Subchronic feeding study with genetically modified stacked trait lepidopteran and coleopteran resistant (DAS-ط15ط7-1xDAS-59122-7) maize grain in Sprague-Dawley rats

DAS-ط15ط7-1xDAS-59122-7 (1507 × 59122) is a genetically modified (GM) maize hybrid that was produced by crossing of two GM maize inbreds; DAS-ط15ط7-1 and DAS-59122-7. This hybrid cross expresses four transgenic proteins: Cry1F and PAT (from DAS-ط15ط7-1) and Cry34Ab1/Cry35Ab1 and PAT (from DAS-59122-7) that confer resistance to lepidopteran and coleopteran pests and tolerance to the herbicidal active ingredient glufosinate-ammonium. The current subchronic feeding study was conducted in Sprague-Dawley rats to evaluate the potential health effects of long-term consumption of a rodent diet containing 1507 × 59122 maize grain compared with a diet containing maize grain from its near-isogenic control (091). Diets formulated with three unrelated non-GM commercial hybrids (3573, 35P12, 36G12) were also included for within study reference data. All diets contained 34% (w/wt) maize grain and were prepared according to the specifications of PMI® Nutrition International, LLC Certified Rodent LabDiet® 5002 (PMI® 5002). Diets were fed ad libitum to rats for at least 92 days. OECD 408 response variables from rats fed the 1507 × 59122 diet were compared with those from rats fed the 091 control diet. No toxicologically significant differences were observed in nutritional performance variables, clinical and neurobehavioral signs, ophthalmology, clinical pathology (hematology, clinical chemistry, coagulation, and urinalysis), organ weights, and gross and microscopic pathology between rats in the 091 and 1507 × 59122 treatment groups. The results from this study demonstrate that 1507 × 59122 maize grain is as safe and nutritious as non-GM maize grain and support the concept that crossing of two safe GM maize events results in production of a safe stacked GM event.