CRISPR: A Geneticist dream
HBO’s John Oliver opened a Last Week Tonight bit with a sequence of video clips; some of them were news reports promising amazing breakthroughs, others movie scenes illustrating genetic engineering gone terribly wrong. He concluded his segment by saying “It seems gene editing is going to eliminate all disease, or kill every last one of us.”
Well, he has a point. If used with the wrong ambitions, genetic engineering can have deadly consequences. And because the invention of CRISPR is extremely beneficial, it is actually making the “bad guys’” mission to destroy the world easier.
CRISPR is a simple yet amazingly powerful tool for editing genomes. It allows genetic engineers to alter DNA sequences and modify the function of a specific gene. Its many potential applications include correcting genetic deformities, enhancing crops, preventing the spread of diseases, and curing maladies.
CRISPRs are specialized strands of DNA with two distinct characteristics: the presence of nucleotide repeats and spacers. Repeated sequences of nucleotides, the structural unit of the DNA, are distributed among a CRISPR region. The spacers are parts of the DNA gathered from viruses that previously tried to attack the cell. CRISPR acts like a pair of molecular scissors, capable of cutting strands of DNA.
The main brain behind this tool, Dr. Jenniffer Doudna, is a celebrity in the genetic engineering field because she was among the first scientists to propose the “microbial immunity mechanism” could be harnessed for programmable genome editing. Dr. Doudna’s discovery is very beneficial for genetic engineering because CRISPR isn’t as time consuming and tedious as the previous tools. It is more convenient. Together with Dr. Doudna, Dr. Emmanuelle Charpentier was also involved in the “biochemical characterization of guide RNA and Cas9 enzyme-mediated DNA cleavage”. Another popular name that comes into people’s minds when said CRISPR is Feng Zhang. His research redirected the focus from bacteria to eukaryotes which helped advance the technology and expand its applications.
Now that you readers know what CRISPR is, and who invented it; let’s continue with its benefits, risks and ethical concerns.
The biggest advantage CRISPR brings is in the medical field. Thanks to the hard working enzyme, scientists are so close to finding the cure for HIV — a virus that attacks the body’s immune system, and if not treated it can lead to AIDS. In 2017 a group of Chinese scientists were able to increase resistance to HIV in mice by replicating a mutation of a gene that prevents the virus from entering their cells. According to Victor Tangermann “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” (1). CRISPR also helps increase the yield of plants such as tomatoes. The Cold Spring Harbor Laboratory in New York developed a method to edit genes that determine tomato size, branch its architecture and shape for a greater harvest. Another way CRISPR is used is actually similar to the plot behind every Jurassic Park movie: resurrecting animals. Japanese scientists have been trying to recreate a wooly mammoth for many years, and they found out that the key for resurrection animals is not — as anticipated — cloning, but creating hybrids. Since 2015, researchers led by George Church have made 45 edits in the Asian elephant genome. They are very close to resurrecting mammoth-like mammals. The question in many people’s minds is if ‘resurrecting extinct animals are necessary?’, and ‘what will the consequences be?’
In the article Reviving Woolly Mammoths Will Take More Than Two Years Helen Pilcher, a freelance science writer, defends the benefits of reviving extinct animals. “…it is not just about bringing back the dead, it is also about helping the living” When, and if, de-extinct animals start running freely in the environment they are suited in, next to healthy wild populations; “they could vastly boost overall levels of biodiversity, not just by their presence, but by the impact they will have on the other species in their ecosystems”
To give a brief answer to both questions, maybe resurrecting them is not necessary, but the benefits we’ll see if they revive cannot be underestimated! All in all, with CRISPR, we can cure diseases, improve crops AND revive animals among many other benefits. What could possibly be wrong with this miracle invention?
In fact, along with a few small things, there are two main risks of CRISPR. The first one is genetic drive. Because we are manipulating genes and those genes get incorporated into the genome that sits within the cell, they have the potentiality to be transferred on to other organisms. Once they are transferred, they become a part of the environment and the cycle. This means that if something goes wrong, it will affect other organisms too. The second risk is the fact that we are only humans. Research suggests that regardless of the task or activity being conducted, humans make 3 to 6 mistakes per hour. We might think we know what we’re doing. We might think we are measuring every possible outcome that will be created when we’re changing the genes. But there is a possibility of us missing something, or our technology not picking up on the changes we made. The fear is that those changes lead to a mutation that we won’t be able to see on time or be difficult to control. All in all, if we make a teeny tiny mistake, that mistake could become an incurable disease or a virus. Isn’t that wonderful?
As you can see, playing with genes isn’t always very safe. That’s why many people have ethical concerns when it comes to genetic engineering. We all know that CRISPR has many benefits; it cures diseases, eases the harvest of plants etc. What raises ethical implications is whether that change should be made in sperms, eggs or embryos where those changes can be passed onto the next generation. They are concerned about what the next generation would think considering they would be genetically engineered without their consent. Would they be pissed or grateful? Another reason for ethical concerns is the off-target effects and imprecise edit that poses safety risks. In addition, there are many things we still don’t know when it comes to our genetics. That’s why it isn’t strange for people to have these concerns. But one way or another, people will have to make a decision.
Maybe the ones that will be obligated to make the difficult decision will be us, generation Z.
To conclude, CRISPR — one of the most important tools when it comes to genetic engineering — has both advantages and disadvantages. But the advantages are too important for many people and the environment that scientists are willing to take the risk while working on how to eliminate them. Genetic engineering, hopefully, isn’t going to be the reason why we all die — like in almost every movie that includes gene editing. Instead it will be the reason we will thrive.
I initially wrote this for me and my friends’ science blog curiouscientists https://sites.google.com/view/curiouscientist It is a new blog so not much is published yet, but I would be very happy if you guys could go and check it out!
Moon, B. (n.d.). Full stack genome engineering. Retrieved May 09, 2021, from https://www.synthego.com/blog/crispr-scientists#:~:text=2.,Emmanuelle%20Charpentier%3A%20CRISPR%20co%2Dinventor
Foulkes, A., Soda, T., Farrell, M., Giusti-Rodríguez, P., & Lázaro-Muñoz, G. (2019). Legal and ethical implications of crispr applications in psychiatry. Retrieved May 09, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6927684/
Tangermann, V. (2018, January 30). A CRISPR future: Five ways gene editing will transform our world. Retrieved May 09, 2021, from https://futurism.com/crispr-genetic-engineering-change-world
U. (n.d.). HAZARD COMMUNICATION: CRISPR/Cas9 Technology.