title: Conserved and specific responses to hypoxia in Aspergillus oryzae and Aspergillus nidulans determined by comparative transcriptomics.
abstract: Hypoxia imposes stress on filamentous fungi that require oxygen to proliferate. Global transcription analysis of Aspergillus oryzae grown under hypoxic conditions found that the expression of about 50% of 4,244 affected genes was either induced or repressed more than 2-fold. A comparison of these genes with the hypoxically regulated genes of Aspergillus nidulans based on their predicted amino acid sequences classified them as bi-directional best hit (BBH), one-way best hit (extra homolog, EH), and no-hit (non-syntenic genes, NSG) genes. Clustering analysis of the BBH genes indicated that A. oryzae and A. nidulans down-regulated global translation and transcription under hypoxic conditions, respectively. Under hypoxic conditions, both fungi up-regulated genes for alcohol fermentation and the γ-aminobutyrate shunt of the tricarboxylate cycle, whereas A. oryzae up-regulated the glyoxylate pathway, indicating that both fungi eliminate NADH accumulation under hypoxic conditions. The A. oryzae NS genes included specific genes for secondary and nitric oxide metabolism under hypoxic conditions. This comparative transcriptomic analysis discovered common and strain-specific responses to hypoxia in hypoxic Aspergillus species.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Terabayashi
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Shimizu
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kitazume
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Masuo
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fujii
authors.forename: Naoki
authors.initials: N
authors.lastname: Takaya
mesh_terms: D001233:Aspergillus nidulans / Q000378:metabolism / Q000502:physiology*; D001236:Aspergillus oryzae / Q000378:metabolism / Q000502:physiology*; D016000:Cluster Analysis; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D009243:NAD / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D013312:Stress, Physiological; D059467:Transcriptome
chemical_list: D009243:NAD; D010100:Oxygen