IT'S THE answer to a number of women's dreams," says Lucia Valeska, co-executive director of the National Gay Task Force. To others, however, it may just become another ethical and political nightmare growing out of humankind's propensity to tinker with the creation of life.
This time the issue is not merely "test-tube babies" of whether we are capable of cloning duplicate people from an individual's cell. As if those disputes were not startling enough, we may in time be faced with another: the creation of life entirely from females, without need for males for this purpose at all.
Yes, it boggles the mind: the capacity to make males not only unncessary for reproduction but theoretically extinct because, given the fact that sperm determines male sex, the only offspring who could issue from such manipulation would be females. It can't be.
Well, it certainly isn't as yet. But, far-fetched as it may seem, ultimately it could be. Genetic researchers currently are working toward creating offspring of laboratory mice in precisely this fasion, without male fertilization of the female egg in any manner. Moreover, they expect to succeed -- which would likely produce pressures to attempt the same feat with people.
"I don't see any theoretical reason why it shouldn't work" with mice, remarks biologist Clement Markert of Yale, who directs the university's Center for the Study of Reproductive Biology. "We are heading toward developing the capacity" to do this, "and I wouldn't doubt that if we could do it with mice eggs, there would be some people who would like to try it with human eggs. I'm sure that would raise lively ethical issues that society would have to wrestle with, about whether this was an appropriate application of genetic technology to human beings."
Of course the researchers, as they will emphasize to you, are not working to develop fatherless mice because they want to make males obsolete, just as other scientists did not develop atomic fusion because they hungered for the ability to destroy civilization. They have very different purposes in mind, especially benefits for animal husbandry, and some understably get jittery about the political and funding consequences of any questions about human applications. Dr. Pierre Soupart, a prominent gynecologist and obstetrician at Vanderbilt University Medical School who has done work in this area, for example, terms the notion of ever using such genetic technology with people "science fiction."
He, like Yales's Markert, is interested rather in discovering fundamental facts, in answering long-asked questions about reproduction. Scientists know, for example, that there are a number of all-female, fatherless populations in nature. Biologists have documented 13 species of lizards, several types of small fish and one kind of white turkey that do not need males to produce their babies, which are near-duplicates, or clones, of the mother. "These species produce eggs which just start developing without being fertilized," says Markert.
Researchers also have worked for a number of years on parthenogenesis, or "virgin birth." Since each cell contains data necessary to reproduce the whole organism, it was a question of learning to artificially trigger division of the ova, to produce the two sets of chormosomes necessary for an egg to develop. This jiggering, done by applying chemicals or otherwise "disturbing" the egg, has produced young in reptiles and birds.
What, then, does the male sperm do? Does it just "disturb" the egg? Does it provide genetic information? What does it contribute to the process of development?
These are the kind of basic questions that helped prompt the 1977 experiment by Dr. Soupart. "The idea behind the experiment was to find out whether, at the time of fertilization of the egg, the sperm itself brings factors, besides its own chromosomes, which may be critical to the regulation of development," he says.
To understand the makeup of sperm, he needed fatherless mice. To achieve this, he says, he first injected two female mice with a hormone to induce "superovulation." Instead of the normal 10 to 12 eggs, each mouse produced between 50 and 80, which gave him and his research team sufficient material to work with. He then removed the protective outer membrane from the eggs and coated the naked cell membranes with a chemical substance at near-freezing temperatures. When the temperature was raised to nearly 37 degrees, two different cells fused within minutes.
He has discovered, he explains, one function of the male sperm. "We found out that the fertilizing sperm, in the very last few hours before it fertilizes the egg, seems to be genetically programmed to produce chemical substances that have the property of fusing the membranes of two cells to each other." So he substituted the chemical substance, an inactive virus popular in biology labs, and it did the same thing. "We can reach 80 percent fusin by this method," he says, "which is almost as successful as normal fertilization."
While the fatherless cells were growing in a laboratory dish, Soupart and his team prepared a white mouse and two other females to receive implants when they were ready to attach to the uterine wall. Three vasectimized male mice visited the females in their cage overnight, one of several techniques used to pinpoint an animal that has recently ovulated. Only the white mouse mated with her intruder, so to her went the honor of becoming surrogate mother to what Soupart hoped would be the first litter of mice from a union of two females.
The white mouse-puffed up to the size of a grapefruit over 20 days, the normal gestation period for a mouse, Soupart reports. This would be a significant achievement in itself, for a major problem to date has been the inability of a mouse to carry to term in such cases.
Yale's Markert, who is engaged in related experiments with mice -- he is working with single eggs and uses a chemical to trigger the necessary doubling of the chromosomes -- says that "we can make embryos easily that are derived entirely from the female," but "not any of our embryos have ever been born."
There has been one successful case of "virgin birth" reported with mice, an instance in which seven offspring developed entirely from female eggs. But in that experiment, carried out by Peter Hoppe and Karl Ilmensee at the Jackson Laboratory in Bar Harbor, Maine, male sperm initially penetrated the eggs. The sperm nuclei were then removed before they fused with the egg nuclei, and all-female offspring were born.
But a successful birth has never been accomplished without that initial use of sperm, and certainly never following the fusion of two different eggs into one. Dr. Soupart, therefore, waited anxiously as his mouse swelled. But the mouse fooled him. She waited until Soupart and his attendants had left the lab for the day before delivering. The next morning the lab technician found the 20 offspring -- but the heads has been eaten and the technician "panicked" and threw them out, Soupart says.
It would be comforting perhaps to believe that the mouse had chewed off the offsprings' heads because she sensed that delivering fatherless young was unnatural, but it actually is not uncommon for laboratory mice to do this. Soupart does believe, though, that one factor which may have disturbed the mouse was the overcrowding resulting from carrying 20 eggs rather than the normal 10 or so.
In any event, the evidence he had waited so eagerly for was destroyed by the mouse and the technician. Soupart had not done the Cesearian section he had considered, and he now could not identify the remains through the three "genetic markers" he had planned: the eye color of the offspring, their fur color (the fur does not begin to show immediately at birth) or the sex.
So "the experiment was non-conclusive in terms of publication of scientific data but not in terms of my personal conviction," he remarks. He believes it succeeded, and he is seeking funding from the National Science Foundation to do it again "on a much larger scale, so that we can be sure that if this happens again, that the mother crews off the heads of the babies at deliveries, we will have perhaps several others that won't do the same."
Doing this, he says, is needed to obtain "knowledge," but even more so for animal husbandry. "If you are in the dairy industry, you want cows. You don't want steers." Still more important, he says, many developing countries "have prohibitions related to the consumption of meat products -- this is the case in India -- but no prohibition on the consumption of dairy products. So if you could provide these people with the methods that would enable them to produce only dairy cows, they would be much better off nutritionally and economically. This is a very important practical application -- in my opinion, much more important than extrapolating that to people."
This, of course, may not be the view of some others. Lucia Valeska of the National Gay Task Force, for example, says, "It's very understandable that women who want to raise children together should want the children to be part of their biological makeup. The question which will be raised is: 'Is this natural?' Which sort of amuses me, because 'naturally' we can do this." Asked about such sentiments that might exist among lesbian couples, Dr. Soupart says, "I think it's a matter of personal choice, and I am not recommending one way or the other."
At Yale, Prof. Markert adds: "You must remember that many things we have been able to do with animals for a long time -- for example, selective breeding, the main technique now used to produce . . . . cows that produce lots of milk, race horses that run fast -- we don't apply to human beings. If you wanted to produce a race of basketball players, you could breed from only seven-footers, and pretty soon you'd have a race of people who were only seven feet tall or more. It flies in the race of our other human interests, and I doubt we would use any of these other techniques to do so either."