[MUSIC] Welcome back. The instructions for all creatures are written in the code of DNA. In spite of the massive diversity of life on earth, this system is incredibly conservative. All life is based on an alphabet of just four nucleotides, which, when arranged in the right order, spell out proteins, and all life is made of, or by, proteins. So what this means is that the code for making silk in a spider is written in exactly the same language as the code for making goat's milk. Since the advent of genetic engineering, we have been able to exploit the universality of this code and cut and paste bits of DNA from any one species into any other. Thus we can produce an extraordinary creation, an animal that could not have existed in any point in history before the twenty-first century, a goat who has a spider gene in every one of her cells. And because we know how, about how to use promoters, the stretch of DNA that triggers a specific gene to do its thing, we can also arrange the gene only turns on in the goat's mammary glands that use [INAUDIBLE] harvest. Conventional breeding programs based on artificial selection have achieved astonishing things. All the varieties of dogs were produced from wolves by people selecting for the shapes and sizes of dogs they wanted to live with. The breeding programs are constrained by what you can breed together. Transgenic biology crosses species barriers so we can get extreme crossbreeding. Many many aspects of transgenic work are very important. Currently, the widest use of transgenic animals is in medical research. Researchers can introduce a gene into an animal and then observe how the gene affects the animal. Or they can inactivate a gene and see what occurs. That way you can find out what a gene does. When you read about scientists discovering a gene that plays some role in a disease, it's quite likely that they used a transgenic animal. So for example, a mouse has been developed that is resistant to tumors, because of a gene put into it, whereas the so-called oncomouse were genetically altered to be prone to develop cancers. And researchers used it to test anti-cancer drugs. We're getting great insight into the genes involved in cancer, learning how to treat it at a molecular level. It's just a huge white canvas of thousands of people working with transgenics and all aspects of our biology so that eventually we will understand things at a fundamental level. Now, one of the key techniques in medical research is to splice human or mouse genes into bacteria so we can study and experiment on damaged bits of code. This editing technology, with restriction enzymes and ligases, has progressed to the extent that all bits of DNA code are effectively interchangeable between all species. But even this is not on the cutting edge anymore. Does recombinant DNA have a future? In medical research, yes, to understand and analyze our genes. But probably not much of a want in industrial biotechnology. Not in a sense that you recombine DNA from different organisms. A modern paradigm is to make genes from scratch, as an example of synthetic biology. Synthetic biology has the potential to generate a new industrial revolution. The, the great physicist Niels Bohr once said, prediction is very difficult, especially about the future. There's been some hyperbole, but if even part of what proponents propose comes to fruition, synthetic biology will be one of the defining technologies in the twenty first century. The old biology was essentially observational and reductionist, in that it involved taking things apart. The new biology, or biotechnology, including synthetic biology, is about making new things and has unprecedented power to change basic life processes. However, as we've seen with agricultural biotechnology in Europe, without an informed public discourse, fears of synthetic biology may hinder the world-changing promise it harbors. Now, by the way, in the, in this talk I won't be using the very common acronyms GM for genetically modified and GMO for genetically modified organisms. I would refer to transgenic organisms, because humans have been genetically modifying organisms for at least 10,000 years. As Nina Fedoroff of Penn State University points out in an article linked to this lecture, almost everyone believes we've never fiddled with plant genes before. As if beefsteak tomatoes and elephant garlic and corn were somehow products of unfettered nature. All of our domesticated plants and animals were produced by selective breeding. Selective breeding is about a slow procedure, but as I mentioned with the dogs it can have enormous effects. Furthermore, the ability to move genes from one species to another isn't new. Viruses and bacteria do it all the time, naturally. In fact a, a lot of the technologies we use to transfer genes to microbes and plants and animals were co-opted for viruses and bacteria. Whatever you like to call it, it's all genetic modification. Well, let's start by looking at the first genetically engineered commercial products, which were pharmaceuticals used in the treatment of human diseases and disorders. These are usually produced by transgenic bacteria containing human genes so that they make human proteins. Now these were once controversial, because people feared we might by accident create a superbug that could wipe us all out, but now they are mainstrelam and well received for the production of medications. Way back in 1979 the Ely Lilly Corporation became began selling human insulin produced by the workhorse of genetic engineering, the bacteria E.coli acting as a living factory. Prior to this, diabetics were treated with cow and pig insulin harvested from animals killed in slaughterhouses. Well unfortunately, animal insulins differ from our own in a couple of amino acids. And diabetic patients were developing immune reactions. And from then on, they needed treatment with insulin harvested from human cadavers. It's much nicer having bacteria produce the insulin, don't you think? Other pharmaceutical products produced through recombinant DNA technology include human growth hormone for children with growth deficiencies, clotting factors for hemophiliacs, and tissue plasminogen activator used to dissolve blood clots in heart attack patients. Bacteria also play a role in many industrial processes including the production of ethanol from plant material, getting minerals out of oil, and the treatment of sewage and other waste. The bacteria used in these processes have been modified by genetic engineering so that they work more efficiently. Bacteria are also being engineered to produce biodegradable plastics that are otherwise very similar to the petroleum-based ones you see all the time. The very first industry humans developed was agriculture. It is still the most important because without it we wouldn't have urban living and any other industries. Our technology is as old as domestication. Woolier sheep and smarter sheep dogs were improved through many generations of selective breeding. During the last 100 years, new plant breeds were produced by hybridizing different plant species together, or more commonly, by induced, albeit random, mutations using radiation and chemicals to speed up the production of genetic changes. This was a genetic shotgun, producing lots of bad changes and a very, very occasional good one, in disease resistance, size of crop, and flavor. Over 2,000 different type of plants are genetically modified in this fashion, including many you'll probably eat today. That's the best we could until molecular techniques were developed for plant genetic modification. We can now use these methods to make precise improvements by adding just a gene or two, the codes for proteins which functions we know with precision. So unlike the old techniques, recombinant DNA technology is much less random, and it allows you to zero in on just one particular trait. And all developed plants that then have it other undesirable traits you then need to screen out. So transgenics has had a big impact in agriculture, by rapidly creating many crop plants with valuable traits. The crops or, or products represented here include, represent those that have already been genetically engineered. Some of these crop plants could be decorated with extra genes like a, a Christmas tree with decorations. The initial plant provides the framework on which the desired traits are hung. Adding new genes isn't the limit, though, of the engineer's potential. They can remove genes, or take them out and alter them and put them back again. Increasingly they can make fresh genes from scratch. That really is a revolution. But the drawbacks to using these transgenics have been political, at least in Europe. The European Union is already a large-scale consumer of transgenic foodstuffs in the form of animal feed imported from the Americas. But it has a near-blanket refusal to license transgenic varieties for use on European soil. Only two crops, a Bt-expressing maize variety and a potato that mainly produces starch for industrial uses, have been licensed for use in the European Union. And they're grown in Spain, Germany, and France, albeit not widely. Even so, around the world more than 170 million hectares of land are under engineered crops, sustained by 16 million farmers in 28 countries, with no reports of apparent damage to health or the environment. In the United States 93% of all cotton, 85% of all corn and 91% of all soybeans grown were genetically engineered. So, depending on the genetic manipulations performed, the advantages of transgenic food can include an increase in yield, improved flavor and texture. And increased nutritional value and an increased tolerance to cold, heat, and drought can also be achieved. A big objective with transgenic crops has been to genetically engineer pest resistance into plants, to help reduce the chemical insecticides. So for many years, plant pathologists have recognized that plants infected with mild strains of viruses are resistant to infection with virulent strains. Using this knowledge, geneticists have created viral-resistant strains of plants by transferring genes of viral proteins into plant cells. I'm going to make Plum Pox as an example. It's the most devastating viral disease of peaches and apricots and plums and nectarines and almonds and cherries. If you look at this apricot, you'll see a case of Plum Pox. There are rings on the leaves here, and the seed is discolored. There's no cure or treatment for Plum Pox, and the infected trees are to be destroyed. It's a really big problem. There's a lot of effort worldwide in trying to quarantine plants and control the spread of the disease. Now Plum Pox would never happen to this plum tree, and its plump, lush fruit has been genetically engineered to express a Plum Pox virus coat protein that immunizes it against viral infection. [SOUND]
