what is cloning ?
In 1997 scientists in Scotland, led by Dr. Ian Wilmut of the Roslin Institute, cloned the first mammal, a sheep named Dolly. Since then mice, goats,mules,rats,monkeys ,cows and pigs have been successfully cloned around the world. This has made human cloning a real possibility.
Cloning is different from natural fertilization which is "sexual" reproduction that occurs when a sperm fertilizes an egg. In normal fertilization the developing embryo (and person) has the genetic makeup or DNA of both parents 23 chromosomes from the female and 23 from the male. The embryo is the unique human organism with a novel genetic makeup having the full potential to develop to adulthood.
Human cloning, on the other hand, is a type of "asexual" reproduction, which means reproduction not initiated by the union of egg and sperm. Cloning is accomplished by a technique called "somatic cell nuclear transfer." One takes the nucleus from a body (somatic) cell and transfers it into a female egg which has had its nuclear material removed. Then with an electric current or chemical stimulus the cloned embryo begins to divide as does a fertilized embryo.
Most scientists agree that human cloning poses a serious risk of producing children who are stillborn, unhealthy, severely malformed or disabled.
Additional scientific problems with human cloning such as the potential for mutation, transmission of mitochondrial diseases, and the negative effects from the aging genetic material.
Some scientist experts, such as Ian Wilmut and Rudolf Jaenisch, conclude that the most likely cause of abnormal clone development is faulty reprogramming of the genome. This may lead to abnormal gene expression of any of the 30,000 genes residing in the animal. Methods used in routine prenatal screening to detect chromosomal or genetic abnormalities in a fetus cannot detect these reprogramming errors.
If there would be undetectable genetic abnormalities in a developing human clone, then there may also be genetic abnormalities in any tissues or cells derived from human clones. The problem of faulty genetic expression is a major reason why most scientists are opposed to implanting cloned embryos and allowing any development toward childhood. However, the same argument applies then as a major reason why human cloning for medical purposes should be opposed. (Lousy embryos, lousy stem cells.)
Rejection Problem: It is false to say that cloning solves the transplant rejection problem. Each embryo clone would still contain mitochondrial DNA from the egg donor; the clone is NOT an exact genetic copy of the nucleus donor, and its antigens would therefore provoke immune rejection when transplanted. There would still be the problem of immunological rejection that cloning is said to be indispensable for solving.
Reprogramming Problem: Some argue that "therapeutic cloning" must be performed to research reprogramming errors, in order to better develop tissues using embryo and adult stem cells. The argument is that once we understand reprogramming errors, we can take a body cell and reprogram the cells to become stem cells.
All in all, cloning is not a technology to be shunned and hidden in a cupboard, but neither should it be used lightly. The maximum research needs to be put in before any cloning takes place, and governments should be especially careful about what laws they enforce on cloning, and how they are enforced.
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COMPANIES INVOVED IN RESEARCH AND CLONING
1. Advanced Cell Technologies (ACT).One Innovation Drive, Biotech Three, Worcester, MA
2. L'Alliance Boviteq (LAB) 1425, grand rang Saint-Fran ois,
3.Genetic Savings and Clone 3312 Longmire Dr., College Station, TX
4.Geron Corporation Menlo Park, CA
5.Infigen 1825 Infinity Drive, DeForest, WI
6.Lazaron BioTechnologies LLC. Louisiana Business & Technology Center, South Stadium Drive, Baton Rouge LA
7.Nexia Biotechnologies 21,025 Trans-Canada Highway Ste. Anne de Bellevue, QC H9X 3R2, Canada
8.PPL Therapeutics Scotland,U.K.
9.ProBio Level 50 120 Collins Street Melbourne Victoria 3000, Australia.
10.The Roslin Institute Scotland, U.K
    
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