@article{musungu_bhatnagar_brown_payne_obrian_fakhoury_geisler_2016, title={A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways}, volume={7}, ISSN={["1664-8021"]}, DOI={10.3389/fgene.2016.00206}, abstractNote={A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flavus, a link between aflatoxin production and vesicular transport was identified within the network. There was significant interspecies correlation of expression between Z. mays and A. flavus for a subset of 104 Z. mays, and 1942 A. flavus genes. This resulted in an interspecies subnetwork enriched in multiple Z. mays genes involved in the production of ROS. In addition to the ROS from Z. mays, there was enrichment in the vesicular transport pathways and the aflatoxin pathway for A. flavus. Included in these genes, a key aflatoxin cluster regulator, AflS, was found to be co-regulated with multiple Z. mays ROS producing genes within the network, suggesting AflS may be monitoring host ROS levels. The entire GEN for both host and pathogen, and the subset of interspecies correlations, is presented as a tool for hypothesis generation and discovery for events in the early stages of fungal infection of Z. mays by A. flavus.}, journal={FRONTIERS IN GENETICS}, author={Musungu, Bryan M. and Bhatnagar, Deepak and Brown, Robert L. and Payne, Gary A. and OBrian, Greg and Fakhoury, Ahmad M. and Geisler, Matt}, year={2016}, month={Nov} }
 @article{he_price_obrian_georgianna_payne_2007, title={Improved protocols for functional analysis in the pathogenic fungus Aspergillus flavus}, volume={7}, ISSN={["1471-2180"]}, DOI={10.1186/1471-2180-7-104}, abstractNote={Abstract Background An available whole genome sequence for Aspergillus flavus provides the opportunity to characterize factors involved in pathogenicity and to elucidate the regulatory networks involved in aflatoxin biosynthesis. Functional analysis of genes within the genome is greatly facilitated by the ability to disrupt or mis-express target genes and then evaluate their result on the phenotype of the fungus. Large-scale functional analysis requires an efficient genetic transformation system and the ability to readily select transformants with altered expression, and usually requires generation of double (or multi) gene deletion strains or the use of prototrophic strains. However, dominant selectable markers, an efficient transformation system and an efficient screening system for transformants in A. flavus are absent. Results The efficiency of the genetic transformation system for A. flavus based on uracil auxotrophy was improved. In addition, A. flavus was shown to be sensitive to the antibiotic, phleomycin. Transformation of A. flavus with the ble gene for resistance to phleomycin resulted in stable transformants when selected on 100 μg/ml phleomycin. We also compared the phleomycin system with one based on complementation for uracil auxotrophy which was confirmed by uracil and 5-fluoroorotic acid selection and via transformation with the pyr4 gene from Neurospora crassa and pyrG gene from A. nidulans in A. flavus NRRL 3357. A transformation protocol using pyr4 as a selectable marker resulted in site specific disruption of a target gene. A rapid and convenient colony PCR method for screening genetically altered transformants was also developed in this study. Conclusion We employed phleomycin resistance as a new positive selectable marker for genetic transformation of A. flavus . The experiments outlined herein constitute the first report of the use of the antibiotic phleomycin for transformation of A. flavus . Further, we demonstrated that this transformation protocol could be used for directed gene disruption in A. flavus . The significance of this is twofold. First, it allows strains to be transformed without having to generate an auxotrophic mutation, which is time consuming and may result in undesirable mutations. Second, this protocol allows for double gene knockouts when used in conjunction with existing strains with auxotrophic mutations. To further facilitate functional analysis in this strain we developed a colony PCR-based method that is a rapid and convenient method for screening genetically altered transformants. This work will be of interest to those working on molecular biology of aflatoxin metabolism in A. flavus , especially for functional analysis using gene deletion and gene expression.}, journal={BMC MICROBIOLOGY}, author={He, Zhu-Mei and Price, Michael S. and OBrian, Gregory R. and Georgianna, D. Ryan and Payne, Gary A.}, year={2007}, month={Nov} }
 @article{meyers_o'brian_du_bhatnagar_payne_1998, title={Characterization of aflj, a gene required for conversion of pathway intermediates to aflatoxin}, volume={64}, number={10}, journal={Applied and Environmental Microbiology}, author={Meyers, D. M. and O'Brian, G. and Du, W. L. and Bhatnagar, D. and Payne, G. A.}, year={1998}, pages={3713–3717} }
 @misc{boston_bass_obrian_1996, title={DNA encoding a ribosome inactivating protein}, volume={5552140}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Boston, R. S. and Bass, H. W. and OBrian, G. R.}, year={1996} }
 @misc{boston_bass_obrian_1994, title={DNA encoding a ribosome inactivating protein}, volume={5332808}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Boston, R. S. and Bass, H. W. and OBrian, G. R.}, year={1994} }