A role for the velvet protein VE-1 on transcription in Neurospora crassa?

The molecular mechanisms of the perception of light have been investigated in detail in Neurospora crassa. Light causes many effects on behaviour and development in N. crassa, including the formation of asexual and sexual structures, and the regulation of carotenoids biosynthesis and the circadian clock. The velvet family of regulatory proteins is highly conserved among fungi. All the velvet proteins contain a velvet domain with a DNA binding domain, presumably for gene regulation. The Aspergillus nidulans velvet protein VeA plays a key role in coordinating secondary metabolism and developmental regulation, and its localization in the cell is regulated by light. The genome of N. crassa contains four genes with the velvet domain. A strain with a deletion of ve-1 (orthologous of veA) has defects in aerial hyphal growth and increased conidiation. In order to characterize the potential transcriptional regulatory role of VE-1 we have performed RNAseq analysis of the N. crassa wild type and ∆ve-1 mutant grown in the dark or exposed to light. In addition, we have analysed the transcriptome of the two strains as they progress from vegetative growth to conidiation. Our results will allow us to identify genes regulated by VE-1 during the transcriptional response to light and during conidiation. We observed a higher number of genes regulated during the conidiation stage in the wild type (2653) compared to the mutant (916). These significant differences suggest an important role of VE-1 as a transcriptional regulator of conidiation.