A common factor between different cloning technologies is that all cloning techniques produce genetic twins of living organisms. The three basic types of cloning include recombinant DNA technology or DNA cloning, reproductive cloning, and therapeutic cloning. DNA cloning (also called molecular and gene cloning) refers to the process of transferring DNA fragments from one organism to another, according to the U.S. Department of Energy Office of Science. Reproductive cloning is the process of generating an animal with same nuclear DNA as another, or previously existing animal (the technique used to create the sheep clone, Dolly). And therapeutic cloning (also referred to as embryo cloning) is the production of human embryos for scientific research.
Dolly was the first mammal to ever be cloned. She was cloned using the technique of reproductive cloning (not embryo cloning) at the Roslin Institute in Scotland in 1997. This significant scientific breakthrough generated much scientific and ethical debate. Dolly was cloned from adult DNA and lived to the age of 6. Towards the end of her life, she suffered from lung cancer and arthritis. Other than that, she lived quite a normal life for a sheep, with few physical problems, according to the U.S. Department of Energy Office of Science.
Embryo cloning involves collecting eggs from ovaries and removing genetic material from the eggs. After genetic material is removed, a skin cell is inserted into the enucleated egg in order to serve as the egg's new nucleus. When the chemical ionomycin is applied, the egg begins to divide. Stem cells are extracted from the egg five days after division. During this stage of development, the egg is a blastocyst, and the extraction of stem cells destroys the embryo. The end goal of embryo cloning is not to clone a human being, but rather to harvest stem cells for medical research.
In November 2001, Advanced Cell Technologies was the first company to clone a human embryo for the purpose of embryo-cloning research. Since then there have been certain breakthroughs in therapeutic cloning research, such as 2003's production of therapeutic nerve cells that cure Parkinson's like disease in mice. Furthermore, in 2006, Children's Hospital Boston announced that it begun experiments with somatic cell nuclear transfer in order to clone diseases such as sickle-cell anemia and diabetes.
Stems cells are important new area of biomedical research because they have the ability to grow into virtually any type of specialized cell. As a result, scientists hope that they can be used to treat a variety of diseases and disorders. Embryo cloning may some day be used to produce healthy cells to replace damaged cells and to create entire organs from a single stem cell. A lot of research still needs to be done, however, embryo cloning has the potential to be a cure for many degenerative disease including cancer and Alzheimer's.
Embryo cloning is an area of stem-cell research that focuses on embryos and is the process of harvesting human stem cells for scientific study. Embryonic stem-cell research is sometimes also referred to as research cloning and therapeutic cloning. Cloning is a general term that scientists use to describe various processes for duplicating biological organisms and is an ethically controversial area of biomedical research. The debate regarding cloning is centered mainly around the ethical implications of using embryos and stem cells in scientific study.