Researchers in California said Thursday that they have produced human clone embryos from adult skin cells, in an advancement toward developing stem cells which could be used to cure degenerative diseases such as Alzheimer's and Parkinson's.

Scientists used a technique called somatic cell nuclear transfer (SCNT). They first removed the nuclei of mature egg cells from healthy young women and then inserted DNA from an adult male donor into the eggs. The DNA used in the experiment was retrieved from skin cells called fibroblasts.

In genetic tests, three of the embryos developed from the reconstructed eggs were proved to have the same DNA as their male skin cell donors. The research was published in Thursday's issue of the science journal Stem Cells.

The achievement is "a critical milestone in the development of patient-specific embryonic stem cells for human therapeutic use, potentially including developing treatments for Parkinson's, Alzheimer's and other degenerative diseases," said Dr Samuel Wood, who is CEO of the embryonic stem cell research company La Jolla which conducted the study and a co-author of the paper as well as donor of the skin cells from which the embryos were cloned.

However, some scientists said that the real breakthrough would be to create a human embryonic stem cell line from cloned embryos, which has not been achieved in this study, although Dr Wood said his team is trying to produce stem cell lines from the embryos.

Some U.S. religious groups criticized the study for involving creating human lives in the lab solely to destroy them for alleged benefit.

(Xinhua News Agency January 17, 2008)