(1) Goals of the Human Genome Project
The Human Genome Project is an international research project. Its goal is to complete the genome mapping and full-length DNA sequence analysis of 24 human chromosomes in about 15 years, and identify and analyze the genes through global international cooperation, mainly in the United States. The international human genome project involving the United States, Britain, Japan, Germany, France and China is one of the greatest scientific innovations in the history of human civilization. Its core content is to determine all the DNA sequences of human genome, so as to obtain the most important biological information for human beings to fully understand themselves. China officially joined the project on 1 June 65438+September 991,and undertook the task of sequencing 1% human genome (about 30 million bases).
(2) The research content of human genome.
A. Establishing genetic map
Genetic map, also called linkage map, refers to the relative position and genetic distance of genes or DNA markers on chromosomes. Genetic distance is usually expressed by the frequency of gene or DNA fragment separation (cM) during chromosome exchange. 1 mmol means that the recombination frequency of each meiosis is 1%. The higher the friction value, the farther the distance between two points, the lower the friction value and the closer the distance between two points.
B. Create a physical map
Physical map refers to the actual distance between two points in DNA sequence, which is usually made up of restriction endonuclease fragments of DNA or cloned DNA fragments in an orderly arrangement. Physical map reflects the actual distance between two points in DNA sequence, while genetic map reflects the linkage between these two points. In areas where DNA exchange is frequent, two physically close genes or DNA fragments may have a great genetic distance, while two physically distant genes or DNA fragments may have a close genetic distance because of little exchange in the genetic process.
C.DNA sequencing
The Human Genome Project will finally determine the entire sequence of the human genome. This sequence determination is different from the previous work of DNA sequence analysis only for specific regions of interest. It needs more efficient scale sequencing, and each detected DNA fragment is accurately arranged according to its chromosome position. So as to get the whole picture of the base arrangement of human genome DNA sequence.
D. Identification and analysis of genes
Identifying each gene and studying its structure, characteristics and function is another important content of the human genome project. through
By determining all the DNA sequences of the human genome, we can use a computer to find out all the possible genes encoding protein distributed on two complementary DNA strands.
(3) China's research on the human genome.
China has built a number of powerful State Key Laboratories of Life Sciences and established Beijing and Shanghai Human Genome Research Centers. With the conditions and foundation for studying the human genome, a number of new technologies for genome research have been introduced and established. China's HGP has achieved satisfactory results in the comparative study of multi-ethnic gene preservation and genome diversity, and has also made great progress in the research of susceptible genes such as leukemia, esophageal cancer, liver cancer and nasopharyngeal carcinoma. China is the most populous country in the world, with 56 ethnic groups, and is extremely rich in disease resources. Due to the long-term social closure, extremely rare ethnic groups and genetically isolated groups have formed in some areas. Some large families and individuals with many generations have typical genetic traits and are valuable materials for cloning related genes. However, due to the late start of HGP research in China, weak foundation, insufficient capital investment and lack of a stable high-quality youth force, compared with the amazing development speed of foreign countries in recent years, HGP research in China is still far behind, which is in danger of further increase. If we can't hold our ground in this gene war, we will be in a passive position in the competition of 2 1 century: we can't freely apply the power of gene diagnosis and gene therapy, we can't freely produce and develop biopharmaceuticals, and we can't freely promote the development of other gene-related industries.
2. Introduction of China Hybrid Rice Genome Project.
Rice is one of the most important food crops in the world, the main food for half of the world's population, and an important part of China's economy, culture, tradition and history with a history of 7000 years. The annual output value of rice exceeds 1000 billion yuan, which is the most important grain related to the national economy and people's livelihood in China. Academician Yuan Longping's hybrid rice has a wide influence on rice breeding in China and Southeast Asian countries. The "China Hybrid Rice Genome Project" takes indica rice, the main grain variety in China, and hybrid rice with indica rice as the genetic background as the research object. Its significance in agriculture can be compared with that of human genome project in human health.
By analyzing the whole genome sequence of rice, a large number of genetic information and functional genes related to fertility, high yield, high quality, disease resistance, stress resistance and maturity of rice can be obtained. It can promote the improvement of rice varieties and cultivate better new varieties with high quality and high yield; It is also helpful to understand the related genes in the genomes of other important crops such as wheat and corn, thus driving the basic and applied research of whole grain crops; It can also protect excellent germplasm resources through patents, which is conducive to the sustainable development of agriculture.
As we all know, Academician Yuan Longping is the most important invention and founder of China rice male sterile line, and enjoys the reputation of the father of rice and the pioneer of green revolution in the world. Choosing this rice plant as the breakthrough point of sequencing analysis is of positive significance in politics, science and economy. The research of super hybrid rice genome is closely related to industrial production practice; Scientifically, it is a supplement and development to the international rice genome research; In the national task, it will promote and help China to complete the genome sequence map of rice chromosome 4.
China hybrid rice is in a leading position in the world and is one of the important resources for food security and sustainable agricultural development in China. Super hybrid rice cultivated by Academician Yuan Longping and others is the pride and national treasure of China. Studying the molecular genetic mechanism of hybrid rice is a problem raised in production practice, and it is also the only way for high yield and good quality of rice. By sequencing the genome of super hybrid rice, its genetic secret was solved. Promoting rice application research and industrial development by informatization; Apply for corresponding patent protection to lay a good foundation for sustainable development. And push our discipline to the forefront of the world.
Based on rice genome sequencing, China Hybrid Rice Genome Project focuses on comparative genomics and functional genomics of rice, focusing on the exploration and application of important functional genes with independent intellectual property rights in China. The whole genome sequence frame of Peiai 64S and 93 1 1, two parents of super hybrid rice Liangyou Peijiu bred by Academician Yuan Longping, was determined. Pei 'ai 64S is a photo-thermo sensitive genic male sterile variety. Its genome includes indica rice, japonica rice and melon-edge rice, and it is the female parent of hybrid rice. 93 1 1 is a typical indica rice variety, as a male parent.
The rice genome sequence, like the human genome sequence, is the basis for studying the genetic variation, development and evolution of rice. Especially as a crop, it is the basis of cultivating high yield, high quality and delicious varieties. Its significance is self-evident, which is why there are three "rice genome projects" in the world:
(1)1992-1997 The formally established International Rice Genome Collaboration Group has published the data of 200 Mb BAC clone and the complete sequence of a chromosome;
(2) In April, 2000, Monsanto Company published the "working frame diagram" of rice;
③ In February, 20065438+0, Syngenta, another company, also announced the completion of the "working frame diagram" of rice.
China's "working frame diagram" of hybrid rice will provide information for global rice research and breeding, and will promote the research of rice genome and other crop genomes. The research on the genome of hybrid rice and its indica parents can not only aim at the actual production of hybrid rice in China, but also make up for the deficiency of the international rice genome project.
In September, 20001year, we completed the internationally advanced "working frame map" and database of China hybrid rice (indica rice) genome, and will publish the data for global free enjoyment.
According to the results of assembly and data analysis, China's hybrid rice genome "working frame map" and database are in the leading position in the world, which marks a leap from following the world-class project (1% project) to independently conducting world-class research.
3. Somatic cell cloning technology
Cloning is a transliteration of English CLone, which means asexual reproduction. It is a biological process and feature that cells or molecules become a group of the same cells or molecules through replication and amplification. Cloning at the individual level is common in plant propagation, and the offspring produced by cutting grafting widely used in agriculture are clones. It is also common to clone trees and flowers at the cellular level by using plant cells, and to thin fruits and vegetables. However, it is much more complicated and difficult to copy and express genes and clone them at the molecular level.
In 1950s, scientists transplanted tadpoles from the skin nucleus of small intestine into Xenopus cells without enucleation, which proved the totipotency of differentiated somatic nuclei. But in mammals, this technology has never been successful.
In 1980s, people turned to cloning mammals with embryonic cells. First of all, the blastomeres of early embryonic cells were separated to make them into eggs with multiple identical genes, so as to breed offspring with the same genes from one variety. 1986, British scientists cloned a sheep from embryonic cells. Since the mid-1980s, scientists in China have successfully cloned mice, goats, rabbits, pigs and cows from embryonic cells. Just as the cloned sheep in Britain stirred the world public opinion like a whirlwind, American scientists announced that they had successfully cloned two close relatives of human beings from embryonic cells last year: monkeys.
But all this splendor can't be compared with this sheep cloned by British scientists using somatic cells.
This extraordinary sheep was named after Dolly, a popular English country singer, by its creator. Its life experience is really unprecedented. It has three mothers, but no father. Its embryonic development and birth process are controlled by wilmot Group of Rowling Institute. They first induced ewe A to ovulate with drugs, and then sucked all the chromosomes of this unfertilized egg, making it an active "eggshell" without genetic material. Then they took an ordinary cell from the mammary gland of 6-year-old ewe B, and through current stimulation, they combined the nucleus of the mammary gland cell with the "eggshell" to form an egg cell containing new genetic material. After the egg cell developed into an embryo in a test tube, it was implanted. 1July, 996, Dolly came to this world with anxiety about scientists. What is exciting is that this naive "Miss Jiao" is ok so far. All three ewes gave birth to her, but only the 6-year-old ewe B who provided her with the nucleus was her real "biological mother". Dolly inherited all its DNA genes, in other words, Dolly is a 100% copy of ewe B.
Dolly's birth marks the gorgeous pause of bioengineering technology at the end of this century, and also marks a resounding high note for this technology that people in 2 1 century unanimously expect and attach importance to. Once the cloning technology is mature, it means that any mammalian somatic cell can become a donor material for cloning. It is estimated that an adult human body has about 40 billion cells. As a reference, you just need to think about how many cells are contained in a small piece of meat. This is almost endless. The biggest advantage of cloning is that it can 100% copy all parents' personalities. Therefore, cloning technology has opened up a unique way to solve the thorny problems in the fields of basic medicine, medicine and animal husbandry production and protect the biodiversity of the earth.
Many chronic diseases that devour human health can't break out for a long time because they only show a ferocious face and hide a mysterious life experience. Scientists imagine introducing "suspected" genes in somatic cells that may be related to diseases into the genes of experimental animals, and then cloning a number of transgenic experimental animals. Because there are many similarities between human and animal disease pathogenesis, if the input suspect gene is sick in animals, it proves that that gene is the culprit, otherwise it is ruled out. In this way, mankind can find a sword to cut off the evil clutches of disease.
If protein drugs extracted from blood are expensive, and some blood products may contain viruses such as AIDS and hepatitis B, people will be suspicious and even afraid when using these drugs. If a large number of genetic animals with special medicinal value are cloned, protein drugs with special efficacy can be produced from the blood and milk of such animals. "Borrowing flowers to offer Buddha" can not only improve efficiency, but also sit back and relax.
In order to cultivate a good variety, it takes several generations of cross selection, and variation and degradation often threaten the stability of quality, which makes the efforts of researchers for several years give up. Using somatic cell cloning technology, this century's problems will be solved. For example, with a high-yield cow as a donor, ten, one hundred, one thousand and ten thousand cows with the same high yield can be cloned. Of course, this must ensure that the feeding conditions are roughly the same as those of the donor. "Good horses don't eat grass" won't work there.
Every year, some species become eternal passers-by of our planet. Giant pandas, golden monkeys ... the low sobs and lonely figures of endangered species have always touched the nerves of the world. Cloning technology undoubtedly brings good news to the children and grandchildren of rare animals, and also provides technical possibilities for human beings to protect the biodiversity of the earth.
At present, the attractive prospect of cloning technology is only the tip of the iceberg. At present, the repetitive experiment of somatic cell cloning of the same animal needs to be improved, and its application will not be achieved overnight. Cloning different kinds of animals will be a bolder and more important research direction in the future. For example, the somatic cell nucleus of a sheep is heterozygous with the egg cell of a cow, and then the reconstructed embryo is implanted into the uterus of a horse for pregnancy. But there are still many unsolved theoretical and technical problems waiting for scientists to explore.
But at the same time, we can also see that, like many scientific technologies, cloning technology is also a double-edged sword. Because theoretically, since mammalian sheep can be cloned, human cloning will not be a big obstacle. People imagine that now that cloned sheep have arrived, will cloning be far away from us?
The emergence of human cloning may challenge the politics, religion, law and ethics of human society, and will have an unpredictable impact on the lifestyle, family structure and marriage mode of human society. Therefore, all countries in the world declare human cloning as persona non grata, which sets an insurmountable minefield for human cloning research.
US President Bill Clinton announced that the federal government banned human cloning with government funds, and ordered the establishment of a special group to examine the ethical impact of the breakthrough in cloning technology.
The Vatican's Roman Observer called for: "Human beings have the right to be born in a human way, not in a laboratory. Any kind of anti-human way is unacceptable. "
Chen Minzhang, Minister of Health of China, announced that China would not approve, participate in, fund or accept foreign scientists' research on human cloning.
The French Secretary of State for Health said: "It is not advisable to clone human beings", and the French Agricultural Research Institute stated: "We are firmly opposed to any technology of cloning human beings."
We are gratified and proud that in the face of cloning, human beings are more mature, rational and far-sighted than ever before. If cloning technology is really another Pandora's box that God put in front of human beings, then human beings will reach for it with confidence. One hand is called wisdom or spirituality, which will make cloning technology work for us and benefit the world, and the other hand is called reason, which will control and prevent cloning technology from going to the opposite side.
4, gene therapy:
With the development of human genetics, researchers realize that the most basic genetic unit of human beings is the gene on chromosome, which is the blueprint for "manufacturing" and "manipulating" the human body, and it guides cells to synthesize protein, which is the basis of human life. However, when the gene changes, the protein encoded by it cannot function normally, and in this case, diseases may occur. In recent 10 years, gene therapy, as a technology to correct defective genes, has become the focus of research and experiment in many countries, especially in western developed countries.
After years of research, researchers have found many ways to correct defective genes, among which the most common method is to insert normal genes into non-specific positions in the genome to replace defective (also known as ineffective or pathogenic) genes. In this method, researchers usually use vectors called vectors to deliver normal or therapeutic genes to the target cells of patients. At present, the most common vector is a virus that has been artificially modified to carry normal human DNA. In the long process of evolution, viruses have formed a unique way to transport their genes into human cells, causing human diseases. Researchers try to remove the genes that cause human diseases from the virus genome and add therapeutic genes, and then use the special ability of virus to transmit genes to treat human diseases.
When the virus vector reaches the target cell (such as liver or lung cell), it will "unload" the genetic material it carries for treating human genes and leave it in the target cell. Under the genetic instruction given by the therapeutic gene, the cells began to produce protein with corresponding functions, thus restoring the normal function of the target cells. Generally, virus types used as gene therapy vectors include retrovirus, adenovirus, adeno-associated virus (AAV) and herpes simplex virus. Different viruses attack different targets in human body, so when they are used as vectors, they carry different therapeutic genes and target cells.
Of course, in addition to using vectors to deliver therapeutic genes to treat diseases, there are several other non-viral gene delivery methods for researchers to choose from. One of the simplest methods is to "inject" therapeutic DNA directly into target cells. However, the application of this method is very limited, because it is only suitable for a few human tissues, but it needs a lot of DNA. Now, researchers are experimenting with injecting an artificial chromosome, the 47th chromosome, into the target cell. This artificial chromosome will coexist with 23 pairs (46 chromosomes) of human cells, and will not affect its work or cause its variation, nor will it be attacked by the human immune system. Researchers hope that artificial chromosomes can be used as a large carrier to spread diseases and carry a large number of genetic codes. The current problem with this method is that it is difficult to transport such a large molecule into the nucleus of the target cell.
Although gene therapy is feasible in theory, it has encountered many difficulties in practice. The first clinical trial of gene therapy in the United States began at 1990, and no obvious effect has been achieved so far. 1999, Jess, 18 years old? When Gessinger received experimental gene therapy for ornithine transferase deficiency, he died on the fourth day of treatment due to multiple organs stopping working. It is believed that the strong reaction of human immune system caused by adenovirus as a disease vector is the cause of Jess's death.
The most serious blow to the research of gene therapy was the failed gene therapy experiment in France in June 5438+10. A boy with X-chromosome-related severe comprehensive immunodeficiency syndrome (X-SCID, commonly known as "bubble baby syndrome") suffered from a leukemia-like disease after undergoing gene therapy experiments. In August 2002, a boy with the same disease had the same situation after receiving experimental gene therapy. After the failure of the second trial, in order to be prudent, the US Food and Drug Administration (FDA) immediately took measures to temporarily suspend all gene therapy trials of blood stem cells in the United States with retrovirus as the carrier.
At the end of February, 2003, the BRMAC Committee under the US Food and Drug Administration held a meeting to discuss whether some experiments of retrovirus gene therapy can be allowed for diseases that threaten human life under the premise of corresponding safety, but the Food and Drug Administration has not yet given a reply. At present, gene therapy is still in the experimental stage in the United States, and the Food and Drug Administration has not approved the marketing of any human gene therapy products.
Researchers have found that there are many factors that affect the effect of gene therapy on genetic diseases, including short natural life span of gene therapy, strong response of human immune system, virus vector problems, polygenic diseases and so on. Specifically, therapeutic DNA is not easy to "integrate" into the genome and many cells divide rapidly, which leads to the short-lasting therapeutic effect of gene therapy and patients have to receive treatment many times; The strong reaction of human immune system to "invaders" affects the effectiveness of gene therapy, and the immune response produced by immune system makes it more difficult for patients to receive gene therapy repeatedly. Virus vector will bring potential harm to patients, such as toxicity, immunity and inflammatory reaction. In addition, people are worried that the vector may regain its pathogenic activity after entering the human body; Gene therapy is the most effective method to treat diseases caused by single gene mutation. But in fact, many diseases in the human body are caused by polygenic variation, and it is difficult for a single gene therapy to work.
Although gene therapy is far from clinical application, in recent years, the research of gene therapy has made encouraging progress in some aspects. On March 20th this year, New Scientist magazine reported that the research team of the University of California successfully used micro-lipid particles (or liposomes) coated with PEG (polyethylene glycol) polymer to deliver therapeutic genes to the human brain. This is a major breakthrough and achievement, because previous studies have shown that the virus carrier "body" is too big to cross the "blood-brain barrier". New research results are expected to treat Parkinson's disease. For another example, new scientists also reported in March 13 that some researchers said that because cells can degrade RNA with special sequences by using short double-stranded ribonucleic acid (siRNA), if an siRNA is designed to match the RNA copy of the defective gene, the defective gene will not be able to produce abnormal protein. A few days ago, scientists from hammersmith Hospital in London reported in the online edition of the British journal Nature Medicine that they had achieved initial success by injecting ribonucleic acid (RNA) into experimental mice with Duchenne muscular dystrophy, and the effect could last for three months.
Perhaps one day, with the firm belief and unremitting efforts of researchers, gene therapy can be applied to the prevention and treatment of human diseases, so that people who carry defective genes and live in the shadow of diseases at any time can be completely liberated from pain.
5. Genetically modified organisms
(1) transgenic crops
At the annual meeting of the Biotechnology Industry Organization held in Washington, DC, USA, Fieldbaum, president of the Biotechnology Industry Organization, announced: "By the end of 2002, 870 million mu of biotechnology crops had been planted in 16 countries around the world. The United States, Argentina, Canada and China are the four countries with the most genetically modified crops. In the United States alone, 55 biotech crops have been approved for commercialization. At present, the most genetically modified crops are soybeans (3 varieties), cotton (6 varieties), corn (13 varieties) and rapeseed (1 1 variety). "
15000 entrepreneurs and scientists from 47 states in the United States and more than 50 countries around the world attended the three-day annual meeting. The topics discussed are very wide, from biological science and its management to bioethics and homeland security. The contents of the sub-venue include biological defense, global biotechnology trading, drug discovery and development, fund raising and intellectual property protection.
The number of people attending this annual meeting is much larger than in previous years. This is because the share price of American biotechnology has soared recently, and the Nasdaq biotechnology stock index has risen by nearly 50% this year. Great progress has also been made in biotechnology research, and the US Food and Drug Administration has also approved the listing of several new drugs. Fieldbaum said: "As we all know, biotechnology and information technology are undergoing a major combination, but now there has been a trend of combining biotechnology with other technologies, especially nanotechnology, resulting in a new, highly computerized' dry laboratory'."
The so-called "dry laboratory" means that in the laboratory, a large number of electronic technologies such as computers are used for experiments, and chemicals such as solvents and solutions are not used. This is a major change in the biological laboratory, which enables people to carry out thousands of experiments in the laboratory than in the past. From the panel discussion at the meeting, the reporter saw that biotechnology has been widely used in industry. It can be used to make plastics, fuels, paper and detergents, so it has little impact on the environment.
At the conference on biotechnology and developing countries held at noon on June 22, 2003, the organizer specially provided a "biotechnology lunch" for reporters. From the main course to the snack fruit, every food is a product that has been transformed by biotechnology. The first appetizer is biotechnologically modified tomatoes and papaya. After the reporter tasted this yellow tomato, he felt that it was no different from ordinary tomatoes except a little sour. Transgenic papaya can resist a papaya disease, which once cost Hawaii's papaya industry $6.5438+0.7 million. The staple food is grilled shrimp with rice, plus plums and peanuts. Genetically modified rice is rich in iron and vitamin A. Plums after biotechnology can prevent plum rash virus, while shrimp and peanuts will not have shrimp allergy and peanut allergy after eating, because scientists have completely eliminated allergens through biotechnology.
(2) Poplar and birch began to change their faces. Russia has developed transgenic trees.
The Siberian Institute of Plant Physiology and Biochemistry of Russian Academy of Sciences has successfully cultivated transgenic poplars through genetic engineering. The Institute of Forest Genetics and Breeding in Voronezh cloned high-quality Kareli birch. Researchers found through experiments that transgenic trees and cloned trees have the advantages of fast growth and pest resistance while ensuring the quality of wood.
Genetic engineering has been widely used in medicine, food and agricultural production in the 20th century, but the research on improving the quality of trees and forests by genetic engineering started late. In recent years, scientists began to pay attention to the research of transgenic trees and cloned trees.
Researchers at the Siberian Institute of Plant Physiology and Biochemistry found that the maize gene ugt can control the synthesis of auxin enzyme. If the content of auxin in trees can be increased, the growth speed of trees will be accelerated. Researchers implanted ugt gene into Populus davidiana, Populus alba and Cedar to obtain transgenic Populus davidiana, Populus alba and Cedar. Years of experiments have proved that the growth rate of Populus davidiana, Populus alba and Cedar containing ugt corn gene has been greatly improved.
Researchers from Voronezh Forest Genetics and Breeding Institute chose the most valuable Kareli birch for cloning research. They extracted cells and callus from the stems of the most beautiful pattern birch, and then cultivated birch from the callus, and successfully obtained cloned birch. Experiments show that the cloned birch grows faster: in 3 to 4 years, there are traces of patterned knots or edges on the trunk, and in 5 to 8 years, all the trunks become beautiful patterns. However, it usually takes 65,438+00 to 65,438+02 years for Careli birch planted by traditional methods to have patterned wooden signs.
In this regard, some Russian scientists believe that, like other genetically modified products, there is still a lack of complete understanding of the structure and performance of genetically modified trees. Fast-growing trees will make the soil fail in advance, and the pollen of transgenic trees may change the natural structure of forest population, thus destroying forest ecosystem. Therefore, the study of transgenic trees needs long-term observation.
(3) Tobacco grown in the United States "grows" rabies virus antibodies.
American scientists have cultivated a transgenic tobacco crop for the first time, which can contain antibodies against rabies virus. The new results show that transgenic crops are expected to become a cheap "production workshop" for rabies virus antibodies.
Researchers at Thomas Jefferson University say they have inserted genes encoding antibodies to human rabies virus into new transgenic tobacco crops. At present, 900 mu of transgenic tobacco can harvest at least 1 1,000 grams of rabies virus antibody and produce about 654,380+10,000 copies of medical preparations. The researchers said that after the improvement, the productivity of the crop "production workshop" can be further improved. Cell culture experiments show that the antibody obtained from transgenic tobacco can inhibit rabies virus, and its efficacy is similar to or even stronger than that of rabies virus antibody naturally produced by human body. Animal experiments in vivo also show that antibodies produced by transgenic tobacco can protect hamsters from rabies virus infection.
More than 50,000 people die of rabies every year in the world, and the market space for rabies drugs and vaccines is quite large. Traditionally, rabies virus antibodies are mainly extracted from humans and horses, but the former is too expensive, and the antibodies obtained from horses will cause serious allergic side effects. At present, there is a serious shortage of rabies virus antibodies worldwide. Dr Koprowski, head of research on new transgenic tobacco crops and Thomas Jefferson University, believes that it is safer and cheaper to obtain rabies virus antibodies from transgenic crops than other methods.
(4) Response:
In the early 1970s, when scientists used recombinant gene technology for the first time to construct recombinant gene molecules from phage viruses of Escherichia coli and SV40 viruses of apes, people had a fear. Will this method create a super-individual beyond human control and cause devastating damage to human beings and nature? So scientists began to pay attention to the safety of modern biotechnology, that is, biosafety.
Experts believe that modern biotechnology has extensive, potential and long-term dangers, which may affect the ecological structure of non-target organisms in the environment, change the competitive relationship between species, and cause a series of problems such as weeds of transgenic plants and toxicity, pathogenicity and allergy of some products.
How to treat these potential dangers? Wang Guoying, a professor at China Agricultural University, believes that attention should be paid to the potential danger of biotechnology, and it is necessary to take preventive measures, but the harm of biotechnology should not be exaggerated. Some foreseeable potential dangers can be avoided by biological safety measures @ not as terrible as people think. For example, the problem of weeds in transgenic plants, most of the existing cultivated crops have lost their adaptability and natural competitiveness under natural conditions after artificial domestication, and the possibility of their degradation into weeds is very small.
Another aspect involving biosafety inspection is gene drift. Will genetic drift of transgenic crops change the ecological structure of non-target organisms and the competitive relationship between species? Wang Guoying explained that gene drift can only be carried out between closely related species.