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With the introduction of the central government's "orderly advancement of the industrialization of biological breeding", and the introduction of technical breakthroughs in seed sources, "gene editing" and other terms have once again attracted attention.
"Biological breeding includes gene editing technology, transgenic technology, and whole-genome selection technology. In my opinion, the most important thing is gene editing technology." December 29, 2020, Director of Shanghai Plant Stress Biology Research Center, Chinese Academy of Sciences, Member of the National Academy of Sciences Zhu Jiankang said at the 9th National Media GMO Reporting Salon that if the biological breeding technology is used well, my country's seed industry can catch up with the world and solve the bottleneck problem facing agriculture.
Many experts called for the supervision of gene editing breeding should not be managed in accordance with genetically modified breeding, and should be liberalized appropriately.
Is gene editing genetically modified?
Gene editing and genetic modification are often confused.
Li Jiayang, an academician of the Chinese Academy of Sciences and a researcher at the Institute of Genetics and Development of the Chinese Academy of Sciences, introduced that, as an example of writing an article, the editor modifies the check and inserts a large paragraph. This is genetically modified; and if only one or a few number words are modified, for example "Making an'important' contribution" was changed to "Making an'excellent' contribution", and a word was changed, which has no effect on the structure of the article, but the meaning is different. This is gene editing.
Li Jiayang said that by modifying a base or an amino acid in the gene, rice can change from hard rice to soft rice or even glutinous rice. Also by modifying genes, the research group of Gao Caixialu, a scientist from the Institute of Genetics and Development of the Chinese Academy of Sciences, applied the "CRISPR-Cas9" gene editing technology to achieve a major breakthrough in wheat resistance to powdery mildew.
"CRISPR-Cas9 is a tool, like gene scissors, an endonuclease that can cut DNA. The biggest magic is that you can cut where you want it to cut, and you can precisely locate the place that needs to be cut. After the gene is broken, the cell repairs and breaks. Errors occur in the emergency repair process. Most of the time, the error effect inactivates the gene, and the gene is mutated by shearing the gene, which is a subtraction." Zhu Jiankang Said that 99.9% of gene editing is done by subtraction.
Zhu Jiankang said that gene editing tools are biological mutagens. Compared with traditional chemical mutagenesis and physical mutagenesis, the principle is basically the same. They all cause DNA damage and DNA breakage, and genetic mutations occur during cell repair.
"Some people say whether the artificial manipulation of biological mutagens breaks the balance between cells and organisms and causes potential danger? In fact, it is not the case. What really breaks the balance and causes huge changes is traditional chemical and physical mutagenesis." Zhu Jiankang said, For example, the genome may be interrupted by nuclear radiation at thousands of sites, and gene editing is very precise in locating the sites that need to be changed.
According to Li Jiayang, the traditional breeding method selects the genes that we humans need through the domestication of crops, but the domestication process is very long; if humans can precisely edit and transform each gene, any wild thing can be edited with editing technology. Domesticating it is called artificial rapid domestication. "It used to be domesticated for thousands of years, but now it has been completed in a few years. What is more difficult to do may be successful in 10 years and 8 years. In short, it is very fast and effective."
Zhu Jiankang said that the difference between gene editing and genetic modification is that although the gene editing process requires the operation of gene transfer, the product of gene editing does not contain foreign genes in the end, and foreign tools can be used after editing. Separate out. "It is equivalent to a traditional mutagenic product. It does not contain foreign genes and is exempt from supervision in many countries."
How to regulate gene editing
"Gene (group) editing is the commanding height of the international breeding community." Li Jiayang said that if hybrid breeding is version 1.0, molecular marker breeding is 2.0, and transgenic breeding is 3.0, then gene (group) editing breeding is version 4.0.
Regarding this 4.0 version of the breeding method, Zhu Jiankang said that currently, the United States, Japan, Argentina, Israel, Chile, Brazil, Colombia, Honduras, Paraguay, Canada, Australia and other countries have regulations on gene-edited crops. If the actual product genome is If it does not contain new genetic material, it does not belong to the scope of supervision of genetically modified organisms. The European Union has not formulated corresponding regulations on gene editing products. The European Court of Justice ruled that gene editing products are regulated as genetically modified products. "But many EU countries disagree with this ruling and are doing research and studying this issue." Zhu Jiankang said.
There are different opinions in China on how to regulate gene editing breeding. Some people think that gene editing breeding is equivalent to conventional breeding, while others think that it should be managed in accordance with genetically modified breeding. At present, the domestic management of genetically modified organisms research and breeding is supervised in accordance with the "Regulations on the Safety Management of Agricultural Genetically Modified Organisms", from the experimental research stage, the intermediate test stage, the environmental release stage, the productive test stage, to the application for safety certificate and commercial production stage. All have clear and detailed regulations, requiring approval or filing. Conventional breeding does not have such strict requirements.
Zhu Jiankang believes that my country can manage gene-edited breeding in the same way as conventional breeding, because gene-edited crops are essentially equivalent to traditionally induced crops, and cannot be distinguished from traditional crops in terms of genetics and safety. Compared with traditional crops, there are additional risks. If some evaluation indicators are artificially set to evaluate its safety, it is meaningless.
Even from the perspective of the "Regulations on the Safety Management of Agricultural Genetically Modified Organisms", Zhu Jiankang still believes that gene editing breeding should not be managed in accordance with genetically modified breeding.
The Regulations on the Safety Management of Agricultural Genetically Modified Organisms stipulate that agricultural genetically modified crops refer to animals, plants, microorganisms and their products that are used in agricultural production or processing of agricultural products by using genetic engineering technology to change the composition of their genome.
Zhu Jiankang believes that after gene editing, the final exogenous tool can be separated, and only a subtraction is made on the genome composition. Can this simple modification be regarded as changing the genome composition? There was no gene editing at the time of genetic modification legislation. Concept, without this technology, "altering the genome composition" should be understood as introducing foreign gene sequences. Gene-edited crops are not managed in accordance with genetically modified crops and do not conflict with existing laws and regulations on genetically modified management.
Zhu Jiankang suggested that, as soon as possible, clear, scientific, and operable related regulations and policy measures for plant gene editing should be issued, that is, gene-edited crops without foreign genes should be treated as conventional breeding crops and not regulated as genetically modified. "(This can) enable my country's leading advantage in plant gene editing research and development to be transformed into product advantages and industrial advantages as soon as possible, and provide strong technical support for ensuring national food security, nutrition security, and ecological security."
Regarding the “stuck neck” problem that the core patent of “CRISPR-Cas9” gene editing technology is held in foreign hands, Zhu Jiankang said that this problem can be solved. "In addition to the foreign Cas9, the Cas12i and Cas12j discovered by Chinese scientists have laid a solid foundation for solving the "stuffed neck" technical problem in the field of life sciences. These two will soon have patent authorization to solve the "stuck neck" problem. Need to rely on foreign Cas9 patents or other Cas patents."
"my country has also done a lot of basic work in the industrial application of gene editing technology, and has a lot of very good accumulation. For example, our center has cooperated with Jinan City to build a gene editing industrialization platform in the past few years. A series of gene-edited new varieties have been improved through gene editing methods, including those with improved yield traits and improved quality.” Zhu Jiankang said, for example, the new rice varieties have increased the yield of more than 15% per mu, and the content of oleic acid. More than 80% of soybeans and 700 catties of quinoa per mu.
"Gene editing breeding can break the bottleneck of traditional breeding and achieve'precise breeding' and'precise nutrition'." Zhu Jiankang said, taking quinoa, which can meet the basic nutritional needs of the human body with a single food, as an example, it is expected to be able to cultivate a mu of yield in the next few years Qianjin variety