Editors' Choice

Science  25 Jul 2014:
Vol. 345, Issue 6195, pp. 414
  1. Genomics

    Marmoset DNA shows why it's small

    1. Elizabeth Pennisi

    The common marmoset has a sequenced genome

    PHOTO: © PETE OXFORD/MINDEN PICTURES/CORBIS

    A New World monkey joins a growing list of primate species with sequenced genomes, improving genomicists' ability to tell what genes make primates—and humans—unique. Brazil's common marmoset is unusual among primates: It is tiny—the size of a guinea pig—and always produces twins. During development, the twins share placental blood supply; after birth, each carries stem cells from the other that produce foreign blood cells with no ill effect. The Marmoset Genome Sequencing and Analysis Consortium fouwnd five genes likely involved in making the monkey small and eight genes that may help it adjust its metabolism and temperature control to deal with being tiny.

    Nat. Genet. 10.1038/ng.3042 (2014).

  2. Optical Imaging

    Stealthy spying on a moving target

    1. Ian S. Osborne

    Ghost imaging can create an image of a moving target without the target ever knowing that it is being watched. The traditional way to observe an object, either stationary or in motion, is to illuminate it and use the light that it reflects or scatters to create an image on a detector such as a camera. However, the observation of the object can itself be detected, which compromises the stealth of the process. Ghost imaging, a technique that forms an image with photons that have never even come into contact with the object, has been used to detect objects at rest, and now Li et al. show that it also can be used to reconstruct the image of moving targets, such as the small wafer that they use in their demonstration.

    Appl. Phys. Lett. 104, 251120 (2014).

  3. Transcription

    TRF2 gets transcription started, too

    1. Beverly A. Purnell

    Transcribing DNA into RNA involves an intricate dance of proteins and nucleic acids. Transcription starts at specific promoter sequences near genes, including one called the TATA box. For most genes, a protein called TBP binds to the TATA box and attracts other proteins required for transcription. Wang et al. studied fruit flies, hoping to learn whether the transcription of genes that encode ribosomal proteins (proteins that help translate RNA to protein), which contain a different promoter (a TCT motif), work in the same way. They found that the TBP-related factor TRF2, rather than TBP, bound to TCT motifs near the transcription start site, and the cell needed TRF2 to transcribe ribosomal proteins.

    Genes Dev. 10.1101/gad.245662.114 (2014).

  4. Metabolic Disease

    A vitamin's dark side in liver disease

    1. Paula A. Kiberstis

    Too much of a good thing can be bad for the liver. Chen et al. find that mice with high levels of thiamine (vitamin B1) in their livers develop fatty liver disease, a metabolic disorder that affects one-third of adults in the United States. A protein called organic cation transporter 1 (OCT1) carries dietary thiamine into the liver. When the researchers deleted the Oct1 gene in mice or fed mice a diet low in thiamine, the mice did not develop the disease. OCT1 also carries the diabetes drug metformin into the liver, which might explain why metformin decreases symptoms of fatty liver disease: By competing with thiamine for OCT1, metformin reduces the amount of dietary thiamine that reaches the liver.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1314939111 (2014).

  5. Nanowire Growth

    Avoiding instabilities while creating wires

    1. Marc S. Lavine

    A template is a great tool for making an object of a particular size and shape, but it works only if the template fills completely. Shin et al. show that ions race to fill the pores in the template during template-assisted electrodeposition of nanowires. When fast-growing wires fill the template, however, neighboring wires stop growing, creating instabilities in the wire growth. The authors show that they can overcome this problem of “diffusion-limited” deposition by making the template hotter at one end and colder at the other.

    Nano Lett. 10.1021/nl501324t (2014).

  6. Range Shifts

    Warming waters create new bedfellows

    1. Sacha Vignieri

    Climate change alters the geographical range of species. Such shifts can affect species in major ways, such as changing their abundance or bringing adjacent, closely related species into contact. Potts at al. found that rapidly warming waters in the Angola-Benguela Frontal Zone over the last three decades caused the African kob fish Argyrosomus coronus to move southward, where they now live—and spawn—in some of the same places as a related species. Species often overlap at range boundaries, but climate-driven overlap makes it harder for people to manage economically important species and changes the way species fit into their ecosystems.

    Glob. Change Biol. 10.1111/gcb.12612 (2014).

  7. Planetary Topography

    Springtime sighting at Titan's coastline

    1. Margaret M. Moerchen

    Seasonal warming on Saturn's largest moon, Titan, is changing the shoreline of one of its methane seas. Titan hosts an active methane cycle like the water cycle on Earth, and a local year lasts 30 Earth years. Titan's northern summer solstice will occur in May 2017, and although seasonal shoreline changes have been seen in the south, they have not yet been observed in the north. Hofgartner et al. describe Cassini RADAR images that reveal a ~20-km feature coming and going in Titan's northern sea Ligeia Mare in July 2013. They interpret this signal as a change in the position of the boundary between the frozen shoreline and the liquid sea during the thaw after the winter's freeze.

    Nat. Geosci. 10.1038/ngeo2190 (2014).

  8. Conservation

    Making protection of biodiversity count

    1. Andrew M. Sugden

    Kenya's Lake Nakuru National Park

    PHOTO: BJØRN CHRISTIAN TØRRISSEN/WIKIMEDIA COMMONS

    Global protected areas aim to protect biodiversity, but they do not currently protect threatened species very well. Venter et al. report that 85% of threatened vertebrates need greater protection. Governments plan to increase protected areas from 13 to 17% of the land surface by 2020. But if governments continue to select cheap, marginal lands to protect, the protected species will increase only marginally. The authors suggest that choosing to protect areas where threatened species live would lead to a fivefold improvement in threatened species protection for only 1.5 times the cost of purchasing and protecting the cheapest land.

    PLOS Biol. 10.1371/journal.pbio.1001891 (2014).

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