Submitted to: Fungal Genetics Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 18, 2001
Publication Date: N/A
Technical Abstract: During the last decade, fusarium head blight, or scab, reached epidemic proportions in the United States, resulting in over 2.6 billion dollars in losses to U.S. agriculture. Fusarium graminearum and closely related fungi are the causative agents of scab, and produce trichothecene mycotoxins that act as virulence factors on some hosts, and pose a serious threat to animal health and food safety. In order to investigate the evolution of trichothecene chemotypes within the genus Fusarium, and to provide an evolutionary framework for understanding the role of trichothecene mycotoxins in pathogenesis, a 19kb region of the trichothecene gene cluster (including 8 trichothecene genes) was sequenced in F. graminearum strains selected to represent the global genetic diversity of this pathogen. Comparisons of trichothecene gene-genealogies with each other and with those derived from genes outside the cluster, in conjunction with an examination of molecular evolutionary patterns, indicated that the species phylogeny is not representative of the evolutionary history of the trichothecene gene cluster. An evolutionary model incorporating multiple population level processes is discussed.