Editors' Choice

Science  30 Oct 2015:
Vol. 350, Issue 6260, pp. 525
  1. Microbiology

    Genomes share shortcuts to cheese

    1. Pamela J. Hines

    By swapping portions of their genomes, Penicillium species optimized themselves for cheesemaking

    PHOTO: © ADAM WOOLFITT/CORBIS

    Making cheese requires fermentation, which means that it can be a messy business. To better understand the process at a molecular level, Ropars et al. analyzed the genomes of several Penicillium fungal species, including those used to make Roquefort and Camembert cheese. Different species shared large portions of their genomes, as much as 80 kilobases in size. The genes embedded in these shared islands helped the fungi to break down milk components more effectively and compete with other microbes. The fungi probably acquired these genomic islands through horizontal gene transfer rather than by reproducing. During the centuries that humans have been selecting fungi to make better cheese, the fungi have apparently been passing notes under the table to get the job done.

    Curr. Biol. 25, 2562 (2015).

  2. C-H Bond Activation

    Threading the needle with manganese

    1. Jake Yeston

    It's rather straightforward to oxidize hydrocarbons indiscriminately—that's the type of reaction that supplies heat to gas-powered stoves and furnaces. Chemists interested in making pharmaceuticals or consumer products do not want to end up with just carbon dioxide and water though. Instead, they want to transform certain specific C-H bonds without disturbing the rest of the molecule. Paradine et al. report a manganese catalyst that slides pendant N into C-H bonds with high tolerance for otherwise-reactive C=C double bonds nearby. At the same time, the catalyst shows surprisingly high reactivity toward very strong C-H bonds (including primary alkyl sites) that previous selective catalysts failed to engage.

    Nat. Chem. 10.1038/NCHEM.2366 (2015).

  3. Aging

    Skin cell–derived neurons act their age

    1. Stella M. Hurtley

    The main risk factor for neurodegenerative disorders is aging. To better understand cellular aging, scientists seek to model it using human neurons in tissue culture. Given the difficulty of obtaining neurons directly from human donors, scientists can derive them from either induced pluripotent stem cells (iPSCs) or by directly inducing them from another cell type. Mertens et al. compared the gene signatures of neurons obtained by these two methods and found that although the iPSC-derived neurons erased their signatures of aging, the induced neurons retained their original aged characteristics. Thus, directly converted induced neurons could provide a key resource for modeling neuronal aging.

    Cell Stem Cell 10.1016/j.stem.2015.09.001 (2015).

  4. Physics

    Tweaking atomic interactions optically

    1. Jelena Stajic

    Control over interactions in ultracold atomic gases makes them an appealing setting for quantum simulations. To exert this control, researchers typically tune external magnetic fields. However, varying interactions in time and space using this method remains tricky. Now, Clark et al. implement an optical scheme that enables such modulations. By carefully choosing the wavelength of the laser light they shone at a gas of Cs atoms, the researchers were able to modulate the interactions without the side effects that plagued earlier approaches. The work extends the potential of cold gases for quantum simulation.

    Schematic view of the optical control of Feshbach resonances

    PHOTO: CLARK ET AL., PHYSICAL REVIEW LETTERS 115, (9 OCTOBER 2015) © PHYSICS

    Phys. Rev. Lett. 115, 155301 (2015).

  5. Atmospheric Chemistry

    A suite in flux

    1. H. Jesse Smith

    Understanding the chemistry of the atmospheric boundary layer is an exercise that requires knowledge of a tremendous number of chemical species, their interactions with one another, and how those interactions vary under different physical conditions. To date, most observational efforts have focused on measuring the concentrations of the most important gases, but such limited information makes it difficult to construct a model of the atmosphere that is at once quantitative, comprehensive, and self-consistent. Wolfe et al. improve on existing methodologies by developing an airborne system capable of quantifying not only concentrations but fluxes for a suite of reactive gases. Their approach will improve our knowledge of biogenic and anthropogenic emissions, photochemical mechanisms, and deposition.

    Geophys. Res. Lett. 10.1002/2015GL065839 (2015).

  6. Cell Aging

    Yeast reveal the secrets for a long life

    1. Barbara R. Jasny

    For scientists, the genetic basis of aging largely remains a mystery. McCormick et al. sought to shed light on this mystery by conducting a 10-year study of the replicative life span (that is, the number of daughter cells that a given cell produces) in 4698 strains of yeast, each of which had a different gene deleted. The authors detected 238 genes that promoted longevity when deleted. They then grouped them into functional categories, the largest being genes that encode components of the ribosome, a large molecular machine that drives protein synthesis. Many genes associated with yeast longevity overlapped with those that regulate this process in Caenorhabditis elegans.

    Cell Metab. 10.1016/j.cmet.2015.09.008 (2015).

  7. Psychology

    Trusting robots but not androids

    1. Gilbert Chin

    Robots that resemble humans often make people uncomfortable.

    PHOTO: MAX AGUILERA-HELLWEG

    Robots collect warehoused books, weld car parts together, and vacuum floors. As the number of android robots increases, however, concerns about the “uncanny valley” phenomenon—that people dislike a vaguely human-like robot more than either a machine-like robot or a real human—remain. Mathur and Reichling revisited whether human reactions to android robots exhibit an uncanny valley effect, using a set of 80 robot head shots gathered from the Internet and a systematically morphed set of six images extending from entirely robot to entirely human. Humans did adhere to the uncanny valley curve when rating the likeability of both sets of faces; what's more, this curve also described the extent to which those faces were trusted.

    Cognition 146, 22 (2016)