SciShow Tangents - Viruses with Deboki Chakravarti

Episode Date: March 3, 2020

Viruses are the subject of confusion & misinformation. Luckily, we have a friend who knows a lot about them! We sit down with microbiology genius Deboki Chakravarti to talk viruses. Be sure to check ...out more of Deboki’s work on Journey to the Microcosmos, and the upcoming Crash Course Organic Chemistry! Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Stefan: @itsmestefanchin Ceri: @ceriley Sam: @slamschultz Hank: @hankgreenIf you want to learn more about any of our main topics, check out these links:[Truth or Fail]Tulipshttps://www.nytimes.com/2017/05/11/science/broken-tulips.htmlhttps://amsterdamtulipmuseumonline.com/blogs/tulip-facts/broken-tulips-the-beautiful-curseCoffinshttps://blogs.weta.org/boundarystones/2016/12/21/then-there-were-no-coffinshttps://www.acf.org/the-american-chestnut/[Fact Off]Multicomponent Viruseshttps://www.cell.com/cell-host-microbe/fulltext/S1931-3128(16)30310-9https://www.sciencedaily.com/releases/2016/08/160825141714.htmPolydnaviruseshttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4424053/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758193/https://www.sciencedirect.com/science/article/pii/B9780123846846000264https://www.sciencedirect.com/science/article/pii/B9780123848581000096https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553618/[Butt One More Thing]Caribou poop frozen virushttps://www.sciencemag.org/news/2014/10/virus-resurrected-700-year-old-caribou-dunghttps://www.pnas.org/content/111/47/16842

Transcript
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Starting point is 00:00:00 Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. This week, Hank is not here, but I'm here, Sam Schultz, hosting instead of Hank. And joining me is Stefan Chun. Hello. Okay, and then I'll ask you the kind of question Hank asks you. Stefan, what's your favorite dinosaur? Stegosaurus.
Starting point is 00:00:39 That's everybody's favorite dinosaur. No, wait, that's not the one I was thinking of. I visualized the ankylosaurus. The one with the big tail. Second best one. Any of them with the weapons for tails. Those are all really good. Also with us is Sari Riley. Hello. Sari, what's your favorite dinosaur? Oh, I got
Starting point is 00:00:55 the same question. Yeah. Maybe a plesiosaur. I think those are the ocean ones. That's not a kind of dinosaur. Ah, shoot. If it swims or flies, it's not a dinosaur. Ah, shoot. So we or flies it's not a dinosaur ah shoot so try again raptors like little raptors a velociraptor a little velociraptor i feel like they didn't look they're like chicken sized instead of like small more cute than scary yeah it's a respectable choice whoa who's that well surprise hank is on assignment he's gone but in his place we have
Starting point is 00:01:22 deboki chakravarti our editorial assistant and also the host of the upcoming Crash Course Organic Chemistry. Hi, Deboki. Hi. I'm excited to be here, but also so nervous. It's like when you go on Jeopardy, I feel like. Which one of us is Alex Trebek? Banks on here, I think. Sam, probably. Me? No, it would be Ken Jennings, the bad boy.
Starting point is 00:01:43 No, Ken Jennings is not the bad boy. Yes, he is. No, the new guy. James, who bets all of his stuff. Oh, the guy who's like the gambler guy. A thousand percent the bad guy. Who's like all in. Yeah. Yeah, you're right. Well, anyway, who's your favorite dinosaur? I think I would go with the Triceratops.
Starting point is 00:01:59 Great answer. And I'm Sam Schultz, like I said before, and my favorite dinosaur is the long neck one every week here on tangents we get together and try to one-up amaze and delight each other with science facts we're playing for glory but we're also keeping score and awarding sandbox from week to week we do everything we can to stay on topic but judging by previous conversations we are not very good at that and we'll maybe be even worse without hank here to us straight. So if the rest of the team deems a tangent unworthy, we'll force you to give up one of your sandbox.
Starting point is 00:02:29 So tangent with care. And this week, as always, we introduce the topic with a traditional science poem. This week by me in the style of Emily Dickinson's Hope is a Thing with Feathers. A virus is a thing with proteins that perches on a cell and replicates its nasty genes and never stops at all till t-cells and their friends arrive and sore must be your body while they smash the little guys making your nose snotty i've had the chills and fever too i've thrown up quite a lot because a virus drifted in and an illness I have got. That's very beautiful, but I know a lot of that was Emily Dickinson.
Starting point is 00:03:09 Oh, almost none of it was anymore. Just the rhymes. And the words and the structure. Well, so thanks, Emily Dickinson, but I did a lot of the work too, okay? If Emily Dickinson had known about viruses, I think she would have. She would have wrote that poem instead of the one about birds or whatever it was about this week's theme is viruses deboki and sari what is viruses what b yes basically they're little capsules with genetic material inside either dna or rna there are different kinds depending on the virus. They are extremely tiny.
Starting point is 00:03:45 Most of them, by and large, are much smaller than bacteria. And they can cause some of the diseases that we have, like the ones you listed in your poem, like the common cold is a viral infection, the flu is a viral infection, but you can have bacterial infections as well. One of the key things about viruses, I think, is that they use other cells to reproduce.
Starting point is 00:04:06 They can't do anything really on their own. They're just like a bit of DNA or RNA or whatever. Like a shell, right? It's like a gene pill. And then other cells swallow. Sorry. Oh, no, no. Keep going.
Starting point is 00:04:19 So other cells swallow them and then they're like, do my bidding, cell. You should have let the bokeh start taking over. So virus, yeah, like you're saying, they are, their DNA packed up or some kind of genetic material packed up in protein. And they just, they don't have that machinery to basically do what you need to do when you're a living thing, which is to keep replicating your DNA. So they hijack other cells and basically say, hey, you've got all that machinery. Why don't you do this for me? I mean, they don't ask. They just do.
Starting point is 00:04:50 And so they have different ways of doing this. They have different proteins that will basically get them into a cell. They have mechanisms to integrate into the DNA, all of these things. And then the cell will not only make the DNA, they'll make those proteins and everything to like get recapitulated back into a virus. And the cycle repeats. Where do they come from? We're not entirely sure. The big debate about viruses is whether they're alive or not. Why they're on the edge is because, like Deboki said, they can't reproduce without a host. So if we couldn't survive and create energy and reproduce on our own,
Starting point is 00:05:29 then should we be considered alive? But they have genetic material and they can do things. What can they do? What do you mean? I guess by do things, they can infect things. And they have the genetic material to replicate themselves. They just can't make it work. So they have like moving parts? Yeah, maybe.
Starting point is 00:05:48 I don't know. How are they squirting things and stuff like that? Chemical binding starts getting into the weird mathy part of biology where it's like there's a probability of these two things connecting and chemicals make their have a higher probability, statistics, etc. We don't need to talk about subatomics. probability, statistics, etc. We don't need to talk about subatomics stuff again.
Starting point is 00:06:06 But as far as why they exist, people are like, I don't know, maybe there was some floating genetic material because our bodies have a bunch of proteins in them too. I don't know, how did any cell exist at some point? Genetic material got
Starting point is 00:06:21 encapsulated by something else. In this case, instead of getting encapsulated by a cell membrane, it was just encapsulated by something else. And so in this case, instead of getting encapsulated by a cell membrane, it was just encapsulated by a protein and then somehow kept replicating. I don't know. Life is weird. The first line of my poem was, they have proteins. And that was a big swing on my part. That was right? That's true. Is there like a virus family tree or are they just a bunch of weirdos who are floating around?
Starting point is 00:06:45 It's hard to figure out because a lot of our trees that we use in biology are built on understanding how genetic sequences are related to each other. And with viruses, both because they mutate so much, that's super tough. And then they're so tiny, hard to isolate. Like it's very tough to figure out how they're all related. Do you want to know the etymology of virus? Oh, gosh, yes. It's from the Latin, also virus, for poison, sap of plants, slimy liquid, a potent juice, or like basically Latin and Greek roots for poison, which is interesting because they
Starting point is 00:07:20 were just like, this is a bad thing. Didn't quite understand microbes yet or disease yet. And on Wikipedia, it looked like we've only been like aware of viruses from like the 1840s or something like that. Yeah, it's very recent. People have sort of had a sense that like there are invisible things that are like affecting your health for a long time. Before we knew what microbes even were. So I think this was like just narrowing down the different types of invisible things that are out there. It's not necessarily about stink.
Starting point is 00:07:51 It's a tiny little guy. Yeah. And we learned about bacteria and things first. And so it's like we can grow those on a Petri dish. But because viruses need hosts, they're harder to isolate. So that happened, I think, even in the early 1900s with a virus in a tobacco plant. It wasn't even an animal virus. It was like, oh, this plant
Starting point is 00:08:09 is acting weird. Why? Finally isolating the structure. That was what Wikipedia said. I can back you up on that. Fact check. I think we know what viruses are, so we're going to move on to Truth or Fail. One of our panelists has prepared three science facts for our education and enjoyment, but only one of them is true.
Starting point is 00:08:28 The other two are giant lies. The three other panelists had to figure out by deduction or wild guess which fact is true. And if we do, we get a sandbuck. And if we don't, then Deboki, who is our truth or failure this week, gets the sandbucks. So, Deboki, what are your facts? Okay. Viruses don't just infect us, they don't just infect humans, they can also infect plants. And so that is kind of terrifying
Starting point is 00:08:51 because plants and crops are important to us. So the following three things that I'm going to tell you about are stories from history of a time when viruses wreaked some havoc on us indirectly through plants. Fact number one, tulips made their way to the Netherlands towards the beginning of the 17th century, where, as the tulip mania story goes, they may have set off a bit of a bubble, as people spent large amounts of money trying to buy the most beautiful varieties. The most striking one of all was the broken tulip Semptor Augustus, which had these gorgeous stripes that everyone wanted but had a hard time cultivating. Unfortunately, they didn't know that the breaking of the tulip into those stripes were the product of a podivirus that, as viruses are wont to do, killed off the
Starting point is 00:09:33 tulip, making the market that much more of a gamble. Fact number two, in 1898, the dreaded endothia virus decimated the American chestnut tree population, which was a problem because this was the tree of choice to produce coffins in the U.S. Cities and towns faced a critical shortage of coffins that turned into a public health concern as corpses began to pile up. In responses to this reduced supply, the cost of coffins went way up, leaving many public health officials in panic over what to do with the unburied corpses in their town. One official in Pittsburgh became so concerned for a city that he turned to robbery, rerouting a train to D.C. that had some precious coffin supply to his own city. Fact number three, sumer oranges or decopans are, in my opinion, the best oranges, and they're also the product
Starting point is 00:10:21 of a 1974 viral epidemic in Japan. The culprit was citrus tristezavirus, a virus that is the bane of many a fruit grower because it basically wipes citrus fruit out. During the Japanese outbreak, which destroyed many of their trees, one of the few trees remaining was the Dekopon tree, a cross that one grower had been experimenting with between two other varieties that was somehow resistant to the virus. And now we have the Dekopon. These are the new and improved oranges. So we got fact number one, Bodivirus was making striped tulips but also was deadly to those tulips. Yeah.
Starting point is 00:10:57 Fact number two, the Endothia virus decimated American chestnut trees leading to coffin shortages. Yes. Or number three, sumo oranges or decoupons are the best orange, according to Deboki, and they are also the product
Starting point is 00:11:12 of a 1974 viral epidemic. Not the product of, but the solution to. Yeah. Okay. Let's go ahead. Tulips, chestnuts, or oranges. Yeah.
Starting point is 00:11:20 They could just burn the bodies, right? So I don't know if I believe that one. Also, just use a different tree. Yeah. I do know that the American chestnut tree, well, I shouldn't say I know. I think the American chestnut tree underwent some kind of decimation, but I don't know at the hand of what. It is like a pretty hefty tree. You won't take, I think, a birch tree.
Starting point is 00:11:43 Is that the white one that's really skinny? Yeah. No coffin maker worth their salt is using birch trees. I don't know what these oranges taste like but I want to try one now. This makes sense to me that they like almost killed out all the trees and then they were like ah yes
Starting point is 00:11:59 turns out this one's fine because that's kind of like what happened to bananas maybe. Yeah. That makes it a good lie. Change it to a different fruit. Yeah, just a different fruit. Easy. And tulips, I have no idea. So it would be a gamble because sometimes it would kill the stripey one and sometimes it wouldn't kill the stripey one? Is that what the word is?
Starting point is 00:12:14 Well, the virus is the source. Right, of the stripey-ness. So it was just like reducing the supply because they would die? Is that the thing? Yes. Okay. Making it harder for them to grow in mass amounts because you have to grow a bunch. That's a great business model, I have to say.
Starting point is 00:12:29 What do you mean? Pick something that's in short supply and charge a lot for it. And it's pretty. I'm going to vote for oranges. I think I'm also going to go for the oranges. But I do think there's something to be said about just switch bananas out for oranges. Yes. I also think
Starting point is 00:12:46 the tulips seem pretty convincing. I was on the fence between those two and if Sam had gone first, I would have voted for tulips. I feel like the tulips is the real one. Nobody's going for coffins. I think that's the fakest fake of everything. I agree with that. If it's real, I'm going to be mad because I got persuaded.
Starting point is 00:13:01 I didn't think for myself at all. Do you want to change to coffins? No. All right. The bogey? Okay. Are you guys ready? It was the tulips.
Starting point is 00:13:11 You're right that the fruit one was definitely just to sub out the fruit. But I was thinking about Meyer lemons, which was in the 1960s. There was a huge epidemic of this virus, the citrus virus, that wiped out almost all the trees in California. And then it was just this one tree left that was the one that somehow was not infected. And that is the source of our Meyer's on this team. All Meyer lemons? I don't know about all of them, but that's, yeah.
Starting point is 00:13:37 That's the new and improved Meyer lemon, I think is what it's called. With regards to the coffin shortage, as you guys said, there was an epidemic that kind of wiped, not kind of, definitely wiped out the American chestnut trees, but it was a fungal thing. But in 1918, there was an actual coffin shortage in DC, but it was because of an influenza epidemic. That's a Spanish flu, right? Was that Spanish flu? Yeah. And so the public official in charge was pretty much like we don't have coffins this is becoming terrible they couldn't get people to bury the bodies it was this whole thing and he actually got a train that was en route to pittsburgh to be rerouted to dc
Starting point is 00:14:15 so that they could take their coffins then because he had wartime powers i guess like i guess this was a great time to be a public health official the cost cost of coffins had been getting super, super high. And so, like, everyone was getting frustrated. Like, there was actually an op-ed in the Washington Post about how, like, stupidly expensive coffins were at this time. And he seized on his wartime powers and basically demanded that all the coffins be sent to him. And then said, like, this is going to be the price of the coffins. He adjusted them for the better or for the worse? Yes, yeah.
Starting point is 00:14:45 So he made it so that they could actually get coffins to bury people in. Were they made out of chestnut trees? I don't know. But yes, the tulips of that basically inspired so much obsession and love in the Netherlands that some people have called tulip mania. Apparently economists now sort of debate whether that's actually the case. It might not be a bubble because supposedly there was like some rational behavior associated with it because it was a good, that was actually a compelling thing to buy. They still got a ton of tulips over there.
Starting point is 00:15:17 So yeah, it's still a thing. Except for this one tulip that everyone was most obsessed with, which had these gorgeous, gorgeous stripes. They're called broken tulips because I guess it's like breaking into color. And they were infected with this virus called the tulip breaking virus, which we didn't know about, I think, until like the 1930s. The flowers were so frail because of the virus that artists were actually commissioned to paint them. People were so proud of this flower that they own but also so worried about them dying that they were like paint my flower I guess. Still people Capture the beauty forever.
Starting point is 00:15:49 Yeah. But still they didn't know it was a virus. They just knew that this flower was gorgeous and somehow died easily. They also didn't know how to cultivate it
Starting point is 00:15:59 because they didn't know that the reason why these different flowers were getting this pattern was because these insects I think were transmitting the virus between them. So they just pop up every now and then. Yeah.
Starting point is 00:16:08 And you'd be like, oh, my goodness. It's like a four-leaf clover. Yeah. And so that's what actually made this market is people were basically speculating around tulip bulbs. They were getting these tulip bulbs that they were, like, hoping would end up being the super beautiful flower and, like, having to wait to see what would happen. It's like a gachapon machine. That's just freaking. That's amazing.
Starting point is 00:16:26 They're like loot boxes. Yeah. Are you going to get a rare tulip or are you going to get a stupid common? Except like everything back then you had to wait like seven months. Yeah, no instantaneous like jolt, which is probably why it actually went away. My favorite stat from this, like in terms of the money, again, not all tulips went for like a stupid amount of money, but one went for 3,000 guilders,
Starting point is 00:16:52 which was a lot of money apparently. There's a list that I saw that tallies like how much you could buy for 3,000 guilders. It includes eight fat pigs. I knew it was going to be more things that I have no idea how to judge well a thousand pounds of cheese is in there
Starting point is 00:17:09 yes that's true and a ship and like that's still not the whole list you get like a hundred pigs or a ship no and a ship
Starting point is 00:17:16 not even or this is everything together yeah how much are pigs worth well quite a bit you can make more pigs out of them
Starting point is 00:17:23 you can make bacon out of them endless I don make bacon out of them. Endless. I don't know what else. But maybe they're like cheap enough that you could just like that's what your
Starting point is 00:17:29 leftover money was pig money. One additional postscript you can get stripy tulips now that don't have the virus but people had to cultivate those
Starting point is 00:17:36 and I think that took a lot of work. All right. That was very good. That was extremely good and extremely tricky. I'm so glad.
Starting point is 00:17:43 It was really tricky. I'm glad. I wasn't sure. You wrote like big historical fanfic about yourself. That's what I like to do. Yeah. All right. Next up, we're back. Let's go over the scores, shall we? Sarah, you have zero points. I know.
Starting point is 00:18:19 I have one point for my poem. Stefan has one point for guessing real good. And Deboki has two points for being very, very tricky. Now, get ready, Stefan and Sari, for the fact-off, where each of you will bring a science fact
Starting point is 00:18:31 to present to us in an attempt to blow our minds. We each have a Hank book to award to the fact that we like the most, but if both facts are bad, we're going to throw them
Starting point is 00:18:39 in the trash. And to decide who goes first, you're going to answer this question. Whoever's closest gets to decide if they go first or not. In what decade was human coronavirus first identified?
Starting point is 00:18:50 I'm going to say the 1970s. Let's go 90s. Oh, radical. We'll see. We'll see. Deboki, you want to guess just for fun? I'll go 80s. Oh, boy.
Starting point is 00:19:01 It was the 1960s. Oh. An even better decade. Stefan, you go first. Okay. In 2016, a team at the U.S. Army Medical Research Institute of Infectious Disease was looking for mosquito borne diseases to help fight epidemics. And they found a virus that was infecting mosquitoes in Trinidad. As we talked about earlier, like viruses, you've got a bit of genetic data that's contained in a protein capsule. And in most cases, all of the data is contained in this protein capsule. But there's a type of virus that they found in these mosquitoes that's very weird. Because instead of all the information being contained in that one package,
Starting point is 00:19:42 this virus splits the genome into multiple pieces and then individually wraps them into five unique packages and they call this a multi-component virus and so you have these five different packages of info that get sent out into the world and then in order to infect a new cell the new cell has to like collect the whole set and like get at least four out of the five of these packages in order to make it work. And it's a specific four out of the five. The fifth one has the smallest amount of gene information in it, and it seems like it's optional for making the virus work. So it's not any four. It's like the Monopoly tokens on McDonald's bags. You need a set
Starting point is 00:20:26 of at least four or five to win the prize, which is being infected. Yes. And the fifth one is like Baltic Avenue. Exactly. This specific virus they found is called Guico-Coolex virus or GCXV. And Guico, I'm
Starting point is 00:20:42 sure I'm saying that terribly. That's the city in Trinidad where they found the mosquitoes. And Culex or Culex is the genus of mosquitoes. So after sequencing this genome, they found that it's part of a group of viruses that are called the Qingmin viruses. And that's named after a virus that they found in a city in China. But all of the viruses in that group have these segmented genomes with at least four segments each. But GCXV is the only one that we know of that uses this multi-component like packaging system. One of the viruses in this group has been found in monkeys. So that one can infect
Starting point is 00:21:18 non-human primates. But with this virus, GCXV seems to be specific to mosquitoes. So it's not something that we probably have to worry about. The piece of information that I've been a little bit like avoiding talking about until now is that this multi-component packaging strategy is something that's pretty common in viruses that infect plants and fungi. But it's not something that we found in animals until this 2016 paper it seems like we don't really know why that is i mean splitting up the genome and like having to wrap each one and then having to get all four into a cell is like a pretty inefficient way of transmitting data so it seems like that's a disadvantage to doing it that way but they think that it might be an adaptation to some of the differences between plant and animal cells, maybe having to do with plant cell walls. But with this discovery now, we at least know that it's possible for these kinds of viruses to be infecting animals
Starting point is 00:22:14 as well. That's so cool. I had no idea these things existed and they're like evil trading cards. Yeah. It kind of reminds me a little bit of how we use viruses actually for genetic engineering purposes. I don't think it's the exact same because this is different virus particles that have different components of the genetic material, right? But when you use viruses for genetic engineering purposes, which people like to do because they're really great at integrating DNA into other cells, You also want to be safe because you're dealing with viruses. And one way that people have engineered safety into this process is by taking the different pieces of viral DNA and putting them on different parts of DNA that you can store separately until you actually need them to make your virus. So you only mix them together like when you're actually getting ready to make your virus particle. So they're like kind
Starting point is 00:23:04 of like a multi-component system that only get mixed at the ready to make your virus particle. So they're like kind of like a multi-component system that only get mixed at the end to make that final virus. I was like, Stephanie will go first so that I can build up my confidence to do my fact. But now his fact was so good. And mine is also vaguely related, which is weird. There are lots of different kinds of viruses, but the one I want to talk about is half of an unlikely dream team, a parasitic wasp and a polyDNA virus. So different species of parasitic wasps have different polyDNA viruses
Starting point is 00:23:32 specific to them, and not all of them have this partnership going on, but the general symbiotic relationship between them is the same. The parasitic wasp wants to lay its eggs in a caterpillar so that they can hatch and eat the caterpillar flesh because it's tasty. We and caterpillars have immune systems to protect us from invaders. So the polyDNA viruses basically act as the wasp's venom and get injected into the caterpillar to compromise their immune system so that the wasp eggs can survive and grow, which is what the packages made me think of. It's just like, here, have some virus. And then also my eggs. And the polyDNA virus, as much as a virus can want anything, like wants to make more of itself, normally it would need a host because all viruses need hosts,
Starting point is 00:24:14 but it particularly needs these parasitic wasps because it doesn't have the genetic material to do it without them. So proviruses get passed down from generation to generation of wasp just because they're incorporated in their genome. And the virus is only created in calyx cells in the reproductive tract of female wasps because the viruses don't have the genetic material for replication themselves. And so they don't proliferate on their own in the caterpillar. They need the wasp to make more of themselves. So basically, poly DNA viruses are really weird because they mess up the definition of virus even more because it's in the middle ground of having everything for replication except for the host and remnant virus ingrained into our DNA. It's like ingrained into something else's DNA. And when the wasp is like, time to lay eggs, then there are viruses. Why is that considered a virus at all i think it's considered a virus because the genetic sequence that it's from was originally
Starting point is 00:25:15 from a virus that we think infected the wasp and it acts like a virus in that it like replicates it has the pieces of a virus which is genetic material surrounded by a protein. And in the caterpillar, it's like a distraction to the immune system because the caterpillar's immune system is like, ah, a virus! And then starts dealing with that without realizing there's a bigger problem, which is this egg that is going to hatch. So we have multi-part viruses. You have to collect the right group to get sick.
Starting point is 00:25:43 Or we've got parasitic wasp virus egg babies is that about right? yeah 1, 2, 3 Sari what? you have said my name
Starting point is 00:25:57 oh no I got stole from I'm like the coffin train I got rerouted I wasn't smart enough to understand yours and then these guys said whoa that's so cool and I was like oh yeah okay I would have voted for Stefan thanks honorary buck
Starting point is 00:26:15 alright well let's move on to ask the science couch where we ask science questions to our couch of finely honed scientific minds our question is from at flux filter and they ask, can viruses jump from plants to people in the same way they can sometimes jump from other animals to people? So animals that can be vectors of disease like rats or mosquitoes can carry viruses.
Starting point is 00:26:38 And then like we can get in contact with their poop or they can bite us and somehow get the virus into our system. But plants don't poop. But even more you consume them oh that's true so there's still ways to engage with plants because deboki's here i now have science couch seniority and so i'm going to be the hank of this episode and just take a wild stab in the dark and say that because animals and humans have similar kinds of cells so like we have like squishy cell membranes then the viruses that infect our different populations can more easily like they recognize an animal cell and can recognize a human cell and there's probably similar proteins to let it go inside. But with plant cells, they're just like structured differently. They're cell walls holding everything in.
Starting point is 00:27:29 They have chloroplasts and mitochondria, and we just have mitochondria. So there's like differences in the structure of plant cells that I imagine to be a plant virus, you need to have like a different set of breaking and entering skills. And so that's why there's not a lot of cross transmission because you need to be like a very, very multi-talented virus to jump from plant to human. So I don't think there are any, but Deboki actually did research. Yeah. So the answer is that we don't really quite know, which is how all good biology questions really go.
Starting point is 00:28:05 So sort of like in line with what Siri is saying, like there is sort of this general belief that plant viruses cannot make it over into animals, in particular vertebrates. Like there are a lot of insects that will act as like vectors for transmission of viruses from one plant to another, but it doesn't seem like there are really any plant viruses that have made their way into humans, except that researchers have also looked into
Starting point is 00:28:31 whether or not there is evidence of plant viruses ever having been inside of us. So there's a study where the scientists looked at the human subjects' fecal samples and isolated viral particles to get their sequences, and they found that from those viruses, there was a bunch that looked like plant viruses, and that some of those plant viruses actually look like viruses that come out of commercial crops, so things that you're probably eating. And one of the ones that I think people are kind of latching onto as potential evidence that there are plant viruses that can make it into us, is this virus called pepper mild model virus, or PMMOV, which apparently in other follow-up studies people have found
Starting point is 00:29:12 does seem to make its way into humans. There was another study where they actually, again, tested stool samples and then also looked at food products that had chili pepper in it to see if that virus was in the chili pepper and also in the stool samples. And they found it in both. It was definitely in a higher percentage of the chili pepper products compared to people, but it was there. Were we able to see if it was like actually interacting with our cells or is it just that like it passed through and we poop it out? So there was evidence that there were antibodies that were able to bind to the virus, was evidence that there were antibodies that were able to bind to the virus, which is potentially a sign that there is some kind of interaction between our immune system and this virus.
Starting point is 00:29:53 But it does not mean that we are actually dealing with transmission of this full disease from a plant to us either. So basically, one of the problems is that we're not actually seeing that the virus is making its way into a cell, putting its DNA in there, getting it in there, really hijacking machinery again. That's like going full virus, taking advantage of it and replicating in that way. So it seems to be there, but we don't really know what it's doing. So no one has eaten a chili and then gotten the flu based on a virus out of that plant. There was evidence of fever, abdominal pain, and itchiness, but they're eating chili peppers.
Starting point is 00:30:36 Again, they're not sure that it's really a virus that is causing problems for the people. If you want to ask the Science Couch, follow us on Twitter at SciShowTangents, and every week we'll tweet out the topic for upcoming episodes, and you can send us whatever you want to know. Thank you to TheJayman222, sounds like a cool dude, at Krebshouting, and everyone else who tweeted us your questions for this episode.
Starting point is 00:31:02 Final Sandbox scores. Sari, you came back back and you have two points. Tied for first with the Boki, who also has two points. I have one point. Stefan has one point. The way it should be. No. That seems about right to me.
Starting point is 00:31:15 If you like this show and you want to help us out, it's really easy to do that. First, leave us a review wherever you listen. It's super helpful, especially on iTunes. Puts us up on them charts. Second, tweet out your favorite moment from this episode and finally if you want to show your love for sci-show tangents just tell people about us at the same time we say it okay okay well i won't try it again next week
Starting point is 00:31:37 to book you try to remember please though thank you for joining us if you want to hear more from deboki be sure to keep an eye out for Crash Course Organic Chemistry coming in April. Deboki, is there anywhere else you want people to check you out? Yeah, I'm on Twitter at okidoki underscore boki. And I also write for Journey to the Microcosmos, so you should also check that out, especially if you want to learn about the things that are a little bit bigger than viruses, but also just as cool. All right, so thank you. And for SciShow Tangents, I have been Sam Schultz.
Starting point is 00:32:04 I've been Stephen Chin. I've been Schultz. I've been Stephen Chin. I've been Sari Riley. I've been Deboki. Chuck Ravarty. Okay, close enough. SciShow Tangents is a co-production of Complexly
Starting point is 00:32:14 and the wonderful team at WNYC Studios. It's created by all of us and produced by Caitlin Hoffmeister and me, Sam Schultz, who also edits a lot of these episodes
Starting point is 00:32:22 along with Hiroko Matsushima. Our sound design is by Joseph Tuna-Medish. Our social organizer is victoria bongiorno and we couldn't make any of this without our patrons on patreon thank you and remember uh should i just say hank's thing yeah if you want to or you can make something up thank you and remember use your brain bro You're praying, bro. But one more thing. A DNA virus and part of an RNA virus were resurrected from 700-year-old frozen caribou poop. But they're very different from modern viruses, and we're not sure what they infected.
Starting point is 00:33:14 We think it's maybe a plant or a lichen. But part of why we don't know is because we don't study a lot of subarctic viruses. Basically, what this means is we don't have to really worry, but maybe we should be a tiny bit worried because viruses can be frozen and then resuscitated after hundreds of years. Ancient thawing viruses legitimately freak me out. How big of a concern is that? Should it be to me? Low. But higher now that climate change is a thing. Now that everything is melting?
Starting point is 00:33:39 Now that everything is very melting.

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