Rodent and broiler feeding studies with maize containing genetically modified event DP-915635-4 show no adverse effects on health or performance.

Several regulatory agencies continue to require animal feeding studies to approve new genetically modified crops despite such studies providing little value in the safety assessment. Feeding studies with maize grain containing event DP-915635-4 (DP915635), a new corn rootworm management trait, were conducted to fulfill that requirement. Diets fed to Crl:CD®(SD) rats for 90 days contained up to 50% ground maize grain from DP915635, non-transgenic control, or non-transgenic reference hybrids (P1197, 6158, and 6365).

Protein familiarity is a fundamental but rarely operationalized concept in the safety assessment of genetically modified crops: example of phosphomannose isomerase (PMI).

Fundamental to the safety assessment of genetically modified (GM) crops is the concept of negligible risk for newly expressed proteins for which there is a history of safe use. Although this simple concept has been stated in international and regional guidance for assessing the risk of newly expressed proteins in GM crops, its full implementation by regulatory authorities has been lacking. As a result, safety studies are often repeated at a significant expenditure of resources by developers, study results are repeatedly reviewed by regulators, and animals are sacrificed needlessly to complete redundant animal toxicity studies.

Non-seed plants are emerging gene sources for agriculture and insect control proteins.

The non-seed plants (e.g., charophyte algae, bryophytes, and ferns) have multiple human uses, but their contributions to agriculture and research have lagged behind seed plants.

Simulated gastric fluid assay for estimating the digestibility of newly expressed proteins in GE crops: Missteps in development and interpretation.

Digestive stability of a food protein in simulated gastric fluid (SGF) continues to be considered a risk factor for allergy, even though the current science does not support this belief. Methodological shortcomings of the adaption of the SGF assay for use with purified proteins has been cited as a reason to discount results that do not conform to this belief. Missteps in conducting and interpreting the results of SGF assays are reviewed here.

Slow alignment of GMO allergenicity regulations with science on protein digestibility.

The current science on food allergy supports the dual allergen exposure hypothesis where sensitization to allergenic proteins is favored by dermal and inhalation exposure, and tolerization against allergy is favored by exposure in the gut. This hypothesis is bolstered by the epidemiological evidence showing that regions where children are exposed early in life to allergenic foods have lower rates of allergy. This led medical experts to replace the previous recommendation to exclude commonly allergenic foods from the diets of young children with the current recommendation that such foods be introduced to children early in life.

Safety assessment of the insecticidal protein IPD079Ea from the fern, Ophioglossum pendulum.

As agricultural biotechnology continues to develop solutions for addressing crop pests through newly expressed proteins from novel source organisms, with different modes or sites of action and/or different spectra of activity, the safety of these proteins will be assessed. The results of hazard-identification and characterization studies for the insecticidal protein IPD079Ea, which is derived from a fern (Ophioglossum pendulum) and active against the maize pest western corn rootworm (Diabrotica virgifera virgifera, Coleoptera: Chrysomelidae) are provided. Collectively these results indicate that IPD079Ea is unlikely to present a hazard to human or animal health and support the safety of genetically modified maize expressing IPD079Ea.

Comprehensive COMPARE database reduces allergenic risk of novel food proteins.

The comprehensiveness of the allergen database used to bioinformatically compare a novel food protein with known allergens is critical to the ability to assess the allergenic risk of newly expressed proteins in genetically engineered crops. The strength of the relationship between a candidate GE protein's amino acid sequence and that of known allergens is used to predict cross-reactive risk. The number of truly novel allergen sequences added annually to the COMPARE database reflects on the comprehensiveness of our knowledge of allergen amino acid sequence diversity.

Erroneous Belief that Digestive Stability Predicts Allergenicity May Lead to Greater Risk for Novel Food Proteins.

There continues to be an erroneous belief that allergens (especially food allergens) are more resistant to gastrointestinal digestion than non-allergens. Government regulations based on this erroneous belief may result in technology developers altering the amino acid sequences of digestively stable native proteins to create digestively unstable modified versions for expression in genetically engineered crops. However, an investigation where a known stable allergen was modified to make it more digestible eliminated the protein's ability to tolerize against allergy in a mouse model, which is consistent with the dual allergen exposure hypothesis.

Transparency in risk-disproportionate regulation of modern crop-breeding techniques.

Despite over 25 years of safe deployment of genetically engineered crops, the number, complexity, and scope of regulatory studies required for global approvals continue to increase devoid of adequate scientific justification. Recently, there have been calls to further expand the scope of study and data requirements to improve public acceptance. However, increased regulation can actually generate consumer distrust due to the misperception that risks are high.

Mass spectrometric analysis of digesta does not improve the allergenicity assessment of GM crops.

An investigation of the potential allergenicity of newly expressed proteins in genetically modified (GM) crops comprises part of the assessment of GM crop safety. However, allergenicity is not completely predictable from a definitive assay result or set of protein characteristics, and scientific opinions regarding the data that should be used to assess allergenicity are continuously evolving. Early studies supported a correlation between the stability of a protein exposed to digestive enzymes such as pepsin and the protein's status as a potential allergen, but over time the conclusions of these earlier studies were not confirmed.

History of safe exposure and bioinformatic assessment of phosphomannose-isomerase (PMI) for allergenic risk.

Newly expressed proteins in genetically engineered crops are evaluated for potential cross reactivity to known allergens as part of their safety assessment. This assessment uses a weight-of-evidence approach. Two key components of this allergenicity assessment include any history of safe human exposure to the protein and/or the source organism from which it was originally derived, and bioinformatic analysis identifying amino acid sequence relatedness to known allergens.

Hypothesis-based food, feed, and environmental safety assessment of GM crops: A case study using maize event DP-202216-6.

Event DP-2Ø2216-6 (referred to as DP202216 maize) was genetically modified to increase and extend the expression of the introduced gene relative to endogenous gene expression, resulting in plants with enhanced grain yield potential. The gene expresses the ZMM28 protein, a MADS-box transcription factor. The safety assessment of DP202216 maize included an assessment of the potential hazard of the ZMM28 protein, as well as an assessment of potential unintended effects of the genetic insertion on agronomics, composition, and nutrition.

Evidence-based regulations for bioinformatic prediction of allergen cross-reactivity are needed.

The bioinformatic criteria adopted by regulatory agencies to predict the potential cross reactivity between newly expressed proteins in genetically engineered crops and known allergens involves amino acid identity thresholds and was formulated nearly two decades ago based on the opinion of allergy experts. Over the subsequent years, empirical evidence has been developed indicating that better bioinformatic tools based on amino acid similarity are available to detect real allergen cross-reactive risk while substantially reducing false-positive detections. Although the formulation of safety regulations, in the absence of empirical evidence, may require reliance on expert opinion, such expert opinion should not trump empirical evidence once it becomes available.

DP-2Ø2216-6 maize does not adversely affect rats in a 90-day feeding study.

Maize plants containing event DP-2Ø2216-6 (DP202216), which confers herbicide tolerance through expression of phosphinothricin acetyltransferase and enhanced grain yield potential via temporal modulation of the native ZMM28 protein, were developed for commercialization. To address current regulatory expectations, a mandatory 90-day rodent feeding study was conducted to support the safety assessment. Diets containing 50% by weight of ground maize grain from DP202216, non-transgenic control, and 3 non-transgenic reference varieties, were fully characterized, along with the grain, and diets were fed to Crl:CD®(SD) rats for at least 90 days.

Template-based peptide modeling for celiac risk assessment of newly expressed proteins in GM crops.

Newly expressed proteins in genetically modified (GM) crops are subject to celiac disease risk assessment according to EFSA guidelines. Amino acid identity matches between short peptides (9aa) and known celiac restricted epitopes are required to be further evaluated through peptide modeling; however, validated methods and criteria are not yet available. In this investigation, several structures of HLA-DQ2.

Obligatory metabolomic profiling of gene-edited crops is risk disproportionate.

It has been argued that the application of metabolomics to gene-edited crops would present value in three areas: (i) the detection of gene-edited crops; (ii) the characterization of unexpected changes that might affect safety; and (iii) building on the track record of rigorous government regulation in supporting consumer acceptance of genetically modified organisms (GMOs). Here, we offer a different perspective, relative to each of these areas: (i) metabolomics is unable to differentiate whether a mutation has resulted from gene editing or from traditional breeding techniques; (ii) it is risk-disproportionate to apply metabolomics for regulatory purposes to search for possible compositional differences within crops developed using the least likely technique to generate unexpected compositional changes; and (iii) onerous regulations for genetically engineered crops have only contributed to unwarranted public fears, and repeating this approach for gene-edited crops is unlikely to result in a different outcome. It is also suggested that article proposing the utility of specific analytical techniques to support risk assessment would benefit from the input of scientists with subject matter expertise in risk assessment.

Increasing allergy: are antibiotics the elephant in the room?

Antibiotics cause dramatic changes to the human microbiome. The composition of the microbiome has been associated with changes in the immune system and these changes are beginning to be linked to immune diseases. Thus, antibiotics have been implicated as a significant contributor to the continual rise of allergies and autoimmune disease in developed countries.

Clarification on "EFSA Genetically Engineered Crop Composition Equivalence Approach: Performance and Consistency".

A recent perspective defends the approach of the European Food Safety Authority (EFSA) for evaluating the compositional normality of genetically engineered (GE) crops using a concurrently grown subset of non-GE varieties within the risk assessment. While the approach of the EFSA manages the risk of falsely claiming equivalence, this is achieved at the expense of low power to detect true equivalence. This generates inconsistent findings and safety conclusions across studies for the same GE event based on the selected non-GE comparators.

Identification of iron-chelating phenolics contributing to seed coat coloration in soybeans (Glycine max (L.) Merr.) expressing aryloxyalkanoate dioxygenase-12.

Soybeans (Glycine max (L.) Merr.) genetically modified to express aryloxyalkanoate dioxygenase-12 (AAD-12), an enzyme that confers resistance to the herbicide 2,4-D, can sometimes exhibit a darker seed coat coloration than equivalent unmodified soybeans.

Allergen false-detection using official bioinformatic algorithms.

Bioinformatic amino acid sequence searches are used, in part, to assess the potential allergenic risk of newly expressed proteins in genetically engineered crops. Previous work has demonstrated that the searches required by government regulatory agencies falsely implicate many proteins from rarely allergenic crops as an allergenic risk. However, many proteins are found in crops at concentrations that may be insufficient to cause allergy.

Transgene expression in sprayed and non-sprayed herbicide-tolerant genetically engineered crops is equivalent.

Regulations governing the safety assessment of genetically engineered (GE) crops require studies that measure the expression levels of the transgene products (proteins and double-stranded RNA) in the GE crop; furthermore, the regulations also often mandate the inclusion of an entry of the GE crop that is sprayed with the herbicide to which tolerance was engineered and a non-sprayed entry of the GE crop in said studies. The hypothesized unique risk of altered transgene expression in response to application of herbicides related to herbicide-tolerant GE crops, compared with application of other herbicides, is not readily apparent. Field studies were conducted with GE maize, soybean, and cotton breeding stacks containing multiple herbicide tolerance traits; studies included plots that were sprayed with the trait-related herbicides and plots that were unsprayed.

Trypsin cleavage sites are highly unlikely to occur in celiac-causing restricted epitopes.

To assess risk, the European Food Safety Authority requires that the amino-acid sequences of newly expressed proteins in genetically engineered (GE) crops should be searched for partial matches with 9-mer restricted epitopes known to cause celiac disease. None of the 26 known celiac-causing 9-mer epitopes contain an predicted trypsin cleavage site. The probability of this occurring by chance alone is 0.

Evidence runs contrary to digestive stability predicting protein allergenicity.

A dogma has persisted for over two decades that food allergens are more stable to digestion compared with non-allergenic proteins. This belief has become enshrined in regulations designed to assess the allergenic risk of novel food proteins. While the empirical evidence accumulated over the last 20+ years has largely failed to confirm a correlation between digestive stability and the allergenic status of proteins, even those who accept this finding often assert that this shortfall is the result of faulty assay design rather than lack of causality.

Will Following the Regulatory Script for GMOs Promote Public Acceptance of Gene-Edited Crops?

Risk-disproportionate regulation of gene-edited crops has been proposed to gain public acceptance for this breeding technique. However, confounding safety regulations with advocacy for an underlying technology risks weakening achievement of both objectives. Dedicated factual communication and education from trusted sources is likely to better support public acceptance of gene-edited crops.

Validation of bioinformatic approaches for predicting allergen cross reactivity.

Part of the allergenicity assessment of newly expressed proteins in genetically engineered food crops involves an assessment of potential cross-reactivity with known allergens. Bioinformatic approaches are used to evaluate the amino acid sequence identity or similarity between newly expressed proteins and the sequences of known allergens. To be useful, such approaches must be sensitive to detecting cross-reactive potential, but also capable of excluding low-risk sequences.