College of Agriculture
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As the foundation of the land grant mission at Montana State University, the College of Agriculture and the Montana Agricultural Experiment Station provide instruction in traditional and innovative degree programs and conduct research on old and new challenges for Montana’s agricultural community. This integration creates opportunities for students and faculty to excel through hands-on learning, to serve through campus and community engagement, to explore unique solutions to distinct and interesting questions and to connect Montanans with the global community through research discoveries and outreach.
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Item Proteomic and Transcriptomic Analyses Reveal Genes Upregulated by cis-Dichloroethene in Polaromonas sp. Strain JS666(American Society for Microbiology, 2009-06) Jennings, Laura K.; Chartrand, Michelle M. G.; Lacrampe-Couloume, Georges; Sherwood Lollar, Barbara; Spain, Jim C.; Gossett, James M.Polaromonas sp. strain JS666 is the only bacterial isolate capable of using cis-dichloroethene (cDCE) as a sole carbon and energy source. Studies of cDCE degradation in this novel organism are of interest because of potential bioremediation and biocatalysis applications. The primary cellular responses of JS666 to growth on cDCE were explored using proteomics and transcriptomics to identify the genes upregulated by cDCE. Two-dimensional gel electrophoresis revealed upregulation of genes annotated as encoding glutathione S-transferase, cyclohexanone monooxygenase, and haloacid dehalogenase. DNA microarray experiments confirmed the proteomics findings that the genes indicated above were among the most highly upregulated by cDCE. The upregulation of genes with antioxidant functions and the inhibition of cDCE degradation by elevated oxygen levels suggest that cDCE induces an oxidative stress response. Furthermore, the upregulation of a predicted ABC transporter and two sodium/solute symporters suggests that transport is important in cDCE degradation. The omics data were integrated with data from compound-specific isotope analysis (CSIA) and biochemical experiments to develop a hypothesis for cDCE degradation pathways in JS666. The CSIA results indicate that the measured isotope enrichment factors for aerobic cDCE degradation ranged from −17.4 to −22.4‰. Evidence suggests that cDCE degradation via monooxygenase-catalyzed epoxidation (C═C cleavage) may be only a minor degradation pathway under the conditions of these experiments and that the major degradation pathway involves carbon-chloride cleavage as the initial step, a novel mechanism. The results provide a significant step toward elucidation of cDCE degradation pathways and enhanced understanding of cDCE degradation in JS666.Item Application of Feeding Behaviour to Predict Morbidity of Newly Received Calves in a Commercial Feedlot.(2001-09) Quimby, W. F.; Sowell, Bok F.; Bowman, J. G. P; Branine, M. E.; Hubbert, M. E.; Sherwood, H. W.The objective of this study was to use feeding behavior of newly received steers (average initial weight 191 kg) to detect morbidity in animals in a commercial feedlot. Two separate 32 d feeding trials were conducted in Wellton, Arizona, in July and November 1996. Radio frequency technology was used to record the total time spent within 50 cm of the feedbunk (animal presence every 5.25 s times 5.25 s) in 3 h intervals from 0600 to 2400 on a daily basis for 103 and 122 male calves in trial 1 and 2, respectively. Statistical procedures based on the cumulative sums (CUSUM) of the 3 h feeding intervals were used to detect morbid animals, compared with detection of animals deemed morbid by experienced pen riders. In trial 1, the CUSUM procedure detected animal morbidity 4.5 d earlier (P < 0.001) than the feedlot personnel. In trial 2, the CUSUM procedure detected animal morbidity 3.7 d earlier (P < 0.001) than feedlot pen riders. Overall accuracy, positive predictive value and sensitivity of the CUSUM prediction method were 87, 91, and 90%, respectively. Combined trial data suggest that feeding behavior during the first 30 d cattle are in a receiving pen, as collected with radio frequency technology and analyzed with CUSUM charts, may be used to detect animal morbidity approximately 4.1 d earlier (P < 0.001) than conventional methods typically employed in commercial feedlots.Item Inducible bronchus-associated lymphoid tissue elicited by a protein cage nanoparticle enhances protection in mice against diverse respiratory viruses(2009-09) Wiley, James A.; Richert, Laura E.; Swain, Steve D.; Harmsen, Ann L.; Barnard, Dale L.; Randall, Troy D.; Jutila, Mark A.; Douglas, Trevor; Broomell, Chris; Young, Mark J.; Harmsen, Allen G.Background Destruction of the architectural and subsequently the functional integrity of the lung following pulmonary viral infections is attributable to both the extent of pathogen replication and to the host-generated inflammation associated with the recruitment of immune responses. The presence of antigenically disparate pulmonary viruses and the emergence of novel viruses assures the recurrence of lung damage with infection and resolution of each primary viral infection. Thus, there is a need to develop safe broad spectrum immunoprophylactic strategies capable of enhancing protective immune responses in the lung but which limits immune-mediated lung damage. The immunoprophylactic strategy described here utilizes a protein cage nanoparticle (PCN) to significantly accelerate clearance of diverse respiratory viruses after primary infection and also results in a host immune response that causes less lung damage. Methodology/Principal Findings Mice pre-treated with PCN, independent of any specific viral antigens, were protected against both sub-lethal and lethal doses of two different influenza viruses, a mouse-adapted SARS-coronavirus, or mouse pneumovirus. Treatment with PCN significantly increased survival and was marked by enhanced viral clearance, accelerated induction of viral-specific antibody production, and significant decreases in morbidity and lung damage. The enhanced protection appears to be dependent upon the prior development of inducible bronchus-associated lymphoid tissue (iBALT) in the lung in response to the PCN treatment and to be mediated through CD4+ T cell and B cell dependent mechanisms. Conclusions/Significance The immunoprophylactic strategy described utilizes an infection-independent induction of naturally occurring iBALT prior to infection by a pulmonary viral pathogen. This strategy non-specifically enhances primary immunity to respiratory viruses and is not restricted by the antigen specificities inherent in typical vaccination strategies. PCN treatment is asymptomatic in its application and importantly, ameliorates the damaging inflammation normally associated with the recruitment of immune responses into the lung.Item Cytoprotective Nrf2 pathway is induced in chronically txnrd 1-deficient hepatocytes(2009-07) Suvorova, Elena S.; Lucas, Olivier; Weisend, Carla M.; Rollins, MaryClare F.; Merrill, Gary F.; Capecchi, Mario R.; Schmidt, Edward E."Background Metabolically active cells require robust mechanisms to combat oxidative stress. The cytoplasmic thioredoxin reductase/thioredoxin (Txnrd1/Txn1) system maintains reduced protein dithiols and provides electrons to some cellular reductases, including peroxiredoxins. Principal Findings Here we generated mice in which the txnrd1 gene, encoding Txnrd1, was specifically disrupted in all parenchymal hepatocytes. Txnrd1-deficient livers exhibited a transcriptome response in which 56 mRNAs were induced and 12 were repressed. Based on the global hybridization profile, this represented only 0.3% of the liver transcriptome. Since most liver mRNAs were unaffected, compensatory responses were evidently effective. Nuclear pre-mRNA levels indicated the response was transcriptional. Twenty-one of the induced genes contained known antioxidant response elements (AREs), which are binding sites for the oxidative and chemical stress-induced transcription factor Nrf2. Txnrd1-deficient livers showed increased accumulation of nuclear Nrf2 protein and chromatin immunoprecipitation on the endogenous nqo1 and aox1 promoters in fibroblasts indicated that Txnrd1 ablation triggered in vivo assembly of Nrf2 on each. Conclusions Chronic deletion of Txnrd1 results in induction of the Nrf2 pathway, which contributes to an effective compensatory response."Item Pneumococcal surface protein A contributes to secondary Streptococcus pneumoniae infection after influenza virus infection(2009-08) King, Quinton O.; Lei, Benfang; Harmsen, Allen G.We compared the growth of Streptococcus pneumoniae mutants with a disruption in the gene for either pneumococcal surface protein A (PspA−), neuraminidase A (NanA−), or hyaluronidase (Hyl−) to that of the parental strain D39 by means of a competitive growth model in mice with and those without prior influenza virus infection. The numbers of total bacteria recovered from mice with prior influenza virus infection were significantly greater than those recovered from mice without prior influenza virus infection. Although the Hyl− and NanA− mutants did not display attenuation in mice with or without prior influenza virus infection, the PspA− mutant exhibited attenuation both in mice with and in mice without prior influenza virus infection. This defect was severe in influenza virus–infected mice, for which growth of the PspA− mutant was 1800-fold lower than that of the parental strain D39. Furthermore, PspA immunization significantly reduced secondary bacterial lung burdens and concentrations of specific markers of lung damage in mice receiving serotypes 2, 3, and 4 pneumococci. Our findings indicate that PspA contributes to secondary S. pneumoniae infection after influenza virus infection and that PspA immunization mitigates early secondary pneumococcal lung infections.Item TmpL, a transmembrane protein required for intracellular redox homeostasis and virulence in a plant and an animal fungal pathogen(2009-11) Kim, Kwang-Hyung; Willger, Sven D.; Park, Sang-Wook; Puttikamonkul, Srisombat; Grahl, Nora; Cho, Yangrae; Mukhopadhyay, Biswarup; Cramer, Robert A.; Lawrence, Christopher B.The regulation of intracellular levels of reactive oxygen species (ROS) is critical for developmental differentiation and virulence of many pathogenic fungi. In this report we demonstrate that a novel transmembrane protein, TmpL, is necessary for regulation of intracellular ROS levels and tolerance to external ROS, and is required for infection of plants by the necrotroph Alternaria brassicicola and for infection of mammals by the human pathogen Aspergillus fumigatus. In both fungi, tmpL encodes a predicted hybrid membrane protein containing an AMP-binding domain, six putative transmembrane domains, and an experimentally-validated FAD/NAD(P)-binding domain. Localization and gene expression analyses in A. brassicicola indicated that TmpL is associated with the Woronin body, a specialized peroxisome, and strongly expressed during conidiation and initial invasive growth in planta. A. brassicicola and A. fumigatus DtmpL strains exhibited abnormal conidiogenesis, accelerated aging, enhanced oxidative burst during conidiation, and hypersensitivity to oxidative stress when compared to wild-type or reconstituted strains. Moreover, A. brassicicola DtmpL strains, although capable of initial penetration, exhibited dramatically reduced invasive growth on Brassicas and Arabidopsis. Similarly, an A. fumigatus DtmpL mutant was dramatically less virulent than the wild-type and reconstituted strains in a murine model of invasive aspergillosis. Constitutive expression of the A. brassicicola yap1 ortholog in an A. brassicicola DtmpL strain resulted in high expression levels of genes associated with oxidative stress tolerance. Overexpression of yap1 in the DtmpL background complemented the majority of observed developmental phenotypic changes and partially restored virulence on plants. Yap1-GFP fusion strains utilizing the native yap1 promoter exhibited constitutive nuclear localization in the A. brassicicola DtmpL background. Collectively, we have discovered a novel protein involved in the virulence of both plant and animal fungal pathogens. Our results strongly suggest that dysregulation of oxidative stress homeostasis in the absence of TmpL is the underpinning cause of the developmental and virulence defects observed in these studies.Item Something old, something new, something borrowed; how the thermoacidophilic archaeon Sulfolobus solfataricus responds to oxidative stress(2009-09) Maaty, Walid S.; Wiedenheft, Blake A.; Tarlykov, Pavel V.; Schaff, Nathan; Heinemann, Joshua V.; Robison-Cox, James; Dougherty, Amanda; Blum, Paul; Lawrence, C. Martin; Douglas, Trevor; Young, Mark J.; Bothner, BrianTo avoid molecular damage of biomolecules due to oxidation, all cells have evolved constitutive and responsive systems to mitigate and repair chemical modifications. Archaea have adapted to some of the most extreme environments known to support life, including highly oxidizing conditions. However, in comparison to bacteria and eukaryotes, relatively little is known about the biology and biochemistry of archaea in response to changing conditions and repair of oxidative damage. In this study transcriptome, proteome, and chemical reactivity analyses of hydrogen peroxide (H2O2) induced oxidative stress in Sulfolobus solfataricus (P2) were conducted. Microarray analysis of mRNA expression showed that 102 transcripts were regulated by at least 1.5 fold, 30 minutes after exposure to 30 µM H2O2. Parallel proteomic analyses using two-dimensional differential gel electrophoresis (2D-DIGE), monitored more than 800 proteins 30 and 105 minutes after exposure and found that 18 had significant changes in abundance. A recently characterized ferritin-like antioxidant protein, DPSL, was the most highly regulated species of mRNA and protein, in addition to being post-translationally modified. As expected, a number of antioxidant related mRNAs and proteins were differentially regulated. Three of these, DPSL, superoxide dismutase, and peroxiredoxin were shown to interact and likely form a novel supramolecular complex for mitigating oxidative damage. A scheme for the ability of this complex to perform multi-step reactions is presented. Despite the central role played by DPSL, cells maintained a lower level of protection after disruption of the dpsl gene, indicating a level of redundancy in the oxidative stress pathways of S. solfataricus. This work provides the first “omics” scale assessment of the oxidative stress response for an archeal organism and together with a network analysis using data from previous studies on bacteria and eukaryotes reveals evolutionarily conserved pathways where complex and overlapping defense mechanisms protect against oxygen toxicity.Item HHsvm: Fast and accurate classification of profile-profile matches identified by HHsearch(2009-12) Dlakic, MensurMotivation: Recently developed profile–profile methods rival structural comparisons in their ability to detect homology between distantly related proteins. Despite this tremendous progress, many genuine relationships between protein families cannot be recognized as comparisons of their profiles result in scores that are statistically insignificant. Results: Using known evolutionary relationships among protein superfamilies in SCOP database, support vector machines were trained on four sets of discriminatory features derived from the output of HHsearch. Upon validation, it was shown that the automatic classification of all profile–profile matches was superior to fixed threshold-based annotation in terms of sensitivity and specificity. The effectiveness of this approach was demonstrated by annotating several domains of unknown function from the Pfam database.Item Risk Management Options for Wyoming Farms(2009-05) Johnson, James B.; Smith, Vincent H.Farm managers know they are involved in financially risky enterprises and, as a result, develop strategies and tools to manage that risk. Typically, those strategies involve the use of multiple production, price and business risk management tools.Item Risk Management Options for Montana Farms(2009-05) Johnson, James B.; Smith, Vincent H.Agricultural production is a financially risky business. In Montana, production losses from natural hazards do occur (for example, drought, fire, hail and insect damage). Farm managers also face substantial price risks, both in resource markets where they purchase their inputs and in commodity markets where they sell their crops. Energy prices can vary substantially from one month to the next, as can nitrogen and other fertilizer prices. Crop prices can be volatile. Moreover, the link between farm-level production losses and commodity prices is weak. At the market level, when production is relatively low prices tend to be relatively high, but an individual agricultural producer may experience low levels of production because of locally adverse production conditions when commodity prices are also low.