Life secret: Scientists try to nurture human sperm and eggs

At present, scientists try to cultivate eggs and sperm in the laboratory, the future can replace the normal way of human reproduction? The “man-made” process continues to accelerate, and Japanese scientists use mouse tail cells to grow egg cells in experimental utensils and then grow into mice. Japanese scientists turned mouse tail cells into induced pluripotent stem cells, and then developed into eggs. This is the first time in human history to create artificial eggs in the body. With these synthetic eggs, they nurtured eight young rats. According to foreign media reports, at present, scientists try to cultivate eggs and sperm in the laboratory, the future can replace the normal way of human reproduction? We temporarily call him “Mr. B.D” because his wife described it in her infertility blog “shotgun”. A few years ago, 36-year-old Mr. B.D knew he had sperm deficiency (azoospermatic), which meant that his body would not produce sperm at all. In a recent phone interview, I could hear the real demands of his wife. Now she is 35 years old, facing a life without a child, she is facing a terrible countdown, she wrote on her blog: “No child is my fate, it is impossible.” So far , Mr. BD after years of drug treatment, taking vitamin supplements, major surgery, but he rarely had the opportunity to become a father. In 2012, Mr. B.De came to Stanford University in the United States, a technical staff of his skin perforation, from his shoulder to remove a small piece of skin tissue. Using a technique called “reprogramming”, his skin cells are transformed into stem cells that can be transformed into stem cells that can develop into different types of human cells. After which they are implanted in a testicle of a mouse, so whether it will cultivate successful sperm cells? Two years later, scientists announced that they had found evidence of primitive human germ cells, a controversial finding that immediately sensed the United States. Artificial gametes Mr. B. D recalls that I was shocked by the news at the National Public Radio in the United States, which would give hope for my childbearing child! The aim of this experiment is to convert adult cells into functional gametes – sperm or egg cells. No one has been able to do this yet, but scientists say they are about to confirm their possibilities. If they can develop a technique for making eggs and sperm in the laboratory, the problem of many infertility can be solved. At the same time, this technology also has a certain negative impact, it is disturbing, although the scientific and technological progress, but this reduces the natural fertility of future generations, the future of human reproduction will become a laboratory of a procedural operation? Is this part of a subversive study involving how cells determine their fate, is it a neuronal cell, or a cardiomyocyte? From the moment of fertilization of eggs, a series of biochemical signals coordinate cell division, growth and differentiation. The goal of research and development biologists is to understand every step of the process and, if possible, to copy the process into their labs. Any kind of cells cultivated in the laboratory will not produce greater scientific and social effects than sperm and eggs. The re-cultivation of these cells will allow scientists to start touching a secret area where the connection of human normal generations does not exist. Renee Reijo Pera, a researcher who experimented with Mr B. D, points out that is it more interesting than that? This study is so amazing! I know that some people study how the life of the earth originated, or someone studied the edge of the universe, but these studies are not enough to combine with sperm and eggs developed into human comparable. We have two arms, two legs, which is very accurate. The “man-made workers” process continues to accelerate, and Japanese scientists use mouse tail cells to grow egg cells in experimental utensils and then grow into mice. After the Chinese scientists said that the mouse has been identified to produce the desired molecular signal of the precise sequence. So far, humans have not yet found an accurate biochemical formula that allows stem cells to be converted into functional human oocytes or sperm, and human skin cells can not become truly human germ cells. But many scientists say that this is only a matter of time, maybe only one or two years, they will find the right way. “Recent advances in science are remarkable and amazing!” This latest study has taken place, taking into account the control of the basic units of reproduction, says George Daley, dean of the Harvard Academy of Sciences and stem cell biologist. The attention of entrepreneurs, legal experts, bioethics and in vitro fertilization experts. Some people believe that artificial gametes may be the first time since 1977, the first attempt to test fertilization since the biggest leap in technology. Because of the problems of cancer, accidents, age, and genetic factors, there are millions of people in the world who do not have normal births. “Based on this latest study, you can say that as long as you have skin, as long as you are alive, then you have sperm.” However, this technology may bring social destructive consequences, female fertility children no longer suffer Age restrictions, as long as the human body to extract some skin cells can produce egg cells. If the laboratory can breed sperm and eggs, why not a one-time manufacture of dozens of embryos, the lowest risk of disease testing or fertility of the highest IQ baby? Henry Greely is one of the most influential ethical thinkers at Stanford University in the United States, and he thinks it is very likely that it will happen. In 2016, in the “sexual end” edited by Greeley, half of the couples were expected to stop the natural births in 2040, and the future would be based on the use of skin or blood. Others think it’s okCan even cultivate artificial gametes in the laboratory, eliminate the risk of disease through genetic engineering, in addition to more imagination. For example: Scientists say that male skin can be used to cultivate egg cells, while female skin can be used to cultivate sperm cells. The latter is more difficult, because women lack the Y chromosome, this process is called “sexual reversal”, theoretically allows two people of the same sex to reproduce. After Grieli thought that “the parents go to the same” – with their own sperm and eggs to produce their own offspring. This strange possibility may occupy a prominent position in the major media, the latest progress reports show that even some people think that this technology from the Hollywood movie star George Clooney (George Clooney) body to steal a few hair, which can create a About the singer bank of Hollywood stars. Renee Reijo Pera, deputy head of research at Montana State University in the United States, argues that speculation like this is misleading and harmful. She said, “but I do not think it’s horrifying to be like a gamete in vitro, and on the contrary I see people who are in trouble because of their inability to give birth,” he said. To create a child, you can let the infertility out of sadness and doubt. She said: “I think this will make those who infertility people feel sad, because the normal people do is through the natural way to give birth to future generations. Maybe I think too simple, but I think the way to get healthy children or Should be combined with two heterosexuals, with wine and delicious dinners. “Reprogramming cells As a postdoctoral researcher in the 1990s, Paula helped to study the key genes that led to the complete loss of male sperm. This is called the DAZ spermless gene is very interesting, because they only exist in primates, which means that in addition to our hands and wisdom, in the reproductive offspring of human beings have unique details of the characteristics. The problem faced by scientists is that many of these details are hidden outside the line of sight. Scientists for research purposes can only survive in the laboratory for 14 days, and then enter a critical period, about 40 cells began to “mysterious journey”, they toward the gonadal ridge development, that is, the future of ovarian or testicular tissue The During this journey, the gamete gained the ability to form a new life, but the scientist was not fully aware of the stage. Paihara has a hobby, that is, how to rebuild the process, and in her early career, she was diagnosed with ovarian cancer, a rare disease called “granulosa cell tumor” The disease caused her to inherit her children. Just as Paia began to pay attention to the related health care problems of infertility, some people said to her, “Oh, there is nothing to do, it’s easy to adopt a child, it’s easy to do, and it will not affect life.” She and her husband decided to adopt a child from Guatemala. In 2006, she began to study Spanish, in an interview with Newsweek, she said she was about to become a mother, when she was named “the United States one of the most influential 20 women.” But then Guatemala stopped allowing foreigners to adopt local children, when Pai La was 49 years old. “So I started such a life, my husband and I, and a pet dog called Boo, that’s what I can do.” Despite giving up as a mother, Pira did not give up science In contrast, she found the final answer to the treatment of infertility. In 2006, a Japanese scientist named Shinya Yamanaka pointed out in his research report that he had found a way to treat infertility, converting any adult cells, including skin and cells, into so-called “induction Pluripotent stem cells (referred to as iPS) “, they undergo a molecular forgetting process, as in the newly formed human embryos found in the same cell, they do not have a fixed identity, but can form bone, fat or other parts of the body. The technology was confirmed to be very simple, and some people even compared it to the field of biological research, “the Berlin Wall collapsed.” Six years later, the mountain won the Nobel Prize, with the induction of pluripotent stem cell research to further enhance the development, he solved the long-standing ethical controversy. He found a way to explore the early stages of human development, rather than using test tubes fertilized embryos. In addition, the induction of pluripotent stem cells from the special population, which means that the cells can be obtained and patients fully match, at present, scientists began to discuss the transplant operation to provide “personalized” neurons or cardiac cells supply. Paihe, like many scientists, know the importance of the same stem cells in the reproductive system, how to get biologically related babies from skin cells? Even if the mountains of the “anti-wrap” cell technology can be quickly applied to solve this problem is still a huge challenge. Scientists do not yet know what factors make cells develop into neurons without becoming part of toenails. The calculation of such a biochemical formula, promoting cell development, precise composition and steps has become one of the most daunting problems in the field of biology. In June, 3900 development biologists, biotechnology executives and physicians gathered at the Boston Convention and Exhibition Center to attend the 15th Annual International Association of Stem Cell Research Associations. Japanese television journalists have focused on the mountain, and most of the scientists attending the conference are dedicated to researching the creation of specific cell types. Douglas Melton, a scientist at Harvard University in the United States, says he spent ten years deciding how to turn stem cells into pancreatic cells, a cell tissue that responds to insulin, and is finally implemented in 2014. It is reported that Melton has two children with diabetes, he hopes to cure their disease through cell transplantation. He told reporters: “We want to completely control and master the fate of cells.” Life secret During the meeting, I interviewed two Japanese scientists Saito Tongji (Mitinori Saitou) and Katsuhiko Hayashi, who reported in a November 2016 study that they turned mouse tail cells into induced pluripotent stem cells and then developed into eggs. This is the first time in human history to create artificial eggs in the body. With these synthetic eggs, they nurtured eight young rats. These mice are not only healthy, but also continue to reproduce. The discovery took five years to complete and published a 17-page study in the journal Nature, which was a “genius”. The current goal of the two scientists is to use the same method to cultivate human germ cells, Saito Tongji said that the mountains have extended personally guide him how to create human gametes. He said: “The mountain is close to this matter, he thinks we should do so, because it is very interesting in science, I am very fascinated, especially why these cells can form a new individual, which is controlled The ultimate way of cell fate. “The team led by Yamamoto to prove that the induction of pluripotent stem cells with practical application of the Nobel Prize’s important findings into treatment, has become the country’s primary task. In 2014, Japanese researchers first tested pluripotent stem cells for the treatment of blindness. But Saito Tongji pointed out that artificial gametes are not currently on the agenda, it can not even be compared with alternative cell therapy. I think it is difficult to use in vitro germ cells to make human individuals, but that’s not impossible. This is not only a technical problem, Saito Tongji for the ethical impact of the process of concern. He received a letter from a large number of infertile couples, but in Japan, the prohibition of scientists using such cells to breed human embryos in principle, the government is measuring the need to relax the relevant restrictions. Technical barriers may be resolved before the legal issues, although Saito Tongji is very worried about the ethical issues, but now there is a perfect on the human egg competition experiments in full swing. Saito Tongji admitted that he now has a “less enjoyable” game with Azim Surani, a mentor from Cambridge University, to see who can be the first to solve the problem. Katsuhiko Hayashi, currently a student at Kyushu University in Japan, was a student of Su Rani, and Katsuhiko Hayashi was working hard. If any of them could do better, other researchers might not hesitate Decided. When I asked Katsuhiko Hayashi how long it was to create a human gamete, he said: “10 years or 20 years, this is the most difficult question to answer, because I am doing experiments, and these experiments are not easy, I do not want When a liar says that only five years can be achieved, then someone will blame me for five years. “Scientists are now able to transform pluripotent stem cells into primordial germ cells, but how to convert these cells into functional sperm or eggs The problem remains unresolved. In the natural development of mankind, this transformation until the completion of adolescence. Using these cells, Saito Tongji and colleagues used them to produce small mice that could induce pluripotent stem cells by placing induced pluripotent stem cells in simulated ovaries, which were constructed using tissue extracted from mouse embryos. However, it is unrealistic to cultivate such dishes from human embryonic cells because they are difficult to obtain. In contrast, Saito Tongji believes that he needs to simulate the incubator from the induction of pluripotent stem cells, and this additional challenge may delay the experiment’s success time. If they do create eggs or sperm, scientists will still encounter another obstacle, because the only way to prove the effectiveness of these cells is to create a human descendant. At present, this is the Japanese scientists do not want or ready to consider. In order to confirm this final experimental step, Saito Tongji and colleagues used monkeys to experiment, and pointed out that experiments on animals that are closely related to humans are a very good model that will confirm whether their technology is safe for “primates” of”. What we need to prove is that we can cultivate high quality egg cells, for which we need to produce offspring. At the time of my talks with Katsuhiko Hayashi, Hardy Kagimoto, chief executive of a Japanese biotech company, was attracted to our conversation, hoping to work with Katsuhiko Hayashi to work together, and to work with Katsuhiko Hayashi, Explore laboratories to create human gametes. He said a group of in vitro fertilization physicians are also interested in this, they run a global clinical network medical team. A big thing is happening, and most people do not mean to this point, of course, we should not misunderstand me, if we do, will be in accordance with the consensus of the whole society to do. Although Katsuhiko Hayashi has obtained an invention patent, but he is not willing to join any company. In November 2016, the Japanese venture capitalists wanted to work with him to develop human eggs. Katsuhiko Hayashi said: “At that time I refused, because I can not do now, technology to achieve a certain distance.In addition, the technology is not enough to make a significant contribution to the community.” In Japan, the survey report shows that about 30% of the recipients accept the idea of ​​making gametes in the lab, and have the highest rate of support for couples who have tried the fertilization technique and failed. Some investors see more possibilities, and if the eggs can be manufactured by human-induced pluripotent stem cells, this infinite supply will lead to so-called “embryo farming”. Hardy Kagimoto mentions an image of Katsuhiko Hayashi’s paper, which was taken under a microscope,In the broth by dozens of laboratory-grown rat egg cells. In this case, gene sequencing techniques can be used to examine each embryo, allowing people to choose “the best” – those with ideal genes or no bad genes, such as: associated with schizophrenia. This is predicted by the legal scholar Greeley, he pointed out that if the parent parents have enough income, they will choose to reproduce the artificial descendants. Good New World During the Boston Cell Conference, students were listening nervously at the doorway about the ethical issues that sparked ethical issues. Spokesman George Daley, Dean of the Harvard Academy of Sciences, and the stem cell biologist George Daley Aldous Huxley published the book “Beautiful New World” in 1932, which describes a society that controls reproduction and nurtures children in a centralized facility, which is anti-utopian , But also has a “foresight” that can predict IVF technology. Daley believes that scientific progress will make the scenarios described by Hexelie become a reality, in addition to Japanese scientists to create gametes, some scientists also created a “gastruloids”, which is a self-assembled cells Mission, its appearance and behavior is similar to human embryos. At the same time, the researchers are changing the nature from another direction, in February this year, the United States Philadelphia doctors from the ewes to remove the lamb embryo, will be placed in a full culture of artificial uterus to continue growth and development. These techniques show that throughout the breeding process, from conception to birth, can be completed in the laboratory. “We can only figure out how long we need to completely replicate the individual in vitro, and then the question becomes: Are you sure?” Daley paid particular attention to the process of transforming pluripotent stem cells into human eggs and sperm, He calls it “disruptive technology”. One of the important reasons is that he believes that artificial gametes are likely to be combined with CRISPR gene editing techniques, which were developed four years ago, making it easier to change DNA within living cells. This is the manufacture of artificial gametes into the baby’s great controversy, that is, the so-called “germ cell line gene modification.” In 2015, the Chinese scientists’ family study reported that they used CRISPR techniques for embryos in laboratory petri dishes to try to remove genes that cause blood β-thalassemia. The study initially attracted widespread attention from the scientific community, partly because CRISPR technology was not without error. Experiments show that embryos may be due to genetic editing defects, the birth of children caused by unknown and unbearable risks. Although some commentators say that modifying the genebank is a moral bottom line that should not cross, it is not a scientific point of view. A report released this year by a national scientist in the United States concluded that if the technique was used to eliminate serious illnesses, such as Huntington’s chorea, it would be possible to edit the human embryonic genes. Although the committee is opposed to using genetic work to transform humans, such as turning eyes into blue eyes or improving intelligence, the report does not give a definable definition of the disease. The reason why the report is particularly concerned with artificial gametes is that in the induction of pluripotent stem cells, the editing may be very accurate. Once it has a perfect ability to induce pluripotent stem cells, it is possible for scientists to induce gametes through specific genetic improvements. The idea of ​​using CRISPR technology in stem cells has now been successfully implemented in the mouse body. Chinese scientist Li Jin-song edited the mouse stem cells and eliminated the genes associated with cataracts. When he made sperm and later fertilized eggs, they showed “100% effective” gene editing effect. Such research reports have become the best argument for scientists to oppose germline modifications, and the so-called absolutely impossible or inadequate security is quickly being eliminated. Richard Hynes, a professor at the Massachusetts Institute of Technology, says one of the authors of the National Academy of Sciences, says: “It is impossible to say that it is impossible.” The huge demand at the Harvard Stem Cell Institute, Werner Neuhausser, a test-tube baby scientist, is studying how to perform gene sequencing, stem cell and genomic editing, which can change fertility. Nu Hauser every week in Boston to test tube fertilization in a large fertility center where they met with the patient. The other four days of the week are used to validate and verify the latest discoveries in Japan and around the world. As an in vitro fertilization doctor, Nu Hauser told me that he “absolutely” saw the need for laboratory manufacture of sperm, especially in the laboratory to nurture eggs. If possible, it will be a big deal. At the same time, Nu Hauser believes that the embryo may be measured and its properties will be quantified: we can eliminate embryos with heart disease and psychiatric risk, and how would you choose? Nu Hauser believes that parents may not have such a choice, on the contrary, parents can choose to improve their germ cells through genetic editing. You can align your parents’ genome sequencing, and then you can ask: “Do you need to correct these mutations before you have children?” This is something we never thought of, and it will be very risky. In many cases we do not understand. “Nobody is willing to use this treatment in the short term,” he said. “The Harvard University Laboratory is exploring the gamete gene editor, who is working on a male body that carries the genes that cause muscle atrophic lateral sclerosis Get sperm, and plan to use CRISPR technology to remove this gene mutation. In his laboratory to correct the error, the scientists will be gene therapy of sperm cells, and observe the experimental results. But the more precise way is to genetically transform pluripotent stem cells, which grow and multiply in the laboratory, and once they are edited, they can create eggs or sperm cells. “You can get the genome and change the genes at will,” he saysGroup, of course, this is controversial, but we must study whether it is effective. “For Mr. BD, this man-made gamete technique does not take place in a short time, he told me that if the treatment program using laboratory sperm is approved, he wants to be the first person to carry out artificial gamete experiments. But it may be too late for him, and he said he and his wife set a deadline – in September 2019, if more than this time, they will give up childbearing.

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