, is a bizarre, microscopic creature that looks like something out of a Disney nightmare scene: strange but not particularly threatening. The pudgy, eight-legged, water-borne creature appears to be perpetually puckering. It's the farthest thing from what you'd expect an unstoppable organism to look like.

Yet, water bears can withstand even the vacuum of space, as one experiment showed. A sort of microscopic Rasputin, tardigrades have be frozen, boiled, exposed to extreme doses of radiation, and remarkably still survive. How they do this has been a mystery to science, until now.

Being a water-borne creature, scientists in this experiment examined how it survived desiccation, or being completely dried out. When it senses an oncoming dry period, the critter brings its head and limbs into its exoskeleton, making itself into a tiny ball. It'll stay that way, unmoving, until it's reintroduced into water.

It's this amazing ability that piqued Thomas Boothby's interest. He's a researcher at the University of North Carolina, Chapel Hill. Boothby told TheNew York Times, "They can remain like that in a dry state for years, even decades, and when you put them back in water, they revive within hours." After that, "They are running around again, they are eating, they are reproducing like nothing happened."

Originally, it was thought that the water bear employed a sugar called trehalose to shield its cells from damage. Brine shrimp (sea monkeys) and nematode worms use this sugar to protect against desiccation, through a process called anhydrobiosis. Those organisms produce enough of the sugar to make it 20% of their body weight.

Not the water bear. Trehalose only takes up about 2% of its entire system, when it's in stasis. Though employing a sugar to preserve one's body sounds strange, the newly discovered process that the water bear goes through is even more bizarre. It turns itself into glass.


[Continues . . . (https://bigthink.com/surprising-science/scientists-finally-figure-out-why-the-water-bear-is-nearly-unstoppable/)]

The paper is open access:

"Tardigrades Use Intrinsically Disordered Proteins to Survive Desiccation" | Molecular Cell (https://www.cell.com/molecular-cell/fulltext/S1097-2765(17)30133-8)

QuoteAbstract:

Tardigrades are microscopic animals that survive a remarkable array of stresses, including desiccation. How tardigrades survive desiccation has remained a mystery for more than 250 years. Trehalose, a disaccharide essential for several organisms to survive drying, is detected at low levels or not at all in some tardigrade species, indicating that tardigrades possess potentially novel mechanisms for surviving desiccation.

Here we show that tardigrade-specific intrinsically disordered proteins (TDPs) are essential for desiccation tolerance. TDP genes are constitutively expressed at high levels or induced during desiccation in multiple tardigrade species. TDPs are required for tardigrade desiccation tolerance, and these genes are sufficient to increase desiccation tolerance when expressed in heterologous systems.

TDPs form non-crystalline amorphous solids (vitrify) upon desiccation, and this vitrified state mirrors their protective capabilities. Our study identifies TDPs as functional mediators of tardigrade desiccation tolerance, expanding our knowledge of the roles and diversity of disordered proteins involved in stress tolerance.

Interesting. I didn't follow the Youtube link at the end  ;D

Continuing on the tardigrade beat...

"A New Clue Into How 'Water Bears' Evolved to Survive the Literal Vacuum of Space" | The Daily Beast (https://www.thedailybeast.com/a-new-clue-into-how-tardigrades-evolved-to-survive-space)

QuoteTardigrades are some of the most compelling organisms to have ever evolved on Earth. Also known as water bears, these 1-millimeter long eight-legged creatures have been known to survive the vacuum of space, withstand boiling water for at least an hour, endure high amounts of radiation, and make it through unscathed from some of the most extreme colds imaginable. As a result, tardigrades have managed to find a home on nearly every place on the planet.

How did such an organism evolve? Scientists have been trying to answer that question for a long time now, with few clues. Now, a team of Korean and Chinese researchers believe they have some insight into how tardigrades developed into the hardiest animals ever.

Tardigrades are descended from an extinct organism known as lobopodians, which lived on the planet during the Cambrian Period (which lasted from roughly 541 million years ago to 485.4 million years ago). Lobopodians themselves are an informal group of ancient marine worms with several stubby legs that lived in the ocean. Up until now, however, we've never been able to drill down exactly what groups of lobopodians today's tardigrades may descend from.

The new findings, published this week in PNAS, are the result of an analysis of 79 different subcategories of lobopodians, including 40 species of tardigrades. The new analysis found the likely ancestors of two classes of tardigrade species currently alive today, and suggest that a group of Cambrian lobopodians called luolishaniids are the most recent Cambrian ancestors of water bears. In the intervening hundreds of millions of years, it looks like tardigrades evolved into animals with shorter limbs and fewer trunk segments, developing into organisms with more miniaturized bodies.

While the study is really more of a pure science finding to fill the gaps in tardigrade evolution, they aren't without more practical implications. Tardigrades have learned to survive by essentially hitting pause on their metabolic processes until they are returned to safer conditions—something that had to have been learned over time, in the species' predecessors. They're also able to make proteins that do not degrade in what would normally be considered extreme environments—another quality that needed to have been learned over time. If we're able to pinpoint when these traits were acquired, then we may be able to do a better job of pinpointing what kinds of genes are responsible.

And given the advent of gene-editing technologies like CRISPR, that knowledge could allow us to artificially emulate those qualities in other organisms, and even ourselves.

[Continues . . . (https://www.thedailybeast.com/a-new-clue-into-how-tardigrades-evolved-to-survive-space)]

The paper (https://www.pnas.org/doi/10.1073/pnas.2211251120) is behind a paywall.

QuoteAbstract:

Phylum Tardigrada (water bears), well known for their cryptobiosis, includes small invertebrates with four paired limbs and is divided into two classes: Eutardigrada and Heterotardigrada. The evolutionary origin of Tardigrada is known to lie within the lobopodians, which are extinct soft-bodied worms with lobopodous ["blunt-footed (https://www.palaeocast.com/episode-47-lobopodians/)"] limbs mostly discovered at sites of exceptionally well-preserved fossils. Contrary to their closest relatives, onychophorans and euarthropods, the origin of morphological characters of tardigrades remains unclear, and detailed comparison with the lobopodians has not been well explored.

Here, we present detailed morphological comparison between tardigrades and Cambrian lobopodians, with a phylogenetic analysis encompassing most of the lobopodians and three panarthropod phyla. The results indicate that the ancestral tardigrades likely had a Cambrian lobopodian–like morphology and shared most recent ancestry with the luolishaniids. Internal relationships within Tardigrada indicate that the ancestral tardigrade had a vermiform body shape without segmental plates, but possessed cuticular structures surrounding the mouth opening, and lobopodous legs terminating with claws, but without digits. This finding is in contrast to the long-standing stygarctid-like ancestor hypothesis. The highly compact and miniaturized body plan of tardigrades evolved after the tardigrade lineage diverged from an ancient shared ancestor with the luolishaniids.

If there be life on "long-dead" planets like Mars, I suspect it's something like them 'grades. As many legs as an spider, looking like a alien hippo and able to out-survive a roach. Fascinating creatures. :smilenod:

Some revision of understanding of the diversity of tardigrades.  :)

"Tardigrades are less cosmopolitan and more diverse than believed, researchers show" | Phys.org (https://phys.org/news/2024-10-tardigrades-cosmopolitan-diverse-believed.html)

QuoteTardigrades are microscopic invertebrates measuring between 0.2 mm and 1.1 mm in length. They are close relatives of arthropods (spiders, insects, crustaceans), and can live in a wide variety of environments. Yet little is known about them.

Many species were described in the twentieth century when few traits were thought necessary to differentiate species, and the molecular tools used today to compare one or more genes did not exist.

For this reason, in a study published in the Zoological Journal of the Linnean Society, researchers at the State University of Campinas (UNICAMP) in Brazil stress the importance of ignoring historical records of tardigrades in the Neotropical region, as an analysis of tardigrade distribution patterns shows they were probably misidentified.

"Many species were first described in the northern hemisphere and were believed to be cosmopolitan, in the sense that they could live anywhere. As a result, whenever researchers found a similar species here, they concluded it was the same as a previously described species," said Pedro Danel de Souza Ugarte, first author of the article and a master's candidate at the Institute of Biology (IB-UNICAMP).

In the article, the scientists propose to disregard a large number of records of known tardigrades in Central and South America, and to take into account only those described recently, since species are now distinguished on the basis of several traits, as well as molecular data. Tardigrade diversity in the region may be much greater than previously thought despite the large number of exclusions, they suggest.

"The diversity is probably enormous, but currently concentrated in a few countries due to the lack of specimens. Several twentieth-century studies were important but probably don't represent the actual species richness," said André Rinaldo Senna Garraffoni, last author of the article. He is a professor at IB-UNICAMP.

[Continues . . . (https://phys.org/news/2024-10-tardigrades-cosmopolitan-diverse-believed.html)]

The paper (https://academic.oup.com/zoolinnean/article-abstract/201/3/zlae091/7724047) is behind a paywall.

QuoteAbstract:

Large-scale databases are crucial for macroecology research, yet not entirely bias-free. Studying the biogeography of metazoan microfauna utilizing such databases is challenging, and added biases can further hinder them. Incidence data of tardigrade species from Central and South America are geographically biased, comprising mostly species erroneously considered cosmopolitan. The impact of these biases on macroecological studies is still unknown.

This paper evaluates how biased distribution records affect understanding of non-marine tardigrade distribution patterns in the Neotropical region. Using two datasets (including and excluding dubious records of allegedly cosmopolitan species), we assess how well biogeographic regions are sampled, estimate tardigrade species' richness, and analyse whether including dubious records can alter our comprehension of their macroecology.

We demonstrate how biogeographic regions are still not fully sampled, and that including unreliable records influences how many species remain to be discovered. Since records of 'false cosmopolitan species' represent most records, their removal increases uncertainty while yielding distribution patterns more likely to be accurate. Disregarding untrustworthy distribution records of 'false cosmopolitan species' is the first step to better understanding tardigrade macroecology in the Neotropics, and probably worldwide. However, additional, preferably systematic sampling is required before we can infer general tardigrade biodiversity patterns in under-sampled regions.

Borrowing the tardigrade resistance to radiation exposure. Sounds promising.

"Tardigrade Protein Could Soon Make Cancer Patients More Radiation Proof" | Science Alert (https://www.sciencealert.com/tardigrade-protein-could-soon-make-cancer-patients-more-radiation-proof)

QuoteWhen it comes to surviving radiation, tardigrades really know their stuff, shrugging off doses that would annihilate most other life forms. Now researchers are using this knowledge to find ways to protect healthy cells during cancer treatments.

A team led by Ameya Kirtane from Harvard Medical School and Jianling Bi from the University of Iowa has isolated this superpower in the form of messenger RNA, which when injected into cells protects them from radiation.

When people undergo radiotherapy for cancer, it's not just the tumor that suffers. The radiation causes DNA breaks in healthy cells, too, leading to massive cell death and inflammation, which is responsible for the treatment's unpleasant side-effects.

[. . .]

Despite their cute monikers like moss piglet and water bear, the microscopic, eight-legged animals known as tardigrades are notoriously tough. Aside from surviving the hottest setting of your oven and pressures of 7.5 Gpa, they can handle around a thousand times the dose of ionizing radiation that would kill a human.

They can do this because of their ability to produce a unique protein Dsup (short for 'damage suppressing'), which helps them tolerate both the initial blast and the hydroxyl radicals that form in cells as a result, which would otherwise tear up one or even both strands of DNA.

Scientists have had their eyes on this protein as a potential aid to cancer treatment since it was discovered in 2016, and now they're one step closer.

That 2016 study showed that when expressed in human cells, Dsup reduces X-ray-induced DNA damage by about 40 percent, which is why the researchers are hopeful it could protect cancer patients from the serious side-effects of their treatment.

But Dsup has to be inside a cell's nucleus to work. Delivering this protein directly into each cell is not feasible, and integrating the genes for Dsup directly into DNA has its own risks.

"One of the strengths of our approach is that we are using a messenger RNA, which just temporarily expresses the protein, so it's considered far safer than something like DNA, which may be incorporated into the cells' genome," Kirtane says.

By wrapping the mRNA in specific polymer-lipid nanoparticles (one design best-suited to the colon, and one ideal for the mouth) they were able to smuggle the strands into lab-grown cells where they were used to generate large amounts of Dsup before disintegrating.

[Continues . . . (https://www.sciencealert.com/tardigrade-protein-could-soon-make-cancer-patients-more-radiation-proof)]

The paper (https://www.nature.com/articles/s41551-025-01360-5) is behind a paywall.

QuoteAbstract:

Patients undergoing radiation therapy experience debilitating side effects because of toxicity arising from radiation-induced DNA strand breaks in normal peritumoural cells. Here, inspired by the ability of tardigrades to resist extreme radiation through the expression of a damage-suppressor protein that binds to DNA and reduces strand breaks, we show that the local and transient expression of the protein can reduce radiation-induced DNA damage in oral and rectal epithelial tissues (which are commonly affected during radiotherapy for head-and-neck and prostate cancers, respectively).

We used ionizable lipid nanoparticles supplemented with biodegradable cationic polymers to enhance the transfection efficiency and delivery of messenger RNA encoding the damage-suppressor protein into buccal and rectal tissues. In mice with orthotopic oral cancer, messenger RNA-based radioprotection of normal tissue preserved the efficacy of radiation therapy. The strategy may be broadly applicable to the protection of healthy tissue from DNA-damaging agents.

Patients will exit the radiation regimen looking like giant tardigrades.  :P

The people doing this kind of research are quiet heroes.

This is not the kind of news, or hope for the future, that is likely to capture the attention of the great unwashed.

Quote from: Icarus on February 27, 2025, 04:55:41 AMThe people doing this kind of research are quiet heroes.

This is not the kind of news, or hope for the future, that is likely to capture the attention of the great unwashed.

Sad, but true. The great unwashed's ranks will increase immensely if the chump's policies continue. It's appalling how ignorant people are. I got a haircut this morning , and two guys were discussing how great it was that $65Bn had been shaved off the budget. They're going to find out the hard way, eventually.

One thing is certain, nobody except perhaps a few Muskovites knows how much has been "saved." On the other hand the full extent of the damage that is being done is likewise unknown, but the country will likely be dealing with it for a long time. Speaking of damage, voting with the UN murderers' row (Russia, Belarus, North Korea etc.) in regard to affirming the sovereignty of an ally, that will be remembered.


Back to somewhere in the orbit of the topic. . .

Dark Lightning your comment about looking like a tardigrade got me thinking. Would I be willing to look like a tardigrade if the astounding durability came with it? I'm thinking centuries of life as well. Truly unpleasant looking like the interstellar navigators in the Dune universe, but with eight legs. :bogey:

It's something I might consider, depending on what sort of life was available to such a monstrosity. It'd have to be good.   :lol:   

An idea for a science fiction story maybe. A twist on Kafka's "Metamorphosis" where the narrator has chosen to transform and is loving it.  :thumbsup2: