title: Subchronic feeding study of grain from herbicide-tolerant maize DP-Ø9814Ø-6 in Sprague-Dawley rats.
abstract: This 13-week feeding study conducted in Sprague-Dawley rats evaluated the potential health effects from long-term consumption of a rodent diet formulated with grain from genetically modified (GM), herbicide-tolerant maize DP-Ø9814Ø-6 (98140; trade name Optimum GAT (Optimum GAT is a registered trademark of Pioneer Hi-Bred)). Metabolic inactivation of the herbicidal active ingredient glyphosate was conferred by genomic integration and expression of a gene-shuffled acetylase coding sequence, gat4621, from Bacillus licheniformis; tolerance to acetolactate synthase (ALS) inhibiting herbicides was conferred by overexpression of a modified allele (zm-hra) of the endogenous maize ALS enzyme that is resilient to inactivation. Milled maize grain from untreated (98140) and herbicide-treated (98140+Gly/SU) plants, the conventional non-transgenic, near-isogenic control (091), and three commercial non-transgenic reference hybrids (33J56, 33P66, and 33R77) was substituted at concentrations of 35-38% w/w into a common rodent chow formula (PMI) Nutrition International, LLC Certified Rodent LabDiet 5002) and fed to rats (12/sex/group) for at least 91 consecutive days. Compared with rats fed diets containing grain from the conventional near-isogenic control maize, no adverse effects were observed in rats fed diets containing grain from 98140 or 98140+Gly/SU maize with respect to standard nutritional performance metrics and OECD 408-compliant toxicological response variables [OECD, 1998. Section 4 (Part 408), Health Effects: Repeated Dose 90-Day Oral Toxicity Study in Rodents, Guideline for the Testing of Chemicals. Organisation of Economic Co-operation and Development, Paris, France]. These results support the comparative safety and nutritional value of maize grain from genetically modified Optimum GAT and conventional, non-transgenic hybrid field corn.
authors.affiliation: Pioneer, A DuPont Company, Johnston, IA, USA.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Appenzeller
authors.forename: Susan M
authors.initials: SM
authors.lastname: Munley
authors.forename: Denise
authors.initials: D
authors.lastname: Hoban
authors.forename: Greg P
authors.initials: GP
authors.lastname: Sykes
authors.forename: Linda A
authors.initials: LA
authors.lastname: Malley
authors.forename: Bryan
authors.initials: B
authors.lastname: Delaney
mesh_terms: D000821:Animal Feed / Q000633:toxicity*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001774:Blood Chemical Analysis; D001835:Body Weight / Q000187:drug effects; D004361:Drug Tolerance / Q000235:genetics*; D004435:Eating / Q000187:drug effects; D005123:Eye / Q000187:drug effects; D005260:Female; D006403:Hematologic Tests; D008297:Male; D053580:Muscle Strength / Q000187:drug effects; D009420:Nervous System / Q000187:drug effects; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018675:Toxicity Tests; D003313:Zea mays / Q000235:genetics / Q000378:metabolism / Q000633:toxicity