Gene Cloning is Natural or Not... Is It a Dangerous Tale?
- Cagatay Ustun, M.D., Ph.D.
Ege University, Faculty of Medicine, Department of Medical Ethics, Bornova, Izmir, TURKEY
Eubios Journal of Asian and International Bioethics 14 (2004), 148-149.
Gene cloning is a new technique and term of today. Cloning is the process of making a genetically identical organism through nonsexual means. This technology became familiar with the team from the Roslin Institute near Edinburgh, Scotland. The birth of the cloned sheep "Dolly" was announced in Nature, on 27 February 1997. Dr. Wilmut and his colleagues wanted to see if specialized cells could be reprogrammed into thinking that they were not specialized and develop all over again, thus creating a clone. Cloning means the production of a precise genetic copy of a molecule (including DNA), cell, tissue, plant, animal, or human. On 1998 July 22, Dr. Ryuzo Yanagimachi of the University of Hawaii announced the cloning of mice. The team had produced 22 mice; seven of them are clones of clones from the cells of a single mouse. Japanese researchers from Kinki University in Nara, Japan cloned 8 calves from a single adult cow's DNA. They used techniques similar to those which produced "Dolly." By the end of the year 2000, eight species of mammals have been cloned, including mice, cows, rhesus monkeys, sheep, goats, pigs, and rats. Between 3,000 and 5,000 cloned animals have been produced to date. During the past six years, various scientists and theologians, physicians, legal and ethical experts, medical or the other editorial writers have been busily responding to the news, some trying to calm fears, while others fuel the controversy.
Today, human cloning is now significantly closer to becoming reality. Scientists have created the first embryonic clones of an adult primate and are preparing to implant them into surrogate mothers. 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 15 August 2000, 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.'' On 15 November 2001 the British High Court ruled that previous regulations regarding fertilized embryos did not apply to cloned human embryos because they were not created by fertilization. This ruling meant that both reproductive and therapeutic human cloning was technically legal in the United Kingdom.
Advanced Cell Technology announced in 2001 that they have cloned an early human embryo from a adult cumulus cell nucleus. The cumulus cells are cells that surround the egg when it is ovulated. The furthest any of the cloned human embryos developed to was to six cells. The research is primarily aimed at therapeutic cloning (producing cloned stem cells to cure disease), but it has also prompted hopes by certain infertile couples that they may be able to conceive a biologically related child via this technology. Now in February 2004 Korean researchers have made a cloned human embryonic stem cell line.
There are, however, ethical dilemmas in using human cloning methods. Because parthenogenesis would involve female egg cell manipulation with no additional genetic materials, some scientists believe that it is a more ethically acceptable method of producing stem cells than the conventional transfer of nuclear DNA material from another person. Others, however, still think that it is still just another example of science going too far.
During the last three decades, since the handling of genetic material (molecular cloning) was made possible, hundreds of new questions arose regarding on how ethical it is. In short, the risks associated with reproductive human cloning haven't been conclusively established. Perhaps future research will establish the safety of the procedure for both mother and child, but other ethical, sociological and religious objections would almost certainly remain. Science is changing enormously. I think, we should ask this question: "Who wants to be a clone?" and we should remember to answer Hippocrates's primary principle: First do not harm! Yes, I am sure, we should care about human genes... Can readers tell me whether cloning is natural or not?
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