Tag Archives: tardigrades

New insights into the evolutionary origins of tardigrades from Cretaceous amber fossils

Posted on by
Reply

Tardigrades are a diverse group of microinvertebrates widely known for their remarkable ability to survive. Molecular clocks suggest that tardigrades diverged from other panarthropods (arthropods, tardigrades, velvet worms, and lobopods) before the Cambrian, but the fossil record is extremely poor. Now, paleontologists have described a new species of tardigrade and redescribed previously known species. readBoth are from Canadian Cretaceous amber.

Artistic Restoration read (Top) and Aerobius dactylus (Bottom) A hypothetical fossilization environment. Image courtesy of Franz Anthony.

First discovered in 1773, tardigrades are a diverse group of microscopic invertebrates best known for their ability to survive in extreme environments.

Also known as tardigrades or moss pigs, these creatures can live up to 60 years and grow to a size of up to 0.5mm. They are best seen under a microscope.

They can survive up to 30 years without food or water, and can survive temperatures as low as -272°C and as high as 150°C for a few minutes, and as low as -20°C for decades.

Tardigrades can withstand pressures ranging from nearly zero atmospheres in outer space to 1,200 atmospheres at the bottom of the Mariana Trench, and can also tolerate radiation levels of up to 5,000-6,200 Gy.

They survive by entering a state of suspended animation called biostasis, using proteins that form a gel inside the cells and slow down vital processes.

“Tardigrades are microscopic invertebrates characterized by a compact body shape with lobopod legs with four pairs of claws, and are closely related to the clawed pterygota and euarthropods. Panarthropods“Harvard doctoral student Mark Mapalo and his colleagues said:

“Tardigrades are widely known for having several species with cryptobiotic capabilities that allow them to survive extreme conditions such as the vacuum of space, ionizing radiation and freezing temperatures. Tardigrades are also found in marine, freshwater and terrestrial habitats around the world.”

“Despite their ubiquity in the modern biosphere, tardigrades have a notoriously poor fossil record, and research into their macroevolution, such as the origin of their body shape, the timing of their terrestrialization, and the acquisition of their cryptic abilities, is limited.”

“Currently, only four fossil crown-group tardigrades are known, all preserved as amber inclusions, but only two of these have an established taxonomic position relative to extant tardigrades.”

Aerobius dactylusImages/Photos: Mapalo others., doi: 10.1038/s42003-024-06643-2.

For the study, the authors looked at a piece of amber containing a tardigrade fossil that was discovered in Canada in the 1960s. read and what was presumed to be another tardigrade, which was virtually unexplained at the time.

Using confocal laser scanning microscopy, a technique commonly used to study cell biology, the researchers were able to examine the microscopic structure of the tardigrade fossils in astonishing detail.

This study read It has been identified as a new species in the Tardigrade family tree, Aerobius dactylus.

“Both were found in the same Cretaceous amber, which means that these tardigrades coexisted with dinosaurs,” said Dr Javier Ortega-Hernández of Harvard University.

” read The seven claws are well preserved, and those that curve towards the body are smaller than those that curve away from it, a pattern seen in modern tardigrades.”

“The second, previously unidentified specimen had claws of equal length on each of the first three pairs of legs, but the outer claws on the fourth leg were longer.”

Both species serve as important calibration points for an analysis called a molecular clock analysis, which helps scientists estimate important evolutionary timing.

For example, new research suggests that modern tardigrades likely branched off during the Cambrian period, more than 500 million years ago.

The study also sheds light on the origins of tardigrades' remarkable ability to survive extreme environments by entering a state of torpor.

“This study estimates that this survival mechanism likely evolved during the middle to late Palaeozoic and may have played a key role in helping tardigrades survive the end-Permian mass extinction, one of the most severe extinction events in Earth's history,” Dr Ortega-Hernández said.

of result Published in a journal Communication Biology.

_____

MA Mapalo others2024. Inclusions in Cretaceous amber shed light on evolutionary origins of tardigrades. Communication Violet 7, 953; doi: 10.1038/s42003-024-06643-2

Source: www.sci.news

Can tardigrades survive on Mars?

Posted on by
Reply

Tardigrades These eight-legged marvels of survival are tiny aquatic invertebrates, also known as tardigrades. UV rays, The vacuum of space,and, Shot by a gunThe scientists 1400 species of tardigrades The creatures, which are collected from freshwater and marine habitats around the world, are seemingly indestructible and “The toughest animals on earth“But are they strong enough to survive on Mars?

Space agencies around the world are currently Sending humans to MarsBut life on Mars comes with its own environmental challenges: Researchers have shown that tardigrades can survive the radiation, extreme temperatures, dehydration and lack of oxygen that characterize the Red Planet. Studying Martian soil I realized it contained toxic salts. PerchloratePerchlorates dissolve rapidly in solution to form salt solutions or brineIt inhibits the cells' ability to retain moisture and produces reactive chemicals, such as hydrogen peroxide, which can damage cells. Oxidative stressScientists have found perchlorate concentrations in Martian soil as high as 0.6 percent, roughly 1,000 times higher than the highest concentrations found in Earth's desert soils.

Scientists have previously found that some soil bacteria can survive perchlorate using special enzymes that fight it and protect cells from oxidative stress. Unfortunately, animals lack these enzymes. Other researchers have found that tardigrades Paramacrobiotus experimentalis Can survive Short-term exposure Animals living on the Martian surface would be exposed to perchlorates for up to 24 hours, but animals living on the Martian surface would have to contend with these toxins indefinitely.

A team of Polish researchers recently tested whether tardigrades could perform this task. They Pam.Experimental The tardigrades were exposed to high concentrations of perchlorate, similar to those found in Martian soil, for eight weeks to see how long they would survive. The researchers reasoned that because this species of tardigrade can tolerate short-term exposure to perchlorate, it may be able to survive for longer periods of time.

The researchers: Pam.Experimental Tardigrades were collected from moss in Madagascar and fed a diet of earthworms and plankton. For each experiment, 24 newly hatched tardigrades were transferred to solutions containing 0.10%, 0.15%, 0.20%, or 0.25% magnesium perchlorate. As a control, another 24 were transferred to a solution without perchlorate. The tardigrades were kept in these solutions for 56 days in the dark, at 18 °C (approximately 64 °F) and 40% relative humidity. The solutions were changed every 7 days, and dead tardigrades were removed.

At the end of the experiment, the researchers Phase contrast microscopeThis type of microscope makes use of the fact that light waves change height and direction when they interact with an object. amplitudeand location, or stepThe human eye can see amplitude changes in brightness and color intensity, but not phase changes. Phase contrast microscopes convert invisible phase changes into visible brightness changes, allowing scientists to see fine details in transparent specimens like tardigrades.

The team counted live and dead tardigrades under a phase-contrast microscope and found that 83% survived on 0.10% magnesium perchlorate, compared with 87% in the control group. They also found that about 58% of the tardigrades survived on 0.15% perchlorate, 29% on 0.20% perchlorate, and 20% on 0.25% perchlorate. The team interpreted this trend as meaning that although more than 0.10% perchlorate is toxic to most tardigrades, some individuals can survive at about half the perchlorate concentration found on Mars.

The researchers also measured the body length of the surviving tardigrades, which were about two-thirds as long as those raised without perchlorate. The researchers suggested that tardigrades grow slower in the presence of perchlorate because the salt directly inhibits the tardigrades' growth or stops them from feeding.

These scientists demonstrated that tardigrades can survive Mars-like perchlorate levels for eight weeks, but did not reveal how they did this. They suggested that tardigrades must use a special technique to withstand the toxic perchlorate. Dry hibernation For example, when faced with high salinity or other extreme conditions. Damage suppressor proteins It protects them from radiation and helps them survive.

The team recommended that future researchers investigate whether tardigrades can survive and thrive when simultaneously exposed to perchlorate and other harsh conditions present on Mars. They also suggested that scientists study the biochemical pathways involved in tardigrades' perchlorate resistance to see if these pathways can be genetically engineered to confer perchlorate resistance to other animals that colonize Mars. One day, future humans may stroll under the Martian sky wearing tardigrade-reinforced skin.


Post View: 115

Source: sciworthy.com

New study shows tardigrades display unusual responses to ionizing radiation

Posted on by
Reply

Tardigrades can withstand amazing amounts of ionizing radiation, about 1,000 times more lethal than humans. How they do so is not fully understood. In a new study, scientists at the University of North Carolina found that tardigrade species Hypsibius exemplaris Gamma irradiation causes DNA damage, but that damage can be repaired. This study shows that this species has a specific and strong response to ionizing radiation. In short, irradiation induces rapid upregulation of many DNA repair genes.

Artist's impression of tardigrade species Hypsibius exemplaris.

First discovered in 1773, tardigrades are a diverse group of microscopic invertebrates famous for their ability to withstand extreme conditions.

Also known as tardigrades or moss piglets, they can live up to 60 years, grow to a maximum size of 0.5 mm, and are best seen under a microscope.

Tardigrades can survive for up to 30 years without food or water at temperatures as low as -272 degrees Celsius (-457 degrees Fahrenheit) or as hot as 150 degrees Celsius (-302 degrees Fahrenheit) and for a few minutes at temperatures as low as -20 degrees Celsius. can. Minus 4 degrees Celsius (minus 4 degrees Fahrenheit) continues for decades.

It can withstand pressures from virtually 0 atmospheres in outer space to 1,200 atmospheres at the bottom of the Mariana Trench.

It is also resistant to radiation levels up to 5,000-6,200 Gy.

“What we saw surprised us. Tardigrades are behaving in ways we didn’t expect,” said researcher Professor Bob Goldstein from the University of North Carolina at Chapel Hill.

In their research, Professor Goldstein and his colleagues Hypsibius exemplaris Tardigrades can also withstand strong radiation.

The researchers found that although tardigrades are not immune to DNA damage, and that radiation damages their DNA, tardigrades can repair extensive damage.

They were surprised to discover that tardigrades can increase production of DNA repair genes.

Unlike humans, they are able to produce extremely high levels of DNA repair gene products, making them some of the most abundant gene products of any animal.

“These animals have an incredible response to radiation, and that seems to be the secret to their extreme survivability,” said Dr. Courtney Clark-Hachtel, a researcher at the University of North Carolina at Asheville. Ta.

“What we’re learning about how tardigrades overcome radiation stress could lead to new ideas about how we try to protect other animals and microorganisms from harmful radiation. “

of findings appear in the diary current biology.

_____

Courtney M. Clark Hucktell other.Tardigrade Hypsibius exemplaris Dramatically upregulates DNA repair pathway genes in response to ionizing radiation. current biology, published online on April 12, 2024. doi: 10.1016/j.cub.2024.03.019

Source: www.sci.news

Research: Protein from tardigrades found to inhibit human cell metabolism

Posted on by
Reply

New research led by University of Wyoming Laramie provides additional evidence that tardigrade proteins could ultimately be used to provide life-saving treatments to people for whom refrigeration is not possible and to enhance storage of cell-based treatments.

Sanchez Martinez other. We provide insight into how tardigrades induce reversible biostasis through self-assembly of labile CAHS gels.

First discovered in 1773, tardigrades are a diverse group of microscopic invertebrates best known for their ability to survive in extreme conditions.

Also known as tardigrades or moss piglets, these creatures can live up to 60 years, grow to a maximum size of 0.5 mm, and are best seen under a microscope.

They can survive temperatures as low as -272 degrees Celsius (-457 degrees Fahrenheit) or as high as -150 degrees Celsius (-302 degrees Fahrenheit), and temperatures as low as -20 degrees Celsius for several minutes, and for up to 30 years without food or water. Masu. Minus 4 degrees Celsius (minus 4 degrees Fahrenheit) continues for decades.

Tardigrades can withstand pressures from nearly 0 atmospheres in space to 1,200 atmospheres at the bottom of the Mariana Trench, and radiation levels of up to 5,000 to 6,200 Gy.

They survive by entering a state of suspended animation called biostasis, using proteins that form gels within their cells and slow down life processes.

“Surprisingly, when you introduce these proteins into cells, they gel and slow down their metabolism, much like tardigrades do,” says researcher Sylvia Sánchez Martinez, Ph.D., of the University of Wyoming, Laramie.

“Furthermore, just like tardigrades, putting human cells with these proteins into biostasis makes them more resistant to stress, giving human cells some of the tardigrade's abilities.”

“Importantly, our study shows that the entire process is reversible,” said researcher Thomas Boothby, Ph.D., of the University of Wyoming, Laramie.

“When stress is reduced, the tardigrade gel dissolves and human cells return to normal metabolism.”

“Our findings provide an avenue to pursue technologies centered on inducing biostasis in cells and even whole organisms to slow aging and increase shelf life and stability.”

of findings appear in the diary protein science.

_____

S. Sanchez Martinez other. 2024. Unstable assembly of tardigrade proteins induces homeostasis. protein science 33 (4): e4941; doi: 10.1002/pro.4941

Source: www.sci.news

Scientists have made a breakthrough in understanding how tardigrades are able to survive in extreme conditions

Posted on by
Reply

Tardigrade observed using a fluorescence microscope.Some organs are highlighted with fluorescent markers

Smythers et al/PLoS ONE (CC-BY 4.0)

Tardigrades are known for their ability to withstand extreme environments, and we now know how they do this. Small molecular sensors inside cells can detect when harmful molecules called free radicals are produced in excess, causing a state of dormancy.

Tardigrades, also known as tardigrades, are eight-legged microscopic invertebrates found throughout the world. Under adverse conditions such as sub-zero temperatures and strong radiation, the creatures shrink into a dry ball called a tongue and enter a deep hibernation state.

“Tardigrades do not breed under extreme conditions, but they can overwinter.” Derrick Colling At Marshall University in West Virginia. “We wanted to understand how they could step in there.”

To study, Kolling and colleagues exposed tardigrades to high levels of hydrogen peroxide, sugar, salt, or temperatures of -80°C (-112°F) to induce Tun. As a result of these stresses, tardigrades produce harmful, highly reactive molecules called oxygen free radicals.

The free radicals then go on to react with other molecules, team members say. leslie hix At the University of North Carolina at Chapel Hill. Importantly, the research team discovered that free radicals oxidize an amino acid called cysteine, which is one of the building blocks of proteins in the body. These reactions change protein structure and function and signal the onset of quiescence.

In experiments where cysteine ​​oxidation was prevented, tardigrades were unable to enter the tun state. “Cysteine acts like a kind of regulatory sensor,” Hicks says. “This allows the tardigrade to sense its environment and respond to stress.”

When conditions improved, the researchers discovered that the cysteine ​​was no longer oxidized and instructed the tardigrades to wake up from the tongue.

“Whether this is a universally conserved protection mechanism and whether this is conserved across tardigrade species is a really important question,” Hicks says. Her answers, she says, could help us better understand the aging process and how to make long-term space travel a reality.

topic:

Source: www.newscientist.com