Applications of genetic engineering

Genetic engineering has become an indispensable part of biological science. It is also the science that fills mankind with endless imagination. Since the human genome was unraveled, The ancient legend of immortality has become popular again. Although current genetic technology cannot make you truly immortal, the emergence of technologies such as gene therapy has allowed people to see the vitality of genetic engineering. This article starts from the perspective of environmental protection, Military and other aspects briefly discussed the application of genetic engineering.

At present, many countries in the world regard biotechnology, information technology and new material technology as the three most important technologies, and biotechnology can be divided into For traditional biotechnology, industrial biofermentation technology and modern biotechnology.

What people often call biotechnology now is actually modern biotechnology. Modern biotechnology includes five major engineering technologies: genetic engineering, protein engineering, cell engineering, enzyme engineering and fermentation engineering. Among them, genetic engineering technology is the core technology of modern biotechnology. The core technology of genetic engineering is DNA recombination technology, which is also gene cloning technology. Since genetic engineering is so important, what is genetic engineering?

Genetic engineering refers to inserting nucleic acid molecules into viruses, plasmids or other vector molecules in vitro to form a new combination of genetic material and incorporate it into Host cells that originally did not have such molecules can reproduce continuously and stably. According to this concept, people can extract useful gene fragments from the genes of one organism and implant them into another organism, so that the organism can acquire certain new genetic traits. Thus, the required new biological variants are obtained. The use of genetic engineering can speed up biological variation and make biological variation develop in a direction that is beneficial to human beings. Moreover, genetic engineering is an operation at the molecular level, so it can span Operate on different species. This has greatly improved the traditional method of hybridizing only similar organisms and unable to control the direction of variation. For example, the traditional rice cultivation method is to cross many different rice species, then cultivate the seeds into rice, and then select from them. Excellent varieties. But this method not only requires a lot of work, but also the effect is not very good. According to the principle of DNA recombination, some recessive traits have only about a 1/4 probability of being expressed. In this way, a lot of useless work is done. But using For genetic engineering, we only need to extract the nucleotide combinations of the traits that need to be expressed from different rice species, transplant them to other rice species, and then they can be expressed. This greatly saves the engineering cycle and also improves the efficiency of genetic engineering. This improves the accuracy of genetic trait expression. In addition, organisms of different species generally cannot mate. For example, fish and cattle cannot mate to produce the next generation. However, using genetic engineering, we can transplant certain genes from fish into cattle. On fertilized eggs, or by transplanting cow genes into fertilized fish eggs and cultivating them, a new species can be produced that has both cow and fish traits. Although genetic engineering has so many benefits, it is not It is said that it can be abused. Because every organism can adapt to its living environment through natural selection of survival of the fittest. If foreign genes are transplanted, it may break the balance of cells in the body, leading to rapid aging of cells or even Death. It can be seen that genetic engineering must correctly handle cell compatibility.

So, what are the applications of genetic engineering?

1: In the production field, People can use genetic technology to produce genetically modified food. For example, scientists can implant genes that control the growth of meat in certain pigs into chickens, so that chickens can also gain the ability to gain weight quickly. However, genetically modified foods have high-tech content. , are afraid that eating foreign genes in genetically modified foods will change people's genetic traits. For example, eating genetically modified pork will make them hyperactive, and drinking genetically modified milk will easily lead to breast fetishism, etc. Academician Zhang Qifa from Huazhong Agricultural University believes: "GM technology provides new means for crop improvement, but it also brings potential risks. Gene technology itself can conduct precise analysis and evaluation, thereby effectively avoiding risks. The research on GM technology Risk assessment should be based on traditional technology. Scientific and standardized management can provide safety guarantee for the use of genetically modified technology. Popularization and public education of basic knowledge of life sciences are very important.

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Two: Military applications. Biological weapons have been used for a long time. Bacteria and poisonous gases are all embarrassing. However, now the legendary genetic weapons are Even more frightening. Genetic weapons are only lethal to people with certain genes (such as a certain race), but have no effect on people of other races. The use of such weapons will undoubtedly put the races attacked by genetic weapons at risk. Catastrophe.

Three: In environmental protection, genetic weapons can also be used. We can develop genetic weapons for some animals and plants that disrupt the ecological balance. Specialized genetic drugs can kill them efficiently without affecting other organisms. They can also save costs. For example, if there is a genetic product that can kill water hyacinth, which has been harming freshwater areas in our country, it will be killed every year in universities. Billions can be saved.

Science is a double-edged sword. Genetic engineering is no exception. We must make use of the part of genetic engineering that can benefit mankind and suppress it.

Fourth, medical aspects

With the continuous deepening of human research on genes, scientists have discovered that many diseases are caused by changes in gene structure and function. Discovering defective genes and knowing how to diagnose, repair, treat and prevent them is the forefront of biotechnology development. This achievement will bring immeasurable benefits to human health and life.
The so-called gene therapy refers to the use of genetic engineering techniques to transfer normal genes into the cells of disease patients to replace diseased genes to express the missing products, or to achieve treatment by shutting down or reducing abnormally expressed genes. The purpose of certain genetic diseases. Currently, there are more than 6,500 genetic diseases, of which about 3,000 are caused by single gene defects. Therefore, genetic diseases are the main targets of gene therapy. Gene therapy was carried out in the United States in 1990. At that time, two little girls aged 4 and 9 suffered from severe combined immunodeficiency due to a lack of adenosine deaminase in their bodies. Scientists performed gene therapy on them and achieved success. Success. This pioneering work marked the transition of gene therapy from experimental research to clinical trials. In 1991, my country's first clinical trial of gene therapy for hemophilia B was also successful.

The latest development in gene therapy is the use of gene gun technology. The method is to introduce specific DNA into the muscles, liver, spleen, intestine and skin of mice to achieve successful expression. This success indicates that in the future, people may use gene guns to deliver drugs to specific parts of the human body to replace traditional vaccinations, and use gene gun technology to treat genetic diseases.

Currently, scientists are working on this. The research is on fetal gene therapy. If the current experimental efficacy is further confirmed, it may be possible to expand fetal gene therapy to other genetic diseases to prevent the birth of newborns with genetic diseases, thereby fundamentally improving the health of future generations.

5. Research on genetically engineered drugs

Genetically engineered drugs are expression products of recombinant DNA. Broadly speaking, anything that involves genetic engineering in the production process of drugs can become genetically engineered drugs. Research in this area has very attractive prospects.

The focus of genetic engineering drug research and development is shifting from protein drugs, such as molecular proteins such as insulin, human growth hormone, erythropoietin, etc., to the search for smaller molecule protein drugs. This is because protein molecules are generally relatively large and cannot easily pass through cell membranes, thus affecting their pharmacological effects. Small molecule drugs have obvious advantages in this regard. On the other hand, the treatment ideas for diseases have also broadened, from simple medication to the use of genetic engineering technology or the gene itself as a treatment method.

Now, there is another issue that needs everyone's attention, that is, many infectious diseases that were conquered in the past have come back because bacteria have developed drug resistance. The most noteworthy of these is tuberculosis. According to the World Health Organization, there is now a global tuberculosis crisis. Tuberculosis, which was about to be eliminated, has resurgence, and multiple drug-resistant tuberculosis has emerged. According to statistics, 1.722 billion people around the world are infected with tuberculosis bacteria, there are 9 million new tuberculosis patients every year, and about 3 million people die from tuberculosis, which is equivalent to one person dying from tuberculosis every 10 seconds. Scientists also pointed out that in the coming period, hundreds of people infected with bacterial diseases will have no cure, and at the same time, viral diseases are becoming increasingly common and difficult to prevent.

However, at the same time, scientists have also explored ways to deal with it. They have found some small-molecule antimicrobial peptides in humans, insects and plant seeds. Their molecular weight is less than 4,000, with only more than 30 amino acids, and they have strong broad-spectrum effects. The activity of killing pathogenic microorganisms can produce a strong killing effect on pathogenic microorganisms such as bacteria, germs, and fungi, and may become a new generation of "super antibiotics." In addition to using it to develop new antibiotics, these small molecule peptides can also be used in agriculture to breed new varieties of disease-resistant crops.

6. Accelerate the cultivation of new crop varieties

Scientists have made significant progress in using genetic engineering technology to improve crops, and a new green revolution is just around the corner. A distinctive feature of this new green revolution is the convergence of the biotechnology, agriculture, food and pharmaceutical industries.

In the 1950s and 1960s, due to the promotion of hybrid varieties, increased use of chemical fertilizers, and expansion of irrigated areas, crop yields doubled. This is what everyone calls the "green revolution." However, some researchers believe that these methods are currently difficult to further significantly increase crop yields.

Breakthroughs in genetic technology have allowed scientists to improve crops in ways unimaginable by traditional breeders. For example, genetic technology could allow crops to release pesticides on their own, allow crops to be grown on dry or saline soil, or produce more nutritious food. Scientists are also developing crops that could produce vaccines and foods that can protect against disease.
Gene technology has also greatly shortened the time for developing new varieties of crops. Using traditional breeding methods, it takes seven or eight years to develop a new plant variety. Genetic engineering technology allows researchers to inject any gene into a plant to create a brand new crop variety. The time is shortened by half.

Although the first genetically engineered crop varieties became available only five years ago, half of the corn, soybeans and cotton grown in the United States this year will use genetically engineered seeds. It is estimated that in the next five years, the market size of genetically engineered agricultural products and foods in the United States will expand from US$4 billion this year to US$20 billion, and will reach US$75 billion in 20 years. Some experts predict that "by the beginning of the next century, it is likely that every food in the United States will contain some genetic engineering ingredients."

Although there are still many people, especially in European countries, Consumers are skeptical about genetically modified agricultural products, but experts point out that it is imperative to use genetic engineering to improve crops. This is primarily due to increasing pressure on the global population. Experts estimate that in the next 40 years, the global population will increase by half compared to the current level. To this end, food production will need to increase by 75%. In addition, the aging of the population is placing increasing pressure on the medical system, making it necessary to develop foods that can enhance human health.

Accelerating the cultivation of new crop varieties is also a common goal of developing biotechnology in third world developing countries. The research and application of agricultural biotechnology in our country has been widely carried out and has achieved Significant benefits.

7. Research on Molecular Evolution Engineering

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Molecular evolution engineering is the third generation of genetic engineering after protein engineering. It simulates the biological evolution process in nature by exerting selective pressure on a multi-molecule system based on nucleic acids in a test tube to achieve the purpose of creating new genes and new proteins.

This requires three steps, namely amplification, mutation, and selection. Amplification is to obtain a large number of copies of the extracted genetic information DNA fragment molecules; mutation is to exert pressure on the genetic level to cause the bases on the DNA fragment to mutate. This mutation provides raw materials for selection and evolution; selection is the expression of At the type level, variation is fixed through the survival of the fittest and elimination of the unfit. These three processes are closely linked and indispensable.

Now, scientists have applied this method and obtained DNA molecules that can inhibit thrombin activity through directed evolution in test tubes. This type of DNA has anticoagulant effects and may replace dissolution. Thrombus protein drugs are used to treat myocardial infarction, cerebral thrombosis and other diseases.

The results of my country’s genetic research

Scientific research aimed at deciphering all the genetic information of the human genome is the current international biological One of the cutting-edge topics to be tackled by the medical community. According to reports, the most interesting aspect of this research is the clonal isolation and identification of genes related to human diseases and genes with important biological functions, so as to obtain the possibility of gene therapy for related diseases and the right to produce biological products.

The human genome project is an important part of the national "863" high-tech plan. In medicine, human genes are related to human diseases. Once the specific relationship between a certain gene and a certain disease is clarified, people can create genetic drugs for the disease, which will have a huge impact on human health and longevity. According to reports, the total number of human genetic samples is about 100,000, and about 8,000 have been found and sequenced.

In recent years, my country has paid great attention to human genome research. With funding from the National Natural Science Foundation, the "863 Project" and local governments, it has established research centers in Beijing and Shanghai. It has established a national genetic research center with advanced scientific research conditions. At the same time, scientific and technological personnel keep up with the development of new technologies in the world and have made breakthrough progress in the key technologies of genetic engineering research and the industrialization of results. Our country's human genome research has become one of the world's most advanced, and some genetically engineered drugs have also begun to enter the application stage.
At present, some of my country's basic research results in projects such as protein gene mutation research, gene therapy for blood diseases, esophageal cancer research, molecular evolution theory, and structural research on leukemia-related genes are already at the international leading level. Some have formed their own technical systems. More than ten genetically engineered drugs, including hepatitis B vaccine, recombinant alpha interferon, recombinant human erythropoietin, and drug producers for transgenic animals, have all entered the industrialization stage.

Gene technology: dilemma and duality

Genetic crops have caused a stir in public opinion circles Controversy is no surprise. However, on both sides of the Atlantic in the developed world, the completely different treatment of genetically modified technology is an intriguing phenomenon. When 40% of the farmland in the United States is planted with genetically modified crops and consumers mostly buy genetically modified foods calmly, why do such foods encounter waves of opposition in Europe?
Looking at the direct social background, it is understandable that "GMO phobia" is currently prevalent in Europe. From the discovery of mad cow disease in the United Kingdom in 1986 to the discovery this year of carcinogenic dioxins in contaminated chickens in Belgium and Coca-Cola causing hemolytic disease in children in France, Europeans are quite concerned about food safety. The assumption that genetically modified foods may harm human health has become a conditioned reflex. They are afraid of hearing it.

At the same time, Europe has always adopted a more sensitive and even radical attitude towards environmental and ecological protection issues than the United States. This is another reason why genetically modified foods are in a different situation in Europe and the United States. On the one hand, the media in various European countries have become increasingly aware of environmental protection, and they often pursue and even exaggerate issues that may harm the environment and ecology. This largely affects the public's attitude towards issues such as genetic modification. On the other hand, the "environmentalist forces" represented by the "Green Party" have risen in European politics in recent years, and their power in governments and parliaments has continued to expand, exerting increasing influence on the decision-making process.

However, there seems to be a more hidden but important underlying reason why Europeans adopt such a repulsive attitude towards genetically modified technology. In fact, on the issue of genetically modified genes, there are not only differences in values ??between Europe and the United States, but also a dispute over economic interests. Unlike ordinary commodities, genetically modified technology has a unique monopoly. Technically, American "life science" companies generally use bioengineering to make their products self-protective. The most prominent of these is the "terminator gene", which causes seeds to self-destruct and cannot be replanted like traditional crop seeds. Another technology is that the seeds must undergo some kind of "chemical catalysis" that is only controlled by the seed companies in order to develop and grow. Legally, genetically modified crop seeds are generally provided through a special leasing system, and consumers are not allowed to keep and replant them themselves. The United States is the largest investor in costly genetic engineering research, and American companies engaged in the development of genetically modified technology are familiar with using intellectual property and patent protection laws to seek huge returns. The United States is currently believed to control a sizeable share of the genetically modified product market and can thus manipulate market prices. Therefore, resisting genetically modified technology is actually resisting the U.S. monopoly in this field.

Biotechnology is playing an increasingly important role in many fields: genetically engineered products are pervasive in the agricultural field, and genetically engineered crops have begun to occupy an important position in American agriculture; biotechnology has made great achievements in the medical field. Significant progress has been made, some genetically engineered drugs have replaced conventional drugs, and the medical community has benefited from genetic research in several aspects; the progress of cloning technology has provided unprecedented opportunities to save endangered species and explore treatments for various human diseases. Now researchers are preparing to push biotechnology into more challenging areas. But voices wary of the behavior of geneticists have been gaining traction recently.

Today, hundreds of genetic substrates can be studied simultaneously with the help of so-called DNA slices.

Gene research has reached such a high level of development that a few years later, with the completion of the analysis of human genetic material, people began to focus all means on systematically studying the advantages and disadvantages of other parts of human genetic material. But advances in biology also have a negative side: they can easily provide new genetic grounds for racism. Critics of new genetics like to paint a scary picture: endless testing. , manipulation and cloning, emotionless soldiers, genetically perfect factory workers... The genetic code allows genetic researchers to penetrate deep into people's hearts and provides them with the tools to manipulate life. However, whether they can lead to good research in genetics is completely unpredictable.