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Focus 234 236 242 Was Mars The unsung News from the a dirty iceball? side of targeted ACS meeting therapies virus in cell culture and plans to slog through proposed that they submit three papers to coronavirus. “It appears there’s enough flesh all drugs currently approved for any condition NEJM: one produced by three groups in on the bones for everybody,” says Osterhaus. by the Food and Drug Administration, says Hong Kong, one co-authored by German re- Meanwhile, Stöhr is also compiling a pa- Army virologist Peter Jahrling. If an approved searchers and CDC, and one by groups that per for The Lancet chronicling the current drug works against SARS, it could be available found the metapneumovirus. That plan fell collaboration. He concedes to being slightly much faster than a new one. CDC and other apart when CDC, which had been invited by taken aback last week when, after each lab labs are comparing the virus’s genome se- NEJM to write a paper, decided it preferred had submitted 250 words about its own role, quence to those of other coronaviruses— to go it alone. Fortunately, NEJM editors Gerberding stole some of the network’s which can infect a range of avian and mam- said they would consider publishing all four. thunder in an NEJM editorial that was malian species—to determine its likely origin. Drosten has teamed with colleagues across posted online 2 April. But his hope is that For network scientists, Stöhr has tried to Germany as well as Osterhaus and a group the example set by the SARS network will orchestrate the fair distribution of a key from the Pasteur Institute in Paris to de- long outlast any debate over who came first. commodity: scientific credit. He initially scribe the methods they used to track the –MARTIN ENSERINK AND GRETCHEN VOGEL NUCLEAR TRANSFER Misguided Chromosomes Foil Primate Cloning While governments around the world debate oped into a pregnancy when implanted. When transfer experiments at his previous laborato- how to prevent human reproductive cloning, the researchers looked more closely, they re- ry at the University of California, San Fran- it seems that nature has put a few hurdles of alized why: Many of the cells in a given em- cisco. “Primate eggs are biologically differ- its own in the way. On page 297, a team re- bryo had the wrong number of chromosomes. ent.” Schatten says preliminary data suggest ports that in rhesus monkeys, cloning robs Some had just a few, whereas others had the proteins are also concentrated near the nu- an embryo of key proteins that allow a cell twice as many as they should. Although em- clear material in unfertilized human eggs. to divvy up chromosomes and divide prop- bryos can survive for a few cell divisions with A cloning lab might surmount the hurdle, erly. Unpublished data from this and other such defects, soon the develop- groups suggest that the same problem may mental program becomes hope- also thwart attempts to clone humans. lessly derailed. There are potential ways around the new- To f ind out what was inter- found obstacle, but for now, groups that made fering with proper cell division, controversial claims that they would use the the team fluorescently labeled techniques that produced Dolly the sheep to the cell-division machinery. The create human babies are unlikely to succeed. cells’ mitotic spindles, which It is almost as if someone “drew a sharp guide chromosomes to the right line between old-world primates—including place during cell division, were people—and other animals, saying, ‘I’ll let completely disorganized. And you clone cattle, mice, sheep, even rabbits and two proteins that help organize cats, but monkeys and humans require some- the spindles, called NuMA and thing more,’ ” says Gerald Schatten of the HSET, were missing. University of Pittsburgh School of Medicine, A look at unfertilized rhesus a leader of the rhesus monkey study. oocytes explained why. The Schatten and his colleagues have tried team found that the spindle pro- Missing in action. In human embryos, as in this egg fertilized hundreds of times to clone monkeys, only to teins are concentrated near the by two sperm (red lines), proteins from egg and sperm combine fail. Indeed, although several groups have at- chromosomes of unfertilized (yellow) to guide cell division. Embryos formed by nuclear tempted it, no one has yet produced a mon- egg cells—the same chromo- transfer lack these proteins. key through somatic cell nuclear transfer, somes that are removed during the process by which a nucleus from one cell the first step of nuclear transfer. In most other says Schatten, by reversing the order of the is extracted and injected into an egg whose mammals, Schatten says, the proteins are traditional nuclear transfer procedure: First own nucleus has been removed. “The failure scattered throughout the egg, and removing add an extra nucleus, then activate cell divi- to clone any primate has so far been star- the egg’s chromosomes seems to leave sion, and finally remove the egg’s DNA. The tling,” says Rudolf Jaenisch of the Massa- enough of the key proteins behind for cell di- find “will make people think differently chusetts Institute of Technology in Cam- vision to proceed. about the optimum sequence of nuclear bridge, who studies cloning in mice. The work “explains why no one has yet transfer procedures,” says Ian Wilmut of the The scientists had suspected for several succeed in achieving normally developing Roslin Institute in Midlothian, Scotland, a years that something was disturbing cell divi- embryos from human nuclear transfer,” says leader of the team that cloned Dolly. sion in cloned embryos. The embryos seemed Roger Pedersen of the University of Cam- Even if scientists could overcome the obsta- ▲ CREDIT: G. OF PITTSBURGH SCHOOL OF MEDICINE SCHATTEN/UNIVERSITY normal at their earliest stages, but none devel- bridge, U.K., who attempted human nuclear cles, however, another study suggests that www.sciencemag.org SCIENCE VOL 300 11 APRIL 2003 225 further developmental problems threaten procedure might help solve the cell-division clones of all species. Jaenisch and his col- problem, it is harder to imagine a solution ScienceScope leagues report in the 15 April issue of Develop- for the faulty gene regulation that Jaenisch ment that genes important to early development and his colleagues see. “We’re looking at a India,WHO Attack Polio frequently fail to turn on in mouse embryos more fundamental problem,” he says. NEW DELHI—Calling India “the number one cloned from adult cells. That failure helps ex- The biological roadblocks would seem to priority for stopping the transmission of plain the low survival rate of such embryos, be good news for those worried about the eth- polio,”WHO Director-General Gro Harlem Jaenisch says. But he notes that the team’s ical implications of human cloning, says Brundtland this week traveled to the work—which examined the expression of just Schatten. “This reinforces the fact that the north Indian state of Uttar Pradesh to 11 genes—is only the tip of the iceberg. In oth- charlatans who claim to have cloned humans launch a final assault on the disease.With er experiments, the researchers have found that have never understood enough cell or devel- 55 new cases already this year, Brundt- even apparently healthy cloned mice show ab- opmental biology” to succeed, he says. The land says that “Uttar normal levels of gene expression. “There may debate will go on, but nature already seems to Pradesh is the epicenter” be no normal clones,” Jaenisch says. have imposed its own limits on cloning. of a global battle to eradi- Although revising the nuclear transfer –GRETCHEN VOGEL cate polio by 2005. India joins Nigeria, Egypt, Pakistan, GENE EVOLUTION Afghanistan, Niger, and Somalia as the only coun- Cannibalism and Prion Disease May tries with indigenous wild polio, and last year it was home to five of every six Have Been Rampant in Ancient Humans new cases. Uttar Pradesh was also the Some call it the laughing disease; others, had a tradition of eating the dead. In the source of outbreaks in two other Indian kuru. This neurodegenerative disorder is 1960s, Carleton Gajdusek of the National provinces, and this winter a Lebanese youth who never left his village was para- universally fatal and 40 years ago killed al- Institute of Neurological Diseases and lyzed by a virus traced back to India. most 10% of a small New Guinea tribe called Stroke in Bethesda demonstrated that kuru WHO officials say the latest epidemic the Fore. Now molecular biologists propose was an infectious disease: Once cannibalism is the result of fewer vaccination cam- that similar epidemics plagued prehistoric hu- was banned, kuru disappeared. paigns than planned and a failure to mans. Both then and more recently, kuru, Gajdusek blamed a slow-growing virus achieve blanket coverage during home a prion disease, was transmitted through for the disease, but now the prime suspect visits. This year officials hope to reach cannibalism, Simon Mead and John in kuru is a malformed miniature protein every child under 5 in six campaigns. Al- Collinge of University College London and called a prion. Contorted prions cause though Brundtland says that “we have their colleagues claim in a report online in other, native prions to misfold, clump to- the tools and the strategies to finish this Science this week (www.sciencemag. gether, and kill brain cells. A similar job,”WHO remains $275 million short of org/cgi/content/abstract/1083320). They process is believed to cause Creutzfeldt- what it estimates is needed to eradicate base their conclusions on the worldwide dis- Jakob disease (CJD) in humans and the disease.

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