CLONING TECHNOLOGY: There is much public confusion about what is involved in using cloning technology for medical research, added to by lobbies both for and against its use. People must also weigh the potential for important medical discoveries against the reality that embryos will be destroyed in conducting the experiments.
The first point to make is that these will not be conventional embryos produced by joining sperm and egg cells. They will be created using techniques originally used to produce Dolly the cloned sheep. The nucleus of a viable egg cell is replaced with a cell nucleus from a donor. When the egg is stimulated with a shock, it begins to grow like a normal embryo, but it would probably never be capable of producing a healthy human. Any number of constructed embryos can be produced in this way and the resultant stem cells harvested.
The UK legislation demands that any embryo produced for research, cloned or otherwise, may not be kept alive for more than 14 days. So this research is all about experimentation and nothing to do with attempting to clone a human being.
The researchers will produce copy embryos, allow them to grow for several days through several dozen cell divisions and then stop growth and take the embryos apart while still just a ball of cells. The purpose is to harvest a special cell type known as stem cells.
Stem cells represent one of the most exciting and promising research areas under study. They are special because they are capable of growing into any of the cell types in the body, from bone and blood to liver and skin.
Researchers believe that if they have a supply of stem cells and can learn how the body converts neutral stem cells into specific or differentiated cells, this may open up radical new treatments for degenerative diseases.
They argue that converted stem cells could be used to replace the missing insulin producing islet cells in diabetes or the damaged brain tissues of Parkinson's or Alzheimer's diseases.
Although that is the promise, no disease has yet been cured using them, nor is this approach likely to be used in patients for many years.
Detractors, opposed on ethical grounds, argue that while the developing embryo has a plentiful supply of stem cells, these are also available in the umbilical cord and in adult tissues. These represent alternative sources that do not involve the destruction of the embryo.
