BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Crispr-Cas9

CRISPR/CAS9: Potential to destroy malaria?

CRISPR. Sounds more like a new brand of potato chip than something potentially revolutionary (Bold new flavor. Bold new crunch. CRISPR.). Nevertheless, this tool used for easy gene editing and slicing is tearing up the science world because it could be the key to combatting disorders and diseases.

Recent research indicates that CRISPR/Cas9 based genome editing tools could aid in the fight against malaria, one of the “big three” diseases that has long affected and continues to affect humans worldwide. How is CRISPR/Cas9 able to do this?

CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats) originally are how bacteria protect themselves from foreign viruses. CRISPRs contain DNA from viruses that have attacked the bacteria, and so when a similar virus attacks, the bacteria knows that this virus and his DNA are bad. Essentially, CRISPRs allow bacteria to build up immunity. When foreign DNA is detected, the Cas9 enzyme is guided by the CRISPR and is able to cut the desired DNA. Scientists have come up with a way to engineer and manipulate the CRISP/CAS9 system into other organisms (such as mosquitoes) so that we can successfully edit genome sequences and genes to produce desired results. We take advantage by specifying which genes the Cas9 should cut/replace, and then it does just that. Therefore, the CRISPR/Cas9 system allows us new genome editing potential like none before.

Made by Viktoria Anselm.

How does this apply to mosquitoes and malaria? Scientists experimented with genetically modified malaria-transmitting mosquitoes (Anopheles gambiae), altering the fibrinogen-related protein 1 (FREP1) gene on them. This gene essentially codes for a protein that makes mosquitoes a vector for malaria. The scientists used the CRISPR/Cas9 to inactivate this gene.

The results produced mosquitoes with significantly less transmission of malaria to both human and rodent cells. However, these mosquitoes have “reduced fitness”: a significantly lower blood-feeding propensity, egg hatching rate, a retarded larval development, and reduced longevity after a blood meal. Essentially this means that these mosquitoes have a low chance of affecting populations of mosquitoes in the wild without being “pushed” by scientists, where scientists are “forcing DNA to inherit particular sets of genes.” This is called a gene drive. With a strong push for a couple of years, there is potential for worldwide mosquito populations to be significantly changed in 10-15 years.

Photo taken by JJ Harrison

I chose to write about this new research and potential breakthrough because it really means something to me, as I have lived in and visited countries threatened by malaria. I had to take preventative pills every morning, and I would have to sleep in a restrictive mosquito net. All that made me wonder about and feel for a kid in the same country who didn’t have those things and how he or she would manage without those barriers to malaria. Having said that, I really do believe this is a worthwhile option we should explore, and I think it can make a difference for the world.

What do you think? Do you think it is realistic for theses mosquitoes to change the entire mosquito population and effectively help reduce malaria transmission? Will CRISPR/Cas9 work as we hoped? Or is it too good to be true?

Deleting Genes to Stop Malaria

A new discovery has highlighted the positive effects that the revolutionary new gene editing tool, CRISPR-Cas9, can have. Scientists at the Johns Hopkins Bloomberg School of Public Health’s Malaria Research Institute have discovered that the deletion of a single gene from the Anopheles Gambiae mosquito, called the FREP1 gene, yields promising results in the eradication of the malaria disease.

 

Image result for mosquito gene editing

Gene Editing

The FREP1 gene has been associated with being a malaria “host factor” gene because it helps the parasite live in the gut of the mosquitoes.  However, the scientists, using the CRISPR-Cas9 gene editing procedures, have been able to delete the FREP1 gene from the mosquitoes and have seen significant decreases in the spread of malaria. Without the host factor gene, the parasite has difficulty surviving in the mosquito, which decreases the spread of the disease to other organisms.

 

The deletion of the FREP1 gene had other effects in addition to the resistance of the malaria parasites. In the mosquitoes where the gene was deleted, many showed no signs of sporozoite-stage parasites in their salivary glands, which can spread to humans through mosquito bites. George Dimopoulos, PhD, professor in the Bloomberg School’s Department of Molecular Microbiology and Immunology, commented on the study, saying that “if you could successfully replace ordinary, wild-type mosquitoes with these modified mosquitoes, it’s likely that there would be a significant impact on malaria transmission”.

CRISPR Cas-9 is the New Key to Curing Parkinson’s Disease

A new screening tool for Parkinson’s Disease was just discovered by a team of researchers at the University of Central Florida. They did this by using cutting edge gene-editing technology, CRISPR Cas-9, which allows scientists to detect levels of alpha-synuclein, a brain protein associated with Parkinson’s.

What is alpha-synuclein?

This protein can be found in our brain, it is something all humans have. When someone develops Parkinson’s, the levels of this protein become abnormal. This protein can become dangerous to neurons and kill them. This person would gradually loose brain cells, affecting their motor functions.

What is CRISPR Cas-9?

CRISPR Cas-9, Clustered Regularly Interspaced Short Palindromic Repeats, is a gene-editing system that enables scientists to edit DNA while preserving the cell. Instead of extracting all of the proteins from a cell and measuring them, CRISPR Cas-9 allows us to edit one gene.

How is used?

The specific gene the team wanted to edit was the alpha-synuclein. The CRISPR Cas-9 helped them edit the gene and add a luminescent tag, made up of similar proteins that make fireflies glow, in order to track how much of this protein is produced in a brain cell. When the brain cell produces alpha-synuclein, it glows, making it easier to visualize once the cell is in a diseased state. Furthermore, scientists can treat these cells with different medications, whether or not they glow will tell if the medications tested are successful.

The Future:

Engineered cells and light detection are a great duo for the future of researchers. Light detection on these engineered cells is helpful for high throughput screening where multiple drugs can be tested at the same time. This research can potentially lower the number of Parkinson’s cases per year. Currently, 60,000 new cases are reported per year in just the United States! Could these numbers drop in the future? Can CRISPR help find a cure to other diseases as well? Reading this article opened my mind to the endless possibilities CRISPR unlocked, I am excited to see where else it could take science.

 

 

 

CRISPR-cas9: Coming to a Human Near You

CRISPR

What is CRISPR?

As the world becomes more technologically developed, CRISPR is a new and upcoming technique to genetically edit genes. Being able to alter DNA sequences and revise gene roles, scientists now have the ability to correct defects, prevent diseases/mutations and improve genes overall.  As time goes on, scientists now feel that they are ready to genetically alter humans.

This image represents what CRISPR is capable of. The two wrenches represent that CRISPR edits the DNA strands and creates new and improved DNA.

How does CRISPR work?

CRISPRs are specialized stretches of DNA recognized by the protein Cas9. Cas9 is an enzyme that acts like a pair of molecular scissors, capable of cutting strands of DNA. Without that enzyme, CRISPR would not be successful.

CRISPR stands for “clusters of regularly interspaced short palindromic repeats.” It is a specialized region of DNA with two obvious characteristics

  1. the presence of nucleotide repeats and spacers.
  2. Repeated sequences of nucleotides — the building blocks of DNA — are distributed throughout a CRISPR region.

Spacers are bits of DNA that are interspersed among these repeated sequences.

***According to livescience.com, there is a built-in safety apparatus, which guarantees that Cas9 will not cut anywhere in a genome. Short DNA sequences become tags and stay adjacent to the target DNA sequence. If the Cas9 complex doesn’t see a short DNA sequence next to its target DNA sequence, it won’t cut.***

Is this really safe for humans?

Not too long ago, a study by Columbia University Medical Center was published in May, in the journal Nature Methods, about this “revolutionary” CRISPR gene-editing technique. It claimed that CRISPR caused unwanted and dangerous mutations and left the medical community baffled. The paper questioned how effective gene-editing technology is and called for a reassessment of the technique’s safety. However, this publication has to do with how CRISPR was first tested: 3 mice and very controversial results. Editage.com stated that “two of the three study subjects, the CRISPR-edited mice, happened to be more closely related and thus shared more mutations. Therefore, the paper claimed that “the premise of the old study was incorrect.”



If you have the choice, will you use CRISPR to design your children? Comment!

CRISPR The End of ALS?

ALS, amyotrophic lateral sclerosis, is a nervous system disease that weakens muscles and impacts physical functions. ALS is diagnosed in less than 20,000 people a year but there is currently no cure. Amyotrophic lateral sclerosis is caused by protein clumps in the brain which make voluntary movements progressively harder. The protein clumps destroy neurons in the brain through toxins. Scientist are yet to figure out how the toxins do this. A group of researches then decided to use CRISPR-Cas9 to get a better understanding of what is actually happening. During their research they realized that when a gene was affected it protected the neurons. It was already known that a gene called C9orf72 caused for unnatural repeating in certain parts of DNA and is the cause for the build up of proteins in ALS. The research group isolated certain genes by knocking out others. During this process they realized that when the gene Tmx2 is inactive it hindered cell deaths in mouse neurons. “If you have a small molecule that could somehow impede the function of Tmx2, there might be a therapeutic window there” said co-author Micheal Haney. Michael Bassik, Ph.D., assistant professor of genetics at Stanford and other reaserchers plan to do more studies on Tmx2 to get more detailed and accurate information. They also plan on doing CRISPR screens to find other possible causes for ALS and work on cures for other neurodegenerative disorders.

Other researchers are trying to use CRISPR-Cas9 to find a cure to ALS. Researchers are beginning to focus on editing RNA in hopes to cure a form ALS and other neurodegenerative diseases.This technique has produced mixed results. Research at the University of California, Riverside, has made progress in developing a molecule which can target EphA, this is a “gene that’s known to govern the onset and progression of neurodegenerative diseases”.

You can read more here.

CRISPR/Cas9: Is it really the cure?

There are many benefits to the CRISPR/Cas9 defense system. But, do the pros outweigh the cons?

CRISPR is a molecule that can be programmed to target a specific sequence in a genome. It guides an enzyme, such as Cas9, to chop the code like scissors. There have been many studies and tests done using the defense. The most important advantages of CRISPR/Cas9 over other genome editing systems are its simplicity and efficiency. Since it can be applied directly in the embryo, CRISPR/Cas9 reduces the time required to change certain genes compared to other systems.

However, many attempts to use this mechanism have failed. Using the mechanism is not as easy as it sounds. A Cas9 repair is not always precise. On ZMEScience, one HIV patient tried the process. But, the HIV cells were only made stronger. Researchers equipped T-cells to hurt the virus with the enzyme Cas9. T cells are a type of lymphocyte that play a central role in cell-mediated immunity. T cells equipped with Cas9 were seen to successfully hurt the HIV genome, and make it unable to properly reproduce. This project led by Chen Liang from McGill University in Montreal, Canada seemed to work fine. But, the team noticed that two weeks later T cells were producing copies of virus particles that had escaped the CRISPR attack. The area around Cas9 only developed more mutations, aka it made the HIV stronger. It is also impossible to direct the Cas9 exactly where one wants it to go. So in essence, it is a risky gamble.

Although there are hopes for this technique to be more refined and successful in the future, for now, its uses are limited.

For more information click here.

CRISPR Cas9: A Pathway for Designer Babies?

Can embryo modification allow parents to “custom order a baby with Lin-Manuel Miranda’s imagination or Usain Bolt’s speed?”

https://www.pexels.com/photo/adorable-baby-baby-feet-beautiful-266011/

Within the past decade, there has been an explosion in the use of CRISPR-Cas9, a gene editing tool that allows scientists to edit parts of the genome by removing, adding, or altering sections of the DNA sequence, in science research. Yet the promising technology renews the ethical issues rooted in genetic engineering and brings up the question: of what practices and ideas could become a reality in the near future? What about designer babies– embryos that have been genetically modified to produce desirable traits, such as greater athletics or higher intelligence?

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CRISP New Technology: CRISPR

If you have ever seen GATTACA, and thought ‘Wow! I want to edit my genes!’… you may be in luck! CRISPR technology is a simple tool for editing ones genomes. (CRISPR is just a nickname for “CRISPR-Cas9”. ) A genome is an organism’s complete set of genes, including non-coding nucleic acid sequences. CRISPR technology has many different applications, including altering DNA sequences, modifying gene function, correcting genetic defects, and preventing the spread of diseases. Although all of these functions sound positive, CRISPR technology seems to raise ethical concerns.

 

DNA Pencil: Edit Photo By: mcmurryjulie

CRISPR stands for “clusters of regularly interspaced short palindromic repeats”, and is a specialized region of DNA with two definitive characteristics: the presence of nucleotide repeats and spacers. Nucleotides are the building blocks of DNA, and eventually proteins. CRISPR technology was adapted from the natural defensive mechanisms of bacteria. In order to repel attacks, these organisms use CRISPR derived RNA and various Cas proteins (including Cas 9), to attack foreign viruses, or other unknown bodies. CRISPRs are specialized stretches of DNA. The protein Cas9 is an enzyme that acts like a pair of “molecular scissors” which acts to cut strands of a person’s DNA. This protein usually binds to two RNA molecules: cRNA and another called tracrRNA. These two forms of RNA guide Cas9 to the target site, where it will make it’s “cut”. Cas9 cuts both strands of the DNA double helix, making what is known as a “double strand break”. This is how genes are editing.

Bouncing back to the defensive bacteria organisms that started this all, they attack foreign invaders by chopping up, and therefore destroying, the DNA. This allows for the manipulation of genes. These bacteria also use the spacers as a bank of memories which allows the bacteria to recognize viruses and other invaders.

However, due to these discoveries of how CRISPR technology works in bacteria, CRISPR technology is now going to be used to edit the genes of people to change genomes and possible diseases and phenotypes. This has caused some ethical concerns to arise in regards to CRISPR technology being used for human genome editing. Most of the changed involving genome editing are limited to somatic, or body cells, (not sperm or egg cells). Changes in body cells can’t be passed from generation to generation, but changes in sex cells can be passed onto future generations. Some of the previously mentioned ethical concerns include whether it would be a good idea to use this technology to enhance normal human traits (including height and intelligence). Due to these ethical concerns these genome edits are actually illegal in many countries!

Scientists Edit a Mutation from Genes in Human Embryos

https://upload.wikimedia.org/wikipedia/commons/6/6b/Embryo%2C_8_cells.jpg

Did you know that there are over six thousand genetic disorders? Have you ever wondered whether it was possible to prevent or “cure” a genetic disorder? Well, for the first time in history, a group of scientists have succeeded in editing a dangerous disease-causing mutation out of human embryos.

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What is CRISPR-Cas9?

CRISPR-Cas9 is a new(ish) technology that is used for knocking out human genes in cell lines for the purpose of seeing what these genes do. CRISPR-Cas9 has a “protein scissor”, the cas-9 protein, and a location that shows the cas9 where to bind to. The “location” is actually a strand of RNA that is complementary to a specific strand of DNA. This RNA strand is like glue in that it binds to the DNA and allows the Cas9 to cut the DNA. This process or the CRISPR-Cas9 technology is like an endless cycle of cutting and repairing DNA until the repair enzyme can no longer repair the DNA or makes a mistake. This technology can make the process of cutting and disabling genes five times faster. It allows scientists to edit parts of a genome by altering, removing, or adding certain sections of DNA. While this technology can be very useful in trying to understand what genes do it does have a downside, “these approaches are costly and time-consuming to engineer, limiting their widespread use, particularly for large scale, high-throughput studies.” The picture below shows what this process looks like on a very basic scale. Hopefully this technology will eventually allow us to fully understand what every gene does.

 

Playing God: New Technology Gives Scientists the Ability to Delete DNA

Since the relatively recent discovery of CRISPR-Cas9, scientists have explored multiple uses of this new technology, from eliminating a patient’s cancer to making super plants, furthering our understanding of DNA and how it works. CRISPR-Cas9 has become the most advanced and efficient gene-editing tool there is. However, thus far, its use has been largely limited to silencing protein-coding genes in the DNA. This leaves out what’s called the DNA “dark matter” — the non-coding DNA that covers about 99 percent of our genetic code. That’s about to change; this article from Futurism explains how a recent study from PLOS Computational Biology is creating a new technique, based on CRISPR, but delving deeper into this unexplored territory.

This brand-new software technology called CRISPETa evolved from a breakthrough tool (which uses CRISPR-Cas9) called DECKO. DECKO was designed for deleting pieces of non-coding DNA using two sgRNAs as molecular scissors. While the concept might seem simple, designing deletion experiments using DECKO was time-consuming due to the lack of software to create the required sgRNAs.

This is where the new tool, CRISPETa, comes in. According to the report, users can tell CRISPETa which region of DNA they wish to delete. The software then generates a pair of optimized sgRNAs that can be used directly for that experiment. Pulido, leader of the research team, stated that “We hope that this new software tool will allow the greatest possible number of researchers to harness the power of CRISPR deletion in their research.”

The software has already demonstrated its efficiency in deleting desired targets in human cells. The research team hopes that its use will go beyond a basic research tool, and be utilized as “a powerful therapeutic to reverse disease-causing mutations,” Johnson added. Herein lies the hidden value of CRISPR-Cas9 and all further developments from it: The more we understand DNA and genomics, the better we will be able to fight diseases and other aspects of human life that cause harm, ultimately leading to a higher quality of life for all.

 

HIV Adapts to CRISPR-Cas9 Treatment

There has been an abundance of research using CRISPR/Cas9 gene editing to search for a cure for HIV. The HIV virus enters immune cells and uses the host cell’s method of replication to replicate the viral genome. With CRISPR/Cas9, specific mutations can be introduced in order to make it more challenging for the HIV virus to enter Helper T-Cells. Guided by specific strands of RNA, the Cas9 enzyme can cut a particular piece of the viral genome out, rendering it useless.

When a team of researchers at McGill University attempted to use the CRISPR method to disable the HIV viral genome, they found a major roadblock. Two weeks after the CRISPR/Cas9 treatment, the host cells appeared to be creating copies of the virus. This may be attributed to an error in the enzymes that copy the viral DNA, causing a change in the genome, and a mutation that allows it to evade the CRISPR treatment. However, the McGill researchers believe that this mutation was a result of the CRISPR treatment itself.

After DNA is cut by the Cas9 enzyme, the host cell usually attempts to repair the damage. Occasionally, this results in the addition or deletion of a few nitrogenous bases. While these changes usually result in the inactivation of the cut gene, sometimes they don’t. The active cut DNA is no longer recognized by the machinery used to prevent HIV infection of the cell, and the mutated viral genome is resistant to the usual methods of disablement.

More researchers at the University of Amsterdam had similar results in their research. While it is not that surprising that HIV can overcome the CRISPR/Cas9 gene editing at some point, the leader of the research (Atze Das) said “What is surprising is the speed- how fast it goes”.

If CRISPR was used at the same time as HIV-attacking drugs (inhibitors of protease, reverse transcriptase, and integrase), perhaps the mutations would be less  detrimental. This roadblock does not mean that a CRISPR cure for HIV is impossible, but it does make it far more challenging to overcome.

More CRISPR Improvements

Crispr-Cas9 is a genome editing tool that is creating a whole lot of buzz in the science world. It is the newest faster, cheaper and more accurate way of editing DNA.  Crispr- Cas9 also has a wide range of potential applications. It is a unique technology that enables geneticists and medical researchers to edit parts of the genome by cutting out, replacing or adding parts to the DNA sequence.  The CRISPR-Cas9 system consists of two key molecules that introduce a mutation into the DNA. The first Molecule is an enzyme called Cas9. Cas9 acts as a pair of scissors that can cut the two strands of DNA at a specific location in the genome so that bits of DNA can be added or removed.  The second is a piece of RNA called guide RNA or gRNA. This consists of a small piece of pre-designed RNA sequence located within a longer RNA scaffold. The scaffold part binds to DNA and the pre-designed sequence guides Cas9 to the right part of the genome. This makes sure that the Cas9 enzyme cuts at the right point in the genome.Screen Shot 2016-04-10 at 4.50.55 PM

CRISPR-Cas9 is efficient compared to previous gene-editing techniques, but there’s still plenty of room for improvement. CRISPR is less efficient when employing the cellular process of homology-directed DNA repair, or HDR, as opposed to nonhomologous end joining.  Jacob Corn, the scientific director of the Innovative Genomics Initiative at the University of California, Berkeley, and his colleagues have come up with a way to improve the success rate of homology-directed repair following CRISPR-Cas9. “We have found that Cas9-mediated HDR frequencies can be increased by rationally designing the orientation, polarity and length of the donor ssDNA to match the properties of the Cas9-DNA complex,” the researchers wrote in their paper, “We also found that these donor designs, when paired with tiled catalytically inactive dCas9 molecules, can stimulate HDR to approximately 1%, almost 50-fold greater than donor alone.”

“Our data indicate that Cas9 breaks could be different at a molecular level from breaks generated by other targeted nucleases, such as TALENS and zinc-finger nucleases, which suggests that strategies like the ones we are using can give you more efficient repair of Cas9 breaks,” coauthor Christopher Richardson, a postdoc in Corn’s lab, said in a statement.

Original Article:

http://www.the-scientist.com/?articles.view/articleNo/45159/title/More-CRISPR-Improvements/

Other Addtional Helpful Links:

http://www.yourgenome.org/facts/what-is-crispr-cas9

 

CRISPR-Cas9 Providing New Treatment Possibilities

The genetic editing tool, CRISPR-Cas9, is making greater strides regarding RNA linked diseases. The knowledge of how CRISPR-Cas9 can affect DNA has increased over the past couple of years. By targeting the DNA with CRISPR-Cas9 scientists have found new ways to modify protein production and treat certain diseases, which led to editing genes. However, now there is inquiry about what would occur if CRISPR-Cas9 targeted RNA.  Many diseases are linked to RNA and by targeting RNA with CRISPR-Cas9 we could find new treatments to fight off cancer, autism, and X-syndrome. Researchers at University of California, San Diego School of Medicine have been able to accomplish targeting the RNA. Gene Yeo, PhD, associate professor of cellular and molecular medicine hopes to use this technique to fix RNA behavioral diseases.

PDB_1wj9_EBI

Image Source

RNA can affect when and where proteins will be produced, but if the RNA transport is deficient than it can cause diseases from autism to cancer. Evaluating RNA movement will allow new treatments to be found.  Yeo and colleagues at the University of California, Berkeley, have created RCas9, which is targeting RNA in live cells. They were able to do so by altering certain features of the CRISPR-Cas9. A short nucleic acid, PAMmer, that they designed was used to direct CRISPR-Cas9 to an RNA molecule. They then targeted RNA that encodes certain proteins which were ACTB, TFRC, and CCNA2. The CRISPR-Cas9 would combine with a fluorescent protein to reveal the movement of RNA into stress granules. This allowed the team to track RNA through the live cells without using artificial tags, which are normally used to track RNA.

CRISPR-Cas9 is opening new ways to find out more information to fix diseases regarding DNA and now RNA. There has been controversy regarding CRISPR-Cas9 because it is a tool to edit genetic material, but in this case it is helping us fight off diseases that have been affecting lives for ages. Do you believe that CRISPR-Cas9 should only be used for certain cases or that people should be able to use it freely?

Original Article

Other sources:

1.https://health.ucsd.edu/news/releases/Pages/2016-03-17-CRISPR-Cas9-targets-RNA-in-live-cells.aspx

2. http://www.techtimes.com/articles/142061/20160318/gene-editing-tool-crispr-cas9-can-now-monitor-and-target-rna-in-living-cells.htm

 

 

Crispr-Cas9: Coming to a Theater Near You

This sequel to GATTACA is to be released shortly, and this time, they’re transcending the movie screen and bringing the experience to reality!

Crispr-Cas9 is a fairly recent DNA-editing technique that has been developed, and allows for extremely easy and precise gene editing, a development said to be at least on par with PCR for bio engineering. In many ways, this is great. Now biologists won’t have to spend the time nor undergo the difficulty of creating variant DNA through old methods, meaning that all these cool genetic breakthroughs should be happening at an unprecedented pace! The problem is, it may be going too fast for humans to wrap their head around.

Similar to the ethical questions raised by the film GATTACA, countries and scientists are debating what regulations should be put on this new and powerful tool. With Crispr-Cas9, the possibility to genetically modify humans becomes a very real option to consider. Scientists could remove DNA sequences which lead to defects and diseases such as albinism and Huntington’s Disease. Or anything else, really.

(The miracle protein)

The main point of Crispr-Cas9 is not necessarily the ability it gives to scientists to easily modify DNA, but the increased rate at which we can understand what specific sequences of DNA do by altering them. Not only are we more able to modify DNA, we are now able to figure it out at breakneck speed.

 

Where it gets complex is, as always, how humans deal with it. Some people, such as Mark Leach, whose daughter has down-syndrome, believes that children with disabilities not only are still able to live rich lives, but also teach others to be more compassionate. Although debating if I would choose to let my child have down-syndrome or not for that reason seems like an absurd consideration, and most likely a coping mechanism, the point still stands that some people are uneasy with fixing genetic-related problems because “they wouldn’t be the same person.” (That’s the point!)

People are really afraid of change, aren’t they?

 

However, for those on the more lethal/completely disabling part of the genetic spectrum, the answer is more than clear.  Charles Sabine, the brother of the renown British lawyer John Sabine, who both have Huntington’s Disease at varying stages, says “If there was a room somewhere where someone said, ‘Look, you can go in there and have your DNA changed,’ I would be there breaking the door down.” Similarly, Matt Wilsey, a parent of a child with a terminal genetic illness, is awestruck at the ridiculousness of the situation: “As a parent with an incredibly sick child, what are we supposed to do — sit by on the sidelines while my child dies?” The oddity of the situation is, we have the capability to start figuring out how to solve these genetic issues with a very effective and efficient technique, it’s just that humans are riding the brakes, trying to slow down the almost inexorable progress of the freight train that is Crispr-Cas9. The irony is that many are afraid with tampering with the “sanctity” of human embryos. I would agree, except that humans defile it all the time. Birth defects, genetic diseases, miscarriages, etc. Of course, this is not intentional, but the parents have the largest hand in these outcomes, as they provide all the material,genetic and otherwise, to create the embryo, fetus, and eventually child. We are already making horrible mistakes with human embryo’s that cripple or kill the resulting child through the natural birth process. Personally, I would go off of this to say we should at least learn from this, so we could eventually progress far enough to prevent these things from ever happening, but I only ask all of the readers to keep this in mind: Nature (very badly) screws up too.

File:Crispr.png

(The process Cas9 facilitates)

I’m not saying that we should be careless with this new and potentially dangerous or aberrant-spawning technology, but I think it’s time that humans come to terms with the fact that their world, and their lives, are entering a new era of existence. For millennia, structured humans have lived in a world where the outside world is the only thing we can manipulate, but now the very structure and formation of ourselves as well. I understand that such a change from a thousands-year-running viewpoint can be hard to make. We’ve never had to think about these things before as a species, because it wasn’t understood and out of our reach. It is daunting. It is terrifying. Only because it is unknown. But how are we to learn, to benefit, from this great potential, if we are too afraid to explore it? I understand that like any form of potential, it can go either way, but this is a great new time of possibilities that simply won’t go away, but reemerge constantly.

I think it’s time we gathered the courage to face it.

Gaining a CRISPR Understanding

There have been some very exciting, recent biological findings involving gene editing. The CRISPR-Cas9 findings allow for the exact and purposeful changes to the genome of a cell. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats, and it is used in bacteria and archaea as a way to protect the bacteria from intruding genetic material. Essentially, CRISPR is used to remove a faulty gene and put another in its place. This is exciting because in humans, this technology could be used to remove extremely harmful DNA from our bodies, only to be replaced by healthy DNA. This method could then be used to cure cancer. In fact, another genome editing technology, called TALEN, was actually used to cure  an 11 month old girl named Layla who had what doctors thought was an untreatable form of leukemia. Described as “biological scissors”, doctors editing genes in cells in the immune system. The new genes then hunted down the dangerous red blood cells that were putting Layla’s life at risk. What is so exciting about CRISPR, however, is that unlike TALENS, which used proteins to edit genes in a very time consuming process, CRISPR uses nucleic acids such as RNA, which are significantly easier to use. Ultimately, these findings should bring a lot of good to the world and are a promising step towards curing cancer and other dangerous diseases.CRISPR-Cas9_mode_of_actionImage creator unknown. https://commons.wikimedia.org/wiki/File:CRISPR-Cas9_mode_of_action.png

How to Proofread the Genome

CRISPR-Cas9 is an emerging technology in the field of genetics that has opened an incredible number of  doors and revolutionized the field. It permanently changes the genome of cells while they are alive. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. This sounds confusing but the actual technology is simple. Feng Zhang uses the analogy of proofreading a book to explain it.Let us say you are proofreading your novel and you find the phrase “twinkle twinkle big star”. Now you want to change it to “twinkle twinkle little star”. In this scenario, the words are base pairs and the change from “little” to “big” is a mutation. You can not just delete “big” or just “add” little you must do both. And that is what CRISPR does. It uses an enzyme to cut the DNA and silences that gene. It also can do the opposite and activate certain genes.

A diagram of how CRISPR works

This precise controls of genes have allow scientists to do research faster and cheaper. Its applications go beyond just research however. This technology can be used to treat certain genetic mutations by correcting the incorrect base pairs accurately.

Link to article:

https://www.broadinstitute.org/what-broad/areas-focus/project-spotlight/questions-and-answers-about-crispr

Other Links:

https://www.sciencedaily.com/releases/2015/12/151210125648.htm

https://www.addgene.org/crispr/guide/

The New and Improved CRISPR-Cas9

The CRISPR-Cas9 genome editing system has transformed into an even better version of itself. A new, elegant technique, coined by researches at the Broad Institute of MIT and Harvard and the McGovern Institute for Brain Research at MIT, has resolved one of the most reoccurring technical issues in genome editing.

https://commons.wikimedia.org/wiki/File:Crystal_Structure_of_Cas9_in_Complex_with_Guide_RNA_and_Target_DNA.jpg

Primarily, the CRISPR-Cas9 system works to specifically modify a cell’s DNA. CRISPR is dependent on protein Cas9, as it is specialized for cutting DNA. The DNA, at a location identified by a RNA’s sequence matching the target site, is altered by Cas9. Though it very efficient at cutting its target sites, there is a large complication in the process. Once the Cas9 is inside the cell, it can also bind and cut additional sites that are not targeted. Because of this, undesired edits are produced which can alter gene expression or kill off a gene completely. These setbacks can lead to cancer or other problems. Feng Zhang, along with his colleagues at MIT, reported that by just changing 3 out of the approximately 1,400 amino acids composing the Cas9 enzyme from S. pyogenes, a considerable reduction of “off-target editing” to undetectable levels are observed.

This newfound information was derived from studying the structure of the Cas9 protein. Since DNA is negatively charged, it binds to a positively charged groove in the Cas9 protein. The scientists predicted that by replacing some of the positively charged amino acids with a neutral charge, there would be a decrease in binding to “off target” sequences than to “on target” sequences. By mutating three amino acids, their technique proved to be successful.

The team is calling this newly-engineered enzyme “enhanced S. pyogenes Cas9” or “eSpCas9.” It’ll be particularly useful for genome editing that requires precise specificity and it is said to be available for researches worldwide.

I believe that this newfound resolution for the CRISPR-Cas9 genome editing hurtle is a huge game changer. This charge-changing approach might also be able to be used for other experiments involving RNA-guided DNA targeting enzymes. Ethical and societal concerns have also risen due to the idea of rapid and efficient genome editing. The eSpCas9 is highly beneficial in the scientific community, however there is a lot more research needed to be done in order to be used clinically.

 

Original article can be found here.

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