Think Out Loud

WSU receives FDA approval for gene-edited livestock in human food

By Elizabeth Castillo (OPB)
May 15, 2023 4:26 p.m.

Broadcast: Monday, May 15

Researchers at Washington State University have made history with a German-style sausage. It’s the first university to receive authorization from the Food and Drug Administration to have gene-edited pigs enter the food chain for human consumption. A company called Acceligen had previously received such an authorization for cattle, according to the university. We’ll learn more about what this means for food production from Jon Oatley, a professor in the School of Molecular Biosciences at WSU.


The following transcript was created by a computer and edited by a volunteer:

Dave Miller: From the Gert Boyle Studio at OPB, this is Think Out Loud. I’m Dave Miller. It’s not every day that a sausage is part of history but researchers at Washington State University announced recently that they got authorization from the Food and Drug Administration to have gene edited pigs enter the food chain for human consumption. The researchers took the resulting pork and used it to make a German-style sausage. Jon Oatley is a professor in the School of Molecular Biosciences at WSU. He joins us to talk about the implications of this work. Welcome to Think Out Loud.

Jon Oatley: Hi, Dave. Thanks for having me on the show.

Miller: Yeah. Thanks for joining us. The gene editing technology that you used is known as CRISPR. Can you remind us what CRISPR is?

Oatley: Sure. Think of CRISPR like a molecular scissor-like tool. We can use it for cut and paste outcomes at precise locations in DNA. When we make those changes, we can alter the traits or the characteristics of an animal.

Miller: How is this kind of gene editing different from existing GMO or genetically modified organism technology that has now been around for decades?

Oatley: Conventional genetic modification involved what we call transgenesis, which introduces a foreign molecule into the DNA. It’s something that could never arise in nature. It’s something that has to be put together in a laboratory and purposely inserted into DNA.

Gene editing is different in that we can make changes in the DNA using these molecular scissor-like tools that can and do arise in nature. So we’re not putting something foreign or unnatural into the DNA. We’re just making little changes in the ATGs and Cs that make up DNA and therefore we can change the trait in a way that could arise in nature, whereas conventional strategies in GMO is something that could have never arisen in nature without humans intentionally doing it.

Miller: Is what you’re describing inherent in the difference in CRISPR technology and conventional genetic modification or is it more in the way you’re using it? I mean, would anything prevent you from using CRISPR to put in some genetic sequence that would never, say, be in a pig to begin with?

Oatley: Absolutely, CRISPR can be used to insert foreign DNA,

something that is not natural. But what we are doing with CRISPR and what a lot of developers in the food animal space are doing with CRISPR is to bring about changes that can and do arise in nature, not to insert foreign things. But when you insert foreign DNA into the genome of an animal, it’s more for biomedical purposes or bio-pharmaceutical purposes, rather than trying to shape traits to improve resiliency or improve welfare of the animal or improve their production efficiency. So you can use CRISPR to bring about those conventional GMO outcomes. But most developers that are creating gene editing CRISPR applications for food animal production are not doing that. Instead, they’re making changes in the DNA that could arise in nature.

Miller: So let’s turn to the work that you and your team actually did. How does this work with pigs, can you give us a sense for what the work entails?

Oatley: Sure. At WSU we’re using gene editing technologies to try to enhance the traits of food animals to improve things like their resiliency, their welfare, their health, and their production efficiency. We’re trying to do it in a climate smart way. The reason we’re doing that is to try to address food insecurities that exist now but also fortify the future of food security as the human population continues to grow and the climate changes.

So we design strategies. We have a trait in mind and we design strategies to try to improve that trait or alter that trait. Then we can design the molecular scissor in CRISPR to go in and make a change in the DNA that we think is gonna lead to an outcome that is gonna improve the production and the efficiency and the welfare and the resiliency of that animal. We do that initially in a laboratory setting; we create a change in the DNA and we create an [inaudible] for that change. Then we study it to see if the change that we made leads to the outcome we are hoping it will. If it does, then we’re at the next step in the process, which is, how do we advance it from a laboratory into the public domain to have an impact on how food animals are produced.

So that’s where we were at a couple of years ago, when we had developed a concept of a genetic change that we would be making in animals using CRISPR. We did all of the research to show that the change we were trying to make led to the outcome we were hoping it would and then we needed to start to advance it out of the lab. One of the key things to advance out of the lab into the public domain is to go through the federal regulatory process with the Food and Drug Administration.

Miller: Before we get to that, can you give us a sense for the actual... maybe even just one trait in particular that you think is really important? You mentioned resiliency, health efficiency all in the context of a changing climate. So, what’s one trait that you think is going to be especially helpful for pigs as protein sources for humans going forward?

Oatley: For the pigs that we produce the trait we went after was to improve their reproductive capacity. The reason we go after reproduction is because it’s a key aspect of food animal production. If we want to introduce new genetics or change the genetic makeup of a population, it has to happen through sperm and eggs. Those are the only cells in the body that have information that’s transmitted [inaudible] across generations.

So, if you can improve the reproductive capacity and the availability of genetic information through reproduction, it can have a dramatic impact on shaping the traits of an entire population. With these pigs, the one trait that we went after is to alter their reproductive capacity. So to do that, we made a genetic change with CRISPR into a very specific gene in the DNA that we thought was gonna be important for the reproductive performance. So that was the one trait that we targeted with these pigs.

Another key trait for targeting in pig production is disease resistance. So we have some projects working on that as well. But those have not been advanced through the FDA authorization process.


Miller: Is ‘reproductive capacity’ the number of piglets that a sow would have?

Oatley: Right. So it is on the female side. There’s two sides to the ‘reproductive capacity’ aspect, one is on the male side and the other is on the female side. On the female side, it’s the number of offspring that they can have and then they can rear to a weaning stage.

On the male side, it’s about the genetics of the sperm containing the amount of sperm that that one male is producing because the more sperm available, the more impact that his breeding performance can have on a population. With these pigs, we are actually targeting the male side. So we are increasing the availability of sperm that have important genetics, important elite genetics.

Miller: You said elite genetics?

Oatley: Correct.

Miller: To go back to the big part of this announcement, in a lot of ways, it seems more like the scientific breakthroughs happened a number of years ago and then it takes, again, a number of years to get regulatory approval. And that’s what this new announcement was. What did it actually take to convince the FDA to allow meat from these gene-edited pigs to enter the human food supply chain?

Oatley: This is really a groundbreaking step because there’s not a solidified blueprint with the current regulatory framework on how to advance animals that possess a gene-edit  into the food chain. We are working kind of hand in hand with the FDA to figure out what is the right process. It took us about two years to go through that process. The reason it took about two years is there’s a lot of data collection that we have to do in order to show the normalcy of the animals and that the DNA is normal except for the specific spot in which we chose to make a change. So it takes a long time to collect all of that data, do the health parameter assessments, do all of the genomic analysis we need to do in order to demonstrate that the animals are normal in every way except for the one trait that we chose to change. It takes a long process to do that and we were figuring out step by step along the way, to give the information to the FDA that they felt they could review and make an informed decision on the safety of introducing the edible product from these animals into the food chain.

Miller: In the final analysis, any kind of meat - in this case, that came from animals where there had been gene-editing - how do they decide, ‘Yes, this is safe?’

Oatley: Yeah, it’s a tough one to address fully because just normal selective breeding and everyday animal production produces new combinations of DNA. Every time an offspring is born, it has a new combination of DNA that may produce some change in property to the meat. So, distinguishing between just normal production practices of a meat animal versus gene-editing production of a meat animal is really hard to break those two apart, because they’re almost identical. We have to go off of our best scientific knowledge that we have.

One of the ways is to look at the health of the animal in terms of their health parameters. What their growth characteristics are like, what their meat properties look like, what the changes in the DNA did, what didn’t change, and what we would predict to be a composition of the meat product. The last step in the process is the US Department of Agriculture’s Food Safety Inspection Service doing a pre-mortem and an anti-mortem inspection of the animal including the carcass to judge that there really is no abnormalities that were observable.

Miller: Does this approval mean that now any producer could use the same techniques that you did and the FDA will approve the pork that results?

Oatley: It does not necessarily. The approval process right now, in the current regulatory framework, requires individual approvals. We were granted approval for this handful of animals – authorization for this handful of animals - for their edible product to enter the food chain. Any producer or other scientific investigator that wants to get their animals that they’ve created authorized would have to go through the same regulatory process that we did. So this isn’t a blanket approval. This is a ‘proof of concept’ blueprint for how to do it going forward.

Miller: Are large-scale commercial operators in the process of following in your footsteps now?

Oatley: That’s what we’re hoping to do. So, we’re hoping to be able to advance the ‘proof of concept’ applications in food, animal agriculture, out of a laboratory setting, out of a university setting, and getting it into the hands of producers for scaling up. Universities aren’t really built for scale-up. They’re built for doing proof of concept and then translating that out to producers…

Miller: Translating, potentially licensing the intellectual property that you created there and then getting some money from the producers?

Oatley: Potentially, or through the extension system that exists in land grant universities to transfer the technical know-how out of the laboratories to producers hands. So it can come in a couple of forms. One can be developing a commercial channel through licensing the intellectual property but the other is through a channel that would be advancing technical know-how out of the university setting into a producer hand.

Miller: Before we go, I’ve got to go back to some of the science about the sperm that we talked about earlier, because I guess I just have a basic misunderstanding about this, perhaps. I used to [think] that there are hundreds of thousands or millions of individual sperm in ejaculate. I guess I would have thought that there’d be enough there that you wouldn’t necessarily need to go to a lot of trouble to get sperm that producers could then use. Am I wrong about that? I mean, are the numbers not really high in any individual sample?

Oatley: They are really high but millions need to be deposited in the female reproductive tract just to get one pregnancy. So even though males make millions and millions of sperm every day, millions and millions of sperm need to be delivered every time the female is bred in order to just get one pregnancy. So reproductive capacity is really not a highly efficient process in a lot of species.

The other is an individual male can have elite or desirable genetics that we want to use for breeding purposes in say 1,000 different production settings that one male can only have a regional impact. So trying to get that one male to be able to produce more sperm or carbon copy the sperm that are available to be able to disseminate out on a large worldwide scale is something that requires biotechnologies.

Miller: Jon Oatley, thanks very much for explaining this to us. I appreciate it.

Oatley: Absolutely. Thank you for having me.

Miller: Jon Oatley is a professor in the School of Molecular Biosciences at WSU, part of the team that recently got FDA approval for meat for human consumption from gene-edited pigs.

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