Editors' Choice

Science  15 Dec 2017:
Vol. 358, Issue 6369, pp. 1398
  1. Mate Choice

    Too much alike to be receptive

    1. Sacha Vignieri
    MHC-similar stallions reduce pregnancy rate in mares.PHOTO: PHOTO-EQUINE/SHUTTERSTOCK.COM

    Female choice exerts important selective forces and has shaped many obvious phenotypic traits. Cryptic female choice is choice after insemination and generally has less obvious, but no less important, impacts. Burger et al. showed that cryptic female choice may play a role in a well-known mechanism of mate choice, major histocompatibility complex (MHC) matching. Specifically, they found that in warmblood horses, which are bred for equestrian sport, mares exposed to stallions with dissimilar MHC alleles were more likely to get pregnant than those exposed to MHC-similar males. In this case, pregnancy occurred through artificial insemination with semen from stallions other than those exposed to the females; thus, the effect was driven by physical exposure of the mares to “stimulus” males, rather than by the genetic similarity of the donors.

    Proc. R. Soc. B 10.1098/rspb.2017.1824 (2017).

  2. Cell Biology

    Mechano-induced mitochondrial fission

    1. Stella M. Hurtley

    The inside of a cell is crowded with lots of different organelles that need to be accommodated in a constrained environment. What happens when different organelles bump into one another? Dynamic reticular organelles, such as the endoplasmic reticulum and mitochondria, are continually being remodeled. The fusion and fission of mitochondria is essential for their efficient function and healthy maintenance. The mechanism of mitochondrial fission has been well studied, but what physiological stimuli promote fission? Helle et al. show that mechanical stimulation of mitochondria—when bumped into by intracellular bugs, when poked by an atomic force microscope tip, or when moving across contoured surfaces—causes recruitment and activation of the mitochondrial fission machinery and, subsequently, mitochondrial division.

    eLife 6, e30292 (2017).

  3. Biotechnology

    Editing genomes without breaks

    1. Steve Mao

    By introducing DNA doublestrand breaks (DSBs), most genome-editing technologies initiate endogenous DNA repair mechanisms that modify the sequences at target sites. DSBs are often toxic, and their repair is usually inefficient, thereby limiting the accuracy and scalability of these technologies. Bypassing DSBs completely, Barbieri et al. developed a new editing platform in budding yeast. DNA oligos targeting the replication fork directly replaced the genetic sequence of the region of interest after the completion of DNA replication. This technology can be easily multiplexed and can achieve single–base pair precision.

    Cell 10.1016/j.cell.2017.10.034 (2017)

  4. Social Science

    It just takes one “like”

    1. Barbara R. Jasny

    The power of using social media to target ads was demonstrated in a study of 3.7 million women. Matz et al. first used data from myPersonality, an app that provides users with psychological tests, to generate a set of Facebook “likes” that would appeal to different people based on their level of extroversion or openness to the unusual. Graphic designers then created ads that would appeal to these personality types. In three field experiments, individuals who associated with as little as one target “like” used to establish a profile were more likely to click on the appropriate ad and to make a purchase than if they were mismatched or unmatched.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1710966114 (2017).

  5. Microbiology

    Trehalose confers superpowers

    1. Caroline Ash
    Trehalose provides Acinetobacter with high temperature resistance.PHOTO: DENNIS KUNKEL MICROSCOPY/SCIENCE SOURCE

    Trehalose is a disaccharide that can endow organisms with extraordinary survival abilities. It is implicated in desiccation resistance, osmoprotection, and heat and cold tolerance, as well as acting as a radical scavenger. Acinetobacter baumannii has emerged as a notably stress-tolerant nosocomial pathogen that accumulates trehalose. In addition to the sugar, Zeidler et al. have discovered that this pathogen produces mannitol and takes up glycine betaine in response to osmotic stress under high salt concentrations. A. baumannii has to survive not only high-salt environments in mammalian niches and drying out in the wider hospital environment, but also occasional blasts of high temperatures. Although mannitol and glycine betaine relieve osmotic stress, it seems that trehalose may be specifically required for survival at temperatures above 37°C. Other pathogens use similar protective solutes to promote survival during transitionary stages in their life cycles.

    Environ. Microbiol. 10.1111/1462-2920.13987 (2017).

  6. Psychology

    When intuition overrides reason

    1. Gilbert Chin

    Given two paths to winning, our choice under time pressure often differs from what we would opt for after deliberation, especially if the decision requires a numerical calculation of probabilities. Walco and Risen show that a third to a half of us will elect to rely on gut feelings even after having demonstrated an accurate understanding of which choice is more likely to pay off. This pattern of behavior applies across situations ranging from picking a specific color of marble to blackjack to fourth-down options in American football.

    Psychol. Sci. 10.1177/0956797617723377 (2017).

  7. Seismology

    Fiber-optic earthquake detection

    1. Brent Grocholski

    The seismic networks used to detect earthquakes are limited spatially because they require expensive seismometers to be placed, monitored, and maintained. Lindsey et al. show how fiber optics can be used for seismic recording, using a technique known as distributed acoustic sensing (DAS). Three examples show how DAS can detect ground motions—in Alaska, in the Geysers Geothermal Field in California, and even using fiber-optic cables in existing telecommunication conduits. These case studies show the potential for using DAS systems as massive seismometer arrays in hard-to-access locations, possibly by using preexisting fiber-optic networks.

    Geophys. Res. Lett. 10.1002/2017GL075722 (2017).