Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: June 1, 2006
Publication Date: February 1, 2007
Citation: Yu, J., Cleveland, T.E. 2007. Aspergillus flavus Genomics for Discovering Genes Involved in Aflatoxin Biosynthesis. In: Rimando, A.M., Baerson, S.R., editors. American Chemical Society Symposium Series: Polyketides - Biosynthesis, Biological Activity, and Genetic Engineering. Washington, DC: American Chemical Society. 955:246-260. Interpretive Summary: Aflatoxins are toxic and cancer inducing compounds produced by fungal molds. It contaminates agricultural food and feed commodities. Health risk to human and animal as well as economic losses due to aflatoxin contamination are significant. Understanding the mechanism of aflatoxin formation is important for devising strategies to control the problem of aflatoxin contamination. Information obtained through fungal genomics could provide such valuable information.
Technical Abstract: Aflatoxins are polyketide-derivatives synthesized initially by condensation of carbon units into decaketide norsolorinic acid. Aflatoxins are toxic and most carcinogenic natural compounds. In order to better understand the molecular mechanisms that control aflatoxin production, identification of genes involved in aflatoxin biosynthesis employing Aspergillus flavus genomics strategy was carried out. Sequencing and annotation of A. flavus expressed sequence tags (ESTs) identified 7,218 unique EST sequences. Genes that are involved in or potentially involved in aflatoxin formation were identified from these ESTs. Gene profiling using microarray has thus far identified hundreds of genes that are highly expressed under aflatoxin-producing conditions. Primary annotation of the A. flavus whole genome sequence data showed that there are over two dozens of unique polyketide synthase genes. Further investigations on the functional involvement of these genes in aflatoxin biosynthesis are underway. The results are expected to provide information for developing novel strategies to control aflatoxin contamination.