Jae-Hyuk Yu

The genus Aspergillus encompasses the most common fungi in our environment. Many Aspergillus species are beneficial to humans, but they also include serious animal and plant pathogens. Moreover, most (if not all) Aspergillus species have the ability to produce one or more toxic secondary metabolites called mycotoxins. All Aspergilli produce asexual spores as the main means of dispersion and biosynthesis of certain mycotoxins is intimately related with fungal sporulation. The primary interest of my research program is to understand how fungi coordinate growth, sporulation and toxin biosynthesis employing the model fungus Aspergillus nidulans. We showed that two antagonistic regulatory pathways govern vegetative growth and sporulation in A. nidulans. Vegetative growth is primarily mediated by a heterotrimeric G protein, which stimulates fungal growth while inhibiting asexual/sexual sporulation as well as production of the carcinogenic mycotoxin sterigmatocystin. We found that the initiation, progression and completion of sporulation are directed by the balanced activities of multiple positive and negative regulators. We are further investigating the detailed molecular mechanisms regulating these fundamental biological processes via forward/reverse genetics, genomics and biochemical analyses.