Aflatoxins are carcinogenic secondary metabolites produced by the fungi Aspergillus flavus and Aspergillus parasiticus. Previous studies found that repeated serial mycelial transfer or treatment of A. parasiticus with 5-azacytidine produced colonies with a fluffy phenotype and inability to produce aflatoxins. To understand how these treatments affect expression of genes involved in aflatoxin pr...

Two routes for the conversion of 5'-hydroxyaverantin (HAVN) to averufin (AVF) in the synthesis of aflatoxin have been proposed. One involves the dehydration of HAVN to the lactone averufanin (AVNN), which is then oxidized to AVF. Another requires dehydrogenation of HAVN to 5'-ketoaverantin, the open-chain form of AVF, which then cyclizes spontaneously to AVF. We isolated a gene, adhA, from the ...

AIMS To establish a relationship between lipase gene expression and aflatoxin production by cloning the lipA gene and studying its expression pattern in several aflatoxigenic and nontoxigenic isolates of Aspergillus flavus and A. parasiticus. METHODS AND RESULTS We have cloned a gene, lipA, that encodes a lipase involved in the breakdown of lipids from aflatoxin-producing A. flavus, A. parasi...

Disruption of the aflatoxin biosynthesis cluster gene aflY (hypA) gave Aspergillus parasiticus transformants that accumulated versicolorin A. This gene is predicted to encode the Baeyer-Villiger oxidase necessary for formation of the xanthone ring of the aflatoxin precursor demethylsterigmatocystin.

240 Mold Sensitization in Chronic Rhinosinusitis Patients Radoslaw Gawlik, MD, PhD, and Eugeniusz Czecior, MD, PhD. Internal Medicine, Allergy and Clin Immunology, Silesian University of Medicine, Katowice, Poland; Silesian University of Medicine, Zabrze, Poland. Background: It is estimated that about 10% of the population have IgE antibodies to common inhalant molds. Exposure to fungal allerge...

240 Mold Sensitization in Chronic Rhinosinusitis Patients Radoslaw Gawlik, MD, PhD, and Eugeniusz Czecior, MD, PhD. Internal Medicine, Allergy and Clin Immunology, Silesian University of Medicine, Katowice, Poland; Silesian University of Medicine, Zabrze, Poland. Background: It is estimated that about 10% of the population have IgE antibodies to common inhalant molds. Exposure to fungal allerge...

Aspergillus flavus is the major producer of carcinogenic aflatoxins in crops worldwide and is also an important opportunistic human pathogen in aspergillosis. The sexual state of this heterothallic fungus is described from crosses between strains of the opposite mating type. Sexual reproduction occurred between sexually compatible strains belonging to different vegetative compatibility groups. ...