Hi! We’re here to talk about all things CRISPR and NIH’s Center of Excellence in Genomic Science. We’re researchers from Jennifer Doudna’s lab at UC-Berkeley and program directors from the National Human Genome Research Institute, part of NIH. Ask us anything!


The Doudna lab's research on CRISPR biology led to the 2012 discovery of the mechanism by which small RNAs direct the protein Cas9 to bind and cut specific DNA sequences within cells, thereby altering a chosen DNA sequence and changing the cells’ activity in a programmed way. This work opened up a world of possibilities by providing a simple and effective means of making targeted changes in the genomes of virtually any cell type or organism. By supporting this research, the NIH is achieving its mission to advance the promise of genomic medicine through the precise manipulation of genes at a scale and level of accuracy that is not currently realized.

The National Human Genome Research Institute (NHGRI), part of NIH, has awarded a five-year grant to to the Doudna lab to establish the Center for Genome Editing and Recording as part of the Center of Excellence in Genomic Science (CEGS) program. The Center is pursuing two technological goals: 1) the improvement of the CRISPR technology to enable more efficient, rapid and accurate genome alterations; and 2) the implementation of robust readout technologies to quickly and accurately assess natural gene variations, as well as the success of CRISPR gene editing. In addition to work through the new Center, research efforts in the Doudna lab include discovering the mechanisms of novel Cas proteins and exploring new anti-CRISPRs which protect self DNA from CRISPR cleavage.

Our goal is to harness the power of CRISPR to benefit humankind by curing disease and caring for the environment. We’d love to hear your questions about this technology and the new Center of Excellence in Genomic Science. Ask us anything!

Your hosts today are:

Jennifer Doudna, Ph.D., Professor of Chemistry; Biochemistry and Molecular Biology at the University of California, Berkeley and members of her lab

Lisa Brooks, Ph.D., Program Director in the Division of Genome Sciences at NHGRI

Dan Gilchrist, Ph.D., Program Director in the Division of Genome Sciences at NHGRI

Lu Wang, Ph.D., Program Director in the Division of Genome Sciences at NHGRI

Carolyn Hutter, Ph.D., acting Division Director in the Division of Genome Sciences at NHGRI

Lawrence Brody, Ph.D., Division Director in the Division of Genomics and Society at NHGRI

Nicole Lockhart, Ph.D., Program Director in the Division of Genomics and Society at NHGRI

Mike Smith, Ph.D., Program Director in the Division of Genome Sciences at NHGRI

Relevant links:

Learn more about the Center of Excellence in Genomic Science (CEGS) program: https://www.genome.gov/10001771/centers-of-excellence-in-genomic-science/#al-4

Learn more about Dr. Doudna’s research: http://rna.berkeley.edu/

UPDATE: Hi Reddit-ers! We're wrapping up for today, but thanks for all the great questions! We're thrilled and honored that you find CRISPR science as cool as we do! If you want to see/hear more, Dr. Doudna will be live-streaming a chat with Siddhartha Mukherjee, author of the book, The Gene today at 4:30-6 pm PT. See the event here! https://www.facebook.com/igisci/

I recently read an article about a study published explaining that some people have an immune system primed against CRISPR, making any potential CRISPR treatments ineffective for them. What are some ways researchers could get around this to treat genetic disorders in people 'immune' to CRISPR?


Hello, this is Lu Wang from NHGRI.

Thanks for the question! An immune response is the human body’s defensive reaction that recognizes an invading substance (antigen) and produces an antibody specific against that antigen. Examples of antigens include viruses, fungi, bacteria, or transplanted organs. An antibody can tag an antigen for attack by other parts of the immune system, or can neutralize its target directly.

CRISPR are DNA sequences in bacteria containing bits of DNA from viruses that have attacked the bacterium. Bacteria recognize these bits in DNA from similar viruses during subsequent attacks. Cas proteins, including the various versions of Cas9, are enzymes that chop up the recognized DNA of a foreign invader. CRISPR/Cas form the basis of the CRISPR/CAS technology that can specifically change genes within organisms.

The Cas9 enzymes often used for research are originally from common bacteria that can live in the human body that may have already formed immune responses against those proteins. Modifications of the CAS enzymes or finding different enzyme from microorganisms that do not cultivate in human bodies are among the ways to get around this challenge.

Are any of you familiar with the DIY Bio movement, "Bio hackers", or any of the people that have injected themselves with CRISPR (such as Josiah Zayner or Tristan Robers)? Do you think these types self-injections will be more common in 2018? Is there any way regulations can "keep up" or control how individuals use this technology? Do you know if steps are already being taken to do this?

What do you think the worst-possible outcome is for someone injecting themselves with CRISPR? Would it be possible for the genetic alteration to spread (like the "gene-drive" concept) through a human population? Could CRISPR be passed from one person to another through transmission of bodily fluids or otherwise? How long does CRISPR stay active in the body?


Hi, this is Kevin from the Innovative Genomics Institute. We are very familiar with the DIY Bio movement and talk with a lot of the DIY hubs around the country. Individuals who advocate self-injection with gene editing reagents do not represent the views of the majority of people in this community, though they get the majority of the attention. These types of injections are both pointless and potentially hazardous. You could potentially get an infection at the injection site or have an immune reaction to the injected material. There’s also the risk of an off-target/unintended change being made. However, without more sophisticated equipment/reagents, the odds of the CRISPR components successfully entering a cell and editing any DNA at all is essentially zero.

The biosecurity community is actively discussing how best to regulate DIY experiments. Each country approaches these issues in unique ways.

Gene drives are highly deliberate schemes that won’t arise spontaneously and be spread from person to person. Most groups developing CRISPR-based therapeutics do not plan to let the CRISPR enzymes stick around for a long time or to introduce them in a way that will make them transmissible in the long-term. That said, if embryos or reproductive cells (eggs or sperm) are gene-edited, the changes made will be transmitted to the next generation. This is a key reason for the intensive ethical discussions surrounding human embryo editing.

Dr. Doudna. We’re a group of undergraduates from the University of Maine Presque Isle and Fort Kent campuses attending an INBRE “Genome Engineering with CRISPR/Cas9” course. We’d love if you can address any of the following three questions:

Gene editing with CRISPR now seems simple and straightforward. To treat disease the real hurdle is cell-specific delivery of the editing machinery. What new advances are being made on this front?

We grow a lot of the world’s potatoes here in Northern Maine and are very aware that things like potato viruses cost our state millions each year. In theory, CRISPR can fix this, so should we give it a shot?

Anti-CRISPRs are an exciting new discovery. Can you speak on their potential to improve CRISPR-based treatments?


Hi, this is Mike Smith from NHGRI. There are a lot of efforts utilizing CRISPR in agriculture ongoing in laboratories worldwide. One of the beauties of CRISPR is that it allows you to approach genetic modifications in potatoes to address the issues you know about. Given the many efforts ongoing, it’s always advisable to work in areas where you have special expertise and need.

Thanks so much for coming to talk with us!

There has been a lot of discussion of potential catastrophic risks of misuse of CRISPR. Which risks do you think are the most over-hyped, and which do you think deserve more attention?


Hi, this is Kevin from the Innovative Genomics Institute. One potential misuse of CRISPR gene editing technology would include the release of gene edited organisms into the wild Gene Drives. This poses the risk of impacting fragile environments in unpredictable ways. Organisms can also cross international boundaries, which poses diplomatic risks. I think this risk deserves plenty of attention. One risk that is over-hyped is editing viruses to become hyper-infective and virulent. I think this is over-hyped because viruses quickly evolve and any modification may quickly be removed.

How concerning is the recently published finding that CRISPR-cas9 faces antibody resistance in humans? Is there a good workaround?


Hi, this is Kevin from the Innovative Genomics Institute. The recent finding of human immune responses to CRISPR-Cas9 proteins in human cells is an important finding. When gene therapies reached clinical trials in the late 1990’s, unpredicted immune responses affected the patients. Possible work-arounds for CRISPR clinical trials would include using Cas9 proteins from different bacterial species, which humans bodies have never seen. This would include GeoCas9 from a thermophilic bacteria. Another work-around includes using ex vivo editing in which the human cell is removed from the body, edited, and put back in the body. This is what researchers are using for Sickle Cell Disease.

Everyone likes to speculate on the enormous potential of CRISPR for the treatment of genetic disease, however we're not there and there will be more hurdles just like with any other pharmaceutical development. Based on your knowledge of the area, how far off are we looking? Is the promise of CRISPR more like solar panels (improvements are real and on the way) or nuclear fusion (It's been 20 years off for the last 50 years.)


Hi, this is Meredith working with Jennifer Doudna. There are several aspects to be considered when thinking about the timeline of clinical applications of CRISPR. First, a disease needs to be well-mapped; scientists have to know which gene was mutated to cause the disease. Secondly, CRISPR is best designed to treat monogenic mutations (where there is only one mutation, not several). Thirdly, there is an issue of drug delivery: how is the CRISPR system going to get to the tissues that are impacted by the mutation? Fourthly, there are still some issues of off-target effects and efficiency of mutation. Finally, the process to ensure that a new drug is safe for general use is lengthy, and requires years of clinical trials. For diseases where the current mutation is understood, I expect clinical applications to appear in 5-20 years. Beyond that, I expect CRISPR technologies to be applied to more and more diseases.

What would you say is the most misunderstood thing about crispr that can cause people to be opposed to your research? Also thank you for everything you guys have contributed to science, you’re amazing!


Hi, this is Carolyn Hutter from NHGRI - I think a major misunderstanding is that CRISPR is equivalent to germline editing in humans, and that all work in this area should be opposed because of concerns related to genetic modification in humans. In fact the vast majority of proposed applications of CRISPR are in basic research, as well as applications in plants, bacteria, and non-human animals. Further, a major focus of human applications are on somatic (non-inheritable) editing. A broader understanding of the potential benefits, risks and applications of CRISPR would likely lessen some of the opposition.

For more about pubic opinions on gene editing go to: https://www.genome.gov/27569226/what-do-people-think-about-genome-editing/

I teach high school biology. Our standards are leaning more into molecular biology and there is room to incorporate more molecular biology labs into our curriculum. We talk about CRISPR and genetic engineering, but don’t conduct labs associated with the concepts. Is the CRISPR technique likely to reach high school labs any time soon?


Hi this is Kevin Doxzen from the Innovative Genomics Institute. We are working with two other non-profits to make a “CRISPR kit” specifically for High Schools and educational settings. This kit will be affordable and come with a curriculum that meets state standards. We are hoping this will be available later in 2018. Please visit the Innovative Genomics Institute website (https://innovativegenomics.org/resources/educational-materials/genome-engineering/) for more educational material.

There's been a recent pre-publish paper that has been released calling attention to the fact that most adults are immune to the CRISPR-CAS9 system. Do you foresee this derailing a certain amount of the promise that CRISPR holds? Are the any ways around this immunity? How has the gene editing community reacted to this news?


Hi, this is Kevin from the Innovative Genomics Institute. The recent finding of human immune responses to CRISPR-Cas9 proteins in human cells is an important finding. When gene therapies reached clinical trials in the late 1990’s, unpredicted immune responses affected the patients. Possible work-arounds for CRISPR clinical trials would include using Cas9 proteins from different bacterial species, which humans bodies have never seen. This would include GeoCas9 from a thermophilic bacteria. Another work-around includes using ex vivo editing in which the human cell is removed from the body, edited, and put back in the body. This is what researchers are using for Sickle Cell Disease. The gene editing community was kind of expecting this result, but glad that researchers took the time to do a thorough study. This also speaks to the benefits of pre-publishing results.

The litigation surrounding the patenting of CRISPR/Cas9 has been drawn out and quite vicious. That's somewhat understandable given the potential of the technology (and its potential valuation). How has the battle over intellectual property affected the research your lab does?


The patent fight is unfortunate, but I’m grateful that it has not affected my lab’s research. We are working on fundamental aspects of CRISPR biology and technology, and we’re also partnering with various academic teams to move our developments into the clinic and into use for agricultural applications. As a scientist I try to stay focused on the things I can control, like our research directions and training my students, and leave the legal wranglings to the lawyers!


I reckon human trials for critical treatments are still ways off, so what will be the first big direct impact CRISPR should have in our lives? Commodity crops? Animals? Food? Memes?


Hi, this is Meredith from UC Berkeley. Yes, you’re right that there is a lot of work that needs to be done before we will have CRISPR treatments approved for widespread clinical use. I expect that agriculture will be the first area to be impacted. Scientists have already invested a lot of effort into developing crops that are healthier, better for the environment, and easier for farmers to grow. There is more work to do to make sure that the public is comfortable with the targeted updates applied to crops, but there are great benefits to be gained, ranging from availability of pork to drought-resistant chocolate.

CRISPR seems to hold such promise and I'm excited to see what's in store for the technology. What sort of 'fixes' so to speak have the most stability/promise/success so far and therefore perhaps the soonest application? Ie deleted genes, typo genes, mutated genes etc. I ask with my cousin in mind, since she has Rett Syndrome and the mutated MECP2 gene is to blame. She's fifteen and I wonder if CRISPR-assisted gene therapy for her could happen in the near future, or in the more distant future.

Thank you for all that you do!!!


Hi, this is Brett at UC Berkeley. For CRISPR-Cas applications in the body, gene inactivation has the most success and highest efficiency of editing cells thus far. Gene correction is being rapidly improved. Rett Syndrome mostly affects girls. It is caused by epigenetic X-inactivation of a normal copy of the MECP2 gene, so only the mutant version is on. This occurs randomly in all cells in the body-- 50% are normal, 50% are mutant. Attempting to correct the mutant allele is one possibility. Another possibility is reactivating the normal version of the gene in cells. Here is an article: https://genomemedicine.biomedcentral.com/articles/10.1186/s13073-017-0411-7

Ok I don’t know enough to even know if this is a good question, so if not sorry.

Is this technology something that could potentially be used to turn on/off genes in a living adult? If so, does that mean it could be used to combat the physical effects of PTSD/trauma that result in permanent genetic and hormonal changes? I realize this kind of thing is probably a ways off.

Thanks for what you do!


Hi, Dan from NHGRI here. I think this is a great question. The possibility to use CRISPR-based technologies to turn genes on and off definitely exists. One thing to keep in mind – to use CRISPR to impact the course of any particular disease, we’d need to have a really strong understanding of the molecular basis of that disease, so we could predict what changes we’d need to make with CRISPR. Scientists are working hard to understand the biological underpinnings of PTSD and many other diseases, but there remains a huge amount to learn. We’ve got to keep hammering away to develop and apply techniques like CRISPR-Cas-based gene editing, but also to understand the underlying biology. As one example, NIH has started a new program developing quality tools for effective and safe genome editing of the disease-causing DNA within the non-reproductive (“somatic”) cells https://commonfund.nih.gov/editing.

How far away are we in terms of technology with CRISPR or otherwise from the first actual transgender person who has modified their sex chromosomes?

Could you help to promote the saving of endangered species as valuable stable sets of genetic data, which can be used to further advance the knowledge needed to modify the genetic code as we see fit?

How much data would be required, and how long, before it's possible to create new forms of life with stable genetic code that have never existed on Earth before?


Hi, this is Brett at UC Berkeley. We need to have a firm understanding of the genetic changes or mutations that underlie a trait or characteristic or pathogenic disease state before we can apply CRISPR-Cas to alter the genes in a therapeutic manner. The things you are mentioning are multigenic, increasing the complexity. We can use CRISPR-Cas to gain insight into a trait or characteristic or pathogenic disease state in the research setting. Once this knowledge is in hand, therapeutic use of CRISPR-Cas may be attempted.

My girlfriend has an extreme case of IC (interstitial cystitis) of the bladder. She's tried everything under the sun to ease her pain yet she suffers extreme pain everyday. She's taken pills, bladder infusions, and plenty of surgeries including an experimental spinal surgery. And none of it has worked. Are there any plans or research in using CRISPR to treat IC?


Hi, Brady here (Doudna lab postdoc). For diseases with unknown or cryptic causes (like IC), a CRISPR-based therapeutic is likely not imminent, especially considering the average duration of clinical trials. However, the exciting news is that genome-wide CRISPR screens (CRISPRi/a) will continue to enable elucidation of the genetic basis of diseases at an unparalleled rate. You can think of CRISPRi/a screening as a way to individually turn off (CRISPRi, or CRISPR interference) or turn on (CRISPRa, or CRISPR activation) all genes across a genome in a high-throughput fashion, while searching for a gene (or set of genes) whose altered expression is associated with reduction in disease phenotype/symptoms. These screens can be performed in cell culture or in animal models. A final note: I think it is a safe assumption that any basic research lab focusing on the genetic basis of IC has probably considered or might already be using CRISPR as a tool to study the disease. Find a lab studying IC and ask them--if they haven't started a CRISPR screen, they should! For a comprehensive review written by another Doudna lab postdoc on utilizing CRISPRi/a toward this end, see: https://doi.org/10.1038/nrd.2016.238 (behind paywall, but the abstract is worth a read).

When are you guys gonna cure type one diabetes? Please hurry. It's been 14 years for me and over 30 for my papá.


Hi, this is Kyle from the Doudna lab. I looked into what research is being done on type 1 diabetes, and came across this review from about a year ago (open access): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5345178/. It looks like there’s been some work so far trying to reactivate genes to ‘restart’ insulin production, but it seems pretty early days.

There’s a particular study referenced in that review (paywall): https://www.nature.com/articles/gt201628 where the authors showed that they could reactivate the human INS gene, which is responsible for insulin production.

How far away are we from treating diseases like LGMD, which is responsible by a single incorrect gene?


Hi, this is Kevin from the Innovative Genomics Institute. Researchers are actively working to address muscular dystrophy using genome editing. Eric Olson is leading the way in using gene editing for MD.

My daughter is a junior in high school, but is really interested in this field of study. What should she look to major in, in college? What can I do to help her over the next year and a half? She's in AP Biology now.


This is Dan from NHGRI. It’s great that she’s excited about this – it is exciting science! There are a lot of majors that can be entry points into a career in the life sciences. A strong background in molecular biology is helpful, but expertise in math, data science and programming, and engineering are all becoming increasingly important in the life sciences (and are all featured in the NHGRI CEGS program). Maybe most importantly, she should keep following her interests and see where they lead.

Don't want to stir the pot here, but what's the relationship like between you and Feng Zhang. A key part of science is collaboration, would you ever consider working together to improve CRISPR based technologies?


Hi, this is Jennifer Doudna. For obvious reasons, it would be hard for my lab to work directly with Dr. Zhang, but we have active collaborations with other faculty at the Broad Institute and at MIT.

  1. As the only microbiologist in Congress, I have long been a champion of women in STEM. Dr. Doudna, you are a prominent scientist whose profile continues to rise as a direct result of your revolutionary scientific discoveries. What challenges and opportunities have you experienced as a woman in science?

  2. The discovery of CRISPR has brought the promises of using gene editing technology to cure debilitating and life-threatening diseases closer to reality, but with those promises come concerns that it could open new avenues for discrimination, inequality, and inequity. In 2008, I sponsored a bill that became law, called the Genetic Information Nondiscrimination Act or more commonly as GINA. GINA prevents genetic discrimination in employment and health insurance. How do we ensure CRISPR-based genome editing doesn’t create new avenues for genetic-based discrimination in future generations?


Hi, this is Jennifer Doudna, and thanks for these questions. Challenges I’ve encountered include being told that “girls don’t do science” (high school), doubting my abilities to do science (college) and trying to balance work and home life. Opportunities have included working with amazing scientists throughout my career, first as a student and later as a mentor. I feel very lucky to working on projects that involve science and broader questions about technology and society. And that leads to your second question about the potential for genetic discrimination. I think we need to work with scientists and stakeholders across the fields of medicine, agriculture and synthetic biology to ensure responsible progress with gene editing. For example, I’m working with a team at UC Berkeley and UCSF through the Innovative Genomics Institute to develop procedures for clinical use of gene editing in adults that will ultimately provide affordable options for patients with genetic disease.

How far away do you think the technology is from being used on humans with genetic problems like cystic fibrosis?

Knowing that this technology is being researched by other teams and governments worldwide do you feel you have to rush past any ethical concerns you may have about the ramifications of how this technology could effect the planet and our species before you have a chance to truly contemplate them?


Hi - This is Mike Smith from NHGRI. I am sure many researchers are working on many specific diseases like cystic fibrosis now. Those diseases that can be addressed with the most easily accessible tissues (e.g., bone marrow) are cases where the first successes are reasonable to expect. There are also several mutations that can play a role in causing CF; CRISPR works best to treat monogenic diseases (where only one mutation is involved). This might slow treatment for some CF patients. However, CRISPR has already been used to help CF patients by developing better model cell systems to assess the impact of medication on CF patients.

On rushing the ethics, the field is well aware of the potential issues. I would point you to the National Academy of Sciences Human Gene Editing Initiative (http://nationalacademies.org/gene-editing/index.htm). This is an area where researchers took the ethics issue quite seriously. We need to continue to take ethics seriously. We lead by example. FYI-NHGRI takes these issues seriously and is running a session on the Ethics of Human Genome Editing at an upcoming Cold Spring Harbor Biology of Genomes meeting in May.

In terms of timing… It’s difficult to say how long it will take and exactly what the results will be, but given the importance of the diseases and questions, many efforts are underway. It feels likely that some efforts will be successful in the coming years and decade. Others certainly can take decades, especially if you consider the process of basic research reaching the clinic and patient. Some may not be addressable with CRISPR, but biomedical researchers are using many tools to address disease, agriculture, infectious disease vectors, and many other areas of high need.

There is a rather large controversy surrounding the notion of designer babies, which is something that may be possible with tools like CRISPR. Regardless of if designer babies are morally right or not, do you fear the passing of any laws that would hinder CRISPR research in the name of preserving morality? Why or why not?


Thanks for your question! This is Nicole Lockhart from the NHGRI Division of Genomics and Society. Regulation of emerging technologies is always challenging due to the difficulty of predicting where the science might lead. As evident from the interest in this AMA, CRISPR has sparked the imagination of both the scientific community and the public at large. Continued engagement of the public will be vital to ensures access to accurate information and that both the possibilities and limitations of CRISPR are well understood. In theory, morality would be discussed in many circles. As these discussions start to lead to consensus, legislation should be aligned with the will of the people.

Based on your research, what do you think will be the most widely used clinical application of CRISPR/Cas9 in the future? Genome editing to cure disease seems to be the most hyped use for CRISPR, but implementing that into the clinic is notoriously difficult, and the technology has so many other applications. For example, dCas9 has many applications and might be safer for clinical use as it doesn’t actually cut the DNA. Keep up the great work!


Hi, this is Mike Smith from NHGRI. It’s easiest to think about the near future. Common diseases caused by changes to a single gene (monogenic) and specific base changes in easily accessible tissues (e.g., eye, blood, bone marrow, accessible surfaces in the gut and lungs) are a good bet for future widely used clinical applications. In terms of other applications, changes to agricultural species and pets that modify disease susceptibility or desirable traits should also be expected and have already been accomplished.

Now on dCas9, let’s first say what that is - an inactive form of Cas9 that can be guided to a specific place in the genome without making changes in the genome. In the laboratory, this technology is being used to activate or deactivate specific genes. In terms of safety of dCas9, this approach will have its own safety concerns and many of the same regulatory hurdles to overcome.

Thanks for the shout out on the good work - it’s an exciting time in biomedicine!

Edit to add to Mike's answer from the perspective of the Doudna lab:

Hi, Brady from D-lab. Great question. I'm very fond of CRISPR applications outside of the therapeutic realm. Of course some of the most exciting applications involve therapies, but there are some recent CRISPR-based diagnostic applications that could be game-changing due to their specificity and sensitivity. Specifically, check out our lab's recent pre-print manuscript, where our colleagues demonstrated a really awesome new CRISPR application with clinical relevance: Cas12a can detect DNA from human papilloma virus (HPV) using a fluorescent assay and can distinguish between closely related HPV serotypes (https://www.biorxiv.org/content/early/2017/11/29/226993).

This type of assay could prove incredibly useful for detecting dsDNA virus genomes in human samples in the clinic. Analogously, the class of RNA targeting CRISPR effectors known as Cas13 has already been developed for sensitive and selective detection of RNA virus genomes.

With respect to your question about dCas9, catalytically inactive CRISPR effectors are great tools (also near and dear to my heart), but I don't see an immediate role in the clinic. dCas9 is certainly making waves in basic research, though, so it is undoubtedly leading to discoveries that expedite development of clinical applications.

Edit Edit: just checked in with a few colleagues to see if my answer about dCas9 was shortsighted. You could imagine transient treatments with dCas9 to knock-down gene expression in the clinic, but this would likely require repeated administrations and might face similar hurdles to those encountered by other RNA-based drugs. Epigenome editing (with dCas9 fusions to epigenome modifying domains) to stably activate or silence genes over a long duration might hold more potential as a dCas9-based clinical therapy. To circumvent potential issues with DNA cutting, many treatments will likely involve ex vivo editing of a patient's cells with Cas9, isolation of a clonal, perfect edit, and then expansion of the cell line and reintroduction into the patient.

Why haven't we used CRISPR to fix alleles in people affected by Huntington's disease yet? I understand that CRISPR isn't 100% accurate and mutating the wrong genes could increase cancer risk etc, but isn't the possibility of developing cancer still better than the certainty of developing Huntington's? Am I missing something? Cheers!


Hello, this is Lu Wang from NHGRI. There has been work done in mice affected by the disease that informs treatment of the disease in human.

Isn't CRISPR very unfair for the poor, who cannot enhance their bodies, or for the old, who may no longer be able to?


This is Nicole Lockhart from the NHGRI Division of Genomics and Society. I’m seeing a lot of interest in issues related to fairness and access to new technologies, which is hugely important! First, it’s important to consider where we currently are in the use of technologies like CRISPR for clinical use in humans. Before CRISPR can be used in humans, it must be proven safe and effective. Further, initial use of CRISPR will focus on clinical uses to eliminate severe disease - see the examples highlighted by several Reddit-ers. Enhancement, i.e. changing human function beyond what would be found naturally, would be a distinct use of the technology which many in society would likely find untenable. Issues of health disparities exist across biomedicine, and are not unique to CRISPR.

Undergraduate in genetics and cell biology from DCU here, greetings from Ireland!

Will crispr eventually replace more traditional methods of introducing site directed mutagenesis and other protein engineering methods, if not what are the practical challenges to overcome? My knowledge of crispr is limited mainly to that podcast by RadioLab (which I highly recommend to anyone interested)


Hello! This is Larry Brody at NHGRI. CRISPR-Cas and its many variations may eventually replace site directed mutagenesis. The first place this would happen is when you want to change a gene (or many genes) in vivo. This is happening now in many labs. I am not sure it will replace traditional oligo-driven engineering of plasmids. These established methods are well established, efficient and inexpensive.

PS Congrats at being at DCU. I collaborate with some of the researchers there. I’ve been very impressed with the training the students receive.

What's your time estimate for CRISPR therapies being available to the public (assuming trials go well and the public accepts what might be perceived as a controversial treatment)?


What application for CRISPR do you personally look forward to the most?


This is Mike Smith and Lu Wang at NHGRI. See the timing part of the answer to “How far away do you think the technology is from being used on humans with genetic problems like cystic fibrosis?...” from user Epyon214. In terms of applications I personally look forward to the most, that is a tough one. I would pick monogenic diseases where we currently know over 3500 single “disease genes,” which would make good candidates for CRISPR-based somatic (not inherited) tissue gene editing to fix the genetic problem. Those more common monogenic diseases affecting the most accessible human tissues and causing severe diseases are where we might expect the first successes.

Will you be able to end aging altogether?


Hi, this is Lisa from NHGRI. Aging is an incredibly complex process related to how all the systems of the body work. Although many specific aspects of the body’s functioning are known, and some behaviors can delay aging (don’t smoke, do exercise), researchers are a long way (hundreds of years at least, I would guess) from understanding how these processes work together to result in aging, or how to intervene. After all, it takes only one system to not work for someone to die. How can all systems be made to work together? This requires an understanding of how the many genes and environmental factors work together. This is such a long way from single-base changes in DNA. In fact, ending aging might never be possible.

Designer babies. When?


Hi, this is Christine He, a postdoc in the Doudna lab. With human trials for CRISPR-Cas editing already underway, it is natural to wonder if the technology can be used to enhance desirable traits in humans. However, there are two important factors to keep in mind. First, the genetic basis for many physical attributes is not well understood. For example, variation in human height--a trait that you might guess would be determined by a single or a few genes--is actually influenced by thousands of genes. CRISPR-Cas can be utilized to target a very specific sequence in a gene, but manipulating a complicated network of genes to produce a desired phenotype is far less straightforward. The second factor to consider is that many traits you might associated with designer babies--such as high IQ or athletic ability--are likely determined by both heritable genetic factors and environmental factors. Even if we were able to edit the genome with exact precision and efficiency, the influence of environmental factors cannot be discounted.

Three questions:

First, how has the patent dispute impacted CRISPR research? Has it delayed it at all? Any other comments you can make on the dispute?

Second, could CRISPR be used on cells already existing to decrease gene expression, or would it only be efficacious to use in an embryonic stage? Sorry for the vague question, I'm curious but not very knowledgeable on the subject.

Third, I'm just starting to think about my financial future and am starting investments. I want to invest in something I believe in and CRISPR seems to be a great place to start. I don't have much information or knowledge on this subject, so where would you recommend I start looking? I understand Intellia Therapeutics is your (Dr. Doudna's) company, are there any resources or information they provide for someone looking to invest?

Thank you so much for your incredible work and for doing this AMA!


Hi, Jennifer here. First, the patent dispute has not had any impact on CRISPR research; collaborative efforts are ongoing. Secondly, yes, CRISPR can be used on both adult and embryonic cells to fix mutations. Third, there are several start-up companies commercializing CRISPR, and even more using CRISPR. Use Google! I’m not going to give any investment advice. ;)

Ethically speaking - if CRISPR is determined to be relatively risk free, would it be considered inhumane to NOT use it to eradicate the possibility of disease in my offspring?
And if so, I suppose we would need to set some sort of societal regulationsto ensure we don’t end up with a race of rich, more genetically enhanced humans and another race of poorer natural humans. Thoughts?


This is Nicole Lockhart from the NHGRI Division of Genomics & Society.Thanks for the thoughtful question! We are a long ways off from a comprehensive knowledge of the possible risks of using CRISPR in humans. If we take your presumption at face value and assume that in the future CRISPR is definitively demonstrated to carry minimal risks, then an ethical argument could be made for the use of the technology to eliminate severe disease. Even in these limited circumstances where CRISPR is determined to be “risk-free,” there would still be challenges related to determining what diseases are sufficiently severe to warrant use of CRISPR or other similar technologies. As with any new technology, there will also be significant challenges related to access, particularly given the ongoing and persistent health disparities in the US and many other countries. These will be important and ongoing issues to consider both within the scientific community and broader society as a whole.

Quick plug - the NHGRI Ethical, Legal, and Social Issues Program will be hosting a Reddit AMA on January 29th at 11am ET if you would like to explore issues related to genomics more broadly.

What can the average, non-scientist person do to help? Are there studies we can participate in or is there a way to provide samples for study?



Hello. This is Larry Brody from NHGRI. Depending on where you live, there may be studies in your area that would take you as a volunteer. Many studies are focused on individuals with disease. You can find a listing of these trails in the US at www.clinicaltrials.gov.

One other thing you can do is to learn more about science and the role it plays in modern life. This will allow you to spread the world to those who do not understand how science works or confuse scientific results with opinions.

what projects are you most excited by outside of your lab/work? anything you're keeping an eye on?


This is Jennifer. I’ve taken up weight lifting, and it’s been fun to be able to do real push-ups for the first time in my life! Scientifically, I like to read about the rapid advances happening in artificial intelligence and astronomy, both areas that are incredibly exciting right now.

I'm red-green color blind. How soon might my condition be correctable?


Hello, this is Natalia from Jennifer’s lab! Some types of red-green color blindness are caused by mutations that could be potentially targeted by genetic therapy; however, it seems more than likely that the first genetics therapy applications that will be approved for use in patients will be targeting diseases that cause severe and life-threatening conditions. Genetic therapy is still in its very early days, and it is associated with a lot of risks, therefore the disease has to be severe enough to justify the risks. Therefore, red-green color blindness would probably be treated by genetic therapy after genetic therapy applications are successfully used to treat more severe diseases.

What are your thoughts on the concept of "Designer Babies", and how CRISPR may lead to humanity customizing their children genetically? Should people use this technology to make their children "genetically superior", as in changing genes to maximize their child's mental/physical potential, or should it only be used for removing genetic diseases?


Hi, this is Christine He, a postdoc in the Doudna lab. With human trials for CRISPR-Cas editing already occurring, it is natural to wonder if the technology can be used to enhance desirable traits in humans. However, there are two important factors to keep in mind. First, the genetic basis for many physical attributes is not well understood. For example, variation in human height--a trait that you might guess would be determined by a single or a few genes--is actually influenced by thousands of genes. CRISPR-Cas can be utilized to target a very specific sequence in a gene, but manipulating a complicated network of genes to produce a desired phenotype is far less straightforward. The second factor to consider is that many traits you might associate with “designer babies”--such as high IQ or athletic ability--are likely determined by both heritable genetic factors and environmental factors. Even if we were able to edit the genome with exact precision and efficiency, the influence of environmental factors cannot be discounted.

Can you explain CRISPR in layman's terms?

To my very basic "understanding" CRISPR allows us to just go in and snip and splice DNA. Is this correct?


Hi, this is Tina from UC Berkeley. Yes, in general, CRISPR acts like a pair of molecular scissors that can hone in on a specific region of DNA and cut it. It uses an RNA molecule as a “guide” to find a certain DNA sequence, allowing researchers to program the CRISPR molecule to target a specific location in the genome. CRISPR actually does not do the “splicing” part of this operation. The cell’s own DNA repair abilities lead it to either delete or insert in a new piece of DNA at the position where CRISPR makes the cut. Taken together, this enables one to pinpoint a specific place in a gene, and then either delete it to disrupt its function, or change the DNA sequence (e.g. to correct a disease-causing mutation). Basically, we can now rewrite the genetic code in all sorts of cells and organisms, enabling unprecedented research possibilities, products, and therapeutics.

Hello scientists!

I do research on the human microbiome, and was curious if you guys thinks it's possible to do selective crispr engineering in complex microbial communities like has been done in human genomes. That is, if I want to selectively delete a gene in bug 'x', but a similar gene is present in millions of other bacteria, is that possible?

Keep doing you, peeps, and I hope you guys eventually win that patent battle if it's not over already.


Hi, this is Christine He, a postdoc in the Doudna lab. The prospect of genome editing in complex microbial communities is definitely an area of interest! For example, the ability to selectively inhibit the growth of harmful microbes in the human microbiome--in a way that is much more specific than an antibiotic--would be very exciting. Not as much research has been done on editing in prokaryotes compared to eukaryotes, and similar problems need to be addressed in microbes (ex: how do we effectively deliver CRISPR-Cas to a broad range of bacterial cells?). However, editing of microbial communities is an area we are actively pursuing.

What barriers exist that might keep CRISPR from being more widely used once it is completed?


Hi, this is Kevin from the Innovative Genomics Institute. I think that the most significant barrier is the health insurance system. Many of the therapeutic applications will cost hundreds of thousands of dollars. We hope that health care systems will evolve to make this technology available to those in need.

Is there any way CRISPR and current genetic science could help someone with muscular dystrophy within the next ten years? What about if they have no money?


Hi, this is Kevin from the Innovative Genomics Institute. Researchers are actively working to address muscular dystrophy using genome editing. Eric Olson is leading the way in using gene editing for MD. We hope that health insurance companies can make this technology accessible to those in need.

Hi guys. I'm an undergraduate student who hopes to go on to graduate school to study genetics and agriculture. Do you feel that CRISPR has made research into RNAi obsolete? If not, what applications can RNAi perform better than CRISPR?


Hi, this is Kevin from the Innovative Genomics Institute. Great question! I am a huge fan of Argonaute proteins, so your question made my day! Using Cas9 (or dCas9, which is the “dead” version that has mutated catalytic domains) has fewer off-targets than RNAi. If the researcher already has RNAi materials and reagents, then using RNAi can produce efficient knockdown of gene expression. Sometimes it is great to use both techniques to confirm previous results. Check out this article. Here is another article if you can find a way to access it.

Hi guys, thanks for the AMA!

Could you give me a summary of all of the CRISPR gene editing (un)successfully performed on human DNA at this time?

Also, is there a serious concern amongst researchers that when human genome alteration becomes a reality, those who are less morally scrupulous will abuse the technology in ways many would disagree with- for example, breeding compliant soldiers/builders/workers etc...



Hi - thanks for the question. This is Nicole from the NHGRI Division of Genomics and Society. At this time, CRISPR is being used in human cells that we can grow in the dish. It is not being clinically used in humans. I think scientists are taking the issue of potential misuse seriously and trying to be forward-looking in terms of both potential benefits and harms.

The scientific community has a history of considering the implications of their work and many of the concerns related to “unscrupulous” use of CRISPR are similar to earlier discussions related to recombinant DNA and gene therapy. You correctly point out the importance of considering societal values in the development of new technologies. Continued engagement of the public will be vital to ensure access to accurate information about both the possibilities and limitations of CRISPR.

If someone wanted to work with/research CRISPR and all of its potential uses as a career what kind of schooling and degrees would they need to get? For anyone looking to with with CRISPR as a career what kind of path should they follow?


This is Meredith from UC Berkeley. I’m assuming you’re referring to a career as a scientist in a clinical or research setting. Either way, you’d first want to get a degree in chemistry, biochemistry, or biology, and then pursue advanced training in a PhD or MD/PhD program. The former would be best suited for a career in academia, where the latter would be especially helpful to prepare for clinical research. If you had a PhD in molecular and cell biology or in biophysics, you could apply for jobs in industry at one of the many places that are researching CRISPR (such as Caribou). If you wanted to pursue a tenure track position, I’d recommend getting a postdoc in a lab that does CRISPR research, including the Doudna lab and other IGI researchers, but of course much beyond that too. Many labs use CRISPR, though, so there are lots of great options for CRISPR research! Of course, there are also jobs in CRISPR as related to ethics and communication; those jobs would require a base level of scientific background, as well as demonstrated skills in communication, education, and outreach.

Are there any major hurdles in relevant technologies (like battery density for engineering, or quantum tunneling for computer science) that are expected to prevent otherwise-possible uses of CRISPR?


Hello, This is Larry Brody from NHGRI. CRISPR-Cas does not face any major unsolved physical or chemical hurdles. It operates following the laws of biology. Unfortunately, these are less well understood than the physical sciences. So far, the technology works in many organisms and many settings. I suspect that there will be biological obstacles that pop up as the technology is applied to different settings. One example of this was a recent preliminary report that some people may carry antibodies to some of the proteins in the CRISPR-Cas system. This could limit the use of the technology.

How will CRISPR change the regulatory process for GM seed?


Hi, this is Meredith from UC Berkeley. As I’m sure you’re aware, there is an ongoing debate about the safety and efficacy of genetically modified organisms. Given the public concern about GMOs in food, researchers and corporations want to be very intentional about including the public and responding to their concerns as CRISPR is used to create new GM seed. It can be helpful to put this in perspective of the long history of domestication and breeding, from the biased seed-planting of early farmers, to the intentional cross-breeding of early genetics, to now the targeted breeding of CRISPR. To make a long story short, the regulation of these products is similar to what has been done previously; the bigger battle is public perception.

One detail to note is that regulatory agencies have given early indications that when CRISPR is used to delete a gene, this modification will not be regulated under the same rules as traditional GMOs. Because there is no introduction of foreign DNA (as there is for transgenic crops), the same regulatory hurdles may not apply.

Hey guys, I'm thinking about running some CRISPR/Cas9 knockouts of song genes in Hawaiian crickets but my adviser isn't as excited as I am. How do I convince her this is the best idea ever?


Hi, this is Megan from the Innovative Genomics Institute. CRISPR editing has been established in the cricket species Gryllus bimaculatus, but to my knowledge it has not been applied in any other cricket. If you do make those song gene knockouts, we’ll get to add your work to our soon-to-be-launched “CRISPR-edited organism gallery”! We feature a nice image of each species along with its common and scientific names, plus have image links to the PubMed entry for the primary paper.

Also, that just sounds super cool! Jennifer is from Hawaii so maybe your gene-edited Hawaiian crickets would make it into one of her talks as an example of all the awesome stuff scientists can do with CRISPR. :D

I've heard that CRISPR can be used to easily correct color blindness. I've also read that some people have an extra cone in their eyes, giving them the ability to see millions more colors than the average human.

Now, I don't see anyone having a problem with people correcting their color blindness. However, I see wanting to have an extra cone added to your eyes as a sort of "Genetic cosmetic surgery" that would not be covered by insurance.

In a future where genetically "improving" yourself is only inhibited by personal wealth and access to procedures, do you foresee a future where the divide between the rich and the poor is more than just money?


Hello! It’s Natalia from UC Berkeley. What should be taken into account is that currently genetic therapy is in its early days and it is associated with a lot of risks. Currently the goal is to use genetic therapy to cure severe diseases that are life treating and can justify the risks. Because of the risks associated with genetic therapy, in my opinion, the “genetic cosmetic surgery” is not something that can happen anytime soon.

Do you personally believe that CRISPR-Cas9 will be, regardless of the hurdles it's facing with people scared of it's capabilities, remembered in history as the biggest step humanity has taken so far? If so, what timeframe would you say it would take for public opinion to shift?


Hello! This is Larry Brody from NHGRI. Certainly, the CRISPR-Cas technology will go down in history as a major advance in science and technology. It might be too soon to say if it will become an important step for humanity. Most important technical advances soon become part of the fabric of life (and we take them for granted). This is especially true of technical tools. What happens in the public sphere is influenced by more than just science. One good example is genetically modified crops. They are accepted by some and other places are vigorously opposed to these crops being part of the food supply. It is even more complex because some believe that this type of engineering is morally wrong, some believe that it is not safe, and still others object to the economic structure that comes along with genetically modified organisms. Ideally, an informed public would reach some consensus after many public discussions that include all elements of society.

Dear Dr Doudna and team,

How likely is it that gene-therapy will find a cure for DADA2 within the next decade ?

Thanks Dr Gaurav Agarwal


Hi, I’m Meredith from UC Berkeley. DADA2 is a bit hard to treat for two reasons: 1) it’s recessive, where dominant diseases are easier to treat; and 2) not much is known about it, as it’s so uncommon. However, since it appears that it is a mutation in a single gene, CRISPR is a viable treatment method. Personally, I don’t expect a treatment in the next 10 years, but perhaps in 20.

Is CRISPR going to be for modifying things while they are in the womb, or will modifications outside the womb be possible? Say, in an adult?


This is Carolyn Hutter from NHGRI. Yes, modifications in adults are possible. In fact, many of the current therapeutic applications for CRISPR are focused on potential modifications in adults. An important distinction can be made between germline therapy and somatic therapy. Germline therapies change genes in reproductive cells (like sperm and eggs). These changes can be passed down from generation to generation. Somatic therapies target non-reproductive cells. Changes made in these cells affect only the person who receives the gene therapy and do not pass on to future generations. Somatic gene editing therapies are being considered for the potential to slow or reverse the disease process. For more information on this topic see: https://www.genome.gov/27569224/how-is-genome-editing-used/

How do you see CRISPR benefitting humankind 10 years from now?


Hello, this is Lu Wang from NHGRI. Thanks for the excellent question! CRISPR is a powerful tool for altering and detecting changes in the genome and for tracing the effect of a change.This will allow us to have much improved understanding of normal and pathologic functions of the human genome and to create more therapies that precisely target the genetic underpinnings of various diseases.

I don't have a question, just a statement: Thank you folks, so much, for what you are doing. Please know that at least one person in this tiny town in SE Illinois keeps up with your progress, and really appreciates what you are doing.


This is Carolyn Hutter from NHGRI. We are always excited to hear from people interested in science - be they from the big city of NYC or the tiny town in SE Illinois. Thanks for your enthusiasm and your support!

Is it possible to use this technology to create superhumans? By superhumans I mean an individual who is harder/faster/better/stronger than your average human. If so, are you at all bothered that this will further divide the rich and the poor? Are you guys looking into democratizing this technology?



Hi, this is Christine He, a postdoc in the Doudna lab. With human trials for CRISPR-Cas editing already underway, it is natural to wonder if the technology can be used to enhance desirable traits in humans (and the dystopian societal implications that follow). However, there are two important factors to keep in mind. First, the genetic basis for many physical attributes is not well understood. For example, variation in human height-- a trait that you might guess would be determined by a single or a few genes-- is actually influenced by thousands of genes. CRISPR-Cas can be utilized to target a very specific sequence in a gene, but manipulating a complicated network of genes to produce a desired phenotype is far less straightforward. The second factor to consider is that many of the traits you hinted at-- athletic ability or intelligence-- are likely determined by both heritable genetic factors and environmental factors. Even if we were able to edit the genome with exact precision and efficiency, the influence of environmental factors cannot be discounted.

Could CRISPR be used to combat antibiotic resistant diseases?


Hi, this is Kyle from the Doudna Lab. Yes! There are some applications being worked on to use CRISPR-enabled viruses that target antibiotic resistance genes (paywall) https://www.nature.com/news/modified-viruses-deliver-death-to-antibiotic-resistant-bacteria-1.22173. It’s a bit ironic, given that CRISPR is a prokaryotic (bacteria/archaea) system for combating viruses.

Do you think tools like crispr could one day edited out chronic illnesses in kids or adults like asthma or allergies? Or possibly enhanced repairing capabilities of the human body?

I'm excited for these type of tools!


Hi, this is Christine He, a postdoc in the Doudna lab. Conditions like asthma and allergies are a complex combination of both genetic and environmental factors. Even when just considering the genetic component, researchers still have an extremely poor understanding of which genes influence these conditions and how this complex network of genes interact. CRISPR-Cas is capable of editing a precise DNA sequence, but the problem with tackling a condition like asthma is identification of which genes to target. There is still a lot of work to be done before we can even begin to address these conditions with CRISPR-Cas. However, our understanding of human genetics and CRISPR-Cas systems is improving all the time and you are right to be excited about the potential impact of this tool!

Dou you think CRISPR could be used as a gene regulation system by prokaryotes (resembling miRNA regulation in Eukaryotes) carrying RNA-targeting effectors and reverse transcriptases (i. e. Type III) ?

Thank you for your time!


Hi, this is Addison from the Doudna lab. Great question-- there are actually a number of examples of CRISPR systems being repurposed for regulation by prokaryotes! Knocking out native CRISPR systems can interfere with things like biofilm formation or virulence in some bacteria, meaning they’re involved in the regulation of these processes. Surprisingly, this has so far been seen more in type I and type II systems, which aren’t really thought of as RNA-targeting (though some Cas9s from type II systems definitely can). The mechanisms of regulation aren’t well understood yet, so it’s still a really interesting open question. Here’s a review on non-immune functions of CRISPR (behind a paywall, sorry!): https://www.nature.com/articles/nrmicro3241

Would Biochemistry be able to help in genomic research and advancements in any way? P.S. I plan on becoming a biochemist.


Hi, this is Kyle from the Doudna Lab. Of course! Biochemistry is large part of our lab and is important for determining how proteins function and how processes in our cells work.

Is there any potential for CRISPR to go really badly? I understand the typical potential downsides people raise from ethical and sociological perspectives, but does it have any application as a bioweapon we should be worried about, or is that less of an issue as any effective CRISPR based weapon would just as 'easily' be countered with a CRISPR based therapy?


Hello! This is Larry Brody from NHGRI. I am glad that you see the ethical and social issues related to genetic engineering. Many of these are old issues and not unique to CRISPR-Cas and related technologies. This is also true with the issue of using genetic engineering to create weapons. The one difference is that CRISPR-Cas are quite easy to use. This has caused many in the defense realm to study these issues. In the short term, I would be more concerned about the existing repertoire of conventional weapons. Many of these are more readily available.

On a practical level, how do you actually use CRIPSR? I have heard of using virus vectors, but are these injected into the afflicted body part(s)? Do the genetic changes spread throughout the body or do they stay more localized?


Hi, this is Kyle from the Doudna Lab. This is a great question. For gene editing, the effector (i.e. Cas9) is delivered by injection, typically near the cells you would want to edit. As you suggest, however, cell-specific delivery is very difficult, and all cells contain the same DNA. However, accessibility of individual sequences may not be the same in all cells. That being said, once a genetic change is made, it is local to that cell, such that only that cell and its progeny will have the change. This means that treating an area of cells requires many individual gene editing events to occur, adding to the delivery challenge. Drug delivery in general has been a challenge for biologic drugs, not just CRISPR, and solving these problems will greatly help make biological drugs more common.

A lot of people seem to be worrying about "flashy" misuses of CRISPR, such as creating super-soldiers, pathogens, etc. But what about more "sneaky" misuses, such as a racist biologist inserting genes in babies, that makes them and their offspring have white skin, regardless of their ancestry? How could someone stop this from hapenning?


Hi, this is Christine He, a postdoc in the Doudna lab. With human trials for CRISPR-Cas editing already underway, it is natural to wonder if the technology can be used (or misused) for nefarious and unethical purposes. However, there are two important factors to keep in mind when considering CRISPR-Cas editing in humans. First, the genetic basis for many physical attributes is not well understood. For example, variation in human height--a trait that you might guess would be determined by a single or a few genes--is actually influenced by thousands of genes. Skin color is also another trait that is based upon the action of thousands of genes, and is poorly understood. CRISPR-Cas can be utilized to target a very specific sequence in a gene, but manipulating a complex network of genes to produce a desired phenotype is far less straightforward. The second factor to consider is that many “designer” traits--such as athletic ability or intelligence--are likely determined by both heritable genetic factors and environmental factors. Even if we were able to edit the genome with exact precision and efficiency, the influence of environmental factors cannot be discounted.

Genetic manipulation technology will make the world either a paradise or a corrupted wasteland. Do you think such technology should be rigidly regulated and supervised with a overwatch agency? There are many scenarios that would lead to disaster, such as a doomsday cult crafting a spliced e.coli with salmonella or psychotic (think intelligent Harris & Klebold) biology students playing with pathogens. Monster organisms could even be created accidentally and ineptly released. Imagine North Korea with this tech: they would have a real deterrent!


Thanks for your question - this is Nicole Lockhart from the NHGRI. I think we need to recognize that all technologies have potential risks and benefits. Some risks will be predictable and could perhaps be addressed through regulation, other risks may be more difficult to anticipate. The same could be said for benefits - we’re just beginning to realize the potential uses and applications of CRISPR. Continued engagement with the public will be vital to ensure access to accurate information and that both the possibilities and limitations of CRISPR are well understood. Such engagement will also be important to incorporate societal values into both scientific priorities and regulatory frameworks.

I'm a high school biology teacher. Could you please tell me what you feel is the most important and interesting aspects of the future of generic engineering the general public should understand?


Hi, this is Kyle from the Doudna Lab. I love this question, education is important! There are two things off the bat that I think are important. First, I think it’s important that the general public should understand how these tools work in general, that is, what is basic biology behind how CRISPR and other gene editors work. There is a lot proposed both good and bad that is not really feasible in the foreseeable future because of basic biological limitations/barriers. Better understanding how these tools work and how the body responds to editing may help allay fears and make more a more intelligent conversation. Second, I think people should be aware of both the potential pros and cons of gene editing. It’s important that people can have intelligent conversations about what applications of gene editing are important to us as a population to proceed forward as responsibly as possible.

What do you think about Cas13a and Cas13b Crispr proteins which are capable of editing RNA instead of DNA? Do they hold any advantage over Cas9 proteins?


Hi, this is Kyle from the Doudna Lab. Great question! So others know, Cas13 is another CRISPR protein like Cas9, but it targets RNA instead of DNA. Another difference is that Cas9 cuts one specific site, and Cas13 has been shown to be non-specific RNA nuclease after it finds its target – this is somewhat debated though as it may be more specific in cells.

Anyway, they have an advantage in that Cas13 is the only single Cas protein (as in, not a multi-component complex) that can target RNA naturally. This means you could try to treat diseases or combat viruses, etc. without having to edit the genome. It could mean multiple injections though, it’s a work in progress and new to the field in general. There’s also an application for diagnostics I really like that came out of the Boston area (open access): https://www.ncbi.nlm.nih.gov/pubmed/28408723.

How is Cas9 capability to be fused with other proteins or specific domains? I'm not sure how to correctly express myself, but what I mean is, given the marvel of CRISPR/Cas9 is its specificity, could this be taken advantage off for another things? Like for example, attaching an expression factor domain and directing it to Cas9, having some kind of "jack-of-all-trades" kind of expression system that could be widely investigated (as it currently is) and used in several different systems as well as a cheap investigation tool.

Is there difficulties when it comes to attaching Cas9 to other proteins in a plasmid? Does too much of the protein surface have to be exposed/available for it to perform its function?


Hi, this is Dan. To begin to answer your question, fusion of Cas9 to other proteins is a powerful strategy being exploited in many areas, and the Doudna lab has been among the pioneers in this area (e.g., see http://pubmedcentralcanada.ca/pmcc/articles/PMC4900928/). Fusions at either end of the Cas9 protein are relatively easy, and the work cited here identified lots of possible internal spots where proteins might be fused. It’s also pretty easy to chemically conjugate additional elements to the protein. This is why we sometimes call Cas9 a “Swiss army knife” - lots of functionality can be added on.

Which Cas9 ortholog is currently being used? SpCas9?

Any plans on changing it to other like Cpf1 or FnCas9?

Or something like a combination to increase efficiency?


Hi, this is Kyle from the Doudna Lab. Yes, SpyCa9 (from Streptococcus pyogenes) is the most common. There’s another Cas9 from Staphylococccus aureus (SauCas9) that is also commonly used. FnCas9 isn’t used because it’s too big (FnCas9 > SpyCas9 > SauCas9), making delivery challenging. Cpf1 (or synonymously Cas12) is also being pursued, but not to the same extent. SpyCas9 is highly active, and discovered early, which is a big part of why it’s popular. We haven’t really come across other Cas9s that are significantly more active, at least to my knowledge.

Thank you so much for this! Dr. Doudna, and associates,

I am immensely interested in the potential for CRISPR’s use in agriculture in terms of biotechnology and economy. Do you think CRISPR has the ability to help farmers regain ownership of their seeds? What hurdles do you see in the way of biotechnology having an equalizing effect (especially in agriculture)?


Hi, this is Kyle from the Doudna Lab. This is a really interesting question that I hadn’t really thought about before. I suppose I would ask, what are the current barriers/challenges? Naturally, there is proprietary interest from companies to use gene editing tools to create new crops that they can sell for cultivation. Because CRISPR and other gene editing tools are really just a tool to improve the speed of development, it’s unclear (at least to me) how gene editing tools would have an impact. It’s possible that farmers or smaller interest groups could use gene editing tools to develop their own seeds, but this still requires a lot of time and effort. And while gene editing tools make it easier to develop new crops, you still need the expertise to know what genes to target, as well as the core lab skills to be able to do the editing. I hope this answers your question!

Hello, I am currently a first year medical student here in the United States. I am wondering medical specialties will see the biggest impact in the next 10 years?

Thank you so much for your time.


This is Carolyn Hutter from NHGRI. There will be a number of advances in genomics and medicine over the next 10 years that will likely impact various medical specialties. As you continue through your medical studies try to explore opportunities in different areas and find the field that best fits your expertise and your interests!

I have an admittedly very limited understanding of how CRISPR works, but since you're altering DNA, is it possible that there are some unseen side effects from the procedure that might not show themselves for many years? Could removing one genetic disorder cause the body to completely flip out and create some sort of unforseen super disease?

Again, very limited understanding but it's a very worrying thing being able to alter our genetic code, designer babies aside what other uses do you and your team think will be the most common?


Hello, Lu Wang here. Great questions. There are various ways to predict and prevent side effects. As for side effect of removing the genetic underpinning of a genetic disorder, a lot of studies have been done and will continue to understand how a particular genetic change confers a particular phenotype. These studies look at the roles of the many biological systems that the human genome encode, how they interact with each other, and at what developmental stages they are expressed. The knowledge obtained will inform development of therapies for different diseases, including ways to avoid side effects.

What’s the best candidate for delivery into the body? Or is it just a simple injection / ingestion?


Hi, this is Kyle from the Doudna Lab. There’s a few ways that protein/nucleic acid drugs are typically delivered, and vary based on application. Some common delivery vectors include: the adeno-associated virus (AAV) to infect cells without being pathogenic and encasing the biological molecules in an ionic lipid or nanoparticles. The main differences between them being how the cells uptake the drug, as well as what form it’s in (DNA, RNA, protein) and some of the drugs properties (acidity, charge, etc.). In general, biological drugs need to be delivered by injection; drugs that survive ingestion and are taken up in the small intestine are actually really hard to design and are general small molecules. Great question!

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