Scientists successfully clone primate embryonic stem cells

Scientists at the Oregon Health and Science University's (OHSU) National Primate Research Centre have announced a successful attempt to derive embryonic stem cells (ES cells) from the skin cells of a macaque monkey. The research, which represents the first time a cloned ES cell line has been derived from a primate, was published in the journal Nature last week.

Using a technique called SCNT (somatic cell nuclear transfer), the team transplanted the nucleus of the monkey's skin cell into an unfertilised egg cell that had had its genetic material removed. The egg was then encouraged to grow into an embryo, from which stem cells can be extracted. The stem cells from the embryo are a genetic match for the source of the DNA, in this case the monkey that donated the skin cell.

The results are exciting for two main reasons. Firstly, because the stem cells have the ability to grow into any tissue in the body scientists believe they could be used to develop treatments for degenerative diseases. Secondly, the team believe that the breakthrough in cloning primate stem cells shows that it is theoretically possible to do so in humans. This potentially means that a patient could be treated with their own stem cells, avoiding the risk of transplant rejection. Dr Shoukhrat Mitalipov, director of the OHSU-based research team commented that 'many scientists believe that embryonic stem cells hold great promise for treating a variety of diseases including Parkinson's, multiple sclerosis, cardiac disease, and spinal chord injuries'.

As well as the hope for people living with degenerative diseases, the team's discoveries are also welcomed because they avoid the use of fertilised embryos, which have caused considerable ethical debate. However, this has not prevented some groups urging caution with respect to the new discoveries. Helen Wallace of Genewatch said the work gave rise to 'a real worry' that a renegade scientist would attempt to create a cloned baby, especially in countries that did not have the same legal safeguards as Britain.

That the team was successful where others had failed was due to a new technique of handling the donor eggs during the cloning process, pioneered by Dr Mitalipov. Instead of dying the genetic material, or using an imaging technique that exposes the cell to ultraviolet light, which Dr Mitalipov believed could damage the primate eggs, they used a new illumination technique called Oosight, employing polarised light, resulting in a higher survival rate for the clones. Dr Mitalipov commented 'while development of stem cell lines requires hundreds of attempts, this research proves it can be done and will likely lead to refinements which will make the process more efficient and lead to a higher success rate. This is the next step for our research team as other scientists continue to investigate the promise of stem cell therapies'.