Analysis of genome-wide coexpression and coevolution of Aspergillus oryzae and Aspergillus niger.

Analysis of coexpressed genes in response to different perturbations at the genome-level can provide new insight into global regulatory structures. Here we performed integrated data analysis for a crossspecies comparative investigation by exploring genomes and transcriptional coexpression profiles in Aspergillus oryzae and Aspergillus niger. Based on our analysis of conserved coexpressed genes, fatty acid catabolism via beta-oxidation, fatty acid transport, the glyoxylate bypass, and peroxisomal biogenesis were identified as core coevolved pathways between the two species. The occurrence of coexpression patterns, allowed for identification of DNA regulatory motifs and putative corresponding transcription factors, and we hereby show that comparative transcriptome analysis between two closely related fungi allows for identification of how genes involved in the utilization of fatty acids, peroxisomal biogenesis, and the glyoxylate bypass are regulated. Interestingly, "CCTCGG" was identified as a core binding site for the putative FarA and FarB transcription factors that govern the underlined biological processes. Phylogeny and domain architecture analysis of amino acid sequences of FarA and FarB in eight species of aspergilli, clearly indicate that these proteins are evolutionarily conserved across Aspergillus species as well as they are conserved in other fungi.