̽��ֱ�� of Cambridge - CRISPR

Researchers call for greater awareness of unintended consequences of CRISPR gene editing

jg533 — Mon, 12 Apr 2021 08:11:52 +0000

CRISPR-Cas9 genome editing is a widely used research tool which allows scientists to remove and replace sections of DNA in cells, allowing them, for example, to study the function of a given gene or to repair mutations. Last year the researchers who developed CRISPR-Cas9 were awarded the Nobel Prize in Chemistry.

In the study published in the journal PNAS, scientists retrospectively analysed data from previous research in which they had studied the role of the OCT4 protein in human embryos during the first few days of development.

̽��ֱ��team found that while the majority of CRISPR-Cas9-induced mutations were small insertions or deletions, in approximately 16% of samples there were large unintended mutations that would have been missed by conventional methods to assess DNA changes.

Research is ongoing to understand the exact nature of the changes at the target sites, but this could include deletions of sections of DNA or more complex genomic rearrangements.

̽��ֱ��discovery highlights the need for researchers who use CRISPR-Cas9-mediated genome editing to edit human cells, whether somatic or germline, to be aware of and test for these potential unintended consequences. This is even more essential if they hope their work will be used clinically, as unintended genetic changes like this could lead to diseases like cancer.

“Other research teams have reported these types of unintended mutations in human stem cells, cancer cells and other cellular contexts, and now we’ve detected them in human embryos,” said Professor Kathy Niakan, group leader of the Human Embryo and Stem Cell Laboratory at the Francis Crick Institute and Professor of Reproductive Physiology at the ̽��ֱ�� of Cambridge, and senior author of the study.

“This work underscores the importance of testing for these unintended mutations to understand exactly what changes have happened in any human cell type.”

̽��ֱ��researchers have developed an open-source computational pipeline to identify whether CRISPR-Cas9 has caused unintended on-target mutations based on different types of next-generation sequencing data.

“We and others are trying to develop and refine the tools to assess these complex mutations, “ added Niakan.

“It is important to understand these events, how they arise and their frequency, so we can appreciate the current limitations of the technology and inform strategies to improve it in the future to minimise these mutations.”

Gregorio Alanis-Lobato, lead author and former postdoctoral training fellow in the Human Embryo and Stem Cell Laboratory at the Crick, said: “Conventional tests used to check the accuracy of CRISPR-Cas9 can miss the types of unintended on-target mutations we identified in this study. There’s still so much for us to learn about the effects of CRISPR-Cas9 technology and while this valuable tool is refined, we need to thoroughly examine all changes.”

There are important ongoing debates around the safety and ethics of using CRISPR-Cas9 genome editing on human embryos for reproductive purposes. And in 2019, there was international condemnation of the work of a researcher in China who edited embryos which led to the birth of twins. In the UK, its use on human embryos is closely regulated and is only allowed for research purposes. Research is restricted to the first 14 days of development and embryos are not allowed to be implanted into a womb.

̽��ֱ��data for this work related to embryos previously studied by the Crick’s Human Embryo and Stem Cell Laboratory. ̽��ֱ��embryos were at the blastocyst stage of early development, consisting of around 200 cells. They had been donated to research by people undergoing in vitro fertilisation (IVF) and were not needed during the course of their treatment.

̽��ֱ��research was led by scientists at the Francis Crick Institute, in collaboration with Professor Dagan Wells at the ̽��ֱ�� of Oxford. Kathy Niakan is Director of the ̽��ֱ�� of Cambridge’s Centre for Trophoblast Research, and Chair of the Cambridge Strategic Research Initiative in Reproduction.

Reference
Alanis-Lobato, G., et al: Frequent loss-of-heterozygosity in CRISPR-Cas9-edited early human embryos. PNAS, April 2021. DOI: 10.1073/pnas.2004832117

Adapted from a press release by the Francis Crick Institute.

CRISPR-Cas9 genome editing can lead to unintended mutations at the targeted section of DNA in early human embryos, researchers have revealed. This highlights the need for further research into the effects of CRISPR-Cas9 genome editing, especially when used to edit human DNA in laboratory research.

We and others are trying to develop and refine the tools to assess these complex mutations.

Kathy Niakan

Arek Socha on Pixabay

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Women in STEM: Dr Alexis Braun

sc604 — Thu, 26 Sep 2019 06:00:00 +0000

̽��ֱ��major turning point in my career as a scientist happened only a couple of years ago during my first postdoc. I was given the freedom to develop my own project with the support of my current boss/mentor, Professor David M Glover. I was evaluating whether or not I wanted to continue on in academia when I approached him with a project idea and asked if he could teach me how to be a primary investigator. He taught me how to write a grant and we were eventually successful in getting funding for my project. With his advice, I have been given the freedom to design my own project and choose the methodology I use in answering the questions that I have. He also supported me in mentoring students and is currently helping me build the career I want. Without this opportunity, I would not have gotten the chance to see if the track I was on was what I really wanted.

I initially became interested in biology growing up in my First Nations/Native American community in the Great Bear Rainforest. My grandfather taught me about many of the animals and plants in the region we are from (Bella Coola, Canada). I continued on this interest throughout my undergraduate studies and into my postgraduate studies, where I became more focused on animal development. I continued on the academic route and became a scientist because I could not picture my life any other way. I cannot think of any other career that offers the type of freedom and creativity that science offers. To anyone interested in becoming a scientist, I will pass on the same advice that I was given: if you love it then do it. Nothing is ever set in stone, if you try something and don't like it then you can always do something else. Additionally, don't be afraid of not fitting the mould. Anyone can be a scientist.

I switched fields of study between all of the degrees that I have obtained, as well as during my postdocs. You are never stuck studying only one thing. I am Canadian, and I completed a double major in Biology and Biochemistry at the ̽��ֱ�� of Victoria. I moved to Sweden and completed my Masters in Biotechnology at the Royal Institute of Technology in Stockholm. I completed my PhD in developmental biology in the Department of Zoology in Cambridge with Dr Isabel Palacios. I stayed in Cambridge to do my first postdoc in the Department of Genetics with Dr Yuu Kimata, studying cell cycle regulation and the role of centrosomes within the female germline of Drosophila. I am now on my second postdoc in the lab of Professor David M Glover, still in the Department of Genetics. I am now focused on female reproduction and evolution.

My research sets out to understand one of the fundamental principles of animal fertility, asexual reproduction, using different species of Drosophila as a model. I am interested in this topic because although there are huge differences in the development and intimate body structure that animals have, there are key principles that all animals abide by during their development and how they produce offspring. I hope that my research will help understand fertility in animals and potentially aid in conservation efforts.

One of the unexpected fun parts of my job is collaborating with friends who have complementary skill sets. Since starting my current project, I have found that I enjoy discussing my work more and have built new collaborations with people doing a wide variety of different work. These collaborations have helped my work but also made me enjoy it more fully.

Cambridge is a great place to study and work because of the freedom I have always felt to research 'out-of-the-box' things. In my experience, there is a respect for independent thought and creativity that I have not noticed to such a degree in other universities. A lot of other competitive research institutes put emphasis on productivity, whereas here I feel like there is a lot more emphasis on the overall question one is approaching. There are also very few places in the world where you have access to great thinkers in so many different disciplines. I feel like I can talk to anyone because of the sense of community here. Additionally, there are also amazing facilities and huge support for fledgling scientists.

Dr Alexis Braun is a postdoctoral researcher in the Department of Genetics. Here, she tells us about the importance of mentors, how her research might aid in conservation efforts, and how growing up in a First Nations community in Canada spurred her interest in biology.

Alexis Braun

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Genome-editing tool could increase cancer risk in cells, say researchers

cjb250 — Mon, 11 Jun 2018 15:00:48 +0000

̽��ֱ��team, led by Professor Jussi Taipale, now at the Department of Biochemistry, Cambridge, found that CRISPR-Cas9 triggers a mechanism designed to protect cells from DNA damage, making gene editing more difficult. Cells which lack this mechanism are easier to edit than normal cells. This can lead to a situation where genome-edited cell populations have increased numbers of cells in which an important mechanism protecting cells against DNA damage is missing.

Discovered in bacteria, the CRISPR-Cas9 system is part of the armoury that bacteria use to protect themselves from the harmful effects of viruses. Today it is being co-opted by scientists worldwide as a way of removing and replacing gene defects.

One part of the CRISPR-Cas9 system acts like a GPS locator that can be programmed to go to an exact place in the genome. ̽��ֱ��other part – the ‘molecular scissors’ – cuts both strands of the faulty DNA so that it can be replaced with DNA that does not have the defect.

However, in a study published today in the journal Nature Medicine, researchers found unexpected consequences from using CRISPR-Cas9.

“We managed to edit cancer cells easily, but when we tried to edit normal, healthy cells, very little happened,” explains Dr Emma Haapaniemi from the Karolinska Institutet, Sweden, the study’s first author.

“When we looked at this further, we found that cutting the genome with CRISPR-Cas9 induced the activation of a protein known as p53, which acts like a cell’s alarm system, signalling that DNA is damaged, and opens the cellular ‘first aid kit’ that repairs damage to the DNA. ̽��ֱ��triggering of this system makes editing much more difficult.”

In fact, this process went further, leading to the strong selection of cells that lacked the p53 pathway. Absence of p53 in cells makes them more likely to become tumorous as damage can no longer be corrected. Around a half of all tumour cells are missing this pathway.

“CRISPR-Cas9 is a very promising biological tool, both for research purposes and for potential life-saving medical treatments, and so has understandably led to great excitement within the scientific community,” says Professor Taipale, who led the work while at the Karolinska Institutet.

“We don’t want to sound alarmist, and are not saying that CRISPR-Cas9 is bad or dangerous. This is clearly going to be a major tool for use in medicine, so it’s important to pay attention to potential safety concerns. Like with any medical treatment, there are always side effects or potential harm and this should be balanced against the benefits of the treatment.”

̽��ֱ��team found that by decreasing activity of p53 in a cell, they could more efficiently edit healthy cells. While this might also decrease the risk of selecting for p53-deficient cells, it could leave cells temporarily vulnerable to mutations that cause cancer.

Professor Taipale says that once they better understand how the DNA response is triggered by the cut, it may be possible to prevent this mechanism kicking in, reducing the selective advantage of cells deficient in p53.

“Although we don’t yet understand the mechanisms behind the activation of p53, we believe that researchers need to be aware of the potential risks when developing new treatments,” he adds. “This is why we decided to publish our findings as soon as we discovered that cells edited with CRISPR-Cas9 can go on to become cancerous.”

̽��ֱ��research was supported by the Knut and Alice Wallenberg Foundation, Cancerfonden, Barncancerfonden and the Academy of Finland.

A second team in Novartis Research Institute in Boston, MA, has independently obtained similar results. They are also published today in the same journal.

Reference
Haapaniemi, E et al. CRISPR/Cas9-genome editing induces a p53-mediated DNA damage response. Nature Medicine; 11 June 2018; DOI: 10.1038/s41591-018-0049-z

More research needs to be done to understand whether CRISPR-Cas9 – molecular ‘scissors’ that make gene editing a possibility – may inadvertently increase cancer risk in cells, according to researchers from the ̽��ֱ�� of Cambridge and the Karolinska Institutet.

We don’t want to sound alarmist, and are not saying that CRISPR-Cas9 is bad or dangerous. This is clearly going to be a major tool for use in medicine, so it’s important to pay attention to potential safety concerns

Jussi Taipale

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Scissors cut metal

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Genome editing reveals role of gene important for human embryo development

sc604 — Wed, 20 Sep 2017 17:00:00 +0000

̽��ֱ��team used genome editing techniques to stop a key gene from producing a protein called OCT4, which normally becomes active in the first few days of human embryo development. After the egg is fertilised, it divides until at about 7 days it forms a ball of around 200 cells called the ‘blastocyst’. ̽��ֱ��study found that human embryos need OCT4 to correctly form a blastocyst.

“We were surprised to see just how crucial this gene is for human embryo development, but we need to continue our work to confirm its role” says Dr Norah Fogarty from the Francis Crick Institute, first author of the study. “Other research methods, including studies in mice, suggested a later and more focussed role for OCT4, so our results highlight the need for human embryo research.”

Dr Kathy Niakan from the Francis Crick Institute, who led the research adds, “One way to find out what a gene does in the developing embryo is to see what happens when it isn’t working. Now we have demonstrated an efficient way of doing this, we hope that other scientists will use it to find out the roles of other genes. If we knew the key genes that embryos need to develop successfully, we could improve IVF treatments and understand some causes of pregnancy failure. It will take many years to achieve such an understanding, our study is just the first step.”

̽��ֱ��research was published in Nature and led by scientists at the Francis Crick Institute, in collaboration with colleagues at Cambridge ̽��ֱ��, Oxford ̽��ֱ��, the Wellcome Trust Sanger Institute, Seoul National ̽��ֱ�� and Bourn Hall Clinic. It was chiefly funded by the UK Medical Research Council, Wellcome and Cancer Research.

̽��ֱ��team spent over a year optimising their techniques using mouse embryos and human embryonic stem cells before starting work on human embryos. To inactivate OCT4, they used an editing technique called CRISPR/Cas9 to change the DNA of 41 human embryos. After seven days, embryo development was stopped and the embryos were analysed.

̽��ֱ��embryos used in the study were donated by couples who had undergone IVF treatment, with frozen embryos remaining in storage; the majority were donated by couples who had completed their family, and wanted their surplus embryos to be used for research. ̽��ֱ��study was done under a research licence and strict regulatory oversight from the Human Fertilisation and Embryology Authority (HFEA), the UK Government's independent regulator overseeing infertility treatment and research.

As well as human embryo development, OCT4 is thought to be important in stem cell biology. ‘Pluripotent’ stem cells can become any other type of cell, and they can be derived from embryos or created from adult cells such as skin cells. Human embryonic stem cells are taken from a part of the developing embryo that has high levels of OCT4.

“We have the technology to create and use pluripotent stem cells, which is undoubtedly a fantastic achievement, but we still don’t understand exactly how these cells work,” explains Dr James Turner, co-author of the study from the Francis Crick Institute. “Learning more about how different genes cause cells to become and remain pluripotent will help us to produce and use stem cells more reliably.”

Sir Paul Nurse, Director of the Francis Crick Institute, says: “This is exciting and important research. ̽��ֱ��study has been carried out with full regulatory oversight and offers new knowledge of the biological processes at work in the first five or six days of a human embryo’s healthy development. Kathy Niakan and colleagues are providing new understanding of the genes responsible for a crucial change when groups of cells in the very early embryo first become organised and set on different paths of development. ̽��ֱ��processes at work in these embryonic cells will be of interest in many areas of stem cell biology and medicine.”

Dr. Kay Elder, study co-author from the Bourn Hall Clinic, says: "Successful IVF treatment is crucially dependent on culture systems that provide an optimal environment for healthy embryo development. Many embryos arrest in culture, or fail to continue developing after implantation; this research will significantly help treatment for infertile couples, by helping us to identify the factors that are essential for ensuring that human embryos can develop into healthy babies.”

Dr Ludovic Vallier, co-author on the study from the Wellcome Trust Sanger Institute and the Wellcome - MRC Cambridge Stem Cell Institute, said: “This study represents an important step in understanding human embryonic development. ̽��ֱ��acquisition of this knowledge will be essential to develop new treatments against developmental disorders and could also help understand adult diseases such as diabetes that may originate during the early stage of life. Thus, this research will open new fields of opportunity for basic and translational applications.”

Reference:
Norah M.E. Fogarty et al. 'Genome editing of OCT4 reveals distinct mechanisms of lineage specification in human and mouse embryos.' Nature (2017). DOI: 10.1038/nature24033.

Adapted from a Francis Crick Institute press release.

Researchers have used genome editing technology to reveal the role of a key gene in human embryos in the first few days of development. This is the first time that genome editing has been used to study gene function in human embryos, which could help scientists to better understand the biology of our early development.

This knowledge will be essential to develop new treatments against developmental disorders and could also help understand adult diseases such as diabetes that may originate during the early stage of life.

Ludovic Vallier

Dr Kathy Niakan/Nature

Day 2 embryo

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Snip, snip, cure: correcting defects in the genetic blueprint

lw355 — Fri, 14 Jul 2017 08:01:02 +0000

Dr James Thaventhiran points to a diagram of a 14-year-old boy’s family tree. Some of the symbols are shaded black.

“These family members have a very severe form of immunodeficiency. ̽��ֱ��children get infections and chest problems, the adults have bowel problems, and the father died from cancer during the study. ̽��ֱ��boy himself had a donor bone marrow transplant when he was a teenager, but he remains very unwell, with limited treatment options.”

To understand the cause of the immunodeficiency, Thaventhiran, a clinical immunologist in Cambridge’s Department of Medicine, has been working with colleagues at the Great Northern Children’s Hospital in Newcastle, where the family is being treated.

Theirs is a rare disease, which means the condition affects fewer than 1 in 2,000 people. Most rare diseases are caused by a defect in the genetic blueprint that carries the instruction manual for life. Sometimes the mistake can be as small as a single letter in the three billion letters that make up the genome, yet it can have devastating consequences.

When Thaventhiran and colleagues at the National Institute for Health Research (NIHR) BioResource in Cambridge carried out whole genome sequencing on the boy’s DNA, they discovered a defect that could explain the immunodeficiency. “We believe that just one wrong letter causes a malfunction in an immune cell called a dendritic cell, which is needed to detect infections and cancerous cells.”

Now, hope for an eventual cure for family members affected by the faulty gene is taking shape in the form of ‘molecular scissors’ called CRISPR-Cas9. Discovered in bacteria, the CRISPR-Cas9 system is part of the armoury that bacteria use to protect themselves from the harmful effects of viruses. Today it is being co-opted by scientists worldwide as a way of removing and replacing gene defects.

One part of the CRISPR-Cas9 system acts like a GPS locator that can be programmed to go to an exact place in the genome. ̽��ֱ��other part – the ‘molecular scissors’ – cuts both strands of the faulty DNA and replaces it with DNA that doesn’t have the defect.

“It’s like rewriting DNA with precision,” explains Dr Alasdair Russell. “Unlike other forms of gene therapy, in which cells are given a new working gene but without being able to direct where it ends up in the genome, this technology changes just the faulty gene. It’s precise and it’s ‘scarless’ in that no evidence of the therapy is left within the repaired genome.”

Russell heads up a specialised team in the Cancer Research UK Cambridge Institute to provide a centralised hub for state-of-the-art genome-editing technologies.

“By concentrating skills in one area, it means scientists in different labs don’t reinvent the wheel each time and can keep pace with the field,” he explains. “At full capacity, we aim to be capable of running up to 30 gene-editing projects in parallel.

“What I find amazing about the technology is that it’s tearing down traditional barriers between different disciplines, allowing us to collaborate with clinicians, synthetic biologists, physicists, engineers, computational analysts and industry, on a global scale. ̽��ֱ��technology gives you the opportunity to innovate, rather than imitate. I tell my wife I sometimes feel like Q in James Bond and she laughs.”

Russell’s team is using the technology both to understand disease and to treat it. Together with Cambridge spin-out DefiniGEN, they are rewriting the DNA of a very special type of cell called an induced pluripotent stem cell (iPSC). These are cells that are taken from the skin of a patient and ‘reprogrammed’ to act like one of the body’s stem cells, which have the capacity to develop into almost any other cell of the body.

In this case, they are turning the boy’s skin cells into iPSCs, using CRISPR-Cas9 to correct the defect, and then allowing these corrected cells to develop into the cell type that is affected by the disease – the dendritic cell. “It’s a patient-specific model of the cure in a Petri dish,” says Russell.

̽��ֱ��boy’s family members are among a handful of patients worldwide who are reported to have the same condition and among around 3,500 in the UK who have similar types of immunodeficiency caused by other gene defects. With such a rare group of diseases, explains Thaventhiran, it’s important to locate other patients to increase the chance of understanding what happens and how to treat it.

He and Professor Ken Smith in the Department of Medicine lead a programme to find, research and provide diagnostic services to these patients. So far, 2,000 patients (around 60% of the total affected in the UK) have been recruited and sequenced by the NIHR Bioresource, making it the largest worldwide cohort of patients with primary immunodeficiency."

“We’ve now made 12 iPSC lines from different patients with immunodeficiency,” adds Thaventhiran, who has started a programme for gene editing all of the lines. “This means that for the first time we’ll be able to investigate whether correcting the mutation corrects the defect – it’ll open up new avenues of research into the mechanisms underlying these diseases.”

But it’s the possibility of using the gene-edited cells to cure patients that excites Thaventhiran and Russell. They explain that one option might be to give a patient repeated treatments of their own gene-edited iPSCs. Another would be to take the patient’s blood stem cells, edit them and then return them to the patient.

̽��ֱ��researchers are quick to point out that although the technologies are converging on this possibility of truly personalised medicine, there are still many issues to consider in the fields of ethics, regulation and law.

Dr Kathy Liddell, who leads the Cambridge Centre for Law, Medicine and Life Sciences, agrees: “It’s easy to see the appeal of using gene editing to help patients with serious illnesses. However, new techniques could be used for many purposes, some of which are contentious. For example, the same technique that edits a disease in a child could be applied to an embryo to stop a disease being inherited, or to ‘design’ babies. This raises concerns about eugenics.

“ ̽��ֱ��challenge is to find systems of governance that facilitate important purposes, while limiting, and preferably preventing, unethical purposes. It’s actually very difficult. Rules not only have to be designed, but implemented and enforced. Meanwhile, powerful social drivers push hard against ethical boundaries, and scientific information and ideas travel easily – often too easily – across national borders to unregulated states.”

A further challenge is the business case for carrying out these types of treatments, which are potentially curative but are costly and benefit few patients. One reason why rare diseases are also known as orphan diseases is because in the past they have rarely been adopted by drug companies.

Liddell adds: “CRISPR-Cas9 patent wars are just warming up, demonstrating some of the economic issues at stake. Two US institutions are vigorously prosecuting their own patents, and trying to overturn the others. There will also be cross-licensing battles to follow.”

“ ̽��ֱ��obvious place to start is by correcting diseases caused by just one gene; however, the technology allows us to scale up to several genes, making it something that could benefit many, many different diseases,” adds Russell. “At the moment, the field as a whole is focused on ensuring the technology is safe before it moves into the clinic. But the advantage of it being cheap, precise and scalable should make CRISPR attractive to industry.”

In ten years or so, speculates Russell, we might see bedside ‘CRISPR on a chip’ devices that screen for mutations and ‘edit on the fly’. “I’m really excited by the frontierness of it all,” says Russell. “We feel that we’re right on the precipice of a new personalised medical future.”

Gene editing using ‘molecular scissors’ that snip out and replace faulty DNA could provide an almost unimaginable future for some patients: a complete cure. Cambridge researchers are working towards making the technology cheap and safe, as well as examining the ethical and legal issues surrounding one of the most exciting medical advances of recent times.

I’m really excited by the frontierness of it all. We feel that we’re right on the precipice of a new personalised medical future.

Alasdair Russell

̽��ֱ��District

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Enhanced CRISPR lets scientists explore all steps of health and disease in every cell type

cjb250 — Tue, 29 Nov 2016 17:15:06 +0000

Two complementary methods were developed: sOPiTKO is a knock-out system that turns off genes by disrupting the DNA, while sOPTiKD is a knock-down system that silences the action of genes by disrupting the RNA. Using these two methods, scientists can turn off or silence genes in any cell type, at any stage of a cell’s development from stem cell to fully differentiated adult cell. These systems will allow researchers world-wide to rapidly and accurately explore the changing role of genes as the cells develop into tissues such as liver, skin or heart, and discover how this contributes to health and disease.

̽��ֱ��body contains approximately 37 trillion cells, yet the human genome only contains around 20,000 genes. So, to produce every tissue and cell type in the body, different combinations of genes must operate at different moments in the development of an organ or tissue. Being able to turn off genes at specific moments in a cell’s development allows their changing roles to be investigated.

Professor Ludovic Vallier, one of the senior authors of the study from the Wellcome Trust–Medical Research Council Cambridge Stem Cell Institute at the ̽��ֱ�� of Cambridge and the Sanger Institute said: “As a cell develops from being stem cell to being a fully differentiated adult cell, the genes within it take on different roles. Before, if we knocked out a gene, we could only see what effect this had at the very first step. By allowing the gene to operate during the cell’s development and then knocking it out with sOPTiKO at a later developmental step, we can investigate exactly what it is doing at that stage.”

̽��ֱ��sOPTiKO and sOPTiKD methods allow scientists to silence the activity of more than one gene at a time, so researchers are now able to investigate the role of whole families of related genes by knocking down the activity of all of them at once.

Dr Alessandro Bertero, one of the first authors of the study from the Cambridge Stem Cell Institute, said: “In the past we have been hampered by the fact we could study a gene’s function only in a specific tissue. Now you can knock out the same gene in parallel in a diversity of cell types with different functions.”

In addition, the freely available system allows experiments to be carried out far more rapidly and cheaply. sOPTiKO is highly flexible so that it can be used in every tissue in the body without needing to create a new system each time. sOPiTKD allows vast improvements in efficiency: it can be used to knock down more than one gene at a time. Before, to silence the activity of three genes, researchers had to knock down one gene, grow the cell line, and repeat for the next gene, and again for the next. Now it can do it all in one step, cutting a nine-month process down to just one to two months.

Reference
Bertero A et al. (2016) Optimized inducible shRNA and CRISPR/Cas9 platforms for in vitro studies of human development using hPSCs. Development 143: 4405-4418. doi:10.1242/dev.138081

Adapted from a press release by the Wellcome Trust Sanger Institute.

Researchers from the Wellcome Trust Sanger Institute and the ̽��ֱ�� of Cambridge have created sOPTiKO, a more efficient and enhanced inducible CRISPR genome editing platform. Today, in the journal Development, they describe how the freely available single-step system works in every cell in the body and at every stage of development. This new approach will aid researchers in developmental biology, tissue regeneration and cancer.

In the past we have been hampered by the fact we could study a gene’s function only in a specific tissue. Now you can knock out the same gene in parallel in a diversity of cell types with different functions

Alessandro Bertero

Rob Walker

Light Switch (cropped)

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