title: Event specific qualitative and quantitative polymerase chain reaction detection of genetically modified MON863 maize based on the 5'-transgene integration sequence.
abstract: Because of the genetically modified organisms (GMOs) labeling policies issued in many countries and areas, polymerase chain reaction (PCR) methods were developed for the execution of GMO labeling policies, such as screening, gene specific, construct specific, and event specific PCR detection methods, which have become a mainstay of GMOs detection. The event specific PCR detection method is the primary trend in GMOs detection because of its high specificity based on the flanking sequence of the exogenous integrant. This genetically modified maize, MON863, contains a Cry3Bb1 coding sequence that produces a protein with enhanced insecticidal activity against the coleopteran pest, corn rootworm. In this study, the 5'-integration junction sequence between the host plant DNA and the integrated gene construct of the genetically modified maize MON863 was revealed by means of thermal asymmetric interlaced-PCR, and the specific PCR primers and TaqMan probe were designed based upon the revealed 5'-integration junction sequence; the conventional qualitative PCR and quantitative TaqMan real-time PCR detection methods employing these primers and probes were successfully developed. In conventional qualitative PCR assay, the limit of detection (LOD) was 0.1% for MON863 in 100 ng of maize genomic DNA for one reaction. In the quantitative TaqMan real-time PCR assay, the LOD and the limit of quantification were eight and 80 haploid genome copies, respectively. In addition, three mixed maize samples with known MON863 contents were detected using the established real-time PCR systems, and the ideal results indicated that the established event specific real-time PCR detection systems were reliable, sensitive, and accurate.
authors.affiliation: School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
authors.forename: Litao
authors.initials: L
authors.lastname: Yang
authors.forename: Songci
authors.initials: S
authors.lastname: Xu
authors.forename: Aihu
authors.initials: A
authors.lastname: Pan
authors.forename: Changsong
authors.initials: C
authors.lastname: Yin
authors.forename: Kewei
authors.initials: K
authors.lastname: Zhang
authors.forename: Zhenying
authors.initials: Z
authors.lastname: Wang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhou
authors.forename: Dabing
authors.initials: D
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D001517:Coleoptera; D018744:DNA, Plant / Q000737:chemistry; D004731:Endotoxins / Q000235:genetics; D006460:Hemolysin Proteins; D007306:Insecticides; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D003313:Zea mays / Q000235:genetics*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D018744:DNA, Plant; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis