A rather standard-looking white button mushroom has just planted itself at the center of the debate over genetically modified foods in the US. In a letter published on April 13 (pdf), the US Department of Agriculture (USDA) announced that it won’t regulate a genetically modified mushroom as it does other “genetically modified organisms” (GMOs).
The mushroom was developed by Yinong Yang of Pennsylvania State University using a revolutionary new technology called CRISPR. The technology allows modification of genes with greater precision than ever before. Yang used CRISPR to change two letters of the mushroom DNA code to create a variant that is more resistant to browning from oxidization.
Despite being directly and purposely genetically modified, USDA has allowed Yang’s mushroom to sidestep the regulatory system. The reason? Yang’s method does not contain “any introduced genetic material” from a plant pest such as bacteria or viruses. Conventional GMOs, the ones that the USDA’s rules are designed to deal with, are created by introducing foreign genes—for example, those of a bacteria might be introduced to give the crop some pest resistance.
CRISPR’s use is fundamentally changing how scientists approach genetic engineering. Instead of introducing genes, CRISPR allows scientists to dream up new ways of modifying the genome without the help of foreign genes.
Yang’s mushroom is the first one to use the much-discussed CRISPR system to sidestep the USDA regulations. However, in the past five years, some 30 new crops have used this loophole, with gene-editing techniques similar to CRISPR, that modify the already existing genome to give the crop new abilities.
For scientists working on CRISPR and related genetic tools, the USDA’s decision is a cause for celebration. They argue that sidestepping unnecessarily strict GM regulations is good and will lead to more innovation. “Everyone I talk to who is doing any genetics research is using CRISPR,” says Rodolphe Barrangou of North Carolina State University. “The first instance is always compelling, but in six months the number will be much higher.”
The global behemoth DuPont is working on developing CRISPR-edited drought-resistant wheat and corn. Korean scientists are working to CRISPR-edit a banana so that it can resist a fungus that is threatening to make it extinct. The biotech company Cibus used a related technology to modify a herbicide-resistant oilseed so that farmers could start using weed killers again.
Some scientists and activists are concerned. “The USDA decision is a perfect illustration of how weak regulations for evaluating genetically engineered crops are,” says Patty Lovera of Food & Water Watch, a group focused on corporate and government accountability relating to food, water, and fishing.
One concern is that CRISPR works by using a bacteria’s defense system against viruses. There have been cases where, while using CRISPR’s precision editing in crops, the process has inadvertently inserted bacterial genes in the crop genome. The European Union’s regulation would label such crops “GMOs” and make them go through the normal regulatory process.
It’s unclear what US regulators would do. When it comes to GM crops, the US has other problems to sort out. Unlike Europe, the US doesn’t have a central body that regulates GMOs. The USDA deals with GM crops that use foreign genes from plant pests such as bacteria or viruses. The Environmental Protection Agency (EPA) deals with GM crops that were made to be resistant to a certain pest. Finally, the US Food and Drug Administration has a voluntary review process, but considers all GM crops safe.
Some see the CRISPR era as a chance to redefine what a GMO really means, and to re-engage society in a more scientifically informed debate. On April 18, the US National Academy of Sciences is organizing its first meeting to revamp the government’s GM regulations.