Dow AgroSciences, LLC, Indianapolis, IN 46268, USA.
Regul Toxicol Pharmacol. 2012 Mar;62(2):363-70. doi: 10.1016/j.yrtph.2011.10.018. Epub 2011 Nov 13.
DAS-40278-9 maize (corn) plants have been genetically modified by the insertion of the aad-1 gene (aryloxyalkanoate dioxygenase), which confers tolerance to 2,4-dichlorophenoxyacetic acid (2,4-D) and aryloxyphenoxypropionate (AOPP) acetyl coenzyme A carboxylase (ACCase) inhibitors ("fop" herbicides) to enable the effective use of these herbicides on maize. The aad-1 gene, derived from Sphingobium herbicidovorans, encodes the aryloxyalkanoate dioxygenase (AAD-1) enzyme. As part of the safety assessment of the AAD-1 protein expressed in maize, acute and repeated dose mammalian toxicology studies were conducted. AAD-1 protein (heterologously produced) was orally administered to mice at a dose of 2000mg/kg, and no acute lethality or adverse effects were observed. Similarly, no adverse effects were observed in mice in a 28-day repeated-dose dietary toxicity study that incorporated the AAD-1 protein into diets at concentrations up to 1000-fold greater than the highest estimate of human exposure to maize. These results support the conclusion that the AAD-1 protein, as expressed in biotechnology derived DAS-40278-9 maize, represents a negligible risk to human health.
DAS-40278-9 玉米（corn）植株通过插入 aad-1 基因（芳氧基烷酸双加氧酶）进行了基因改造，该基因赋予了对 2,4-二氯苯氧乙酸（2,4-D）和芳氧基苯氧基丙酸（AOPP）乙酰辅酶 A 羧化酶（ACCase）抑制剂（“fop”除草剂）的耐受性，使这些除草剂能够有效地用于玉米。aad-1 基因源自鞘氨醇单胞菌，编码芳氧基烷酸双加氧酶（AAD-1）酶。作为对玉米中表达的 AAD-1 蛋白的安全性评估的一部分，进行了急性和重复剂量哺乳动物毒理学研究。以 2000mg/kg 的剂量口服给予 AAD-1 蛋白（异源生产），未观察到急性致死性或不良反应。同样，在一项为期 28 天的重复剂量饮食毒性研究中，当将 AAD-1 蛋白掺入饮食中时，浓度高达人类暴露于玉米的最高估计值的 1000 倍以上，在小鼠中也未观察到不良反应。这些结果支持这样的结论，即如生物技术衍生的 DAS-40278-9 玉米中所表达的 AAD-1 蛋白，对人类健康的风险可以忽略不计。
