Why the FDA's Plan to Regulate Gene Editing in Animals Has Some Scientists Worried

The agency's new plan retains several key limitations on animal biotechnology, despite language promoting innovation.
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Cows walk from a barn after being milked on Hinchley's Dairy Farm near Cambridge, Wisconsin.

For decades, researchers have said that genetic modification of plants and animals can reduce agriculture's environmental impact: by creating disease-resistant animals, plants that tolerate pesticides, or more efficient livestock, for example. More recently, however, some creators of this technology have turned against its more far-reaching applications, fearing interventions that could alter the natural world for generations to come, while environmental groups have spent years petitioning the government to rein it in.

Now, it seems like the trend toward regulation will continue. Despite the Trump administration's calls to increase innovation in biotechnology in a new draft proposal, experts say the classification of genetic editing and engineering as a drug continues to choke the industry.

On Tuesday, the federal agency that oversees genetic modification of animals announced plans to "advance an efficient, science-based pathway to market for safe animal biotechnology-derived products." The United States Food and Drug Administration bills this "Action Plan" as a way to help scientists and start-ups bring plants and animals with edited genomes to the public, but retains some key limitations. (Genetically edited plants are currently regulated by the Department of Agriculture, which has historically been much more lenient.)

The FDA has long regulated food-producing animals that have been modified with genetic material added from unrelated organisms, known "transgenic" animals. The first of these—the "AquaAdvantage" salmon—took more than 20 years to be cleared for consumption in the U.S., but, so far, it's only been sold in Canada. The company behind the fish says it grows twice as fast as unmodified salmon due to the addition of genes from two different fish species.

Eric Hallerman, professor of fish conservation at Virginia Tech, advised the FDA to approve the fish in 2015. Currently, genetically engineered animals must go through a rigorous regulatory approval, showing that the alteration does not harm the animal or the environment. Scientists like Hallerman have argued that this stymies innovation. "The government is still overseeing animals as a drug, which is ridiculous," he told Virginia Tech Daily in 2016.

While genetically engineered animals have been met with controversy, animal geneticist Alison Van Eenennaam believed her own work would be immune. In her lab at the University of California–Davis, Van Eenennaam uses genetic editing technology to develop cows without horns. The process, she says, is no different than traditional breeding, in which breeders select for naturally occurring mutations. "Nature does this routinely, because there are always breaks getting introduced into double-stranded DNA by radiation and sunlight and alcohol, you name it," she says. "That's how evolution happens."

Some cows are already hornless in the wild, and the mutation is considered advantageous for dairy farmers because horned cattle can gore each other and people. Removing a cow's horns is a painful process, so Van Eenennaam and the start-up Recombinetics opted to do it through gene editing, knocking out the genes that grow horns before they manifest.

But in 2017, on the last day of the Obama administration, the FDA extended its rules to include gene editing as well as engineering—meaning that developers cannot remove or add genes, even if they are a normal variation. Van Eenennaam says this could end investment in research like hers, enabling "the only people who can afford to do it: large multinational companies," she says.

Van Eenennaam believes that some regulation can protect food safety—so that a researcher does not enable a gene that makes an animal more disease-prone, for example. But she also argues that current FDA policies restrict technologies that could make agriculture more efficient by reducing the environmental footprint of food production.

"If you can use a breeding technique that develops animals that don't get sick or plants that are resistant to insects and don't have to be sprayed with insecticide, those types of developments really do contribute to the sustainability of agriculture," she says.

Part of the government's hesitation regarding this technology likely comes from its more controversial uses, Van Eenennaam says. As Rowan Jacobsen wrote for Pacific Standard in June, a recent application promises new benefits—and risks—for agriculture and public health:

Known as a gene drive, the ability to force particular genes into future generations of an entire species only became available to humans with the development of CRISPR, the gene-editing tool that has enabled us to make precise changes to an organism's DNA. Kevin Esvelt was a fellow at Harvard University's Wyss Institute for Biologically Inspired Engineering in 2013 when he figured out how to build a gene drive. In a 2014 paper, he proposed several applications for his invention, including hobbling weeds that had become resistant to herbicides, reducing malaria-carrying mosquitoes, and eliminating invasive rodents on islands, where they wreak havoc on indigenous birds and plants.

As Pacific Standard reported in 2017, Esvelt later cautioned that "a standard, self-propagating ... gene drive system is likely equivalent to creating a new, highly invasive species: Both will likely spread to any ecosystem in which they are viable, possibly causing ecological damage." In other words, some of the same scientists who pioneered this technology are now advocating for greater oversight. Animal rights and environmental activists have also voiced ethical concerns.

The agency's new plan makes fleeting reference to gene drives, promising to "address the novel ecological, environmental, and public health challenges" that it imposes. But Van Eenennaam argues that her work has little bearing on public safety, and in regulating these technologies the same way, the government may send her hornless cattle the way of the AquaAdvantage salmon: confined to pasture—and regulatory limbo—forever.