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What is reproductive cloning (a.k.a.adult DNA Cloning)?Cloning is the production of one or more individual plants or animals that are genetically identical to another plant or animal. Adult DNA cloning involves removing the DNA from an embryo and replacing it with the DNA from an adult animal. Then, the embryo is allowed to develop into a new animal with the same DNA as the donor. It has been used to clone a sheep and other animals. It has not been tried on humans.
How reproductive cloning is done:With the exception of the sperm and egg, every cell in the body contains all of the genetic material in its DNA to theoretically create an exact clone of the original body. But cells have been "biochemically programmed to perform limited functions." 1 The other functions are turned off. Most scientists had believed that such differentiated cells could not be reprogrammed to be capable of behaving as a fertilized egg. In the case of the sheep "Dolly" (described below), a cell was taken from the mammary tissue of a mature 6 year old sheep while its DNA was in a dormant state. It was fused with a sheep ovum which had had its nucleus removed. The "fertilized" cell was then stimulated with an electric pulse. Out of 277 attempts at cell fusion, only 29 began to divide. These were all implanted in ewes. Thirteen became pregnant but only one lamb, Dolly, was born. Similar experiments to clone mice were initially unsuccessful. One speculation was that the DNA in sheep may not be used by the cells until after three or four cell divisions have completed. This would give the ovum "sufficient time to reprogram the DNA from [its original] mammary cell functions to egg cell functions." 1 Both human and mouse use the DNA after the second cell division. So, some researchers had predicted that humans as well as mice may not be "clonable". However, mice were successfully cloned later. Thus, cloning of humans might also be possible. Scientists wondered whether "Dolly" would be fertile. Some cloned frogs are infertile. Also, cells seem to have an internal clock that causes them to die off after a normal life. Since Dolly was conceived from a 6 year old cell, her life expectancy may be reduced from about 11 to only 5 years. This did not take place. Dolly, currently 4.5 years of age, continues to live a normal life. This essay continues below.
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History of cloning using adult DNA:1997: On 1997-MAR-4, apparently in reaction to "Dolly", President Clinton ordered a widespread ban on the federal funding of human cloning in the US. Research continues in other countries. 1998: Japanese researchers from Kinki University in Nara, Japan cloned 8 calves from a single adult cow's DNA. They used techniques similar to that which produced "Dolly." Four died shortly after birth due to what the researchers called "environmental factors." Their study was published in the issue of Science magazine published on 1998-DEC-9. On 1998-DEC-14, researchers at the Infertility Clinic at Kyeonghee University in Korea announced that they had successfully cloned a human. 2 Scientists Kim Seung-bo and Lee Bo-yeon took an ovum from a woman, removed its DNA and inserted a somatic cell from the same 30 year old woman. Their report states: "We were able to confirm division up to the fourth cell stage, the stage of embryo development when a test tube embryo is usually placed back in the uterus, where it then further develops into a fetus." The goal of their research was not to clone humans, but to clone specific, genetically identical organs for human transplant. They did not implant the morula into a human uterus because of ethical considerations. They destroyed it. The Korean Federation for the Environmental Movement (KFEM) immediately issued a statement criticizing the study. Members of the Life Safety Ethics Association held a protest demonstration in front of the university. Public opinion is having a chilling effect on cloning research in North America. Dr. Alan DeCherney of the University of California at Los Angeles said that if anyone tried to clone humans, they would "become the Dr. Kevorkian of reproduction." 2000: Current speculation is that the cloning process seems to create random errors in the expression of individual genes. The egg must have its genes reprogrammed in minutes or hours during the cloning process. Ova normally take years to ripen naturally in the ovaries. It appears that the extremely fast rate of programming can produce random errors in the clone's DNA. 4
Is adult human DNA cloning possible?One of many concerns with human cloning is that cloning of animals sometimes cause fetal overgrowth (aka large-offspring syndrome.) The fetus grows unusually large and generally dies just before or after birth. They have under-developed lungs and reduced immunity to infection. Duke University researchers announced on 2001-AUG-15 that this particular problem would not exist in humans. The DNA of all primates, such as humans, monkeys and apes, have two copies of a gene that regulates fetal growth, whereas almost all other animals have only one. This spare copy should prevent fetal overgrowth in cloned human fetuses. Randy Jirtle, professor of radiation oncology at Duke University in Durham, NC, said: "It's going to be probably easier to clone us than it would be to clone these other animals because you don't have this problem -- not easy, but easier.'' 7 Kevin Eggan, of MIT's Whitehead Institute works with cloned mice. He called the Duke study "interesting from the perspective of the evolution of imprinting genes." But he cautioned that there is no proof that abnormally large babies are born as a result of this one genetic difference. His lab has a "four-times normal size" mouse clone, which has normal IGFR2R genes. He suggests that there are other factors that can contribute to abnormal development in clones. 8
Plans to attempt human DNA cloning:Richard Seed, a physicist from Illinois, attempted to establish a human cloning clinic. 5 He claimed on 1998-JAN-7 that he was "90% complete" in hiring a team of experts to attempt the cloning of a human being, following the experiments on "Dolly." If successful, the resultant child would have identical DNA to one of its parents. Lord Robert Winston, a London based fertility expert who helped produce the first test-tube baby in 1978, said: "My first reaction is that here is somebody who is trying to make a quick buck off of self-advertising, because of course there is no way you could clone a human being safely at this point. I think the man is clearly unhinged and I don't think he is to be taken seriously." Marian Damewood, a member of the board of the American Society for Reproductive Medicine said: "I have very serious reservations about cloning human beings." The Society has declared a 5 year voluntary ban on cloning humans. Mr. Seed responded: "I can't really answer the critics who think it's a bad idea. They'll never be persuaded. As far as I'm concerned, they have rather small minds and a rather small view of the world and a rather small view of God." 6 Dr. Seed apparently did not succeed in his project. As of 2001-AUG, there are two publicized projects underway to clone humans. There may be others which are secret:
"In an effort to stall these attempts, Congress is planning to pass a bill banning human cloning by any organization in the United States. However, it is unlikely that this will prevent these efforts from being made elsewhere." 11 On 2001-AUG-14, Nobel Prize-winning scientist Sir Joseph Rotblat said that our understanding of cloning is "too meager" at this time to succeed. He suggested that many of the scientists involved are motivated by money. He said: "Inevitably the problems will be overcome, and it's then that the real ethical problems begin." He suggested that ethics evolve: "Ethics are not absolute. Look at in-vitro fertilization. This was originally considered unethical but is now widely accepted..."I feel that this [cloning], too, will become acceptable." In early 2002-APR, Dr. Severino Antinori announced that a woman who joined his program for infertile couples is now eight weeks pregnant with a fetus derived by human reproductive cloning. Although such cloning is banned in Italy where he lives, he was allegedly able to go to another country to perform the experimental technique. If the woman's pregnancy produces a live newborn, it will probably suffer from one or more serious genetic disabilities. 12 Surprisingly, some researchers do not seem to be deterred by the high levels of mortality, deformities and other genetic problems observed in animal cloning. At a National Academy of Sciences, three human cloning researchers spoke. "One Kentucky-based researcher, for example, offered only a vague assurance that cloning for human fertility purposes wouldn't be done if it couldn't be done right, and then angrily objected to being lectured by a scientist who wanted more of an answer. Another, a chemist who directs a Bahamas company and belongs to a [Raelian] religious sect that seeks cloning, made the extreme claim that 'it is a fundamental right to reproduce in any way you want.' " 10
Is adult human DNA cloning moral?Some say yes:
Some say no:
At the current stage in cloning research using adult DNA, the random appearance of genetic defects, noted above, appears to be an overwhelming problem. Such dangers would seem to put an indefinite halt on all ethical cloning of humans.
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