Cloning
The history behind the concept of cloning dates all the way back to 1902 when Walter Sutton proved chromosomes contained genetic information. This is what is widely accepted as the “beginning” of cloning, as we know it today. Also in 1902, Hans Spemann divided a salamander embryo into halves and showed early embryo cells contained all the genetic information necessary to create new organisms. A few years later, in 1907, American scientist Thomas Hunt Morgan began work on the first “chromosome map.” This map was created to show the location of genes. Morgan used fruit flies in his experiments because of their “simple genetic structure and rapid breeding.” (http://library.thinkquest.org/C0122429/history/history.htm). In 1928, Hans Spemann conducted the first nuclear transfer experiment. He used “salamander embryos, where he transferred the nucleus of a salamander embryonic cell into a cell with no nucleus. Using a strand of hair, he tightened a loop around a newly fertilized egg, until he separated the nucleus and some of the cytoplasm. The side with the nucleus divided until it has sixteen cells. Spemann then loosened the loop and let the nucleus from one of the embryonic cells to
The majority of the article discusses what really can be called therapeutic cloning; that is- using the genetic material from patients’ own cells to produce replacement cells and tissue. Scientists began this experiment in early 2001. Their goal was to create a cloned human embryo. One issue that posed a major obstacle to them was the question of what was “ethical” and what was not. After consulting with ethicists, lawyers, fertility specialists, and counselors- the time had come to recruit women willing to donate eggs “to be used in the cloning procedure and also collect cells from individuals to be cloned (the donors).” (Article, 46). Though the cloning process doesn’t seem very complicated, there are many small and intricate steps that go into it. Some of theses factors are yet to be understood by scientists. Scientists are enthusiastic that the day when they will be able to offer therapeutic cloning to patients who are ill is going to happen, hopefully sooner than later. Their efforts are to not only heal damaged spinal cords but to treat brain disorders also. Even more encouraging is a potential for theses cloned cells to “differentiate into cells of the blood and bone marrow.” (Article, 48). This development could be used to help people inflicted with autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. This could also be used to help Cancer patients. The timing of each attempt depended greatly on the menstrual cycles of the woman because they had to be given special hormone injections so that they would produce approximately ten eggs instead of the normal one or two. The efforts were thought to be successful after the third cycle. This was when the nucleus of the injected fibroblast appeared to divide; however it never separated into two different cells. After trying a different method that was used by Teruhiko Wakayama, they were more successful. It took 71 eggs from seven volunteers before they got their first cloned embryo. “Of the eight eggs we injected with cumulous cells, two divided to form early embryos of four cells- and one progressed to at least six cells-before growth stopped.” (Article, 47). The next step was to determine whether or not they could make human eggs divide into early embryos without being fertilized by a sperm or being enucleated and injected with a donor cell. “Stem cells derived from such parthenogenetically activated cells would be unlikely to be rejected after transplantation because they would be very similar to a patient’s own cells and would not produce many molecules that would be unfamiliar to the persons immune system.” (Article, 47).
Some topics in this essay:
Alzheimer’s Disease,
Teruhiko Wakayama,
Hans Spemann,
Steen Willadsen,
Thomas King,
Human Clone,
Karl Illmensee,
Briggs King,
John Gurdon,
Hunt Morgan,
genetic information,
reproductive cloning,
therapeutic cloning,
article 46,
article 47,
nuclear transfer,
differentiated cells,
contained genetic information,
claimed cloned,
willing donate,
cloned embryo,
willing donate eggs,
nucleus blastula cell,
own cells produce,
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Approximate Word count = 1955
Approximate Pages = 8 (250 words per page double spaced)
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