This Week in Science

Science  10 Jun 2016:
Vol. 352, Issue 6291, pp. 1288
  1. Carbon Sequestration

    Inject, baby, inject!

    1. H. Jesse Smith

    Northern Lights above borehole at Iceland power station.

    PHOTO: GUNNAR SVANBERG

    Atmospheric CO2 can be sequestered by injecting it into basaltic rocks, providing a potentially valuable way to undo some of the damage done by fossil fuel burning. Matter et al. injected CO2 into wells in Iceland that pass through basaltic lavas and hyaloclastites at depths between 400 and 800 m. Most of the injected CO2 was mineralized in less than 2 years. Carbonate minerals are stable, so this approach should avoid the risk of carbon leakage.

    Science, this issue p. 1312

  2. Cancer Immunotherapy

    Outsourcing cancer immunotherapy

    1. Kristen L. Mueller

    Successful cancer immunotherapy depends on a patient's T cells recognizing tumor-specific mutations and then waging a lethal attack. Despite tumors harboring many mutations, most individuals have very few T cells that respond to these so-called “neo-antigens.” Strønen et al. isolated T cells from healthy donors that responded to predicted neo-antigens expressed by melanomas taken from three patients, sometimes including neo-antigens that the patient's own T cells ignored (see the Perspective by Yadav and Delamarre). Testing whether such an outsourcing strategy could improve clinical outcomes will be an important next step.

    Science, this issue p. 1337; see also p. 1275

  3. Neuronal Plasticity

    Ocular dominance plasticity reconsidered

    1. Peter Stern

    How neuronal circuits are established and reformed during development and learning is unclear. One idea is that cortical circuits have virtually unlimited plasticity and are rebuilt routinely from random components. An alternative view is that some of these connections are more or less preformed and rigid. Working in mice, Rose et al. looked at how visual cortical neurons change their response after monocular deprivation. After recovery, the response properties of the neurons returned to their pre-deprivation pattern. Thus, it is not the strong connectivity backbone but perhaps inhibitory and weaker connections that are changed temporarily during sensory deprivation, whereas a core circuitry returns to default mode even after several days of altered activity.

    Science, this issue p. 1319

  4. Nanomedicine

    Knocking down adhesion and inflammation

    1. Megan Frisk

    Inflammatory cells lodge in damaged regions of blood vessels (called plaques) by rolling along the vessel wall, planting themselves, and then passing through endothelial cells that line blood vessels. Cell adhesion molecules (CAMs) mediate this recruitment and transmigration process. Working in mice, Sager et al. delivered five CAM-targeting small interfering RNAs (siRNAs) inside nanoparticles optimized to reach endothelial cells. The siRNAs reduced leukocyte recruitment to plaques engineered to develop certain features of human atherosclerosis. The siRNAs also attenuated inflammation after myocardial infarction. Current therapies for cardiovascular disease do not target inflammatory cells, and this multipronged nanomedicine approach could complement existing options.

    Sci. Transl. Med. 8, 342ra80 (2016).

  5. Brain Research

    Brain activity to represent the future

    1. Peter Stern

    How do humans navigate from A to B? Brown et al. developed a virtual reality task to investigate the neural representations that support human navigational planning. Highly specific activity of the hippocampus and related brain areas represented the future locations to which participants eventually moved. Network-level interactions of the hippocampus with the prefrontal cortex thus enable flexible representation of planned destinations.

    Science, this issue p. 1323

  6. Geophysics

    A microseismic turn off

    1. Brent Grocholski

    Certain strike-slip faults do not have the expected number of microearthquakes between larger earthquakes. Jiang and Lapusta suggest that this behavior is down to what the last big earthquake looked like. They found that microseismicity turns off if an earthquake's rupture runs deeper than the fault's locking depth. This appears to be the case along the famous San Andreas Fault and also along other strike-slip faults around the world. The discovery may allow for better estimates of historic earthquake magnitudes and improve hazard assessments.

    Aerial view of the San Andreas Fault.

    PHOTO: © KEVIN SCHAFER/ALAMY STOCK PHOTO

    Science, this issue p. 1293

  7. Development

    Altered fluid flow causes curved spine

    1. Beverly A. Purnell

    Adolescent idiopathic scoliosis is characterized by three-dimensional spinal curves and affects 3% of the world's children. However, the biological basis of this condition is unclear. Grimes et al. studied zebrafish models that likewise display a curved spine. Defects in the formation and function of motile cilia in the central nervous system perturbed the flow of cerebrospinal fluid (CSF), leading to abnormal spinal curvatures as the fish grew. Curves could be partially rescued by restoring CSF flow, suggesting potential therapeutic strategies if the same mechanism is shared in humans.

    Science, this issue p. 1341

  8. Optical Materials

    Converting infrared into visible

    1. Ian S. Osborne

    There is a constant societal drive to develop new light sources that are both efficient and environmentally benign. Rosemann et al. developed an amorphous material that emits a broadband (warm white) spectrum of light upon excitation with an infrared laser via highly nonlinear processes. Inorganic nanocrystals form the core of their material and are coated with organic ligands on the surface. When excited with infrared light, nonlinear optical processes cause the material to emit broadband white light.

    Science, this issue p. 1301

  9. Transcription

    An end to gene transcription

    1. Guy Riddihough

    Much attention has been focused on regulating the start of gene transcription. But transcription must also be terminated, and the mechanisms are only now being defined in detail in eukaryotes. Proudfoot reviews how termination happens for RNA polymerase II genes, mainly in mammals, covering the various steps that can lead to messenger RNA (mRNA) 3′ end formation and how they can be regulated. Termination can occur at various positions throughout the gene, forming the wild-type mRNA, preventing the synthesis of aberrant mRNAs, or generating alternative mRNAs with different regulatory or coding properties.

    Science, this issue p. 10.1126/science.aad9926.

  10. Proteomics

    Expanded proteomic analysis of metabolism

    1. L. Bryan Ray

    Combined analysis of large data sets characterizing genes, transcripts, and proteins can elucidate biological functions and disease processes. Williams et al. report an exceptionally detailed characterization of mitochondrial function in a genetic reference panel of recombinant inbred mice. They measured the metabolic function of nearly 400 mice under various environmental conditions and collected detailed quantitative information from livers of the animals on over 25,000 transcripts. These data were integrated with quantitation of over 2500 proteins and nearly 1000 metabolites. Such analysis showed a frequent lack of correlation of transcript and protein abundance, enabled the identification of genomic variants of mitochondrial enzymes that caused inborn errors in metabolism, and revealed two genes that appear to function in cholesterol metabolism.

    Science, this issue p. 1292

  11. Organic Chemistry

    A tip of the HAT to C-C bond formation

    1. Jake Yeston

    Iridium and nickel are already a proven team for forging carbon-carbon bonds. The iridium harvests blue light from a simple light-emitting diode and orchestrates the coupling by the nickel. Shaw et al. now add a third player to the team, a hydrogen atom transfer (HAT) catalyst (see the Perspective by Fruit). Together, the trio of catalysts can link bromo- or chloroaryl rings directly to C-H sites adjacent to nitrogen or oxygen, with no need for prior modification. The reaction is highly selective across a broad range of substrates.

    Science, this issue p. 1304; see also p. 1277

  12. Glass Transition

    Making a critical point about glass

    1. Brent Grocholski

    Glasses are often thought of as frozen liquids without long-range order. Albert et al. used fifth-order dielectric susceptibility measurements to show that the real reason behind the stiffness of glass is more complicated. Measuring the response of two traditional glass formers to very high electric fields is challenging, but reveals the growth of compact domains across the glass transition. The emerging amorphous order is only weakly dependent on the specific molecular properties, suggesting a more universal governing behavior for making glasses.

    Science, this issue p. 1308

  13. Sleep and Memory

    Perceptual memory needs slow-wave sleep

    1. Peter Stern

    We know little about the mechanisms by which the brain consolidates nondeclarative (perceptual) memories. In a series of behavioral, optogenetic, and electrophysiological experiments, Miyamoto et al. show that coordinated neuronal information flow during sleep is required for perceptual memory formation. Activity spreading from the secondary motor area (brain area M2) to the primary sensory region S1 is necessary for this particular kind of memory consolidation. Disturbing this coordinated input during slow-wave sleep immediately after memory acquisition prevented mice from learning a simple texture discrimination task.

    Science, this issue p. 1315

  14. Neurodevelopment

    One size does not fit all

    1. Pamela J. Hines

    Oligodendrocytes are best known for their ability to myelinate brain neurons, thus increasing the speed of signal transmission. Marques et al. surveyed oligodendrocytes of developing mice and found unexpected heterogeneity. Transcriptional analysis identified 12 populations, ranging from precursors to mature oligodendrocytes. Transcriptional profiles diverged as the oligodendrocytes matured, building distinct populations. One population was responsive to motor learning, and another, with a different transcriptome, traveled along blood vessels.

    Science, this issue p. 1326

  15. Transcription

    Transcription activation all about timing

    1. Guy Riddihough

    Regulating transcription by RNA polymerase (RNAP) is central to controlling gene expression. Transcription factors influence the activity of the RNAP. Feng et al. determined the crystal structure of a bacterial transcription activation complex. The transcription activator protein (TAP) converts the closed RNAP-promoter complex into an open complex through simple stabilizing protein-protein interactions with RNAP. The critical contacts did not go through the RNAP active center or the RNAP clamp. Instead, it seems that the timing of the interaction during transcription complex formation is critical for activation.

    Science, this issue p. 1330

  16. Enzymology

    A hit-and-run metal ion

    1. Valda Vinson

    DNA polymerase is an enzyme that uses existing DNA as a template to build new DNA by adding new nucleotides to the end of the newly forming daughter strand. The enzyme mechanism that catalyzes formation of a phosphodiester bond is known to require two Mg2+ ions, and recent crystal structures have shown that a third metal ion is present after bond formation. Gao et al. used time-resolved crystallography to visualize bond formation. The enzyme-substrate complex captures a third cation before bond formation occurs, and DNA synthesis cannot occur without the third metal ion. Binding of this metal ion requires thermal motion of the enzyme-substrate complex, so that catalysis is achieved by acquiring a transient cofactor.

    Science, this issue p. 1334

  17. Cancer

    A cancer-promoting histone protein

    1. Guy Riddihough

    Mutations in the chromatin protein histone H3 are found in a number of pediatric cancers. The lysine-36–to–methionine (K36M) “oncohistone” mutation is seen in almost all chondroblastomas. Fang et al. show that the K36M mutant histones inhibit the normal methylation of this same residue in wild-type H3 histones. They do so by interfering with the enzymes that normally methylate this residue. The altered chromatin methylation patterns alter the expression of known cancer-related genes and impart cancer-related characteristics to the chondrocyte cells.

    Science, this issue p. 1344

  18. Environment

    Calls for inclusive governance

    1. Julia Fahrenkamp-Uppenbrink

    Human populations around the world face growing challenges of ecosystem degradation and climate change. In a Perspective, Mistry and Berardi argue that engaging with indigenous knowledge and acknowledging its distinctiveness from scientific knowledge will be crucial for meeting these challenges. In a related Perspective, Brondizio and Le Tourneau emphasize the importance of sparsely populated landscapes for addressing the degradation of ecosystems and for mitigating and adapting to climate change. International agreements acknowledge the importance of local and indigenous populations in these efforts, but more-inclusive governance practices are emerging only slowly.

    Science, this issue pp. 1274 and 1272

  19. Geology

    Making mountains

    1. Kip Hodges

    Magmatism—the conversion of magma into rock—is important in the formation of mountains and increasing Earth's crust. Although the regions behind island arcs in the world's oceans are known for their magmatic activity, our understanding of how and in what form that magmatism is distributed remains imperfect. Hamling et al. present evidence for ongoing intrusion of a deep (12 km) magmatic body near the Taupo Volcanic Zone of New Zealand. Such studies may indicate that the formation of new crust in back-arc settings is more complex than generally assumed.

    Sci. Adv. 2, 10.1126.sciadv.00288 (2016).

  20. Neuroscience

    Normalizing neuronal shape in fragile X

    1. Leslie K. Ferrarelli

    Lack of the RNA-binding protein FMRP results in fragile X syndrome, a common inherited intellectual disability, and is associated with abnormal neuronal morphology. FMRP selectively suppresses messenger RNA translation, and Kashima et al. identified the transcript encoding the receptor BMPR2 as an FMRP target (see the Focus by Broihier). BMPR2 levels and activity of the downstream kinase LIMK1 were increased in the brains of FMRP-deficient flies and mice and in postmortem brain tissue from patients. LIMK1 triggers changes in cell shape, and a LIMK1 inhibitor suppressed abnormal neuronal morphology in mice lacking FMRP.

    Sci. Signal. 9, ra58 and fs12 (2016).

  21. Quantum Simulation

    Hundreds of ions simulate magnetism

    1. Jelena Stajic

    Strongly interacting quantum systems present a challenge to computational methods even at a relatively low particle number of a few dozen. Researchers are looking to tackle such problems by simulating them in a well-understood and controllable system. A linear array of ions is one such system; however, assembling a large enough number of ions is tricky. Bohnet et al. show that a two-dimensional “crystal” of around 200 9Be+ ions held together by magnetic and electric fields in a so-called Penning trap can simulate quantum magnetism. The work sets the stage for simulations with more complicated forms of interaction that classical computers would find intractable.

    Science, this issue p. 1297