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Main Idea: Scientists predict that, provided the technology is relatively affordable, reliable and convenient to use, CRISPR may theoretically speed up the drug discovery process. Some of the world’s drug manufacturers are now integrating CRISPR technologies in their process of drug testing and discovery.

Arguments/Facts:
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Dialogue:
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Summary: In any genome editing experiment, editing performance can be affected by multiple factors and can seriously hamper your efforts. Editing performance basically represents the number of cells in your culture vessel that have been successfully edited. An editing efficiency of less than 100% is by no means a failure, but it does mean that the findings need to be closely viewed. The unedited cells inside your population can mask any subtle impact of your editing.
A basic distinction needs to be made in medical applications between improvements to body cells and modifications to germ-line cells such as egg and sperm cells. The next generations are inherited through changes to the germ line.

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11 Must-Know Advantages and Disadvantages of CRISPR

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Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns. Here is a discussion of the key advantages and disadvantages of CRISPR and the process involved with genome editing using CRISPR.

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Main Idea: Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns.

Arguments/Facts:
-Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns.
-Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns.
-Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns.
-Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns.

Dialogue:
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Summary: Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns. Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns.

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11 Must-Know Advantages and Disadvantages of CRISPR

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Genome editing is an immensely effective technique that can assist you with your study to address a multitude of concerns. Here is a discussion of the key advantages and disadvantages of CRISPR and the process involved with genome editing using CRISPR.

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Main Idea: Advantages of CRISPR Genome Engineering

Arguably, the most important advantage of CRISPR/Cas9 over other genome editing technologies is its simplicity and efficiency.

Since it can be applied directly in embryos, CRISPR/Cas9 reduces the time required to modify target genes compared to gene-targeting technologies based on embryonic stem (ES) cells. Improved bioinformatics tools — identifying the most appropriate sequences to design guide RNAs — and optimization of the experimental conditions enabled very robust procedures which guarantee the successful introduction of the desired mutation.

Arguments/Facts:
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Dialogue:
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Summary: CRISPR/Cas9 genome engineering technology has provided researchers with an invaluable tool to accelerate the generation of mouse models for biomedical in vivo research. The furious pace of CRISPR development, combined to its versatility and ease of use, have already left a mark in the field of molecular genetics. Its combination with established technologies will greatly expand opportunities for the generation of new and valuable genetically engineered mouse models for basic and translational research.

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Four years after the debut of CRISPR/Cas9 in mouse genetics, it is time to start drawing some conclusions on its performance, advantages, and limitations as a genome engineering technology¹,²,³.

Advantages of CRISPR Genome Engineering

Arguably, the most important advantages of CRISPR/Cas9 over other genome editing technologies is its simplicity and efficiency.

Since it can be applied directly in embryo, CRISPR/Cas9 reduces the time required to modify target genes compared to gene targeting technologies based on the use of embryonic stem (ES) cells. Improved bioinformatics tools - to identify the most appropriate sequences to design guide RNAs - and optimization of the experimental conditions enabled very robust procedures which guarantee successful introduction of the desired mutation.

Limitations of the CRISPR/Cas9 System

The molecular mechanism exploited to insert DNA fragments (e.g. cDNAs) is mediated by DNA repair machinery activated by the double strand break introduced by Cas9. Since the scope of the DNA repair system is not to integrate DNA fragments in the genome, targeted alleles often carry additional modifications, such as deletions, partial or multiple integrations of the targeting vector, and even duplications⁶,⁷,⁸.

Secondary unwanted mutational events at the target locus plague standard ES cell based projects as well, and researchers have learned how to avoid generating mice carrying passenger mutations. To identify the correct recombination events in ES cells, most laboratories use a combination of positive and negative selection procedures and validation procedures aimed at detecting additional mutations at the target site.

When performing the CRISPR/Cas9 procedure directly on embryos, on the other hand, it is impossible to select for the desired event, greatly limiting the possibility to identify the desired allele. Moreover, the mosaicism observed in founder mice generated using the CRISPR/Cas9 approach makes the identification of unwanted genomic modifications at the target site very challenging⁶,⁹,¹⁰.

CRISPR Performance in the Field

CRISPR/Cas9 in embryos works extremely well for the generation of simple alleles such as constitutive knockout and knock in of point mutations¹,⁶, but is not the technology of choice for the introduction of more complex modifications relying on homologous recombination over larger regions, such as introduction of paired loxP sites or cDNAs.

Although Taconic Biosciences and others have been successful in introducing complex modifications in the mouse genome using CRISPR/Cas9 in embryos⁶,¹¹, the complexity of the genome editing and validation procedures for these projects can result in increased timelines and costs, reducing or even canceling out the intrinsic advantages of the technology.

View the Taconic Biosciences' Webinar:

Future Applications

To harness the full potential of CRISPR/Cas9 to modify the mouse genome, an intriguing option is to take a step back and use it to genetically engineer ES cells rather than embryos.

The main advantage of using CRISPR/Cas9 in ES cells, compared to the traditional gene targeting approaches, is that Cas9-induced DNA damage increases the frequency of homologous recombination events by many order of magnitudes. As a consequence, there is no need to identify ES cell clones carrying the modified allele, which streamlines procedures for generating the targeting vector, ES cell screening, and validation.

By isolating clonal populations of cells, it is possible to avoid mosaicism and perform in-depth quality control procedures to verify that the modified allele does not carry any passenger mutations. Since no selection marker cassettes are present in the targeted ES cells, chimaeras derived from the validated clones can be directly used in rapid colony expansion to expedite the generation of mouse models.

Conclusions

CRISPR/Cas9 genome engineering technology has provided researchers with an invaluable tool to accelerate the generation of mouse models for biomedical in vivo research. The furious pace of CRISPR development, combined to its versatility and ease of use, have already left a mark in the field of molecular genetics. Its combination with established technologies will greatly expand opportunities for the generation of new and valuable genetically engineered mouse models for basic and translational research.

Download the Taconic Biosciences' White Paper:

References:

1. Wang, H., Yang, H., Shivalila, C.S., Dawlaty, M.M., Cheng, A.W., Zhang, F., and Jaenisch, R. One-step generation of mice carrying mutations in multiple genes by CRISPR/Cas-mediated genome engineering. Cell. (2013); 153: 910-918.

2. Hsu, Patrick D., Lander E., and Zhang F. (2014). Development and Applications of CRISPR-Cas9 for Genome Engineering. Cell, Volume 157, Issue 6, 1262 - 1278.

3. Tschaharganeh, D., Lowe, S., Garippa, R., & Livshits, G. (2016). Using CRISPR/Cas to study gene function and model disease in vivo. Febs Journal, 283(17), 3194-3203.

4. Yang H., Wang H., and Jaenisch R. (2014) Generating genetically modified mice using CRISPR/Cas-mediated genome engineering. Nature Protocols 9, 1956-1968.

5. Singh P, Schimenti J.C., Bolcun-Filas E. (2015) A Mouse Geneticist's Practical Guide to CRISPR Applications. Genetics January 1, vol. 199 no. 1 1-15.

8. Li J, Shou J, Guo Y, et al. (2015) Efficient inversions and duplications of mammalian regulatory DNA elements and gene clusters by CRISPR/Cas9. Journal of Molecular Cell Biology; 7(4):284-298.

9. Yen, S., Zhang, M., Deng, J., Usman, S., Smith, C., Parker-Thornburg, J., Swinton, P., Martin, J., & Behringer, R. (2014). Somatic mosaicism and allele complexity induced by CRISPR/Cas9 RNA injections in mouse zygotes. Developmental Biology, 393(1), 3-9.

10. Oliver D, Yuan S, McSwiggin H, Yan W (2015) Pervasive Genotypic Mosaicism in Founder Mice Derived from Genome Editing through Pronuclear Injection. PLoS ONE 10(6): e0129457.

11. Yang, H., Wang H., Shivalila C.S., Cheng A.W., Shi L., Jaenisch R. et al. (2013) One-Step Generation of Mice Carrying Reporter and Conditional Alleles by CRISPR/Cas-Mediated Genome Engineering. Cell, Volume 154, Issue 6, 1370 - 1379.

# data[].attributes.attachment_link.title
CRISPR Genome Engineering: Advantages and Limitations

# data[].attributes.attachment_link.description
Four years after the debut of CRISPR/Cas9 in mouse genetics, it is time to start drawing some conclusions on its performance, advantages, and limitations as a genome engineering technology1 , 2 , 3 . Arguably, the most important advantages of CRISPR/Cas9 over other genome editing technologies is its simplicity and efficiency.

# data[].attributes.body
Main Idea: The molecular mechanism exploited to insert DNA fragments (e.g. cDNAs) is mediated by DNA repair machinery activated by the double-strand break introduced by Cas9. Since the scope of the DNA repair system is not to integrate DNA fragments in the genome, targeted alleles often carry additional modifications, such as deletions, partial or multiple integrations of the targeting vector, and even duplications

Arguments/Facts:
-
-
-
-
Dialogue:
-
-
-
-
Summary: CRISPR/Cas9 in embryos works exceptionally well for the generation of simple alleles such as constitutive knockout and knock-in of point mutations, but is not the technology of choice for the introduction of more complex modifications relying on homologous recombination over more significant regions, such as the introduction of paired loxP sites or cDNAs.

Although Taconic Biosciences and others have been successful in introducing complex modifications in the mouse genome using CRISPR/Cas9 in embryos, the complexity of the genome editing and validation procedures for these projects can result in increased timelines and costs, reducing or even cancelling out the intrinsic advantages of the technology.

# data[].attributes.attachment_link.readable_text
Four years after the debut of CRISPR/Cas9 in mouse genetics, it is time to start drawing some conclusions on its performance, advantages, and limitations as a genome engineering technology¹,²,³.

Advantages of CRISPR Genome Engineering

Arguably, the most important advantages of CRISPR/Cas9 over other genome editing technologies is its simplicity and efficiency.

Since it can be applied directly in embryo, CRISPR/Cas9 reduces the time required to modify target genes compared to gene targeting technologies based on the use of embryonic stem (ES) cells. Improved bioinformatics tools - to identify the most appropriate sequences to design guide RNAs - and optimization of the experimental conditions enabled very robust procedures which guarantee successful introduction of the desired mutation.

Limitations of the CRISPR/Cas9 System

The molecular mechanism exploited to insert DNA fragments (e.g. cDNAs) is mediated by DNA repair machinery activated by the double strand break introduced by Cas9. Since the scope of the DNA repair system is not to integrate DNA fragments in the genome, targeted alleles often carry additional modifications, such as deletions, partial or multiple integrations of the targeting vector, and even duplications⁶,⁷,⁸.

Secondary unwanted mutational events at the target locus plague standard ES cell based projects as well, and researchers have learned how to avoid generating mice carrying passenger mutations. To identify the correct recombination events in ES cells, most laboratories use a combination of positive and negative selection procedures and validation procedures aimed at detecting additional mutations at the target site.

When performing the CRISPR/Cas9 procedure directly on embryos, on the other hand, it is impossible to select for the desired event, greatly limiting the possibility to identify the desired allele. Moreover, the mosaicism observed in founder mice generated using the CRISPR/Cas9 approach makes the identification of unwanted genomic modifications at the target site very challenging⁶,⁹,¹⁰.

CRISPR Performance in the Field

CRISPR/Cas9 in embryos works extremely well for the generation of simple alleles such as constitutive knockout and knock in of point mutations¹,⁶, but is not the technology of choice for the introduction of more complex modifications relying on homologous recombination over larger regions, such as introduction of paired loxP sites or cDNAs.

Although Taconic Biosciences and others have been successful in introducing complex modifications in the mouse genome using CRISPR/Cas9 in embryos⁶,¹¹, the complexity of the genome editing and validation procedures for these projects can result in increased timelines and costs, reducing or even canceling out the intrinsic advantages of the technology.

View the Taconic Biosciences' Webinar:

Future Applications

To harness the full potential of CRISPR/Cas9 to modify the mouse genome, an intriguing option is to take a step back and use it to genetically engineer ES cells rather than embryos.

The main advantage of using CRISPR/Cas9 in ES cells, compared to the traditional gene targeting approaches, is that Cas9-induced DNA damage increases the frequency of homologous recombination events by many order of magnitudes. As a consequence, there is no need to identify ES cell clones carrying the modified allele, which streamlines procedures for generating the targeting vector, ES cell screening, and validation.

By isolating clonal populations of cells, it is possible to avoid mosaicism and perform in-depth quality control procedures to verify that the modified allele does not carry any passenger mutations. Since no selection marker cassettes are present in the targeted ES cells, chimaeras derived from the validated clones can be directly used in rapid colony expansion to expedite the generation of mouse models.

Conclusions

CRISPR/Cas9 genome engineering technology has provided researchers with an invaluable tool to accelerate the generation of mouse models for biomedical in vivo research. The furious pace of CRISPR development, combined to its versatility and ease of use, have already left a mark in the field of molecular genetics. Its combination with established technologies will greatly expand opportunities for the generation of new and valuable genetically engineered mouse models for basic and translational research.

Download the Taconic Biosciences' White Paper:

References:

1. Wang, H., Yang, H., Shivalila, C.S., Dawlaty, M.M., Cheng, A.W., Zhang, F., and Jaenisch, R. One-step generation of mice carrying mutations in multiple genes by CRISPR/Cas-mediated genome engineering. Cell. (2013); 153: 910-918.

2. Hsu, Patrick D., Lander E., and Zhang F. (2014). Development and Applications of CRISPR-Cas9 for Genome Engineering. Cell, Volume 157, Issue 6, 1262 - 1278.

3. Tschaharganeh, D., Lowe, S., Garippa, R., & Livshits, G. (2016). Using CRISPR/Cas to study gene function and model disease in vivo. Febs Journal, 283(17), 3194-3203.

4. Yang H., Wang H., and Jaenisch R. (2014) Generating genetically modified mice using CRISPR/Cas-mediated genome engineering. Nature Protocols 9, 1956-1968.

5. Singh P, Schimenti J.C., Bolcun-Filas E. (2015) A Mouse Geneticist's Practical Guide to CRISPR Applications. Genetics January 1, vol. 199 no. 1 1-15.

8. Li J, Shou J, Guo Y, et al. (2015) Efficient inversions and duplications of mammalian regulatory DNA elements and gene clusters by CRISPR/Cas9. Journal of Molecular Cell Biology; 7(4):284-298.

9. Yen, S., Zhang, M., Deng, J., Usman, S., Smith, C., Parker-Thornburg, J., Swinton, P., Martin, J., & Behringer, R. (2014). Somatic mosaicism and allele complexity induced by CRISPR/Cas9 RNA injections in mouse zygotes. Developmental Biology, 393(1), 3-9.

10. Oliver D, Yuan S, McSwiggin H, Yan W (2015) Pervasive Genotypic Mosaicism in Founder Mice Derived from Genome Editing through Pronuclear Injection. PLoS ONE 10(6): e0129457.

11. Yang, H., Wang H., Shivalila C.S., Cheng A.W., Shi L., Jaenisch R. et al. (2013) One-Step Generation of Mice Carrying Reporter and Conditional Alleles by CRISPR/Cas-Mediated Genome Engineering. Cell, Volume 154, Issue 6, 1370 - 1379.

# data[].attributes.attachment_link.title
CRISPR Genome Engineering: Advantages and Limitations

# data[].attributes.attachment_link.description
Four years after the debut of CRISPR/Cas9 in mouse genetics, it is time to start drawing some conclusions on its performance, advantages, and limitations as a genome engineering technology1 , 2 , 3 . Arguably, the most important advantages of CRISPR/Cas9 over other genome editing technologies is its simplicity and efficiency.

# data[].attributes.body
Main Idea:
The gene editing technology CRISPR has prompted both predictions of medical breakthroughs. Yale Insights asked Dr. Greg Licholai, a biotech entrepreneur and a lecturer at Yale SOM, to explain CRISPR’s dangers.
Arguments/Facts:
-A series of studies have suggested that CRISPR may cause cells to lose their cancer-fighting ability, and that it may do more damage to genes than previously understood.
- “is sure to renew ethical concerns that some might try to design babies with certain traits, like greater intelligence or athleticism.”
- We think we know what we’re affecting if we manipulate one gene for that particular species. The truth is we probably don’t.
Dialogue:
- Are the dangers really that bad to not try using it?
-As we continue developing CRISPR, will we find more positive or negative effects?
Summary:
We think we know what we’re affecting if we just affect one particular species in an ecosystem. The truth is we probably don’t, and there’s always some surprises. “It seems gene editing is going to eliminate all disease,” he concluded. “Or kill every last one of us.”

Licholai G. (AUGUST 21, 2018) Is CRISPR worth the risk, Yale Insights. Retrieve from:https://insights.som.yale.edu/insights/is-crispr-worth-the-risk

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Greg Licholai

Lecturer, Yale School of Management; Chief Medical and Chief Innovation Officer, ICON plc

Recently, HBO's John Oliver opened a Last Week Tonight segment with a series of video clips about gene editing-some of them news reports promising amazing breakthroughs, others movie scenes depicting genetic engineering gone terribly wrong.

"It seems gene editing is going to eliminate all disease," he concluded. "Or kill every last one of us."

For decades, advances in genetic engineering have prompted both breathless predictions of a wondrous future and warnings of apocalypse. Both have gotten louder in the five years since the development of CRISPR, which allows for much more precise editing of genes than previously existing tools.

In 2017, for the first time, scientists used CRISPR to repair a genetic mutation-one that could cause a heart defect-in an embryo. Reporting the breakthrough, the New York Times said that "it raises the prospect that gene editing may one day protect babies from a variety of hereditary conditions." But in the article's third paragraph, the newspaper added that the successful experiment "is sure to renew ethical concerns that some might try to design babies with certain traits, like greater intelligence or athleticism."

In the last few months, more immediate concerns have arisen about CRISPR. A series of studies have suggested that CRISPR may cause cells to lose their cancer-fighting ability, and that it may do more damage to genes than previously understood. "It is important that anyone thinking of using this technology for gene therapy proceeds with caution, and looks very carefully to check for possible harmful effects," said researcher Allan Bradley in a release from the Wellcome Sanger Institute.

Do CRISPR's benefits outweigh the risks? Yale Insights asked Dr. Gregory Licholai, a biotech entrepreneur who serves as a lecturer at Yale SOM and chief medical and information officer at PRA Health Sciences, to explain the technology's potential and dangers.

What is CRISPR and how is it different from the methods that have been used to manipulate genetics before?
CRISPR is this fascinating, powerful technology. It's got a very clunky name. It's called Clustered Regularly-Interspaced Short Palindromic Repeats. Now what does that mean? The name actually refers to the way it interacts with DNA. It's a way to manipulate DNA, to edit DNA, in a way that is much more powerful than previous methods, much simpler, much cheaper. And the important part is it's exceptionally precise.

So as you probably know, our book of life is made of DNA. DNA itself is many millions of base-pairs, which is like a language. And within that language, there are certain regions which code for genes, and those genes are incredibly important because those genes go on to make up everything about us. There's 40,000 proteins that become outputs of those genes and they are involved in our health, our wellbeing, and any defect in those genes becomes problematic and causes disease.

What was previously attempted with gene editing was to manipulate genetic information in blocks, basically in big pieces. It's kind of like trying to edit a book by only being able to rip out a page at a time and transfer a page at a time, without really being able to control the actual words. The power of this technology: it literally comes down to the individual letters. So the precision is far better than anything that has happened before. The excitement in the scientific community is being able to go in and very precisely make changes in DNA of actual genes that you can actually turn off bad genes or you can potentially repair genes that have got mutations in them where the code is written incorrectly.

There had been previous gene-editing technologies, such as viral gene editing, gene replacement, and those have developed over several decades. One of the most fascinating things about CRISPR is how quickly everything is developed, so in less than 10 years since the initial descriptions and initial papers were written, this technology has just exploded. It's been less than five years since the initial patents were written, and since then at least a half-dozen companies have been formed, all of them are racing forward to try to get a leg up on each other to try to proceed with using CRISPR for various applications.
What are some of the applications, in the somewhat reasonable, predictable future?
"We think we're measuring exactly what changes we're doing to the genes, but there's always the possibility that our technology can't pick up on other changes."

There are three main applications for CRISPR. One is in manipulating genes to turn them on or off within people. Another is to create medications that can be infused, or in some cases, self-therapy-taking blood and certain cells out of a body, manipulating them with CRISPR, and then putting them back in. The third, which sometimes is overlooked, is actually in farming. Both farming with animals as well as farming with crops. And in fact, the application of CRISPR to foods has already been done. There are companies that have already been using CRISPR to create enhanced foods to resist bacteria or viruses. To create even better-tasting foods. And that's already being done.

Similarly, the application of CRISPR to animals has already been done. They actually call them CRISPR mice, and they are already being used in the research community. The ability to apply it to larger animals such as food animals is in the very near future.
Can you give an example of a disease that could be treated?
In terms of human health, we can divide that into two different categories. One is taking cells out of the body, manipulating them in the laboratory-either removing a defective gene or adding and enhancing an ability to do something by turning on a gene or fixing a gene-and then putting those cells back in the body. That's one category. The other category would be actually injecting something into the body which can edit people's genes so that within their own tissues those genes can either be turned on or off. And all of these have got some pretty profound complications and risks.

There are over 7,000 monogenetic diseases that we can trace back to a single gene that has a defect. Often those genes have multiple mutations. But at least a single gene has been identified. The most promising application of CRISPR would be to modify those monogenetic diseases. And those monogenetic diseases, they broadly fall into two categories, curiously named toxic gain of function and toxic loss of function.

Toxic loss of function is kind of intuitive. That means the gene has got a defect in it; the person loses the function of that protein and that causes the disease. So a well-known, well-studied example would be sickle-cell anemia. A single base-pair mutation actually causes a change in the structure of hemoglobin that then creates this unique sickle-cell shape for red blood cells.

An example of toxic gain of function is disease called transthyretin in which a mutation causes a clumping up of different proteins. And that leads to a disease called amyloidosis, where these proteins, which normally don't stick together, because of this kink in them due to the mutation, they become very sticky. They form aggregates and those aggregates can build up in various cells in the body. Sometimes the brain, sometimes the heart.

CRISPR could potentially be useful in either one of those, and in fact there are companies that are looking at those diseases, as well as a number of others. Other monogenetic diseases would be cystic fibrosis, beta thalassemia, glycogen storage disease, Behçet's disease, Fabry disease. Some of these are quite rare, like Fabry disease, but some are more common, like cystic fibrosis, which is the most common genetic disease in Caucasians.

So genetic diseases is one category. Another category is oncology. It's been well known now for some years that our own immune system has the ability to fight cancer cells and essentially dissolve micro-tumors. But cancer is a clever entity-it evades the body's internal immune system. So what that means is that the cancer becomes invisible to our immune cells, and that invisibility is due to certain proteins that are created as checkpoints to interfere with the immune system attacking ourselves. Cancers, essentially, mimic our own cells by taking advantage of these checkpoints.
What are the risks of this? Are the risks to the patient? Or to all of us?
So one of the applications of CRISPR would be to remove immune cells from the body, apply the CRISPR technology, and then turn off these checkpoints and put those immune cells back in the body with the hope that then those immune cells would clear the tumor away.

One of the biggest risks of CRISPR is what's called gene drive, or genetic drive. What that means is that because you're actually manipulating genes and those genes get incorporated into the genome, into the encyclopedia, basically, that sits within cells, potentially those genes can then be transferred on to other organisms. And once they're transferred on to other organisms, once they become part of the cycle, then those genes are in the environment.
Is there consensus on how to proceed?
That's probably the biggest fear of CRISPR. Humans manipulating the genetic code, and those manipulations get passed on generation to generation to generation. We think we know what we're doing, we think we're measuring exactly what changes we're doing to the genes, but there's always the possibility that either we miss something or our technology can't pick up on other changes that have been made that haven't been directed by us. And the fear then is that those changes lead to antibiotic resistance or other mutations that go out into the population and would be very difficult to control. Basically creating incurable diseases or other potential mutations that we wouldn't really have control over.

There's been discussion in the scientific community in the United States and globally about how to proceed with CRISPR. And particularly some very high-placed scientists, in the United States, for example, the former director of the National Institute of Health, have called for a self-imposed ethical moratorium on CRISPR until more is known. Not on all types of CRISPR research, but for certain types of CRISPR research. Particularly on these germline mutations that could potentially be passed on through generations. Some of the inventors of the patent-holders of CRISPR technologies who are now the inventors of the various companies in biotechnology, they've also imposed their own moratoria on working in germ lines until more is understood. So there are parts of the scientific community that are very concerned and are trying to be very thoughtful about how to proceed and how to proceed safely.
You mentioned that there's, in the U.S. at least, there's a moratorium on germline mutations. Do the kinds of treatments that you've talked about before, do those require the germline modification, or can they be done within the stricture of that moratorium?
In the United States, there have been some regulations against moving forward in areas that aren't safely understood. That doesn't exist in other parts of the world, in particular in China. So there's been several examples now of where China has leaped ahead of what's going on in Europe or the United States but, the concern is, without the kind of regulatory and ethical safeguards that are in place in other countries.

No, the treatment of most of those diseases, monogenetic diseases-things like cystic fibrosis, sickle-cell, beta thalassemia-those are not germline mutations. So theoretically, it would be safe to be able to treat those patients without the theoretical concern of affecting germ lines and affecting gene drive. The same thing with oncology. Theoretically you're just taking cells out. You're only treating immune cells and they're not going replicate. On the other hand, as soon as people start talking about stem cells and then manipulating stem cells and then reusing those, then those stem cells can potentially affect other cells that replicate. The risk is low, but there's definitely a risk there.
You mentioned that Chinese researchers are operating in different structure. Can you expand on that, on what regulations they have and what that means in terms of their competition with companies in the U.S.?
One of the other places that this is being actively worked on is, again, in animals. The idea would be to introduce mutations into, say, malaria-bearing mosquitoes, and let them in the wild and eradicate mosquitoes. Or eradicate certain types of invasive plants by introducing some kind of genetic manipulation that gets passed on and, again, you take out that one particular species. Again, it raises concerns. We think we know what we're affecting if we manipulate one gene for that particular species. We think we know what we're affecting if we just affect one particular species in an ecosystem. The truth is we probably don't, and there's always some surprises.

One of the dramatic examples happened in 2016. There had been a self-imposed moratorium in the United States and Europe to work on germ cells, germ lines. And that would include human embryos. Now, at the same time, reports came out of China that researchers had begun working on human embryos. Initially in 2015 and '16, the reports were that the experiments were negative, and at least the Chinese researchers had claimed that they were working with nonviable human embryos anyway. In the short time since then, in the year and a half since then, those experiments have been repeated, apparently with scientific success, whatever that means. But without the kind of self-imposed regulation or even organizationally imposed regulation that we would have by the NIH or the scientific community in the United States and Europe.

Another example is that researchers in China have actually proceeded to human clinical trials using CRISPR much faster than has been possible in the United States. Normally, the clinical trial process to test any new therapy requires several very well studied stages. The first stage is to test in animals to make sure that there's complete safety. Then it goes into very limited testing in human beings, just for safety, and then proceeds from there. Apparently in China, they took the animal data and they went right into therapeutic trials in human beings. And the most recent reports that are that somewhere between 80 and 100 people are already being tried, or already being tested using CRISPR.
How fast is this technology changing? Given that it's moved as far as it has in 10 years, where do you expect it to move in another 5 or 10 years?
We know that in China, they're using CRISPR for cancer therapy. That's the example where cells are taken out of the body, their immune cells are manipulated with CRISPR and then they're re-infused. It's too early to tell if it's successful or not. But there is a lot of concern that the regulatory authorities in China have been extremely permissive with allowing these technologies to move forward. And that has a lot of profound implications.

It's changing pretty fast. Just in the last few months, there's new developments in the field in CRISPR. Some is around competition, with new companies being formed. In fact, one of the original developers of CRISPR science that comes out of the Broad Institute at Harvard/MIT just set up a new company. Another scientific development is that there's now scientific evidence that perhaps in some people, they have naturally occurring immunity, if you will, to CRISPR. They have naturally occurring substances that actually will turn off any kind of CRISPR that's put into them.
Are there any other safety concerns with CRISPR?
All of these things are brand new, and they're all being sorted out by scientific community, by these biotech companies. So it is changing very quickly. And the other thing that's changing is the effect of this international competition. I don't think anybody could have predicted that other countries, and China in particular, would be so quick to embrace this technology and really leap forward ahead of everybody else.
How can we ensure that the field progresses in a safe way?
As with any new technology, there could be scientific bumps in the road. The safety concern is that in this field is moving so quickly and some researchers want to get into human clinical trials right away, even before the CRISPR technology paradigm has been fully validated. There are some recent reports in the scientific literature that this approach is not as precise as advertised. In other words, we think we are editing one letter of the book of life, but it actually entire pages might be getting altered in unintended areas. The long-term danger is unintended changes to the genome of an organism that go on and get carried through to the next generation. The safety risk is unknown changes in genes that get transferred to the population that could have no consequence or could be harmful.
Interviewed and edited by Ben Mattison.
The drug development process is tightly regulated across the world. In the United States the FDA closely monitors safety of any investigational drug, and all CRISPR drugs intended to go into people would have to meet the same rigorous testing standards. The same situation exists for Europe and the rest of the world where regulatory authorities largely work in harmony. However, there are exceptions, as with some of the human embryo testing that has been reported in China. We should make sure that the level of international scientific regulation and cooperation continues so the scientific developments can continue but also ensure safety.

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Dr. Greg Licholai, a biotech entrepreneur and a lecturer at Yale SOM, explains the gene-editing technology's potential and its dangers.

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Main Idea:
CRISPR's Pros
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Summary:
CRISPR has developed into one of the most powerful and effective gene-editing tools available today. CRISPR, unlike other genetic engineering tools, is cheap, simple to use, and precise. but what are its pros?
Cancer Therapeutics: CRISPR can be used to create new gene therapies for cancer treatment. Using CRISPR, scientists can genetically modify cells to locate and kill cancer cells.

Curing genetic diseases: CRISPR has the ability to eliminate genes that cause genetic diseases such as diabetes and immune disorders.

Drug research: Scientists believe that because CRISPR is relatively cheap, precise, and simple to use, it could potentially speed up the drug discovery process. Some of the world's pharmaceutical companies are already incorporating CRISPR technology into their drug research and development processes, and are quite happy with the results.

Pest resilient crops: Genetic modification could resolve agriculture's pest and nutrition challenges, particularly in the context of climate change and rapid population growth.

Sara Gillan. (September 2, 2018). Benefits and Ethical Concerns of CRISPR - Pros and Cons. Retrieved from: https://explorebiotech.com/crispr-pros-and-cons/

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CRISPR has become one of the most powerful gene-editing tools today. Unlike other genetic engineering tools, CRISPR is cheap, relatively easy to use and precise. Undoubtedly, its popularity has surged amongst scientists in the biotechnology industry.

Pros and Cons of CRISPR

While the benefits of CRISPR range from curing genetic conditions to organ transplants, ethicists fear its use in promoting desired traits rather than life-saving traits such as intelligence that could have long-term implications.

Benefits of CRISPR [Pros]

CRISPR technology has wide-ranging applications in various industries. Some of the benefits are discussed below.

Cancer Therapeutics: New immunotherapies can be developed using CRISPR to treat cancer. Scientists can genetically modify T-cells using CRISPR to locate and kill cancer cells.

Curing Genetic Diseases: CRISPR technology can eliminate the genes that cause genetic diseases such as diabetes, cystic fibrosis. Given that the scientific community has already mapped many genes that cause genetic disease, CRISPR could be used to cure faulty genes that cause genetic diseases.

Drug Research: Scientists are predicting that CRISPR could potentially speed up the drug discovery process, given the technology is relatively cheap, precise, and simple to use. Some of the drug makers in the world are already incorporating CRISPR technology into their drug research and discovery phase.

Pest Resilient Crops: According to Jennifer Doudna, CRISPR pioneer, genome editing could address pest and nutrition challenges facing agriculture, especially in light of climate change and rapid population growth. Earlier in 2018, USDA decided not to regulate about a dozen crops edited with CRISPR as GMOs partially due to the accuracy of the technology.

Ethical Concerns of CRISPR [Cons]

Changes to the Germ-line Cells: Genetically modifications to human embryos and reproductive cells such as eggs and sperms are called germline editing. Changes to the germline can be passed to the next generation. If the desired traits such as intelligence and strong muscles can be passed to the next generation, then how far are we from the designer babies?

Many countries have an outright ban on germline editing, whereas some countries do not have clear guidance. The United States and the United Kingdom are testing the water by considering exemptions in the case of monogenic hereditary disorders such as muscular dystrophy, cystic fibrosis, and Huntington's disease.

Bioweapons: The former U.S. director of national intelligence James Clapper listed "genome editing" among six threats in the section on weapons of mass destruction in 2016. Compared to other genetic engineering tools, CRISPR technology is relatively inexpensive and simple, which could make it attractive to terrorist organizations. The technology can be used to genetically modify bacteria or viruses to wage biological attacks against humans.

DARPA, US's secretive Defense Advanced Research Projects Agency, announced to invest US$65 million in 2017 over four years in seven teams that will investigate ways to make gene editing technologies safer and targeted. The program relates to both intentional and unintended consequences of gene editing technologies. Three main objectives of the program are

to develop processes that allow greater control of genome editing in living systems

to develop countermeasures that protect genome integrity in populations

and to investigate a way to remove engineered genes from living systems

Also Read - Pros and Cons of Having a Designer Baby

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Benefits and Ethical Concerns of CRISPR - Pros and Cons

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CRISPR has become one of the most powerful gene-editing tools today. Unlike other genetic engineering tools, CRISPR is cheap, relatively easy to use and precise. Undoubtedly, its popularity has surged amongst scientists in the biotechnology industry.

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Main Idea: CRISPR is a technology that can be used to edit genes and, as such, will likely change the world.

The essence of CRISPR is simple: it’s a way of finding a specific bit of DNA inside a cell. After that, the next step in CRISPR gene editing is usually to alter that piece of DNA. However, CRISPR has also been adapted to do other things too, such as turning genes on or off without altering their sequence.

Arguments/Facts:
-CRISPR technology also has the potential to transform medicine, enabling us to not only treat but also prevent many diseases.
-CRISPR is being used for all kinds of other purposes too, from fingerprinting cells and logging what happens inside them to directing evolution and creating gene drives.

-The key to CRISPR is the many flavours of “Cas” proteins found in bacteria, which they help defend against viruses.
-When the CRISPR Cas9 protein is added to a cell along with a piece of guide RNA, the Cas9 protein hooks up with the guide RNA and then moves along the strands of DNA until it finds and binds to a 20-DNA-letter long sequence that matches part of the guide RNA sequence.

Dialogue:
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Summary:
So why do we call it CRISPR? Cas proteins are used by bacteria to destroy viral DNA. They add bits of viral DNA to their own genome to guide the Cas proteins, and the odd patterns of these bits of DNA are what gave CRISPR its name: clustered regularly interspaced short palindromic repeats.

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CRISPR is a technology that can be used to edit genes and, as such, will likely change the world.

The essence of CRISPR is simple: it's a way of finding a specific bit of DNA inside a cell. After that, the next step in CRISPR gene editing is usually to alter that piece of DNA. However, CRISPR has also been adapted to do other things too, such as turning genes on or off without altering their sequence.

There were ways to edit the genomes of some plants and animals before the CRISPR method was unveiled in 2012 but it took years and cost hundreds of thousands of dollars. CRISPR has made it cheap and easy.

CRISPR is already widely used for scientific research, and in the not too distant future many of the plants and animals in our farms, gardens or homes may have been altered with CRISPR. In fact, some people already are eating CRISPRed food.

CRISPR technology also has the potential to transform medicine, enabling us to not only treat but also prevent many diseases. We may even decide to use it to change the genomes of our children. An attempt to do this in China has been condemned as premature and unethical, but some think it could benefit children in the future.

CRISPR is being used for all kinds of other purposes too, from fingerprinting cells and logging what happens inside them to directing evolution and creating gene drives.

The key to CRISPR is the many flavours of "Cas" proteins found in bacteria, where they help defend against viruses . The Cas9 protein is the most widely used by scientists. This protein can easily be programmed to find and bind to almost any desired target sequence, simply by giving it a piece of RNA to guide it in its search.

When the CRISPR Cas9 protein is added to a cell along with a piece of guide RNA, the Cas9 protein hooks up with the guide RNA and then moves along the strands of DNA until it finds and binds to a 20-DNA-letter long sequence that matches part of the guide RNA sequence. That's impressive, given that the DNA packed into each of our cells has six billion letters and is two metres long.

What happens next can vary. The standard Cas9 protein cuts the DNA at the target. When the cut is repaired, mutations are introduced that usually disable a gene. This is by far the most common use of CRISPR. It's called genome editing - or gene editing - but usually the results are not as precise as that term implies.

CRISPR can also be used to make precise changes such as replacing faulty genes - true genome editing - but this is far more difficult.

Customised Cas proteins have been created that do not cut DNA or alter it in any way, but merely turn genes on or off : CRISPRa and CRISPRi respectively. Yet others, called base editors, change one letter of the DNA code to another .

So why do we call it CRISPR? Cas proteins are used by bacteria to destroy viral DNA. They add bits of viral DNA to their own genome to guide the Cas proteins, and the odd patterns of these bits of DNA are what gave CRISPR its name: clustered regularly interspaced short palindromic repeats. Michael Le Page

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CRISPR is a technology that can be used to edit genes and, as such, will likely change the world. The essence of CRISPR is simple: it's a way of finding a specific bit of DNA inside a cell. After that, the next step in CRISPR gene editing is usually to alter that piece of DNA.

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Main Idea:
Compared to other tools used for genetic engineering, CRISPR is precise, cheap, easy to use and powerful.
Arguments/Facts:
-Scientists still haven't found a cure for HIV. That could change with CRISPR. In 2017, a team of Chinese researchers successfully increased resistance to HIV with a mice by replicating a mutation of a gene that effectively prevents the virus from entering cells.
-CRISPR could bring back extinguished species. Harvard geneticist George Church claimed that his team was two years away from developing embryos of an elephant-mammoth.
-CRISPR could also create new healthier food, as the genetic modification could also be used for plants. They have already developed a method to edit the genes that determine tomato size, branching and shape of the plant for a greater harvest.
Dialogue:
- Is it really possible to achieve all this in a short period of time ? For it to be implied as earlier as possible.
Summary:
Current scientific advancements show that CRISPR is not only a versatile technology, it's proving to be precise and increasingly safe to use. Scientists are still in the earliest stages of figuring out how we can use CRISPR to change the world for the better. Of course, the power to alter DNA brings with it many ethical questions and concerns.We can have a with engineered food, eliminate genetic disorders, or bring extinct animal species back to life.

Tangermann V. (JANUARY 30, 2012) A CRISPR Future: Five Ways Gene Editing Will Transform Our World, Futurism. Retrieved from: https://futurism.com/crispr-genetic-engineering-change-world

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A CRISPR Future

Over the past few years, CRISPR has been making headlines. Experts predict that this gene editing technology will transform our planet, revolutionizing the societies we live in and the organisms we live alongside. Compared to other tools used for genetic engineering, CRISPR (also known by its more technical name, CRISPR-Cas9) is precise, cheap, easy to use, and remarkably powerful.

Discovered in the early 1990s, and first used in biochemical experiments seven years later, CRISPR has rapidly become the most popular gene editing tool among researchers in fields such as human biology, agriculture, and microbiology.

Scientists are still in the earliest stages of figuring out how we can use CRISPR to change the world for the better. Of course, the power to alter DNA - the source code of life itself - brings with it many ethical questions and concerns. With this in mind, here are some of the most exciting uses for this revolutionary technique, and the hurdles that might slow or prevent these technologies from reaching their full potential.

1. CRISPR Could Correct The Genetic Errors That Cause Disease

Hypertrophic cardiomyopathy (HCM) is a heart condition that affects roughly 1 in every 500 people worldwide. Its symptoms are painful and often deadly. Mutations in a number of dominant genes cause the heart tissues to stiffen, which can lead to chest pain, weakness, and, in severe cases, sudden cardiac arrest. Thanks to recent medical advances, the average life expectancy of someone with HCM is close to that of the general population, but the condition can lead to life-threatening situations if left untreated.

But someday, we may be able to use gene editing to cure this disease once and for all.

In summer 2017, scientists at the Oregon Health and Science University used CRISPR to delete one of these defective genes ina number of viablehuman embryos. The results were promising: Of the 54 embryos that were injected with the CRISPR-Cas9 machinery 18 hours after fertilization, 36 did not show any mutations in the gene (practically no chance of developing the disease) and 13 were partially free of mutations (with a 50 percent chance of inheriting HCM).

Off-target genetic mutations and mosaics (only some cells adopt the changes, meaning that a fraction of people would inherit the mutation) were only present in 13 of the 54 embryos.

To further reduce the chance that only some cells would be changed, the researchers carried out another experiment in which they corrected the same gene in embryos directly at the time of fertilization. They found that only one was a mosaic - an impressive result, making the study substantially more efficient than similar studies (a 2015 clinical trial in China was not able to eliminate the possibility of mosaics).

"By using this technique, it's possible to reduce the burden of this heritable disease on the family and eventually the human population," Shoukhrat Mitalipov, lead author of the study and a researcher at the Oregon Health and Science University, said in a press release. Catching the mutation at in the earliest stages of embryonic development would either reduce or eliminate the need for treatment later in a patient's life.

While some stem-cell scientists questioned if these dozens of mutations were actually fixed, the research helped scientists better understand CRISPR's efficacy. Moreover, one of the co-authors of the HCM study has already expressed interest in applying the same technique to specific gene mutations (BRCA1 and 2) that increase the risk of breast cancer.

That said, scientists know that changing the genetic code in human embryos could have unintended consequences. What if CRISPR makes changes in the wrong place and unintentionally alters or removes healthy genes? How could that affect the patient?

In some parts of the world, such as China, scientists are free to experiment on human embryos largely unfettered. But this is not the case in the United States, Canada, or the United Kingdom.

In the U.S., the Food and Drug Administration (FDA) currently does not consider using public funding for studies that alter genes that can be inherited (the embryos in the Oregon researchers' study were not destined for implantation and the study was funded privately). In Canada, editing genes that can be passed down to future generations is a criminal offense with a maximum penalty of ten years in jail. Meanwhile, in the U.K., the Human Fertilization and Embryology Authority gave a team of scientists in London the license to edit genes in human embryos in 2016. Scientists in the U.K. are hoping this will establish a precedent, and keep the door open for future applications.

2. CRISPR Can Eliminate the Microbes That Cause Disease

Though treatments for HIV have turned the infection from a virulent killer to a livable health condition, scientists still haven't found a cure. That could change with CRISPR. In 2017, a team of Chinese researchers successfully increased resistance to HIV in mice by replicating a mutation of a gene that effectively prevents the virus from entering cells. For now, scientists are only conducting these experiments in animals, but there's reason to think the same methods could work in humans. The mutation that encourages HIV resistance naturally occurs in a small percentage of people. By using CRISPR to introduce the mutation to human stem cells that lack it, researchers could substantially bolster HIV resistance in humans in the future.

Another gene-editing trial in China is due to begin in July 2018 and will attempt to use CRISPR to disrupt the genes of the human papillomavirus (HPV) - a virus that has been shown to cause cervical cancer tumor growth - effectively destroying it.

In a slightly different approach, scientists in North Carolina used CRISPR to engineer bacteriophages, a type of virus that infects and duplicates itself inside a bacterium, to kill harmful bacteria. Since the 1920s, phages have been used in clinical trials to treat bacterial infections. But harvesting them from nature proved difficult, a lack of understanding at the time made results unpredictable, and the growing antibiotics market made their use unpopular.

Even today, some researchers fear that flooding the body with a large volume of phages may trigger immune reactions or cause antibiotic-resistant bacteria to also become resistant to phages that would otherwise eliminate them.

Still, while human trials have yet to begin, researchers are optimistic about using CRISPR to engineer phages, since they are a proven, safe method to treat bacterial infections. In fact, in a 2017 trial, researchers managed to save the lives of mice infected with antibiotic-resistant infections using CRISPR-engineered bacteriophages.

3. CRISPR Could Resurrect Species

In February 2017, Harvard geneticist George Church made a surprising announcement before the annual meeting of the American Association for the Advancement of Science. He claimed his team was just two years away from developing an embryo for an elephant-mammoth hybrid.

Church hopes that bringing back the woolly mammoth could keep global warming in check. "[Mammoths] keep the tundra from thawing by punching through snow and allowing cold air to come in," Church told the New Scientist.

Church and his team are hoping to use CRISPR to combine genetic material from the Asian elephant (an endangered species that could potentially be saved) and the woolly mammoth. Samples of the latter were harvested from DNA recovered from frozen hairballs found in Siberia. By adding the mammoth's genome to that of the Asian elephant, the resulting organism would have characteristics common to the woolly mammoth, such as long fur, which would serve as insulation in cold climates. The end goal is to implant this hybrid embryo into an elephant and bring it to full term, according to the New Scientist.

The work is promising, but many experts think that Church's timeline is a bit too optimistic. Even if researchers had a functional hybrid embryo, growing it inside an artificial womb as Church suggests will be yet another hurdle to overcome. Granted, Church's lab is already capable of growing a mouse embryo inside an artificial womb for half of its gestation period, about 10 days. But that doesn't guarantee that we'll witness the birth of a woolly mammoth hybrid in the next couple of years.

4. CRISPR Could Create New, Healthier Foods

CRISPR gene editing has proven to be promising in the field of agricultural research. Scientists from Cold Spring Harbor Laboratory in New York used the tool to increase the yield of tomato plants. The lab developed a method to edit the genes that determine tomato size, branching architecture and, ultimately, shape of the plant for a greater harvest.

"Each trait can now be controlled in the way a dimmer switch controls a light bulb," said lead researcher and Cold Spring Harbor Laboratory professor Zachary Lippman in a press release. "We can now work with the native DNA and enhance what nature has provided, which we believe can help break yield barriers."

High-yield crops to feed a hungry world are just the beginning - scientists hope CRISPR could also help shed the stigma surrounding genetically modified organisms (GMOs). In 2016, agriculture technology company DuPont Pioneer announced a new variety of CRISPR-edited corn that, because of how researchers altered its genes, is technically not a GMO.

The distinction between GMOs and gene-edited crops is fairly simple. Traditional GMOs are made by inserting foreign DNA sequences into a crop's genome, transmitting traits or properties to future organisms. Gene editing is more precise than that: it makes precise alterations to genes in specific locations of the native genome, often knocking out certain genes or changing their location, all without introducing foreign DNA.

While GMOs have been contentious among consumers, companies like DuPont Pioneer are hoping that gene-edited foods will be better received. In the decades that GMOs have been available in the American market, scientists have detected no health risks, though even the biggest proponents of GMOs admit that scientists still don't know all of the long-term risks. The same goes for crops edited by CRISPR. Of course, scientists will continue to test and evaluate these crops to ensure there are no unexpected side effects, but this early work is remarkably promising. Eventually, CRISPR-edited crops will likely flood global markets.

DuPont Pioneer hopes to bring its "waxy" gene-edited corn to market in the U.S. by 2020. A gene-edited mushroom has already bypassed U.S. Department of Agriculture regulation, as it doesn't contain foreign DNA from viruses or bacteria, becoming the first CRISPR-edited organism to be green-lit. Sweden has already declared it will categorize and regulate CRISPR-edited crops differently than GMOs, but the European Commission has yet to choose its stance.

5. CRISPR Could Eradicate The Planet's Most Dangerous Pest

Gene-editing techniques like CRISPR could directly combat infectious diseases, but some researchers have decided to slow the spread of disease by eliminating its means of transmission. Scientists at the University of California, Riverside developed a kind of mosquito that is uniquely susceptible to changes made with CRISPR, giving scientists unprecedented control over the traits that the organism passes to its offspring. The result: yellow, three-eyed, wingless mosquitoes, created by altering genes responsible for eye, wing, and cuticle development.

By disrupting target genes in multiple locations of the mosquito's genes, the team is testing a "gene drive" system to spread these inhibiting properties. Gene drives are a way to essentially ensure that a genetic trait will be inherited. By impairing the mosquito's flight and vision, the Riverside team is hoping to greatly reduce its ability to spread dangerous infectious diseases among humans, such as dengue and yellow fever.

Other researchers are getting rid of mosquito populations by interfering with how they reproduce. At the Imperial College London in 2016, a team of researchers used CRISPR to target female reproduction of the type of mosquito that carries malaria through a gene drive system that influenced female-sterility traits into being more likely to be inherited.

But interfering with mosquito populations could have unforeseen consequences. Eliminating a species, even one that doesn't appear to have much ecological value, could upset the careful balance of ecosystems. That could have disastrous consequences, such as disrupting the food web or increasing the risk that diseases like malaria could be spread by different species entirely.

CRISPR Tomorrow

Current scientific advancements show that CRISPR is not only an extremely versatile technology, it's proving to be precise and increasingly safe to use. But a lot of progress still has to be made; we are only beginning to see the full potential of genome-editing tools like CRISPR-Cas9.

Technological and ethical hurdles still stand between us and a future in which we feed the planet with engineered food, eliminate genetic disorders, or bring extinct animal species back to life. But we are well on our way.

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A CRISPR future: five ways gene editing will transform our world

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Over the past few years, CRISPR has been making headlines. Experts predict that this gene editing technology will transform our planet, revolutionizing the societies we live in and the organisms we live alongside. Compared to other tools used for genetic engineering, CRISPR (also known by its more technical name, CRISPR-Cas9) is precise, cheap, easy to use, and remarkably powerful.

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Main Idea:
Because CRISPR gene editing enables genome editing considerably easier and faster than ever before, it has swiftly gained favor as a research tool. Additionally, the technology is being studied as a potential cure for a variety of hereditary illnesses.

Arguments/Facts:
-CRISPR could correct genetic errors that cause diseases. Some hereditarian diseases could become ended if in some time we may be able to use gene editing to cure this diseases once and for all.
-Genome editing technologies have been developed at a rapid pace over the past decade. Within the past five years, a system has been developed based on fundamental research of bacterial systems’ immunity to viral infections.

-Current advances in genome editing tools allow us not only to target monogenic diseases but also polygenic diseases, such as cancer and diabetes.
Dialogue:
-What will possibly CRISPR achieve in the next decade?
Summary:
CRISPR-Cas9 is a gene-editing tool that only requires a custom guide RNA molecule to find its target. Tony Ho, Head of Research and Development at CRISPR Therapeutics, shares his views on the potential of the technology. The CRISPR system can modify DNA with greater precision than existing technologies. Manufacturing is considered a challenge for the field, but it is not a main limitation.

Warneck-silvestrin L. (MARCH 3, 2021) The Promises of CRISPR Genome Editing in Biomedicine, LABIOTECH.eu retieved from:https://www.labiotech.eu/interview/crispr-therapeutics-genome-editing/

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Tony Ho, Head of Research and Development at CRISPR Therapeutics, offers his insights into the advantages of CRISPR gene editing over other technologies and what the future holds for the genome editing field.
For decades, gene editing required engineering DNA-cutting enzymes, such as zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), for every specific genetic modification. The advent of CRISPR-Cas9, a gene-editing tool that only requires a custom guide RNA molecule to find its target, revolutionized the field.

CRISPR gene editing has quickly risen in popularity as a research tool because it makes genome editing much simpler and faster than ever before. The technology is also being researched as a potential treatment for a wide range of genetic diseases.

That is the case of CRISPR Therapeutics, a company that is running clinical trials testing the technology in two blood conditions as well as in cancer. Tony Ho, who leads research efforts at the company, shares his views on the potential of the technology and his expectations for the future of gene editing.

How have genome editing tools advanced in recent years?

Genome editing technologies have been developed at a rapid pace over the past decade. Within the past five years, a novel system has been developed based on fundamental research of bacterial systems' immunity to viral infections.

CRISPR-Cas9 is based on RNA-guided targeting and is much simpler and faster than earlier methods. The ease of design, together with the remarkable specificity, efficiency, and versatility of the CRISPR-Cas9 system have revolutionized the field of genome editing and enabled rapid development of novel therapies.

What are the benefits of using genome editing tools for therapeutic purposes?

The advent of programmable nucleases has accelerated the development of gene editing from concept to clinic. Current advances in genome editing tools allow us not only to target monogenic diseases but also polygenic diseases, such as cancer and diabetes. Genomic editing also provides a degree of precision not previously possible by other therapeutic approaches through its ability to target individual cell types.

It also allows us to build on synthetic biology [techniques] that confer novel abilities to the cells. With these abilities, we can develop potentially curative therapies that may not be possible using traditional modalities.

What are the advantages of CRISPR over other genome editing tools?

The CRISPR-Cas9 system can modify DNA with greater precision than existing technologies. An advantage the CRISPR-Cas9 system offers over other mutagenic techniques, like ZFN and TALEN, is its relative simplicity and versatility.

Additionally, CRISPR-Cas9 has the potential of simultaneous multiple loci editing, making the technology easier, more efficient, and more scalable compared to other genome editing technologies. The programmability of the CRISPR-Cas9 system allows rapid prototyping of different therapeutic approaches, which leads to faster development cycles compared to other genome editing approaches.

What are the main challenges and limitations of genome editing tools?

While manufacturing is considered a challenge for the field, it is not a fundamental limitation. Companies are committed to overcoming challenges in order to bring medicines to patients at scale.

Additionally, it's important to push the boundaries of what genome editing tools can offer to medicine. For example, it's critical to move the field beyond therapeutic areas of rare diseases and hematologic malignancies, and into common diseases, like cancer and diabetes, where there is the potential to continue to see a dramatic impact and benefit to patients.

How do you expect the genome editing field to develop in the future?

We expect to see increased enthusiasm for the gene editing field, particularly around CRISPR-Cas9, as it is a powerful platform that is facile and scalable. We believe the next generation of cell therapies will be driven by increased edits. We have published papers at oncology conferences that demonstrate that CRISPR-Cas9 can generate perfectly viable and enhanced CAR-T cells with 10 or more edits.

What do you expect CRISPR will achieve in the next decade?

CRISPR-Cas9 is a revolutionary tool that can change the future of medicine. At CRISPR Therapeutics, we have five programs in the clinic, led by our two hematology programs, where we have demonstrated that a one-time CRISPR-based treatment can result in a functional cure for patients with sickle cell disease and beta-thalassemia.

We also have three ongoing clinical trials for allogeneic CAR-T therapies targeting B-cell malignancies, multiple myeloma, and renal cell carcinoma. Excitingly, we showed positive topline data in patients with relapsed or refractory B-cell malignancies, which demonstrate the potential of CRISPR gene editing for the treatment of cancers. We believe a number of cancers could be cured with CRISPR-based treatments, and we could replace a number of diseased or defective organs with regenerative medicine.

There is a world full of possibilities for CRISPR applications and I am very hopeful about what the future can bring.

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The Promises of CRISPR Genome Editing in Biomedicine

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Tony Ho, Head of Research and Development at CRISPR Therapeutics, offers his insights into the advantages of CRISPR gene editing over other technologies and what the future holds for the genome editing field. For decades, gene editing required engineering DNA-cutting enzymes, such as zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), for every specific genetic modification.

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Main Idea:
What is DNA, and how does CRSPR work?
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Summary:
What is DNA?

DNA consists of two strands, twisted into a double helix and held together by a simple pairing rule. A pairs with T, and G pairs with C. Our genes shape who we are as individuals and as a species.

Genes have a significant impact on health, and thanks to advances in DNA sequencing, scientists have identified thousands of genes that influence our risk of disease. Researchers need ways to control genes in order to understand how they work.

How does CRISPR work?

The CRISPR method is based on a natural system used by bacteria to protect themselves from infection by viruses. When the bacterium detects the presence of a virus in the DNA, it produces two types of short RNA, one of which contains a sequence that matches that of the invading virus. These two RNAs form a complex with a protein called Cas9 (Cas9 is a nuclease, a type of enzyme that can cut DNA). When the matching sequence, known as a guide for the RNA, finds its target within the viral genome, Cas9 cuts the target of the DNA, disabling the virus. This can be done not just in a test tube, but also within the nucleus of a living cell. Once inside the nucleus, the resulting complex will lock onto a short sequence known as the PAM. The Cas9 will unzip the DNA and match it to its target RNA. If the match is complete, the Cas9 will use two tiny molecular scissors to cut the DNA. When this happens, the cell tries to repair the cut, but the repair process is an error, leading to mutations that can disable the gene.

CRISPR can also be used to replace mutant genes with healthy copies, allowing for the creation of transgenic animals and studying complex human diseases. It has many applications in basic research, drug development, agriculture and, eventually, treating genetic diseases.

McGovern Institute. (November 5, 2014). Genome Editing with CRISPR-Cas9. Retrieved from: https://www.youtube.com/watch?v=2pp17E4E-O8&t=4s

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Main Idea:
CRISPR's Ethical problems
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Summary:
CRISPR has developed into one of the most powerful and effective gene-editing tools available today. CRISPR, unlike other genetic engineering tools, is cheap, simple to use, and precise. but what are its cons?

Changes to the Germ-line Cells: Germline editing refers to genetic modifications made to human embryos and reproductive cells such as eggs and sperms. Changes in the germline can be passed down to future generations. How far are we from artificial wombs if characteristics like intelligence and strong muscles can be passed down to the next generation

Many countries have severe restrictions on germline editing, while others lack clear guidance. Since muscular dystrophy, cystic fibrosis,Hhuntintong's diesease may increase there percentage

Bioweapons: In 2016, the United States' director of national intelligence, James Clapper, listed "genome editing" as one of six threats in the section on weapons of mass destruction. CRISPR technology is relatively inexpensive and simple in comparison to other genetic engineering tools, which may attract to terrorist. The technology has the potential to be used to genetically modify bacteria or viruses in order to plan biological attacks on humans.

DARPA, the US Defense Advanced Research Projects Agency, is looking into ways to make gene editing safer. The program is concerned with both the intended and unintended consequences of gene editing technologies.

Sara Gillan. (September 2, 2018). Benefits and Ethical Concerns of CRISPR - Pros and Cons. Retrieved from: https://explorebiotech.com/crispr-pros-and-cons/

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CRISPR has become one of the most powerful gene-editing tools today. Unlike other genetic engineering tools, CRISPR is cheap, relatively easy to use and precise. Undoubtedly, its popularity has surged amongst scientists in the biotechnology industry.

Pros and Cons of CRISPR

While the benefits of CRISPR range from curing genetic conditions to organ transplants, ethicists fear its use in promoting desired traits rather than life-saving traits such as intelligence that could have long-term implications.

Benefits of CRISPR [Pros]

CRISPR technology has wide-ranging applications in various industries. Some of the benefits are discussed below.

Cancer Therapeutics: New immunotherapies can be developed using CRISPR to treat cancer. Scientists can genetically modify T-cells using CRISPR to locate and kill cancer cells.

Curing Genetic Diseases: CRISPR technology can eliminate the genes that cause genetic diseases such as diabetes, cystic fibrosis. Given that the scientific community has already mapped many genes that cause genetic disease, CRISPR could be used to cure faulty genes that cause genetic diseases.

Drug Research: Scientists are predicting that CRISPR could potentially speed up the drug discovery process, given the technology is relatively cheap, precise, and simple to use. Some of the drug makers in the world are already incorporating CRISPR technology into their drug research and discovery phase.

Pest Resilient Crops: According to Jennifer Doudna, CRISPR pioneer, genome editing could address pest and nutrition challenges facing agriculture, especially in light of climate change and rapid population growth. Earlier in 2018, USDA decided not to regulate about a dozen crops edited with CRISPR as GMOs partially due to the accuracy of the technology.

Ethical Concerns of CRISPR [Cons]

Changes to the Germ-line Cells: Genetically modifications to human embryos and reproductive cells such as eggs and sperms are called germline editing. Changes to the germline can be passed to the next generation. If the desired traits such as intelligence and strong muscles can be passed to the next generation, then how far are we from the designer babies?

Many countries have an outright ban on germline editing, whereas some countries do not have clear guidance. The United States and the United Kingdom are testing the water by considering exemptions in the case of monogenic hereditary disorders such as muscular dystrophy, cystic fibrosis, and Huntington's disease.

Bioweapons: The former U.S. director of national intelligence James Clapper listed "genome editing" among six threats in the section on weapons of mass destruction in 2016. Compared to other genetic engineering tools, CRISPR technology is relatively inexpensive and simple, which could make it attractive to terrorist organizations. The technology can be used to genetically modify bacteria or viruses to wage biological attacks against humans.

DARPA, US's secretive Defense Advanced Research Projects Agency, announced to invest US$65 million in 2017 over four years in seven teams that will investigate ways to make gene editing technologies safer and targeted. The program relates to both intentional and unintended consequences of gene editing technologies. Three main objectives of the program are

to develop processes that allow greater control of genome editing in living systems

to develop countermeasures that protect genome integrity in populations

and to investigate a way to remove engineered genes from living systems

Also Read - Pros and Cons of Having a Designer Baby

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Benefits and Ethical Concerns of CRISPR - Pros and Cons

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CRISPR has become one of the most powerful gene-editing tools today. Unlike other genetic engineering tools, CRISPR is cheap, relatively easy to use and precise. Undoubtedly, its popularity has surged amongst scientists in the biotechnology industry.

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Main Idea:
The revolution of DNA
Arguments/Facts:
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Dialogue:
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Summary:
CRISPR puts a completely new capability in the hands of humanity. For the first time, scientists have discovered that they can alter, delete, and reorganize the DNA of almost any living organism, including our species. This genetic editing technology has transformed biology over the last three years. Using animal models, researchers from all over the world have already used CRISPR technology to correct significant genetic flaws. No new discovery in the last century has carried as much promise as CRISPR is bringing to the world.

Michael Specter. (October, 07, 2020). La revolución del ADN. Retrieved from: https://www.nationalgeographic.com.es/ciencia/grandes-reportajes/revolucion-del-adn_10762

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Por primera vez podemos alterar, borrar o reaorganizar el ADN de cualquier organismo vivo. La pregunta es: ¿debemos hacerlo?

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Main Idea:
CRISPR is very easy to use.

Arguments/Facts:
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Dialogue:
-  Are there major consequences?
- Will everybody be able to access this science?
- in a long run will this be affective?

Summary:
CRISPR-Cas9 (or CRISPR) has provided scientists with a powerful method for making precise changes to DNA in bacteria, plants, animals and even human cells. Scientists may be able to use the technique to engineer crop failure crops, develop better drugs, cure genetic disorders, eradicate infectious diseases, and much more. Any biologist will likely tell you that CRISPR is revolutionary. It is inexpensive and efficient, and in many cases, it outperforms older methods of genetic modification.

Annie Sneed. (November, 2, 2017). Mail-order CRISPR kits Allow Absolutely Anyone to Hack DNA. Retrieved from: https://www.scientificamerican.com/article/mail-order-crispr-kits-allow-absolutely-anyone-to-hack-dna/

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"We aren't going to get sick, are we?" my roommate Brett asked me. He cringed as I knelt down and stuffed a plate of E. coli bacteria-which came as part of the DIY CRISPR-Cas9 kit I bought online-into our fridge next to cartons of eggs, strawberry jam, bottles of beer and a block of cheese.

"No, we won't. The label says 'non-pathogenic,'" I replied, trying to sound assuring. But honestly, I had no clue what I was doing. I nudged all the food up against the fridge wall, and left a two-inch border around the plate of living cells-a no man's land between the microbes and our dinner. A couple inches probably would not stop the bugs, but I figured it couldn't hurt.

CRISPR-Cas9 (or CRISPR, for short) has given scientists a powerful way to make precise changes to DNA-in microbes, plants, mice, dogs and even in human cells. The technique may help researchers engineer drought-resistance crops, develop better drugs, cure genetic disorders, eradicate infectious diseases and much more. Ask any biologist, and they'll likely tell you that CRISPR is revolutionary. It's cheap and effective, and in many cases, it works much better than older methods for making genetic modifications. Biologists will also tell you that CRISPR is very easy to use. But what does "easy to use" mean?

I am not a DIY scientist, much less a professional scientist. You won't find me swabbing my cheek cells for DNA or tinkering with yeast in a lab on the weekend. But I wondered: Is CRISPR so easy thateven amateurs like me can make meaningful contributions to science? And also, does this new technique make gene editing so accessible that we need to worry about DIY scientists cooking up pandemic viruses in their basements? If you Google 'DIY CRISPR,' stories such as "What Happens If Someone Uses this DIY Gene Hacking Kit to Make Mutant Bacteria?" pop up.

I attempted to find answers to all these questions myself, starting with the plate of bacteria in the kitchen of my San Francisco apartment.

CUT AND SPLICE

CRISPR stands for "clustered regularly interspaced short palindromic repeats." The CRISPR system is made up of two components: a protein called Cas9 and a guide RNA,a string of nucleic acid molecules with a certain genetic code. Put them together, and they create a tool you can use to tweak an organism's genome. To do this, CRISPR searches the organism's DNA for a certain sequence-specifically, the one encoded by the guide RNA, which holds the inverse sequence of your target DNA. "Cas9 opens up the DNA, it separates the strands of the double helix in a very small area, and allows the guide RNA to pair with one of the strands," explains Dana Carroll, a professor of biochemistry at the University of Utah. "If it is a good match, cutting occurs. If it is not a good match, Cas9 and [the] guide RNA fall off and try again somewhere else." When it finds the right sequence, the Cas9 protein slices the DNA at that precise spot.

At this point, if you leave the cell alone, it will usually mend CRISPR's cut-but it will occasionally also make a mistake in the repair process, breaking a gene or other parts of the genome. Since CRISPR repeatedly goes back and slices the DNA again after the cell mends it, the gene eventually breaks, or, in technical terms, gets knocked out. And, if you add new DNA, the cell may incorporate it while fixing the cut. This means you can insert DNA where you want to in the genome-you just need to know the organism's genetic sequence of your desired target area.

Scientists originally discovered this sophisticated system in archaea and bacteria, which deploy CRISPR to chop up invading viruses. But a few years ago, researchers figured out how to repurpose CRISPR to run inpretty much any living thingthey want. And now it's made genetic engineering easier than ever before.

For my own experiment, everything I needed came in a small cardboard box-an assortment of bottles, tubes, plates, powders and liquids (plus E. coli). I ordered my kit for $130 from the crowd-funding site Indiegogo as part of a campaign created by Bay Area biohacker Josiah Zayner. Zayner has a PhD in molecular biophysics and spent two years as a research fellow at NASA. He ran the crowdfunding campaign out of his apartment, and by the end of it, he had raised over $70,000 and sold 250 DIY CRISPR kits-one of which now sat on my kitchen table. Zayner has now soldover a thousand kits, largely on his company's website, The Odin.

The idea behind the kit experiment is quite simple. The goal: modify the E. coli so that it can grow on an antibiotic called streptomycin, which normally kills bacteria. With materials and instructions from the kit, I will introduce CRISPR into the bacteria cells, and use it to rewrite a tiny part of their DNA, creating genetically altered cells that happily thrive on streptomycin. In the end, CRISPR will track down and then change only a single base pair (which are the building blocks for DNA)out of the 4.6 million base pairs in the E. coli genome. It will swap out the chemical compound adenine for cytosine-or, in terms of the genetic alphabet, an "A" for a "C." Because of that tiny code change, my bacteria cells will make the amino acid lysine instead of another one, threonine. If my gene editing succeeds, this will stop streptomycin from interfering with the E. coli.

On a Monday afternoon in May, I donned latex gloves and spread newspaper over the dinner table. I grabbed three small plastic tubes from the freezer, picked up a pipette-a hand-held instrument, used in labs to measure out liquids-from my DIY kit, and started adding the CRISPR ingredients to tubes of E. coli.

I put in the Cas9 protein and guide RNA,which came as liquids in small, plastic test tubes,to my bacteria cells. Then I dipped my pipette into a small tube of DNA and tried to suck up 10 microliters. Nothing came out. I squinted at the tiny drop of clear liquid, and realized it had frozen solid. I had no clue why. Uh oh, I hope that's not a problem. Would it harm my experiment? I had absolutely no idea, so I just waited for the DNA solution to thaw and then squirted it into the bacteria tube. After several more steps, I spread my CRISPR'd bacteria onto three plastic plates and put them in my laundry room. The instructions said to wait 24-48 hours, then check for small white dots of bacteria. If I saw dots, CRISPR had done its job of splicing in the streptomycin-resistance gene. If not ... well, failure is also part of the scientific process.

I had no problem conducting the experiment- CRISPR is easy, I concluded. I basically just measured, scraped and stirred a bunch of ingredients, occasionally cooling them or heating them up. But for all the godlike powers that I imagined CRISPR gave me, I actually had little say over what I did to my bacteria. Everything was predetermined, with instructions laid out for me like steps in a cookbook: "Add 100 microliters Transformation mix to a new centrifuge tube," "Incubate this tube in the fridge for 30 minutes," and so on. Ultimately, I had made zero decisions. Of course, I could have designed a custom-made CRISPR experiment-but it would have taken more time, more materials, more money, and a lot more knowledge than I currently had.

I inspected my bacteria 48 hours later. Crossing my fingers, I lifted the lid on the first plate. No white dots. Then the second plate: nothing. My stomach sank with disappointment. Then I gently raised the lid off the third plate, and saw ... something. The plate had two faint milky white circles. Had CRISPR worked? Maybe. But then why did one plate have white spots, but not the other plates? I'd followed the same steps for each of them. Maybe my mind was playing tricks on me. Or perhaps I had contaminated the third plate. If only I could show my plates to someone who knew how to interpret them. Like a scientist. Unfortunately, there was no one to ask in my kitchen.

OPEN TO EVERYONE

A few weeks later, I drove 40 miles south of San Francisco to meet a DIY scientist named Johan Sosa, who knows way more about CRISPR than I do. We met at BioCurious, a community laboratory in Sunnyvale where he works most weekends and some evenings. Located in Santa Clara, BioCurious is a co-working space outfitted with science equipment and shared by "scientists, technologists, entrepreneurs, and amateurs who believe that innovations in biology should be accessible, affordable, and open to everyone," according to its Web site.The lab is funded by donations and members-Sosa is one of itsseveral dozenmembers.

At six foot, five inches, Sosa towers over most people. "I'm probably the tallest DIY biologist," he jokes. He laughs easily, which offsets his height to lend him a gentle, laid-back manner. He is 40 years old, his dark hair flecked with silver. Originally from Sri Lanka, Sosa came to the U.S. for college at 15 years old to study computer science, and he's worked for Bank of America and IBM as a computer security specialist and software engineer. He now has a day job in computer security-but he spends most of his free time at BioCurious. "You could say I have no life," he chuckles, "This is my biggest hobby." He has learned everything he knows about science (both theory and lab techniques) from others at BioCurious, by reading science papers, watching YouTube videos, attending lectures, and also through trial-and-error in his own research.

Sosa is one of a few DIY scientists at BioCurious using CRISPR. He first read about the technique in 2012, from one of biochemist Jennifer Doudna'spapers in the journal Science. Doudna, a professor at University of California, Berkeley, is one of the pioneers of CRISPR. "I didn't think it was that big of a deal, because I knew there were already other ways of modifying DNA," he recalls, "But I did think, 'This is something I could do.'" He started experimenting with CRISPR in 2013.

On a muggy, overcast afternoon, I followed Sosa inside BioCurious. We strolled through a lobby and into a large windowless room. It had big cabinets crammed with bottles of liquid, racks of latex gloves, a giant bio-hood, microwave and fridge. Microscopes, scales, centrifuges and a bunch of other well-worn science equipment lay scattered across lab desks. A calm thrum of buzzing machinery filled the room, and test tubes shook quietly in an incubator nearby. Johan walked around the room, searching for a thermometer. "One thing about a DIY lab is that you leave something somewhere, and it always ends up somewhere else," he told me.

I had joined Sosa at BioCurious so I could learn more about what CRISPR means for DIY scientists, and also to do a (hopefully) more successful experiment, with his help. We decided on a very basic goal: we would use the powerful editing tool to cut DNA he had already extracted from yeast cells. This task is easier than the one I tried in my kitchen, because you don't need to get CRISPR inside cells in order to slice the DNA. Professional scientists might use such a method as an intermediate step, such as when they need to cut and paste DNA together to make a gene as part of a bigger research project. "That's a type of experiment everyone does every day," explains Charles Gersbach, a professor of biomedical engineering at Duke University-though he notes that traditionally, researchers have used a type of protein called a restriction enzyme, not CRISPR, to do this.

Sosa and I pulled on latex gloves and carefully pipetted liquids into tubes to make our guide RNA from scratch-we first synthesized DNA strands with a specific sequence we wanted, used that as a template for the RNA, then destroyed the DNA and isolated the guide RNA from our test tube mixture. Later, we put the RNA in a new test tube, along with the other materials needed to make CRISPR work in this experiment: protein buffer, bovine serum albumin (a protein isolated from cows),water. Sosa sucked up the yeast DNA in his pipette. Without warning, the plastic needle-nose tip fell off into the tube of DNA. Someone, he told me, had donated the tips to their lab, but they weren't the correct size. "I guess you got the full DIY experience," he smiled, and pushed the plastic tip back onto the pipette. Then he picked up the Cas9 protein. "Here's the world-famous Cas9," he said, and handed it to me. I added it to our test tube.

Until CRISPR, DIY scientists didn't have an easy, cheap or reliable way to precisely edit DNA. Many of them couldn't afford the pricey and imperfect tools that professional scientists used for gene editing at the time. "Before CRISPR, there was TALENS [transcription activator-like effector nucleases] and zinc finger nucleases-older technologies that were not as precise or reliable," explains Sosa. "They were out of the budget and the time constraints of DIY scientists." Sosa says that if a DIY-er used those other technologies, it might cost him or her thousands of dollars to do a genetic engineering experiment. But with CRISPR, it's vastly more affordable, especially if you want to attempt an experiment more than once. "With TALENS, you try it once and fail," says Sosa. "With CRISPR, you can try it multiple times. That alone is a big deal."

This means that CRISPR gives DIY-ers a whole new way to do science. So far, Sosa and his lab mates have tried out CRISPR in a number of ways: cutting yeast genomes, slicing DNA inside E. coli cells, and attempting to modify the CRISPR system by shrinking it or attaching other molecules to it. Sosa has goals for his CRISPR research. "I want to understand how a cell really functions, and what are all the little things that happen in it," he explains. "And when something goes wrong [such as in diseases], how to fix it or make it do what I want."

After several hours, Sosa and I checked to see if CRISPR had cut our yeast DNA. We dyed our DNA-CRISPR mixture blue and ran it through an electrically charged gel, which separates bigger DNA pieces from smaller ones. Tiny channels in the gel run from one charged end to the other, and the sliced DNA strands are pulled through them towards the positively charged side. If our experiment succeeded, we should see two blue bands for the short CRISPR-cut DNA strands in one spot, and one blue band for a longer, uncut piece of DNA (our control) in another location.

Sosa carried the gel into the bathroom, where we turned off the lights and looked at it under blue light. I held my breath while I inspected the gel for markings. One light-blue band gleamed in the dark-the control-and another single band lit up the spot where we should have seen our CRISPR'd DNA. "I don't know what happened, but it doesn't look right," Sosa said, "I don't think it worked."

I left the lab feeling defeated, and headed back to San Francisco. Sosa texted me a few minutes later.

Hey, I figured out what happened. There was no DNA to start with, he wrote.

What happened? I texted back.

I think the DNA had either degraded or gotten too diluted, he wrote.

Even if we had got all the other parts (RNA, proteins, etc.) working, it didn't matter. We hadn't given CRISPR any DNA to cut. My second attempt at CRISPR had utterly failed.

BETTER, FASTER, CHEAPER

My own frustrating struggles with CRISPR aside, I wanted to see what professional biologists are doing with CRISPR, so I visited the lab of Nipam Patel at the University of California, Berkeley. After a quick tour of the lab, I sat down and stared into the microscope at a small, writhing marine creature: Parhyale hawaiensis, commonly called a beach hopper. At one centimeter long, Parhyale looks puny-you'd step on it at the beach without even noticing. But under the microscope, this female hopper resembled a giant translucent shrimp with many powerful, kicking legs. Parhyale is the star of this lab. "We're looking at how you develop an individual body," explains Erin Jarvis, a PhD student in Patel's lab, "And also how you build a body form over evolutionary time." And they're using CRISPR to do it.

With CRISPR, these researchers knock out so-called Hox genes in Parhyale. Hox genes are found in all animals, including humans, and they control the development of their body plans. Among other things, they determine what appendages-such as swimming legs, claws and antennae-grown on which section of the body.Knock out a certain Hox gene with CRISPR and Parhyale will grow forward-walking legs where it should have jumping legs, for example.

Parhyale has nine Hox genes, and Patel's team has knocked out seven of them. The researchers also have plans to add completely new genes to Parhyale using CRISPR-they've already done it once, by inserting a gene that codes for green fluorescent proteins, which allowed the researchers to visualize where a specific Hox gene is expressed in Parhyale."From an evolutionary perspective, this [gives] us insight into how body plans evolve between species," when comparing Parhyale to, for example, the well-studied fruit fly, Drosophila, explains Patel. "We believe that such evolutionary patterns help us understand the general mechanisms by which evolution creates animal diversity.... What we learn improves our knowledge about the function of these genes in other animals, including humans."

CRISPR has transformed how Patel and his colleagues do their research. His lab has looked at Parhyale for about 20 yearsnow. Before CRISPR they used another technique to knock out genes that required a lot more money, and even then, it wasn't very efficient. It cost them about $900 to knock out a single genein a group of Parhyale embryoswith their other method. The technique, called "RNA interference," silences expression of a gene-it doesn't genetically knock it out as CRISPR does. The problem was, sometimes the method didn't work at all.

Now it costs them less than $100 to knock out a gene. "Suddenly, with CRISPR, you don't have to decide, 'Which one gene do I want to put all my resources into?'" Jarvis says, "You can try a lot of different genes." And with CRISPR, they're able to break genes in up to 75 percent of Parhyale embryos, versus a maximum 25 percent success rate with the old technique. Even better, they now have the ability to mutate several genes at once with CRISPR, which means they can now see how genes interact. When the researchers had tried to mutate multiple genes with their old technique, it rarely worked. (Though Patel notes that the older RNA technique is still very useful for certain applications).

Their research takes less time with CRISPR, too-in a study Patel's lab published in Current Biology in 2015, they knocked out six Hox genes in about a year. Before that, they had already spent yearstrying to break a specific Hox gene with their old method, but were never able to do it. "Everything just goes faster," says Patel, a professor of genetics, genomics and development. "CRISPR-Cas9 is an incredibly elegant system, and it's very easy to control." It also makes it simpler to study more exotic creatures (beyond the standard flies and mice), such as animals like Parhyale or butterflies. "It's always been hard to work with a new organism," says Jarvis, "CRISPR is awesome because suddenly, you don't have to spend decades developing a model." As long as you have the sequence of the gene you want to target, you're set.

Patel's lab is hardly the only one capitalizing on CRISPR-scientists around the world are exploring all sorts of different uses for the gene editing tool, like wiping out malaria-spreading mosquitoes, finding new ways to treat cancer, or engineering disease-resistant crops. In July, researchers announced they had successfully edited the genome of viable human embryos with CRISPR; the technique allowed them to fix a disease-causing mutation in the embryos' DNA (though some are now skeptical of the researchers' results). Just a few weeks later, scientists in Massachusetts reported they had made a significant advance towards pig-to-human organ transplants. They used CRISPR to inactivate 25 viruses intrinsic to pigs' genomes, overcoming a big obstacle in making porcine transplants safe for humans.

PLAYING GOD

I had reached the end of my CRISPR experiment-so what had I learned? First, I found out it was not completely crazy for my roommate to wonder whether a DIY CRISPR kit in our fridge would make us sick. This year, German authorities restricted imports of the Odin DIY CRISPR bacteria kit after the Bavarian Health and Food Safety Authority tested two kits and found them to contain potentially pathogenic bacteria. But even theEuropean Center for Disease Prevention and Control concluded that there was little to worry about-that "the risk of infection by the contaminating strains in the kit is low for the users ... assuming that they are healthy people." (Zayner declined to comment on the record about the incident, but he publicly posted a response on Twitter, where he criticized the methodology used by the Bavarian agency and denied wrongdoing by his company. The kits are still available for purchase online through The Odin.)

As for my bigger question-could untrained DIY-ers actually achieve scientific breakthroughs?-I asked academic researchers what they thought. Dana Carroll, for his part, believes amateurs could make meaningful discoveries. "In the professional science community, people keep coming up with new ways to use this technology-people are really only limited by their imagination," he explains. "It's possible that people working in their garages or their kitchens will come up with a novel application or a solution to a problem that professionals just haven't gotten around to." And Carroll says it would be easy for a DIY-er to share any discoveries with researchers, by attending their talks or simply by contacting them through their Web sites. Yet he notes that the DIY community faces limitations, because amateur scientists likely would lack the necessary resources. "It's unlikely they will bring a major application all the way to fruition," he says, "But they could certainly get started on something."

Finally, what about the nightmare scenario: Is CRISPR so easy to use that we need to worry about biohackers-either accidentally or intentionally-creating dangerous pathogens? Carroll and others think that the danger of putting CRISPR in the hands of the average person is relatively low. "People have imagined scenarios where scientists could use CRISPR to generate a virulent pathogen, " he says. "How big is the risk? It's not zero, but it's fairly small." Gersbach agrees. "Right now, it's difficult to imagine how it'd be dangerous in a real way," he explains, "If you want to do harm, there are much easier and simpler ways than using this highly sophisticated genetic editing technique."

Back in Patel's lab, Jarvis replaced the squirming female beach hopper under my microscope with a tiny Parhyale embryo. Jarvis told me she knocked out a Hox gene called Abd-B in this one-the embryo will grow jumping legs where it should have swimming legs, and forward walking legs instead of anchor legs. At this point, it just looked like an opaque ball of goo to me.

Next to me, another grad student examined a fragment of a brown and goldbutterfly wing-Patel's lab is also knocking out butterfly genes with CRISPR to see how they build wing color. "An old grad student used to joke that we were genetically modifying the wings to make the Mona Lisa," Jarvis told me. I laughed and glanced back under the microscope. A puff of my breath suddenly struck the Parhyale embryo. It danced wildly around the petri dish, like a grain of sand caught in a windstorm.

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Mail-Order CRISPR Kits Allow Absolutely Anyone to Hack DNA

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"We aren't going to get sick, are we?" my roommate Brett asked me. He cringed as I knelt down and stuffed a plate of E. coli bacteria-which came as part of the DIY CRISPR-Cas9 kit I bought online-into our fridge next to cartons of eggs, strawberry jam, bottles of beer and a block of cheese.

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Main Idea:
CRISPR-Cas9

Arguments/Facts:
- In 2017 a group of researchers in the university of Japan showed how CRISPR looks like when in action, manipulating genes.
- CRISPR was originally discovered in 1987, but they didn't understand the biological significance of DNA.
-In medicine, CRISPR has been tested in early-stage cancer therapy and treatment for inherited disorders that cause blindness.
-In 2018 He Jiankui edited human embryos and created the world's first gene-edited babies, he was sent 3 years to prison.

Dialogue:
- Should the use of CRISPR be regulated as we advance in discovering it?
- Could it fail in modifying DNA in a living human and cause other problems?
-Is there a lot more to discover about the negative effects?

Summary:
CRISPR-Cas9 is an enzyme that acts as molecular scissors being able to cut strands of DNA. This technology was adapted from the natural world of bacteria and archea. It ca edit genomes and allows scientists to easily alter DNA sequences and modify gene function. However, the technology also raises ethical concerns.

Lanese N. (MAY 13, 2022) What is CRISPR? Livescience. Retrieved from:https://www.livescience.com/58790-crispr-explained.html

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CRISPR is a powerful tool for editing genomes, meaning it allows researchers to easily alter DNA sequences and modify gene function. It has many potential applications, including correcting genetic defects, treating and preventing the spread of diseases, and improving the growth and resilience of crops. However, despite its promise, the technology also raises ethical concerns.

In popular usage, "CRISPR" (pronounced "crisper") is shorthand for "CRISPR-Cas9." CRISPRs are specialized stretches of , and the protein Cas9 - where Cas stands for "CRISPR-associated" - is an that acts like a pair of molecular scissors, capable of cutting strands of DNA.

CRISPR technology was adapted from the natural defense mechanisms of and archaea, a domain of relatively simple single-celled microorganisms. These organisms use CRISPR-derived , a molecular cousin to DNA, and various Cas proteins to foil attacks by . To foil attacks, the organisms chop up the DNA of viruses and then stow bits of that DNA in their own genome, to be used as a weapon against the foreign invaders should those viruses attack again.

When the components of CRISPR are transferred into other, more complex, organisms, those components can then manipulate genes, a process called "gene editing." No one really knew what this process looked like until 2017, when a team of researchers led by Mikihiro Shibata of Kanazawa University in Japan and Hiroshi Nishimasu of the University of Tokyo showed, for the very first time, what it looks like when a CRISPR is in action, Live Science previously reported.

Related: Genetics by the numbers: 10 tantalizing tales

Key components of CRISPR

CRISPRs: The term "CRISPR" stands for "clusters of regularly interspaced short palindromic repeats" and describes a region of DNA made up of short, repeated sequences with so-called "spacers" sandwiched between each repeat.

When we talk about repeats in the genetic code, we're talking about the ordering of rungs within the spiral ladder of a DNA molecule. Each rung contains two chemical bases bound together: A base called adenine (A) links up to another called thymine (T), and the base guanine (G) pairs with cytosine (C).

In a CRISPR region, these bases appear in the same order several times, and in these repeated segments, they form what's known as "palindromic" sequences, according to the Max Planck Institute. A palindrome, like the word "racecar," reads the same forward as it does backward; similarly, in a palindromic sequence, bases on one side of the DNA ladder match those on the opposing side when you read them in opposite directions.

For example, a super simple palindromic sequence might look like this:

Short palindromic repeats appear throughout CRISPR regions of DNA, with each repeat bookended by "spacers." Bacteria swipe such spacers from viruses that have attacked them, meaning they incorporate a bit of viral DNA into their own genome. These spacers serve as a bank of memories, which enables the bacteria to recognize the viruses if they should ever attack again. You can also think of spacers like "Wanted" posters, providing a snapshot of the bad guys so they can be easily spotted and brought to justice.

Related: Going viral: 6 new findings about viruses

Rodolphe Barrangou and a team of researchers at Danisco, a food ingredients company, first demonstrated this process experimentally. In a 2007 paper published in the journal Science, the researchers used Streptococcus thermophilus bacteria, which are commonly found in yogurt and other dairy cultures, as their model, according to the Joint Genome Institute, part of the U.S. Department of Energy. They observed that after a viral attack, the bacteria incorporated new spacers into their CRISPR regions. Moreover, the DNA sequence of these spacers was identical to parts of the virus genome.

The team also manipulated the spacers by removing them and inserting new viral DNA sequences in their place. In this way, the researchers were able to alter the bacteria's resistance to an attack by a specific virus, confirming CRISPRs' role in regulating bacterial immunity.

CRISPR RNA (crRNA): CRISPR regions of DNA act as a kind of bank of viral memories; but for that stored information to be useful elsewhere in the cell, it must be copied, or "transcribed," into a different genetic molecule called RNA. Unlike DNA sequences, which remain lodged inside the DNA molecule, this CRISPR RNA (crRNA) can roam about the cell and team up with proteins - namely the molecular scissors that snip viruses to bits.

RNA also differs from DNA in that it's only one strand, rather than two, meaning it looks like just a half of a ladder. To build an RNA molecule, one part of the CRISPR acts as a template and proteins called polymerases swoop in to construct an RNA molecule that is "complementary" to that template, meaning the two strands' bases would fit together like puzzle pieces. For example, a G in the DNA molecule would get transcribed as a C in the RNA.

Each snippet of CRISPR RNA contains a copy of a repeat and a spacer from a CRISPR region of DNA, according to a 2014 review by Jennifer Doudna and Emmanuelle Charpentier, published in the journal Science. The crRNA interacts with the Cas9 protein and another kind of RNA, called "trans-activating crRNA" or tracrRNA, in order to help bacteria fend off viruses.

Cas9: The Cas9 protein is an enzyme that cuts foreign DNA. The protein binds to crRNA and tracrRNA, which together guide Cas9 to a target site on the virus's DNA strand where the protein will make its cut. The target DNA that the Cas9 will cut through is complementary to a 20-nucleotide stretch of the crRNA, where a "nucleotide" is a building block of DNA that contains one base.

Using two separate regions or "domains" on its structure, Cas9 cuts both strands of the DNA double helix, making what is known as a "double-stranded break," according to the 2014 Science article.

There is a built-in safety mechanism that ensures that Cas9 doesn't just cut just anywhere in a genome. Short DNA sequences known as "protospacer adjacent motifs," or PAMs, serve as tags and sit adjacent to the target DNA sequence. If the Cas9 complex doesn't see a PAM next to its target DNA sequence, it won't cut. This is one possible reason that Cas9 doesn't ever attack the CRISPR region in bacteria, according to a 2014 review published in Nature Biotechnology.

How CRISPR works as a genome-editing tool

Genomes encode a series of messages and instructions within their DNA sequences, and genome editing involves changing those sequences, thereby changing the messages they contain. This can be done by inserting a cut or break in the DNA and tricking a cell's natural DNA repair mechanisms into introducing the targeted changes. CRISPR-Cas9 provides a means to do so.

In 2012, two pivotal research papers were published in the journals Science and , describing how the bacterial CRISPR-Cas9 could be used to chop up any DNA, not just that of viruses. In this way, the natural CRISPR system could be transformed into a simple, programmable genome-editing tool.

To direct Cas9 to snip a specific region of DNA, scientists can simply change the sequence of the crRNA, which binds to a complementary sequence in the target DNA, the studies concluded.In the 2012 Science article, Martin Jinek and his colleagues further simplified the system by fusing crRNA and tracrRNA to create a single "guide RNA." Thus, genome editing requires only two components: a guide RNA and the Cas9 protein.

"Operationally, you design a stretch of 20 base pairs that match a gene that you want to edit," and from there, one can figure out what the complementary crRNA sequence would be, George Church, a professor of genetics at Harvard Medical School, told Live Science. Church emphasized the importance of making sure that the nucleotide sequence is found only in the target gene and nowhere else in the genome.

"Then the RNA plus the protein [Cas9] will cut - like a pair of scissors - the DNA at that site, and ideally nowhere else," Church explained. Once the DNA is cut, the cell's natural repair mechanisms kick in and work to piece the DNA back together, and at this point, edits can be made to the genome. There are two ways this can happen:

According to the Huntington's Outreach Project at Stanford University, one repair method involves gluing the two cuts back together. This method, known as "non-homologous end joining," tends to introduce errors where nucleotides are accidentally inserted or deleted, resulting in that could disrupt a gene.

In the second method, the break is fixed by filling in the gap with a sequence of nucleotides. In order to do so, the cell uses a short strand of DNA as a template. Scientists can supply the DNA template of their choosing, thereby writing-in any gene they want, or correcting a mutation.

Who discovered CRISPR?

Scientists originally discovered the CRISPRs in bacteria in 1987, but they didn't initially understand the biological significance of the DNA sequences, and they didn't yet call them "CRISPRs," according to Quanta Magazine. Yoshizumi Ishino and colleagues at Osaka University in Japan first found the characteristic nucleotide repeats and spacers in the gut microbe , and as the technology for genetic analysis improved in the 1990s, other researchers found CRISPRs in many other microbes.

Francisco Mojica, a scientist at the University of Alicante in Spain, was the first to describe the distinct characteristics of CRISPRs and found the sequences in 20 different microbes, according to a 2016 report in the journal Cell. At one point, he dubbed the sequences "short regularly spaced repeats" (SRSRs), but he later suggested that they be called CRISPRs instead. The term CRISPR first appeared in a 2002 report, published in the journal Molecular Microbiology and authored by Ruud Jansen of Utrecht University, with whom Mojica had been in correspondence.

In the following years, scientists also discovered Cas genes and the function of Cas enzymes, and they figured out that the spacers in CRISPRs came from invasive viruses, Quanta reported.

Among these pioneering researchers was Jennifer Doudna, a professor of biochemistry, biophysics and structural biology at the University of California, Berkeley, who went on to share the 2020 Nobel Prize in chemistry with Emmanuelle Charpentier, director of the Max Planck Unit for the Science of Pathogens. The two scientists are credited with adapting the bacterial CRISPR/Cas system into a handy gene-editing tool, Live Science previously reported.

Charpentier initially discovered tracrRNA while studying the bacteria Streptococcus pyogenes, which causes a range of diseases from tonsillitis to sepsis. Having uncovered tracrRNA as a previously unknown component of the CRISPR/Cas system, Charpentier began collaborating with Doudna to recreate that system in a test tube. In 2012, the team published their seminal work in the journal Science, announcing that they'd successfully simplified the molecular scissors into a gene-editing tool.

Some thought that biochemist Feng Zhang of the Broad Institute might also earn the Nobel for his own, separate work with the CRISPR system, Science Magazine reported. Zhang demonstrated that the CRISPR system works in mammalian cells, and based on this work, the Broad Institute earned the first patent for the use of CRISPR gene-editing technology in eukaryotes, or complex cells with nuclei to hold their DNA.

How has CRISPR been used?

(Image credit: KEITH CHAMBERS/SCIENCE PHOTO LIBRARY via Getty Images)

In 2013, researchers in the labs of Church and Zhang published the first reports describing the use of CRISPR-Cas9 to edit human cells in an experimental setting. Studies conducted in lab dish and animal models of human disease have demonstrated that the technology can effectively correct genetic defects. Examples of such diseases include cystic fibrosis, cataracts and Fanconi anemia, according to a 2016 review article published in the journal Nature Biotechnology. These studies have paved the way for therapeutic applications in humans.

In the realm of medicine, CRISPR has been tested in early-stage clinical trials as cancer therapy and as a treatment for an inherited disorder that causes blindness. It's also been investigated as a strategy for preventing the spread of Lyme disease and malaria from viral vectors to people, and it's also been studied in animal models of HIV as a way to rid infected cells of the virus, Live Science previously reported. One research team in China attempted to treat a human patient's HIV using CRISPR, and while the treatment wasn't successful in curing the infection, the gene therapy also didn't cause any harmful effects, Live Science reported.

"I think the public perception of CRISPR is very focused on the idea of using gene editing clinically to cure disease," said Neville Sanjana of the New York Genome Center and an assistant professor of biology, neuroscience and physiology at New York University. "This is no doubt an exciting possibility, but this is only one small piece."
Related: 10 amazing things scientists just did with CRISPR
CRISPR technology has also been applied in the food and agricultural industries to engineer probiotic cultures and to vaccinate industrial cultures (yogurt, for example) against viruses. It is also being used in crops to improve yield, drought tolerance and nutritional properties.

One other potential application is to create gene drives, a genetic engineering technique that increases the chances of a particular trait passing on from parent to offspring; this kind of genetic engineering derives from a natural phenomenon, where specific versions of genes are more likely to be inherited. Eventually, over the course of generations, the trait spreads through entire populations, according to the Wyss Institute. Gene drives could be used for various applications, such as eradicating invasive species or reversing pesticide and herbicide resistance in crops, according to a 2014 report published in the journal .

During the COVID-19 pandemic, the CRISPR-Cas9 system has been used to develop various diagnostic tests for the viral infection, BBC News reported.

In April 2017, a team of researchers released research in the journal Science that they had programmed a CRISPR molecule to find strains of viruses, such as Zika, in blood serum, urine and saliva.

On Aug. 2, 2017, scientists revealed in the journal Nature that they had removed a heart disease defect in an embryo successfully using CRISPR.

On Jan. 2, 2018, researchers announced that they may be able to stop fungi and other problems that threaten chocolate production using CRISPR to make the plants more resistant to disease.

On April 16, 2018, researchers upgraded CRISPR to edit thousands of genes at once, according to research published by the journal BioNews.

In addition, CRISPR has recently been used in the following ways:

However, despite its wide range of uses, the tool is not without its drawbacks.

"I think the biggest limitation of CRISPR is it is not a hundred percent efficient," Church told Live Science. That means, in a given experiment, CRISPR may successfully edit only a percentage of the targeted DNA. According to the 2014 Science article by Doudna and Charpentier, in a study conducted in rice, gene editing occurred in nearly 50% of the cells that received the Cas9-RNA complex. Meanwhile, other analyses have shown that depending on the target, editing efficiencies can reach as high as 80% or more.

The technology can also create "off-target effects" when DNA is cut at sites other than the intended target. This can lead to the introduction of unintended mutations. Furthermore, Church noted, even when the system cuts on target, there is a chance of not getting a precise edit. He called this "genome vandalism."

Potential risks and ethical concerns of using CRISPR

The many potential applications of CRISPR technology raise questions about the ethical merits and consequences of tampering with genomes. And in particular, a slew of ethical debates flared up in 2018 when He Jiankui, formerly a biophysicist at the Southern University of Science and Technology in Shenzhen, announced that his team had edited DNA in human embryos and thus created the world's first gene-edited babies.

He was subsequently sentenced to three years in prison and fined 3 million yuan ($560,000) for practicing medicine without a license, violating Chinese regulations on human-assisted reproductive technology and fabricating ethical review documents, Live Science previously reported. But even after his sentencing, He's experiments raised questions about how the use of CRISPR should be regulated going forward, especially given that the technology is still fairly new.

Illegal experimentation in human embryos represents an extreme misuse of CRISPR, of course, but even seemingly ethical uses of the technology could carry risks, scientists say.

In general, making genetic modifications to human embryos and reproductive cells such as sperm and eggs is known as germline editing. Since changes to these cells can be passed on to subsequent generations, using CRISPR technology to make germline edits has raised a number of ethical concerns.

Variable efficacy, off-target effects and imprecise edits all pose safety risks. In addition, there is much that is still unknown to the scientific community. In a 2015 article published in Science, David Baltimore and a group of scientists, ethicists and legal experts note that germline editing raises the possibility of unintended consequences for future generations "because there are limits to our knowledge of human genetics, gene-environment interactions, and the pathways of disease (including the interplay between one disease and other conditions or diseases in the same patient)."

In the 2014 Science article, Oye and colleagues point to the potential ecological impact of using gene drives. An introduced trait could spread beyond the target population to other organisms through crossbreeding. Gene drives could also reduce the genetic diversity of the target population, potentially hampering its ability to survive.

Other ethical concerns are more nuanced. Should we make changes that could fundamentally affect future generations without having their consent? What if the use of germline editing veers from being a therapeutic tool to an enhancement tool for various human characteristics?

To address these concerns, the National Academies of Sciences, Engineering and Medicine put together a comprehensive report with guidelines and recommendations for genome editing.

Although the National Academies urge caution in pursuing germline editing, they emphasize "caution does not mean prohibition." They recommend that germline editing be done only on genes that lead to serious diseases and only when there are no other reasonable treatment alternatives. Among other criteria, they stress the need to collect data on the health risks and benefits and to maintain continuous oversight during clinical trials. They also recommend that, after a trial concludes, trial organizers should follow up with the participants' families for multiple generations to see what changes persist in the genome over time.
This article includes additional reporting by Alina Bradford, Live Science contributor. Originally published on Live Science.
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CRISPR is a powerful tool for editing genomes, meaning it allows researchers to easily alter DNA sequences and modify gene function. It has many potential applications, including correcting genetic defects, treating and preventing the spread of diseases, and improving the growth and resilience of crops. However, despite its promise, the technology also raises ethical concerns.