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0:00
Can I can make things a little complicated. Gone are the good old days where we could all just sort of hover around, you know, with a cocktail and network for the first half hour. So we're just going to wait a minute or two, just to let everybody in, we had almost 400 people register for for tonight's session, so might be a bit of a backlog, so I'm afraid you'll just have to bear with me. But for those 140 of you who are already here, welcome to our second session for the new
0:28
faculty lecture series. We're super excited to do this tonight. Hopefully, some of you are someplace where the weather is a little nicer than we have here in Waterloo. Perhaps you could help a girl out and maybe we could get everyone used to the chat function. I'd love to know where some of you are from. I know in the registration we had people from almost all the continents actually so that would be really cool. If anybody wanted to start in the chat. Let me know where you're from or the
0:57
year you graduated. There's 152 of you I know one of you wants to start typing London, Ontario. Alright, thanks for being the first There we go. Oh, it's coming in Ottawa. White Rock welcome. Oh, Kitchener boring. Well, you know, that's okay. We've got Australia here. Oh, gosh. Now they’re coming in so fast, places I've never even heard of. A ‘99 Grad, welcome.
1:24
Oh, hello from Calgary. Calgary. 2007. Oh, hi Leslie. Oh, Ajax Look at this. Mississauga. Cool. West Vancouver, Kentucky. Look at that. I didn't even know anybody in Kentucky, California.
1:43
Oh bio grad, class of 2018. Well, welcome back. It hasn't been long. Connecticut. Excellent. Not sure the weather there'll be much nicer. Okay, we're up to 160 people. Wet and rainy Maple Bay on Vancouver Island, biology 1972 grad. Look at that Dr. Roger downer. Oh, and cockroaches. I don't know that anything has actually changed too much. Calgary 1974. BSc in chemistry. Welcome. Oh, we got Charlotte, North Carolina. Now. I said we're gonna have a bit of a test to
2:17
win on I know my acronyms for the states. 1983 grad. Welcome, Peggy. Okay, we're up to 170 people, so I think we'll just wait one more minute if you don't mind. Oh, we've got someone here from India. Look at this professor Prem. Oh gosh.
2:35
Satsanji from India PhD 1969. I don't even know what time it is in India. Collingwood, oh Ottawa, Victoria, BC 1967 grad. Well, this is pretty great. Can't wait for this talk. Yes, me too. It's going to be it's going to be great. India. 5:30am. My goodness. Jozef. Look at that. Someone got up super early to listen to this. No pressure. A 1964 grad. Oh, we got somebody from Boston. Oh, 11am. Friday in Melbourne. Goodness, gracious, weather's great for winter. Oh, well, I'm
3:11
not sure. I'm not sure where you are. But we're about to get a big snowstorm. The other thing I should mention to everyone is when you're when you're chatting in are typing in the chat, there will be two options one to the panelists and one to all attendees. So please make sure that you're sending your message to all attendees, especially you know, if you're putting in comments or compliments for Joseph, and we have a 73, astrophysics. Amazing. Okay, so we’re up to about 180 people, so
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I think we'll probably get started now.
3:45
I always forget to introduce myself. So I'm Meaghan Middleton. I'm part of the advancement team in science at Waterloo. And it's my pleasure to introduce everybody tonight. This is something we started in September or in the in the fall of last year with the idea that perhaps our alumni would actually be really interested to hear you know, what our new faculty is doing and how the university is expanding their research profile. So we had someone Dr. Karen Cummings, from
4:10
physics start in the fall tonight as you know, we have Dr. Jozef Nissimov from Biology. Clearly, it's a it's a timely topic, especially, you know, given the fact that I'm sure at least half of us are in some sort of a lockdown. But before we get started, I have to do a bit of housekeeping. So in the good old days, this would have been where I told you when to raise your hand and how to find the washrooms but instead, I'll walk you through some zoom etiquette. So we are recording
4:35
this evening. We can't see you or hear you. So don't worry about that. We have a Q&A feature. So for anyone new to zoom, it should be on the bottom of your screen, you'll see Q&A. If you have questions, please put them there and there'll be addressed at the end of the session. But please continue to use the chat. You know, tell Joseph what you're enjoying, anything like that. Engage with the audience. You know, we'll try and make this as fun, as engaging as we can in a virtual
5:02
platform. I just want to check my notes and make sure that I've got everything else here. No. So that's it. So it is now my pleasure to introduce Dr. Kirsten Müller. Kirsten has been at the university for just a few years, you know, I think was it Kirsten? and is new to the Chair of Biology as of January. So I'm going to disappear and I'm going to turn it over to the event. Thanks Kristen.
5:28
Thank you very much, Meaghan, and welcome everyone and welcome to our new faculty lecture series from the Faculty of Science at the University of Waterloo. To begin with tonight, we're going to start with an Indigenous land acknowledgement.
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We acknowledge that much of our work at the University of Waterloo takes place on the traditional territory of the Neutral, or Attawandaron, the Anishinaabe and the Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land promise to the Six Nations that includes six miles on each side of the Grand River. This past fall, marks the 236th anniversary of the Haldimand Treaty that noted six miles deep from each side of the river,
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beginning at Lake Erie and extending in the proportion to the head of said River, which them and their posterity are to enjoy forever. I encourage everyone to go to native_ land.ca and take a look at the indigenous lands that you live on and work on. So tonight it is my absolute pleasure to host this event and to provide a very warm welcome to Dr. Jozef Nissimov. So our Department of Biology covers broad areas of research from environmental biology, microbiology, molecular
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biology and genetics to physiology and developmental biology, and even to broad areas including bioinformatics and evolution. Our faculty members have been a resource for numerous media outlets and organizations on topics ranging from invasive species, contamination and waterways, to understanding toxins, disease, and even viruses, which is the focus of Jozef's research program. So Jozef joined our department at the beginning of March 2020, just before the
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entire world shut down to COVID-19. And I know that viruses have been on our minds extensively over the past year. But tonight we're going to learn more about viruses, which includes a broader perspective, including their role in the evolution of life on Earth, climate change, use and combating disease, and also harmful algal blooms, which many of you may know is a real concern here in Southern Ontario in the Great Lakes. Jozef obtained his PhD from the
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University of Nottingham in 2013, and completed his master's and bachelor's degree in marine biology at the University of Plymouth. Following his PhD, he was a postdoctoral fellow at Rutgers University, examining algal virology in the marine environment. Following this role, Dr. Nissimov took a position at the Scottish Marine Institute where he coordinated a project to establish the first of its kind culture collection of aquatic viruses. Jozef's research has covered diverse
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topics are examining the role that viruses play in the marine environment, and their associated algal hosts. And he's also been an important resource for media interest and COVID-19. Again, it is with great pleasure that I now welcome Jozef to present his talk on viruses: the good, the bad, and the weird. Thank you.
8:42
Hello, everyone. Thank you for attending this talk today. Thank you, Kirsten, for the introduction and Meaghan and the Faculty of Science, for inviting me and organizing the seminar.
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My goal today is to try and shine a positive light on viruses and give an overview on what viruses do other than being disease mediators. And in a way we live in these strange times that probably more people than ever before, know what a virus is, which is something that I hope will make my job today much easier. Having said that, I think that it is important to recap on what a virus actually is. So what is a virus? Here is a traditional definition of a virus as per the Oxford
9:28
dictionary. It's an infective agent that typically consists of nucleic acids, which you can see inside here. Nucleic acids are either DNA or RNA. It has it has a protein coat, which is called the capsids. It's made of protein. It's too small to be seen by light microscopy and he's able to multiply orally within the living cells of a host. A similar definition is provided by the Cambridge dictionary. It's an extremely small piece of organic material which what is DNA, RNA and
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Proteins of the capsid that causes disease in humans, animals, and plants. Now, although the goal of my talk today is to focus on the positives of viruses, it is hard to ignore the grim reality we're all currently experiencing. And the fact that viruses are agents of human disease with the potential to cause pandemics. One such example, as I'm sure we all are aware of a SARS CoV-2 which causes COVID-19. It was first discovered in Wuhan in China in December 2019. It's a
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virus which is part of the Coronavirus. It's part of a large family of viruses. It has a zoonotic origin, with close genetic similarity to bat Coronavirus. And in fact, in this phylogenetic tree, you can see that it also clusters in a sub group called the beetle coronaviruses. It's about 50 to 200 nanometers in diameter, and it's a single stranded RNA virus is the RNA virus of a single strand. If a virus such as SARS CoV-2 catches us off guard, it can get out of control pretty
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quickly. And if you just a timeline of COVID-19, the World Health Organization decried SARS CoV-2 as an outbreak on January 30, 2020. Then, it declared as a pandemic on March 11 2020. And if we don't take the appropriate measures on time, an outbreak can become an epidemic and an epidemic can become very quickly a pandemic. It is nicely illustrated in this time lapse of the spread of COVID-19, which shows not only its global spread, but also the emergence of new variants. As you can see
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here, on the right hand side, it shows you different claims. And to put this in context, we all hear about new variants emerging across the globe. But it's important to remember that this is what viruses do, they mutate. And in fact, we have known of thousands of variants from the beginning of the pandemic, as you can see here, in this time lapse. By December 2020, SARS CoV-2 has reached all seven continents including Antarctica. Recently, it was reported that more than 30 people were
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infected in the Chilean Antarctic research base, you might have seen this in the news in December. A pandemic of such proportion can be indeed devastating. As we all know, as of January 12, this year, there have been nearly 100 million COVID-19 cases worldwide, I think we actually reached that number. Now, with a case fatality rate of 1-8%. That very much depends on the healthcare system of a country, the age of the population and lots of different factors. And the
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pandemic has resulted in the death of nearly 2 million people But there is light at the end of the tunnel. The global research globally.
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community is collaborating on a scale we have never seen before, which I'm very excited to see and read about. Vaccines are already here and on their way to people's arms. And they're really innovative efforts at the moment globally, to monitor wastewater, including in Canada as a means to detect early the emergence of new outbreaks. We have seen this approach being successful in other countries. And Canada is following through as well, including here by some of my colleagues at the
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University of Waterloo. An expansion to this approach also includes the sequencing of wastewater samples for the early detection of emerging variants. And this is something that I'm currently collaborating on with Trevor Charles and his lab here at the University of Waterloo. But it is important to note, however, that we have kind of been here before and that is, can actually be the situation could be much worse. Right? Many outbreaks and pandemics have ravaged our world throughout
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history. And these are just some examples. So for instance, we've had measles that dates back to the fourth century BCE, which in the 19th century and early 21st century alone has been estimated to infect, you know, 200 million, resulting 200 million deaths. We have also smallpox, for example, which dates back to the third century BCE, by the late 19th century wiped out almost 90% of all Native American people, they were not exposed to these viruses before white people moved into the into
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the Americas. And in the 20th century alone, you've had more than 300 million deaths in results due to smallpox. And again, Spanish flu, that's something that is probably the biggest global pandemic that we've experienced in recent history. It resulted in a third of the world population being infected, and in more than 50 million deaths worldwide, and that was in 1918, 1917, very close to at the same time as the First World War was ending. Another pandemic that we don't
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talk about much these days. days is the HIV pandemic, which is declared in 1991. And it's still very much ongoing. And of course, finally, there have been other notable outbreaks that had the potential to become pandemics. But luckily didn't. These include Ebola, SARS, and MERS outbreaks. One thing that I would like to point out here, and it's really it relates to the title of the slide, is an infection by many of these viruses that can result in very high CFRs, which is the case
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fatality rate, which is essentially, the percentage of people that have died from the total number of people that contracted the virus. You can see here, for example, in the case of Ebola, case fatality rate can be as high as 90%. So there's these bugs out there that are very, very deadly. And luckily, they haven't become pandemics or major, major epidemics. And of course, there are also other epidemics that I have not included here, such as the swine flu and the bird flu
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epidemics, which also infected and killed a lot of people globally in the late 20th, early 21st century. Now, viruses are not unique to humans. They infect animals and plants. And they even infect, microbes, such as bacteria, and micro algae, and also other viruses. And I'm going to talk about some of these later during the talk. And the fact that viruses interact with so many different other microorganisms brings me to the next part of my talk, which we focus on the benefits of viruses
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and some of their roles in the environment. Now, to understand the role of viruses in the environment, we need to first put them into the context of our entire biosphere and the habitats that they are found in. Astonishingly, viruses are the most abundant biological entities in the biosphere. So if you take one milliliter of seawater, you're probably going to see about 10 million viruses in that one milliliter of seawater. And this is what it looks on epi fluorescence
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microscopy, the little dots basically represent the little viruses that fluoresce because you stain them with a specific die and binds to the DNA. And the big dots that you see are actually the bacteria. So there's a lot of viruses out there, and to emphasize their abundance, I would like to mention that, you know, the estimates of 10 to the 30 viruses to be present in one way or another in the oceans alone. And to put into the context, the carbon contained within all the
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ocean viruses is equivalent to that in carbon and mass containing 75 million blue whales. And if you take all the viruses in the ocean, and align them head to tail that will span a distance that is equivalent to the diameter of 100 times the The sheer abundance makes them ecologically important. They're Milky Way.
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associated with a diverse range of habitats such as soil, sea ice, coastal and open ocean regions, coral reefs, permafrost, hydrothermal vents, the deep sea and lakes. I'm not sure if you remember, but a few years ago, viruses made headlines across the world with reports that focused on the Association of viruses with aerosols in the atmosphere and how they can be transported across different geographical regions. And you saw these headlines viruses ranging from
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the Earth's atmosphere say scientists, more than 800 million viruses fall to the skies every day in a single square meter. And there were other headlines like that in the news at the time. So one question you may be asking yourself at this point is okay, they are everywhere and a very abundant, so what? To I answer this question, we need to consider the fact that they are not just there, but they are actively involved in biogeochemical cycles and in
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structuring aquatic food webs. To put this in context, almost half of the oxygen we breathe is produced by photosynthetic microorganisms living in the ocean. That basically means that every second you, every second breath that you take is due to oxygen produced by microorganisms living in the ocean. And what this map shows you is these green areas where a lot of these photosynthetic microorganisms living, some in temperate regions, and also some of the Arctic and Antarctic
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regions, and this is the chlorophyll in the surface of the ocean. And these are some of the microorganisms such as coccolithophores, you have other ones which are diatoms and you have bacteria and archaea. Now, another thing that's important to know is that half of these microorganisms are basically killed on a daily basis. And you might think well hang on a second, that's actually quite worrying if you just told us that half of the oxygen is produced by these microorganisms
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that we breathe and half of them are being killed on a daily basis that can be quite worrying. However, this is actually an essential process in most aquatic systems. In essence, what viruses do is that they exert a bottom app control on different microbial species and particularly those that bloom and here you can see a nice picture of an algal bloom off the coast of Plymouth in the UK. And this is a general diagram of what happens to algal blooms in the ocean. So while
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you have bottom down control exerted by grazers and then fish that eat on those grazers, you have viruses that prey on these microalgae. So when viruses infect the algae, which lives in the sunlight, part of the water column, nutrients are being released from the dying cells and become available to other microorganisms such as bacteria, these bacteria preyed upon by other organisms by which they these nutrients can move back up to higher trophic levels. So viruses help recirculate
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nutrients within a system and keep it actually quite healthy.
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Now, at the same time, virus infection releases other organic contents reaching pattern from dying cells. These organics can clump into larger particles, and then after they become quite buoyant, negatively buoyant, they can sink to the bottom of the ocean. By doing so, viruses help sequence straight carbon from the top of the system to the very bottom. And this is a crucial aspect of biological carbon pump and the ability of our oceans to act
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Another thing that viruses do by infecting blooms, blooms of dominant algae, is their contribution towards the formation of local climate patterns. And an example for that are these coccolithophores, which are infected by particular algae, called EHVs. And this is what happens in some of these blooms, the virus goes inside between these calcium carbonate plates, which are stuck on the outside of the algae, the virus goes, releases its genome into the nucleus where replication
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occurs, then new copies of the genome of the virus are getting released into the cytoplasm, new viral particles are being released. And eventually, the cells lies and die. And these calcium carbonate plates and all the organic content in the nutrients from the cell can leak. And as I mentioned earlier, it can be available to other organisms in that habitat. Now, unfortunately, viruses cannot distance themselves do social distancing, like we can. And what happens is that when
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the population of the house is quite dense, you usually get many of the other neighboring cells being infected by these viruses, and then subsequently, they're dying. An interesting aspect here is that these cells, these infected algae, release these dimethyl sulfide, which is a very interesting compounds. When it mixes with the atmosphere and other molecules in the atmosphere, you can actually see the creation of clouds above these blooms. So I like really, this system and
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this example, quite a lot, because it's a really nice link from the micro when you see this interaction between the host and the virus to the macro, which is these climate processes in the formation of these clouds, due to these compounds being released by the algae. Now viruses can also come with ecologically important pathogens, for example, coral reefs are important habitats globally, you may be aware that they're harmful, almost 2 million species and 25% of all
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marine life is associated in one way or another, with coral reefs,and that includes a very high diversity of different microbes.
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So in this particular case, what at high temperatures, what happens calls become more vulnerable to disease. And therefore, they get infected by these bacteria which can cause bleaching and the way that the bleaching happens is that the symbiotic algae, that is associated with the corals, basically gets exposed, expelled and we symbiotic algae is essential for the, for the life of these corals. And then you have coral bleaching, and it results in this horrible picture
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that you can see here on the right. Interesting and when scientists went back to the same location on the barrier reef in Australia, where the coral pathogen and its host exist, they managed to isolate the virus that infects the coral pathogen. Subsequent conflict incubation with the scientists did, experiments in the lab, show that the virus can affect the bacterial pathogen […] with the end result being more exposure of the causing via the algae and this now bleaching. So
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in other words, these viruses here in the system can be used in some sort of a probiotic effect fighting the pathogen of the corals and preventing aging. In a similar fashion, viruses infecting harmful algae are gaining attention. For example, a study from 2007 showed that harmful algal bloom forming species, which causes brown tides, and kills filter feeders by clogging their feeding apparatus off the East Coast of the United States is infected by viruses and these viruses are
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called AAV's and this is the host, the algae that we're talking about, [...]. When the scientists isolate these viruses and conduct uncontrolled experiments in the lab, they saw that some of these viral isolates can reduce the growth of their algal hosts significantly. And you can see that in one of the fingers of the scientists, they added different strains here and some of them affected the growth of the of the algae of the harmful algae quite significantly.
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Nevertheless, in comparison to what we know of algal virus interaction in marine systems, we know a little about how viruses affect harmful algae and major gaps in our understanding exists specifically in freshwater habitats. So to address some of these gaps, a graduate student in my lab is currently collaboratively working with members in Kirsten Müller's lab in Waterloo, investigating samples from harmful algal blooms in Canadian lakes, for the presence and
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identification of viruses using sequencing methodologies. Now beyond the environmental impacts and probiotic effects that I just mentioned, that viruses can have, viruses are also useful as human tools. And we kind of have use viruses as tools to benefit us for a while now. We have used viruses to create live attenuated vaccines, we basically reduce a viruses that vaccines that are made by viruses, which have reduced virulence of pathogenicity. Examples for such vaccines
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include vaccines against smallpox, measles, mumps, rubella, and some influenza vaccines as well. We've used viruses also as transgenic tools, which basically means using viruses as vectors for the delivery of genetic material into cells. And that kind of use of virus is gaining attention in recent years and things like gene therapy, and it has really interesting implications and applications in cystic fibrosis, and cancer treatment. So for instance, this is a figure from
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this paper down here at the bottom by Leah Tao, which shows that these adenoviruses that have been engineered when they're added to cancerous cells, they replicate and kill them. But they don't do that in healthy cells, as you can see here at the top. And I'm not gonna expand too much on that. But I just wanted to mention that viruses have a lot of potential in that area. Another aspect is […] therapy, which basically means the use of very hot specific bacteria phages
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with targeted bacteria, to attack pathogens, pathogenic microorganisms, and that it's been proven quite useful in combating antibiotic resistant bacteria, which I'm sure some of you are aware of very dominant in certain hospitals. And it's very hard to combat some of these bacteria, because they have developed resistance through historical use of antibiotics. So viruses can attack these, these bacteria and kill them and then be used in a cure, in a sense. And this
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brings me to the last section really, which is the weird now, viruses come in all shapes and forms and are very diverse in their genomic content and its composition. So for instance, in this chart, here, you can see you can have small viruses 20 to 40 kilobases, this is the genome size on the left hand side here. viruses can be double stranded DNA they can be small, single stranded RNA, and it can be single stranded DNA, and they can infect some diatoms and other microorganisms such as
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bacteria and cyanobacteria, that can be double stranded DNA viruses, fairly large four to 500 kilobases coccolithophores, which I mentioned earlier, and I showed it animation getting infected by viruses, which are in that same range. And that can be even bigger than 1000 kilobase pairs, some of viruses that infect current algae, for instance, they can be lytic. In other words, infect and kill other hosts immediately, or shortly after they have infected the host, or that can be
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lysogenic, which means that they remain dormant in their host and only switch to a lytic phase when there is potentially a reason for them to do so. And this reason can be a compromised cellular physiology due to an external factors such as temperature, or nutrient in destress. I'm not going to talk today about lysogeny. But it's something to keep in mind when we talk about viruses. And knowing that there is this other form of a viral lifestyle that we often seen some host virus
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systems, not only in the ocean, but in other ecosystems as well.
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Now, viruses can also be giants. For example, a virus that infects Amoeba and was isolated from Brazilian lakes has a size, you know, the capsid, which is basically this here that you see, which is the protein shell, almost 450 nanometers in diameter. It can have a very big genome size 1.5 million base pairs.
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Not only that, but some can have incredible morphologies. Sometimes resembling something from a science fiction movie. And in addition to their strange shape, they also have a hundreds of genes that code for hundreds of different functions. To put this into perspective, HIV codes for only nine genes, and further if in the fact and if the fact that that these viruses code for so many different genes was not impressive enough, consider the fact that they're larger than some bacteria. For instance,
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this one on the right is the most abundant bacteria in the ocean called pelagic factor ubiq or SAR 11. Yet, it's much smaller and has less genes than this […] virus that have more than almost 1500 genes. So it can be very big. Another interesting thing about giant viruses is that they can have some very interesting morphological features. A double stranded DNA virus that infects Amoeba, again, uses a single portal for genome delivery and packaging, called the Stargate
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and the authors actually didn't name this the Stargate. What the Stargate does is that it forms a membrane conduit, which you can see here with the infected cell to which the viral DNA enters the cell. And if these science fiction references weren't enough, we now know that viruses can prey on and infect other viruses. And this is one of the first studies that describing some 2008 was a paper in Nature. And these two giant viruses and their hosts. Basically, what happens is the co-infection of
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two different viruses happen. The small viruses a small double stranded DNA viruses that can infect with the larger virus, they take advantage of the transcription machinery and the virus factories of the large virus to make copies of themselves. The result of this is that the large viruses are deactivated. And you can see here in this transmission electron microscopy that some of them don't look very healthy, that lack the capsid. And then basically, that's a result of
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the coinfection done with the smaller viruses, which is called […]. In this particular case, the large virus is called summer virus. And the general name that has been given to these pathogenic viruses of other viruses is viral phages. Viral because the virus phage means basically eating. So in a similar fashion is bacteria phages that are viruses that bacteria. Viruses are also strange in that they can drive evolutionary processes. A few years ago, there was this
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headline in the New York Times and maybe in a few other media outlets saying that ancient viruses are buried in our DNA. What he was referring to is that basically after the sequencing of the human genome, it became apparent that nearly 8% of the human genome is borrowing origin. And in essence, what scientists found is these EVE (endogenous virus elements), which have been integrated into our genomes over hundreds of thousands of years. What is fascinating about these viral
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elements, which are essentially viral fossils buried in our DNA, is that they are occupying more space in our genome than human genes. Now importantly, although certain diseases and conditions have been attributed to these EVEs, they also play a role in immunity and the regulation of certain genes. More recently, through the analysis of these EVEs, scientists have even hypothesized that these viruses have been involved in the development of a placenta. And this is quite quite interesting
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and quite striking to know that so much of what makes us is basically viral in origin. Now, while these endogenous virus elements are relics of the past, many extant viruses currently live in or on our bodies. Recent estimates suggest that our bodies are habited for more than 380 trillion viruses and these viruses, or what is now called the human viron, have real implications to our daily health. And another interesting fact is that people that have found that people when they live
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together in the same households have similar viral communities associated with their bodies. And these viruses are not just there, they also help you immunity in ways that they can combat often other infections and prey on bacteria that are also associated with the human body. Now going back to viruses that infect other microorganisms, viruses can steal genes from their host and make use of these stolen genes by a process called horizontal gene transfer.
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Some examples horizontal gene transfer and of genes that had been acquired by viruses from the host, include photosynthesis genes in these viruses, this […] that infect prochlorococcus, which is the cyanobacteria found in many marine and freshwater systems, genes involved in phosphate sensing and parent metabolism. Scavenging of oxygen radicals, for example, is another type of another group of genes that have been found in these viruses that have been stolen from the host.
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Expeditions that gone and looked at viruses in the deep sea discovered the genes in viruses that they involve in sulfur metabolism. In other cases, scientists have found genes in viruses that code for polysaccharides. So this is an example of a virus that codes was a gene is called PBCV1, and it infects chlorella that lives and it's associated with […].
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And what I've been mainly interested in as well and I've worked quite a lot on is viruses that infect these coccolithophores, these micro algae that produce these calcium carbonate plates, and are very abundant in in our oceans and important in expansion of chemical cycles that I mentioned earlier. And in these viruses, we know that there's almost an entire pathway that codes for sphingolipid metabolism, which is an essential part of the infection process. Now, many of
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these genes are not just stolen, but they're actively used by the viruses for their own benefit during replication. Using these genes, viruses can essentially temporarily enhance the functionality of the host that they have infected before they actually collect. Now, these are some cool examples of what a term is these auxiliary metabolic gene viruses. But what about other ones given that some of these viruses that I talked about had large genomes, one would expect that to be other
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viral genes coding for interesting functions. Unfortunately, only a subset of viral genes and functional predictions and have been described in different publicly available databases. And this makes genome-wide investigation of large viral genomes quite challenging. What I'm showing here is a figure from a paper from a few years ago when I compare the genomes of different virus strains, which in fact, according to […], as I just mentioned earlier, the colors
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here represent different regions in the genome that are similar to each other. Other big data, and the lines between them show where some of the major differences between different genomes are. And when we try to compare different genomes to each other in that kind of a manner, and to what they're these genes are similar to in the public domain, we say that more than 80% of the genes are basically a mystery, we don't really know what they do and what they code for, or their
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functions. And to reveal their identity. More of more the jeans, a co-op student in my lab is working collaboratively with Andrew Doxey’s lab in Waterloo and his team. The approach here is to use a combination of different protein prediction pipelines and platforms and get an insight on some of these unknown genes that we see in these viruses. What we also tried to do in this project is to elucidate which genes in these viruses are essential. In other words, which ones are the
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core genes shared between these different viral strengths, and which ones are essentially ones that potentially are less important and is an essential during infection.
38:27
Some of the take-home messages and in conclusion: viruses, as I mentioned, are much more than a bunch of bad news in a bag in a bag of protein. They play evolutionary roles, they're not always small. And I gave some examples. They have a global distribution. They're the most abundant biological entities in the biosphere. They’re important in global climate processes that are crucial in aquatic food web dynamics and how nutrients move between the different trophic levels. And we can really use
38:59
viruses as tools as human tools to do a lot of good in the world. Now, if you're interested in learning more about viruses, I really recommend these two books. The first titled Spillover here on the left, focuses on viruses that jump from animals to humans. It's a really cool book. And it's written almost as a mystery novel, I would say. The second is called Viruses: Agents of Evolutionary Invention, and talks a lot about many of the aspects that I mentioned today.
39:27
And it's very digestible, maybe if you're not a biologist, or have a biology background. Other resources you may be interested in checking is the weekly podcast this week in biology, at the moment is quite heavily focused on COVID-19. It has a lot of virologists that speak there. So But again, it's very kind of approachable and digestible. It's easy to understand, and also, this website called Out of Virology on the web, which in my opinion is like Wikipedia for those
39:57
interested in virology. Now, given everything that I talked about today, I often ask myself, are viruses alive? And many also ask that question in my field. I believe so, but not in the way we're used to thinking about viruses. And that is really the talk for today. I'm just going to remind everyone that next in the series, we have Dr. Rodney Smith of the Department of Chemistry, and it will get further details about registration about that particular talk. So I, it was
40:36
quite a short presentation. And I probably went through a lot of information very quickly. But I'm very happy to answer any questions that you may have. And with that, I'm open for questions.
40:49
Thank you very much, Joseph. That was a really interesting talk. And just as a little reminder, if you have questions, please put them into the Q&A, which you'll see at the bottom right hand side of your screen, and we will start asking Jozef these for you. Okay, so first question, Jozef, at the end of your talk, you just mentioned that viruses are alive. But aren't they obligate parasites and can't self replicate? So I even think of this as coming from me being a taxonomist. What
41:27
is your definition of life with respect to these fascinating organisms? Well, that's a great question I have I, every time I mentioned that, I get asked that, well, it very much depends on how you define what is alive and what is not. So if the definition that one goes by is that it has to be able to self replicate in order to be alive And sure, viruses are probably not alive, but if you are flexible with your definition, and you know, I
41:53
talked a lot about the different functions that viruses have, in the fact that viruses can be actually themselves being affected by the viruses. And they have these very important roles in evolution and almost also obey by similar biological rules, molecular rules, as a lot of the other organisms in the tree of life. I think, I think that, you know, if that's your definition, then yeah, I think they can be considered alive. And again, I think also, there are a lot of other organisms out
42:26
there that have these parasitic associations, yet we consider them to be alive, for instance, earlier, I get this example of coral reefs and how they're associated with these, these algae that that are living inside their tissue. Now, they cannot live without this, this, this algae, right? So you can basically say that, okay, well, is that also not life, or in a similar way, you know, there's trees require my microbes in the roots for a lot of different functions. So I think it's
42:57
really very much depending on the definition that you have of life. And at the end of the day, I don't even think that the definition really matters, because these viruses will keep on doing what they do, and have the roles that they have in our world.
43:12
That's great. And I have another question that's going to follow up on that. But I wonder if we should stop sharing your presentation so people can see you. Sorry, they cannot see me? Well, no, I think so we can see your face larger on the screen while you're answering the questions. Right. Can you see me now? But Oh, stop, share. Okay. Just stop sharing. There we go. Excellent. So the next question kind of goes on the same lines of that, and big broad question,
43:41
what is the evolutionary purpose of viruses? Since we know living organisms are part of the food chain. And, you know, we understand the evolutionary connectivity of other living organisms, what purpose do you think viruses serve?
43:58
Well, I mean, I don't know if, as biologists, you know, we so often can really think about purpose, right. But in a way, I guess the purpose that they have, and as we've seen today, is basically, you know, moving genes around driving evolution in a sense, because they're so abundant, they can, they can really be very impactful. They're now I don't know if they can really have a purpose. A lot of the things that viruses do happen by chance, for instance, I'll give one example. We hear
44:31
at the moment about viruses and new variants of COVID-19 forming, you know, viruses becoming potentially more infectious. But you know, that can also have go the other way. In other words, viruses can also mutate and change to a less infection stage. So I'm not I wouldn't say really they have a purpose per se. And but they definitely have a role. They have a role just like all the other three domains of life: Eukarya, Bacteria and Archaea and, and they are crucial and we
45:05
wouldn't be here as I get the examples earlier, for instance, the human placenta and other other aspects, we we just wouldn't be here without the viruses. And there's also a lot of hypotheses now about the early evolution of life and the role of viruses of creating the first kind of cell, if you'd like. So, so yeah, I'm not sure if that answers the question, but they definitely have a big role. I don't know if they have a purpose. But we can use them for our purposes.
45:36
So I'm kind of touching on now, COVID-19. Some of the viruses prey on other viruses, is there a potential to use this in control of Coronavirus?
45:49
I don't know. I, I would have to say probably not. Because most of these viruses. First of all, viruses are very specific. So you really need to be able to isolate a virus that infects this other virus in this case Coronavirus in order to be able to use it in some particular way. But most of the times when we see these viruses infecting other viruses, these viral phages, they're mainly associated with the big viruses, these “giruses”, we call them in my field. And they, I mean,
46:22
COVID-19 doesn't necessarily use viral factories like these giant viruses have, which the small virus the Sputnik virus, actually takes advantage of, again, these big viruses that have the satellite viruses, the harmful viruses, the viral phages, they also code for hundreds and thousands of different genes, the machinery of these viruses is quite, quite heavy. COVID-19 doesn't have that. And we haven't we haven't discovered viruses that target those, so I would probably have
46:52
to say no. You never know. I mean, we discovering in virology things all the time.
46:59
And this is this question isn't really on COVID-19. But it probably applies. Our species hopping viruses common and is there a protect particular role they play different from same-species viruses.
47:13
So if you some of you decide to do read that book Spillover, a lot of the things that basically talk about, viruses jumping from hosts, so and to a large extent, there are some ideas out there that have suggested that this is increasing in recent years, especially in the case of climate change. And the fact that there is a lot of we live much closer to wildlife populations. There's forest, there's forest destruction, in a lot of places, people feed, because of lack of food, and to
47:50
supplement the nutrition, they feel feed on wild animals. And that allows a lot of these viruses that are usually associated with animals, whether they're chimpanzees or bats or other animals to eventually jump, sometimes to a random chance, but to adapt to a human host. And I think that, you know, we're quite lucky in the sense that we haven't seen more of these jumps becoming pandemics. But as I mentioned earlier, there's definitely potential for a lot of these to
48:20
cause a lot of harm. And, and for that to be more predominant in the future. And that comes back to what I said earlier, it's very much related to climate change, and how we interact with our environment and other species that we share this planet.
48:38
So yeah, so the next question is, what about CRISPR? Is CRISPR a virus? Is it a viral element?
48:47
CRISPR is I mean, I guess this is not really my area of expertise. But it's, it's basically a defense mechanism of bacteria, as far as, as far as I know. And we use that now to kind of introduce and engineer, viruses and cells, also in drug therapy, but again, I mean, it has a viral origin. Of course, it's a defense mechanism of of other microorganisms against against pathogenic viruses, and we can tweak that CRISPR system for our own advantage.
49:19
Great. Um, you mentioned the role of viruses and chemical recycling in the ocean. And do viruses play a similar role on land, similar to what we see in fungi and bacteria? Or is that role just left to those two groups of organisms?
49:37
Again, this is outside of my area of expertise, but I would, I would assume that they play some sort of a similar role, just because usually what happens is that when a cell dies, regardless of whether it's an algal cell or whether it's any other type of cell, you have these components, these metabolites these other compounds that are associated with the cell, which basically are being released in into the environment, and then other microorganisms can make use of
50:03
those, those compounds to grow and use those as nutrients. So I would probably say that that probably exists to a certain extent as well in a lot of other habitats. And I mentioned that, you know, viruses have been really associated with all of these different habitats, including soil and permafrost and ice, and but I wouldn't be able to 100% say what, it's exactly the same mechanism as what we see in aquatic systems. But I would think that they play a similar role there as well. Yeah, for sure.
50:33
Thank you, Jozef. So I think the next question ties back to when you were talking about wastewater. So if COVID is passed through the air, and and that's one of the reasons why we're all wearing masks, and we're doing social distancing. Why examine water? And why are we looking for COVID in water? Well, the idea, so basically, the idea of looking at wastewater, and it's actually not, it's not a new method in epidemiology, people have used it quite successfully to look at
51:04
lots of different outbreaks. And to use wastewater as an early warning system. In other words, wastewater is being collected usually from these wastewater plants, where you get water being collected from many thousands and hundreds of thousands of households that gets gets accumulated in today's wastewater plants, it gets treated there. And the idea there is, you know, rather than just looking at clinical data to try and because this is coming, you know, from cities and
51:36
neighborhoods used wastewater, the idea there is to also look for early signs of the pandemic. In other words, before you have major outbreaks, in in different cities have different neighborhoods. Another aspect here is that with clinical samples, and the way that we usually at the moment, mainly detect COVID-19 is through people that actually become sick and come into the hospital. And then they they do a QPCR and they detect the virus at a certain threshold to the QPCR,
52:09
the wastewater approach also ends up getting in these asymptomatic people. In other words, you know, you can have a city or a neighborhood where you don't see any visible infection, people are not ending up in hospitals. But you may be able to see potentially how it will play out several weeks afterwards, if you look at the wastewater, because we know that it takes several weeks until we actually see symptoms, sometimes days, sometimes weeks, and you see symptoms of COVID-19. And we
52:38
know we all go to the bathroom several times a day. And the idea is to look at these early signatures of of the viruses and try and get an early warning system. So this is and this has been done already in several places. There was a place I think in the States in one university that actually used similar approach. I don't remember if it was in Arizona or somewhere else, but they managed to prevent an entire outbreak in one of their dormitories by using that particular approach.
53:05
So it could have a lot of benefits. And and we're getting some of that work done here at Waterloo at the moment.
53:11
Right, great. So given that variants are evolving, and you know, we're hearing a lot about that in the news right now, is there a predictable pattern that we can see with respect to these variants arising?
53:26
I mean, there's this is, it's difficult to say, right, because as I said earlier, viruses mutate, this is what they do. So I would probably say that, the more the pandemic continues, the more people are getting infected, the more variants we're going to see, the more the virus will change. Sometimes just because of a pure chance, whether there's a way to predict that. There are certain studies happening at the moment, if we, first of all, if we sequence enough of these genomes, we can
54:00
start elucidating, which areas of the different of these different genomes are more prone to mutation than others? And then certain studies have started taking that particular approach, and try and try to apply some sort of machine learning approach where they're trying to predict, okay, this is the number of people potentially being infected in a given time. And this is the how different areas of the genome is mutating. Maybe this is what may may happen in the future. But it's
54:29
just difficult, difficult to say. And data is coming from lots of different places in this website that I showed earlier, next strain with a spread of of COVID-19 throughout the last year in this platform that have deposited more than I think 4000 different genomes, slightly different variations of the virus. And we need more data. We need more more of that more sequencing in order to get more more understanding and this is and I mentioned earlier, that we're trying to work here on
54:58
trying to get some sequencing on wastewater samples. Currently, a lot of the sequencing is done mainly on samples from patients. There has been some success of in Europe of doing sequencing, I think in Australia of doing sequencing of the entire genomes in wastewater. So we need to do that more here in Canada, I think. And that will give us a little bit more of an idea of how things are changing and what we can do about it in the future.
55:24
Right. So, so kind of continuing with this, but really focusing a little bit more on treatment. So the World Health Organization has said that there is a major issue with antibiotic resistance and that 10 million people per year might die as a result. And you've mentioned phage therapy as a solution, but it's not approved yet in many countries. How far away do you think we are from implementing this type of therapy or technology? Sorry, can you repeat that? So that's that's relating to
55:53
COVID-19 phage therapy now? Well, just phage therapy in general? And how far away Do you think we are from from actually being able to use this in treatment? I'm not exactly sure. I mean, this is a very, it's not a new, a new approach, phage therapy, and I think in the 70s, and the 60s and 50s, I think there's been a lot of research and a lot of ideas, especially in the Soviet Union, trying to invest and develop phage therapy methodologies. I think at the
56:21
moment, phage therapy is only really used in very extreme cases. In other words, in situations where you don't, you know, there's no other way. It's very experimental. And again, I'm not the expert of phage therapy, there's an entire group of phage therapy researchers out there. But I am not sure how, how, how common the use of that would be, but the potential is definitely there. And there's more and more people every day working on phage therapy, and trying to push it through to the
56:54
different organizations to make it make it approved for different uses. I think it will probably be more applicable at the beginning. For viruses, for, for treating diseases of potentially maybe in agriculture, or maybe animals that are important, like the cattle industry and things like that, but I'm not sure whether, you know, we have seen humans how that will that will play out. Right. So the next question is kind of an interesting one. And
57:22
I don't know that you have an answer, because it is a bit of a challenging one. But actually, two people have asked it, and it's have viruses been found in outer space? Do you think that viruses could be existing in other places within our solar system?
57:40
I love science fiction, as you probably can tell from my talk, so I'd like to think yes, but I don't think that they I mean, I don't think that they have been found yet not as not as I know.
57:55
There were a few studies or few reports from I think it was at the end of last year, that they may have detected some elements that resemble DNA, I can't I can't remember. Yeah. So I mean, not not, as we know, at the moment, right. But you know, I mean, who knows, we may find some sort of nucleic acid, or something similar to that one day in another place. But I don't know.
58:25
Great. So back more to your kind of area. Why are viruses so specific to certain hosts? And that in some virus lineages, we don't see switching happening very often? Well, so it very much depends on the type of virus. So one of the things that I didn't talk about here today is that there's a big difference between whether viruses are DNA viruses or RNA viruses. DNA viruses have a proofreading system, which basically allows them to, when they replicate and transcribed
59:02
in the, in the host, they, in fact, to correct errors during that replication process. RNA viruses don't have that they're much more primitive in a way. However, these primitive mode of RNA viruses, the fact that they lack this proofreading system, does allow them to mutate much, much quicker, and to change much quicker just because of, you know, the lack of this proofreading system. So this is one thing that you know, the difference between different types of viruses and how they
59:33
change. I'm not sure that answer the question, but
59:37
That's great. So another kind of interesting one is, how do you think the best way is to describe what a virus is to a child or to someone who's young? I'm assuming kind of under the age of 10, or 12.
59:54
Yeah, that is a good one. I don't know. I mean, You need to really know at least some basic terminology or something, right, because we talk about DNA. And I guess what you can say is that it's some sort of a small thing that you cannot see that's made of, of sugars. You know, and, and children know what sugars are. And, but But yeah, I don't know, I have to think about that. That's, that's, uh, you know, and that makes you sick or basically lives in your cells. I mean, yeah, I mean, it's a it
1:00:31
depends on how old the child is. Yeah. Awesome. Yeah, it's a challenging question. I'm even trying to think here. How would I would explain that to my eight year old? And I think that's a tough one. I don't think we've actually had that conversation. So. So, um, and this is kind of touching back on COVID. And kind of going back to the variant question, and, you know, you noted that there's something like, what 1000 variants of COVID? So far, you know, we're
1:00:57
hearing certainly about the variants from the UK and Brazil and South Africa. And there's a perception that these variants
1:01:08
arise really quickly. But others do not. Can you explain what's happening there?
1:01:15
Again, I mean, I, I think this is not really my in my area. So I would be a little bit hesitant to kind of talk too much about these variants and what's happening in COVID. And, again, I mean, we have to also think that a lot of the stuff that we hear about in the including in the news are what we call these preprints, where there's a lot of scientific information is being released out there, for other scientists to be able to see in a more quicker, quick, quick way, rather than waiting
1:01:45
for the traditional peer review. And a lot of news outlets, take these stories, and, and they talk about them, I think that we really have to wait a little bit longer, probably until that pandemic is finished in order to really understand, you know, are some variants really evolving quicker than others? I mean, in a way, it would make sense because if you're if you're variant that you're more transmissible like they like it's claimed for some of these new variants that we see in the
1:02:12
UK, South Africa, in Brazil, it makes sense that if this variant, these variants infecting more people, then there'll be more predominant in the population. If there's more people infected by them, then this virus will keep on changing because it's infecting more hosts, rather than its ancestors, which is infecting potentially less people, therefore, it has less of an opportunity to change just because it's not impacting so many people, it doesn't have so
1:02:39
many available hosts. So that's one. Yeah. Yeah, I wonder, too. And I've because there's another question here, and it talks about variants as well. And I wonder if you could define what a variant is, because, you know, we've got, obviously COVID that started in the early part of last year, and we've seen all these different variants, and now we have these ones that are different. So what is unique about each of these variants that separate separates them
1:03:08
from each other, that we would call them a new variant or a new strain? They're all still part of COVID. SARS-CoV-2. correct. So there's a lot of debates at the moment in where people actually come in with a lot of the names and the phylogeny. And the terminology of and I think that there's a lot of confusion also within the scientific community of exactly, you know, what defines a strain or defines a variant? What is a mutation? I think the take home, what's really important here is that,
1:03:41
you know, I think some of these variants are categorized by numerous mutations in the same place. In other words, we know that we're talking here, I think about the spike protein that has had mutations, which makes it the virus more transmissible.
1:03:57
And is the number of these mutations on the sequence. In other words, substitutions of different nucleic acids on the genome and where these substitutions are. And by analyzing enough of these genomes, you can put these different variations of the genomes into different groups and different claims of how similar or how different they are from each other. And these are what are kept basically, you know, described as, as variants, it's a variation of the genome.
1:04:23
But again, there's a lot of kind of miscommunication and even within the scientific community of exactly what defines, in this particular case, variant, and I think that's an epidemiologist, someone that specializes in human viruses, and in those particular viruses might be able to answer that question much better than me.
1:04:47
Great, and we have a couple of questions now on the evolutionary relationships of viruses. And, and one of the questions asks, Is there do viruses have their own evolutionary tree and then it Another one asks, How early do we know that viruses arose on this planet since we know the green, and they actually said green and red algae here, so maybe it's someone that I taught at one point, but we know like red algae date to about 1.7 billion years. So what do we
1:05:16
know about the early evolution of viruses and what is their evolutionary tree like?
1:05:22
So, as I mentioned earlier, ther have been some hypotheses an viruses in some sort of a for have been around since th beginning of bacteria an archaea development. The firs viruses, I think, we know tha have been RNA viruses, and th DNA viruses are the ones tha occurred later on. Specifically talking about dates and tim again, I mean, I think it' similar to, to whenever lif suddenly started occurring on t e planet. Single cellular l fe, had viruses, RNA viruses, l
1:06:00
kely, and then higher o ganisms afterwards. But as far a the Tree of Life, the problem w th viruses is that there r ally isn't a single gene that y u can use in order to classify a l viruses. So for instance, s me of these big viruses that I w s talking earlier, the capsid p otein, which is you know, the m jor capsid protein, which c des for these protein shell, i one way to classify these p rticular viruses. Then we have D A polymerase, which, you know, i 's more useful for other g
1:06:35
oups of viruses as far as t eir classification that so it's difficult to know, you know and to build these domain of l fe, like we have eukaryotes, bac eria and archaea, for vir ses, we can definitely say, whi h viruses are more related to ach other. In fact, I think tha the old way of people, the way that they've classified vir ses was based on the host tha they were infecting now. And quite for a long time. Now, act ally, that's that has swi ched, it's no longer based on
1:07:04
he host of viruses, in fact, but it's more about molecular str cture and genomes and the pre ence or absence of some of the e viruses. And one thing to thi k about is that, you know, you can have these conserved gen s, but there are a lot of the e other functional genes, esp cially in these very large vir ses can differ. So sometimes thi classification may not nec ssarily mean what we what it me ns in, in eukaryotes, a chaea, archaea, bacteria. So eah.
1:07:34
So the next question touches back on to vaccine development, and I'll just read it out, how are viral fragments identified for vaccine development? And as CRISPR cast nine being used for the COVID 19? vaccine?
1:07:52
I don't know either of those. Yeah, sorry. Yeah. It's not something that I kind of can answer to, unfortunately, I'm not sure.
1:08:02
Okay, thank you. Um, so, the next one is about viruses and their, their limits in terms of, of spatial limits. So do you are viruses observed to only be found in in certain areas, so a marine virus, say, for example, would only be found in the marine environment and maybe in one small location in that marine environment?
1:08:28
So not necessarily, because some of the viruses that I have, I have worked with, for instance, they're very closely related to each other. But for instance, some of them come from the English Channel, south of the UK, and some other ones come from Norwegian fjords, right? But they can still be very similar to each other, and how exactly they, you know, they separately coevolve in these s parate regions, because they, i fact, the similar hosts, hich are these calcula
1:08:58
ors I was talking about, there's also another aspect that we know that diseases, viral disease , for instance, in the fishing industry, you know, can be tran ported in ballast water in ship . Right, that's another thing, or instance, ships coming nto Canadian waters in the Gre t Lakes, you know, sometim s, you know, you have entire iral communities that come fr m one place, and then they're being transported to another place. This is not just specifi to viruses, that's general
1:09:25
y invasive species is one of he ways that they move, especia ly in aquatic systems. But as ar as the transport of viru es, I mentioned, the ae osols, you know, I mean, vir ses need to still be able to eplicate in a particular host, ight? So they'll be useless in a particular place. f they can find a host to rep icate. They still after all, ev n though I mentioned earlier t at I do consider them as be ng alive, they still require host in order to replicate.
1:09:55
And you know, even though v ruses may be transported from on place to another There's no uarantee that they'll be abl to find a host in time. And t ey're also subject to disinteg
1:10:05
ation due to physical chemical f rces, UV radiation, temperat re, and some viruses are very te perature specific as well. S they may not in fact it high r or lower temperatures. So wh n they move to a different plac , they may not necessarily do hat they're supposed to do. So eah.
1:10:25
Yeah. And that kind of brings us to the next question, which is about viruses and sensitivity to temperature. And so what you're noting is that viruses are very specific temperatures when it comes to it to infection as well. So some of them are Yeah, again, it very much depends on the type of virus we're talking about. We know that some viruses are called active. In other words, viruses, I think, that had been discovered in ice in Antarctica, they they are very, they need
1:10:56
low temperatures in order to operate. Other viruses, you know, they require maybe higher temperature where the host is aybe compromised, or when it's feral house. So it could be a ery narrow range. But you know, hat goes back to you have iruses that can be classified o either being generalist or pecialist. So the generalist iruses and that's not only bout viruses, that's basically ind of ecological theory.
1:11:26
enerally, these viruses might ave a better ability to kind of perate in different emperatures may be different osts, specialist viruses are ore specific, but maybe they roduce more viruses one day hen the effect as opposed to he generalist that maybe can nfect in lots of different onditions, different hosts, but aybe it's not producing, eproducing so well in the host.
1:11:49
Right. So the next question actually is a little bit more on algo viruses. And could you speak a little bit about which factors have been observed to most heavily influence horizontal gene transfer in virus and their hosts when it comes to algal viruses? which factors? Yeah, are there factors that influence horizontal gene transfer?
1:12:14
Well, I think the main, the main thing is long, long term evolutionary association with the house. In other words, when a virus is kind of so closely associated with its host, through hundreds of 1000s of years and millions of years, you end to get these sometimes, you know, acquisition on some of the e genes. And, you know, there's some hypotheses that maybe c rtain environmental conditi ns may select for the acquisi ion of particular genes that th virus may find useful such as
1:12:47
for instance, there have be n hypotheses where in areas w th which are low in phospho us, for instance, may be that se ects for acquisitions on some ge es that coding for phospho us transporters that you know, t at the virus was able to, to cquire. Now, one thing that I idn't mention is that there i a recent study came out where I was talking about earlier about these EVEs, right, these g netic elements that are in the uman genome. Recently, scienti ts found that these EVEs also e
1:13:21
ist in algal genomes. In othe words, they have found very big chunks of algal virus s integrated into the genom s of the house that linger there for a very long period of time. And when eventually, I presu e they become lytic, then they ake some of these genes from he host. But it's diffi ult to do with experiments with ome of these viruses, doubl stranded DNA viruses, which are a lot of these algal viru es that I've been studying, and hey're a little bit less pron
1:13:52
to evolution than the sing e stranded DNA viruses that mist ke single stranded RNA viru es.
1:13:59
Right, thank you very much, Joseph. So we have reached pretty much 8:14. So we're prett much about 15 minutes over th time when we plan to end so think we there are a lot o questions we didn't get to. An maybe at some point, we'll ha e to come back and give an ther talk and another session ma be in the biology seminar se ies. So thank you very much, Jo ef. And I just like to note to ll our guests that the sem nars will be uploaded to the Fac lty of Science YouTube channe
1:14:31
probably sometime next week. nd please join us on Tuesda , March 23 for the next seminar in the new faculty series iven by Dr. Rodney Smith, rom the Department of Chemist y, Have a great evening and if ou're in Waterloo, hopeful y you're not driving anywher . It looks like the roads a e going to get pretty snow snow for us. Take care. Bye Bye.
1:14:54
Take care everyone. Bye bye.
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