This Week in Science

Science  04 Nov 2016:
Vol. 354, Issue 6312, pp. 593
  1. Vascular Biology

    Keeping hearts and blood vessels young

    1. Wei Wong

    Superoxide generation visualized in a mouse aorta

    CREDIT: MEYER ET AL.

    Activation of the G protein–coupled receptor GPER is thought to confer cardiovascular benefits. Unexpectedly, Meyer et al. found that aged mice that were deficient in Gper did not develop as much cardiac fibrosis as aged mice in the control group and retained greater cardiovascular function. Gper deficiency was associated with reduced production of tissue-damaging superoxide in blood vessels and the myocardium. A GPER-blocking drug reduced blood pressure and superoxide production in hypertensive mice, suggesting that GPER inhibitors could be used to treat cardiovascular diseases caused by excessive superoxide generation.

    Sci. Signal. 9, ra105 (2016).

  2. Chemical Biology

    Radicals push proteins beyond genes

    1. Nicholas S. Wigginton

    Chemically modifying proteins after their translation can expand their structural and functional roles (see the Perspective by Hofmann and Bode). Two related methods describe how to exploit free radical chemistry to form carbon-carbon bonds between amino acid residues and a selected functional group. Wright et al. added a wide range of functional groups to proteins containing dehydroalanine precursors, with borohydride mediating the radical chemistry. Yang et al. employed a similar approach, using zinc in combination with copper ions. Together, these results will be useful for introducing functionalities and labels to a wide range of proteins.

    Science, this issue pp. 597 and 623; see also p. 553

  3. Physics

    Exotic molecule tests fundamental symmetry

    1. Jelena Stajic

    Spectroscopy of exotic molecules can offer insight into fundamental physics. Hori et al. studied the transition frequencies of an unusual helium atom in which one of the two electrons was substituted by an antiproton, the negatively charged antiparticle partner of the proton (see the Perspective by Ubachs). The antiprotonic helium was cooled down to low temperatures to allow the frequencies to be measured with high precision. The extracted mass of the antiproton (relative to the electron mass) was in good agreement with previous measurements of the proton mass. This finding is in keeping with the implications of the combined charge, parity, and time-reversal symmetry of physical laws.

    Science, this issue p. 610; see also p. 546

  4. Cancer Etiology

    Assessing smoke damage in cancer genomes

    1. Paula A. Kiberstis

    Cigarette smoking produces a variety of mutational signatures.

    CREDIT: LUCKY STRIKE CIGARETTES PACK (B/W PHOTO)/UNDERWOOD ARCHIVES/UIG/BRIDGEMAN IMAGE

    We have known for over 60 years that smoking tobacco is one of the most avoidable risk factors for cancer. Yet the detailed mechanisms by which tobacco smoke damages the genome and creates the mutations that ultimately cause cancer are still not fully understood. Alexandrov et al. examined mutational signatures and DNA methylation changes in over 5000 genome sequences from 17 different cancer types linked to smoking (see the Perspective by Pfeifer). They found a complex pattern of mutational signatures. Only cancers originating in tissues directly exposed to smoke showed a signature characteristic of the known tobacco carcinogen benzo[a]pyrene. One mysterious signature was shared by all smoking-associated cancers but is of unknown origin. Smoking had only a modest effect on DNA methylation.

    Science, this issue p. 618; see also p. 549

  5. Vaccines

    Rejuvenating viral vectors

    1. AC

    Adenoviral (Ad5) vaccine vectors elicit mixed responses: They induce protective CD8+ T cells, but these cells may be partially exhausted. Now Larocca et al. demonstrate that this exhausted phenotype may result from Ad5 vector–induced antigen-specific CD4+ T cells that express interleukin-10 (IL-10) and PD-1 in both mice and macaques. These IL-10+ CD4+ T cells suppress the vaccine-induced CD8+ T cell response, and their inhibitory function may depend in part on IL-27. Targeting this inhibitory pathway may thus enhance protection of viral vector–based vaccines.

    Sci. Immunol. 1, eaaf7643 (2016).

  6. Optics

    Shrinking spectrometers

    1. Ian S. Osborne

    Dual-comb spectroscopy is a powerful technique that uses the interference of two closely related combs to map spectroscopic features directly into a frequency domain that can be read by electronics. Suh et al. developed a dual-comb spectroscopy approach using combs produced by silica microresonators fabricated on a silicon chip. Perhaps high-resolution spectroscopy will soon be shrunk to the chip scale, doing away with the need for bulky spectrometers.

    Science, this issue p. 600

  7. Ocean Chemistry

    Uranium in the deep sea

    1. H. Jesse Smith

    The ratio of 234U to 238U in seawater underlies modern marine uranium-thorium geochronology, but it is difficult to establish the ratio precisely. Chen et al. report two 234U/238U records derived from deep-sea corals (see the Perspective by Yokoyama and Esat). The records reveal a number of important similarities to and differences from existing records of the past 30,000 years. Higher values during the most recent 10,000 years than during earlier glaciated conditions may reflect enhanced subglacial melting during deglaciation.

    Science, this issue p. 626; see also p. 550

  8. Neuroregeneration

    Spinal cord regeneration in zebrafish

    1. Pamela J. Hines

    Unlike humans, zebrafish can regenerate their spinal cord. Mokalled et al. identified a growth factor in zebrafish that helps this process (see the Perspective by Williams and He). The protein encoded by ctgfa (connective tissue growth factor a) is secreted after injury and encourages glial cells to form a bridge across the spinal lesion. Addition of this protein improved spinal cord repair in injured zebrafish.

    Science, this issue p. 630; see also p. 544

  9. Plant Science

    Soil microbes yield insecticidal peptide

    1. Pamela J. Hines

    The microbial peptide BT, derived from the bacterium Bacillus thuringiensis, is widely used to protect crops from insect pests. Schellenberger et al. identified another insecticidal peptide from a different soil-dwelling bacterium, Pseudomonas chlororaphis (see the Perspective by Tabashnik). Corn plants expressing the Pseudomonas peptide were protected from attack by western corn rootworm. Rootworms that were resistant to BT were susceptible to the Pseudomonas peptide. Addition of another insecticidal peptide diversifies the arsenal against insect pests, which may slow down the development of resistance.

    Science, this issue p. 634; see also p. 552

  10. Science Community

    Scientific impact—that is the Q

    1. Barbara R. Jasny

    Are there quantifiable patterns behind a successful scientific career? Sinatra et al. analyzed the publications of 2887 physicists, as well as data on scientists publishing in a variety of fields. When productivity (which is usually greatest early in the scientist's professional life) is accounted for, the paper with the greatest impact occurs randomly in a scientist's career. However, the process of generating a high-impact paper is not an entirely random one. The authors developed a quantitative model of impact, based on an element of randomness, productivity, and a factor Q that is particular to each scientist and remains constant during the scientist's career.

    Science, this issue p. 596

  11. Systems Biology

    Complex transcription factor interactions

    1. Laura M. Zahn

    To respond to environmental changes, such as drought, plants must regulate numerous cellular processes. Working in the model plant Arabidopsis, Song et al. profiled the binding of 21 transcription factors to chromatin and mapped the complex gene regulatory networks involved in the response to the plant hormone abscisic acid. The work provides a framework for understanding and modulating plant responses to stress.

    Science, this issue p. 598

  12. Yeast Genetics

    A global genetic suppression network

    1. Laura M. Zahn

    The genetic background of an organism can influence the overall effects of new genetic variants. Some mutations can amplify a deleterious phenotype, whereas others can suppress it. Starting with a literature survey and expanding into a genomewide assay, van Leeuwen et al. generated a large-scale suppression network in yeast. The data set reveals a set of general properties that can be used to predict suppression interactions. Furthermore, the study provides a template for extending suppression studies to other genes or to more complex organisms.

    Science, this issue p. 599

  13. Optical Processing

    Taking the pulse of optimization

    1. Ian S. Osborne

    Finding the optimum solution of multiparameter or multifunctional problems is important across many disciplines, but it can be computationally intensive. Many such problems defined as computationally difficult can be mathematically mapped onto the so-called Ising problem, which looks at finding the minimum energy configuration for an array of coupled spins. Inagaki et al. and McMahon et al. show that an optical processing approach based on a network of coupled optical pulses in a ring fiber can be used to model and optimize large-scale Ising systems. Such a scalable architecture could help to optimize solutions to a wide range of complex problems.

    Science, this issue pp. 603 and 614

  14. Autoimmunity

    TYK2's balancing act

    1. Orla M. Smith

    Determining the biological consequences of the thousands of genetic variants that contribute to common diseases is challenging. Genetic variants that influence autoimmune diseases have been identified in the gene encoding TYK2 (tyrosine kinase 2), but conflicting evidence regarding their biological impact obscures the therapeutic potential of TYK2. In resolving this conflict, Dendrou et al. have revealed a genetic effect that drives an optimal degree of immune signaling: low enough to be protective against autoimmunity but high enough to prevent immunodeficiency. These findings indicate that TYK2 may be a potential drug target in a number of autoimmune conditions.

    Sci. Transl. Med. 8, 363ra149 (2016).

  15. Conservation

    Can Europe's migratory birds be saved?

    1. Julia Fahrenkamp-Uppenbrink

    Many migratory birds breed in Europe and overwinter in sub-Saharan Africa. In a Perspective, Bairlein outlines several factors that are causing their populations to decline. Illegal takings and killings reduce populations, particularly during migration. Climate change causes ecological mismatches between birds and their insect prey. But, perhaps most importantly, human land-use changes are causing habitat degradation and loss in the birds' breeding and winter habitats, as well as along their migration routes. Political agreements and action plans are already in place but must be implemented to halt the population declines and avoid species extinctions.

    Science, this issue p. 547

  16. Quantum Gases

    Shaking the lattice uncovers universality

    1. Jelena Stajic

    Most of our knowledge of quantum phase transitions (QPTs)—which occur as a result of quantum, rather than thermal, fluctuations—comes from experiments performed in equilibrium conditions. Less is known about the dynamics of a system going through a QPT, which have been hypothesized to depend on a single time and length scale. Clark et al. confirmed this hypothesis in a gas of cesium atoms in an optical lattice, which was shaken progressively faster to drive the gas through a QPT.

    Science, this issue p. 606

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