Submitted to: Fungal Genetics Conference/Asilomar
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 2005
Publication Date: March 20, 2005
Citation: Butchko, R.A., Brown, D.W., Proctor, R. 2005. In silico subtraction of Fusarium verticillioides EST libraries to identify potential transcriptional regulators of the FUM gene cluster [abstract]. Proceedings of the 23rd Fungal Genetics Conference. p. 190. Technical Abstract: Fumonisins are polyketide derived mycotoxins produced by the maize pathogen Fusarium verticillioides. Fumonisins can disrupt sphingolipid biosynthesis in animal cells, cause diseases in horses and swine, and have been associated with cancer in laboratory rodents. A cluster of genes responsible for fumonisin biosynthesis has been described in F. verticillioides. Conspicuously absent from this FUM gene cluster is any transcription regulatory element. Previous Northern analysis indicated that FUM genes appear to be differentially expressed over time under fumonisin inducing conditions. Recently, EST libraries have been constructed from F. verticillioides mRNA’s isolated from the fungus grown under various conditions including synthetic fumonisin inducing liquid media. Comparison of libraries from a 24-hr culture and a 96-hr culture confirmed the differential expression of the FUM gene cluster. Further comparison of these two libraries revealed the presence of a number of EST’s with similarities to transcription factors and activators, DNA binding proteins, and zinc finger proteins expressed only at 96-hr and not at 24-hr similar to the expression of the FUM gene cluster. We are investigating if these may have a role in the regulation of the FUM genes. We have disrupted a number of these candidates and developed a rapid screen for assaying for FUM gene cluster activity. Understanding the transcriptional regulation of the FUM gene cluster should provide information that can be used to control fumonisin contamination in maize.