Genetic Engineering

One of the most widespread and controversial applications of genetic engineering or GE is on food. In one sense, genetic modification of plants and animals extends far back into history. Through the use of selective breeding and cross breeding, but there's at least one big difference between classical plant breeding and recombinant DNA engineering. You know, in nature, we can cross some biological boundaries. For example, we can take a horse and a donkey and we can cross them and we get a sterile mule. But of course, in classical breeding, we can't cross a horse in an apple tree. The point here is in theory and practice we can now cross all the biological boundaries. So you can take genes from bacteria, viruses, animals, plants, and humans, and mix them. You can take a gene that creates antifreeze from a flounder and put it in tomatoes of the tomato will not react to frost. Here at UC Berkeley, my laboratory focuses on doing genetic engineering of serial crops like wheat, barley, rice, corn, sorghum. We're involved in a developing country project with Africa trying to improve the nutritional quality of sorghum. 

There are other projects that we work on that are more directed toward perhaps consumers in the United States because we work on a project where we're trying to develop a hypoallergenic tweet. That is a wheat that people who otherwise are allergic to it and can't eat it, would be able to eat. Creating the raw material for genetic insertion happens inside this small machine that is revolutionized biotechnology. It's a polymerase chain reaction or PCR machine. Inside, enzymes called polymerases synthesize an unwound strand of DNA. In 45 minutes, it can generate millions of copies of a specific DNA sequence. A device called a gene gun, then blasts the DNA from the foreign organism into the host organism. You use tiny little pellets about one 30th the size of an actual cell. You coat that pellet, which is actually made of gold with DNA. You shoot it at a very high speed about 600 mph down a chamber. And at the bottom of the chamber is our plant cells. And those little tiny beads go inside of the plant cells and end up inside and become incorporated into the DNA of the plant cell. 

The gene gun also injects a genetic promoter, which makes sure the new gene is permanently switched on. And there you have it. A genetically modified organism for critics, the promoter is just one of GE's problems. The promoter turns on the inserted gene permanently, but we now know that it can potentially turn on other genes inside the DNA permanently, which can create all sorts of things allergies, toxins, new diseases, carcinogens, anti nutrients, or things good, we don't know what will happen if we change the DNA of our own organisms or of our gut bacteria. It's the unknown that causes critics of GE to urge caution. Unintended effects have been a common result of genetic engineering since it began. When genocide modified cotton was first introduced, many of the cotton balls just fell to the ground, genetically modified soy, cracked in the sun. These are examples that when you make changes at the fundamental level of the DNA, it's not like Legos. We don't just snap a gene into place and get one desired trait. In 2000, a brand of genetically engineered corn called Starlink, which had been approved for animal but not human consumption. Became mixed with human coin supplies in grain silos. 

Starlink, which was engineered to produce its own pesticide, caused widespread allergic reactions. Some severe. After the contaminated corn was destroyed, losses stood at a $1 billion. It was found in 22% of all samples by the USDA. And even after millions and millions of dollars in a $1 billion loss from Starlink, two years later, was still found in over 1% of the samples collected by the USDA. But perhaps the biggest surprise for genetic engineering came in June of 2000. When scientists from the human genome project made the shocking announcement that our genome contained only 30,000 genes. Up to that time, the human genome was assumed to contain 100,000 genes. 

Each producing one of the 100,000 proteins known to make up the human body. But the numerical gap made it clear that many of our genes perform more than one function. It was a wake-up call. The foundation of genetic engineering is that they introduce one gene into a species, it'll create one protein, it'll be the desired protein, it'll act correctly, and this foundation was destroyed when scientists acknowledge that a single gene can produce more than one protein. Critics say such a basic miscalculation of the human genome raises doubts about the precision with which any genes can be spliced. Especially when dealing with the world's food supplies. Studies have shown the potential for unforeseen consequences on human health. Or on the crops themselves, which then infect non GE crops with the spread of their pollen. But chances are you've eaten genetically modified food, at least once today. 85% of the U.S. soy crop is GE. Along with 76% of the cotton crop and 40% of corn. Where do soy protein, cottonseed oil, and corn syrup and up? It's estimated that about 75% of the processed foods actually contain some element from a genetically engineered organism.