Fungal development is regulated by a variety of transcription factors in Aspergillus nidulans. Previous studies demonstrated that the NF-κB type velvet transcription factors regulate certain target genes that govern fungal differentiation and cellular metabolism. In this study, we characterize one of the VosA/VelB-inhibited developmental genes called vidA, which is predicted to encode a 581-amino acid protein with a C2H2 zinc finger domain at the C-terminus. Levels of vidA mRNA are high during the early and middle phases of asexual development and decrease during the late phase of asexual development and asexual spore (conidium) formation. Deletion of either vosA or velB results in increased vidA mRNA accumulation in conidia, suggesting that vidA transcript accumulation in conidia is repressed by VosA and VelB. Phenotypic analysis demonstrated that deletion of vidA causes decreased colony growth, reduced production of asexual spores, and abnormal formation of sexual fruiting bodies. In addition, the vidA deletion mutant conidia contain more trehalose and β-glucan than wild type. Overall, these results suggest that VidA is a putative transcription factor that plays a key role in governing proper fungal growth, asexual and sexual development, and conidia formation in A. nidulans.
Keywords: Aspergillus nidulans; asexual development; beta-glucan; velvet.