Project description:The fungal specific APSES family proteins involve in regulating fungal growth, development, and multiple biological processes. In this study, AoMbp1, an ortholog of Saccharomyces cerevisiae APSES-type transcription factor Mbp1, was functionally analyzed in a representative nematode-trapping fungus Arthrobotrys oligospora. Inactivation of Aombp1 caused a severe affect on the mycelial growth and development, the mycelial growth rate of ∆Aombp1 mutant was remarkably decreased, the hyphal septa were increased whereas the number of nuclei were significantly reduced, and the lipid droplet accumulation was remarkably increased. Meanwhile, the deletion of Aombp1 resulted a considerable reduction in the number of conidiophores and spore yield, which also caused abnormal spore morphology. In addition, the ∆Aombp1 mutants became more sensitive to several chemical stressors, especially to hyperosmotic reagents. Importantly, disruption of Aombp1 caused the number of traps and nematode-trapping ability were significantly reduced, and most of the traps have changed from their original three-dimensional structure to a planar shape. RNA-Seq, DAP-Seq and Y2H assay showed that AoMbp1 interacted with AoSwi6, and involved in regulating cell cycle, meiosis, lipid metabolism, DNA replication, mismatch repair and nucleotide excision repair. Our study elucidated the functions and potential regulatory mechanism of APSES protein Mbp1 in the mycelial development and trap morphogenesis of nematode-trapping fungi.
Project description:This SuperSeries is composed of the following subset Series: GSE32542: Murine serum reactivity to common autoantigens in response to immunization with neutrophil extracellular traps GSE32543: Human and murine serum reactivity to specific histone posttranslational modifications in neutrophil extracellular traps Refer to individual Series
Project description:As a dynamic structure with a barrier between the cell and the outside world, maintenance of cell wall integrity (CWI) is important for fungal growth, development and pathogenicity processes. Here we characterized a MADS-box transcription factor RlmA (AoRlmA) downstream of the CWI regulatory pathway in the nematode-trapping fungus Arthrobotrys oligospora. Deletion of AorlmA caused a reduction in mycelial growth and the number of nuclei, and significant downregulation of transcript levels of genes related to nucleus synthesis and DNA damage repair, such as rad3, spo11, and rad25. Meanwhile, the ΔAorlmA mutant strains showed a significant reduction in spore production compared with the wild-type (WT) strain, and the transcript levels of sporulation-related genes was downregulated in the ΔAorlmA mutant during the early and middle stages of condiation, such as flbA, medA, and vosA. Meanwhile, the mycelial cell wall of the ΔAorlmA mutant strain showed breakage. Also, the transcript levels of genes related to cell wall synthesis were significantly down-regulated in the mutant strain compared to the WT strain, and the mutant strain was more sensitive to stresses of cell wall synthesis disruptors, oxidative stress and osmotic stress than the WT strain. Compared with the WT strain, the ΔAorlmA mutant strain not only had a reduced number of traps and nematicidal ability, but also, the shape of the traps of the mutants has also changed. In addition, In addition, AoRlmA also regulates autophagy and endocytosis. Transcriptome analysis of ΔAorlmA mutant strains showed that AorlmA regulates redox, cell wall synthesis, DNA replication and damage repair, and pathogenic processes. Metabolomic analysis showed that AorlmA is involved in the biosynthesis of secondary metabolites of A. oligospora. To summarise, our data suggest that AorlmA is involved in growth, sporulation, spore germination, maintenance of cell wall integrity, DNA replication and damage repair, pathogenesis, autophagy and secondary metabolite biosynthesis processes.
Project description:Spores of Bacillales and Clostridiales species contain 100s of different mRNAs, and their major function in Bacillus subtilis is to provide ribonucleotides for new RNA synthesis when spores germinate. In new work, RNA was isolated from spores of five Bacillales and one Clostridioides species and relative spore mRNA levels were determined by RNA-seq. Determination of RNA levels in single spores allowed calculation of RNA nt/spore, and assuming mRNA is 3% of spore RNA allowed calculation that only ~6% of spore mRNAs were present at ≥ 1/spore. Bacillus subtilis, Bacillus atrophaeus and Clostridioides difficile spores had 49, 42 and 51 mRNAs at >1/spore, respectively. Numbers of mRNAs at ≥1/spore were ~10 to 50% higher in Geobacillus stearothermophilus and Bacillus thuringiensis Al Hakam spores, respectively, and ~ 4-fold higher in Bacillus megaterium spores. Notably, in all species: i) many of the 60 most abundant spore mRNAs were transcribed by RNA polymerase with forespore-specific s factors; ii) some to many of the most abundant spore mRNAs encoded orthologs of those encoded by abundant B. subtilis spore mRNAs and proteins present in dormant spores ; and iii) some spore mRNAs were likely transcribed in the mother cell compartment of the sporulating cell. Indeed , analysis of the coverage of RNA-seq reads on mRNAs from all six species suggested that abundant spore mRNAs were at least somewhat fragmented. This observation was confirmed by RT-qPCR analysis of three abundant mRNAs each from B. subtilis and C. difficile spores. These data add to a growing body of evidence indicating that the great majority of mRNAs in spores of Firmicutes are degradation and function as a ribonucleotide depot for new RNA synthesis when spores germinate.
Project description:Bacillus subtilis forms dormant spores upon nutrient depletion. Under favorable environmental conditions, the spore breaks its dormancy and resumes growth in a process called spore germination and outgrowth. To elucidate the physiological processes that occur during the transition of the dormant spore to an actively growing vegetative cell, we studied this process in a time-dependent manner by a combination of microscopy, analysis of extracellular metabolites and a genome-wide analysis of transcription. The results indicate the presence of abundant levels of late sporulation transcripts in dormant spores. In addition, results suggest the existence of a complex and well-regulated spore outgrowth program, involving the temporal expression of at least 30 % of the B. subtilis genome. Keywords: time course, spore outgrowth
Project description:A microarray analysis was conducted to investigate transcriptional differences between traps and vegetative hyphae of the nematophagous fungus Monacrosporium haptotylum. Our goal was to identify genes that show differential regulation in the two different cell types; 1) traps (knobs) and 2) vegetative hyphae (mycelium) grown in the same medium. The entire design involved nine slides; four of these were hybridisations of knobs versus mycelium and five were mycelium against mycelium, 10 labelled extracts, and 3 biological replicates. The microarray experiments were designed as two-sample comparisons (i.e. knobs versus mycelium or mycelium versus mycelium) using three independent biological replicates, which also included technical and dye-swapped control hybridisations.
Project description:To gain insight into spore germination and outgrowth, the transcriptome changes during Bacillus subtilis spore conversion to vegetative cells were analyzed. The transcriptome analysis also allowed us to trace the different functional groups of genes expressed during this conversion. . Our analysis identified 34 abundant mRNA transcripts in the dormant spores, at least 31 of which were rapidly degraded after the phase transition and observed 3152 differentially expressed genes during spore germination and outgrowth.
Project description:Arthrobotrys oligospora, a widely distributed nematode-trapping fungus, utilises adhesive mycelial nets (traps) to capture nematodes. As key components of the MAPK cascade, Sho1 and Opy2 are critical in the fungal stress response. This study examined the roles of homologous Sho1 (AoSho1) and Opy2 (AoOpy2) through gene knockdown, phenotypic analysis, and multi-omics approaches. The results revealed that knockdown of Aosho1 and Aoopy2 led to reduced mycelial growth, a significant decrease in spore production, trap formation, and nematode predation capacity. Furthermore, deletion of Aosho1 and Aoopy2 increased autophagic activity and heightened sensitivity to osmotic stress. Transcriptome analysis indicated that AoOpy2 functions as a multifaceted regulator in fungal growth, development, and environmental adaptation. Metabolomics data also suggested that AoSho1 and AoOpy2 are involved in several metabolic pathways. In conclusion, AoSho1 and AoOpy2 are essential for mycelial growth, osmoregulation, and the pathogenicity of A. oligospora. This study lays the groundwork for understanding the roles and potential mechanisms of the MAPK signalling pathway in the development and pathogenicity of nematode-trapping fungi.