Project description:This SuperSeries is composed of the following subset Series: GSE9275: A tri-species Aspergillus array (nidulans arrays) GSE9276: A tri-species Aspergillus array (niger arrays) GSE9277: A tri-species Aspergillus array (oryzae arrays) Keywords: SuperSeries Refer to individual Series
Project description:Aspergillus flavus and A. oryzae represent two unique species predicted to have spent centuries in vastly different environments. A. flavus is an important opportunistic plant pathogen known for contaminating crops with the carcinogenic mycotoxin, aflatoxin and A. oryzae is a domesticated fungus used in food fermentations. Remarkably, the genomes of these two species are still nearly identical. We have used the recently sequenced genomes of A. oryzae RIB40 and A. flavus NRRL3357 along with array based comparative genome hybridization (CGH) as a tool to compare genomes across several strains of these two species. A comparison of three strains from each species by CGH revealed only 42 and 129 genes unique to A. flavus and A. oryzae, respectively. Further, only 709 genes were identified as being polymorphic between the species. Despite the high degree of similarity between these two species, correlation analysis among all data from the CGH arrays for all strains used in this study reveals a species split. However, this view of species demarcation becomes muddled when focused on only those genes for secondary metabolism.
Project description:The full genome sequencing of the filamentous fungi Aspergillus nidulans, Aspergillus niger and Aspergillus oryzae has opened the possibilities for studying the cellular physiology of these fungi on a systemic level. As a tool to explore this, we are presenting an Affymetrix GeneChip developed for transcriptome analysis of any of the three above-mentioned aspergilli. Transcriptome analysis of triplicate batch cultivations of all three aspergilli on glucose-and xylose media has been performed, and used to validate the performance of the micro array. By doing gene comparisons of all three species, and cross-analysing this with the expression data, 23 genes, including the xylose transcriptional activator XlnR, have been identified to be a conserved response across the Aspergillus sp. Promoter analysis of the upregulated genes in all three species suggest the XlnR-binding site to be 5’-GGNTAAA-3’. We are thus presenting a validated tool for transcription analysis of three Aspergillus species and a methodology for comparative transcriptomics. Keywords: Physiological response
Project description:Aspergillus flavus and A. oryzae represent two unique species predicted to have spent centuries in vastly different environments. A. flavus is an important opportunistic plant pathogen known for contaminating crops with the carcinogenic mycotoxin, aflatoxin and A. oryzae is a domesticated fungus used in food fermentations. Remarkably, the genomes of these two species are still nearly identical. We have used the recently sequenced genomes of A. oryzae RIB40 and A. flavus NRRL3357 along with array based comparative genome hybridization (CGH) as a tool to compare genomes across several strains of these two species. A comparison of three strains from each species by CGH revealed only 42 and 129 genes unique to A. flavus and A. oryzae, respectively. Further, only 709 genes were identified as being polymorphic between the species. Despite the high degree of similarity between these two species, correlation analysis among all data from the CGH arrays for all strains used in this study reveals a species split. However, this view of species demarcation becomes muddled when focused on only those genes for secondary metabolism. CGH comparison between 3 strains of A. flavus and 3 strains of A. oryzae, analyzed at the probe level
Project description:The full genome sequencing of the filamentous fungi Aspergillus nidulans, Aspergillus niger and Aspergillus oryzae has opened the possibilities for studying the cellular physiology of these fungi on a systemic level. As a tool to explore this, we are presenting an Affymetrix GeneChip developed for transcriptome analysis of any of the three above-mentioned aspergilli. Transcriptome analysis of triplicate batch cultivations of all three aspergilli on glucose-and xylose media has been performed, and used to validate the performance of the micro array. By doing gene comparisons of all three species, and cross-analysing this with the expression data, 23 genes, including the xylose transcriptional activator XlnR, have been identified to be a conserved response across the Aspergillus sp. Promoter analysis of the upregulated genes in all three species suggest the XlnR-binding site to be 5’-GGNTAAA-3’. We are thus presenting a validated tool for transcription analysis of three Aspergillus species and a methodology for comparative transcriptomics. Keywords: Physiological response Two conditions (glucose and xylose) and three biological replicates
Project description:DNA methylation is an important epigenetic modification widespread in eukaryotes and bacteria. However, genomic methylation levels show a dramatic diversity throughout the evolution of life, varying even between closely-related species and strains. In Aspergillus, a genus of filamentous fungi, the existence of DNA methylation has been controversial with previous studies reporting different conclusions using different species and detection methods. Here, we report DNA methylation analysis of Aspergillus oryzae, an important species in the Japanese fermentation industry, and a close relative of the pathogen Aspergillus flavus whose DNA methylation has been denied by the recent previous study using bisulfite sequencing. In this study, we conduct bisulfite-seq and RNA-seq of A. oryzae using three biological replicates from each of liquid and solid culture conditions. The statistical analysis of these data reveals thousands of highly-confident methylated cytosines (mCs), while the re-analysis of data from A. flavus detects few mCs being consistent with the previous study. Based on the comparative genome analysis of A. oryzae and A. flavus, we find that a substantial fraction of mCs are observed in syntenic segments including the aflatoxin biosynthesis gene cluster. Together, our results are the first evidence of DNA methylation in A. oryzae, providing a new example of the evolutionary diversity of DNA methylation as well as a new insight into its industrial applications.
Project description:DNA methylation is an important epigenetic modification widespread in eukaryotes and bacteria. However, genomic methylation levels show a dramatic diversity throughout the evolution of life, varying even between closely-related species and strains. In Aspergillus, a genus of filamentous fungi, the existence of DNA methylation has been controversial with previous studies reporting different conclusions using different species and detection methods. Here, we report DNA methylation analysis of Aspergillus oryzae, an important species in the Japanese fermentation industry, and a close relative of the pathogen Aspergillus flavus whose DNA methylation has been denied by the recent previous study using bisulfite sequencing. In this study, we conduct bisulfite-seq and RNA-seq of A. oryzae using three biological replicates from each of liquid and solid culture conditions. The statistical analysis of these data reveals thousands of highly-confident methylated cytosines (mCs), while the re-analysis of data from A. flavus detects few mCs being consistent with the previous study. Based on the comparative genome analysis of A. oryzae and A. flavus, we find that a substantial fraction of mCs are observed in syntenic segments including the aflatoxin biosynthesis gene cluster. Together, our results are the first evidence of DNA methylation in A. oryzae, providing a new example of the evolutionary diversity of DNA methylation as well as a new insight into its industrial applications.
Project description:The filamentous fungus Aspergillus oryzae is an important microbial cell factory for industrial production of useful enzymes, such as α-amylase. In order to optimize the industrial enzyme production process, there is a need to understand fundamental processes underlying protein production, here under how protein production links to metabolism through global regulatory structures. In this study, two α-amylase-producing strains of A. oryzae, a wild type strain and a transformant strain containing additional copies of the α-amylase gene, were characterized at a systematic level. Based on integrated analysis of ome-data together with genome-scale metabolic network and flux calculation, we identified key genes, key enzymes, key proteins, and key metabolites involved in the processes of protein synthesis and secretion, nucleotide metabolism, and amino acid metabolism that can be the potential targets for improving industrial protein production. Keywords: Two Aspergillus oryzae strains and two different carbon sources