Gene editing may be more palatable than GMOs, but it’s up to the public to decide.
Genetically modified organisms, or GMOs, have caused quite a stir in agriculture in recent years. While some have touted its potential to help us solve hunger problems, others have raised concerns about its health and environmental impacts. Although scientists and regulators generally consider GMO foods safe, the public remains hesitant.
Now, a new player has emerged in the genetic engineering field—genome editing.
GMOs vs. Gene Editing
GMOs and gene editing are both forms of genetic engineering that have potential uses in agriculture and other areas, but they’re not the same process.
The creation of GMOs involves inserting genes from other species into DNA. Gene editing, on the other hand, allows scientists to alter the DNA of an organism without adding genes from a different organism. Gene editing is the precise editing of an existing genome.
Scientists have been researching this technology in healthcare for years. One in 25 people is born with a genetic disorder. With gene editing, scientists are able to delete the genes that cause disorders like sickle cell anemia, muscular dystrophy, and cystic fibrosis. We can also use the technique to make immune cells better at fighting cancers and other diseases. Scientists are even working on using it to grow human organs in pigs for transplants.
Gene Editing Technologies
To edit genes, scientists use nucleases, a sort of molecular pair of scissors, to create double-strand breaks in the genome in the desired locations. They then re-attach the separated ends, creating a targeted gene mutation.
Researchers have discovered and bioengineered several types of gene editing tools, including:
- CRISPR-Cas9: Clustered, regularly interspaced, short palindromic repeats are the most recent, advanced, and well-known of the gene editing technologies. Cas9 is an enzyme that cuts the DNA, while CRISPR are segments of prokaryotic DNA that tell the enzyme where to cut.
- ZFNs: Zinc-finger nucleases are proteins that bind DNA sequences and create a double-stranded break at a specified location in the genome.
- TALENs: Transcription Activator-Like Effector Nucleases come from Xanthomonas bacteria where they bind and activate host promoters.
- rAAV: Recombinant Adeno-Associated Virus exchanges nucleotide sequences rather than creating a double-stranded break. Instead, it causes endogenous homologous recombination.
- Transposons: Transposons are segments of chromosomes that can be moved to a new location in DNA.
Gene Editing Pros and Cons
Gene editing has an advantage over genetic modification for several reasons. It’s more precise than GMO processes, and technology keeps getting more reliable. It’s also relatively cost-effective compared to other methods, meaning more scientists could gain access to it. All of these advantages mean more potential innovation.
How successful gene editing is, though, will also depend in large on how it’s perceived. Some of the public is still resistant to GMOs, and genetically edited crops (GECs) could face some of those same problems.
They do have one advantage over GMOs in this department though. Because they don’t introduce foreign genes to the crop, consumers might view them as more natural and therefore more appealing. However, there will still be some who will take issue with this so-called “Franken-food.”
Uses of Gene Editing
Gene editing has several potential uses, but the most impactful and most soon-to-be-realized will likely be in the agricultural space. It will have many of the same applications as GMOs but hopefully with broader acceptance.
Scientists could potentially create GECs that stay fresh longer, are resistant to drought, insects, and disease, grow bigger and taste better, among other things.
GMOs have long contended with heavy regulation and lengthy approval processes. Some believe that GECs will be able to avoid such strict controls because the technique avoids introducing foreign genes to a crop. A simpler regulatory process would reduce the cost of creating GECs and lower the barrier to entry so more people could use the technology.
So far that seems to be the case. A team of researchers from Penn State University recently sent a letter to the United States Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) asking if their mushroom, which they had edited with CRISPR, was regulated. APHIS responded that it is not.
States could still decide to regulate the process, however. A third of the vegetables and around two-thirds of nuts and fruits grown in the United States come from California, which is a highly regulated state. Consumers might also, in a sense, regulate it themselves too by choosing to buy products labeled as GEC-free as many do with GMOs.
Of course, though, it remains to be seen how exactly regulation of genome editing will play out.
Gene editing technology, especially as we understand it now, does have its limitations. Scientists have to know what a gene does before they edit it, and we don’t yet know how many genes work.
Because the technique doesn’t introduce any outside genes, scientists also can’t add a characteristic to a crop that isn’t already present somewhere in the genome. Some plants might have a gene that deals with drought resistance, for example, but not one that protects against a particular virus. You would have to genetically modify the plant to give it that characteristic.
As the associated technology and scientific knowledge improve, our capabilities will expand, but genome editing does have certain limitations.
It’s hard to say where exactly the technology, science, regulations, and public opinion will go from here, especially since the ability to edit genes in this way is so new. In the near future, we can expect more edited crops to become available. As they do, we’ll begin to get a glimpse of how the public reacts.
While there are many potential ways the story of gene editing could unfold, the technology certainly has a lot of potential to change various parts of our lives from the food we eat to how we treat medical conditions.