Japan is making an overdue effort to regulate experimental stem-cell treatments. A clearly defined legal framework is needed to protect patients.
It is in Britain’s best interests to keep looking for a site for a deep nuclear-waste repository.
The identification of a long-dead king is not simply an academic event.
NASA prepares to launch satellite that will continue historic record of global change.
Commissioners say that geological faults make some reactors too dangerous to restart.
Government moves to tighten oversight after string of hydrogen fluoride accidents.
Maintenance, improvement work and data analysis will keep scientists busy as collider’s planned closure begins.
Plush San Francisco medical hub seeks to safeguard academic research.
Many tropical species never experience extreme heat or cold. That may doom them in a warming world.
As director of the NIH's bold new translational research centre, Christopher Austin has to show that he can jump-start a tortuous drug-discovery process.
News & Views
Our planet's soils teem with microorganisms that regulate processes from crop productivity to carbon sequestration. Molecular analysis contributes hugely to the characterization of microbial communities, but how can we better understand their ecological functions? Two microbiologists discuss the advantages of data-mining approaches versus targeted experiments.
By harnessing the way charge carriers move in a magnetic field, computing blocks based on semiconductor junctions have been made that are reconfigurable and can be interconnected to perform complex logic functions. See Letter p.72
Salt is important in health and disease, yet how mammals sense it is not completely clear. Evidence in worms suggests that TMC proteins, which are implicated in human hearing, are salt receptors involved in taste. See Letter p.95
Unusual strains of the pathogen Candida albicans have been found that contain a single set of chromosomes. Formation of such haploid strains weeds out damaged copies of genes to promote evolution in the human body. See Article p.55
When massive stars die as supernovae, these explosions can be seen out to the 'edge of the Universe'. But the stars' nature is often unclear. New observations provide insight into the life of one such star before it exploded. See Letter p.65
The current experimental and theoretical status of spin–orbit coupling in ultracold atomic systems is discussed, highlighting unique features that enable otherwise impossible physics.
Candida albicans, the most prevalent human fungal pathogen, is considered to be an obligate diploid that carries recessive lethal mutations throughout the genome. Here we demonstrate that C. albicans has a viable haploid state that can be derived from diploid cells under in vitro and in vivo conditions, and that seems to arise through a concerted chromosome loss mechanism. Haploids undergo morphogenetic changes like those of diploids, including the yeast–hyphal transition, chlamydospore formation and a white-opaque switch that facilitates mating. Haploid opaque cells of opposite mating type mate efficiently to regenerate the diploid form, restoring heterozygosity and fitness. Homozygous diploids arise spontaneously by auto-diploidization, and both haploids and auto-diploids show a similar reduction in fitness, in vitro and in vivo, relative to heterozygous diploids, indicating that homozygous cell types are transient in mixed populations. Finally, we constructed stable haploid strains with multiple auxotrophies that will facilitate molecular and genetic analyses of this important pathogen.
Interferon-induced proteins with tetratricopeptide repeats (IFITs) are innate immune effector molecules that are thought to confer antiviral defence through disruption of protein–protein interactions in the host translation-initiation machinery. However, it was recently discovered that IFITs can directly recognize viral RNA bearing a 5′-triphosphate group (PPP-RNA), which is a molecular signature that distinguishes it from host RNA. Here we report crystal structures of human IFIT5, its complex with PPP-RNAs, and an amino-terminal fragment of IFIT1. The structures reveal a new helical domain that houses a positively charged cavity designed to specifically engage only single-stranded PPP-RNA, thus distinguishing it from the canonical cytosolic sensor of double-stranded viral PPP-RNA, retinoic acid-inducible gene I (RIG-I, also known as DDX58). Mutational analysis, proteolysis and gel-shift assays reveal that PPP-RNA is bound in a non-sequence-specific manner and requires a 5′-overhang of approximately three nucleotides. Abrogation of PPP-RNA binding in IFIT1 and IFIT5 was found to cause a defect in the antiviral response by human embryonic kidney cells. These results demonstrate the mechanism by which IFIT proteins selectively recognize viral RNA, and lend insight into their downstream effector function.
A mass-loss event 40 days before the explosion of the type IIn supernova SN 2010mc has been detected; the outburst indicates that there is a causal relation between explosive mass-loss events seen in some massive stars before their explosion and the onset of the supernova explosion.
An imaging technique has been developed to characterize state mixtures caused by partial coherence and fluctuations in dynamical systems.
A microchannel made from InSb, which has current–voltage characteristics that are strongly dependent on the sign and magnitude of an applied magnetic field, is used to demonstrate that circuits made from such structures can be programmed — and reprogrammed — to perform elementary logic functions, such as AND, OR, NAND and NOR.
An efficient and scalable strategy with robust error correction is reported for encoding a record amount of information (including images, text and audio files) in DNA strands; a ‘DNA archive’ has been synthesized, shipped from the USA to Germany, sequenced and the information read.
Changes in ocean circulation are the most plausible explanation for the early Southern Hemisphere deglacial warming and its lead over Northern Hemisphere temperature.
Persistent anthropogenic disturbance is shown simultaneously to drive plant species loss and stabilize some attributes of ecosystem function, analogous to a high-yield, low-diversity agricultural system, but increase the likelihood of irreversible collapse after sudden environmental change.
Chronic inflammation is a feature of the ageing brain and some neurodegenerative diseases; the authors show that astrocytes normally suppress neuroinflammation through activation of their DRD2 receptor by CRYAB, potentially opening new avenues for treatments.
The membrane protein TMC-1 is required for salt avoidance behaviour in C. elegans, functions as an ion channel directly activated by NaCl in vitro and is a candidate salt chemosensor; the human homologue of TMC-1 is linked to deafness and may be the cochlear hair-cell mechanotransduction channel.
Immune rejection may limit the therapeutic use of induced pluripotent stem cells (iPSCs); here, terminally differentiated mouse iPSCs are shown to generate negligible immune rejection in their host.
This study demonstrates that an inheritable adult onset heart disease can be modelled in vitro within months with the help of metabolic maturation induction.
The livers of obese mice and humans show increased levels of miR-802 resulting in impaired glucose tolerance and decreased insulin sensitivity through silencing of Hnf1b, revealing a novel pathway with potential relevance for type 2 diabetes.
In mice, commensal bacteria are shown to provide critical signals that limit bacterial trafficking to the mesenteric lymph nodes by immune cells, thus preventing the induction of mucosal immune responses.
The crystal structure of prolyl tRNA synthetase simultaneously bound to its substrate ATP and its inhibitor halofuginone, a derivative of a compound used to treat malaria, indicates that (through interactions with ATP) halofuginone occupies both the amino acid and tRNA binding sites on the synthetase, revealing a new model for developing synthetase inhibitors.
Drosophila epithelial tracheal placode invagination is shown to be driven by mitotic cell rounding along with epithelial growth factor receptor signalling and myosin contractility in neighbouring cells, revealing a new cell-division-independent role for mitotic events in morphogenesis.