Cloning is the process of creating an identical copy of something. In biology, it collectively refers to processes used to create copies of DNA fragments (molecular cloning), cells (cell cloning), or organisms. Human cloning is the creation of a genetically identical copy of a human being, human cell, or human tissue. The term is generally used to refer to artificial human cloning; human clones in the form of identical twins are commonplace, with their cloning occurring during the natural process of reproduction.
Although genes are recognized as influencing behavior and cognition, "genetically identical" does not mean altogether identical; identical twins, despite being natural human clones with near identical DNA, are separate people, with separate experiences and not altogether overlapping personalities. The relationship between an "original" and a clone is rather like that between identical triplets raised apart; they share nearly the entire same DNA, but little of the same environment. A lively scientific debate on this topic occurred in the journal Nature in 1997. Ultimately, the question of how similar an original and a clone would be boils down to how much of personality is determined by genetics, an area still under active scientific investigation.
If human cloning proceeds, one method scientists can use is somatic cell nuclear transfer, which is the same procedure that was used to create Dolly the sheep. Somatic cell nuclear transfer begins when doctors take the egg from a donor and remove the nucleus of the egg, creating an enucleated egg. A cell, which contains DNA, is then taken from the person who is being cloned. The enucleated egg is then fused together with the cloning subject's cell using electricity. This creates an embryo, which is implanted into a surrogate mother through in vitro fertilization. If the procedure is successful, then the surrogate mother will give birth to a baby that is a clone of the cloning subject at the end of a normal gestation period. Of course, the success rate is only about one or two out of 100 embryos. It took 277 attempts to create Dolly.
A California company it used cloning technology to make five human embryos, with the eventual hope of making matched stem cells for patients. Other experts were skeptical about the claims, published in the journal Stem Cells. If verified, the team would be the first to prove they have cloned human beings as a source of stem cells, the master cells of the body. There are several types of stem cells. Embryonic stem cells, made from days-old embryos, are considered the most powerful because they can give rise to all the cell types in the body.
"Since a significant percentage of couples undergoing fertility treatments appear willing to participate in this type of research, we believe the method described to obtain donated oocytes is a viable and ethically acceptable strategy," the researchers wrote.” This is the most successful description so far of the use of the cloning techniques with purely human material. However, it is still a long way from achieving the goal of obtaining embryonic stem cells”.
South Korean scientist Hwang Woo-suk made headlines when he was found to have faked key parts of a report that his team had used cloning technology to make human embryos in 2004. "We need to be ultra-cautious after the Hwang scandal and not make the same mistake all over again," said Dr. Robert Lanza of Advanced Cell Technology, a Massachusetts company that is also trying to make human embryonic stem cells. "I'd really like to believe it, but I'm not sold yet”.
Other teams have made stem cells they believe are similar to embryonic cells using a variety of techniques, including reprogramming a human egg cell alone, reprogramming ordinary skin cells into what are called induced pluripotent stem cells, or by taking one cell from a human embryo without harming the embryo. But most stem cell experts agree it is important to continue trying to make stem cells from embryos too.
For more details on US company claims cloned humans, made stem cells visit www.halfvalue.com and www.halfvalue.co.uk For more information on books visit www.Lookbookstores.com
Although genes are recognized as influencing behavior and cognition, "genetically identical" does not mean altogether identical; identical twins, despite being natural human clones with near identical DNA, are separate people, with separate experiences and not altogether overlapping personalities. The relationship between an "original" and a clone is rather like that between identical triplets raised apart; they share nearly the entire same DNA, but little of the same environment. A lively scientific debate on this topic occurred in the journal Nature in 1997. Ultimately, the question of how similar an original and a clone would be boils down to how much of personality is determined by genetics, an area still under active scientific investigation.
If human cloning proceeds, one method scientists can use is somatic cell nuclear transfer, which is the same procedure that was used to create Dolly the sheep. Somatic cell nuclear transfer begins when doctors take the egg from a donor and remove the nucleus of the egg, creating an enucleated egg. A cell, which contains DNA, is then taken from the person who is being cloned. The enucleated egg is then fused together with the cloning subject's cell using electricity. This creates an embryo, which is implanted into a surrogate mother through in vitro fertilization. If the procedure is successful, then the surrogate mother will give birth to a baby that is a clone of the cloning subject at the end of a normal gestation period. Of course, the success rate is only about one or two out of 100 embryos. It took 277 attempts to create Dolly.
A California company it used cloning technology to make five human embryos, with the eventual hope of making matched stem cells for patients. Other experts were skeptical about the claims, published in the journal Stem Cells. If verified, the team would be the first to prove they have cloned human beings as a source of stem cells, the master cells of the body. There are several types of stem cells. Embryonic stem cells, made from days-old embryos, are considered the most powerful because they can give rise to all the cell types in the body.
"Since a significant percentage of couples undergoing fertility treatments appear willing to participate in this type of research, we believe the method described to obtain donated oocytes is a viable and ethically acceptable strategy," the researchers wrote.” This is the most successful description so far of the use of the cloning techniques with purely human material. However, it is still a long way from achieving the goal of obtaining embryonic stem cells”.
South Korean scientist Hwang Woo-suk made headlines when he was found to have faked key parts of a report that his team had used cloning technology to make human embryos in 2004. "We need to be ultra-cautious after the Hwang scandal and not make the same mistake all over again," said Dr. Robert Lanza of Advanced Cell Technology, a Massachusetts company that is also trying to make human embryonic stem cells. "I'd really like to believe it, but I'm not sold yet”.
Other teams have made stem cells they believe are similar to embryonic cells using a variety of techniques, including reprogramming a human egg cell alone, reprogramming ordinary skin cells into what are called induced pluripotent stem cells, or by taking one cell from a human embryo without harming the embryo. But most stem cell experts agree it is important to continue trying to make stem cells from embryos too.
For more details on US company claims cloned humans, made stem cells visit www.halfvalue.com and www.halfvalue.co.uk For more information on books visit www.Lookbookstores.com
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