Genetic Engineering

Genetic Engineering is the manipulation of microbes, plants and animals to make products that are useful to people. As such, this technology is not new. It began a long time ago. I would say that biotechnology began with agriculture.

What is Genetic Engineering?

Estimates are that agriculture probably began about 10000 years ago, in what is now the region near Iraq. We have evidence that Sumerians living there at the time learned that barley plants growing around their homes made seeds that could be used to make bear and bread. They started growing these seeds near their settlements. They would use some of the seeds to make bear and bread, and then they would grow the rest of the seeds nearby. This was the first biotechnology.

A History of Genetic Engineering

Werner Arber was born in 1929. As a graduate student at the University of Geneva in the 1950’s, he studied with a physics professor who converted from doing pure physics to biophysics. Arber’s PhD thesis was on the phenomenon of bacteriophages restriction. He didn’t even suspect that his research would begin a revolution.

In 1973, scientists had taken two chromosomes, cut them open, put them back together, and showed that they were functional in a cell. They had created genetically functional recombinant DNA. It was a revolutionary discovery.

Review the timeline of genetic engineering.

Benefits of Genetic Engineering

The first major product of biotechnology was human insulin. This type of insulin is now used to treat type 1 diabetics. Another example is the blood-clotting protein that is missing in hemophilia.

There is a protein called Erythropoietin (EPO). EPO is a hormone-like substance made by the kidneys. The gene coding for EPO was isolated, EPO was made by recombinant DNA technology, and this is now widely used for people who are undergoing kidney dialysis and also people who are being treated with cancer chemotherapy.

There are a significant number of humans that lack adequate amounts of growth hormone. These people are very short in stature. The growth hormone is a protein. So, again, we got to get it through recombinant DNA technology.

We can use biotechnology to have a plant make a vaccine. You could become immune to a disease simply by eating a fruit. Pretty nice, eh?

These are just a few benefits of this new technology.

Genetic Engineering in Agriculture

According to UN estimates, human population will level off at about 10 billion people. Can biotechnology help solve this issue? A real problem in agriculture that existed for millennia is that most plants cannot grow in salty soils. Salt-tolerant transgenic plants may make deserts bloom again.

Other applications of biotechnology in agricultura are:

• Plants That Make Their Own Insecticide
  
• Plants Resistant to Herbicides
  
• Nutritionally Rich Crops

Problems with Genetic Engineering

The first supposed problem is that genetic manipulation is an unnatural manipulation of nature. This is what philosophers call the “yuck factor”. According to this argument, eating food from a plant that has genes from bacteria is just “going too far”. There is no real response to this emotional argument.

The second of the supposed problems is that genetically modified foods might be unsafe to eat. It turns out that most genetically modified plants grown today are not altered in the food part of the plant. We’ve got to be careful with allergies, however.

The third of the risks is that genetically modified plants may be dangerous to the environment. This is maybe a real risk, but not a really serious one.

The revolution that this new technology caused is profound.

Risks of Genetic Engineering

What are the risks of genetic engineering? The revolution that genetic engineering caused was profound. There was initially great concern about genetic engineering. The concerns centered on several aspects of this work. First, the bacteria used in these experiments were E. coli. This bacterium commonly lives on our intestines. People were worried about what will happen if this laboratory organism got out into our gut. Could the bacteria lead to cancer? This fear led almost to hysteria. Municipalities passed laws banning all genetic engineering work. A very famous scientist arrived to his laboratory one day to find the police out front, saying “you’ve broken our municipal ordinance against doing any gene swapping”. Doom scenarios were all over the place.

In 1975, a conference was held in California which brought together scientists, ethicists, physicians and lawyers to deal with this situation. This was a unique event in the history of science and government relations. The meeting was called by the scientists who were doing the work. They wanted some sort of feedback on what they were doing, because they were worried about the possible risks of genetic engineering.

At this meeting, after several days of heated discussions, they decided to do a moratorium on certain types of experiments. For example, until they knew what they were doing, they weren’t allowed to put cancer genes into bacteria to study them. They imposed extreme safety precautions on all of their types of experiments. Government agencies and institutional boards at research universities were set up to oversee this.

Scientists really asked for this oversight, which is very unusual, because scientists usually are of the type “just let us do our work and leave us alone, we would never harm you”. In this case, scientists were quite worried because this was so profound a change in biological manipulation.

In retrospect, these concerns were overblown, and no dangerous events have really occurred with genetic engineering. In fact, experiments that required severe precautions in 1975 are now done in high-school science labs. This doesn’t mean that we don’t need to constantly monitor this research. If we are dealing with harmful genes we must take extreme precautions.

What is Genetic Engineering

What is Genetic Engineering? Genetic Engineering is the manipulation of microbes, plants and animals to make products that are useful to people. As such, genetic engineering is not new. It began a long time ago. I would say that genetic engineering, or biotechnology, began with agriculture. Agriculture I define as the harvesting, planting of cultivation of plants for food and fiber. This was the first biotechnology. Estimates are that agriculture probably began about 10000 years ago, in what is now the region near Iraq.

We have evidence that Sumerians living there at the time learned that barley plants growing around their homes made seeds that could be used to make bear and bread. They started growing these seeds near their settlements. They would use some of the seeds to make bear and bread, and then they would grow the rest of the seeds nearby.

In ancient Egypt, the hieroglyphic symbol for food is a picture of bear and bread. You may ask, why bear? Just to have a good time? Answer is no. When people began to live in settled places, they realized by trial and error that water purity was a big issue. As they would be going to the bathroom in the same water they were drinking, people would become sick. Alcoholic beverages kill most of the bad things that are in water. It’s not surprising that they were invented quite early on by humans.

The process of making alcohol from seeds is actually carried by yeast cells that live in the grain or grapes. This process is called fermentation, and it is a form of biotechnology. Modern genetic engineering, however, refers to the use of a technique called recombinant DNA. To illustrate what is genetic engineering and what are its uses I’d like to tell a story:

As Tom drove home from work, he felt his face twitching and had a really bad headache. Tom was one of the several million people who have a stroke each year in the United States. A blood clot was blocking an artery leading from the heart to his brain. This deprived brain cells of oxygen, and irreversible damage to the brain could occur quite quickly. When you think of blood clots, you got to consider that they do go away eventually. “Go away” is not a really good biochemical term. We say that the clot dissolves, but this happens rather slowly. The way this happens is the following: as the wound is healed, a series of cells that is healing the wound make a substance called TPA (Tissue plasminogen activator), which activates the blood clotting system. The clot then dissolves.

The time factor is important biologically speaking. If the clot dissolved the minute it was formed it wouldn’t do much good. The blood would flow out and you’ll lose it all. Slow dissolving of the clot is a good thing, but not for Tom. Tom was having a stroke, and that’s not a situation in which we want a blood clot for a long time. Every minute the blood flow to the brain is blocked is harmful.

Luckily for Tom, he was near a hospital. He drove to the parking lot; the emergency stuff got him and immediately injected a drug right on the surface of the blood clot. The clot dissolved right away, blood flow was restored and there was minimum damage to the brain. Tom was home the next day and he was fine.

The drug that the emergency room stuff had injected was TPA. This drug is also called PLAT in medical terms. This is the protein that initiates the clot-dissolving process. Without using TPA, the clot would have gone away, but his brain would have gotten damage in the meantime. Adding this substance right away to the site of the clot activated the clot-dissolving system right there.

TPA is made in very small amounts and only when it is needed. The bad thing is that if we want to use that as a medication, we’d better get a lot of it. It’s virtually impossible to get enough TPA from the cells of a body to store in the emergency room. This is when genetic engineering enters the scene.

First, DNA was extracted from human cells. The gene coding for TPA was isolated and inserted in hamsters. This allowed to produce TPA in amounts far greater than you could ever extract from blood. The TPA is then purified and sat on the shelves ready for a patient like Tom.

The scenario of using a gene to produce a useful protein, by this genetic engineering technology, has now been played out for dozen of products. This is part of a revolution. The revolution of genetic engineering.

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