Paper 1 transgenic technology: transgenic technology
abstract
As the frontier technology of life science, transgenic technology has gradually entered people's lives, and its application field has been expanding. It has played a more and more important role in solving the major problems faced by mankind, such as food shortage, environmental pollution, resource shortage and benefit attenuation, and has gradually developed into a powerful modern biotechnology industry. However, the potential risks of genetically modified organisms and their products are still inconclusive, so the safety of genetically modified organisms and their products has become a global hot issue, which has attracted great attention from governments all over the world and many international organizations.
Transgenic technology; Development status; Controversy; Biosafety management
1 introduction of transgenic technology
Transgenic technology refers to introducing artificially separated and modified genes into the genome of an organism by means of molecular biology according to people's wishes. Due to the expression of introduced genes, the traits of organisms can be genetically modified. People often say that "genetic engineering", "genetic engineering" and "gene transformation" are synonyms for transgenic. Organisms transformed by transgenic technology are often referred to as genetically modified organisms (GMO) in the media.
The advantages of transgenic technology are as follows: firstly, transgenic technology breaks through some limitations of traditional technology, and its transferred genes are not limited by the genetic relationship between organisms, such as introducing human insulin gene into bacteria and crossing the boundaries between species. Secondly, transgenic technology generally operates and transfers clearly defined genes, with clear functions, and the performance of future generations can be accurately expected. Therefore, transgenic technology has extensively developed and perfected traditional breeding technology.
2 Transgenic technology and methods
2. 1 Plant transgenic method.
Transgenic plants refer to plants that integrate cloned excellent target genes into plant genomes and express them through recombinant DNA technology to obtain new genetic traits. There are the following methods:
Agrobacterium-mediated method: There is a kind of circular DNA in Agrobacterium, called Ti plasmid. The reason why plants infected by Agrobacterium grow tumors is precisely because T-DNA is inserted into plant chromosomes. Since then, people have used this natural transformation system to genetically modify plants.
Gene gun: using gunpowder explosion or high-pressure gas acceleration (this acceleration device is called gene gun), high-speed micro-bullets wrapped with DNA solution containing the target gene are directly sent into complete plant tissues and cells, and then plants are regenerated by cell and tissue culture technology, and transgenic positive plants are selected as transgenic plants. The main advantage is that it is not limited by the range of recipient plants. Moreover, the construction of its vector plasmid is relatively simple, so it is also a widely used method in transgenic research.
Pollen tube pathway method: after pollination, the DNA solution containing the target gene is injected into the ovary, and the exogenous DNA is introduced into the fertilized egg cell by using the pollen tube pathway formed during flowering and fertilization, and further integrated into the genome of the recipient cell, and becomes a new transgenic individual with the development of the fertilized egg. The biggest advantage of this method is that it does not rely on tissue culture to regenerate plants artificially, and the technology is simple, and it does not need a well-equipped laboratory, which is easy for conventional breeders to master.
2.2 Animal transgenic methods.
Transgenic animals introduce other genes into animal cells through artificial experiments, integrate with the genes of animals themselves, reproduce with the division of cells, and transmit other genetic information to future generations. Strictly speaking, transgenic animals are artificially created new animals.
The cells that transgenic animals receive foreign genes are generally fertilized eggs. The main transgenic animal technologies include:
Nuclear microinjection is the most commonly used method in animal transgenic technology. It injects foreign genes into the pronucleus of fertilized eggs under a microscope, fuses the injected foreign genes with the embryonic genome, then carries out in vitro culture, and finally transplants them into the uterus of the recipient female animals for development, so that every cell in the parturient animals contains new DNA fragments. Pure lines can be obtained directly, and the experimental period is short.
Retrovirus vector method: refers to recombining the target gene into retrovirus vector to make high-concentration virus particles, artificially infecting the embryo before or after implantation, or directly incubating the embryo with single-layer cultured cells that can release retrovirus to achieve the purpose of infection, and inserting the foreign target gene into the host genome DNA through virus. The advantage of this method is that it does not need rearrangement and can integrate a single copy of the transferred gene at the integration point. When the embryo is placed in a high concentration virus container, or co-cultured with infected cells in vitro, or microinjected into chicken blastoderm, the embryo rate of integrating retrovirus DNA is higher.
Embryonic stem cell-mediated method: introducing genes into cells; Then, after the transgenic embryonic stem cells are injected into animal blastocysts, they can participate in the embryonic formation of the host and form chimeras until they reach the species chimera. Its advantages are that before transplanting embryonic stem cells into embryos, a special genotype can be selected in vitro, after transfection with exogenous DNA, embryonic stem cells can be cloned, and then cells containing integrated exogenous DNA can be screened for cell fusion, so that many genetically identical transgenic animals can be obtained.
3 Development Status of Transgenic Technology
At present, more than 100 transgenic plants have been obtained internationally. Genetically modified crops have been widely planted in the United States, Argentina and Canada. Among all genetically modified crops, the planting area of genetically modified soybeans, corn, cotton and rape accounts for more than 99%. China government attaches great importance to the research of biotechnology. There are 47 kinds of transgenic crops and trees being developed in China, involving more than 65,438+000 genes. LAt-PA is produced by transgenic goats and cattle, and human hemoglobin is produced by transgenic pigs. These gene products have high efficiency, good quality and low cost, and have the same biological activity as the corresponding human proteins, and are mostly secreted with milk, which is convenient for separation and purification.
4 Controversy of transgenic technology
With the issue of genetic modification becoming a hot topic, more and more people begin to pay attention to genetic modification. The original intention of scientists to invent transgenic technology is to use it to benefit mankind, which can not only accelerate the improvement of crops and livestock varieties and improve the quality of human food, but also produce precious medicinal protein and bring good news to patients.
However, will human intervention in nature cause potential and unpredictable dangers? As a result of a series of debates, the United Nations has also made public statements, trying to explain that genetically modified products are harmless and safe. International Economic Cooperation Organization 1993 put forward the principle of substantial equivalence in food safety evaluation. If the products produced by genetically modified animals and plants are essentially equivalent to traditional products, they can be considered safe. However, the government's attitude towards genetic modification has turned in two directions. On the one hand, the loose policy represented by the United States believes that as long as the harm of genetically modified products cannot be scientifically proved, it should not be restricted. On the other hand, the representative of the European Union believes that as long as its harmfulness is undeniable, it should be restricted.
Our government attaches great importance to the safety management of genetically modified organisms. In May of 20001year, the State Council promulgated the Regulations on the Safety Management of Agricultural Genetically Modified Organisms. China pays more and more attention to the safety of genetically modified organisms and their products, and pays close attention to the trend of relevant international management regulations.
The second part of transgenic technology paper: detection technology of genetically modified food
Under the influence of genetic engineering technology, the research and development of genetically modified foods in various countries is also slowing down from time to time. With the emergence of genetically modified foods, people's trust in genetically modified foods is not high. In order to prevent people from choosing genetically modified foods independently, various countries and organizations require enterprises to stop labeling genetically modified products, which also puts forward higher requirements for the analysis and detection technology of genetically modified foods. This paper introduces the contents of analysis and detection technology of genetically modified food, discusses the research process of analysis and detection technology of genetically modified food, and looks forward to the future development of analysis and detection technology of genetically modified food.
Keywords: genetically modified food; Analysis and detection technology; gene engineering
The emergence of recombinant DNA technology in the 1970s brought biotechnology into the era of genetic engineering. Agricultural biotechnology has risen rapidly in the world, and genetically modified animals have lost extensive cultivation in the world, which is followed by the rapid development of genetically modified food. Due to the wide application of genetically modified biotechnology and the large-scale planting of genetically modified crops, the safety of genetically modified foods has attracted more and more attention.
First, the labeling system and analysis and detection technology of genetically modified foods
In China, there is a clear instruction in the revision of the Leaf Food Safety Law in 20 15 that enterprises must stop labeling genetically modified foods according to regulations. At present, the labeling system of genetically modified foods in the world is mainly divided into compulsory labeling and voluntary labeling. In China, there is a strict legal system for the labeling of genetically modified foods. If the content of genetically modified foods exceeds the threshold, enterprises must stop labeling. However, in some European and American countries, there is no strict requirement for the labeling of genetically modified foods, and only the labeling of genetically modified foods containing allergic ingredients is stopped. However, China's products export, it is necessary to stop strict analysis and testing. It is also the key to the circulation of products that qualified genetically modified foods agree to export and stop genetically modified labeling. This shows the importance of logo [1]. The labeling requirements of genetically modified products are completed through analysis and testing, so the labeling system of genetically modified foods is an important labeling of genetically modified foods. Only the actual detection can determine the establishment of the labeling system, and make qualitative and quantitative analysis on the detection limit reached by the detection technology, so as to provide superstitious basis for the labeling system; However, in the practice of inspection and quarantine, the identification system is completed by detection technology. Therefore, the relationship between identification system and analytical detection technology is very close, and they influence and interact with each other [2].
Second, the current situation of genetically modified food
2. 1 Overview of genetically modified food
In genetic engineering, foreign genes are transferred to other organisms by using DNA recombination technology, so that organisms show special genetic and biological characteristics, and organisms that lose new gene recombination are the content of transgenic. The so-called genetically modified food is the food that stops being processed with these special organisms. To some extent, transgene only uses foreign genes to slow down the growth process of organisms. In genetic engineering, the main purpose of genetically modified food is to prolong the growth cycle of crops, increase crop yield and the ability to resist pests and diseases, thus effectively reducing consumption cost and improving the consumption efficiency of crops. In the current transgenic research, it is not found that food contains a small amount of toxins. However, because the genetically modified food belongs to an artificially made alien organism rather than a naturally selected species, the changes of gene sequence during gene drift cannot be fully grasped, and the exogenous gene has uncontrollable characteristics when it stops recombining with DNA, so the exact conclusion on the safety of genetically modified food cannot be prevented [3].
2.2 Achievements of genetically modified foods
Genetically modified food has become a controversial food since its appearance. More and more genetically modified foods enter the market and are fermented by the media, which makes people question the safety of genetically modified foods. As for the safety achievements of genetically modified food, there are no rigorous superstitious conclusions and research reports to give exact evidence conclusions about its safety. The existing achievements mainly include the following aspects. First, genetically modified food is a new organism composed of gene implantation and gene recombination. Can its original structure and composition be changed? Second, genetically modified food is not a product produced in nature. Will eating genetically modified food have a negative impact on the human body? Will it accumulate toxins when eaten temporarily? What is the impact on the development and growth of the human body? Third, genetically modified crops are not the product of natural selection. Will they affect the biological chain and destroy the ecological balance? Fourthly, transgenic crops are the products of gene activities, and whether they can be purified in this case involves other crops in nature, so that their genes can be changed [4]. Because these achievements have not been lost, there is an urgent need for complete, accurate and rigorous analysis and detection technology of genetically modified food to ensure its safety, so as to further improve the superstitious standards of genetically modified food supervision in China.
2.3 Contents and Classification of Detection Techniques for Genetically Modified Foods
At present, the safety of genetically modified food mainly depends on the analysis and testing of genetically modified food to stop testing. In the process of analysis and detection of genetically modified food, the second thing is to stop the detection of DNA, protein and nucleic acid. Three kinds of detection methods can be allocated according to these three substances, and the combination of detection methods can be stopped as needed in practice. Because the protein content detection method is only suitable for the detection of foods that have not stopped processing and new foods, it has great limitations, so the application scope of exogenous gene detection method is more common at this stage [5].
Three. Discussion on detection technology of genetically modified food
3. 1 protein blot detection technology
Protein blot detection mainly uses polyacrylamide gel electrophoresis to stop the separation of foreign protein in transgenic food and stop the combination with chromogenic enzyme reaction, so as to effectively stop the separation and detection of foreign protein. The main purpose of this detection method is to stop the analysis of insoluble protein in genetically modified food, detect the content of protein in genetically modified food, and stop the comparison with the predetermined limit in protein.
3.2 Multiplex PCR detection technology
At present, multiplex PCR detection technology is widely used in the detection of genetically modified foods. PCR Deep polymerase chain reaction can only prevent the detection of 1 DNA fragment. In order to obtain more one-sided gene sequence information in the detection of genetically modified food, the principle of PCR reaction was applied to stop multiple detection when the gene detection stopped, thus forming a composite amplification PCR detection technology for genetically modified food. Using this detection technology can effectively improve the detection efficiency, and stop detecting multiple target sites of gene sequence at the same time, and complete the accuracy and reliability of genetically modified food detection [6].
3.3 Detection Technology of Exogenous DNA
Genetically modified food mainly introduces exogenous DNA into organisms, and the detection of exogenous DNA is mainly aimed at detecting the gene sequence characteristics of genetically modified food, and the detection of nucleic acid degree of genetically modified food is the most important detection technology of genetically modified products, followed by the detection of promoter Yao gene and terminator, so as to facilitate the detection of genetically modified food.
3.4 Gene Chip Detection Technology
Gene chip is to stop the determination of the genome sequence of genetically modified organisms, and arrange the DNA of genetically modified foods regularly on silicon wafers or glass slides to form a macro array. By calculating and processing the gene sequence on the gene chip by computer software, the genetic characteristics and biological information of genetically modified food can be obtained, which can accurately and effectively stop detecting the gene expression characteristics of genetically modified organisms [7-9].
3.5 lamp detection technology
LAMP loop-mediated isothermal amplification is one of many nucleotide amplification techniques. This technology has no specific environmental requirements when it is used, and it only needs to be at a constant temperature to stop the detection experiment. The operation technology is complicated. LAMP detection technology is a complex detection technology, which mainly uses color reaction to terminate the detection of genetically modified organisms and turbidity meter to terminate the detection and discrimination of sediments in the reaction process.
3.6 Joint detection technology
Joint detection technology mainly integrates the advantages of various detection technologies to stop the ineffective analysis and detection of genetically modified foods, which can play a role in fostering strengths and avoiding weaknesses. In gene detection, the existing combined detection technologies include PCR and enzyme-linked immunosorbent assay [10- 1 1].
Four. conclusion
The analysis and detection technology of genetically modified food is mainly to evaluate the safety of genetically modified food. At present, there are many analysis and detection technologies for genetically modified foods. Because the gene fragments of genetically modified foods are different, the selection of detection technology should be stopped according to actual needs to ensure the ineffectiveness of detection technology. In the future, there will be more and more genetically modified foods on the market. As one of the important detection technologies, analytical detection technology will surely have new development.
Transgenic Technology Paper III: On the Protection System of Consumers' Right to Know about Genetically Modified Foods
Abstract: The information asymmetry and the uncertainty of food safety in the consumption of genetically modified food have aroused widespread concern among consumers. Effectively protecting consumers' right to know is conducive to the rational consumption of genetically modified food and the healthy development of genetically modified technology.
Therefore, we should learn from the main systems of protecting consumers' right to know in the United States and the European Union, and construct and improve the protection system of consumers' right to know in genetically modified foods in China from the aspects of labeling system, safety evaluation and testing system and public participation system.
[Keywords:] genetically modified food; Consumers; Right to know.
Since the end of the twentieth century, genetically modified foods have been widely promoted in our lives.
The so-called transgene is to transfer the genes of some organisms to other biological species by means of molecular biology, so that they have traits or products that the original species does not have. The food produced by genetically modified organisms is genetically modified food. On the other hand, with the increasing application of transgenic technology, the potential safety hazards of this technology to human health have gradually attracted the attention of all walks of life. In the case that genetically modified foods have been produced and listed, consumers' right to know is legitimate and should be protected.
First, the connotation of consumers' right to know.
Consumers have the right to require business operators to indicate the true ingredients, raw materials and sources of genetically modified foods and related services in a manner prescribed by law. Food contains genetically modified ingredients, and the raw materials used are genetically modified products, which are directly derived from crops cultivated by genetically modified methods. If the catering services provided involve genetically modified foods, consumers have the right to require operators to indicate them when selling genetically modified foods or providing services related to genetically modified foods. Consumers have the right to inquire and understand the food they sell or the services they provide during the transaction, and business operators should answer and explain it patiently and carefully. When providing genetically modified foods or services related to genetically modified foods, business operators shall truthfully introduce the advantages and disadvantages of the foods or services to consumers.
Second, the significance of the consumer's right to know protection system.
(1) Protecting consumers' right to know about genetically modified foods is an important aspect of food safety.
Because transgenic crops can better control pests and diseases, resist drought, increase production and have high nutritional content, their development prospects are very broad. However, experts also stressed that the development of genetically modified food must have strict supervision, scientific inspection, and strengthen legislation and management to avoid its harm to human health and the environment. [1] The legal system to protect consumers' right to know about genetically modified foods is helpful to urge food producers to use genetically modified technology more cautiously through consumer supervision and avoid harmful foods from entering the consumption field, so it is an important way and means to ensure food safety.
(2) Protecting consumers' right to know about genetically modified foods is an important embodiment of consumers' rights and interests.
As the inevitable result of political democratization, the right to know is a basic personal right enjoyed by citizens according to law. As a specific civil subject, consumers' right to know is an inevitable requirement for the democratic principle in the political field to extend to economic life, which is clearly stipulated in relevant laws and regulations in China. In particular, consumers' right to know is the premise of exercising their right to choose, and consumers have the right to decide whether to buy genetically modified foods. Therefore, the right to know plays a vital role in fully realizing the basic rights and interests of food consumers. However, as far as the research and development, production, processing and sales of genetically modified foods in China are concerned, there is a big gap between consumers' right to know and social reality, and the existing laws are not perfect in this respect. This situation is not conducive to protecting the basic rights and interests of consumers, but also has a negative impact on the standardized management of genetically modified foods.
Third, the current situation of foreign consumers' right to know about genetically modified foods.
The disclosure of genetically modified food information and the protection of consumers' right to know are important issues that need to be solved in the process of genetically modified biotechnology from research and development to commercial production and sales around the world. Developed countries such as Europe and America have relatively perfect legislation and management systems. The research and practice of foreign advanced information transparent management mode and consumer's right to know protection legal system have great reference significance for our country. Mainly can be summarized into three modes:
(1) A strict restrictive model represented by the European Union.
The identification of genetically modified foods in the EU is based on the process rather than the final product. In order to ensure consumers' full right to know about food, the European Union has set up a special agency, namely the European Food Safety Agency (EFSA), which is responsible for assessing the risks related to the whole food chain, working independently and not under the jurisdiction of other agencies. [2] And establish a special website to remind the public of food risks and fully disclose the information of genetically modified foods from research and development to sales.
In the aspect of legal protection of consumers' right to know, the European Union takes general food law as the main body, supplemented by a large number of food labeling laws and advertising laws, and has formed a highly orderly and well-structured information disclosure system for genetically modified foods. In 2003, Law 1829 and Law 1830 stipulated that no matter whether there is DNA or protein from genetically modified organisms, as long as the food contains or is made of genetically modified organisms, it must be marked with special labels. Laws and regulations are refined to label specifications and restrictions on genetically modified content. , the species expanded to dozens of categories, 100.
(2) The relaxed and encouraging model represented by the United States.
What is the management of genetically modified food in the United States? Principles of reliability science? Adopt loose management mode and pursue self-discipline control. However, we still attach great importance to the legal protection of the public's right to know, emphasize the transparency of research, development, practice, production and promotion of transgenic technology, establish an effective food safety information system, regularly publish the detection information of genetically modified foods, publish the list of genetically modified foods and food safety resources information on the Internet, and disclose food safety information to the maximum extent. [3] The draft safety management of genetically modified foods in the United States, the public health law and the modernization law of the Federal Food and Drug Administration of the United States stipulate the application process for commercialization of genetically modified foods, and the disclosure of relevant technical information is a necessary condition for obtaining legal permission from the Food and Drug Administration (FDA).
(III) Compromise model represented by Japan Japan adopts the principle of encouraging genetically modified foods while strictly controlling them. In order to protect consumers' right to know, the Japanese government promulgated the Law on Labeling of Genetically Modified Foods, which formulated specific labeling measures for protein foods that use genetically modified agricultural products that have passed safety evaluation as the main raw materials and still retain recombinant DNA or its code after processing. At the same time, the Japanese Ministry of Science and Technology, the Ministry of Agriculture, Forestry and Fisheries and the Ministry of Health and Welfare jointly manage genetically modified technical matters, and regularly publish research and development materials of genetically modified foods and lists of genetically modified foods circulating in the market.
The management mode of foreign genetically modified food, whether cautious about genetically modified products or not, gives priority to information transparency and ensures consumers' full right to know, which is worth learning from the relevant legislation and law enforcement departments in China.
Fourthly, the current situation of Chinese consumers' right to know about genetically modified foods.
Our government attaches great importance to modern biotechnology and supports and encourages the research of genetically modified organisms and genetically modified foods. Article 23 of the Cartagena Protocol on Biosafety signed by China on August 8, 2000 stipulates that all parties shall solicit public opinions in the decision-making process of genetically modified organisms according to their own laws and regulations, and inform the public without violating confidential information; Parties shall make efforts to make the public aware of the public access to biosafety information. [4] On May 23, 20065438+0, the State Council issued the Regulations on the Safety Management of Agricultural Genetically Modified Organisms, which clearly stipulated that agricultural genetically modified organisms should implement safety evaluation system, label management system, production license system, business license system and safety approval system. As the highest and most comprehensive regulation of transgenic technology management in China, the information disclosure system and the right to know protection system are not among them.
Great achievements have been made in the legislation of protecting consumers' right to know about genetically modified foods in China, but there are also some drawbacks. If there is a lack of special biotechnology safety legislation, the level of legislation is not high, and information disclosure in important stages such as research, production and sales of transgenic technology appears? Vacuum management? , [5] leading to a serious lack of information disclosure system and informed consent system. Mandatory labeling of genetically modified foods is the most important means to protect consumers' right to know. However, with the rapid development of transgenic technology, the types of labels stipulated in the Measures for the Administration of Labeling of Agricultural Genetically Modified Organisms have not been updated and supplemented, and the management of tobacco and alcohol labels has not been refined and standardized, resulting in confusion of labels and extremely limited information disclosure, which greatly hinders consumers from fully exercising their right to know.
V. Measures to improve the protection system of consumers' right to know about genetically modified foods in China.
Chinese academic circles have also done a lot of research on the legal protection of consumers' right to know about genetically modified foods. Specifically, to improve the protection system of consumers' right to know about genetically modified foods in China, we should strengthen the following three key points:
First, strengthen the labeling management of genetically modified foods. Although the genetically modified labeling system has been implemented for many years, there are still many problems in the labeling of genetically modified foods. On the one hand, there are still many genetically modified foods that are not labeled; On the other hand, most of the existing labeled genetically modified foods do not meet the specifications. Therefore, the relevant state departments should strengthen the supervision of genetically modified food labeling in the future.
Second, emphasize the public's right to know and choose genetically modified foods. The public should have the right to know and choose the food they consume. Only by fully obtaining the right to know can the public enjoy the right to choose and protect their own rights and interests to the maximum extent. At present, the risks and harms of genetically modified foods are still unclear, and consumers are inevitably at a loss when choosing. Therefore, relevant government departments should improve the transparency of genetically modified information and public participation in safety management, such as increasing public hearing procedures when approving the environmental release and commercial production of genetically modified organisms.
Third, improve the detection and evaluation system of genetically modified foods. First of all, establish an independent authoritative testing institution to strictly test genetically modified foods to ensure their quality and safety, and gradually form a nationwide agricultural biotechnology management supervision and monitoring network system. Regularly publish the list of genetically modified foods for consumers' reference. Secondly, strictly control the production, processing, storage, transportation, sales, import and export of genetically modified foods to minimize safety risks. [6] Based on the actual situation in China, a set of feasible safety assessment system of genetically modified food was established, which put genetically modified food under standardized management and monitoring, so that consumers can safely eat genetically modified food. Third, we should strengthen law enforcement. For commercial production without declaration and approval, units and individuals who do not implement the labeling system for genetically modified foods should bear corresponding legal responsibilities to ensure the healthy development of the genetically modified food market.
Sixth, the conclusion.