There was a breakthrough in the field of genetics in the year 1996, when the first cloned mammal named Doily came into existence. Clones are nothing but organisms with same genetic makeup, and identical twins are natural clones. There were several previous attempts made to make clones in laboratory using techniques such as “artificial embryo twinning.” But, Dolly was the first mammal to be cloned by “Somatic cell nuclear transfer” (SCMT) technique. In embryo twinning, a fertilized egg, which is in the differentiated multi-cell stage, is separated, and individual cell is allowed to grow into a whole organism. In the case of Dolly, her genetic material was obtained from the mammary cell of a 6 year old sheep. This somatic cell nuclear material was transferred into an oocyte in-vitro, grown into an embryo and then implanted into the uterus of a surrogate mother sheep. It was a great achievement, since Dolly proved that a viable progeny could be obtained from a non-reproductive or somatic cell, without the need for fertilization, and it triggered several other genetic cloning experiments using SCMT.
Cloning by SCMT is a technological boon to the society through which, sterile couples can have children, we can overcome incompatibility issues with organ transplantation, and study cell differentiation better. But, several ethical issues are also raised about cloning. If human cloning can be done, we need to address issues such as rights of clones, possibilities of impersonation, loss in genetic variation as well as individuality etc. (Farnsworth). The fate of Doily further triggered anti-cloning arguments and this technology is still wrapped-up with controversies.
Dolly was healthy up to six years of age and gave birth to several lambs before her death in 2002 due to a lung disease, and she had prematurely developed a kind of arthritis too. However, reason for the lung disease was not clearly identifiable (Trix). Following her death, there were several arguments about the ethics of cloning and genetic research as a whole. Life expectancy of a sheep is normally, 11 to 12 years, and it was claimed “Dolly died prematurely as a result of being a clone” (Trix). Following her death, it was stated in NewScientist “Some cloned mammals, including Dolly, have shorter telomeres than other animals of the same age” (Knight). Telomeres are the ends of chromosomes, and they shorten during each cell division. So, shorter the telomeres, older are the cells. Dolly came from an adult sheep’s, completely differentiated cell. So, she is a clone with the same genetic material as the mother and technically not her offspring. This fact can be extrapolated to say that dolly was as old as her biological mother at birth itself. So, she developed arthritis and aged early. In the contrary, lambs resulting from natural reproduction would vary in their genetic makeup from their parents. Similar to Dolly, several other cloned animals also died prematurely or developed aging related diseases.
Thus, cloning allowed man to play God, letting him introduce and modify life according to his will. Today, cloned cells and organs are used to save valuable lives, and this is not possible without Dolly and other previous experiments. Dolly, thus changed genetics forever and also helped in refining cloning techniques. Mistakes and failures with genetic experiments paved way to the development of strict regulations and bioethical principles. Cloning complying with ethical norms has now become a routine procedure in medical research and treatment. Further, the regulations are constantly being updated and reviewed to facilitate beneficial research activity in Genetics.
Works Cited
Farnsworth, Joseph. "To Clone or not to Clone: The Ethical Question." To Clone or not to Clone: The Ethical Question. N.p., 7 Apr. 2000. Web. 25 June 2014. <http://thefarnsworths.com/science/cloning.htm>.
Knight, Will. "Dolly the sheep dies young.” NewScientist, 14 Feb. 2003. Web. 25 June 2014. <http://www.newscientist.com/article/dn3393-dolly-the-sheep-dies -young.html#.U6sCxhZSaAE>.
Trix, VIctoria. "Learn About Dolly the Sheep, the First Cloned Animal in History." Bright Hub. N.p., 9 Apr. 2009. Web. 25 June 2014. <http://www.brighthub.com/science/genetics/articles/5070.aspx>.
