# News this Week

Science  16 Dec 2005:
Vol. 310, Issue 5755, pp. 1748
1. STEM CELLS

# Korean University Will Investigate Cloning Paper

1. Dennis Normile,
2. Gretchen Vogel*
1. With reporting by Sei Chong, Ji-soo Kim, and Richard Stone. Chong and Kim are freelance writers in Seoul.

SEOUL AND TOKYO— Embattled Korean stem cell scientist Woo Suk Hwang and his university have bowed to pressure for an investigation into a growing list of questions about a landmark paper he and colleagues published in Science in June 2005 (17 June, p. 1777). On 12 December, Seoul National University (SNU), where Hwang works, announced it will conduct an investigation at the scientist's request. This follows a 7 December petition for an investigation from 30 SNU faculty members to university president Un Chan Chung. Prompted initially by anonymous allegations made on a public Web site about irregularities in the paper, scientists in Korea and elsewhere are calling for the paper's key DNA fingerprinting tests to be redone by an independent researcher.

(As Science went to press, one of Hwang's co-authors, Gerald Schatten of the University of Pittsburgh in Pennsylvania, asked Science to remove his name from the paper.)

Meanwhile, stem cell researchers elsewhere are worried about the possible fallout. The lab's as-yet-unreplicated feat of creating human embryonic stem (ES) cell lines that match the DNA of patients inspired a global ramp-up in stem cell efforts. Such ES cell lines might one day provide replacement cells genetically matched to a patient suffering from Parkinson's disease or diabetes. Hwang's team not only showed that producing such ES cell lines was possible but also that it could be done efficiently, with relatively few donated oocytes per cell line. Alan Colman, head of Singapore-based ES Cell International and a member of the team that produced Dolly the sheep, the first cloned mammal, says, “I'd still like to believe this is a case of sloppy presentation but good science.” If the results of the paper do not hold up, he says it could set the field back to a time when many thought the research “was too difficult and inefficient to pursue.” It would also provide ammunition to opponents of the research, he says.

The latest revelations center on the DNA fingerprinting in the paper's supplementary online material first posted on 19 May 2005; the fingerprinting data purportedly show that the ES cells are genetically identical to the patients. There are also new allegations about another set of images in the online material that Hwang last week told editors at Science had been erroneously duplicated (Science, 9 December, p. 1595). All the scientific questions can apparently be traced to anonymous observations about the paper posted on an Internet message board hosted by the Biological Research Information Center (BRIC) (bric.postech.ac.kr). BRIC officials declined to comment, but a senior Korean scientist who has followed the postings agreed to discuss the issue provided he not be identified. (The Korean scientists contacted for this article requested anonymity because they fear a backlash against what are perceived to be attacks on Hwang, who has become a national icon. “This issue is now completely beyond the realm of science,” one laments.)

The senior scientist says the message board writer, who claims to be a life science researcher, first pointed out the possibility of duplicated images early on 5 December Korea time. Hwang's e-mailed notice of problems with duplicate images arrived at Science's editorial offices on 4 December at 11:29 p.m. Eastern Standard Time, which would have been 1:29 p.m. on 5 December in Korea, or several hours after the images were posted on the message board.

On 7 December, a critique of the DNA fingerprinting results appeared on the BRIC site. DNA fingerprinting shows a genetic match between two samples when peaks in the traces line up. But because the height and shapes of peaks are influenced by random factors, they should not be identical. The anonymous poster pointed out that the traces for several cell lines appear to be identical to the traces from the respective patients. In other cases, the background noise on the two traces looks very similar.

Alec Jeffreys, a genetic fingerprinting expert at the University of Leicester, U.K., said in an e-mail that “some of the traces do look unusually similar in peak shape and background noise.” He declined to comment further without seeing the original data.

The anonymous poster also notes that Hwang's admission of duplicated images does not include other images that appear to have been duplicated.

The postings have elicited a flurry of responses. The consensus, says the senior scientist following the BRIC postings, seems to be that if Korean scientists don't take the lead in reviewing the paper, “the integrity of the Korean scientific community might be questioned by the world community.”

Two of the 30 SNU professors who signed the petition asking for an investigation told Science the group first learned of the questions surrounding the paper from the BRIC discussion. One of the two professors contacted by Science says that they are not trying to discredit Hwang. “Dr. Hwang is a pioneer researcher in the field, and his studies should be pursued. We just see a serious need for a review.”

The investigation comes amid a flurry of claims and counterclaims in the Korean media. On 10 December, a Korean news Web site called Pressian reported that it had seen a transcript from an unaired documentary by the Korean Munhwa Broadcasting Corp. MBC pulled the documentary, prepared for a weekly TV show called PD Notebook, in response to public outcry over allegations that the investigative team had coerced its sources; MBC later apologized for the investigative team's transgressions. Pressian claimed that in an interview for the unaired segment, a member of Hwang's team alleged that Hwang had directed him to manipulate photographs of stem cells. The lab member had previously said that the interview was coerced. On 11 December, Hwang's team issued a statement dismissing the allegations.

In this charged atmosphere, SNU held a press conference on 12 December to announce its investigation. Jung Hye Roe, SNU's dean of research affairs, said SNU would form an investigative committee of experts from within and outside the university. They will not be publicly identified and will not respond to press inquiries. Roe said SNU may cooperate with the University of Pittsburgh, which started its own investigation at Schatten's request. One of the two SNU professors contacted by Science says the announcement of the investigation is welcome. But this professor added that because the details have not yet been set, “we need to keep an eye on how the investigation goes.” On 9 December, Science Editor-in-Chief Donald Kennedy wrote to Hwang encouraging him to cooperate with efforts to verify his findings.

Colman thinks the only way to prove whether and how many of the ES cell lines match the donors is a new genetic analysis. “There is an absolute necessity now to have an independent investigator redo the fingerprinting,” he says. But this could be problematic. Fresh samples might have to be taken from the donors, and that would entail again gaining informed consent. The university has not yet set any timeline for its investigation.

2. SPACE SCIENCE

# ESA Hits the Right Note, and Funding Flows

1. Daniel Clery

To stay afloat, the European Space Agency (ESA) is forced to go through an often painful routine: It has to convene ministers from its 15 member states every few years and ask them to hammer out a long-term budget, generally requiring some hard sacrifices. But ESA got a pleasant surprise last week. Following the latest such meeting in Berlin, it came away with almost everything it asked for. ESA said it needed a total of $10.04 billion for current programs and new initiatives covering everything from launcher development to exploration of Mars; it was granted$9.87 billion, 98% of its request. There was one casualty: Ministers dropped a proposed collaboration with Russia to develop a crewed shuttle called Clipper.

The pain factor at ESA ministerial meetings usually involves haggling over how much member states are willing to pledge to mandatory programs—to which all must contribute in line with their gross domestic products—and how much each will splurge on optional programs. The largest chunk of mandatory funding goes to ESA's highly regarded science program. It has been suffering a decade-long erosion of resources as funding increases were pegged below inflation at earlier meetings. This time, science won $2.5 billion for 2006-10, which includes annual increases of 2.5%, slightly above inflation. “Psychologically, this is a very positive step,” says David Southwood, the program's director. Cost overruns in several missions over the past few years have put the science program under severe pressure. It forced the cancellation of the Eddington planet-hunting mission in 2003 (Science, 14 November 2003, p. 1130) and put the BepiColombo mission to Mercury under threat. The program “was facing a major crisis,” says space scientist Mark Sims of the University of Leicester, U.K. Last week's reversal “makes many difficulties go away but not all of them,” he adds. Southwood says the program will host a meeting of researchers in January to plan future priorities; in February, ESA's Science Program Committee will meet to decide which of four missions on the program's roster—Solar Orbiter, BepiColombo, the Gaia star-mapper, and LISA, a gravitational-wave interferometer—will get the go-ahead. The agency also won$4.3 billion to continue its programs in the earth sciences, telecommunications research, participation in the international space station, development of the new, small Vega rocket, and further refinements to the giant Ariane 5. A new program, dubbed Global Monitoring for Environment and Security (GMES), won $300 million, 26% more than ESA had asked for. GMES is a collaboration between ESA and the European Union to provide decision-makers with environmental data from satellites. Aurora, ESA's new optional program of planetary exploration (Science, 25 November, p. 1272), won enthusiastic backing. Aurora's first mission, the$700 million ExoMars, will search for signs of life on the Red Planet. It was oversubscribed by about 8% at Berlin. “This should enable the mission to be bigger” than currently planned, says Sims, who chairs the U.K.'s Aurora Advisory Committee. The extra money could pay for a small orbiter in addition to the rover and base station already planned.

The one sour note was the failure of any of Europe's large spacefaring nations—France, Germany, Italy, and the U.K.—to support Clipper. ESA asked for $60 million for 2 years of joint studies with Russian researchers to see if the minishuttle could give European astronauts independent access to space. Manuel Valls of ESA's exploration program says officials will spend the next 6 months or so refining the proposal and then present it again to member states. “It's a long-term program,” Valls says. “Making it right will be worthwhile.” 3. PALEONTOLOGY # How Fast Does Your Dinosaur Grow? 1. Carolyn Gramling The name may mean “thunder lizard,” but dinosaurs are not actually reptiles. One key difference, paleontologists will tell you, is how fast they grew. Modern reptiles such as turtles and crocodiles grow relatively sluggishly and may reach widely different adult sizes depending on their diet and what the climate was like along the way. But studies of dinosaur bones have shown that the ancient nonlizards grew faster and attained a more or less standard adult size regardless of environmental changes—just as birds and mammals do today. That sharp distinction has just lost its focus. New studies of bone “growth ring” patterns reveal that at least one abundant early dinosaur grew more like a reptile. The results, reported on page 1800, suggest that—in that respect, at least—the common ancestor from which all dinosaurs descended may not have been dinosaurlike at all. “The results are very exciting,” says Robert Reisz, a paleontologist at the University of Toronto's Mississauga campus in Canada. “It suggests that much of what we think of as the overall story of dinosaur evolution may have evolved independently, in different lineages.” The dino maverick is Plateosaurus engelhardti, a member of the prosauropods, a group of early two-legged dinosaurs that thrived from the Upper Triassic through the Lower Jurassic (about 220 million to 180 million years ago). P. Martin Sander and Nicole Klein of the Universität Bonn's Institut für Paläontologie in Germany set out to determine how it grew by scrutinizing the microscopic structure of the creature's fossilized bones—particularly a fast-growing type of bone known as fibrolamellar complex. To distinguish faster-growing P. engelhardti from the slower-growing specimens, Sander and Klein counted growth rings in limb and pelvic bones from animals of similar size. Near the end of its growth phase, a slower-growing animal switches from fibrolamellar to a different kind of bone called lamellar-zonal. Full-grown specimens can be distinguished by a lack of blood vessel spaces in the bone's outer rings. In Plateosaurus, that full size turned out to be highly variable, Sander says. Some animals were full-grown at less than 5 meters in length, while others grew to twice that size. That plasticity could have evolved in either of two different ways, Sander says. In one scenario, the common “ancestral” dinosaur lacked plasticity, as later species did, but plateosaurs reverted back to an earlier, pre-dinosaurian growth pattern. In the other, the common ancestor had plasticity, and different dinosaur lineages independently evolved uniformly speedy growth rates—but plateosaurs missed the boat. So far paleontologists don't have enough fossils of other early dinosaurs to tell which way it happened, Sander says. The finding also may help paleontologists understand how the prosauropods' more recent relatives—giant four-legged sauropods such as Apatosaurus—attained such enormous sizes, says Matthew Bonnan of Western Illinois University in Macomb. “The study shows that the development of the plastic rate of growth can affect maximum attainable size,” he says. The challenge now, he adds, is to understand how prosauropods can shed light on the evolutionary changes that enabled sauropods to outgrow any other land animal. The study highlights how little we still know of early dinosaur evolution, says Thomas Holtz of the University of Maryland, College Park. “There has been the tendency to infer that features found in all advanced dinosaurs were found in all of their ancestors,” he says. “This emphasizes the importance of tree-based thinking. We have to look at as many branches of the evolutionary tree to get as big a picture as possible.” 4. U.S. COMPETITIVENESS # Summit Lists Ways--but Not Means--to Strengthen Science 1. Jeffrey Mervis In an unusual show of unity, 50 business, academic, and legislative leaders came to Washington, D.C., last week to proclaim what they believe is obvious: The United States should be paying more attention to science and engineering. But although there was a rousing consensus on the need to improve teaching, graduate more science majors, and boost spending on research and translating the results to the workplace, there was mostly silence on how these changes might come about and who would pay for them. The 1-day meeting, hosted by the Department of Commerce, was billed as the National Summit on Competitiveness. Although such business-oriented meetings are commonplace in the nation's capital, this one was distinguished by an intermingling of industry CEOs with university presidents, who have long lobbied for many of these changes. After a morning roundtable, the invitees attended closed sessions led by Cabinet secretaries and senior Bush Administration officials who, by several accounts, extolled the president's accomplishments in energy technology, trade, education, and research. In turn, participants maintained a relentlessly positive tone about how the United States should respond to heavy investments by other countries in their scientific workforces and high-tech industries. “We're doing OK, but we need to do better,” said Representative Sherwood Boehlert (R-NY), chair of the House Science Committee, one of the organizers of the congressionally mandated meeting. “I don't think we should be intimidated by the scope of the problem,” remarked Dana Mead, chair of the MIT Corp. and former CEO of Tenneco, after moderating the morning roundtable. “Remember, the way to eat an elephant is one bite at a time.” The group's series of recommendations, announced before the meeting began, include more federal spending on basic research and set-asides for high-risk research, a doubling over the next 10 years of the number of undergraduates earning science and engineering degrees, changes in immigration laws to make it easier for foreign-born graduates to remain in the United States, and greater support for advanced manufacturing technologies. Drawn from a series of recent reports by blue-ribbon panels assembled by the likes of the National Academies, the Council on Competitiveness, and the Business Roundtable, the recommendations offer a surfeit of solutions and a dearth of details (http://www.usinnovation.org/). Participants made no attempt to rank the importance of those recommendations, for instance. “There are no priorities for essentials, and these are all essential,” said Mead. Asked by reporters whether the Administration's signature No Child Left Behind program was likely to raise the performance of U.S. students on international science and math tests, Richard Templeton, CEO of Texas Instruments, grew testy. “The point is that we need to improve science and math education,” he said. “The details are less important.” Nowhere was that hands-off approach more visible than in the summit's key recommendation to double the number of science-related bachelor's degrees awarded annually to U.S. students. The recommendation draws on testimonials from industrialists about their inability to find qualified domestic engineers for vacant positions. “My company has 180 employees, and we have 10 unfilled engineering positions,” says Kellie Johnson, president of ACE Clearwater Enterprises, an aerospace and power-generation manufacturing company in Torrance, California. “Our customers are asking us to design products for them, and we can't find the right people.” The recommendation also asserts that the federal government can influence the number of students pursuing such degrees by offering financial incentives such as scholarships and forgivable student loans. But although the suggestion may seem like a no-brainer to CEOs, many educators say the situation is more complicated and that their institutions must shoulder part of the blame. The production of science, technology, engineering, and math (STEM) majors is determined by many factors, some impossible to predict, they note, and the impact of financial incentives is not clear. An annual survey of incoming freshmen, for example, shows that nearly one in three declare an interest in STEM fields, a fraction that has remained constant over the past 40 years. But only about 5% of students actually graduate with a STEM degree. “A lot of students come to top research universities with good science backgrounds, and it takes us only 1 year to drive this interest out of them,” says Thomas Cech, president of the Howard Hughes Medical Institute in Chevy Chase, Maryland. “Incentives for teachers may be a better way to go than incentives for students.” In particular, poor introductory courses can discourage the most promising scientists by emphasizing rote learning over conceptual knowledge, says Alan Merten, president of George Mason University in Fairfax, Virginia. Mark Wrighton, chancellor of Washington University in St. Louis, Missouri, and member of the National Science Board, which oversees the National Science Foundation, agrees that universities should focus on nurturing budding scientists. The former Massachusetts Institute of Technology chemistry professor says his university has decided to make research opportunities for undergraduates a priority for one simple reason: “It's so much more fun to actually do science.” Regardless of how it happens, getting more people to do science is a worthy goal, say participants. Paying for it, however, is another story. In a meeting with White House budget director Josh Bolten on the morning of the summit, Boehlert says he and two House colleagues, Representatives Vern Ehlers (R-MI) and Frank Wolf (R-VA), learned that the Administration's concern about U.S. competitiveness has its limits. “He gets it,” Boehlert said about Bolten's response to the summit's recommendations. “Then he challenged us to find sources of revenue to finance these programs.” 5. AFTER KATRINA # Struggling New Orleans Universities Cut Hundreds of Faculty 1. Jocelyn Kaiser Faced with financial crisis, the two largest research institutions in hurricane-ravaged New Orleans are making painful cuts. Last week, Tulane University announced it will eliminate 230 faculty positions and phase out many degree programs in one of the largest-ever restructurings of a U.S. university. Louisiana State University's (LSU's) Health Sciences Center, meanwhile, has furloughed indefinitely more than 100 faculty members, some of them young researchers. The flooding of New Orleans after Hurricane Katrina on 29 August shuttered universities and sent researchers and students to host institutions across the country (Science, 25 November, p. 1267). Even though 86% of its students are expected to return when the main campus opens in January, Tulane faces a budget shortfall and needs$200 million to pay for hurricane recovery. On 8 December, university president Scott Cowan announced a “renewal plan” that involves trimming weaker programs to save $55 million a year. Academic departments must lose about 50 of 500 faculty positions by May 2007, and 14 doctoral programs including sociology, economics, and several in engineering and computer science will close down. The heaviest blow will fall on Tulane's medical school, which doesn't plan to reopen in New Orleans until next fall. It has lost income from clinical care due to the city's drastically reduced population and the closure of nine of the city's 11 hospitals. The school had hoped to receive “bridge money” from the federal government, but it didn't come through, says Paul Whelton, senior vice president for health sciences of the Tulane University Health Sciences Center. So the Tulane renewal plan calls for trimming 180 faculty positions at the center—about one-third of the total—by 31 January 2006 and focusing on the school's strengths, in infectious disease, cancer, gene therapy, organ transplantation, and heart disease. “It's a necessary action, and it's a sad one,” says Whelton. The contraction “is probably unprecedented for a research university,” says William Brody, president of Johns Hopkins University in Baltimore, Maryland, who served on a panel that helped Tulane develop the plan. “It's a Hobbesian choice between two difficult decisions: Close or lose good people.” The cuts were made after department chairs compiled a list of faculty members most essential to teaching, patient care, and research, Whelton says. He adds, however, that Tulane is easing the transition by giving “very generous” separation packages with up to 1 year of paid salary for some tenured faculty. James Karam, chair of the biochemistry department, which is losing two junior professors, says he and others are hopeful that Tulane is now stable financially—the university has committed to paying salaries of remaining faculty members through spring semester 2007. A sharp drop in revenues from patient care has also devastated LSU's Health Sciences Center. On 1 December, the center placed more than 300 staff and 150 faculty members, or about 20% of the total faculty, on indefinite leave without pay. Acting chancellor Lawrence Hollier explains that the school is losing$10 million a month and could close down after February if it can't find bridge funding. Decisions about layoffs were based partly on how much independent research funding a professor had, he says.

Cell biology and anatomy assistant professor Roderick Corriveau, who says his department chair called on 21 November to tell him his last paycheck would be 9 days later, calls the furloughs “brutal.” The 41-year-old developmental neurobiologist is now contacting colleagues at other institutions, trying to find spots for himself and his three graduate students. “It is like starting over,” Corriveau says. “Hopefully, new doors will open.”

6. GENETICS

# Zebrafish Researchers Hook Gene for Human Skin Color

1. Michael Balter

People come in many different hues, from black to brown to white and shades in between. The chief determinant of skin color is the pigment melanin, which protects against ultraviolet rays and is found in cellular organelles called melanosomes. But the genetics behind this spectrum of skin colors have remained enigmatic. Now, on page 1782 of this week's issue of Science, an international team reports the identification of a zebrafish pigmentation gene and its human counterpart, which apparently accounts for a significant part of the difference between African and European skin tones. One variant of the gene seems to have undergone strong natural selection for lighter skin in Europeans.

The new work is raising goose bumps among skin-color researchers. “Entirely original and groundbreaking,” says molecular biologist Richard Sturm of the University of Queensland in Brisbane, Australia. Anthropologist Nina Jablonski of the California Academy of Sciences in San Francisco, California, notes that the paper “provides very strong support for positive selection” of light skin in Europeans. Researchers have not been sure whether European pale skin is the result of some selective advantage or due to a relaxation of selection for dark skin, after the ancestors of modern Europeans migrated out of Africa into less sunny climes.

Yet the authors agree that the new gene, SLC24A5, is far from the whole story: Although at least 93% of Africans and East Asians share the same allele, East Asians are usually light skinned too. This means that variation in other genes, a handful of which have been previously identified, also affects skin color.

The Science paper is the culmination of a decade of work, says team leader Keith Cheng, a geneticist at Pennsylvania State University College of Medicine in Hershey. He and his colleagues were using the zebrafish as a model organism to search for cancer genes and became curious about a zebrafish mutation called golden, which lightens the fish's normally dark, melanin-rich stripes. Cheng's team identified the mutated gene and found that the zebrafish version shared about 69% of its sequence with the human gene SLC24A5, which is thought to be involved in ion exchange across cellular membranes—an important process in melanosome formation. And when Cheng and his co-workers injected human SLC24A5 messenger RNA (an intermediary molecule in protein synthesis) into golden zebrafish embryos, wild-type pigmentation pattern was restored.

Researchers say the ability of human SLC24A5 to “rescue” the mutant zebrafish is strong evidence that the gene has a similar function in fish and humans. “The zebrafish data are extremely compelling,” says human geneticist Neil Risch of the University of California, San Francisco.

The team then searched for genetic variants among humans. Data from the HapMap database of human genetic diversity (Science, 28 October, p. 601) showed that SLC24A5 has two primary alleles, which vary by one amino acid. Nearly all Africans and East Asians have an allele with alanine in a key locus, whereas 98% of Europeans have threonine at that locus. These marked frequency differences combined with the pattern of variation in nearby genes suggest that the threonine variant has been the target of a recent selective sweep among the ancestors of modern Europeans, Cheng's team concluded.

Finally, the team measured the pigmentation levels of 203 African Americans and 105 African Caribbeans—groups that represent an admixture of African and European ancestry—and compared their SLC24A5 genotypes. Subjects homozygous for the threonine allele tended to be lightest skinned, those homozygous for the alanine allele were darkest, and heterozygotes were in between, as shown by the degree of reflectance of their skin. The team concludes that between 25% and 38% of the skin-color difference between Europeans and Africans can be attributed to SLC24A5 variants. The experiments provide “a beautiful example of the critical role that model organism genetics continues to play for understanding human gene function,” says geneticist Gregory Barsh of Stanford University in California.

The new work doesn't solve the question of why fair skin might have been favored among Europeans. However, it is consistent with a long-standing but unproven hypothesis that light skin allows more absorption of sunshine and so produces more vitamin D, a trait that would be favored at less sunny European latitudes.

Barsh adds that the paper “indicates how the genetics of skin-color variation is quite different from, and should not be confused with, the concept of race.” Rather, he says, “one of the most obvious characteristics that distinguishes among different humans is nothing more than a simple change in activity of a protein expressed in pigment cells.” Jablonski agrees: “Skin color does not equal race, period.”

7. INDIAN SCIENCE

# Booming Computer Sector Seen as a Mixed Blessing

1. Pallava Bagla

NEW DELHI— India cemented its claim to leadership in information technology (IT) last week when three U.S. companies—Microsoft, Intel, and Advanced Micro Devices (AMD)—announced plans to spend nearly $6 billion on research and manufacturing here over the next few years. The economy will benefit, but some scientists are concerned that the IT bonanza could drain talent away from basic research. Microsoft chief Bill Gates announced on 7 December that his company will double its workforce in India to 7000 and increase its R&D investment by$1.7 billion over the next 4 years. “We depend on India for manpower, and that is why we are scaling up operations,” said Gates, who unveiled plans to add a second R&D center in Bangalore to an existing one in Hyderabad.

Earlier in the week, Intel's chief executive Craig R. Barrett announced that his company will invest $1 billion over the next 5 years, including$200 million for development of a microprocessor being researched at its center in Bangalore. AMD is investing $3 billion in a chip-manufacturing plant at an undisclosed location. According to the National Association of Software and Service Companies (NASSCOM) in New Delhi, Indian software and services exports grew more than 34% from 2004 to 2005, earning revenues of$17.2 billion over a 12-month period. India attracts IT companies, NASSCOM argues, because it has a well-educated English-speaking workforce, low labor costs, and a time zone that allows Western companies to run operations around the clock.

Although the IT sector is booming, some leaders fear that its rapid growth could hurt other areas of research. Astrophysicist Rajesh Kochhar, former director of the National Institute of Science, Technology, and Development Studies in New Delhi, says: “There can be no doubt that information technology is acting as a brain sink.” New entrants in the Indian IT sector are paid roughly three times as much as entry-level scientists, he says. The result, he argues, is that “highly qualified engineers are doing stupid, repetitive work.” Echoing this view, aeronautics engineer Gangan Prathap, chief of the Centre for Mathematical Modelling and Computer Simulation in Bangalore, says foreign investments like those announced this week could “seduce” Indians into becoming “a nation of techno-coolies.” He claims that academic centers already must “scrounge at the bottom of the barrel” for talent.

Other science community leaders take a more optimistic view. M. Vidyasagar, executive vice president of software company Tata Consultancy Services in Hyderabad, dismisses internal brain-drain concerns as nothing more than “disguised envy.” And Raghunath Anant Mashelkar, a polymer engineer and president of the Indian National Science Academy in New Delhi, says there is undoubtedly “a war for talent at the top of the ladder.” But if it leads to a stronger economy, he thinks that both commercial R&D and basic science will benefit.

8. SCIENTIFIC PUBLISHING

# Echoing Other Cases, NEJM Says Vioxx Safety Data Withheld

1. Jennifer Couzin

When the New England Journal of Medicine (NEJM) last week released a scathing editorial asserting that a study on Vioxx had omitted safety data, the episode became the latest chapter in the efforts of medical journal editors to keep what they consider misleading drug studies from their pages. The editorial contended that the authors of the influential 2000 study in NEJM failed to report three out of 20 heart attacks among patients treated with Vioxx and data on cardiovascular ailments such as angina.

A string of similar cases have prompted journals to tighten requirements of authors, ask increasingly pointed questions before publishing, and require that clinical trials be publicly registered before papers are reviewed. Yet those measures may not be enough, say editors. “We now hold [a paper] up to the light and say, 'This seems like a very well done study; can we believe it?'” says Drummond Rennie, a deputy editor at the Journal of the American Medical Association (JAMA). “What can we do? … We can't go wired into their lab.”

The latest case came to light when Gregory Curfman, an NEJM editor, was deposed on 21 November in the third Vioxx lawsuit. (The jury deadlocked, producing a mistrial this week.) Curfman learned from a Merck memo of three unreported heart attacks, which he realized had been deleted from a paper comparing the gastrointestinal effects of Vioxx with those of the anti-inflammatory naproxen, says Karen Pedersen, an NEJM spokesperson. (Curfman was not available for comment.) Data showing other cardiovascular problems were removed just 2 days before the manuscript was submitted, according to NEJM. Pedersen says the journal's editors crafted their editorial, sent it to the paper's lead author Claire Bombardier of the University of Toronto, and published it online. They also invited the authors to submit a correction.

In an e-mail to Science, Bombardier said that she and the other authors are preparing a reply to NEJM and declined to comment until that's complete. In a statement, Merck denied any wrongdoing, asserting that the three heart attacks occurred after the study's prespecified completion and thus did not warrant inclusion. The company also noted that the heart attacks were disclosed to the Food and Drug Administration.

This new Vioxx flap produced “flashbacks,” says Christine Laine, senior deputy editor of the Annals of Internal Medicine. Last spring, her journal learned from a reporter that a 2003 Vioxx paper reporting several heart attacks excluded a sudden cardiac death. Because the paper was not technically in error—the cardiac death was not necessarily due to a heart attack—the journal published only a letter from the Merck co-authors. As part of its detailed author questionnaire, the Annals now asks whether a professional or industry writer was involved in the paper. And rather than simply asking authors what contributions they made to the research, the journal inquires at which stage they became involved.

JAMA, which was also singed by a COX-2 inhibitor paper it published in 2000, now insists on an independent statistical analysis of raw data from clinical trials and uses a questionnaire that's increasingly specific, querying the authors about their separate contributions. The International Committee of Medical Journal Editors, a consortium of 12 medical journals and the U.S. National Library of Medicine, has also tried to tighten guidelines around conflict-of-interest disclosure and press its members to publish more negative trials.

In September, the consortium, which includes JAMA, NEJM, and Annals, began requiring registration of clinical trials before it would consider publishing them. The goal is to ensure that reported results conform to the trial's design, and that there is a public record of trials whose results go unreported—often because the findings are negative. At the National Institutes of Health's ClinicalTrials.gov, the number of trials registered shot from 12,000 in the spring to more than 30,000 today. “It really looks like the policy … had a big impact,” says Deborah Zarin, director of the database.

9. SPONGIFORM DISEASES

# After the Crisis: More Questions About Prions

1. Martin Enserink

With “mad cow disease” declining sharply, public anxiety about prion diseases has diminished. But cutting funds would be a big mistake, prion researchers say

DÜSSELDORF, GERMANY— Peering over an audience of more than 700 researchers on19 October, Nobel laureate Stanley Prusiner seemed pleased. “This is probably the largest gathering of prion scientists ever,” boasted the field's controversial godfather, who gave the keynote speech at a recent meeting.* As the crowd attested, prion science had come along way since Prusiner proposed a heretical idea 23 years ago that it is not viruses or bacteria, but weird proteins, that cause a family of lethal brain diseases.

But now, leaner times may be ahead. Public health efforts to combat prion infections in cattle have worked so well that reports about “mad cow disease” have all but vanished from the newspapers; the clamor for action is fading, and governments are looking for ways to scale back costly safety measures. And many worry that research may suffer; trimming has begun in Germany and France. Prusiner captured the atmosphere best in a private quip after his keynote speech, according to conference organizer Detlev Riesner of Heinrich Heine University, when he said the largest prion meeting to date could end up being the largest in history.

Prion researchers admit there's reason to breathe a little easier. Outbreaks of mad cow disease, or bovine spongiform encephalopathy (BSE), have declined ever since reaching a peak in the United Kingdom, by far the hardest-hit nation, in1992. Fears of a massive wave of an associated human brain disease called variant Creutzfeldt-Jakob disease (vCJD) have not materialized.

But a slowdown in research would be the wrong response, prion scientists say. The British vCJD outbreak could still be in its infancy, and medical procedures could trigger a second wave. (Tests to screen blood, organs, and tissue are still some time away.) There are other reasons to stay alert as well. Europeans have reported the appearance of a new form of scrapie, an age-old prion disease in sheep. And a prion disease in North American deer and elk is spreading rapidly. “The fire is out, but there are still glowing red spots everywhere,” says Jean-Philippe Deslys, head of the prion research group at the French Atomic Energy Commission.

And leaving aside public and animal health, researchers say their field has barely begun to crack its mysteries.

## Debatable

Even after decades of research, the most fundamental question about the prion family of diseases remains open: What is the infectious agent? Many researchers today say recent experiments have convinced them that Prusiner's dogma-defying theory is correct: A rogue protein imposes its own misfolded shape on other, healthy proteins—but some still have doubts (see sidebar on p. 1758).

And other riddles remain. For example: After oral infection, how do prions travel from the gut to the brain? They are known to pass through lymphoid tissue and peripheral nerves, but do individual misfolded proteins make that journey, or do they infect their neighbors, causing them to fall like dominoes? Once present in the brain, misfolded proteins form aggregates that appear to be involved in killing neurons. But exactly how is unclear.

Fortunately, answers to these questions weren't needed to start bringing the BSE and vCJD epidemics under control. Primarily as a result of a 1988 ban on feeding so-called rendered protein, including brain tissue, from ruminants to ruminants, the number of BSE cases in the United Kingdom began to fall in 1993; there were only 343 last year and just 151 so far in 2005 (see graphic). Other countries in Europe, after discovering about the year2000 that they had their own BSE problems, now report rapid declines, too.

In reaction, the European Union (E.U.) is beginning to loosen measures to stop BSE and limit human exposure. A “road map” for prion diseases, published by the European Commission in July, listed restrictions that might eventually be lifted, arguing that resources should be concentrated on new health threats such as avian influenza. (Testing of apparently healthy animals at the slaughterhouse cost about €1.6 billion between 2001 and 2004—€1.6 million per BSE case detected.)

And in October, the commission delighted lovers of T-bone steak and other meat on the bone by raising the age from 12 to 24 months at which the vertebral column—one place where prions concentrate—is removed. (Generally produced from cattle aged 22 to 30 months, such cuts had virtually disappeared.) That decision was premature, says Martin Groschup of the Friedrich Löeffler Institute, Germany's federal animal health center. His lab is still carrying out a long-term BSE pathology study to discover at what age and where in the cow's body infectious particles collect; the decision should have been stayed pending the outcome, he says.

Thanks in part to the decline of BSE, more scientists are now turning their attention to sheep. Scrapie has been known to infect flocks for at least 250 years and is harmless to humans. But in the lab, sheep can also be infected with BSE. Researchers have long worried that the resulting disease—simply called “BSE in sheep”—could get into Europe's flocks, for instance, through feed. If it were transmissible among sheep, like scrapie, it would pose a special problem because a feed ban would not get rid of it, says Lucien van Keulen of the Central Institute for Animal Disease Control in Lelystad, the Netherlands. But so far, there's no evidence of this.

The increased surveillance has turned up a new problem, however. In the last 3 years, researchers in Germany, Portugal, and France have discovered a new variety of scrapie whose prion proteins accumulate in different parts of the brain, have different biochemical properties, and produce a slightly different set of symptoms. Most likely, says Groschup, it's a variant of scrapie that flew under the radar until now. What's disconcerting is that it also appears to affect sheep with a genotype called ARR/ARR, thought to confer resistance to scrapie. Now, some worry that an ambitious E.U. breeding program aimed at spreading that genotype could just replace classical scrapie with a new form. “It's another thing we need to get to the bottom of,” says Neil Cashman of the University of British Columbia in Vancouver, Canada.

Meanwhile, in the United States and Canada, chronic wasting disease (CWD), first discovered in deer and elk in Colorado and Wyoming in the 1980s, keeps turning up in new places. In 2005, New York became the 13th state affected, and moose the fourth species. So far, there is no evidence that CWD can cross the species barrier to humans—nor, for that matter, nonmembers of the deer family. CWD hasn't appeared in Europe, but the E.U. is planning a survey in 2006 to make sure.

## Deceptive calm?

In BSE's wake, vCJD is declining too; there were just nine deaths last year in the United Kingdom, down from 28 in 2000 (see graph), and the total death toll stands at 153 (plus fewer than 20 in other countries), far below worst-case predictions in the late 1990s.

But some believe the curve may be deceptive. John Collinge of the National Hospital for Neurology and Neurosurgery in London notes that vCJD's peak came barely 10 years after the highest BSE exposure in Britain. The delay is just too short, he says. Kuru, a disease among the Fore people in the highlands of New Guinea that resulted from cannibalistic rituals in the 1950s, has a mean incubation period of about 12 years. BSE ought to take longer, Collinge says, because in all known instances, crossing a species barrier lengthens a prion disease's incubation period.

Collinge suggests another possibility: Only the most genetically susceptible people have developed symptoms so far. Researchers know that having the “wrong” amino acid at codon 129 of both copies of the prion gene makes a person more susceptible to vCJD. All patients so far except one, who likely contracted vCJD through a blood transfusion, had this genotype, called MM. But other genes may be involved as well, says Collinge; the victims so far may just be an especially susceptible vanguard of the MM population at large, which comprises 40% of U.K. residents.

The possibility that many more people harbor the disease without symptoms—and the fact that probable vCJD transmission through blood transfusions has now been shown twice—means that, rather than slacking off now, efforts to develop drugs and diagnostic techniques should be intensified, Riesner says. At the meeting, several groups reported encouraging data that could lead to a blood test within the next several years. Drug development has been slower, in part because the pharmaceutical industry has little interest in a disease that affects about one in a million people.

Researchers have tried at least half a dozen compounds on CJD patients, but most seem to prolong life by only a few weeks—if they do anything. An ongoing U.K. trial of a drug called quinacrine for vCJD and CJD, in which 53 patients have been enrolled, is primarily a way to discover how to run future tests, says Collinge, whose group is one of three massscreening small compounds in vitro in a search for promising new candidates.

Because of the countless remaining questions, many scientists say they worry about the unmistakable decline in public interest. Cashman, for instance, says he was amazed a “media firestorm” didn't break out after a paper in the October issue of Nature Medicine showed that prions can lurk in the inflamed mammary glands of scrapie-infected sheep—and presumably their milk as well. If the same is true in cows, he said, “it would be a hugely important finding for public health.”

So far, funding doesn't appear under threat in the United States or the United Kingdom, and it is even expanding in Canada. Three weeks ago, the Canadian government announced a new U.S. $30 million network of centers of excellence; separately, the government of the province of Alberta has committed$33 million to launch a prion research institute. The reason: Canada recently learned how devastating prion diseases be. Four cases of BSE since 2003 have cost the economy an estimated $5.5 billion. (As Cashman puts it, “those cattle might as well have been space shuttles—they cost the same.”) But in Germany, prion projects worth about €10 million, funded by three federal ministries since 2001, will come to an end in 2006; they include the German Transmissible Spongiform Encephalopathy Research Platform, which coordinates studies and sample sharing through three depositories. Several German states' programs will end next year as well, says Kerstin Dressel, the platform's scientific secretary. In France, funding is set to decline as well, Deslys says. Still, not everyone is worried. If it turns out that after BSE, prion diseases pose no major new health risks, well, “then it would only be natural that the money goes elsewhere,” says Byron Caughey, a veteran prion researcher at the U.S. National Institute of Allergy and Infectious Diseases Rocky Mountain Laboratories in Hamilton, Montana. “Then we'll have to adapt, as scientists do.” • * Prion 2005. Between Fundamentals and Society's Needs. Düsseldorf, 19-21 October. 10. SPONGIFORM DISEASES # Waiting for the Final Experiment 1. Martin Enserink The Nobel Committee went out on a limb in 1997, some biologists thought, when it awarded science's highest honor to neurologist Stanley Prusiner of the University of California, San Francisco. Prusiner had championed the idea that a mysterious class of infectious particles called prions consisted of nothing but protein. Even some who thought he was on the right track wanted more evidence. The theory has stronger support today. Some, like Detlev Riesner of Heinrich Heine University in Düsseldorf, Germany, say papers published in the past 18 months, including one by Prusiner, have nailed the case for infectious proteins. “It's beyond any doubt now,” says Riesner. But not everyone agrees. A few researchers believe Prusiner is spectacularly wrong; many more say the evidence is getting stronger but isn't irrefutable yet. The “protein-only hypothesis,” as it's often called, holds that the infectious agent in prion diseases consists of an abnormally folded protein, PrPSc, with a bizarre power over its neighbors. It can impose its own three-dimensional shape on an abundant protein in mammalian cells (called PrPC) that has the same amino acid sequence but a different structure. The altered proteins then help recruit more PrPC, according to theory, and over the years the chain reaction causes large amounts of PrPSc to build up in the brain and cause death. No bacterium or virus is needed to accomplish this. Yale researcher Laura Manuelidis is among the people who think this scenario is all wrong. For decades, she has advocated the notion that the true culprits in prion diseases are slow-acting, elusive viruses. That would explain far better why so-called strains of prion diseases with slightly different characteristics have been found, she says. Manuelidis published a paper in Science in October showing that infection with a slow-acting Creutzfeldt-Jakob strain protects mouse cells from infection with a faster one—a finding she says points to an immune defense reaction and thus a virus. But many researchers say her results can also be interpreted within the protein-only theory. Although Manuelidis's studies are good, says Riesner, “her conclusions are wrong.” The experiment that could irrefutably prove Prusiner right, meanwhile, is easy on paper but difficult to perform, says Byron Caughey of the U.S. National Institute for Allergy and Infectious Diseases lab in Hamilton, Montana: Synthesize PrPSc in vitro and show that it can, by itself, produce an infectious disease in healthy animals. Several labs have tried to do this and failed, leading to renewed speculation that something other than proteins is involved after all, Caughey says. Prusiner and his team reported last year in Science (30 July 2004, p. 673) that they had created such “synthetic prions. “The group engineered Escherichia coli bacteria to produce part of a mouse prion protein, polymerized it into misfolded fibrils akin to PrPSc, and injected these into the brains of mice, where they triggered a neurodegenerative disease that could be transmitted to other animals. The work won over Riesner, but other researchers saw problems. Prusiner's mice were engineered to express 16 times the normal amount of prion protein, which could lead them to develop prions spontaneously, Caughey says. The “very important control” to show that they don't is missing. Meanwhile, a group led by Claudio Soto of the University of Texas Medical Branch in Galveston has tried a different tack. Building on earlier work by Caughey, Soto developed a technique called protein misfolding cyclic amplification (PMCA), which can multiply PrPSc in the test tube. In PMCA, the brain of a hamster infected with a prion disease called scrapie is ground up till it becomes a cell-free soup called a homogenate; when a similar brain homogenate from a healthy hamster is added, PrPSc from the sick brain will transform any PrPC to PrPSc. (The test tubes are blasted periodically with a short sound wave to break up growing PrPSc fibers.) The mixture is diluted into more healthy brain homogenate, and the process is repeated. In a Cell paper published in April, the group showed that even after hundreds of cycles and a 1020-fold dilution—meaning not a single molecule of the original sick brain was left—the reaction produced PrPSc that sickened healthy hamsters. The study demonstrates that molecules made entirely in vitro and free of viruses—which can't live without cells—can generate infection, Soto says. Although it's a “fantastic result,” Caughey says, the study doesn't clinch the case for the protein-only theory. Because the reaction takes place in a complex, brain-derived chemical mix, one cannot rule out that, say, a small piece of nucleic acid that's essential to infectivity was replicated along with PrPSc in each cycle. Soto says that's unlikely. Nonetheless, he is now planning experiments in which the PMCA process is fed with purified PrPC rather than brain homogenate. He believes that should dispel the skepticism once and for all. 11. CONSERVATION BIOLOGY # Hawaii's Coral Trees Feel the Sting of Foreign Wasps 1. Carolyn Gramling Island researchers are desperate to find a natural enemy of the parasitic wasps that are killing a local treasure, the wiliwili The once-beautiful coral trees on the University of Hawaii's Manoa campus where botanist David Duffy works have deformed lumps where the leaves and flowers should be. “Trees here look like they have been hit by a flamethrower,” says Duffy. The bulbous growths are infested with tiny wasps, a recently identified parasitic species that first appeared in southern Taiwan in 2003. Within a year, the wasps had spread across the island and had also reached Singapore, Reunion, and Mauritius. By 2005, they appeared in Hong Kong and China and were first seen on Hawaii's Oahu island this April. By August, the wasps had invaded every island in the state, threatening the existence of one of Hawaii's most enduring symbols, a native tree locally known as the wiliwili that provides flowers and seeds for leis and bark for canoes. Threats to Hawaii's native species by foreign invaders are nothing new. Long cut off from the rest of the world, Hawaii's endemic species are particularly vulnerable to invasion by foreign insects, plants, and other organisms, and state officials constantly race to keep up with the latest threat (Science, 2 December, p. 1410). But even the state's weary conservationists have been stunned by the speedy efficiency with which this latest pest has spread from island to island. And now, researchers are struggling to identify any measure, from burning infested trees to chemical or biological defenses, that can halt the wasps' devastation of the native wiliwili and other nonnative species of coral trees. “Either all the trees are going to die, or they'll never be the same again,” says botanist Art Medeiros of the U.S. Geological Survey's Haleakala Field Station on Maui. The wasps, dubbed Quadratichus erythrinae in 2004, lay their eggs in green stems and leaves of the trees, creating outbreaks of tumors that stunt the trees'growth and eventually kill them. The wasps disperse easily as larvae-infested tissue falls off and is scattered with the wind, or as adult wasps emerge to lay more eggs in new growth. The Asian-Pacific path of the wasps parallels the habitat of the genus of trees called Erythrina, popularly known as coral trees. Erythrina's 115 species are found around the world in tropical and warm temperate regions, from Southeast Asia to the southeastern United States. With their bright red flowers, they are highly prized as ornamental trees and have figured widely in local mythology. Native and nonnative Erythrina are both extensively cultivated in Hawaii, but the wiliwili is the only species of the tree that is found exclusively in the state. A dominant species in the large dry forests that form on the leeward slopes of many of the islands, wiliwili grow on rocky lava substrates called aa, a forbidding terrain that has helped discourage previous invaders. “The species has been bulletproof,” says Medeiros. But now, he fears, the trees are in danger of extinction. That danger has resulted in a concerted effort by state and federal officials and university researchers to find an effective remedy. Cutting down infested trees and burning the detritus has proved ineffective, Duffy says: The wasps simply spread too quickly. Another possible solution is injecting the trees with an insecticide, says Anne Marie LaRosa of the U.S. Department of Agriculture's Forest Service in Hilo. However, such a strategy is very expensive, costing nearly$30 per tree, and is likely to prove impractical on trees in the wild. “The only point in treating them chemically is as a stopgap method,” LaRosa says. Injections could preserve some trees for a while, giving researchers more time to identify a biological control agent—now considered the only viable long-term solution.

But biological control agents are fraught with their own dangers, as Hawaii well knows. Fifty years ago, a different species of parasitic wasp was brought into Hawaii to repel sugar-cane pests; those wasps now dominate the food web of the Alakai Swamp, a wilderness preserve on Kauai island. Such cautionary tales highlight the need for stringent prerelease testing to ensure that the new agents won't run amok, researchers say (Science, 17 August 2001, p. 1241). “We need to be incredibly sure that whatever we try to introduce will not attack native species in Hawaii,” says entomologist Daniel Rubinoff of the University of Hawaii, Manoa.

Because the coral tree wasp is brand-new, adds Rubinoff, he and other researchers seeking a biological control agent have their work cut out for them. Rubinoff, with colleagues Russ Messing and Mark Wright, is working on identifying the origin of the wasp. Africa is the likeliest source, they believe: Scientists in South Africa have seen similar gall-forming parasitoid wasps on Erythrina species in the region. As a result, Hawaiian researchers are soliciting wasp samples from colleagues in Kenya and South Africa, and they are preparing to mount expeditions to other possible hot spots on the continent, hoping to locate a natural enemy that will be specific to the wasp.

The University of Hawaii team will head to South Africa in March 2006, which should coincide with the end of the rainy season there, when the trees will be sporting new growth and infestations will be easier to find. Meanwhile, state of Hawaii entomologist Mohsen Ramadan hopes to leave by the end of 2005 for Tanzania, also to coincide with the rainy season in that country.

Back in Hawaii, scientists are working on a last-ditch solution. Called the Noah of wiliwili,” Alvin Yoshinaga, a botanist at the University of Hawaii's Center for Conservation Research and Training in Honolulu, is overseeing a collection of the trees' seeds, harvested by volunteers on all the islands and hoarded against the day that a wasp-control method is found.

“We are trying to gather seeds from as many subpopulations on different islands as possible,” Duffy says. Identifying an effective but safe biological control agent could take anywhere from 1 to 50 years, he adds—and the trees almost certainly wouldn't last that long. “We have very little time,” Rubinoff agrees. “All of the Erythrina are being hammered.”

12. ENVIRONMENTAL EPIGENOMICS MEETING

# Food, Tobacco, and Future Generations

1. Elizabeth Pennisi

DURHAM, NORTH CAROLINA— Geneticists, molecular biologists, and epidemiologists discussed epigenetics from 2 to 4 November at the Environmental Genomics, Imprinting, and Disease Susceptibility conference.

One day, doctors taking family histories may ask not just about patients' diet and smoking habits, but also about their parents' and grandparents' food and tobacco consumption. The reason: There's increasing evidence that a person's health may be influenced by the lifestyle of past generations.

At the meeting, Marcus Pembrey, a geneticist at University College London, offered two new studies supporting this surprising link. He reported that a man's taste for tobacco as a boy appears to increase the risk that his sons will be overweight as children. In a second study, Pembrey and his Swedish colleagues found that a person's risk of early death, and in some cases, diabetes, is influenced by the eating patterns of their paternal grandparents. (The results of both studies appeared online 14 December in the European Journal of Human Genetics.)

Pembrey says the mechanism is unclear, but it may be that certain eating patterns or smoking at critical periods in life cause epigenetic changes—chemical modifications of a gene's DNA rather than direct mutations—that can silence genes in sperm and eggs. These changes may persist for more than one generation. These two epidemiological studies “highlight the profound impact of our behavior on the health of future generations,” says Moshe Szyf, an epigeneticist at McGill University in Montreal, Canada.

Pembrey's evidence for the effects of smoking comes from the Avon Longitudinal Study of Parents and Children. This long-term U.K. study enrolled about 14,000 pregnant women almost 15 years ago and has tracked lifestyle, diet, growth, and disease in these women's families. Because the study included data on smoking, Pembrey decided to look at whether tobacco consumption influenced transgenerational health outcomes. About 5400 fathers in the database were smokers; most had taken up the habit by age 16. (There were too few women smokers to study.)

Pembrey and his colleagues examined whether there was any connection between when a father had begun smoking and his children's weight at age 9, a measurement included in the Avon study. There were 166 fathers who started smoking before age 11, and Pembrey found that these fathers' sons were on average heavier than sons of fathers who took up this habit later in life or who never smoked. To his surprise, daughters were unaffected. “This is the first report of an acquired parental exposure, smoking, influencing metabolic processes in sons but not daughters,” says Bruce Richardson, a geneticist at the University of Michigan, Ann Arbor.

In another effort to pinpoint transgenerational risk factors, Pembrey reanalyzed data from a provocative 2002 study in which Swedish researchers had delved into more than a century of birth, death, health, and genealogical records on 300 Swedish families in an isolated village. This rich data set also included crop records and food prices. The Swedish team determined that the grandchildren of individuals who enjoyed a surplus of food during childhood had a higher risk of diabetes than those whose grandparents grew up in times of food scarcity.

When Pembrey and his Swedish colleagues looked more closely at these data, they found that these effects were sex-specific. The health of grandsons, but not granddaughters, was related to the food supply of their paternal, but not maternal, grandfathers. And the health of granddaughters was tied only to that of paternal grandmothers, Pembrey reported.

As in the case of smoking, timing seems to be critical. Food surpluses during a paternal grandfather's preteen years adversely affected the health of his grandsons, increasing their relative risk of an early death by about twofold. Surplus food for a paternal grandmother in utero or during infancy adversely affected the health of her granddaughters, to a slightly greater degree.

Given the limits of epidemiological analyses, Richardson and others are concerned that unrecognized factors might have influenced these results, and they wonder if these intergenerational associations could be statistical flukes. Pembrey thinks not, noting that the critical periods revealed in the smoking and food studies coincide with when eggs are maturing in girls and sperm production is about to begin in boys.

Based on his findings, Pembrey speculates that smoking, nutrition, and perhaps other lifestyle factors can cause semipermanent changes in the germ line during these critical periods. Most researchers had thought that such epigenetic changes only occurred while a person was developing in the womb. Pembrey's results also indicate that postdevelopment effects can be transmitted through the paternal line. They're “proof of principle. The sperm have captured information about the ancestral environment, and this is modifying the development and health of subsequent generations,” he says.

If so, epigeneticists need to give more thought to what fathers contribute, says James Curley of the University of Cambridge, U.K. “The mechanism underlying [sperm-based transmission] will be a big area in epigenetics,” he predicts.

13. ENVIRONMENTAL EPIGENOMICS MEETING

# Supplements Restore Gene Function via Methylation

1. Elizabeth Pennisi

DURHAM, NORTH CAROLINA— Geneticists, molecular biologists, and epidemiologists discussed epigenetics from 2 to 4 November at the Environmental Genomics, Imprinting, and Disease Susceptibility conference.

It has long been known that pregnant women who consume insufficient folic acid, a B vitamin, run an increased risk of having babies with spina bifida or similar neural tube defects. Yet biologists are still teasing out exactly what this vitamin does for the developing fetus. At the meeting, Robert Waterland, an epigeneticist at Baylor College of Medicine in Houston, Texas, presented evidence from mice that methylation of DNA—a chemical modification that can shut down genes—can be key.

Folic acid does restore gene function in mutant mice that have improper DNA methylation patterns, the researcher reported. However, Waterland has also found that the supplement-induced changes in DNA methylation might not be all that predictable—they appear to occur at different points in time during embryonic development and to affect only specific tissues, he reported.

These mouse results may have implications for supplement use in both pregnant women and the public at large. “People are taking massive quantities of vitamins, and we don't have any idea what these potential methyl donors are doing,” says Adele Murrell, a geneticist at the University of Cambridge, U.K.

Waterland first observed the embryonic impact of folic acid and other methyl donors 2 years ago, while working with Randy Jirtle at Duke University in Durham, North Carolina. At that time, he examined a strain of off-colored mice that has a defect in a pigment gene called agouti—the gene is defective because a mobile bit of DNA called a transposable element had inserted itself in some of the nearby DNA that regulates the gene's expression. The transposable element short-circuits methylation of this regulatory region, causing the gene to be overactive. As a result, yellow or mottled coats are common in these animals. But litters born to dams fed supplements of folic acid, a rich source of methyl groups, were primarily the typical brown. Waterland and his colleagues subsequently found that the supplements caused an increase in the density of methyl groups on and around the agouti gene, overriding the transposable element's effects.

Waterland has since investigated a gene that may be more relevant to human disease. The axin gene helps set up the dorsal-ventral axis in embryos and also requires methylation to work properly. Many mice with an axin disrupted by a transposable element embedded in it typically develop mild to tightly angled kinks in their tails. Again, methyl donors can come to the rescue. Waterland reported that receiving folic acid supplements during pregnancy reduced by half kinking in the pups' tails. Taken together, “Waterland's data are the most convincing positive finding with respect to whether diet has any effect on the methylation patterns and expression of a particular [gene],” says Carmen Sapienza, a geneticist at Temple University in Philadelphia, Pennsylvania.

Folic acid supplementation altered the methylation of the two genes in different ways, however, illustrating the complexity of the phenomenon. In the agouti mice, the supplements increased methylation of the gene in a variety of tissues, and the change was most pronounced early in pregnancy. But in the case of the axin mice, that gene's methylation remained low early in pregnancy and only increased later on, as the tail formed, Waterland reported. Moreover, the increase occurred only in the tissue giving rise to the tail. These two observations suggest to him that DNA methylation produced by vitamin supplementation can be tissue-specific and, depending on the gene involved, can occur at different times over the course of a pregnancy.

Waterland's research may one day lead to more sophisticated timing of when to give vitamin supplements to pregnant women or anyone else. “If we can understand critical windows and when methylation is beneficial,” says Patrick Stover, a nutritional biochemist at Cornell University, “that would totally change the concept of how we set dietary requirements during pregnancy and how we think about preventive medicine.”

14. ELECTRONICS

# Organic LEDs Look Forward to a Bright, White Future

1. Robert F. Service

A new type of light-emitting diode may be set to give light bulbs and fluorescent tubes a run for their wattage

BOSTON— If you want to save the world, you might start by getting rid of the light bulb. In the United States alone, lighting sucks up more than 6 quadrillion BTUs of energy every year, 17% of all the energy used in buildings. Incandescent bulbs turn about 90% of that energy into not light but heat. Fluorescents do better, converting 70% of the energy they use into light. But researchers have spent decades working to create novel semiconductor-based light-emitting diodes (LEDs) that do even better. Red LEDs and other colors made from inorganic compounds are already in widespread use in traffic lights, car taillights, and other niche applications. Inorganic white LEDs are also on the market. But so far, all of them remain too costly for general lighting use. Now a new competitor is coming on strong.

At a recent meeting of the Materials Research Society* here, researchers from Japan, Germany, and the United States reported steady progress in turning thin organic films into high-efficiency lights. Because such films are likely to be made with inexpensive organic starting materials, they are potentially very cheap to manufacture, even in large panels. That day isn't here yet, but with prototype products already in development, the first white organic light-emitting diodes (OLEDs) for general lighting are expected to hit the market in 2007. The efficiency of these new OLEDs “is moving up quite fast,” says Stephen Forrest, an OLEDs researcher at Princeton University.

That pace of improvement has recently caught the attention of numerous lighting companies, which are also pushing the technology forward. “No one cared about [white OLEDs] until a few years ago,” says Anil Duggal, an OLED researcher at General Electric in Niskayuna, New York. Duggal says most of the interest in OLEDs until now has been for making flat-panel displays for everything from cell phones to wall-sized televisions. That's partly because the display market, which brings in about \$100 billion a year worldwide, is twice the size of the lighting market. For displays, OLEDs also had the advantage of being ultrathin, a feature many experts believe will command a premium on the market and compensate for the fact that the early devices had relatively poor efficiency. But to compete in the lighting market, where their sleek appearance isn't as critical, OLEDs had to become both better and cheaper. “You need higher efficiency and brightness for lights, in order for OLEDs to carve out a niche in the market,” Duggal says. Now, there is impressive progress on both fronts.

At the meeting, Junji Kido, an OLED expert at Yamagata University in Japan, reported that he and his colleagues have produced white OLEDs with an efficiency of up to 57 lumens per watt (lm/W) of power that's fed into them. That's nearly the efficiency of fluorescent bulbs and almost four times that of incandescent lights, which typically operate at 15 lm/W.

That efficiency is a big step up from the first white OLED, which Kido and colleagues produced in 1993. Like all LEDs, that device was made by sandwiching a light-emitting material between two electrodes. When turned on, positive and negative charges pass from the electrodes and into the light-emitting material, where they combine and give off a photon of light. In Kido's initial OLED, the device contained red, green, and blue light-emitting compounds that together produced white light. But the early devices had problems. Their efficiency was meager, at less than 1 lm/W, they required large voltages to drive charges into the light-emitting materials, and they burned out quickly.

Kido and his colleagues have worked through numerous generations of devices, steadily improving their efficiency, lifetime, and operating characteristics. One of the biggest changes, pioneered by Kido's and Forrest's groups and others, has been in switching from light emitters that fluoresce to ones that are phosphorescent. The change comes in the quantum-mechanical details of how these materials turn electrical charges into light. When negatively charged electrons and positively charged “holes” meet in organic materials, they create electron-hole pairs called excitons that quickly “decay” and give off their energy either as a photon of light or as heat. In addition to carrying charge, electric charges harbor a property known as spin. And because of the precise way in which the spins align in these excitons, 25% of the excitons become what is known as “singlet” excitons, whereas the other 75% become “triplet” excitons. That's important, because fluorescent compounds can convert only singlet excitons into photons as the exciton decays. The triplets, meanwhile, just give up their energy as heat. Phosphorescent dyes, however, can convert both singlet and triplet excitons into light, making them potentially much more efficient.

At the meeting, Kido reported that he and his colleagues have synthesized novel phosphorescent compounds and used them to make high-efficiency white OLEDs. Kido's group, for example, reported that they have made a new blue OLED with a record-breaking efficiency of 42 lm/W when it puts out a relatively dim 100 candelas per square meter (cd/m2) and 31 lm/W at a bright 1000 cd/m2. At the heart of the blue device was a blue light-emitting phosphorescent compound called Flrpic. One key to improving the device was that the researchers surrounded the Flrpic-containing layer with layers of other compounds that allow triplet excitons to reside there only if they have very high energies. In effect, this creates an energetic well in the light-emitting material, so that once the excitons fall into that region, they can't get back out, raising the likelihood that they will decay in the presence of the blue phosphor and give off blue light. To get white light, the researchers then added a yellow phosphor to their blue light-emitting layer, converting some of the emitted light to yellow, which combined with the blue to give off white. The new results are “fantastic work,” says Yang Yang, a physicist at the University of California, Los Angeles (UCLA). And at 57 lm/W, the efficiency, Yang adds, “is a very impressive number.”

## Bright idea

It was far from the only impressive number reported at the meeting. Forrest outlined a new strategy for improving OLED efficiency that eventually may surpass even the all-phosphorescent devices. Working with chemist Mark Thompson at the University of Southern California in Los Angeles, Forrest has been reconsidering the trend toward making OLEDs with phosphors only. The reason, he explains, is that for phosphor-based OLEDs to turn out white light, they must first convert singlet excitons to triplets, which then emit the light. “You pay a price for that,” as this initial conversion step lowers the overall efficiency of the device.

So Forrest and his colleagues have made LEDs with a combination of phosphorescent and fluorescent light emitters. They designed the devices so that the singlet excitons, which have a higher amount of energy than the triplet excitons, were directed to a fluorophore to generate blue light, which requires higher energy charges to make than other colors. The lower energy triplet excitons were then directed to additional layers harboring red and green phosphors. The researchers were able to target them in that way because the singlet excitons are too short-lived to travel far through the device before decaying and giving up their energy. By contrast, triplet excitons are long-lived and can travel comparatively long distances.

Forrest's team placed their blue light-emitting fluorescent dopants in a central region where the excitons initially form and sandwiched them between layers containing the red and green phosphors. Because the triplet excitons couldn't generate blue light in the fluorophores, they passed right through that layer on their way to the phosphorescent-containing layer. For rest reported that the device achieved 27 lm/W, even though it used a relatively low-efficiency blue-light fluorophore. If the best blue fluorophore were used in its place, For rest estimates, the efficiency would likely double.

Both Forrest and Kido say they can also boost the efficiency of their OLEDs by adding specialized coatings to the outside of the glass that sits at the top of OLED devices. Without such a coating, most photons reflect off the glass-air interface and bounce back inside the device, where many of them are reabsorbed and wind up generating heat instead of light. When Kido's group added an antireflective coating to their best white OLEDs, the efficiency climbed from 36 lm/W to 57 lm/W. Forrest says he expects he would get a similar jump. Given the steady progress with white OLEDs, Karl Leo, an OLED expert at the Technical University of Dresden in Germany, says the future looks bright. “With OLED lighting, it should be possible to surpass the fluorescent tube,” Leo says. “Whether it will be cheap enough and stable enough is still an issue.”

But groups reported progress on those fronts as well. Kido is part of a large Japanese consortium that is creating industrial-scale machines to manufacture large white OLED panels at high speed and low cost. Working with Matsushita and other companies, the group has already produced 30-by-30-centimeter panels and expects to begin selling products within 2 years.

Even with novel machinery, however, conventional OLEDs, which are produced by depositing as many as 10 or more successive layers of materials in a vacuum, could still be relatively expensive to make. But progress is also coming quickly in making much simpler devices with a single polymer layer between electrodes. Such devices typically have far lower efficiencies than the standard OLEDs. But at the meeting, Yang's group at UCLA reported creating white polymer-based OLEDs that put out 14 lm/W, and a group led by Franky So of the German lighting company OSRAM reported reaching 16 lm/W—already as efficient as incandescent light bulbs. And because the devices consist of simple polymers that can be cast from solution over large areas, they look to be very cheap to make—perhaps cheap enough to dethrone the light bulb and do their part to save the world.

• * 28 November-2 December.