Brave New Embryos

By Christine Gorman

There is no greater miracle in all of biology than the nine-month journey that begins with a fertilized egg and culminates in the birth of a tiny human being. From the moment the egg and sperm unite, an ancient and astonishingly intricate ballet unfolds. The still microscopic sphere divides into two, then four, then eight parts. Soon after, individual cells begin an extraordinary trek across this globe of living matter. Some dive deep into the core, where < they give rise to the intestinal tract. Others bunch along the surface, forming a hollow tube -- one end of which buds into a brain. Somehow every cell knows its place and fulfills its destinyas heart, bone, blood and sinew weave together into a single, organic whole.

For the past 14 years, scientists in the U.S. could only marvel at such complex choreography. To learn any more about it, they would have had to conduct experiments on human embryos and aborted fetal tissue. But federal funding for any such research was forbidden by the pro-life Administrations of Ronald Reagan and George Bush. Last year President Clinton quietly called for an end to his predecessors' ban and asked the National Institutes of Health to develop rules to guide the research. And since February an expert NIH advisory panel has been debating the details of what is sure to be one of the most controversial policies to come out of the Clinton Administration.

The panel's recommendations are not expected to be made public until next month at the earliest, but according to a report in last week's issue of the journal Science, the group has already made some tentative decisions that will upset pro-lifers -- and perhaps many others as well. To begin with, the committee apparently favors federal funding for experiments conducted on "spare" embryos collected at fertility clinics. During the process of in vitro fertilization, many eggs are fertilized but not all are implanted in the would-be mother. The extra ones are routinely discarded, and some countries already allow experiments on such embryos. But the proposed U.S. guidelines would go further: they would allow scientists to create and discard human embryos solely for research purposes. In other words, eggs and sperm could be donated by men and women who had no intention of becoming parents.

Scientists argue that such work could lead to breakthroughs in the treatment of everything from infertility to aging to cancer. Moreover, the guidelines would bring some discipline to the currently unregulated field of fertility research. But experiments on embryos raise the same tough question already at the center of the abortion debate: When do life -- and human rights -- begin? "This represents moral terra incognita for us as a society," says James Nelson, an ethicist at the Hastings Center in New York. "We have a huge range of definitions of what an embryo is -- anywhere from a person to just a bunch of tissue like any clump in the body."

Pro-life organizations are not waiting for the official release of the NIH recommendations; they are lining up political allies in an effort to derail the guidelines. A group of 32 members of Congress, led by Representative Robert Dornan, a California Republican, has sent NIH director Dr. Harold Varmus a letter of protest. "It's Frankensteinesque," Dornan says. "What they are doing is embryo destruction, and there's no way that they can adjust that to suit me." The uproar could be louder than the denunciations last year of the two George Washington University doctors who announced that they had split a human embryo in a process called cloning.

The expected debut of the NIH guidelines is hardly coming at an ideal time for the White House, since September will be a make-or-break month in the Administration's push to pass health-care reform legislation this year. Among the many parts of the Democrats' health plan that have stirred opposition is the President's insistence that abortion services be covered by insurance. Some pro-life members of Congress may turn against the entire plan on this issue alone, and they will be doubly upset by the proposals for federally funded embryo research.

Sensitive to ethical concerns, the NIH advisory panel intends to recommend strict limits on embryo studies. In most cases, for example, the embryos would not be allowed to develop for more than 14 days, which is the standard in countries that allow such research. Under no circumstance would experiments on embryos be allowed after the 20th day, when the tube of cells that is destined to become the brain and spine closes off.

The panel will come down against cloning to create duplicate babies. Specifically, the proposed rules will bar fertility specialists from splitting a fertilized egg into two, thereby creating identical embryos, and then placing them in a woman's uterus. Nor would researchers be allowed to make copies of adults by taking genetic information from, say, a skin cell and placing it in a fertilized egg stripped of its own DNA. But cloning like that performed by the George Washington doctors would be allowed. Because the eggs they used had been fertilized by more than one sperm, the embryos were destined to die within a few days anyway.

While treading cautiously in many areas, the NIH panel is supportive of several innovative lines of research. For example, biologists have learned how to trick unfertilized animal eggs into developing as if they had been fertilized. Without the sperm's DNA, however, these so-called parthenotes quickly perish. One tentative NIH proposal would allow scientists to produce parthenotes from human eggs. Such experiments could yield information on how embryonic cells influence each other's growth.

Most likely, the first people to benefit from embryo research would be the millions of couples (including an estimated 5 million in the U.S. alone) who have trouble conceiving. Much of the information in textbooks on developmental biology comes from research conducted between the turn of the century and the late 1940s. "It's a static picture, and some of it is wrong," says Dr. John Gearhart of the Johns Hopkins Medical Center. "Now we know what the questions are, and we have the tools we need to make the most of the small amount of material we could get."

Studying development could also bring advances in cancer research. Rapidly dividing embryonic cells behave a lot like tumors. A difference, though, is that young cells mature into various types of tissue while cancer cells do not. "If we can understand what happens in a normally dividing cell, then we can understand an abnormally dividing cell," says Dr. Maria Bustillo at the Mount Sinai Medical Center in New York City. "We can figure out what turns the cancer cells on."

Of course, no one knows what all the benefits of embryo research will be. Nor can anyone claim to know all the ethical questions that will have to be dealt with before studies can proceed. What seems certain is that the debate will soon move beyond a select circle of scientists and policymakers and into the public arena. The decisions made will set out nothing less than the definition of fetal rights and the limits of scientific freedom.

With reporting by Alice Park/New York and Dick Thompson/Washington