'Super stem cell' tested in mice

The mice were given stem cell transplants

A stem cell derived from the bone marrow of adult mice can develop to form virtually any other cell in the body, say scientists.

This is the "ultimate" stem cell, claims the research team, who are publishing details of their work in the journal Cell.

Stem cells are the body's master cells, which have the ability to develop into a wide variety of other cell types.

Control over this cell "differentiation" could give scientists the ability to manufacture replacement tissues for those damaged by disease or injury.

In this case, a modified stem cell replaced into the bone marrow of a mouse then supplied the blueprint for cells in the lung, throat, stomach, intestine, liver and skin.

Full flexibility

This suggests potential for the delivery of gene therapy to various parts of the body simply by putting a cell with different genetic modifications back into the bone marrow.

Dr Neil Theise, an associate professor of pathology at New York University School of Medicine, US, said: "It had been thought that only embryonic stem cells had such wide-ranging potential.

"This study provides the strongest evidence yet that the adult body harbours stem cells that are as flexible as embryonic stem cells."

The study was a joint effort between researchers in New York, Yale University, and Johns Hopkins School of Medicine in Baltimore.

Stem cells from the bone marrow of male mice were purified, and a single cell selected. This was transplanted back into a female mouse which had had its own bone marrow destroyed by radiation treatment.

Migration of cells

Eleven months later, the Y chromosome - found only in male cells - was not only found in cells of the bone marrow and blood, but also in the other tissues.

Dr Diane Krause, of Yale University, said: "It's astounding that there are cells in our bone marrow that can become so many different cell types including blood, lung, gastrointestinal tract and skin.

"The challenges now are to elucidate how these changes occur and to harness these findings to develop therapies for many different human diseases."

In theory, this natural migration of stem cells from the marrow to different organs could be used to carry cells which have been modified in different ways, perhaps to carry the correct versions of defective genes in a variety of genetic illnesses.