Latest news with #archaea
Yahoo
06-07-2025
- Science
- Yahoo
What is life? A little microbe raises big questions.
It's tiny and needy, but is it alive? That's a question prompted by recent research that highlights a surprisingly complex part of biology. The organism in question is a microbe called Sukunaarchaeum mirabile, discovered by researchers in Canada and Japan who were looking at the DNA of a species of marine plankton, according to a new paper published on bioRxiv. They've found it's unusually reliant on an alive host to survive, which could further blur the lines between cellular life and viruses — which generally considered to not be alive. The National Human Genome Research Institute describes viruses as existing "near the boundary between the living and the nonliving." Viruses can't function without interacting with a living cell. On their own, they're also essentially inert – unable to move – as a 2017 study notes. Enter Sukunaarchaeum mirabile, which could complicate things further. "This organism represents a totally new branch in the archaeal tree of life," lead researcher Takuro Nakayama of the University of Tsukuba told USA TODAY. (Archaea are microorganisms that define the limits of life on Earth.) "Sukunaarchaeum is not a virus, but a highly streamlined cellular organism," Nakayama said. According to the new study, which has yet to be peer-reviewed, "the discovery of Sukunaarchaeum pushes the conventional boundaries of cellular life and highlights the vast unexplored biological novelty within microbial interactions." Named for a Japanese deity known for its tiny size, Sukunaarchaeum has one of the smallest genomes ever recorded: "Its genome is drastically reduced – less than half the size of the previously smallest known archaeal genome," Nakayama said. The authors in the study write that "its genome is profoundly stripped-down, lacking virtually all recognizable metabolic pathways, and primarily encoding the machinery for its replicative core: DNA replication, transcription, and translation." "This suggests an unprecedented level of metabolic dependence on a host, a condition that challenges the functional distinctions between minimal cellular life and viruses,' the study says. "Sukunaarchaeum could be just the tip of the iceberg, pointing to a hidden diversity of life forms with ultra-reduced genomes within the so-called 'microbial dark matter,'" Nakayama told USA TODAY. Indeed, the discovery of Sukunaarchaeum's bizarrely viruslike way of living 'challenges the boundaries between cellular life and viruses,' Kate Adamala, a synthetic biologist at the University of Minnesota Twin Cities who was not involved in the work, told Science magazine. 'This organism might be a fascinating living fossil – an evolutionary waypoint that managed to hang on.' The study concludes that "further exploration of symbiotic systems may reveal even more extraordinary life forms, reshaping our understanding of cellular evolution." "I am not an expert on the philosophical definition of 'life," Nakayama said, adding that the definition is not uniform among scientists and is a subject of continuous debate. "Many scientists would agree that cellular structure, the ability to replicate, and the ability to metabolize are key features of life. Viruses typically lack these features," he said. "The discovery of Sukunaarchaeum is interesting in this context because it lacks one of those key features: metabolism. The existence of a cellular organism that seemingly lacks its own metabolism provides a new and important perspective to the ongoing discussion about the definition and minimal requirements of life." Contributing: Joel Shannon, USA TODAY This article originally appeared on USA TODAY: A mysterious microbe raises questions about life
Yahoo
01-07-2025
- Science
- Yahoo
Scientists Just Discovered a Creature That Breaks the Rules of Life
In the ever-expanding universe of microscopic life, scientists have uncovered something that might force us to redraw the boundaries of what counts as 'alive.' Meet Sukunaarchaeum mirabile, a tiny cellular oddity recently discovered by researchers in Canada and Japan, according to a new paper published on the bioRxiv server. It's not quite a virus, and it's not fully a living cell either, but it carries traits of both. Named after a Japanese deity famed for its small size, Sukunaarchaeum sports one of the smallest genomes ever recorded—just 238,000 base pairs, less than half that of the previous smallest-known archaeal genome. And while viruses are typically excluded from the tree of life due to their reliance on host cells for key functions, this organism complicates that definition in a big way. Like a virus, Sukunaarchaeum relies on a host to carry out many of its biological tasks. But unlike a virus, it's capable of building its own ribosomes and messenger RNA. These are the basic building blocks that enable an organism to translate genetic code into protein, which is something viruses can't do on their own. Its stripped-down genome reveals an obsessive focus on replication. It contains little else besides the machinery needed to copy itself. 'Its genome is profoundly stripped-down, lacking virtually all recognizable metabolic pathways, and primarily encoding the machinery for its replicative core: DNA replication, transcription, and translation,' the researchers wrote. This means it leans heavily on its host for everything from energy to nutrients. The discovery happened almost by accident. Molecular biologist Ryo Harada and his team at Dalhousie University were examining the DNA of a marine plankton species when they found a strand of genetic material that didn't match any known organism. After digging deeper, they identified it as part of the Archaea domain—a group of ancient microbes from which modern complex cells likely evolved. If Sukunaarchaeum proves anything, it's that nature doesn't follow strict definitions. In fact, this discovery could fundamentally reshape how we think about cellular evolution and the blurry line between life and Just Discovered a Creature That Breaks the Rules of Life first appeared on Men's Journal on Jul 1, 2025
Yahoo
30-06-2025
- Science
- Yahoo
Scientists Discovered a New Creature That Exists Between Life and Not-Life
Here's what you'll learn when you read this story: Viruses typically aren't considered 'alive,' as many core biological functions are outsourced to their hosts. But a newly discovered organism appears to straddle the line between virus and cell. Like a virus, this new organism 'Sukunaarchaeum mirabile' outsources some functions to its host, but can still create its own ribosomes and RNA. Its genome is also surprisingly small, and is roughly half the size (238,000 base pairs) of the next-smallest archaeal genome. At first glance, creating a definition for 'life' seems somewhat straightforward. Sentient animals all the way down to single-celled organisms capable of reproduction are welcome on the tree of life, but there are other organisms that challenge this understanding, like viruses. Because virus don't grow, reproduce on their own, or make their own energy, they're typically excluded from definitions of life. But once a virus infects a host, it's immensely active, and can be responsible for world-altering events (see: Spanish flu, ebola, COVID-19, and so on). However, life is complicated, and this controversial categorization of 'life' and 'not life' can have gray areas in which organisms appear to defy the expectations of both camps. Recently, scientists found a new member of this head-scratching cadre. In a new paper published on the bioRxiv server, researchers in Canada and Japan outlined how they identified a new cellular entity that appeared to straddle the typical definitions of a virality and cellular life. Currently named 'Sukunaarchaeum mirabile' (after a deity in Japanese mythology known for its small stature), this entity contains the necessary genes to create its own ribosomes and messenger RNA—something your typical virus lacks. But like a virus, it offloads certain biological functions onto its host and it appears singularly obsessed with replicating itself. 'Its genome is profoundly stripped-down, lacking virtually all recognizable metabolic pathways, and primarily encoding the machinery for its replicative core: DNA replication, transcription, and translation,' the authors wrote. 'This suggests an unprecedented level of metabolic dependence on a host, a condition that challenges the functional distinctions between minimal cellular life and viruses.' Led by Ryo Harada, a molecular biologist from Dalhousie University in Halifax, Nova Scotia, the team chanced upon this strange creature while studying the bacterial genome of the marine plankton Citharistes regius. Within the genomic data, Harada and his team found a loop of DNA that didn't match with any known species. They eventually determined that the organism belonged to the domain Archaea—a group associated with prokaryotic cells, but from which eukaryotic cells (i.e. you and me) ultimately descended a couple billion years ago. Perhaps the most remarkable feature of Sukunaarchaeum is its extreme genome reduction, with only 238,000 base pairs of DNA. Viruses, as Live Science points out, can contain many hundreds of thousands more base pairs, and can even reach up into the millions. As for fellow archaea, the smallest known complete genome within this group stretches to 490,000 base pairs, meaning that Sukunaarchaeum contains less than half the number of base pairs posessed by even the smallest archaeal genome. 'The discovery of Sukunaarchaeum pushes the conventional boundaries of cellular life and highlights the vast unexplored biological novelty within microbial interactions,' the authors wrote. 'Further exploration of symbiotic systems may reveal even more extraordinary life forms, reshaping our understanding of cellular evolution.' You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
NZ Herald
02-05-2025
- Health
- NZ Herald
Understanding gut microbiome and what it means for your health
Speaking to Francesca Rudkin and Louise Ayrey on their NZ Herald podcast, The Little Things, he said it is amazing to consider how familiar people are with the gut microbiome now, given it wasn't long ago that there was 'zero awareness' even among the medical community. 'We've come a long way to where now this is bordering on a mainstream conversation that you may be having with other people. I love that. 'It's important for everyone to understand that there has been this huge discovery that's taken place during the last 20 years in science, and it's transforming the way that we think about our own body as humans – and that is the microbiome. 'So it turns out that we are completely covered from the top of our head to the tip of our toes with invisible micro-organisms, bacteria, yeasts, these things called archaea. 'They're there in all of those places. Our skin, our nose, our mouth, but they're most concentrated inside of the large intestine, which is the colon. 'And in that place, just that place alone, your large intestine, you will find approximately 38 trillion micro-organisms now.' To put that into context, Bulsiewicz said if you took every star in our galaxy and put them into a ball and put it into your large intestine, you would have to do this 380 times. 'So you have 380 galaxies full of stars. And perhaps even more shocking to me is that we only have about 30 trillion human cells. 'So with total clarity, I can say you are less than 50% human.' He said that among the 380tn micro-organisms, the viruses, bacteria and parasites in there aren't necessarily always working in harmony, but we have evolved to give these micro-organisms a lot of control over our bodies, including our relationship to nutrition, inflammation, metabolism, and the immune system. 'Seventy percent of your immune system resides within the wall of your gut. 'And in fact, so close to these microbes that just let me pretend for a moment that we pick up our microscope and we take a look and we're zooming in on this very, very minute part of what's happening inside of you. 'And what you would see is you would see these microbes and then there's a single layer of cells, we call it the epithelial layer, and it's thinner than a fraction of a hair off the top of your head. And the epithelial layer separates those microbes from the immune system on the other side, 70% of the immune system is on the other side.'
