Human cloning in China. Towards a cure for cancer and the possibility of human cloning: Scientists in China have made a breakthrough in cloning monkeys. End justifies the means

Scientists at the Institute of Neuroscience of the Chinese Academy of Sciences in Shanghai were the first to clone monkeys using technology that produced the first ever cloned animal, Dolly the sheep, in 1996. Although 23 species of mammals have since been cloned - including pigs, cats, dogs, rats, cows and camels - until now monkeys have been immune to such experiments.

Monkeys have enormous potential because they inherit exactly the same genetic material as humans, the Chinese research team explains. It is expected that scientists will be able to correct in individual monkey clones those genes that are responsible for the corresponding diseases in humans, and monitor how this changes the biology of animals compared to unchanged identical clones. This should speed up the hunt for genes that cause a specific disease and allow selection effective methods their corrections.

As you know, in 2000, researchers cloned monkeys for the first time, but they did this by dividing the embryos after fertilization - that is, in essence, they were genetically identical twins. However, this method can only be used to create a maximum of four identical animals. And the “Dolly technology,” based on somatic cell nuclear transplantation (when the nucleus is removed from a donor egg and replaced with a nucleus from a cell of another animal), makes it possible to create a theoretically unlimited number of clones.

In order to deceive the egg, making it understand that it has already been fertilized, it is used electricity. The early embryo is implanted into the surrogate mother's uterus, becoming a copy of the animal that donated its nucleus. Previous attempts to do this with monkeys have not gone beyond the early embryonic stage (blastocyst).

But Dr. Qiang Sun and his colleagues at the Institute of Neuroscience were able to make significant progress by introducing two new ingredients into the diet of the embryos, which helped them become strong enough before they were implanted with a surrogate mother. As explained, these ingredients - messenger RNA and the compound trichostatin A - allowed the stimulation of at least 2,000 genes that are vital for various stages of embryonic development.

During experiments by Chinese scientists, a total of 79 embryos were implanted into 21 surrogate mothers. And the couple Zhong-Zhong and Hua-Hua turned out to be the only live births during six pregnancies. Dolly the sheep, by comparison, was the only success out of 277 implanted embryos. Let's remember that Dolly died in 2003 at the age of six - veterinarians had to euthanize her after a veterinary examination revealed signs of a progressive pulmonary disease.

Those who recently presented a project for the world's largest “clone factory” declare their readiness to clone people. The only obstacle to this, according to the Chinese, is the public reaction.

As reported, Xu Xiaochun, executive director of the future cloning center, spoke about large-scale plans in the field of cloning. Note that the world's largest cloning enterprise is going to be built in North China's Tianjin. The creation of the center will be carried out by the Chinese company Boyalife Group in collaboration with the South Korean Sooam Biotech Research Foundation, as well as the Chinese Academy of Sciences.

It is expected that this enterprise will begin to operate within the next seven months. According to plans, by 2020 the production volume of cloned cows will be one million animals per year. Also in the future, the “clone factory” is going to produce horses for racing and police dogs with specialized characteristics (increased sense of smell and search).

In addition, another area of ​​interest of this enterprise is cloning for medical experiments of primates. In this regard, the statement by the leaders of the future factory regarding their readiness to move from cloning primates to humans is quite logical.

According to Xu Xiaochun, the technology for human cloning already exists. The executive director also noted that if this is allowed, it is unlikely that anyone will be able to cope with this better than Boyalife. At the same time, the executive director drew attention to the fact that at present the company’s scientists are not carrying out any experiments in the field of human cloning.

begins large-scale cloning.

Let us recall that it was previously reported that in Chinese city Tianjin is going to build the world's largest animal cloning center, whose employees will “release” cows, horses and even rare breeds dogs.

As one of the Chinese media reported, citing a statement by the Economic and Technological Development Committee of the administration of the mentioned city, the initial investment in the creation of the center will be 200 million yuan (more than $31 million). This center will create special laboratories, gene and even exhibition halls. At the same time, the officially stated purpose of creating such a center was the development of livestock farming in the state.

The Committee signed a strategic agreement with the management of Yingke Boya Gene Technology, which is a subsidiary of Boyalife Group (one of the leading Chinese enterprises in the field of biological medicine and stem cells). Also participating in the project will be the South Korean company Sooam Biotech Research Foundation, with which Chinese researchers previously collaborated during dog cloning experiments. By the end of this year, this Korean company intends to clone 550 dogs for airport customs services.

As you know, the People's Republic of China, together with South Korea, are the leaders in the Asian genetic research market. So, in 2004, a gene bank was created in which panda cells began to be collected in order to preserve this species of animal from destruction.

In addition, Chinese scientists began developing the technology of cloning cows for industrial purposes. At the end of the summer of this year, the Chinese cow Niu Niu, which was the result of cloning and genetic modifications, was able to give birth to an absolutely healthy calf. This cow was one of two clones of cows that were created in 2012 with a genome that promotes more fat in the muscles. According to researchers, this was the state's first step towards starting its own production of marbled beef. The results of testing a newborn calf showed that the goal of increasing the proportion of fat in total body weight was achieved. In addition, a calf born from a cloned cow showed significantly less susceptibility to the negative influences of the surrounding world than its “natural” counterparts.

At the same time, there is a very ambiguous attitude outside to conducting experiments on animal cloning in order to saturate the market with meat. Thus, on September 8 of this year, the European Parliament approved a decision regarding a complete ban on the cloning of all types of farm animals without exception. The European Parliament also banned the sale of livestock obtained as a result of cloning, as well as its offspring and any products that were obtained from it.

As one of the scientific publications reported then, new measure The European Parliament goes beyond the scope of the directive adopted earlier (in 2013). This directive prohibited the cloning of only five types of farm animals: horses, cows, pigs, sheep and goats. However, the European Parliament's ban does not apply to the use of cloning for research purposes or to attempts to restore populations of endangered animals using cloning technology.

Dozens of human embryos cloned in China
11.06.2002 |
________________________________________
Chinese scientists claim that they have achieved great success in human cloning - cloning dozens of embryos that developed into sufficiently- so that samples of embryonic stem cells can be taken from them.

Their goal is not to "copy" human beings, but only. No scientific journal has yet published articles on this kind of work, but on Thursday, Liu Guangjiu from medical institute Jiangia spoke about her research to The Wall Street Journal. Experts who are aware of its activities say that three or four other Chinese laboratories have achieved comparable achievements.

One of these teams works in the Second Shanghai Medical University. Scientists say they have been able to isolate stem cells from hybrid embryos created from human cells and a rabbit egg.

Jiangzong "Jerry" Yang, a Chinese cloning expert now at the University of Connecticut, said he has long been aware of the successes of Chinese scientists.

“These are amazing people,” he says. “I advised them to publish the results of their work in scientific journals to gain recognition so that the world knows about their achievements."

Those who have taken the lead

The report confirms the concerns of many cloning experts, who have warned that political and ethical concerns are holding back progress. research work in the US and UK, the rest of the world may pull ahead.

"It makes no sense to talk about how we can stop the technology by passing laws," said Robert Lanza of the Laboratory of Advanced Cell Technologies in Massachusetts.

This is not the first time information about human cloning experiments has appeared. In 1998, scientists South Korea stated that they were able to clone an embryo that was able to reach the four-cell stage of development. The company Clonaid, created by ufologists, also reported success in this work.

The Advanced Cell Technologies Laboratory recently published a paper announcing that it is cloning human embryos to produce embryonic stem cells (ESCs). It turned out that this was impossible. Their embryos were capable of dividing into very Not a large number of cells.

Liu's team stated that they were able to reach the two-hundred-cell blastocyst stage of development, which already makes it possible to isolate ESCs. Lanza says he is not at all surprised by the success of his Chinese competitors.

"Cloning is a game large numbers, he explains. “They have access to more material.” The essence of the cloning process is as follows: all the genetic material is removed from the egg; then the nucleus of a donor cell is introduced into it. In the United States, it is quite difficult to obtain a human egg and obtain permission, so the laboratory of modern cell technologies was able to create a total of 19 embryos.

Remnants of eggs

In China the rules are much less strict. Liu, who runs a large fertility center, simply asks some of the patients who come into her office every day to act as egg donors. She claims that five percent of the embryos she cloned reached the blastocyst stage.

From these embryos they managed to select cells - in their opinion, these are ESCs - and grow them in laboratory conditions. ESCs are capable of transforming into any type of cell found in human body.

If confirmed, these findings represent a significant step forward, although it is not yet known whether the cells they grow have any medical value or whether they are truly ESCs.

Many human cells are capable of dividing in vitro over several developmental cycles. To convince scientists that she has succeeded in producing hESCs, Liu will have to grow the cells for many cycles, which could take as long as a year. In addition, she will have to confirm that
the molecular structure of the cells she selected corresponds to ESCs

Source - Orthodox Medical Server

For the first time, cynomolgus macaques (Macaca fascicularis) were cloned using the same method that led to the birth of Dolly the sheep. This gave biologists the opportunity to clone primates, including humans. Lenta.ru talks about a study published in the journal Cell.

This has never happened before

Thanks to the efforts of scientists, two females were born - Zhong Zhong and Hua Hua. Both females are healthy and currently living in the incubator. The age difference between them is one week, but both macaques are genetically identical copies: they were obtained from the same culture of embryonic monkey cells.

In fact, these macaques are not the world's first cloned monkeys. In 1999, researchers cloned a rhesus monkey by splitting the primate's embryo into multiple pieces to create identical twins. In other work, cloned monkey cells were used to create stem cell lines. However, all this was done exclusively in Petri dishes, and obtaining developed monkeys was not part of the scientists’ plans.

Why are cloned monkeys considered a big breakthrough in 2018? The fact is that for this purpose a technique called somatic cell nuclear transfer was used. Unlike embryo cleavage, this method, in theory, allows you to obtain an unlimited number of clones from a single donor. And what could be more convenient for biomedical research than a genetically homogeneous population of primates close to humans?

Since Dolly the Sheep, scientists have cloned 23 species of animals, including dogs, cats, rabbits, pigs and cows. However, obtaining genetically identical primates means that in principle we can also obtain human clones (even though macaques are not apes like gorillas or chimpanzees). However, scientists assured that they have no goal of cloning people.

Benefits all around

Naturally, among people who are far from science and opponents of cloning, suspicions may arise that scientists have decided to once again encroach on the laws of nature for a reason - perhaps they will deliberately or accidentally create some kind of biological weapon that will ultimately destroy humanity. However, one should not forget that general level The mortality rate of people, including all kinds of opponents of biotechnology (from anti-vaxxers to GMO-phobes) at the end of the 20th - beginning of the 21st century decreased significantly precisely thanks to the achievements of biology and medicine. Although many people have unfounded fears about cloning, this method will give scientists unprecedented opportunities to create new drugs.

We are talking primarily about creating convenient model organisms. Macaques are used for research in medicine, neuroscience and behavior. Their genome is 93 percent identical to that of humans (our common ancestor lived 25 million years ago), and the differences are largely due to genomic rearrangements rather than individual mutations. In other words, the human genome is a kind of anagram of the macaque genome. At the same time, those gene variants that are normal in macaques can cause diseases in humans, for example, phenylketonuria.

Cloning allows you to obtain pure lines, that is, groups of genetically homogeneous organisms. This can be achieved through crossing, but for monkeys with their relatively for a long period During maturation, this method is impractical. Clones are very convenient for drug testing. Imagine that you have several dozen primates and you randomly divide them into two groups. You give the animals in one group medicine and the animals in the other a pacifier. It would seem that if the drug is effective, then the health of the primates in the first group should improve. But in fact, the result may be masked by genetic differences. Thus, some animals may be immune to the medicine or, conversely, be too sensitive, which will cause their death. For reliable results, you have to use large groups of animals, which is difficult and expensive, but clean lines solve this problem.

Often animal models in medical research genetically prone to developing diseases similar to human ones: cancer, different kinds dementia, Parkinson's disease, inherited disorders or autism. It is on them that new ones are tested therapeutic methods. Cloning will allow researchers to be sure that all animals in a group will definitely develop a particular disease because of their identity.

She's not your Dolly

Cloning using the somatic cell nuclear transfer method is carried out as follows. The nucleus is removed from an unfertilized egg, after which the nucleus from a somatic cell is transplanted into it, for example, from a fibroblast (cell connective tissue) embryo. The method was developed in 1996, when Scottish biologists led by Ian Wilmut were able to clone Dolly the sheep. Breast epithelial cells were used as nuclear donors. However, not all of the eggs to which the nuclei were transplanted survived. It took about three hundred attempts to get a healthy embryo.

The difficulty with cloning monkeys is that for each species protocols must be developed for chemical treatment of the DNA of the donor nucleus in order to “rejuvenate” it. Early attempts at nuclear transfer in primates failed precisely because of improper reprogramming of the donor cells. However, it later turned out that the efficiency of transplantation can be increased using a number of chemical substances, blocking the activity of histone deacetylase enzymes. In addition, DNA regions resistant to reprogramming were identified - they contained high level methyl groups that prevent gene activation.

As easy as pie

To understand what exactly the scientists did, you only need to know the very basics of epigenetics. Proteins are called histones various types, uniting into a globule (nucleosome), around which a piece of DNA is wound in 1.67 turns. One strand of DNA contains a large number of nucleosomes, which influence the packing density of genetic material and gene activity. They do this with the help of four tails protruding from two histones H3 and two histones H4. TO different areas Both methyl (methylation) and acetyl (acetylation) groups can be attached to these tails.

There are a great variety of types of histone methylation, in which from one to three methyl groups are attached to different parts of the tails. In methylation, referred to as H3K9me3, three groups (me3) are added to the ninth-to-last amino acid, which is lysine (K), found on the tail of histone H3. In the DNA region enriched with H3K9me3, genes are usually blocked. Acetylation occurs in a similar way, but on the contrary, it promotes gene activation.

Acetylation and methylation are necessary for cell differentiation, when embryonic stem cells choose their “professions”. In this case, some genes are turned on and others are turned off. It turned out that H3K9me3 protects genes that are not needed by the fibroblast from reactivation, which is the main obstacle to reprogramming. To solve this problem, scientists used trichostatin A, which promoted histone acetylation, and also introduced an RNA molecule encoding histone demethylase, an enzyme that removes methyl groups from histones, into eggs with an already transplanted nucleus.

A total of 127 eggs were used. Scientists were able to obtain 109 embryos, but only 79 of them were transplanted into the uterus of 21 female cynomolgus monkeys. Pregnancy was confirmed in only four animals, but only two monkeys gave birth to healthy babies.

Do not panic

When it comes to the new possibilities of biotechnology, those who see it as nothing more than an attack on ethical standards come to the scene. Organizations advocating for the protection of animals generally consider experiments on animals (especially those similar to humans) unacceptable - apparently forgetting the fact that it was thanks to animals that humanity defeated dangerous infectious diseases, including smallpox, which killed millions of people. Many medical breakthroughs would not have happened without the use of animal models.

Some scientists, such as neuroscientists and ethologists, believe that animals can be replaced to some extent by computer models, but the technology does not yet exist to simulate whole organism and the effect of drugs on it. Even tissue cultures (or organs grown “in vitro”) cannot replace an animal, since these objects will react to drugs in completely different ways. So the question of whether it is necessary to conduct experiments on living beings in order to develop medicine requires a perhaps uncomfortable but honest answer: now these experiments are necessary.

Should we be afraid of human cloning? It may be possible to make genetically identical copies of people in a few years, although it is worth considering why this would be done? It is very difficult to take DNA from an adult and make a copy of it in the form of a baby - without a perfected technique for reprogramming somatic cells, the entire biological material from the donor will go into the trash bin. Spending money on copies of the same human embryos is simply not practical yet. But cloning Hitler, Jesus Christ or a dinosaur, from which there are no cells with nuclei left, is possible only in the genre of science fiction.

BEIJING, July 13 - RIA Novosti, Zhanna Manukyan, Anna Ratkoglo. Since British scientists managed to clone the famous sheep Dolly in 1996 using the cells of an adult animal, science has made great strides forward and dozens of different animals have been created artificially; Last week the world learned about the world's first dog, Lun Lun, bred from a somatic cell using gene knockout.

RIA Novosti correspondents visited the laboratory of the Beijing biotechnology company SinoGene, where Lun Lun was born, to find out why Chinese scientists chose a dog and for what purpose they decided to modify the genome four-legged friend person.

The very small SinoGene laboratory is located in one of the remote industrial parks in the north of Beijing. A fact-finding tour for journalists was held CEO company Mi Zidong and his deputy Zhao Jianping, who promised that you can not only look at the dog, but also touch it. To the surprise of the correspondents, not only Lun Lun was in the laboratory, but also two more clones absolutely identical to him.

Meet Lun Lun

There were two cages in a small sterile room. In one of them there was Lun Lun and his surrogate mother, in the second there were two more clones with another dog who carried them. All three puppies did not inherit the genes of their surrogate mothers, but are clones of the Beagle dog Pingo ("Apple"), bred at SinoGene in December 2016. Pingo became the world's first dog bred using gene editing. Lun Lun was born on May 28th, and the two younger clones were born on June 14th. As Zhao Jianping said, tests showed that all three animals are 99.9% similar.

U ordinary person the very expression “cloned genetically modified dog” may cause ambiguous associations, however, Lun Lun and his clones, with their behavior and appearance They are no different from ordinary puppies. They ran out of the cages without showing any fear or aggression towards strangers, and allowed themselves to be stroked and picked up.

Names for the new clones have not yet been invented, but, as Mi Zidong assured, the decision, as in the case of Long Long, will be made on the basis of consensus. Lun Lun translated from Chinese language means "dragon", and this animal occupies a special place in Chinese culture.

Superdog?

Breeding one cloned GMO dog takes from two to several months. As Mi Zidong said, in one experiment scientists are trying to breed 10 dogs, but modification in the genome can only occur in two individuals. At the same time, he emphasized that it is impossible to predict the success rate, since there is always an uncertainty factor. In some cases, the experiment may be completely unsuccessful.

According to Zhao Jianping, GMO dogs retain reproductive capacity and can breed from 10 months of age when they reach sexual maturity. The changes in the genes that were carried out are also passed on to the next generation.

Mi Zidong reported that in general, the life expectancy of such animals does not differ from the life span of ordinary animals. However, according to the company's leading scientist Lai Liangxue, GMO dogs suffer from hyperlipemia ( increased content fat in the blood) and may live shorter than other dogs.

“The life of a dog cloned using gene knockout (a method of molecular genetics in which specified genes are removed from the body or made inoperative) depends on the course of treatment and diet. If it is fed with foods with high content fat, initial stage The disease will occur earlier, and life expectancy will accordingly be reduced. But now I cannot give the exact life expectancy of such a dog,” the scientist told RIA Novosti.

Some media have already dubbed Long Long a “superdog”, but SinoGene does not agree with this formulation.

A “super dog” can be called an animal with fairly developed motor and olfactory functions that performs special work. This could be, for example, a guide dog, a sniffer dog or a search and rescue dog. But what we are creating is a gene-edited model of a dog, causing diseases. In simple words, the dog subsequently acquires the ability to suffer from human diseases, so it cannot be called a “super dog,” explained Lai Liangxue.

End justifies the means

Gene modification technologies are of great importance for the development of medicine, noted Lai Lianxue. According to him, they can be used to treat tumors and genetic diseases.

Initially, the company's scientists had two areas of research: dog cloning and gene editing.

"Each of these areas has different areas of application. For example, animal models can be used to study the safety of medicines and check their effect. Previously, dogs have been used relatively little in such experiments because the process of editing a dog's genes is quite complex. We conduct these studies because the course of the disease in dogs and humans is quite similar, and in dogs and humans as well. high degree similarity of genes,” said Mi Zidong.

In particular, the company's scientists have already studied diseases such as atherosclerosis, autism, muscular dystrophy and diabetes in dogs.

“Through animal experiments, we can study the risk of disease, the frequency of symptoms, methods of prevention and treatment,” said Mi Zidong.

Chinese scientists, speaking about the moral side of the issue, said that, unfortunately, the development of science and medicine requires sacrifice.

“All experiments are carried out on the basis of the principle of full respect for the welfare of the animal, but at the same time, I fully understand the point of view of animal protection organizations. However, in the process of development of medicine and science, this sacrifice is necessary,” Mi explained his position Zidong.

Future plans

Company experts said that the next step in their research could be the breeding of a genetically modified cat.

"However, in currently we don't have it yet necessary technologies, we should accumulate experience and knowledge, then we will be able to plan further. With the help of this knowledge, it will be possible to conduct relevant research on the entire cat family, especially in relation to endangered species, for example, the Amur tiger and some species of leopards,” said Mi Zidong.

He also emphasized that the company takes an open position in conducting its research and is ready to share its discoveries with the global community for the development of science.