转基因动植物(英文翻译)
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Transgenic plants and animals
Transgenic plants and animals result from genetic engineering experiments in which genetic material is moved from one organism to another, so that the latter will exhibit a characteristic. Business corporations, scientists, and farmers hope that transgenic techniques will allow more cost-effective and precise plants and animals with desirable characteristics that are not available using up to date breeding technology. Transgenic techniques allow genetic material to be transferred between completely unrelated organisms.
In order for a transgenic technique to work, the genetic engineer must first construct a transgene, which is the gene to be introduced plus a control sequence. When making a transgene, scientists usually substitute the original promoter sequence with one that will be active in the correct tissues of the recipient plant or animal.
The creation of transgenic animals is one of the most dramatic advanced derived from recombinant DNA technology. A transgenic animal results from insertion of a foreign gene into an embryo. The foreign gene becomes a permanent part of the host animals’ genetic material. As the embryo develops, the foreign gene may be present in many cells of the body. If the transgenic animal is fertile, the inserted foreign gene (transgene) will be inherited by future progeny. Thus, a transgenic animal, once created, can persist into future generations. Transgenic animals are different from animals in which foreign cells or foreign organs have been engrafted. The progeny of engrafted animals do not inherit the experimental change. The progeny of transgenic animals do.
The techniques for creating a transgenic animal include the following:1)picking a foreign gene, 2) placing the foreign gene in a suitable form called a “construct”which guides the insertion of the foreign gene into the animal genome and encourages its expression, and 3) injecting the construct into a single fertilized egg or at the very early embryo stage of the host animal. Much genetic engineering goes into the choice of a foreign gene and building a construct. The construct must have promoters to turn on foreign gene expression at its new site within the host animal genome. By choosing a particular promoter and splicing it in front of the foreign gene, we can encourage expression of our transgene within a specific tissue.
转基因植物和动物
转基因植物和动物,源于遗传物质从一个有机体转移到另一个,从而使后者表达前者特征的基因工程实验。商业机构,科学家和农民希望转基因技术将产生更多当今最新的育种技术无法培养出的带有理想特性的高成本使用率和令人满意的植物和动物。转基因技术允许遗传物质在完全不相关的生物体之间转移。
为了使转基因技术工作,基因工程师必须首先建立一个加入了一个控制序列的转基因。当进行转基因时,科学家通常用一个能在正确组织接受转基因的植物和动物的生命活动中取积极作用的序列来代替原来的启动子序列。
转基因动物理论的建立是从最被看好的先进的技术之一的DNA重组技术而得。转基因动物是外源基因插入胚胎的结果。外源基因成为该宿主动物的遗传物质的永久部分。随着胚胎的发展,外源基因可能存在于动物身体的许多细胞。如果转基因动物能够长大成熟,被插入的外源基因(转基因)将被未来后代所继承。因此,转基因动物,一旦被创造出来,便可以延续到子孙后代。转基因动物不同于外来细胞或外来器官移植的动物。移植动物的后代不继承实验所产生的变化。而转基因动物的后代会继承。
培养转基因动物的技术包括以下内容:1)选择一个外源基因,2)将外源基因放置在一个能引导外源基因插入动物的基因组并支持其表达的被称为“培养基”的合适环境中。3)向培养基注入一个单一的受精卵或处于宿主动物十分早期阶段的胚胎。许多基因工程进入了一个选择外源基因和建立培养基的阶段。培养基必须有促使外源基因在宿主动物基因组的新场所表达的触发装置。通过选择一个特定的启动子和将其与前诉的外源基因拼接,我们也鼓励转基因在一个特定的组织的表达。