On March 28, 2018, U.S. Secretary of Agriculture Sonny Perdue made an an announcement that new plant varieties produced using genome editing are not subject to regulatory oversight by the United States Department of Agriculture (USDA). The rationale for this policy decision is based on USDA’s conviction that genome editing is an innovation that poses “no risk.” Furthermore, it claims genome editing, “can introduce new plant traits more quickly and precisely.”1 At first glance, the decision for deregulation appears to be a step in the right direction towards spurring innovation, but USDA is incorrect when it implies genome editing is perfectly precise in the current form. This inaccurate assessment of genome editing technology by a trusted federal agency leaves food innovators vulnerable, and they should seek expert consultants to mitigate the risks and maximize the potential of their products.
Genome Editing With CRISPR-Cas9
Genome editing is a general term for technology that makes specific changes to an organism’s genome. The current wave of genome editing technology fueling food innovation and the presumed impetus for Secretary Perdue’s statement is colloquially referred to as CRISPR/Cas9 or just CRISPR. The discovery and implementation of CRISPR is a testament to human creativity and ability to repurpose nature and has been described in great detail elsewhere.2 CRISPR works like a pair of molecular scissors. These scissors are able to cut out portions of DNA from the genome. This functionality is useful in food innovation because CRISPR can be employed to quickly eliminate undesirable genetic traits. Historically, eliminating an undesirable genetic trait is achieved through selective breeding, which relies on quite a bit of serendipity and time.
Genome Editing Versus Genetic Modification (GM)
Presumably, the basis for USDA’s belief that CRISPR poses “no risk” is the commonly asserted position that because CRISPR involves deletion of DNA rather than adding foreign, recombinant DNA (rDNA), there is no “Frankenfood” type additions of foreign DNA, which is a central concern for GM food opponents. In fact, even though scientific consensus affirms the safety of GM technology, the fear of foreign rDNA is so widespread that the government is seeking to assuage public anxiety with implementation of “Bioengineered” (BE) labeling requirements, as Burdock Group Toxicologist Julie Brickel recently discussed in her article, “Proposed Rule for Labeling Bioengineered Foods: Key Information for Stakeholders.”
Unfortunately, this wholesale idea that CRISPR-mediated deletions of DNA pose no risk is a flawed concept. There are conditions that must be met to ensure a DNA deletion event is not deleterious, such as eliminating the undesirable trait cannot result in the food becoming toxic (e.g. the gene deleted could normally suppress a poisonous metabolite). Furthermore, the deletion must be completely specific so as not to disrupt non-targeted genes or create truncated proteins (i.e. prions that could be harmful).3
CRISPR Not Risk-Free Technology
Over the years, many researchers have tried to perfect the targeting ability of CRISPR. However, even with advances in design of targeting sequences and mutations in the nuclease activity of the Cas9 protein, there are still unexpected deletions and rearrangements in the genome. This phenomenon was recently highlighted in an article published in Nature Biotechnology in which the authors made the statement, “observed genomic damage in mitotically active cells caused by CRISPR-Cas9 editing may have pathogenic consequences.”4 While the subject of concern for this referenced article is using CRISPR in the treatment of human disease, the problems with specificity are not limited to disease or human application. Off-targeting can occur in any type of CRISPR application, including use in healthy animals or plants. This potential for off-target effects necessitates confirmation of complete specificity in all applications, including food innovation, to avoid potential for harm.
The USDA’s statement that there is no risk associated with genome editing technologies could ultimately backfire and stifle food innovation. If the public experiences harm from a food produced with CRISPR, the government will inevitably restrict this technology. Additionally, the trust that the public has bestowed in using genome editing for food production will be significantly damaged. As a result of USDA providing ill-informed or uninformed statements that are disregarding potential risks, the future of food innovation is firmly in the hands of the private sector. Anyone involved in food innovation and production can contact Burdock Group to help with assessing risks in food innovation strategies. Our team prides itself on having a strong scientific background including expertise in cutting-edge technology such as genome editing. Combining scientific acumen and regulatory expertise, we can accurately assess potential risks and ensure our clients always deliver a safe product to consumers.
Press Release No. 0070.18. Site last visited Aug. 23, 2018
Doudna, JA and Charpentier, E. The new frontier of genome engineering with CRISPR-Cas9. (2014) Science.
Paul, KR. et al. Generating new prions by targeted mutation or segment duplication. (2015) PNAS. p.8584-8589
Kosicki, M., Tomberg, K. & Bradley, A. Repair of double-strand breaks induced by CRISPR–Cas9 leads to large deletions and complex rearrangements. (2018) Nature Biotechnology.