- This topic has 2 replies, 1 voice, and was last updated 4 years, 11 months ago by
.
-
Posts
-
by California Institute of Technology
https://phys.org/news/2019-09-otherworldly-worms-sexes-mono-lake.html
Caltech scientists have discovered a new species of worm thriving in the extreme environment of Mono Lake. This new species, temporarily dubbed Auanema sp., has three different sexes, can survive 500 times the lethal human dose of arsenic, and carries its young inside its body like a kangaroo.
Mono Lake, located in the Eastern Sierras of California, is three times as salty as the ocean and has an alkaline pH of 10. Before this study, only two other species (other than bacteria and algae) were known to live in the lake—brine shrimp and diving flies. In this new work, the team discovered eight more species, all belonging to a class of microscopic worms called nematodes, thriving in and around Mono Lake.
The work was done primarily in the laboratory of Paul Sternberg, Bren Professor of Biology. A paper describing the research appears online on September 26 in the journal Current Biology.
The Sternberg laboratory has had a long interest in nematodes, particularly Caenorhabditis elegans, which uses only 300 neurons to exhibit complex behaviors, such as sleeping, learning, smelling, and moving. That simplicity makes it a useful model organism with which to study fundamental neuroscience questions. Importantly, C. elegans can easily thrive in the laboratory under normal room temperatures and pressures.
As nematodes are considered the most abundant type of animal on the planet, former Sternberg lab graduate students Pei-Yin Shih (Ph.D. ’19) and James Siho Lee (Ph.D. ’19) thought they might find them in the harsh environment of Mono Lake. The eight species they found are diverse, ranging from benign microbe-grazers to parasites and predators. Importantly, all are resilient to the arsenic-laden conditions in the lake and are thus considered extremophiles—organisms that thrive in conditions unsuitable for most life forms.
When comparing the new Auanema species to sister species in the same genus, the researchers found that the similar species also demonstrated high arsenic resistance, even though they do not live in environments with high arsenic levels. In another surprising discovery, Auanema sp. itself was found to be able to thrive in the laboratory under normal, non-extreme conditions. Only a few known extremophiles in the world can be studied in a laboratory setting.
This suggests that nematodes may have a genetic predisposition for resiliency and flexibility in adapting to harsh and benign environments alike.
“Extremophiles can teach us so much about innovative strategies for dealing with stress,” says Shih. “Our study shows we still have much to learn about how these 1000-celled animals have mastered survival in extreme environments.”
The researchers plan to determine if there are particular biochemical and genetic factors that enable nematodes’ success and to sequence the genome of Auanema sp. to look for genes that may enable arsenic resistance. Arsenic-contaminated drinking water is a major global health concern; understanding how eukaryotes like nematodes deal with arsenic will help answer questions about how the toxin moves through and affects cells and bodies.
But beyond human health, studying extreme species like the nematodes of Mono Lake contributes to a bigger, global picture of the planet, says Lee.
“It’s tremendously important that we appreciate and develop a curiosity for biodiversity,” he adds, noting that the team had to receive special permits for their field work at the lake. “The next innovation for biotechnology could be out there in the wild. A new biodegradable sunscreen, for example, was discovered from extremophilic bacteria and algae. We have to protect and responsibly utilize wildlife.”
The paper is titled, “Newly Identified Nematodes from Mono Lake Exhibit Extreme Arsenic Resistance.”
Journal information: Current Biology
Provided by California Institute of TechnologyHypothetical types of biochemistry are forms of biochemistry speculated to be scientifically viable but not proven to exist at this time. The kinds of living organisms currently known on Earth all use carbon compounds for basic structural and metabolic functions, water as a solvent, and DNA or RNA to define and control their form. If life exists on other planets or moons, it may be chemically similar; it is also possible that there are organisms with quite different chemistries—for instance, involving other classes of carbon compounds, compounds of another element, or another solvent in place of water.
The possibility of life-forms being based on “alternative” biochemistries is the topic of an ongoing scientific discussion, informed by what is known about extraterrestrial environments and about the chemical behaviour of various elements and compounds. It is also a common subject in science fiction.
The element silicon has been much discussed as a hypothetical alternative to carbon. Silicon is in the same group as carbon on the periodic table and, like carbon, it is tetravalent. Hypothetical alternatives to water include ammonia, which, like water, is a polar molecule, and cosmically abundant; and non-polar hydrocarbon solvents such as methane and ethane, which are known to exist in liquid form on the surface of Titan.
-https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry-
-https://www.amazon.com/Sirens-Titan-Kurt-Vonnegut/dp/B001W9TE6O/-
-https://www.amazon.com/Cats-Cradle-Novel-Kurt-Vonnegut/dp/038533348X/-
A Tiny Worm Frozen in Siberian Permafrost For 42,000 Years Was Just Brought Back to Life
MIKE MCRAE 27 JUL 2018
https://www.sciencealert.com/40-000-year-old-nematodes-revived-siberian-permafrost
Samples of permafrost sediment frozen for the past 42,000 years were recently thawed to reveal living nematodes.
Within weeks the roundworms began to move and eat, setting a record for the time an animal can survive cryogenic preservation.
Aside from revealing new limits of endurance, it just might prove useful when it comes to preserving our own tissues.
Russian biologists dug up more than 300 samples of frozen soil of different ages and locations throughout the Arctic and took them back to their lab in Moscow for a closer look.
Samples retrieved from remote parts of north eastern Russia contained nematodes from two different genera, which the researchers placed into Petri dishes with a nutrient medium.
The worms were left for several weeks at a relatively warm 20 degrees Celsius (68 Fahrenheit) as they gradually showed signs of life.
Some of the worms – belonging to the genus Panagrolaimus – were found 30 metres (100 feet) underground in what had once been a ground squirrel burrow which caved in and froze over around 32,000 years ago.
Others from the genus Plectus were found in a bore sample at a depth of around 3.5 metres (about 11.5 feet). Carbon dating was used to determine that sample to be about 42,000 years old.
Contamination can’t be ruled out, but the researchers maintain they adhered to strict sterility procedures.
They aren’t known for burrowing so deep into permafrost, seasonal thawing is limited to around 80 centimetres (under 3 feet), and there’s been no hint of thawing beyond 1.5 metres (5 feet) when the area was at its warmest around 9000 years ago.
So we can be fairly confident these worms really did awaken from one incredibly long nap.
Reviving ancient organisms is itself nothing new. In 2000, scientists pulled spores from Bacillus bacteria hidden inside 250 million year old salt crystals and managed to return them to life.
We might be impressed by their fortitude, but we can’t apply bacteria’s life-preserving tricks to our own complicated tissues. So finding animals that can remain dormant for tens of thousands of years is a discovery well worth paying attention to.
Roundworms are known to be hardy creatures. Nematodes have been revived in 39-year-old herbarium samples, but nothing has previously been seen on a scale quite like this.
Close relatives, the tardigrade, are also well known for having a talent for surviving extreme conditions, repairing broken DNA and producing a vitrifying material when they dry out.
Even those superpowered critters have never been seen to survive so long in states of preservation, with the current tardigrade record being only around 30 years.
Learning more about the biochemical mechanisms nematodes use to limit the damage of ice and hold off the ravages of oxidation on DNA over the millennia might point the way to better cryopreservation technologies.
We’ve studied other organisms that can handle having their liquids turned to ice for inspiration, such as wood frogs, in the hope of finding better ways to store human tissues for transplants, or even – just maybe – whole bodies for revival.
“It is obvious that this ability suggests that the Pleistocene nematodes have some adaptive mechanisms that may be of scientific and practical importance for the related fields of science, such as cryomedicine, cryobiology, and astrobiology,” the researchers write in their report.
But the find does have a slightly darker side.
There are concerns that the melting of permafrost could release pathogens locked up in deep freeze for tens of thousands of years.
Nematodes are unlikely to pose much of a concern, but their survival is evidence that a diverse array of organisms – from bacteria to animals, plants to fungi – could potentially return after a long absence.
Exactly what this means for surrounding ecosystems is still anybody’s guess.
We can only hope a few groggy worms are all we have to worry about in Siberia’s melting ice.
This research was published in Doklady Biological Sciences.
JANUARY 9, 2020
Biologists identify pathways that extend lifespan by 500%
by Mount Desert Island Biological Laboratory
https://phys.org/news/2020-01-biological-scientists-pathways-lifespan.html
Scientists at the MDI Biological Laboratory, in collaboration with scientists from the Buck Institute for Research on Aging in Novato, Calif., and Nanjing University in China, have identified synergistic cellular pathways for longevity that amplify lifespan fivefold in C. elegans, a nematode worm used as a model in aging research.
The increase in lifespan would be the equivalent of a human living for 400 or 500 years, according to one of the scientists.
The research draws on the discovery of two major pathways governing aging in C. elegans, which is a popular model in aging research because it shares many of its genes with humans and because its short lifespan of only three to four weeks allows scientists to quickly assess the effects of genetic and environmental interventions to extend healthy lifespan.
Because these pathways are “conserved,” meaning that they have been passed down to humans through evolution, they have been the subject of intensive research. A number of drugs that extend healthy lifespan by altering these pathways are now under development. The discovery of the synergistic effect opens the door to even more effective anti-aging therapies.
The new research uses a double mutant in which the insulin signaling (IIS) and TOR pathways have been genetically altered. Because alteration of the IIS pathways yields a 100 percent increase in lifespan and alteration of the TOR pathway yields a 30 percent increase, the double mutant would be expected to live 130 percent longer. But instead, its lifespan was amplified by 500 percent.
“Despite the discovery in C. elegans of cellular pathways that govern aging, it hasn’t been clear how these pathways interact,” said Hermann Haller, M.D., president of the MDI Biological Laboratory. “By helping to characterize these interactions, our scientists are paving the way for much-needed therapies to increase healthy lifespan for a rapidly aging population.”
The elucidation of the cellular mechanisms controlling the synergistic response is the subject of a recent paper in the online journal Cell Reports entitled “Translational Regulation of Non-autonomous Mitochondrial Stress Response Promotes Longevity.” The authors include Jarod A. Rollins, Ph.D., and Aric N. Rogers, Ph.D., of the MDI Biological Laboratory.
“The synergistic extension is really wild,” said Rollins, who is the lead author with Jianfeng Lan, Ph.D., of Nanjing University. “The effect isn’t one plus one equals two, it’s one plus one equals five. Our findings demonstrate that nothing in nature exists in a vacuum; in order to develop the most effective anti-aging treatments we have to look at longevity networks rather than individual pathways.”
The discovery of the synergistic interaction could lead to the use of combination therapies, each affecting a different pathway, to extend healthy human lifespan in the same way that combination therapies are used to treat cancer and HIV, Pankaj Kapahi, Ph.D., of the Buck Institute, has said. Kapahi is a corresponding author of the paper with Rogers and Di Chen, Ph.D., of Nanjing University.
The synergistic interaction may also may explain why scientists have been unable to identify a single gene responsible for the ability of some people to live to extraordinary old ages free of major age-related diseases until shortly before their deaths.
The paper focuses on how longevity is regulated in the mitochondria, which are the organelles in the cell responsible for energy homeostasis. Over the last decade, accumulating evidence has suggested a causative link between mitochondrial dysregulation and aging. Rollins’ future research will focus on the further elucidation of the role of mitochondria in aging, he said.
More information: Jianfeng Lan et al. Translational Regulation of Non-autonomous Mitochondrial Stress Response Promotes Longevity, Cell Reports (2019). DOI: 10.1016/j.celrep.2019.06.078
Journal information: Cell Reports
-https://medicalxpress.com/news/2019-10-scientists-neural-role-human-longevity.html-
-https://phys.org/news/2019-10-reveals-collapse-protein-driver-aging.html-
Provided by Mount Desert Island Biological Laboratory
- You must be logged in to reply to this topic.