Editors' Choice

Science  10 Jul 2015:
Vol. 349, Issue 6244, pp. 151
  1. Development

    Planaria have model kidneys

    1. Beverly A. Purnell

    Protonephridia of the planarian excretory system

    PHOTO: H. T.-K. VU ET AL., ELIFE (9 JUNE 2015) © 2015 ELIFE SCIENCES PUBLICATIONS LTD.

    Individuals with polycystic kidney disease (PKD) develop fluid-filled cysts in their nephrons that interfere with kidney function. Looking for a suitable invertebrate model of PKD, Vu et al. discovered that the excretory system of planarian flatworms is a good model for normal and diseased human kidneys. The planarian protonephridia shares structural similarities with the subsegments of the vertebrate nephron, and both organisms use cilia-driven ultrafiltration and filtrate modification. Moreover, mutating planarian orthologs of human genes resulted in phenotypes and pathologies similar to those seen in human PKD.

    eLife 10.7554/eLife.07405 (2015).

  2. Influenza

    Geometry and virus evolution

    1. Caroline Ash

    An influenza pandemic is only a couple of mutations away. Or is it? Meyer and Wilke analyzed how the hemagglutinin protein of the H3 subtype of influenza has evolved, to learn how mutation allows this virus to escape host immune surveillance. This method combines sequencing data with data on protein structure and present and past antigenic sites (that is, sites recognized by antibodies) on hemagglutinin. Surprisingly, antigenic information revealed little, but the geometrical changes wrought by mutations in the host cell receptor-binding site did. This analysis indicates that mutation in sites that we understand to be antigenic may not influence how influenza evolves as much as previously assumed.

    PLOS Pathol. 11, e1004940 (2015).

  3. Cancer Therapy

    (Mis)matching tumors to immunotherapy

    1. Paula A. Kiberstis

    Despite the amazing success stories seen in some patients receiving cancer immunotherapy, the sobering reality is that not all patients or cancer types respond. For instance, colorectal cancer does not respond in the dramatic way that melanomas and other cancers do to the so-called “immune checkpoint inhibitors.” A subset of colorectal cancers cannot repair mismatched bases in DNA and therefore harbor high levels of somatic mutations. In a small clinical trial, Le et al. found that patients with mismatch repair–deficient colorectal tumors responded more favorably to an immune checkpoint inhibitor than those with mismatch repair–proficient tumors. The greater response observed in the former group is probably due to a higher abundance of mutation-associated neoantigens that boost antitumor immunity.

    N. Engl. J. Med. 372, 2509 (2015).

  4. Surface Chemistry

    Standing differently on nanoparticles

    1. Phil Szuromi

    Bonding of molecules on a metal surface might be expected to be the same whether the surface is a single crystal or a large nanoparticle. Yim et al. studied the adsorption of carbon monoxide (CO) on curved palladium (Pd) nanoparticles (20 to 30 nm across) grown on titanium dioxide and exposing the hexagonal (111) surface. They observed regions with CO in an atop bridge binding site with scanning tunneling microscopy, and tilting of CO from the surface normal in x-ray spectroscopy, features not seen on bulk Pd (111) surfaces. Theoretical calculations attribute these changes to strain in the nanoparticle.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1506939112 (2015).

    Lattice of supported Pd nanoparticles used to study CO adsorption

    PHOTO: C. M. YIM ET AL., PNAS 112 26, (30 JUNE 2015) © 2015 NATIONAL ACADEMY OF SCIENCES
  5. Animal Physiology

    How to weather a storm

    1. Sacha Vignieri

    Extreme weather causes sugar gliders to enter a torpid state

    PHOTO: DAVIDCALLAN/ISTOCKPHOTO

    Storms challenge animals with inclement conditions and reduced foraging opportunities. Generally, animals that cannot avoid a storm hunker down until it passes. The success of this strategy depends on whether the storm lasts longer than the animal's energy supplies. Species that can flexibly enter a torpid state are able to tip the scales, which suggests that such an ability is adaptive. Nowack et al. found that a population of sugar gliders, a small Australian marsupial, entered deep torpor during a severe cyclone event. The animals didn't just remain inactive, they actively decreased their metabolic rates, as is typical for true torpor but rare in this subtropical species.

    Sci. Rep. 10.1038/srep11243 (2015).

  6. Mercury Microbiology

    Microbes track pollution through time

    1. Nicholas S. Wigginton

    Genes present in buried lake sediments can help reconstruct how microbial ecosystems responded to past exposure to mercury. When atmospheric mercury transported around the globe is eventually deposited in terrestrial or aquatic environments, microorganisms control its cycling and bioaccumulation. Poulain et al. isolated ancient microbial DNA from sediments in remote subarctic lakes in the Hudson Bay Lowlands of Canada. The distribution of genes coding for mercuric reductase (merA), the primary enzyme involved in mercury detoxification, correlates with historical mercury deposition, including a rapid population shift at the onset of the Industrial Revolution.

    ISME J. 10.1038/ismej.2015.86 (2015).

  7. Education

    Making sure that inquiry is elementary

    1. Melissa McCartney

    Undergraduate childhood education majors are often taught science in a traditional lecture class, yet are expected to teach their future students using a hands-on approach. Steinberg et al. describe a threecourse sequence for education majors in which future teachers learn science content through interactive, inquiry-based lessons. The curriculum focuses less on scientific facts than on the scientific process. Future teachers are expected to make observations, ask questions, develop models, and reason scientifically. Assessments are problem-based and interactions during laboratory sessions are observed, methods that mirror the needs of future elementary school teachers. The result? Allowing future teachers to act as scientists improves their perceptions of the nature of science and how it is learned.

    J. Coll. Sci. Teach. 44, 51 (2015).

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