Mechanisms of Atoxigenicity: Characterizing Genetic Properties of Atoxigenic Aspergillus flavus Isolates

Persistent Link:
http://hdl.handle.net/10150/297507
Title:
Mechanisms of Atoxigenicity: Characterizing Genetic Properties of Atoxigenic Aspergillus flavus Isolates
Author:
Almader, Angelica Estella
Issue Date:
2013
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Aspergillus flavus is the primary causal agent of aflatoxin contamination in crops. Aflatoxins are highly toxic carcinogens that threaten many agricultural systems throughout the world. Twentyeight genes located in a single aflatoxin biosynthesis gene cluster are required for aflatoxin production. A. flavus isolates that are not capable of producing aflatoxins (atoxigenics) have been utilized commercially as biocontrol agents. Atoxigenicity results from the modification of genes within the aflatoxin biosynthesis cluster. Mechanisms by which A. flavus isolates become atoxigenic are unknown for many atoxigenics. Twelve atoxigenic isolates under development as biocontrol agents in the United States and Africa were subjected to several genetic analyses including multiplex PCR and sequencing of aflatoxin biosynthesis genes. Deletion patterns within the aflatoxin gene cluster varied among the atoxigenics, but certain deletion patterns were shared by multiple isolates. Sequence analysis revealed that either breakpoints or insertions exist in several isolates. The data obtained from this study will be used to develop assays to interrogate large populations of A. flavus for specific DNA features. This will aid the search for elite atoxigenic vegetative compatibility groups with superior value as biocontrol agents and allow for monitoring specific genotypes in the environment for detection of adaptive differences.
Type:
text; Electronic Thesis
Degree Name:
B.S.
Degree Level:
bachelors
Degree Program:
Honors College; Microbiology
Degree Grantor:
University of Arizona
Advisor:
Cotty, Peter J.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleMechanisms of Atoxigenicity: Characterizing Genetic Properties of Atoxigenic Aspergillus flavus Isolatesen_US
dc.creatorAlmader, Angelica Estellaen_US
dc.contributor.authorAlmader, Angelica Estellaen_US
dc.date.issued2013-
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractAspergillus flavus is the primary causal agent of aflatoxin contamination in crops. Aflatoxins are highly toxic carcinogens that threaten many agricultural systems throughout the world. Twentyeight genes located in a single aflatoxin biosynthesis gene cluster are required for aflatoxin production. A. flavus isolates that are not capable of producing aflatoxins (atoxigenics) have been utilized commercially as biocontrol agents. Atoxigenicity results from the modification of genes within the aflatoxin biosynthesis cluster. Mechanisms by which A. flavus isolates become atoxigenic are unknown for many atoxigenics. Twelve atoxigenic isolates under development as biocontrol agents in the United States and Africa were subjected to several genetic analyses including multiplex PCR and sequencing of aflatoxin biosynthesis genes. Deletion patterns within the aflatoxin gene cluster varied among the atoxigenics, but certain deletion patterns were shared by multiple isolates. Sequence analysis revealed that either breakpoints or insertions exist in several isolates. The data obtained from this study will be used to develop assays to interrogate large populations of A. flavus for specific DNA features. This will aid the search for elite atoxigenic vegetative compatibility groups with superior value as biocontrol agents and allow for monitoring specific genotypes in the environment for detection of adaptive differences.en_US
dc.typetexten_US
dc.typeElectronic Thesisen_US
thesis.degree.nameB.S.en_US
thesis.degree.levelbachelorsen_US
thesis.degree.disciplineHonors Collegeen_US
thesis.degree.disciplineMicrobiologyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorCotty, Peter J.-
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