Enhancer Priming Enables Fast and Sustained Transcriptional Responses to Notch Signaling.

Information from developmental signaling pathways must be accurately decoded to generate transcriptional outcomes. In the case of Notch, the intracellular domain (NICD) transduces the signal directly to the nucleus. How enhancers decipher NICD in the real time of developmental decisions is not known. Using the MS2-MCP system to visualize nascent transcripts in single cells in Drosophila embryos, we reveal how two target enhancers read Notch activity to produce synchronized and sustained profiles of transcription. By manipulating the levels of NICD and altering specific motifs within the enhancers, we uncover two key principles. First, increased NICD levels alter transcription by increasing duration rather than frequency of transcriptional bursts. Second, priming of enhancers by tissue-specific transcription factors is required for NICD to confer synchronized and sustained activity; in their absence, transcription is stochastic and bursty. The dynamic response of an individual enhancer to NICD thus differs depending on the cellular context.Wellcome Trus

The atypical mammalian ligand Delta-like homologue 1 (Dlk1) can regulate Notch signalling in Drosophila

<p>Abstract</p> <p>Background</p> <p>Mammalian <it>Delta-like 1 </it>(<it>Dlk-1</it>) protein shares homology with Notch ligands but lacks a critical receptor-binding domain. Thus it is unclear whether it is able to interact with Notch <it>in vivo</it>. Unlike mammals, <it>Drosophila </it>have a single Notch receptor allowing a simple <it>in vivo </it>assay for mammalian <it>Dlk1 </it>function.</p> <p>Results</p> <p>Here we show that membrane-bound DLK1 can regulate Notch leading to altered cellular distribution of Notch itself and inhibiting expression of Notch target genes. The resulting adult phenotypes are indicative of reduced Notch function and are enhanced by <it>Notch </it>mutations, confirming that DLK1 action is antagonistic. In addition, cells expressing an alternative <it>Dlk1 </it>isoform exhibit alterations in cell size, functions previously not attributed to Notch suggesting that DLK1 might also act via an alternative target.</p> <p>Conclusion</p> <p>Our results demonstrate that DLK1 can regulate the Notch receptor despite its atypical structure.</p

Enabling Hospital Staff to Care for People with Dementia

This is the fourth and final article in a short series that presents case study examples of the positive work achieved by trusts who participated in the Royal College of Nursing’s development programme to improve dementia care in acute hospitals. Dementia training in hospitals is often inadequate and staff do not always have sufficient knowledge of dementia to provide appropriate care. It can also be difficult for them to identify when patients with dementia are in pain, especially when their communication skills deteriorate. The case studies presented illustrate how two NHS trusts have worked to ensure that their staff are fully equipped to care for people with dementia in hospital. Basildon and Thurrock University hospitals NHS Foundation Trust in Essex made dementia training a priority by including dementia awareness in staff induction across a range of roles and providing additional training activities tailored to meet staff needs. Nottingham University Hospitals NHS Trust focused on pain assessment, aiming to standardise its approach for patients with dementia. The pain assessment in advanced dementia tool was chosen and piloted, and is being implemented across the trust after a positive response

Recombination-Mediated Host Adaptation by Avian Staphylococcus aureus

Staphylococcus aureus are globally disseminated among farmed chickens causing skeletal muscle infections, dermatitis, and septicaemia. The emergence of poultry-associated lineages has involved zoonotic transmission from humans to chickens but questions remain about the specific adaptations that promote proliferation of chicken pathogens. We characterized genetic variation in a population of genome-sequenced S. aureus isolates of poultry and humanorigin. Genealogical analysis identified a dominant poultry-associated sequence cluster within the CC5 clonal complex. Poultry and human CC5 isolates were significantly distinct from each other and more recombination events were detected in the poultry isolates. We identified 44 recombination events in 33 genes along the branch extending to the poultry-specific CC5 cluster, and 47 genes were found more often in CC5 poultry isolates compared with those from humans. Many of these gene sequences were common in chicken isolates from other clonal complexes suggesting horizontal gene transfer among poultry associated lineages. Consistent with functional predictions for putative poultry-associated genes, poultry isolates showed enhanced growth at 42 degrees C and greater erythrocyte lysis on chicken blood agar in comparison with human isolates. By combining phenotype information with evolutionary analyses of staphylococcal genomes, we provide evidence of adaptation, following a human-to-poultry host transition. This has important implications for the emergence and dissemination of new pathogenic clones associated with modern agriculture.Peer reviewe

Mitochondrial Genomes Reveal an Explosive Radiation of Extinct and Extant Bears near the Miocene-Pliocene Boundary

Background: Despite being one of the most studied families within the Carnivora, the phylogenetic relationships among the members of the bear family (Ursidae) have long remained unclear. Widely divergent topologies have been suggested based on various data sets and methods. Results: We present a fully resolved phylogeny for ursids based on ten complete mitochondrial genome sequences from all eight living and two recently extinct bear species, the European cave bear (Ursus spelaeus) and the American giant short-faced bear (Arctodus simus). The mitogenomic data yield a well-resolved topology for ursids, with the sloth bear at the basal position within the genus Ursus. The sun bear is the sister taxon to both the American and Asian black bears, and this clade is the sister clade of cave bear, brown bear and polar bear confirming a recent study on bear mitochondrial genomes. Conclusion: Sequences from extinct bears represent the third and fourth Pleistocene species for which complete mitochondrial genomes have been sequenced. Moreover, the cave bear specimen demonstrates that mitogenomic studies can be applied to Pleistocene fossils that have not been preserved in permafrost, and therefore have a broad application within ancient DNA research. Molecular dating of the mtDNA divergence times suggests a rapid radiation of bears in both the Old and New Worlds around 5 million years ago, at the Miocene-Pliocene boundary. This coincides with major global changes, such as the Messinian crisis and the first opening of the Bering Strait, and suggests a global influence of such events on species radiations

ManyDogs Project: A Big Team Science Approach to Investigating Canine Behavior and Cognition

Dogs have a special place in human history as the first domesticated species and play important roles in many cultures around the world. However, their role in scientific studies has been relatively recent. With a few notable exceptions (e.g., Darwin, Pavlov, Scott, and Fuller), domestic dogs were not commonly the subject of rigorous scientific investigation of behavior until the late 1990s. Although the number of canine science studies has increased dramatically over the last 20 years, most research groups are limited in the inferences they can draw because of the relatively small sample sizes used, along with the exceptional diversity observed in dogs (e.g., breed, geographic location, experience). To this end, we introduce the ManyDogs Project, an international consortium of researchers interested in taking a big team science approach to understanding canine behavioral science. We begin by discussing why studying dogs provides valuable insights into behavior and cognition, evolutionary processes, human health, and applications for animal welfare. We then highlight other big team science projects that have previously been conducted in canine science and emphasize the benefits of our approach. Finally, we introduce the ManyDogs Project and our mission: (a) replicating important findings, (b) investigating moderators that need a large sample size such as breed differences, (c) reaching methodological consensus, (d) investigating cross-cultural differences, and (e) setting a standard for replication studies in general. In doing so, we hope to address previous limitations in individual lab studies and previous big team science frameworks to deepen our understanding of canine behavior and cognition

The Registry of Senior Australians outcome monitoring system: quality and safety indicators for residential aged care.

ObjectivesTo introduce the Registry of Senior Australians (ROSA) Outcome Monitoring System, which can monitor the quality and safety of care provided to individuals accessing residential aged care. Development and examination of 12 quality and safety indicators of care and their 2016 prevalence estimates are presented.DesignRetrospective.Setting2690 national and 254 South Australian (SA) aged care facilities.Participants208 355 unique residents nationally and 18 956 in SA.Main outcome measuresRisk-adjusted prevalence of high sedative load, antipsychotic use, chronic opioid use, antibiotic use, premature mortality, falls, fractures, medication-related adverse events, weight loss/malnutrition, delirium and/or dementia hospitalisations, emergency department presentations, and pressure injuries.ResultsFive indicators were estimated nationally; antibiotic use (67.5%, 95% confidence interval (CI): 67.3-67.7%) had the highest prevalence, followed by high sedative load (48.1%, 95% CI: 47.9-48.3%), chronic opioid use (26.8%, 95% CI: 26.6-26.9%), antipsychotic use (23.5%, 95% CI: 23.4-23.7%) and premature mortality (0.6%, 95% CI: 0.6-0.7%). Seven indicators were estimated in SA; emergency department presentations (19.1%, 95% CI: 18.3-20.0%) had the highest prevalence, followed by falls (10.1%, 95% CI: 9.7-10.4%), fractures (4.8%, 95% CI: 4.6-5.1%), pressure injuries (2.9%, 95% CI: 2.7-3.1%), delirium and/or dementia related hospitalisations (2.3%, 95% CI: 2.1-2.6%), weight loss/malnutrition (0.7%, 95% CI: 0.6-0.8%) and medication-related events (0.6%, 95% CI: 0.5-0.7%).ConclusionsTwelve quality and safety indicators were developed to monitor aged care provided to older Australians based on the synthesis of existing literature and expert advisory input. These indicators rely on existing data within the aged care and healthcare sectors, therefore creating a pragmatic tool to examine quality and unwarranted care variation

Synergistic roles of climate warming and human occupation in Patagonian megafaunal extinctions during the Last Deglaciation

The causes of Late Pleistocene megafaunal extinctions (60,000 to 11,650 years ago, hereafter 60 to 11.65 ka) remain contentious, with major phases coinciding with both human arrival and climate change around the world. The Americas provide a unique opportunity to disentangle these factors as human colonization took place over a narrow time frame (~15 to 14.6 ka) but during contrasting temperature trends across each continent. Unfortunately, limited data sets in South America have so far precluded detailed comparison. We analyze genetic and radiocarbon data from 89 and 71 Patagonian megafaunal bones, respectively, more than doubling the high-quality Pleistocene megafaunal radiocarbon data sets from the region.We identify a narrowmegafaunal extinction phase 12,280 ± 110 years ago, some 1 to 3 thousand years after initial human presence in the area. Although humans arrived immediately prior to a cold phase, the Antarctic Cold Reversal stadial, megafaunal extinctions did not occur until the stadial finished and the subsequent warming phase commenced some 1 to 3 thousand years later. The increased resolution provided by the Patagonian material reveals that the sequence of climate and extinction events in North and South America were temporally inverted, but in both cases, megafaunal extinctions did not occur until human presence and climate warming coincided. Overall, metapopulation processes involving subpopulation connectivity on a continental scale appear to have been critical for megafaunal species survival of both climate change and human impacts.Fil: Metcalf, Jessica L.. University of Adelaide; Australia. State University of Colorado Boulder; Estados UnidosFil: Turney, Chris. University of New South Wales; AustraliaFil: Barnett, Ross. University of Oxford; Reino Unido. Universidad de Copenhagen; DinamarcaFil: Martin, Fabiana. Universidad de Magallanes. Instituto de la Patagonia. Centro de Estudios del Hombre Austral; ChileFil: Bray, Sarah C.. University of Adelaide; Australia. University of South Australia; AustraliaFil: Vilstrup, Julia T.. Universidad de Copenhagen; DinamarcaFil: Orlando, Ludovic. Universidad de Copenhagen; DinamarcaFil: Salas-Gismondi, Rodolfo. Université de Montpellier. Institut des Sciences de l’Evolution; Francia. Universidad Nacional Mayor de San Marcos; PerúFil: Loponte, Daniel Marcelo. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Medina, Matias Eduardo. Centro de Estudios Históricos ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Nigris, Mariana Eleonor. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Civalero, Maria Teresa. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, Pablo Marcelo. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gasco, Alejandra Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Paleoecología Humana; ArgentinaFil: Duran, Victor Alberto. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Paleoecología Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Seymour, Kevin L.. Royal Ontario Museum. Department of Natural History; CanadáFil: Otaola, Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; ArgentinaFil: Gil, Adolfo Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla | Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla | Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla; ArgentinaFil: Paunero, Rafael. Universidad Nacional de La Plata; ArgentinaFil: Prevosti, Francisco Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Bradshaw, Corey J. A.. University of Adelaide; AustraliaFil: Wheeler, Jane C.. Instituto de Investigación y Desarrollo de Camélidos Sudamericanos; PerúFil: Borrero, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; ArgentinaFil: Austin, Jeremy J.. University of Adelaide; AustraliaFil: Cooper, Alan. University of Adelaide; Australia. University of Oxford; Reino Unid

Effects of S1 Cleavage on the Structure, Surface Export, and Signaling Activity of Human Notch1 and Notch2

Notch receptors are normally cleaved during maturation by a furin-like protease at an extracellular site termed S1, creating a heterodimer of non-covalently associated subunits. The S1 site lies within a key negative regulatory region (NRR) of the receptor, which contains three highly conserved Lin12/Notch repeats and a heterodimerization domain (HD) that interact to prevent premature signaling in the absence of ligands. Because the role of S1 cleavage in Notch signaling remains unresolved, we investigated the effect of S1 cleavage on the structure, surface trafficking and ligand-mediated activation of human Notch1 and Notch2, as well as on ligand-independent activation of Notch1 by mutations found in human leukemia.The X-ray structure of the Notch1 NRR after furin cleavage shows little change when compared with that of an engineered Notch1 NRR lacking the S1-cleavage loop. Likewise, NMR studies of the Notch2 HD domain show that the loop containing the S1 site can be removed or cleaved without causing a substantial change in its structure. However, Notch1 and Notch2 receptors engineered to resist S1 cleavage exhibit unexpected differences in surface delivery and signaling competence: S1-resistant Notch1 receptors exhibit decreased, but detectable, surface expression and ligand-mediated receptor activation, whereas S1-resistant Notch2 receptors are fully competent for cell surface delivery and for activation by ligands. Variable dependence on S1 cleavage also extends to T-ALL-associated NRR mutations, as common class 1 mutations display variable decrements in ligand-independent activation when introduced into furin-resistant receptors, whereas a class 2 mutation exhibits increased signaling activity.S1 cleavage has distinct effects on the surface expression of Notch1 and Notch2, but is not generally required for physiologic or pathophysiologic activation of Notch proteins. These findings are consistent with models for receptor activation in which ligand-binding or T-ALL-associated mutations lead to conformational changes of the NRR that permit metalloprotease cleavage

The Cinderella syndrome:why do malaria-infected cells burst at midnight?

An interesting quirk of many malaria infections is that all parasites within a host-millions of them-progress through their cell cycle synchronously. This surprising coordination has long been recognized, yet there is little understanding of what controls it or why it has evolved. Interestingly, the conventional explanation for coordinated development in other parasite species does not seem to apply here. We argue that for malaria parasites, a critical question has yet to be answered: is the coordination due to parasites bursting at the same time or at a particular time? We explicitly delineate these fundamentally different scenarios, possible underlying mechanistic explanations and evolutionary drivers, and discuss the existing corroborating data and key evidence needed to solve this evolutionary mystery. © 2012 Elsevier Ltd