Another cloning first: This time, a monkey
Scientists split primate embryos - a different type of cloning - and
SCIENCE — The birth of a cloned rhesus monkey named Tetra, announced today, raises new questions about humans' ability to manipulate the earliest stages of life, and pushes even further the progress toward the eventual cloning of a human being.
Hailed as the first cloned primate, Tetra was the product of experiments at the Oregon Health Sciences University (OHSU), where a team has been perfecting techniques of splitting primate embryos to create clones.
While this research does notrepresent true cloning - taking genetic information from a live animal and using it to create an identical copy - experts say the research is a major achievement.
Moreover, the successful splitting of primate embryos raises nettlesome ethical questions about this process in particular and cloning in general.
For one, these advances could make the prospect of splitting and researching human embryos more enticing, some observers say, despite assurances to the contrary from the scientific community. In addition, Tetra takes science further down the path of the contentious topics of cloning and genetic manipulation of humans.
"This represents another step towards cloning homo sapiens," says Arthur Caplan, director of the Center for Bioethics at the University of Pennsylvania in Philadelphia. "It makes the need for ... discussion about human cloning even more imperative."
Splitting embryos to create identical copies of animals has been done before. In fact, nature does it when identical twins emerge from a single egg-and-sperm combination. Other scientific teams have split embryos in other mammals, bringing healthy babies to term.
The problem with primates
But manipulating embryos of primates has remained a tricky proposition. Because of the position of primates as some of the most highly evolved mammals, many scientists have posited that cloning monkeys and manipulating their gestation cycles would prove more difficult than performing similar activities on mice or cattle.
"Many people believed that primates are different," notes Dr. Caplan. "This is a confirmation that some forms of cloning are at least feasible in primate mammals."
Some scientists believe this technique holds more promise for genetic research and treatments than the true cloning of adult animals, like that of Dolly the sheep, which took place in 1997 at the Roslin Institute in Scotland.
According to current theory, even newborn clones of adults carry genetically damaged data due to the tendency of DNA to degrade and mutate over time. This may have caused the high proportion of miscarriages and fetal problems that scientists have observed in embryos and animals replicated from adults.
Granted, Tetra was the only successful embryo brought to term out ofmore than a dozen attempts. But the purity of the genetic information should make Tetra's model a more appealing one.
"We have obviated some of the perils of cloning in the formation of identical twin, triplet, and larger sets of identical rhesus monkey embryos,"wrote the OHSU team in a paper that appears in today's issue of the journal Science.
Scientists would prefer to study DNA from embryos that do not bear any of the stresses of age. To that end, primate embryos represent the closest analogue to a human embryo and the best vehicle, at this point, for embryo research on human-health problems.
For its part, the animal-rights community has vehemently objected to plans to use animal embryos.
Yet many researchers anticipate using the primate embryos for research, particularly in light of the widespread social and religious objections to studying human embryos created specifically for scientific research.
"I would argue that no human life should be created for someone's utilitarian purposes," says Daniel McGee, a theologian at Baylor University in Waco, Texas. "Every human life should be celebrated for its value, not for the value it might bring to someone else."
While the true importance of cloning primates through embryo-splitting remains to be seen, experts agree that developments like the birth of Tetra should spur debate on an issue that has largely been avoided or ignored.
"The real questions lie ahead in the area of eugenics," says Caplan, referring to the field of science that concerns itself with improving humans through controlling hereditary factors.
"Copying genes is very important for cell research and study, but I don't think it will be the most interesting way to make people," he adds. "Most people are not going to want genetic copies of themselves. What they will want to do is improve themselves."
But theologians offer a warning that self-improvement might not be such a worthy goal in light of the immense problems suffered by much of the planet.
"Cloning is a rich man's toy," says Mr. McGee. "Go to ... an impoverished country, and they are not thinking about how to make a perfect child. They are thinking about how to feed their child."
Research won't stop
No one, however, expects the momentum of genetic research to stop. Some experts even say the type of embryo-splitting performed with monkeys in the Oregon lab has likely been performed on human embryos in secret somewhere in the world.
Thus far, human-embryo research remains largely confined to aborted or miscarried fetuses.
But pressures will likely mount as researchers, either openly or covertly, seek to study human embryos to get the best information possible for what could result in health-care breakthroughs.
The challenge of scientists and theologians alike is to come to a consensus on an acceptable moral and legal framework for cloning and genetic manipulation.
"We are born with a high level of responsibility and ability," says McGee. "We should view these abilities not so much as a privilege to do what you want to but as a responsibility to serve the created order and humanity. To the degree that we can improve the lot of humankind, should accept the responsibility,"
But the clock is clearly ticking.
"We have seen politicians dawdle and a fair amount of hemming and hawing from the religious and philosophical communities, but there is not much more time for a debate," says Caplan.
(c) Copyright 2000. The Christian Science Publishing Society