| | Cancer: Diagnosis by extracellular vesicles
The detection of a single molecule anchored to circulating extracellular vesicles allows late-stage pancreatic cancer to be identified from just one drop of a patient's blood. | Palaeontology: Hallucigenia's head
The finding of pharyngeal teeth and circumoral mouthparts in fossils of the Cambrian lobopodian animal Hallucigenia sparsa improves our understanding of the deep evolutionary links between moulting animals. | The core spliceosome as target and effector of non-canonical ATM signalling
Transcription-blocking DNA lesions result in chromatin displacement of core spliceosomes containing U2 and U5 snRNPs; consequently, R-loops containing the nascent transcript are formed, which activate ATM in a feed-forward fashion to influence spliceosome dynamics and alternative splicing. | The architecture of the spliceosomal U4/U6.U5 tri-snRNP
This study determines the structure of the spliceosomal tri-snRNP complex (containing three small nuclear RNAs and more than 30 proteins) by single-particle cryo-electron microscopy; the resolution is sufficient to discern the organization of RNA and protein components involved in spliceosome activation, exon alignment and catalysis. | Glypican-1 identifies cancer exosomes and detects early pancreatic cancer
Glypican-1 identifies cancer exosomes and serves as a biomarker for detection of early pancreatic cancer in patients and mouse models of the disease; the findings may enable early and non-invasive identification, and prevention of malignant cancer. | Redox rhythm reinforces the circadian clock to gate immune response
The master immune regulator NPR1 of Arabidopsis is a sensor of the plant’s redox state and regulates transcription of core circadian clock genes even in the absence of pathogen challenge. | Impermanence of dendritic spines in live adult CA1 hippocampus
A new microendoscopic method reveals that hippocampal dendritic spines in the CA1 region undergo a complete turnover in less than six weeks in adult mice; this contrasts with the much greater stability of synapses in the neocortex and provides a physical basis for the fact that episodic memories are only retained by the mouse hippocampus for a few weeks. | A Middle Triassic stem-turtle and the evolution of the turtle body plan
A new Middle Triassic stem-turtle from Germany sheds new light on the evolutionary transition of turtles and their long-contentious relationships to other amniotes. | Rapidly rotating second-generation progenitors for the ‘blue hook’ stars of ω Centauri
The observed range of luminosities of the extremely hot ‘blue hook’ stars of the globular cluster ω Centauri is successfully explained by a model in which the progenitors of these stars are second-generation helium-rich stars characterized by a range of rotation rates arising during the cluster’s very early evolution. | X-ray structure of a mammalian stearoyl-CoA desaturase
The crystal structure of mouse SCD1 bound to fatty acid stearoyl-CoA is solved at 2.6 Å resolution; the structure reveals a novel geometry for the dimetal centre, and the acyl chain of the bound fatty acid is shown to be shielded and shaped to a particular conformation by the enzyme, providing a structural basis for the selectivity of fatty acid metabolism. | | An early modern human from Romania with a recent Neanderthal ancestor | Hallucigenia’s head and the pharyngeal armature of early ecdysozoans
A re-analysis of the 508-million-year-old stem-group onychophoran Hallucigenia sparsa from the Burgess Shale shows that its anterior gut has structures that indicate evolutionary links with more disparate phyla such as nematodes and kinorhynchs; Hallucigenia now provides concrete evidence of structures that might have existed in the last common ancestor of the Ecdysozoa, previously a matter of conjecture. | Hypoxia fate mapping identifies cycling cardiomyocytes in the adult heart
Fate-mapping hypoxic cells in the mouse heart identifies a rare population of cycling cardiomyocytes, which show characteristics of neonatal cardiomyocytes, including smaller size and mononucleation, and contribute to new cardiomyocyte formation in the adult heart. | Engineered CRISPR-Cas9 nucleases with altered PAM specificities
CRISPR-Cas9 nucleases are widely used for genome editing, but the range of sequences that Cas9 can recognize is constrained by the need for a specific protospacer adjacent motif (PAM); here the commonly used Streptococcus pyogenes Cas9 (SpCas9) is modified to recognize alternative PAM sequences, enabling robust editing of endogenous gene sites in zebrafish and human cells not currently targetable by wild-type SpCas9. | Distinct lineages of Ebola virus in Guinea during the 2014 West African epidemic OPEN
An analysis of 85 Ebola virus sequences collected in Guinea from July to November 2014 provides insight into the evolution of the Ebola virus responsible for the epidemic in West Africa; the results show sustained transmission of three co-circulating lineages, each defined by multiple mutations. | The ancestry and affiliations of Kennewick Man OPEN
Kennewick Man, a 8,500-year-old male human skeleton discovered in Washington state, USA, has been the subject of scientific and legal controversy; here a DNA analysis shows that Kennewick Man is closer to modern Native Americans than to any other extant population worldwide. | | Erratum: No signature of ejecta interaction with a stellar companion in three type Ia supernovae | | Erratum: A strong ultraviolet pulse from a newborn type Ia supernova | | Corrigendum: In vivo engineering of oncogenic chromosomal rearrangements with the CRISPR/Cas9 system | | The changing form of Antarctic biodiversity
Recent research has shown that while large fauna and flowering plants in the Antarctic are scarce, there are considerable levels of marine and terrestrial biodiversity, particularly the microbiota; what drives it, and how the Antarctic can meet conservation targets, are the subject of this review.
Steven L. Chown, Andrew Clarke, Ceridwen I. Fraser et al. | | Competitive binding of antagonistic peptides fine-tunes stomatal patterning
An investigation of the molecular mechanism of stomatal development and patterning finds an unexpected signalling mechanism: two signalling peptides (STOMAGEN, a positive regulator of stomatal development; and EPF2, a negative regulator of this process) use the same receptor kinase, ERECTA, to fine-tune stomatal development.
Jin Suk Lee, Marketa Hnilova, Michal Maes et al. | HIF-driven SF3B1 induces KHK-C to enforce fructolysis and heart disease
Myocardial hypoxia activates HIF1α, which activates the splicing factor SF3B1, which mediates a splice switch of the fructose-metabolising enzyme KHK, so that the C isoform that has superior affinity for fructose is expressed in the heart—pathological heart growth and contractile dysfunction can therefore be suppressed by depleting SF3B1 or deleting KHK.
Peter Mirtschink, Jaya Krishnan, Fiona Grimm et al. | Atomic structure of the APC/C and its mechanism of protein ubiquitination
A cryo-electron microscopy determination of the atomic structures of anaphase-promoting complex (APC/C)–coactivator complexes with either Emi1 or a UbcH10–ubiquitin conjugate.
Leifu Chang, Ziguo Zhang, Jing Yang et al. | | Sexual selection protects against extinction
Populations of the flour beetle Tribolium castaneum with histories of strong versus weak sexual selection purge mutation load and resist extinction differently.
Alyson J. Lumley, Łukasz Michalczyk, James J. N. Kitson et al. | Contribution of changes in atmospheric circulation patterns to extreme temperature trends
This study identifies statistically significant trends in mid-atmospheric circulation patterns that partially explain observed changes in extreme temperature occurrence over Eurasia and North America; although the underlying cause of circulation pattern trends remains uncertain, most extreme temperature trends are shown to be consistent with thermodynamic warming.
Daniel E. Horton, Nathaniel C. Johnson, Deepti Singh et al. | Cell death during crisis is mediated by mitotic telomere deprotection
Cells that bypass senescence in the absence of the p53 tumour suppressor protein have shortened telomeres that undergo fusion, and these fusions trigger mitotic arrest and cell death in crisis.
Makoto T. Hayashi, Anthony J. Cesare, Teresa Rivera et al. | New cofactor supports α,β-unsaturated acid decarboxylation via 1,3-dipolar cycloaddition
The Fdc1 protein from Aspergillus niger (which is homologous to the UbiD enzyme) uses a new prenylated flavin cofactor to achieve 1,3-dipolar cycloaddition chemistry and catalyse the reversible decarboxylation of aromatic carboxylic acids.
Karl A. P. Payne, Mark D. White, Karl Fisher et al. | A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b
In the ultraviolet spectrum, the Neptune-mass exoplanet GJ 436b is shown to have transit depths far greater than those seen in the optical spectrum, indicating that it is surrounded and trailed by a large cloud composed mainly of hydrogen atoms.
David Ehrenreich, Vincent Bourrier, Peter J. Wheatley et al. | Viraemia suppressed in HIV-1-infected humans by broadly neutralizing antibody 3BNC117
A phase I study of passive immunization with a CD4 binding-site-directed broadly neutralizing antibody shows that it transiently reduces HIV-1 viral loads in humans.
Marina Caskey, Florian Klein, Julio C. C. Lorenzi et al. | Galaxies at redshifts 5 to 6 with systematically low dust content and high [C ii] emission
Measurements of [C ii] emission and dust emission from nine typical star-forming galaxies about one billion years after the Big Bang show that galaxies of this age have dust levels that are significantly lower than those of typical galaxies about two billion years later and comparable with those of local low-metallicity galaxies.
P. L. Capak, C. Carilli, G. Jones et al. | A naturally occurring variant of the human prion protein completely prevents prion disease
This study looks at a polymorphism of the human prion protein gene, which results in a G-to-V substitution at residue 127, in transgenic mice expressing different human prion proteins, finding that mice heterozygous for the G127V polymorphism are resistant to both kuru and classical CJD prions, but there is some transmission of variant CJD prions; most remarkable, however, is that mice homozygous for V127 are completely resistant to all prion strains.
Emmanuel A. Asante, Michelle Smidak, Andrew Grimshaw et al. | The Drosophila TNF receptor Grindelwald couples loss of cell polarity and neoplastic growth
Cell polarity is an important feature of many tissues and is often disrupted in cancer; the TNF receptor Grindelwald is now shown to have an important role in coordinating cell polarity and neoplastic growth in a Drosophila model.
Ditte S. Andersen, Julien Colombani, Valentina Palmerini et al. | Linking high harmonics from gases and solids
High-harmonic generation in zinc oxide illuminated by an intense, pulsed, mid-infrared laser is found to involve a recollision effect in which electrons recollide with holes causing harmonics to be emitted, a process similar to that which occurs in atomic systems.
G. Vampa, T. J. Hammond, N. Thiré et al. | PPAR-α and glucocorticoid receptor synergize to promote erythroid progenitor self-renewal
Some types of anaemia do not respond to erythropoietin (Epo) treatment because patients do not have sufficient numbers of Epo-sensitive erythroid precursor cells; here, two agonists of PPAR-α are found to synergize with glucocorticoid treatment to promote early erythroid progenitor self-renewal, increasing the production of mature red blood cells in both human and mouse cultures and alleviating anaemia in mouse models.
Hsiang-Ying Lee, Xiaofei Gao, M. Inmaculada Barrasa et al. | UbiX is a flavin prenyltransferase required for bacterial ubiquinone biosynthesis
Ubiquinone is an essential component of electron transfer chains found both in bacteria and in mitochondria; the bacterial enzyme UbiX involved in ubiquinone biosynthesis is a flavin prenyltransferase, and the flavin-derived cofactor synthesized by UbiX is used by the UbiD decarboxylase in the ubiquinone biosynthetic pathway.
Mark D. White, Karl A. P. Payne, Karl Fisher et al. | | | | |
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