Health Canada has notified Pioneer Hi-Bred International, Inc. that it has no objection to the food use of the transgenic maize line MON 809, which is resistant to insect damage. Pioneer Hi-Bred International, Inc., under license from Monsanto Company, St. Louis, Missouri, USA, has developed several insect resistant maize hybrids from the genetically modified line MON 809. The Department conducted a comprehensive assessment of MON 809 according to its Guidelines for the Safety Assessment of Novel Foods (September, 1994). These guidelines are based upon internationally accepted principles for establishing the safety of foods derived from genetically modified organisms.
The following provides a summary regarding the Pioneer Hi-Bred International, Inc. notification to Health Canada and contains no confidential business information.
Hybrids derived from MON 809 offer the Canadian grower protection against the loss of yield due to infestation with the European Corn Borer (ECB), an important Lepidopteran insect pest, with reduced use of chemical pesticides.
Protection against ECB is provided by the Cry1A(b) insect control protein derived from the common soil bacterium Bacillus thuringiensis subsp. kurstaki (B.t.k). The Cry1A(b) protein has a long history of safe use in biological pesticides and is ecologically benign. It breaks down rapidly in the soil and is safe to non-target organisms such as fish, birds, mammals and beneficial insects.
Line MON 809 was transformed with recombinant DNA carrying the cryIA(b) gene and genes encoding the following selectable markers: EPSPS, an enzyme involved in the synthesis of aromatic amino acids, which is derived from the CP4 strain of the bacterium Agrobacterium; and, glyphosate oxidoreductase (GOX) derived from the bacterium Ochrobactrum anthropi. Production of the CP4 EPSPS and GOX proteins in the modified plants allows researchers to select the plant cells which carry the cry1A(b) gene on medium containing the herbicide glyphosate. Line MON 809 also contains a marker gene which permitted selection of the recombinant DNA in bacteria during development. This gene confers resistance to the antibiotic kanamycin, but is not functional in plants.
Small amounts of the introduced proteins, CryIA(b) and CP4 EPSPS are present in leaves, seeds and roots of line MON 809 but, not in the pollen. Hybrids derived from MON 809 are agronomically similar to their non-transgenic counterparts in terms of growth characteristics and resistance to non-Lepidopteran pests and produce similar yields in the absence of ECB. However, under heavy infestations of ECB, MON 809 hybrids out yield their non-transgenic counterparts by 10 - 15%. Hybrids derived from MON 809 are not tolerant to the concentrations of glyphosate herbicide that are typically used for weed control.
Grain from insect resistant hybrids is primarily intended for animal feeding. However, such field corn may be dry- or wet-milled into various processed corn products for human food use. The human food uses of grain from insect resistant hybrids is not expected to be different from the uses of non-transgenic field corn varieties. As such, the dietary exposure of Canadians to grain from insect resistant hybrids will not be different from that for other commercially available field corn varieties.
The nutritional quality of grain from MON 809 is similar to that of grain from an equivalent non-transgenic line and to grain that is currently in commerce. Grain was analysed for proximate (i.e., ash, moisture content, crude protein, crude fat), amino acid and fatty acid composition. Some minor differences were observed between MON 809 and an equivalent non-transgenic line, but these components were within the range of variation normally observed in the commercial grain supply and are attributed to variations in the plant genotypes rather than to the presence of the introduced genes.
a) Potential Toxicity:
The CryIA(b) and CP4 EPSPS proteins should pose no risks for consumption of products produced from insect resistant maize. The introduced proteins were compared to databases of known protein toxins and neither shows any significant amino acid sequence similarity to known protein toxins. Both proteins are rapidly broken down and their enzymatic activity lost under conditions that simulate mammalian digestion. Neither protein was toxic when fed to mice.
b) Potential Allergenicity:
The CryIA(b) and CP4 EPSPS proteins are extremely unlikely to be allergens. The introduced proteins were compared to known allergens. Neither protein comes from an allergenic source or is structurally similar to known allergens. In addition, the potential for allergicity was assessed based upon the characteristics of known food allergens (stability to digestion, stability to processing, abundance in foods). The introduced proteins do not possess characteristics typical of known protein allergens.
Health Canada's review of the information presented in support of the food use of insect resistant maize MON 809 concluded that this maize does not raise concerns related to safety. Health Canada is of the opinion that MON 809 is as safe and nutritious as current commercial maize varieties.
Health Canada's opinion deals only with the food use of insect resistant maize. Issues related to growing insect resistant maize in Canada and its use as animal feed have been addressed separately through existing regulatory processes in Agriculture & Agri-Food Canada.
This Novel Food Information document has been prepared to summarize the opinion regarding the subject product provided by the Food Directorate, Health Protection Branch, Health Canada. This opinion is based upon the comprehensive review of information submitted by the petitioner according to the Guidelines for the Safety Assessment of Novel Foods.
For further information, please contact:
Office of Food Biotechnology
Health Protection Branch
Ottawa, Ontario K1A 0L2
Telephone: (613) 952-5137
Facsimile: (613) 952-6400