517 research outputs found
Mediale Inszenierung prekĂ€rer Lebenswelten : am Beispiel von âIn der Schuldenfalleâ
Starting from the âconcept of disarticulationâ (McRobbie), in this article I want to have a detailed look at social interactions between women with different class backgrounds in Lifestyle-TV. The âconcept of disarticulationâ refers to the undermining of feminist achievements of the last years. Postfeminism as a form of Antifeminism is regarded as a base of this concept. Focussing on the ATV-programme âIn der Schuldenfalleâ I want to show, from a feminist perspective, how precarious lifestyles are represented in mass media and how they (re)produce gendered class differences in these representations. In popular Lifestyle-TV programmes female experts with a middle and upper class background transmit knowledge about everyday life (education, beauty, body, debt, etc.) from their perspective to women from lower strata. This kind of knowledge is not being taught in school; it implies and promises social mobility. Looking at âIn der Schuldenfalleâ, I particularly concentrate on the interaction between the financial expert and the so called âvictimâ involved in a âdebt trapâ in the context of class and gender. Finally, I raise the question of possible social gender identifications implied in watching Lifestyle- TV and the circulation of its practice of degrading speech in social space
Bleeding skin lesions in gestating sows of a piglet producing farm in Austria.
BACKGROUND
Stomoxys calcitrans, the stable fly, occurs in pig producing countries worldwide. While in cattle the impact of this blood sucking insect is quite well described, its role in pig production is poorly investigated. Here we describe a case of a massive stable fly overpopulation in the gestation unit of a piglet producing farm in Austria that resulted in bleeding skin lesions in bitten sows.
CASE PRESENTATION
In October 2021, the responsible herd veterinarian of the case farm reported of sows in the gestation area presenting with bloody crusts on the whole skin surface of the body and of bleeding skin lesions. 33/55 sows were affected by moderate to severe skin lesions. Reproductive performance decreased during the time of massive stable fly overpopulation. Sows in the gestation unit showed defensive behaviour and at a certain time point resigned and accepted being bitten by stable flies. After controlling the fly population, reproductive performance improved and even exceeded the performance before the massive overgrowth of the stable fly population.
CONCLUSIONS
Stable flies are a serious harm to pigs and should be kept in mind for improved animal health and welfare. Knowledge about the determination of Stomoxys calcitrans and early recognition of an increasing stable fly population in pig farming systems followed by proper insect control measures have to be performed to reduce losses caused by this harming insect
Molecular Taxonomy of Phytopathogenic Fungi: A Case Study in Peronospora
Background: Inappropriate taxon definitions may have severe consequences in many areas. For instance, biologically
sensible species delimitation of plant pathogens is crucial for measures such as plant protection or biological control and for
comparative studies involving model organisms. However, delimiting species is challenging in the case of organisms for
which often only molecular data are available, such as prokaryotes, fungi, and many unicellular eukaryotes. Even in the case
of organisms with well-established morphological characteristics, molecular taxonomy is often necessary to emend current
taxonomic concepts and to analyze DNA sequences directly sampled from the environment. Typically, for this purpose
clustering approaches to delineate molecular operational taxonomic units have been applied using arbitrary choices
regarding the distance threshold values, and the clustering algorithms.
Methodology: Here, we report on a clustering optimization method to establish a molecular taxonomy of Peronospora
based on ITS nrDNA sequences. Peronospora is the largest genus within the downy mildews, which are obligate parasites of
higher plants, and includes various economically important pathogens. The method determines the distance function and
clustering setting that result in an optimal agreement with selected reference data. Optimization was based on both
taxonomy-based and host-based reference information, yielding the same outcome. Resampling and permutation methods
indicate that the method is robust regarding taxon sampling and errors in the reference data. Tests with newly obtained ITS
sequences demonstrate the use of the re-classified dataset in molecular identification of downy mildews.
Conclusions: A corrected taxonomy is provided for all Peronospora ITS sequences contained in public databases. Clustering
optimization appears to be broadly applicable in automated, sequence-based taxonomy. The method connects traditional
and modern taxonomic disciplines by specifically addressing the issue of how to optimally account for both traditional
species concepts and genetic divergence.Peer reviewe
Front line defenders of the ecological niche! Screening the structural diversity of peptaibiotics from saprotrophic and fungicolous <i>Trichoderma/Hypocrea</i> species
Approximately 950 individual sequences of nonribosomally biosynthesised peptides are produced by the genus Trichoderma/Hypocreathat belong to a perpetually growing class of mostly linear antibiotic oligopeptides, which are rich in the non-proteinogenic α-aminoisobutyric acid (Aib). Thus, they are comprehensively named peptaibiotics. Notably, peptaibiotics represent ca. 80%of the total inventory of secondary metabolites currently known from Trichoderma/Hypocrea. Their unique membrane-modifying bioactivity results from amphipathicity and helicity, thus making them ideal candidates in assisting both colonisation and defence of the natural habitats by their fungal producers. Despite this, reports on the in vivo-detection of peptaibiotics have scarcely been published in the past. In order to evaluate the significance of peptaibiotic production for a broader range of potential producers, we screened nine specimensbelonging to seven hitherto uninvestigated fungicolous orsaprotrophic Trichoderma/Hypocrea species by liquid chromatographycoupled to electrospray high resolution mass spectrometry.Sequences of peptaibiotics found were independently confirmedby analysing the peptaibiome of pure agar culture
WRR4, a broad-spectrum TIR-NB-LRR gene from Arabidopsis thaliana that confers white rust resistance in transgenic oilseed brassica crops
White blister rust caused by Albugo candida (Pers.) Kuntze is a common and often devastating disease of oilseed and vegetable brassica crops worldwide. Physiological races of the parasite have been described, including races 2, 7 and 9 from Brassica juncea, B. rapa and B. oleracea, respectively, and race 4 from Capsella bursa-pastoris (the type host). A gene named WRR4 has been characterized recently from polygenic resistance in the wild brassica relative Arabidopsis thaliana (accession Columbia) that confers broad-spectrum white rust resistance (WRR) to all four of the above Al. candida races. This gene encodes a TIR-NB-LRR (Toll-like/interleukin-1 receptor-nucleotide binding-leucine-rich repeat) protein which, as with other known functional members in this subclass of intracellular receptor-like proteins, requires the expression of the lipase-like defence regulator, enhanced disease susceptibility 1 (EDS1). Thus, we used RNA interference-mediated suppression of EDS1 in a white rust-resistant breeding line of B. napus (transformed with a construct designed from the A. thaliana EDS1 gene) to determine whether defence signalling via EDS1 is functionally intact in this oilseed brassica. The eds1-suppressed lines were fully susceptible following inoculation with either race 2 or 7 isolates of Al. candida. We then transformed white rust-susceptible cultivars of B. juncea (susceptible to race 2) and B. napus (susceptible to race 7) with the WRR4 gene from A. thaliana. The WRR4-transformed lines were resistant to the corresponding Al. candida race for each host species. The combined data indicate that WRR4 could potentially provide a novel source of white rust resistance in oilseed and vegetable brassica crops
Evidence for suppression of immunity as a driver for genomic introgressions and host range expansion in races of Albugo candida, a generalist parasite
How generalist parasites with wide host ranges can evolve is a central question in parasite evolution. Albugo candida is an obligate biotrophic parasite that consists of many physiological races that each specialize on distinct Brassicaceae host species. By analyzing genome sequence assemblies of five isolates, we show they represent three races that are genetically diverged by âŒ1%. Despite this divergence, their genomes are mosaic-like, with âŒ25% being introgressed from other races. Sequential infection experiments show that infection by adapted races enables subsequent infection of hosts by normally non-infecting races. This facilitates introgression and the exchange of effector repertoires, and may enable the evolution of novel races that can undergo clonal population expansion on new hosts. We discuss recent studies on hybridization in other eukaryotes such as yeast, Heliconius butterflies, Darwinâs finches, sunflowers and cichlid fishes, and the implications of introgression for pathogen evolution in an agro-ecological environment
Natural history of Arabidopsis thaliana and oomycete symbioses
Molecular ecology of plantâmicrobe interactions has immediate significance for filling a gap in knowledge between the laboratory discipline of molecular biology and the largely theoretical discipline of evolutionary ecology. Somewhere in between lies conservation biology, aimed at protection of habitats and the diversity of species housed within them. A seemingly insignificant wildflower called Arabidopsis thaliana has an important contribution to make in this endeavour. It has already transformed botanical research with deepening understanding of molecular processes within the species and across the Plant Kingdom; and has begun to revolutionize plant breeding by providing an invaluable catalogue of gene sequences that can be used to design the most precise molecular markers attainable for marker-assisted selection of valued traits. This review describes how A. thaliana and two of its natural biotrophic parasites could be seminal as a model for exploring the biogeography and molecular ecology of plantâmicrobe interactions, and specifically, for testing hypotheses proposed from the geographic mosaic theory of co-evolution
Exploring the genomic diversity of black yeasts and relatives (Chaetothyriales, Ascomycota)
The order Chaetothyriales (Pezizomycotina, Ascomycetes) harbours obligatorily melanised fungi and includes numerous etiologic agents of chromoblastomycosis, phaeohyphomycosis and other diseases of vertebrate hosts. Diseases range from mild cutaneous to fatal cerebral or disseminated infections and affect humans and cold-blooded animals globally. In addition, Chaetothyriales comprise species with aquatic, rock-inhabiting, ant-associated, and mycoparasitic life-styles, as well as species that tolerate toxic compounds, suggesting a high degree of versatile extremotolerance. To understand their biology and divergent niche occupation, we sequenced and annotated a set of 23 genomes of main the human opportunists within the Chaetothyriales as well as related environmental species. Our analyses included fungi with diverse life-styles, namely opportunistic pathogens and closely related saprobes, to identify genomic adaptations related to pathogenesis. Furthermore, ecological preferences of Chaetothyriales were analysed, in conjuncture with the order-level phylogeny based on conserved ribosomal genes. General characteristics, phylogenomic relationships, transposable elements, sex-related genes, protein family evolution, genes related to protein degradation (MEROPS), carbohydrate-active enzymes (CAZymes), melanin synthesis and secondary metabolism were investigated and compared between species. Genome assemblies varied from 25.81 Mb (Capronia coronata) to 43.03 Mb (Cladophialophora immunda). The bantiana-clade contained the highest number of predicted genes (12,817 on average) as well as larger genomes. We found a low content of mobile elements, with DNA transposons from Tc1/Mariner superfamily being the most abundant across analysed species. Additionally, we identified a reduction of carbohydrate degrading enzymes, specifically many of the Glycosyl Hydrolase (GH) class, while most of the Pectin Lyase (PL) genes were lost in etiological agents of chromoblastomycosis and phaeohyphomycosis. An expansion was found in protein degrading peptidase enzyme families S12 (serine-type D-Ala-D-Ala carboxypeptidases) and M38 (isoaspartyl dipeptidases). Based on genomic information, a wide range of abilities of melanin biosynthesis was revealed; genes related to metabolically distinct DHN, DOPA and pyomelanin pathways were identified. The MAT (MAting Type) locus and other sex-related genes were recognized in all 23 black fungi. Members of the asexual genera Fonsecaea and Cladophialophora appear to be heterothallic with a single copy of either MAT-1-1 or MAT-1-2 in each individual. All Capronia species are homothallic as both MAT1-1 and MAT 1-2 genes were found in each single genome. The genomic synteny of the MAT-locus flanking genes (SLA2-APN2-COX13) is not conserved in black fungi as is commonly observed in Eurotiomycetes, indicating a unique genomic context for MAT in those species. The heterokaryon (het) genes expansion associated with the low selective pressure at the MAT-locus suggests that a parasexual cycle may play an important role in generating diversity among those fungi
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