Transgenic maize event TC1507: Global status of food, feed, and environmental safety

Abstract

Maize (Zea mays) is a widely cultivated cereal that has been safely consumed by humans and animals for centuries. Transgenic or genetically engineered insect-resistant and herbicide-tolerant maize, are commercially grown on a broad scale. Event TC1507 (OECD unique identifier: DAS-Ø15Ø7-1) or the Herculex®(#) I trait, an insect-resistant and herbicide-tolerant maize expressing Cry1F and PAT proteins, has been registered for commercial cultivation in the US since 2001. A science-based safety assessment was conducted on TC1507 prior to commercialization. The safety assessment addressed allergenicity; acute oral toxicity; subchronic toxicity; substantial equivalence with conventional comparators, as well as environmental impact. Results from biochemical, physicochemical, and in silico investigations supported the conclusion that Cry1F and PAT proteins are unlikely to be either allergenic or toxic to humans. Also, findings from toxicological and animal feeding studies supported that maize with TC1507 is as safe and nutritious as conventional maize. Maize with TC1507 is not expected to behave differently than conventional maize in terms of its potential for invasiveness, gene flow to wild and weedy relatives, or impact on non-target organisms. These safety conclusions regarding TC1507 were acknowledged by over 20 regulatory agencies including United States Environment Protection Agency (US EPA), US Department of Agriculture (USDA), Canadian Food Inspection Agency (CFIA), and European Food Safety Authority (EFSA) before authorizing cultivation and/or food and feed uses. A comprehensive review of the safety studies on TC1507, as well as some benefits, are presented here to serve as a reference for regulatory agencies and decision makers in other countries where authorization of TC1507 is or will be pursued.

Keywords: Bt, Bacillus thuringiensis; CFIA, Canadian Food Inspection Agency; CTNBio, Comissão Técnica Nacional de Biossegurança; Cry, crystalline; Cry1F; DA-BPI, Department of Agriculture-Bureau of Plant Industry; DNA, deoxyribonucleic acid; EFSA, European Food Safety Authority; ELISA, enzyme-linked immunosorbent assay; ERA, environmental risk assessment; EU, European Union; FAO, Food and Agriculture Organization of the United Nations; FDA, Food and Drug Administration; FFP, food, feed, and processing; FSANZ, Food Standards Australia New Zealand; GAIN, Global Agricultural Information Network; GE maize; GE, genetically engineered; HGT, horizontal gene transfer; ISAAA, International Service for the Acquisition of Agri-biotech Applications; LD50, median lethal dose; NCGA, National Corn Growers Association; NTOs, non-target organisms; OECD, Organisation for Economic Co-operation and Development; PAT, phosphinothricin-N-acetyltransferase; PCR, polymerase chain reaction; SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis; SE, Substantial Equivalence; SGF, simulated gastric fluid; TC1507; US EPA, United States Environment Protection Agency; USDA APHIS, US Department of Agriculture-Animal and Plant Health Inspection Service; WHO, World Health Organization; aa, amino acid; environmental safety; food and feed safety; global authorizations; nptII, neomycin phosphotransferase II.