GMOIT: a tool for effective screening of genetically modified crops.

BACKGROUND: Advancement in agricultural biotechnology has resulted in increasing numbers of commercial varieties of genetically modified (GM) crops worldwide. Though several databases on GM crops are available, these databases generally focus on collecting and providing information on transgenic crops rather than on screening strategies. To overcome this, we constructed a novel tool named, Genetically Modified Organisms Identification Tool (GMOIT), designed to integrate basic and genetic information on genetic modification events and detection methods. RESULTS: At present, data for each element from 118 independent genetic modification events in soybean, maize, canola, and rice were included in the database. Particularly, GMOIT allows users to customize assay ranges and thus obtain the corresponding optimized screening strategies using common elements or specific locations as the detection targets with high flexibility. Using the 118 genetic modification events currently included in GMOIT as the range and algorithm selection results, a "6 + 4" protocol (six exogenous elements and four endogenous reference genes as the detection targets) covering 108 events for the four crops was established. Plasmids pGMOIT-1 and pGMOIT-2 were constructed as positive controls or calibrators in qualitative and quantitative transgene detection. CONCLUSIONS: Our study provides a simple, practical tool for selecting, detecting, and screening strategies for a sustainable and efficient application of genetic modification.

[Exploration of an online and offline mixed teaching mode for "Protein Engineering" based on BOPPPS+flipped classroom].

Protein Engineering is a core compulsory course of biotechnology major, which is the first-class undergraduate major being constructed in Shanxi Province. In view of the problems of single teaching mode of Protein Engineering, such as insufficient students' participation, short teaching time, and expensive experiment cost, the course team carried out the reform and practice of teaching mode for this course, and put forward a new teaching strategy. Under the guidance of the "Golden Course" standard for advancement, innovation and challenge, the course team developed the materials for massive open online courses (MOOC), and carried out the online and offline mixed teaching of Protein Engineering based on BOPPPS+flipped classroom by using the Chao-Xing Fan-Ya network teaching platform. Through this, a comprehensive, systematic and dynamic new teaching system of Protein Engineering was developed. Using the teaching mode based on BOPPPS+flipped classroom, the offline classroom teaching was combined with students' online self-study and homework completion, chapter test and discussion, and this mixed teaching mode was fully integrated into the flipped classroom. After three rounds of teaching practice, the course team had developed a complete, reproducible, scientific and reasonable online and offline mixed teaching mode, which included course materials preparation, exploring experiment guidance, classroom discussion design and course performance evaluation. The online and offline mixed teaching mode of Protein Engineering based on BOPPPS+flipped classroom was helpful for students to improve their autonomous learning ability, to be deeply engaged in the whole teaching process, and to develop a comprehensive and profound understanding of Protein Engineering. This teaching mode improved the teaching quality of Protein Engineering, and facilitated students to learn other follow-up professional courses. Moreover, it provides a reference for the course teaching reform.

N-region of Cry1Ia: A novel fusion tag for Escherichia coli and Pichia pastoris.

Secretory signal peptides (SPs) can increase enhanced green fluorescent protein (eGFP) expression in cytosol. In this study, SPs Iasp (Cry1Ia), Vasp (Vip3A), and their local sequences were used as fusion tags to compare their effects on eGFP expression in Escherichia coli MC4100 and Pichia pastoris GS115. In E coli, the solubility was almost opposite between the proteins encoded by Vegfp and Iegfp. This may be because the overall hydrophobicity of the SPs differed. When the hydrophobic H-region and C-region were removed, the negative effects on eGFP solubility of the N-regions of both SPs (IaN and VN) were significantly reduced without compromise on the expression level. IaN promotes eGFP protein yield 7.1-fold more than Iasp, and using this peptide in tandem (Ia3N) further enhanced fluorescent fusion protein solubility with an efficacy similar to that of a polycationic tag. Furthermore, the GS-IaNeGFP strain produced the highest fluorescent signal intensity when these fusion proteins were expressed in P. pastoris, and the expression was higher than in other strains, including eGFP. In conclusion, we revealed the potential of the N-region of Iasp as a fusion tag in both prokaryotic and eukaryotic cells and further demonstrated the value of the N-regions of abundant SPs.

Evaluation of the effects of feeding glyphosate-tolerant soybeans (CP4 EPSPS) on the testis of male Sprague-Dawley rats.

Glyphosate tolerant soybeans represent a large portion of soybeans grown and fed to farm animals around the world. Despite their widespread use for many years, some have raised questions regarding their safety because the soybeans were genetically modified. The CP4 EPSPS gene which imparts resistance to topical application of the herbicide glyphosate was introduced into soybeans. Application of glyphosate to soybean fields will reduce weed pressure and increase soybean yield. To assess their safety on the rat reproduction system, male Sprague Dawley rats were fed either glyphosate-tolerant (GM) soybean (40-3-2) or near-isogenic, non-GM (A5403) (control) soybean meal. The processed soybean meal was added to formulated rodent diets at 20% (w/w) and fed to rats for 90 days. Some rats from the control group were separately administered mitomycin C for 40 days and served as positive controls in the sperm abnormality test. Body weights and behavior were monitored daily, serum enzymes and histologic and EM appearance of the testis, and sperm morphology were also examined. After 90 days of feeding, no adverse effects were observed in rats fed glyphosate-tolerant soybeans.

Bisphenol A-induced apoptosis, oxidative stress and DNA damage in cultured rhesus monkey embryo renal epithelial Marc-145 cells.

Bisphenol A (BPA) is widely used in the production of epoxy resins and polycarbonate plastics. Under harsh situations, these plastics likely desorb BPA, which then can seep into the environment. Various concentrations of BPA have been detected in most biological fluid. However, there is paucity of information on the detrimental effects of BPA and its subsequent cellular events in chronic kidney disease (CKD). Hence, in this in vitro study, we aimed to investigate the effects of BPA on renal epithelial cell activation, apoptosis, and DNA damage. Rhesus monkey embryo renal epithelial Marc-145 cells were exposed to 0, 10-1, 10-2, 10-3, 10-4, 10-5, and 10-6 M of BPA. Alterations in intracellular apoptosis, oxidative stress, and DNA damage were evaluated. The results showed that BPA decreased cell viability, superoxide dismutase (SOD) activity and glutathione (GSH) level, with concomitant increases in apoptosis related indices, lactate dehydrogenase (LDH) activity, reactive oxygen species (ROS) generation, thiobarbituric acid reactive substances (TBARS) content, and the rate of comet Marc-145 cells with a dose-dependent manner. The data indicated that increased oxidative stress, apoptosis and DNA damage in epithelial Marc-145 cells might play a pivotal role in the mechanism of BPA-induced nephrotoxicity.

[Analysis of exogenous gene and protein digestion and absorption of SD rats (Rattus norvegicus) fed roundup ready soybean meal].

Metabolism and deposition of exogenous gene and protein from transgenic glyphosate herbicide-tolerant soybean meal in SD rats were studied in the experiment. The transgenic soybean GTS40-3-2 meal and its non-transgenic counterpart (parent A5403) were fed to the generation and the second generation Sprague-Dawley (SD) rats (Rattus norvegicus). The study added the genetically modified (GM) soybean meal and its non-transgenic control soybean meal (parent A5403) in a ratio of 20% respectively to the feeds. By using qualitative, quantitative PCR and ELISA methods to detect transgenic soybean residues of metabolism ingredients in rats, the safety and influence of GM soybean were evaluated. The results showed that the intestinal fecal and cecum contents of rats were detected with residues of GM ingredients, intestinal flora and organs were not found related genes and protein. These results indicated that transgenic glyphosate herbicide-tolerant soybean GTS40-3-2 meal was as safe as its non-GM soybean meal in long-term feeding study.

[Detection of transgenic components in animal feeds on Shanxi markets].

To assess the presence of genetically modified (GM) maize and soybean in a range of commercialized feed in Shanxi province of China in 2015, improved hexadecyltrimethy ammonium bromide (CTAB) method was used to extract DNA. The screening of packed feeds was carried out by qualitative PCR. Then positive feeds were unpacked and detected by the CaMV 35S promoter, NOS terminator, zSSIIb, Lectin and CryIA (b) genes. The identified maize and soybean events were confirmed by event-specific MON810 and GTS40-3-2. Results showed that 83.3% of the feeds was tested positive for GMOs, in which positive rates of maize, soybean, pig and layer feeds were 6.67%, 100%, 93.3% and 73.3%, respectively. The results of real-time PCR were consistent with qualitative PCR. These results indicated that commercialized GM feed had a wide positive product scope in Shanxi province of China. Further studies are necessary to study effects of feeding livestock and poultry with feed containing GM ingredients on animals and their products.