121 research outputs found
Mitochondrial dysfunction causes Ca2+ overload and ECM degradation-mediated muscle damage in C. elegans
This is the final version. Available on open access from the Federation of American Society of Experimental Biology via the DOI in this recordMitochondrial dysfunction impairs muscle health and causes subsequent muscle wasting. This study explores the role of mitochondrial dysfunction as an intramuscular signal for the extracellular matrix (ECM)-based proteolysis and, consequentially, muscle cell dystrophy. We found that inhibition of the mitochondrial electron transport chain causes paralysis as well as muscle structural damage in the nematode Caenorhabditis elegans. This was associated with a significant decline in collagen content. Both paralysis and muscle damage could be rescued with collagen IV overexpression, matrix metalloproteinase (MMP), and Furin inhibitors in Antimycin A-treated animal as well as in the C. elegans Duchenne muscular dystrophy model. Additionally, muscle cytosolic calcium increased in the Antimycin A-treated worms, and its down-regulation rescued the muscle damage, suggesting that calcium overload acts as one of the early triggers and activates Furin and MMPs for collagen degradation. In conclusion, we have established ECM degradation as an important pathway of muscle damage.-Sudevan, S., Takiura, M., Kubota, Y., Higashitani, N., Cooke, M., Ellwood, R. A., Etheridge, T., Szewczyk, N. J., Higashitani, A. Mitochondrial dysfunction causes Ca2+ overload and ECM degradation-mediated muscle damage in C. elegans.Ministry of Education, Culture, Sports, Science, and Technology (MEXT)Cross-Ministerial Strategic Innovation Promotion ProgramAdvanced Research and Development Programs for Medical Innovation (AMED-CRESTBiotechnology and Biological Sciences Research Council (BBSRC)UK Space AgencyScience and Technology Facilities Council (STFC)Otsuka Toshimi FoundationTohoku UniversityJapan Student Services Organizatio
Pathotype variation of barley powdery mildew in Western Australia
Barley powdery mildew caused by the fungus Blumeria graminis f. sp. hordei (Bgh) has emerged as the most damaging disease of barley in Western Australia (WA). Many of the available cultivars display high levels of disease in the field when climatic conditions are conducive. As a result, fungicides have become the main method of disease control in the last 10 years. Different types and sources of genetic disease resistance are available but to optimise their deployment it is necessary to evaluate the spectrum of pathotypes present in the pathogen population. Sixty isolates of Bgh were collected in the 2009 season from 9 locations, single spored and characterised by infection on reference barley lines and cultivars. Eighteen unique pathotypes were resolved. Virulence against many of the R-genes in the reference lines was present in at least one pathotype. Isolates were virulent against 16 out of a total of 23 resistance gene combinations. Undefeated resistance genes included the major R-genes Mla-6, Mla-9, Ml-ra and the combinations of Mla-1 plus Mla-A12 and Mla-6 plus Mla-14 and Mla-13 plus Ml-Ru3 together with the recessive resistance gene mlo-5. There was significant pathotype spatial differentiation suggesting limited gene flow between different regions with WA or localised selection pressures and proliferation. On the basis of the results we recommend a number of strategies to manage powdery mildew disease levels within WA
Anticaries potential of a fluoride mouthrinse evaluated in vitro by validated protocols
An active-radio-frequency-identification system capable of identifying co-locations and social-structure: Validation with a wild free-ranging animal
Abstract
Behavioural events that are important for understanding sociobiology and movement ecology are often rare, transient and localised, but can occur at spatially distant sites e.g. territorial incursions and co‐locating individuals. Existing animal tracking technologies, capable of detecting such events, are limited by one or more of: battery life; data resolution; location accuracy; data security; ability to co‐locate individuals both spatially and temporally. Technology that at least partly resolves these limitations would be advantageous. European badgers (Meles meles L.), present a challenging test‐bed, with extra‐group paternity (apparent from genotyping) contradicting established views on rigid group territoriality with little social‐group mixing.
In a proof of concept study we assess the utility of a fully automated active‐radio‐frequency‐identification (aRFID) system combining badger‐borne aRFID‐tags with static, wirelessly‐networked, aRFID‐detector base‐stations to record badger co‐locations at setts (burrows) and near notional border latrines. We summarise the time badgers spent co‐locating within and between social‐groups, applying network analysis to provide evidence of co‐location based community structure, at both these scales.
The aRFID system co‐located animals within 31.5 m (adjustable) of base‐stations. Efficient radio transmission between aRFIDs and base‐stations enables a 20 g tag to last for 2–5 years (depending on transmission interval). Data security was high (data stored off tag), with remote access capability. Badgers spent most co‐location time with members of their own social‐groups at setts; remaining co‐location time was divided evenly between intra‐ and inter‐social‐group co‐locations near latrines and inter‐social‐group co‐locations at setts. Network analysis showed that 20–100% of tracked badgers engaged in inter‐social‐group mixing per week, with evidence of trans‐border super‐groups, that is, badgers frequently transgressed notional territorial borders.
aRFID occupies a distinct niche amongst established tracking technologies. We validated the utility of aRFID to identify co‐locations, social‐structure and inter‐group mixing within a wild badger population, leading us to refute the conventional view that badgers (social‐groups) are territorial and to question management strategies, for controlling bovine TB, based on this model. Ultimately aRFID proved a versatile system capable of identifying social‐structure at the landscape scale, operating for years and suitable for use with a range of species.
EPSRC WILDSENSING projec
Pleosporales
One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae
Mitochondrial hydrogen sulfide supplementation improves health in the C. elegans Duchenne muscular dystrophy model
This is the final version. Available on open access from the National Academy of Sciences via the DOI in this record. Data Availability: All study data are included in the article.Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder characterized by progressive muscle degeneration and weakness due to mutations in the dystrophin gene. The symptoms of DMD share similarities with those of accelerated aging. Recently, hydrogen sulfide (H2S) supplementation has been suggested to modulate the effects of age-related decline in muscle function, and metabolic H2S deficiencies have been implicated in affecting muscle mass in conditions such as phenylketonuria. We therefore evaluated the use of sodium GYY4137 (NaGYY), a H2S-releasing molecule, as a possible approach for DMD treatment. Using the dys-1(eg33) Caenorhabditis elegans DMD model, we found that NaGYY treatment (100 µM) improved movement, strength, gait, and muscle mitochondrial structure, similar to the gold-standard therapeutic treatment, prednisone (370 µM). The health improvements of either treatment required the action of the kinase JNK-1, the transcription factor SKN-1, and the NAD-dependent deacetylase SIR-2.1. The transcription factor DAF-16 was required for the health benefits of NaGYY treatment, but not prednisone treatment. AP39 (100 pM), a mitochondria-targeted H2S compound, also improved movement and strength in the dys-1(eg33) model, further implying that these improvements are mitochondria-based. Additionally, we found a decline in total sulfide and H2S-producing enzymes in dystrophin/utrophin knockout mice. Overall, our results suggest that H2S deficit may contribute to DMD pathology, and rectifying/overcoming the deficit with H2S delivery compounds has potential as a therapeutic approach to DMD treatment.Medical Research Council (MRC)NASABiotechnology and Biological Sciences Research Council (BBSRC)Medical Research Council (MRC)United Mitochondrial Disease FoundationMRC Versus Arthritis Centre for Musculoskeletal Ageing ResearchNational Health and Medical Research CouncilUniversity of Nottingham School of MedicineFulbright U.S. Student ProgramGermanistic Society of AmericaBrian Ridge ScholarshipUniversity of ExeterUniversity of New South WalesUniversity of MelbourneRebecca L. Cooper Medical Research FoundationOsteopathic Heritage Foundatio
Bioinformatics approaches for cross-species liver cancer analysis based on microarray gene expression profiling
BACKGROUND: The completion of the sequencing of human, mouse and rat genomes and knowledge of cross-species gene homologies enables studies of differential gene expression in animal models. These types of studies have the potential to greatly enhance our understanding of diseases such as liver cancer in humans. Genes co-expressed across multiple species are most likely to have conserved functions. We have used various bioinformatics approaches to examine microarray expression profiles from liver neoplasms that arise in albumin-SV40 transgenic rats to elucidate genes, chromosome aberrations and pathways that might be associated with human liver cancer. RESULTS: In this study, we first identified 2223 differentially expressed genes by comparing gene expression profiles for two control, two adenoma and two carcinoma samples using an F-test. These genes were subsequently mapped to the rat chromosomes using a novel visualization tool, the Chromosome Plot. Using the same plot, we further mapped the significant genes to orthologous chromosomal locations in human and mouse. Many genes expressed in rat 1q that are amplified in rat liver cancer map to the human chromosomes 10, 11 and 19 and to the mouse chromosomes 7, 17 and 19, which have been implicated in studies of human and mouse liver cancer. Using Comparative Genomics Microarray Analysis (CGMA), we identified regions of potential aberrations in human. Lastly, a pathway analysis was conducted to predict altered human pathways based on statistical analysis and extrapolation from the rat data. All of the identified pathways have been known to be important in the etiology of human liver cancer, including cell cycle control, cell growth and differentiation, apoptosis, transcriptional regulation, and protein metabolism. CONCLUSION: The study demonstrates that the hepatic gene expression profiles from the albumin-SV40 transgenic rat model revealed genes, pathways and chromosome alterations consistent with experimental and clinical research in human liver cancer. The bioinformatics tools presented in this paper are essential for cross species extrapolation and mapping of microarray data, its analysis and interpretation
A ten-dimensional action for non-geometric fluxes
The NSNS Lagrangian of ten-dimensional supergravity is rewritten via a change
of field variables inspired by Generalized Complex Geometry. We obtain a new
metric and dilaton, together with an antisymmetric bivector field which leads
to a ten-dimensional version of the non-geometric Q-flux. Given the involved
global aspects of non-geometric situations, we prescribe to use this new
Lagrangian, whose associated action is well-defined in some examples
investigated here. This allows us to perform a standard dimensional reduction
and to recover the usual contribution of the Q-flux to the four-dimensional
scalar potential. An extension of this work to include the R-flux is discussed.
The paper also contains a brief review on non-geometry.Comment: 47 pages; v2: minor modifications, references added, version to be
published in JHE
Predicting sulfotyrosine sites using the random forest algorithm with significantly improved prediction accuracy
addresses: School of Biosciences, University of Exeter, Exeter EX4 5DE, UK. [email protected]: PMCID: PMC2777180types: Journal Article; Research Support, Non-U.S. Gov't© 2009 Yang; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Tyrosine sulfation is one of the most important posttranslational modifications. Due to its relevance to various disease developments, tyrosine sulfation has become the target for drug design. In order to facilitate efficient drug design, accurate prediction of sulfotyrosine sites is desirable. A predictor published seven years ago has been very successful with claimed prediction accuracy of 98%. However, it has a particularly low sensitivity when predicting sulfotyrosine sites in some newly sequenced proteins
Comprehensive annotation of the Parastagonospora nodorum reference genome using next-generation genomics, transcriptomics and proteogenomics
Parastagonospora nodorum, the causal agent of Septoria nodorum blotch (SNB), is an economically important pathogen of wheat (Triticum spp.), and a model for the study of necrotrophic pathology and genome evolution. The reference P. nodorum strain SN15 was the first Dothideomycete with a published genome sequence, and has been used as the basis for comparison within and between species. Here we present an updated reference genome assembly with corrections of SNP and indel errors in the underlying genome assembly from deep resequencing data as well as extensive manual annotation of gene models using transcriptomic and proteomic sources of evidence (https://github.com/robsyme/Parastagonospora_nodorum_SN15). The updated assembly and annotation includes 8,366 genes with modified protein sequence and 866 new genes. This study shows the benefits of using a wide variety of experimental methods allied to expert curation to generate a reliable set of gene models
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