Now we know the recipe. Can a cloned baby be far behind?
By Nell Boyce
I
H uman cloning activist Randolfe Wicker can hardly contain his excitement. A man who has long wanted to reproduce himself through cloning, Wicker was thrilled to learn that a team in South Korea had created 30 human embryos--the first persuasive case of human cloning. "It's about time! Somehow, somewhere, one of them is going to be implanted into a woman's womb," exclaims Wicker, "and then you know what will happen."
II
Indeed, that's just what worries many experts and the vast majority of the public. Ever since the birth of Dolly the cloned sheep in 1996, the world has waited with fascination and unease to see if human cloning would ever leave the realm of science fiction. After a seemingly endless number of false starts and wild claims, the news convinced almost everyone that a baby clone is startlingly feasible. It appears that there is nothing about our species that would make humans any less clonable than sheep, mice, goats, cows, cats, or any other animal in the rapidly growing clone menagerie.
III
As if that wasn't enough controversy, the Korean team also took one of their cloned embryos and carefully extracted its stem cells, blank-slate cells that can live indefinitely in a lab dish and give rise to an endless supply of all the different cell types of the body. It's a step toward "therapeutic cloning," a prospect that tantalizes some researchers and patient advocates even as it dismays others. In theory, embryos cloned from the cells of people with diseases like diabetes or Parkinson's could someday provide perfectly matched, made-to-order transplant tissue.
IV
That vision, not baby making, is what inspires Shin Yong Moon of Seoul National
University, a member of the group that published its work last week in Science: "We are against reproductive cloning and we have to ask all countries or the United Nations for a law to prevent it." But it's not clear that even this dramatic demonstration of human cloning will break the deep legislative impasse over how to regulate the procedure, since the work gives fresh ammunition to both sides of the fight.
V
Many people, like President Bush, want to stop all human cloning, even for research, because of a moral objection to destroying embryos and a fear that maverick fertility doctors might adopt researchers' tricks to create babies. A bill that would ban all cloning has bogged down in Congress, and a similar ban has faltered in the United Nations. That's because other people want to permit research cloning while forbidding baby making.
VI
This kind of limited ban governs work in South Korea, allowing scientists to plunge ahead without fear that their research might get outlawed. And so it was that last June, cloning expert Jose Cibelli at Michigan State University got a friendly E-mail message from Woo
Suk Hwang, a well-known biologist at Seoul National University. Hwang had sent along a draft of a technical manuscript to get Cibelli's opinion. "He said, `Well, you should take a look at this,' " Cibelli recalls, "and I almost fell off my chair."

VII
Curious volunteers. Hwang's group had managed to find 16 women willing, without pay, to undergo the hormone injections and uncomfortable procedures needed to donate eggs.
"Many young women have much curiosity about cloning," explains Hwang, who says the researchers contacted women who had visited their Web site with inquiries about the science. Altogether, the team collected 176 usable eggs. They removed each egg's nucleus, then inserted genetic material from a kind of adult cell found next to the egg.
Animal studies suggest these cells offer especially good odds for cloning, and the group failed when they tried cells from men or other women. After waiting a bit for the egg's innards to "reprogram" the adult DNA, the team simulated these newly constructed embryos with a chemical kick, and they started dividing.
VIII
While other human-cloning efforts haven't seen embryos go past a few cell divisions, 30 of these embryos grew into blastocysts, pinhead-sized spheres of 100 to 150 cells. Each blastocyst encloses a small mass of stem cells. Hwang's group managed to extract stem cells from one embryo, and they are now growing in a dish. Any new tissue made from them could serve as a perfect transplant match for the person who was the source of the original adult cell, in this case the same woman who donated the egg.
In sharp contrast to their skepticism over earlier human cloning claims, top scientists hail this as the real deal. "I believe the work. I feel confident about the results," says John
Gearhart, a stem cell pioneer at Johns Hopkins University.
IX
Why did the Korean lab succeed when others failed? According to Cibelli, it all boiled down to eggs. When he worked on human cloning at a company called Advanced Cell
Technology, for example, he got his hands on only 19 donated eggs. The Seoul group had far more, so it could tinker with the cloning recipe in a process of trial and error that brought a dramatic success.
X
Studies on lab mice underscore the potential of cloned stem cells like those gleaned from one of the embryos. Stem cells from cloned mice have yielded specialized cells that could provide perfectly matched repair tissue for an ailing body. But other experts, like Gearhart, doubt that cloning is practical as a medical treatment, because human eggs are so hard to come by. Still, since embryonic stem cells can turn into any body cell, they themselves might someday provide a limitless supply of human eggs--as transformation scientists have already demonstrated with mouse stem cells. Or, cloners might someday use animal eggs instead of human ones--an approach the Korean group has practiced with cow eggs.
XI
Even if therapeutic cloning never reaches the clinic, it could nonetheless aid medical science. Scientists could gain new insights into diseases by watching them develop in a dish. Cloning an embryonic stem cell line from a person with Alzheimer's, for example, would let scientists watch every step as the cloned brain cells matured and then began to malfunction and die.
XII
But all of these potential boons remain far in the future. The science of stem cells from ordinary human embryos, first isolated in 1998, is still in its infancy. Labs still can't reliably generate different types of cells and show that they're safe and effective as transplants.

XII
The positive aspect of cloning can't sway people who favor a total cloning ban. "It's very hard to figure out what a compromise would look like," says Richard Doerflinger of the
U.S. Conference of Catholic Bishops. He and others view embryos, cloned or otherwise, as nascent human life that should not be sacrificed on the altar of scientific progress. Other avenues of research, like work on stem cells found in the adult body, could prove just as fruitful, they say. And they believe that allowing research cloning inevitably will lead to making babies, even if legislators try to outlaw it.
That's a rare point of agreement between Doerflinger and many proponents of human cloning. "Therapeutic cloning and reproductive cloning are two sides of the same coin," says Wicker. Even Hwang notes that the technique he reported last week "cannot be separated from reproductive cloning."
If Hwang's embryos had ended up in a womb, there's no reason why they wouldn't have kept growing into a fetus, says fertility expert Alan Trounson of Monash University in
Australia. He hopes it doesn't happen, noting that many cloned animals die in the womb or suffer myriad health problems, possibly because the egg fails to completely reprogram the adult cell's genetic material. "I'm very firmly against any form of reproductive cloning simply on the basis that it's completely unsafe."
The few physicians who say they're pursuing cloning for infertile couples counter that many cloned animals seem perfectly fine, and that people are willing to take a risk to have a child. Panos Zavos, an expert on male infertility based in Kentucky who has published a paper about his human-cloning project, says such a birth is inevitable, especially now that anyone can open a science journal and read the recipe for human cloning. He vows to push ahead with his own efforts. "Banning it?" Zavos says wryly. "That time has passed a long time ago. The genie is out of the bottle."
Assignment
1. Explain or translate the underlined words.
2. Learn the words and their derivatives in the table below for a vocabulary quiz.
3. Answer the following questions :
a. Why was Randolfe Wicker happy ? ( I )
b. Why are many experts worried ? ( II )
c. What is "therapeutic cloning" ? How can it help medical science ? ( III, XI )
d. What does Shin Yong Moon favour and what does he oppose ? ( IV )
e. Why does President Bush oppose cloning ? ( V )
f. How did Hwang's team manage to collect so many eggs ? ( VII )
g. Why do top scientists welcome Hwang's experiment ? ( VIII )
h. Why are embryonic stem cells so special ? ( IX )
i. What are the arguments put forward against cloning ? ( XII )
j. What, in your opinion, are the advantages and the dangers of cloning ?
k. Why does Panos Zayos say : "The genie is out of the bottle" ?

Fill in the following table :
Noun Verb controversy extract inspire regulate inquiry insert construct isolate infancy sacrifice
Adjective persuasive feasible effective
(in)fertile
Adverb