Cloning is a technique to produce the genetic twin of another organism, but it can also be used for other purposes. There are three main types of cloning technologies.
- Recombinant DNA technology or DNA cloning,
- Reproductive cloning and
- Therapeutic cloning.
DNA cloning refers to a process where a DNA fragment of interest is transferred from one organism to a self ï¿½ replicating genetic element such as a bacterial plasmid. The DNA of interest can then be propagated in a foreign host cell. This technology has been around since the 1970ï¿½s, and it has become a common practice in molecular biology laboratories today. This technology is important for learning about other related technologies, such as gene therapy, genetic engineering of organisms, and sequencing genomes. Gene therapy can be used to treat certain genetic conditions by introducing virus vectors that carry corrected copies of faulty genes into the cells of a host organism. Genes from different organisms that improve taste and nutritional value or provide resistance to particular types of disease can be used to genetically engineer food crops.
Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal. Dolly was created by this technology. If the low success rates can be improved (Dolly was only one success out of 276 tries), reproductive cloning can be used to develop efficient ways to reliably reproduce animals with special qualities. For example, drug producing animals or animals that have been genetically altered to serve as models for studying human disease could be mass-produced. Reproductive cloning also could be used to repopulate endangered animals or animals that are difficult to breed. Cloning extinct animals presents a much greater challenge to scientists because the egg and the surrogate needed to create the cloned embryo would be of a species different from the clone.
Therapeutic cloning, also called “embryo cloning” is the productive of human embryos for use in research The goal of this process is not to create cloned human beings, but rather to harvest stem cells that can be used to study human development and to treat disease. Stem cells are important to biomedical researchers because they can be used to generate virtually any type of specialized cell in the human body. Many researchers hope that one day stem cells can be used to serve as replacement cells to treat heart disease, Alzheimerï¿½s, cancer, and other diseases. Therapeutic cloning technology may some day be used in humans to produce whole organs from single cells. Much work still needs to be done before therapeutic cloning can become a realistic option for the treatment of disorders. Another potential application of cloning to organ transplants is the creation of genetically modified pigs from which organs suitable for human transplant could be harvested.
Should humans be cloned? Physicians from the American Medical Association and scientists with the American Association for the Advancement of Science have issued formal public statement, advising against human reproductive cloning. Due to the inefficiency of animal cloning and the lack of understanding about reproductive cloning, many scientists and physicians strongly believe that it would be unethical to attempt to clone humans. Scientists do not know how cloning could impact mental development. While factors such as intellect and mood may not be as important for a cow or a mouse, they are crucial for the development of healthy humans. With so many unknowns concerning reproductive cloning, the attempt to clone humans at this time is considered potentially dangerous and ethically irresponsible.
Several attempts and trials have been made to produce improved quality of animals. Similar experiments are also underway to improve the level of human beings. Scientists aim at producing individuals having desired qualities. The attempts to improve the cell quality in animals and humans by changes in genes have not yielded the desired results. Attention of scientist has now shifted from genes to electro magnetic fields for improving the quality of cell. Experiments by several researchers have shown that these methods are successful to some extent in improving the body structure but fail to produce the desired qualities. The scientific attempts can not assure that the moral, intellectual and social qualities will improve. Such conclusions were drawn by yogis in the past. They had ruled that the only way to improve the quality of the offspring is that both the parents should prepare themselves by spiritual practices before they decide to have a child.
Yogic practices like penance and meditation reform the chromosomes which improve the quality of the offspring. This is the only way to improve the moral, intellectual and social qualities in the offspring.