A landmark step in human stem cell and genomic research in 2007
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Last Update: 2020-07-03
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Source: Internet
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Author: User
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2007, the field of biomedical research has made rapid progress, many breakthrough results are amazing, but also bring many interesting problemsFor example, can skin cells grow into fetuses? Will racism re-emerge with the discovery of individual genetic differences? Does "gene determinism" lead to genetic discrimination or "pedigree theory"? Some of the problems arising from the advance of these technologies have even reached the point of exploring the origin of species, while others are tied to social, economic and political effects beyond the scientific arenaFrom skin cells to human fetus
2007, the most impressive scientific progress is undoubtedly stem cell research progressIn a report published on November 30 in Cell, Shinya Yamanaka, a professor at Kyoto University in Japan, claims that his team has genetically modified skin cells in adults with a modified virus to reverse them, giving them the characteristics of omnipotent stem cells, or IPS cells" We transplanted these modified human cells into miceAfter 90 weeks, we observedtumorsform thesetumors
have inner, middle and outer embryo-like tissues similar to those of the human fetal periodProfessor Yamanaka saidThe results immediately shook the scientific community and the community as a milestone in stem cell researchPreviously, stem cell research often required the use of human embryos, or cells that could develop into human embryos, creating great ethical controversyIn 2005, Kevin Eggan of Harvard University's Stem Cell Institute used embryonic stem cell lines instead of egg cells to fuse with adult skin cells to produce "hybrid" cellsThese "hybrid" cells have stem cell properties that can be used for research without ethical controversy However, the genomes of these "hybrid" cells are twice as large as those of normal human cells and do not fully simulate the properties and applications of human stem cells In 2006, Professor Yamanaka and Rudolf Jaenisch of the Massachusetts Institute of Technology genetically engineered skin cells in mouse fetuses to have embryonic stem cell properties and participate in the development of mouse fetuses in the body, which was hailed as "dazzling" by colleagues at the time Just over a year later, similar modifications have been successful in adult skin cells, clearing ethical hurdles for human stem cell research "We can now build specific IPS cells that for each patient or specific disease and then produce different kinds of cells, such as myocardial cells, liver cells, and nerve cells," says Professor Yamanaka These cells can be used to study disease mechanisms and screen for safe and effective drugs If we can overcome the security problem, human IPS cells can be used for transplant treatment However, Yamanaka also stressed that "it is too early to think that embryonic stem cells can be completely replaced by IPS cells" Donald Kennedy, editor-in-chief of Science magazine, says there are "good reasons to continue embryonic stem cell research." New technologies may have some unrecognized risks "
just months before IPS cell research progressed, Stemagen, a Private California company that conducts stem cell research, announced that it had successfully cloned human embryos from adult skin cells Unlike Yamanaka's genetic modification technology, Stemagen uses Nuclear Transfer Nuclear transfer technology is nothing new, as early as 1996, the Rawlings Institute in Scotland used this technology to give birth to the world's first cloned animal - cloned sheep "Dolly." This time, the technology is used in people Stemagen transfers the nucleus of adult skin cells to human egg cells, which show the same developmental process as humans during in vitro culture Although Stemagen claims to be the first successful cloning of human embryos in the world, it is not the first to use adult skin cells for nuclear transfer experiments Four years ago, Professor Sheng Huizhen of Shanghai Second Medical University in China published an article in the journal Cell Research in China, announcing that the human nucleus of different ages will be transferred to the egg cells of rabbits, and the resulting cells have the characteristics of human stem cells, which can further develop into nerve cells and muscle cells Thus, it is only a matter of time before the transition from skin cells to the human fetus, however, there may be an unrecognized and uncontrollable risk behind such an experiment In particular, a mix of human and animal experiments crosses the boundaries between species, and the potential risks are unpredictable Although biological genes are mainly found in the nucleus of cells, there are doubts about whether animal egg cells transplanted into the nucleus of human cells are not affected by a small number of "residual" animal genes, or whether these effects are negligible Why are we so different
there are no identical two people in the world, as if there are no identical two leaves, and not to say that the body between different species of the clear difference
in skin, that is, in the same population, people are also very different, some people are not forgotten
, some people are suffering from amnesia; In ancient times, it was believed that every one was born with a different destiny In recent years, the discovery of individual differences in the human genome has shed light on the genetic reasons behind these human-to-human differences Donald Kennedy commented that the breakthrough in 2007 was undoubtedly the human genome and genetics But we don't mean the "human genome" specifically, we mean the specific genome of you or me Seven or eight years ago, the human genome was scanned for the first time Since then, "every new gene sequencing and study of every new human body has painted more detail on the panorama of the genome." Science's Elizabeth Pennis, a news writer, said In 2007, a large study by researchers revealed individual differences in the genome before humans and humans, saying these genetic differences are related to complex diseases and personal characteristics In 2007, researchers found genes associated with diabetes, AIDS response, height, coronary heart disease, and european genes that control hair, eyes and skin color Although 2007 was a year of great success for the study of individual differences in the human genome, the concept and discussion of "individual differences in the human genome" did not begin since that year In 2003, Jeff Long of the University of Michigan School of Medicine in the United States of America gave a report entitled "Individual Differences in the Human Genome: The Results of Microevolution" In the report, Jeff Long points out, "No two genes are exactly the same." These differences are caused by random genetic mutations The relationship between the difference of human genes and the geographical environment In the population of Europe and Asia, the degree of differences between nucleotides (the basic components of genes) is similar, but the differences between Africans are much greater He also points out that the genetic distance between people (Genetic Distance) is proportional to the geographic distance between them It's worth noting that Jeff Long argues that the traditional concept of "race" is not accurate, and that the relatively accurate concept of "population" should be used when discussing individual differences in the human genome He says that previously, people have defined ethnography as people who are distinguished by different anatomical characteristics This anatomical feature is determined by congenital genetics Although genetic differences have also been observed in the so-called "human ity", these differences are seen as "noise" signals and ignored Conversely, one of the best concepts in Darwin's theory of evolution is that the genetic differences within the same "human race" are considered to be the basic source of genetic differences between different "human species" In fact, studies of genetic differences on species-specificity have begun to push species origin, and the "crazy" question is: If there is a mandatory change in the gene retention point of species specificity, will it change the characteristics of the species or even produce new ones? The "crazy" question is left to biologists to think about! The most realistic and optimistic use of "individual differences in the human genome" is to build an individual's own gene library This will help doctors determine an individual's chances of developing a genetic disease and how it responds to the drug, enabling personalized treatment However, the current cost of genome scanning is about $300,000 to $1 million, which is still too expensive for the general public " It is hoped that genomic scanning technology is not used for the pursuit of wealth, but for scientific research purposes or for personal medical treatment "Donald Kennedy initiative The technology could raise new social problems, such as the new "pedigree theory" of genetic discrimination and racial discrimination based on genetic differences between "ethnic groups" How the future, can only "touch the stone across the river", in practice groping (Jiang Jianping)
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