Aspergillus nidulans has been widely used as a model filamentous fungus for studies of cell biology, gene regulation and genetic analysis. It is an obligate aerobe, which grows rapidly and produces a high amount of biomass in few days A. nidulans has been genome sequenced, revealing a genome size of ca. 30 Mb. It was anticipated that an improved understanding of the factors controlling sexual reproduction would provide fundamental insights into biological processes controlling sex in ascomycete fungi as a whole, as well as providing insights to enable methods to be designed to promote sexual reproduction in the laboratory. The sexual cycle could then be used in classical genetic studies and strain improvement programmes.
The principal aim of the present study were firstly to identify suitable isolate/strain (2-139 VeA and 2-154 VeA1) of Aspergillus nidulans and secondly to determine conditions to reliably and consistently induce the sexual reproduction of the homothallic (self fertile) species A. nidulans under a variety of conditions including sealing or non-sealing of plates at different time points and incubating plates in three different stacking arrangements.
Overall results showed that the sexual fertility of (isolate 2-139 and strain 2-154) was highest in plates that were sealed 12-18 hr after inoculation at 32ºC in the dark and also revealed that there was a significant overall effect of incubation in different stacks on production of cleistothecia and also a significant interaction between strains and stacks on production of cleistothecia. The two isolate 2-139 (veA-wild-type) and strain 2-154 (veA1-Ku mutant) of A. nidulans. produced maximum numbers of cleistothecia when incubated individually, and showed a general trend of decreased numbers of cleistothecia when plates were incubated in stacks of two or three Petri dishes.