英语听力文摘 English Digest 421、植皮有新招
时间：2019-02-16 作者：英语课 分类：英语听力文摘 English Digest
Silkworms and Skin Grafts
Don: One of the neater things that’s going on in biology is the genetic modification of species 1. By changing the instructions in their genes 2, we can make certain plants and animals produce things that are useful to humans.
Ya?l: Well, I guess people have been using animals and plants to produce things we can use for centuries. We drink cow’s milk, for example. And we make clothes out of cotton.
D: Very true. We also use silk.
Y: Yes, and silk is made by silkworms.
D: But genetic modification is a whole new ball game. For example, research being done at Hiroshima University has shown that your everyday silkworm can be genetically altered to produce a form of human collagen. They build it right into their silk.
Y: Cool! What's collagen?
D: Collagen is just a protein. It's important though because it happens to be the structural 3 protein that goes into building your skin, tendons, ligaments, and even your bones.
Y: OK, so what would you actually do with it?
D: One thing you could do is use it to make skin grafts. Silkworms already spin 4 about sixty thousand tons of silk every year, so if collagen-laced silk can be reliably produced, it would be a cheap and ready supply of grafting material–say for people who have burn injuries and need new skin.
You might also be able to produce albumen, which is a protein found in human blood. And what about bones, tendons, ligaments? There might be more uses down the road.
Y: And all "human-silkworm"!
蚕与植皮
Don: 从生物学上来说，对物种基因的改造可谓是一件相对来说比较好的事情。通过改变物种的基因构造，人类可促使某些动物或是植物产生出对人类有用的东西来。
Ya?l: 照我说，这应该已经是上百年的事情了吧！比如说，我们要喝牛奶，我们还会用棉花来做衣服。
D: 相当正确，我们还用丝。
Y: 嗯，丝是由蚕吐出的。
D: 但是，基因改造完全又是另外一回事了。比如说，在广岛大学的一项研究就说明，我们可以通过对蚕的基因改造获得一种人体所需的胶原质。蚕在吐丝时会产生这种物质。
Y: 太酷了！什么是胶原质呢？
D: 胶原质就是一种蛋白质。胶原质正好是组成人体皮肤、肌腱、韧带甚至是骨骼的结构蛋白，因而，胶原质是相当重要的。
Y: OK！那人类可以用这种胶原质来做什么呢？
D: 当然有许多了，其中之一就是用这种胶原质来进行皮肤移植。蚕一年可吐丝六万吨，因而如果含有胶原质的丝产量能有所保障，对那些有烧伤在身或是需要植入新皮的人来说，这的确是比较便宜的理想植皮材料。
植入后，人体还可能能够产生人体血液中常见的蛋白质——血清蛋白。除此之外，对骨骼、肌腱和韧带又有什么作用呢？相信随着日后研究的深入，人们能挖掘出它更多的用处。
Y: 到处都是“蚕人”！
- Are we the only thinking species in the whole of creation?我们是万物中惟一有思想的物种吗？
- This species of bird now exists only in Africa.这种鸟现在只存在于非洲。
- You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
- Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
- The storm caused no structural damage.风暴没有造成建筑结构方面的破坏。
- The North American continent is made up of three great structural entities.北美大陆是由三个构造单元组成的。