Development of a novel method for specific detection of genetically modified Atlantic salmon, AquAdvantage, using real-time polymerase chain reaction

Identification of Fish Species and Targeted Genetic Modifications Based on DNA Analysis: State of the Art

Food adulteration is one of the most serious problems regarding food safety and quality worldwide. Besides misleading consumers, it poses a considerable health risk associated with the potential non-labeled allergen content. Fish and fish products are one of the most expensive and widely traded commodities, which predisposes them to being adulterated. Among all fraud types, replacing high-quality or rare fish with a less valuable species predominates. Because fish differ in their allergen content, specifically the main one, parvalbumin, their replacement can endanger consumers. This underlines the need for reliable, robust control systems for fish species identification. Various methods may be used for the aforementioned purpose. DNA-based methods are favored due to the characteristics of the target molecule, DNA, which is heat resistant, and the fact that through its sequencing, several other traits, including the recognition of genetic modifications, can be determined. Thus, they are considered to be powerful tools for identifying cases of food fraud. In this review, the major DNA-based methods applicable for fish meat and product authentication and their commercial applications are discussed, the possibilities of detecting genetic modifications in fish are evaluated, and future trends are highlighted, emphasizing the need for comprehensive and regularly updated online database resources.

Development and Interlaboratory Validation of a Novel Reproducible Qualitative Method for GM Soybeans Using Comparative Cq-Based Analysis for the Revised Non-GMO Labeling System in Japan

Many countries have implemented the labeling system of genetically modified organisms (GMO). In Japan, the regulatory threshold for non-GMO labeling will be revised and restricted to undetectable by April 2023. The practical criterion for the revised system is based on the limit of detection (LOD). However, determining whether the commingling of GMO levels exceeds the LOD is challenging because GM contents close to the LOD are usually below the limit of quantification. In this study, we developed a qualitative method based on comparative Cq-based analysis targeting cauliflower mosaic virus 35S promoter and GM soybean MON89788 event-specific sequences that could be applicable to the revised non-GMO labeling. ΔCq values between the target and endogenous sequences were calculated, and the ΔΔCq value obtained was used as a criterion to determine analytical samples with GM contents exceeding the threshold. To improve the reproducibility of the method, we used a standard plasmid that yields equivalent and stable ΔCq values comparable with those obtained from LOD samples. The developed method was validated with an interlaboratory study. The new qualitative detection concept would be useful for ensuring robust and reproducible results among laboratories, particularly for detecting low-copy-number DNA samples.

Aquatic food animals in the United States: Status quo and challenges

This review summarizes (1) the U.S. status quo for aquatic food animal production and marketing; (2) major food safety and quality issues/concerns for aquatic food animals in the United States, including fish misbranding, finfish/shellfish allergies, pathogens, toxins and harmful residues, microplastics, and genetically engineered salmon; and (3) various U.S. regulations, guidances, and detection methods for the surveillance of fishery products. Overall, fish misbranding is the biggest challenge in the United States due to the relatively low inspection rate. In addition, due to the regulatory differences among countries, illegal animal drugs and/or pesticide residues might also be identified in imported aquatic food animals. Future regulatory and research directions could focus on further strengthening international cooperation, enhancing aquatic food animal inspection, and developing reliable, sensitive, and highly efficient detection methods.

Novel CRISPR-Cas Systems: An Updated Review of the Current Achievements, Applications, and Future Research Perspectives

According to Darwin's theory, endless evolution leads to a revolution. One such example is the Clustered Regularly Interspaced Palindromic Repeats (CRISPR)-Cas system, an adaptive immunity system in most archaea and many bacteria. Gene editing technology possesses a crucial potential to dramatically impact miscellaneous areas of life, and CRISPR-Cas represents the most suitable strategy. The system has ignited a revolution in the field of genetic engineering. The ease, precision, affordability of this system is akin to a Midas touch for researchers editing genomes. Undoubtedly, the applications of this system are endless. The CRISPR-Cas system is extensively employed in the treatment of infectious and genetic diseases, in metabolic disorders, in curing cancer, in developing sustainable methods for fuel production and chemicals, in improving the quality and quantity of food crops, and thus in catering to global food demands. Future applications of CRISPR-Cas will provide benefits for everyone and will save countless lives. The technology is evolving rapidly; therefore, an overview of continuous improvement is important. In this review, we aim to elucidate the current state of the CRISPR-Cas revolution in a tailor-made format from its discovery to exciting breakthroughs at the application level and further upcoming trends related to opportunities and challenges including ethical concerns.

Identification of peptide biomarkers for authentication of Atlantic salmon and rainbow trout with untargeted and targeted proteomics approaches and quantitative detection of adulteration

Atlantic salmon is often adulterated or substituted by rainbow trout with much lower price and quality. However, it is extremely difficult to distinguish Atlantic salmon and rainbow trout due to their similar appearance and close relationship in species. In the present work, untargeted and targeted proteomics approaches were both implemented to identify species-specific peptide biomarkers of Atlantic salmon and rainbow trout. Potential peptide biomarkers were obtained through matching HRMS data with UniProt database, screened by BLAST and then verified with real samples. Five peptide biomarkers were identified each for Atlantic salmon and rainbow trout. MRM method was established for quantitative measurement of rainbow trout Adulteration in Atlantic salmon, showing high sensitivity and repeatability. The biomarker peptide GDPGPGGPQGEQGVVGPAGISGDK was used for quantification. The limit of the detection (LOD) of adulteration of rainbow trout is 0.19%, and the limit of quantitation (LOQ) is 0.62%. Furthermore, this method was successfully applied to analyze a number of Atlantic salmon and Rainbow trout samples from different regions and different batches, as well as commercially available processed products.

Data representing applicability of developed growth hormone 1 (GH1) gene detection method for detecting Atlantic salmon (Salmo salar) at high specificity to processed salmon commodities

This article is referred to the research article entitled “Development of a novel method for specific detection of genetically modified Atlantic salmon, AquAdvantage, using real-time polymerase chain reaction” by Soga et al. (2020).

Applicability of the developed growth hormone 1 (GH1) and 18S ribosomal DNA (18S rDNA) detection methods using real-time polymerase chain reaction (PCR) for detecting Atlantic salmon (Salmo salar) to processed food commodities was examined. DNAs extracted and purified from 24 commodities labelled to include salmon as an ingredient were used as template. Yield and purity of DNAs obtained and Cq values from real-time PCR analyses were provided.