The First Cloning Superpower

Inside China’s race to become the clone capital of the world. I am peering into a laboratory microscope at what is sort of a cloned human being.Sort of a cloned human being because it’s only a blastocyst, a very early stage embryo that’s floating under the microscope like a tiny bit of soap foam. And […]

Inside China's race to become the clone capital of the world.

I am peering into a laboratory microscope at what is sort of a cloned human being.

Sort of a cloned human being because it's only a blastocyst, a very early stage embryo that's floating under the microscope like a tiny bit of soap foam. And also sort of because this blastocyst was created by inserting all the DNA from a human being into the egg of a rabbit.

Sacha Waldman

This little swimming experiment in interspecies biology is taking place not in some high tech office park or Ivy League research lab, but on the top floor of an emergency ward at a shabby hospital complex in mainland China. Downstairs, the reception area is lined with battered folding chairs occupied by patients with makeshift bandages or open wounds. Splashed across the linoleum is what looks like dried blood. But here on the top floor, the elevator opens to a world of $100,000 microscopes, sperm-washing machines, and egg-denucleating micropipettes.

Major scientific journals won't publish research that has been described in the popular media, so I have promised not to divulge identifying details about the experiment or the scientist performing it, whom I'll call Dr. X. But I can say that Dr. X's laboratory is one of three I visited in China where researchers are investigating interspecies clones. And I can also say that this experiment would be illicit if not completely illegal in the United States and most of the developed world. But in China it's all legal, every bit of it, which is a big reason why Dr. X moved here after spending a decade at a public institution in the US.

Dr. X has not the slightest interest in creating an actual cloned human being that will one day walk the earth. Instead, this researcher - like the other Chinese scientists working in the field - is pursuing a much more important goal: using special cells within the blastocyst to grow replacement organs and tissues. The cells, called embryonic stem cells, are arguably the most important subject in biology today, and certainly the most controversial. With new organs made from these cells, biologists believe it will be possible to cure many ailments - and add years, if not decades, to the human lifespan.

In the Americas and Europe, stem-cell research is the subject of such visceral dismay - and so many government restrictions - that it has been nearly impossible for scientists to make progress. Things are different in China. Not only is the field less controversial, but the government is erecting state-of-the-art lab buildings, creating university appointments with princely perks, and providing the capital to establish new biotech firms. If the current trend continues, the next great discoveries in biomedical science - and the industries they spawn - will occur not in San Francisco and Boston but in Shanghai and Beijing.

"I loved working in the States," Dr. X says. The training, the laboratories, the equipment - all were first-rate. So were the colleagues. But because embryonic stem cells are nearly impossible to obtain in the US, this researcher felt it necessary to move to China, even though it meant leaving spouse and children behind. "China," Dr. X says, "is the future."

A new era in medicine

Last May, more than 300 scholars and politicians gathered at Shandong University, in Jinan, about 250 miles south of Beijing, to honor the late embryologist Tong Dizhou. Above a large bronze bust of Tong hung a ceremonial banner emblazoned with the phrase: FATHER OF CLONING.

In 1963, 34 years before Dolly the sheep came into the world, Tong plucked the DNA from a cell in a male Asian carp, stuck it into an egg from a female Asian carp, and produced the world's first cloned fish. In previous decades, researchers had cloned microorganisms and nematodes, as well as amphibians, which readers of Jurassic Park will remember are genetically malleable. But before Tong, nobody had ever managed to clone such a complex organism. To all appearances, the experiment was entirely successful. The cloned carp swam around, ate its fill, and even sired baby carp.

Ten years later, Tong inserted the DNA from an Asian carp into an egg from a European crucian carp, a related species, and created the first interspecies clone. Based on such research, Chinese scientists developed fish-breeding techniques so powerful that the nation now produces more than half of the world's aquaculture harvest. But few if any Western scientists knew of Tong's work, partly because he published in relatively obscure Chinese journals; Acta Zoologica Sinica, in which the interspecies cloning research appeared, didn't even offer the English-language abstracts common in non-Western scientific periodicals. In any case, Tong performed his experiments not to study cloning per se but to investigate the interactions between DNA and the egg containing it. To the Chinese, extending this work to humans seemed pointless. "We have a huge population problem and a one-child policy," says Qi Yaqiang, a demographer at Peking University (which retains Beijing's old Romanized name). "Why would you think about making people in a laboratory?"

Attitudes toward cloning changed in November 1998, when James Thomson of the University of Wisconsin announced the isolation of embryonic stem cells. Five days later, a team led by John Gearhart of the Johns Hopkins University School of Medicine made a similar proclamation. Together the two stem-cell papers, one published in Science, the other in Proceedings of the National Academy of Sciences, created enormous excitement. And suddenly, cloning - or, more precisely, one special type of cloning - seemed to have real value.

Most of the cells in the body can't reproduce themselves; instead, they simply perform their specific function until they die. Creating new cells is the province of stem cells, a distinct class that can, in the jargon, proliferate. Stem cells are located in many parts of the body; the best known are those in the bone marrow, which make billions of red blood cells, white blood cells, and platelets each day. When doctors perform bone-marrow transplants, they're essentially stocking patients with new stem cells that they hope will proliferate, creating healthy new blood cells.

As a rule, stem cells are specialized: Liver stem cells make liver cells, retinal stem cells make retina cells. Some are less specialized than others. Neural stem cells, for example, make three types of brain cell and maybe even blood and muscle cells. The least specialized are those in the blastocyst, the embryonic stem cells isolated by Thomson and Gearhart. Unlike ordinary stem cells, those in the early stage embryo can develop into every kind of cell in the body: nerve, stomach, bone, you name it.

Todd Eberle
Todd Eberle. Ultraviolet rays spill into the scrub room in Deng Hongkui's research garage in Beijing.

In theory, doctors should be able to manipulate embryonic stem cells to grow lungs, livers, hearts, or any other tissue, which could then be transplanted into people who need new organs. Because this process begins with DNA from a patient's cells, it's cloning, except that what's being created isn't a whole human being, but pieces of one. In the short run, this special kind of cloning - therapeutic, as opposed to reproductive - could make transplants far more feasible. In the long run, it could open a new medical era in which doctors regenerate people as they age.

There's a catch, though: Embryonic stem cells can be obtained only from human embryos. These can either be made to order in a lab by inserting a patient's DNA into an egg and producing a blastocyst that is a clone of the patient, or else taken from aborted fetuses or embryos left over from in vitro fertilization. Neither source is free of controversy, to put it mildly. Cloning of either type is opposed by such powerful entities as the Roman Catholic Church, the right-to-life movement, the president of the United States, and Jeremy Rifkin. Even fiercer is the battle over embryonic stem cells from abortions or in vitro fertilization. Much of the West finds the thought of using either source repellent, and legislatures have raced to outlaw the entire field. Last year, President Bush banned the use of federal funds for creating new embryonic stem cells. For its part, the European Union has imposed a moratorium on funding the creation of new stem cells and prohibited the use of existing stem cells in most research.

Private enterprise isn't filling the gap. Learning how to use embryonic stem cells to grow organs will require the kind of long-term, basic research that few companies are willing to undertake, especially when throngs of angry demonstrators could be involved. PPL Therapeutics, the firm that bankrolled Dolly, got out of the cloning business in September; Geron, one of only two US-based companies to admit researching embryonic stem cells, has faced so much political pressure that its investors are running scared and capital is drying up. "Nothing is happening," says James Michael Weimann, a stem-cell researcher at Stanford. "The field is moving at a crawl. We can't get our hands on the materials we need, and neither can anyone else."

Across the Pacific, though, public opposition to stem-cell research is weak or nonexistent. In Singapore, stem cells are a key part of a long-standing government initiative to develop new technology industries; Japan is building a stem-cell center in the southern city of Kobe that will have a $45 million annual research budget. South Korea's government endorsed experimentation with frozen embryos this summer, though it banned the cloning of human beings after the Raélian sect, which attributes Jesus' resurrection to "an advanced cloning technique," claimed it had implanted a cloned embryo into a Korean woman.

No country is pursuing the field more aggressively than China. Stem-cell research fits the Chinese Ministry of Science and Technology's ambitious plans to vault the country to the top research ranks - and win a Nobel, which has never been awarded to scientists on the mainland. China has turned on the funding spigots, pumping money through multiple sources: cities, provincial governments, two special national research initiatives. There are also venture capital-like funds from large universities, which set up companies owned by their researchers; national subsidies, including those established to create special research parks; and direct private investment, most of it from Hong Kong tycoons. US venture capitalists have also begun sniffing around.

Flush with cash, researchers can explore the new field with almost complete freedom. A Ministry of Science and Technology panel has begun to consider rules for supervising stem-cell research, though nobody knows if or when these rules will emerge. For now, the sole national regulation in the field is what scientists call the Four Nos - a single-sentence directive promulgated by the Ministry of Health last November: "Under no situation, under no circumstances, will human reproductive cloning experiments be 1) endorsed, 2) permitted, 3) supported, or 4) accepted." Everything else is fair game. And even the Four Nos are toothless, because Ministry of Health rules don't apply to the other branches of the government that are actually funding the research.

REVERSE BRAIN DRAIN

One of the world's fastest-growing and most important stem-cell centers is a converted garage located on the campus of Peking University. Tacked to the front door, a handwritten sign claims the lab is a storehouse for samples of the AIDS virus. "Keeps away random visitors," explains Deng Hongkui, co-director of the facility.

Deng's facility has been slapped together Silicon Valley-style by carving up the garage into a warren of glassed-in cubicles crisscrossed by improvised ductwork and wiring. Deng himself has an office smaller than Larry Ellison's desk. When my translator and I sit down, Deng boots up the Universal Scientific Tool: PowerPoint.

Ambitious and financially sophisticated, Deng is a paradigmatic example of the scientists China has lured back to work on stem-cell research. Raised in China, Deng obtained his PhD in immunology in the United States. In 1996, he led a New York University team that was one of the five groups to simultaneously uncover the exact biochemical pathway by which the AIDS virus enters cells. The finding was Science magazine's "breakthrough of the year." Having made his reputation, Deng did what a lot of other bright young scientists do these days: vanished into the private sector. He couldn't talk about his work there with anyone - he could barely acknowledge it. Frustrated, Deng did the unthinkable and moved back to China.

Between 1978 and 1998, according to the semiofficial China News, China sent more than 380,000 students, the great majority in science and engineering, to earn advanced degrees in countries in the West. Fewer than one out of three returned - a textbook example of brain drain. "Read any issue of Science or Nature, and I would be very surprised if you could find one without [articles written by] overseas Chinese," suggests Cao Cong, a sociologist at the National University of Singapore. In Cao's view, the thousands of overseas Chinese scientists play a big but little-known role in the West's technological dominance. "Now China is beginning to take real steps to lure back its children. If they return, it will be a very big blow to America and Europe."

Todd Eberle
Todd Eberle. Zhao Chunhua (right), with a technician sorting cells for analysis, worked on stem cells in Minnesota before returning to Tianjin.

If Deng is an example, the West should worry. When he returned in 2001, Peking University gave him and his co-director Ding Mingxiao a budget sufficient to pay 40 grad students and postdocs enough to make them think twice about studying abroad. Foreigners can freely visit their laboratory, in striking contrast to prior restrictions. (In fact, the constraints on intellectual exchange are now tougher in the US; after September 11, Chinese scientists are frequently denied visas.) The university will help Deng commercialize his discoveries, potentially making him a rich man. "The administrators here are very supportive," he tells me in fluent English. "They just bought me a $380,000 cell-sorting machine. And they're making us a real building" - a multistory facility now under construction at the edge of the campus. "I couldn't turn down the opportunity to have my own laboratory," he says. "Besides, I don't know if you've noticed, but this city is full of really good Chinese food."

Given the opportunity to work in almost any area, Deng decided to investigate the means by which stem cells differentiate, transforming themselves from the biological equivalent of blank slates into cells of particular types and abilities. "What signal tells them to do this?" Deng says. If the cells are to be harnessed, doctors must identify the molecular signals - the programming factors, as they are known - that command them to differentiate. According to Deng, his group has already discovered five of these factors. "We have several quite exciting stories," he says.

When Deng tells me this, it's close to midnight. He's leaving the next morning to see a lawyer in New York. "Patents," he says. "I have to get that straightened out first." It is widely believed that, in the future, companies will be pumping out streams of tissue and organs from stem-cell banks. When that happens, Deng hopes, they'll have to license his programming factors. If his discoveries work, it will be like controlling the rights to X rays. Only when he controls the technology will he submit a paper to Science or Nature.

"The Chinese used to not understand intellectual property," Deng says. "But now I really think they get it."

The confucian tradition

Before Confucius, China had four great sages. You Chao showed the people how to avoid wild animals by making tent houses in the trees. Sui Ren brought fire. Fu Xi taught how to make nets and raise livestock. Shen Nong introduced the plow and agriculture. All of this is legend, but every Chinese person knows it and gets the point: The sages gave China the technology to control Nature. Which to this day - or so it is widely argued - accounts for the enormous respect given to scientists in China. And which in turn explains why the Chinese aren't dismayed when their scientists experiment with human embryos.

In the Confucian tradition, human beings achieve personhood only when they're able to participate in society. By this way of thinking, fetuses aren't human - they're part of Nature. And because Nature, in turn, is regarded as the raw material for human existence, people can do with fetuses what they will. "Abortion, which destroys embryos, has never been seen as wrong in Chinese society," says Qi, the demographer. "Not having a male heir - that is an issue."

As a consequence, the Chinese government has adopted a position regarding stem-cell research, therapeutic cloning, and regenerative medicine that might be described as brutal realism. Beijing recognizes that some people are going to do stupid things with the technology, possibly even cloning themselves. But the Chinese aren't concerned enough by this prospect to ban the research outright.

In fact, Chinese scientists are counting on the West's cultural revulsion to build their lead. Consider Huang Shaoliang, who was so sure the West would take itself out of the stem-cell race that he thought he would make Nobel-worthy advances in his outdated lab in the southern city of Guangzhou. A researcher at Sun Yat-Sen University, Huang spent the early 1990s studying umbilical-cord blood, which is teeming with stem cells. In theory, injecting patients with the blood from infant umbilical cords should be better than transplanting bone marrow, because umbilical-cord stem cells are less likely to transmit infectious diseases, are collectible without surgery, and seem to be less differentiated. Cord blood is difficult to use, however. As a practical matter, the only cord blood that can be transplanted into patients without rejection is from siblings. Usually, patients can get cord blood only if their parents have another child. In most cases, this is hardly possible; in China, with its one-child policy, it's especially difficult. So Huang decided to investigate a substitute for cord blood: embryonic stem cells.

At the time, Western researchers were extracting embryonic stem cells from mice and trying to differentiate them into blood cells. Huang wanted to do the same thing with humans. He knew that working with human embryos in the West was difficult at best, illegal at worst. But the Chinese research environment, Huang dryly observes, "is not as strict."

In 1995, the National Science Foundation of China gave Huang money to investigate human embryonic stem cells. The Sun Yat-Sen medical school had an in vitro fertilization clinic, and after implanting the best embryos in patients, it simply let Huang have the leftovers.

By the end of 1997, Huang and his chief graduate student, Xu Ling, thought they had isolated embryonic stem cells, though they were able to keep them alive for only six generations. To check their results completely, they needed to run cells through multiple tests. But they couldn't perform the newest, best tests, which looked for the presence of specific chemical markers on the surface of the cells, because they required special reagents made to order by university-affiliated companies in the West. The reagents aren't advertised; they circulate by word of mouth in the small community of researchers. Huang, who speaks no English, couldn't find what he needed.

Todd Eberle
Todd Eberle. In new government buildings and private firms like Union Stem Cell & Gene Engineering Co., Chinese researchers are developing the means to clone organs in everything from humans to pandas; clinical trials could begin by next year.

Huang asked Xu, who knows some English, to beg for the compounds from a Western scientist. Xu chose James Thomson, whom she had never met, but whose work on primate stem cells she admired. Using the email address provided on a scientific paper, she sent Thomson what she calls "a very detailed account" of their methodology and results, asking if he would help them obtain the reagents. Thomson didn't respond.

In January 1998, Huang, Xu, and four other coauthors published "Differentiation and Proliferation of Human Embryonic Stem Cells" in the Journal of the Sun Yat-Sen University of Medical Sciences. Because the journal is small and written in Chinese, the study was almost completely ignored. Eleven months later, Thomson created worldwide headlines with his Science article about embryonic stem cells.

Thomson's paper, Huang concedes, was "beautiful - much better than ours." But he says that its appearance was "very surprising." It had never occurred to him that an American scientist would be permitted to work on embryos - and, in fact, Thomson was forced to set up a separate, privately funded lab to do so. Until I contacted him, Thomson says, he had never heard of Huang or his work. But he thinks Huang "may well have succeeded" in isolating embryonic stem cells. The relatively bad conditions in Guangzhou may have posed no problem; Thomson's own makeshift stem-cell lab, he notes, was "poorly equipped," with "a culture hood, an old microscope, and a clinical centrifuge and not much else."

President Bush's efforts to ban cloning "came too late," Huang says wryly. But now that stem-cell research has almost stopped in the West, "I should have another chance" to make a major discovery. The only problem is that the university in vitro clinic, smelling opportunity, won't give him any more embryos. "They want to exploit them for themselves," he says. "They don't want to share."

The theory of the gene

In the 1920s, a young scientist named Lu Huilin spent two years working at Columbia University under T. H. Morgan, arguably the century's greatest geneticist. Upon his return, Lu became a prominent exponent of the gospel of evolutionary biology, even translating Morgan's classic Theory of the Gene. But his efforts were undone in the 1950s, when the Chinese government embraced Lysenkoism, a doctrine that claimed Darwinism was wrong because it contradicted Marx. Lu stepped out of public life, but his youngest daughter, Lu Guangxiu, decided to follow her father into medical research. Again, politics intervened. In 1966, two years after Guangxiu graduated, Mao unleashed the Cultural Revolution. Because even the Red Guards wouldn't attack hospitals, she took a job as a surgeon.

In 1980, after the Cultural Revolution had ended, the middle-aged Lu joined Xiangya Medical University in Changsha, the gritty south-central flyover city where her father lived ("I am a Chinese daughter - I had to take care of him"). At the time, the school had little money for science. To pay for her research, Lu opened China's first in vitro fertilization clinic. She did all of the work herself, even basic tasks like boiling water. Four years after the clinic opened, her father wrote Human Reproduction and Reproductive Engineering, a textbook that predicted the advent of cloning (he died in 1997). Today, his daughter carries on his work. Although not well known outside Changsha, Lu's operation has grown into an important center for human stem-cell research, partly because of her determination - and partly because the clinic supplies all the frozen human eggs and embryos she needs.

Because IVF frequently fails, clinicians use drugs to induce super-ovulation, producing 10 to 15 eggs at once. The eggs are harvested and placed in a bath of sperm. After the eggs are fertilized, Lu picks the most viable zygote in the bunch, and implants it. She keeps the rest in tanks of liquid nitrogen the size and shape of pony kegs. After two years, if the patient has given birth to a healthy baby, Lu offers the parents a choice: The leftover embryos can be destroyed, given to infertile couples, or donated to science. Most choose the last option. Ultimately, Lu says, she ends up with "a few tens of embryos every year that are usable."

That number is bigger than it sounds. The US has at least 100,000 surplus frozen embryos in its hundreds of IVF clinics, but none of them, practically speaking, can be used for research. As a result, US university scientists now have only five lines of stably reproducing cells that they can work with, according to the American Society of Reproductive Medicine. (A few private companies also have stem-cell lines, but they aren't available to outside researchers.) Lu, who was able to learn her trade on countless mice and 30 to 40 human embryos, says she has three lines firmly established, just two fewer than are publicly available than in the entire US. She's testing another five or six.

To control stem cells for human benefit, scientists need to develop what they sometimes call fingerspitzengeféhl, a German term that could be translated as "knowledge of the fingertips" - the combination of experience and intuition that indicates precisely when to jiggle the dish or turn down the heat to assure the right result. The only way to acquire this expertise is to make lots of mistakes with actual eggs and embryos. Researchers without access to frozen eggs and embryos can't develop any of the necessary hands-on expertise. Lu, who has freezers full of them to herself, has a significant advantage.

Fingerspitzengeféhl is important because embryonic stem cells are tricky to work with. They exist solely in a special inner portion of the blastocyst and are only totipotent - able to transform themselves into any kind of cell - between the fourth and seventh day after the egg is fertilized. In the laboratory, they are difficult to maintain in their totipotent state, because they constantly seek to differentiate themselves into normal, dead-end cells. The most widely used method for keeping stem cells alive involves growing them in petri dishes atop thin sheets of mouse embryo cells, in a goo made from cow-blood serum. To test the cells, researchers inject them into mice that have been genetically engineered to have almost no immune system (without immune systems, their bodies can't reject foreign tissue). If the stem cells are totipotent, they will grow inside the mice and differentiate themselves into bizarre tumors called teratomas, clumps of tissue that appear where they don't belong. Most are just jumbles of flesh, but recognizable hair, teeth, eyes, and even entire tiny skeletons can also appear. Being a stem-cell researcher frequently involves plucking miniature human tissues from the cadavers of mice.

Todd Eberle
Todd Eberle. "We have a huge population and a one-child policy. Why would you think about making people in a laboratory?"

All over China, stem-cell researchers are carving up the field into chunks and attacking each one. Deng, with his well-supported operation in Beijing, is examining how the body directs stem cells to differentiate. Lu's largely self-funded group is tackling half a dozen problems at once. In addition to creating new lines of stem cells, she is also looking at the basics of creating the embryos that produce them to begin with. The Changsha researchers are taking the DNA-filled nucleus from an adult cell, "de-differentiating" it to reprogram the DNA to its fetal state, inserting the result into an egg, and forming blastocysts - the first steps toward therapeutic cloning. (The embryos are frozen or destroyed after study.)

In this manner, Lu says her team has created more than a hundred cloned embryos. They will need to make many more before they can claim to have mastered the process - before cloning becomes routine. Still, Lu says that they have already made major advances. "Five percent of our attempts form blastocysts," she explains. "That's better than any place else I know."

The xu factor

Some Western critics scoff at the claims of Chinese stem-cell researchers, many of whom have yet to publish their work. In a recent report, the US embassy in Beijing warned against researchers making "false claims simply to draw media attention." In part, the skepticism comes from cultural arrogance. But at least some of it is justified, due to what might be called the Xu Factor.

Xu Rongxiang has an office in the Beijing Hotel, a half-dozen old buildings in the city center that have been glued together, end to end, into a massive marble bricolage hundreds of yards long. Suite 5301, from which Xu runs his empire, is so private that the hotel reception doesn't even know it exists - my translator has to call Xu from the lobby telephone to ask directions. Xu directs us to an unmarked elevator, where we meet one of his subordinates. Upstairs, the office is dominated by Xu's desk and Xu himself, brilliant in a gray double-breasted sharkskin suit. We're here because, last August, Xu made the astounding claim that he had cloned 55 organs and tissues - an announcement that caused a media sensation in China.

In the inevitable PowerPoint presentation, Xu shows us mercifully blurry photographs of people with horrible burns all over their bodies. The conventional treatment for burn victims is skin grafting, a method that keeps people alive but leaves them with scars and permanently frozen joints. Back in the 1980s, Xu got the idea of smearing their wounds with gunk made from traditional ingredients like Baikal skullcap root and Chinese cork tree bark - a method, Xu tells us, that had incredible success. An hour into the pitch, his proof shows up in the form of Shi Yufa, 44. Shi walks into the hotel suite and immediately doffs his clothes to reveal a perfectly ordinary torso. At Xu's insistence, I palpate Shi's skin to feel the absence of scars. Meanwhile, Shi brandishes a ghastly photo of his burns.

Soon after, Xu moves his caravan - Xu, me, our respective translators, and a couple of Xu's minions - from the hotel to a dinner theater in a plush neighborhood. We sit in the center of the front row as barely dressed young women reenact historical tableaux in a style that might best be characterized as Late-'70s Oscar Dance Number. Meanwhile, Xu tells me about his stem-cell breakthroughs. The gratitude of thousands of former burn victims, Xu explains, led him to found MEBO Group, which sells Xu's patented burn ointment and various cosmetic fluids. It also led him to make revolutionary advances in stem-cell research. Every part of the body, he says, has a few "potential regenerative cells" tucked inside. In other words, a smattering of embryonic stem cells remains in our tissues even as we grow old. By isolating and stimulating them, Xu promises, he'll be able to clone 206 organs and tissues within five years. To back up his claims, Xu presents a slick, colorful press release headlined "CHINESE SCIENTIST REVEALS THE MYSTERY OF LIFE."

In itself, the notion that some embryonic or very early stage stem cells might survive to adulthood is not crazy - Pei Xuetao, director of the Beijing Institute of Transfusion Medicine, is looking for more or less the same thing in his research. But Xu's hypotheses weren't why a dozen high-profile scientists publicly denounced him in September. In China, Communist party functionaries control research funding, and researchers fear that they can be too easily swayed by the promises of charlatans. The obvious example is Trofim Lysenko, who gained support by guaranteeing miraculous agricultural advances to the credulous Russian government; his Lysenkoism movement set back Communist-bloc biology by two decades. Xu has already won backing for his amazing burn therapy from the Chinese government, which has set up 4,500 hospitals to practice his methods. Now he's looking for new worlds to conquer. The prospect of people like him - hypermodern, commercially minded, media-savvy versions of Lysenko - is "very worrisome," says Pei Gang, director of the Chinese Academy's Shanghai Institutes for Biological Sciences.

Over the years, Pei says, "many people have done similar things, either for commercial reasons or to obtain funding." The public attack on Xu was a first attempt by scientists to fight back. "They've been successful in the past," Pei says. "We must be on guard."

BROKEN-BACK RATS

Ultimately, the acme of stem-cell research is organ transplants without donors - the possibility that one day heart-attack patients will receive glistening new cloned hearts from a tray. If this is achieved, it will transform human life. And as the Chinese know, big changes lead to big fortunes; they want tomorrow's biotech tycoons to speak Mandarin.

In all likelihood, the therapeutic cloning of the future will involve what is known as autologous transplantation: nipping a dot of flesh from a patient's inner arm, sucking out the DNA from a few cells, de-differentiating the genetic material into the embryonic state, inserting it into eggs and creating blastocysts, then using those cells to clone new hearts from the patient's own DNA. Doctors perhaps one day will be able to grow some organs directly from adult stem cells, bypassing the embryo stage, but this is an even more distant possibility. For now, scientists have only created blastocysts in the lab and are just beginning to unravel the mysteries of de-differentiating the stem cells inside.

Jumping the remaining scientific hurdles will not be easy. If therapeutic cloning is to become widespread, for example, doctors will need huge numbers of human eggs. Alas, extracting eggs from women is painful, costly, and unreliable. Even if large numbers of eggs somehow become available, many scientists believe that de-differentiating adult DNA back to its fetal state degrades genetic material, which may explain why many of today's cloned animals have health problems.

Chinese scientists are attacking both problems. To avoid the need to take huge numbers of eggs from women, Dr. X is trying to create blastocysts from rabbit eggs. This is not as crazy as it might sound. As the DNA in the zygote divides, it creates new cells - that is, the embryo - inside the egg wall. Eventually, these cells take over the developmental process from the egg. In other words, as the human DNA in Dr. X's experiment produces new cells, the embryo will lose all traces of its rabbit origin.

To attack the second problem, scientists must trick the immune system, which recognizes invading cells by sampling their surfaces for chemical signatures called HLA markers. An individual's collection of HLA markers is a bit like an immunological fingerprint - except that fingerprints are unique, whereas HLA markers are thought to have up to 100,000 combinations. It should be possible to build banks of stem cells that have every combination of HLA marker and with them produce organs that would evade rejection.

Han Zhongchau and Zhao Chunhua are working toward establishing such a bank. An intense, stocky man with rimless glasses, Han spent 11 years in Paris before the Chinese Academy of Science recruited him to run its Institute of Hematology in Tianjin, China's fourth-largest city; Zhao, who worked at the University of Minnesota's highly regarded stem-cell lab, is his chief investigator. Tianjin researchers have isolated adult stem cells from "pretty much every tissue of the body," Zhao says, and are learning how to guide them into developing cloned organs and tissues. They hope to be in early clinical trials in one or two years.

Like Deng in Beijing, Han is getting a brand-new building from the government. Besides this, he has three privately funded buildings in a research office park at the edge of town, plus a columnar, nine-story structure with a big green marquee sign that reads UNION STEM CELL & GENE ENGINEERING CO.

Among the several programs at Union Stem Cell is a kind of pilot project for tomorrow's stem-cell banks. Under Han's direction, every one of the 50-odd hospitals in Tianjin is sending umbilical-cord blood from the babies born in its childbirth centers to a cord-blood bank funded by the China Medical Board of New York, an independent foundation. The cord-blood bank identifies the HLA markers and freezes each cord-blood sample for future use. For similar reasons, the US has almost 50 cord-blood banks, including the world's oldest and biggest, in Manhattan. Established 10 years ago, the New York facility has 18,000 samples. The bank in Tianjin, in operation for just one year, already has 6,000. "We'll pass New York soon," Han says. Eventually, the Tianjin bank plans to have 500,000 cord-blood samples. "There are advantages to living in a truly big country."

With a limitless supply of eggs and stores of frozen stem cells, autologous cloning could become as common as bypass surgery - but with far greater impact. Such claims, frequently heard from stem-cell supporters, may sound abstract, even glib. But they aren't, as I was forcefully reminded when I visited Li Linsong, director of Peking University's Stem-Cell Research Center.

A trim, energetic man, sleek in black knits, Li is so ebullient about his research that the postdocs he summons to explain their work can hardly get a word in. As he gives us a ride in his plush new car, cell phone constantly chirping, I can easily imagine him as chief scientist at a well-financed startup in Silicon Valley. Li spent almost a decade working at Stanford and the University of Washington, returning to China in 2002. The opportunities back home for a young scientist, he tells me, were impossible to turn down. In addition to creating the stem-cell center for his team, the university also set up SinoCells Biotechnologies, a public-private partnership intended to commercialize Li's research.

In Beijing, Li runs half a dozen scientific teams concentrating on two areas of research, one of which is the creation of neural stem-cell lines. In as-yet unpublished experiments, Li and his collaborators dropped weights on the backs of rats, breaking their spines - a lab-model version of the injury suffered by actor Christopher Reeve. Afterward, the rats were unable to walk. Then the team injected human stem cells into their wrecked spinal cords. Within days, Li says, the nerves regenerated.

Li describes his work with proper scientific dispassion, but his words make the hairs on the back of my neck stand up. Years ago I visited a spinal-cord injury ward. Accident victims lay motionless in their cots, faces racked with pain, watching me and the doctor I'd come to interview walk easily around the room. Out of earshot of his patients, the doctor said, "We can't do a damn thing for them except treat their bedsores." I imagine the concentrated suffering in that ward dissipating like smoke as Li shows me videos of the healed rats circling about their cage, two or three crawling over and under one another at a time.

Li's work may not be verified. Like much of the research I saw in China, it's unpublished and might be wrong - in science, it's easy to fool yourself. But the odds of all the stem-cell research in China not producing anything of value are miniscule. And even if only a small percentage works out, so much is happening that China will still shape our medical future. "We also have some interesting stem-cell results with Parkinson's disease," Li says, the light from the video flickering on his face. "I believe many things will happen, and they will happen here." All the while, the miraculous rats climb obliviously around their cage.