Fang Jin, Feng Yongquan, Zhi Yuan, Zhang Lan, Yu Zhou, Jia Xudong
Key Laboratory of Food Safety Risk Assessment of Ministry of Health, National Center for Food Safety Risk Assessment, Beijing 100021, China.
Biotechnology Research Institute, National Key Facility of Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Regul Toxicol Pharmacol. 2017 Apr;85:48-54. doi: 10.1016/j.yrtph.2017.01.004. Epub 2017 Jan 27.
GmTMT transgenic maize is a genetically modified maize plant that overexpresses the γ-tocopherol methyltransferase (γ-TMT) from Glycine max (Gm). The γ-TMT gene was introduced into maize line Zhen58 to encode the GmTMT2a protein which can convert γ-tocopherol into α-tocopherol. Overexpression of GmTMT2a significantly increased the α-tocopherol content in transgenic maize. The present study was designed to investigate any potential effects of GmTMT maize grain in a 90-day subchronic rodent feeding study. Maize grains from GmTMT or Zhen58 were incorporated into rodent diets at low (12.5%), medium (25%) or high (50%) concentrations and administered to Sprague-Dawley rats (n = 10/sex/group) for 90 days. The negative control group of rats (n = 10/sex/group) were fed with common maize diets. Results from body weights, feed consumption, clinical chemistry, hematology, absolute and relative organ weights indicated no treatment-related side effects of GmTMT maize grain on rats in comparison with rats consuming diets containing Zhen58 maize grain. In addition, no treatment-related changes were found in necropsy and histopathology examinations. Altogether, our data indicates that GmTMT transgenic maize is as safe and nutritious as its conventional non-transgenic maize.
GmTMT转基因玉米是一种经过基因改造的玉米植株，它过量表达来自大豆（Gm）的γ-生育酚甲基转移酶（γ-TMT）。γ-TMT基因被导入玉米品系振58中，以编码能够将γ-生育酚转化为α-生育酚的GmTMT2a蛋白。GmTMT2a的过量表达显著提高了转基因玉米中α-生育酚的含量。本研究旨在通过一项为期90天的亚慢性啮齿动物喂养研究，调查GmTMT玉米籽粒的任何潜在影响。将来自GmTMT或振58的玉米籽粒以低（12.5%）、中（25%）或高（50%）浓度掺入啮齿动物饮食中，并给予斯普拉格-道利大鼠（每组雌雄各10只），持续90天。大鼠阴性对照组（每组雌雄各10只）喂食普通玉米饮食。体重、饲料消耗、临床化学、血液学、绝对和相对器官重量的结果表明，与食用含振58玉米籽粒饮食的大鼠相比，GmTMT玉米籽粒对大鼠没有与处理相关的副作用。此外，在尸检和组织病理学检查中未发现与处理相关的变化。总之，我们的数据表明，GmTMT转基因玉米与其传统非转基因玉米一样安全且营养丰富。
