115 research outputs found
Base excision repair deficient mice lacking the Aag alkyladenine DNA glycosylase.
3-methyladenine (3MeA) DNA glycosylases remove 3MeAs from alkylated DNA to initiate the base excision repair pathway. Here we report the generation of mice deficient in the 3MeA DNA glycosylase encoded by the Aag (Mpg) gene. Alkyladenine DNA glycosylase turns out to be the major DNA glycosylase not only for the cytotoxic 3MeA DNA lesion, but also for the mutagenic 1,N6-ethenoadenine (epsilonA) and hypoxanthine lesions. Aag appears to be the only 3MeA and hypoxanthine DNA glycosylase in liver, testes, kidney, and lung, and the only epsilonA DNA glycosylase in liver, testes, and kidney; another epsilonA DNA glycosylase may be expressed in lung. Although alkyladenine DNA glycosylase has the capacity to remove 8-oxoguanine DNA lesions, it does not appear to be the major glycosylase for 8-oxoguanine repair. Fibroblasts derived from Aag -/- mice are alkylation sensitive, indicating that Aag -/- mice may be similarly sensitive
Molecular Analysis of Serum and Bronchoalveolar Lavage in a Mouse Model of Influenza Reveals Markers of Disease Severity That Can Be Clinically Useful in Humans
Background:
Management of influenza, a major contributor to the worldwide disease burden, is complicated by lack of reliable methods for early identification of susceptible individuals. Identification of molecular markers that can augment existing diagnostic tools for prediction of severity can be expected to greatly improve disease management capabilities.
Methodology/Principal Findings:
We have analyzed cytokines, proteome flux and protein adducts in bronchoalveolar lavage (BAL) and sera from mice infected with influenza A virus (PR8 strain) using a previously established non-lethal model of influenza infection. Through detailed cytokine and protein adduct measurements of murine BAL, we first established the temporal profile of innate and adaptive responses as well as macrophage and neutrophil activities in response to influenza infection. A similar analysis was also performed with sera from a longitudinal cohort of influenza patients. We then used an iTRAQ-based, comparative serum proteome analysis to catalog the proteome flux in the murine BAL during the stages correlating with “peak viremia,” “inflammatory damage,” as well as the “recovery phase.” In addition to activation of acute phase responses, a distinct class of lung proteins including surfactant proteins was found to be depleted from the BAL coincident with their “appearance” in the serum, presumably due to leakage of the protein following loss of the integrity of the lung/epithelial barrier. Serum levels of at least two of these proteins were elevated in influenza patients during the febrile phase of infection compared to healthy controls or to the same patients at convalescence.
Conclusions/Significance:
The findings from this study provide a molecular description of disease progression in a mouse model of influenza and demonstrate its potential for translation into a novel class of markers for measurement of acute lung injury and improved case management.Singapore. National Research FoundationSingapore-MIT Alliance for Research and Technology (ID-IRG research program
Extensive variation in the intelectin gene family in laboratory and wild mouse strains
Intelectins are a family of multimeric secreted proteins that bind microbe-specific glycans. Both genetic and functional studies have suggested that intelectins have an important role in innate immunity and are involved in the etiology of various human diseases, including inflammatory bowel disease. Experiments investigating the role of intelectins in human disease using mouse models are limited by the fact that there is not a clear one-to-one relationship between intelectin genes in humans and mice, and that the number of intelectin genes varies between different mouse strains. In this study we show by gene sequence and gene expression analysis that human intelectin-1 (ITLN1) has multiple orthologues in mice, including a functional homologue Itln1; however, human intelectin-2 has no such orthologue or homologue. We confirm that all sub-strains of the C57 mouse strain have a large deletion resulting in retention of only one intelectin gene, Itln1. The majority of laboratory strains have a full complement of six intelectin genes, except CAST, SPRET, SKIVE, MOLF and PANCEVO strains, which are derived from different mouse species/subspecies and encode different complements of intelectin genes. In wild mice, intelectin deletions are polymorphic in Mus musculus castaneus and Mus musculus domesticus. Further sequence analysis shows that Itln3 and Itln5 are polymorphic pseudogenes due to premature truncating mutations, and that mouse Itln1 has undergone recent adaptive evolution. Taken together, our study shows extensive diversity in intelectin genes in both laboratory and wild-mice, suggesting a pattern of birth-and-death evolution. In addition, our data provide a foundation for further experimental investigation of the role of intelectins in disease
Performance limits due to thermal transport in graphene single-photon bolometers
In high-sensitivity bolometers and calorimeters, the photon absorption often
occurs at a finite distance from the temperature sensor to accommodate antennas
or avoid the degradation of superconducting circuitry exposed to radiation. As
a result, thermal propagation from the input to the temperature readout can
critically affect detector performance. In this report we model the performance
of a graphene bolometer, accounting for electronic thermal diffusion and
dissipation via electron-phonon coupling at low temperatures in three regimes:
clean, supercollision, and resonant scattering. Our results affirm the
feasibility of a superconducting readout without Cooper-pair breaking by mid-
and near-infrared photons, and provide a recipe for designing graphene
absorbers for calorimetric single-photon detectors. We investigate the tradeoff
between the input-readout distance and detector efficiency, and predict an
intrinsic timing jitter of ~2.7 ps. Based on our result, we propose a
spatial-mode-resolving photon detector to increase communication bandwidth
Building on the past, shaping the future: The environmental mutagenesis and genomics society
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97167/1/em21765.pd
Unification of New Zealand's local vertical datums: iterative gravimetric quasigeoid computations
New Zealand uses 13 separate local vertical datums (LVDs) based on normal-orthometric-corrected precise geodetic levelling from 12 different tide-gauges. We describe their unification using a regional gravimetric quasigeoid model and GPS-levelling data on each LVD. A novel application of iterative quasigeoid computation is used, where the LVD offsets computed from earlier models are used to apply additional gravity reductions from each LVD to that model. The solution converges after only three iterations yielding LVD offsets ranging from 0.24 m to 0.58 m with an average standard deviation of 0.08 m. The so-computed LVD offsets agree, within expected data errors, with geodetically levelled height differences at common benchmarks between adjacent LVDs. This shows that iterated quasigeoid models do have a role in vertical datum unification
Metabolic characterization of Palatinate German white wines according to sensory attributes, varieties, and vintages using NMR spectroscopy and multivariate data analyses
1H NMR (nuclear magnetic resonance spectroscopy) has been used for metabolomic analysis of ‘Riesling’ and ‘Mueller-Thurgau’ white wines from the German Palatinate region. Diverse two-dimensional NMR techniques have been applied for the identification of metabolites, including phenolics. It is shown that sensory analysis correlates with NMR-based metabolic profiles of wine. 1H NMR data in combination with multivariate data analysis methods, like principal component analysis (PCA), partial least squares projections to latent structures (PLS), and bidirectional orthogonal projections to latent structures (O2PLS) analysis, were employed in an attempt to identify the metabolites responsible for the taste of wine, using a non-targeted approach. The high quality wines were characterized by elevated levels of compounds like proline, 2,3-butanediol, malate, quercetin, and catechin. Characterization of wine based on type and vintage was also done using orthogonal projections to latent structures (OPLS) analysis. ‘Riesling’ wines were characterized by higher levels of catechin, caftarate, valine, proline, malate, and citrate whereas compounds like quercetin, resveratrol, gallate, leucine, threonine, succinate, and lactate, were found discriminating for ‘Mueller-Thurgau’. The wines from 2006 vintage were dominated by leucine, phenylalanine, citrate, malate, and phenolics, while valine, proline, alanine, and succinate were predominantly present in the 2007 vintage. Based on these results, it can be postulated the NMR-based metabolomics offers an easy and comprehensive analysis of wine and in combination with multivariate data analyses can be used to investigate the source of the wines and to predict certain sensory aspects of wine
Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle
International audienceAbstractBackgroundWhite spotting of the coat is a characteristic trait of various domestic species including cattle and other mammals. It is a hallmark of Holstein–Friesian cattle, and several previous studies have detected genetic loci with major effects for white spotting in animals with Holstein–Friesian ancestry. Here, our aim was to better understand the underlying genetic and molecular mechanisms of white spotting, by conducting the largest mapping study for this trait in cattle, to date.ResultsUsing imputed whole-genome sequence data, we conducted a genome-wide association analysis in 2973 mixed-breed cows and bulls. Highly significant quantitative trait loci (QTL) were found on chromosomes 6 and 22, highlighting the well-established coat color genes KIT and MITF as likely responsible for these effects. These results are in broad agreement with previous studies, although we also report a third significant QTL on chromosome 2 that appears to be novel. This signal maps immediately adjacent to the PAX3 gene, which encodes a known transcription factor that controls MITF expression and is the causal locus for white spotting in horses. More detailed examination of these loci revealed a candidate causal mutation in PAX3 (p.Thr424Met), and another candidate mutation (rs209784468) within a conserved element in intron 2 of MITF transcripts expressed in the skin. These analyses also revealed a mechanistic ambiguity at the chromosome 6 locus, where highly dispersed association signals suggested multiple or multiallelic QTL involving KIT and/or other genes in this region.ConclusionsOur findings extend those of previous studies that reported KIT as a likely causal gene for white spotting, and report novel associations between candidate causal mutations in both the MITF and PAX3 genes. The sizes of the effects of these QTL are substantial, and could be used to select animals with darker, or conversely whiter, coats depending on the desired characteristics
European Competition Policy in International Markets
International audienceChanges in the institutional, technological and economic environment raise new challenges to the European competition policy. In this context, it is timely for European authorities to appraise the external dimension of the European competition policy as well as its articulation with current internal reforms. Globalisation can increase the costs of monitoring and seriously reduce the ability of European authorities to tackle cross-border anti-competitive conducts. In addition, conflicts are exacerbated by industrial policy motivations. As it is unlikely that the sole application of the territoriality and extraterritoriality principles to competition rules could yield an optimal international competition system, globalisation calls for higher levels and types of cooperation. Given that bilateral cooperation and especially the implementation of comity principles could be of no value when laws or interests are sources of international conflicts, three main paths could be therefore encouraged: The continuous harmonization of rules through the joint action of OECD and ICN; the higher cooperation in the confidential information exchange; the establishment of global anti-trust institutions. Although WTO is legitimate in judging questions related market access and entry barriers, it is less equipped to assess international hard core cartels or M&A reviews. As a substitute for WTO, a multilevel system, like the EU system, could be promoted. For political and pragmatic reasons, it could be composed in a first step of a hard core of countries like the EU, Japan and the U.S. It could be associated with the creation of an international Court of Justice for competition. In addition to these external reforms, some internal reforms could be required. Competition authorities have to develop further competition advocacy to give a higher priority to competition issues in other EU policies and national regulation. A parallel and complementary reform could consist in making the European competition agency independent from State Members' interference
- …
