12 research outputs found
Лингвистическая модель времени в представлении носителей неблизкородственных языков
В статье рассматривается возможность существования единой темпоральной модели, свойственной неблизкородственным европейским языкам. Представления о пространстве и времени следует считать синкретичными.У статті розглядається можливість існування у неблизькоспоріднених європейських мовах єдиної темпоральної моделі. Уявлення про час і простір слід вважати синкретичними.The article deals with the problem of the universal temporal model that exists in European languages. The main idea is that time and distance are visualized as syncretic notions
Heterogeneity of Aspergillus niger Microcolonies in Liquid Shaken Cultures▿ †
The fungus Aspergillus niger forms (sub)millimeter microcolonies within a liquid shaken culture. Here, we show that such microcolonies are heterogeneous with respect to size and gene expression. Microcolonies of strains expressing green fluorescent protein (GFP) from the promoter of the glucoamlyase gene glaA or the ferulic acid esterase gene faeA were sorted on the basis of diameter and fluorescence using the Complex Object Parametric Analyzer and Sorter (COPAS) technology. Statistical analysis revealed that the liquid shaken culture consisted of two populations of microcolonies that differ by 90 μm in diameter. The population of small microcolonies of strains expressing GFP from the glaA or faeA promoter comprised 39% and 25% of the culture, respectively. Two populations of microcolonies could also be distinguished when the expression of GFP in these strains was analyzed. The population expressing a low level of GFP consisted of 68% and 44% of the culture, respectively. We also show that mRNA accumulation is heterogeneous within microcolonies of A. niger. Central and peripheral parts of the mycelium were isolated with laser microdissection and pressure catapulting (LMPC), and RNA from these samples was used for quantitative PCR analysis. This analysis showed that the RNA content per hypha was about 45 times higher at the periphery than in the center of the microcolony. Our data imply that the protein production of A. niger can be improved in industrial fermentations by reducing the heterogeneity within the culture
Hyphal heterogeneity in Aspergillus oryzae is the result of dynamic closure of septa by Woronin bodies
Hyphae of higher fungi are compartmentalized by septa. These septa contain a central pore that allows for inter-compartmental and inter-hyphal cytoplasmic streaming. The cytoplasm within the mycelium is therefore considered to be a continuous system. In this study, however, we demonstrate by laser dissection that 40% of the apical septa of exploring hyphae of Aspergillus oryzae are closed. Closure of septa correlated with the presence of a peroxisome-derived organelle, known as Woronin body, near the septal pore. The location of Woronin bodies in the hyphae was dynamic and, as a result, plugging of the septal pore was reversible. Septal plugging was abolished in a ?Aohex1 strain that cannot form Woronin bodies. Notably, hyphal heterogeneity was also affected in the ?Aohex1 strain. Wild-type strains of A.?oryzae showed heterogeneous distribution of GFP between neighbouring hyphae at the outer part of the colony when the reporter was expressed from the promoter of the glucoamylase gene glaA or the a-glucuronidase gene aguA. In contrast, GFP fluorescence showed a normal distribution in the case of the ?Aohex1 strain. Taken together, it is concluded that Woronin bodies maintain hyphal heterogeneity in a fungal mycelium by impeding cytoplasmic continuity
Mixed colonies of Aspergillus niger and Aspergillus oryzae cooperatively degrading wheat bran
In both natural and man-made environments, microorganisms live in mixed populations, while in laboratory conditions monocultures are mainly used. Microbial interactions are often described as antagonistic, but can also be neutral or cooperative, and are generally associated with a metabolic change of each partner and cause a change in the pattern of produced bioactive molecules. A. niger and A. oryzae are two filamentous fungi widely used in industry to produce various enzymes (e.g. pectinases, amylases) and metabolites (e.g. citric acid). The co-cultivation of these two fungi in wheat bran showed an equal distribution of the two strains forming mixed colonies with a broad range of carbohydrate active enzymes produced. This stable mixed microbial system seems suitable for subsequent commercial processes such as enzyme production. XlnR knock-out strains for both aspergilli were used to study the influence of plant cell wall degrading enzyme production on the fitness of the mixed culture. Microscopic observation correlated with quantitative PCR and proteomic data suggest that the XlnR Knock-out strain benefit from the release of sugars by the wild type strain to support its growth
Hyphal heterogeneity in Aspergillus oryzae is the result of dynamic closure of septa by Woronin bodies
Hyphae of higher fungi are compartmentalized by septa. These septa contain a central pore that allows for inter-compartmental and inter-hyphal cytoplasmic streaming. The cytoplasm within the mycelium is therefore considered to be a continuous system. In this study, however, we demonstrate by laser dissection that 40% of the apical septa of exploring hyphae of Aspergillus oryzae are closed. Closure of septa correlated with the presence of a peroxisome-derived organelle, known as Woronin body, near the septal pore. The location of Woronin bodies in the hyphae was dynamic and, as a result, plugging of the septal pore was reversible. Septal plugging was abolished in a ?Aohex1 strain that cannot form Woronin bodies. Notably, hyphal heterogeneity was also affected in the ?Aohex1 strain. Wild-type strains of A.?oryzae showed heterogeneous distribution of GFP between neighbouring hyphae at the outer part of the colony when the reporter was expressed from the promoter of the glucoamylase gene glaA or the a-glucuronidase gene aguA. In contrast, GFP fluorescence showed a normal distribution in the case of the ?Aohex1 strain. Taken together, it is concluded that Woronin bodies maintain hyphal heterogeneity in a fungal mycelium by impeding cytoplasmic continuity
Mixed colonies of Aspergillus niger and Aspergillus oryzae cooperatively degrading wheat bran
In both natural and man-made environments, microorganisms live in mixed populations, while in laboratory conditions monocultures are mainly used. Microbial interactions are often described as antagonistic, but can also be neutral or cooperative, and are generally associated with a metabolic change of each partner and cause a change in the pattern of produced bioactive molecules. A. niger and A. oryzae are two filamentous fungi widely used in industry to produce various enzymes (e.g. pectinases, amylases) and metabolites (e.g. citric acid). The co-cultivation of these two fungi in wheat bran showed an equal distribution of the two strains forming mixed colonies with a broad range of carbohydrate active enzymes produced. This stable mixed microbial system seems suitable for subsequent commercial processes such as enzyme production. XlnR knock-out strains for both aspergilli were used to study the influence of plant cell wall degrading enzyme production on the fitness of the mixed culture. Microscopic observation correlated with quantitative PCR and proteomic data suggest that the XlnR Knock-out strain benefit from the release of sugars by the wild type strain to support its growth
Identification of MOAG-4/SERF as a Regulator of Age-Related Proteotoxicity
SummaryFibrillar protein aggregates are the major pathological hallmark of several incurable, age-related, neurodegenerative disorders. These aggregates typically contain aggregation-prone pathogenic proteins, such as amyloid-beta in Alzheimer's disease and alpha-synuclein in Parkinson's disease. It is, however, poorly understood how these aggregates are formed during cellular aging. Here we identify an evolutionarily highly conserved modifier of aggregation, MOAG-4, as a positive regulator of aggregate formation in C. elegans models for polyglutamine diseases. Inactivation of MOAG-4 suppresses the formation of compact polyglutamine aggregation intermediates that are required for aggregate formation. The role of MOAG-4 in driving aggregation extends to amyloid-beta and alpha-synuclein and is evolutionarily conserved in its human orthologs SERF1A and SERF2. MOAG-4/SERF appears to act independently from HSF-1-induced molecular chaperones, proteasomal degradation, and autophagy. Our results suggest that MOAG-4/SERF regulates age-related proteotoxicity through a previously unexplored pathway, which will open up new avenues for research on age-related, neurodegenerative diseases
Nat Methods. 2009 Jul;. Epub 2009 Jun 21
Abstract
The use of fluorescently labeled MHC multimers has become an essential technique for the analysis of disease- and therapy-induced T cell immunity. While classical MHC multimer analyses are well-suited for the detection of immune responses against a few epitopes, limitations on patient sample size preclude a comprehensive analysis of T cell immunity.
To address this issue, we have developed a combinatorial encoding strategy that allows the parallel detection of a multitude of different T cell populations within a single sample. Detection of antigen-specific T cells from peripheral blood by combinatorial encoding is as efficient as detection with conventional PE labeled multimers, but results in a significantly increased sensitivity, and most importantly, allows comprehensive screens to be performed on patient material. Proof of principle for the feasibility of large-scale screening of patient material was obtained by analysis of HLA-A3 restricted T cell responses against known and potential melanoma-associated antigens in peripheral blood from melanoma patients.