PULLMAN – Savory sausages sizzled on the grill at a spring cookout last week outside Washington State University’s meat lab. The fruition of over a decade of research, these special links were produced from gene-edited pigs.
WSU is the first university to seek or to receive approval from the U.S. Food and Drug Administration to produce gene-edited meat for human consumption.
Head researcher Jon Oatley called it a landmark for introducing biotechnologies into animal agriculture, which is essential for producing more resilient protein sources in the face of climate change and a growing human population.
“For me it’s exciting because all of the work we do in the lab is for naught if we cannot work through a regulatory process to get it out of the lab into the public domain,” Oatley said.
His team of researchers celebrated last week by barbecuing the pork as German sausage, prepared by WSU Meats Lab.
Meat scientist Blake Foraker made some of the pork into sausages, which will be used in catering services that raise travel funds for the student members of the WSU meat judging team.
Oatley, a professor in the School of Molecular Biosciences in WSU’s College of Veterinary Medicine, said the pork tasted outstanding.
“I went back for seconds,” he said. “If I was still hungry, I probably would have gone back for thirds.”
The team uses the gene-editing tool CRISPR-Cas9 to select desirable genetic traits in food animals including cattle, sheep and goats.
The tool could be used to improve meat quality and to make animals more resistant to heat and parasites.
Gene editing works by making changes to an organism’s DNA that could occur in nature or through selective breeding, but would take much longer without a tool like CRISPR.
The process uses sterile males, known as surrogate sires, to sire offspring with traits from another male pig.
The sires are produced by turning off a gene in males called NANOS2 that is specific to fertility. The surrogates are then implanted with another male’s stem cells that create sperm with that male’s desired traits to be passed on to the next generation through natural reproduction.
Once introduced, the genes are inheritable throughout the population.
The sausage meat came from five surrogate sires that were two years old.
The project spent two years collecting data to show that the animals, other than the specific change they made, were otherwise completely normal and safe for humans to eat.
“As best we can tell, there is no inherent risk to the welfare of the animal or risks to humans for consumption,” Oatley said.
The only known function of NANOS2 is to drive sperm production. Other than an inability to produce sperm, the researchers could not measure any other difference compared to veterinary health standards.
The U.S. Department of Agriculture also inspected the meat and could find no difference.
The FDA authorization is investigational and limited to these particular pigs. The surrogate sires’ progeny, which are themselves not gene-edited, have not yet been reviewed by the FDA for possible inclusion in the food chain.
Only one other organization, a company by the name of Acceligen, has had a gene-edited animal receive an OK from the FDA to enter the food supply. In 2020, the FDA made a low-risk determination for products made from “Slick-Haired Cattle,” which are gene-edited to have coats that increase the animals’ resilience to higher temperatures.
The project was a team effort involving graduate students, doctoral fellows, post-Ph.D. programs and lab technicians.
As a Ph.D. student, Michela Ciccarelli was the first to observe sperm produced in the surrogate sires.
“It was the best day of my life,” she said.
Now an assistant professor, Cicarelli stayed at WSU to continue with the project.
Oatley hopes that the WSU example will help dispel misinformation and improve perceptions of the technology.
Gene editing is different from genetic modification, he explained.
Gene editing is a cutting-edge technology that only introduces genes to an organism that naturally occur within that species. Genetic modification, on the other hand, introduces DNA from other species in combinations that never could have arisen in nature without human intervention in a lab.
Editing is essentially a faster, more precise form of selective breeding, which humans have been doing for tens of thousands of years.
“This is just a modern way of creating those same unique genetic combinations in the animals to improve or enhance their traits, their resiliency and their welfare,” Oatley said.
The technology could also help protect endangered species.
With enough resources, Oatley estimates the technology could be widely available to meat producers within a decade.
Adapting the food supply for a changing world is critical, he said.
“If we don’t devise strategies to improve the resiliency and efficiency of food production systems, whether meat production or plant production, we’re going to have a real challenge on our hands for the global population,” Oatley said.
And that’s not even addressing the food insecurity that already exists globally.
“It is imperative, I think, for the future of the human race,” he said.