自用|醫(yī)學英語視聽說U2Ⅲvideo 1History of Genetic E

History of Genetic Engineering ... if we had to find one time to have as the beginning of genetic engineering it would be 1953 with the discovery of the structure of DNA by James Watson, Francis Crick and Rosalind Franklin. With the discovery of DNA we understood that traits could be passed on from generation to generation and that every living creature is built from this blueprint within them, within their cells called “DNA”. And now that we know that this blueprint exists we can start modifying the DNA to change the final product, to change the organisms to have them do different things. A great example would be how genetic engineering totally revolutionized the production of insulin. Before the discovery of DNA, insulin used to be produced by gathering up cow pancreases and smashing them together and getting the juice and purifying it a little bit and giving it to people with diabetes. And a lot of people had allergic reactions, some people died, it didn’t work too well on these people, and there was always the problem of production, how many cows can you squeeze the pancreatic juices out of to make insulin? But now that we know about DNA we don’t need cows, we can just take the human insulin, we can take the letters, the code for human insulin, put it into any creature of our choice and have that creature make insulin for us, and an ideal creature would be something that is really controllable, that we can grow lots of and then we could collect and purify the product from, and they chose E. coli. And we take human insulin now and we just put that writing into the DNA of E. coli and have the E. coli produce the insulin for us and now it’s very safe and it’s readily available.
So in that sense genetic engineering has really taken off because we’ve only seen the beginning. We’ve realized that our bodies, that all living things, plants, animals, creatures, microbes, are essentially little factories and that the DNA is just schematics that we can feed into these factories and have them create whatever we want. And as the days pass we’re getting better and better at learning what we can create. What do we write to have it create this? What do we write to have it create this? A great example right now is many scientists are creating oil, fuel, with microbes. They just program into the algae, they program into the E. coli, they program into the bacteria to make oil and they do. They even program it into trees. There’s a project going on right now in Brazil where they’re growing...if you get syrup from the tree you don’t get sugars, you get terpine that you can burn and use as gasoline. So it really is a way for us to harness the power of nature to really do what we need to do.