Cloning humans is widely misunderstood mainly due to its depiction in popular culture. A useful analogy is that of clones being 'delayed [identical twin]?s'. It is debatable how closely a clone would resemble his or her genetic double. A clone shares only DNA with its predecessor, and not any of the knowledge, experience, or environment that shaped him. However studies, such as those on identical twins raised separately, seem to show a strong genetic influence on personality?.
However the majority of scientists including [Ian Wilmut]?, who led the first team to clone [Dolly the sheep]? at the [Roslin Institute]?, claim that there are many further complications to human cloning in its current form. Aside from the ethics involved the scientists claim that it is simply too risky. In a debate for the [American National Academy of Sciences]? Wilmut quoted the low survival-rate of cloned animals as evidence that human cloning would be dangerous.
Dr Zavos thinks that by screening? embryo?s pre and post implantation this risk would be reduced significantly. Don Wolf, a researcher at [Oregon Regional Primate Research Centre]?, finds this hard to believe. He suggests that screeners would not even know what to look for.
Zavos works with the Italian infertility expert Severino Antinori, who was recently expelled from the [International Association of Private Assisted Reproductive Technology]? (APART) for his well publicised wish to be the first to clone a human. Antinori claims that cloning humans would actually be safer than in animals. He quotes research from [Duke University]? in Durham, North Carolina which seems to suggest a vital genetic difference between primates and other animals with regard to cloning. A problem discovered when cloning was first developed was that many of the clones grew much too large in the uterus, consequently dying at birth. A researcher at the university, Randy Jirtle, suggests this is down to the growth controlling gene IG2FR being suppressed. In animals a process known as imprinting can cause this gene not to develop. If the remaining gene is also turned off then 'large offspring syndrome' (LOS) occurs. Jirtel, however, claims this is a case of your LOS, my gain. Research he has done suggests that in primates neither gene can be subject to imprinting. Jirtel thinks that because of these extra-safeguards, human cloning would be much safer.
This is disputed by scientists who say that large-offspring syndrome is just one of many problems that result from cloning. Controlling this gene would not prevent many other genetic disorders which have yet to be fully understood or discovered.
Zanos and Antinori also say that the many of the developmental problems in animals were due to non-ideal conditions in which the embryos were cultured?. Researchers at the [Whitehead Insitute for Biomedical Research]?, MIT, have found that this disrupts genes so that apparently normal-looking animals die early. Zanos points out that reproductive science is actually more advanced in humans due to the widespread use of treatments such as In Vitro Fertilisation, and therefore cloning in humans is not such a large step as animal-cloning was.
The Whitehead team, however, conclude that human-cloning for fertilisation treatment is not a good idea. They did suggest, though, that cloning organs might be possible. This is because the imprinting experienced during culture is less important when cells specialize and start to grow in to specific tissues.
A surprising development to do with aging? resulted from finds that Dolly was apparently born old. This is thought to be due to telomere?s. These are regions at the tips of chromosone?s which prevent genetic threads fraying every time a [cell divides]?. Over time telomeres get worn down until cell-division is no longer possible - this is thought to be a cause of aging. However, when researchers cloned cows they appeared to be younger than they should be. Analysis of the cow's telomeres showed they had not only been 'reset' to birth-length, but they were actually longer - suggesting these clones would live longer life spans than normal cows. Researchers think that this could eventually be developed to reverse aging in humans.
Not all scientists want to clone whole humans. Therapeutic cloning, it is hoped, could be used to provide replacement organs or tissue for people who have had theirs damaged. Like nuclear transfer, DNA is inserted in to a cell which has had its nucleus removed. This DNA would come from the transplant patient. The cell divides to form an embyro and stem cells are removed. Stem cells are able to grow in to any tissue or organ in the body. These would be compatible with the person's immune system so no anti-immunity drugs would have to be taken after the operation.
In fact these techniques do not provide exact clones - they would be 99.7% identical to the DNA donor. This is because some important genes which are present outside the nucleus in mitochondrion are contributed by the egg-cell. How much change this would result in the clone is being investigated, but it could spell problems for theraputic cloning where compatibility is essential because of the risk of rejection.
Some claims seem more incredible than others. Dr Richard Seed thinks that human cloning will help us understand, and eventually reverse, the human aging process. A cure for cancer by a better understanding of the cell-differentiation process, as well as better treatments for heart attacks and [cosmetic surgery]? are being cited as being possible with the new technology. A mother in America plans to pay $500,000 to the Clonaid? organisation to clone her deceased daughter.
The [British government]? introduced legislation in order to allow licensed therapeutic but not reproductive cloning in a debate in January. However on 15th November opposition groups won a High Court legal challenge that effectively blocked cloning of embryos for therapeutic purposes. They discovered a loophole which allows reproductive cloning to be performed also. Scientists will now have to wait longer to apply for therapeutic cloning liscenses while the government appeals on the ruling. Pro-Life groups say that a new debate is necessary because of recent technologies having been developed that might circumvent the need for embryonic cloning.
Australia has a government comittee still considering the issues, having already introduced a variety of regulations on cloning in general. However organisations devoted to clone humans, such as the Raelites and the Las-Vegas based Clonaid, as well as Doctor's Antinori and Zavos, are very hard to control. Many think these groups would shift their operations to other countries, where a lack of regulation could bring dangerous results.
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