Perspectives on genetically modified crops and food detection

A rapid on-site visualization platform based on RPA coupled with CRISPR-Cas12a for the detection of genetically modified papaya 'Huanong No.1'

The Papaya ringspot virus (PRSV)-resistant genetically modified (GM) papaya 'Huanong No.1' has been certified as safe for consumption and widely planted in China for about 18 years. To protect consumers' rights and facilitate government supervision and monitoring, it is necessary to establish a simple, rapid, and specific detection method for 'Huanong No.1'. Herein, we developed a platform based on recombinase polymerase amplification (RPA) coupled with CRISPR-Cas12a for the detection of 'Huanong No.1'. The RPA-CRISPR-Cas12a platform was found to have high specificity, with amplification signals only present in 'Huanong No.1'. Additionally, the platform was highly sensitive, with a limit of detection (LOD) of approximately 20 copies. The detection process was fast and could be completed in less than 1 h. This novel platform enables the rapid on-site visualization detection of 'Huanong No.1', eliminating dependence on laboratory conditions and specialized instruments, and can serve as a technical reference for the rapid detection of other GM plants.

A rapid and high-throughput system for the detection of transgenic products based on LAMP-CRISPR-Cas12a

With the increasing acreage of genetically modified crops worldwide, rapid and efficient detection technologies have become very important for the regulation and screening of GM organisms. We constructed a method based on loop-mediated isothermal amplification (LAMP), CRISPR-Cas12a and lateral flow assay (LAMP-CRISPR-Cas12a-LFA). It is an intuitive, sensitive and specific fluorescence detection and test strip system to detect CP4-EPSPS and Cry1Ab/Ac genes in field screening. The LAMP-CRISPR-Cas12a-LFA method has a limit of detection (LOD) of 100 copies based on lateral flow test strips after optimization of the conditions with screened specific primers, and the entire detection process can be completed within 1 h at 61 °C. The system was used to evaluate field test samples and showed high reproducibility after testing products containing CP4-EPSPS and Cry1Ab/Ac genes, and both were detectable. The LAMP-CRISPR-Cas12a-LFA method established in this paper functions as a rapid field detection method. It requires only one portable thermostatic instrument, which renders it compatible with the rapid detection of field samples and useable at experimental workstations, in law enforcement field work, and in local inspection and quarantine departments.

A sensitive immunosensor based on graphene-PAMAM composites for rapid detection of the CP4-EPSPS protein in genetically modified crops

A simple electrochemical immunosensor based on nitrogen-doped graphene and polyamide-amine (GN-PAM) composites was proposed for the detection of the CP4-EPSPS protein in genetically modified (GM) crops. In this immunosensor, the amplification of the detection signal was realized through antibodies labeled with gold nanoparticles (AuNPs). The electrochemical responses of the immunosensor were linear (R2 = 0.9935 and 0.9912) when the GM soybean RRS and maize NK603 content ranged from 0.025% to 1.0% and 0.05% to 1.5%, respectively. The limits of detection for the GM soybean RRS and maize NK603 were as low as 0.01% and 0.03%, respectively. The immunosensor also exhibited high specificity, and satisfactory stability, reproducibility, and accuracy. Our findings indicated that the constructed immunosensor provides a new approach for the sensitive detection of the CP4-EPSPS protein. Notably, the sensor may be applied to other proteins or pathogenic bacteria by simply changing the antibodies, and may also be used for multi-component analysis.

GmoDetector: An accurate and efficient GMO identification approach and its applications

The rapid increase of genetically modified organisms (GMOs) entering the food and feed markets, and the contamination of donor (micro)organisms of transgenic elements make it more challenging for the existing GMO detection. In this study, we developed a high-throughput and contamination-removal GMO detection approach named as GmoDetector. GmoDetector targeted 64 common transgenic elements and 76 GMO-specific events collected from 251 singular GM events, and combined with next generation sequencing (NGS) and target enrichment technology to detect various GMOs. As a result, GmoDetector was able to exclude the donor (micro)organism contamination, and detect the authorized and unauthorized GMOs (UGMOs) in any forms of food or feed, such as processed or unprocessed. The sensitivity of GmoDetector is as low as 0.1% (GMO content), which has met the GMO labeling threshold for all countries. Therefore, GmoDetector is a robust tool for accurate and efficient detection of the authorized and UGMOs.

A choice experiment on consumer perceptions of three generations of genetically modified foods

Genetically modified (GM) foods remain a contentious issue worldwide, yet consumer preferences in this field have received too little attention in the academic research. The present paper helps fill this gap by investigating the hypothetical consumer behaviour towards and willingness to pay (WTP) for a specific type of GM food (of the first, second or third generation) using a choice experiment with 1444 respondents from three European cities. A random parameter logit-error component (RPL-EC) model allows for heterogeneity in consumer preferences and potential correlation across utilities and across taste parameters. The results show that consumers seem to attach utility to GM foods insofar as they perceive that generational traits improve their nutritional qualities or bring health benefits. Moreover, the role played by education in improving people's understanding of the issues associated with GM foods provides insights to assist marketers in developing differentiated strategies. Marketers would be able to help consumers dampen the effect of fear and allow them to develop more informed opinions, which, however, do not necessarily translate into purchasing behaviour.

Development of a lateral flow test strip for simultaneous detection of BT-Cry1Ab, BT-Cry1Ac and CP4 EPSPS proteins in genetically modified crops

A colloidal gold immunochromatographic strip (ICS) for simultaneous detection of multiple transgenic proteins, including CP4 EPSPS, BT-Cry1Ab and BT-Cry1Ac, was developed in this study. The sensitivity of the strip to the target protein was 5 ng/mL for CP4 EPSPS, 100 ng/mL for BT-Cry1Ab and Cry1Ac, respectively. Parallel analysis for maize, soybean, sugar beet and cotton showed the strip could detect 1% of transgenic content in crops containing BT-Cry1Ab and Cry1Ac, and, at least, 0.1% of content in crops containing CP4 EPSPS. The detection results for seed samples indicated the multicomponent analysis ICS had good accuracy. The analysis could be completed within 10 min and had the advantages of being high-throughput, easy to operate and visual detection. This is the first report of semi-quantitative ICS for detecting three transgenic proteins simultaneously. The developed approach may provide insights into the development of ICS for analyzing simultaneously multiple components in genetically modified crops.

Nitrogen direct analysis in real time time-of-flight mass spectrometry (N2 DART-TOFMS) for rapid screening of forensic drugs

RATIONALE

Over the last ten years, helium direct analysis in real time time-of-flight mass spectrometry (He DART-TOFMS) has become an established technique in rapid screening of forensic drugs to decrease the time necessary to triage forensic drug cases, therefore contributing to backlog reduction and more timely criminal prosecution. Recently, we demonstrated that N₂ DART was able to efficiently ionize all polar compounds except for a few extremely small ones such as methanol and acetonitrile. Therefore, N₂ DART-TOFMS should be a suitable technique for rapid screening of forensic drugs.

METHODS

Nitrogen direct analysis in real time time-of-flight mass spectrometry (N₂ DART-TOFMS) was performed using a JEOL AccuTOF mass spectrometer with an IonSense DART-100 ion source. A 3-min analytical protocol was used for the analysis of each sample. Sample introduction was accomplished by moving the closed end of a melting point capillary where approximately 1 μL sample solution was deposited or the exposed inside of a freshly cut tablet across the N₂ gas stream between the DART-100 ion source and orifice 1 of the AccuTOF.

RESULTS

Ten commonly abused drugs, eight synthetic cannabinoids and four controlled prescription drugs (CPDs) were analyzed. The limit of detection (LOD) was determined to be approximately 10 μg/mL or 10 pg in quantities. All drugs at the LOD level were positively identified using their [M + H]⁺ ions with mass errors less than 5 mDa. The identification were further supported by in-source fragment ions and characteristic N₂ DART ions that are not commonly generated by He DART, e.g. [M + H + O]⁺ and [M + H + 2O]⁺ ions.

CONCLUSIONS

It was concluded that the 3-min analytical protocol could be utilized in the analysis of seized drugs in the form of tablets and powders or prepared in solution. In consideration that N₂ is readily available in the air and He is a non-renewable resource, N₂ DART-TOFMS is a greener, cheaper and more convenient alternative to He DART-TOFMS in rapid screening of forensic drugs.

Safety Assessment of Genetically Modified Feed: Is There Any Difference From Food?

Food security is one of major concerns for the growing global population. Modern agricultural biotechnologies, such as genetic modification, are a possible solution through enabling an increase of production, more efficient use of natural resources, and reduced environmental impacts. However, new crop varieties with altered genetic materials may be subjected to safety assessments to fulfil the regulatory requirements, prior to marketing. The aim of the assessment is to evaluate the impact of products from the new crop variety on human, animal, and the environmental health. Although, many studies on the risk assessment of genetically modified (GM) food have been published, little consideration to GM feedstuff has been given, despite that between 70 to 90% of all GM crops and their biomass are used as animal feed. In addition, in some GM plants such as forages that are only used for animal feeds, the assessment of the genetic modification may be of relevance only to livestock feeding. In this article, the regulatory framework of GM crops intended for animal feed is reviewed using the available information on GM food as the baseline. Although, the majority of techniques used for the safety assessment of GM food can be used in GM feed, many plant parts used for livestock feeding are inedible to humans. Therefore, the concentration of novel proteins in different plant tissues and level of exposure to GM feedstuff in the diet of target animals should be considered. A further development of specific methodologies for the assessment of GM crops intended for animal consumption is required, in order to provide a more accurate and standardized assessment to the GM feed safety.

Evaluation of a lateral flow immunoassay for the detection of the synthetic opioid fentanyl

In 2017, 47,600 overdose deaths were reported to be associated with the abuse of opioids, including prescription painkillers (e.g. oxycodone), opiates (e.g. heroin), or synthetic opioids (e.g. fentanyl) within the United States. The recent spike in the presence of synthetic opioids in lots of heroin distributed on the street present specific and significant challenges to law enforcement. Synthetic opioids are extremely toxic substances, which can easily be inhaled. This type of exposure can lead to accidental overdoses by law enforcement and other first responders answering calls involving illicit drugs containing these substances. Due to this extreme toxicity, it is important for these individuals to have tools that can be easily deployed for accurate presumptive field tests. Currently, there are only a limited number of presumptive tests available for fentanyl detection. In this study, we addressed this technology gap by evaluating newly developed lateral flow immunoassays (LFIs) designed for the detection of fentanyl and its derivatives. These LFIs were evaluated for effectiveness in different biofluid matrices, following an in vivo exposure, cross-reactivity with fentanyl analogs, and in case samples. This study demonstrates that LFIs have the potential to be used by law enforcement for the detection of synthetic opioids.

Lifelong Consumption of Plant-Based GM Foods

Genetically modified (GM) crops are cultivated in over 30 countries with their products and by-products imported by over 60 countries. This chapter seeks to highlight general concerns and potential lifelong effects of consuming GM plant-based food. The consumption of GM plant-based food is as risky as consuming conventional plant-based food. However, the alien genes in these products may be unstable leading to antinutritional and unintended short-term consequences. Due to the paucity of research, no long-term effects have been attributed to the lifelong consumption of these products. Nonetheless, possible lifelong health and socioeconomic effects may result from outcrossing of genes, increasing antibiotic resistance, development of new diseases, as well as potential effects on the environment and biodiversity. Biotechnology companies need to invest more in interdisciplinary research addressing the potential lifelong effects of these products. Although GM foods are safe for consumption, clarification of current risks and lifelong effects are required.

The potential of aerosol eDNA sampling for the characterisation of commercial seed lots

Seed shipments, silos and storage houses often contain weed seeds or seeds of restricted crops such as undeclared genetically modified (GM) varieties. Random sub-sampling is the favoured approach to detect unwanted biological materials in seed lots but is prohibitively expensive or else ineffective for the huge volumes of seeds moved in commercial operations. This study uses maize and cowpea seed admixtures as an exemplar to evaluate the feasibility of using aerosol sampling of "seed dust" as an alternative to seed sub-sampling. In an initial calibration phase, qPCR of the rbcL barcode followed by high-resolution melting (HRM) of a DNA titration series revealed a strong linear relationship between mix composition and HRM profiles. However, the relationship became skewed when flour mixes were used to build the titration, implying a DNA extraction bias favouring cowpea. Aerosol samples of seed dust above a titration of mixed seed samples were then collected along vertical and lateral axes. Aerosols were characterised by light microscopy, qPCR-HRM and next-generation DNA sequencing (Illumina MiSeq). Both molecular approaches again showed bias but this time in a reverse direction to flour samples. Microscopic examination of the aerosol sample suggested this divergence could be attributed to differences in abundance of airborne starch particles. Despite the bias, it was nevertheless possible to estimate relative abundance of each species using the abundance of minibarcodes. In light of these results we explore the feasibility of aerosol sampling for commercial seed lot characterisation.

Acute exposure to TiO2 nanoparticles produces minimal apparent effects on oyster, Crassostrea virginica (Gmelin), hemocytes

The response of oyster (Crassostrea virginica) hemocytes was studied following exposure to anatase nanoparticles (ca. 7.4nm), surface-coated rutile nanocomposites (UV-Titan M212, ca. 86nm) and bulk titanium dioxide (TiO₂) particles (anatase and rutile crystalline forms; 0.4-0.5μm). Hemocytes were collected from oysters and exposed to one of the four particle types at concentrations of 0.1, 0.5, and 1.0mg/L under dark and environmentally-relevant light conditions for periods of two and four hours. Hemocyte mortality, phagocytosis, and reactive oxygen species (ROS) production were then evaluated using flow-cytometric assays. Bulk and nanoparticulate TiO₂ had little effect on viability of oyster hemocytes or on production of ROS. Significant changes in phagocytosis occurred after exposure to anatase nanoparticles for 4h under dark conditions, and UV-Titan for 2h under light conditions. Results demonstrate that TiO₂ particles (bulk or nanoscale) produce minimal effects on hemocyte biomarkers examined following acute, in vitro exposures.

Current perspectives on genetically modified crops and detection methods

Genetically modified (GM) crops are the fastest adopted commodities in the agribiotech industry. This market penetration should provide a sustainable basis for ensuring food supply for growing global populations. The successful completion of two decades of commercial GM crop production (1996-2015) is underscored by the increasing rate of adoption of genetic engineering technology by farmers worldwide. With the advent of introduction of multiple traits stacked together in GM crops for combined herbicide tolerance, insect resistance, drought tolerance or disease resistance, the requirement of reliable and sensitive detection methods for tracing and labeling genetically modified organisms in the food/feed chain has become increasingly important. In addition, several countries have established threshold levels for GM content which trigger legally binding labeling schemes. The labeling of GM crops is mandatory in many countries (such as China, EU, Russia, Australia, New Zealand, Brazil, Israel, Saudi Arabia, Korea, Chile, Philippines, Indonesia, Thailand), whereas in Canada, Hong Kong, USA, South Africa, and Argentina voluntary labeling schemes operate. The rapid adoption of GM crops has increased controversies, and mitigating these issues pertaining to the implementation of effective regulatory measures for the detection of GM crops is essential. DNA-based detection methods have been successfully employed, while the whole genome sequencing using next-generation sequencing (NGS) technologies provides an advanced means for detecting genetically modified organisms and foods/feeds in GM crops. This review article describes the current status of GM crop commercialization and discusses the benefits and shortcomings of common and advanced detection systems for GMs in foods and animal feeds.

GMOs in Russia: Research, Society and Legislation

Russian legislation lags behind the rapid developments witnessed in genetic engineering. Only a scientifically based and well-substantiated policy on the place of organisms that are created with the use of genetic engineering technologies and an assessment of the risks associated with them could guarantee that the breakthroughs achieved in modern genetic engineering technologies are effectively put to use in the real economy. A lack of demand for such breakthroughs in the practical field will lead to stagnation in scientific research and to a loss of expertise.