By Will Dunham

One gene directs both embryonic and adult stem cells to perform the self-renewal function that is crucial in their potential broad use in medical treatments, researchers said on Thursday.

While the biology of these types of stem cells is very different, a study published in the journal Cell showed that they share at least this one key feature -- a gene called Zfx that controls their ability to self-renew.

Stem cells are a kind of master cell for the body, capable of transforming into various tissue and cell types, offering hope that they can be used to repair tissue damaged by disease or injury.

One reason they are valuable to medical researchers is because they can self-renew -- living and dividing in a lab dish for months or even years without differentiating into specific cell and tissue types.

Working with mouse cells, researchers led by Boris Reizis of Columbia University Medical Center in New York found that the gene Zfx governed self-renewal in embryonic stem cells and in blood-generating hematopoietic adult stem cells.

Reizis said it is quite likely this gene does the same thing in people that it does in mice. The finding expands the understanding of the biology of these cells.

Embryonic stem cells are present during early embryo development and give rise to all cell types in the body.

Advocates say embryonic stem cell research may offer revolutionary new ways to treat conditions such as diabetes, Parkinson's disease and spinal cord injuries. But this research requires destruction of days-old embryos, and opponents call it immoral.

In adults, the body is replenished by adult stem cells that continuously generate all the cell types that comprise specific types of tissues. They may not be as malleable as embryonic stem cells but scientists think they also are potentially useful for medical purposes.

"For quite a while, one outstanding question in the field was whether this self-renewal of embryonic stem cells and adult tissue-specific stem cells has a common molecular basis," Reizis said. "Basically there were data both for it and against it, and overall it's one big controversy."

Reizis said his finding demonstrates the common molecular basis in the role of Zfx, a type of gene that controls the action of other genes.

He said that a greater understanding of how this gene works might enable scientists to boost the self-renewal of different kinds of stem cells, which could help for example in producing embryonic stem cells for use in medical research or potential future treatments.