Adult cells in mice shown to mimic embryonic stem cells

German scientists said on Friday they had isolated sperm-producing stem cells that have similar properties to embryonic stem cells from adult mice.

If the same type of cells in humans show similar qualities the researchers from the Georg-August-University of Goettingen believe they could be used in stem cell research which would remove the ethical dilemma associated with stem cells derived from human embryos.

"These isolated spermatogonial stem cells respond to culture conditions and acquire embryonic stem cell properties," Gerd Hasenfuss and his colleagues said in report published online by the journal Nature.

Stem cells are master cells that have the potential to develop into any cell type in the body. Scientists believe they could act as a type of repair system to provide new therapies for illnesses ranging from diabetes to Parkinson's.

But their use is controversial because the most promising stem cells for treating human disease are derived from very early human embryos left over from fertility treatments.

In the report Hasenfuss and his team described how they isolated the sperm-producing stem cells from mice testes.

The cells, which they call multipotent adult germline stem cells (maGSCs), under certain conditions, acted like embryonic stem cells. When the researchers injected the cells into early embryos they found the cells contributed to the development of different organs.

Professor Chris Higgins, the director of Britain's Medical Research Council (MRC) Clinical Sciences Center, said the possibility of using the cells as an alternative to embryonic stem cells for therapy is intriguing.

"However, much more research is required before the similarities and differences between these testes cells and embryonic stem cells are understood, and before their potential for use in therapy can be properly assessed," Higgins said in a statement.

Dr Stephen Minger, a stem cell biologist at Kings College London, described the findings as "pretty amazing" but said more research is needed.

"We would need to replicate this in humans, just because it works in a mouse doesn't necessarily mean it will also work in people," he said.

If it is possible to isolate the cells in humans and show that they work it would give scientists another source of stem cells for research.

Copyright 2006 Reuters News Service. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Copyright © 2006 ABC News Internet Ventures