Editors' Choice

Science  26 Feb 2021:
Vol. 371, Issue 6532, pp. 902
  1. Perception

    Feel the light

    1. Sacha Vignieri

    Each arm of an octopus is capable of an autonomous response to light to ensure that it remains hidden when predators are active.


    Octopuses have remarkable bodies that they stretch and reshape in response to the environment and to the animal's needs. How control over such flexibility is managed is an ongoing question. Work in this area has shown that octopus arms exert a degree of individual control. Katz et al. found that octopus arms display a phototactic response to light, automatically withdrawing when the arm (especially the tip) is illuminated. Unlike previously described photoresponsive cells in the skin of the arms, this response appears to be both autonomic and channeled through the central nervous system. Perhaps, the authors suggest, this allows the arms to be protected from foraging predators during the day, but gives the octopus an override option during their own foraging bouts.

    J. Exp. Biol. 10.1242/jeb.237529 (2021).

  2. Population Genetics

    Linking phenotype with genotype

    1. Laura M. Zahn

    In humans, it is difficult to work out how natural selection affects phenotypic variation. With the accumulation of huge repositories of human genetic data and new computational methods, the impact of medical conditions and their evolutionary importance can be estimated. One challenge is that many complex diseases are linked to phenotypes with common and widely occurring genetic variants. Vy et al. predicted the overall number of deleterious genetic variants in coding proteins (known as the deleterious load) within individuals from the UK Biobank. Although overall deleterious load is not linked with any specific disease states, the authors found statistically significant associations between 27 traits and phenotypes associated with disease, including body mass, metabolic rate, and adiposity. Thus, the accumulative effect of deleterious load might be a useful indicator for general health.

    PLoS Genet. 17, e1009337 (2021).

  3. Epigenetics

    Inheriting female infertility

    1. Gemma Alderton

    Polycystic ovary syndrome (PCOS) is a major cause of female infertility. It is characterized by hormonal and often metabolic dysfunction but little is understood about its etiology. For women with PCOS who do become pregnant, there is a high probability that their daughters will develop PCOS. This heritability has been proposed to arise, at least partially, if the embryos are exposed to abnormal levels of hormones. Mimouni et al. studied a mouse model of PCOS and found several differentially methylated genes in the ovaries of third-generation mice, indicating epigenetic-mediated heritability. Several of these genes were also differentially methylated in blood samples from mothers and daughters with PCOS, indicating the potential for methylation as a diagnostic biomarker.

    Cell Metab. 10.1016/j.cmet.2021.01.004 (2021).

  4. Thin Films

    Ionic liquids assist in vacuum

    1. Phil Szuromi

    Molecular layer deposition, an analog of atomic layer deposition, alternates self-limiting reactions to grow materials such as polymers. However, the vacuum conditions in practice generally limit the choices to polymers in which the barrier to reaction is low without solvent assistance, such as those with thionyl or acyl backbones. Shi and Bent show that an ionic liquid, 1-ethyl-3-methylimidazolium, can create a solvation environment for the Friedel-Crafts reaction in vacuum. This ionic liquid did not evaporate at reaction temperatures, wetted a silicon substrate, and formed a eutectic with the AlCl3 catalyst. The authors alternated deposition of isophthaloyl dichloride and diphenyl ether along with the catalyst to grow polyetherketoneketone thin films at a rate of about 5.5 angstroms per reaction cycle.

    ACS Nano 10.1021/acsnano.0c09329 (2021).

  5. Materials Science

    Robust water-repellant fabrics

    1. Marc S. Lavine

    Wrinkled poly(ethylene terephthalate)-coated fibers can make durable, water-repellent fabrics.

    IMAGE: XU ET AL., ACS APPL. MAT. INTERFACES, 13, 6758 (2021)

    Materials that aggressively repel water are useful for protective fabrics and self-cleaning surfaces. However, it can be challenging to make coatings on woven fabrics that can resist rubbing and frequent washing cycles without using fluorinated molecules. Drawing inspiration from earthworms, which have wrinkled skins, Xu et al. created a similar surface texture on poly(ethylene terephthalate) fabric coating with poly(dimethylsiloxane) (PDMS). The PDMS is treated with an argon plasma, leading to the formation of cross links that have a graduated depth concentration profile. This causes the PDMS surface to wrinkle, which leads to water repellence. The fabrics could survive hundreds of washing or rubbing cycles, and damage to the PDMS could be repaired using heat or further argon plasma treatment.

    ACS Appl. Mat. Interfaces 13, 6758 (2021).

  6. Workforce

    The chemistry of inequality

    1. Melissa McCartney

    More and more data on the issues surrounding diversity and inclusion in STEM are surfacing. Stockard et al. contribute to these data by providing evidence of inequities in experiences and career plans of doctoral students in chemistry. Using mixed-model regression analyses, they show that graduate students identifying as part of a traditionally underrepresented group were less likely to report supportive relationships with peers and postdocs. Women were less likely to (i) report supportive relationships with advisers, (ii) commit to remaining in chemistry, and (iii) aspire to academic research careers. Overall, the results suggest that the reality for traditionally underrepresented graduate students remains full of subtle obstacles, which are likely not specific to the chemistry field, that continue to impede efforts toward a diverse and inclusive scientific workforce.

    Proc. Natl. Acad. Sci. U.S.A. 118, e2020508118 (2021).

  7. Signal Transduction

    Signaling for stress

    1. L. Bryan Ray

    Guanosine triphosphatase–activating protein-binding proteins called G3BP1 and G3BP2 function as a core component of stress granules. Stress granules are dynamic assemblages of ribonucleoproteins that form in distressed cells found in tumors or neurodegenerative disease states. G3BP1 also has an unexpected role in tethering the tuberous sclerosis complex (TSC) of proteins to lysosomes. At the lysosome, the TSC regulates a key metabolic regulator called mTORC1. Prentzell et al. detected G3BP1 in a screen for proteins that interact with mTORC1. If G3BP1 levels are low, then mTORC1 becomes hyperactive, stimulating cell motility in tumors or neuronal hyperactivity, which could be bad news for patients.

    Cell 184, P655 (2021).

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