Project description:Transcriptional profiling of wild-type and kdmA deletion mutant in response to white light exposure, against a wild-type dark-incubated reference
Project description:A. nidulans kdmA encodes a member of the KDM4 family of jumonji histone demethylase proteins, highly similar to metazoan orthologues both within functional domains and in domain architecture. This family of proteins exhibits demethylase activity toward lysines 9 and 36 of histone H3 and plays a prominent role in gene expression and chromosome structure in many species. Mass spectrometry mapping of A. nidulans histones revealed that around 3% of bulk histone H3 carried trimethylated H3K9 (H3K9me3) but more than 90% of histones carried either H3K36me2 or H3K36me3. KdmA functions as H3K36me3 demethylase and has roles in transcriptional regulation. Genetic manipulation of KdmA levels is tolerated without obvious effect in most conditions, but strong phenotypes are evident under various conditions of stress. Transcriptome analysis revealed that M-bM-^@M-^S in submerged early and late cultures M-bM-^@M-^S between 25% and 30% of the genome is under KdmA influence, respectively. Transcriptional imbalance in the kdmA deletion mutant may contribute to the lethal phenotype observed upon exposure of mutant cells to low-density visible light on solid medium. While KdmA acts as transcriptional co-repressor of primary metabolism (PM) genes it is required for full expression of several genes involved in biosynthesis of secondary metabolites (SM). Two strains, wild type and kdmA deletion, at two conditions, growth at primary (17h) and secondary (48h), were analyzed. Each sample was replicated.
Project description:Light is a major environmental signal regulating many different biological processes. In Aspergillus nidulans light controls asexual and sexual development as well as the production of secondary metabolites. In order to get a global view of genes regulated during asexual development and of genes involved in other light-regulated biological processes, a genome-wide approach was undertaken. Total RNA was isolated from surface-grown, developmentally competent mycelia of the wild-type strain FGSC4 exposed to white light (11 W/m2) for 30 minutes or grown in the dark, labelled, and hybridized to a spotted microarray of A. nidulans.
Project description:Investigation of whole genome gene expression level changes in Aspergillus nidulans AN1599 (PbcR) overexpression mutant, compared to the FGSC A4 wild-type strain. Overexpression of the Zn(II)2Cys6 –type transcription factor, AN1599.4 (PbcR, pimaradiene biosynthetic cluster regulator), activates a secondary metabolite gene cluster in Aspergillus nidulans. Activation of the pathway in Aspergillus nidulans lead to a production of ent-pimara-8(14),15-diene.
Project description:Experimental evolution was conducted using Drosophila melanogaster populations that developed as larvae on breeding substrate that was infested with Aspergillus nidulans wild type, A. nidulans toxin-impaired mutant strain delta-laeA, the mycotoxin sterigmatocystin, or on fungi and toxin free substrate. Overall population were reared under these conditions for 11 generations, where after each confrontation generation one relaxation generation (fungi and toxin free breeding substrate) was conducted. Nine generations after the last selection treatment, first instar larvae were confronted with 3 days old A. nidulans wild type colonies or control conditions. 24 hours after confrontation start larvae were collected. For each biological replicate 52 larvae were collected from 4 independent confrontation units, balanced design. Three populations per selection regime were conducted, resulting in: 2 conditions x 4 selection regimes x 3 biological replicates (equal to fly population) = 24 samples. Selection regimes: sCO= control; sWT= A. nidulans wild type; sLA= A. nidulans mutant strain; sST= Sterigmatocystin. confrontation condition: cCO= control; cWT= A. nidulans wild type.
Project description:Phytochrome-dependent light signaling has been studied in several fungi. In Aspergillus nidulans light-stimulated phytochrome activates the HOG signaling pathway and thereby controls the expression of a large number of genes, many of which are related to stress responses. In a genome-wide expression analysis in A. nidulans we found that phytochrome, fphA, is under strict expression control of the central regulator of the sulfur-starvation response, MetR. This transcriptional regulator is required for the expression of genes involved in inorganic sulfur assimilation. In the presence of organic sulfur, MetR is probably ubiquitinated and possibly degraded and the transcription of sulfur-assimilation genes, e.g. sulfate permease, is turned off. The expression analysis described here revealed, however, that MetR additionally controls the expression of hundreds of genes, many of which are required for secondary metabolite production. We also show that metR mutation phenocopies fphA deletion, and five other histidine-hybrid kinases are down-regulated in the metR1 mutant. Furthermore, we show that light and phytochrome regulate the expression of at least three carbon-sulfur hydrolases. This work is a further step towards understanding the interplay between light sensing and metabolic pathways.