Add like
Add dislike
Add to saved papers

Genes differentially expressed by Aspergillus flavus strains after loss of aflatoxin production by serial transfers.

Aflatoxins are carcinogenic fungal secondary metabolites produced by Aspergillus flavus and other closely related species. Levels of aflatoxins in agricultural commodities are stringently regulated by many countries because of the health hazard, and thus, aflatoxins are of major concern to both producers and consumers. A cluster of genes responsible for aflatoxin biosynthesis has been identified; however, expression of these genes is a complex and poorly understood phenomenon. To better understand the molecular events that are associated with aflatoxin production, three separate nonaflatoxigenic A. flavus strains were produced through serial transfers of aflatoxigenic parental strains. The three independent aflatoxigenic/nonaflatoxigenic pairs were compared via transcription profiling by microarray analyses. Cross comparisons identified 22 features in common between the aflatoxigenic/nonaflatoxigenic pairs. Physical mapping of the 22 features using the Aspergillus oryzae genome sequence for reference identified 16 unique genes. Aflatoxin biosynthetic and regulatory gene expression levels were not significantly different between the aflatoxigenic/nonaflatoxigenic pairs, which suggests that the inability to produce aflatoxins is not due to decreased expression of known biosynthetic or regulatory genes. Of the 16 in common genes, only one gene homologous to glutathione S-transferase genes showed higher expression in the nonaflatoxigenic progeny relative to the parental strains. This gene, named hcc, was selected for over-expression in an aflatoxigenic A. flavus strain to determine if it was directly responsible for loss of aflatoxin production. Although hcc transformants showed six- to ninefold increase in expression, no discernible changes in colony morphology or aflatoxin production were detected. Possible roles of hcc and other identified genes are discussed in relation to regulation of aflatoxin biosynthesis.

Full text links

We have located links that may give you full text access.
Can't access the paper?
Try logging in through your university/institutional subscription. For a smoother one-click institutional access experience, please use our mobile app.

For the best experience, use the Read mobile app

Mobile app image

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app

All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

By using this service, you agree to our terms of use and privacy policy.

Your Privacy Choices Toggle icon

You can now claim free CME credits for this literature searchClaim now

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app