Europe's re-examination of stem-cell rules is a waste of time and money.
Efforts to understand cancer genomes should take on a fresh focus.
Downgrading practical science will impede UK students in the global workplace
Treatment guidelines for virus highlight challenge of paying for expensive drugs in low-income countries.
Stress alters the expression of small RNAs in male mice and leads to depressive behaviours in later generations.
Cherenkov Telescope Array will track high-energy photons to probe black holes, dark matter and relativity.
Critics attack panel’s lack of specific guidance on how countries should lower emissions.
Japanese author of controversial papers denies wrongdoing and stands by results as testing of her protocol begins.
Proliferation of ‘CubeSats’ offers fresh and fast way to gather space data.
After years in the doldrums, the quest to harvest energy from the oceans is gathering speed.
When toxicologists warned that the plastics ingredient BPA might be harmful, consumers clamoured for something new. But problems persist.
News & Views
Genetic research has tracked lineages of male chimpanzees thousands of years into the past, opening the door to the study of long-term behavioural evolution in our close primate relatives.
A comparison of identical human twins, only one of whom has Down's syndrome, reveals a genome-wide flattening of gene-expression levels in the affected individual. See Article p.345
A fresh take on an established chemical reaction has solved a long-standing problem in organic synthesis: how to prepare single mirror-image isomers of groups known as isolated quaternary stereocentres. See Article p.340
Cellular biocircuit design has taken a major step forward. The circuit reuses the cell's own protein-degradation system to synchronize the expression of two synthetic modules throughout an entire bacterial population. See Letter p.387
Single crystals of tin selenide have been shown to display, along one crystallographic direction of their high-temperature state, the highest thermoelectric efficiency of any bulk material. See Letter p.373
An investigation into cellular stress responses reveals how cell compartments called mitochondria use information about the surrounding metabolites and microorganisms to protect themselves from damage. See Letter p.406
Allostery is the process by which biological macromolecules transmit the effect of binding at one site to another, often distal, functional site, allowing for the regulation of activity; here facilitation of allostery through dynamic and intrinsically disordered proteins is discussed, and a framework to unify the description of allosteric mechanisms for different systems is proposed.
A catalytic and enantioselective intermolecular Heck-type reaction of trisubstituted-alkenyl alcohols with aryl boronic acids provides direct access to quaternary stereocentres remote from a carbonyl group.
By studying the transcriptome of fetal cells of monozygotic twins discordant for trisomy 21, this paper finds that differential expression between the twins is organized in domains along all chromosomes; these gene expression dysregulation domains are conserved in the mouse model of Down’s syndrome and correlate with the lamina-associated domains and replication domains.
The authors use a combination of viral tracing and genetics to characterize the diversity of neurons projecting from mouse brainstem to motor neurons that control limb movements; in particular they discover that the medullary reticular formation ventral part (MdV) is functionally specialized for skilled forelimb motor control.
Cervical propriospinal neurons (PNs) form a genetically accessible subclass of V2a interneurons that convey both premotor output and precerebellar copy signals; their ablation in mice impairs reaching movements selectively, and activation of their internal copy projection recruits a rapid cerebellar feedback loop that modulates forelimb movement.
Isotopic analyses of 40 Martian meteorites indicate that assimilation of sulphur into Martian magmas was a common occurrence throughout much of the planet’s history and that the atmospheric imprint of photochemical processing preserved in Martian meteoritic sulphide and sulphate is distinct from that observed in terrestrial analogues.
The long-predicted suppression of quasiparticle dissipation in a Josephson junction when the phase difference across the junction is π is inferred from a sharp maximum in the energy relaxation time of a superconducting artificial atom.
The main obstacle to improving the thermoelectric efficiency of a material arises from the common interdependence of electrical and thermal conductivity, whereas one ideally wants to raise the former while lowering the latter: a simple layered crystalline material — SnSe — is now reported that seems to have these qualities built in.
Tropical and subtropical speleothems show that the latitudinal migration of the Intertropical Convergence Zone tends to produce increased precipitation in one hemisphere and drying in the other; now it is shown using speleothems from the Korean peninsula that this phenomenon extended to the mid-latitudes during the past 550,000 years.
Phylogenetic analysis of a new species of fossil toothed whale, Cotylocara mace, from the Oligocene epoch places it in a basal clade of odontocetes, and its features suggest that rudimentary echolocation evolved in the early Oligocene and was followed by convergent evolution in their skulls.
Protease competition is used to produce rapid and tunable coupling of genetic circuits, enabling a coupled clock network that can encode independent environmental cues into a single time series output, a form of frequency multiplexing in a genetic circuit context.
The lengthening phase of ventral furrow formation in Drosophila gastrulation is driven by cytoplasmic flows triggered by apical constriction of mesoderm cells independent of the mechanical inputs from the basolateral membranes.
A committed precursor to innate lymphoid cell lineages, but not classical natural killer and lymphoid tissue inducer cells, is derived from common lymphoid precursors and distinguished by high levels of expression of the transcription factor PLZF.
A broad-spectrum antiviral small molecule is reported to act as an inhibitor of viral polymerase activity and is shown to be effective in protecting non-human primates from lethal filovirus infection when administered after exposure.
A genome-wide RNA interference screen in Caenorhabditis elegans identifies 45 genes with roles in protective pathways following drug- and genetic-disruption-induced mitochondrial inhibition.
The generation of widespread epigenetically activated short interfering RNAs by the targeting of microRNAs to transposon transcripts in Arabidopsis thaliana is shown to be a latent mechanism that only becomes active when the transcripts are epigenetically reactivated, for example, during reprogramming of the germ line.
In bacterial cells, processing of double-stranded DNA breaks for repair by homologous recombination is dependent upon the recombination hotspot sequence χ (Chi) and is catalysed by either an AddAB- or RecBCD-type helicase–nuclease (reviewed in refs 3, 4). These enzyme complexes unwind and digest the DNA duplex from the broken end until they encounter a χ sequence, whereupon they produce a 3′ single-stranded DNA tail onto which they initiate loading of the RecA protein. Consequently, regulation of the AddAB/RecBCD complex by χ is a key control point in DNA repair and other processes involving genetic recombination. Here we report crystal structures of Bacillus subtilis AddAB in complex with different χ-containing DNA substrates either with or without a non-hydrolysable ATP analogue. Comparison of these structures suggests a mechanism for DNA translocation and unwinding, suggests how the enzyme binds specifically to χ sequences, and explains how χ recognition leads to the arrest of AddAB (and RecBCD) translocation that is observed in single-molecule experiments.