This Week in Science

Science  20 Nov 2015:
Vol. 350, Issue 6263, pp. 923
  1. Camouflage

    Disappearing act

    1. Sacha Vignieri

    A small school of silvery lookdown fish (Selene vomer)

    PHOTO: © SANTIAGO URQUIJO/OCEAN/CORBIS

    Unlike coastal regions and reefs, the open ocean is mostly empty. Many fish species, nonetheless, spend most of their lives there. Such emptiness makes camouflage exceedingly difficult, so how does an organism hide in water filled with bouncing and reflected light? Brady et al. show that some families of fish have evolved skin that reflects and polarizes light, allowing them to blend into their mirrorlike conditions more easily. These results help to explain the silvery coloration found in sea-living fish across the world's oceans.

    Science, this issue p. 965

  2. Cancer

    Blocking transcription in tumors, STAT

    1. Yevgeniya Nusinovich

    STAT3 is a transcription factor known to contribute to many cancers, but it is very difficult to target with conventional drugs. Taking an alternative approach, Hong et al. used antisense molecules that bind to messenger RNA to prevent STAT3 protein from being made. The potent antisense molecules penetrated cells without being dissolved in lipid. One new antisense drug, AZD9150, successfully inhibited cancer in a variety of preclinical models, as well as in cancer patients for whom one or more previous treatments had failed. These findings pave the way for additional clinical testing.

    Sci. Transl. Med. 7, 314ra185 (2015).

  3. Parasitology

    Parasitic worms influence human fecundity

    1. Caroline Ash

    Bolivian women surrounded by their children

    PHOTO: MICHAEL GURVEN

    Parasitic worms infect 2 billion people globally. Mostly, such infections are symptomless and individual worm burdens are low. Blackwell et al. monitored the fecundity of Tsimane women in Bolivia. These women have on average of 10 children in their lifetimes. However, if they had successive hookworm infections, lifetime births dropped to 7. Surprisingly, if the women were chronically infested with roundworm, they had as many as 12 children. These effects may relate to the balance of immune responses that the different worms induce, rather than to the physiological costs of parasitism.

    Science, this issue p. 970

  4. Solar Cells

    Perovskites go large

    1. Phil Szuromi

    Solar cells made of planar organic-inorganic perovskites now have reported efficiencies exceeding 20%. However, these values have been determined from small illuminated areas. Chen et al. used highly doped inorganic charge extraction layers to make solar cells on the 1 cm2 scale (see the Perspective by Sessolo and Bolink). The layers helped to protect the active layer from degradation by air. The cells achieved governmentlab–certified efficiencies of >15%. Furthermore, 90% of the efficiency was maintained after 1000 hours of operation.

    Science, this issue p. 944; see also p. 917

  5. Superconductivity

    Discerning charge patterns in a cuprate

    1. Jelena Stajic

    Copper oxides are well known to be able to achieve the order required for superconductivity. They can also achieve another order—one that produces patterns in their charge density. Experiments using nuclear magnetic resonanceand resonant x-ray scattering have both detected this so-called charge density wave (CDW) in yttrium-based cuprates. However, the nature of the CDW appeared to be different in the two types of measurement. Gerber et al. used pulsed magnetic fields of up to 28 T, combined with scattering, to bridge the gap (see the Perspective by Julien). As the magnetic field increased, a two-dimensional CDW gave way to a three-dimensional one.

    Science, this issue p. 949; see also p. 914

  6. Biological Materials

    A set of strong eyes

    1. Marc S. Lavine

    Although many biological tissues serve more than one purpose, rarely are they optimized to do multiple tasks well. When you try to optimize for one functionality, it comes at the expense of another. Li et al. investigated the biomineralized armor of the small mollusc chiton Acanthopleura granulata. The armor appears to be optimized for both mechanical strength and for image capture by hundreds of integral aragonite-based lenses.

    Science, this issue p. 952

  7. Cancer Immunology

    Monocytes block tumor access to the lung

    1. Kristen L. Mueller

    Tumor cells (red) in mouse lungs recruit patrolling monocytes (green)

    PHOTO: RICHARD N. HANNA, LA JOLLA INSTITUTE FOR ALLERGY AND IMMUNOLOGY

    Metastatic cancer is especially hard to treat. In order to find potential new therapeutic targets, scientists are trying to understand the cellular events that promote or prevent metastasis. Hanna et al. now report a role for patrolling monocytes in blocking tumor metastasis to the lungs in mice. Tumors in mice engineered to lack patrolling monocytes showed increased metastasis to the lung but not to other tissues. Patrolling monocytes resided in the microvasculature of the lung, where they engulfed tumor material, which may explain how these cells prevent tumors from colonizing the lung.

    Science, this issue p. 985

  8. Sleep Research

    Neurons that regulate sleep stages

    1. Peter Stern

    Just what sleep is for remains a bit of a mystery. During sleep, we switch several times between so-called rapid eye movement (REM) and non-REM sleep. Hayashi et al. used sophisticated developmental cell fate mapping to look at the neurons involved in the two types of sleep in mice (see the Perspective by Vyazovskiy). They identified a genetically marked population of neurons that promote non-REM sleep at the expense of REM sleep.

    Science, this issue p. 957; see also p. 909

  9. Plant Biotechnology

    Would an electrical rose still smell as sweet?

    1. Zakya H. Kafafi

    Can electricity and plants be mixed? Stavrinidou et al. built key electronic components using conducting polymers inside roses. They based their approach on the similarity between roots, stems, leaves, and vascular circuitry in plants; and contacts, interconnections, devices, and wires in electronic circuits. This technology may lead to new ways of monitoring and regulating plant physiology, of harvesting energy from photosynthesis, and of achieving genetic modification for plant optimization. Thus, the term “power plant” may soon have a new meaning!

    Sci. Adv. 10.1126.sciadv.01136 (2015).

  10. Neurodevelopment

    Help for neurodevelopmental disorders

    1. Pamela J. Hines

    When the brain does not develop normally, the disabilities that ensue can affect a person for life. Sahin and Sur review how emerging knowledge of the molecular biology behind a suite of neurodevelopmental disorders is shedding light on the group as a whole. The new knowledge offers tantalizing leads toward more effective therapies.

    Science, this issue p. 10.1126/science.aab3897

  11. Stem Cell Regulation

    Notch role in multipotency or cell fate

    1. Beverly A. Purnell

    Multipotent Drosophila intestinal stem cells (ISCs) generate either nutrient-absorbing enterocytes (ECs) or secretory enteroendocrine cells (EECs). Guo and Ohlstein investigated the role of Notch signaling in this process. They tracked ISC asymmetric divisions and found that EEC daughter cells, which have a low level of Notch, signal back to the ISC in order to keep it multipotent. However, during EC production, ISCs activate strong Notch signaling in daughters. Thus, Notch signaling functions in two directions to achieve stem cell multipotency.

    Science, this issue p. 10.1126/science.aab0988

  12. Nonhuman Genetics

    Recombination: The birds and the yeast

    1. Laura M. Zahn

    Apes and mice have a specific gene, PRDM9, that is associated with genomic regions with high rates of recombination, called hotspots. In species with PRDM9, hotspots move rapidly within the genome, varying among populations and closely related species (see the Perspective by Lichten). To investigate recombination hotspots in species lacking PRDM9, Singhal et al. examined bird genomes, which lack a PRDM9 gene. They looked closely at the genomes of finch species and found that recombination was localized to the promoter regions of genes and highly conserved over millions of years. Similarly, Lam and Keeney examined recombination localization within yeast, which also lacks PRDM9. They found a similar more-or-less fixed pattern of hotspots. Thus, recombination in species lacking a PRDM9 gene shows similar patterns of hotspot localization and evolution.

    Science, this issue p. 913, p. 928; see also p. 932

  13. Batteries

    A concentrated effort for battery safety

    1. Marc S. Lavine

    Aqueous electrolytes are limited to run below 1.23 V to avoid degradation. Suo et al. smash through this limit with an aqueous salt solution containing lithium (Li) bis(trifluoromethane sulfonyl)imide to create an electrolyte that has an electrochemical window of 3 V (see the Perspective by Smith and Dunn). They used extremely high-concentration solutions, which suppressed hydrogen evolution and electrode oxidation. At these concentrations, the Li solvation shell changes because there simply is not enough water to neutralize the Li+ charge. Thus, flammable organic electrolytes could potentially be replaced with a safer aqueous alternative.

    Science, this issue p. 938; see also p. 918

  14. Axon Guidance

    No going back

    1. Pamela J. Hines

    The mammalian spinal cord coordinates neuronal systems across the body. Axons that cross the spinal cord midline during development first need permission to cross and then instruction not to keep crossing back and forth. Jaworski et al. studied the axonal guidance receptor ROBO3 and found a ligand NELL2 in mice that appears to help in this process.

    Science, this issue p. 961

  15. Gene Regulation

    Noncoding RNA helps protein binding

    1. Beverly A. Purnell

    Besides reading the coding regions of genes, RNA polymerase generates RNA at promoter-proximal and -distal DNA elements, but the function of these molecules is largely unknown. Sigova et al. show that these RNAs facilitate interactions between gene regulators and the regulatory elements they occupy. Nascent RNA associates with the transcription factor YY1 and increases its ability to bind DNA. Thus, transcription at active regulatory elements may provide a positive feedback loop that reinforces regulatory elements contributing to the stability of gene expression programs.

    Science, this issue p. 978

  16. Immunology

    Establishing a longtime residency

    1. Kristen L. Mueller

    Innate lymphoid cells (ILCs) are a subset of immune cells that promote barrier immunity in tissues such as the gut and lungs and help to maintain immune homeostasis. Gasteiger et al. investigated how the body maintains its pools of ILCs in such peripheral tissues, as well as in immune tissues such as the lymph nodes and the spleen. In mice surgically joined to share their bloodstreams, unlike lymphocytes, most ILCs did not circulate through the blood. Instead, ILCs resided long term in tissues, even in the face of inflammation or infection.

    Science, this issue p. 981

  17. Cancer Immunology

    How dying tumor cells get noticed

    1. Kristen L. Mueller

    Besides killing tumor cells directly, some chemotherapies, such as anthracyclines, also activate the immune system to kill tumors. Vacchelli et al. discovered that in mice, anthracycline-induced antitumor immunity requires immune cells to express the protein formyl peptide receptor 1 (FPR1). Dendritic cells (DCs) near tumors expressed especially high amounts of FPR1. DCs normally capture fragments of dying tumor cells and use them to activate nearby T cells to kill tumors, but DCs lacking FPR1 failed to do this effectively. Individuals with breast or colon cancer expressing a variant of FPR1 and treated with anthracyclines showed poor metastasis-free and overall survival. Thus, FPR1 may affect anti-tumor immunity in people, too.

    Science, this issue p. 972

  18. Geology

    Pioneer of plate tectonics

    1. Julia Fahrenkamp-Uppenbrink

    Why do the contours of Earth's continents fit together like a puzzle? 100 years ago, Alfred Wegener argued in his famous monograph on “continental drift” that all continents were once part of one supercontinent. In a Perspective, Romano and Cifelli chart the history of this theory, which is now called plate tectonics. At first derided by most scientists, plate tectonics became widely accepted in the 1960s as supporting evidence accumulated. Today, the theory is universally accepted. Scientists are even looking for signs of plate tectonics on other planets beyond the solar system.

    Science, this issue p. 915

  19. Cancer

    Targeting drug-resistant prostate tumors

    1. Leslie K. Ferrarelli

    The activity of the mTOR pathway is often increased in various cancers. Hsieh et al. found that the levels of 4EBP1, an mTOR target that inhibits protein synthesis, determined whether different cell types in prostate tumors were resistant to an mTOR inhibitor. Compared to basal cells, luminal prostate epithelial cells expressed more 4EBP1, synthesized protein at lower rates, and were less sensitive to the mTOR inhibitor. Decreasing 4EBP1 levels suppressed resistance to the mTOR inhibitor, so co-targeting 4EBP1 may improve therapeutic outcomes for prostate cancer patients.

    Sci. Signal. 8, ra116 (2015).

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