Development of an event-specific hydrolysis probe quantitative real-time polymerase chain reaction assay for Embrapa 5.1 genetically modified common bean (Phaseolus vulgaris)

Sensitive detection of genetically modified maize based on a CRISPR/Cas12a system

With the vigorous development of biotechnology, genetically modified organisms (GMOs) have become more and more common. In order to effectively supervise and administrate them, the rapid and accurate detection of GMOs is urgently demanded. Here, GMO gene-specific sensing methods based on colorimetry and surface-enhanced Raman scattering (SERS) were proposed based on the lateral branch cleavage function of the CRISPR/Cas12a system. Two transgenes, pCaMV35S and M810 Cry1Ab, were chosen as targets for transgenic crops. By using these methods, we performed transgenic detection on five types of maize leaves and successfully distinguished transgenic from non-transgenic samples. The colorimetric method is rapid, economical and available for field detection. The SERS approach, giving a higher sensitivity to 100 fM, is more suitable for laboratory application scenarios. This study explores practical transgenic detection approaches and will be valuable for the supervision of GMOs.

Review of CRISPR/Cas Systems on Detection of Nucleotide Sequences

Nowadays, with the rapid development of biotechnology, the CRISPR/Cas technology in particular has produced many new traits and products. Therefore, rapid and high-resolution detection methods for biotechnology products are urgently needed, which is extremely important for safety regulation. Recently, in addition to being gene editing tools, CRISPR/Cas systems have also been used in detection of various targets. CRISPR/Cas systems can be successfully used to detect nucleic acids, proteins, metal ions and others in combination with a variety of technologies, with great application prospects in the future. However, there are still some challenges need to be addressed. In this review, we will list some detection methods of genetically modified (GM) crops, gene-edited crops and single-nucleotide polymorphisms (SNPs) based on CRISPR/Cas systems, hoping to bring some inspiration or ideas to readers.

Development of a certified genomic DNA reference material for detection and quantification of genetically modified rice KMD

Qualitative and quantitative detection of genetically modified products is inseparable from the application of reference materials (RMs). In this study, a batch of genomic DNA (gDNA) certified reference materials (CRMs) was developed using genetically modified rice Kemingdao (KMD) homozygotes as the raw material. The gDNA CRMs in this batch showed good homogeneity; the minimum sample intake was determined to be 2 μL. The stability study showed that transportation by cold chain is preferable, no significant degradation trend was observed during a 12-month period when storing the gDNA CRMs at 4 °C and - 20 °C, and the number of freeze-thaw cycles cannot exceed 10. The property values of the copy number ratio of transgene and endogenous gene and the copy number concentration for gDNA CRMs were determined by a collaborative characterization of eight laboratories using the duplex KMD/PLD droplet digital PCR (ddPCR) assays. The uncertainty components of characterization, potential between-unit heterogeneity, and potential degradation during long-term storage were combined to estimate the expanded uncertainty of the certified value with a coverage factor k of 2.0. The certified value of copy number ratio for KMD gDNA CRM is 0.99 ± 0.05, and that of copy number concentration is (1.76 ± 0.10) × 10⁵ copies/μL. Compared to the gDNA CRMs in availability, this batch of KMD gDNA CRMs is assigned accurate property values and can be directly used for qualitative and quantitative detection of GMOs as well as evaluation of the parameters of analytical methods with no need of further DNA concentration measurement. Graphical abstract.

Investigation of transgenic soybean components in soybean from an area of China

BACKGROUND

To evaluate the large quantities of genetically modified soybeans that are imported into China, we evaluated the presence of transgenes in soybean samples from an area, which are major soybean-producing areas. We evaluated the presence of exogenous genes in a total of 254 soybean samples from farms and 35 commercially available soybean samples using polymerase chain reaction amplification and sequence analysis.

RESULTS

The farm soybean samples contained a total of 67 CaMV35S-positive samples, 46 NOS-positive samples, 16 CP4-EPEPS-positive samples, and 66 BT-positive samples. The commercially available soybean samples contained a total of 12 CaMV35S-positive samples, 19 NOS-positive samples, 13 CP4-EPEPS-positive samples, and 15 BT-positive samples.

CONCLUSION

Several exogenous genes were detected in the farmed and commercially available soybeans. We should use caution in the management of genetically modified soybeans. © 2015 Society of Chemical Industry.

Comparative Proteomic Analysis of Two Varieties of Genetically Modified (GM) Embrapa 5.1 Common Bean (Phaseolus vulgaris L.) and Their Non-GM Counterparts

The genetically modified (GM) common bean event Embrapa 5.1 was commercially approved in Brazil in 2011; it is resistant to golden mosaic virus infection. In the present work grain proteome profiles of two Embrapa 5.1 common bean varieties, Pérola and Pontal, and their non-GM counterparts were compared by two-dimensional gel electrophoresis (2-DE) followed by mass spectrometry (MS). Analyses detected 23 spots differentially accumulated between GM Pérola and non-GM Pérola and 21 spots between GM Pontal and non-GM Pontal, although they were not the same proteins in Pérola and Pontal varieties, indicating that the variability observed may not be due to the genetic transformation. Among them, eight proteins were identified in Pérola varieties, and four proteins were identified in Pontal. Moreover, we applied principal component analysis (PCA) on 2-DE data, and variation between varieties was explained in the first two principal components. This work provides a first 2-DE-MS/MS-based analysis of Embrapa 5.1 common bean grains.