- This is what the future of genetic engineering looks like. With advanced DNA editing techniques, vaccines for deadly infectious diseases with no side effects are developed in a matter of weeks. Genes from any plant or animal can be combined to create new hybrid organisms resilient to climate change. This technique can even restore extinct species.
Doctors can detect every known genetic disorder early on and repair mutations quickly, giving children happy and healthy lives. - Our environmental clock is ticking. Today, scientists are blazing a trail to this very future. - Tinkering with genes is actually an ethical thing to do. - I want to know what breakthroughs are being made. - Technologies like CRISPR are incredibly powerful.
- What we're doing here is really the beginning of a true revolution. - That will forge the future to... That is incredible. The rise of genetic engineering.
[dramatic music] ♪ ♪ My name is Kondwani Phiri. I'm a genetic researcher. You can say it's in my blood. From an early age of about eight or nine or so, I had just a natural curiosity for the natural world.
Cancer runs in my family. In fact, I lost my aunt to breast cancer. And that piqued my interest in genetics.
I'm fascinated by how the genes we inherit shape our biological destiny, including our health. I believe the key to treatment and cures for diseases like these lies in explicit efforts to engineer human genes. But can we fix not only what's broken, but also enhance our genetic codes and improve on Mother Nature? Someday, will humans direct their own evolution, and should we? [inquisitive music] I'm starting my journey in Washington D.C. to visit a family who's grappling with the difficulties caused by genetic disease.
Hello! Hi, Annabel. - Can you shake hands, Annabel? - Hi. Oh, my gosh. How are you?
Oh, I think she's shy. [chuckles] Four-year-old Annabel Frost has a heart-wrenching genetic disorder. Could you tell me a little bit about Annabel? - When Annabel was born, it was such a wonderful moment. But we were in this happy fog and didn't notice the nystagmus, the eye movements.
We didn't notice the jerky muscle movements. We didn't notice any of that. But the doctors realized that something was wrong. - They diagnosed Annabel with alternating hemiplegia of childhood, or AHC. - Hi. - This extremely rare disorder causes debilitating spells of paralysis, delayed development, and life-threatening seizures.
- She'd have days of paralysis where her whole one side of her body, she'd drag it along behind her as she crawled. - You know, once a day she will have these choking episodes where I need to pick her up and hit her on the back to make sure that she can breathe. - Annabel's condition is a result of a problem in her DNA.
The twisting double helix of DNA is made up of four different base pairs or nucleotides. The unique sequence of these base pairs are instructions for the body to make proteins. The base pairs are like musical notes in a score that tell a musician how to play a song. When all the different sections of the DNA are played, the result is a biological symphony.
[lively classical music] But like a musical note played out of key that compromises the entire performance, there is an error in one of Annabel's genes. - [cries] - The mutation in the ATP1A3 gene is disrupting her nerve cells, leading to her severe condition. AHC is fundamentally intertwined in her genetic code.
There is no restorative treatment or cure. - The medicines that they have are kind of more about masking symptoms in a very unspecific, untargeted way. - And we wanted to try to figure out if there was a way to address the cause and not the symptoms. - Without targeted treatment, Annabel could die any day. both: ♪ Happy birthday dear Annabel ♪ - There's a timeline on this for us. We've got a ticking clock in the back of our minds all the time.
- The Frosts are desperate for any kind of help. From sickle cell anemia to Huntington's disease, millions of people suffer from thousands of genetic disorders much like Annabel's. Unless scientists can address these genetic errors, children like Annabel will suffer agonizing pain, and some will die young. I want to know, can genetic engineering help families like this in the future? Oh, my God. - Oh, that's so nice. [dynamic music] - The double helix structure of DNA was first revealed in 1953 by Rosalind Franklin, Francis Crick, and James Watson.
And within a few decades, scientists discovered how to alter the DNA of living organisms. But gene editing really took off around 2013 when scientists harnessed a molecular mechanism found in certain bacteria. This remarkable mechanism is called CRISPR-Cas9, or CRISPR for short.
CRISPR-Cas9 contains an enzyme that serves as the bacteria's defense mechanism against viruses. When viruses infect the bacteria, the CRISPR machinery targets a specific section of DNA. Then the enzyme responds like a pair of scissors and literally cuts the virus' genetic code apart.
Scientists are now harnessing this natural mechanism to target and precisely edit the DNA of numerous organisms. To find out how, I'm heading to a biotech lab in Brooklyn, New York. I'm on my way to Genspace, which is the world's first community biology lab. Beth Tuck is the Director of Science Education at Genspace.
- We are an open-access science lab or a community biology lab. - So are you telling me if I'm a computer programmer and I wanted to learn more about biology, I could essentially come down here and take a class and use your facility? - That's it. - Beth is going to show me how to use CRISPR in the lab to edit a bacteria's genes in new and novel ways. I brought this kit. Could you explain a little bit how this kit works? - Yeah, sure. Got a pipette. This is our measuring device.
Got a rack where we'll put some of our plastic tubes, some plates, petri dishes, and then our E. coli. - E. coli is a type of bacteria that lives in the intestines of humans and animals. Though some strains can be deadly, most are harmless. Gloved up. Let's do this.
- All right, so we've got our E. coli here. These are called DH5-Alpha, which is a type of species that isn't harmful to people with normal immune systems. - That's good to know.
- So our first thing that we need to do is actually get these bacteria out of this jar. And so you just kind of scoop it in there--yup. swirl it around, bring a little bit up.
The way that this experiment works is we're gonna spend a day to prepare the bacteria. - Next, we insert a CRISPR construct that will alter their DNA. - So we're going to add in the CRISPR machinery and then change the cells. - Ah. The CRISPR machinery targets and edits a specific gene in the E. coli, so that it can adapt to a lethal dose of antibiotics. Normally, bacteria can't grow in the presence of this antibiotic.
The drug kills the bacteria. - We need to get these bacteria onto this plate so they can grow. You're just gonna gently drag it across the surface of the plate. - That's it? - Yeah, that's it. - Over the course of several days, Beth grows the gene-edited bacteria in a petri dish laced with the E. coli-killing antibiotic,
but despite this toxic onslaught, the genetically altered E. coli continued to grow. I see plenty of growth. - The whole point of this is to show that changing an organism's DNA can change its features, and that you can do it with CRISPR in a really precise way, in a way that wasn't feasible before.
- What kind of positive outcomes can we expect from using CRISPR? - You can use it to design new on-the-spot testing for infectious diseases. You can use it to cut out HIV from human cells. There are so many more uses that we haven't even imagined yet. That, to me, is why this stuff is so exciting. - Harnessing the natural ability of CRISPR and transforming it into a technological tool has the potential to address all sorts of problems.
- In the future, advanced gene editing techniques are reworking microbes to create healthier lives. Bacteria are engineered into many pharmaceutical factories. These microorganisms generate an inexpensive, abundant supply of medicines for diseases like malaria, rabies, and coronavirus.
And specially modified yeast converts organic waste into green bio fuels. This innovative energy source is not only renewable, but it also packs more of a punch than regular fossil fuels. [light dramatic music] - Formulated by Charles Darwin, natural selection is the driving force of evolution. While many individuals perish, the species best adapted to their environment survive and reproduce, passing along their advantageous genetic traits to their offspring.
These traits like height, eye color, strength, and even personality are contained in genes. Over generations, the process of natural selection perpetually fine tunes the species at the genetic level, helping individuals to continually adapt to changes in their environment. Humans learned to direct this evolutionary process through artificial selection.
Through the intentional selection of mates, humans facilitated the breeding of animal offspring with desired characteristics. Arguably, the first known example of artificial selection happened more than 15,000 years ago when humans domesticated the wolf, breeding what we now know today as the dog. ♪ ♪ In agriculture, artificial selection has improved and even created new fruits and vegetables.
Through selective breeding for certain traits, the simple wild mustard plant was transformed into cauliflower, cabbage, and even broccoli. But even artificial selection takes at least a few generations to work. Capitalizing on the natural CRISPR process, gene editing in the lab can compress evolution down to a matter of months. Using CRISPR to manually engineer DNA is the next step in accelerated evolution. And with this remarkable tool, scientists can even improve our food supply. This matters, because over 10% of the world suffers from hunger and malnourishment.
I'm in Raleigh, North Carolina, where pioneering food scientist Dr. Rodolphe Barrangou is using gene editing to boost food production and feed the planet. - We're going to be able to breed crops that are more efficient, that are more resistant to disease. The biggest impact CRISPR may have short-term, maybe the next decade or so, will to be to revolutionize the food supply chain.
- In fact, Rodolphe had a hand in the discovery of the natural CRISPR mechanism in bacteria. And his use of CRISPR as a technology in milk is leading to remarkable innovations in dairy products. - So what we're looking at here is milk that is in the process of fermenting. - Okay, so this is in the earlier stage of things? - Very early stage. So we add the bacteria to start the fermentation process and then use the lactose to solidify milk into cheese and yogurt. - In most dairy facilities, regular bacteria and yeast kickstart the fermentation process.
But before starting, Rodolphe added a twist. He used CRISPR technology to enhance the bacteria used in the fermentation of milk. - We used it to build just instant bacteria to make cheese and yogurt, to have better fermentations and better manufacturing of dairy products. - By vaccinating the bacteria, his dairy cultures almost always succeed, which improves the process of making yogurt and cheese. Processes like these also make them healthier. - CRISPR has been a life changer.
And it also has opened tremendous avenues to provide a healthier and more sustainable food supply for humanity. - But the true revolutionary potential of CRISPR technology is just now starting to be realized. - Other people caught on to using these molecular machines to actually cut DNA to do genome editing, not just in bacteria, but in other organisms. By understanding what CRISPR is and how it works, scientists were able to develop technologies that enable us to now change the world. [bright electronic music] - By 2050, the world population is expected to soar to 10 billion people. Food production will need to increase 70% to catch up.
To feed our growing population with the same amount of farm land, the mass production of food must be hyper efficient. At NC State Plants and Microbial Biology Lab, Rodolphe's colleague, Mary Beth Dallas, is facing this daunting prospect. - I manage this lab, and I also do research on cassava. - Also known as the yucca plant, cassava is the primary food staple of nearly one billion people. - Cassava plant is very close to my heart.
- This root vegetable is kind of like a potato, and is widely grown across Africa and the Americas. - They can actually harvest the tubers and make flour, and they can make breads out of that. They can also eat the greens. It's really a nice plant. - Yeah, and me being a native Zambian-- that's where I was born. I grew up eating cassava as well as cassava leaves, so...
- You know all about it. - I know all about it. It has a special place in my heart as well too. But there's a problem. A malady called cassava mosaic disease is ravaging this critical food source.
In Africa alone, it's destroyed cassava crops, leading to numerous famines. - You can see here the devastation of the plants. It gets really thin leaves, and a mosaic pattern occurs. When the leaves get destroyed like this, they cannot photosynthesize properly and the tubers that are under the ground cannot get the right nutrients, and they get all shriveled, and then you can't use the tubers for the food.
We want to combat and try to find a way to stop the devastation of these crops. - To wage this war, Mary's lab must take an experimental approach. [energetic music] Using what's called a gene gun, CRISPR-altered DNA is injected into the cassava plant. - We bombard the stems with the CRISPR construct, and what happens is the leaves grow up. - Ah. In principle, as the leaves and the tubers grow from the stem, the plant will become more resistant to the crippling mosaic disease.
When can we see a possible usage in African countries that are afflicted? - We're still trying to hone in that technique. So hopefully, we'll get it soon. - Hopefully soon. [laughter]
Imagine--gene editing could help end world hunger. - This is also applicable beyond crops to things like trees. Forests may be the biggest farms that we have. - But as the human population grows, so do our agricultural needs. This leads to deforestation, which is one of the primary causes of climate change, contributing to the record high temperatures we see today. To reverse this scary trend, one solution is to plant more trees to absorb greenhouse gases like carbon dioxide.
Rodolphe is collaborating with tree biologist Dr. Jack Wang to grow more trees, and fast. What do we have here? - So these are transgenic trees. - Jack's lab has created over 10,000 types of genetically modified trees.
The goal is to optimize traits for different industries, like timber or paper, to reduce their environmental footprint. - We deliver CRISPR into these cells. - Once CRISPR has altered the tree DNA, the embryos then grow enhanced roots and shoots.
- so these have been engineered precisely for a specific genetic change using CRISPR. - This helps Jack to select for specific traits more quickly and efficiently than traditional plant breeding. - So this little bit of seedling is now a tiny little CRISPR-edited forest tree species.
- This is at the stage just before it goes into the greenhouse? - That's right. So it's now ready to be grown for five to six months. - Fantastic. So cool.
Jack's next step is taking these seedlings over to the greenhouse where they'll be fully grown and studied. - Compared to 15, 20 years it takes to breed a tree in a natural population, in the greenhouse setting, we can analyze and produce new genetically improved trees in as little as five to six months. - That is incredible. Six months?
Here they're quickly growing poplar trees, which is the most effective species at absorbing carbon dioxide from the air. - Yeah, they can capture a very large amount of carbon from the atmosphere, and we have to start solving the problem right here, right now. We cannot afford to wait for another 20 or 30 years. - This technique for breeding trees has given reforestation efforts a major jump-start. Our environmental clock is ticking, and if we want to create a better, healthier environment for future generations, it's something that has to be done now. - What we're doing here is really the beginning of a true revolution.
The next green revolution, coming to a forest near you. - Yes. - I think it's going to revolutionize our world and solve the grand challenges that we have on the planet. - A new CRISPR-fueled green revolution will forge a path to a more bountiful world. [dramatic music] - In the future, gene edited plants are addressing world hunger and climate change. Enhanced food crops grow in harsh conditions, even in water-parched deserts.
Thanks to these disease-resistant plants, famines across the world are a thing of the past. New fast-growing forests collectively take in the excess carbon dioxide from the atmosphere, cooling the climate and restoring balance to the world's ecosystem. [inquisitive music] - As I see it, gene editing is both a faster and more precise method for artificial selection. While it works in microbes and plants, how feasible is gene editing in more biologically complex organisms like animals? I'm in Davis, California, to meet geneticist Alison Van Eenennaam. She's a pioneer in this field, and I'm getting acquainted with her work. Oh, no.
- Scientists tend to be problem solvers, and want to try and address problems using the best method they can, and my lab is trying to breed better cattle. - There are about 1 billion cattle on earth. That's a lot of animals to manage, but Alison is making cattle farms safer by eliminating one particular trait.
- I see some horns up here. - Okay. - Dairy cows have been bred to be very optimal for dairy production, and, as it happens, dairy cows grow horns. - And these horns are a problem because they injure other cattle and ranchers. - You can imagine if this was a particularly aggressive bull, that he could hurt his pen mates. - Instead of manually sawing off these horns, Alison is breeding a dairy cow that doesn't grow them in the first place. Working with a type of cattle that has no horns, she had their hornless gene inserted into horned dairy bull cells.
These cells were cloned to make the hornless animals. These hornless cows are descendants of a gene-edited hornless bull. - These are proof of concept animals. They are kind of a prototype of how you could use genome editing. - This genetic technique produces offspring with a desired trait much more quickly than the decades of breeding normally required in traditional animal husbandry. - That's really what editing does for us, is it enables us to bring in one useful characteristic that we want-- in this case, not growing horns-- and not alter the rest of the genetics.
- This technique shows that gene editing tools can be used to introduce desirable traits from one animal into another. [light music] Outside of trying to remove the horns, are there any other expressions that you would want to get rid of or add? - So what else might we do? One of the targets that's a really obvious one for plant and animal breeders is disease resistance. And so globally it's estimated we lose about 20% of all animal production to disease. - That's a large percent. That's hundreds of millions of cattle needlessly lost every year.
- To me, genetics is the best approach to deal with disease, 'cause if they don't get sick, they don't need to be treated with antibiotics. They're more productive. Farmer's happy, cattle are happy, consumers are happy. So it's kind of a triple win for sustainability.
- But there's an even more fundamental trait that Alison is trying to select for. - In the beef cattle industry, we would actually prefer males. - That's because male beef cattle produce quantitatively more meat per pound of feed than females.
So Alison is also using gene editing to breed cattle who only produce male offspring. To achieve this, she inserts a special gene into cow embryos in the lab. This makes selecting the male sex possible.
This could save more animals from being slaughtered, and techniques like these could be used to insert disease resistance, potentially reducing the need for antibiotics. In fact, a gene-edited embryo was implanted into this cow just three months ago. - And there is Princess.
- So in a few short moments, we're about to see an ultrasound of a cow here. Veterinarian Bret McNabb is going to perform an ultrasound on Princess to see if the gene-edited embryo has taken hold. - We're just gonna make sure that the pregnancy is still healthy and viable from what we can tell.
- So an ultrasound on a cow is not quite the same as an ultrasound on... [laughter] - The principles are the same, but our approach is a little bit different. - Alison's checkup may depend on the whims of this mama cow to get the ultrasound scanner up her... well, you know. [quirky music] ♪ ♪ [cow lows] - [chuckles] You're doing that next time.
- You know, I'm learning quite a bit just observing, so... - Oh, I see. [laughter] - She's pregnant. - That's good news. - It appears the embryo implant has successfully taken hold. - So on ultrasound, you know, we use sound waves, and so anything that's more dense is gonna bounce the sound wave back to my probe. And then you can start to see floating around in there are those bright white structures.
Those are all parts of the calf. - Oh, yeah. Okay. - Based on certain structures, we can sex the calf, and it looks like a male. - For Alison's endeavor to breed male-only beef cattle, this is a significant milestone.
While these techniques are still experimental and haven't yet been approved by the FDA, Alison believes that consuming products from gene edited cattle poses no threat to human health. Artificially selecting for the male sex could make cattle production more humane and more efficient. - There are some pretty compelling benefits that outweigh the risks.
- Seeing the genetic engineering of livestock up-close and personal is absolutely mind-blowing. [bright music] - In the future, engineering the genes of farm animals speeds up their evolution as useful domestic species. A new variety of cow gene edited to dramatically reduce the emission of the climate-damaging gas methane is vastly reducing global warming. Organs from genetically modified pigs are safely implanted into humans without fear of rejection from the immune system.
No one dies from a lack of an organ donor anymore. [energetic music] - Humans have selectively bred plants and animals, refining their traits, for thousands of years. We've even created hybrids by mating creatures from two different species.
For example, a donkey and a horse make a mule. But in the lab, mixing up genetics can result in anything and, well, everything. Jellyfish DNA spliced into a bunny results in a fluorescent bunny. When spider DNA is edited into goats, their milk can be spun into spider silk. Hybrids like these are often bioengineered for research purposes.
But one scientist is using CRISPR's crossbreeding ability to do something truly ambitious. He's bringing back the genes of extinct species. I'm in Cambridge, Massachusetts, to meet Dr. George Church, a legend in the field of genetics, one of the originators of gene engineering.
He's been working in Russian Siberia to find the remains of woolly mammoths with the aim of resurrecting their DNA to fight climate change. - There's unfortunately lots of melting ice in Siberia. As there are millions of mammoths that are frozen that are becoming exposed, we had access to six really excellently frozen specimens. They had never thawed in 40,000 years. - When you were grabbing the samples from the woolly mammoth, anatomically where... - We're dissecting big chunks of mammoth legs with a drill bit, and we're kind of suited up because there's meat flying all over the place.
- Due to overhunting and environmental changes, woolly mammoths began going extinct around 10,000 years ago. But George is extracting their DNA from the cold preserved remains in Siberia and mapping their genome. - So we read the genome into the computer and then we write it into modern Asian elephant cells.
- Modern Asian elephants and woolly mammoths share common ancestry, but are two distinct species. George is using advanced CRISPR techniques to resurrect multiple cold resistant genes from the woolly mammoth that grow extra hair and produce more fat. He then plans to integrate these genetic traits into the eggs of Asian elephants. - We can make dozens of edits to the genome and then clone them into baby elephants.
- But why? It turns out cold-resistant elephants could also help mitigate global warming. In the frigid tundra of Siberia, grass is more effective at keeping the Arctic cold than the current forced environment, which retains heat. - Those millions of square kilometers are at risk of warming, and the only herbivore that can knock down the trees is the elephant.
Oddly, the herbivores can change it back to grasslands, which is more photosynthetic. - A sizable population of cold-resistant elephants would help maintain this region as grasslands through grazing. And a more photosynthetic Arctic would absorb more carbon dioxide. - So it's part of what will hopefully be a big international effort to convert the Arctic, at least partially, back to the form that was more conducive to fighting climate change.
- Is it outside of the realm of possibility to, say, bring back an extinct creature like a woolly mammoth? - Once we get that good at it, we may switch the cold-resistant elephants into fully genetically identical mammoths. - Who knew resurrecting woolly mammoth DNA could help restore icy conditions across the Arctic? - In the future, genes from most creatures can be safely inserted into other species to create revolutionary hybrids. Engineered jellyfish with genes from plastic-eating microbes now clean up the oceans by organically breaking down non-decomposing trash. Some scientists have even extracted DNA from dinosaur remains and are on the brink of resurrecting these extinct species.
The hope is by bringing a single dinosaur back to life, new technologies will be developed to help other species on the brink of extinction. - Speaking with George Church firsthand is both humbling and inspiring. As if resurrecting the DNA of the woolly mammoth wasn't enough, he also helped start the $3 billion Human Genome Project. This landmark study identified every base pair of DNA and mapped the entire human genome.
Its primary purpose was to conquer disease. It was and remains a really big deal. - We are here to celebrate the completion of the first survey of the entire human genome. - This roadmap of the intricate genetic codes across the human body empowers doctors to better diagnose and treat disease. - We've worked really hard on bringing down the costs of reading genomes, which I think is a thing that most people could benefit from. - Thanks to advances in DNA sequencing technology, the cost of reading entire genomes has plummeted.
- All it would take is a small tipping point event to shift it over so that everybody's using this. And in the case of genetics, that would be reading everybody's genome and giving them information that was actionable. - By actionable, he means letting individuals know what kinds of diseases they're genetically susceptible to.
This empowers people to be proactive in avoiding or managing imminent diseases. - I think we're on a trajectory where everybody in the world are gonna get sequenced within a few years. - The Human Genome Project continues to have a big impact in treating all kinds of human diseases. [light dramatic music] To find out how, I'm at the historic Cold Spring Harbor Laboratory in Long Island, New York, to meet with Dr. Bruce Stillman. - There has been a revolution coming from the Human Genome Project and a lot of cancer research is linked to that.
We now have a very deep understanding of that genetics and what that can do is to link new therapeutics to individual patient's genetics. - I have an interest in oncology. - Mm-hmm. - I lost an aunt to breast cancer, and I think that took me down this journey towards finding a solution.
- One of our scientists used a very interesting genetic technique of genetic selection, and now we're gearing up to use that information to improve cancer therapy. - Founded in 1890, this lab is home to eight Nobel Prize winners. - So this was the first lab at Cold Spring Harbor, and still used. This is a cancer laboratory, so still used for cancer research.
- Scientists here are using gene editing techniques, including CRISPR, to develop new ways to fight cancer. These advances are leading to treatments, tailored to work with an individual's unique genetics. - So for instance, if you have a mutation in a particular gene that causes lung cancer, there is a therapeutic that is targeted to that lung cancer. - But in the shadow of its long history of using genetics to improve human life, Cold Spring Harbor Labs do have an unfortunate and dark past. - What happened in the 1910s and the 1920s was that scientists began to believe that a lot of traits were inherited by individual genes, when in fact they weren't.
- This led to an era of what's called eugenics-- that is, the selective breeding of humans. Cold Spring Harbor Labs even opened a eugenics records office to gather biological information on the American population. At the time, people of certain traits that some believed to be desirable were deemed fit to reproduce, while minorities and those with disabilities were blocked from marrying and were even sterilized. - That eugenics movement got way off track from science. Scientists pushed back against this eugenics movement, and, by the 1930s, it was effectively shut down in the United States. - Despite this skeleton in the closet, it's important to know our history so as not to repeat it.
And from what I see at Cold Spring Harbor Labs today, I think there's plenty of room to be optimistic. When real science is conducted, true progress can be made. And the best place to start is with affected children. - We have worked on a disease called spinal muscular atrophy, which is a mutation that children inherit. The child will eventually die.
But the laboratory developed a drug, which actually prevents these children from dying and actually gives them a fairly high quality of life. - All this makes me think of young Annabel Frost and her debilitating genetic disorder. And this kind of research fills me with hope. In fact, genetic engineering can even remedy genetic disorders like sickle cell anemia. Caused by a mutation, this disease deforms blood cells into hook-like shapes, which can stick together and cause life-threatening blood clots.
- CRISPR's now being used to change genes in sickle cell anemia, where you then transplant back into those patients cells in the blood system that will essentially reverse the sickle cell disease. And so those types of trials are occurring now with CRISPR. - Recently, scientists gene edited a patient's own stem cells that produce bone marrow. They then reinjected these altered cells back into her body. Amazingly, this therapy cured the patient's sickle cell disease for the first time in history. - Technologies like CRISPR are incredibly powerful and can change the world.
They also have the potential for changing humanity as itself. - But there are limitations. The CRISPR technology is not perfect, and sometimes it makes mistakes in the genetic reworking that could be catastrophic. This means CRISPR's implementation directly into humans remains a risky prospect. But one visionary scientist is aiming to give gene editing techniques an even higher level of precision. Dr. David Liu of the Broad Institute of Harvard and MIT
is working on tools and techniques that may one day lead to the safe gene editing of humans. He's developing a new gene editing tool called prime editing. Can you tell me a little bit about your work in that regard? - So the machines that nature provides us, like CRISPR-Cas9, often don't do what we want them to do. The results of breaking that double helix most frequently disrupts things to cause the deletion or insertion of small numbers of DNA letters at the cut site. - Both CRISPR and prime editing technologies work by cutting DNA. But in some sensitive situations, CRISPR technology can be too blunt of a tool.
That's because it breaks both strands of the double helix. In rare instances, this can disrupt the gene in unintended ways. But prime editing is more like a pair of tweezers. It breaks only one strand of the double helix, allowing scientists to very precisely change a single base pair. This is like changing one note in a musical score. - For most diseases with a genetic component, it's believed that in order to treat the disease, you need to precisely change that mutated gene back to the normal DNA sequence.
- This ultra-precise technique means David can replace an individual mutation on a single step of DNA and not an entire section of the ladder. - So you can make those kinds of changes using prime editors, the kinds of changes that we believe could directly correct genetic disease-causing mutations. - In the lab, David has successfully corrected mutations for genetic diseases, including Tay-Sachs and cystic fibrosis. And he thinks this prime technology will soon be ready to help people with genetic disorders, like Annabel.
How far off would you say is a potential human application? - We should have some of the first drugs ready by perhaps as early as within the next five or ten years. It's an incredibly exciting time. If you had asked me about five or ten years ago, I would have said it still was in the realm of science fiction. - Yeah, that's wonderful. This experimental technique will become science fact, giving affected individuals the prospect of a better life. But for now, reworking the genetic codes of people remains controversial.
In 2018, a researcher stunned the world by using CRISPR to gene edit HIV resistance into the embryos of a pair of twins. Called germline editing, this technique on humans was considered premature and was widely condemned in the scientific community. - The first gene editing in humans was a profound misuse of science with profound implications in society in general. - The involved parties were punished for disregarding safety regulations.
Fortunately or unfortunately, the Pandora's box of genetic engineering has been thrown wide-open. - In many ways, this is one of the costs of doing science. The technology itself is agnostic.
It's neither good nor bad. The real question is, "What do people do "with that technology and how careful and/or mindful are they to the potential unintended consequences that we have?" - With the depth of control over evolution that gene editing enables in breeding plants, animals, and eventually humans, we are entering uncharted waters as a species. It's difficult to draw a hard line between where progress should stop and where our morality or our ethics should come in.
Some might argue that some lines have to be crossed to make progress. And there has been much progress, especially in agriculture. Today, more than 90% of corn and soybeans are genetically modified, or GMO. These crops require less pesticide, land, and water. Scientists are also using gene editing to develop crops that are more nutritious and even drought-resistant.
Though many in the public remain skeptical, the vast majority of scientists believe GMO foods are safe. - Tinkering with genes for benefit and for good purpose is actually an ethical thing to do. - And as for humans, many believe the benefits of gene editing outweigh the risks. - There are 10,000 monogenic diseases affecting hundreds of millions of children across the world.
Precise medicine would help, and then we start building on that. - In the right hands, I think genetic engineering will usher in a much better future for people and our planet. Some think it will even shift human evolution into overdrive.
- In 30 years, we may be unrecognizable. I don't think that's going to be our intention, but when you take these big leaps and get comfortable with them, people get addicted. - I'm hopeful that gene editing technology will ultimately help people like my aunt and Annabel and, for those reasons and many more, I believe the rise of genetic engineering can't come fast enough.
2024-02-06