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van der Merwe M, Jukes MD, Knox C, Moore SD, Hill MP. Naturally Occurring Yeasts Associated with Thaumatotibia leucotreta Can Enhance the Efficacy of the Cryptophlebia Leucotreta Granulovirus. Pathogens 2023; 12:1237. [PMID: 37887753 PMCID: PMC10610352 DOI: 10.3390/pathogens12101237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/02/2023] [Accepted: 10/09/2023] [Indexed: 10/28/2023] Open
Abstract
Yeasts associated with lepidopteran pests have been shown to play a role in their survival, development, and oviposition preference. It has been demonstrated that combining these yeasts with existing biological control agents can enhance their efficacy. The tortricid Thaumatotibia leucotreta is a phytosanitary pest in the South African citrus industry, with the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV) being one of the components that can control this pest. Several yeast species were shown to be associated with T. leucotreta larvae, which affected their behaviour and development. A series of detached fruit bioassays were performed to determine whether the combination of yeast with CrleGV enhances its efficacy. These assays included determining the optimal yeast/virus ratio, testing all isolated yeast species in combination with CrleGV, and further improving yeast/virus formulation by adding an adjuvant. The optimal yeast concentration to use alongside CrleGV was determined to be 106 cells·mL-1. Pichia kluyveri, P. kudriavzevii, Kluyveromyces marxianus, and Saccharomyces cerevisiae in combination with CrleGV reduced larval survival compared to CrleGV alone. The addition of molasses and BREAK-THRU® S 240 to P. kudriavzevii and S. cerevisiae in combination with CrleGV did not notably improve their effectiveness; however, there was an observed decrease in larval survival. In future studies, field trials will be conducted with combinations of CrleGV and P. kudriavzevii or S. cerevisiae to investigate whether these laboratory findings can be replicated in orchard conditions.
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Affiliation(s)
- Marcel van der Merwe
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa; (M.D.J.); (C.K.)
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa; (S.D.M.); (M.P.H.)
| | - Michael D. Jukes
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa; (M.D.J.); (C.K.)
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa; (S.D.M.); (M.P.H.)
| | - Caroline Knox
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa; (M.D.J.); (C.K.)
| | - Sean D. Moore
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa; (S.D.M.); (M.P.H.)
- Citrus Research International, P.O. Box 5095, Walmer, Gqeberha 6065, South Africa
| | - Martin P. Hill
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa; (S.D.M.); (M.P.H.)
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Abstract
16S rRNA gene sequences are commonly analyzed for taxonomic and phylogenetic studies because they contain variable regions that can help distinguish different genera. However, intra-genus distinction using variable region homology is often impossible due to the high overall sequence identities among closely related species, even though some residues may be conserved within respective species. Using a computational method that included the allelic diversity within individual genomes, we discovered that certain Escherichia and Shigella species can be distinguished by a multi-allelic 16S rRNA variable region single nucleotide polymorphism (SNP). To evaluate the performance of 16S rRNAs with altered variable regions, we developed an in vivo system that measures the acceptance and distribution of variant 16S rRNAs into a large pool of natural versions supporting normal translation and growth. We found that 16S rRNAs containing evolutionarily disparate variable regions were underpopulated both in ribosomes and in active translation pools, even for an SNP. Overall, this study revealed that variable region sequences can substantially influence the performance of 16S rRNAs and that this biological constraint can be leveraged to justify refining taxonomic assignments of variable region sequence data. IMPORTANCE This study reevaluates the notion that 16S rRNA gene variable region sequences are uninformative for intra-genus classification and that single nucleotide variations within them have no consequence to strains that bear them. We demonstrated that the performance of 16S rRNAs in Escherichia coli can be negatively impacted by sequence changes in variable regions, even for single nucleotide changes that are native to closely related Escherichia and Shigella species; thus, biological performance is likely constraining the evolution of variable regions in bacteria. Further, the native nucleotide variations we tested occur in all strains of their respective species and across their multiple 16S rRNA gene copies, suggesting that these species evolved beyond what would be discerned from a consensus sequence comparison. Therefore, this work also reveals that the multiple 16S rRNA gene alleles found in most bacteria can provide more informative phylogenetic and taxonomic detail than a single reference allele.
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Affiliation(s)
- Nikhil Bose
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Sean D. Moore
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
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Moore SD, Peyper M, Kirkman W, Marsberg T, Albertyn S, Stephen PR, Thackeray SR, Grout TG, Sharp G, Sutton G, Hattingh V. Efficacy of Various Low Temperature and Exposure Time Combinations for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) Larvae. J Econ Entomol 2022; 115:1115-1128. [PMID: 35536661 DOI: 10.1093/jee/toac064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Indexed: 06/14/2023]
Abstract
A systems approach was developed as an alternative to a standalone quarantine disinfestation treatment for Thaumatotibia leucotreta in citrus fruit exported from South Africa. The systems approach consists of three measures: pre and postharvest controls and measurements, postpacking inspection, and postharvest exposure to low temperatures. Different cold treatment conditions with a range of efficacy levels can be used for this last measure. A series of trials reported here evaluated the efficacy of seven temperatures ranging from 0 to 5°C for durations from 14 d to 26 d. Mortality of the most cold-tolerant larval stages of T. leucotreta was determined. Temperatures of 0, 1, 2, and 3°C for 16, 19, 20, and 24 d respectively, induced 100% mortality of the tested populations. Probit 9 level treatment efficacy was achieved at 0 and 1°C for 16 and 19 d respectively. Mortalities higher than 90% were obtained with temperatures of 4, 4.5, and 5°C, after exposure for the longer durations. We demonstrated a significant difference in cold-induced insecticidal efficacy between 1, 2, 3, and 4°C. There was no significant difference in insecticidal efficacy between 4 and 4.5°C, but both of these temperatures were more efficacious than 5°C. The results of this study are valuable to support the use of cold treatment conditions with lower risk of fruit chilling injury in an effective systems approach, where the cold treatment efficacy can be augmented with other components of the systems approach.
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Affiliation(s)
- Sean D Moore
- Citrus Research International, Walmer, Gqeberha, South Africa
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
| | - Mellissa Peyper
- Citrus Research International, Walmer, Gqeberha, South Africa
| | - Wayne Kirkman
- Citrus Research International, Walmer, Gqeberha, South Africa
| | - Tamryn Marsberg
- Citrus Research International, Walmer, Gqeberha, South Africa
| | - Sonnica Albertyn
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
| | | | - Sean R Thackeray
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
| | - Tim G Grout
- Citrus Research International, Nelspruit, South Africa
| | - Gary Sharp
- Department of Statistics, Nelson Mandela University, Gqeberha, South Africa
| | - Guy Sutton
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
| | - Vaughan Hattingh
- Citrus Research International, Department of Horticultural Sciences, Stellenbosch University, Stellenbosch, South Africa
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Catala-Valentin A, Bernard JN, Caldwell M, Maxson J, Moore SD, Andl CD. E-Cigarette Aerosol Exposure Favors the Growth and Colonization of Oral Streptococcus mutans Compared to Commensal Streptococci. Microbiol Spectr 2022; 10:e0242121. [PMID: 35377225 PMCID: PMC9045065 DOI: 10.1128/spectrum.02421-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 03/02/2022] [Indexed: 11/20/2022] Open
Abstract
E-cigarettes (e-cigs) have drastically increased in popularity during the last decade, especially among teenagers. While recent studies have started to explore the effect of e-cigs in the oral cavity, little is known about their effects on the oral microbiota and how they could affect oral health and potentially lead to disease, including periodontitis and head and neck cancers. To explore the impact of e-cigs on oral bacteria, we selected members of the genus Streptococcus, which are abundant in the oral cavity. We exposed the commensals Streptococcus sanguinis and Streptococcus gordonii and the opportunistic pathogen Streptococcus mutans, best known for causing dental caries, to e-liquids and e-cig aerosols with and without nicotine and with and without menthol flavoring and measured changes in growth patterns and biofilm formation. Our results demonstrate that e-cig aerosols hindered the growth of S. sanguinis and S. gordonii, while they did not affect the growth of S. mutans. We also show that e-cig aerosols significantly increased biofilm formation by S. mutans but did not affect the biofilm formation of the two commensals. We found that S. mutans exhibits higher hydrophobicity and coaggregation abilities along with higher attachment to OKF6 cells than S. sanguinis and S. gordonii. Therefore, our data suggest that e-cig aerosols have the potential to dysregulate oral bacterial homeostasis by suppressing the growth of commensals while enhancing the biofilm formation of the opportunistic pathogen S. mutans. This study highlights the importance of understanding the consequences of e-cig aerosol exposure on selected commensals and pathogenic species. Future studies modeling more complex communities will provide more insight into how e-cig aerosols and vaping affect the oral microbiota. IMPORTANCE Our study shows that e-cigarette aerosol exposure of selected bacteria known to be residents of the oral cavity hinders the growth of two streptococcal commensals while enhancing biofilm formation, hydrophobicity, and attachment for the pathogen S. mutans. These results indicate that e-cigarette vaping could open a niche for opportunistic bacteria such as S. mutans to colonize the oral cavity and affect oral health.
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Affiliation(s)
- Alma Catala-Valentin
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Joshua N. Bernard
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Matthew Caldwell
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Jessica Maxson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Sean D. Moore
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Claudia D. Andl
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
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Ramsey J, McIntosh B, Renfro D, Aleksander SA, LaBonte S, Ross C, Zweifel AE, Liles N, Farrar S, Gill JJ, Erill I, Ades S, Berardini TZ, Bennett JA, Brady S, Britton R, Carbon S, Caruso SM, Clements D, Dalia R, Defelice M, Doyle EL, Friedberg I, Gurney SMR, Hughes L, Johnson A, Kowalski JM, Li D, Lovering RC, Mans TL, McCarthy F, Moore SD, Murphy R, Paustian TD, Perdue S, Peterson CN, Prüß BM, Saha MS, Sheehy RR, Tansey JT, Temple L, Thorman AW, Trevino S, Vollmer AC, Walbot V, Willey J, Siegele DA, Hu JC. Crowdsourcing biocuration: The Community Assessment of Community Annotation with Ontologies (CACAO). PLoS Comput Biol 2021; 17:e1009463. [PMID: 34710081 PMCID: PMC8553046 DOI: 10.1371/journal.pcbi.1009463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Experimental data about gene functions curated from the primary literature have enormous value for research scientists in understanding biology. Using the Gene Ontology (GO), manual curation by experts has provided an important resource for studying gene function, especially within model organisms. Unprecedented expansion of the scientific literature and validation of the predicted proteins have increased both data value and the challenges of keeping pace. Capturing literature-based functional annotations is limited by the ability of biocurators to handle the massive and rapidly growing scientific literature. Within the community-oriented wiki framework for GO annotation called the Gene Ontology Normal Usage Tracking System (GONUTS), we describe an approach to expand biocuration through crowdsourcing with undergraduates. This multiplies the number of high-quality annotations in international databases, enriches our coverage of the literature on normal gene function, and pushes the field in new directions. From an intercollegiate competition judged by experienced biocurators, Community Assessment of Community Annotation with Ontologies (CACAO), we have contributed nearly 5,000 literature-based annotations. Many of those annotations are to organisms not currently well-represented within GO. Over a 10-year history, our community contributors have spurred changes to the ontology not traditionally covered by professional biocurators. The CACAO principle of relying on community members to participate in and shape the future of biocuration in GO is a powerful and scalable model used to promote the scientific enterprise. It also provides undergraduate students with a unique and enriching introduction to critical reading of primary literature and acquisition of marketable skills.
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Affiliation(s)
- Jolene Ramsey
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
- Center for Phage Technology, Texas A&M University, College Station, Texas, United States of America
| | - Brenley McIntosh
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Daniel Renfro
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Suzanne A. Aleksander
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Sandra LaBonte
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Curtis Ross
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
- Center for Phage Technology, Texas A&M University, College Station, Texas, United States of America
| | - Adrienne E. Zweifel
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Nathan Liles
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Shabnam Farrar
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Jason J. Gill
- Center for Phage Technology, Texas A&M University, College Station, Texas, United States of America
- Department of Animal Science, Texas A&M University, College Station, Texas, United States of America
| | - Ivan Erill
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States of America
- Department of Computer Science and Electrical Engineering, University of Maryland Baltimore County, Baltimore, Maryland, United States of America
| | - Sarah Ades
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Tanya Z. Berardini
- The Arabidopsis Information Resource, Phoenix Bioinformatics, Newark, California, United States of America
| | - Jennifer A. Bennett
- Department of Biology and Earth Science, Otterbein University, Westerville, Ohio, United States of America
| | - Siobhan Brady
- Department of Plant Biology and Genome Center, University of California Davis, Davis, California, United States of America
| | - Robert Britton
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Seth Carbon
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Steven M. Caruso
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States of America
| | - Dave Clements
- Department of Biology, John Hopkins University, Baltimore, Maryland, United States of America
| | - Ritu Dalia
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Meredith Defelice
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Erin L. Doyle
- Biology Department, Doane University, Crete, Nebraska, United States of America
| | - Iddo Friedberg
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Susan M. R. Gurney
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Lee Hughes
- Department of Biological Sciences, University of North Texas, Denton, Texas, United States of America
| | - Allison Johnson
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Jason M. Kowalski
- Biological Sciences Department, University of Wisconsin-Parkside, Kenosha, Wisconsin, United States of America
| | - Donghui Li
- The Arabidopsis Information Resource, Phoenix Bioinformatics, Newark, California, United States of America
| | - Ruth C. Lovering
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Tamara L. Mans
- Department of Biochemistry and Biotechnology, Minnesota State University Moorhead, Brooklyn Park, Minnesota, United States of America
| | - Fiona McCarthy
- Department of Basic Science, College of Veterinary Medicine, Mississippi State University, Starkville, Mississippi, United States of America
| | - Sean D. Moore
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida, United States of America
| | - Rebecca Murphy
- Department of Biology, Centenary College of Louisiana, Shreveport, Louisiana, United States of America
| | - Timothy D. Paustian
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Sarah Perdue
- Biological Sciences Department, University of Wisconsin-Parkside, Kenosha, Wisconsin, United States of America
| | - Celeste N. Peterson
- Biology Department, Suffolk University, Boston, Massachusetts, United States of America
| | - Birgit M. Prüß
- Microbiological Sciences Department, North Dakota State University, Fargo, North Dakota, United States of America
| | - Margaret S. Saha
- Department of Biology, College of William & Mary, Williamsburg, Virginia, United States of America
| | - Robert R. Sheehy
- Biology Department, Radford University, Radford, Virginia, United States of America
| | - John T. Tansey
- Department of Biochemistry and Molecular Biology, Otterbein University, Westerville, Ohio, United States of America
| | - Louise Temple
- School of Integrated Sciences, James Madison University, Harrisonburg, Virginia, United States of America
| | - Alexander William Thorman
- Department of Environmental and Public Health Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Saul Trevino
- Department of Chemistry, Math, and Physics, Houston Baptist University, Houston, Texas, United States of America
| | - Amy Cheng Vollmer
- Department of Biology, Swarthmore College, Swarthmore, Pennsylvania, United States of America
| | - Virginia Walbot
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Joanne Willey
- Department of Science Education, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States of America
| | - Deborah A. Siegele
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - James C. Hu
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, United States of America
- Center for Phage Technology, Texas A&M University, College Station, Texas, United States of America
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Wang L, Elliott AB, Moore SD, Beran GJO, Hartman JD, Harper JK. Modeling Small Structural and Environmental Differences in Solids with 15 N NMR Chemical Shift Tensors. Chemphyschem 2021; 22:1008-1017. [PMID: 33604988 DOI: 10.1002/cphc.202000985] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/28/2021] [Indexed: 11/09/2022]
Abstract
The ability to theoretically predict accurate NMR chemical shifts in solids is increasingly important due to the role such shifts play in selecting among proposed model structures. Herein, two theoretical methods are evaluated for their ability to assign 15 N shifts from guanosine dihydrate to one of the two independent molecules present in the lattice. The NMR data consist of 15 N shift tensors from 10 resonances. Analysis using periodic boundary or fragment methods consider a benchmark dataset to estimate errors and predict uncertainties of 5.6 and 6.2 ppm, respectively. Despite this high accuracy, only one of the five sites were confidently assigned to a specific molecule of the asymmetric unit. This limitation is not due to negligible differences in experimental data, as most sites exhibit differences of >6.0 ppm between pairs of resonances representing a given position. Instead, the theoretical methods are insufficiently accurate to make assignments at most positions.
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Affiliation(s)
- Luther Wang
- Department of Chemistry and Biochemistry, Brigham Young University, 84602, Provo, UT, USA
| | - Alexander B Elliott
- Department of Chemistry, University of Central Florida, 4111 Libra Drive, 32816, Orlando, FL, USA
| | - Sean D Moore
- Burnett School of Biomedical Sciences, University of Central Florida, 4110 Libra Drive, 32816, Orlando, FL, USA
| | - Gregory J O Beran
- Department of Chemistry, University of California, 92521, Riverside, CA, USA
| | - Joshua D Hartman
- Department of Chemistry, Mt. San Jacinto College, 92583, San Jacinto, CA, USA
| | - James K Harper
- Department of Chemistry and Biochemistry, Brigham Young University, 84602, Provo, UT, USA
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Moore SD. Biological Control of a Phytosanitary Pest ( Thaumatotibia leucotreta): A Case Study. Int J Environ Res Public Health 2021; 18:ijerph18031198. [PMID: 33572807 PMCID: PMC7908599 DOI: 10.3390/ijerph18031198] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/20/2021] [Accepted: 01/23/2021] [Indexed: 11/16/2022]
Abstract
Thaumatotibia leucotreta, known as the false codling moth, is a pest of citrus and other crops in sub-Saharan Africa. As it is endemic to this region and as South Africa exports most of its citrus around the world, T. leucotreta has phytosanitary status for most markets. This means that there is zero tolerance for any infestation with live larvae in the market. Consequently, control measures prior to exporting must be exemplary. Certain markets require a standalone postharvest disinfestation treatment for T. leucotreta. However, the European Union accepts a systems approach, consisting of three measures and numerous components within these measures. Although effective preharvest control measures are important under all circumstances, they are most critical where a standalone postharvest disinfestation treatment is not applied, such as within a systems approach. Conventional wisdom may lead a belief that effective chemical control tools are imperative to achieve this end. However, we demonstrate that it is possible to effectively control T. leucotreta to a level acceptable for a phytosanitary market, using only biological control tools. This includes parasitoids, predators, microbial control, semiochemicals, and sterile insects. Simultaneously, on-farm and environmental safety is improved and compliance with the increasing stringency of chemical residue requirements imposed by markets is achieved.
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Affiliation(s)
- Sean D. Moore
- Citrus Research International, P.O. Box 5095, Walmer, Port Elizabeth 6065, South Africa;
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa
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Acheampong MA, Coombes CA, Moore SD, Hill MP. Temperature tolerance and humidity requirements of select entomopathogenic fungal isolates for future use in citrus IPM programmes. J Invertebr Pathol 2020; 174:107436. [PMID: 32619548 DOI: 10.1016/j.jip.2020.107436] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/21/2020] [Accepted: 06/20/2020] [Indexed: 11/26/2022]
Abstract
Several isolates of Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitacae) and Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitacae) have been investigated as possible microbial control agents of key citrus pests in South Africa. Although laboratory results have been promising, field trials against foliar pests have shown limited success. These findings highlighted the need to investigate other biological attributes of these fungal isolates besides virulence in order to select candidates that may be better suited for the foliar environment. Thus, this study investigated the influence of temperature on the in vitro growth of seven indigenous local isolates and the humidity requirements necessary to promote successful infection, in comparison with two commercial isolates (B. bassiana PPRI 5339 and M. anisopliae ICIPE 69). All the fungal isolates grew across a range of temperatures (8-34 °C) and optimally between 26 and 28 °C. Similarly, fungal infection of Thaumatotibia leucotreta Meyrick (Lepidoptera: Tortricidae) fifth instars occurred across a range of humidity levels (12%, 43%, 75%, 98%) regardless of fungal concentration, although external sporulation was restricted to treatments exposed to 98% relative humidity. It was concluded that neither temperature nor humidity, when considered alone, is likely to significantly influence the efficacy of any of the isolates in the field, given that they are active within temperature and humidity ranges experienced in South African citrus orchards.
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Affiliation(s)
- M A Acheampong
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa.
| | - C A Coombes
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa.
| | - S D Moore
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa; Citrus Research International, Walmer, P.O. Box 5095, Port Elizabeth 6065, South Africa.
| | - M P Hill
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa.
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Wennmann JT, Eigenbrod M, Marsberg T, Moore SD, Knox CM, Hill MP, Jehle JA. Cryptophlebia peltastica Nucleopolyhedrovirus Is Highly Infectious to Codling Moth Larvae and Cells. Appl Environ Microbiol 2019; 85:e00795-19. [PMID: 31227557 PMCID: PMC6696965 DOI: 10.1128/aem.00795-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/19/2019] [Indexed: 11/20/2022] Open
Abstract
Cydia pomonella granulovirus (CpGV) is a cornerstone of codling moth (Cydia pomonella) control in integrated and organic pome fruit production, though different types of resistance to CpGV products have been recorded in codling moth field populations in Europe for several years. Recently, a novel baculovirus named Cryptophlebia peltastica nucleopolyhedrovirus (CrpeNPV) was isolated from a laboratory culture of the litchi moth, Cryptophlebia peltastica, in South Africa. Along with CpGV, it is the third known baculovirus that is infectious to codling moth. In the present study, parameters of infectiveness of CrpeNPV, such as the median lethal concentration and median survival time, were determined for codling moth larvae susceptible or resistant to CpGV. In addition, the permissiveness of a codling moth cell line with respect to infection by CrpeNPV budded virus was demonstrated by infection and gene expression studies designed to investigate the complete replication cycle. Investigations of the high degree of virulence of CrpeNPV for codling moth larvae and cells are of high significant scientific and economic value and may offer new strategies for the biological control of susceptible and resistant populations of codling moth.IMPORTANCE The emergence of codling moth populations resistant to commercially applied isolates of CpGV is posing an imminent threat to organic pome fruit production. Very few CpGV isolates are left that are able to overcome the reported types of resistance, emphasizing the demand for new and highly virulent baculoviruses. Here we report the recently discovered CrpeNPV as highly infectious to all types of resistant codling moth populations with a high speed of killing, making it a promising candidate baculovirus in fighting the spread of resistant codling moth populations.
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Affiliation(s)
- Jörg T Wennmann
- Federal Research Centre for Cultivated Plants, Institute for Biological Control, Julius Kühn Institute, Darmstadt, Germany
| | - Marina Eigenbrod
- Federal Research Centre for Cultivated Plants, Institute for Biological Control, Julius Kühn Institute, Darmstadt, Germany
| | - Tamryn Marsberg
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Sean D Moore
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
- Citrus Research International (CRI), Walmer, Port Elizabeth, South Africa
| | - Caroline M Knox
- Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
| | - Martin P Hill
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Johannes A Jehle
- Federal Research Centre for Cultivated Plants, Institute for Biological Control, Julius Kühn Institute, Darmstadt, Germany
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Motsoeneng B, Jukes MD, Knox CM, Hill MP, Moore SD. Genome Analysis of A Novel South African Cydia pomonella granulovirus (CpGV-SA) with Resistance-Breaking Potential. Viruses 2019; 11:v11070658. [PMID: 31323859 PMCID: PMC6669624 DOI: 10.3390/v11070658] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/20/2019] [Accepted: 06/24/2019] [Indexed: 01/22/2023] Open
Abstract
The complete genome of an endemic South African Cydia pomonella granulovirus isolate was sequenced and analyzed. Several missing or truncated open reading frames (ORFs) were identified, including a 24 bp deletion in the pe38 gene which is reported to be associated with type I resistance-breaking potential. Comparison of single nucleotide polymorphisms (SNPs) with five other fully sequenced CpGV isolates identified 67 unique events, 47 of which occurred within ORFs, leading to several amino acid changes. Further analysis of single nucleotide variations (SNVs) within CpGV-SA revealed that this isolate consists of mixed genotypes. Phylogenetic analysis using complete genome sequences placed CpGV-SA basal to M, I12 and E2 and distal to S and I07 but with no distinct classification into any of the previously defined CpGV genogroups. These results suggest that CpGV-SA is a novel and genetically distinct isolate with significant potential as a biopesticide for management of codling moth (CM), not only in South Africa, but potentially in other pome fruit producing countries, particularly where CM resistance to CpGV has been reported.
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Affiliation(s)
- Boitumelo Motsoeneng
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa
| | - Michael D Jukes
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa.
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa.
| | - Caroline M Knox
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa
| | - Martin P Hill
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa
| | - Sean D Moore
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa
- Citrus Research International, P.O. Box 5095, Walmer, Port Elizabeth 6065, South Africa
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11
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Moore SD, Kirkman W, Peyper M, Thackeray SR, Marsberg T, Albertyn S, Hill MP. Development of a Postharvest Cold Treatment for Cryptophlebia peltastica (Lepidoptera: Tortricidae) for Export of Litchis From South Africa. J Econ Entomol 2018; 111:2637-2643. [PMID: 30260418 DOI: 10.1093/jee/toy287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Indexed: 06/08/2023]
Abstract
The litchi moth, Cryptophlebia peltastica (Meyrick) (Lepidoptera: Tortricidae), is endemic to sub-Saharan Africa and certain Indian Ocean islands. It is an important pest of litchis and to a lesser extent macadamias. Litchis are exported to certain markets that consider C. peltastica as a phytosanitary pest. Consequently, an effective postharvest phytosanitary treatment is required. This study sought to develop a cold disinfestation treatment for this purpose. First, it was established that the fifth instar was the most cold-tolerant larval stage, as it was the only instar for which there was still some survival after 12 d at 1°C. It was then determined that cold treatment trials could be conducted in artificial diet, as there was no survival of fifth instar C. peltastica in litchis after only 9 d at 1°C, whereas it took 15 d at this temperature before no survival of fifth instar C. peltastica was recorded in artificial diet. Consequently, cold susceptibility of fifth instar C. peltastica and the most cold-tolerant larval stages (fourth and fifth instar) of false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), were compared in artificial diet. There was no survival of C. peltastica after 13 d at 1°C, whereas this was only so for T. leucotreta after 16 d. Consequently, it can be concluded that any cold treatment that has been proven effective against T. leucotreta would be as effective against C. peltastica. Finally, it was confirmed that the cold susceptibility of T. leucotreta in artificial diet did not overestimate the effect of cold on T. leucotreta larvae in litchis.
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Affiliation(s)
- Sean D Moore
- Citrus Research International, Humewood, Port Elizabeth, South Africa
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Wayne Kirkman
- Citrus Research International, Humewood, Port Elizabeth, South Africa
| | - Mellissa Peyper
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | | | - Tamryn Marsberg
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Sonnica Albertyn
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Martin P Hill
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
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Marsberg T, Jukes MD, Krejmer-Rabalska M, Rabalski L, Knox CM, Moore SD, Hill MP, Szewczyk B. Morphological, genetic and biological characterisation of a novel alphabaculovirus isolated from Cryptophlebia peltastica (Lepidoptera: Tortricidae). J Invertebr Pathol 2018; 157:90-99. [PMID: 30102885 DOI: 10.1016/j.jip.2018.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/02/2018] [Accepted: 08/10/2018] [Indexed: 11/29/2022]
Abstract
Cryptophlebia peltastica is an agricultural pest of litchis and macadamias in South Africa with phytosanitary status for certain markets. Current control methods rely on chemical, cultural and classical biological control. However, a microbial control option has not been developed. An Alphabaculovirus from C. peltastica was recovered from a laboratory reared colony and morphologically characterised by transmission electron microscopy (TEM). Analysis of occlusion bodies indicated a single NPV (SNPV) varying in size from 421 to 1263 nm. PCR amplification and sequencing of the polh gene region using universal primers followed by BLAST analysis revealed a 93% similarity to a partial polh gene sequence from Epinotia granitalis NPV. Further genetic characterisation involving single restriction endonuclease (REN) digestion of genomic DNA was carried out to generate profiles for comparison against other baculovirus species and potential new isolates of the same virus. The complete genome of the virus was sequenced, assembled and analysed for a more comprehensive genetic analysis. The genome was 115728 base pairs (bp) in length with a GC content of 37.2%. A total of 126 open reading frames (ORFs) were identified with minimal overlap and no preference in orientation. Bioassays were used to determine the virulence of the NPV against C. peltastica. The NPV was virulent against C. peltastica with an LC50 value of 6.46 × 103 OBs/ml and an LC90 value of 2.46 × 105 OBs/ml, and time mortality ranging between 76.32 h and 93.49 h. This is the first study to describe the isolation and genetic characterisation of a novel SNPV from C. peltastica, which has potential for development into a biopesticide for the control of this pest in South Africa.
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Affiliation(s)
- Tamryn Marsberg
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa; Citrus Research International, P.O. Box 20285, Humewood, Port Elizabeth 6013 South Africa
| | - Michael D Jukes
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa.
| | - Martyna Krejmer-Rabalska
- Laboratory of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology of the University of Gdansk and Medical University of Gdansk, Abrahama 58 80-307 Gdansk, Poland
| | - Lukasz Rabalski
- Laboratory of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology of the University of Gdansk and Medical University of Gdansk, Abrahama 58 80-307 Gdansk, Poland
| | - Caroline M Knox
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa
| | - Sean D Moore
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa; Citrus Research International, P.O. Box 20285, Humewood, Port Elizabeth 6013 South Africa
| | - Martin P Hill
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa
| | - Boguslaw Szewczyk
- Laboratory of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology of the University of Gdansk and Medical University of Gdansk, Abrahama 58 80-307 Gdansk, Poland
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13
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Hatting JL, Moore SD, Malan AP. Microbial control of phytophagous invertebrate pests in South Africa: Current status and future prospects. J Invertebr Pathol 2018; 165:54-66. [PMID: 29427636 DOI: 10.1016/j.jip.2018.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 01/26/2018] [Accepted: 02/06/2018] [Indexed: 01/08/2023]
Abstract
Invertebrate pests pose a significant threat to food security on the African continent. In response, South Africa has become one of the largest importers of chemical pesticides in sub-Saharan Africa, with several hundred active ingredients registered. To address the over-reliance on such chemicals, the South African Department of Agriculture, Forestry and Fisheries (DAFF) has eliminated or restricted several pesticides since the late 1970s. The recent launch of the South African National Bio-Economy Strategy and establishment of the South African Bioproducts Organisation (SABO), together with new guidelines for registration of biopesticides in 2015, also support this endeavour. Concurrently, entomopathogen-related research and bioproduct development has increased over the past decade. Currently, 31 products (seven manufactured locally) are registered under the Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act 36 of 1947. Commercially important microbes include Beauveria bassiana (Cordycipitaceae), Metarhizium anisopliae (Clavicipitaceae), Cydia pomonella granulovirus, Cryptophlebia leucotreta granulovirus, Helicoverpa armigera nucleopolyhedrovirus (Baculoviridae) and Bacillus thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai (Bacillaceae). Both parasitic and entomopathogenic nematodes (EPNs) show potential for development as bioinsecticides with one commercial EPN product, based on Heterorhabditis bacteriophora (Heterorhabditidae), registered under the Act. Rapid scientific progression, supported by a favourable legislative environment, should facilitate further advances in microbial control of phytophagous invertebrate pests in South Africa.
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Affiliation(s)
- Justin L Hatting
- Agricultural Research Council-Small Grain, Bethlehem 9700, South Africa.
| | - Sean D Moore
- Citrus Research International, Port Elizabeth 6065, South Africa; Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa
| | - Antoinette P Malan
- Department of Conservation Ecology and Entomology, Stellenbosch University, 7602, South Africa
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Krejmer-Rabalska M, Rabalski L, Lobo de Souza M, Moore SD, Szewczyk B. New Method for Differentiation of Granuloviruses (Betabaculoviruses) Based on Multitemperature Single Stranded Conformational Polymorphism. Int J Mol Sci 2017; 19:ijms19010083. [PMID: 29283392 PMCID: PMC5796033 DOI: 10.3390/ijms19010083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 12/20/2017] [Accepted: 12/23/2017] [Indexed: 12/15/2022] Open
Abstract
Baculoviruses have been used as biopesticides for decades. Recently, due to the excessive use of chemical pesticides there is a need for finding new agents that may be useful in biological protection. Sometimes few isolates or species are discovered in one host. In the past few years, many new baculovirus species have been isolated from environmental samples, thoroughly characterized and thanks to next generation sequencing methods their genomes are being deposited in the GenBank database. Next generation sequencing (NGS) methodology is the most certain way of detection, but it has many disadvantages. During our studies, we have developed a method based on Polymerase chain reaction (PCR) followed by Multitemperature Single Stranded Conformational Polymorphism (MSSCP) which allows for distinguishing new granulovirus isolates in only a few hours and at low-cost. On the basis of phylogenetic analysis of betabaculoviruses, representative species have been chosen. The alignment of highly conserved genes—granulin and late expression factor-9, was performed and the degenerate primers were designed to amplify the most variable, short DNA fragments flanked with the most conserved sequences. Afterwards, products of PCR reaction were analysed by MSSCP technique. In our opinion, the proposed method may be used for screening of new isolates derived from environmental samples.
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Affiliation(s)
- Martyna Krejmer-Rabalska
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-807 Gdansk, Poland.
| | - Lukasz Rabalski
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-807 Gdansk, Poland.
| | - Marlinda Lobo de Souza
- Embrapa Recursos Genéticos e Biotecnologia, Parque Estacao Biológica, 70770-900 Brasilia, Brazil.
| | - Sean D Moore
- Citrus Research International (CRI), P.O. Box 20285, Humewood 6013, Port Elizabeth, South Africa.
- Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa.
| | - Boguslaw Szewczyk
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-807 Gdansk, Poland.
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15
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Moore SD, Kirkman W, Hattingh V. Verification of Inspection Standards and Efficacy of a Systems Approach for Thaumatotibia leucotreta (Lepidoptera: Tortricidae) for Export Citrus From South Africa. J Econ Entomol 2016; 109:1564-1570. [PMID: 27341887 DOI: 10.1093/jee/tow139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/27/2016] [Indexed: 06/06/2023]
Abstract
A systems approach has been developed for mitigation of risk associated with Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), in citrus fruit exported from South Africa, as an alternative to a stand-alone cold treatment. This study was undertaken to assess compliance with inspection standards applicable to various steps within the systems approach and to determine its overall efficacy. Larval infestation of fruit was monitored weekly in fruit from 33 orchards, until the time of harvest, postpicking, and postpacking into export cartons. Significant positive regressions were recorded between infestation of fruit during the full monitoring period in the orchard and the last 4 wk before harvest, between the last 4 wk before harvest and on delivery to the packinghouse, and on delivery to the packinghouse and in the packed carton. There was an improvement in the level of compliance with each of these successive steps in the system, thus verifying that the grading and inspection thresholds were appropriately sensitive and confirmed the effectiveness of the system. The overall risk mitigation efficacy of the systems approach was calculated. The calculation included several known compounding under estimations of efficacy. Nonetheless, the proportion of fruit that could be infested with T. leucotreta after application of the systems approach was between P ≤ 5.328 × 10(-6) and P ≤ 8.380 × 10(-7), 6-38 times less than the proportion associated with the probit 9 (P ≤ 3.2 × 10(-5)) standard for a stand-alone cold treatment, being three survivors in 100,000 at the 95% confidence level.
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Affiliation(s)
- S D Moore
- Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (; ) Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
| | - W Kirkman
- Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (; )
| | - V Hattingh
- Citrus Research International, Department of Horticultural Sciences, Stellenbosch University, Victoria Street, Stellenbosch 7602, South Africa
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Moore SD, Kirkman W, Albertyn S, Hattingh V. Comparing the Use of Laboratory-Reared and Field-Collected Thaumatotibia leucotreta (Lepidoptera: Tortricidae) Larvae for Demonstrating Efficacy of Postharvest Cold Treatments in Citrus Fruit. J Econ Entomol 2016; 109:1571-1577. [PMID: 27341890 DOI: 10.1093/jee/tow137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Accepted: 05/27/2016] [Indexed: 06/06/2023]
Abstract
Some of South Africa's export markets require postharvest cold treatment of citrus fruit for phytosanitary risk mitigation for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). An alternative to a standalone cold treatment may be a reduced intensity cold treatment as a step in a systems approach. For cold treatment trials, large numbers of larvae are required. Due to recent dramatic improvement of T. leucotreta control in the field, sufficient naturally infested citrus fruit are no longer available. Artificial infestation of fruit is not viable due to rapid decay of the fruit. Consequently, it is necessary to use laboratory-reared T. leucotreta larvae in artificial diet. In trials, field-collected larvae from the Eastern Cape were at least as cold-tolerant as those from other regions. Larvae in Navel oranges showed the median level of susceptibility in a range of citrus types evaluated at 6°C, and their use in trials was considered acceptable due to their greater natural susceptibility to T. leucotreta infestation. We demonstrated that larvae at high density in artificial diet were at least as cold-tolerant as larvae at lower densities. When exposed to 2°C for 18 d or longer, larvae in artificial diet as used in the trials were at least as cold-tolerant as larvae in fruit. Very few surviving larvae from fruit completed development, with no subsequent generation. Consequently, it is considered justifiable to conduct cold-treatment trials with laboratory-reared T. leucotreta larvae in artificial diet without risk of overestimating the effect of cold on feral larvae in citrus fruit. [corrected]
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Affiliation(s)
- S D Moore
- Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (; ) Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
| | - W Kirkman
- Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (; )
| | - S Albertyn
- Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
| | - V Hattingh
- Citrus Research International, Department of Horticultural Sciences, Stellenbosch University, Victoria Street, Stellenbosch 7602, South Africa
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Moore SD, Kirkman W, Albertyn S, Love CN, Coetzee JA, Hattingh V. Partial Cold Treatment of Citrus Fruit for Export Risk Mitigation for Thaumatotibia leucotreta (Lepidoptera: Tortricidae) as Part of a Systems Approach. J Econ Entomol 2016; 109:1578-1585. [PMID: 27341886 DOI: 10.1093/jee/tow138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Accepted: 05/27/2016] [Indexed: 06/06/2023]
Abstract
Some of South Africa's citrus export markets require mandatory postharvest cold treatment of citrus fruit as a phytosanitary risk mitigation treatment for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). An alternative to this may be partial cold treatment as one of the final steps in a systems approach to mitigate phytosanitary risk. Consequently, the efficacy of such partial cold treatments was evaluated. It was first determined that a 2°C cold treatment was significantly more effective against fourth and fifth instars (the most cold-tolerant instars) than treatments at 3°C and 4°C for a duration of 18 d. Secondly, it was determined that 2°C for 18 d and 1°C for 16 d were similarly effective, but both treatments were significantly more effective than 1°C for 14 d. Mean mortality of fourth and fifth instars treated with 2°C for 18 d in seven replicates from four trials was 99.94%. Finally, it was determined that the inability of the majority of surviving larvae to develop to adulthood would further increase the efficacy of a 2°C for 18 d treatment to 99.96%. Inclusion of reproductive nonviability of survivors increased mortality to 99.99%.
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Affiliation(s)
- S D Moore
- Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (; ) Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa (; )
| | - W Kirkman
- Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (; )
| | - S Albertyn
- Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa (; )
| | - C N Love
- Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa (; )
| | - J A Coetzee
- Deparment of Botany, Rhodes University, PO Box 94, Grahamstown 6140, South Africa , and
| | - V Hattingh
- Citrus Research International, Department of Horticultural Sciences, Stellenbosch University, Victoria Street, Stellenbosch 7602, South Africa
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Nepgen ES, Hill MP, Moore SD. The Effect of Long-Distance Transportation on the Fitness of Irradiated False Codling Moth (Lepidoptera: Tortricidae) for Use in a Sterile Insect Release Program. J Econ Entomol 2015; 108:2610-2619. [PMID: 26318002 DOI: 10.1093/jee/tov246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 07/26/2015] [Indexed: 06/04/2023]
Abstract
The effect of cold immobilization and long-distance transport of irradiated Thaumatotibia leucotreta (Meyrick) on the flight ability of male (♂) and female (♀) moths, the longevity of male and female moths, and the realized fecundity of mating pairs CIM (chilled irradiated moths) ♀ × CIM♂, CIM♀ × NIP (nonirradiated pupae) ♂, NIP♀ × CIM♂, and NIP♀ × NIP♂ was examined to improve application of the sterile insect technique (SIT). Adult moths treated with 150 Gy of gamma radiation were immobilized with cold temperature between 4 and 6°C inside a polyurethane cooler box and transported for 12 h by road from Citrusdal, Western Cape Province, to Addo, Eastern Cape Province. Nonirradiated moths were transported as pupae inside a cardboard tray and removed by hand after which male and female pupae were separated and placed inside containers for eclosion. Male and female moths were individually placed inside petri dishes to determine longevity or paired with irradiated and nonirradiated counterparts to evaluate realized fecundity before incubation in 100% darkness at 25°C and 75% relative humidity. Flight tests were conducted indoors at 25°C by release of individual moths per hand. A significant decrease in flight ability and longevity of irradiated false codling moth was found after handling, cold immobilization, and transport, although critically, realized fecundity was not affected. Because of the impact of long-distance transport on quality of the released insects as well as the efficacy of SIT, comprehensive protocols for this critical step in the process need to be developed for a pestiferous insect with phytosanitary status such as false codling moth.
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Affiliation(s)
- E S Nepgen
- X Sterile Insect Technique, P.O. Box 86, Kirkwood 6120, South Africa. Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa.
| | - M P Hill
- Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa.
| | - S D Moore
- Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa. Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa
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Naganathan A, Wood MP, Moore SD. The large ribosomal subunit protein L9 enables the growth of EF-P deficient cells and enhances small subunit maturation. PLoS One 2015; 10:e0120060. [PMID: 25879934 PMCID: PMC4399890 DOI: 10.1371/journal.pone.0120060] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 02/03/2015] [Indexed: 01/08/2023] Open
Abstract
The loss of the large ribosomal protein L9 causes a reduction in translation fidelity by an unknown mechanism. To identify pathways affected by L9, we identified mutants of E. coli that require L9 for fitness. In a prior study, we characterized L9-dependent mutations in the essential GTPase Der (EngA). Here, we describe a second class of L9-dependent mutations that either compromise or inactivate elongation factor P (EF-P, eIF5A in eukaryotes). Without L9, Δefp cells are practically inviable. Cell fractionation studies revealed that, in both the Der and EF-P mutant cases, L9's activity reduces immature 16S rRNA in 30S particles and partially restores the abundance of monosomes. Inspired by these findings, we discovered that L9 also enhances 16S maturation in wild-type cells. Surprisingly, although the amount of immature 16S in 30S particles was found to be elevated in ΔrplI cells, the amount in polysomes was low and inversely correlated with the immature 16S abundance. These findings provide an explanation for the observed fitness increases afforded by L9 in these mutants and reveal particular physiological conditions in which L9 becomes critical. Additionally, L9 may affect the partitioning of small subunits containing immature 16S rRNA.
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Affiliation(s)
- Anusha Naganathan
- The Burnett School of Biomedical Sciences, College of Medicine, The University of Central Florida, Orlando, FL, 32816, United States of America
| | - Matthew P. Wood
- Seattle Biomed, 307 Westlake Ave N, Suite 500, Seattle, WA, 98109, United States of America
- Department of Global Health, University of Washington, 1510 N.E. San Juan Road, Seattle, WA, 98195, United States of America
| | - Sean D. Moore
- The Burnett School of Biomedical Sciences, College of Medicine, The University of Central Florida, Orlando, FL, 32816, United States of America
- * E-mail:
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Moore SD, Kirkman W, Richards GI, Stephen PR. The Cryptophlebia leucotreta granulovirus-10 years of commercial field use. Viruses 2015; 7:1284-312. [PMID: 25809025 PMCID: PMC4379571 DOI: 10.3390/v7031284] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/12/2015] [Accepted: 03/10/2015] [Indexed: 11/16/2022] Open
Abstract
In the last 15 years, extensive work on the Cryptophlebia leucotreta granulovirus (CrleGV) has been conducted in South Africa, initially in the laboratory, but subsequently also in the field. This culminated in the registration of the first CrleGV-based biopesticide in 2004 (hence, the 10 years of commercial use in the field) and the second one three years later. Since 2000, more than 50 field trials have been conducted with CrleGV against the false codling moth, Thaumatotibia leucotreta, on citrus in South Africa. In a representative sample of 13 field trials reported over this period, efficacy (measured by reduction in larval infestation of fruit) ranged between 30% and 92%. Efficacy was shown to persist at a level of 70% for up to 17 weeks after application of CrleGV. This only occurred where the virus was applied in blocks rather than to single trees. The addition of molasses substantially and sometimes significantly enhanced efficacy. It was also established that CrleGV should not be applied at less than ~2 × 1013 OBs per ha in order to avoid compromised efficacy. As CrleGV-based products were shown to be at least as effective as chemical alternatives, persistent and compatible with natural enemies, their use is recommended within an integrated program for control of T. leucotreta on citrus and other crops.
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Affiliation(s)
- Sean D Moore
- Citrus Research International, PO Box 20285, Humewood, Port Elizabeth 6013, South Africa.
- Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa.
| | - Wayne Kirkman
- Citrus Research International, PO Box 20285, Humewood, Port Elizabeth 6013, South Africa.
| | - Garth I Richards
- Citrus Research International, PO Box 20285, Humewood, Port Elizabeth 6013, South Africa.
| | - Peter R Stephen
- Citrus Research International, PO Box 28, Nelspruit 1200, South Africa.
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Moore SD, Teter K. Group-effort applied research: expanding opportunities for undergraduate research through original, class-based research projects. Biochem Mol Biol Educ 2014; 42:331-338. [PMID: 24898007 PMCID: PMC4155504 DOI: 10.1002/bmb.20802] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 04/19/2014] [Indexed: 05/30/2023]
Abstract
Undergraduate research clearly enriches the educational development of participating students, but these experiences are limited by the inherent inefficiency of the standard one student-one mentor model for undergraduate research. Group-effort applied research (GEAR) was developed as a strategy to provide substantial numbers of undergraduates with meaningful research experiences. The GEAR curriculum delivers concept-driven lecture material and provides hands-on training in the context of an active research project from the instructor's laboratory. Because GEAR is structured as a class, participating students benefit from intensive, supervised research training that involves a built-in network of peer support and abundant contact with faculty mentors. The class format also ensures a relatively standardized and consistent research experience. Furthermore, meaningful progress toward a research objective can be achieved more readily with GEAR than with the traditional one student-one mentor model of undergraduate research because sporadic mistakes by individuals in the class are overshadowed by the successes of the group as a whole. Three separate GEAR classes involving three distinct research projects have been offered to date. In this article, we provide an overview of the GEAR format and review some of the recurring themes for GEAR instruction. We propose GEAR can serve as a template to expand student opportunities for life science research without sacrificing the quality of the mentored research experience.
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Affiliation(s)
- Sean D. Moore
- To whom correspondence should be addressed. Tel: 407.823.2188.
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Opoku-Debrah JK, Hill MP, Knox C, Moore SD. Overcrowding of false codling moth, Thaumatotibia leucotreta (Meyrick) leads to the isolation of five new Cryptophlebia leucotreta granulovirus (CrleGV-SA) isolates. J Invertebr Pathol 2013; 112:219-28. [DOI: 10.1016/j.jip.2012.12.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/15/2012] [Accepted: 12/17/2012] [Indexed: 10/27/2022]
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Abstract
Background Quantitative polymerase chain reactions (qPCR) are used to monitor relative changes in very small amounts of DNA. One drawback to qPCR is reproducibility: measuring the same sample multiple times can yield data that is so noisy that important differences can be dismissed. Numerous analytical methods have been employed that can extract the relative template abundance between samples. However, each method is sensitive to baseline assignment and to the unique shape profiles of individual reactions, which gives rise to increased variance stemming from the analytical procedure itself. Principal Findings We developed a simple mathematical model that accurately describes the entire PCR reaction profile using only two reaction variables that depict the maximum capacity of the reaction and feedback inhibition. This model allows quantification that is more accurate than existing methods and takes advantage of the brighter fluorescence signals from later cycles. Because the model describes the entire reaction, the influences of baseline adjustment errors, reaction efficiencies, template abundance, and signal loss per cycle could be formalized. We determined that the common cycle-threshold method of data analysis introduces unnecessary variance because of inappropriate baseline adjustments, a dynamic reaction efficiency, and also a reliance on data with a low signal-to-noise ratio. Significance Using our model, fits to raw data can be used to determine template abundance with high precision, even when the data contains baseline and signal loss defects. This improvement reduces the time and cost associated with qPCR and should be applicable in a variety of academic, clinical, and biotechnological settings.
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Affiliation(s)
- Ana C. Carr
- The Burnett School of Biomedical Sciences, College of Medicine, The University of Central Florida, Orlando, Florida, United States of America
| | - Sean D. Moore
- The Burnett School of Biomedical Sciences, College of Medicine, The University of Central Florida, Orlando, Florida, United States of America
- * E-mail:
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Malan AP, Knoetze R, Moore SD. Isolation and identification of entomopathogenic nematodes from citrus orchards in South Africa and their biocontrol potential against false codling moth. J Invertebr Pathol 2011; 108:115-25. [PMID: 21839086 DOI: 10.1016/j.jip.2011.07.006] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 07/13/2011] [Accepted: 07/25/2011] [Indexed: 11/24/2022]
Abstract
A survey was conducted to determine the diversity and frequency of endemic entomopathogenic nematodes (EPN) in citrus orchards in the Western Cape, Eastern Cape and Mpumalanga provinces of South Africa. The main aim of the survey was to obtain nematodes as biological control agents against false codling moth (FCM), Thaumatotibia leucotreta, a key pest of citrus in South Africa. From a total of 202 samples, 35 (17%) tested positive for the presence of EPN. Of these, four isolates (11%) were found to be steinernematids, while 31 (89%) were heterorhabditids. Sequencing and characterisation of the internal transcribed spacer (ITS) region was used to identify all nematode isolates to species level. Morphometrics, morphology and biology of the infective juvenile (IJ) and the first-generation male were used to support molecular identification and characterisation. The Steinernema spp. identified were Steinernema khoisanae, Steinernema yirgalemense and Steinernema citrae. This is the first report of S. yirgalemense in South Africa, while for S. citrae it is the second new steinernematid to be identified from South Africa. Heterorhabditis species identified include Heterorhabditis bacteriophora, Heterorhabditis zealandica and an unknown species of Heterorhabditis. Laboratory bioassays, using 24-well bioassay disks, have shown isolates of all six species found during the survey, to be highly virulent against the last instar of FCM larvae. S. yirgalemense, at a concentration of 50IJs/FCM larva caused 100% mortality and 74% at a concentration of 200IJs/pupa. Using a sand bioassay, S. yirgalemense gave 93% control of cocooned pupae and emerging moths at a concentration of 20IJs/cm(2). This is the first report on the potential use of EPN to control the soil-borne life stages of FCM, which includes larvae, pupae and emerging moths. It was shown that emerging moths were infected with nematodes, which may aid in control and dispersal.
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Affiliation(s)
- Antoinette P Malan
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa.
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Klein RC, Mace BE, Moore SD, Sullivan PM. Progressive loss of synaptic integrity in human apolipoprotein E4 targeted replacement mice and attenuation by apolipoprotein E2. Neuroscience 2010; 171:1265-72. [PMID: 20951774 DOI: 10.1016/j.neuroscience.2010.10.027] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 09/22/2010] [Accepted: 10/12/2010] [Indexed: 01/30/2023]
Abstract
Inheritance of the APOE4 allele is a well established genetic risk factor linked to the development of late onset Alzheimer's disease. As the major lipid transport protein in the central nervous system, apolipoprotein (apo) E plays an important role in the assembly and maintenance of synaptic connections. Our previous work showed that 7 month old human apoE4 targeted replacement (TR) mice displayed significant synaptic deficits in the principal neurons of the lateral amygdala, a region that is critical for memory formation and also one of the primary regions affected in Alzheimer's disease, compared to apoE3 TR mice. In the current study, we determined how age and varying APOE genotype affect synaptic integrity of amygdala neurons by comparing electrophysiological and morphometric properties in C57BL6, apoE knockout, and human apoE3, E4 and E2/4 TR mice at 1 month and 7 months. The apoE4 TR mice exhibited the lowest level of excitatory synaptic activity and dendritic arbor compared to other cohorts at both ages, and became progressively worse by 7 months. In contrast, the apoE3 TR mice exhibited the highest synaptic activity and dendritic arbor of all cohorts at both ages. C57BL6 mice displayed virtually identical synaptic activity to apoE3 TR mice at 1 month; however this activity decreased by 7 months. ApoE knockout mice exhibited a similar synaptic activity profile with apoE4 TR mice at 7 months. Consistent with previous reports that APOE2 confers protection, the apoE4-dependent deficits in excitatory activity were significantly attenuated in apoE2/4 TR mice at both ages. These findings demonstrate that expression of human apoE4 contributes to functional deficits in the amygdala very early in development and may be responsible for altering neuronal circuitry that eventually leads to cognitive and affective disorders later in life.
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Affiliation(s)
- R C Klein
- Department of Psychiatry, Duke University Medical Center, Durham, NC 27710, USA
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Yang AHJ, Moore SD, Schmidt BS, Klug M, Lipson M, Erickson D. Optical manipulation of nanoparticles and biomolecules in sub-wavelength slot waveguides. Nature 2009; 457:71-5. [DOI: 10.1038/nature07593] [Citation(s) in RCA: 620] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2008] [Accepted: 10/21/2008] [Indexed: 11/09/2022]
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Chung L, Moore SD. Cholecystokinin enhances GABAergic inhibitory transmission in basolateral amygdala. Neuropeptides 2007; 41:453-63. [PMID: 17904218 DOI: 10.1016/j.npep.2007.08.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 07/13/2007] [Accepted: 08/11/2007] [Indexed: 11/25/2022]
Abstract
The neuropeptide cholecystokinin (CCK) is anxiogenic in studies of human and animal behavior. As the amygdala formation has been implicated in generation of emotional states such as anxiety, we tested the effect of CCK on spontaneous synaptic events in the basolateral amygdala (BLA) using whole cell patch recordings in rat brain slice preparation. We found that CCK increased the frequency of spontaneous inhibitory postsynaptic potentials (sIPSPs) and currents (sIPSCs). This effect was blocked by the fast sodium channel blocker tetrodotoxin (TTX), indicating that the CCK effect is likely mediated by direct excitation of GABAergic interneurons. The CCK(B) receptor subtype antagonist, CR2945, blocked the CCK effect, while CCK4, a specific CCK(B) agonist, increased sIPSC frequency. We hypothesize that these actions may underlie the anxiogenic effects of CCK observed in behavioral studies.
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Affiliation(s)
- L Chung
- Department of Psychiatry, Duke University Medical Center, Durham, NC 27710, USA
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28
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Abstract
The tmRNA system performs translational surveillance and ribosome rescue in all eubacteria and some eukaryotic organelles. This system intervenes when ribosomes read to the 3' end of an mRNA or pause at internal codons with subsequent mRNA cleavage. A complex of alanyl-tmRNA (which functions as a tRNA and mRNA), SmpB protein, and EF-TucGTP binds stalled ribosomes, the nascent polypeptide is transferred to the alanine on tmRNA, and translation switches from the original message to a short tmRNA open reading frame (ORF) that encodes a degradation tag. Translation of the ORF and normal termination releases the tagged polypeptide for degradation and permits disassembly and recycling of ribosomal subunits for new rounds of protein synthesis. Structural and biochemical studies suggest mechanisms that keep tmRNA from interrupting normal translation and target ribosomes stalled with very short 3' mRNA extensions. Additional biological roles of tmRNA include stress management and the regulation of transcriptional circuits.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Macromolecular Substances
- Models, Molecular
- Molecular Sequence Data
- Nucleic Acid Conformation
- Open Reading Frames
- Peptide Elongation Factor Tu/metabolism
- Protein Biosynthesis
- Protein Conformation
- RNA Stability
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- RNA-Binding Proteins/metabolism
- Ribosomes/metabolism
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Affiliation(s)
- Sean D Moore
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Braga CACA, Carvalho D, Lara FA, Cortines JR, Moore SD, Prevelige PE, Foguel D. An Aggregation-Prone Intermediate Species Is Present in the Unfolding Pathway of the Monomeric Portal Protein of Bacteriophage P22: Implications for Portal Assembly. Biochemistry 2007; 46:7353-64. [PMID: 17542560 DOI: 10.1021/bi700006d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The head of the P22 bacteriophage is interrupted by a unique dodecameric portal vertex that serves as a conduit for the entrance and exit of the DNA. Here, the in vitro unfolding/refolding processes of the portal protein of P22 were investigated at different temperatures (1, 25, and 37 degrees C) through the use of urea and high hydrostatic pressure (HHP) combined with spectroscopic techniques. We have characterized an intermediate species, IU, which forms at 25 degrees C during unfolding or refolding of the portal protein in 2-4 M urea. IU readily forms amorphous aggregates, rendering the folding process irreversible. On the other hand, at 1 degrees C, a two-state process is observed (DeltaGf = -2.2 kcal/mol). When subjected to HHP at 25 or 37 degrees C, the portal monomer undergoes partial denaturation, also forming an intermediate species, which we call IP. IP also tends to aggregate but, differently from IU, aggregates into a ring-like structure as seen by size-exclusion chromatography and electron microscopy. Again, at 1 degrees C the unfolding induced by HHP proved to be reversible, with DeltaGf = -2.4 kcal/mol and DeltaV = 72 mL/mol. Interestingly, at 25 degrees C, the binding of the hydrophobic probe bis-ANS to the native portal protein destabilizes it and completely blocks its aggregation under HHP. These data are relevant to the process by which the portal protein assembles into dodecamers in vivo, since species such as IP must prevail over IU in order to guarantee the proper ring formation.
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Affiliation(s)
- Carolina A C A Braga
- Instituto de Bioquímica Médica, Programa de Biologia Estrutural, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
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Abstract
When protein synthesis stalls in bacteria, tmRNA acts first as a surrogate tRNA and then as an mRNA in a series of reactions that append a peptide tag to the nascent polypeptide and 'rescue' the ribosome. The peptide tag encoded by wild-type tmRNA promotes rapid degradation of rescued proteins. Using a mutant tmRNA that encodes a tag that does not lead to degradation, we demonstrate that the synthesis of approximately 0.4% of all proteins terminates with tagging and ribosome rescue during normal exponential growth of Escherichia coli. The frequency of tagging was not significantly increased in cells expressing very high levels of tmRNA and its binding protein SmpB, suggesting that recognition of 'stalled' ribosomes does not involve competition between tmRNA and other translation factors for A-sites that are unoccupied transiently during protein synthesis. When the demand for ribosome rescue was increased artificially by overproduction of a non-stop mRNA, tmRNA levels did not increase but tmRNA-mediated tagging increased substantially. Thus, the ribosome-rescue system usually operates well below capacity.
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Affiliation(s)
- Sean D Moore
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Schneider DJ, Levi DS, Serwacki MJ, Moore SD, Moore JW. Overview of interventional pediatric cardiology in 2004. Minerva Pediatr 2004; 56:1-28. [PMID: 15249911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Pediatric interventional catheterization is an expanding specialty with a range of mature, emerging, and investigative procedures and technologies. Many dysfunctional obstructions and/or shunts caused by congenital heart defects may be treated or significantly palliated in the catheterization laboratory. These include valvar pulmonary or aortic stenosis, the patent ductus arteriosus, coarctation of the aorta, branch pulmonary stenosis, atrial septal defects and even ventricular septal defects. Valve replacement technology, approaches to complex heart diseases such as single ventricle, and fetal interventions are subjects of active investigations. A comprehensive review of the present and future of interventional pediatric cardiology is presented.
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Affiliation(s)
- D J Schneider
- The Heart Center for Children, St. Christopher's Hospital for Children, Philadelphia, PA, USA
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Abstract
Benzodiazepines are among the most widely prescribed therapeutic agents, having anxiolytic, anticonvulsant, sedative/hypnotic, and amnestic properties (Mehta and Ticku, Brain Res. Rev. 29 (1999) 196). Recent research indicates that these disparate actions are dissociable (Nature 401 (1999) 796; Science 290 (2000) 131; Kralic et al., Neuropharmacology 43 (2002) 685). Behavioral studies indicate that the amygdala plays a critical role in the anxiolytic effect of benzodiazepines (Nagy et al., Neuropharmacology 18 (1979) 573; The amygdala: anxiety and benzodiazepines. The Amygdala: a Functional Analysis. p. 195). However, the neuronal substrates of this anxiolytic effect remain unclear. Our study characterizes the physiological response to acute application of the benzodiazepine diazepam and the non-benzodiazepine sedative zolpidem using whole cell patch recording in two discrete amygdala subnuclei. We found that acute application of diazepam enhances GABA(A) receptor-mediated inhibitory postsynaptic currents (IPSCs) with equal potency in the basolateral (BL) and central (Ce) amygdala subnuclei. However, zolpidem enhanced IPSCs with similar potency only in the BL, and was effective in the Ce only at high concentrations. This finding is in agreement with histochemical data regarding the localization of GABA(A) receptor isoforms in the amygdala (J. Comp. Neurol. 359 (1995) 154; Brain Res. 964 (2003) 91) and suggests that anxiolytic effects of allosteric modulators of the GABA(A) receptor may be further dissociated from their hypnotic/sedative effects.
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Affiliation(s)
- M-H Kang-Park
- Department of Molecular Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
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Affiliation(s)
- Sean D Moore
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Abstract
Bacteriophage with linear, double-stranded DNA genomes package DNA into preassembled protein shells called procapsids. Located at one vertex in the procapsid is a portal complex composed of a ring of 12 subunits of portal protein. The portal complex serves as a docking site for the DNA packaging enzymes, a conduit for the passage of DNA, and a binding site for the phage tail. An excess of the P22 portal protein alters the assembly pathway of the procapsid, giving rise to defective procapsid-like particles and aberrant heads. In the present study, we report the isolation of escape mutant phage that are able to replicate more efficiently than wild-type phage in the presence of excess portal protein. The escape mutations all mapped to the same phage genome segment spanning the portal, scaffold, coat, and open reading frame 69 genes. The mutations present in five of the escape mutants were determined by DNA sequencing. Interestingly, each mutant contained the same mutation in the scaffold gene, which changes the glycine at position 287 to glutamate. This mutation alone conferred an escape phenotype, and the heads assembled by phage harboring only this mutation had reduced levels of portal protein and exhibited increased head assembly fidelity in the presence of excess portal protein. Because this mutation resides in a region of scaffold protein necessary for coat protein binding, these findings suggest that the P22 scaffold protein may define the portal vertices in an indirect manner, possibly by regulating the fidelity of coat protein polymerization.
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Affiliation(s)
- Sean D Moore
- Department of Microbiology, University of Alabama at Birmingham, 845 South 19th Street, Birmingham, AL 35295, USA
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Abstract
Portal proteins are components of large oligomeric dsDNA pumps connecting the icosahedral capsid of tailed bacteriophages to the tail. Prior to the tail attachment, dsDNA is actively pumped through a central cavity formed by the subunits. We have studied the portal protein of bacteriophage P22, which is the largest connector characterized among the tailed bacteriophages. The molecular weight of the monomer is 82.7 kDa, and it spontaneously assembles into an oligomeric structure of approximately 1.0 MDa. Here we present a preliminary biochemical and crystallographic characterization of this large macromolecular complex. The main difficulties related to the crystallization of P22 portal protein lay in the intrinsic dynamic nature of the portal oligomer. Recombinant connectors assembled from portal monomers expressed in Escherichia coli form rings of different stoichiometry in solution, which cannot be separated on the basis of their size. To overcome this intrinsic heterogeneity we devised a biochemical purification that separates different ring populations on the basis of their charge. Small ordered crystals were grown from drops containing a high concentration of the kosmotropic agent tert-butanol and used for data collection. A preliminary crystallographic analysis to 7.0-A resolution revealed that the P22 portal protein crystallized in space group I4 with unit cell dimensions a=b=409.4A, c=260.4A. This unit cell contains a total of eight connectors. Analysis of the noncrystallographic symmetry by the self-rotation function unambiguously confirmed that bacteriophage P22 portal protein is a dodecamer with a periodicity of 30 degrees. The cryo-EM reconstruction of the dodecahedral bacteriophage T3 portal protein will be used as a model to initiate phase extension and structure determination.
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Affiliation(s)
- Gino Cingolani
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Pershing RA, Moore SD, Dinges AC, Thatcher WW, Badinga L. Short communication: Hepatic gene expression for gluconeogenic enzymes in lactating dairy cows treated with bovine somatotropin. J Dairy Sci 2002; 85:504-6. [PMID: 11949852 DOI: 10.3168/jds.s0022-0302(02)74101-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eight lactating Holstein dairy cows (80 d in milk) were used to examine the effects of exogenous bovine somatotropin (bST) on hepatic contents of mRNA encoding pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), and microsomal triglyceride transfer protein (MTP). Concentrations of bST in plasma were higher and milk production increased 20% in bST-treated cows. Liver samples from cows treated with bST had significantly higher total lipid contents than those from control cows. Although there were small numerical tendencies, neither triglyceride concentrations in liver nor nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), or glucose in plasma differed significantly between bST-treated and control cows. Short-term bST treatment had no detectable effects on contents of PC, PEPCK, and MTP mRNA in the liver. In summary, exogenous bST stimulation of milk production is not mediated through enhanced liver gluconeogenesis, but may involve partitioning of glucose and fatty acids for preferential use by the mammary gland.
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Affiliation(s)
- R A Pershing
- Department of Animal Sciences University of Florida, Gainesville 32611, USA
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Abstract
DNA is packaged into preformed bacteriophage capsids to liquid crystalline density by the action of a portal protein complex. Single molecule packaging studies indicate that this is a new and extremely powerful class of molecular motors.
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Affiliation(s)
- Sean D Moore
- Department of Microbiology, University of Alabama at Birmingham 845, 19th St. South, Birmingham, Alabama 35294, USA
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Abstract
Bacteriophage with double-stranded, linear DNA genomes package DNA into pre-assembled icosahedral procapsids through a unique vertex. The packaging vertex contains an oligomeric ring of a portal protein that serves as a recognition site for the packaging enzymes, a conduit for DNA translocation, and the site of tail attachment. Previous studies have suggested that the portal protein of bacteriophage P22 is not essential for shell assembly; however, when assembled in the absence of functional portal protein, the assembled heads are not active in vitro packaging assays. In terms of head assembly, this raises an interesting question: how are portal vertices defined during morphogenesis if their incorporation is not a requirement for head assembly? To address this, the P22 portal gene was cloned into an inducible expression vector and transformed into the P22 host Salmonella typhimurium to allow control of the dosage of portal protein during infections. Using pulse-chase radiolabeling, it was determined that the portal protein is recruited into virion during head assembly. Surprisingly, over-expression of the portal protein during wild-type P22 infection caused a dramatic reduction in the yield of infectious virus. The cause of this reduction was traced to two potentially related phenomena. First, excess portal protein caused aberrant head assembly resulting in the formation of T=7 procapsid-like particles (PLPs) with twice the normal amount of portal protein. Second, maturation of the PLPs was blocked during DNA packaging resulting in the accumulation of empty PLPs within the host. In addition to PLPs with normal morphology, smaller heads (apparently T=4) and aberrant spirals were also produced. Interestingly, maturation of the small heads was relatively efficient resulting in the formation of small mature particles that were tailed and contained a head full of DNA. These data suggest that incorporation of portal vertices into heads occurs during growth of the coat lattice at decision points that dictate head assembly fidelity.
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Affiliation(s)
- Sean D Moore
- Department of Microbiology BBRB 416/6, University of Alabama at Birmingham, 845 19th St. South, Birmingham, AL 35294, USA
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Rodríguez-Casado A, Moore SD, Prevelige PE, Thomas GJ. Structure of bacteriophage P22 portal protein in relation to assembly: investigation by Raman spectroscopy. Biochemistry 2001; 40:13583-91. [PMID: 11695906 DOI: 10.1021/bi0110488] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Salmonella phage P22, which serves as an assembly paradigm for icosahedral double-stranded DNA viruses, packages its viral genome through a capsid channel (portal) comprising 12 copies of a 725-residue subunit. Secondary and tertiary structures of the portal subunit in monomeric and dodecameric states have been investigated by Raman spectroscopy using a His6-tagged recombinant protein that self-assembles in vitro [Moore, S. D., and Prevelige, P. E., Jr. (2001) J. Biol. Chem. 276, 6779-6788]. The portal protein exhibits Raman secondary structure markers typical of a highly alpha-helical subunit fold that is little perturbed by assembly. On the other hand, Raman markers of subunit side chains change dramatically with assembly, an indication of extensive changes in side chain environments. The cysteinyl Raman signature of the portal consists of a complex pattern of sulfhydryl stretching bands, revealing diverse hydrogen-bonding states for the four S-H groups per subunit (Cys 153, Cys 173, Cys 283, and Cys 516). Upon assembly, the population of strongly hydrogen-bonded S-H groups decreases, while the population of weakly hydrogen-bonded S-H groups increases, implying that specific intrasubunit S-H.X hydrogen bonds must be weakened to effect dodecamer assembly and that the molecular mechanism involves reorganization of subunit domains without appreciable changes in domain conformations. Comparison with other viral protein assemblies suggests an assembly process not requiring metastable intermediates. The recently published X-ray structure of the phi29 portal [Simpson, A. A., et al. (2000) Nature 408, 745-750] shows that residues 125-225 lining the channel surface form alpha-helical modules spaced by short beta-strands and turns; a surprisingly close secondary structure homology is predicted for residues 240-350 of the P22 portal, despite no apparent sequence homology. This motif is proposed as an evolutionarily conserved domain involved in DNA translocation.
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Affiliation(s)
- A Rodríguez-Casado
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110-2499, USA
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Abstract
Although the synaptic physiology of the amygdala has been studied with single neuron recordings, the properties of the networks between the various nuclei have resisted characterization because of the limitations of field recording in a neuronally diffuse structure. We addressed this issue in the rat amygdala complex in vitro by using a photodiode array coupled with a voltage-sensitive dye. Low-intensity single pulse stimulation of the lateral amygdala nucleus produced a complex multi-phasic potential. This signal propagated to the basolateral nucleus and the amygdalostriatal transition zone but not to the central nucleus. The local potential, which depended on both synaptic responses and activation of voltage-dependent ion channels, was reduced in amplitude by the non-N-methyl-D-aspartate (non-NMDA) glutamate receptor antagonist 6,7-dinitroquinoxaline (DNQX) and reduced to a lesser extent by the NMDA glutamate receptor antagonist D-2-amino-5-phosphonovaleric acid (D-APV). We next characterized the less complex signals that propagated to more distal regions with or without the addition of the GABA receptor antagonist bicuculline (BIC). BIC alone greatly increased the signal propagation and permitted activation of previously silent areas within the amygdala. DNQX blocked signal propagation to amygdala regions outside of La, even in the presence of BIC, whereas D-APV had minimal effects on these distal signals. These data represent several novel findings: the characterization of the multi-component potential near the site of stimulation, the gating of signal propagation within the amygdala by GABAergic inhibition, the critical role of non-NMDA receptor-mediated depolarization in signal propagation, and the lack of a role for NMDA receptors in maintaining propagation.
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Affiliation(s)
- C Wang
- Department of Pharmacology, Duke University Medical Center, Durham, NC 27705, USA.
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41
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Abstract
The Salmonella typhimurium bacteriophage P22 assembles an icosahedral capsid precursor called a procapsid. The oligomeric portal protein ring, located at one vertex, comprises the conduit for DNA entry and exit. In conjunction with the DNA packaging enzymes, the portal ring is an integral component of a nanoscale machine that pumps DNA into the phage head. Although the portal vertex is assembled with high fidelity, the mechanism by which a single portal complex is incorporated during procapsid assembly remains unknown. The assembly of bacteriophage P22 portal rings has been characterized in vitro using a recombinant, His-tagged protein. Although the portal protein remained primarily unassembled within the cell, once purified, the highly soluble monomer assembled into rings at room temperature at high concentrations with a half time of approximately 1 h. Circular dichroic analysis of the monomers and rings indicated that the protein gained alpha-helicity upon polymerization. Thermal denaturation studies suggested that the rings contained an ordered domain that was not present in the unassembled monomer. A combination of 4,4'-dianilino-1,1'-binapthyl-5,5'-disulfonic acid (bis-ANS) binding fluorescence studies and limited proteolysis revealed that the N-terminal portion of the unassembled subunit is meta-stable and is susceptible to structural perturbation by bis-ANS. In conjunction with previously obtained data on the behavior of the P22 portal protein, we propose an assembly model for P22 portal rings that involves a meta-stable monomeric subunit.
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Affiliation(s)
- S D Moore
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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Hertzberg MA, Moore SD, Feldman ME, Beckham JC. A preliminary study of bupropion sustained-release for smoking cessation in patients with chronic posttraumatic stress disorder. J Clin Psychopharmacol 2001; 21:94-8. [PMID: 11199956 DOI: 10.1097/00004714-200102000-00017] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study was conducted to evaluate the effect of bupropion sustained-release (SR) on smoking cessation in patients with chronic posttraumatic stress disorder (PTSD). Fifteen veterans with chronic PTSD who desired to stop smoking enrolled in a 12-week double-blind evaluation of bupropion SR and placebo. Patients were randomly assigned in a 2:1 ratio to receive either bupropion SR or placebo. Bupropion SR was initiated at 150 mg daily for 3 or 4 days and increased to a final dose of 150 mg twice daily (300 mg daily total). Ten patients received bupropion SR and five received placebo. Nine of the patients who received bupropion SR were already being treated with at least one other psychotropic medication. One of the ten patients did not complete the study because of medication side effects. Eighty percent of patients receiving bupropion SR successfully stopped smoking by the end of week 2, and 6 (60%) of these 10 maintained smoking cessation at the study endpoint (week 12). At the 6-month follow-up, 40% of the patients (4 of 10) who received bupropion SR maintained smoking cessation. One (20%) of the five patients who received placebo stopped smoking and maintained smoking cessation at the 6-month follow-up. Bupropion SR was generally well-tolerated in combination with other psychotropic medications. Bupropion SR may be effective in helping patients who desire to quit smoking and who also have a concomitant anxiety disorder, such as PTSD.
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Affiliation(s)
- M A Hertzberg
- Duke University Medical Center, Department of Psychiatry, Durham, North Carolina, USA.
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Calhoun PS, Sampson WS, Bosworth HB, Feldman ME, Kirby AC, Hertzberg MA, Wampler TP, Tate-Williams F, Moore SD, Beckham JC. Drug use and validity of substance use self-reports in veterans seeking help for posttraumatic stress disorder. J Consult Clin Psychol 2000; 68:923-7. [PMID: 11068979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The present study assessed drug use and the validity of self-reports of substance use among help-seeking veterans referred to a specialty clinic for the assessment of posttraumatic stress disorder (PTSD). Patients (n = 341) were asked to provide a urine sample for use in drug screening as part of an evaluation of PTSD. Self-reports of substance use were compared with same-day supervised urine samples for 317 patients who volunteered to participate in a drug screening. Results suggested that self-reports were generally quite valid. Only 8% of the cases involved patients not reporting substance use detected by urine screens. A total of 42% of the participants were identified as using drugs of abuse (excluding alcohol) through self-report and urine drug screens. Among participants using drugs, PTSD diagnosis was significantly associated with greater marijuana and depressant use as compared with stimulant (cocaine and amphetamines) use.
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Affiliation(s)
- P S Calhoun
- Department of Medicine, Duke University Medical Center, and Health Services Research, Veterans Affairs Medical Center (VAMC), Durham, North Carolina 27705, USA.
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Moore SD, Chen MM, Cox DW. Cloning and mapping of murine superoxide dismutase copper chaperone (Ccsd) and mapping of the human ortholog. Cytogenet Cell Genet 2000; 88:35-7. [PMID: 10773661 DOI: 10.1159/000015480] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Copper does not exist in a free state within cells but is found consistently bound to metalloproteins. Specific metallochaperones escort copper to numerous targets within the cell, providing protection from the toxic effects of intracellular free copper. Many metallochaperones have been characterized in yeast, mouse, and human. To further characterize mouse metallochaperones, we cloned murine Ccsd from an adult mouse cDNA brain library, including both the coding region and the 5' and 3' UTRs. We obtained a 1,174-bp cDNA with an 825-bp open reading frame, translating a 274 amino acid protein that is 86.9% identical to human CCS. Using a mouse x hamster radiation hybrid panel, we mapped Ccsd to a proximal position on mouse chromosome 19. We mapped human CCS to 11q13 (homologous with mouse chromosome 19), utilizing a human x hamster radiation hybrid panel. The human and mouse metallochaperones are ubiquitously expressed in the major tissues of the body but seem to have different transcription products.
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Affiliation(s)
- S D Moore
- Department of Medical Genetics, University of Alberta, Edmonton, Canada
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Beckham JC, Feldman ME, Barefoot JC, Fairbank JA, Helms MJ, Haney TL, Hertzberg MA, Moore SD, Davidson JR. Ambulatory cardiovascular activity in Vietnam combat veterans with and without posttraumatic stress disorder. J Consult Clin Psychol 2000. [PMID: 10780127 DOI: 10.1037//0022-006x.68.2.269] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present study investigated the relationship between daily diary affect ratings and ambulatory cardiovascular activity in 117 male Vietnam combat veterans (61 with posttraumatic stress disorder [PTSD] and 56 without PTSD). Participants completed 12-14 hr of ambulatory monitoring and daily diary affect ratings. Compared with veterans without PTSD, veterans with PTSD reported higher negative affect and lower positive affect in daily diary ratings. No differences were detected for mean laboratory initial recordings or mean ambulatory heart rate (HR), systolic blood pressure (SBP), or diastolic blood pressure (DBP). However, compared with veterans without PTSD, veterans with PTSD demonstrated higher SBP and DBP variability and a higher proportion of HR activity (compared with initial recording values) during daily activity. There was a significant Time of Day x Group interaction for mean HR, with a trend for PTSD participants to maintain HR levels during evening hours.
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Affiliation(s)
- J C Beckham
- Department of Psychiatry, Duke University Medical Center, Durham, North Carolina, USA.
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Beckham JC, Feldman ME, Barefoot JC, Fairbank JA, Helms MJ, Haney TL, Hertzberg MA, Moore SD, Davidson JR. Ambulatory cardiovascular activity in Vietnam combat veterans with and without posttraumatic stress disorder. J Consult Clin Psychol 2000; 68:269-76. [PMID: 10780127 DOI: 10.1037/0022-006x.68.2.269] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present study investigated the relationship between daily diary affect ratings and ambulatory cardiovascular activity in 117 male Vietnam combat veterans (61 with posttraumatic stress disorder [PTSD] and 56 without PTSD). Participants completed 12-14 hr of ambulatory monitoring and daily diary affect ratings. Compared with veterans without PTSD, veterans with PTSD reported higher negative affect and lower positive affect in daily diary ratings. No differences were detected for mean laboratory initial recordings or mean ambulatory heart rate (HR), systolic blood pressure (SBP), or diastolic blood pressure (DBP). However, compared with veterans without PTSD, veterans with PTSD demonstrated higher SBP and DBP variability and a higher proportion of HR activity (compared with initial recording values) during daily activity. There was a significant Time of Day x Group interaction for mean HR, with a trend for PTSD participants to maintain HR levels during evening hours.
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Affiliation(s)
- J C Beckham
- Department of Psychiatry, Duke University Medical Center, Durham, North Carolina, USA.
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Calton JL, Kang MH, Wilson WA, Moore SD. NMDA-Receptor-dependent synaptic activation of voltage-dependent calcium channels in basolateral amygdala. J Neurophysiol 2000; 83:685-92. [PMID: 10669484 DOI: 10.1152/jn.2000.83.2.685] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Afferent stimulation of pyramidal cells in the basolateral amygdala produced mixed excitatory postsynaptic potentials (EPSPs) mediated by N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors during whole cell current-clamp recordings. In the presence of GABA(A) receptor blockade, the mixed EPSPs recruited a large "all-or-none" depolarizing event. This recruited event was voltage dependent and had a distinct activation threshold. An analogous phenomenon elicited by exogenous glutamate in the presence of tetrodotoxin (TTX) was blocked by Cd(2+), suggesting that the event was a Ca(2+) spike. Selective glutamatergic blockade revealed that these Ca(2+) spikes were recruited readily by single afferent stimulus pulses that elicited NMDA EPSPs. In contrast, non-NMDA EPSPs induced by single stimuli failed to elicit the Ca(2+) spike even at maximal stimulus intensities although these non-NMDA EPSPs depolarized the soma more effectively than mixed EPSPs. Elongation of non-NMDA EPSPs by cyclothiazide or brief trains of stimulation were also unable to elicit the Ca(2+) spike. Blockade of K(+) channels with intracellular Cs(+) enabled single non-NMDA EPSPs to activate the Ca(2+) spike. The finding that voltage-dependent calcium channels are activated preferentially by NMDA-receptor-mediated EPSPs provides a mechanism for NMDA-receptor-dependent plasticity independent of Ca(2+) influx through the NMDA receptor.
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Affiliation(s)
- J L Calton
- Department of Psychiatry, Durham, North Carolina 27705, USA
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Calton JL, Wilson WA, Moore SD. Reduction of voltage-dependent currents by ethanol contributes to inhibition of NMDA receptor-mediated excitatory synaptic transmission. Brain Res 1999; 816:142-8. [PMID: 9878711 DOI: 10.1016/s0006-8993(98)01144-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Previous studies have shown inhibitory effects of EtOH on NMDA receptor-mediated synaptic transmission in several brain regions. We examined this effect of EtOH under both current clamp and voltage clamp conditions in the basolateral amygdala because of the putative role of the amygdala in mediating anxiolytic effects of EtOH. We found that EtOH reduced NMDA receptor-mediated synaptic responses. In addition, we found that NMDA receptor-mediated depolarizations could also activate a voltage-dependent regenerative potential which was also sensitive to EtOH. Pharmacological characterization of this current was consistent with a high-threshold Ca2+ current. This current also exhibited a pronounced tendency towards transient enhancement upon withdrawal of EtOH.
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Affiliation(s)
- J L Calton
- Division of Psychiatry, Duke University Medical Center, Durham, NC, USA
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Moore SD, Brodt-Eppley J, Cornelison LM, Burk SE, Slater DM, Myatt L. Expression of prostaglandin H synthase isoforms in human myometrium at parturition. Am J Obstet Gynecol 1999; 180:103-9. [PMID: 9914586 DOI: 10.1016/s0002-9378(99)70157-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The purpose of this study was to identify the isoforms and splicing patterns of prostaglandin H synthase present in pregnant human lower-segment myometrium and determine whether there is differential expression of the isoforms or splice variants with respect to gestational age or parturition. STUDY DESIGN Lower-segment myometrium was collected at cesarean section at term (>37 weeks) or preterm (<37 weeks) from patients who were or were not in labor. Total messenger ribonucleic acid was isolated and reverse transcribed. Polymerase chain reaction for prostaglandin H synthase isoforms 1 and 2 and calponin were performed. Primers designed to characterize the splicing patterns of exon 9 of prostaglandin H synthase-1 were used. RESULTS The predominant polymerase chain reaction product in all samples corresponds to prostaglandin H synthase-1 messenger ribonucleic acid spliced to include exon 9, but a less-abundant polymerase chain reaction product corresponding to prostaglandin H synthase-1 messenger ribonucleic acid spliced at the internal donor site of exon 9 was also detected. Prostaglandin H synthase-2 messenger ribonucleic acid was detected in human myometrium at a lower abundance than prostaglandin H synthase-1, and neither prostaglandin H synthase-1 or prostaglandin H synthase-2 messenger ribonucleic acid expression changed significantly with gestational age or labor. CONCLUSION Both prostaglandin H synthase-1 and prostaglandin H synthase-2 isoforms are present in human myometrium. The prostaglandin H synthase-1 messenger ribonucleic acid that includes all of exon 9 encodes the predominant prostaglandin H synthase-1 isoform present in human myometrium. No significant alterations in the expression or splicing patterns for prostaglandin H synthase-1 were detected with respect to gestational age or the onset of labor; but prostaglandin H synthase-1 expression appeared higher at term in anticipation of labor. Although prostaglandin H synthase-2 is present in human myometrium, induction of prostaglandin H synthase-2 does not occur in lower-segment myometrium at parturition.
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Affiliation(s)
- S D Moore
- Department of Obstetrics and Gynecology, Perinatal Research Institute, College of Medicine, University of Cincinnati, Ohio 45267-0526, USA
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Calton JL, Wilson WA, Moore SD. Magnesium-dependent inhibition of N-methyl-D-aspartate receptor-mediated synaptic transmission by ethanol. J Pharmacol Exp Ther 1998; 287:1015-9. [PMID: 9864287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Previous studies have indicated that ethanol (EtOH) has a relatively specific effect on excitatory synaptic transmission by inhibiting function of the N-methyl-D-aspartate receptor. We have found that EtOH potently inhibits N-methyl-D-aspartate-mediated synaptic currents in the basolateral amygdala, a brain region associated with actions of anxiolytic agents such as EtOH. This inhibitory effect of EtOH requires the presence of magnesium (Mg++). The dependence of the effect of EtOH on the presence of Mg++ suggests a possible molecular site of the action of EtOH in the vicinity of Mg++ binding sites on the N-methyl-D-aspartate receptor-channel complex. Because EtOH consumption may result in reductions in free brain Mg++, this dynamic interaction between EtOH and Mg++ may have important implications for understanding the behavioral effects of EtOH.
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Affiliation(s)
- J L Calton
- Department of Psychiatry, Duke University Medical Center, Durham, North Carolina, USA
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