Most pigs in the US are confined to factory farms where they can be afflicted by a nasty respiratory virus that kills piglets. The illness is called porcine reproductive and respiratory syndrome, or PRRS. A few years ago, a British company called Genus set out to design pigs immune to this germ using CRISPR gene editing. Not only did they succeed, but its pigs are now poised to enter the food chain following approval of the animals this week by the U.S. Food and Drug Administration.

Culbertson says gene-edited pork could appear in the US market sometime next year. He says the company does not think pork chops or other meat will need to carry any label identifying it as bioengineered. "We aren't aware of any labelling requirement," Culbertson says.