News this Week

Science  17 Jul 1998:
Vol. 281, Issue 5375, pp. 314
  1. FUNDING

    U.K. Government, Wellcome Trust Give $1.75 Billion Boost to R&D

    1. Nigel Williams

    london—After more than a decade of budget squeezing by the previous Conservative government, British scientists finally got something to celebrate this week. The new Labour administration's plans for science, announced on Monday, include $1.75 billion in new funds over the next 3 years, a boost that “will transform the science and engineering base,” said Trade and Industry Secretary Margaret Beckett. “This major injection of funds,” she added, “reverses the decline that our predecessors allowed.” And, in an unprecedented partnership, more than one-third of the new money is being provided by the Wellcome Trust, the world's largest biomedical research charity. The announcement is one of the highlights of a detailed review of all government spending, carried out by the new government in its first 14 months in office, that will form the basis of multiyear budget forecasts.

    The government's share of the new funds will boost its annual $2.2 billion science budget by 15% over 3 years, to $2.7 billion by 2001–02. The plan is divided into two main parts: The government and the Wellcome Trust will each pay $480 million into an infrastructure fund to build new labs in universities and refurbish outdated ones. A further $650 million of government money will be allocated to the seven research councils for new projects in priority areas such as genetics. In addition, the Wellcome Trust is making a $160 million contribution to a planned $270 million synchrotron x-ray source. “Major investment in these areas is long overdue and is urgently needed,” says Ken Edwards, vice chancellor of the University of Leicester. “The government has met our concerns,” says Peter Cotgreave, spokesperson for the lobby group Save British Science.

    Researchers have waited patiently since Labour was elected in May last year for it to fulfill its election promise to tackle the plight of the country's crumbling research infrastructure. An independent report on higher education, commissioned by the previous government and chaired by longtime education reformer Ronald Dearing, called last July for an urgent injection of $800 million for university labs and equipment (Science, 1 August 1997, p. 628). The Dearing report also called on the government to rethink the United Kingdom's “dual support” system for research, in which most of the overhead costs of research are paid directly to university departments, while the running costs of individual projects come from grants from the subject-based research councils. Dearing suggested more of the overheads should be paid out of research council grants, a view fiercely opposed by university heads.

    In its new plans, the government seems to have left dual support intact by providing separate funds for a new infrastructure scheme and new projects by the research councils. Martin Harris, chair of the Committee of Vice Chancellors and Principals, says: “Universities desperately need these funds to upgrade their research facilities. The Dearing report stressed the urgency of this issue. … We look forward to further announcements within the comprehensive spending review for the other areas of urgent need in higher education: teaching, support for basic research, and the training of tomorrow's scientists.” Mike Dexter, director of the Wellcome Trust, says that the trust backed the government's plans because Britain needs a university infrastructure “that meets the requirements of our best scientists, an infrastructure that allows us to compete internationally. It is really distressing to see our next generation of scientists being trained on obsolete technology.”

    The infrastructure funds will be awarded following competitive bids from universities, says a Department of Trade and Industry (DTI) official. This process is likely to continue the trend, begun under the Conservatives, of concentrating research activity in departments that are already strong in research. Because of the involvement of the Wellcome Trust, at least half of the infrastructure projects will be in the life sciences. The new money for the research councils will be divvied out to individual councils in the fall, but this week's announcement, well ahead of the normal November date for budget statements, will give councils advance notice of new funds and more time to plan new priorities. Again, much of the emphasis will be on biological sciences.

    The Wellcome Trust's new partnership with the government will strengthen the enormous influence it already has over British science (Science, 26 June, p. 2043, and 22 November 1996, p. 1292). According to a spokesperson, the trust's contribution to the infrastructure fund will come from additional income generated by its investments and will not affect the $400 million it already spends each year on supporting biomedical research—a sum nearly equal to the annual outlay of the Medical Research Council. The trust is already the world's largest single contributor to the human genome project—having committed $480 million to its sequencing facility, the Sanger Center, and the Genome Campus near Cambridge—and Dexter sees the new infrastructure program as essential support for these investments. “Sequencing of the human genome is only the first step in a process that is going to include the whole of the science base, not only the biomedical sciences but also engineering, informatics, computing, chemistry, and so on,” he says. “To reach our goal of exploiting the information emerging from the genome project will require the close interaction of all these scientific disciplines, perhaps on a scale that has not been seen before.”

    That close interaction is evidenced by the trust's contribution to help the government build a high-intensity synchrotron radiation source. Once the playthings of physicists and chemists, synchrotrons are becoming increasingly important to biologists for unraveling molecular structure. By chipping in, the trust has ensured that a new synchrotron machine will be built. Britain currently has an aging synchrotron at Daresbury in northern England, but researchers have been pushing for a unique new high-intensity machine, dubbed Diamond. “A machine will be critical for resolving the structure of small molecules which make up living organisms and is an essential tool for structural biologists,” says Dexter.

    The government's plans have also calmed fears that it may be less concerned with supporting basic research than with the transfer of knowledge to industry to foster innovation—a theme constantly voiced by the previous government. According to Chancellor of the Exchequer Gordon Brown: “It would be shortsighted to ignore the health of the science and engineering base itself. That is why we need to invest now.” Industry seems to agree with the government's strategy. Says a spokesperson for the pharmaceutical company SmithKline Beecham: “This new spending will make the U.K. a more attractive place for investment.”

  2. PALEONTOLOGY

    Smuggled Chinese Fossils on Exhibit

    1. Mutsumi Stone,
    2. Jennifer Couzin,
    3. Li Hui
    1. Mutsumi Stone and Jennifer Couzin in Washington
    2. Li Hui in Beijing

    The Jurassic-era bird fossil from China was a real find for the Miyazaki Prefectural Museum of Nature and History in southwestern Japan. The clay slab containing the remains of a Confuciusornis sanctus served as an important element in a new exhibit on evolution that kicked off the museum's reopening in May. But 2 months later, pride has turned to embarrassment after museum officials learned that the fossil had in all probability been exported illegally.

    The Miyazaki museum is not alone. In response to a 5 July exposé on fossil trading in the Asahi Shimbun, one of Japan's largest daily newspapers, the Tottori Prefectural Museum also removed a Confuciusornis specimen from public viewing. The two museums, along with four others in Japan that have Confuciusornis fossils in their collections, are scrambling to get on the right side of a 1989 Chinese law that prohibits the export of such cultural and scientific treasures without proper certification. And the problem extends beyond Japan. The New Mexico Museum of Natural History and Science in Albuquerque is trying to verify the status of a Confuciusornis put on display on 2 July after a trustee purchased it from a local dealer. The same cloud may also hang over nine specimens acquired in 1996 by the Senckenburg Museum of Natural History in Frankfurt, Germany.

    At the center of the controversy is a chicken-sized creature identified and named in 1995 by avian paleontologist Hou Lianhai of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing from a sample brought in by a local farmer (Science, 15 November 1996, pp. 1083 and 1164). Confuciusornis, thought to have lived more than 120 million years ago, is the second earliest known bird after the 150-million-year-old Archaeopteryx and the oldest to possess such modern characteristics as a toothless beak and the ability to fly. Although the species has considerable scientific value for the early evolution of birds, it is not involved in the debate over their link to dinosaurs.

    Even so, there is an active market in Confuciusornis specimens, hundreds of which have been excavated from the rich fossil beds outside Sihetun in Liaoning Province in northeastern China (Science, 13 March, p. 1626). Philip Currie, dinosaur curator for the Royal Tyrrell Museum of Palaeontology in Alberta, Canada, estimates that up to 75% have been smuggled out of China, leaving a minority in the country for purposes of research and exhibition. The Japanese museums paid between $5000 and $15,000 for their specimens, and the Albuquerque benefactor purchased his for $18,000.

    An official with the State Administration for Cultural Relics (SACR) in China says that the Japanese museum fossils should be considered smuggled cultural relics. “This is robbery,” he says, adding that any country holding the fossils should return them. A press spokesperson says that SACR has never approved the export of Confuciusornis fossils, nor has it received any requests.

    The Ibaragi Nature Museum appears to have been the first in Japan to purchase a Confuciusornis, in December 1993, although it wasn't identified as such until 1997 by visiting British paleontologist Paul Davis. Since then, Miyazaki, Tottori, and city museums in Osaka, Aichi, and Okayama prefectures have all obtained similar specimens. The museums typically dealt with Japanese dealers, who are themselves intermediaries in the alleged illicit trading.

    Japanese scientists and museum officials say that the current incidents reflect their ignorance of the Chinese law. Prefectural and city museums often have only one or few curators in geology, says one Japanese paleontologist, and it is rare for them to be fossil specialists. “It is almost impossible for them to understand the details of Chinese domestic law regarding fossils,” he adds.

    Several museum officials say they asked the dealers if the fossils were legal and were told not to worry, but none of the museums received documents gaining permission from the Chinese government to export the fossils. The dealer who sold the fossils to four of the museums, and who requested anonymity, says the fossils were mailed to him from China without any authorizing documents. Another dealer says that Chinese customs officials “have not requested any documents” during more than a dozen trips to bring home fossils.

    None of the Japanese museums is currently exhibiting the fossils as they ponder their next move. “We are collaborating to solve the problem we all face, as there is no authority in Japan to deal with such a matter,” says Miyazaki's Tetsuo Munekata. In New Mexico, the fossil is on temporary display while museum officials await promised paperwork from the dealer. If documents showing legal export are not produced, director Richard Smartt says that the museum will either relinquish its prize or seek to obtain permission from the Chinese government to display the fossil. The Senckenburg received assurances from its dealer that the fossils had gone through proper channels, says former assistant director Stefan Peters, who adds that “it would bother me a little if they really were illegally imported.” Still, Peters says, “it is better that museums acquire these specimens rather than some private collection.”

    Hou says he hopes the controversy will highlight the importance of proper stewardship of valuable fossils. “Exhibits must come from legal sources,” says Hou, who at a 1996 international conference in Washington collected 75 signatures on a letter condemning the smuggling of bird fossils and asking authorities at the Chinese Academy of Sciences to exercise greater control over fossil excavations. “I think SACR should immediately collaborate with the Ministry of Foreign Affairs to approach the Japanese government for the return of these fossils. At the same time, our government should crack down on fossil dealers.”

    Those not directly involved in the controversy say they hope the outcome will not restrict the ability of museums to serve the public. “I understand the need to ban the export of very rare fossils or fossils under research,” says Keiji Matsuoka, a curator of Toyohashi Museum of Natural History in Aichi. “But if there are already a lot of fossils [of Confuciusornis] for researchers, I hope that the Chinese government clarifies the law and agrees to provide some fossils by a legal route.”

  3. AGRICULTURAL RESEARCH

    Plant Biologists Score Two New Major Facilities

    1. Jocelyn Kaiser

    The city of St. Louis, home to agricultural biotech giant Monsanto, will soon host a powerhouse in basic plant research as well. Later this month, a public-private consortium plans to announce the creation of a $146 million center in St. Louis devoted to basic plant science and sustainable agriculture. With a $15 million annual budget and a staff that will include more than 80 scientists, the new not-for-profit center, to open in 2000, would be rivaled in size nationwide only by the Boyce Thompson Plant Research Institute in Ithaca, New York. And it won't be the only new kid on the block. Later this summer Novartis AG is expected to announce a $250 million plant genomics institute to be built outside San Diego. The blockbuster developments, says Charles Arntzen, president of Boyce Thompson, are “an indication of the emerging importance of plant science in the United States.”

    Although the two centers will fund a wealth of new plant science projects, their patrons each have differing expectations. The St. Louis center will operate independently of its backers, an unusual coalition of public and private organizations. “There's nothing exactly like it that I know of,” says William Danforth, chair of the center's board as well as the board of Washington University in St. Louis. The Danforth Foundation, a St. Louis philanthropy, is chipping in $60 million to the center's endowment; until now it has funded mostly education projects at a national level. The other major contributors are the Monsanto Fund—the philanthropic arm of Monsanto company—and the company itself, which together will provide $81.4 million in funding and other support. The other founders are Washington University, Missouri Botanical Garden (MBG), and the University of Missouri, Columbia.

    Independence for the St. Louis center means that it—not Monsanto or its other sponsors—will receive its own patents and any income from licensing deals that it would award without any special preference to its founders. The payoff for Monsanto, says Sam Fiorello, assistant to the company's president, is the “pool of talented people” that the center will attract to plant science. “Ultimately, it will help us,” he says. According to Chris Somerville, chief of the Carnegie Institution of Washington's plant lab at Stanford University, Monsanto “recognizes the advantages of being nestled up beside a first-class research institute where people and ideas may spill both ways.” A rumored candidate to head the center is Roger Beachy, a plant pathologist at The Scripps Research Institute in La Jolla, California. The center's research plan has been left “deliberately vague” for now, says MBG director Peter Raven, because it will depend largely on the incoming center chief.

    Novartis, a Switzerland-based drug company, is keeping plans for its center close to the vest. But a company spokesperson confirmed that it will be headed by Steven Briggs, a former biotech researcher at Pioneer Hi-Bred International in Johnston, Iowa, and will focus on plant genomics.

    Observers are expecting a big payoff from both ventures. Somerville, who has seen the St. Louis group's business plan, notes that each of the 15 principal investigators will get 370 square meters of lab space: “That's pretty big.” Indeed, he suggests the center could one day rival the John Innes Center in the United Kingdom, at 100 research groups the heavyweight among plant science institutes worldwide. Says Somerville, “I would call this stage one.”

  4. PUBLIC HEALTH

    Epidemiologist Named CDC Director

    1. Eliot Marshall

    Jeffrey Koplan, an epidemiologist now working with a private company, has been chosen to head the U.S. Centers for Disease Control and Prevention (CDC). Donna Shalala, secretary of the Department of Health and Human Services, announced the choice 10 July at CDC's headquarters in Atlanta. The event was “something of a homecoming celebration,” says attendee James Curran, public health school dean at Emory University, because Koplan has spent most of his career at CDC.

    The CDC directorship has been vacant since February when the previous chief, David Satcher, left to become the U.S. Surgeon General under Shalala. Koplan will take charge of both CDC and the Agency for Toxic Substances and Disease Registry on 5 October and is declining comment until then. No Senate confirmation is required.

    Koplan, 53, is currently president of Prudential Insurance Co.'s center for health care research in Atlanta, which studies the costs and outcomes of health services. Before taking this private-sector job, he spent 2 decades rising through the ranks at CDC—from field researcher in the Epidemic Intelligence Service to assistant surgeon general, becoming in 1989 the first director of CDC's national center for chronic disease prevention and health promotion. According to health researchers, Koplan played a key role in devising an AIDS monitoring network in 1982 to 1984 and led an initiative to prevent breast and cervical cancer in the 1980s.

    “He's a terrific choice,” says Curran, who admires Koplan's professionalism and “scientific depth.” Mohammad Akhter, director of the American Public Health Association in Washington, D.C., also says he's “delighted” with the selection, calling Koplan a practical leader who knows how to advance ideas through the bureaucracy.

    Others are more cautious. Public health leader D. A. Henderson of Johns Hopkins University notes that, although Koplan has a great record and is “very capable,” he will also need great leadership skills to reinvigorate CDC. Henderson believes CDC has become “parochial” and needs nudging to “open up” to outside ideas. Infectious diseases researcher Barry Bloom, recently named dean of Harvard University's School of Public Health, also notes that CDC has been slighted in recent federal budgets and needs a strong political champion. Koplan's ability in this area is untested, Bloom says.

  5. PHYSICS PUBLISHING

    Russian Academy to End AIP Journals Deal?

    1. Andrey Allakhverdov*
    1. Andrey Allakhverdov is a writer in Moscow. With additional reporting by Richard Stone.

    moscow—The socialist principles of the Soviet era long forgotten, the Russian Academy of Sciences (RAS) is rapidly learning to play hardball in its dealings with the West. Over the past few months, the RAS has threatened to end an agreement with the American Institute of Physics (AIP), which currently translates and distributes English-language versions of several RAS physics journals, and instead produce the two most profitable journals in its own publishing company. During negotiations in Moscow at the end of last month, the academy told the AIP it could continue publishing the journals for just one more year if it increases the royalties it pays to RAS by 50%. Russian journal staff claim that an agreement was reached on those terms; AIP officials, when contacted by Science, declined to comment.

    The move has dismayed some Russian researchers, who fear that without the international profile and publishing and distribution expertise of the AIP, these prestigious journals will soon wither. “As soon as AIP disappears from the Russian publishing market, competitiveness will disappear as well and the situation might grow much worse,” says Alexei Starobinsky, an expert on gravitational theory and a corresponding member of the RAS. “Physicists will be extremely upset by this move,” says Roald Sagdeev, a former head of Moscow's Institute of Space Research who is now a physics professor at the University of Maryland, College Park.

    RAS officials say they are simply carrying out a resolution passed by the academy's presidium in 1992. The resolution created a new publishing company, dubbed MAIK Nauka, jointly owned by RAS and U.S.-based Pleades Publishing, and it stipulated that the translation and publication of all RAS scientific periodicals in English should be concentrated at MAIK Nauka. By this year, MAIK Nauka was publishing all but six of more than 80 RAS journals that are translated into English. Those six—the Journal of Experimental and Theoretical Physics (JETP), JETP Letters, Physics of the Solid State, Semiconductors, Technical Physics, and Technical Physics Letters—are all being published by AIP. An umbrella organization for a number of learned societies in the physical sciences and astronomy in the United States, AIP has been publishing English-language versions of Russian physics journals since 1955.

    RAS officials apparently saw a chance to bring these remaining journals into the MAIK Nauka fold because the contracts for JETP and JETP Letters come up for renewal later this year, and the other four are due next year. As the renewal deadlines approached, RAS declared in a letter to AIP that they would not be renewed. “This is the fulfillment of the decision of the RAS presidium,” RAS vice president and deputy head of the RAS Scientific Publishing Council, Rem Petrov, told Science in an interview prior to last month's negotiations.

    RAS officials have also accused AIP of making excessive profits from the current arrangements. Petrov claims that the income from the sales of just one of the six journals—JETP—was $1.69 million in 1996, of which $303,000 was paid as royalties to authors and $70,000, or 4% of sales, was transferred to RAS. If AIP insists on the contracts being renewed on the same terms, Petrov argues, AIP would continue to profit “at the expense of Russian intellectual property.” AIP declined to comment on the negotiations, but AIP chief Marc Brodsky said before the Moscow talks that “we at AIP are proud of our productive and mutually beneficial relations with all our [Russian] colleagues, including authors, editors, and academicians.” Brodsky notes that AIP—unlike most of its competitors—is a not-for-profit, noncommercial organization.

    Some of the journals' Russian staff also appear to be upset by the move to publish the English versions from Moscow. JETP Editor Vsevolod Gantmacher told Science that the journal survived Russia's current financial crisis only because of the support of AIP, and it has now become one of the most popular journals among both Western and Russian scientists—a popularity boosted by its appearance on the AIP Web site in 1997. “Scientists turn to our journal only two times less frequently than to Physical Review Letters,” Gantmacher says. To terminate the contracts with AIP, he says, “would mean that the journal would be deprived of all the existing advantages and doomed to become a second-rate journal.” Says Starobinsky: “If all the journals are given to MAIK Nauka, then it will become a total monopolist.”

  6. RUSSIA

    Relief From Finance Farce?

    1. Andrey Allakhverdov,
    2. Vladimir Pokrovsky*
    1. Allakhverdov and Pokrovsky are based in Moscow.

    moscow—Russian scientists got another painful lesson in the vagaries of the country's bureaucracy earlier this year, when the government installed a new system for distributing grants awarded by the Russian Foundation for Basic Research (RFBR) and its offspring, the Russian Humanitarian Scientific Foundation—the country's fledgling competitive grants agencies. Many scientists' grants failed to appear, others got only a fraction of their awards, and nobody at the foundations could track what had happened to the money. Now, the government is trying again. A new distribution system was installed this month, and researchers are keeping their fingers crossed.

    The trouble began when the government decided to free the two foundations from the hassles of handling their own grant money. The foundations would simply choose their grantees and inform a section of the Finance Ministry called the Central Treasury. The ministry and a network of local treasuries around the country would then take care of disbursing the funds.

    The system soon ran into problems, says Mikhail Alfimov, head of RFBR. Because of the weak and irregular flow of finance from the budget, he says, grantees would often receive no money or only a fraction of what they were due. The funds were also not marked as foundation money, so if it was not a sum that the institution was expecting, it would often be used to pay electricity or heating bills and the grantee would be unaware of its fate. Similarly, the foundations received no information on what was getting through. When money did arrive, the Central Treasury put strict limits on how grantees could spend it, says Alfimov. “Suppose a grantee urgently needs to go to a conference, but he receives money for equipment. … The finance ministry does not allow [him to swap] it.”

    The problems came to a head at a meeting of RFBR funding managers in June. “We agreed that if we cannot effectively distribute grants, it would probably be honest to just resign,” says Alexei Reskov of the RFBR's department of biological and medical research. And at a heated meeting of the RFBR's Scientific Council early this month, earth scientist Felix Letnikov from Irkutsk strongly criticized the system, saying that “the foundation's initiative has been hijacked by bookkeepers.”

    Last week, Alfimov says the finance ministry bowed to pressure and established a new system of grant distribution. The Treasury will now send a lump sum to the grantee, who will liaise directly with RFBR on how it should be spent. The funding will also be marked as an RFBR grant, and no institute will be able to use it for any other purpose. Although the new system can do nothing about erratic amounts of funding arriving from the budget, at least now the RFBR and its grantees will know where their money is. “We have managed to educate the Finance Ministry,” says Alfimov. “They are used to operating the big volumes. But we have explained to them the specific needs of the foundations.”

  7. PALEOBIOLOGY

    A Fruitful Scoop for Ancient DNA

    1. Erik Stokstad

    In the movie Jurassic Park, a collector snapped up hundreds of thousands of mosquitoes preserved in amber for DNA they had sucked from dinosaurs. In the real world, however, amber has been a disappointment, yielding no reproducible traces of ancient genetic material. Now researchers report that the treasure of ancient DNA can instead be gleaned from a less glamorous material: fossil feces.

    On page 402, a team led by molecular biologist Hendrik Poinar and geneticist Svante Pääbo of the University of Munich demonstrates a way to unlock DNA trapped inside ancient feces. The dung they studied, a firm lump left by an extinct ground sloth about 20,000 years ago, offers clues to that species' ecology. Applied to other droppings, the method may be able to provide a wealth of clues about the ecology and relationships of extinct animals—and perhaps even about early humans. “This adds several new dimensions to the study of ancient animals,” says Bob Wayne, an evolutionary biologist at the University of California, Los Angeles.

    The Pääbo lab is one of the few to have successfully extracted DNA from ancient bones (Science, 11 July 1997, p. 176). But the team wasn't having any luck with the well-preserved samples of fossilized dung, called coprolites, collected from Gypsum Cave near Las Vegas, Nevada, a gathering place for ice age animals. Then the researchers chemically analyzed the samples and found several compounds that indicated the presence of Maillard products—sugar-rich tangles of proteins and nucleic acids that prevent DNA amplification. “Everyone looks at the Maillard product as evil,” says Poinar. But he realized that the tight cross-links might protect DNA by keeping out damaging water and microbes. The question was how to crack open that coat.

    In 1996, the team spotted a possible answer in a Nature paper on a chemical called N-phenacylthiazolium bromide (PTB), which when given to diabetic rats cleaves the bonds between sugars and proteins—the same kind of bonds that may entangle DNA in the Maillard products. “We thought: ‘Wouldn't it be great if PTB would release DNA?’ But it was still a complete shot in the dark,” recalls Poinar.

    The shot hit home. Extracts from the sloth coprolite treated with PTB yielded sequences of mitochondrial DNA, presumably from intestinal cells shed into the feces. It probably came from an extinct ground sloth, Nothrotheriops shastensis, because the bones of that animal are scattered throughout the cave and because the DNA is a good match to that of a related extinct ground sloth, Mylodon darwinii, whose DNA was derived from bone and soft tissue.

    The team was also able to extract a wide variety of plant DNA from the coprolite—clues to the vegetarian sloth's diet. They identified sequences from eight plant families, including grasses, yucca, grapes, and mint. The coprolite had identifiable fragments of only five families, so DNA analysis may help identify plants chewed beyond recognition, says Poinar.

    The team hopes to study more sloth dung to help answer the question of why these and other large animals vanished from North America about 10,000 years ago. “We'd like to … see if there's a change in diet before they go extinct,” says Pääbo. Climate change, a possible agent of extinction, might show up as a change of diet, he says.

    Right now, Pääbo is analyzing samples of what could be Neandertal feces, from 45,000-year-old cave deposits in Gibraltar. “They look human, but it's hard to be sure that they're not jackal,” he cautions. If the samples do contain Neandertal DNA, they would be the second such sequences ever and could offer additional evidence in the continuing debate over this extinct human's kinship to our own species. “A second sequence would give a real window on Neandertal variation,” says paleoanthropologist Christopher Stringer of The Natural History Museum in London, who discovered the feces last summer. They could also reveal what Neandertals dined on and what parasites may have plagued them. “Five years ago, we wouldn't have thought we would have the possibility of reconstructing Neandertal diet in this way,” says Stringer.

    Still, some paleontologists caution that DNA from dung may not reveal everything its proponents hope for. Changes in coprolite contents could simply reflect seasonal shifts rather than pointing to causes of extinction, says Russ Graham, a paleontologist at the Denver Museum of Natural History. The technique may not work on coprolites found in warmer or wetter conditions, or on very ancient samples, as most DNA is thought to degrade within 100,000 years, says Poinar.

    Despite such caveats, “I'm gathering as much poop as I can,” Poinar says. “There's going to be a run on feces.”

  8. ASTRONOMY

    Glow Reveals Early Star Nurseries

    1. Andrew Watson*
    1. Andrew Watson is a writer in Norwich, U.K.

    The universe shrouds many of its secrets in dust. Among them is the history of star birth, which transformed primordial gas into the countless starry galaxies of the present-day universe. Now a team of U.K. astronomers has used light absorbed by dust and remitted at longer wavelengths to look back in time. They saw signs of galaxies undergoing frenzied star formation when the universe was a fraction of its present age. The observation implies, says team member James Dunlop of the Institute for Astronomy in Edinburgh, that astronomers studying visible light “have only seen about a fifth of the star formation in the early universe.”

    Reported in this week's issue of Nature, the observations are “a very exciting new development,” says Max Pettini, an astrophysicist at Britain's Royal Greenwich Observatory. Star formation is “part and parcel of the broader question of how the universe evolved from the smooth conditions of the big bang into the galaxies we see today,” says Pettini, who has followed the work closely. The finding, along with related work reported in the same issue of Nature, suggests that large-scale star formation may have gotten a surprisingly early start.

    The present-day universe is mostly past its reproductive prime. So astronomers have been searching at great distances—which correspond to earlier times—to find the heyday of star birth. But dust is particularly thick in star-forming regions, where it hides the light of hot, young stars, reradiating it in the infrared. “For objects that are very, very heavily obscured by dust, this is where all the energy comes out,” says Charles Steidel of the California Institute of Technology.

    Observations by infrared satellites have already revealed large numbers of galaxies that shine brightly in the infrared, signifying intense star formation, as much as halfway back to the big bang, says Michael Rowan-Robinson of London's Imperial College. But for even older, more distant stars and galaxies, the expansion of the universe stretches infrared into the submillimeter waveband, a twilight region of the spectrum between the infrared and radio waves. And until recently, astronomers had no way to make submillimeter images of the most distant star nurseries.

    That gap is now being filled by SCUBA (for Submillimeter Common User Bolometer Array), the world's first submillimeter camera, based at the 15-meter James Clerk Maxwell submillimeter telescope on Mauna Kea, Hawaii. SCUBA has a palmtop-sized receiver made up of closely packed metal horns, each a few millimeters across, that funnel incoming radiation to heat sensors, called bolometers. To build an image, SCUBA shuffles through 16 slightly different locations and combines the results, like fingers mapping out a heat pattern by tapping around it.

    Earlier this year, the team pointed SCUBA at the Hubble Deep Field, the small patch of sky where the Hubble Space Telescope captured optical images of some of the most distant galaxies ever. “Thanks to El Niño, we had nearly 2 weeks of absolutely perfect submillimeter weather, [with] almost no water vapor in the atmosphere,” says Rowan-Robinson.

    Rowan-Robinson and his colleagues were able to match five of the brightest submillimeter sources in their image to faint galaxies in the Hubble image, which have known redshifts—an indication of how far back in time they lie. Four of the five have redshifts of between 2 and 4, which means that they date from when the universe was between a third and a fifth of its present age—up to 9 billion years ago. Their submillimeter brilliance indicates that dust is shrouding large populations of hot, newborn stars, implying that these are “starburst galaxies,” spawning stars at 100 times the rate of our own, says Dunlop. Additional SCUBA images made by a U.S.-Japanese group also reveal bright submillimeter galaxies in the distant universe.

    SCUBA offers a mere two-hundredths of Hubble's image quality, which limits the certainty with which the submillimeter images can be matched with optical counterparts. As a result, the distance and hence the age of these submillimeter sources is “somewhat ambiguous,” notes Steidel. “Really, we would like a few hundred sources to begin to say something more statistical and general” about star formation in the early universe, agrees Rowan-Robinson.

  9. PHYSICS

    Hydrogen Coaxed Into Quantum Condensate

    1. David Kestenbaum

    In 1978, physicists at the Massachusetts Institute of Technology (MIT) hatched an ambitious plan to create a new form of matter. They set out to cool a cloud of hydrogen atoms almost to absolute zero, until they snapped into a single quantum blob called a Bose-Einstein condensate. “We thought it would take 5 years, maybe 8,” recalls Tom Greytak, one of the physicists. Twenty years went by and other groups beat them to the punch, with heftier atoms and new laser cooling techniques. The MIT group, however, kept working on hydrogen. And late one night this past June, a phone call from the lab shook Greytak and colleague Dan Kleppner out of bed. They rushed in and at 1:30 a.m. toasted the birth of the tiny superatom with their team. “I was elated,” Kleppner says. “It had been such a long siege.”

    The new achievement, discussed last week at a conference in Washington,* is more than just a heroic example of finishing what you started, says Randall Hulet, a physicist at Rice University in Houston. The MIT team has coerced over 100 million atoms into a single condensate, 10 times more than has been achieved with other atoms, he points out: “For just about any application, more atoms is better.” Hydrogen also turns out to be easier to probe with lasers, he adds.

    Twenty years ago, hydrogen atoms looked like the only ones that could be made both dense enough and cold enough for the atoms' quantum identities to spread out and merge into a Bose-Einstein condensate. Other atoms seemed likely to solidify as they approached absolute zero, which would heat them up and thwart the condensation. In the 1980s, the MIT group got close with a technique called evaporative cooling. They caged the atoms in a magnetic trap and lowered the walls of the trap so the faster, hotter atoms could escape. “[It's] like lowering one end of a bathtub” to let some of the hot water lap out, Greytak explains.

    The problem was that the tub had a hole. Hydrogen only stayed trapped when the spin of its electron and that of the nucleus were pointing in the same direction, giving the magnetic field some purchase. Over time collisions would flip the atoms' spins, and they would leak out faster than they could be cooled. Laser cooling, which slows atoms by bombarding them with photons, offered a faster route toward absolute zero. But existing lasers worked best on heavier atoms. The first condensates were cold clouds of rubidium atoms, sparse enough to avoid solidifying.

    Now the MIT team has sped up evaporative cooling with a radio frequency burst that selectively flips the spins of the hotter atoms so they flee the trap. To see if the remaining atoms—now at about 40 millionths of a degree—had condensed, the researchers pulsed them with a laser and measured the light they reemitted. The high density of a condensate would force the atoms' energy levels closer together, lowering the frequency of the reemitted light. At first they saw “the sort of signal only a mother could love,” Greytak says. But with improvements it grew convincingly large. “Nothing else could give that feature,” Kleppner says.

    Because the laser excites a particularly sharp resonance in hydrogen, Greytak says, it should give cleaner pictures of the condensate's structure than researchers have had with other condensates. The laser pulses should also kick out a stream of synchronized atoms—a rudimentary “atom laser,” which might one day be capable of etching tiny structures. But the physicists cheering the hydrogen condensate aren't worrying much about practical applications. “We're all delighted at the achievement,” says Stanford University physicist Steven Chu, who shared the Nobel Prize for his work with laser cooling. “These guys really started the quest.”

    • * 1998 Conference on Precision Electromagnetic Measurement, Washington, D.C., 6–10 July.

  10. CHEMICAL ECOLOGY

    Building a Better Bug Repellent

    1. Luis Campos*
    1. Luis Campos is a summer intern at Science.

    Chemical warfare is nothing new to the hordes of insects that exude noxious compounds to drive away predators. But in the sophistication of their chemical arms factories, squash beetles stand out. Researchers have now discovered that the pupae of these ladybird beetles concoct an arsenal of chemical deterrents with a technique human chemists thought they had a monopoly on: combinatorial chemistry, in which hundreds of different compounds are assembled from the same set of basic chemical building blocks. The finding, reported on page 428 by a group led by Cornell University organic chemist Jerrold Meinwald, is “the first example of natural combinatorial chemistry,” says organic chemist Gordon Gribble of Dartmouth College in Hanover, New Hampshire.

    The pupae deploy their defensive chemicals in droplets that they secrete from glandular hairs. Ants that attack a pupa and touch the droplets will beat a rapid retreat and try to clean themselves off. To find out what is lurking in the droplets, postdoc Frank Schröder analyzed the secretion with a battery of techniques—nuclear magnetic resonance, high-pressure liquid chromatography, and mass spectrometry—and soon found that the liquid contains an array of complex, large-ring polyamines.

    The team discovered that the compounds were formed from simpler subunits called (ω-1)-(2-hydroxyethylamino)alkanoic acids. The pupae seem to have linked the subunits head to tail, in random order and varying proportions, to form scads of rings. “It's very intriguing to see what we do as organic chemists being done in a random, uninformed way,” says Yale University's Harry Wasserman. Grad student Jay Farmer synthesized one of the rings, suspended it in a droplet, and found that it deterred ants.

    Because the large ring compounds are too heavy to evaporate, they collect in the defensive droplets, where the improvising continues. By analyzing secretions of different ages, the researchers found that over time the rings isomerize (flip bonds) to form compounds with the same molecular formulas but different structures. When combined with newer rings pumped out by the pupa, these isomers add to the potent cocktail that deters predators.

    For now, it's impossible to say whether the beetles began this chemical tinkering to yield a bunch of deterrents that could thwart predators better than a single chemical could. “It could be that the beetle doesn't know how to control the process, that it's sloppy,” says Meinwald. But that doesn't diminish the finding's importance, says Cornell chemical ecologist Thomas Eisner, a co-author. “It's really pretty nifty” for evolution to have come up with this way of upping chemical diversity, he says. “This one's a keeper,” adds May Berenbaum of the University of Illinois, Urbana-Champaign. “This is going into my chemical ecology class next fall,” she says. This mix-and-match approach might also have a practical payoff, says Gribble: It could be used against pests someday, “much like we use DEET to repel mosquitoes.”

    The hunt is now on for other insects that use such sophisticated chemistry. “Once you find something, it's going to turn up all over the place,” Meinwald says. Considering that fewer than 5% of insects have even been identified, let alone studied chemically, Eisner says, “I revel in the thought that insects are the great frontier.”

  11. ARCHAEOLOGY

    Green Farming by the Incas?

    1. Kevin Krajick*
    1. Kevin Krajick is a writer in New York City.

    Many of us once liked to think that ancient peoples lived in harmony with the land, but that romantic notion withered in the 1990s, as studies showed that many civilizations overfarmed the land, damaging their livelihood as well as their environment. Now, however, a sediment record and archaeological evidence from a high South American valley suggest that one ancient people, the Incas, used conservation practices such as canals, terracing, and perhaps even tree planting so successfully that they actually restored degraded farmland. Those same tactics may work to help Peruvian farmers today, says botanist Alex Chepstow-Lusty of the University of Cambridge, England, co-author of the new findings. “We're convinced the [early Inca] built the ideal cultivation system for the highlands,” says another co-author, archaeologist Ann Kendall.

    The findings, appearing last month in Tiahuantinsuyu, an annual compilation of Andean archaeology, and in the journal Mountain Research and Development, are based on an 8-meter core taken from a small, dry lake at the bottom of the 3300-meter-high Patacancha Valley in southern Peru and on nearby archaeological digs. Although the evidence is centered on this intensely studied valley, the researchers think the findings apply to other parts of Peru, where abandoned Inca canals and terraces still cover nearly a million hectares.

    The lowest layers of the core, radiocarbon dated from 2000 B.C. to A.D. 100, paint a picture of a pre-Incan land cleared and intensively farmed. The team found high levels of pollen from ambrosia, a daisylike weed that flourishes in disturbed soil, and from pasture grasses and quinoa, an ancient food crop. The core also shows repeated spikes of inorganic sediments flowing into the lake—a sign that soil washed off the hillsides during floods. And the archaeological record suggests that farmers of the time built only rudimentary terraces. By A.D. 100, a cooling climate—and possibly degraded soil—reduced farming in the valley, but erosion continued, says Chepstow-Lusty.

    Then about A.D. 1000, shortly before the Inca took over, a suddenly warmer and drier climate was accompanied by an enormous increase in pollen from the alder tree Alnus acuminata, a nitrogen-fixing species that thrives on eroded soils. The signature of soil erosion plummeted, and pollen and seeds from maize and other crops appeared.

    At just this time, excavations in the valley point to the beginning of a systematic effort to farm the area with soil-sparing techniques, says Kendall, who directs the Cusichaca Trust in Bellbroughton, England, a rural development project that revives ancient farming practices. The Incan system included a well-built 5.8-kilometer canal to bring in water from streams and lakes at higher altitudes, says Kendall; it had layers of well-fitted stones, sand, and clay, and drop structures to distribute the flow evenly to the plots. Terraces proliferated—so many that Kendall speculates “people may have literally dragged the soil that had fallen into the valleys and riverbeds back to the hillsides” to build them. “What prompted people to say, ‘OK, let's build thousands and thousands of terraces’ is anyone's guess,” says Chepstow-Lusty. “But when they found it worked, they kept developing it.”

    Excavations of nearby dwellings suggest that as the terraces were built, the valley's population quadrupled to modern levels of about 4000, showing that the land was able to support more people with less damage, says Kendall. Alnus trees persist in the pollen record too, even though the growing population apparently relied on the trees for firewood and building. (Excavated buildings have Alnus door lintels and roof beams.)

    The trees may originally have spread because of the warmer climate, but the researchers suggest that there must have been a system for conserving them, and that they would have stabilized soil on the steep slopes. “There were so many people that the very fact there were any trees left means they did something,” says Kendall. Indeed, chroniclers writing shortly after the Spanish conquest in the early 1500s report that the Inca had had a strong tradition of tree planting; Alnus cultivation was overseen by the emperor himself, and illegal woodcutting and burning was punishable by death. After conquest, the terraces and trees went into decline. Alnus now grows only in a few remote ravines.

    Some researchers are skeptical that the Inca consciously practiced agroforestry. “One core doesn't clinch the case for active management,” says Alan Kolata, director of the Center for Latin American Studies at the University of Chicago. Still, he agrees that other features of early agricultural systems, such as terraces, probably did conserve soil and boost crop production.

    Moreover, some of these ancient tactics may still be practical. The Cusichaca Trust has funded a project in the Patacancha Valley to excavate terraces and then rebuild them with old methods. Since 1995, local families have rebuilt the canal and replanted 160 hectares of old terraces in potatoes, maize, and wheat. They report that the terraces produce well and use less fertilizer than other lands. “These people [had] hundreds of years to learn what worked on the land and what didn't,” says University of Florida, Gainesville, geographer Michael Binford. “If we pay attention to what they did, we might just learn something.”

  12. MICROBIAL GENETICS

    Genome Reveals Wiles and Weak Points of Syphilis

    1. Elizabeth Pennisi

    The spirochete that causes this longtime scourge is almost impossible to study in the laboratory, but modern genetic research has finally revealed its secrets

    When Steven Norris first started studying Treponema pallidum more than 20 years ago, the microbe quickly defeated him. A microbiologist at the University of Texas Health Science Center in Houston, Norris wanted to understand how this bacterium causes the many different symptoms of syphilis, a sexually transmitted disease that, if left untreated, can ultimately lead to insanity, cardiovascular problems, or death. His first step had been to try to grow the organism in a laboratory dish so that he could harvest its proteins. But as countless microbiologists before him had already learned, the spiral-shaped bacterium, or spirochete, so tenacious in the body, doesn't survive in the culture dish. It died within days no matter what the mix of nutrient media and growing conditions.

    Now Norris has made a new assault on the syphilis pathogen using the tools of modern genetic research, and this time it has yielded its secrets. On page 375, Norris, Texas microbiologist George Weinstock, and a team led by Claire Fraser at The Institute for Genomic Research (TIGR) in Rockville, Maryland, describe the sequence of the 1.14 million base pairs that make up this microbe's genetic code. The microbiology community at large is thrilled. “[The sequence] is a big step forward,” says Patricia Rosa, a molecular biologist at the National Institute of Allergy and Infectious Diseases' Rocky Mountain Laboratories in Hamilton, Montana. Although complete gene sequences are known for perhaps 14 other microbes,* including a half-dozen that cause disease, none has been so difficult to study with the traditional tools of microbiology.

    And few pathogens have presented a medical conundrum as durable as syphilis, which once raged across Europe, decimating the ranks of royalty and forcing physicians to rely on extreme, often dubious treatments such as mercury vapors and arsenic. Penicillin ended the need for such measures, but even now the disease is common in developing countries, and there is no vaccine. One reason is that “it's a bug that knows very well how to evade the immune system,” says Sheila Lukehart, a microbiologist at the University of Washington, Seattle, who has studied T. pallidum for more than 20 years. “Once you are infected, you are infected for life” if the disease is not treated, says Lukehart.

    This genome sequence, released bit by bit over the past year, is already revealing clues to what makes the spirochete so tenacious and how it might be defeated with a vaccine. The sequences of individual genes are giving Rosa and others instant access to more than 1000 potential proteins—quite a leap from the two dozen or so known when the sequencing began in earnest. In the works are new diagnostic tests and potential vaccines based on the newly identified proteins. “[The genome] has saved us several years of work,” notes Lukehart. “Because the organism is so difficult to work with, it is one that should have been sequenced first.” The genome may also help investigators solve a long-standing mystery: where syphilis originated.

    Norris and Weinstock's team began characterizing the genetic makeup of T. pallidum about 8 years ago. Their progress was slow, however. Because the microbe couldn't be grown in the lab, they had to get DNA by inoculating rabbits and then, weeks later, harvesting tissue and extracting the microbes. And they had to repeat this expensive and tedious procedure for each step of mapping and sequencing. A break came in 1995, when TIGR showed that it could rapidly sequence microbes in just a single step, by breaking their genomes up into many smaller, overlapping pieces, sequencing the pieces separately, and then matching up the overlapping ends to “assemble” the pieces into the complete genome (Science, 28 July 1995, p. 496; 20 October 1995, p. 397). Under Fraser's direction, the TIGR-Texas team was able to finish the sequence.

    Portrait of a parasite

    When the team took a look at the organism's complete collection of genes, they realized right away that “this was a metabolically crippled organism,” says Norris. This spirochete has very few sets of enzymes for building complex molecules such as enzyme cofactors, fatty acids, or even nucleotides, the building blocks of DNA, and no genes for some of the proteins key to transporting electrons. Instead, it steals molecules essential to life from its host. Toward this end, 5% of its genes seem to code for transport proteins, which ferry in amino acids and carbohydrates, for example. This strong reliance on the host is what has made the organism so hard to culture, Norris says.

    The genome also revealed possible clues to the spirochete's virulence, among them genes coding for proteins that may help the organism attach to and infiltrate skin, bone, heart, and other host tissue. It contained genes for 22 different lipoproteins, which serve a variety of functions—many unknown—in the spirochete but also provoke a very strong inflammatory response in infected people.

    For Lukehart, the most exciting features of the genome are some unexpected repetitive sequences. These repetitions slowed the sequencing by making it difficult to match up the ends of the sequence fragments in the right order. But they also represent a family of very similar genes that may explain the organism's ability to evade the immune system—and they could hold the key to an effective vaccine.

    Previously, her group had found two of these genes. She was intrigued because the makeup of the proteins they code for suggested that the spirochete carries them on its surface. As the genome data became available, Lukehart and her colleagues were able to tap into the sequence database and find genes for similar proteins—a total of 10 more members of this protein family. These proteins seem to be the face the spirochete presents to the immune system, as Lukehart found when she exposed the organism to antibodies made to shortened recombinant versions of these proteins. The antibodies coated the spirochete, as if preparing it to be gobbled up by macrophages, cells that are part of the immune system's first line of defense.

    This immune response sometimes does not defeat the spirochete, however, as the course of the disease shows. If the infection is not treated with antibiotics, the initial genital sores still heal, but months later the disease reemerges, causing a full-body rash, and years later it can surface again with its array of crippling, even fatal, symptoms. The variety of surface proteins revealed by the new sequence may aid this insidious behavior, Lukehart says. She speculates that the spirochete easily recombines the genes for these proteins, mixing up their amino acid makeup so that the immune system does not recognize them, allowing some spirochetes to survive the immune system's initial assault and reemerge later.

    The spirochete's ability to change its coat will complicate the development of an effective vaccine, as a vaccine that evokes immunity against a spirochete bearing one set of surface proteins would be blind to another variant, bearing a different set of proteins. But Lukehart and Norris think that these so-called TPR proteins still provide the best targets for a vaccine, because the antibody experiments suggest they stimulate a powerful immune reaction. “This is the only family of molecules with any evidence of showing protection,” says Lukehart.

    To get around the variability of these proteins, she and others hope to identify pieces of the proteins that are common to all strains and use one of those pieces to immunize against multiple strains. Alternatively, vaccine manufacturers could make cocktails of peptides that contain fragments of many different TPR variants—enough to protect against the spirochete in spite of its variations. Lukehart, Norris, and several other research teams are working feverishly to try out these and other strategies.

    But even before these efforts yield a vaccine, the new sequence may help public health workers battle the disease. Syphilis is not very common in the United States, infecting about 9000 people a year, but the genital sores it causes make infected people more vulnerable to a still deadlier infection, HIV. For that reason, and because the disease reemerges as a minor epidemic once every decade or so, public health officials are considering a campaign to eliminate syphilis in the United States (see p. 353).

    To do so, says Michael St. Louis, a physician at the Centers for Disease Control and Prevention in Atlanta who specializes in sexually transmitted diseases, health workers need a way to track the various strains of T. pallidum. “That's a very important part of understanding the transmission of infection, of how cases are linked in time and space, and why [T. pallidum] is able to persist in the population,” St. Louis points out. Both Lukehart's group and a CDC team have already come up with schemes to track the strains based on the TPR genes, which vary from one strain to another.

    Genealogy of a plague

    Weinstock, for his part, hopes to learn not where the microbe is going but where it came from. Syphilis first spread across Europe in the 16th century, and many experts have long assumed that T. pallidum came from the newly discovered Americas. “In retrospect, that isn't clear,” says Weinstock.

    He notes that the few records describing native people at the time of the Spanish conquest say little about a syphilislike disease. But the records do suggest that indigenous people in the tropical Americas had a skin condition called yaws, which is caused by a treponeme that is related to T. pallidum. Weinstock wonders whether it was yaws, rather than syphilis, that made the passage back to Europe, either from South America or from Africa, where it was also endemic. Facing a new environment in Europe—chilly weather and heavy clothing—it might have somehow mutated into a new, more virulent species, he speculates.

    To test the idea, he is already comparing the T. pallidum genome to that of the yaws pathogen. His group is using the polymerase chain reaction to make many copies of both genomes, then chopping up the DNA with restriction enzymes, which cut DNA at specific sequences. Where the two genomes are the same, these molecular shears yield pieces of the same size. Thus far, the syphilis and yaws genomes seem incredibly similar, Norris says, much more so than, say, two strains of Escherichia coli. But he expects to find enough differences between syphilis and yaws so that he can double-check whether syphilis really was absent from the Americas. He hopes to examine pre-Columbian mummies from Latin America for DNA with the distinctive features of T. pallidum.

    For Norris, the genome has revived an old interest: finding a way to grow the spirochete. That would open a more direct route to studying the genes revealed by the new sequence. Growing spirochetes in culture will also make it easier for pharmaceutical companies to identify new drugs or compounds that inhibit spirochete growth.

    Having the genome in hand “is a very good place to start” learning what T. pallidum might need to survive outside mammalian tissue, says Rosa. Besides indicating that the organism has to import building blocks such as amino acids from its host, the genome also suggests that the spirochete lacks genes that protect it from damage by reactive oxygen molecules. It presumably can flourish only in low-oxygen environments. Based on these clues, says Norris, “I'm betting that we can figure out a way to culture it.” And that, says Rosa, “would be wonderful.”

  13. CENTRAL AND EASTERN EUROPE

    Scientists Step Onto the Political Stage

    1. Robert Koenig*
    1. Robert Koenig is a writer in Bern, Switzerland.

    With the Communist ruling class swept away, researchers across eastern and central Europe are reaching high political office

    When Polish officials search for ways to fight air pollution, they don't have to look far to find a government expert: Poland's Prime Minister, Jerzy Buzek, is a chemical engineer who has written dozens of research papers about removing sulfur dioxide from industrial emissions. In earthquake-prone Romania, the political summit is occupied by a geologist: President Emil Constantinescu, a mineralogy professor and former rector of the University of Bucharest. And in the Balkan state of Bulgaria, crunching budget data comes naturally to the Prime Minister, Ivan Kostov, who holds a master's degree in mathematics and a Ph.D. in economics.

    Science and politics don't often mix, but in the postcommunist nations of central and eastern Europe, from the Black Sea to the Baltic, dozens of scientists have swapped their lab coats or professorial sweaters for the jacket-and-tie uniform of government service. A combination of factors—including the prestige of natural scientists during the Soviet-dominated era and their aura of independence, as well as the demise of the top political echelon after Communist regimes fell like dominoes in 1989–90—have led to the flowering of a new class of scientist-politicians in the hothouse atmosphere of Europe's new democracies.

    “A high number of natural scientists in politics is quite usual during unusual times of total change, when formerly accepted values collapse and the future is difficult to predict,” observes Endel Lippmaa, a chemical physics professor who has served as a minister in Estonia in three separate governments and is now a member of the Estonian parliament. “Scientists,” he says, “are in the business of interpreting the unknown and are therefore by nature rather independent in their thinking and actions.”

    In Poland, the rise of politician-scientists “is deeply rooted in the manner in which this country regained its democracy,” Buzek said in an interview with Science. Under the communist system, the natural sciences offered “the safest profession for a person who wanted to keep his own views and not be obligated to adhere to a binding ideology.” As a chemical engineer, Buzek was able to study for a year at Britain's Cambridge University, and as a researcher in the 1980s he spent his spare time organizing the underground movement of the Solidarity workers' union in southwest Poland. Last fall, after the Solidarity-led political coalition won Poland's parliamentary election, Buzek became prime minister. Four other ministers are also professors: a chemist, an electrical engineer, an economist, and a historian.

    Andrzej Wiszniewski, a Polish electrical engineer and former university rector who now holds a minister-level position as president of Poland's State Committee for Scientific Research (KBN), followed a similar route. While still a professor at Wroclaw Technical University in the early 1980s, he established his political credentials by spending 3 months in prison for his work as a Solidarity organizer. He says he and Buzek “entered politics in the '80s not because we wanted to but because we were drawn into it by outside forces.”

    Similar forces pushed Pavel Bratinka into Czech politics. When he was a Ph.D. student in solid state physics in 1974, Bratinka was driven out of an institute of the Czechoslovak Academy of Sciences after he refused to join the Communist Party. He spent several years as a coal stoker, and then—shortly after the nation's Communist regime fell in 1989—he co-founded a conservative political party, the Civic Democratic Alliance. During the 1990s, he was elected to Parliament, later becoming the Czech Republic's deputy foreign minister and, until recently, serving as the minister responsible for scientific research. “Everything was polluted under the old regime, but the natural sciences were perhaps polluted the least,” Bratinka says. “They needed scientists, because the communist system's economic chances depended partly on research and development. So scientists were given a bit more freedom to think for themselves. That's why some people who today might study law or political science used to go into the natural sciences.”

    That was the case with one of the region's most prominent scientist-politicians, Romania's president, Constantinescu. His dissatisfaction with the nation's politically tainted judicial system in the early 1960s led him to switch his studies from law to geology. After the overthrow of the Communist government in 1989, Constantinescu helped found the pro-democracy University Solidarity organization of professors and researchers, became the university's rector, and was elected the nation's president in 1996. Constantinescu is just one of several Romanian scientists and professors serving in the government and in Parliament. The minister for research and technology, Horia Ene, was a mathematician at a Romanian Academy institute before being appointed a minister earlier this year.

    In nearby Bulgaria, Prime Minister Kostov says scientists emerged as “the natural generators of new social and political ideas and took up the challenge to reform society. … Their analytical skills help and are needed in government.” Today, 60 of the nation's 240 members of parliament have advanced degrees, including a dozen professors and two dozen associate professors. The deputy prime minister, Alexander Boshkov, is a thermal engineer; the health minister, Petar Boyadjiev, is a pediatrician; and the environment minister, Evdokia Maneva, is a chemist and economist.

    If researchers were hoping that all this scientific firepower in government would help bolster research funding, they have so far been disappointed: Basic research is suffering in many countries in central and eastern Europe, as cash-strapped economies wean research institutes from formerly generous state subsidies, and restructured industries are not yet able to fill the gaps with their own R&D funding. The region's scientist-politicians are aware of the plight of their former colleagues, but few can help muster enough resources at a time when their nation's economies are going through rapid changes. “There aren't enough resources now,” says Aurel Sandulescu, a theoretical physicist who serves in Romania's Parliament, “but I do what I can in Parliament to help.” Sandulescu has pushed successfully for increased academy funding and a competitive granting process.

    Poland's prime minister, Buzek—whose wife, Ludgarda, still works 3 days a week as a researcher at the Polish Academy's chemical engineering institute in Gliwice—tries to stay above the fray on scientific funding debates. “Of course, I get a lot of information about the status of Polish research,” Buzek says. “But if I show particular interest in these issues, it would look as if I'm not really objective.” This year, Poland's government agreed on a controversial austerity budget that freezes the KBN research budget at about 0.47% of gross domestic product. Although Buzek thinks that level of funding is insufficient, he says the government has too many other pressing needs for him to give special treatment to research.

    Opinion is divided—even among the scientist-politicians themselves—on whether scientists' skills lend themselves well to government service. Estonia's Lippmaa thinks so. “Some of the talents needed in science and politics overlap,” he says. Those skills include “a thorough knowledge of the field of research or political action … a thorough understanding of all the force fields and interactions at play—be it spins, particles, or states and power blocks, and the human factors involved at all levels … and the ability to think faster than opponents.” Wiszniewski agrees. “We are amateurs and, because of that, we make some political errors,” he concedes, but because scientists are trained in objective scientific analysis and are good at recognizing and correcting their missteps, “we learn quickly from our mistakes.” But Bratinka says scientists aren't especially well qualified or effective at the business of government—other than in supervising research efforts. “Many scientists are unwilling to challenge the prevailing orthodoxies,” he contends.

    Even some of those who have joined the influx of scientists into politics say the phenomenon may be short-lived. Estonia's education minister, Mait Klaassen—a professor of veterinary medicine and former university rector—predicts that a new generation of students trained in social sciences eventually “will replace the natural scientists” in many governments. Bratinka, who describes the recent political ascendancy of natural scientists as “an accident of history,” says “a new political class is starting to emerge now.” And in Warsaw, Buzek believes that more Polish researchers will stay in their laboratories once a new generation of political leaders emerges. “In the future, the proportions of scientists in government are going to be more closely equal to those in other countries,” he says. But in the meantime, Buzek and his colleagues are clearly relishing their transition from the lab bench to the pinnacles of government.

  14. INDONESIA

    Turbulent Times Mean Trouble for Science

    1. Jeffrey Mervis

    The economic crisis has triggered sharp cuts in research funding, leaving scientists scrambling to find other ways to keep their projects alive

    Indonesian agronomist Endah Retno Palupi is continuing with her study of the reproductive biology of snake fruit. But since the government's recent decision to freeze funding for her 3-year grant, she has had to pool money left over from the first year of her grant with personal funds. Sangkot Marzuki, director of the 5-year-old Eijkman Institute for Molecular Biology in Jakarta, doesn't have those options. Instead, he's struggling to pay salaries out of a budget that has effectively shrunk by more than 90%, making it almost impossible to buy reagents and other necessities from abroad.

    Throughout Indonesia, scientists are reeling from new policies aimed at reviving a crumbling economy. The crisis began last summer when several Asian currencies took a nosedive. It spread to a general economic and political meltdown that led to the ouster in May of the country's longtime ruler, Suharto, and the elevation of his deputy, B. J. Habibie, the former science and technology minister. This year officials are bracing for a double-digit contraction in the economy, an abrupt turnaround after more than a decade of 7% annual growth rates that fueled significant new investments in research. “I think our situation is worse than in the former Soviet Union,” says Marzuki, who was lured back to Indonesia from Australia in 1992 by the government's commitment to basic biomedical research (Science, 6 March, p. 1471). “I'm afraid that, without outside help, we could lose most of what we have built up over the past decade.”

    That sudden reversal of fortune has left researchers scrambling to preserve the capacity to do science. For Palupi, a faculty member at the country's leading agricultural university, Institut Pertanian Bogor, the blow came with the government's recent decision to cancel what would have been a new competition for RUT grants, which serve all areas of science, and to freeze current awards. Part of the savings will go toward a new applied research program starting this week aimed at increasing the production of food and medicine using existing technology. The grants are intended to foster small and medium-sized businesses, explains Indroyono Soesilo, a senior official at BPPT, the science and technology ministry.

    Ironically, the freeze in the RUT program will slow Palupi's efforts to learn how to manipulate the qualities—taste, texture, and seed size—of a fruit in ways that could boost its value as an export crop. But that's a long-range goal in a country desperate for immediate solutions. “I understand the economic difficulties facing the government and the need to set priorities,” she says.

    Funding for new laboratories, buildings, and other major facilities has also been assigned a low priority, says Triono Soendoro, an administrator with BAPPENAS, the national planning agency. That poses a problem for Marzuki, who is already trying to overcome the double whammy of a 30% across-the-board cut in agency budgets imposed this spring and a rupiah that has lost 80% of its value since last summer. Instead of working in his lab, Marzuki sits in his office, writing up research already completed and trying to interest overseas medical philanthropies in his proposal for a high-rise laboratory and office building—a plan that has been shelved indefinitely by his own government.

    Marzuki recognizes that, with rising unemployment and soaring food and fuel prices, science policy must take a back seat to more basic human needs. But he worries that even a short-term suspension of RUT and other programs aimed at improving Indonesia's scientific infrastructure could come back to haunt the country. “It may be hard to restore the funding,” he frets.

    The government is, however, continuing international scientific collaborations, and it is still providing support for sending students abroad and for other training programs deemed essential to the country's long-term economic health. Oceanographer Arnold Gordon of Columbia University is preparing to welcome one of those students next month. And he's packing up his equipment for a September cruise aboard the Baruna Jaya IV, Indonesia's newest research vessel, to track regional ocean circulation patterns that affect global climate and weather. The cruise is one of three scheduled for the fall by U.S. scientists that builds on Indonesia's recent offer to open up its waters to scientists around the world (Science, 5 December 1997, p. 1703). The surge of cruises will provide a major source of revenue for BPPT's oceanographic program.

    While Gordon is planning additional research projects, he's concerned that his longtime ties to the country could start to fray if the political and economic situation worsens. “Unfortunately, Indonesia is being asked to do more at a time when the government is more hard pressed than ever to support such research,” he says.

    Even with half of BPPT's budget committed to international collaborations, Gordon and others worry that a lack of funds may force the agency to either neglect necessary repairs and routine maintenance on its research vessels or price itself out of the market. “The day rate [for oceanographic cruises] has gone up by two-thirds in the past 6 months,” says program manager Eric Itsweire of the U.S. National Science Foundation, which funds Gordon's Arlindo project. “But they are looking at a key region of the world's oceans and at the connection between El Niño and the Asian monsoon, and so far we think the scientific payoff justifies the cost and the difficulty of working there. We plan to stay flexible and see what happens.”

    Such a wait-and-see attitude has become de rigueur for Indonesian scientists and foreign scientists working in the country. Gordon plans to ship his equipment via Singapore, for example, as a hedge against any last-minute change in plans. But keeping one's options open has its limitations, too. “The worse thing is that you can't make any plans,” says Marzuki. “So we take things one day at a time, preparing for the worst and hoping for the best.”

  15. EVOLUTION

    Tracking the History of the Genetic Code

    1. Gretchen Vogel

    Computer analyses and experiments with RNA molecules offer new insight into the forces that may have shaped the genetic code over time

    vancouver—For the 3 decades since biologists cracked the genetic code—the key to translating DNA into proteins—they have debated its origins. Some claimed it must be a random accident forever frozen in time, while others argued that the code, like all other features of organisms, was shaped by natural selection. Most of those debates have been philosophical, with little data to back up either side. But at the annual meeting of the Society for the Study of Evolution held here last month, two speakers presented evidence suggesting that forces other than chance shaped the code's origin and history.

    Experiments with RNA have shown that chemical attractions between the genetic material and the components of proteins may have helped shape the original code, reported one speaker. Another researcher, using powerful computer analyses, suggested that the modern code is the product of evolution because it is so error-proof: Only one in a million other possible codes is better at producing a workable protein even when the DNA carries mistakes.

    Doubters such as evolutionary biologist Niles Lehman of the State University of New York, Albany, still remain unconvinced that the code is anything but an accident. But he and others say that new studies such as these, as well as other work probing the history of individual genetic “words” (see sidebar, p. 330), are beginning to make a dent in their skepticism. “We're at a turning point” for probing the origins and history of the code, says Lehman.

    Living things use DNA to store the instructions for making the proteins that build cells and direct them to develop into a complete organism. The four different subunits, or bases, that make up the DNA chain are grouped into three-letter “words” called codons, and each codon specifies a protein's amino acid building block. Specialized cellular machinery copies the DNA code into RNA—which has a similar code—and then reads the RNA to piece together the amino acids to make proteins. A codon “means” the same thing in a koala as it does in a rose or a bacterium. Yet there's no clear pattern in the pairing of codons and amino acids, which has persuaded many scientists that the code arose by accident.

    But test tube experiments now suggest that before cellular machinery had evolved to read the code and build proteins, the code could have been shaped by affinities between specific base sequences and amino acids. Many scientists have speculated about such a scenario, but new data from experiments in which short strands of RNA are chosen based on their affinity for an amino acid are allowing them to test the idea. Several years ago, Michael Yarus of the University of Colorado, Boulder, noticed that in his experiments, the RNA strands that were best at binding a given amino acid tended to contain codons for that amino acid. But because the three-base codons often show up at random, the data were inconclusive.

    Now evolutionary biologist Laura Landweber and graduate student Rob Knight of Princeton University have done a more careful analysis, looking specifically at where the amino acid arginine binds to random RNA strands generated in several researchers' experiments. If there is no real affinity, they reasoned, codons for arginine will appear as often in the regions where the amino acid does not bind as in regions that arginine homes in on. They found, instead, that while arginine codons made up 30% of the nonbinding RNA sites—the expected percentage, given that arginine has many possible codons—they made up 72% of the sequences in the binding regions. That suggests, says Landweber, that it's no accident that these codons specify arginine.

    The arginine evidence is intriguing, says evolutionary biologist Leslie Orgel of the Salk Institute in La Jolla, California. “But it's premature to draw any very strong conclusions” from data on the affinities of a single amino acid, he says. Researchers are delighted, however, that experimenters are now tackling the question. “Previously we had to rely solely on theory,” says Lehman, but “if [Landweber's analysis] holds up, it will provide a convincing body of evidence” that basic chemical forces helped to shape the code.

    Once the code was born, a different kind of pressure, the need to minimize errors, might have refined it. While some researchers have argued that any changes to the code over its 3.5-billion-year history would have been like switching the keys on a typewriter, leading to hopelessly garbled proteins, others argued that the existing code is so good at its job that it must have been shaped by natural selection. For example, in 1991, evolutionary biologists Laurence Hurst of the University of Bath in England and David Haig of Harvard University showed that of all the possible codes made from the four bases and the 20 amino acids, the natural code is among the best at minimizing the effect of mutations. They found that single-base changes in a codon are likely to substitute a chemically similar amino acid and therefore make only minimal changes to the final protein.

    Now Hurst's graduate student Stephen Freeland at Cambridge University in England has taken the analysis a step farther by taking into account the kinds of mistakes that are most likely to occur. First, the bases fall into two size classes, and mutations that swap bases of similar size are more common than mutations that switch base sizes. Second, during protein synthesis the first and third members of a codon are much more likely to be misread than the second one. When those mistake frequencies are factored in, the natural code looks even better: Only one of a million randomly generated codes was more error-proof.

    That suggests, Freeland says, that the code has been optimized over the eons and isn't simply the product of chance. Lehman agrees that the one-in-a-million result looks impressive, but cautions that the statistics could be misleading. A high degree of similarity within one clan of amino acids could account for the code's apparent resistance to error, and the rest of the code could be random, he says.

    With both the genesis and history of the code looking less and less accidental, Landweber and Freeland plan to collaborate next year, hoping to “build a grand scheme of the code's raison d'être,” Landweber says—whether it be accident or design.

  16. EVOLUTION

    The First Codon and Its Descendants

    1. Elizabeth Pennisi

    An expert in signal processing, Edward Trifonov excels in gleaning information from complex patterns. While others probe the overall origin of the genetic code, which specifies how the sequence of nucleotide base “letters” spell out the amino acids that make up proteins (see main text, p. 329), this biophysicist at the Weizmann Institute for Science in Rehovot, Israel, has applied his skills to determining which of the code's words came first.

    “There are traces in [modern] sequence of the distant past,” Trifonov said here last month at a New York Academy of Sciences meeting on Molecular Strategies in Biological Evolution. By looking for common features in the messenger RNA (mRNA) molecules that carry genetic messages from genes to the cell's protein factories, he concluded that the first word—a triplet of bases, or codon, that codes for a single amino acid—was GCU; that word stands for the bases guanine, cytosine, and uracil and codes for the amino acid alanine. He then went on to calculate how GCU might have evolved into the current set of 61 codons that specify the 20 amino acids. Trifonov has “come up with a unifying view of the origin of the genetic code,” says Giorgio Bernardi, a molecular biologist at the Jacques Monod Institute in Paris, who considers Trifonov's results quite plausible.

    Trifonov looked at mRNA for clues to the early code, because many researchers think that RNA predated the DNA of modern genomes. He noticed a hidden pattern of GCU repeats in mRNA sequences in many organisms: The GCU repeats are spaced in such a way as to align with matching bases in the ribosome, the structure that translates mRNA into protein. Matching bases attract, so the GCU repeats seem to help bind the mRNA to the ribosome. Because GCU is so common and plays so basic a role in translation, “it could also represent ancient RNA code,” Trifonov thought.

    Word gains.

    Genomic “words” for early amino acids evolved from single base changes; additional base changes led to more complex amino acids.

    SOURCE: ADAPTED FROM E. TRIFONOV

    Then he and his colleague Thomas Bettecken, now at Magdeburg University in Germany, realized that RNA made up of this triplet might have gained an edge over other potential codons early in evolution, by interacting more easily with other nearby molecules. The DNA equivalent of the codon is GCT (T for thymine), a triplet that can cause a glitch in the cell's DNA-copying machinery and result in excess copies in daughter cells—a property that can disrupt gene function in diseases, including myotonic dystrophy and Huntington's disease. Assuming that GCU had the same property when RNA was the genetic material, this triplet would be more likely than others to produce longer RNA molecules that could fold in multiple ways to recognize and interact with amino acids and other molecules. “This exceptional property of expandability would give an advantage to that [triplet],” says Trifonov.

    Once they had identified the potential first codon, the team made a series of one- nucleotide changes in the triplet (GCU to UCU, for example, or to GAU) to come up with six more codons. Because these could have evolved from GCU in a single step, they may have specified the next generation of amino acids. “The earliest changes were one-letter changes in GCU,” Trifonov explains. “[Two-]letter changes were all later.”

    Then last year Trifonov and Bettecken compared their results to two other lists of potentially ancient amino acids, from origin-of-life experiments that came up with amino acids from the primordial soup, and chemical studies that identified amino acids with relatively simple structures. “If you put [these results] together, they overlap,” Trifonov reported.

    Trifonov himself emphasizes that this history is just a theory, and other researchers say no one may ever know for sure if he's right. Still, “these are nice arguments,” says James Shapiro, a bacterial geneticist at the University of Chicago. “They all fit together and are very satisfying.”

  17. PLANT PHYSIOLOGY

    Plant Biology in the Genome Era

    1. Christine Mlot
    1. Christine Mlot is a science writer in Madison, Wisconsin.

    madison, wisconsin—More than 2000 plant scientists dug in here from 24 June to 1 July for two back-to-back meetings: the 9th International Conference on Arabidopsis Research and the annual meeting of the American Society of Plant Physiologists. While some researchers put the wealth of data from genome projects to creative uses such as making vitamin-fortified plants, others use it to enhance work on such questions as how flowers form.

    Engineering Plants, From A to Zn

    In the past 2 decades, genetic engineers have brought us plants that resist disease and herbicides, plants that produce drugs, and even plants that make plastic. Now they have hit on what observers say is a very obvious and good idea: altering plant genomes to crank out increased amounts of vitamins and minerals.

    A handful of academic and industry labs around the world are working on such “nutritional genomics,” as biochemist Dean DellaPenna of the University of Nevada, Reno, calls it. DellaPenna himself is coaxing plants to churn out more vitamin E in a form that the human body can easily use, while other projects still in the works focus on vitamin A and iron. The market for such fortified plants might be health-conscious consumers who dislike taking vitamin pills, or those in the developing world who lack access to the necessary micronutrients, DellaPenna said at the meeting.

    In the case of vitamin E, DellaPenna noted that an average U.S. diet provides the tiny amount needed to keep blood cells and neurons functioning. But many consumers are loading up on vitamin E supplements in response to recent reports that large doses of vitamin E and other antioxidants might protect against cancer and heart disease. “You'd need to eat one to one-and-a-half kilograms of spinach daily, or 3000 calories of soybean oil, to get the therapeutic dose,” said DellaPenna.

    So he and David Shintani of his lab tweaked the experimental plant Arabidopsis, a member of the mustard family, to increase its production of the most useful form of vitamin E, a ring and chain of carbon known as α-tocopherol. They found that Arabidopsis seeds normally produce γ-tocopherol, one enzymatic step short of α-tocopherol. To find the gene responsible for that key enzyme, they hunted through the sequenced genome of the photosynthetic bacterium Synechocystis for a known gene that operates earlier in the pathway. Then they tested nearby genes until they found the one that codes for the enzyme, γ-tocopherol methyltransferase. Finally they scrolled through the growing database of Arabidopsis genes and found its version of the gene, apparently lurking unexpressed in the plant seeds.

    The two next hooked the gene to a regulatory sequence that specifies expression in the plant seed and engineered the whole package back into developing Arabidopsis plants. The result was a 10-fold increase in the amount of α-tocopherol in the seeds. “The bulk of the γ-tocopherol is converted to α-tocopherol,” DellaPenna reported. The offspring of the first-generation plants also produced more vitamin E in their seeds.

    The effort is “an intelligent use of genomic information” with practical promise, says plant scientist Chris Somerville of the Carnegie Institution of Washington's plant laboratory at Stanford University. The next step is to similarly engineer a food plant such as soy, which already makes a small amount of α-tocopherol in its seed. “I'm sure it'll be in crop species very quickly,” says Somerville.

    Plants expressing increased amounts of other micronutrients may not be far behind. For example, Ingo Potrykus at the Swiss Federal Institute of Technology in Zurich and his colleagues have been working to engineer rice to produce vitamin A. They're using genes from bacteria and daffodils, which make the carrot-colored carotenoids that provide vitamin A. If they are successful, vitamin A-rich rice could help alleviate deficiencies of the vitamin in regions where rice is the dietary staple.

    Iron—the most common nutritional deficiency worldwide—is another target, plant biologist Mary Lou Guerinot of Dartmouth College in Hanover, New Hampshire, told the meeting. She hasn't engineered iron-fortified plants yet, but so far they have identified an Arabidopsis gene that codes for a protein that allows the plant to take up iron from the soil. They have also just found a similar group of transporters for zinc, another necessary micronutrient. Manipulating these transporter proteins could allow them to boost the amount of minerals a plant takes in, she says. If such work eventually produces fortified crops, there may be an alphabet of new reasons to eat your vegetables.

    Shaping a Flower's Heart

    The bud of a flower is a picture of petaled symmetry, a look that it usually maintains even as the bloom opens and then fades. But a new look at an early, crucial stage in flower development reveals an asymmetry deep in the heart of the flower, plant anatomist Judith A. Verbeke of the University of Arizona, Tucson, reported at the meeting. In an elegant if painstaking set of experiments, she showed that a flower's cup-shaped inner sanctum, called the carpel, has a lopsided beginning: One half forms first and then later drives an unusual developmental process in which cells in both halves redifferentiate. In the end, the two smaller carpels fuse into a single, symmetrical vessel that will hold the plant's seeds.

    Fused carpels—which allow fruits like tomatoes to grow large rather than being split into several smaller seed chambers—were a key evolutionary innovation and help distinguish flowering plants from more primitive gymnosperms such as conifers which have naked seeds, notes plant developmental biologist Ian Sussex of Yale University. The lopsided developmental progression seen in the carpel will also likely appear among other parts of flowering plants, says Verbeke: “I think [the pattern] will be absolutely general.”

    Verbeke made her discovery in an ornamental plant that is already famous: the Madagascar periwinkle, Catharanthus roseus, the source of two valuable anticancer drugs. She and her colleagues have spent more than a decade studying the early developmental stages of the plant's half-dollar-sized blooms and had already revealed one surprise: An as-yet-unknown substance from the developing carpel causes a cluster of epidermal, or surface, cells to switch fate abruptly and redifferentiate into parenchyma cells, a common internal cell type that allows a tight seam between the two parts to form (Science, 5 May 1989, p. 580). The fusion seems to require the unusual redifferentiation of cells already committed to a particular developmental path.

    Verbeke's group probed this process further with a slew of intricate microsurgical experiments on the barely visible emerging flower bud and turned up a distinct biochemical difference in the two parts of the carpel. The researchers put an extract collected from developing carpels onto test carpels, using wisps of a polycarbonate membrane to transfer the extract and maneuvering the tissue and membrane with tiny instruments cut from razor blades or sheared from needles.

    The technique is so tricky that Verbeke calls it “nuts,” but others appreciate it: “It's a really beautiful system for identifying temporal differences in development,” says plant geneticist Gregory Copenhaver at the University of Chicago.

    When the carpel extract was randomly placed on emerging carpel halves, the cells redifferentiated in only 50% of the trials, Verbeke reported. Similarly, when one of the carpel halves was successfully transplanted onto other flower buds, cells changed course only half the time, indicating that only one of the halves was responding to the chemical signal. The distinction between the two halves was sewn up when Verbeke and her colleagues examined emerging buds under an electron microscope: They saw that one of the carpel halves pops up before the other. Additional experiments confirmed that this older tissue is what later induces redifferentiation in the “younger” half.

    This early developmental difference between two halves of the carpel is also turning up in genes at the molecular level. Verbeke and colleagues found that some messenger RNA sequences were expressed only in the “older,” inducing half of the carpel. So far these sequences have shown little resemblance to any in the plant data banks. The next step, says Verbeke, is to identify the powerful inducing substance, which seems to be a protein—and could be one more claim to fame for Madagascar's periwinkle.

  18. ASTRONOMY

    A Dark Matter Candidate Loses Its Luster

    1. James Glanz

    The dark objects thought to inhabit the Milky Way's halo, accounting for its missing mass, may actually be dim stars in nearby galaxies

    More than 2 years ago, a team of astronomers announced a major breakthrough in the search for the mysterious “dark matter” that makes up most of our galaxy. The flashing of distant stars implied, said the team, that the matter is swarming around the visible disk of the Milky Way in a huge halo of dark chunks, which occasionally pass between the stars and ground-based telescopes. Now, several teams have found that the unseen objects might actually be dim stars in the Magellanic Clouds—nearby, dwarf galaxies that had been used as the backdrop to reveal the objects—and not dark matter in the Milky Way at all. One of astronomy's great mysteries, it seems, is still unsolved.

    The confounding evidence came just last month, when the original team, called the MACHO Collaboration (for Massive Compact Halo Object), alerted other astronomers to an unusual brightening of one of the stars in the Small Magellanic Cloud (SMC). Such brightenings—the basis for the original announcement—take place when the gravity of an unseen object focuses the light of a background star. The events ordinarily say little about the distance of the lensing object. But occasionally, for example when the lens is a pair of objects, the rapid, complicated flashing does carry the extra information. Ten days after MACHO spread the news that such an event was in progress, telescopes in South Africa, Australia, and Chile captured the critical moments: a flicker of brightness lasting many hours.

    An event of that duration “is not consistent with [the object] being within the galactic halo,” says Kailash Sahu of the Space Telescope Science Institute in Baltimore, a member of a collaboration called PLANET (for Probing Lensing Anomalies Network). Instead, the new lens is almost certainly in the SMC. Two earlier events, out of the 20 or so observed so far, had also revealed hints of their distance, and they too had seemed to be in the SMC or the Large Magellanic Cloud (LMC). “All the events where more information could be derived were located in the Magellanic Clouds,” says Nathalie Palanque-Delabrouille of the Centre d'Études de Saclay in France and a member of the EROS team (for Expérience de Recherche d'Objets Sombres). “Thus, a halo interpretation of the other candidates becomes dubious.”

    That's bad news for astronomers who thought they finally had an answer to the puzzle of what could be holding galaxies together. Many galaxies spin too fast in their outer reaches for the gravity of visible stars and gas to do the job, implying that at least 90% of their total mass takes the form of a dark halo. (Astronomers have invoked “dark matter” to explain other problems as well, such as the reservoirs of unseen mass needed to account for the gravitational attractions that have shaped the growth of huge clusters and filaments of galaxies.) Some researchers think the galactic dark matter exists as a cloud of exotic particles, but others have favored a more mundane possibility: burnt-out stellar hulks or smaller chunks of ordinary matter.

    In 1986, Bohdan Paczynski of Princeton University realized that astronomers might be able to detect these objects as they drifted across the lines of sight to distant stars. An object's gravity would act like a magnifying glass passing temporarily in front of a distant streetlight, and observers would see a smooth rise and fall in brightness. Soon astronomers were fitting telescopes around the world with electronic cameras that could monitor tens of millions of stars in the Magellanic Clouds, and the hunt for halo objects was on.

    Based on seven lensing events, MACHO announced in 1996 that compact objects could make up from 15% to 95% of the halo (Science, 2 February 1996, p. 595). But skepticism began to build almost immediately, when astronomers began estimating the lens mass required to explain the duration of the brightenings. The most likely mass range for the objects turned out to be between 0.3 and 0.8 solar masses. Objects of that size, if they are made of ordinary matter, should be small stars—easily visible at the distance of the galactic halo—making them “very hard to reconcile with any plausible scenario” involving dark matter, says Martin Rees of Cambridge University.

    Then came two unusual events. One lasted so long—more than 100 days—that the lens had to be a slow-moving object close to the background star. The other was apparently triggered by a binary lens—a pair of objects in orbit around each other. A binary lens acts like a magnifying glass with scratches or water spattered on it, so that instead of brightening and dimming smoothly, the “streetlight” flashes irregularly. “These are wonderful events,” says Rosanne Di Stefano of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, because they are unusually rich in information.

    Like the streetlight briefly glimmering through a scratch, the duration of the brightness peaks, or caustics, depends on the size of the background star, and also on how fast the lens moves across the star—a function of the lensing object's speed and distance. One variable, the background star's size, can be inferred from its brightness and color. And although a very slow-moving lens in the halo could cause a flash that lasts about the same time as a very fast lens farther away in the background galaxy, for objects coasting through interstellar space at typical speeds there should be a marked difference in the length of the “caustic crossing”—less than an hour for halo objects versus most of a night for objects in the SMC or LMC.

    Observations of the first binary lens were spotty, but they were enough to hint that the object probably lay hard by the background star in the LMC. Although some members of MACHO and EROS disputed the evidence, it supported an earlier suggestion by Sahu that all the lenses might be in the SMC and the LMC. And it left everyone eagerly awaiting a well-observed binary lens—which is just what they got last month.

    On 18 June, EROS, along with MACHO and its collaborating GMAN network, caught part of the caustic crossing with telescopes in Chile and set a lower limit of about 6 hours. But PLANET was able to map the full peak with the help of a telescope at the South African Astronomical Observatory. The time turned out to be 8.5 hours, says Andrew Gould of Ohio State University in Columbus, a member of both PLANET and EROS. That stately crossing implies with 99.5% to 99.9% certainty that the lens is in the SMC, not the halo, Gould says.

    PLANET has submitted a paper on the result to Astrophysical Journal Letters, while EROS has submitted one to Astronomy & Astrophysics. Reaction to the observation was swift. “My guess is that we do not have a proof yet, but we do have a very strong indication that Kailash Sahu was right,” and all the lenses are in the LMC and SMC, says Paczynski. But David Bennett of the University of Notre Dame, a member of MACHO, calls Sahu's interpretation “farfetched.” He argues that the LMC, at least, is too small and contains too few dim stars to account for the number of lensing events seen in that direction.

    Other astronomers note that it's still conceivable that the other lensing events really are due to halo objects. But if not, astronomers will face a double quest: for the galaxy's dark matter—at large once again—and for an undiscovered population of dim stars around the Magellanic Clouds or even a phantom, dwarf galaxy somewhere along the line of sight to the clouds.

    For now, the results have put a new spin on MACHO's original press conference at an American Astronomical Society meeting in January 1996, which rated front-page newspaper coverage. “My guess is either they've solved the greatest mystery in astronomy—or we're confused about what we're doing,” commented John Bahcall, an astrophysicist at the Institute for Advanced Study in Princeton, New Jersey, at the time. Bahcall now says: “It certainly is beginning to look like the second possibility.”

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