VelC positively controls sexual development in Aspergillus nidulans

Area of Science:

• Mycology
• Molecular Biology
• Genetics

Background:

• Fungal development and secondary metabolism are regulated by velvet family proteins.
• VelC, a fungi-specific velvet protein, remained uncharacterized in Aspergillus nidulans.

Purpose of the Study:

• To investigate the role of VelC in asexual and sexual development in Aspergillus nidulans.
• To elucidate VelC's function within the context of fungal development pathways.

Main Methods:

• Gene deletion and overexpression of velC in Aspergillus nidulans.
• Quantitative analysis of asexual spores (conidia) and sexual fruiting bodies (cleistothecia).
• Gene expression analysis (mRNA levels) of key developmental regulators (brlA, abaA, wetA, vosA).
• Protein interaction studies using yeast two-hybrid and GST pull-down assays.

Main Results:

• velC mRNA levels peak during early sexual development.
• Deletion of velC resulted in increased conidia production and reduced cleistothecia formation.
• velC deletion upregulated genes involved in asexual sporulation (brlA, abaA, wetA) and vosA.
• Overexpression of velC led to increased cleistothecia formation.
• VelC interacts with VosA; the ΔvelC ΔvosA double mutant phenocopied the ΔvosA mutant, indicating VosA is epistatic to VelC in sexual development.

Conclusions:

• VelC acts as a positive regulator of sexual development in Aspergillus nidulans.
• VelC likely mediates sexual development control through interaction with VosA, particularly during specific life stages.
• VelC plays a crucial role in balancing asexual and sexual developmental pathways.