washington

One of the leading US professional associations of biologists has adopted a voluntary five-year moratorium on the cloning of human beings. But it is also seeking to keep open a window that would allow research on human embryos that might otherwise fall under a wider ban on cloning-related research.

The Federation of American Societies for Experimental Biology (FASEB) last week announced its approval of the moratorium, which had won unanimous approval on 10 September from the federation's public affairs executive committee.

“We want to reassure Americans that biologists have no intentions of cloning human beings,” Ralph Yount, president of FASEB and a chemist at Washington State University in Pullman, said in a statement. “Indeed, we would regard cloning a human being as an unethical and reprehensible act.”

FASEB has 14 member societies representing more than 52,000 scientists. The moratorium defines “cloning human beings” as “the duplication of an existing or previously existing human being by transferring the nucleus of a differentiated, somatic cell into an enucleated human oocyte, and implanting the resulting product for intrauterine gestation and subsequent birth”.

But text accompanying the moratorium makes a point of contrasting cloning intended for implantation and for in vitro research. “We expect that further research using human cells will also be necessary to secure the benefits of insights from animal cloning and nuclear transfer as applied to human health,” it states.

In the accompanying statement, FASEB also warns against “imprecise or misused technical language” in planned federal and state legislation. “Such laws could hinder vital biomedical research,” it says.

One bill introduced by Representative Vern Ehlers (Republican, Michigan) was amended in July by the House of Representatives Science committee to ban federal funding for the use of cloning for in vitro research in human embryos as well as for producing human beings (see Nature 388, 505 505; 1997).

Although the FASEB moratorium defends “important new research” in human cells made possible by cloning, officials deny they are taking a stand in favour of human embryo research. The FASEB board “wanted to deal only with” the issue of most concern to the public, which is cloning a new adult human being, says Mike Stephens, a lobbyist for the group. The group's position on human embryo research is “still being discussed by FASEB and its societies”, he adds.

Some feel that FASEB may be trying to avoid provoking controversy by steering clear of the heated debate on the ethics of embryo research. “They wanted to reassure the American people without necessarily stirring up other things,” says Brigid Hogan, professor of cell biology at Vanderbilt University School of Medicine in Nashville, Tennessee.

Hogan co-chaired a panel on embryo research set up by the National Institutes of Health which concluded in 1994 that such research was acceptable for federal funding if it was carried out within strict limits.

Arthur Caplan, a bioethicist at the University of Pennsylvania, agrees with Hogan. “By omission they are hoping that research on some human clones at the embryo level might be allowed,” he said.

FASEB officials also deny that the moratorium is intended to respond to the House Science committee's July vote to outlaw the use of cloning technology for in vitro research on human embryos. “It was really not our goal to affect legislation,” says William Brinkley, the group's vice-president, who is dean of the Graduate School for Biomedical Sciences at Baylor College of Medicine in Texas.

Roger Pedersen, a member of FASEB's public affairs executive committee and a reproductive geneticist at the University of California, San Francisco, said that member scientists should be able to use the new cloning technology to do research on human cells in vitro. This, he said, would help scientists understand how adult nuclei are reprogrammed by cellular cytoplasm, possibly opening avenues to novel ways of repairing and regenerating human tissues.

Pedersen led an earlier move by the 2,000-member Society of Developmental Biologists (SDB), a FASEB member society, to adopt the moratorium. About a quarter of SDB's members participated in an electronic and mail-in vote on the moratorium in early September; 93 per cent approved it.

In a report to President Bill Clinton in June, the National Bioethics Advisory Commission called on scientific societies to comply voluntarily with a moratorium on federal funding for cloning human beings (see Nature 387, 644 644; 1997).

Clinton made a similar plea when he announced the moratorium in March (see Nature 386, 97 97; 1997), and has also drafted legislation outlawing the cloning of human beings for five years.