Scientists must push to preserve a small part of a large US survey that provides essential information on the ever-changing scientific workforce.
Pressures in all stages of the news-making process can lead to hype in science reporting.
Climate negotiations in Lima stumbled on transparency, but there is time to adjust.
A front-line report from Sierra Leone examines efforts to change hearts and minds in West Africa’s villages.
Birds get fresh perches in revamped tree of life built by vast collaboration.
Are geopolitical tensions destroying important links with the West, or can Russian research go it alone?
Comets, stem cells and cosmic dust are among the year's top stories.
Eruptions, comets and a see-through mouse all captured the imagination in 2014.
Ten people who mattered this year.
News & Views
An iron catalyst has been developed that mediates bond formation between a wide range of alkene reactants, opening up short synthetic routes to compounds that were previously accessible only through arduous pathways. See Article p.343
The development of RNA-based devices called toehold switches that regulate translation might usher in an era in which protein production can be linked to almost any RNA input and provide precise, low-cost diagnostics.
Intensive longitudinal sampling of malaria mosquitoes in the African semi-desert reveals that three morphologically indistinguishable species have distinctive strategies for surviving the dry season.
New analysis reveals the conservation gains that could be achieved by expanding the global network of protected areas — but also how this may be undermined by land-use change and a lack of international coordination. See Letter p.383
Magnetoelectric materials allow magnetism to be controlled by an electric field. The discovery of an indirect path for switching electrical polarization in one such material brings this idea close to practical use. See Letter p.370
Crystal structures of the complete RNA polymerases from influenza A and B viruses provide insight into how these enzymes initiate RNA synthesis, and reveal targets for antiviral drug design. See Articles p.355 & p.361
Extracts from selected News & Views articles published this year.
Highly substituted carbon–carbon bonds are constructed using a simple iron catalyst and an inexpensive silane: more than 60 examples of this reaction — in which heteroatom-substituted olefins are reacted with electron-deficient olefins — are presented.
Polycomb group proteins are known to maintain gene repression during development; however, when autism susceptibility candidate 2 (AUTS2) associates with some Polycomb group complexes, these complexes have an unexpected gene activation role, offering new insight into the role of AUTS2 in neurological disorders.
The crystal structure of the bat-specific influenza A polymerase in complex with the viral RNA promoter is presented, revealing how binding of the 5′ end of the viral RNA is required to activate or enhance the polymerase allosterically.
Atomic resolution crystal structures of influenza A and B polymerases are presented; comparison of these structures provides mechanistic insight into influenza polymerase functions, explaining the processes of cap-snatching and cap-dependent priming, which are unique to segmented negative-strand RNA viruses.
Hubble Space Telescope observations of the stellar cluster NGC 1651, which is approximately two billion years old, show that the colour–brightness distribution of stars old enough to have left the main sequence can be explained only by a single-age population, despite having a feature usually interpreted to indicate an age spread of more than 300 million years.
Multiferroic devices that can switch magnetization with electric field at room temperature are desirable, but in BiFeO3 the required direct 180-degree switch is thermodynamically forbidden; here it is shown that such switching is possible because the kinetics of the switching process favours a two-step sequence of partial switching.
The dynamics of two correlated electrons can be reconstructed from the quantum interference of low-lying doubly excited states in helium, as observed in attosecond transient-absorption spectra, and can be controlled by tuning the interaction with a visible laser field of variable intensity.
The production of hydrogen gas from the Precambrian continental lithosphere has been underestimated; taking into account hydrogen from serpentinization and radiolysis may double estimates previously based on marine systems alone.
Internationally coordinated expansion of the global protected area network to 17% could triple the average protection of species ranges and ecoregions; if projected land-use changes and consequent habitat loss until 2040 occur, currently feasible protection levels will not be achievable, and more than 1,000 threatened species face reductions in the range of over 50%.
Malaria-carrying mosquitoes nearly disappear in the dry season, yet they reappear suddenly following the first rains; using surveys of mosquito densities, the authors characterize the population dynamics of the three main vector species and use these to infer persistence by long-distance migration in two species and aestivation in the third.
It has been known for some time that limbs share at least some of their molecular patterning mechanism with external genitalia; here, this connection is examined in a variety of species, revealing that once-shared developmental trajectories could help to explain the observed patterning similarities.
Cold exposure activates brown adipose tissue (BAT) through the sympathetic nervous system, and previous studies have reported inhibitory effects of the purinergic transmitter adenosine in BAT from hamster or rat; here adenosine/A2A signalling is shown to be involved in sympathetic activation of human and murine brown adipocytes to allow protection of mice from diet-induced obesity.
The in vitro generation, from pluripotent stem cells, of three-dimensional human gastric organoids (hGOs) that contain a physiological gastric epithelium comprising both progenitor and differentiated cell types, and have expected functional characteristics is described, as is modelling the pathophysiological response of the human stomach to Helicobacter pylori using these hGOs.
An extensive analysis of HERVH (a primate-specific endogenous retrovirus) expression in human pluripotent stem cells is presented, identifying a sub-population of cells within cultured human embryonic stem cells and induced pluripotent stem cells that has characteristics of naive-state cells — the study provides evidence for a new primate-specific transcriptional circuitry regulating pluripotency.
A protein degradation pathway is found at the inner nuclear membrane that is distinct from, but complementary to, endoplasmic-reticulum-associated protein degradation, and which is mediated by the Asi protein complex; a genome-wide library screening of yeast identifies more than 20 substrates of this pathway, which is shown to target mislocalized integral membrane proteins for degradation.
A link between an intracellular stress response, bacterial infection and triggering of the innate immune response is shown in Caenorhabditis elegant; exposure to the pathogen Pseudomonas aeruginosa caused activation of the transcription factor ATFS-1 and innate immunity that is regulated by the mitochondrial unfolded protein response.
The main pathway of somatic mutations leading to the generation of high affinity broadly neutralizing antibodies against the influenza haemagglutinin stem is defined.
Chromosomal rearrangements have a central role in the pathogenesis of human cancers and often result in the expression of therapeutically actionable gene fusions. A recently discovered example is a fusion between the genes echinoderm microtubule-associated protein like 4 (EML4) and anaplastic lymphoma kinase (ALK), generated by an inversion on the short arm of chromosome 2: inv(2)(p21p23). The EML4–ALK oncogene is detected in a subset of human non-small cell lung cancers (NSCLC) and is clinically relevant because it confers sensitivity to ALK inhibitors. Despite their importance, modelling such genetic events in mice has proven challenging and requires complex manipulation of the germ line. Here we describe an efficient method to induce specific chromosomal rearrangements in vivo using viral-mediated delivery of the CRISPR/Cas9 system to somatic cells of adult animals. We apply it to generate a mouse model of Eml4–Alk-driven lung cancer. The resulting tumours invariably harbour the Eml4–Alk inversion, express the Eml4–Alk fusion gene, display histopathological and molecular features typical of ALK+ human NSCLCs, and respond to treatment with ALK inhibitors. The general strategy described here substantially expands our ability to model human cancers in mice and potentially in other organisms.
The CRISPR/Cas system has been used in mice for genome editing to introduce genetic alterations found in human lung tumours, and these genome modifications resulted in mouse lung tumours showing different histopathologies depending on the genes altered; the CRISPR/Cas system offers improved and faster ways to create animal models of human diseases such as cancer.
Genome-wide chromatin conformation capture (Hi-C) is used to investigate three-dimensional genome organization in Schizosaccharomyces bombe; small domains of chromatin interact locally on chromosome arms to form globules, which depend on cohesin but not heterochromatin for formation, and heterochromatin at centromeres and telomeres provides crucial structural constraints to shape genome architecture.
R-loops, which have been considered to be rare and potentially harmful transcriptional by-products, are now shown to be needed for antisense transcription and to induce repressive chromatin marks that reinforce pausing of transcription and thereby enhance its termination.