Editors' Choice

Science  21 Dec 2018:
Vol. 362, Issue 6421, pp. 1373
  1. Migration

    The importance of lugworms

    1. Sacha Vignieri

    Bar-tailed godwits, Limosa lapponica, feed faster on lugworms during shorter winters.

    PHOTO: AGAMI PHOTO AGENCY/ALAMY STOCK PHOTO

    As the climate warms, Arctic ice melts are occurring earlier in spring, and earlier ice melt means an early Arctic summer. For birds that migrate to the poles from temperate and tropical regions to breed, seasonal shifts represent a notable challenge to reproductive physiology. Rakhimberdiev et al. show that a wading bird called a bar-tailed godwit can arrive on the breeding grounds earlier in the year by shortening its over-wintering time by reducing the time it spends on the refueling grounds in the Wadden Sea of northwestern Europe. Increased rates of feeding, especially on lugworms, can compensate for a shorter feeding season. However, mortality is extensive if food sources become scarce, with one major factor being mechanized human harvest of lugworms in the Wadden Sea.

    Nat. Comm. 9, 4263 (2018).

  2. Physiology

    Targeting brown fat to make less fat

    1. L. Bryan Ray

    Heat production by brown fat cells (shown) might reduce appetite.

    IMAGE: STEVE GSCHMEISSNER/SCIENCE SOURCE

    Brown fat can release energy from food as heat instead of storing it and could thus help in battling obesity. Li et al. found that after a meal, brown fat in mice was stimulated to increase thermogenesis by direct action of the gut hormone secretin. The heat produced may be detected by the brain and thus induce a sense of satiety. This signaling relay may increase energy expenditure and decrease appetite, making it a potential target for therapies that attempt to control obesity.

    Cell 175, 1561 (2018).

  3. Immunology

    Lymph node mass transport

    1. Seth Thomas Scanlon

    Cytokines are transported around the body via a network of lymph ducts and lymph nodes. Conduits within lymph nodes convey cytokines from the subcapsular sinus (SCS) into the deep parenchyma. From there, they discharge into high endothelial venules. In the SCS, sinus-lining cells prevent molecules greater than 70 kilodaltons from entering conduits. Nevertheless, Thierry et al. found that the massive 970-kilodalton pentamers of immunoglobulin M antibodies can cross into conduits. Transport is mediated by transient, activated, antigen-specific B cells, thus enabling rapid mobilization of the first wave of antibodies produced during an acute infection.

    J. Exp. Med. 215, 2972 (2018).

  4. Virology

    Revelation in the gut virome

    1. Caroline Ash

    Some of the trillions of bacteria in the human gut are beginning to disclose their secrets. By contrast, we know little about the viruses other than that there are even more of them and most parasitize bacteria and other microbiota. Guerin et al. systematically investigated fecal DNA bacteriophages called crAssphages, which appear to infect Bacteroidetes. These phages are found in about half of individuals, constitute 90% of fecal DNA, and show differences in health and disease (for example, in malnourished infants). crAssphage genes tend not to match known sequences, but, through the use of a variety of methods on almost 100 complete circular genomes extracted from more than 700 human gut microbiota, four crAssphage subfamilies were found, each composed of 10 genera and with short-tailed icosahedral podovirus structures.

    Cell Host Microbe 24, 653 (2018).

  5. Bioorganic Chemistry

    Electrochemically clicking on tyrosine

    1. Phil Szuromi

    Proteins are readily modified at lysine or cysteine residues, but for the other amino acids, general methods still need to be developed. For example, for electron-rich tyrosine, click methods have been developed based on cyclic diazodicarboxyamide anchors, but activation with chemical oxidants can also modify lysine residues or create products with limited aqueous stability. Alvarez-Dorta et al. show that tyrosine residues on proteins, including insulin and bovine serum albumin, can be targeted by electrochemically oxidizing phenyl urazoles without affecting amine or thiol groups of other amino acids. A reactive N=N species generated in the five-membered ring reacts with the C–H bonds adjacent to the tyrosine OH group.

    J. Am. Chem. Soc. 140, 17120 (2018).

  6. Materials Science

    Connecting the dots

    1. Marc S. Lavine

    Much of the power of chemistry comes from the wide range of methods that can be used to connect atoms and molecules selectively at desired positions. Colloidal nanoparticles offer their own range of tunable properties that can be enhanced by connecting them together into superstructures through the bonding of their oligomeric surface ligands. Chen et al. developed a method using a block copolymer and solvent to selectively cover part of the nanoparticles, creating a mask for subsequent attachment of DNA. The coverage of the particles can be tuned by adjusting the ratio of hydrophilic to hydrophobic ligand, because this changes the way the ligands pack on the surface of the nanoparticles.

    Nat. Mater. 10.1038/s41563-018-0231-1 (2018).

  7. Diversity in Stem

    With role models come persistence

    1. Melissa McCartney

    Role model programs centered on women and underrepresented groups have been successful for early career scientists, but are they successful for undergraduate students? Hernandez et al. describe PROGRESS, a role modeling and mentoring program aimed at supporting undergraduate women in the geosciences, a historically male-dominated field. PROGRESS participants reported higher rates of persistence in geoscience-related majors, which was related to the number of female STEM career role models that they were able to identify; participants' odds of persisting in geoscience approximately doubled for each role model identified. The preliminary evidence suggests that presenting undergraduate students with successful female role models can encourage undergraduates to believe that they, too, can be successful scientists.

    Geosphere 14, 2585 (2018).

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