News this Week

Science  17 Jun 2011:
Vol. 332, Issue 6036, pp. 1364
  1. Around the World

    1 - Berlin
    Restaurant Photos Help Nail Sprouts in German Outbreak
    2 - Canberra
    Threats Sent to Australian Scientists Fuel a Debate
    3 - Washington, D.C.
    New Vaccine Research Effort Launched; Advocate Steps Down
    4 - France
    Save Great Hamster of Alsace, E.U. Court Says
    5 - Chevy Chase, Maryland
    15 Plant Biologists to Join HHMI
    6 - Lima
    Peru Set to Forbid GM Crops
    7 - Leuven, Belgium
    Researcher Sacked for Role In Destruction of Field Trial

    Berlin

    Restaurant Photos Help Nail Sprouts in German Outbreak

    CREDIT: GERO BRELOER/AP PHOTO

    German officials announced 10 June that organic sprouts are the source of an epidemic of enterohemorrhagic Escherichia coli (EHEC)—and diners who snapped pictures of their meals were a big help.

    Early epidemiological studies implicated raw tomatoes, cucumbers, and lettuce, but more recent studies connected infected diners to restaurants supplied by an organic sprout farm in Bienenbüttel, a village in Lower Saxony.

    At one restaurant, 19 of 112 diners were infected. Researchers at the Robert Koch Institute, the German center for disease prevention and control, conducted a “recipe-based restaurant cohort study” to zero in on what the infected diners ate. Research teams compared customers' food photos and recollections of orders with kitchen records of food preparation and ingredients.

    People who ate sprouts were 8.6 times more likely to have become infected with EHEC than those with sprout-free meals. All 19 infected guests had eaten sprouts.

    A genome analysis of the German strain suggests that it is a member of a class of microbes that has only been found in humans so far. http://scim.ag/_ecoli

    Canberra

    Threats Sent to Australian Scientists Fuel a Debate

    Australian scientists studying climate change were swept into a political furor last week after acknowledging that they had received death threats and abusive e-mails. More than 30 researchers said that they had been sent threatening e-mails, and some were moved for their safety to more secure offices, according to a 4 June news story in The Canberra Times.

    The news broke as a parliamentary committee in Canberra was considering a carbon tax proposed by the government in February. A member of the opposition Liberal Party, shadow science minister Sophie Mirabella, brushed aside the scientists' claims, saying the threats occurred 12 months to 5 years ago and that scientists are speaking about them now to boost support for the carbon tax. http://scim.ag/_threats

    Washington, D.C.

    New Vaccine Research Effort Launched; Advocate Steps Down

    Scientists and advocates for vaccine research have launched the Foundation for Vaccine Research, based in Washington, D.C. Peter Hale, an advertising specialist who has long worked with HIV/AIDS researchers, started the foundation. “No one has been campaigning or lobbying for all vaccine research, and it's desperately needed,” says Hale. He plans to organize telethons to raise funding, which he says then will be awarded to grants that review committees will rapidly evaluate. The foundation also plans to counter misinformation on vaccines that has convinced thousands of new parents to forgo vaccination for their babies.

    Meanwhile, the head of the New York-based Global HIV Vaccine Enterprise announced his retirement. Alan Bernstein took the helm in 2008. Under his tenure, the enterprise formed a secretariat, published a strategic plan to guide the field, and started a program for young investigators. http://scim.ag/_vaccine

    France

    Save Great Hamster of Alsace, E.U. Court Says

    CREDIT: FREDERICK FLORIN/AFP/GETTY IMAGES/NEWSCOM

    French conservationists were elated on 9 June when the Court of Justice of the European Union in Luxembourg ruled that France has failed to sufficiently protect the European hamster (Cricetus cricetus) from extinction. The country must reverse the destruction of the photogenic rodent's habitat or face fines of up to €720,000 per day.

    The 30-centimeters-long species, also known as the Great Hamster of the Alsace, is still abundant in Eastern Europe. But in the Alsace, one of the hamster's last footholds in Western Europe, urban development and the replacement of its preferred diet of alfalfa and winter cereals by maize have caused its numbers to collapse to a few hundred. A population of at least 1500 is believed to be needed for long-term survival.

    The E.U. court concluded that France has failed to implement the so-called Habitats Directive, which protects more than 1000 endangered animal and plant species of European importance. The case was brought by the European Commission.

    Chevy Chase, Maryland

    15 Plant Biologists to Join HHMI

    In a move to boost plant science, the Howard Hughes Medical Institute (HHMI) has added 15 plant biologists to its portfolio of elite researchers. HHMI and the Gordon and Betty Moore Foundation, which typically supports environmental conservation and microbial research, will spend $75 million over the next 5 years to encourage high-risk research and creative approaches to plant science.

    Although the competition was open to all plant scientists, 14 of the awardees study the model plant Arabidopsis, eight almost exclusively, with one researcher working on wheat. Arabidopsis thaliana was the first plant to have its genome sequenced and the National Science Foundation has just ended a special program for characterizing its genome function. Thus, “this [HHMI program] is really a boost for Arabidopsis research,” says awardee Xinnian Dong, a plant biologist at Duke University in Durham, North Carolina. Typically, new HHMI researchers are appointed within up to 10 years of starting their own lab, but this pool includes some of the pioneers in the Arabidopsis field, such as the California Institute of Technology's Elliot Meyerowitz and Duke's Philip Benfey.

    http://scim.ag/_HHMI, http://scim.ag/hhmi_plant

    Lima

    Peru Set to Forbid GM Crops

    Harvesting potatoes in San Ramon, Peru.

    CREDIT: ENRIQUE CASTRO-MENDIVIL/REUTERS/LANDOV

    On 9 June, Peru's Congress passed a 10-year moratorium on the cultivation of genetically modified (GM) crops, seeking more study. The legislation, which won't stop GM research or its use in pharmaceuticals, is expected to be approved by President Alan García, making Peru the second South American nation to prohibit GM crops after Ecuador, which did so in 2008. Groups representing Peru's indigenous people campaigned for the law, arguing that GM plants could damage native agriculture and threaten the country's diverse flora, including its more than 2000 potato species. Coming less than 2 months after an executive decree allowing GM crop cultivation and trade, the landslide congressional and presidential support for the moratorium depended on a significant concession: GM products will continue to be imported.

    By halting GM agriculture, Peru is going against the regional tide. For 2 years, Brazil has had the world's fastest increasing amount of acreage under biotech cultivation, and 30% of Argentina's pampas is now transgenic cropland. Earlier this month, Bolivian President Evo Morales, an environmental crusader, opened his country's doors to GM planting.

    Leuven, Belgium

    Researcher Sacked for Role In Destruction of Field Trial

    The sacking of a Belgian researcher involved in the partial destruction of a test field for genetically modified (GM) potatoes has triggered a fierce debate about academic freedom in Belgium.

    Barbara Van Dyck, a bioengineer who studies local development and social change at Catholic University of Leuven, says she did not uproot any plants herself during the 29 May operation by a group called the Field Liberation Movement near the Flemish town of Wetteren. But she was present and defended the raid in interviews, referring to the movement as “we.”

    Van Dyck, who was fired 4 days later, says the university never gave her a proper chance to explain the protest, which she says was a form of civil disobedience. Stijn Oosterlynck, a faculty colleague, calls the university's response “disproportionate” pending a judicial inquiry against the group. But university Rector Mark Waer said in an e-mail to staff members that Van Dyck violated one of the institute's core principles. “The university expects its employees to respect each other's research and to not destroy it,” Waer wrote.

  2. Random Sample

    Noted

    >Does the ocean need a mascot? Marine biologists suggest that the giant squid could be the giant panda of marine invertebrates. The squid, Architeuthis, has the right stuff to garner public interest in ocean creatures, say scientists from the Instituto de Investigaciones Marinas de Vigo in Spain and Fisheries and Oceans Canada in St. John's, Newfoundland. It's vulnerable to climate change, pollutants, noise pollution, and overfishing, they note in Biological Conservation. And, best of all, it's already popular.

    On the Shoulders of Giants

    CREDIT: © ROYAL SOCIETY

    Talk about international collaboration. When Polish astronomer Johannes Hevelius began working on his 1687 map of the stars, he wrote to German theologian Henry Oldenburg, secretary of the Royal Society in England. The request: to locate the 15th century star map of astronomer Ulugh Beg of Samarkand and translate it from Persian. The Royal Society fulfilled his request, and the map guided Hevelius's new observations. This frontispiece to Hevelius's map pays homage to Beg; as Hevelius presents the book to Urania, muse of astronomy, the top 10 astronomers of all time look on. Beg is third from left.

    “He crossed many centuries with that image, putting many people shoulder to shoulder,” says astrophysicist Rim Turkmani, curator of Arabick Roots, which opened 9 June at the Royal Society in London. “It's a nice gesture from him to say thank you.” The exhibition's letters, manuscripts, diagrams, and instruments chronicling the flow of scientific knowledge from the Arab world to Europe in the 17th century will be on view until November.

    The Diving Bell and the Spider

    CREDIT: STEFAN K. HETZ, BERLIN

    The water spider spends its life underwater but it needs oxygen to breathe. So when it visits the surface, the spider grabs a bubble of air that sticks to its hairy abdomen. It deposits this bubble into a little silk “diving bell” and breathes from the bell like a tank. The bell functions as a gill: as the spider removes oxygen from the bell, more oxygen flows in. Using a microscopic oxygen sensor, researchers from the University of Adelaide in Australia and Humboldt University in Germany determined how gases move across the bell's surface and found that the spider can stay underwater for up to 24 hours, they report this week in the Journal of Experimental Biology. The spider keeps the bell's volume proportional to its oxygen needs: To eat, it enlarges the bell, puts its food inside, and crawls in after it. Females lay their eggs inside the bell and enlarge it as the brood grows. http://scim.ag/_spiders

    By the Numbers

    13% — Reduction in sensitivity of the planned European Extremely Large Telescope (E-ELT), slated to be built in Chile. The telescope's mirror will be shrunk from 42 meters in diameter to 39.2 meters to save costs.

    94.1% — Percentage of Italian voters in a national referendum who chose to shelve the government's plans to resurrect nuclear energy.

    Matchmaker, Matchmaker

    CREDIT: COURTESY ADVENTURERS AND SCIENTISTS FOR CONSERVATION

    Pikas in the Pacific Northwest, kiss your privacy goodbye. This spring, Gregg Treinish, wildlife biologist, founder, and director of Adventurers and Scientists for Conservation (ASC), recruited 22 hikers on the Pacific Crest Trail from Campo, California, to Manning Park, British Columbia, to spy on the small, furry mammals. The hikers are recording pika sightings, straw nests, and even urine stains as part of a pilot project to track the impacts of climate change on the creatures.

    Recruiting passersby for research is a time-honored tradition: Psychologists designing an experiment often grab stray students for a quick, cheap pilot study before shooting for the big bucks. Treinish wants to apply the same principle to ecological studies: the nonprofit ACS, founded in November 2010, seeks to connect scientists with far-ranging adventurers for “model expeditions that could be repeated on a widespread scale,” he says. Researchers are already using his matchmaking to recruit intrepid explorers to catalog the presence of ice worms in glaciers or record grizzly movements near Yellowstone National Park. “There's no project too big or too small,” Treinish says.

    Elisabeth Holland, a biogeochemist and lead author of the Intergovernmental Panel on Climate Change reports, is on the ASC advisory board. Treinish has also recruited professional adventurers ranging from ocean rower Roz Savage to high-altitude mountaineer Conrad Anker as ASC advisers. Interested adventurers and scientists can register on his Web site: http://adventureandscience.org.

  3. Newsmakers

    Three Q's

    CREDIT: PHOTO COURTESY OF THE SABIN VACCINE INSTITUTE

    Lured by a 5-year, $40 million investment package, neglected diseases expert Peter Hotez, 53, is leaving George Washington University in Washington, D.C., to set up the National School of Tropical Medicine at Baylor College of Medicine in Houston, Texas. The Sabin Vaccine Institute, which he heads, will relocate its 20-person product development arm to Texas Children's Hospital.

    Q:Why the move?

    The Texas Children's Hospital has agreed to become a major investor in Sabin's vaccine development. Other donors, such as the Gates Foundation and the Dutch government, emphasize the need for co-investors because vaccine development is so expensive. At the same time, Baylor is creating the first school of tropical medicine in the United States. It's an extraordinary opportunity.

    Q:There's training in tropical medicine elsewhere. Why a specialized school?

    Schools of public health, where most of the training takes place, don't have the same technology focus that our school will have. Students will really learn the nuts and bolts of pilot manufacturing, regulatory filings, clinical trials—all of the things you need to do to produce vaccines.

    Q:What else makes Texas interesting?

    Because there is a lot of poverty, it has the highest rates of parasitic and neglected infections anywhere in the U.S. In a paper in 2008, I described a group of six neglected diseases that are common both in African Americans and Hispanic Americans. In addition, dengue has emerged along the gulf coast. That's another rationale for being based in Houston.

    Genetic Mapmaker

    CREDIT: GRUBER FOUNDATION

    Ronald Davis of Stanford University has won the 2011 Gruber Prize in genetics, announced 8 June. The prize recognizes Davis's groundbreaking work on recombinant DNA techniques. He showed that sequence variants in genomes could be used to make physical and genetic maps and also helped develop the first microarrays.

    While still a graduate student at the California Institute of Technology, Davis developed a technique to physically map the locations of genes based on differences between strands of DNA visible under an electron microscope. The technology was used to verify that sequences jump around in the yeast genome. David's work encouraged us to think you could map the human genome,” says genomicist David Botstein of Princeton University, who calls Davis “a superior craftsman.” Botstein, a past Gruber prize winner, co-authored with Davis and two others a seminal 1980 paper on making a human genome map.

    Davis's lab boasts several pioneering accomplishments: the development of vectors for cloning DNA in order to isolate genes, artificial chromosomes in yeast, and tools that allowed researchers to replace one nucleotide with another in yeast and bacteria.

    These advances took colleagues some getting used to, says Davis. But, he says, “That was the beginning of the genomic era.”

  4. Plant Biology

    Green Genomes

    1. Elizabeth Pennisi

    With about 30 plant genomes in hand, researchers trace the evolution of our flora and discover that plant DNA is unusually dynamic.

    CREDIT: FOTOSEARCH.COM

    Eleven years ago, scientists publicly unveiled the near-complete DNA sequence of a small weed known as Arabidopsis thaliana. The debut of this first plant genome marked “a very special time in the whole history of plants,” said Daniel Cosgrove, then president of what is now the American Society of Plant Biologists.

    It's still a special time. True, the sequencing of plants has lagged behind that of animal genomes (Science, 20 July 2007, p. 317). But there are now nearly 30 plant genomes available for analysis and comparison, including most recently one belonging to spikemoss, which reproduces via spores rather than seeds and isn't truly a moss (Science, 20 May, p. 960). Buried within all this DNA sequence has been no shortage of surprises and insights into how the planet's flora and their DNA evolve. “These are really exciting days,” says Patrick Schnable, a geneticist at Iowa State University in Ames. “There is a lot of power in comparing genomes.”

    To date, angiosperms, flowering plants that produce seeds and make up the majority of flora seen on Earth today, dominate the roster of the sequenced genomes. Besides A. thaliana, scientists have deciphered DNA from poplar, maize, rice, and about 20 other angiosperms. But a few other genomes come from species—algae, a moss, the spikemoss—representing key stages in the evolution of land plants. These DNA sequences are beginning to reveal what it took for plants to move onto land, grow tall, and produce seeds and flowers. For example, many genes key to the colorful blossoms that brighten the landscape turn out to have unexpectedly deep evolutionary roots, some stretching back to algae. “Very few genes seem to be without precedents,” says Jeffrey Bennetzen, a geneticist at the University of Georgia, Athens.

    The genomes are also showing that plant evolution is surprisingly dynamic. Plants seem to frequently undergo whole genome duplications, their DNA repertoire swelling in size, then shrinking again through time, gaining and losing genes much more quickly than do animal genomes. “You can see what events have led to the evolution of the genome,” says Elliot Meyerowitz, founding director of the Sainsbury Laboratory, a major new plant science facility in Cambridge, U.K.

    Genes that mattered

    The sequenced plant genomes cover a billion years of evolution. The green alga Chlamydomonas reinhardtii represents early photosynthesizers, confined to water and never expanding beyond a simple single cell (Science, 12 October 2007, p. 245). Its genome showed what it took to be “green”: It had everything necessary to utilize photosynthesis. The alga's DNA offered a few surprises as well. Chlamydomonas has the core of a flowering gene discovered first in snapdragons, but in the alga it's involved in sensing copper—another example of how a gene gets co-opted during evolution to serve a new purpose. When researchers compared Chlamydomonas's genome with that of the more complex green colonial alga, Volvox carteri, they were surprised to find that the transition to multicellularity in this group was a small step, relatively speaking, as the two algae have roughly the same number of genes, 14,500 (Science, 9 July 2010, p. 128).

    In 2008, bryophytes, which evolved 450 million years ago and were among the first plants to colonize land, entered the genomic age. This group includes mosses, liverworts, and hornworts; the moss Physcomitrella patens was the first to fully bare its DNA (Science, 4 January 2008, p. 64). Scientists studying its genome have found that the climb to shore required new genes for surviving dry spells and temperature swings, and that resulted in a more complex genome, with expanded families of genes.

    As spore-forming plants, mosses don't produce seeds, yet P. patens unexpectedly revealed genes that in other plants encode proteins that help seeds survive desiccation. The team that decoded this moss's genome, led by Stefan Rensing of the University of Freiberg in Germany, concluded that these progenitors of seed-plant genes must have originated in the earliest land plants to protect the entire plant during dry spells. In a new comparative analysis, Tomoaki Nishiyama and Mitsuyasu Hasebe of the Japan Science and Technology Agency in Okazaki found that this moss also has 80% of the several hundred genes responsible for development in Arabidopsis, indicating that the tool kit for more complex plant architectures was already in place long before angiosperms evolved.

    After plants made the leap to land, a key innovation enabled them to grow tall: a system of tissue that conducts water and nutrients. One group that evolved this vascular tissue early on was the lycophytes, which represent an interim step in plant evolution because they have a vascular system but do not produce seeds. Some 300 million years ago, lycophytes were the first giants of the plant world, dominating the carboniferous forests whose remains became coal beds. Today's lycophytes, which include spikemosses and clubmosses, are small plants with scalelike leaves on branching stems found in forests and gardens.

    Like the moss genome, the spikemoss DNA revealed genes expected in more complex plants, suggesting that those genes have deep roots. “We see the evolution and origin of genes and gene families that we know are very important in wood development” even though lycophytes are not woody plants, says Claude dePamphilis, a plant genomicist at Pennsylvania State University, University Park.

    The emergence of lycophytes also marks a transition in the evolution of plant reproductive strategies. Plants undergo sexual and asexual life stages. In moss and algae, the sexual stage is the dominant phase; in lycophytes, ferns, and seed plants, the asexual stage is the form we are most familiar with. Researchers had thought this transition would have required a lot of genetic innovation, but a comparison of the spikemoss genome with other plant genomes shows that other transitions required much more heavy lifting.

    Purdue University geneticist Jo Ann Banks and her colleagues looked at all the available plant genomes, grouping genes into families. They found 3814 gene families common to every plant from algae to grape, from which they concluded that these were in the common ancestor to all green plants. A comparison of algae and mosses to other plants indicated that the shift in reproductive strategies and the transition to vascular plants required only about 516 new gene families. The evolution of angiosperms required an additional 1350 families. The move to land demanded the most evolutionary innovation, with 3006 new gene families appearing, they reported. “In number and types of genes, the most dramatic change was what was acquired to move onto land,” dePamphilis says.

    Lopsided coverage.

    Flowering plants (angiosperms) have dominated the floral genome scene, with moss, algae, and spikemoss representing the few exceptions.

    CREDITS (CLOCKWISE FROM TOP LEFT): EPA; FOTOSEARCH.COM; ROBERT VIDÉKI/IPM IMAGES; FOTOSEARCH.COM; DAVE POWELL, USDA FOREST SERVICE, BUGWOOD.ORG; WIKIMEDIA COMMONS

    Genomic anarchy

    Comparisons of plant genomes have done more than highlight genes that came on the scene through time. They have also revealed insights into the broader evolution of the genomes themselves. Plant genomes change more quickly than do animal genomes, leading to more variation among closely related species and even within a species. Chimeric DNA—bits of two different genes that have merged—arises relatively frequently, and transposable elements, mobile DNA sequences in a cell, are actively remodeling the genome, creating new regulatory elements. The overall conclusion: Plants practice “genomic anarchy,” says Detlef Weigel, a geneticist at the Max Planck Institute for Developmental Biology in Tübingen, Germany.

    Why such anarchy? Plants have such a different lifestyle from that of animals that they apparently need more flexible genomes. “The different features of their genomes reflect their different evolutionary histories, and these can be correlated with their different survival strategies,” says Andrew Leitch, a plant evolutionary biologist at Queen Mary, University of London.

    A mustardlike weed was the first to alert researchers to this anarchy. In the late 1990s, the expense and difficulty of sequencing prompted researchers to pick small, simple genomes; hence they tackled A. thaliana, with its 125 million bases, ahead of much more economically and politically important maize, an estimated 2.5 billion bases. Also, Arabidopsis was supposedly diploid, with just two copies of each chromosome, whereas maize seemed to come from a polyploid; its extra chromosomes might have made piecing together sequenced DNA an even more daunting task.

    Filling out the tree.

    Now the gymnosperms (left to right) Douglas fir, loblolly pine, sugar pine, and Norway spruce are being sequenced.

    CREDITS (LEFT TO RIGHT): FOTOSEARCH.COM; WIKIMEDIA COMMONS; © WALT ANDERSON/VISUALS UNLIMITED/CORBIS; FOTOSEARCH.COM

    But the Arabidopsis DNA revealed that at least twice, the plant had somehow duplicated its entire genome and survived the unusual event. Subsequent genomes have revealed this to be a recurrent theme in plant evolution, with different species experiencing one or more instances of whole genome duplications at different times in their history. Moreover, it's becoming clear that many plant genomes go through cycles in which their genomes double in size; most extra genes disintegrate over the next few million years, returning genomes to near preduplication gene numbers; and then doubling occurs again. Poplar's duplication was more recent than A. thaliana's, for example, and thus its genome has many more protein-coding genes.

    Indeed, the latter seems to be in the winnowing stage. Tina Hu of the University of Southern California in Los Angeles and her colleagues sequenced a close relative, A. lyrata, and reported online 10 April in Nature Genetics that it has more than 500 additional genes. Moreover, lining up the two Arabidopsis genomes shows that A. thaliana has undergone hundreds of thousands of small deletions in the 10 million years since the two plants diverged.

    These cycles significantly alter a plant's genetic landscape. In A. thaliana, many of the documented deletions occurred in the DNA regions that don't encode proteins and are likely sites of gene regulation. “We are beginning to get a sense for how dramatically the regulatory programs of these plants have been reset with each new round of polyploidization and subsequent diploidization,” says Todd Vision, a plant evolutionary biologist at the University of North Carolina, Chapel Hill.

    Plant genomes are generating novelty in other ways as well. For one, their transposable elements are much more active than are those in animal genomes, hopping in and out of chromosomes, dragging bits of DNA with them and in doing so positioning that DNA where it can help regulate genes in new ways. At the same time, researchers examining plant genomes have discovered thousands of examples of gene shuffling, in which fragments of two or more genes have been brought together to form an apparently functional new gene. What most of them do remains unknown, but in maize, 8% of these chimeras are under some form of selection, indicating that they are important to the species' survival, Bennetzen says.

    “What's also been surprising is how rapidly plant genomes change” compared with those of animals, Bennetzen notes. One can match a fish genome up with a primate's and find noncoding DNA sequences that are conserved between these organisms even though they diverged 400 million years ago. (Noncoding DNA tends to change faster than that which encodes proteins.) But in plants, such conservation disappears fast. Researchers have compared Arabidopsis with rice, maize with sorghum, and rice with sorghum—finding little in common in the noncoding DNA between genes. Even between two corn varieties, this DNA can differ by 20%. “That's much more different than between chimps and humans,” Weigel says.

    Because DNA bases between genes are often sites that control gene activity, plants likely undergo much faster evolution in gene regulation than do animals. “If we don't have changes in gene regulation 100-fold faster than in mammals, I would be shocked,” Bennetzen says.

    Such insights have made plant biologists hunger for more genome sequences. In some cases, researchers are going after just the full set of expressed genes. For example, since 2009, the 1000 Plant Genomes Project has looked at about 500 plant species with the goal of examining a species from every angiosperm family, many medicinal plants, and hundreds of green algae by the end of this year. The dozen subprojects include one that will survey the plants' light-sensitive proteins and one that is examining the more advanced C4 photosynthetic system, which evolved at least 62 times in angiosperms. Moreover, a collaboration of U.S. universities is pulling out all the expressed genes of so-called parasitic plants, which invade the tissues of other plants.

    Some researchers are also looking at varieties of already sequenced species. The 1001 Genomes Project is sequencing that many strains of A. thaliana to get a better sense of how variation affects trait differences among strains, with about 250 already completed. Multiple maize genomes are being deciphered as well.

    Still other researchers are picking specific plant genomes to broaden coverage across the tree of life. DePamphilis is leading an effort to sequence Amborella, which sits at the base of the angiosperms. Four conifer sequencing projects began this year: the loblolly pine, sugar pine, Douglas fir, and Norway spruce. They will be the first gymnosperms, the other major group of seed plants, to be sequenced. Banks and her colleagues are working to get support to study a fern's genome. Despite advances in DNA sequencing efficiency, that would still be daunting; ferns can have up to 1000 chromosomes. Still, a fern genome may help answer why they're so genetically complex. All in all, Vision says, it's “heady days to study plant genome evolution.”

  5. Profile: Zhong You

    'Origami Engineer' Flexes to Create Stronger, More Agile Materials

    1. Zeeya Merali*

    A latecomer to the Japanese art of paper folding helps harness the mathematics behind it to make medical devices, disaster shelters, and, possibly, rockets.

    Thin but tough.

    You's origami-inspired inventions include a flat-folding bag made of rigid steel.

    CREDIT: THE DEPARTMENT OF ENGINEERING SCIENCE, UNIVERSITY OF OXFORD

    Zhong You never cared for origami. As a child growing up in Shanghai, China, in the 1960s, he considered the ancient Japanese art of paper folding pointless at best. “It was all about how to fold a frog or something else that was pretty but had no use,” he says. “Also, I was no good at it!” It took several years and a handful of insights before You—by then a civil engineer working in a distant country—would find himself using the folding techniques that irked him in his youth to design medical instruments, emergency housing, and even space rockets.

    Insider.

    Creased stent is designed to snap open inside an artery.

    CREDIT: THE DEPARTMENT OF ENGINEERING SCIENCE, UNIVERSITY OF OXFORD

    You, now based at the University of Oxford in the United Kingdom, describes himself as an “origami engineer,” one of a small number of researchers who build a variety of objects from folded sheets of rigid material. The discipline first gained prominence in the 1970s, when engineers realized that they could pack solar panels that had been etched with an origami crease pattern into a small volume for transport in shuttles and quickly and easily unfold them in space. But since then, You feels that its potential for transforming a host of structures across a range of scientific disciplines has been largely ignored—and that's something he hopes to rectify.

    At first glance, You's lab appears messy, littered with crumpled paper, grocery bags, and cans. But on closer inspection, the folded sheets are prototypes of foldable building parts, while the old bags and cans have been carefully collected because of their shape. A can picked up in Tokyo, which once held a vodka and lemon drink, caught You's eye because its surface carries a crease pattern of tessellated diamonds. “The drink is nasty,” he says, “but the can made me think about what would happen if you put an origami pattern on a rocket.” A compactly folded paper bag from a takeout in Boston, meanwhile, provides inspiration for squeezing down medical devices for easy transport inside the body.

    You had his first brush with origami engineering as a graduate student at the University of Cambridge in the 1990s. Before coming to England, he had worked in naval architecture at Shanghai University, using conventional foldable structures that bent at hinges and had moving parts that slid over to make objects more compact. But at Cambridge he met a fellow student, Simon Guest, who was using the solar-panel-folding trick to store kilometers of tubing for deployment on space flights, and realized that rigid origami could do more than help save room. “Hinges and sliding parts can stick, especially when you need to open and close structures many times,” he says. “Rigid origami creases are much more reliable.”

    It took another decade, however, before You began to apply origami seriously. Engineers were reluctant to waste time groping for the best folding patterns through trial and error, he explains. At a mathematics conference on origami in Boston, however, You became aware of blossoming research into the geometry of folding and realized that it could provide rigorous blueprints for manufacturing.

    With this mathematical underpinning, You turned his attention to tools for exploring inner rather than outer space, by redesigning the surgical stents, or artificial tubes, inserted into arteries to remove blockages and repair aneurysms. Standard stents are made of an expandable metal scaffold, covered with fabric, which is guided into position and then opened. But like a broken umbrella, the fabric can easily detach from its metal scaffold and fail to make full contact with the artery walls on opening. You's “origami stent,” by contrast, is made of a single material, folded down so that it can pass through the arteries and then snap open once in position.

    You plans to put the origami stent through animal trials early next year. He also hopes to adapt it for use in the brain's delicate blood vessels, which require stents far more flexible than those normally used in other parts of the body. “The synergy with space applications is clear: An object has to be deployed in a hostile environment, and any error could lead to disaster,” says Guest, who still works on foldable structures at Cambridge, independently from You.

    Crush-resistant.

    Pleated columns inspired by a beverage can are strong but lightweight—a combination that may prove useful in silos, rocket bodies, and shock absorbers.

    CREDIT: THE DEPARTMENT OF ENGINEERING SCIENCE, UNIVERSITY OF OXFORD (3)

    Erik Demaine, an expert on origami-based robotics at the Massachusetts Institute of Technology in Cambridge, calls You's origami stent “the most important current application of origami engineering.” He notes that origami engineers have ambitious long-term goals: for instance, building houses that can be reconfigured at the push of a button, with entire rooms that can be folded away and change functionality. One of You's skills is to find useful near-term applications that build toward these futuristic dreams, he says.

    In particular, You and his doctoral student Joe Gattas are turning the vision of reconfigurable housing into the more easily achievable reality of emergency shelters that can be transported as flat sheets and unfolded in the aftermath of natural disasters, where there is little hope of bringing in complicated machinery. Gattas thought of the idea during the recent spate of flooding in his native Australia. “People who have lost their homes need something more solid and comfortable—more homelike—than a tent,” he says.

    Guest likes the concept but notes that in untrained hands, there's no such thing as a foolproof self-assembly kit. You acknowledges the concern with a smile: “It's true, the challenge is to keep things simple. Even the best engineers have difficulty putting together flat-packed furniture.”

    Royal nod.

    Prince Philip views You's work.

    CREDIT: THE ROYAL SOCIETY

    Fittingly, You also has his eyes on packing processes. He recently designed a grocery bag made of steel that can be collapsed down as flat as a paper bag. His prototype proves that any rigid package, including open-topped cardboard boxes, can be folded down if it has the right crease pattern; currently, both top and bottom need to be opened for flat packing. “The packaging industry is the one place people have traditionally thought deeply about paper-folding techniques, and this could really speed up factory assembly lines,” he says.

    Origami can do more than make things more portable, You adds. For example, take the patterned Japanese drink can that inspired him to investigate designs for a shuttle. “The manufacturers put the design there to make the can look pretty, but it makes me think about how a crease pattern can strengthen or weaken the can's ability to withstand the pressure from the carbonated drink inside,” he says. “I realized we could turn the origami concept on its head and look for patterns that would make things hard to fold and crush.”

    You has been thinking about plans for lighter-weight space rocket and silo bodies that use less material but remain strong, thanks to a crease pattern. But even if they pass muster, implementation of such large-scale designs would still be years away. Meanwhile, You is using the same principle to develop a more down-to-earth product: a more effective shock absorber for the Land Rover. In theory, he says, etching origami folds into the metallic cylinders behind car bumpers should increase the energy they absorb on impact by up to two-thirds. His group is in the process of testing the claim.

    It has not all been plain sailing for You. The downside to working on a vast range of projects spanning many fields is that with each new invention, You must establish his reputation afresh and persuade a new group of people to replace standard manufacturing techniques with an origami-based alternative. “It can look like we are reinventing the wheel,” he says. “We have to work hard to prove that origami has benefits.”

    Joseph O'Rourke, a mathematician and expert on the geometry of folding at Smith College in Northampton, Massachusetts, says people are still largely unaware of origami's merits for science. “This is a new area, with academic publishing just starting,” he says. But he adds that the ideas are starting to disseminate as more mathematical books and conferences cover the topic.

    In 2006, You's work also received a royal seal of approval when he was asked to show some of his devices at a science exhibition at Buckingham Palace. “The Duke of Edinburgh came over to me and asked what the function of each piece was. It was quite an honor,” he says. The origami structures have also been a hit with the public at exhibitions. “People keep offering to buy my pieces as stress-relieving toys, and I have to say, ‘No, they are prototypes,’” he laughs. “Still, at least I know that if engineering doesn't work out for me, I can set up a business as a toymaker.”

    For now, however, You remains one of a niche group of researchers “exploring uncharted waters” in design and invention. But that's okay by him. “We're in the position where so much remains to be done,” he says. “Every day, there's huge potential for an important discovery.”

    • * Zeeya Merali is a freelance writer based in London.

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