Editors' Choice

Science  10 Jul 2020:
Vol. 369, Issue 6500, pp. 155
  1. Plant Biology

    Getting to the root of a problem

    1. Stella M. Hurtley

    The model plant Arabidopsis thaliana is used to show how plant roots respond to and repair wounding.

    PHOTO: CUSTOM LIFE SCIENCE IMAGES/ALAMY STOCK PHOTO

    Plants are rooted to a spot; they cannot migrate away from sources of damage, except potentially by growth. If a plant's roots are damaged, then the plant has to restore them. Hoermayer et al. examined restorative root growth in the model plant Arabidopsis thaliana. They used single-cell tracing and live-cell imaging to visualize the processes by which roots perceive a wound and then coordinate their regrowth response. After laser wounding, collapsed damaged cells triggered the release of the plant growth hormone auxin next to the wound site. This in turn regulated cell expansion and restorative division as the root cells divided to fill in the wound in response to changes in turgor pressure. Interfering with auxin signaling leads to overproliferation and the formation of tumorous growths on the repaired roots.

    Proc. Natl. Acad. Sci. U.S.A. 117, 15322 (2020).

  2. Epidemiology

    Early warning signs

    1. Caroline Ash

    Modeling an emerging infectious disease is an inexact science. At an early stage of an epidemic, we only have sparse data, little knowledge of the mechanisms driving emergence, and an urgent need to devise control measures that will be effective. Using epidemiological incidence reports, Brett and Rohani have developed a detection algorithm for disease (re)emergence that is agnostic to the mechanisms involved. This supervised statistical learning algorithm was trained on data collected for mumps outbreaks in England and resurgent pertussis in the United States. The algorithm successfully anticipated reemergence of mumps 4 years in advance, which would have given plenty of time for mitigation efforts to be implemented. The algorithm also performed well for vector-borne diseases, including dengue in Puerto Rico, and predicted the rapid emergence of plague in Madagascar. The success of this approach stems from the common statistical properties of incidence data across disease emergence contexts and has obvious application for monitoring waves of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reemergence.

    PLOS BIOL. 18, e3000697 (2020).

  3. Neuroscience

    Monkeying with the piano

    1. Peter Stern

    Although macaques have the auditory anatomy for speech and making music, they do not speak because they lack control in the upper vocal tract.

    PHOTO: REINHARD DIRSCHERL/ALAMY STOCK PHOTO

    The anatomical organization of auditory cortical pathways in nonhuman primates (NHPs) shows remarkable similarities with humans. So why don't NHPs have a more speech-like communication system? Archakov et al. trained macaques to perform an auditory-motor task using a purpose-built piano. Mapping brain activity by functional magnetic resonance imaging showed that sound sequences activated the auditory midbrain and cortex. More importantly, sound sequences that had been learned by self-production also activated motor cortex and basal ganglia. This shows that monkeys can form auditory-motor links and that this is not the reason why they do not speak. Instead, the origin of speech in humans may have required the evolution of a command apparatus that controls the upper vocal tract.

    Proc. Natl. Acad. Sci. U.S.A. 117, 15242 (2020).

  4. Physiology

    DNA repair in the placenta

    1. Gemma Alderton

    The human developmental disorder called Cornelia de Lange syndrome (CdLS) is caused by mutations that impair the function of cohesin, a protein complex that is important for genome organization and DNA repair. Singh et al. examined placentation in mouse models of CdLS and found evidence of persistent DNA damage, exit from the cell cycle (senescence), and inflammatory cytokine production. This identifies DNA damage responses as an important facet of placenta homeostasis that can affect embryo health. Further studies are needed to determine whether DNA damage responses in the placenta affect embryo development more broadly.

    Dev. Cell 10.1016/j.devcel.2020.05.025 (2020).

  5. Education

    Getting active to increase equity

    1. Melissa McCartney

    Attrition and underrepresentation in science, technology, engineering, and math (STEM) go hand in hand. Part of this relationship is due to underrepresented students experiencing achievement gaps, especially in “gateway” courses. Theobald et al. investigated whether underrepresented students in active-learning classrooms experience narrower achievement gaps than underrepresented students in a traditional lecture course. The research team collected data on exam scores and failure rates for ∼54,000 students in both traditional lecturing and active-learning STEM courses taught by the same instructor. On average, active learning reduced achievement gaps in exam scores and passing rates and offered disproportionate benefits for underrepresented groups. These results provide more support for replacing traditional lecturing with active learning, which now has the added benefit of being a strategy for increasing equity in higher education.

    Proc. Natl. Acad. Sci. U.S.A. 117, 6476 (2020).

  6. Biomolecular Imaging

    Holding protein pairs in place

    1. Phil Szuromi

    Superresolution fluorescence imaging can determine where protein interactions occur in cells. However, this method can suffer from false positives because the detection of protein proximity is a function of optical resolution. Clowsley et al. ensured that the detected signals come from a particular pair of interacting proteins by using the DNA-PAINT (point accumulation imaging in nanoscale topography) method. In this method, proteins bind to two different antibodies that in turn are bound to DNA constructs. DNA-imaging strands are active only if the two constructs are close enough to enable DNA dimerization. This was used to image cardiac proteins in isolated cardiomyocytes with nanoscale resolution.

    J. Am. Chem. Soc. 10.1021/jacs.9b03418 (2020).

  7. Psychology

    Greater variability, greater punishment

    1. Tage S. Rai

    Prior research has linked unpredictability in outcomes to a heightened sense of vulnerability. It has also been found that feelings of vulnerability can generate more severe forms of morality. Building on these lines of research, Ding et al. investigated whether exposing people to greater variability in outcomes may lead to harsher moral judgment. Participants who saw graphs presenting more extreme data or who rolled dice that were manipulated to yield more extreme scores were more likely to support harsher punishment and to engage in more punitive behaviors in economic games. These findings have implications for how individuals may cope with increasingly unpredictable and variable environments.

    J. Pers. Soc. Psychol. 118, 1101 (2020).

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