 all right so we are recording now so welcome back everyone there's a like 20 20-ish slides left to go and then we're done with the lecture for today so I hope everyone's still awake actually so if you're still awake just throw something in chat like I know that people like it's one of these things that if you're doing these lectures live then I can see people falling asleep or saying no I already noticed please just skip this part and that's one of the things that like I'm missing now right like I only see myself talking into a microphone and the slides and I don't have that much feedback and it's nice to when you're doing lectures live you have the feedback and people can comment and but we have to use the chat for that so if you're still awake then just throw something in chat or subscribe or like or just do an animated gif or whatever just so that I know that I'm not just talking to myself for the for the last hour and I know it's not the most interesting lecture by going through all of the different sequencing technologies but at least you guys can do it from home right you can just lay in bed and and and watch it all right Alexander's still awake commander still awake Sandra still here hey Sandra um did you already come at the beginning of the lecture are you just tuning in now so all right good so at least we still have three people are awake so I'm not doing it just for myself and for the people that will watch it later um but yeah it's nice to have a little bit of feedback and I'm doing this for you guys so if you guys have very specific questions or things that you want to know just uh just let me know all right so sequencing we've talked a lot about it um it is a key to biology nowadays so without sequencing um nowadays biological research uh will uh would be impossible there's many techniques um we discussed a whole bunch of them but there's many many more like I could fill just a whole lecture three hours just from um just talking about different sequencing techniques but that would not be fun for me or fun for you guys so um ah here's since minute one very good Sandra very good I hope you're enjoying the lecture um so um there's a lot of techniques and a lot are still based on on PCR and amplification um and and the the problem with sequencing is that there's a complex computational pipeline that that you get after you get your sequencing reads so the part in the lab is is very small compared to the part that a bio bioinformatization needs to do afterwards so some of the things that are already possible or possible in the near future is single cell sequencing um people are working on being able to get DNA from a single cell and sequence that um and and even single DNA molecule sequencing like the buck bio um is getting more and more possible every day um so we're at the the the techniques and are getting better and better every day so when I do it next year there will probably be another couple of new novel sequencing techniques that are more interesting all right so I wanted to talk to you about gene structure because when we're talking about a gene um there's two different very very different definitions of gene so in the previous lecture when we talked about a gene right when we talked about um how Mendel saw a gene or um um how um Thomas and Morgan saw a gene and then we were talking about a unit of inheritance so something which is like a bead uh which is inherited from parent to uh to children however in molecular biology if you're talking to a molecular biologist you're talking so the the the previous lecture was like geneticists so someone who does genetics will see a gene as a unit of inheritance um but in molecular biology a gene is a union of a genomic sequence encoding a coherent set of potentially overlapping functional products um and it's a completely different definition and um I just wanted to show you how a molecular biologist thinks about a gene instead of a geneticist I'm coming more from a genetics point of view so for me a gene is something that is inherited and has certain properties and causes certain phenotypes but in molecular biology a gene is a union of genomic sequences so DNA sequencing which encodes a coherent coherent set um so a set of proteins um which um which can be even overlapping but have like a certain functional product so when we talk about a gene structure there are two different types of gene structure so there's the gene structure for bacteria also called pro prokaryotes um and the prokaryotes um are encoding genes in a different way compared to eukaryotes so compared to humans and mice um so a very quick overview on how it looks like we will talk about RNA and translation um but if you look at the the the DNA of a bacteria then a the DNA of the bacteria genes are coded in something which is called a polycystronic operon um which means that you have like a regulatory sequence um and another regulatory sequence and this regulatory sequence consists of enhancer so things which when a protein binds there will enhance or will silence the production of a gene or of this operon um then we have an operator and a promoter so these three things are in the regulatory sequence and then you still have the five prime UTR so the five prime untranslated region of the mRNA um and then you have something which is called an ORF an open reading frame and this open reading frame actually encodes the protein um so had the protein coding had like normally people say or people used to say that there was a lot of junk DNA DNA which did nothing it didn't encode for proteins and people didn't really know what it did um but nowadays we know that like a lot of the DNA is actually in this regulatory sequences so it actually has a regulatory function on the transcription of proteins or of messenger RNA which then eventually code for proteins um but in a bacteria if you look at a prokaryotic gene structure these things or multiple ORFs are usually transcribed on the same mRNA so when you look at the DNA you have some enhancers or operators and some promoters of things which determine if the gene is going to be transcribed and how it is going to be transcribed then you have the five prime UTR which contains the ribosomal binding site and then you have something which is called an ORF so an open reading frame where the the the three letter code on comes from so hey you have three DNA bases which code for for a single amino acid and in bacteria these things are generally stacked together so you can have a single messenger RNA which is not really a messenger RNA in a in a bacteria um because it's generally directly transcribed at the point where it is uh so the translation in a bacteria more or less happens at the point where the transcription occurs um so but you get a something which is called an mRNA it's it's an RNA it's an intermediate it's a messenger but it's not like in a human cell where it's transported outside of the nucleus um because bacteria don't have a nucleus but there's different there's there's two or three or four or five proteins encoded on a single mRNA so bacteria um generally transcribes multiple genes in one go um so in that this is called a polycystronic operon um so hey there's many open reading frames which encode different proteins and all of these things have their own ribosomal binding site so if you would have something which looks like this and then there would be two ribosomes attaching to this mRNA when it is produced and then they start producing two different proteins um and this is different from how eukaryotic cells work because in eukaryotic cells um you have something which looks like this um so you have still a regulatory sequence at the beginning which can have like again enhancers and promoters which is then split into a proximal and a core part and then you have your five prime utr but then you have your open reading frame and the main difference between the between eukaryotes and the prokaryotes is is that in eukaryotes a single open reading frame is encoding for more or less a single protein so there's no many proteins on a single messenger RNA like there is in bacteria one of the other features which is very different from um from bacteria is that the open reading frames in uh in eukaryotic cells have um introns and exons so that means that there are little parts which are not coding for protein inside the different protein protein coding parts so when the DNA is transcribed or translated into mRNA um the mRNA still contains these intronic parts so the whole part so from the five prime utr all the way in the back to the three prime utr is transcribed on the mRNA and then there's something which is called post-transcriptional modification in which the introns are removed and then we have the protein coding region um kind of being formed from the from the uh from the intron exon structure um one of the other things which happens in the post-translational modification in eukaryotic cells is that there's a poly A tail added to the end of the mRNA um so we will talk about talk about this more when we talk about the RNA part of the lecture um but there's a there's a difference so there's a little five prime cap being added then you have the five prime utr then you have the protein coding region and then you have the three prime utr which doesn't code for a protein but generally has like a leader sequence or a targeting sequence and then you have the poly A tail so the poly A tail is kind of instructing the ribosome to make multiple proteins of the same mRNA because it would be really you uh wasteful that if you need like a thousand proteins to have to produce a thousand uh messenger RNAs right because then you have to transcribe the same gene a thousand times um so in eukaryotic cells the way that they kind of solve this is by doing post-translational modification and adding a poly A tail so the longer the poly A tail the more or the more often the same mRNA will be transcribed into proteins so in eukaryotic cells a single mRNA is carrying a single protein but this protein can for example be transcribed ten times or a hundred times or a thousand times so that hey you don't have to make a or that there's no need to make a thousand um mRNAs and while in bacteria this does not occur there is no poly A tail in bacteria so bacteria one messenger RNA codes for two proteins which can be two different or which are generally two different proteins um in a eukaryotic gene structure there's only one protein coding region but this can be transcribed multiple times depending on the length of the poly A tail all right so a slightly different gene structure so hey if you if you get a question on the exam like what is the main difference between a eukaryotic gene and a prokaryotic gene then one of the answers is well the eukaryotic gene uh encodes for a protein but has introns and axons in there while a bacteria has no introns and axon structure it just has the whole protein as one single kind of unit um while a prokaryotic uh while eukaryotic gene will have these enthronic sequences so sequences which still need to be removed from the mRNA before the protein is produced and of course these have a function as well but we will talk about that when we talk about the RNA lecture all right so and when we look at gene structure we have a very major difficulty in defining what is exactly a gene because um a gene is a unit of inheritance um but there's also some parts of RNA inheritance um how we can have gene fusions which are genes next to each other um that produce a single mRNA leading to a non-functional fusion protein it sometimes happens that that's the case that something in the translation goes wrong and instead of transcribing a single mRNA actually two mRNAs are produced and then the proteins that are made are actually fused together um so they they don't work um and there's also something that is called uh interchromosomal promoter regions and that is for example that the promoter of a gene is actually not located in front of the gene but is located on a completely different chromosome and that is of course because when you think about DNA people always think about DNA in chromosomes and chromosomes are independent units but that's not really the case because in a 3d structure a chromosome 3 can be very could be very close to chromosome 7 well chromosome 5 and chromosome 6 could be very far apart um so and there's there's a lot of evidence that nowadays in in in when you look at how a gene is transcribed and how a protein is made and that in some cases that a promoter on chromosome 1 can drive the expression of a gene on chromosome 3 for example and then there's also a couple of examples where for example axons are located on different chromosomes so instead of just making a single mRNA going on a single chromosome and so going on the DNA um it actually switches chromosomes and that is that that is for example seen in in mitochondria and we will talk about that later but defining what is a gene for a geneticist is very easy it's a unit of inheritance but for someone who does molecular biology it's much harder um and I just wanted to kind of make that point so when you look at the structure of a gene of course a gene is composed of multiple protein domains and when we talk about the protein lecture we will go back and talk about all of the different domains that you have um but protein domains like you have things like alpha helices and beta sheets and you have loycine zippers and yeah protein can be an immunoglobin like yeah or it can be a zinc finger protein which binds DNA to drive transcription um and and the nice thing is that using bioinformatics you can look at the sequence so the DNA sequence and then predict some of these protein domains by just using your computer so without having to do any experiments in the lab so um and all of these protein domains we will talk about in the in the protein lecture so when we talk about gene structure then we talk for a bioinformatician one of the main tasks is to take a DNA sequence and then um predict what are genes or where are the genes so and you can do that in different ways one of these is is up initial um using known signals so for example when we talk about prokaryotes um have we have a very um a very basic structure in a way because there's just a promoter and then there's the there's the protein coding part and then you have another promoter and then you have another or then you have a little ribosomal binding site and then you have another protein coding gene so in prokaryotes it's relatively easy to predict where the genes are and what the proteins are that these things are coding for but it is very difficult when you look at eukaryotes especially because in eukaryotes genes can be very complex you have introns and axons and so it's much harder to predict um how a gene will look just based on the up in each show so based on the DNA sequence it's sometimes very hard to predict um where the genes will be in a eukaryote it's much easier in a prokaryote and of course here you can use things like machine learning so you can take like um 10,000 known genes and how they are coded you can train a machine learning algorithm for that and then hey you can then use this train model to do novel gene prediction so but this only predicts genes which are already looking like genes which we know are there um and this is the same when you do comparative gene findings so for example when we first had the mouse genome sequence published and then most of these genes in the mouse genome were annotated based on genes that were already found in humans and so this is comparative gene finding so we use the conservation between for example mouse and humans to say well in humans we know that there's a gene which goes for immunoglobin and this immunoglobin gene we're just looking at the sequence that humans use and then we look at mouse and if we find a sequence which looks very similar then we just assume that this also codes for immunoglobin so there's three different ways of detecting genes up in each show is just looking at the DNA sequence and then looking for known signals like a data box or a ribosomal binding site machine learning nowadays is used a lot to predict genes and of course you can use comparative gene finding to take the genes that are already known in for example humans and then look at the mouse or a rat or a monkey and then use the knowledge that you have from humans to find similar sequences in in your target species all right so like i told you at the very very beginning is that one of these things that i that i like a lot is transposable elements and transposable elements are very important when you are studying plants because in plants they are ubiquitous there's thousands and thousands of transposable elements in a normal plant genome and the nice thing about transposable elements is that they are also called jumping genes and they are genes which more or less jump around so transposal is a little piece of DNA which has the ability to either like duplicate itself so it can jump from one part of the genome into another part of the genome and this was discovered in 1948 so again if you think about the timeline that we just talked about this is actually before the discovery of DNA so we already knew that there were parts of the genome which could jump around without knowing how the structure of DNA looked like so we knew that DNA was was there right because we already in 1848 knew that there was something called nucleon but before the DNA helix was discovered Barbara McClintock in 1948 discovered that there were parts of this nucleon which could kind of copy themselves into a different position on this this nucleon and of course these transposals are very important because transposals can disrupt genes if you have a transposal located here in a region where there's no gene and here in blue you have the regions which code for genes then of course when a transposal jumps into a gene then it can disrupt the gene so it can kind of silence a gene or make a gene completely non-functional by just jumping from one position to the other and actually Barbara McClintock got a Nobel Prize in 1983 the year that I was born for her discovery of jumping genes and like she has a very interesting life so if you want to read something and read about scientists and and what they did then then read up on Barbara McClintock she's one of my favorite scientists but there are more so we will we will discuss more famous scientists but yeah Nobel Prize 1983 so just a tip I like Nobel Prize winners so I there's generally like a question in the exam about who won the Nobel Prize for medicine in 1983 or something like that so just a tip for when you're doing the exam that learn some of the Nobel Prize winners that are in the slides so transposable elements come in two different forms so you have class one transposable elements and class two transposable elements class one transposable elements are also called retro transposals so a retro transposal looks a little bit like a virus it's the same way that retro viruses work so a little bit like things like HIV and that means that they they are located somewhere in the DNA and then when they are transcribed into RNA then this RNA is using reverse transcriptase to go back to DNA so it is it has an RNA intermediate the class two transposals which are DNA transposals they do a direct copy of themselves so they there's no RNA involved but they use a protein called transposase to kind of help them jump around into the genome so class one is a gene which needs to be transcribed in or is it is a transposal element which needs to be transcribed into RNA and then rolls back using reverse transcriptase while a class 2 DNA transposal makes a direct copy of itself using transposage so if we look at the class one retro transposal so have for example we have a retro transposal here so the the standard DNA machinery comes along and it says oh okay I see a binding site so the polymerase binds and it transcribes the retro transposal into RNA and then you get this formation of this ribonucleon protein complex which is then reverse transcribed and then of course the RNA that has been transcribed is transcribed into DNA and then this DNA can integrate at a random position into the genome and it can integrate within a gene disrupting genes in the neighborhood so it's it's a it's a piece of DNA which through RNA jumps back into the DNA and this is more or less similar to how HIV copies itself around so if you look at the class 2 DNA transposals then they look a little bit like this so this is one specific type the Mariner type and this is you have here the transposage which is encoded on to the transposal so how what happens is that you have these tear molecules binding at the edges the tear molecules then bind together causing this loop of DNA and then they cut the DNA of course the DNA is then fused back together by DNA repair mechanisms and then had this this this complex with the little piece of DNA so with the transposal in there is then moving to a different site in the target DNA and it it recognizes specific motif and then like rolls back into the DNA so it it's a direct DNA copy without an RNA intermediate so very interesting elements and of course in plans they are very very very important because since plans cannot really move they can't really make variation right genetic variation is something that you need to generate to stay alive because you need to adapt to changing circumstances and of course a plant can't just decide to move somewhere else or to mate with with some other plant no because plants are generally close by the chances of plants in breeding is really high and so to kind of combat this inbreeding and dying out because of inbreeding plans use these trans transposals to generate sequence variety by just copy and pasting parts of their genome all over the place and then hoping that these new pieces of DNA will integrate in such a way that they will have like advantages or disadvantages all right so when we talk about transposable elements we don't talk just about class one and class two there's actually a other subdivision so you can have autonomous so transposals which move by themselves so they carry the transposals or they carry the reverse transcriptase in there and you have also non-autonomous transposable elements which require the presence of another transposable element to move so for example these are transposable elements which do not encode reverse transcriptase so they depend on another transposable element to bring in the reverse transcriptase gene when we talk about class one or they are transposable elements which don't have the transposazer gene so when we talk about class two and of course you can say we have autonomous class one autonomous class two non-autonomous class one so you can mix and match these things together so there's actually four types of transposable elements all right hope that's clear all right almost there a couple of slides to go six seven slides and then we're done for today i've been talking a lot so i'm getting a little bit of a dry throat but i'm hoping that you can bear with me for the last six seven slides so when we talk about regulatory elements in the dna then a regulatory element is a segment of a dna molecule which is capable of increasing or decreasing the expression of a specific gene within an organism right so it's a it's a part of the genome where a protein can bind and when the protein binds it either activates the expression of a gene or it represses the the expression of a certain gene because normally when you look at a gene and then this is this is just a strand of dna and then here we have the proximal promoter elements and this is usually the direct regulation of the gene and so proteins bind here here you have the core promoter so the core promoter is where the the RNA polymerase binds to start the transcription of the gene and then the proximal promoter elements are the things which are within like 1000 base pairs of the start of the gene and so these are relatively easy to detect and these are generally like oh if you're a brain cell head then you need to be active if you're a muscle cell then this gene does not need to be active so these are kind of the the regulators which are directly saying be transcribed or not be transcribed here the core promoter is more or less the promoter element where the RNA polymerase binds and then you have all of these additional parts which are like insulators which make sure that the expression of one gene does not affect the expression of another gene and you have silencers and enhancers which will kind of fine tune the regulation of a certain gene and that that's of course so these things the proximal promoter elements are generally for regulation on a cell type level while these distal regulatory elements are generally more for the fine tuning so they are based on signals from the outside of the cell right so I am a brain cell so I need to produce a certain protein because I'm a brain cell so that's regulated here and then well but currently it's very warm outside or the temperature is high so I need to produce like a little bit more of the heat shock proteins compared to like five minutes ago and these things are kind of regulated more distally so farther away from the gene so when we talk about these things then we talk about cis, cis means that it's located nearby the start of the gene and then we talk about distal which is around minus 200 base pairs we talk about proximal which is like 500 to 200 base pairs in front of the start of the gene and then we talk about the core and the core is more or less like surrounding the start of the gene so from like 40 base pairs into the gene to like 50 base pairs in front and then when we talk about trans then we talk about the distal regulatory elements so these are located far away and can even be located on a different chromosome all right so some regulatory elements that people or that I think that that you should be aware of one of the most famous regulatory elements is the Tata box which is also called the Goldberg Hochnus box and the Tata box is present in around 24% of the human genes so this is of course a core element and because here the Tata box is at like minus 30 base pairs compared to where the transcription start site is and the sequence of it is TAT and then three A's so not Tata but Tata and it is the place where the main transcription factor binds so Tata is bound by the transcription factor and this then pushes the polymerase to start transcription of the gene so a very important kind of telltale sign and this sequence of course is something that you can easily find in the DNA just using standard bioinformatics tools so if you just want to say well I want to predict genes and you see the sequence Tata then you know okay so 30 base pairs after this sequence there will be a gene and that's if you just have this simple like detection algorithm saying that well if I find this sequence in my DNA 30 base pairs later there will be a gene then you can kind of catch 24% of all human genes because all if you look at the genome and all genes that we know of then around 25% like one in four genes will have one of these Tata boxes in there of course there's many many regulatory elements and I'm not going to talk about all of them because again that will be a lecture on its own so if you want and if you're interested in like regulatory elements and how they regulate DNA then and how you can use them for like the prediction of genes or looking at like species specificity of genes then we can talk make a lecture about all of these regulatory elements but I just want to name a few so frameshift elements are elements which cause a small frameshift they are used by viruses in the coronavirus there's a frameshift element in the polymerase that the virus uses we have for example things like internal ribosome entry sites which kind of signify where the ribosome should start binding and where it should start pulling the RNA through the ribosome to make a protein we have something called an iron response element because of course regulation of iron and lead and cut neum and all of these like heavy metals within a cell are very important so when like the if you have an iron response element then this is a messenger RNA which kind of has kind of an iron sensor on there so when the iron concentration goes up the iron response element catches one of these iron molecules and then the RNA is transcribed so it is kind of messenger RNA which is produced in large amounts and is just waiting there in the cell to catch an increase of iron to be really quick to respond to an in or a decrease of iron we have things like leader peptide sequences which are sequences which target a protein to be either in the nucleus or in the cell wall or in the endoplasmatic reticulum we have pyrolysine insertion sequences we have ribo switches RNA thermometers and selenocysteine insertion sequences so all of these sequences they have known DNA sequences so how we can use these to predict where there are genes on the genome by just looking at the known like sequences and then just predicting okay so if we see a leader peptide sequence then this has to be a gene right so it's just how do we find genes using bioinformatics tools well it's using knowledge that we have from all of these regulatory elements and then using the sequences to kind of find these sequences into the genome and then saying well if we find a leader peptide then it has to be a protein coding part all right so a couple of other DNA types that are really important and we haven't really talked about is DNA which for example in a eukaryotic cell is not located in the nucleus so I think that most people should know what mitochondrial DNA is but I just want to have it mentioned so mitochondrial DNA is DNA which is located into the my in the mitochondria it is a very small circular DNA so it reminds very much of the ancestry because it is of bacterial origin and it is encoding for genes which are needed in the mitochondria so the mitochondria are the powerhouse of the cell and it's they're very important to produce energy for a eukaryotic cell so they the DNA is just inside of the mitochondria just because of the fact that these proteins are needed there and encoding these things in the in the normal genome would mean that you have to transport these proteins continuously but no these are made inside of the these proteins are directly made inside of the mitochondria so one of the features of mitochondrial DNA is that it's inherited from the mother so generally using mitochondrial DNA we can track back the the female lineage of of of an individual however it is not entirely true because in one in 10 000 cases a sperm cell will inject not only its DNA into an egg cell but will also inject its mitochondria so then you have someone who is a chimer who has two types of mitochondria so mitochondria from the mother who are the majority but there will also be like mitochondria floating around from the father and this happens around in one in 10 000 fertilizations so the main goal of the mitochondrial genome is to produce ATP the the thing that carries energy like the the energy carrier of of of the cell and in humans mitochondrial DNA encodes for 37 genes and it also encodes for its own s RNAs right so the the 16 s and the 12 s so it also codes for its own ribosome so mitochondria have ribosomes themselves which are different from the ribosomes that do transcripts or that do mRNA to protein translation in the in the cytoplasm and of course many of these genes are encoded for cytochrome oxidation and ATP synthesis just because that's kind of the function all right one of the other types of DNA which is often overlooked is chloroplast DNA so chloroplast DNA is very very important when you look at plants so when you look at plants so chloroplast DNA is found in plants in algae and it has also a bacterial origin so it comes from a cyanobacteria as a cyanobacteria and it is the thing that codes for the photosynthesis complex so humans don't do photosynthesis so we don't have a chloroplast but all living creatures that do photosynthesis they require to are they are required to have somewhere encoded this complex that does photosynthesis and these are encoded on the chloroplast so here you see an overview of the chloroplast again the chloroplast comes with its own ribosome so and it comes also with its own tRNA so it uses a slightly different codon structure than the rest of the genome of the plant but it the main thing that it does it is that it comes with its own photosynthesis complex but it has its own ribosomal proteins it has its own RNA polymerase so it is kind of a bacteria within a eukaryotic cell so when you have a eukaryotic cell it is a nucleus but in plants you have the chloroplasts and these chloroplasts do photosynthesis and they come from a cyanobacteria so they're kind of a bacteria which is incorporated into the cell just like the mitochondria is just to do one thing and do it well all right so that was it for today I talked to you about DNA for almost three hours I hope you know a little bit more about DNA a little bit more about DNA sequencing about sequence alignment which is kind of the key to how we do sequencing nowadays so we don't use we don't rebuild a genome from scratch every time and we use a reference genome and then when we sequence another animal or another animal of the same type then we align everything to that reference I talked to you about genes about the structure of genes the difference between eukaryotes and prokaryotes I talked about transposon I talked a little bit about regulatory elements so the only one that you really have to remember is the data box and then I talked to you about two other types of DNA which come from bacterial origin and are located in eukaryotic cells which are the mitochondria and the chloroplasts and that's it for today so the homework for today is just a little bit of r so you will be required to install r and do a very very little bit of programming um and of course um if you have any questions which I'm certain that if you've never programmed before people will have some questions um then mail me because um if you get stuck then try a little bit right try a little bit for yourself like spend like 15 20 minutes on on solving one of the assignments but if you get an error and you don't understand what the error means then just send me an email um one of the things that I could tell you in advance is um that I on my website I have a short overview of of r so it's uh it says it's like uh let me look it up um it's a little pdf file um which has um let me switch actually to the firefox window so on my website you can go to here um and then there's this pdf and I made this when I was still working in Groningen um and it's an introduction into and a little bit of assignments for r um so it's just a it's just a small document just 26 pages um and it explains to you how you can install r and it shows you a little bit of how you how you can learn r so hey if you need help then you can do double question mark search term if you want to know what a certain function does you can use the question mark it talks a little bit about the types of data that there are in r so hey it's something that if you get stuck um you can you can go there um and um you can you can just look at it um so it's uh it's a something that if you really want to solve the question on your own you don't have to mail me like after 15 to 30 minutes you can also take the the the r introduction pdf um and um and just read a couple of pages there and see if you can find how to how to do what you want to do um and of course it's a useful tool to kind of learn r on your own um without having to follow the entire r course um so the r course that i'm giving in the summer semester is based on um this kind of tutorial that i made uh when i was still doing my phd when i was in Groningen all right so i think that's uh that's more or less it for today the uh i will just put the link in the chat so that people can just click the link which is always easier and that also allows people that are rewatching the stream to uh um click the link because the when you watch this or when you rewatch the stream on twitch you also get the uh you also get the chat there all right so for me that's it for today so if there are any questions then speak up or forever be silent um skrita thank you yeah you're you're welcome thank you for being here the whole lecture actually uh testesaurus also thank you for being here um it's always nice um i'm actually thinking like um since i hit 50 followers light uh last time oh let me first stop the recording