This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Shifts in gene expression drive differentiation of tissues and the evolution of new morphologies in multicellular organisms. However, studies linking the evolution of gene expression and the evolution of development are difficult in complex organisms. Fungi in the phylum Ascomycota, a group that includes a large number of important plant and animal pathogens, provide an ideal forum for these studies as they are easily manipulated, develop fruiting structures with a few well-characterized tissue types, and feature many available and complete genome sequences. This project will reveal elements of the underlying transcriptional program of fruiting body development by profiling the genome-wide gene expression in a diverse set of closely-related fungi in the Ascomycota class Sordariomycetes. It will provide data on the evolution of genome-wide gene expression, revealing evolved differences in the transcriptional basis of morphological changes. These developmental processes are fundamental to sexual reproduction, recombination, and to the adaptive dynamics of pathogens and hosts. The project will determine the transcriptome of two plant pathogenic Fusarium species and three species of Neurospora during fruit body development under controlled environmental conditions. This information will then be used to estimate the ancestral evolutionary transitions that resulted in the shifts in morphology of these two genera. It is hypothesized that transcriptional elements identified by this process will display distinct functions in the developmental process, and functional analyses of these genes in F. graminearum and N. crassa will be performed. Ultimately, the transcriptional studies and candidate gene knockouts will reveal the regulatory circuits that control development. Such regulatory circuits and gene identifications will suggest novel targets for fungicides. The intellectual merit of the proposed activity will be to provide a model for how transcriptional shifts drive evolution of morphological variation. In addition, the proposal will identify the regulatory and structural components of genes that function in fruit body development.
Broader Impacts This project will provide opportunities for cross-training in evolutionary biology and functional biology for two graduate students and one postdoctoral associate, and experience in molecular and developmental biology for several undergraduate students. In addition, Dr. Trail will expand her program in microbiology at a local Michigan elementary school. Dr. Townsend will work with staff and students at a local high school designing two outdoor classroom modules featuring ecosystems and the role of decomposers, linking to Connecticut state standards for 6th grade. The modules will also to be applicable to student tours of the school's natural site. Moreover, plant pathogenic taxa frequently rely on the sexual stage to withstand environmental variation, to recombine and create new genotypes, and to successfully evade host defenses, yet it is a stage that may be sensitive to intervention and often occurs under predictable conditions. These characteristics make fruit body development a prime target for efforts to control fungal growth and reproduction.
