Welcome to a new episode of the STEMtereviews. Today we have with us Dr. Noemie Matthey from the University of Lausanne. It’s a great pleasure for me to talk to you today. Because you and I, we’ve been talking, we’ve been working together for over two years now, almost two years, not really sure. But it’s always good to catch up with you talk about microbiology, or science or anything else that pops into our minds. So it’s so good to have you with us today. Thank you very much, very happy to be here. And to talk a bit about microbiology and other things. And yes, as you said, it’s almost two years, I think it will be two years in two months or three something like this. It’s It’s crazy. Famous playing? Yes. Okay, so to have a bit of an introduction to yourself, can you talk about your research? What do you do? What do you currently work on? Which bacteria do you actually work on? Yes, so I’m a postdoc at Justine Collier’s group. And we are working on DNA methylation in bacteria. So basically, it’s, it’s kind of add some syntax to the gene alphabet. So not as we have, when we talk, we don’t have 26 letters in the DNA alphabet, but we have only four. And there. So the bacteria have their genome composed of these four different base that compose the DNA. And when they are assembled together, they form kind of words, that would be translated into genes. And that can uncover the function. So for example, they can suddenly degrade some lactose or other carbon source or things like that. And basically, the methylation is something that is added on top of some of the letters of the DNA. And without changing the words itself. So I think there is a really cool example to kind of translate this and explain this is if you take some sentence, and you had some syntax, or some comma or other things, it might change completely, what it means or what it says. So I, I looked for a very easy sentence, but a very funny one. So if you if you don’t add any comma, or any syntax, so sentence would be: “Let’s eat grandma”. So like, we would eat human flesh, like no. But now, after the word eat, if you add a comma, let’s for: “Let’s eat, grandma.” So it’s from my let’s come to dinner, let’s have lunch. So it’s a completely new meaning with just adding some syntax without changing any words. And basically, DNA methylation is like this, where you add some some methyl group on some bases of the DNA. And it might change the DNA. So only to actually the A, and so adenine, and the C cytosine on the for sale for A, C, T, and G, and it’s only on A and C. And basically, this methylations are found in really like all Kingdom of life. So you find them in bacteria, but also in our own genome. And the in bacteria is the one that has mostly said that I this is on adenine, but it also exists on cytosine. But it’s mostly studied in eucaryotic cells, because actually, as a cytosine methylation, is really studied because it’s involved in cancer development. So it’s a it’s a main interesting topic. So that’s why it’s mainly studied there. Because tumor cells are an our, actually. So I’m for sure I’m not an expert on that part. But what is happening is cytosines that are methylated, they are less stable. And they can have some a process that is called germination. So it we suddenly through chemical processes will become a thymine so another basis of the DNA. So it’s turned C to T, and you have some, if it’s not prepare, if the cells cannot see that there was a problem, and that cells cannot say, Oh, it was a mistake, it needs to stick to stay a C and not a T, then it will have some mutation and this kind of mutation that often can lead to cancer development. Yeah, let’s just change. The sentence changes the whole sentence in that regard. It’s not just adding a comma, but just like changing the whole word, basically, in this exactly in this particular situation is exactly like this. And so that’s why it’s, it’s mainly studied in eucaryotic cells, but in bacteria, it’s really the adenine methylation that has the most that was the most characterized and so These methyl group added on the on the DNA. It’s an it’s done by an enzyme that it’s called methyl transferase. So it’s it’s adding the methyl group. Yeah, it makes sense. And then it’s these methyl transfereses. They can, it’s even more complicated because they can be like, divided in two main groups, depending on what they can do. So you have the one that actually not working alone but are associated with the restriction endonuclease. So it’s kind of some scissors and methyl transferase. What they do, I told you say at some methyl group an adenine or cytosine, but it’s not on any adenine or cytosine, it’s really on a specific words that they will find and locate in the in the genome. And then when they recognize this sentence, this small combination of letters, they will then add as a methyl group on either of the adenine or cytosine depending if it’s an adenine methyl transferase. So working for adenine or cytosine methyl transferese recognizing and adding the methyl group to the cytosine. And basically, when they are in the group, where they are associated with the restriction on the nucleus, this same scissor recognize the same motif, the same word, can when they recognize this word, if it’s not methylated, they can cut it. Okay, if it’s methylated, they cannot cut it. And so what it does, it’s really an protection against foreign DNA that comes into the cells. So you have, for example, a phage virus that can infect the cells, and what they do usually say, I’ve touched on the bacteria and then the injected DNA. And if there is some of the words inside the DNA that can recognize by the scissors, it will be degraded before anything can happen. Because it will be able to cut so that’s It recognises viral DNA instead of its own, okay, yes, with which permits. So really to avoid that, that the virus phages can can invade the cells and then destroys the cells or even that the cells can as a virus can then integrate the DNA into the bacterial genome sources is even slightly more complicated random process. Yes. Okay. So that’s really actually worse than the CRISPR Cas? Good question. I think it’s, is it more efficient? I guess they could say could be even? I think it’s, yeah. But that’s why is it one of the first mechanisms how, DNA methylation was studied, it’s really the first thing that they found. So this main category when the methyl transferase are associated with these scissors that we can send can can and yeah, there is a second category, of course. Okay. Okay. So that was the first one who used this methylation, with a scissors against viruses, as an immune system is kind of, Okay. Yes, just to send to and to, yeah, and also, as with the integration of the DNA, it’s kind of it’s avoid some additional pieces of DNA that might be not wanted or not set down, have a positive fitness or something. But it’s also kind of in the same sense, do some genome maintenance to really keep what you have and to not evolve. So generally, just to keep out all the foreign DNA, but how then, because we know that bacteria always evolve because they take up new DNA, how do they make the difference now? Okay, this is what the piece of DNA that I actually want to have, and then I want to get into this cell so I can evolve and become better. Why do they cut the foreign DNA in the first place? I think it’s I think it’s probably changing a lot between the different bacteria like some of them have a lot of these methyl transferese. They can have five or even more different one, but some of them will have only one. So it’s a I guess, there is already some a lot of differences here some are more protected somehow maybe less protected against some some invaders DNA. And then in the end, it’s always some probability because they only recognize one word. So that word needs to be in the viral DNA, okay. And then also once viral DNA comes in This so scissors are expressed and then we’ll have some time to try to get it but I don’t really know how fast it goes and you know if the viral DNA somehow can still be recognized by the first methyl transferase and then be methylated and suddenly protected. So it’s, I guess it can go both way it’s a bit. Okay. Yeah, we for now the main things that is shown is more that it’s to go against and to be protected against them. But I can I’m sure in some situation, it might, depending on the timing, or the length of the viral DNA, maybe there’s still a chunk that can that is not cut that is long enough to being integrated into places so I can sneak very complex. Yeah. Okay. Okay, so what about the second class, the second class exactly, is the one that I’m more interested about. And it’s the ones that are not associated with with the scissors. So they basically they are called often solitary methyl transferase, because they are alone. Not with the scissors next to them. And those ones, they have been much, much, much more sorry, much less studied. Because we don’t know yet what are their roles, but they do. And a few one that we know a little bit about is that they have an effect on gene regulation. So really like this comma that then affects the whole verse next to it so adding a comma not will change the sentence. and in this situation is for example, if there is a word that is able to degrade something it might completely like inhibit the use of this function or in ends the use of that function. Okay. And for now, what they would say is a few things that they found is that it can have some impact in turning on some virulence function. But also some like motilities or bacteria that suddenly swim in some some media and it has also some, some of them might have some impact on some cell division like to help the cells becoming two cells. Okay, so yes, okay. So So what’s how do we actually know all about this? How do you study this kind of system? You study the coma setting it within a set? What do you do so it’s, it’s, it’s very, it might not change so much than other things that you studied in gene. Also, because we have already in the organism sized I study we already have some information that helps working on so I’m working with Caulobacter crescentus. And Caulobacter crescentus is a nice and nice little bacterium that is in the water. Okay, it has this coma shape, actually. And it’s a it’s a, it’s a very cool organisms because it’s actually not only one shape, and it has a dimorphic lifestyle. So that’s how we call it what is that it’s actually the first one is is one with flagella so it’s something at the end of the bacteria that helps swim in the in the water. So this one is one of the first shape and basically the bacteria will swim around in the water, look for some sugar look for some nice and cozy place to stay in. And when they find that place, they just decided to stick to it. So they get rid of the flagella and they do something to read to really stick to that surface. And to never move never leave from that one. How did I do that? It was just something that is called a stalk. So basically, it’s really something with a triangle at the end. And it acts like it’s really a glue so it’s really like sticking to the surface. And there is a nice blog post in the Bacteria World that you should read about that. And yeah, basically, they tried to to really investigate the force. That is how how much force they used to really stick to that surface because as they are in the waters, they need to really stick to the you know, you have some current you have different things so they really need to stay attached. And they could really, really say that, I think it was was one centimeter squares of surface that they could hold for like 680 kilos, it’s like one, one elephant or for three legs. This is Yeah, really powerful tiny organisms. It’s like a superglue of bacteria. It’s the superglue of bacteria for sure. Like you want to use it for everything else. Okay. What do you think? They they were thinking about doing this? I think they have they think it never when through in the end, maybe there are still some people working on this to say I have no idea, actually. But yeah, that would be really, really nice to be able to use it. That’s something to think about. Yes. Have a bacteria to just see stuff on the wall. That’s Yeah, that’s funny. Yes. Okay, sure. Okay, so now three in blue ocean and the commerce setting has to do with forms of the bacteria. How does it all work? For this product? I don’t know if they have like some specific things in the different shape. But for sure is what is happening with, sorry there is a plane. Oh, okay. That just wait for the plane to pass and then start again. Close to the airport. It’s not the airport actually is one of the army, Swiss Army. Okay. Well, so it’s not the same kind of thing. They do their exercises. And it can It’s not often but it can be very noisy. That’s fine. Yes. I think they’re gone now. For now, we’ll say that’s fine. Okay. Starting, I suppose this? Yes. For this kind of bacterias, it has actually five different methyl transferases. So it’s one with a lot of these methyl transferases. And two of them are in classified as protecting again, invading DNA. And the three others from the category of the orphan that might have been different function. And one of them is involved in the cell division. So not between the difference, morphology of the cells has no influence in the inheritance talk or having to swim. It’s really the bacteria that taking in with nutrition, you train it, we then divide. So basically, says with salt, that will always produce one with the flagella, and that is swimming away with lexis. And that’s actually one of the reasons why this organisms was so much studied, is because you can really nicely seize a cell cycle and study the cell cycle. And also you can synchronize as how we said, the cells because you can really separate the ones that have only the flagella and swim around. And the other one that has the stalk, and I can separate the swimming bacteria from the from the glued bacteria. Oh, yes, exactly, I said is really cool. And then you can only start with one population, and then they will do exactly the same thing kind of at the same time. So it’s really all the shots we go through the whole cycle at the same time. And the same the same time period. Okay. Exactly. That’s how it’s, that’s why it’s one really model organisms that were studied for, for cell division and so on. And that’s also why they found this one of these methyltransferase that has some influence in the cell division. So actually, it’s it’s, the name is CCRM, before cell cycle regulated methyltransferase. So it makes sense. It’s a it’s a, okay, okay, so it’s a methyltransferase. Yes. That is reg, ignore that regulates the cell cycle. Yeah, exactly. Yeah. So yeah, it’s one of the methyl transfers that my lab is working on. For one of my colleagues, mainly focusing on that one. And actually, what they really what they see is, depending on the progression of the cell cycle basically is a new DNA that is replicated. It’s not directly methylated. Okay, and then what, depending on how the methylation will progress, it will influence on the turning on and turning off of some function of the gene. Okay, so wait, and then the bacteria replicates and makes more DNA, and some of them have the methylation, some don’t. And depending on that, does what? So one of us, plane again. So one of the main, it regulates, like, hundreds of deeds, but one of the main ones that I can tell you that will help you understand how it can help in the cell division progress is one that is called FTSE. And it’s how the cells when they elongate, divide that they need to separate at some point and this there is a ring that will actually really close to then have the two cells being two instead of one big one. Okay, so I make a ring in the middle. Yeah, that’s will come through Okay, and then yeah, so this is one of the genes that is regulated and this activist especially more activated when it is methylated so when the cell elongates inside the DNA needs also to to be to two have two genomes into two cells. And so the DNA will replicate have to have a second copy. And when this replication appears, suddenly not all the DNA is methylated and only when it’s methylated it will then activate these genes and help at the end to you have to have to bacteria so it’s really, it’s really crazy to think that you know, it’s also a matter of what genes is where on the genome because it needs to be deeply like replicated and methylated at a certain point to make sure that everything else kind of is already doubled that you have this division at the right at the right moment to have two healthy bacteria daughter cells okay that is crazy Think about that. Like this teeny tiny bacteria in one cell can have such a complex regulatory system right? Yes, yes. That’s crazy. So yeah, so this is one of the of the mature transferase that is the focus of my lab and there are actually two others that are formed this often and those two amongst the five that Caulobacter has it’s the only two that are recognizing and methylating the cytosine. So we have really no idea what they do but as a function and actually that’s my project project now we come to it Yes. Okay. Yeah. So finding finding what these was these two cytosine methyl transferase do so, to really study this because that was the origin of the question what is nice is that we already know as a motif that they recognize and on which words they add methyl group so this is already something that was that was done before and that is already some good information that we can use because we have access to actually the whole book of the bacteria in with Caulobacter and we can really look for this motifs where they are and before which kind of functions they might be and if it can influence or not. This is a function of the next to the to this word that can be methylated or not. Okay, so yeah, we guess right now what do you think your methyl transferase does? Or can you not tell about it because it’s not published yet? For sure it’s not published yet. But we can say one thing that we that we found and that we found before so basically I started as a project just before the pandemic and and we actually had a lockdown so it was a bit I was planning on my first experiment where when you kneel so University of Lousanne should like it was closed for everyone. It was a bit complicated it’s life story your family life during the last one and a half years. Yeah, exactly. But we in the end we were really lucky because we only only close for six weeks, six or seven weeks. It was not so long and then we could come again. So it was it was not that bad. I have to say compared to other people, it was really we were really really lucky. So yeah, we did some first, you know, experiment just trying to put the bacteria in different mediums to see if they could grow better or not. Comparing the bacteria that is a normal healthy bacteria with the bacteria that is lacking the methyl transferees. So basically then some, the words cannot be methylated by change something. And on the growing media it was just like doing standard things to do something to start with. And we saw nothing different, but I was willing to do some motility assays, that’s how we call it so we put some bacteria on the surface and we see how they swim on that surface. Well, basically a swim on a surface. Oh my gosh, it is so it’s so nice to see on this day, it’s really really cool you have so you use some some food where you put some agar like you would put in your jelly to have them to have them a bit sticker and you add a specific quantity of agar that it’s solid, but it’s not so solid. So it’s if you if you take on the side of your of your square where watermedia is exactly it’s a semi semi liquid solid surface. And on that kind of surface, if they have this flagella, they can they can move, they can swim on that on that surface. So when you put that really tiny, tiny little drop of of cells, you if they can move you really really see at the end of circles, which really big circles that can because Wow, exactly, it’s a swimming all direction. So we did that a bit to try different things. And also because in in recent papers, they found one of these in a different species, methyl transferase that could influence the motility and we actually in one of the two methyl transferase that I have, so a defect in the in the motility so they could not swim properly. And now the only thing I can say and what we think is not because they cannot it’s not because they cannot use the flagella to swim. But it’s more because they really suddenly stop also their cell division. So they are blocked. Okay, the cell division because there is some stress. But so wait, just because they can’t divide does mean they can’t swim anymore? What so no, for sure not but also on that surface at various foods, they will also go to other foods and use it and of course, they will also divide it’s not when we when we check out this phenotype is mostly to see if they swim or cannot swim. But also the swim to go to a new to a new source that is appealing to them. So of course on the plate, you have some nutrients, some sugar, and they go further away to find this this food. So it’s also important that they can they can become two cells and divide. So this is really of course preliminary and it’s okay. We think based on other things, but it’s not. It’s not proven yet. It’s really the beginning of an interesting project. Okay, so I’m sure the next time you’re going to tell us more about it. Yeah. Once we do, I hope. I really hope so. That’s good. Okay, yeah. Okay, and then, besides being a microbiologist, you’re also an amazing science artist. And maybe you can just tell us a bit of like, how did you get into science illustration? Why Why do you like it so much? Or is it just a hobby for you? Or at some point you might make it a full time career? What’s the idea? Yeah, so I’m really love doing science art. I think it really came that I always liked drawing when I was a kid I knew draw amazing, I guess we have to say that it’s not just that you like drawing you’re actually really really good at it. Thank you. So I guess it’s I had that from my mom because she was really she really liked drawing and so when I was a baby, she was already you know, finding funny to give me some paints and use my fingers to learn anything. So I, I touched the artistic sides, very, very young. And then I always continue to draw, I really liked it. But I actually stopped during the university studies because I had less time to do hobbies and things like that, like a lot of other people. And I always had that on my mind. Like it was a bit sad that I had to put this on on site. And it’s during my PhD that I started again, because I thought I need to do some poster to talk about my research. I need to do some presentation and it’s a perfect way to combine the two things to really use some drawing to explain and especially I think for the introduction, I think it’s it’s really good combination, because you need something very clear, something very understandable, fast not to lose your audience. And introduction, it’s very, very important. Otherwise, it’s very complicated to follow. And if you can do it simply in in, in an easy and fast way, it’s, it’s the best things because people don’t need to already use all the ranges to understand your introduction. So yeah, I started again, during the PhD, and then I, I decided this is I had so much fun, I really wanted to kind of only draw a microbiology theme. So yeah, I really continue on this, I did this challenge that is called Inktober. So it’s something during the month of October, that people usually draw everyday during one full months. And, and it’s kind of started from this, I was like, this is a perfect opportunity to really draw something every day, to try to have something bacteria-like to explain to people some mechanisms with a nice picture something a bit comic, like with some been added to it. And yeah, it’s really something that I love doing and then and then we met for the BacterialWorld. It was a really good opportunity also to then work not only with some picture, but picture going to a very nice text explain. Really a text that is readable by not only scientists, but by non-scientists, people. And, and yeah, for sure, it’s something that I saw that I am very lucky, because I’m actually still working in the lab, but not five full day per week, but four days per week, because I have one day, you know, work 40 hours, you only work like, what, 30, 32 hours? Oh, yeah. Yeah, let’s be honest, contract is always different from the real world. Yes. Yeah, it’s around 30 to something because we have 8.2 something hour per day. So maybe it’s 32.6? Something like that or 8? I don’t know. But yeah, it’s very, a nice opportunity. And I’m for sure, and I really hope one day may be to only do that is a dream. Yeah. Yeah, good. Okay, so science communication, as we all know, is all about thinking about who is your target audience? Like, if you don’t know what target audience is, you might as well not do any science communication at all. How do you involve this thought process? In your comic drawing? Do you make a difference? Whether you basically draw for kids or draw for adults? How do you how do you involve this? When creating your comics? It’s a very good question. I think most of the time, I try to have something simplify as much as possible, because I think, even if you need to think about the target audience, it’s good if you can reach as many people as you can. And with drawing, I think the advantage is even like compared to words that might be different between adults reading something, compared to a kid reading something, a picture is, is the same, like most of the objects, everyone knows them. And even if you don’t know specifically the name, exactly what a bacterium is carrying on to do something, you have the whole idea of what is happening for example, if if a bacteria is sending some toxic compound to another bacteria, no matter what, what kind of mechanism was the bacteria is holding, if the kid is not understanding exactly what weapon it is, it doesn’t matter it because it will see that it’s something toxic, something with deadly skills, or something like that isn’t his physiology and bacteria. So I think I always try to simplify really, as much as possible. And sometimes when it’s more complex is more like, when I have something very specific, when someone is asking me something for for example, for drawing for some thesis or something like that, then it’s of course much more. It’s it’s Yeah, and it’s it’s really like requests of, you know, something that really needs to be there to go along with with the text on the topic. And then of course, and it’s not for every person, every readers budget, otherwise, I think I tried to make it always as simple as possible. Yeah. So yeah, I mean, that’s a good one. transcends communication make it as simple as possible, but not simpler. Yes. Yeah. Nice. Okay. Thank you so much for your time. Thank you so much for explaining all of us about bacteria about bacteria glue about science comics, it’s been a real pleasure to talk to you. And we can’t wait to talk to you again, once you figure out what these methyl transferase is actually is and where they actually swim to and Yeah, why not? For sure, I will be very happy if I have something interesting to say to reach you again. And to say we need to do it. Episode Two. Sounds good. Sounds perfect. Okay, thank you so much again, and thanks for everybody to listen for listening. Thank you very much for having me, was a nice pleasure. Thank you for watching with STEMcognito. Find more videos using the search box or the drop down menus above. If you think there’s something wrong with this video, please use the Report button to inform the STEMcognito team. Questions about the video content should be directed to the researcher. You can find their details below. Go to our submission pages to find out how to submit your own video and don’t forget to follow us on social media.