Scientists clone human embryo

First human embryo cloned

South Korean and US researchers said today that they had cloned a human embryo and extracted from it sought-after cells called embryonic stem cells.

The experiment, the first published report of cloned human stem cells, means so-called therapeutic cloning is no longer a theory but a reality. Supporters of medical cloning say it can transform medicine, offering tailored and highly effective treatments for diseases ranging from Parkinsons to diabetes. They say it could eventually lead to grow-your-own organ transplants.

The stem cells taken from the tiny embryos, known as blastocysts, have the potential to develop into any kind of cell or tissue in the body. "Our approach opens the door for the use of these specially developed cells in transplantation medicine," Woo Suk Hwang, of Seoul National University in Korea, who led the study, said in a statement.

Critics says cloning unethical
However, critics say it involves destroying a human embryo, however tiny, and is thus unethical. The administration of George W. Bush, the US president, and supporters in Congress are seeking to outlaw the technology both in the US and worldwide.

Writing in the journal Science, Hwang and colleagues said they created the clone using eggs and cumulus cells donated by Korean women. Cumulus cells are found in the ovaries and in some species have been found to work especially well in cloning experiments.

Scientists have cloned sheep, cattle, mice and other species but have had trouble cloning a human being. Last year a Massachusetts company, Advanced Cell Technology, said it had created a human cloned embryo but it had not grown enough to become a source of stem cells. The company is still trying but has not reported publicly on its progress. - Reuters