Fast-growing salmon. Pork containing heart-healthy omega-3 fatty acids. These are two examples of products you might see in your local supermarket soon -- animals developed not through conventional breeding but through genetic engineering.
On Jan. 15, the U.S. Food and Drug Administration decided how it will regulate genetically engineered animals, for the first time paving the way for such animals or their products to be sold as food and medicine. The agency has decided to categorize genetically engineered farm animals, also called transgenic animals, as an "animal drug." They will be held to the same requirements already existing for conventionally bred animals treated with hormones or antibiotics. (In the case of transgenic animals, the "drug" is a snippet of DNA.) Products derived from them or containing them as an ingredient will not necessarily require labeling.
A wide range of interested parties, including companies developing genetically engineered animals and consumer protection groups, are generally comfortable with the FDA decision. And yet, consumer acceptance of transgenic animals, particularly as food products, is still an unknown.
American consumers have been eating food from genetically engineered crops, such as corn, soybeans and canola, for a decade. However, transgenic animals have not been sold, pending the FDA deliberations on how to regulate them.
Why would someone want to genetically engineer animals?
Genetic engineering is a high-tech way to "breed" desirable traits into livestock. The benefits might be for the producer, such as a disease-resistant cow or an easy-to-raise salmon. It might be for the environment -- pigs that produce milder manure, for example -- or for the consumer, say, more nutritious meat.
The old-fashioned way of breeding farmed animals requires selecting offspring with desired traits over successive generations. Ron Stotish, chief executive of Aqua Bounty Technologies in Waltham, Mass., says the power of genetic engineering is that the same end is achieved in "one fell swoop." Transgenic animals also can be fitted with traits they probably would never develop naturally, as in the case of omega-3-producing pigs.
How is an animal genetically engineered?
An extra piece of genetic material (DNA) is inserted into the animal's genome at the earliest stages of development. Sometimes the method involves manipulating a fertilized egg that is then implanted into a surrogate mother; other times, it alters a cell from which an animal will be cloned. As the embryo grows, the DNA splice is replicated with the rest of the genetic material so that it ends up in every cell of the individual.
In fast-growing salmon developed by Aqua Bounty, the inserted gene is a salmon growth hormone, identical to the one the fish have naturally. The benefit comes from the precise placement of the added gene, which makes it active at times that the natural gene is not. "Normal salmon grow very, very slowly, and when it is cold they don't grow at all," Stotish says. "Our gene is active under a broader range of conditions and it allows the animals to grow." At 1 year old, a normal salmon might weigh 30 grams, but the transgenic fish weigh a kilogram, he says.
In pigs developed to contain omega-3 fatty acids, the added gene directs formation of an enzyme that converts naturally occurring omega-6 fatty acids to omega-3s. The gene is derived from tiny roundworms but is modified to make it more mammalian, says Randall Prather, co-director of the National Swine Resource and Research Center at the University of Missouri in Columbia, who developed these pigs.
Why did the FDA opt to regulate genetically engineered animals in this manner and what criteria are used to assess safety?
The FDA is responsible for food safety and already regulates genetically modified crops. By considering a DNA segment a drug, the agency will regulate transgenic animals in the same way it oversees dairy cows that receive growth hormone or beef cattle that get antibiotics, says FDA spokeswoman Siobhan DeLancey.
By using existing guidelines for so-called animal drugs, the FDA can put those products seeking approval into a process that is already up and running. "They have the staff and the process that allows them to look at this. They do it every day," says Stotish of Aqua Bounty, which has been seeking FDA approval for its fast-growing salmon for years.
Companies must show that their genetic manipulation is safe to the animal and that any food or animal-feed products derived from the animal are safe for the consumer and safe for the environment. Companies must also demonstrate that their claims about the gene-carried traits do occur.
Are there concerns beyond what the FDA can regulate?