<p style="text-align: justify;"><b>Dietary Exposure</b></p>

<p style="text-align: justify;">Maize lines T14 and T25 were intended mainly for use in animal feed. The major human food uses for maize are extensively processed starch and oil fractions prepared by wet or dry milling procedures and include products such as corn syrup and corn oil, bran, grits, meal and flour. There was no PAT protein detected in starch or oil. Neither was PAT protein detected in wet milled corn grain fractions with the exception of the bran. Wet milled bran and all of the dry milled corn fractions contained very low levels of the PAT protein (&lt; 0.00035% of crude protein). Overall, the dietary exposure of North Americans to grain from maize from lines T14 and T25 was anticipated to be the same as for other lines of commercially available field corn.</p>

<p style="text-align: justify;"><b>Nutritional Data</b></p>

<p style="text-align: justify;">Compositional analyses of maize grain from T14 and T25 derived lines and current commercial maize varieties were compared for compositional and nutritional parameters including moisture, crude fat, crude protein, crude fiber, ash, carbohydrates, mineral content (calcium and phosphorous), amino acid profile, phytates and oil composition. Overall protein content in the grain and whole plant was significantly higher in the transgenic lines compared to the unmodified controls. The statistical differences were explained by the fact that the transformed plant lines were not complete genetic isolines of the control plants and thus the variation arose from genetic differences unrelated to the transformation event. In all cases protein content was within the normal published range for maize. Similarly, an evaluation of the nutrient values determined that they were well within the range of nutrient values reported for corn grain. The use of corn grain from T14- and T25-derived maize lines was determined not to have a significant impact on the nutritional quality of the North American food supply.</p>

<p style="text-align: justify;"><b>Toxicity</b></p>

<p style="text-align: justify;">The low potential for toxicity of the PAT protein expressed in the transgenic maize lines T14 and T25 was demonstrated by examining the amino aid sequence homology, chemical characteristics of the protein and by acute oral toxicity testing in rats. The nucleotide sequence of the <i>pat</i> gene and the deduced amino acid sequence of the PAT protein were compared with sequences available for known toxins in the GenBank database and showed no significant homology with any known toxins or allergens. PAT protein expressed in bacterial systems was used as the test protein for mammalian feeding trials and studies were performed to demonstrate equivalence with the plant-expressed protein. The molecular weight and immunoreactivity of the PAT enzyme from the plant derived sources were similar to the PAT derived from a bacterial expression system. These similarities indicated that the PAT protein was unlikely to have been glycosylated or undergone other post translational modifications. An acute oral toxicity study demonstrated no evidence of toxicity for PAT protein when administered to rats at dietary concentrations up to 50,000 ppm for 14 days, which represents a concentration 6 orders of magnitude greater than that in grain from T14- and T25-derived maize lines.</p>

<p style="text-align: justify;"><b>Allergenicity</b></p>

<p style="text-align: justify;">The PAT enzyme expressed in T14- and T25-derived maize lines does not possess characteristics typical of known protein allergens and is extremely unlikely to be allergenic. There were no regions of homology when the sequences of the introduced protein was compared to the amino acid sequences of known protein allergens. There was no evidence found of post-translational modifications such as acetylation, glycosylation or phosphorylation of the PAT protein. Unlike known protein allergens, the PAT protein was rapidly degraded by acid and/or enzymatic hydrolysis when exposed to simulated gastric fluids. <i>In vitro</i> digestibility studies, under simulated mammalian gastric conditions, demonstrated that the PAT enzyme was inactivated within one minute and was rapidly degraded. No adverse effects have been reported to be associated with this enzyme.</p>
