Project description:Aspergillus display an amazing level of diversity in physiologies, and environments that they occupy. Strategies for coping with diverse environmental stresses have evolved in different Aspergillus species. Therefore, Aspergillus are considered to be good models for investigating the adaptation and response to many natural and anthropogenic environmental stressors. Recent genome sequencing projects in several Aspergillus have provided insights into the molecular and genetic mechanisms underlying their responses to some environmental stressors. However, to better clarify the conserved and differentiated features of the adaptive response to specific stresses and to trace the evolutionary process of environmental adaptation and response in Aspergillus, insight from more Aspergillus species with different evolutionary positions, such as A. glaucus, and thus offer a large number of models of adaptation and response to various environmental stresses. Here, we report a high-quality reference genome assembly of A. glaucus CCHA from the surface of wild vegetation around saltern of Jilin, China, based on sequence data from whole-genome shotgun (WGS) sequencing platforms of Illumina solexa technologies. This assembly contains 106 scaffolds ( >1 Kb; N50 = ~0.795 Mb), has a length of ~28.9 Mb and covers ~97% of the predicted genome size (~120 Mb). Together with the data analyses from comprehensive transcriptomic surveys and comparative genomic analyses, we aim to obtain new insights into molecular mechanisms of the adaptation to living at high salt in the saltern
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:Using transcriptomics, the strain-specific metabolism was mapped for two whole-genome sequenced strains of Aspergillus niger Keywords: Strain comparison
Project description:Aspergillus flavus and A. parasiticus are two of the most important aflatoxin-producing species that contaminate agricultural commodities worldwide. Both species are heterothallic and undergo sexual reproduction in laboratory crosses. Here, we examine the possibility of interspecific matings between A. flavus and A. parasiticus. These species can be distinguished morphologically and genetically, as well as by their mycotoxin profiles. Aspergillus flavus produces both B aflatoxins and cyclopiazonic acid (CPA), B aflatoxins or CPA alone, or neither mycotoxin; Aspergillus parasiticus produces B and G aflatoxins or the aflatoxin precursor O-methylsterigmatocystin, but not CPA. Only four out of forty-five attempted interspecific crosses between compatible mating types of A. flavus and A. parasiticus were fertile and produced viable ascospores. Single ascospore strains from each cross were isolated and were shown to be recombinant hybrids using multilocus genotyping and array comparative genome hybridization. Conidia of parents and their hybrid progeny were haploid and predominantly monokaryons and dikaryons based on flow cytometry. Multilocus phylogenetic inference showed that experimental hybrid progeny were grouped with naturally occurring A. flavus L strain and A. parasiticus. Higher total aflatoxin concentrations in some F1 progeny strains compared to midpoint parent aflatoxin levels indicate synergism in aflatoxin production; moreover, three progeny strains synthesized G aflatoxins that were not produced by the parents, and there was evidence of putative allopolyploidization in one strain. These results suggest that hybridization is an important diversifying force resulting in the genesis of novel toxin profiles in these agriculturally important species.
Project description:Expression data from batch cultivations of Aspergillus niger wild type strain ATCC 1015 and adrA, facB and creA deletion mutants constructed on ATCC 1015 background strain with glucose or glycerol as carbon sources. Genome-wide transcriptome analysis was used to identify genes either affected directly or indirectly by each transcription factor investigated during growth on a repressing or a derepressing carbon source. For this purpose, batch cultivations under well-controlled conditions were performed with Aspergillus niger wild type strain ATCC 1015 and the three deletion mutants of the corresponding transcription factors AdrA, FacB and CreA. Samples for RNA extraction were collected and further processed for hybridization in custom-designed Affymetrix microarrays containing probes for three Aspergillus species, including A. niger.
