| | | Volume 509 Number 7499 | | | | nature | | The science that matters. Every week. | | | | | | | | | | |  | | | Starting a CRISPR/CAS9 project for genome editing? Come to OriGene for a wide selection of tools: • All-in-one pCAS-Guide vectors,
• gRNA and donor vector cloning services • Genome-wide gene knockout kit | | | | | | | | Jump to the content that matters to you | | | | | | | | | | | | | | | Properties of galaxies reproduced by a hydrodynamic simulation | | Established cosmological models of galaxy formation and evolution have achieved limited success, failing to create the mixed population of elliptical and spiral galaxies that we observe. This new simulation makes full use of the latest advances in computing power and algorithmic developments to successfully recreates a population of ellipticals and spirals. It reproduces the observed distribution of galaxies in clusters and the evolution of dark and visible matter from shortly after the Big Bang until the present day, spanning more than 13 billion years of cosmic evolution. | | | | | | | | | | | | | Tropical forcing of the recent rapid Arctic warming in northeastern Canada and Greenland | | Greenland and Northeastern Canada have experienced rapid warming in recent decades, with human-induced climate change usually assumed to be in play. Qing-Hua Ding et al. show that half of the observed warming can be attributed to changes in sea surface temperature in the equatorial Pacific Ocean which in turn influence the circulation of warm air northwards from the tropics. Further research will be needed to establish whether the changes in the Pacific are themselves a response to the effects of human activity on the climate system. | | | | | | | | | | | | | Niche filling slows the diversification of Himalayan songbirds | | The beginnings of adaptive radiation and speciation have been widely studied – in Darwin's finches, sticklebacks and cichlid fish for example – but relatively little is known about what happens next. Specifically, what is the rate-limiting step for the establishment of new species? This seven-year study of the 358 songbird species found on the Himalayan slopes suggests that it is the rates at which new niches are created and occupied that limit diversification, not the rate at which new species form through reproductive isolation. | | | | | | | | | | | | | | | | | In this week's podcast: scientists turn to crowd-sourcing to figure out the retina, reconstructing the evolution of the Universe, and a semi-synthetic organism with a man-made base pair. In our latest video features, a study on robins shows that man-made electromagnetic noise interferes with birds' magnetic compass, which they use to help them migrate, and a computer simulation that traces 13 billion years of galaxy evolution produces a Universe that's remarkably similar to what we see through our telescopes. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tribal gathering ▶ | | | | Before they can construct a cell, researchers in synthetic biology must first build bridges between disciplines. | | | | | | | | | | | | A cosmic history ▶ | | | | Millions of hours of processing time yield the best picture so far of how the Universe evolved. | | | | | | | | | | | | The game is on ▶ | | | | Amoeba races demonstrate a fun way to promote interest in science. | | | | | | | | | | | | | | | | | | | | | | | | Seven days: 2–8 May 2014 ▶ | | | | The week in science: Polio declared international health emergency; UK considers lifting confidentiality on animal research; and RIKEN panel dogged by further misconduct allegations. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Synthetic biology: Beyond divisions ▶ | | | | Since the birth of synthetic biology nearly 15 years ago, the field has splintered into diverse tribes of scientists, all attempting to bestow cells with new abilities. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Q&A: Canopy composer ▶ | | | | Sound artist Daniel Jones creates self-generating artworks based on human and natural patterns and processes. As he prepares to travel through four UK forests with the installation Living Symphonies, a collaboration with artist James Bulley, he talks about music that emerges from ecosystem dynamics, and works inspired by bacterial genetics and social networks. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Space–time wiring specificity supports direction selectivity in the retina ▶ | | | | Jinseop S. Kim, Matthew J. Greene, Aleksandar Zlateski et al. | | | | Motion detection by the retina is thought to rely largely on the biophysics of starburst amacrine cell dendrites; here machine learning is used with gamified crowdsourcing to draw the wiring diagram involving amacrine and bipolar cells to identify a plausible circuit mechanism for direction selectivity; the model suggests similarities between mammalian and insect vision. | | | | | | | | | | | | c-kit+ cells minimally contribute cardiomyocytes to the heart ▶ | | | | Jop H. van Berlo, Onur Kanisicak, Marjorie Maillet et al. | | | | Whether or not endogenous c-kit+ cells residing within the heart contribute cardiomyocytes during physiological ageing or after injury remains unknown; here, using an inducible lineage tracing system, the c-kit+ lineage is shown to generate cardiomyocytes at very low levels, and, by contrast, contributes substantially to cardiac endothelial cell generation. | | | | | | | | | | | | Genome-defence small RNAs exapted for epigenetic mating-type inheritance ▶ | | | | Deepankar Pratap Singh, Baptiste Saudemont, Gérard Guglielmi et al. | | | | The molecular basis for mating-type determination in the ciliate Paramecium has been elucidated, revealing a novel function for a class of small RNAs — these scnRNAs are typically involved in reprogramming the Paramecium genome during sexual reproduction by recognizing and excising transposable elements, but they are now found to be co-opted to switch off expression of the newly identified mating-type gene mtA by excising its promoter, and to mediate epigenetic inheritance of mating types across sexual generations. | | | | | | | | | | | | A Ctf4 trimer couples the CMG helicase to DNA polymerase α in the eukaryotic replisome ▶ | | | | Aline C. Simon, Jin C. Zhou, Rajika L. Perera et al. | | | | This study shows how the yeast Ctf4 protein couples the DNA helicase, Cdc45–MCM–GINS, to DNA polymerase α — the GINS subunit of the helicase and the polymerase use a similar interaction to bind Ctf4, suggesting that, as Ctf4 is a trimer, two polymerases could be simultaneously coupled to a single helicase during lagging-strand synthesis. | | | | | | | | | | | | Emergence of reproducible spatiotemporal activity during motor learning ▶ | | | | Andrew J. Peters, Simon X. Chen, Takaki Komiyama | | | | Inhibitory neuron activity is found to be relatively stable during motor learning whereas excitatory neuron activity is much more dynamic — the results indicate that a large number of neurons exhibit activity changes early on during motor learning, but this population is refined with subsequent practice. | | | | | | | | | | | | Quantitative flux analysis reveals folate-dependent NADPH production ▶ | | | | Jing Fan, Jiangbin Ye, Jurre J. Kamphorst et al. | | | | A metabolomics quantification of NADPH production and consumption fluxes in proliferating mammalian cells reveals that, in addition to canonical pathways such as the oxidative pentose phosphate pathway, NADPH can also be produced by a folate metabolism pathway, a discovery providing new insights into the metabolism of cell growth. | | | | | | | | | | | | PTEN action in leukaemia dictated by the tissue microenvironment ▶ | | | | Cornelius Miething, Claudio Scuoppo, Benedikt Bosbach et al. | | | | A mouse model of T-cell leukaemia is used to test whether PTEN loss is required for tumour maintenance as well as initiation; although it had little effect on tumour load in haematopoietic organs, PTEN reactivation reduced the CCR9-dependent tumour dissemination to the intestine that was amplified on PTEN loss, exposing the importance of tumour microenvironment in PTEN-deficient settings. | | | | | | | | | | | | Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird ▶ | | | | Svenja Engels, Nils-Lasse Schneider, Nele Lefeldt et al. | | | | For the first time under reproducible and fully double-blinded conditions, it is shown that anthropogenic electromagnetic noise below the WHO limits affects a biological system: night-migrating birds lose the ability to use the Earth’s magnetic field for orientation when exposed to anthropogenic electromagnetic noise at strengths routinely produced by commonly used electronic devices. | | | | | | | | | | | | | | | | A semi-synthetic organism with an expanded genetic alphabet ▶ | | | | Denis A. Malyshev, Kirandeep Dhami, Thomas Lavergne et al. | | | | Triphosphates of hydrophobic nucleotides d5SICS and dNaM are imported into Escherichia coli by an exogenous algal nucleotide triphosphate transporter and then used by an endogenous polymerase to replicate, and faithfully maintain over many generations of growth, a plasmid containing the d5SICS–dNaM unnatural base pair. | | | | | | | | | | | | | | | | FXR is a molecular target for the effects of vertical sleeve gastrectomy ▶ | | | | Karen K. Ryan, Valentina Tremaroli, Christoffer Clemmensen et al. | | | | Bariatric surgical procedures, such as vertical sleeve gastrectomy (VSG), are the most effective therapy for the treatment of obesity; now bile acids, and the presence of the nuclear bile acid receptor FXR, are shown to underpin the mechanism of VSG action, and the ability of VSG to reduce body weight and improve glucose tolerance is substantially reduced if FXR is absent. | | | | | | | | | | | | Astrocyte-encoded positional cues maintain sensorimotor circuit integrity ▶ | | | | Anna V. Molofsky, Kevin W. Kelley, Hui-Hsin Tsai et al. | | | | Populations of astrocytes in the spinal cord are shown to express region-specific genes, with ventral astrocyte-encoded Sema3a necessary for proper motor neuron circuit organization and typical sensory afferent projection patterns; these findings suggest that astrocytes provide a positional cue for maintaining proper circuit formation and refinement. | | | | | | | | | | | | Synapse elimination and learning rules co-regulated by MHC class I H2-Db ▶ | | | | Hanmi Lee, Barbara K. Brott, Lowry A. Kirkby et al. | | | | This study reveals a role for the MHC class I molecule H2-Db in retinogeniculate synapse elimination; expression of this immune system molecule in neurons lacking it is sufficient to rescue proper synapse pruning, as well as the segregation of eye-specific circuits in mice. | | | | | | | | | | | | | | | | | | | | Sensory stimulation shifts visual cortex from synchronous to asynchronous states ▶ | | | | Andrew Y. Y. Tan, Yuzhi Chen, Benjamin Scholl et al. | | | | Intracellular recordings distinguish between mechanisms that can account for variability in primary visual cortex of alert primates, consistent with a scheme in which spiking is driven by infrequent synchronous events during fixation, with sensory stimulation shifting the cortex to an asynchronous state. | | | | | | | | | | | | | | | | | | | | Endosomes are specialized platforms for bacterial sensing and NOD2 signalling ▶ | | | | Norihiro Nakamura, Jennie R. Lill, Qui Phung et al. | | | | The endo-lysosomal transporters SLC15A3 and SLC15A4 provide a portal of entry for extracellular bacterial products that activate the cytoplasmic sensor NOD2; these results establish the importance of endosomes as signalling platforms specialized for triggering innate immune responses. | | | | | | | | | | | | Signal amplification and transduction in phytochrome photosensors ▶ | | | | Heikki Takala, Alexander Björling, Oskar Berntsson et al. | | | | The solution and crystal structures of a bacterial phytochrome photosensory core in both its resting and activated states are determined; switching between closed (resting) and open (activated) forms is found to be mediated by a conserved ‘tongue’, and the structures indicate that smaller changes in the vicinity of the chromophore are amplified in scale as they are transmitted through the tongue and beyond. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |  | | | BRAND NEW: Discounts on lab equipment
Exclusive prices and information - all in one place! Check our listings before you buy. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PTEN action in leukaemia dictated by the tissue microenvironment ▶ | | | | Cornelius Miething, Claudio Scuoppo, Benedikt Bosbach et al. | | | | A mouse model of T-cell leukaemia is used to test whether PTEN loss is required for tumour maintenance as well as initiation; although it had little effect on tumour load in haematopoietic organs, PTEN reactivation reduced the CCR9-dependent tumour dissemination to the intestine that was amplified on PTEN loss, exposing the importance of tumour microenvironment in PTEN-deficient settings. | | | | | | | | | | | | Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird ▶ | | | | Svenja Engels, Nils-Lasse Schneider, Nele Lefeldt et al. | | | | For the first time under reproducible and fully double-blinded conditions, it is shown that anthropogenic electromagnetic noise below the WHO limits affects a biological system: night-migrating birds lose the ability to use the Earth’s magnetic field for orientation when exposed to anthropogenic electromagnetic noise at strengths routinely produced by commonly used electronic devices. | | | | | | | | | | | | | | | | FXR is a molecular target for the effects of vertical sleeve gastrectomy ▶ | | | | Karen K. Ryan, Valentina Tremaroli, Christoffer Clemmensen et al. | | | | Bariatric surgical procedures, such as vertical sleeve gastrectomy (VSG), are the most effective therapy for the treatment of obesity; now bile acids, and the presence of the nuclear bile acid receptor FXR, are shown to underpin the mechanism of VSG action, and the ability of VSG to reduce body weight and improve glucose tolerance is substantially reduced if FXR is absent. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tracking excited-state charge and spin dynamics in iron coordination complexes ▶ | | | | Wenkai Zhang, Roberto Alonso-Mori, Uwe Bergmann et al. | | | | Femtosecond resolution X-ray fluorescence spectroscopy is shown to track the charge and spin dynamics triggered when an iron coordination complex is excited by light, and establishes the critical role of intermediate spin states in the de-excitation process. | | | | | | | | | | | | Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird ▶ | | | | Svenja Engels, Nils-Lasse Schneider, Nele Lefeldt et al. | | | | For the first time under reproducible and fully double-blinded conditions, it is shown that anthropogenic electromagnetic noise below the WHO limits affects a biological system: night-migrating birds lose the ability to use the Earth’s magnetic field for orientation when exposed to anthropogenic electromagnetic noise at strengths routinely produced by commonly used electronic devices. | | | | | | | | | | | | | | | | Properties of galaxies reproduced by a hydrodynamic simulation ▶ | | | | M. Vogelsberger, S. Genel, V. Springel et al. | | | | A simulation that starts 12 million years after the Big Bang and traces 13 billion years of cosmic evolution yields a reasonable population of elliptical and spiral galaxies, reproduces the observed distribution of galaxies in clusters and the characteristics of hydrogen on large scales, and at the same time matches the ‘metal’ and hydrogen content of galaxies on small scales. | | | | | | | | | | | | Circular polarization in the optical afterglow of GRB 121024A ▶ | | | | K. Wiersema, S. Covino, K. Toma et al. | | | | Circularly polarized light is unexpectedly detected in the afterglow of γ-ray burst GRB 121024A measured 0.15 days after the burst, and is shown to be intrinsic to the afterglow and unlikely to be produced by dust scattering or plasma propagation effects. | | | | | | | | | | | | Classical shear cracks drive the onset of dry frictional motion ▶ | | | | Ilya Svetlizky, Jay Fineberg | | | | The transition between ‘static’ and ‘dynamic’ friction in a model system is found to be quantitatively captured by the same theoretical framework as is used to describe brittle fracture, but deviations from this correspondence are observed as the rupture velocity approaches the speed at which sound waves propagate along the interface. | | | | | | | | | | | | Signal amplification and transduction in phytochrome photosensors ▶ | | | | Heikki Takala, Alexander Björling, Oskar Berntsson et al. | | | | The solution and crystal structures of a bacterial phytochrome photosensory core in both its resting and activated states are determined; switching between closed (resting) and open (activated) forms is found to be mediated by a conserved ‘tongue’, and the structures indicate that smaller changes in the vicinity of the chromophore are amplified in scale as they are transmitted through the tongue and beyond. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Increasing CO2 threatens human nutrition ▶ | | | | Samuel S. Myers, Antonella Zanobetti, Itai Kloog et al. | | | | The largest assemblage so far of published data shows that C3 crops have decreased zinc and iron levels under CO2 conditions predicted for the middle of this century, with worldwide nutritional implications. | | | | | | | | | | | | | | | | | | | | Classical shear cracks drive the onset of dry frictional motion ▶ | | | | Ilya Svetlizky, Jay Fineberg | | | | The transition between ‘static’ and ‘dynamic’ friction in a model system is found to be quantitatively captured by the same theoretical framework as is used to describe brittle fracture, but deviations from this correspondence are observed as the rupture velocity approaches the speed at which sound waves propagate along the interface. | | | | | | | | | | | | Tropical forcing of the recent rapid Arctic warming in northeastern Canada and Greenland ▶ | | | | Qinghua Ding, John M. Wallace, David S. Battisti et al. | | | | Human-induced climate change is usually assumed to be responsible for the dramatic thawing of glaciers since the mid 1990s in Greenland and northeastern Canada; approximately half of the observed warming in this region during this period is now found to be attributable to atmospheric circulation changes that may be of natural origin. | | | | | | | | | | | | Consequences of biodiversity loss for litter decomposition across biomes ▶ | | | | I. Tanya Handa, Rien Aerts, Frank Berendse et al. | | | | Field experiments across aquatic and terrestrial ecosystems show that biodiversity positively affects carbon and nitrogen cycling in leaf litter decomposition, indicating that reduced decomposition caused by biodiversity loss would modify the global carbon cycle and limit the nitrogen supply to the organisms at the base of the food chain. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |  | | | Nature Partner Journals is a new series of online open access journals published in collaboration with world-renowned international partners. Each partnership in the portfolio brings together strong editorial leadership with world-class publication systems to deliver high-quality, peer-reviewed original research. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Careers related news & comment | | | | | | | | | | | | | | | | | | | | | | 
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