written by: R. Elizabeth C. Kitchen•edited by: Paul Arnold•updated: 2/8/2010
Did you know that there are actually different types of cloning? This article explores reproductive and therapeutic cloning. Read on to find out more.
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There is a never-ending debate concerning reproductive and therapeutic cloning. Much of the controversy surrounds reproductive cloning and there are laws that ban it for specific purposes. There are two main types of cloning: medical therapy cloning (therapeutic) and reproduction cloning (reproductive).
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What is Cloning?
Cloning is a process in which a genetic duplicate is made of something that is already in existence. Genes, single cells, animals, humans, and various other things can be cloned and there are several ways to clone them. For decades, plants have been cloned, and the first animal, a tadpole, was cloned in the 1950s.
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This type of cloning is done with the intent of making another organism. The clone will be an exact duplicate of the one that exists now. Reproductive cloning includes animals, plants, and humans.
Somatic Cell Nuclear Transfer, also referred to as SCNT, is the technique used for this type of cloning. A recipient egg's genetic material is extracted so that only an empty egg remains. A cell from the organism being cloned is taken and its nucleus is extracted. This nucleus is then implanted in the egg. The egg is then forced to divide, using a mild electric shock or chemicals, creating an embryo which will eventually be placed into the uterus of a surrogate mother.
As of today, this type of cloning has been used for research only, but its future uses are staggering. This type of cloning could be beneficial in making breeding specific animals simpler or in repopulating endangered species. It may also be used to create organisms with specific characteristics like genetically unique animals or drug-producing animals.
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This type of cloning is done to harvest embryonic stem cells that will be used in medical treatments. These types of cells are found within developing embryos. They are capable of creating a variety of different cells, such as muscle, tissue, and organ cells. Stem cells have also been extracted from some adult organs.
The process used for this type of cloning is much like reproductive cloning, but the stem cells are extracted and the embryo is only allowed to reach a certain size of cells.
The idea of the technology is that one of the patient's cells will be removed and used for medical treatment. The nucleus will then be removed and placed into an egg that has had its nucleus removed. An electric current or chemicals encourage division. The embryonic stem cells that result are then extracted from the embryo and used in the patient's treatment.
This type of cloning is meant for medical use. The embryonic stem cells create replacement tissue such as skin for burns victims, or cells for patients with spinal cord injuries. One day they might be used to create organs for transplant patients. There is no risk of rejection because the cells that are used come from the patient. This type of cloning may also be beneficial to patient's suffering from Alzheimer's disease, heart disease, or Parkinson's disease.
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The ethical concerns surrounding reproductive and therapeutic cloning are abundant. Many people are against both types of cloning, but reproductive cloning has far more critics because they view it as interfering with nature's progression. They also fear human cloning will occur, resulting in babies being cloned just so that they have specific genetic characteristics. Therapeutic cloning is also debated because once the stem cells are extracted, the embryos are destroyed. Because of this, some people view it as barbaric and unnatural, resulting in some countries not allowing this type of cloning.
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American Federation for Aging Research. (2008). What is Therapeutic Cloning? Retrieved on January 28, 2010 from Info Aging: http://websites.afar.org/site/PageServer?pagename=IA_b_cloning_3_therapeutic
Center for Genetics and Society. (2009). About Reproductive Cloning. Retrieved on January 28, 2010 from the Center for Genetics and Society: http://www.geneticsandsociety.org/article.php?list=type&type=16
Pregnancy Info. (2009). Therapeutic Cloning vs. Reproductive Cloning. Retrieved on January 28, 2010 from Pregnancy Info: http://www.pregnancy-info.net/StemCell/therapeutic_vs_reproductive.html
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Cloning Process (ethical issues section): Wikibob – Wikimedia Commons