ABSTRACT
Recently we witness the rising number of genetically modified (GM) soybean (Glycine max) events approved for importing from abroad and developed domestically, so it is urgent to establish a rapid screening protocol that can cover more events with less detection targets and fit the national condition. Additionally, in order to control the detection workload, it is also necessary to construct a multi-targets plasmid (MTP) molecule that can be used as the positive material. In this study, the information of the transgenic elements in 29 GM soybean events was collected and the combinations and frequencies of these elements were analyzed, to establish a novel screening protocol. It includes eight detecting targets, CaMV 35S promoter (P-35S), NOS terminator (T-nos), herbicide tolerance gene pat, E9 terminator (T-E9), insecticidal gene cry1Ac, AHAS promoter (P-AHAS), pin Ⅱ terminator (T-pin Ⅱ), and the event-specific sequence of the transgenic event DP305423, and an endogenous reference gene of soybean Lectin. After validation, the 29 GM soybean events described above can be screened by detection of the nine targets. This is referred to as the “8+1” protocol for GM soybean screening. Then these targeted sequences described in the protocol were simultaneously inserted into a cloning vector to construct the corresponding MTP pDDSC-1910. Finally, we tested whether it could be a positive plasmid. As expected, PCR analysis using pDDSC-1910 as a template showed that specific amplicons were observed with high sensitivity. Therefore, the “8+1” screening protocol for GM soybean was established, and the positive plasmid molecule pDDSC-1910 containing corresponding targets was successfully constructed. These results would facilitate the efficient screening and detection of transgenic soybeans.
ABSTRACT
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.