Silencing of velvet gene homolog suppresses cleistothecia formation in Histoplasma capsulatum.

Meggan Laskowski-Peak1, Ana M. Calvo2, Jennifer Rohrssen2, and A. George Smulian1.

Author address: 

1University of Cincinnati and Cincinnati VA, Cincinnati, OH 2Department of Biological Sciences, University of Northern Illinois, Dekalb, IL


Histoplasma capsulatum (Hc) is a dimorphic fungal pathogen, causing pulmonary disease that may progress to severe disseminated disease and death in immune-suppressed individuals. Hc loses mating ability over time in culture, limiting genetic tools available to study the organism. VeA, the velvet gene, regulates cleistothecial and conidial development in Aspergillus nidulans. Our work revealed that expression of the Hc veA homolog (VeA1) in the A. nidulans veA deletion strain rescues capacity to produce fruiting bodies. We hypothesized that VeA1 would play a role in regulation of mating in Hc. We silenced VeA1 in Hc strain UC26, which has re-gained the ability to form cleistothecia with mating competent clinical strains, to study the role of VeA1 in cleistothecia formation. The silencing vector was integrated by Agrobacterium transformation, and silencing was demonstrated by qRT-PCR. Mating structures formed in crosses between VA6 and the UC26 parent or control strains. No mating structures formed between VA6 and VeA1 silenced strains. These results indicate that VeA1 is necessary for cleistothecia formation, or is involved in regulation of cleistothecia formation in Hc. Further studies will determine whether overexpression of VeA1 enables mating in non-mating strains.

abstract No: 


Full conference title: 

26th Fungal Genetics Conference
    • Fungal Genetics Conference 26th (2005)