A tiny cluster of six human cells has become the latest poster child in a highly charged debate in the United States over the movement to ban the cloning of humans.
It's a debate that pits deeply held convictions about the uniqueness of the individual and the sacredness of human life and whether it begins at conception, against deeply held convictions that cloning - at least for research purposes - could lead to a new and potentially lucrative field of "regenerative" medicine.
The announcement Sunday that researchers at a private company had become the first to clone a human embryo using genetic material from adult cells adds urgency to a policy debate in Congress that had been pushed aside since Sept. 11.
The embryos created by Advanced Cell Technology (ACT) in Worcester, Mass., failed to develop for more than a few days. But the company says its efforts will continue, prompting some lawmakers to renew calls for at least a temporary ban on all human cloning - private as well as publicly funded - while Congress decides the controversial issue.
Congress has banned the use of federal funds for such work. The House voted in July on a broad ban, but the Senate would need to follow suit to stop companies such as ACT from moving forward with their research.
The goal, the scientists say, is to clone embryos that grow sufficiently to produce embryonic stem cells, which can develop into all the major cell types the human body uses. By using genetic material from adult cells, scientists believe the resulting stem cells will be less likely to be rejected by a patient under medical care.
"We've taken the first halting steps toward what we think is going to be a new area of medicine," said Michael West, ACT's president and chief executive officer in what appeared to be a carefully orchestrated release of the results.
While the results represent an advance, their significance may lie more in the political than in the scientific realm.
"Each time you do this in a new mammalian species, it's an advance, but [ACT's results are] not a big deal," says Alta Charo, a law professor at the University of Wisconsin and a former member of the president's National Bioethics Advisory Commission, whose federal charter expired last month.
"But it's certainly a political 'wow,' because no one's been willing to do this with humans so far," she adds.
The ACT researchers, operating under the guidance of the company's ethics-advisory panel, tried three approaches to cloning. Scientists first tried to take nuclei from adult skin cells and implant them in eggs whose nuclei had been removed. (The nucleus holds an individual's complete genetic blueprint in chemical form as DNA.) When direct nuclear implants failed, the researchers inserted tiny "cumulus" cells, which typically nurture eggs while they form, into eggs. These yielded three cloned embryos, but none divided beyond six cells before stopping.
The team says it also used a technique that can trigger the formation of early embryos without fertilizing an egg. Known as parthenogenesis, it involved exposing 22 eggs to a chemical bath designed to induce them to form embryos. Five days later, only six eggs appeared to have developed embryos, but these failed to fully form structures that generate stem cells.
ACT's results, though modest, have triggered fresh calls for Congress to finish work on anti-cloning legislation.
"This corporation is creating human embryos for the sole purpose of killing them and harvesting their cells," says Douglas Johnson, legislative director for the National Right to Life Committee.
Proponents argue that if the US bans such research, other nations would take the lead in this important field. But President Bush yesterday called cloning "morally wrong."
"We should not, as a society, grow life to destroy it," he said.
The legislative ball is in the Senate's court. In House measure passed last summer would impose a $1 million fine and up to 10 years in jail for cloning a human embryo, either for research purposes or for implantation in a woman to carry it to term.
The measure won out over a more modest bill that would have banned implantation of cloned human embryos, thus permitting cloning for research.
Even before the terrorist attacks of Sept. 11, which suddenly changed a long list of legislative priorities, senators were in no hurry to deal with the cloning bill.
"This was not a welcomed issue," Dr. Charo notes, because a vote either way will offend vocal groups - either anti-abortion advocates or people diagnosed with illnesses or injuries for which stem-cell therapies might be devised.
Even with ACT's announcement Sunday, some senators from both sides of the aisle are in no hurry to dispose of the issue.
"I think that the Senate moving immediately could be a mistake," Sen. Patrick Leahy (D) of Vermont told NBC's Meet the Press. "If you're legislating, you're legislating for decades to come."
Material from The Associated Press was used in this story.