When Diane Krause, M.D., Ph.D., published findings this spring from her work on adult-derived stem cells in mice, she didn’t expect to become a player in a national political debate. “I thought it would be important for those of us in the field,” she said in July, adding “I didn’t realize it was going to get such press attention.”

Krause, an associate professor of laboratory medicine and pathology, identified adult stem cells in bone marrow that can also create new liver, lung, gastrointestinal and skin cells. Working with collaborators at Johns Hopkins and New York University, she found the first evidence that these progenitor cells are capable of creating up to 15 different mature cell types.

Since the publication of her work in the May issue of Cell, Krause has been besieged by media inquiries from around the world. In early summer, she was asked to testify on Capitol Hill.

Her conclusions were published as the national debate over embryonic stem cell research was heating up and, to her dismay, have provided fodder to opponents of such work, which requires the destruction of human embryos. Those who oppose embryonic stem cell research for moral reasons argue that it is unnecessary because adult stem cell research shows such promise. Krause insists that research down both avenues is vital.

In July she had a chance to make her point before the US Senate Appropriations Subcommittee on Labor, Health and Human Services and Education, which held hearings on the federal government’s role in funding future embryonic stem cell research.

Embryonic stem cell research needs to be funded for three reasons, Krause told the subcommittee. First, these cells can be grown in vitro, unlike adult stem cells. Second, because they are the most versatile cells available, embryonic stem cells yield far more information on how they maintain that versatility than adult-derived cells. And third, she said, “No one can predict which lines of investigation will lead to effective and safe treatments for human disease.”

On August 9 President Bush outlined his plan for funding embryonic stem cell research: only existing lines of embryonic stem cells, left over from in vitro fertilization, could be used in federally funded research. Research using embryonic stem cell lines developed after August 9 would be ineligible for funding. On August 27, the National Institutes of Health released a list of 64 eligible embryonic stem cell lines.

Scientists have questioned that list, noting that many cell lines are unavailable or inappropriate for a variety of reasons.

“The president’s plan is not well thought out,” Krause said. “It doesn’t give federally funded scientists the freedom to pursue scientific questions.”

On September 5, Secretary of Health and Human Services Tommy Thompson told a Senate committee that only about 24 of the 64 cell lines were ready for use in experiments. The usefulness of the remaining cell lines, he said, remains to be proven.