Virus Like Entities That We Never Knew Existed Until Recently

Added: 2026-05-28

[00:00:00]Hello for this is Anton and today we're going to discuss some of the more unusual discoveries when it comes to microbiology that essentially explore the absolute limit of biological simplicity or in other words how small and how tiny something can get while still maintaining properties we usually attribute to life. And specifically even though we believe that viruses sometimes represent the smallest possible living things. It turns out that based on the research from the last few years, there's a whole new subviral world that seems to be filled with entities that are even simpler, smaller, and of course, much more mysterious than we ever thought. And so, in this video, let's talk about some of the studies that you can find in description on a somewhat less known concept of so-called vyroids. Although here, it's such a new concept that it technically doesn't even have a name yet. And to understand why this is important and why this is so bizarre, let's I guess discuss the discovery first. The discovery of these naked molecules. And here the story starts in 1971 with a scientist named Theodore Diner, a Swiss American plant pathologist who was trying to figure out what was happening to various potato crops on various farms. Because here something was destroying potatoes. What this disease referred to as potato spindle tuber disease. And for many years, biologists assumed that this was some kind of a virus that was just not identified yet. Yet, this wonderful person found something that did not fit any of the viral patterns. And specifically, he caught the infectious agent using a filter so fine that it should have let only molecules through, not entire viruses. And so, basically here, he used such a fine filter that it actually should have trapped everything, including viruses. Yet it didn't and the disease was still able to spread which led him to a discovery of a new agent that was not a virus at all and instead was a single naked molecule of RNA.

[00:02:01]Unlike viruses here, it did not have any protective protein shell, something we refer to as a capsid, and was basically just this very tiny circular loop of genetic material only containing RNA.

[00:02:14]And he basically named these vyroids mostly because they were virus-like but not viruses. And ever since then, ever since 1971, they remained as the smallest pathological agents in biology.

[00:02:27]In other words, we know vyroids can be infectious. And so far, they seem to be the smallest. And to give you an idea of the scale, in comparison, the smallest virus would usually have a genome that's about 2,000 nucleotides long. A typical vyroid seems to be 10 times smaller at 246 nucleotides, which basically makes them sort of like an ultimate parasite.

[00:02:50]They don't really carry any of their own tools. They have no means of creating themselves or copying themselves and do not code for any proteins at all. In comparison, viruses very often bring genes that tell the cell how to build new virus parts and how to recreate a viral copy. So here, vyroids cannot even do that. That's because they're basically super small. And so instead, they seem to rely entirely on the host machinery and basically trick the host and specifically the host's enzyme called RNA polymerase, the protein that's responsible for reading the DNA molecules and producing RNA from it to instead make a copy of the vyroid ignoring any DNA instructions. And intriguingly they seem to do this by trapping these proteins in a kind of a loop or a kind of a rolling circle mechanism where the enzyme just keeps spinning around the circular vyroid RNA creating a very long ribbon of copies which are then cut into parts by a special part inside the vyroid referred to as a ribosyme. Okay, so I know this is getting pretty complicated but in a nutshell this is the most primitive parasite known to us. But the thing is for the last 50 years, so once again since 1971, not a lot of biologists paid attention to these mostly because pretty much everyone believed and this is even mentioned on Wikipedia that all nonvyroids are inhabitants of angioperms or flowering plants. In other words, everyone thought that this was just something that plants have and has no relation to us or any other organisms.

[00:04:22]In other words, viros were mostly believed to be some kind of a niche related to plant pathology and possibly farming. Everybody believed they were only affecting plants. But then everything changed in 2021. Between 2021 and 2024, several major studies you can find in description completely changed our understanding of the world of vyroids and mostly thanks to one specific genetic technique. It's known as metat transanscrytoics. basically a way to scan massive amounts of genetic data from environments like soils, oceans, and even the human gut. And to everyone's surprise, a major study in 2023 by Benjamin Lee essentially discovered vyroids everywhere. They identified 11,000 new species existing in different types of life, not just plants. First, they were identified inside fungi, where they're now referred as miccovyroids. Then, they were found inside algae. And more recently in 2024, they were also found inside various invertebrates and of course vertebrates.

[00:05:24]And though at this point it's actually unknown what most of them seem to do because not a lot of them seem to be pathogenic or basically not a lot of them seem to cause disease. At least some of these microvirids have already been discovered to change how a fungus grows, making it grow slower and altering its physical appearance or even making the fungus for some reason a lot less effective at infecting the plant host or basically it seems to have a direct bio control over several types of fungi. So inside fungi they seem to control a lot of things with various vyroids making the fungus more resistant other vyroids making them more susceptible to certain things and obviously because of this discovery this research already suggested that this could be developed into a new class of biological tools to protect crops from fungal disease. But perhaps the most interesting and the most unusual discovery was of course from our bodies.

[00:06:19]This was a joint Canadian American study based on human microbiome. And in this case, a team led by Andrew Fire from Stanford University discovered a never-before-seen class of vyroids that they now named obelisks. Something that's approximately 1,000 nucleotides long. And something that once again folds into these striking rod-like shapes that though not circular are still vyroids. In other words, we also seem to contain quite a lot of them. And in this one study, they've identified quite a bunch. And what makes them different from classic vibroids is that they don't seem to code for proteins.

[00:06:55]Instead, they seem to encode something referred to as oblins, whose function is currently completely unknown to us. We just know that they were detected in about 7% of human gut samples and approximately 50% of oral samples. So possibly not everyone contains them or more likely some people just contain very different types of these obelisks with pretty much all humans containing some with the title of the paper basically summarizing everything vyroid like colonists of human microbiome and to date scientists have already identified nearly 30,000 of them but a lot more are probably still hidden essentially representing a very unusual massive overlooked part of the human genome or technically global viral that we never knew existed until relatively recently. But I guess the scary part is that we have no idea if they're good for us or bad for us. We just know that they appear to be a common part of our internal biological landscape. So essentially pretty much everyone seems to have them. And because these have been discovered in pretty much all other organisms, it of course raises the question of why? What exactly are they doing inside of us? And while quite a few scientists have already suggested that these could be so-called living fossils which was actually the original proposition by Theodor Diner. He hypothesized that they might be the plausible candidates as the living relics from the super early development of life and specifically the idea known as the RNA world hypothesis. Something that quite a lot of scientists today seem to support. And according to this proposition, life when it just began on Earth before using DNA and proteins was possibly only using RNA or actually was RNA. And that's because RNA unlike other molecules is unique in its ability to store information and to also perform various chemical reactions similar to a typical protein enzyme. And so a lot of evolutionary biologists believe that life very likely started as RNA molecules before transforming into DNA and everything else. But in this case, these vyroids, since they seem to contain extremely small RNA particles, potentially represent the minimal version of this, forming a kind of a self-replicating loop that uses its own ribosomes to reproduce. And so, if vyroids are truly the relics of ancient world, studying them gives us a direct window into how life might have functioned over 3 and 1/2 billion years ago. But not everyone agrees with this and some of the recent data presents a slightly different story because some scientists now think that vyroids might be just escape pieces of much more modern genomes that essentially became separated and then created their own functioning RNA loops. And that's because in the past scientists have also discovered what's known as retrozymes.

[00:09:46]Tiny pieces of our own DNA that can pop out and form circular RNA that seems to resemble a typical vyroid. And so it's possible that vyroids and obelisks are just pieces of cellular machinery that somehow grew their own legs and just walked away basically becoming independent parasites instead of being a part of a functioning DNA RNA machinery.

[00:10:08]Although realistically speaking, even though there are some explanations to how they formed, don't know and will probably not know for quite some time.

[00:10:16]But at the moment, they basically represent the smallest possible piece or the absolute minimal requirement for something to basically be alive. And something that's of course subject to evolution. As of 2026, nothing smaller has been found yet. And well, based on a lot of these recent studies, what seems to be pretty clear is that we're really just scratching the surface of modern microbiology. And even though back in the days when I was going to school a lot of textbooks describe the tree of life as made out of cells and viruses, today we know that this is a very incomplete picture and there is just so much more going on inside our bodies and all of the life around us. And in this case, we now have this subviral biosphere that's existed this whole time and has never been seen until recently.

[00:11:02]But because we have no idea if these obelisks or these microyroids make us sick or make us healthy, that's why this research is actually kind of important.

[00:11:11]For all we know, maybe it's actually helping our microbiome and is making it more stable and thus making our lives better. And so since we now have tools to see this and to study them, this is what a lot of new studies are trying to focus on. Right now though, we still have no idea. Anyway, if you want to read these papers by yourselves, I've linked all of them in the description below. But we'll definitely come back and discuss this more in some of the future videos because this is definitely a somewhat interesting topic in microbiology. And so, as always, thank you for watching. Subscribe, come back tomorrow to learn something else.

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[00:11:53]Stay wonderful. I'll see you tomorrow and as always, bye-bye.