Project description:To better understand the effect of hypoxia, RNA-Seq technology was used to profile the Aspergillus fumigatus during adaptation to hypoxia at 12, 24 and 36 h time points. Four samples examined: from the fungus grown under normoxia and hypoxia conditions
Project description:Calcineurin plays an important role in the control of cell morphology and virulence in fungi. Calcineurin is a serine/threonine-specific protein phosphatase heterodimer consisting of a catalytic subunit A and a regulatory Ca2+/Calmodulin binding subunit. A mutant of A. fumigatus lacking the calcineurin A (calA) catalytic subunit exhibited defective hyphal morphology related to apical extension and branching growth, which resulted in drastically decreased filamentation. Here, we investigated which pathways are influenced by A. fumigatus calcineurin during proliferation by comparatively determining the transcriptional profile of A. fumigatus wild type and delta calA mutant strains. Our results showed that although the mitochondrial function is reduced in the delta calA mutant strain, its respiratory chain is functional and the mutant has increased alternative oxidase (aoxA) mRNA accumulation and activity. Furthermore, we identified several genes that encode transcription factors that have increased mRNA expression in the delta calA mutant and that could be involved in the Cal-CrzA pathway. Deletion mutants for these transcription factors had also reduced susceptibility to itraconazole, caspofungin, and sodium dodcyl sulfate.
Project description:The mRNA profiles of [delta]rgsA, [delta]nopA, [delta]rgdA ([delta]swi4), [delta]mbpA ([delta]swi6) mutants and wild-type (AF293) of A. fumigatus.
Project description:Low oxygen conditions are not only common to natural environments but also occur during tissue invasive growth in the human host. Only few cellular factors have been identified up to now that allow the fungus to efficiently adapt its energy metabolism to the lack of O2. In the present study, we cultivated A. fumigatus in an O2-controlled fermenter and analysed its minute-scale responses to O2 limitation. Transcriptome sequencing revealed a group of genes underlying a rapid and highly dynamic regulation. As an initial experimental setup, A. fumigatus was cultivated in an O2-controlled fermenter, which allowed minute-scale variations in O2-fluxes largely independent of other secondary effects. Cultures were initially grown at saturated O2 concentrations (100% saturation M-bM-^IM-^H 260 M-BM-5mol l-1) and rapidly shifted to hypoxic growth conditions at an initial O2 saturation of 5% (M-bM-^IM-^H 13 M-BM-5mol l-1). Dynamics of low and high O2 responses of A. fumigatus cultivated in an O2-controlled fermenter
Project description:Two mutant strains of Aspergillus fumigatus derived from strain A1160, HapB and 29.9, display resistance to the antifungal drug itraconazole. To understand what underlying transcriptional processes contribute to this resistance, A1160, HapB and 29.9 were cultured either in the presence or absence of itraconazole. RNA-sequencing was used to compare transcription profiles of each mutant strain with or without the drug, to A1160 with or without drug.
Project description:Various saprotrophic microorganisms, especially filamentous fungi, can efficiently degrade lignocellulose that is one of the most abundant natural material on earth. It consists of complex carbohydrates and aromatic polymers found in plant cell wall and thus in plant debris. Aspergillus fumigatus Z5 was isolated from compost heaps and showed highly efficient plant biomass-degradation capability.Genome analysis revealed an impressive array of genes encoding cellulases, hemicellulases, and pectinases involved in lignocellulosic biomass degradation. We sequenced the transcriptomes of Aspergillus fumigatus Z5 induced by sucrose, xylan, cellulose and rice straw, respectively. There were 444, 1711 and 1386 significantly differently (q-value ⤠0.0001 and |log2 of the ratio of the RPM values| ⥠2) expressed genes in xylan, cellulose and rice straw,respectively, relative to sucrose control. After incubation at 45 â, 145rpm for 20 hours with sucrose as the carbon source, mycelia were induced for 16 hours using xylan, cellulose and rice straw, respectively. Transcriptome induced by sucrose was used as the control when comparing the differences between other three transcriptomes (induced by xylan, cellulose and rice straw, respectively).
Project description:Calcineurin plays an important role in the control of cell morphology and virulence in fungi. Calcineurin is a serine/threonine-specific protein phosphatase heterodimer consisting of a catalytic subunit A and a regulatory Ca2+/Calmodulin binding subunit. A mutant of A. fumigatus lacking the calcineurin A (calA) catalytic subunit exhibited defective hyphal morphology related to apical extension and branching growth, which resulted in drastically decreased filamentation. Here, we investigated which pathways are influenced by A. fumigatus calcineurin during proliferation by comparatively determining the transcriptional profile of A. fumigatus wild type and delta calA mutant strains. Our results showed that although the mitochondrial function is reduced in the delta calA mutant strain, its respiratory chain is functional and the mutant has increased alternative oxidase (aoxA) mRNA accumulation and activity. Furthermore, we identified several genes that encode transcription factors that have increased mRNA expression in the delta calA mutant and that could be involved in the Cal-CrzA pathway. Deletion mutants for these transcription factors had also reduced susceptibility to itraconazole, caspofungin, and sodium dodcyl sulfate. For the time course microarray experiments, 1.0 x 109 conidia of both A. fumigatus wild type [CEA17 delta akuB(KU80)] and mutant strain (delta calA) were used to inoculate 400 ml of pre-warmed liquid cultures in complete medium (YG) in 1 L erlenmeyer flasks. Cultures were allowed to grow for 6, 8, 12, 18 and 24 hours in a reciprocal shaker (250 rpm) at 37°C. At each time point, germilings were harvested by centrifugation or filtration and total RNA was extracted. Hybridization experiments were competitive using Cy3 or Cy5-labeled probes derived from both wild type and delta calA strain grown for 6, 8, 12, 18 and 24 hours. Hybridizations were performed using the wild type RNA as reference in comparison to the mutant strain (test RNA) for the same time point. Normalized signal intensities were used to generate relative hybridization ratios (query/reference). Following normalization, the values for each gene in-slide replicates were condensed (median variance <0.01), and corresponding flip-dye replicates were averaged to compensate for dye-specific effects (see Supplementary files linked below).
Project description:The unfolded protein response (UPR) is a network of intracellular signaling pathways that supports the ability of the secretory pathway to maintain equilibrium between the load of proteins entering the endoplasmic reticulum (ER) and the protein folding capacity of the ER lumen. Current evidence suggests that human pathogenic fungi rely heavily on this pathway for virulence, but there is limited understanding of the mechanisms involved. The best known functional output of the UPR is transcriptional upregulation of mRNAs involved in ER homeostasis. However, this does not take into account mechanisms of translational regulation that involve differential recruitment of mRNAs to ribosomes. In this study, a global analysis of transcript-specific translational regulation was performed in the pathogenic mold Aspergillus fumigatus to determine the nature and scope of the translational response to ER stress.
Project description:Genomic DNA from five strains, Aspergillus fumigatus Af71, Aspergillus fumigatus Af294, Aspergillus clavatus, Neosartorya fenneliae, and Neosartorya fischeri, were co-hybridized with that of Aspergillus fumigatus Af293 and compared.