Aspergillus flavus Genomics for Discovering GenesInvolved in Aflatoxin Biosynthesis

摘要

Aflatoxins are polyketide-derivatives initially synthesized bycondensation of carbon units into decaketide norsolorinic acid.Aflatoxins are toxic and the most carcinogenic naturalcompounds. In order to better understand the molecularmechanisms that control aflatoxin production, identification ofgenes involved in aflatoxin biosynthesis employing a genomicsstrategy in Aspergillus flavus was carried out. Sequencing andannotation of A. flavus expressed sequence tags (EST)identified 7,218 unique EST sequences. Genes that areinvolved in or potentially involved in aflatoxin formation wereidentified from these ESTs. Gene profiling using microarrayhas thus far identified hundreds of genes that are highlyexpressed under aflatoxin-producing conditions. Primaryannotation of the A. flavus whole genome sequence datashowed that there are over two dozens of unique polyketidesynthase genes. Further investigations on the functionalinvolvement of these genes in aflatoxin biosynthesis areunderway. The results are expected to provide information fordeveloping novel strategies to control aflatoxin contamination.