Editors' Choice

Science  22 Jul 2016:
Vol. 353, Issue 6297, pp. 360
  1. Evolution

    How fish evolved an abyssal glow

    1. Caroline Ash

    Bioluminescence, as seen in this moray eel, has evolved many times.

    PHOTO: ©WATERFRAME/ALAMY STOCK PHOTO

    The darkness of the deep sea presents a particular challenge for fish wanting to mate or eat. Rising to this selective challenge, fish inhabiting these deep waters have evolved—very many times, it turns out—an extraordinary array of luminescent appendages. Davis et al. amassed sequence data from almost 300 fish genera (representing about 1500 bioluminescent species) to determine the evolutionary origins, age, and patterns of diversity of this phenomenon. Bioluminescence in fish is due to either intrinsic biochemistry or symbiotic relationships with luminescent bacteria. Starting in the Early Cretaceous, intrinsic bioluminescence evolved eight times, and relationships with glowing bacterial symbionts have evolved on at least 17 occasions. This work substantially adds to the tally of independent evolutionary occurrences of bioluminescence.

    PLOS ONE 10.1371/journal.pone.0155154 (2016).

  2. Quality Control

    How cells take out the trash

    1. Stella M. Hurtley

    Misfolded proteins are generally sequestered and then degraded by one of a number of quality-control pathways within cells. Lysosomal enzymes in the endolysosomal system or proteasomes in the cytosol can do this. Lee et al. describe a rather unexpected way that some cells, when subjected to proteasomal insufficiency, deal with misfolded cytosolic proteins: They excrete them using an unconventional secretory pathway. The pathway involves an endoplasmic reticulum (ER)–associated deubiquitination enzyme, USP19. Somehow USP19 recognizes misfolded cytosolic proteins and delivers them to ER-associated endosomes, which then seem to spit out the aberrant proteins into the medium. How important or widespread this pathway is in normal physiology or disease remains to be seen.

    Nat. Cell Biol. 18, 765 (2016).

  3. Research Funding

    What price interdisciplinary research?

    1. Barbara R. Jasny

    Although interdisciplinarity is frequently considered to be the path that science is on, it can be rocky for its practitioners. The Australian Research Council Discovery Programme funds research nationally in all academic fields and requires applicants to categorize their proposals according to predefined discipline codes and the percent of the research described by that code. Bromham et al. adapted a measure of biodiversity to examine 18,476 proposals and found that interdisciplinarity was associated with a lower probability of funding. This was attributed to distance between the disciplines rather than the number of disciplines or differences between institutions. These results support suspicions that reviewers find it hard to evaluate interdisciplinary research.

    Nature 534, 684 (2016).

  4. Neurodevelopment

    A long noncoding RNA for neuronal differentiation

    1. Pamela J. Hines

    Noncoding RNAs regulate gene expression. Rani et al. used bioinformatic analysis to identify a long noncoding RNA with a role in neurodevelopment, LncND, that is specific to primates. Human neural progenitor cells expressed higher amounts of LncND compared with mature neurons. During neural development, LncND appears to act as a sponge for the microRNA miR-143-3p, which represses the expression of Notch proteins, key regulators of brain development. In a human cell line, reducing LncND, which allows more loose miR-143-3p and therefore reduces Notch signaling, caused precocious neuronal differentiation. In humans, deletions or mutations in LncND and its surrounding DNA are linked to multiple neurodevelopmental disorders, including intellectual disability, suggesting the importance of LncND to human disease.

    Expansion of radial glial cells in a mouse brain overexpressing LncND

    PHOTO: RANI ET AL., NEURON (15 JUNE 2016) © 2016 CELL PRESS

    Neuron 90, 1174 (2016).

  5. Arctic Sea Ice

    Change in the air

    1. H. Jesse Smith

    Sea ice near Kulusuk, Greenland

    PHOTO: ©INCAMERASTOCK/ALAMY STOCK PHOTO

    How does atmospheric circulation affect the initiation of seasonal melting of Arctic sea ice? Mortin et al. examined 35 years of satellite and meteorological data to tease out the general controls and explain the large annual variability in timing. They found that melt onset is triggered by high water vapor, clouds, and air temperatures, which act to increase the amount of long-wave radiation down-welling to the ice surface. Early melts occur when these conditions persist for weeks beforehand because of changes in springtime atmospheric moisture transport.

    Geophys. Res. Lett. 10.1002/2016GL069330 (2016).

  6. Education

    When leadership meets science

    1. Melissa McCartney

    Today's STEM (science, technology, engineering, and math) graduates will be tomorrow's leaders. Reed et al. have designed an integrated leadership curriculum aimed at increasing student awareness and understanding of what it takes to become a future STEM leader. The curriculum, which is now integrated into biology and chemistry courses at all levels, focuses on several areas where leadership skills and science competencies overlap, including problem-solving, interpersonal communication, and collaborative work. By allowing students multiple opportunities to practice these corresponding skills, the curriculum serves as a metacognitive approach for students to develop their abilities and commitment to leading others. The curriculum is broadly applicable to many different institutions and has the added benefit of encouraging interdisciplinary collaboration for faculty.

    J. Coll. Sci. Teach. 45, 51 (2016).

  7. Organic Chemistry

    Iron takes alcohols to carboxylic acids

    1. Jake Yeston

    The oxidation of alcohols to carboxylic acids is a widely practiced reaction in organic chemistry. Unfortunately, it often requires the use of metal oxides that generate wasteful, sometimes toxic byproducts. Jiang et al. report a mixture of three compounds—iron nitrate, the TEMPO radical, and potassium chloride—that catalyze this reaction for a wide range of substrates, using oxygen in air as the oxidant. The authors demonstrate cetyl alcohol oxidation at a 55-g scale. Preliminary studies of the mechanism implicate NO2 as an active participant in the reaction.

    J. Am. Chem. Soc. 10.1021/jacs.6b03948 (2016).

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