CRISPR-Cas9: Revolutionary Genome Editing Technology

The CRISPR-Cas9 system, a powerful RNA-programmable genome editing technology, allows precise gene surgery in various organisms and has diverse applications.

### The Revolution of CRISPR-Cas9: A Breakthrough in Genome Editing
* CRISPR-Cas9 is a powerful genome editing technology that originated from a bacterial immune system, specifically the Cas9 protein guided by RNA molecules to **target and cleave specific DNA sequences**.
* The system was discovered in Streptococcus pyogenes, a human pathogen, and has since been adapted for use in a wide range of cells and organisms, **revolutionizing genetic research and biotechnology**.
* 🌱 The technology allows for **precise modifications of DNA**, including **correcting mutations**, **deleting genes**, and **inserting new sequences**, with applications in **human medicine, agriculture**, and various fields of life sciences.
* 🔬 The simplicity and efficiency of CRISPR-Cas9 have made it a **preferred tool for genetic manipulation**, enabling **multiplexing and versatile modifications** in a wide range of organisms.
* The system's flexibility has been further enhanced by modifications, such as creating **"base editors" and "epigenome editors,"** expanding its **potential applications**.
* 🌍 CRISPR-Cas9 has broad implications for human health, from creating disease models to potentially developing gene therapies, and has opened up new possibilities for **understanding and treating genetic diseases**.
* 🔍 The technology's rapid adoption and development since its discovery in 2012 highlight its significance in **advancing genetics and molecular biology**, with ongoing research to **further improve its precision and expand its applications**.
* 🔬 The presentation emphasizes the importance of **scientific collaboration, persistence, and exploration** in unlocking the full potential of technologies like CRISPR-Cas9, with a nod to the "**night science**" of intense research and discovery.

yeah, as I said, Chris Parast 9 is about actually mobile genetic elements in bacteria. And to understand mobile genetic elements, it's helpful to be mobile yourself as a big human mobile genetic element. Um, so I will, uh, thank you Jennifer for giving some introduction about Chris Parker systems. And yeah, before I start, I would actually like to thank the foundation, uh, and bank, and the academy, the Royal Swedish Academy of Sciences for hosting this event. I think it's essential in our to provide awareness on chemistry, science, biology for the young audience like you. Uh, so I will speak about Chris Bastan in general and also the ations of the Chris Paras N9 technology. Um, okay, so this is I just want to remind you that this is about this enzyme, Chris Parast 9, here represented as scissors that can be programmed with RNA molecules to target sequ specifically DNA. So the Castan protein works as an enzyme able to to cle DNA in a sequ specific manner.

the RNA components work as a kind of GPS system allowing to to bring the chisar cast n system where one would like to to have it targeted on on the Genome of any cell and organism. So it's a very powerful technology and indeed among all the different chisar cast 9 existing, the chisar cast 9 is is quite minimal. And this was a great surprise to find that that in streptococcus penus, but also in other bacterial species, the chisar 9 is actually a unique enzyme. Guided by two RNA molecules that can form a complex. So so the idea of of using this system for genome engineering is really based on on the Simplicity of the system, yet yet it's sophistication allowing to have a simple programmable genome engineering technology uh. So the the field chisar for the application of the of the technology has been called the the chis Park phrase, and this was highlighted by journalist Elizabeth peni in the journal science in 2013. So summer 2013, nearly four years

ago and already highlighted as a chisar cze with a subtitle a bacterial immune system yelds a potentially revolutionary genome editing technique. And this is really about this technology that allows precise Gene surgery and inl and organism. And this article was published only a year after uh we published with Jennifer Donna uh the the article in in science. So in in June 2012 explaining the last step of of the Chris parastan mechanism and how to harness this mechanism as a powerful technology for for genetics. So this shows to to which extent indeed the the the mechanism was easy to adopt by the scientific community that shows very fast uh the the the possibility to really use this techn techology to to perform genome Engineering in in a large variety of cells and organisms and virtually any cell and organism which which biologist can ethically uh study and very fast as well uh the the crisa cast 9 field has been the highlight of of the media first as a next medical breakthrough but then recognizing as well the potential of of

the technology in diverse fields of Life Sciences and agriculture was mentioned by Gen F earlier, and surely a number of scientific journals have published on the follow-up of understanding the Chris Pastan mechanism, trying to develop better the technology and all kinds of applications. So, this has really been very helpful as a technology for the field of Life Sciences, and it will still remain very helpful in the years to come. My interest initially in Chris Parasian came from my interest in understanding diseases at the fundamental level, and I belong to those scientists who are interested in molecular and cellular mechanisms beyond the diseases. So, a number of my colleagues are focused on cancer, diseases affecting the heart, brain, or genetic diseases, and I belong to those people interested in infectious diseases, focusing mainly on bacteria. And this has been mostly the focus of my career over the last 25 years, working on bacterial pathogens that can cause

diseases in humans, and we always hope when we do fundamental work on different types of cells and organisms. We always hope to identify Pathways, genes, and molecules that allow to really understand the functions of genes and understand all the molecular and cellular mechanisms of life. But we also do this research always hoping that maybe we would find an interesting mechanism that could be harnessed for novel therapies or novel Technologies. Having worked on better for a long time, and I've been trained as well at the Pasteur Institute, always had this notion that it was very important to focus on basic science, and this was the only way to find interesting mechanism that could be harnessed in the case of bacterial diseases. Easier to find new antibiotics that can kill bacteria, but also working with bacteria, the possibility to always improve genetic tools, thanks to the bacteria and viruses that have really been the sources of multiple enzyme that have been used in molecular biology.

genetics. Over the last decades, now having said this, I just also take the opportunity to say that in my laboratory, we don't work on on Chris parast 9. We work on on RNA and protein regulatory mechanisms, uh, allowing to understand how bacteria survive and and in their environment, and how they can cause diseases. Always having in mind that it is critical to continue to work on on bacterial infectious diseases, since it is the leading cause of death in children and Adolescence worldwide, and the antibacterial resistance, uh, poses still a major health threat, and and this has been a field of of Interest highlighted recently by the United Nations. Now having said this, genetics is really critical in Laboratories for understanding functions of genes and and with regard to the to the medical field, for example, to to Really, uh, find new targets for for Therapeutics, and also other purposes. And I just would like to to give you an idea of where Chris parasan can be placed in in the history of genetics towards Gene editing, and surely I mention only, uh

selected did uh um breakthroughs. The 19th century has been uh very critical for fundamental genetics to establish rules of genetics with Darwin. On the Origin of Species, Mandel on the segregation of Els and frish Mish isolated the DNA in 1871. Then the mid-last century was critical to show that the DNA was the carrier of genetic information to also determine the structure of the Bellic of DNA and to also R the genetic code and and this was very exciting with a possibility to really understand the code and and also the need to develop technologies that would allow to to Target genes and and understand uh their their expression and and functions and this came really in starting in the in the 60s and and 70s with a number of scientists interested at the time in microbiology working with bacteria I mean at the times is were the main organism that one could work with Genetically speaking I would like to to mention a quote from Jack mono a French U microbiologist working at the past

Institute um, which uh actually Jac mono together with FR jaob and and Wulf received the the Nobel Prize in 1964, uh regarding very interesting concepts of of proteins with enzimatic properties in back area, uh the the the notion of of genes organized as uh as operons, uh the notion of uh of uh of also uh RNA molecules that could have regulatory functions, not only being the intermediate between the DNA and proteins but also having regulatory function, and this research having been done in in bacteria and and also in uh in uh in trying to understand how bacteria defend themselves against viruses of bacteria, which in the in this case were called lithogenic fges. I just want to mention this because this is exactly what Chris Paras 9 is about. It's an RNA and protein-mediated system in bacteria. Uh, it's all about interactions between bacteria and FES, and this is just to show that uh 45 40 to 50 years later you can take uh um uh

how do you say uh interesting uh uh um breakthroughs that that were highlighted in in the past, and still dig into the the details of of certain types of topics, which may not sound that exciting or fashionable, but you can still find very interesting uh points. And although Jac mono was very V Visionary in 1970, he wrote a book entitled chance and necessity where he was quoting modern molecular genetics offers us no means what whatsoever for acting upon the an ancestral heritage so as to improve it with new features to create a genetic Superman. On the contrary, it reveal the vanity of any such hope. The genome's microscopic proportions today and probably forever rule out manipulation of this sort. So unfortunately he died relatively at an early age, and and I'm I'm sure he will be very glad to see and to hear about Chris parasan that really is about exactly what he was studying. Having said this, I like to mention also FR Jacob who quoted nature is a thinker not an inventor, and and actually if you

look at what every cell and organism is doing. Specifically, bacteria. They are just uh doing bricolage. It's all about tinkering. And US scientists, we are just here to try to understand all the very very tricky mechanisms which bacteria and other organisms have evolved to just do tinkering and and so I think that it's also a very interesting quote. Having said this, the basics for the genetic tools really were developed in the mid-70s with the discovery of a number of enzymes originating from bacteria, also from viruses, and also trying to understand how bacteria defend themselves against mobile genetic elements and I canide. The restriction enzymes are different enzymes that were allowing to recombine DNA, the ability to sequence DNA, the ability to amplify DNA. Uh, on this slide, you don't have mentioned the all those also RNA interference mechanisms that have been developed as Technologies in the beginning of 2000s to really Target gene expression. An interesting aspect of genetics and the ability to do really genetics in the precise minor is really.

the field of Gene editing with engineered nucleuses. So engineered proteins that have the ability to cleave DNA in a sequence-specific manner were developed in the 90s. And with the Zin finger nucleases and later on with the talent nucleases in 2010. And this type of engineered proteins come from research on Mega nucleuses and oming nucleuses in new chaotic systems and some scientists having done really wonderful work thinking that you could take different properties of nucleuses and engineered those nucleases in a way that they will contain a code to be able to recognize a certain sequence of interest on the DNA. But the technology behind those proteins made this Gene editing maybe not as technology that could be really used in a democratic fashion because the idea is that the manipulator has to always engineer a new protein with a certain code to recognize a certain sequence of DNA of interest and protein engineering is not always that fast and easy.

for biologists in the lab. So, these enzymes were very good to introduce changes, but time-consuming and difficult to use in a democratic fashion. And this is really what CRISPR-Cas9 brings with its programmability through this RNA component. So, in my lab, and surely I will mention that a number of scientists have worked on CRISPR-Cas9, there is a very interesting history in this field of research. In my lab, this interest in CRISPR-Cas9 came really from the focus of my laboratory when I started my independent career as a principal investigator. The focus on working on specifically Streptococcus pyogenes, that is a human pathogen responsible for a large number of diseases, from mild infections to more severe infections. And here you can see the cocci Streptococcus pyogenes as a shape cocci. So, here they are colored in red for the purpose of the picture, and they are invading human epithelial cells.

FAL cells are colored in green for the purpose of the picture. We're interested in different types of mechanisms or RNA and protein-based, allowing to understand how bacterial pathogens can attack the human host, and to a certain extent, the human host can defend itself against Bal pathogens. So, we focus on protein quality control, the class of smaller regulatory RNAs, and other regulatory mechanisms that allow to understand our virulence factors and other factors are produced in the bacteria, allowing the bacteria to react very fast with their environment, which leads to, and I would like to refer to the talk of Frances this morning, that leads to a lot of evolution considering the large VAR of the bacterial world with a large variety of bacterial species, which have been also very important for the evolution of the Chris basine system and constant battle of the bacteria with the viruses of bacteria, the fges, but with other types of environments, specifically those encountered in the human host, such as osmotic stress, pH.

changes heat shock and other types of immune responses so we are very much interested in everything that is the dynamic of regulation of gene expression in bacteria. Having said this, we became interested in the family of small RNAs a little bit more than something like 15 years ago, with a notion which U Jenifer Dona explained earlier, that is, that RNA, in addition to being the intermediate molecule between DNA and protein and to be also as ribosomal RNA involved in Translation or as Transfer RNA involved in translation, you have also these RNA molecules that have a regulatory function, some of which can code for small peptides, some of which do not code for any peptide or any protein. And in the bacterial world, this field of research is quite exciting. A large number of small regulatory RNAs have been identified, mostly in the so-called gram-negative bacteria, and what was found is that they use a multitude of types of mechanisms to affect gene expression by directly interacting

with M RNA uh forming antisense uh structures, and by this interaction with the messenger RNA, uh that can uh code for proteins. They can either uh enhance or inhibit the translation, the stability of the messenger RNA, and they can also interact with the messenger RNA to activate or inhibit translation via different means. They can also interact directly with proteins to activate their function or sequester uh them from their function. When we started to work on crisper and the small RNAs, uh there was a type of mechanism that uh was not yet described in bacteria, uh which will be small RNAs that can uh activate the expression of another small RNA so really through a direct interaction. Then this is what Chris Paras 9 brought, and also the fact that small RNAs can interact directly with DNA and affect the fate of this DNA, and this is really what Chris barass biology brought in terms of New Concept, new dogma, and we were kind of interested in picking up U uh uh our our a unique bacterium.

stenus in having the chance to, uh, to really highlight new mechanisms. And I'm just going to, to give you a little bit the beginning of how we, we came to Chris Parastan. And then I will go very fast but in principle, uh, we were working in my lab on, on some, on some small regulatory RNAs for which we found a biological function in, uh, in influencing, uh, the potential of the bacterium to cause diseases via direct regulation of, of, of gene, of expression of genes coding for virulence factors. And a little bit more than 10 years ago, we were interested in finding new small regulator RNAs in Streptococcus pyogenes and have an idea of, of the panel of these molecules that could out regulatory functions. So we, we approached the, the problem by using bioinformatics that allowed us to highlight a number of sequences on, on the Genome of Streptococcus pyogenes that potentially could code for RNA molecules, which maybe could have interesting biological functions. And we focused on, on a molecule that we called at the time spna.

foran that was renamed Tracer RNA. And what we found is that this uh RNA molecule was actually uncoded uh in the vicinity of a gene uh on the Genome of streptococus penus that was already highlighted at the time as as a gene uncoding a crisper system related protein containing two nucleus domains from streptococus Theophilus. And this is really about this castan protein that had different names before the nomenclature was agreed on with with the terminology C9. But this is really about this protein that contains indeed two nucleus domains to to cleave the DNA. Having said this, we were focusing mainly on on Tracer RNA with an as an RNA molecule uh being expressed within three forms and with a very interesting pattern of of very abundant expression. We were also interested in in chisar shy um because we wanted to show that in streptococus spus chisar could have a role in uh in uh limiting the acquisition of the

viruses of bacteria. Which in Streptococcus pyogenes can carry genes encoding factors that allow bacteria to cause severe forms of diseases. And indeed, we could show ultimately that in this bacterium, CRISPR can limit in a way the acquisition of genes that are important for the severe aspects of diseases caused by Streptococcus pyogenes through limiting the acquisition of this genomes of viruses. So in principle, we're also interested in CRISPRs, but we were in a way working on this stressor RNA molecule and working on these CRISPR RNA molecules independently until we came to the point that it was important to look at the interaction of those two components. Having said this, CRISPR really brought us to this another type of infection biology where the bacteria are not pathogens of the human host, but the bacteria can be host themselves and they can be attacked by this genetic element. So I mentioned the viruses, but you have also

the plasmids that are autonomous small genomes that can bring to the bacteria very interesting genes. Allowing the bacteria to resist the action of antibiotics are allowing the bacteria to adapt better to their environment. And surely enough the bacteria have evolved defense uh systems against those mobile genetic elements. So here, for example, you have a Fage infecting a bacterial cell. And those phages can enter uh in some of the classes of the phages can enter so-called the lytic cycle whereby uh the Genome of the Phage can be injected into the bacterial cell. The invading DNA will replicate to form a phage particles that will kill a bacterial cell and propagate to kill other bacterial cells. And here you have the case where the phage can enter so-called lithogenic cycle. So in this case are called temperate phages and their genomes can be inserted as prophages into the Genome of the bacteria. So in this case the viruses bring new new traits new genetic traits to the bacteria. But in either cases or also

when bacteria are attacked by plasmids or transposome that are mobile genetic elements, they have defense system that allow them to attack those mobile genetic elements. So, you have different types of Defense systems, most of which are considered as innate immunity. So, in reference to innate and adaptive immunity in your chaotic organisms, for example, the restriction enzymes. So, these enzyme that are used to really cleave DNA and clone DNA, those restriction enzymes have been identified through really understanding defense mechanisms in bacter against viruses, using restriction modification systems. So, you have other types of innate immunity existing in bacteria, and CRISPR is really the first and only adaptive immune system existing not only in bacteria but also in ARA. It's adaptive because you have a first recognition of the mobile genetic element prior to attack of the mobile genetic element. So, Jennifer already explained you that the system is composed genetically by a CRISPR array that is composed of short sequences here highlighted in Black that are identical to one another that are called

repeats so they are repeated in in the genome, and they they're interspaced by so-called spacal sequences that have as Origins um mobile genetic element sequences. And this crispa array contains a region Upstream of of the array that allows this array to be transcribed into a long RNA molecule, and in the V of this Cris bar, you have a series of genes that code for the protein components. So, in principle, you have the proteins, and you have the the crispa rnas, and you have three steps in the in the immune system: spal acquisition, expression of the rnas and the proteins, and then interference whereby the system is able to really recognize a mobile genetic element and affect its maintenance. And so you have a first recognition of of the invading DNA uh through crispa Associated proteins that will recognize the invading DNA, cleave a portion of this invading DNA to insert it into uh the crisa array at the level of the of the leader sequence allowing to provide memory of of this first infection with.

the mobile genetic element. So this is a series of memorized infections. These spal sequences. Then you have expression of the system, mainly here at this level transcription of this chisar into long precursor chisar molecule that will undergo maturation. In the sense that this long molecule will be able to be cleaved and produce individual crispa RNAs that can guide a complex of crisal associated proteins to the cognite Genome of the virus. So this is by recognition through the memorized mark on the crisal RNA and base pairing with the cognet sequence on the invading Genome of the virus. And ultimately, one crispa Associated protein of the complex will recognize this interaction and will be able to cleave the DNA of the virus. And this will be the end for the possibility of the virus to replicate and to propagate and be maintained. Having said this, there is a very interesting story.

field of Chris Paras in biology. Briefly, I just want to mention this because it's important that you realize that surely there are a lot of scientists having been involved and bringing different pieces in the puzzle. So, 30 years ago, a Japanese group identified this series of repeats in the Genome of E. coli but they didn't have any idea about the functions of those repeats. Then, at the end of the 90s, beginning of 2000s, some scientists showed that actually this CRISPR array could be produced into RNA molecules of different sizes. They did Southern blot analysis and they found that actually this CRISPR could be really RNA molecules of different sizes. So, they saw that there was obviously also cleavage of RNAs involved and activation of RNAs. And then, by informaticians in the beginning of 2000s, mid-2000s, found out that actually in the vicinity of those series of repeats, you had genes including the CRISPR.

parotic proteins, with interesting features of proteins being very similar to proteins that have been identified prior to the cast proteins. Proteins that can interact with DNA and RNA or cleff DNA and RNA. And then what was also found is that in this series of repeats were interspaced by sequences that seem to be constantly matching sequences of viruses, plasms, and transposon. And so as Jennifer mentioned, the idea was that this system could be an interference system existing in back and ARA that would be RNA mediated, composed of RNA protein complexes allowing really the back and ARA to fight the invasion of mobile genetic elements. And indeed, so you have had and actually I miss a lot of studies, but the group of orvs and muu with bongu showed in 2017 and in 20087, sorry, 2007, working on streptococus therophilus that Chris Paras was an Adaptive immune system in bacteria. And then a number of colleagues.

showing and this you already saw these slides. The showing the the the evolution of the Chris Paras systems in multiple types mainly through uh different uh composition and nature of the crispa associated genes. So, I have the group of of marinian stimer and and uh John V OST and Stan Bron showing Willie that uh the actually the type one was Michael turns and and and Stan Bron and and John V showing that actually the type one system could Target DNA. And then Mara and sometime show that also the type three systems could also Target DNA using different types of mechanisms but always one chisar RNA molecule and a complex of chisar associated proteins. So, surely I miss the implication of of number of scientist uh since the last 10 years but what is really peculiar with the Chris barine system is really its Simplicity and the mechanism that was different from the mechanisms of the type one and type three system that were started to be studied when we uh got interested in in chisar cast systems. And chisar cast 9 is unique because instead

of a complex of proteins targeting the genomes. You have only one protein involved, Cas9, and instead of one RNA molecule that contains the memorized mark of the mobile genetic element, you have two RNA molecules. So the idea for me was really to ask whether trace RNA, which initially we thought was a regulatory RNA that was involved in the regulation of expression of a variance factor, and we had found actually a very interesting target, but we could not make any sense of this interaction. And then the idea that I had was really that mouse RNA would have an active role in the CRISPR-Cas system because at the time we didn't know anything about the regulation of this system and also because when you work in the RNA field, you know that sometimes you have some RNA molecules uncoded next to their target that can work in CIS or in trans. And so this was the idea behind, and then we started really to decipher the mechanism, showing well that the three components of the

system very early on where really cast 9 with stressor RNA so this duplex of RNA stabilized with cast 9 with the first event that allows to really produce uh the ultimate mature crispa RNA that can guide castline protein to the to the targeting genome so we we did not work only on on strepto cuse pyogenes actually uh very early on we we understood the diversity of this system in in the bacterial world and this is by looking at the evolution of the system that we understood really the rules of how the components could interact with one another and we really looked at multiple uh bacal species and understood very early on that uh the the sequences including Tracer RNA the crisper RNA and the castan protein were extremely diverse. When comparing different bacal species, however, by looking at this diversity we could really understood the the conservation of the system that was really a base paing between Tracer RNA and the crispa RNA and in interaction with castan protein so very fast we we

synthesized the RNAs and the proteins of different bacteria species, uh knocked out all the domains important, etc., and ultimately, uh, finding what would be really the targeting mechanism that surely was also on the DNA. So, this is also something that we have shown that the RNA was not targeted but the DNA. So, then, um, um, Jennifer, explain you a little bit the principles of how the system works. What is important to mention is that it's a really a unique, uh, system, very flexible for the case of streptococcus penus. And this is where maybe, uh, we were very lucky to work on this bacterium. Uh, as I said, this system exists in a number of bacterial species, and we and others have tried to adopt this mechanism, uh, not only on streptococcus of streptococcus penus but originating from different B species to try to adopt this mechanism in the technology. Chris parcast to Target DNA in any cell.

and organism. And it seems like the system from Streptococcus pyogenes works particularly well, thanks to the flexibility of this protein that undergoes specific conformational rearrangement each time that the protein will first bind to the RNA molecules, and then recognize the DNA, and then cleave the DNA. Something that I would like to mention, nevertheless, is that we always speak about a protein guided by two RNA molecules forming a duplex. And Jennifer explained the idea to really simplify the system by adding a link that would allow to use a single guide RNA instead of two RNAs, which can be useful in certain types of application. There is another component that is important for the system to work, is a mark on the DNA that is called protospacer adjacent motif. It's a short stretch of letters of DNA nucleotides NGG for the case of Streptococcus pyogenes, and this motif has to be present for Cas9 system to work.

work of Silva Moano who published a paper in Nature in 2010 was really critical to uh came really to to to come to the conclusion of this of this uh uh motive being important for Chris Paras n system to cleave uh DNA in a double stranded uh by introducing double-stranded DNA breaks except that at the time TR RNA was not known so the exact mechanism was not really known so when we we really saw how the the enzyme was working and when ultimately we really showed that that in a very simple manner by just uh exchanging a portion of this RNA molecule one could really bring uh this system to an RNA programmable technology uh it was clear as it was working so well in the test tube very efficient enzyme from strus penus uh that it could really offer considerable potential for genome editing in cells in the six kingdoms of life for biotechnological biomedical and gene therapeutic purposes and indeed as I said uh already six months a little bit more than six months after we

published with Jennifer the paper in Science. A number of scientists showed, and these were publications from January to March 2013, that the technology was working very well in human cells to perform genome editing and engineering in human cells, in mice, in bacteria, in plants, in model organisms that are really studied in the laboratory, and also monkeys and also organoids. With a lot of efforts, I would like to mention from the scientific community early on from the Boston area working on human cells with a groups of Fang Zhang and George Church. And very fast, actually the entire world picked up on those technologies to really see whether they could develop the technology for their own purposes to have a precise genetic tool for genome engineering. So everyone agrees to say that the technology offers a number of advantages. It's cheap and easy, it's very efficient, it's versatile, and it allows multiplexing in the sense that one can design different

programmable RNA molecules to target at once different sequences on the genome. The system naturally is already highly specific, and the number of improvements have been done to bring the technology to even more specificity. So, the idea that if you use the technology, and it's an important point for the applications of the technology, is that you would really like to modify a sequence of DNA of interest and not any other sequences on the genomes. The system has low toxicity, and a lot of efforts from the scientific community to really develop delivery systems that allow to bring the technology to the right cell and the right organism for different purposes. So, you can correct mutations, you can delete portions of genes, you can add new sequences at the site of interest, you can replace a certain gene or a certain sequence by another sequence of interest. And as I said, it's really useful and working in any type of cells and organisms. These are just some aspects of the genetic tool books. What is really fascinating with this um

enzyme is that it has U by its nature domains that allow uh will to cleave uh the the the DNA, but you can mutate easily those domains, and this was shown also by the group of of sies. And you can bring the the enzyme that cleaves DNA into RNA programmable protein that can target DNA but not cleave DNA. Then you can fuse to this uh RNA programmable cast nine different uh domains that allow here, for example, to activate gen uh expression or to inhibit gene expression. So you have a lot of screen that have been developed using this aspect of the technology. You can also fuse to the to the castan protein some effector domains that allow to modify uh DNA and to study epigenetic phenomenon. You can also mark the DNA so you can really do um different tricks. So it are large application in human medicine in synthetic biology in agriculture for the production of new crops. And I would like to to finish by really mentioning the aspect in human medicine so it's it has an indirect and

direct implication for an indirect application. It's very useful to now be able to work with the right types of human cells. We were always a little bit restricted, specifically in my field of research, infection biology, in working with always the same type of human cell lines that are not always the best cells to work with, depending on the focus of diseases we are interested in studying. Here, you can really target and work with more types of cells, having the right technologies that allow us to understand functions of genes and unravel new pathways. Also, to engineer disease models, humanized disease models, to understand better diseases. A lot of effort has been developed by the community to really have these new types of screenings for targets for therapeutics, to have new ways to validate new therapeutic targets and medicine under development. The bench-to-bench approach that is with all the knowledge of sequences of patients and the idea

of certain possible genetic predispositions for certain diseases. The ability to go back to the bench and really test, uh, the mutation that may be causative for diseases. And the big challenge that is really to develop the technology as direct therapeutics for the field of human gene therapy, which is, uh, specifically a field of my interest. So what I want to say by this is that it's a technology that is really helpful in not only in basic science but, but also in biotechnology and pharmaceutical industry. And in addition to human medicine, it really allows to study the diversity of the world. And it's really important to be able in the future to break certain dogmas or to bring to new breakthroughs in the knowledge of biology. So we continue working on different types of mechanisms, uh, in my lab focusing on infectious diseases, hoping that Chris Pakistan will be very helpful here. I just would like to finish by some acknowledgements. Um, indeed, research in

our days is quite exciting actually because you have the possibility to Really travel around the world, and this is important to at least for me. It has been very important so this research in particular developed in Austria, Sweden, and Germany, and prior to Austria, Sweden, and Germany, I was working in the US and France. I will encourage you to travel because you can really appreciate different types of cultures, per se, but also cultures of approaching science. You have the opportunity to meet great scientists. Sometimes you don't really realize that they may have really affected your life, and you realize after a while that you knew that they were inspiring you. But so this aspect is very important, and also because in science you need a little bit to rest, find potentially new aspects of topics, and it's important as a challenge, as I think to move. It's always very challenging. It's a challenging field in general, but specifically to get to

to know different types of administration and funding organization so I would like to thank Austria and Germany, but specifically Sweden because this idea to really focus on Chris bar and bring those two passway trar and Chris Par together really came in Sweden at the laboratory for molecular infection medicine Sweden at UMO University um so up North next to the polar Circle. I would like to thank for sure wonderful team of scientists. I mean without talented young researchers, nothing will happen, and I just would like to mention specifically El shinski and also others. It's always a very inspiring International environment with young scientists bringing always new ideas and being always enthusiastic, so it's really refreshing. And my collaborators, the group of Y voger in VB Jennifer D, surely with Martin y andin for studying the evolution of the system. This is my lab when there were summer students last summer. I would like to mention SS genomics and chisar Therapeutics for conflict of interest and some quotes are um one was lost from Louis pter in the field.

which was 150 years ago in the field of observation. Chance favors the prepared mind. I think it's very true. Let me tell you the secret that has led me to my goal. My strength lies solely in my tenacity, and I think this is important in science. Persistence in scientific research leads to what I call Instinct for truth, and this is also important. The last one I cannot read. I like also this one, and this is my last slide. It's from Fris Jaob. I say night science is because I was in UMO, and most of the time it's dark. But I mean there is another part of the time where it's full light, and I think it's interesting. And again, it was quoted number of years ago, night science, a stumbling wandering exploration of the natural world that relies on intuition as much as it does on the cold orderly logic of science. In today's vastly expanded scientific Enterprise obsessed with impact factors and competition, we will need much more night science to unveil the many Mysteries that remain.

about the workings of organisms. And at least for my part, Sweden has been great. You go to the north, no one cares about whether you're alive or not. You can be quiet and you can focus, and it's great. [Applause] [Music]

Emmanuelle Charpentier: Gene editing and genome engineering with CRISPR-Cas9

MoleCluesTV

The Impact of CRISPR-Cas9 Technology on Genome Engineering

CRISPR-Cas9 is a powerful and unique enzyme found in bacterial species, allowing for simple programmable genome engineering.

The technology has rapidly gained recognition in the scientific community for its potential in precise gene surgery and its wide range of applications in diverse fields.

CRISPR-Cas9's impact on life sciences and its potential for future advancements make it a valuable tool for research and therapy.

The Importance of Genetics in Understanding Bacterial Survival and Disease

Genetics plays a critical role in understanding how bacteria survive in their environment and cause diseases, especially in children and adolescents.

It is also essential for identifying new targets for therapeutics.

The history of genetics, from the 19th century to the mid-20th century, has been crucial in establishing fundamental rules and technologies for gene editing and understanding gene expression.

The Evolution of Gene Editing Technologies

Engineered nucleases, such as Zin finger nucleases and TALEN nucleases, were developed in the 90s for cleaving DNA in a specific sequence, but their use was limited by the time and difficulty of protein engineering.

The emergence of CRISPR-Cas9 revolutionized gene editing with its RNA programmability, allowing for easier and more democratic use.

CRISPR-Cas9's impact on the regulation of gene expression in bacteria, including its ability to activate other small RNAs and interact directly with DNA, brought about a new concept in gene editing technology.

The Discovery of CRISPR and Its Role in Bacterial Defense

Researchers discovered a new small regulatory RNA, Tracer RNA, in Streptococcus pyogenes, which was found to have a significant impact on the bacterium's ability to cause disease.

The study also revealed that CRISPR plays a crucial role in limiting the acquisition of disease-causing genes in Streptococcus pyogenes by restricting the uptake of viral genomes.

CRISPR is the first and only adaptive immune system in bacteria, providing a defense mechanism against mobile genetic elements such as viruses and plasmids.

The Role of CRISPR in Bacterial Immune Systems

CRISPR arrays in bacteria have a three-step immune response: spacer acquisition, RNA and protein expression, and interference with foreign DNA.

Scientists have made significant contributions to the understanding of CRISPR, including its RNA-mediated interference with genetic elements.

The CRISPR system's simplicity and unique mechanism set it apart from other immune systems and have drawn significant scientific interest in the past decade.

The Role of Mouse RNA in the CRISPR-Cas System

Mouse RNA plays an active role in the CRISPR-Cas system, with the interaction of Cas9 and two RNA molecules stabilizing the duplex.

The system shows diversity in bacterial species, but the conservation lies in the interaction between Tracer RNA, crispr RNA, and the Cas9 protein.

The flexibility of the system from Streptococcus pyogenes allows for specific conformational rearrangements, making it particularly effective in targeting DNA.

The Impact of CRISPR Technology on Genome Engineering

CRISPR technology has been widely adopted for genome editing in various organisms due to its cost-effectiveness, efficiency, and versatility.

The technology allows for precise genetic modifications, with low toxicity and the ability to target different sequences simultaneously.

CRISPR technology has diverse applications in human medicine, synthetic biology, agriculture, and has opened up new possibilities for studying gene function and developing therapeutics.

The technology also plays a crucial role in human gene therapy and has the potential to revolutionize the biotechnology and pharmaceutical industry, while contributing to a better understanding of biology and genetic diseases.

The Impact of International Travel on Scientific Research

International travel has allowed the researcher to experience and appreciate diverse cultures and approaches to science, as well as to meet inspiring scientists.

The collaboration and inspiration from teams in Austria, Germany, and specifically Sweden, have been crucial to the research.

The researcher emphasizes the importance of persistence and intuition in scientific research, highlighting the need for "night science" to uncover the mysteries of the natural world.