First salmon, up next pigs?

February 09, 2016

Late last year the first genetically engineered animal — a salmon that is designed to grow twice as fast as wild salmon — was approved by the FDA and deemed safe for human consumption. Now, new research is showing another animal may soon join the list as scientists from the University of Missouri and Kansas State University have developed a new breed of pigs that is resistant to an incurable disease that plagues hog barns — porcine reproductive and respiratory syndrome (PRRS). 

“[PRRS] is a devastating disease,” Kristin Whitworth, a research scientist at the University of Missouri who worked on the project said in a recent article. “It causes persistent infection. It causes abortions in pigs so they lose their litter. It causes a lot coughing and the pigs get very sick.”

Once the virus enters a pig, it spreads with the help of a protein. Whitworth and her team genetically edited the gene that makes this protein, effectively removing it.

“Once that molecule is no longer present, then the virus could not only not get inside the macrophages, but could not spread from pig to pig,” Whitworth explained.

The scientists said they hope the hogs produced with the gene editing technology will be on U.S. dinner tables in a matter of years. However, this hope resides in garnering approval from the FDA, which took decades to approve the GE salmon, which still may not be in the clear, as the FDA issued a new ruling earlier this month that could block its sale for years to come.

“Up until this point, even though the technology was developed more than 30 years ago, that’s the only thing that’s ever gotten through regulatory [procedure],” said Alison Van Eenennaam, an animal biotechnology and genomics specialist at the University of California, Davis. “And it took about 20 years and tens of millions of dollars to get it through.”

Scientists have developed genetically engineered livestock in the past and there are other genetically engineered animals in the works, from hornless cattle to hypoallergenic cows. None have yet made it to stores, largely because of the novelty of the underlying technology, which is expensive and untested by regulators and consumers alike.

“The animal breeding community is looking to see what the response of the regulators is going to be to this technology,” Van Eenennaam said in the article. There is no one-size-fits all study that will quell scientific concerns. Each animal and genetic modification is different.

“For example if you’re introducing a brand-new protein that perhaps humans don’t typically eat, is that something we’re allergic to?” asked Kevin Wells, an assistant professor at the University of Missouri who worked with the PRRS-resistant pigs and sat on the federal advisory committee for the genetically engineered salmon. “Whereas you wouldn’t necessarily have to ask that question of something we eat every day.”

The companies spending millions on this technology are also worried about consumer response, especially as genetically modified food remains a hot-button issue.

For example, opponents of genetic engineering in animals argue there are too many risks and too many unknowns associated with GE animals. They worry about environmental impacts and changes to human health, along with a handful of other concerns including labeling of the animals in the grocery store.

When it comes to the PRRS-resistant pigs, researcher Whitworth says the company that purchased the technology, will do the hoop-jumping for federal approval.

“They’ll look at feed efficiency and growth and they’ll introduce the edit into their genetic lines,” she said. And if that happens, it likely won’t be long before the pigs are in grocery stores across the country.

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Category: Food Safety, Animal Safety, Genomics