What Are Genes?
Genes are the substance within the nucleus of a cell that transmit genetic
codes. In human beings and other bio-species, the synthesis of protein
and the reproduction of cells and tissue take place according to the genetic
blueprint contained in the genes. There are approximately 7,000 to 10,000
kinds of genes of differing sizes and properties in the human body. After
several decades of research, people have gained a preliminary understanding
of the structure and properties of about 1,500 small genes. However, knowledge
of large genes, especially chromosomes, is very limited. The larger the
gene, the more difficult it is to determine its structure and properties.
Chromosomes and other genes are composed of DNA. There are four types of nucleotides (DNA building blocks) labeled A, T, G, and C [according to the four types of nitrogenous bases occurring in the nucleotides, namely, adenine, thymine, guanine, and cytosine]. These four types of nucleotides combine in different sequences to form long chains. The sequencing of A, T, G, and C nucleotides is called the primary structure. The twisting of the long chains is called the secondary structure. Pairs of long chains couple together in a double helix structure. The G in one chain couples with the C in another chain, and the T in one chain couples with the A in another chain. A human chromosome can be as long as 3 billion nucleotides. The genetic codes are stored in these DNA sequences.
What Is Genetic Engineering?
Genetic engineering aims to re-arrange the sequence of DNA in gene using artificial methods. To determine the DNA sequence on such a long chain, a high-speed, low-cost method is needed. Unfortunately, the currently available method (gel-electrophoresis) does not satisfy these requirements. It cannot provide sufficient information about the genetic structure. For example, the DNA chain in the gene of E. coli is approximately one million nucleotides long. Its DNA sequence analysis took 12 years. Thus, high-speed determination of DNA sequence in genes is critical to the development of genetics. Without such a technique, it will be impossible to understand the genetic mechanism, and GE will be built on thin ice. Given this predicament, the scientific community, supported by the U.S. Congress has delegated substantial resources to be used in determining gene structure under the auspices of the Human Genome Project (HGP). In addition to improving the gel-electrophoresis method, HGP has also invested a huge amount of capital in supporting the discovery of a new method for DNA analysis. Several new mass-spectroscopic techniques, such as MALDI-TOF (matrix-assisted laser desorption and ionization - time-of-flight mass spectrometer) and FTMS (Fourier transform mass spectrometer), have been developed and applied to analyze the DNA segment. However, these methods run into difficulties when the DNA segment is larger than 200 nucleotides. As the size of the DNA increases, the sensitivity and resolution of the signal greatly decreases and analysis using these methods gradually becomes unreliable. To date this difficulty has not been overcome despite intensive research. What is more, the method of gel-electrophoresis has seen little improvement in recent years. Due to the overall lack of information about gene structure, our knowledge of the genetic mechanism is very limited.
The Current Stage of Genetic Engineering
With every new scientific discovery, there are always those who use it to seek profit. The field of genetics is no exception in this matter. Investors began getting into GE business several years ago. What is the current stage of development of GE? Roughly, it can be seen in three major fields. 1) The determination of DNA sequence in chromosomes and other genes. Work in this field is mainly supported by the U.S. government, which considers long-term development to be of national interest. Many private industrial enterprises are also extensively involved, since the patent owner of such an analytic technique will reap a huge return. Several years ago, there were many reports on developments in this field. The excitement has gradually subsided because scientists have realized the complexity of the problem. This problem is not going to be solved in the near future. There has been very little overall advance in this field during the past several years. 2) Artificial horizontal gene transfer--a synthetic method of gene transfer between different species. Since the structure and function of some small genes are relatively well known, biologists try to transfer these genes to other bio-species to improve their functions. Private enterprises have actively been testing this method on animals and vegetables in order to obtain "super products." Government-supported research institutes mainly use horizontal gene transfer to obtain knowledge about the genetic mechanism. Since the genetic mechanism is a very complicated system, they can mostly conduct blind tests by means of horizontal gene transfer. There are many unknown factors in this field, regardless of whether the method used is direct insertion of genes or simple mixing of genes. The probability of success is very small, and only a few products exist. The possible side effects of these GE experiments are still unclear. There has not been much successful advance in this field. 3) Cloning. This "Dolly" is a sheep genetically duplicated using a complete set of chromosomes from an adult sheep. This success was based on a large number of failures. But scientists have not been able to repeat it. The validity of scientific results is based upon their reproducibility. Since the experiment has not been repeated, many people doubt its validity. About 50% of the scientific community is not convinced by the result. It would be extremely difficult to clone a human being even in the absence of pressure from social objections.
Why We Study Genetic Engineering
What benefit could GE bring to humankind? Some scientists believe that,
since genetic codes determine the appearance, personality, health, and
aging process of human beings, if that genetic information in the chromosomes
could be decoded and the genetic mechanism were understood, we could potentially
control and improve our health, quality of life, and the biochemical processes
in our bodies. In other words, we could control our own fate. Also, weíd
be able to improve the genes of other animals and vegetables so that they
could serve humankind better. At first sight, these ideas seem reasonable
and attractive. However, careful analysis reveals that they are based upon
an incorrect theory--the theory of gene determinism.
Gene determinism says that gene structure determines everything about life. This theory is based on an incomplete view of things. It not only denies the mutual interaction between the body and mind, but also neglects the fact that genes survive through mutations. Buddhists know that body and mind are inseparable. They interact and influence each other. The structure and function of chromosomes and genes can change as the mind changes. It would be erroneous to reduce life to its material aspects. A personís traits and health depend on his/her state of mind and environment as well as on gene structure. Thus the theory of gene determinism is merely a form of materialism and does not reflect reality. Not only a personís thoughts and actions in the present life, but also his past life history exerts a great influence on his metabolic processes, and his genetic inheritance is only of secondary importance.
Although the chromosomes and genes are the blueprint of protein synthesis, not all parts of such a long chain are used in the synthesis of protein. Generally, only a small segment of the chain is essential. In different organs or under different conditions, different segments are used in synthesis. Protein synthesis and cell reproduction are extremely complicated processes that are determined not by a single DNA chain, but by various other conditions working together. Human mental factors, such as emotions and habits, play an important role in these processes. Sometimes they become the decisive factors. Therefore, it is impossible for GE to fulfill its promise of improved health and quality of life for humankind. A large number of examples in psychology can be used to prove this point.
For instance, last year I met the director of an Institute of Psychology in a certain country, who related the following incident. The Institute had requested that the government provide it with a criminal sentenced to death for use in an experiment. On the day of the execution, they tied the man to a chair and told him that they were going to cut one of his veins and let him bleed to death. They blindfolded him and made a cut on his arm but immediately stopped the blood. They placed a hose that dripped warm water next to his arm, so that the warm water running down his arm felt like blood flowing. Then the psychologist told the man that he had started to bleed...that a third of his blood was gone...that half of his blood was gone... By that time the manís face had turned ashen. When the man was told that his blood was all gone, his head rolled to one side and he died.
Another erroneous assumption of gene determinism is that the structure of genes rarely or never changes. Scientific research in recent years indicates that the structure of genes is dynamic and subject to change during interaction with the environment. These changes can also be passed on to the next generation. If the gene structure is dynamic, then the design of gene structure becomes insignificant. Given the correlation between gene function and psychological factors as well as the influence of the environment on gene structure, we may conclude that attempts to design or alter gene structure will not achieve the "expected goal." Furthermore, the "expected goal" is only a blind guess since we know so little about the genetic mechanism. Under such circumstances, how can GE bring the benefits it has promised? In fact, it may bring more harm than good. Although genetic engineers have through extensive experimentation invented some GE products such as tomatoes that do not spoil easily, their side effects on human health are unknown at present. When many pesticides were first invented, people didnít know their detrimental effects either.
The Potential Harm of Genetic Engineering
What harm could GE bring? The main potential harm of GE is associated with artificial horizontal gene transfer experimentation. Horizontal gene transfer occurs commonly in nature. Genes can be exchanged between different bio-species. But the frequency of these natural transfers is limited by the defense systems, i.e. immune systems, of each bio-species. The immune system serves to prevent invasion by harmful foreign genes, viruses, and so forth, so that the bio-species can maintain its characteristic traits and normal metabolism. The GE method of artificial horizontal gene transfer works by penetrating or weakening the immune system and using virulent genes as delivery vehicles. That is, the gene to be transfered is combined with a virulent gene to effect penetration. This method allows harmful virulent genes, especially those with resistance to antibiotics, to become widespead in nature. This results in two severe consequences:
1) The production of virulent genes with multi-resistance to antibiotics will be accelerated. If such virulent genes combine with the genes of harmful viruses to form new viruses, it will be disastrous for humankind.
2) The frequency of horizontal gene transfer will greatly increase. Bio-species rely on their immune systems to limit horizontal gene transfers. If virulent genes with the ability to penetrate immune systems spread widely in nature, the frequency of horizontal gene transfers will inevitably increase. Once genes can freely transfer between species, bio-species start to lose their distinguishing characteristics. The mutant insects producted in GE laboratories are a strong indication of this trend. GE is also a potential threat to the human food supply. GE reduces biodiversity. The nutritional level of our food depends on its diversity. In the long term, GE leads to the destruction of the human food supply. At present there is no evidence that GE food and GE protein is harmless to human health. The possibility of harm cannot be eliminated. To develop potentially harmful food when there is an adequate supply of natural food is not a wise thing to do.
The Venerable Masterís Prediction
The Venerable Master [Hsuan Hua, the late Chinese Zen Patriarch] said
early on that the combination of pneumonia and the AIDS virus would kill
a large number of people. This prediction is a definite possibility from
the point of view of science. For such an event to occur, two conditions
1) A virus must be transmitted by air.
2) There must be a latency period for the disease (a short latency period would prevent extensive spreading of the disease).
The combination of pneumonia and AIDS satisfies these two conditions. In current GE experiments, a virulent gene similar in structure to the HIV virus is used as the delivery vehicle. Thus, GE greatly increases the possibility of the Masterís prediction coming true.
What Should Our Attitude Be?
Clearly, GE brings more harm than benefit. We should use various channels to influence the direction of research, oppose the cruel treatment of animals used in GE experiments, and oppose the policy of not labeling GE food products. However, care is needed in reading scientific reports. Many scientific reports in the United States have been exaggerated for the sake of competition. It is advisable to observe clearly before offering criticism. On the other hand, there is no need to worry that scientists might soon create a horde of freaks and monsters. The genetic mechanism is an extremely complex process. Genetic engineers will quickly realize their limitations. We still have enough time to avert potential disasters.
*About the author: Dr. Yifei Zhu is from the city of Hangzhou, Zhejiang Province of China. He graduated from the University of Hangzhou in China and taught there for a few years. After earning his doctorate degree in chemistry from Purdue University in Indiana in1993, he worked for Oak Ridge National Laboratory in Tennessee. During the past academic year, he has been doing volunteer teaching in a Buddhist secondary school.