Cloning: promises and issues
The last decades of the XX century brought the rapid development of one of the main branches of biological science – molecular genetics. Already in the early 1970’s, scientists in the lab began to receive and clone the recombinant DNA molecules in test tubes to cultivate the cells and tissues of plants and animals. There was started a new direction of genetics – genetic engineering. On the basis of its methodology were made various types of biotechnology, were created genetically modified organisms (GMOs). Now it is possible the gene therapy of certain human diseases, and the last decade of the XX century was marked by another important event: there was a tremendous progress in cloning animals from somatic cells. Especially great response from the international community had Scottish research scientists from the University of Roslyn, who succeeded to get from the cells of the breast pregnant sheep an exact genetic copy of it. The cloned a sheep was named Dolly, she was developing normally and brought into life first one, and then another three normal lambs. (Kfoury 2007)
After that there were a number of new posts on reproducing genetic twins of cows, mice, goats, pigs from somatic cells of these animals. In primates, in particular in monkeys, it was not possible to get clones using adult cells, fetal or embryonic stem cells. Nevertheless, in few years it was reported about the clonal reproduction of primates by dividing the embryo. American researchers managed to obtain genetically identical embryos of rhesus monkeys by dividing blastomere of the embryo at the stage of division. In that way from an embryo was born a normal monkey called Tetra. (Kfoury 2007)
This type of cloning provides a genetically identical offspring, and as a result it is possible to get twins, triplets or more genetic twins. This allows to conduct theoretical research on the effectiveness of new therapies of various diseases, it is possible to repeat scientific experiments on completely genetically identical material. By implanting embryos to the surrogate female, it is possible to investigate the influence of her body to the fetus. Though the developed methods for cloning animals are still far from being perfect, as in the experiments there is a high mortality of fetuses and newborns. Also many theoretical problems of cloning animals from a single somatic cell are not yet clear. (Kfoury 2007; Henderson 2007)
Nevertheless, success in cloning sheep and monkeys showed the theoretical possibility of creating genetic copies of people from a single cell, taken from any of their organs. Many scientists are enthusiastic about the idea of human cloning, saying that this method can be used to obtain spare organs, which can be used to treat patients. A well known evolutionist professor at Oxford University, R. Dawkins wrote that he would like to be clond. “I think that it would be an excellent incentive to watch a copy of myself, only 50 years younger” he wrote. ( Phan, 2007)
Many other scientists, including Nobel laureates, also support the idea of creating genetic copies of humans. An opinion poll in the U.S. showed that 7% of Americans are willing to undergo cloning. However, most scientists and many politicians speak out against the creation of human clones. And their objections and concerns are justified.
Cloning of Rhesus Monkey to Produce Stem Cells
In 2007, the American scientist made a statement that he had cloned monkey embryos and isolated stem cells from them. Shoukhrat Mitalipov, an associate professor of the National Center for Research on primates in Oregon, said that he had used somatic cells transplantation, or the so-called therapeutic cloning, to produce 21 embryos from rhesus monkeys. Mitalipov delayed the development of embryos, so they did not become animals. He presented his results at the annual meeting of the International Society for Stem Cell Research In Kern, Australia, to get support in his work. It happened for the first time in the world and may help researchers to develop new treatments. (The Independent, 2007)
The new scientific discovery was made by Shoukhrat Mitalipov, a scientist who received his doctorate in genetics and microbiology at the Russian Academy of Medical Sciences, and then moved to the University of Utah in 1995 to conduct research in the field of stem cell and developmental biology. In 1998 he started to work in the Primate Research Center in Beaverton, Oregon. The work of Mitalipov was called a first important step to the therapeutic cloning. (Connor, 2007)
For cloning DNA of adult animal is introduced into the unfertilized egg, from which is pre-removed her own genetic material. Then embryo is got out of this egg, from which stem cells are extracted. These cells and tissues grown from them are an exact genetic copy of the source of DNA (in this case it is an adult macaques). For the cloning of embryos of macaques was used the method of somatic cell nuclear transfer (SCNT), which was used to create the sheep Dolly and other cloned mammals. But Shukhrat Mitalipov has developed an alternative method of visualizing of DNA, that is very important for its removal from the donor egg. Normally to remove genetic material from the egg scientists use Hoechst dye and ultraviolet light to stimulate fluorescence. Mitalipov and his colleagues, however, felt that all this could damage the egg of primate, so they used polarized light instead of paint and UV lighting to remove the cell nucleus. (Connor, 2007)
The world scientific community called the new discovery of American researchers a breakthrough, because until then it was believed that it was impossible to create cloned embryos from primates. “Some believed that monkeys and humans are too complex material for cloning. But those who work with such animals as sheep and cows, assumed that the probability of success will be about the same as our achievements in the experiments on these species”- said Professor Alan Trunson, a prominent expert on stem cells from Monash University in Melbourne. “The necessary technical skills have already been developed, and now we can go ahead and think about what is possible to get and achieve on the material” – said Alan Trunson. (The Connor, 2007)
The results of the scientific breakthrough: positive and negative implications
In the 10 years after the birth of the sheep Dolly, in the Scottish Roslyn Institute scientists were forced to receive primates by cloning. But problems with cloning of monkeys significantly prevented research of new treatments for diseases using embryonic stem cells. Now the results of research Oregon scientists were confirmed a separate group of experts. According to the website of the Center study of primates, the use of primates for the study of embryonic stem cells gives a model to evaluate the feasibility and effectiveness of stem therapy. Experts have already stated that in the same way, in principle, can be cloned a man and be obtained embryonic stem cells. Shukhrat Mitalipov also is confident that this technology is applicable to humans. (Kolata 2007)
The new method consists of removing the nucleus from an egg and replacing it with the nucleus from a cell taken from an animal whose tissues to clone. Embryonic stem cells are among the first cells that appear after conception. Since they can be converted into other types of cells, scientists are exploring the possibility of their use in place of damaged or missing brain tissue, heart or immune system. If further experiments are successful, scientists will be using stem cells from cloned embryos to create tissue for transplant and a new generation of medications that can help overcome many of the currently incurable diseases, including Parkinson’s disease and Alzheimer’s. Also, scientists hope that by using stem cells, they can create tissue for transplantation, which, thanks to precise genetic or tissue patient will not be rejected by his body. (Kolata 2007; Phan, 2007)
Though there are a lot of arguments and claims about the negative aspects of animals cloning in the world community. Cloning of living creatures, no doubt, is the most important technological and fundamental breakthrough in biology of reproduction in the early twenty-first century. Moreover, new technology could dramatically change our world, being one of the risky technologies. This dilemma, scientists believe, will be resolved in the further scientific development of the phenomenon, while solving the problems of whether it is morally and legally acceptable or unacceptable such an interference in the lives of living creatures. (Phan, 2007)
What are the main arguments of scientists and the public, who argue for the limitation of experiments to clone living organisms? Firstly, there are fears of intervention in the area of unknown, which may bring unexpected results. Second, many advocate the view that animals and human cloning is unacceptable because it violates the principle of the uniqueness of each living creation. Third, with regard to research of fetal in the uterus has already been developed ethical guidelines that allow intervention only in cases where the expected benefit outweighs the risk of a life of the fetus. Consequently, under this approach, experiments on embryos or cloning is permissible only in laboratory conditions, and the result of these operations can only be the production of cell mass, rather than tissues and organs.
It should be noted that in this case we are talking only about therapeutic cloning, which does not assume creation of a clone of the animal or human. In general, therapeutic cloning raises fewer ethical objections, but there are also arguments for limiting cloning, due to the moral and ethical position in relation to human embryos. Nevertheless, in many countries therapeutic cloning is prohibited. The law does not permit the use of human eggs, even if the embryo with transplanted nucleus is designed to create stem cells, and not to develop a clone organism.
Considering the topic of cloning living organisms with the ethical side most people rely on the moral and ethical precepts. However, those precepts unfortunately do not assume opportunities and possibilities, which brings science to our life. That is why, today it seems very important to develop new laws that take into account current realities and achievements of scientific and technological progress.
The significance of the breakthrough of rhesus monkey cloning can hardly be overestimated, as this is a new stage in the development of genetic medicine. If further experiments are successful, scientists will be able to use stem cells from cloned embryos to create tissue for transplant and generation of new medications that can help overcome many of the currently incurable diseases, including Parkinson’s and Alzheimer’s diseases.
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Henderson, M. (2007, November 15). First cloning of monkey embryo raises hope of a great leap in medical science. The Times. Retrieved from: http://www.timesonline.co.uk/tol/news/science/article2870675.ece
Highfield, R. (2007, November 12). Scientists make monkey cloning breakthrough. The Telegraph. Retrieved from: http://www.telegraph.co.uk/science/science-news/3314155/Scientists-make-monkey-cloning-breakthrough.html
Kfoury C. (2007). Therapeutic cloning: promises and issues. Mcgill Journal of Medicine, 10(2), 112–120.
Kolata, G. (2007, November 15). Scientists Use Monkey Clones to Extract Stem Cells. The New York Times. Retrieved from: http://www.nytimes.com/2007/11/15/science/15primate.html
Phan, K. T. (2007, November 15). Stem Cell Advance in Cloned Monkey Embryos Renews Human Cloning Debate. The Christian Post. Retrieved from: http://www.christianpost.com/news/stem-cell-advance-in-cloned-monkey-embryos-renews-human-cloning-debate-30096/
Rowe, A. (2007, December 27). Top 10 Scientific Breakthroughs of 2007. Wired. Retrieved from: http://www.wired.com/science/discoveries/news/2007/12/YE_10_breakthroughs