转基因生物安全性评价.doc

摘要 1 Abstract 2 1. 前言 3 1.1 转基因生物安全性评价的必要性及评价体系的建立现状 3 1.2 评价转Bt基因抗虫棉对鱼类安全性的意义 4 1.3 对鱼类安全性的评价方法 7 1.4 有关斑马鱼的研究 10 2 材料和方法 14 2.1 材料 14 2.1.1 实验动物 14 2.1.2 实验用棉籽 14 2.1.3 试剂 14 2.1.4仪器 15 2.2 方法 17 2.2.1 实验处理 17 2.2.2急性毒性实验 18 2.2.3 慢性毒性实验 18 3 结果 20 3.1 急性毒性实验 20 3.2 慢性毒性实验 20 3.2.1器官和组织的形态、结构 20 3.3 微核试验 24 3.3.1阳性对照物试验 24 3.3.2 正式实验 24 3.3.3 红细胞的测量 27 4. 讨论 28 4.1急性毒性试验 28 4.2慢性水平的毒性试验 29 4.3微核试验 31 4.4结论： 33 参考文献 34 附录Ⅰ 39 附录Ⅱ 40 附录Ⅲ 41 图版说明 42 摘要 以斑马鱼(Brachydanio rerio)为实验材料，从一般毒性（急性，慢性），遗传毒性两个层次评价转Bt基因抗虫棉棉籽粉对鱼类的生物安全性。急性毒性试验结果显示转Bt基因抗虫棉对斑马鱼无急性致死毒性，也没有急性非致死性毒性。慢性毒性试验的病理学检查表明，肝脏、脾脏和肠均未发现解剖观察水平和光镜水平的病变。采用斑马鱼外周血红细胞微核试验的遗传毒性方法，证明诱变剂氟化钠可以明显诱导斑马鱼外周血红细胞微核率升高，并确定了合适的阳性反应条件。运用改进的小型鱼采血方法和建立的斑马鱼微核试验检测方法，检测了转Bt基因抗虫棉的细胞遗传毒性，结果表明转Bt基因抗虫棉没有诱发斑马鱼红细胞微核的遗传毒性。实验结果表明在鱼类饲料中使用规范比例的转Bt基因棉籽粉是安全的。 关键词：转Bt基因抗虫棉、斑马鱼、安全性评价 Abstract The biosafety of transgenic Bt cottonseed to fish is assessed by means of regular toxicity test (acute test and chronic test) and genetoxicity test. Zebrafish (Brachydanio rerio) is chosen as model experimental animal. No acute lethal toxicity and other acute toxicity of transgenic Bt cottonseed to zebrafish is observed. After chronic toxicity test, liver, spleen and intestine of all experimental groups are examined with help of pathological methods. No pathological change on morphology level and on microscopic level is observed. Micronucleus test (MNT) is chosen on behalf of genetoxicity test. NaF is found out to be a kind of mutagens to zebrafishes and appropriate conditions for NaF to induce Micronucleus (MN) in peripheral erythrocytes is also set up. The size of peripheral erythrocytes, their nuclei, and MN is measured. The size of them shows that peripheral erythrocytes of zebrafishes are a kind of good materials for MNT. The result of MNT shows that transgenic Bt cottonseed does not induce raise of MN ratio significantly. On base of the experimental results, a primary conclusion is made that the regular proportion of transgenic Bt cottonseed in