Dr. Harris is currently Chair of the Departments of Plant Pathology, Microbiology, and Entomology at Iowa State University and Adjunct Professor member in our department.  His research focuses on the regulation of morphogenesis in the filamentous fungus Aspergillus nidulans. Spores from this fungus germinate to form long tubular hyphae that are composed of multinucleate cells. Whereas the hyphal tip cell is actively engaged in the duplication cycle, the remaining subapical cells lie dormant until they form a branch. The morphogenetic events involved in the formation of nidulans hyphae include the establishment and maintenance of cellular polarity and the partitioning of hyphae through the formation of septa. His team's goal is to dissect the molecular mechanisms underlying these morphogenetic events using a combinbation of genetic, molecular, genomic, and biochemical approaches.

In addition, they have recently uncovered an intimate link between hyphal morphogenesis and the nidulans DNA damage response, and are using a similar set of approaches to further understand the molecular basis of this link. Since A. nidulans is a close relative of many economically important plant pathogenic fungi, our research will provide key insights into the morphogenetic events underlying pathogenesis. Moreover, the experimental tractability of A. nidulans makes it an excellent model system for characterizing eukaryotic cellular processes. In particular, the organization and structure of fungal hyphae is strikingly similar to that of several plant cell types, including pollen tubes, root hairs and trichomes. Accordingly, this research should also identify key regulators of these processes.