UMAN GROWTH HORMONE GEN MT ROMOTER PBR Figure 10.15 (d)These two mice are genetically the same strain,except that the one on the right has been transfected with the human growth hormone gene (shown in its circular plasma vector).The new gene spurred an increase in this mouse's growth rate until it dwarfed its normal-sized companion.(b)Comparison of the meat from a pig into which bovine growth hormone genes were introduced (left) and a normal pig(right).A section taken at the same rib area of the two pigs indicates significantly reduced fat content in the transgenic pig.Both animals weighed approximately the same. ()Goat as drug factory.This normal-looking goat carries a human gene for synthesizing the cystic fibrosis transmembrane regulator (CFTR)protein.If tests go as planned,the CFTR will be marketed as a replacement factor for children with cystic fibrosis
0.5m FIGURE 9.16 Production of an insect toxin by genetic engineering techniques.Root-dwelling Pseudomonas fluorescens bacteria have been genetically engineered to TEM0.25 um FIGURE 9.11 E. produce the insecticidal toxin normally produced by red to produce human insulin.T Bacillus thuringiensis.The crystal of toxin can be seen in t promotes an im- indicated by the arr this cell of P.fluorescens,which is capable of producing the re as an orange mass, micrograph. toxin in much larger amounts than B.thuringiensis can. When root-eating insect larvae ingest the engineered bacteria,they are killed by the toxin.The use of the engineered bacteria is several times more effective than the conventional method of applying B.thuringiensis spores and toxin to the plant leaves
二、基因工程的发展历史 对基因工程的建立与发展具有重要意义 的几项关键技术： *DNA的特异切刻 *DNA的分子克隆（人工转化方法的建立） *DNA的快速测序 *DNA合成技术 *聚合酶链式反应(PCR)(DNA的体外扩增) *DNA的定位诱变技术
二、基因工程的发展历史 对基因工程的建立与发展具有重要意义 的几项关键技术: *DNA的特异切割 *DNA的分子克隆(人工转化方法的建立) *DNA的快速测序 *聚合酶链式反应(PCR) (DNA的体外扩增) *DNA合成技术 *DNA的定位诱变技术
三、微生物学与基因工程的关系 1)基因工程所用克隆载体主要是用质粒、病毒、噬 菌体改造而成： 2)基因工程所用工具酶绝大多数是从微生物中分离 纯化得到的； 微生物学不仅为基因工程提供了 理论基础， 同时也提供了操作技术 6)基因工程得以建立与发展的理论基础主要来自对 傲生物的研究； 7）微生物的多样性，为基因工程提供了极其丰富而独 特的基因资源；
三、微生物学与基因工程的关系 1)基因工程所用克隆载体主要是用质粒、病毒、噬 菌体改造而成； 2)基因工程所用工具酶绝大多数是从微生物中分离 纯化得到的； 3)将外源DNA导入宿主细胞的人工转化方法,是在微 生物自然转化现象的基础上发展起来的； 4)微生物细胞是基因克隆的重要宿主， 5)微生物是基因产物的重要表达载体； 6)基因工程得以建立与发展的理论基础主要来自对 微生物的研究； 7)微生物的多样性,为基因工程提供了极其丰富而独 特的基因资源； 微生物学不仅为基因工程提供了 理论基础, 同时也提供了操作技术
第二节微生物与基因工 基因工程所用到的绝大 同微生物中分离和纯化而 一、限制性核酸内切酶 能识别双链DNA分子的： 点或其附近切割DNA的一 性酶(restrition enzyme)。 在细菌细胞内限制性酶 构成细菌的限制一修饰条 Figure 15.1 Restriction Endonuclease Binding to DNA.(a)The 入细胞内的外源DNA,同时 structure of BamHI binding to DNA viewed down the DNA axis. The enzyme's two subunits lie on each side of the DNA double helix The a-helices are in green,the B conformations in purple to red,and DNA is in orange.(b)A space-filling model of the complete,dimeric 本身DNA,以避免被酶降 EcoRI endonuclease bound to DNA.The DNA substrate.with its green and blue strands,faces forward.The endonuclease lies behind the DNA.Its two subunits are colored orange and yellow
第二节 微生物与基因工程工具酶 基因工程所用到的绝大多数工具酶都是从不 同微生物中分离和纯化而获得的. 一、限制性核酸内切酶(restriction endonuclease) 能识别双链DNA分子的特定序列,并在识别位 点或其附近切割DNA的一类内切酶.简称为限制 性酶(restrition enzyme)。 在细菌细胞内限制性酶与DNA甲基化酶共同 构成细菌的限制–修饰系统,利用限制酶降解进 入细胞内的外源DNA,同时用甲基化酶修饰细菌 本身DNA，以避免被酶降解