Scientists Produce Human Embryos of Mixed Gender

By Rick Weiss

Washington Post Staff Writer
Thursday, July 3, 2003; Page A10

Scientists in Chicago have for the first time made human embryos that are part male and part female, raising ethics questions and prompting calls for more oversight of the rapidly evolving field of human embryo manipulation.

The experiments, described at a meeting of the European Society of Human Reproduction and Embryology in Madrid, proposed to answer basic questions about human embryo development and to foster therapies for congenital diseases.

The hybrid embryos were destroyed after six days, when they had grown to a few hundred cells organized into a microscopic, mixed-gender ball, according to a written synopsis of the work submitted by the research leader, Norbert Gleicher of the Center for Human Reproduction.

Such work is legal in the United States if federal funds are not used and if the male and female embryos that Gleicher merged were freely donated for research, as Gleicher reported they were.

Nonetheless, his presentation yesterday drew criticism from some fellow scientists at the meeting, according to a report from Madrid. Reuters news service quoted one official of the society as saying, “There are very good reasons why this type of research is generally rejected by the international research community.”

The experiments also angered U.S. opponents of human embryo research and prompted some ethicists to refresh their long-standing call for a national debate about the pros and cons of human embryo studies — and perhaps creation of a national ethics board to review proposed experiments.

“I don’t know if this work is ‘right’ or ‘wrong,’ but it should be reviewed and discussed long and hard before it’s done,” said George Annas, a professor of health law and bioethics at Boston University. “It’s one thing if the right-to-life community has problems with your work. But if scientists hear you talk about your work for the first time and say it’s outrageous, that says something.”

Gleicher could not be reached for comment yesterday. An abstract of his work published in the program of the Madrid meeting says the experiments were part of an effort to find out whether human embryos with genetic defects might develop normally if, during the first few days of their existence, they were “seeded” with healthy cells that could take over the work of the defective cells.

To see if cells could survive transplantation from one embryo to another — and if transplanted cells could multiply normally in recipient embryos — Gleicher transplanted one, two or three embryo cells from male embryos into 21 one-day-old female embryos. He used different sexes, because male cells are easy to track in a female embryo by virtue of the males’ Y chromosome.

In 12 cases, the hybrid embryos developed normally, with male and female cells intermixed. In nine cases, the embryos developed abnormally. The team concluded that transplants of normal embryo cells represent a “possible treatment option” for embryos harboring genetic defects.

Jeffrey Kahn, director of the University of Minnesota’s Center for Bioethics, said the controversy is the latest manifestation of a problem that dates back 20 years, when the federal government decided it would neither fund nor oversee experimentation on human embryos. That has pushed the work into the private sector, he said, where oversight is all but nonexistent even as bigger and bigger ethics questions are raised.

“It all comes back to what you think the moral status of the embryo is,” Kahn said, adding that the situation is only going to get more complicated as embryos get altered to the point of perhaps not being embryos. “The question is, ‘What is it?’ ” Kahn said of Gleicher’s creation. “If you think it is something with the moral status that you or I have, then you have a big problem.”

Douglas Johnson, legislative director of National Right to Life, said in an e-mail message that Gleicher’s work was clearly unethical.

“Each member of the species Homo sapiens is genetically male or female from conception,” Johnson wrote. “These are truly female human embryos who are being used as subjects for lethal and unethical experimentation.”

Annas, the Boston University ethicist, said he favored creation of a national review board that could consider the scientific and ethical value of such studies. Local hospital- or university-based boards that review the ethics of proposed studies “are totally ill-equipped to consider these kinds of proposals,” Annas said.

The President’s Council on Bioethics, headed by Chicago physician and philosopher Leon Kass, has recently turned its attention to the question of whether reproductive medicine ought to be more thoroughly regulated.