This Week in Science

Science  26 May 2017:
Vol. 356, Issue 6340, pp. 816
  1. Neuroscience

    Neuroplasticity in learning to read

    1. Philip Yeagle

    Even in adults, learning to read changes the brain.

    CREDIT: HOWARD DAVIES/GETTY IMAGES

    Rather than causing dyslexia, subcortical changes in the brain may result from reduced literacy. Skeide et al. studied illiterate adults from rural northern India. They used brain imaging to see whether learning to read invoked changes in the human brain. After 6 months of teaching illiterate adults to read, the authors assessed brain responses compared with those of controls who were not learning to read. The new readers had increased functional plasticity in the subcortical computation centers of the visual system.

    Sci. Adv. 10.1126/sciadv.1602612 (2017).

  2. Gas Giant Planets

    Juno swoops around giant Jupiter

    1. Keith T. Smith

    Jupiter is the largest and most massive planet in our solar system. NASA's Juno spacecraft arrived at Jupiter on 4 July 2016 and made its first close pass on 27 August 2016. Bolton et al. present results from Juno's flight just above the cloud tops, including images of weather in the polar regions and measurements of the magnetic and gravitational fields. Juno also used microwaves to peer below the visible surface, spotting gas welling up from the deep interior. Connerney et al. measured Jupiter's aurorae and plasma environment, both as Juno approached the planet and during its first close orbit.

    Science, this issue p. 821, p. 826

  3. Quantum Measurement

    Enhancing quantum sensing

    1. Ian S. Osborne

    The quantum properties of the nitrogen vacancy (NV) defect in diamond can be used as an atomic compass needle that is sensitive to tiny variations in magnetic field. Schmitt et al. and Boss et al. successfully enhanced this sensitivity by several orders of magnitude (see the Perspective by Jordan). They applied a sequence of pulses to the NV center, the timing of which was set by and compared with a highly stable oscillator. This allowed them to measure the frequency of an oscillating magnetic field (megahertz bandwidth) with submillihertz resolution. Such enhanced precision measurement could be applied, for example, to improve nuclear magnetic resonance–based imaging protocols of single molecules.

    Science, this issue p. 832, p. 837; see also p. 802

  4. Geophysics

    Sediments tell a tsunami story

    1. Brent Grocholski

    Trying to understand where major earthquakes and tsunamis might occur requires analysis of the sediments pouring into a subduction zone. Thick sediments were expected to limit earthquake and tsunami size in the Sumatran megathrust event in 2004, but the magnitude 9.2 earthquake defied expectations. Hüpers et al. analyzed sediments recovered from the Sumatran megathrust. They found evidence of sediment dehydration, which increased fault strength and allowed for the much larger earthquake to occur. Thus, models of other subduction zones, such as the Gulf of Alaska, may underestimate the maximum earthquake magnitude and tsunami risk.

    Science, this issue p. 841

  5. Neuroscience

    Representing direction in the fly

    1. Peter Stern

    A population of cells called compass neurons represents a fruitfly's heading direction. Kim et al. used imaging and optogenetics in behaving flies to elucidate the functional architecture of the underlying neuronal network. They observed local excitation and global inhibition between the compass neurons. The features of the network were best explained by a ring attractor network model. Until now, this hypothesized network structure has been difficult to demonstrate in a real brain.

    Science, this issue p. 849

  6. Small RNA Decay

    Breaking down miRNAs

    1. Beverly A. Purnell

    Although much work has examined microRNA (miRNA) biogenesis, relatively little is known about miRNA decay. Elbarbary et al. now identify Tudor-SN, an endonuclease that interacts with the RNA-induced silencing complex. Tudor-SN targets miRNAs at CA and UA dinucleotides located more than five nucleotides from miRNA ends. Tudor–SN-mediated miRNA decay removes miRNAs that silence genes encoding proteins that are critical for the G1-to-S phase transition in the cell cycle.

    Science, this issue p. 859

  7. Neuroscience

    A neuronal circuit for overeating

    1. Peter Stern

    Mice can be stimulated to binge-eat high-fat food.

    PHOTO: ANTHONY VAN DEN POL

    Recurrent binge eating is a common eating disorder. Zhang and van den Pol investigated an understudied brain region known as the zona incerta and found that it projects inhibitory inputs to the paraventricular thalamus, a brain region involved in suppressing feeding behavior. In mice, acute stimulation of this inhibitory projection resulted within seconds in overeating, especially high-fat food. Chronic stimulation induced persistent overeating and weight gain.

    Science, this issue p. 853

  8. Protein Dynamics

    Trapping RNA polymerase in the act

    1. Valda Vinson

    The enzyme RNA polymerase (RNAP) finds promoter elements in the genome, separates (or “melts”) the DNA strands, and transcribes the template DNA strand to give RNA. A mobile clamp in RNAP plays a key role in initiating transcription. Feklistov et al. locked the clamp of bacterial RNAP in distinct conformations by using small molecules. They then used fluorescent probes to monitor binding as the promoter DNA was separated. Unexpectedly, they found that the clamp transiently closed to nucleate DNA melting, opened to load single-stranded DNA into the active site, and then closed around the template strand to start transcription.

    Science, this issue p. 863

  9. Cancer

    No safe haven for metastases

    1. Yevgeniya Nusinovich

    Although targeted therapies for cancer offer great promise, they are often much less effective against brain metastases than against peripheral tumors. This is generally attributed to the drugs' difficulty in penetrating the blood-brain barrier. Kodack et al. discovered that, at least in breast cancer that has spread to the brain, the brain microenvironment itself plays a role in treatment resistance. In mouse models and human cancer samples, human epidermal growth factor receptor 3 (HER3) expression increased in breast cancer–associated brain lesions. The HER3 facilitated the tumors' survival in the presence of targeted treatment. Thus, inhibiting HER3 could help overcome tumor resistance to therapy.

    Sci. Transl. Med. 9, eaal4682 (2017).

  10. Symbiosis

    Taking a look at plant-microbe relationships

    1. Caroline Ash

    Ever since plants colonized land, they have evolved a range of mutualistic associations with bacteria and fungi. Indeed, such associations were probably required for plants to grow on harsh, nutrient-poor surfaces. Martin et al. review the spectrum of plant-microbe symbioses and their evolution, including evidence from the Rhynie Chert of the Devonian period and modern associations. Surprisingly, diverse functional plant-microbial symbioses have several common conserved features, including signaling pathways, immune evasion, and root development.

    Science, this issue p. eaad4501

  11. Proteomics

    Mapping the proteome

    1. Valda Vinson

    Proteins function in the context of their environment, so an understanding of cellular processes requires a knowledge of protein localization. Thul et al. used immunofluorescence microscopy to map 12,003 human proteins at a single-cell level into 30 cellular compartments and substructures (see the Perspective by Horwitz and Johnson). They validated their results by mass spectroscopy and used them to model and refine protein-protein interaction networks. The cellular proteome is highly spatiotemporally regulated. Many proteins localize to multiple compartments, and many show cell-to-cell variation in their expression patterns. Presented as an interactive database called the Cell Atlas, this work provides an important resource for ongoing efforts to understand human biology.

    Science, this issue p. eaal3321; see also p. 806

  12. Graphene

    Flicking the Berry phase switch

    1. Jelena Stajic

    When an electron completes a cycle around the Dirac point (a particular location in graphene's electronic structure), the phase of its wave function changes by π. This so-called Berry phase is tricky to observe directly in solid-state measurements. Ghahari et al. built a graphene nanostructure consisting of a central region doped with positive carriers surrounded by a negatively doped background. Scanning tunneling spectroscopy revealed sudden jumps in conductivity as the external magnetic field was increased past a threshold value. The jumps occurred when electron orbits started encompassing the Dirac point, reflecting the switch of the Berry phase from zero to π. The tunability of conductivity by such minute changes in magnetic field is promising for future applications.

    Science, this issue p. 845

  13. Conservation

    Who needs to know where species live?

    1. Julia Fahrenkamp-Uppenbrink

    Poaching of endangered species is contributing to the loss of biodiversity around the world. In an Essay, Lindenmayer and Scheele argue that publication of location data for endangered or newly discovered species can increase the threats from poaching and can accelerate habitat destruction when nature enthusiasts travel to the sites. To avoid unwittingly contributing to further species decline, researchers, journal editors, and data custodians should take these threats into account when deciding whether to publish full location and habitat information for endangered species.

    Science, this issue p. 800

  14. Economics

    Unintended victims of fighting corruption

    1. Julia Fahrenkamp-Uppenbrink

    Corruption comes in many guises, from bribery to false accounting. But efforts to combat corruption can have unintended consequences as those who benefitted from the original corruption adapt to and exploit the new systems. In a Perspective, Fisman and Golden highlight two recent studies that show how such unintended consequences can arise. In one study, preventing fraudulent accounting by shopkeepers accepting welfare vouchers in the United States led to higher prices for all customers for products covered by the vouchers. In another, preventing large-scale cheating in high school exit exams in Romania led to fewer low-income students being accepted at universities. Anticorruption programs must be designed to avoid such negative effects, particularly on low-income groups.

    Science, this issue p. 803

  15. Cancer

    Creating a weakness in prostate cancer

    1. Leslie K. Ferrarelli

    Breast cancer cells with BRCA mutations are selectively vulnerable to PARP inhibitors, but these mutations are less frequent in other types of cancer. Li et al. found that androgen receptor inhibition decreased BRCA1 expression in prostate cancer cells. In a mouse model of prostate cancer, treatment first with the androgen receptor inhibitor, then with a PARP inhibitor, suppressed tumor growth better than when either drug was used alone or when both drugs were administered simultaneously. Thus, a BRCA-deficient state could be induced therapeutically to increase the utility of PARP inhibitors, not only for prostate cancer but also for other cancers lacking BRCA mutations.

    Sci. Signal. 10, eaam7479 (2017).