Though out many years, movies and television shows such as Star Wars, Star Trek, and many others have enlightened our imagination on cloning organisms. Today, it appears that this idea that looked unreachable, now seems to be within our grasp due to our technological leap in genomic science. But we are not interested in just regular cloning, we want to reach for the stars and successfully be able to produce copies of not just other animals, but humans as well. This turns to the new scientific phenomenon that is reproductive cloning.
Cloning is a form of asexual reproduction that makes identical genomic copies of the original animal either by producing specific cells or tissue, where reproductive cloning has the ability to clone the entire animal that is produced by a single cell. This process differs drastically from original sexual reproduction. Normal sexual reproduction occurs when a sperm that contains one set of chromosomes (23) reaches and fertilizes with an egg with another set of twenty-three chromosomes. This results in the formation of a zygote, or single-cell fertilized egg, containing two sets of chromosomes (46) to later develop into a living organism.
Reproductive cloning occurs when the nucleus is removed from an egg, and replaced with the nucleus of an adult somatic cell containing forty-six chromosomes, and then the clonal zygote is stimulated to divide and develop into an embryo (McCabe & McCabe 209). This procedure is known as somatic cell nuclear transfer (SCNT). This process was used to create the most wellknown cloned animals, a sheep named Dolly. Dolly the sheep captured the imagination of the world, as the clone made its announcement of its birth made front page news in February 1997 (Birth in January 1996).
Interestingly, Dolly was ot the first organisms to be successfully cloned. Tadpoles have been able to be cloned since 1962, cattle and other sheep have been cloned using nuclei from embryonic or fetal tissue. So what makes Dolly the sheep separate for all the other cloned animals? To generate Dolly, a mammary gland cell from a whitefaced (Finn Dorset) ewe in her last trimester of pregnancy was fused to an enucleated egg from a sheep that had a black face (Scottish Blackface) (McCabe & McCabe 210). Dolly therefore showed phenotypic similarities of the Finn Dorset, otherwise getting the mothers nuclear genome derived from the mammary gland and not the recipient egg.
This is important due to Dolly’s notoriety coming from the fact that she was the first animal to be cloned using the nuclear genome of an adult somatic cell (McCabe & McCabe 210). Though the production of cloning a sheep showed signs of success, there were also some downfall within this project. First, SCNT has a high rate of failure. In the reports of cloning Dolly, in 277 attempts, 247 cloned zygotes were generated. Once the zygotes were “cultured” in the surrogate mothers (one for early development and second for later development), only 29 of the original 247 survived.
Only one of the 29 developed normally to birth, which was Dolly (McCabe & McCabe 211). This is an issue, as this process results in hundreds of undeveloped embryo deaths. Secondly, Dolly experienced major health concerns throughout her life. Dolly developed health issues such as obesity and severe arthritis. Scientists were troubled with this fact, as this could have been due to the premature aging in the animal. She also developed severe lung infection, which resulted in her short life that ended on February 14, 2003 at age six.
Ian Wilmut, who was the lead author on the 1997 report of Dolly’s cloning, argued that features such as lung infection and length of her life were not unusual in a sheep maintained in a pen indoors for long periods of time (McCabe & McCabe 212). Though it seemed that Dolly experienced these health issues, scientists have not successfully cloned more animals, such as horses, mice, lambs, and cats. Unfortunately, An article from Nature Genetics have shown that early death is present in mice cloned from somatic cells, as the mice were more likely to develop severe pneumonia and hepatic failure (Оgonuki 253).
Though research with reproductive cloning animals have shown health complications and low embryonic survival rates, many scientist are looking to use this technology into creating a human clone. Still, the idea of producing a fully functioning human from reproductive cloning have not been entirely proven, there have been claims in the past. Clonaid is a private company funded by Rael, announced the birth of the first cloned baby, Eve, on December 26, 2002. Eve is a clone of a 31 year old American woman, where she donated the DNA for the process, having the resulted embryo implanted and then gestated the baby (Dakss 2002).
Though the company claims that Eve is the first cloned human, there is no independent genetic testing of the reportedly cloned human child. There have been cases of companies cloning human embryos, but have been used for therapeutic purposes, not reproductive. This therapeutic measure have been used to create human tissue that can be beneficial for medicinal purposes. In 2001, Scientists were able to demonstrate that human adipose tissues contained cells with the characteristics of stem cells, which could be induced in cell cultures to separate into differentiate fat, bone, cartilage, and muscle tissue.
This is subsequently known as adipose tissue-derived stem cells (ADSCS). This procedure helped with the characterization of human embryonic stem cells (HES). Scientists grow these hES cells on a mouse embryonic fibroblast feeder layer that had been irradiated so that the feeder layer could not divide but can still provide essential growth factors (McCabe & McCabe 230). With the combination of reproductive and therapeutic cloning practices, scientists believe that these methods will be able to generate a “designer baby”“.
The potential capabilities of creating a synthetic “designer baby” can lead to major ethical, social, and legal issues outside of the laboratory. One of the more social aspects on how reproductive cloning can be an issue is the belief that this process can be considered “playing God”“. Reproductive cloning has a negative perspective on religious backgrounds, going against the aspect on how every living organism should be born naturally under Gods rule. In orthodox Christian thinking, human precreation is seen an indissolubly linked in the committed love of a man and a woman (BioEthics Web).
Another issue people will have towards reproductive cloning is the safety that surrounds human cloning. Current scientific experience indicates that between 95-98% of mammalian cloning experiments have resulted in miscarriages, still births, and life threatening abnormalities (BioEthics Web). This subject goes back to the potential health issues that the offspring may possess, where most of the mammalian clones (including Dolly) have developed a variety of health complications (organ failure, arthritis, circulatory problems) that can result in premature death.
Lastly, if cloning a human is successful, the person may feel social and psychological consequences from the cloned birth. It has been argues that a child clone would inevitably suffer adversely from the existence of their nuclear donor and from the knowledge that they were created for a specific purpose (BioEthics Web). The child born this way could question his reason for living, question who his/ her real parents are, and be in position to be quickly judged by people that see them as just an experiment.
With all of the issues of creating new synthetic life through reproductive cloning, the United States Food and Drug Administration (FDA) has regulatory jurisdiction over clinical research using cloning techniques, which lead to The Human Cloning Prohibition Act of 2007. Introduced on June 5, 2007, defeated the House of Republicans, stating the ban of human cloning, but only the implantation of a cell into a woman (Laws and public Policy about Cloning Web).
Reproductive cloning has made great strides in biotechnology, as scientists are able to successfully clone a variety of animals. This process has also been lead to great strides in therapeutic cloning that can be used for medicinal purposes. One popular example is xenotransplantation, an animal to human organ transplant. Pigs are interesting subjects for xenotransplantation because of their physiological similarities to humans and their ready availability, in contrast to nonhuman primates (McCabe & McCabe 219).
I we are able to mass clone organisms, like pigs, this will be beneficial in having a good supply of organs to cure human diseases and abnormalities. Reproductive cloning also gives people the opportunity to genetically create an identical donor. The SCNT procedure has the capability to genetically “resurrect” a lost beloved pet. Lastly, human cloning would provide lesbian couples or single women with the opportunity to have a child without using donor sperm (BioEthics Web).
Overall, Reproductive cloning remains an extremely inefficient process, and to date the cloning of a human has not been scientifically confirmed (McCabe & McCabe 221). This proves how reproductive cloning is still a very young subject that needs more time to come to conclusions on how it should be brought to our society. Hopefully future research in cloning will be able to successfully clone animals, without having any health issues. Cloning animals can be beneficial for medicinal purposes, and able to produce more food to malnourished areas.
With all of the social and ethical issues that come with human cloning, I believe that the process will never have the opportunity to lift off the ground. Just the idea of having human created in vitro will frighten many people who don’t have a good idea on how they are created. The world will not act kindly if the research of human cloning is a success. The therapeutic technology related to animal cloning and human embryos is more than enough for our medical practices.
