Editors' Choice

Science  16 Mar 2018:
Vol. 359, Issue 6381, pp. 1228
  1. Vocal Behavior

    Speaking in parts

    1. Sacha Vignieri

    Marmoset phee calls occur in units, like human speech.

    PHOTO: SAAD315/SHUTTERSTOCK

    The complexity of human speech is an anomaly among primates, where calls have typically been thought of as stereotyped and not variable. Recent work has shown that there is more learning and control present in nonhuman primate vocalizations than previously believed, but adult calls have nevertheless seemed to be stable. Pomberger et al. interrupted calling marmosets with acoustic playbacks triggered by their own calls and found that the animals could extend their “phee” calls beyond normal lengths by restarting them rapidly after perturbation, but they could only alter their calls at periodic time points. These results suggest that the phee call is not one long stereotyped series, but rather is composed of small sequential segments, like human speech.

    Curr. Biol. 10.1016/j.cub.2018.01.070 (2018).

  2. Microbiota

    Predicting fecal transplant success

    1. Caroline Ash

    Consumption of fecal matter is taboo, unless you have a life-threatening disease, such as Clostridium difficile infection. In these cases, fecal microbiota transplantation (FMT) is extraordinarily effective at restoring gut function to a healthier state. However, FMT does not work so well for other indications that are less strongly associated with the microbiota. We have a weak understanding of what factors allow microbial engraftment in the gut. Smillie et al. took genomic data from FMT-treated C. difficile patients to build a machine-learning statistical model that tells us which bacterial strains will engraft. The main predictive factors are abundance of a strain in the donor and the species present in the patient. Donor strains whose species are also present in the patient always engraft. If the taxa are discordant, then it appears that microbial interactions prevent engraftment.

    Cell Host Microbe 10.1016/j.chom.2018.01.003 (2018).

  3. Molecular Biology

    Secrets of CRISPR enzymes revealed

    1. Steve Mao

    CRISPR-Cas9 cleaves DNA, enabling genome editing. Surprisingly, three studies have concurrently uncovered an intrinsic RNA cutting activity of Cas9. Cas9 cuts endogenous RNA in some bacteria and, when programed, targets RNA in test tubes as well. Strutt et al. showed that Cas9 expression in a heterologous bacterium protects against infection by an RNA virus. Rousseau et al. showed that the activity can be switched off by virus-derived anti-Cas9 proteins. Dugar et al. profiled the cellular RNAs that are subjected to endogenous Cas9 targeting. Although how it is used to fend off intruders or regulate gene expression by bacteria remains to be investigated, this newly identified activity of Cas9 provides an exciting tool in our increasing arsenal for modulating RNA metabolism.

    eLife 10.7554/eLife.32724 (2018); Mol. Cell. 10.1016/j.molcel.2018.01.025, 10.1016/j.molcel.2018.01.032 (2018).

  4. Linguistics

    Tracking expanding dimensions of words

    1. Barbara R. Jasny

    Language can evolve by adding new meanings or “senses” to old words. Thus, the word “face” can refer to the body part or the front surface of a cliff. There are several theories regarding how new senses of words arise historically. Ramiro et al. used an algorithmic approach to study 5000 English words taken from a digital historical dictionary that covers word usage from Anglo-Saxon times to the present. They found that one model—nearest-neighbor chaining—predominates, possibly because it minimizes the cognitive costs of communicating new ideas.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1714730115 (2018).

  5. Tumor Immunology

    Tumor sensing by the immune system

    1. Lisa D. Chong

    The idea that innate lymphoid cells (ILCs) play a role in cancer is of interest because these immune cells respond to IL-33, a cytokine proposed to regulate cancer development. Saranchova et al. report that the subgroup called ILC2s may limit tumor growth rate and metastasis. In a mouse model engineered to lack ILC2s, lung cancer cells implanted into the leg enlarged more rapidly than in mice expressing ILC2s. Moreover, in the absence of ILC2, cancer cells spread to other tissues, including the lung, brain, and adrenal gland. The authors propose that IL-33 released by the cancer cells locally stimulates ILC2s, which in turn produce other cytokines that promote an immune response to cancer, limiting its growth and spread.

    Sci. Rep. 10.1038/s41598-018-20608-6 (2018).

  6. Plant Morphology

    Plant puzzle patterns

    1. Andrew M. Sugden

    Jigsaw patterning in plant cells counters mechanical stress.

    CREDIT: A. SAPALA ET AL., ELIFE 10.7554/ELIFE.32794 (2018)

    The epidermal cells of plants have a jigsaw-like appearance when viewed microscopically. What is the function of this intricate pattern, and how does it arise? Sapala et al. suggest that the interlocking arrangement reduces mechanical stress in the cell wall—stress that arises from the turgor pressure from within. Simulation modeling and observations of several plant species and organs show that as growth proceeds, stress causes localized cellulose deposition, leading to small surface indentations in cell walls that gradually develop into the jigsaw pattern.

    eLife 10.7554/eLife.32794 (2018).

  7. Climate Change

    Seeing the human hand

    1. H. Jesse Smith

    Environmental temperature changes occur both naturally and because of human activity (anthropogenic global warming), and distinguishing those two types is difficult. Wills et al. present a method that can be used to make that distinction for Pacific sea surface temperatures, which allows them to identify the separate effects of global warming, the Pacific Decadal Oscillation (PDO), and the El Niño–Southern Oscillation. They do this on the basis of differences in time scale and spatial pattern, which enables them to circumvent the use of climate models. Among other results, they find that midlatitude PDO anomalies are more persistent than previously thought.

    Geophys. Res. Lett. 10.1002/2017GL076327 (2018).