Hopes, Fears Swirl Around Future of Cloning
When Dolly the sheep was born on a Scottish research compound in an unassuming brick farm building, her arrival was hailed by the outside world as a harbinger of human cloning.
Though scientists already had manufactured animals copied from embryos and cloned adult frogs, Dolly was the world’s first mammal cloned from an adult creature.
Dolly’s creators at Edinburgh’s Roslin Institute boasted that she embodied the promise of animals that could produce drugs and organs for humans. But from the moment her birth was announced Feb. 23, 1997, many interpreted her arrival as confirmation that cloning of humans lurked around the corner--despite the institute’s careful attempt to play down that prospect.
“I’d be absolutely flabbergasted if we saw it in my lifetime,” Grahame Bulfield, Roslin’s chief executive, reiterates more than three years later. “It’s a nonsensical bit of hype.”
Still, scientists say some of their colleagues are undoubtedly working on it, encouraged by further success with cloning animals such as cows and pigs. Because of the controversy, experts say most are likely to keep their research secret --at least until they succeed in producing a healthy baby.
One scientist willing to acknowledge his desire to clone humans is a prominent Italian fertility specialist, Dr. Severino Antinori, who heads the International Associated Research Institute for Human Reproduction in Rome.
Antinori says he has an application pending with the Italian National Committee on Bioethics--a 40-member advisory group that includes a Roman Catholic cardinal and several other religious figures--seeking permission to start working on the technique as a fertility treatment.
“In Italy it’s not easy because the church is very influential, but we are going to try,” he says.
The Catholic Church opposes cloning and in vitro fertilization as an artificial interference with the creation of life.
Antinori says many fertility experts are beginning to take more seriously the idea of cloning babies. He notes that when international fertility experts meet in September to discuss advances in their field, the use of cloning as a fertility treatment will be on the agenda for the first time.
“Now it’s not taboo to use cloning in some cases--not like two years ago,” he says.
Antinori, who has cloned cows successfully while awaiting approval to use the technique on humans, says he intends to use cloning only to enable men who have no spermatagonia cells--the precursors of sperm--to have children of their own.
Biologist Brigitte Boisselier, the Montreal-based scientific director of Clonaid, a company set up the month after Dolly’s birth was heralded with banner headlines worldwide, says her lab is trying to perfect cloning in humans.
“The goal is to produce a human clone as soon as possible,” Boisselier says. “We have a list of about 100 people wanting to be cloned.”
But experts do not consider Clonaid a front-runner in the quest to produce a cloned baby.
And it has a potential credibility problem: It was founded by Rael, the leader of a religious organization called the Raelian Movement, which argues that all life on Earth was created in laboratories by extraterrestrial scientists.
Eric Schon, a molecular biologist at New York’s Columbia University, believes the creation of cloned babies could be two to five years away.
“If it can be done, it will be done. And this can be done,” he says. “The moment it could be done in sheep and mice and cows, it was only a matter of time for human cloning.”
He then notes one of the reasons the prospect of human cloning is so repugnant to many: “People with the scruples to clone a baby have the scruples to discard 25.”
Due to Dolly, legislation or guidelines to ban human cloning are now pending in dozens of nations, including the United States and Japan. Several countries, including Britain, Israel and Germany, already have banned it. In many others no laws specifically ban the practice, but ethical guidelines would appear to prohibit it.
The reaction to Dolly’s birth was intense and uniform worldwide--a sort of moral panic, says John Durant, assistant director of London’s Science Museum, who studied the reception the little lamb received in the days after the announcement of her birth.
“We have to accept that it was a bloody good story,” says Harry Griffin, director of science at the Roslin Institute. “It drew up a tremendous culture and literature on cloning.”
Indeed, the idea of cloning is nothing new, at least in literature and science-fiction fantasy.
Witness Aldous Huxley’s 1932 novel “Brave New World,” which depicted a controlled society consisting of lab-grown clones, or the 1978 movie “The Boys From Brazil,” in which Nazi scientist Josef Mengele created a new race of cloned Hitlers in an attempt to take over the world.
“It’s the idea that clones are subhuman, malleable--a concept made up obviously by someone who doesn’t have children,” Griffin says.
What seems to have gotten lost in the furor is the reality that a cloned baby would be a copy of a person’s genes, not a copy of the person. The child would have a completely different life experience from the adult it was cloned from, and the result would be a child with its own personality .
And that’s only if scientists could actually manage to produce a healthy human clone.
Although scientists have improved the technique since Dolly, animal experiments have resulted mostly in failures. Deformed animal fetuses have died in the womb with oversized organs, while others were born dead. Still others died days after being born, some twice as large as they should have been.
The average woman produces 10 to 15 eggs at one time with the help of fertility drugs. Bulfield, the Roslin chief executive, says it would take more than 400 eggs and 50 surrogate mothers--and lots of money--to produce a cloned baby.
“Start with 100 million pounds [$150 million] and maybe you can get some progress,” he says. “And if any physician is going to attempt it, they’d better have good liability insurance.”
The technique used to produce Dolly, and other clones since, involved removing the genetic material from an egg and replacing it with the nucleus of a cell from an adult sheep. The reconstructed eggs were then grown in a lab for a few days before being implanted in a womb to develop into a clone.
Dolly’s creators started with 277 reconstructed eggs. The 29 embryos that appeared to develop normally were implanted in 13 sheep. Dolly was the only success, an achievement rate far below 1%.
Subsequent experiments with cows have achieved a success rate of about 10%.
The Scottish group that worked with the Roslin Institute to produce Dolly, PPL Therapeutics, managed to produce five piglets cloned from an adult pig in March, but other scientists trying to clone adult monkeys have been unable to produce any successful pregnancies.
Researchers at the Oregon Regional Primate Research Center started by implanting cloned embryos in the monkeys’ wombs three days after they created them, then tried letting the embryos develop even further before implanting them. But that didn’t seem to work either; the embryos’ growth stalled after four or five days.
“It’s as though there’s something deficient in the embryo,” says Don Wolf, who runs the Oregon lab. “At the very least it should raise a red flag for doing it in humans.”
Many experts believe cloning should not even be attempted in humans until it has proven successful in primates, but they concede progress probably won’t wait.
Wolf says there’s no reason to believe human cloning is impossible, but adds that the current risks involved, compared to the benefits, are “ludicrous.”
Making babies would not be the only purpose for human cloning, and might not be the most common. Another big goal is the production of cells, tissues and perhaps even organs for transplant.
The idea is that by cloning a cell of a transplant patient, doctors could manufacture replacement tissue that would be perfectly compatible, eliminating the problem of organ rejection.
The key is stem cells--the parent cells of all the body’s cells before they develop into specific types of cells such as blood cells, nerve cells or muscle cells.
Scientists have been able to extract stem cells from embryos and grow them in labs until they become sorted into muscle cells and neurons. Scientists also have been able to make bone marrow cells turn into liver cells, offering hope that specialized cells can be made to regress and redirect themselves to form different types of cells.
Cloning would be used to create an embryo, building on a cell from the patient. Thus far, the procedure would be the same as creating an embryo to implant in a womb.
Those pursuing human cell research are eager to distance their work from the prospect of cloned babies, however, emphasizing that they are not creating embryos for implantation.
Fertility doctors would implant an embryo in a womb within days of creating it. Cell scientists, however, would extract the stem cells from the embryo at that point and grow those cells in a lab to make tissues. The extracted cells could never become a baby.
To further sidestep the moral debate, cell biologists already are looking for a way to clone without using an egg cell, so that an embryo would not be created.
The hope is that one day it will be possible to grow neurons to replace brain nerve cells killed by Parkinson’s disease; skin to repair burns; and pancreatic cells to produce insulin for diabetics, whose bodies cannot make the hormone.
It may be possible to make a simple organ such as a bladder, but “lung, kidney and heart are not going to be on the horizon any time soon,” says James Thomson of the University of Wisconsin at Madison, a leader in stem cell research.
And then there’s Dolly.
Nobody knows whether she will live out a healthy life, but her creators have noticed that the cells in her 3-year-old body--cloned from a 6-year-old sheep--have started to show signs of wear more typical of an older animal, though she so far shows no sign of any abnormalities.
Roslin’s Bulfield says that if Dolly contracted something like cancer early or died an untimely death, the experience of one sheep would not be enough to tell whether the cloning was at fault.
But there’s always a chance that inserting older DNA into an egg and producing a baby would saddle the child with health problems.
“Our DNA is picking up mistakes as we get older--there are free radicals that damage the DNA, leading to aging, cancer and general degeneration,” says Griffin of the Roslin Institute. Those deteriorations could be passed on in cloning, so that the baby starts off with damaged DNA.
“It might be impossible to get round,” Griffin says.
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On the Net:
Roslin Institute, cloning information and research: https://www.ri.bbsrc.ac.uk/library/research/cloning
Bioethics.net, information on cloning ethics: https://www.med.upenn.edu/bioethics/cloning/index1.html
National Institutes of Health primer on stem cells: https://www.nih.gov/news/stemcell/primer.htm
New Scientist magazine article on cloning: https://www.newscientist.com/nsplus/insight/clone/clone.html
