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Christopher S Hayes - One of the best experts on this subject based on the ideXlab platform.
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convergent evolution of the barnase endou colicin rele becr fold in antibacterial trnase toxins
Structure, 2019Co-Authors: Grant C Gucinski, Karolina Michalska, Fernando Garzasanchez, William H Eschenfeldt, Lucy Stols, Josephine Y Nguyen, Celia W Goulding, Andrzej Joachimiak, Christopher S HayesAbstract:Summary Contact-dependent growth inhibition (CDI) is a form of interbacterial competition mediated by CdiB-CdiA two-partner secretion systems. CdiA effector proteins carry polymorphic C-terminal toxin domains (CdiA-CT), which are neutralized by specific CdiI immunity proteins to prevent self-inhibition. Here, we present the crystal structures of CdiA-CT⋅CdiI complexes from Klebsiella pneumoniae 342 and Escherichia coli 3006. The toxins adopt related folds that resemble the ribonuclease domain of colicin D, and both are isoacceptor-specific tRNases that cleave the acceptor stem of deacylated tRNAGAUIle. Although the toxins are similar in structure and substrate specificity, CdiA-CTKp342 activity requires translation factors EF-Tu and EF-Ts, whereas CdiA-CTEC3006 is intrinsically active. Furthermore, the corresponding immunity proteins are unrelated in sequence and structure. CdiIKp342 forms a dimeric β sandwich, whereas CdiIEC3006 is an α-solenoid monomer. Given that toxin-immunity genes co-evolve as linked pairs, these observations suggest that the similarities in toxin structure and activity reflect functional convergence.
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programmed secretion arrest and receptor triggered toxin export during antibacterial contact dependent growth inhibition
Cell, 2018Co-Authors: Zachary C Ruhe, Josephine Y Nguyen, David A Low, Poorna Subramanian, Kiho Song, Taylor A Stevens, Grant J Jensen, Christopher S HayesAbstract:Contact-dependent growth inhibition (CDI) entails receptor-mediated delivery of CdiA-derived toxins into Gram-negative target bacteria. Using electron cryotomography, we show that each CdiA effector protein forms a filament extending ∼33 nm from the cell surface. Remarkably, the extracellular filament represents only the N-terminal half of the effector. A programmed secretion arrest sequesters the C-terminal half of CdiA, including the toxin domain, in the periplasm prior to target-cell recognition. Upon binding receptor, CdiA secretion resumes, and the periplasmic FHA-2 domain is transferred to the target-cell outer membrane. The C-terminal toxin region of CdiA then penetrates into the target-cell periplasm, where it is cleaved for subsequent translocation into the cytoplasm. Our findings suggest that the FHA-2 domain assembles into a transmembrane conduit for toxin transport into the periplasm of target bacteria. We propose that receptor-triggered secretion ensures that FHA-2 export is closely coordinated with integration into the target-cell outer membrane.
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the cdi toxin of yersinia kristensenii is a novel bacterial member of the rnase a superfamily
Nucleic Acids Research, 2017Co-Authors: Gaelle Batot, Karolina Michalska, Andrzej Joachimiak, Christopher S Hayes, Greg Ekberg, Ervin M Irimpan, Grazyna Joachimiak, Robert Jedrzejczak, Gyorgy BabniggAbstract:Contact-dependent growth inhibition (CDI) is an important mechanism of inter-bacterial competition found in many Gram-negative pathogens. CDI+ cells express cell-surface CdiA proteins that bind neighboring bacteria and deliver C-terminal toxin domains (CdiA-CT) to inhibit target-cell growth. CDI+ bacteria also produce CdiI immunity proteins, which specifically neutralize cognate CdiA-CT toxins to prevent self-inhibition. Here, we present the crystal structure of the CdiA-CT/CdiIYkris complex from Yersinia kristensenii ATCC 33638. CdiA-CTYkris adopts the same fold as angiogenin and other RNase A paralogs, but the toxin does not share sequence similarity with these nucleases and lacks the characteristic disulfide bonds of the superfamily. Consistent with the structural homology, CdiA-CTYkris has potent RNase activity in vitro and in vivo. Structure-guided mutagenesis reveals that His175, Arg186, Thr276 and Tyr278 contribute to CdiA-CTYkris activity, suggesting that these residues participate in substrate binding and/or catalysis. CdiIYkris binds directly over the putative active site and likely neutralizes toxicity by blocking access to RNA substrates. Significantly, CdiA-CTYkris is the first non-vertebrate protein found to possess the RNase A superfamily fold, and homologs of this toxin are associated with secretion systems in many Gram-negative and Gram-positive bacteria. These observations suggest that RNase A-like toxins are commonly deployed in inter-bacterial competition.
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contact dependent growth inhibition cdi and cdib cdia two partner secretion proteins
Journal of Molecular Biology, 2015Co-Authors: Julia L E Willett, Celia W Goulding, David A Low, Zachary C Ruhe, Christopher S HayesAbstract:Bacteria have developed several strategies to communicate and compete with one another in complex environments. One important mechanism of inter-bacterial competition is contact-dependent growth inhibition (CDI), in which Gram-negative bacteria use CdiB/CdiA two-partner secretion proteins to suppress the growth of neighboring target cells. CdiB is an Omp85 outer-membrane protein that exports and assembles CdiA exoproteins onto the inhibitor cell surface. CdiA binds to receptors on susceptible bacteria and subsequently delivers its C-terminal toxin domain (CdiA-CT) into the target cell. CDI systems also encode CdiI immunity proteins, which specifically bind to the CdiA-CT and neutralize its toxin activity, thereby protecting CDI(+) cells from auto-inhibition. Remarkably, CdiA-CT sequences are highly variable between bacteria, as are the corresponding CdiI immunity proteins. Variations in CDI toxin/immunity proteins suggest that these systems function in bacterial self/non-self recognition and thereby play an important role in microbial communities. In this review, we discuss recent advances in the biochemistry, structural biology and physiology of CDI.
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contact dependent growth inhibition toxins exploit multiple independent cell entry pathways
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Julia L E Willett, Grant C Gucinski, David A Low, Jackson P Fatherree, Christopher S HayesAbstract:Contact-dependent growth inhibition (CDI) systems function to deliver toxins into neighboring bacterial cells. CDI+ bacteria export filamentous CdiA effector proteins, which extend from the inhibitor-cell surface to interact with receptors on neighboring target bacteria. Upon binding its receptor, CdiA delivers a toxin derived from its C-terminal region. CdiA C-terminal (CdiA-CT) sequences are highly variable between bacteria, reflecting the multitude of CDI toxin activities. Here, we show that several CdiA-CT regions are composed of two domains, each with a distinct function during CDI. The C-terminal domain typically possesses toxic nuclease activity, whereas the N-terminal domain appears to control toxin transport into target bacteria. Using genetic approaches, we identified ptsG, metI, rbsC, gltK/gltJ, yciB, and ftsH mutations that confer resistance to specific CdiA-CTs. The resistance mutations all disrupt expression of inner-membrane proteins, suggesting that these proteins are exploited for toxin entry into target cells. Moreover, each mutation only protects against inhibition by a subset of CdiA-CTs that share similar N-terminal domains. We propose that, following delivery of CdiA-CTs into the periplasm, the N-terminal domains bind specific inner-membrane receptors for subsequent translocation into the cytoplasm. In accord with this model, we find that CDI nuclease domains are modular payloads that can be redirected through different import pathways when fused to heterologous N-terminal "translocation domains." These results highlight the plasticity of CDI toxin delivery and suggest that the underlying translocation mechanisms could be harnessed to deliver other antimicrobial agents into Gram-negative bacteria.
Kovaleski A. - One of the best experts on this subject based on the ideXlab platform.
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Erradicação de Cydia pomonella no Brasil.
AGAPOMI Vacaria n. 126 p. 8-9 2004., 2019Co-Authors: Kovaleski A.Abstract:A carpocapsa ,Cydia pomonella (Lepid?ptera: Tortricidae) e uma praga quarentenana da maçã no Brasil. Apesar de restrita a áreas urbanas, ela ameaça a fruticultura temperada devido à capacidade de dispersão do inseto e ao transporte de frutos infestados pelo homem. A dispersão para áreas comerciais e estabelecimento como praga da macieira teriam conseqüências sérias ao programa de MIP e PIF.Além disso, o estabelecimento de uma nova praga seria negativo para o setor justamente no momento em que o país está conquistando mercados externos, com a possibilidade de exportar para países livres da carpocapsa.bitstream/item/199975/1/6121-2004-p.8-9.pd
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Programa de erradicação da Cydia pomonella no Brasil.
Agapomi Vacaria n. 181 p. 5 2009., 2019Co-Authors: Kovaleski A.Abstract:Programa de Erradicação da Cydia pomonella no Brasil - Programa Nacional Prevenção e Controle da Cydia pomonella (PNPCCP) teve início na década de 90 com o descobrimento do primeiro foco na área urbana de Vacaria. Mais tarde, a partir de um amplo monitoramento nas principais áreas produtoras de frutas temperadas também foram localizados focos em Caxias do Sul, Bom Jesus e Lages. Apartir do aumento na densidade de armadilhas nessas áreas o monitoramento indicou que a praga estava atingindo níveis críticos e com alto risco de dispersão para áreas comerciais.bitstream/item/200490/1/11259-2009-p.5.pd
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Avanços no Programa de Erradicação da Cydia pomonella no Brasil.
Agapomi Vacaria n. 200 p. 5 jan. 2011., 2019Co-Authors: Kovaleski A., Carbonari J., A. F. C. P. Da ,silvaAbstract:A Cydia pomonella é uma das mais importantes pragas da maçã e da pera nas principais regiões de produção dessas frutas. Em muitos países o Azinfós-rnetil ainda é o inseticida mais utilizado para o seu controle e são realizadas, em muitos casos, mais de 10 aplicações durante a safra.bitstream/item/200756/1/12801-2011-p.5.pd
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Esforço concentrado.
Cultivar Hortaliças e Frutas Pelotas v. 11 n. 76 p. 30 32 out. nov. 2012., 2019Co-Authors: Kovaleski A., Carbonari J. J.Abstract:Praga quarentenária, a traça da maçã (Cydia pomonella) é responsável por entraves comerciais que extrapolam os danos diretos à produtividade. Mesmo restrito a algumas áreas urbanas do Sul do Brasil, o inseto exige monitoramento rigoroso e sua erradicação é uma busca necessária para que o país possa manter e conquistar novos mercados na exportação de frutas.bitstream/item/200929/1/14208-2012-p.30-e-32.pd
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Erradicação da Cydia pomonella no Brasil: resultados da safra 2007/2008.
AGAPOMI Vacaria n. 165 p. 11 2008., 2019Co-Authors: Kovaleski A.Abstract:os recursos liberados pelo Ministério da Agricultura, Pecuária e Abastecimento e mais a contra-partida nos produtores de maçã, através da Associação Brasileira dos Produtores de Maçã e da Associação Gaúcha dos Produtores de Maçã, permitiram mais um avanço significativo no Programa de Erradicação da Cydia pomonella no Brasil.bitstream/item/200315/1/9492-2008-p.11.pdfPublicado também no Jornal da Fruta, Lages, v. 16, n. 195, p. 19, 2008
Hernández, Carmen Marcela - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of Mastrus ridens Horstman (Hymenoptera: Incheumonidae) and Ascogaster quadridentata Wesmael (Hymenoptera: Braconidae) as biological control agents of Cydia pomonella L. (Lepidoptera: Tortricidae)
Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires, 2015Co-Authors: Hernández, Carmen MarcelaAbstract:La carpocapsa (Cydia pomonella) es una de las plagas clave del cultivo de pomáceas en todo el mundo. En la Argentina, si bien actualmente se están implementando medidas de control de bajo impacto ambiental, como la técnica de confusión sexual, la principal forma de control continúa siendo el empleo de productos químicos. El objetivo general de esta tesis fue estudiar aspectos básicos de la biología de Mastrus ridens y Ascogaster quadridentata a los efectos de evaluar su potencial como agentes de control de Cydia pomonella en nuestro país. Los principales aportes de este trabajo son: -Disponibilidad de un sistema de cría a nivel experimental para M. ridens y A. quadridentata en condiciones de laboratorio. -Conocimiento de los principales atributos biológicos y poblacionales de A. quadridentata sobre C. pomonella. -Estudio de la fecundidad y preferencia de M. ridens sobre dos especies de lepidópteros plaga presentes en nuestro país (C. pomonella- Grapholita molesta). -Determinación de la selectividad de los principales insecticidas utilizados en la producción de pomáceas para M. ridens. -Colonización y evaluación del establecimiento de M. ridens y A. quadridentata en el Alto Valle de Rio Negro. Los estudios realizados proporcionaron información y herramientas para impulsar el empleo de estos parasitoides a través del desarrollo de una estrategia de control biológico clásico de C. pomonella.The codling moth is a key pest of apple crops. In Argentina, pest management strategies mainly relay on chemical control, although recently the technique of sexual confusion has been implemented with success. The aim of this thesis was to study the potential of the parasitoids, Mastrus ridens and Ascogaster quadridentata as biological control agents of Cydia pomonella in our country. The most important contributions from this thesis are: -Better understanding of rearing methodologies for M. ridens y A. quadridentata in the laboratory. -Knowledge of the reproductive biology and population parameters of A. quadridentata in C. pomonella. -Knowledge of the biology and host preference by M. ridens for C. pomonella and G. molesta. -Determination of the side effect of some pesticides use in apple crops on M. ridens. -Colonization and evaluation of establishment of M. ridens y A. quadridentata in the field. These results provided useful information to enhance the use of the parasitoids in classical biological control strategies against C. pomonella in Argentina.Fil:Hernández, Carmen Marcela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
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Evaluation of Mastrus ridens Horstman (Hymenoptera: Incheumonidae) and Ascogaster quadridentata Wesmael (Hymenoptera: Braconidae) as biological control agents of Cydia pomonella L. (Lepidoptera: Tortricidae)
Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires, 2015Co-Authors: Hernández, Carmen MarcelaAbstract:La carpocapsa (Cydia pomonella) es una de las plagas clave del cultivo de pomáceas en todo el mundo. En la Argentina, si bien actualmente se están implementando medidas de control de bajo impacto ambiental, como la técnica de confusión sexual, la principal forma de control continúa siendo el empleo de productos químicos. El objetivo general de esta tesis fue estudiar aspectos básicos de la biología de Mastrus ridens y Ascogaster quadridentata a los efectos de evaluar su potencial como agentes de control de Cydia pomonella en nuestro país. Los principales aportes de este trabajo son: -Disponibilidad de un sistema de cría a nivel experimental para M. ridens y A. quadridentata en condiciones de laboratorio. -Conocimiento de los principales atributos biológicos y poblacionales de A. quadridentata sobre C. pomonella. -Estudio de la fecundidad y preferencia de M. ridens sobre dos especies de lepidópteros plaga presentes en nuestro país (C. pomonella- Grapholita molesta). -Determinación de la selectividad de los principales insecticidas utilizados en la producción de pomáceas para M. ridens. -Colonización y evaluación del establecimiento de M. ridens y A. quadridentata en el Alto Valle de Rio Negro. Los estudios realizados proporcionaron información y herramientas para impulsar el empleo de estos parasitoides a través del desarrollo de una estrategia de control biológico clásico de C. pomonella
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Estudios biológicos sobre los parasitoides, Mastrus ridens Horstman y Ascogaster quadridentata Wesmael, para evaluar su potencial como agentes de control biológico de Cydia pomonella (L.) plaga clave del manzano
Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires, 2024Co-Authors: Hernández, Carmen MarcelaAbstract:La carpocapsa (Cydia pomonella) es una de las plagas clave del cultivo de pomáceas en todo el mundo. En la Argentina, si bien actualmente se están implementando medidas de control de bajo impacto ambiental, como la técnica de confusión sexual, la principal forma de control continúa siendo el empleo de productos químicos. El objetivo general de esta tesis fue estudiar aspectos básicos de la biología de Mastrus ridens y Ascogaster quadridentata a los efectos de evaluar su potencial como agentes de control de Cydia pomonella en nuestro país. Los principales aportes de este trabajo son: -Disponibilidad de un sistema de cría a nivel experimental para M. ridens y A. quadridentata en condiciones de laboratorio. -Conocimiento de los principales atributos biológicos y poblacionales de A. quadridentata sobre C. pomonella. -Estudio de la fecundidad y preferencia de M. ridens sobre dos especies de lepidópteros plaga presentes en nuestro país (C. pomonella- Grapholita molesta). -Determinación de la selectividad de los principales insecticidas utilizados en la producción de pomáceas para M. ridens. -Colonización y evaluación del establecimiento de M. ridens y A. quadridentata en el Alto Valle de Rio Negro. Los estudios realizados proporcionaron información y herramientas para impulsar el empleo de estos parasitoides a través del desarrollo de una estrategia de control biológico clásico de C. pomonella
Reinhard Dallinger - One of the best experts on this subject based on the ideXlab platform.
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molecular phylogeny and population structure of the codling moth Cydia pomonella in central europe ii aflp analysis reflects human aided local adaptation of a global pest species
Molecular Phylogenetics and Evolution, 2008Co-Authors: R Thaler, Anita Brandstatter, A Meraner, M Chabicovski, Walther Parson, R Zelger, Dalla J Via, Reinhard DallingerAbstract:Originally resident in southeastern Europe, the codling moth (Cydia pomonella L.) (Tortricidae) has achieved a nearly global distribution, being one of the most successful pest insect species known today. As shown in our accompanying study, mitochondrial genetic markers suggest a Pleistocenic splitting of Cydia pomonella into two refugial clades which came into secondary contact after de-glaciation. The actual distribution pattern shows, however, that Central European codling moths have experienced a geographic splitting into many strains and locally adapted populations, which is not reflected by their mitochondrial haplotype distribution. We therefore have applied, in addition to mitochondrial markers, an approach with a higher resolution potential at the population level, based on the analysis of amplification fragment length polymorphisms (AFLPs). As shown in the present study, AFLP markers elucidate the genetic structure of codling moth strains and populations from different Central European apple orchard sites. While individual genetic diversity within codling moth strains and populations was small, a high degree of genetic differentiation was observed between the analyzed strains and populations, even at a small geographic scale. One of the main factors contributing to local differentiation may be limited gene flow among adjacent codling moth populations. In addition, microclimatic, ecological, and geographic constraints also may favour the splitting of Cydia pomonella into many local populations. Lastly, codling moths in Central European fruit orchards may experience considerable selective pressure due to pest control activities. As a consequence of all these selective forces, today in Central Europe we see a patchy distribution of many locally adapted codling moth populations, each of them having its own genetic fingerprint. Because of the complete absence of any correlation between insecticide resistance and geographic or genetic distances among populations, AFLP markers do not have a prognostic value for predicting an outbreak of pesticide resistance in the field. By combining mitochondrial genetic data and AFLP analysis it was possible, however, to track the recent evolutionary history of Cydia pomonella on three different time scales: from population splitting in Pleistocene, to interbreeding of mitochondrial haplotypes in Holocene, to human-aided complete intermixing and splitting into many locally adapted populations in very recent times. The case of Cydia pomonella is reminiscent of examples of sympatric speciation and another example of a human-induced globally successful pest species.
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molecular phylogeny and population structure of the codling moth Cydia pomonella in central europe i ancient clade splitting revealed by mitochondrial haplotype markers
Molecular Phylogenetics and Evolution, 2008Co-Authors: A Meraner, R Thaler, Anita Brandstatter, Walther Parson, R Zelger, Dalla J Via, B Aray, M Unterlechner, Harald Niederstatter, Reinhard DallingerAbstract:Abstract The codling moth ( Cydia pomonella L., Tortricidae, Lepidoptera) is an important pest of pome fruit with global distribution. It has adapted successfully to different habitats by forming various ecotypes and populations, often termed strains, which differ among each other in several morphological, developmental, and physiological features. Many strains of Cydia pomonella have developed resistance against a broad range of chemically different pesticides. Obviously, pesticide-resistant strains must have a genetic basis inherent to the gene pool of codling moth populations, and this deserves our particular attention. The primary intention of the present study was to contribute novel information regarding the evolutionary phylogeny and phylogeography of codling moth populations in Central Europe. In addition, we aimed at testing the hypothesis that differential biological traits and response patterns towards pesticides in codling moth populations may be reflected at a mitochondrial DNA level. In particular, we wanted to test if pesticide resistance in codling moths is associated repeatedly and independently with more than one mitochondrial haplotype. To this end, we analyzed mitochondrial DNA and constructed phylogenetic trees based on three mitochondrial genes: cytochrome oxidase I (COI), the A + T-rich region of the control region (CR), and the nicotinamide adenine dinucleotide dehydrogenase subunit 5 (ND5). The results indicate that Central European populations of Cydia pomonella are clearly divided in two ancient clades. As shown by means of a molecular clock approach, the splitting of the two clades can be dated to a time period between the lower and middle Pleistocene, about 1.29–0.20 million years ago. It is assumed that the cyclic changes of warm and cold periods during Pleistocene may have lead to the geographic separation of codling moth populations due to glaciation, giving rise to the formation of the two separate refugial clades, as already shown for many other European animal species. Due to their inclination towards developing novel detoxification gene variants, codling moth individuals from both clades independently and multifariously may have developed pesticide resistance, and this process may be ongoing. During their more recent evolutionary history, natural events such as the gradual disappearance of climate-specific geographic barriers, as well as human-aided dispersal in recent historic times, may have allowed codling moth haplotypes from the original clades to interbreed and completely merge again, creating a globally successful insect species with a gene pool capable of responding to novel selective challenges by rapid adaptation.
Johannes A Jehle - One of the best experts on this subject based on the ideXlab platform.
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diversity and evolution of the Cydia pomonella granulovirus
Journal of General Virology, 2009Co-Authors: Karolin E Eberle, M. Rezapanah, Samy Sayed, Sharareh Shojaiestabragh, Johannes A JehleAbstract:Eight new field isolates of Cydia pomonella granulovirus (CpGV) originating in Iran and Georgia and one English CpGV isolate were analysed for restriction fragment length polymorphisms (RFLPs) and by partial genome amplification and sequencing. According to the observed RFLPs, most of the predominant genotypes of these isolates could be assigned to those present in previously found isolates originating from Mexico (CpGV-M), England (CpGV-E) and Russia (CpGV-R). We suggest that these isolates should be designated genome A, B and C types, respectively. A fourth genome type was identified in three isolates and is designated D type. The isolates with A, B and D type genomes contained four open reading frames (ORFs) (ORF63–ORF66) not present in C type genomes. The lack of these ORFs in other granuloviruses suggests that the C type genome is evolutionarily ancestral to the other genome types. The B and D type genomes contained an additional insertion of a non-protein coding region of 0.7 kb, which was at different genome locations. Analysis of the partial gene sequences of late expression factor 8 (lef-8), lef-9 and polyhedrin/granulin (polh/gran) genes revealed single nucleotide polymorphisms (SNPs) that corresponded to the RFLP types. Phylogenetic analyses based on these SNPs corroborated the proposed ancestry of the C type genome. C type viruses were also less virulent to neonate codling moth larvae than the other virus types. In conclusion, the known diversity of CpGV isolates can be described by four major genome types, which appear to exist in different isolates as genotype mixtures.
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Molecular and biological characterization of new isolates of Cydia pomonella granulovirus from Iran
Journal of Pest Science, 2008Co-Authors: M. Rezapanah, S. Shojai-estabragh, J. Huber, Johannes A JehleAbstract:The Cydia pomonella granulovirus (CpGV) is a very effective biological control agent of the codling moth, Cydia pomonella L. (Lep.: Tortricidae). Only a few CpGV isolates originating from Mexico (M), England (E), and Russia (R) have been described so far. In a field survey at different locations in Iran, CpGV isolates were collected from single or pooled codling moth larvae. The isolates, designated I1, I7, I8, I15, I22, I28, I30, I66, I67, I68, and I70 showed genetic (DNA restriction endonuclease profiles) and biological (bioassays) differences. Most isolates could be attributed to genome types similar to those found in CpGV-M, -E, and -R. Some of them were clear mixtures of different genotypes. Thus, the CpGV isolates found in the North–West of Iran make an important contribution to the known diversity of CpGV. The occurrence of novel, naturally occurring CpGV isolates emphasize the necessity of further studies towards the diversity and evolution of CpGV.
