2. At the cellular level, a clone is essentially a population of cells formed by the division of a single ****same ancestor cell. Each of these cells is genetically identical. For example, a cell clone is a collective of cells with identical genetic backgrounds formed by dividing a cell in culture in vitro for several generations. Another example is that in vertebrates, when an exogenous agent (e.g., a bacterium or a virus) invades the body, specific recognizing antibodies are produced by an immune response. All of the plasma cells that produce a particular antibody divide from a single B cell, and such a population of plasma cells is also a cell clone. Cell cloning is a low-level form of reproduction- asexual reproduction, in which the offspring have the same heredity as the parent without the union of the sexes. The lower the level of biological evolution, the more likely it is that this type of reproduction will be practiced.
3. At the individual level, a clone is a group of two or more individuals with identical genotypes. For example, two identical twins are a clone! Because they come from the same egg cell, they have exactly the same genetic background. By this definition, Dolly is not a clone! Because Dolly is just one person. Only if the British embryologists were able to transplant more than two identical nuclei into more than two identical enucleated oocytes, resulting in more than two Dollys with identical genetic backgrounds, could the word "clone" be used. That's why the authors of the sensational paper, published in the February 1997 issue of Nature, did not describe Dolly as a clone.
Also, cloning can be used as a verb, meaning the process of acquiring the DNA, cells, or groups of individuals described above.
II. Cloning Technology
1. DNA Cloning
Now there are many different methods of DNA cloning, and the basic process is shown in the following diagram (not to scale)
It can be seen that the DNA obtained in this way can be used in many aspects of biological research, including the analysis of the base order of the specific DNA and processing, as well as the biotechnology industry, the mass production of valuable proteins and so on. the mass production of valuable proteins in the biotechnology industry, and so on.
2. Cloning of individual organisms
(1) Cloning of individual plants
In the 1950s, botanists used carrots as a model to study the loss of genetic material in differentiated plant cells, and they were surprised to find that a complete plant could be developed from a single highly differentiated carrot cell
! plant! From this, they concluded that plant cells have totipotency. The carrot population that developed from more than two somatic cells from a single carrot had exactly the same genetic background and was therefore a clone. The cloning process of such a plant is a completely asexual reproduction process!
(2) cloning of individual animals
①"Dolly" birth
February 27, 1997, Edinburgh, England, Roslin (Roslin) Institute of Ian Wilmot scientific research group to the world to announce that the world's first cloned sheep "Dolly" (Dolly) was born, the news immediately stirred the world.
"Dolly" is associated with three ewes. One was a Finnish Dorset ewe in her third month of pregnancy and two were Scottish Blackface ewes. Finnish Dorset ewes provide a full set of genetic information, that is, to provide the nucleus (called the donor); a Scottish black-faced ewes to provide a nucleus-free egg cell; the other Scottish black-faced ewes to provide the environment for the development of the sheep embryo - the uterus, is the "Dolly" sheep "Dolly" sheep. The other female Scottish black-faced sheep provides the environment for the development of sheep embryos - the uterus, which is the "birth" mother of the "Dolly" sheep. The whole cloning process is briefly described as follows:
From the mammary glands of the Finnish Dorset ewes to take out mammary cells, and put them into a low concentration of nutrient medium, the cells gradually stopped dividing, this cell is called the donor cell; to a Scottish black-faced ewe injected with gonadotropin, prompting it to ovulation, take out the unfertilized egg cells, and immediately remove the nucleus, leaving a nucleusless egg cells, this cell is called the recipient cell; this cell is called the recipient cell. This cell is called the receptor cell; using the method of electric pulse, the donor cell and the receptor cell are fused, and finally the fusion cell is formed, as the electric pulse can also produce a series of reactions similar to those in the natural fertilization process, so that the fusion cell can also undergo cell division and differentiation like a fertilized egg, thus forming the embryonic cell; transferring the embryonic cell to the uterus of another Scottish black-faced ewe sheep. The embryonic cells were then transferred to the uterus of another Scottish black-faced ewe, where they further differentiated and developed to form a lamb. The resulting "Dolly" lamb is identical to the Dorset ewe.
A year later, another group of scientists reported that transplanting the nucleus of a mouse oocyte (a highly differentiated cell that surrounds the periphery of the oocyte) into an oocyte with the nucleus removed resulted in more than 20 fully developed mice. If Dolly is not enough to be called a cloned sheep because there is only one, these mice
are truly cloned mice.
②Basic process of cloning mice by cell nuclear transplantation
In this experiment, the ovary cells were obtained through the following process: the female mice were induced into a state of high egg production by several consecutive injections of chorionic gonadotropin. The complex of oocytes and oocytes was then collected from the oviducts of female rats. The oocytes were dispersed by hyaluronic acid treatment. Oviductal cells with a diameter of 10-12 micrometers were selected to be used as nucleus donors (preliminary experiments showed that oocytes that underwent nucleus transplantation rarely developed to the 8-cell stage if nuclei from oviductal cells with smaller or larger diameters were used). The selected oocytes were kept in a certain solution environment and the nuclei were transplanted within 3 hours (in contrast to the mammary cells used as nucleus donors in the acquisition of "Dolly", which were first passaged 3-6 times in culture)
Oocytes (generally at meiosis II) were collected from female mice of different species by a method similar to that described above. The nuclei of the oocytes were carefully removed under the microscope with a fine tube of about 7 micrometers in diameter, trying not to remove the cytoplasm. The nuclei of the oocytes were similarly carefully removed, also trying to remove as much cytoplasm as possible (by making the removed nuclei move back and forth in the glass tube several times to remove the small amount of cytoplasm that was carried). Within 5 minutes after the nuclei were removed, they were injected directly into the oocytes from which the nuclei had been removed. Nucleus-transplanted oocytes were placed in a special solution for 1-6 hours, and then divalent strontium ions (Sr2+) and cytokinin repressor B were added, the former to activate the oocytes and the latter to inhibit polar body formation and chromosome exclusion. The treated oocytes were then removed and placed in a special solution without strontium and cytokinin inhibitor B to allow the cells to divide and form an embryo.
Embryos at different stages (from the 2-cell stage to the blastocyst stage) were implanted separately into the oviducts or uteri of pseudo-pregnant females that had mated with already ligated males a few days earlier to develop. Fully developed fetal rats were surgically removed after approximately 19 days.
Animals currently cloned by embryonic cell nuclear transfer include mice, rabbits, goats, sheep, pigs, cows and monkeys. In China, all the cloned animals except monkeys are available, and it is also possible to clone goats by successive nuclear transplants, a technique that goes further than embryo splitting and will result in the cloning of more animals. Because the more times an embryo is split, the fewer cells per part, the less capable the individual that develops. There is only one animal that has been cloned by somatic cell nuclear transfer, and that is the "Dolly" sheep.
Three, the gospel of cloning technology
1. Cloning technology and genetic breeding
In agriculture, people use "cloning" technology to cultivate a large number of drought-resistant, anti-fallout, pest-resistant high-quality high-yield varieties, greatly increasing food production. In this regard, China has stepped into the forefront of the world's most advanced.
2. Cloning technology and the protection of endangered species
Cloning technology for the protection of species, especially rare and endangered species is a gospel, has great prospects for application. From a biological point of view, this is one of the most valuable aspects of cloning technology.
3. Cloning and medicine
In the modern era, doctors are able to perform transplants on almost all human organs and tissues. But as far as science and technology are concerned, rejection in organ transplantation remains the biggest headache. The cause of rejection is poor compatibility due to tissue mismatch. If the organs of a "cloned human being" are provided to an "original human being" for organ transplantation, there is absolutely no fear of rejection because the two are genetically compatible and the tissues are compatible as well. The question is: Is it humane to use "clones" as organ donors? Is it legal? Is it economically viable?
Cloning technology can also be used to reproduce valuable genes in large quantities. In medicine, for example, it is through "cloning" that insulin has been produced for the treatment of diabetes, growth hormone to make people with dwarfism grow taller again, and stem cells that can fight a wide range of viral infections, among other things.
Clone is the phonetic translation of the English word clone, which is derived from the Greek word klone, meaning seedling or shoot, and is used in asexual or nutritive reproduction of plants, such as by pole insertion and grafting.
Today, cloning refers to the asexual reproduction of organisms through somatic cells, and to populations of genotypically identical offspring individuals formed by asexual reproduction. Cloning can also be understood as replication, copying, that is, the production of an identical replica from a prototype, which is identical in appearance and genetics to the prototype.
In February 1997, the birth of the sheep "Dolly" news disclosure, immediately attracted the attention of the world, this by the British biologists through the cloning technology of cloned sheep, means that human beings can use the animal body of a body cell, and the animal to produce exactly the same life form, breaking the millennia-old laws of nature.
What can be cloned?
It should be said that anything that has life can be cloned.
What has been cloned now?
Frog:1962, unsuccessful.
Carp: In 1963, Chinese scientist Tong Dizhou successfully cloned a female carp by injecting genetic material from a male into the eggs of a female, 33 years before Dolly the sheep was cloned. However, the paper was published in a Chinese-language scientific journal and was not translated into English, so it was not known internationally. (Source: PBS)
The ancient myth of the Monkey King, who used his own sweat to turn into countless little Monkeys, expressed mankind's fantasies about replicating themselves. 1938, German scientists first put forward the idea of mammal cloning, and after the birth of the somatic-cell cloned sheep Dolly in 1996, cloning quickly became the focus of world attention. After the birth of the somatic cell cloned sheep "Dolly" in 1996, cloning quickly became the focus of the world's attention, and people could not help but ask: Will we follow the sheep? This doubt has made all of us anxious and uneasy. However, the clamor against cloning did not offset the persistent pursuit of scientists, along with cattle, rats, pigs and even monkeys, which are the most similar to human biological characteristics of primates have been successfully cloned one after another, people already believe that one day, scientists will use a human cell to duplicate a person exactly the same as the person who provided the cell, cloning is no longer a dream in science fiction, but a reality that is on the verge of coming out. At present, there have been three foreign organizations officially announced that they will carry out experiments in human cloning, the United States University of Kentucky, Professor Zavos is working with an Italian expert named Antinori, plans to clone a person within two years.
Since human cloning may bring complex consequences, some biotechnology developed countries, most of them now take this explicitly prohibited or severely restricted attitude. Clinton said, "To clone human beings through this technology is dangerous and should be eliminated!" Hong Guofan, a member of the National Committee of the Chinese People's Political Consultative Conference (CPPCC) and director of the National Genetic Research Center of the Chinese Academy of Sciences (CAS), also made it clear that he was opposed to conducting research on human cloning, and instead advocated distinguishing between cloning technology and human cloning.
Is human cloning really as scary as the devil in Pandora's box?
In fact, the most important reason why people cannot accept human cloning experiments lies in the obstruction of traditional ethical and moral concepts. For thousands of years, human beings have followed a sexual reproduction method, while human cloning is a product of the laboratory, a life created under human manipulation. Especially in the West, cloning, which "abandons God and separates Adam and Eve," is opposed by many religious organizations. Moreover, the relationship between the clone and the cloned person is contrary to the traditional ethical way of determining kinship by blood. All these make it impossible for clones to find a suitable place in the traditional human ethics. However, as Dr. He Joao, an academician of the Chinese Academy of Sciences, said, "The ethical problems arising from human cloning should be faced squarely, but there is no reason to oppose scientific and technological progress for this reason." The development of human society itself tells us that it is historical progress for science and technology to drive the updating of people's concepts, while it is rigidity to fetter the development of science and technology with obsolete concepts. Historically, blood transfusion technology and organ transplantation have brought about great ethical debates, and when the first test-tube baby was born in 1978, it even set off an uproar, but now, people have been able to deal with all this correctly. This shows that the constant updating of ideological concepts in the face of scientific and technological development has not brought disaster to mankind; on the contrary, it has benefited mankind. As far as cloning technology is concerned, "therapeutic cloning" will bring about breakthroughs in the production of transplanted organs and in overcoming diseases, revolutionizing biotechnology and medical technology. For example, when your daughter needs a bone marrow transplant and no one can provide it for her; when you have unfortunately lost your 5-year-old child and cannot get rid of the pain; when you want to raise your own child but cannot give birth to a child ...... perhaps you will be able to realize the great scientific value and practical significance of cloning. Research on therapeutic cloning and experiments on complete human cloning are complementary and mutually reinforcing. The end point of therapeutic cloning is the emergence of complete human clones, and if utilized correctly, they can and should both bring a blessing to human society.
Science has always been a double-edged sword. But whether a particular technological advancement is truly beneficial to mankind depends on how mankind treats and applies it, rather than choking on it just because it is temporarily unconscionable. It is true that cloning technology, like atomic energy technology, can benefit mankind as well as cause infinite harm. However, the essence of "technophobia" is the fear of the wrong application of technology, not the fear of technology itself. At present, the attitude of countries around the world towards human cloning is mostly "ambiguous". Last year, the United Kingdom passed a bill allowing the cloning of early human embryos with a majority of more than two thirds of the votes cast, and in the United States, Germany and Australia, we have gradually heard voices calling for the relaxation of the restrictions on therapeutic cloning. It can be said that whichever country is the first to master the technology of human cloning means that this country possesses an advantage and takes the initiative, while the country that starts late may suffer losses that cannot be predicted now as a result. As in the case of the United States, it was the first country to master the atomic energy technology, and although this technology showed its sinister side from the very beginning, all countries had to step up their research and experiments in this respect later on. From this point of view alone, it is also worthwhile to discuss the simple negative attitude towards human cloning experiments.
As for people's concern that once the cloning technology is matured, there will be ill-intentioned people who will clone a thousand "Hitlers" or another celebrity to confuse the public, it is a misunderstanding of cloning. Clones are only copied genetic characteristics, but by the acquired environment, many factors affect the thinking, personality and other social attributes can not be exactly the same, that is, no matter how the development of cloning technology, can only clone the human body, but can not clone the human soul, and the clone and the cloned people have an age gap between them. Therefore, the so-called clone is not an exact copy of the person, historical figures will not be resurrected, and real people do not have to worry about an additional "self".
Sheep:1996, Dolly
Macaques:January 2000, Tetra, female
Pigs:March 2000, five Scottish PPL piglets; August, Xena, female
Cattle:2001, Alpha and Beta, males
Cats:2001, CopyCat (C), end of year. End of year, CopyCat (CC), female
Rat:2002
Rabbit:March-April 2003, independently realized in France and Korea, respectively;
Mule:May 2003, Idaho Gem, male; June, Utah Pioneer, male
Deer:2003, Dewey
Horse. Prometea, female, 2003
Dog: Snappy, Seoul National University Experimental Team, Korea, 2005
Despite the advances in cloning research, the current success rate of cloning is still quite low: Dolly's birth was preceded by 276 unsuccessful attempts on the part of the researchers; the births of the 70 calves came after 9,000 attempts to be successful, and one-third of them were born at a young age. It took 9,000 attempts for 70 calves to be born and a third of them died at a young age; Prometea took 328 attempts to be born. For some species, such as cats and orangutans, there are no reports of successful cloning. In the case of dog cloning, it took hundreds of repeated attempts.
An age test after Dolly's birth showed she was born old. By the time she was 6 years old, she had developed arthritis, which is usually found in old age. Such aging is thought to be caused by wear and tear on telomeres. Telomeres are chromosomes located at the ends. As cells divide, telomeres wear out during replication, which is usually thought to be a cause of aging. However, researchers who cloned successful cows found that they were actually younger. Analyzing their telomeres showed that not only were they back to their birth length, but they were longer than the telomeres that are typically found at birth. This means they can live longer than the average cow, but many of them die prematurely due to overgrowth. The researchers believe related studies could eventually be used to change human lifespans.
Human cloning violates human life ethics
Modern science and technology, especially modern life science and technology, should we respect ethical principles and listen to ethical voices? Relevant experts pointed out in response to some science maniacs in the United States secret human cloning - human cloning contrary to the ethics of human life, there is a great controversy and difficult to solve a series of legal and other issues.
Many media in China have recently reprinted a shocking news reported by foreign media: a group of scientific maniacs manipulated by cult organizations are conducting a secret experiment of human cloning in the depths of the desert in Nevada, the United States. Based on the same principle used by British scientists to create the world's first cloned sheep, "Dolly," they are extracting cells from a 10-month-old American baby girl who died in February of this year to create a human clone. "If things go well, the world's first human clone will be born by the end of next year," it said.
After the news was disclosed, cloning technology and the ethical issues it raises once again became a hot topic of discussion. If this news is true, how should we look at this matter, how to correctly evaluate and think about this issue, the reporter visited the National Human Genome South Research Center, director of the Ethics, Law and Society Department, the Shanghai Academy of Social Sciences Institute of Philosophy Shen Mingxian researcher.
Professor Shen said: Since 1997, when the Rosslyn Institute in the UK successfully cloned the "Dolly" sheep, there have been people abroad who have proposed and attempted to engage in human cloning research, driven by fame and fortune. Although governments have explicitly prohibited it, human cloning-related reports have appeared in the press more than once in the past two years. However, it is indeed shocking that this time it is so fast and linked to a cult organization.
It is understandable that parents who have lost their daughters would want to bring them back to life through cloning. But if scientists use it to conduct experiments on human cloning, it is worth discussing. Prof. Shen believes that even if we put aside the cult, this practice is not desirable. As far as the individual "clone" is concerned, he will live in the shadow of "I am a replica of a dead person", what kind of effect will this have on his psychology?
According to bioethics, science and technology should be used for the long-term benefit of all mankind. It must follow the four internationally recognized ethical principles of "doing good, doing no harm, autonomy and justice". The successful cloning of the "Dolly" sheep has gone through more than 200 failures, and there have been deformed or aborted sheep. Human cloning is even more complex and will undoubtedly encounter more failures, and it would be a violation of human rights if unhealthy, deformed or short-lived people were created.
The diversity of human genes is the biological basis of human evolution, and the so-called "immortal life" that those science fanatics want to create is actually a replica of the same gene, which may reduce the diversity of genes, and is not conducive to the evolution of human beings themselves. Therefore, human cloning should be firmly opposed, whether from the perspective of the individual, the whole, or from the perspective of social evolution and bioethics.
Professor Shen pointed out that the scientific community now divides cloning into two kinds: therapeutic cloning and reproductive cloning. The former is the use of embryonic stem cells to clone human organs for medical research and to solve the problem of insufficient organ transplantation donors, which is supported by both the international scientific community and the ethical community, but there is a prerequisite, that is, the embryos used for therapeutic cloning can not be beyond the limit of 14 days of pregnancy. As for reproductive cloning, commonly known as human cloning, the mainstream opinion of scientists is firmly against it because it violates the principle of bioethics in general. The United Nations Educational, Scientific and Cultural Organization (UNESCO), the World Health Organization (WHO) and the International Human Genome Ethics Committee (IHGE), as well as the governments of various countries, have also made it very clear that they are against reproductive cloning. Even if clones are really born, we still have to stick to this basic position.
Modern science and technology is a double-edged sword, and while it benefits mankind, it also brings some negative effects. This raises a question to us: should modern science and technology, especially modern life science and technology, respect the principle of ethics and listen to the voice of ethics? Prof. Shen pointed out that: nowadays, some scientists propose that as long as it is scientifically possible to do so, it should be done. In fact, this is the wrong view. If it is technically possible for us to create a kind of super-life that would seriously jeopardize mankind, is it also possible to go ahead and do it? It is under the banner of "scientific freedom" that some science nuts do things that are harmful to mankind. Therefore, we have to be vigilant against modern science and technology being utilized by people with ulterior motives. In addition, we should not oppose scientific freedom to ethics and morality. The facts of the development of modern life sciences show that the regulation and guidance of ethics have not fettered the development of science, and listening to the voice of ethics is conducive to the healthier and smoother development of science.
Nowadays, there are various ways to carry out DNA cloning, and the basic process is shown in the following diagram (not to scale)
It can be seen that the DNA thus obtained can be applied to many aspects of biological research, including the analysis and processing of the base order of specific DNA, and the mass production of valuable proteins for the biotechnology industry, and so on.
2. Cloning of individual organisms
(1) Cloning of individual plants
In the 1950s, botanists used carrots as a model material to study whether the genetic material was lost in the differentiated plant cells, and they were amazed to find that a complete plant could be developed from a single carrot cell that had already been highly differentiated
. plant! From this, they concluded that plant cells have totipotency. The carrot population that developed from more than two somatic cells from a single carrot had exactly the same genetic background and was therefore a clone. The cloning process of such a plant is a completely asexual reproduction process!
(2) cloning of individual animals
①"Dolly" birth
February 27, 1997, Edinburgh, England, Roslin (Roslin) Institute of Ian Wilmot scientific research group to the world to announce that the world's first cloned sheep "Dolly" (Dolly) was born, the news immediately stirred the world.
"Dolly" is associated with three ewes. One was a Finnish Dorset ewe in her third month of pregnancy and two were Scottish Blackface ewes. Finnish Dorset ewes provide a full set of genetic information, that is, to provide the nucleus (called the donor); a Scottish black-faced ewes to provide a nucleus-free egg cell; the other Scottish black-faced ewes to provide the environment for the development of the sheep embryo - the uterus, is the "Dolly" sheep "Dolly" sheep. The other female Scottish black-faced sheep provides the environment for the development of sheep embryos - the uterus, which is the "birth" mother of the "Dolly" sheep. The whole cloning process is briefly described as follows:
From the mammary glands of the Finnish Dorset ewes to take out mammary cells, and put them into a low concentration of nutrient medium, the cells gradually stopped dividing, this cell is called the donor cell; to a Scottish black-faced ewe injected with gonadotropin, prompting it to ovulation, take out the unfertilized egg cells, and immediately remove the nucleus, leaving a nucleusless egg cells, this cell is called the recipient cell; this cell is called the recipient cell. This cell is called the receptor cell; using the method of electric pulse, the donor cell and the receptor cell are fused, and finally the fusion cell is formed, as the electric pulse can also produce a series of reactions similar to those in the natural fertilization process, so that the fusion cell can also undergo cell division and differentiation like a fertilized egg, thus forming the embryonic cell; transferring the embryonic cell to the uterus of another Scottish black-faced ewe sheep. The embryonic cells were then transferred to the uterus of another Scottish black-faced ewe, where they further differentiated and developed to form a lamb. The resulting "Dolly" lamb is identical to the Dorset ewe.
A year later, another group of scientists reported that transplanting the nucleus of a mouse oocyte (a highly differentiated cell that surrounds the periphery of the oocyte) into an oocyte with the nucleus removed resulted in more than 20 fully developed mice. If Dolly is not enough to be called a cloned sheep because there is only one, these mice
are truly cloned mice.
②Basic process of cloning mice by cell nuclear transplantation
In this experiment, the ovary cells were obtained through the following process: the female mice were induced into a high egg-laying state by several consecutive injections of chorionic gonadotropin. The complex of oocytes and oocytes was then collected from the oviducts of female rats. The oocytes were dispersed by hyaluronic acid treatment. Oviductal cells with a diameter of 10-12 micrometers were selected to be used as nucleus donors (preliminary experiments showed that oocytes that underwent nucleus transplantation rarely developed to the 8-cell stage if nuclei from oviductal cells with smaller or larger diameters were used). The selected oocytes were kept in a certain solution environment and the nuclei were transplanted within 3 hours (in contrast to the mammary cells used as nucleus donors in the acquisition of "Dolly", which were first passaged 3-6 times in culture)
Oocytes (generally at meiosis II) were collected from female mice of different species by a method similar to that described above. The nuclei of the oocytes were carefully removed under the microscope with a fine tube of about 7 micrometers in diameter, trying not to remove the cytoplasm. The nuclei of the oocytes were similarly carefully removed, also trying to remove as much cytoplasm as possible (by making the removed nuclei move back and forth in the glass tube several times to remove the small amount of cytoplasm that was carried). Within 5 minutes after the nuclei were removed, they were injected directly into the oocytes from which the nuclei had been removed. Nucleus-transplanted oocytes were placed in a special solution for 1-6 hours, and then divalent strontium ions (Sr2+) and cytokinin repressor B were added, the former to activate the oocytes and the latter to inhibit polar body formation and chromosome exclusion. The treated oocytes were then removed and placed in a special solution without strontium and cytokinin inhibitor B to allow the cells to divide and form an embryo.
Embryos at different stages (from the 2-cell stage to the blastocyst stage) were implanted separately into the oviducts or uteri of pseudo-pregnant females that had mated with already ligated males a few days earlier to develop. Fully developed fetal rats were surgically removed after approximately 19 days.
Animals currently cloned by embryonic cell nuclear transfer include mice, rabbits, goats, sheep, pigs, cows and monkeys. In China, all the cloned animals except monkeys are available, and it is also possible to clone goats by successive nuclear transfer, a technique that goes further than embryo splitting and will result in the cloning of more animals. Because the more times an embryo is split, the fewer cells per part, the less capable the individual that develops. There is only one animal that has been cloned by somatic cell nuclear transfer, and that is the "Dolly" sheep.
Three, the gospel of cloning technology
1. Cloning technology and genetic breeding
In agriculture, people use "cloning" technology to cultivate a large number of drought-resistant, anti-fallout, pest-resistant high-quality high-yield varieties, greatly increasing food production. In this regard, China has stepped into the forefront of the world's most advanced.
2. Cloning technology and the protection of endangered species
Cloning technology for the protection of species, especially rare and endangered species is a gospel, has great prospects for application. From a biological point of view, this is one of the most valuable aspects of cloning technology.
3. Cloning and medicine
In the modern era, doctors are able to perform transplants on almost all human organs and tissues. But as far as science and technology are concerned, rejection in organ transplantation remains the biggest headache. The cause of rejection is poor compatibility due to tissue mismatch. If the organs of a "cloned human being" are provided to an "original human being" for organ transplantation, there is absolutely no fear of rejection because the two are genetically compatible and the tissues are compatible as well. The question is: Is it humane to use "clones" as organ donors? Is it legal? Is it economically viable?
Cloning technology can also be used to multiply valuable genes, for example, in medicine, it is through the "cloning" technology to produce insulin to treat diabetes, growth hormone to make dwarfism patients grow taller again, and can be resistant to a variety of viral infections of the stem flexin, and so on.