Validity Assessment of the Detection Method of Maize Event Bt10 through Investigation of Its Molecular Structure

• Published in: Journal of agricultural and food chemistry 2009-04, Vol.57 (8), p.3156-3163
• Main Authors: Milcamps, Anne, Rabe, Scott, Cade, Rebecca, De Framond, Anic J, Henriksson, Peter, Kramer, Vance, Lisboa, Duarte, Pastor-Benito, Susana, Willits, Michael G, Lawrence, David, Van den Eede, Guy
• Format: Article
• Language: English
• Subjects: Bacillus thuringiensis; Bacterial Proteins - analysis; Bacterial Proteins - genetics; Biological and medical sciences; Blotting, Southern; Chemical Aspects of Biotechnology/Molecular Biology; corn; crystal proteins; DNA, Plant - analysis; DNA, Recombinant - analysis; Endotoxins - analysis; Endotoxins - genetics; Europe; event Bt10; Feed and pet food industries; Food industries; Fundamental and applied biological sciences. Psychology; Gene Library; General aspects; genetically modified foods; Hemolysin Proteins - analysis; Hemolysin Proteins - genetics; insecticidal proteins; Legislation, Food; Methods of analysis, processing and quality control, regulation, standards; Plants, Genetically Modified - genetics; Polymerase Chain Reaction; recombinant DNA; Seeds - genetics; Sequence Analysis, DNA; transgenes; transgenic plants; United States; Zea mays; Zea mays - genetics
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf802627f

In March 2005, U.S. authorities informed the European Commission of the inadvertent release of unauthorized maize GM event Bt10 in their market and subsequently the grain channel. In the United States measures were taken to eliminate Bt10 from seed and grain supplies; in the European Union an embargo for maize gluten and brewer’s grain import was implemented unless certified of Bt10 absence with a Bt10-specific PCR detection method. With the aim of assessing the validity of the Bt10 detection method, an in-depth analysis of the molecular organization of the genetic modification of this event was carried out by both the company Syngenta, who produced the event, and the European Commission Joint Research Centre, who validated the detection method. Using a variety of molecular analytical tools, both organizations found the genetic modification of event Bt10 to be very complex in structure, with rearrangements, inversions, and multiple copies of the structural elements (cry1Ab, pat, and the amp gene), interspersed with small genomic maize fragments. Southern blot analyses demonstrated that all Bt10 elements were found tightly linked on one large fragment, including the region that would generate the event-specific PCR amplicon of the Bt10 detection method. This study proposes a hypothetical map of the insert of event Bt10 and concludes that the validated detection method for event Bt10 is fit for its purpose.