As the battle over GMO labeling plays out in supermarkets and in Congress, the definition of genetically modified organisms is fuzzier than ever. GMO regulation—insofar it exists in the US—relies on old statutes for plant pests, animal drugs, and pesticides repurposed for GM technology. The rules never worked well, and new, precise gene-editing techniques are stretching them to the breaking point.
When the Reagan administration cobbled together the first GM rules in the 80s, the primary technique for creating GM crops involved a soil microbe called Agrobacterium tumefaciens. The bacterium can sicken crops by inserting its own DNA into plant cells, but scientists learned to coax it to insert any piece of DNA—genes for proteins poisonous to insects, for example—to create genetically modified crops. In the beginning, then, the US Department of Agriculture regulated GMOs as potential plant pests or noxious weeds.
But new and more precise genetic engineering techniques don’t need Agrobacterium, allowing them to sidestep USDA regulation. Researchers can, for example, freely plant crops with genes knocked out with TALENs, or transcription activator-like effector nucleases. And Monsanto is studying how to spray RNA into fields to block the expression of certain plant genes—without directly modifying the plant. These technological advances are fast making the old regulations obsolete. “We’ve basically got a gaping hole in the USDA’s jurisdiction,” says Alison Peck, an agricultural law professor at West Virginia University.
The regulatory loopholes don't end with the USDA. Unlike in Europe, which has a central authority on food biotech, responsibility for GMOs in the US is fractured among three separate agencies. The USDA regulates GMOs it considers potential plant pests or noxious weeds, and the EPA regulates crops engineered to carry a insect-killing toxin under pesticide rules. Lastly, the FDA has a “voluntary consultation” process but generally considers all GM plants safe to eat. “Based on the technology at the time, the rules arguably were sufficient,” says Peck. But in 2015? Not so much.
The feds recognize the dilemma. The USDA in February scrapped a proposed GMO regulation rule that had been languishing since 2008. And in July, the White House directed the three agencies to rehaul their GMO rules—or at least begin the process for doing so. “It’s starting this year, and then it will go on forever,” says Ron Sederoff, a plant geneticist at North Carolina State University who is studying how to bioengineer trees. His frustration at the politicized regulatory process is a common refrain among scientists.
New genetic engineering methods are circumventing regulations, but they're also dredging up a more fundamental question: Should GMOs be regulated based on the process used to create them or the the novelty of the DNA sequence?
This question is now urgent thanks to rapid introduction of gene editing techniques like TALENs and an even newer, more hyped technology called CRISPR. Both techniques allow scientists to make precise tweaks, deleting a few letters to inactivate a gene or rewriting a few to recreate a naturally occurring mutation. But they each have their own risks and benefits: The newer technique, CRISPR, is especially prone to making off-target mutations, and while biotech companies should do DNA sequencing to catch these mutations, not much regulation exists in this area.
Perhaps more importantly, though, those techniques have made it easier to create new, distinct categories of GMOs. Animals or plants can be modified to lack a gene, modified to contain a gene from the same species but different breed, or modified to contain genes from a different species entirely.
Traditionally, most GMOs have belonged to the last category, called “transgenic” because it mixes genes from different species. But last week’s 10th international Transgenic Animal Research Conference in Davis, California featured plenty of presentations about non-transgenic genetic engineering. Earlier this year, Korean biologists used TALENs to create a super muscular pig lacking a single gene inhibiting muscle growth. The pig is genetically engineered, yes, but it doesn’t contain any foreign genes.
Non-transgenic GMOs—especially those that involve deleting genes instead of adding them—may seem like they need less regulation, but that's not necessarily the case, says Peck. Even a single gene deleted can have multiple effects. It could, say, make pigs bigger, but how might it affect pigs under heat or disease stress?
Some biotech companies, though, are betting on the fact that regulations will take it easier on products without foreign DNA. This could be especially important for GM animals, which trigger different regulations than plants. The FDA regulates GM livestock as animal drugs—basically medicine for animals, yet another example of GMO regulation relying on outdated statues. A GM salmon, engineered with a trout DNA for faster growth, has spent nearly two decades in the FDA review process. (The USDA has not taken much initiative in overseeing GM animals, so its role is less clear.)
Recombinetics, a biotech modifying livestock to promote animal welfare, is hoping to avoid that kind of regulatory purgatory, because its GMOs only share intra-species DNA. “Of course it’s a business concern,” says Mark Walton, Recombinetics’ chief marketing officer.
One of the company's projects takes the hornless mutation in Angus cattle and puts it in other breeds, like Holsteins. (Dairy farmers routinely dehorn cows for safety, but it’s painful for the animal.) Its genetic tweak—using TALENs or CRISPR technology—creates cows that are 100-percent cow DNA, recombined from different breeds.
Regulations tailored to GMOs have been thirty years in coming, and the current rehaul will undoubtedly take a long time. Hopefully, not so long that the new regulations are obsolete again by the time they’re ready.
