News this Week

Science  22 May 2015:
Vol. 348, Issue 6237, pp. 842

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  1. This week's section

    A rival for opium poppies?

    An enzyme engineered into yeast allows researchers to see which microbes are making L-Dopa (yellow), a key step in the pathway to making opiates.


    Researchers are closing in on a long-standing goal of engineering a suite of genes into yeast that would allow the microbes to synthesize morphine, codeine, and other medicines harvested from opium poppies for thousands of years. In a paper published online this week in Nature Chemical Biology, scientists reported inserting an enzyme from sugar beets into yeast that carries out one of the few remaining steps needed to enable microbes to synthesize opiates. The work could lead to the cheap, easy production of widely used medicines with new capabilities and fewer side effects. But policy specialists worry that the new strains could allow narcotics dealers to convert sugar to morphine or heroin as easily as beer fans create homebrews. “There really is potential for screwing things up,” says Kenneth Oye, a biotech policy expert at the Massachusetts Institute of Technology in Cambridge. In a Nature commentary this week, Oye and colleagues proposed regulations such as asking gene synthesis companies not to distribute genes needed to produce illicit compounds and engineering morphine-producing yeast strains with traceable genetic watermarks.

    Trees set birds' hatching schedule

    Great tits know when caterpillars will be most plentiful.


    While most expecting moms never quite know when they will give birth, great tits (Parus major) have their timing nailed down. Their eggs hatch right when nearby oak trees—those within 50 meters—produce leaves, says ornithologist Ben Sheldon of the University of Oxford in the United Kingdom. That leafing out triggers a 2-week explosion in the abundance of the winter moth caterpillars that munch on the leaves—and great tit parents depend on that caterpillar bonanza to feed their chicks. Researchers have shown that the birds' reproductive timing is shifting with global climate change. But for individual birds, the cues are local: They set their mating schedule according to when the trees they are likely to visit leaf out, Sheldon and his colleagues report in the July issue of American Naturalist, based on 45 years' worth of data on great tits living near the university. The researchers don't know what the birds are looking for, but some trees always leaf out early; others later, the researchers showed. And “the birds match that local effect,” he says.

    70%—Target set by Representative John Culberson (R–TX), chair of a panel that sets the National Science Foundation's budget, for spending on so-called core disciplines—excluding the geo and social sciences. Currently, those areas get 65%.

    Around the world

    Washington, D.C.

    New avenue for fusion research

    The Advanced Research Projects Agency-Energy, the Department of Energy's agency for blueskies energy research, announced a slew of projects on 14 May that it hopes will break the logjam in fusion research, which has been trying to replicate the power source of the sun for more than 60 years without success. The Accelerating Low-cost Plasma Heating and Assembly program seeks a middle way between the two primary approaches: high-density laser fusion and low-density magnetic fusion. Under the program, nine projects will share $30 million to investigate whether plasma jets, ion beams, current pulses, high-pressure gas, and pneumatic pistons may be able to achieve the temperatures and pressures necessary to get hydrogen ions to fuse together, releasing energy. A lack of funds has hindered U.S. government labs from investigating such approaches, prompting a new breed of startups (Science, 25 July 2014, p. 370).


    German scientists push for GM

    Those who oppose genetically modified (GM) food usually advocate for labels on it, and those who support it usually see no need. But this week, a group of German scientists joined other GM proponents to launch a campaign to require labeling of food, feed, drugs, textiles, chemicals, and other products produced with the help of GM organisms. The petition to the German parliament is actually a gamble: The groups hope the new law will show Germans how widespread such products already are and that there is nothing to be afraid of. The petition also calls on the government to advocate for a similar law at the E.U. level. The text has the backing of several prominent scientists, including Nobel Prize winner Christiane Nüsslein-Volhard, as well as some politicians. If it receives more than 50,000 signatures in the next 4 weeks, the German parliament has to consider the proposal.

    Washington, D.C.

    Tackling embryo gene editing

    Responding to an uproar over attempts to genetically modify human embryos, the U.S. National Academies is launching an international initiative to discuss this ethically fraught area. Although genetically modifying the human germ line—eggs, sperm, or embryos—to create a baby has long been considered taboo, new gene-editing technologies such as CRISPR have heightened concerns that genetically modified babies are on the horizon. Whether even basic research in this area should move forward is hotly debated, particularly following an April report by a Chinese team describing its editing experiment on defective human embryos. A fall meeting by the National Academy of Sciences and National Academy of Medicine is intended to set the stage for a committee to begin working out guidelines.


    Three Q's


    Agriculturalist Cary Fowler was executive director of the Global Crop Diversity Trust from 2005 to 2012, helping create the Svalbard Global Seed Vault in Norway. This month, Seeds of Time, a documentary that chronicles Fowler's efforts to protect the genetic diversity of the world's crops, opens in New York and Los Angeles. Fowler discussed his work with Science.

    Q:When will Svalbard be complete?

    A: There isn't an endgame. We have samples of 864,000 distinct crop populations. I guess we have upwards of 1.5 million samples around the world that could go in Svalbard. [So] you might be tempted to say we're more than halfway there, but that's not the way to look at it. It's not a numbers game. It's a diversity game.

    Q:How would you rate the overall security of crop diversity today?

    A:I'd rate the diversity that's in Svalbard at a 10 [safe as can be]. We're really put an end to extinction. For the genetic material that's not in Svalbard, the number is much lower. That depends on its location. It could be anywhere from 1 to 6 or 7.

    Q:How do you hope scientists use Svalbard in the future?

    A:I hope they never use Svalbard. It's an insurance policy. I do worry that while we have really big collections for the top 15 major crops, we're deficient in the rest. That doesn't bode well in an era of climate change, where we need to use that diversity to adapt our crops.


    Unraveling a day care—cancer link

    Scientists have long noticed that children who went to day care early in life are less likely to develop the most common childhood cancer: acute lymphoblastic leukemia (ALL). Now, a study that unravels the molecular mechanism driving ALL may explain why early exposure to routine infections might boost the immune system and ultimately help protect against the disease. The immune system's B cells reprogram their DNA to recognize different infections through a sequence of enzymes. Researchers suspected that, in children with a genetic abnormality linked to ALL, repeated infections later in childhood could trigger unregulated mutations in the B cells, causing leukemia. The team took mouse B cells with the genetic flaw and subjected them to repeated “infections”—exposure to a molecule that triggers an immune response. All 14 mice injected with those B cells got leukemia and died, the team reported online this week in Nature Immunology.