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Joachim Kurtz - One of the best experts on this subject based on the ideXlab platform.
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Specificity of oral immune priming in the Red Flour Beetle Tribolium castaneum.
Biology letters, 2017Co-Authors: Momir Futo, Marie P. Sell, Megan A. M. Kutzer, Joachim KurtzAbstract:Immune specificity is the degree to which a host9s immune system discriminates among various pathogens or antigenic variants. Vertebrate immune memory is highly specific due to antibody responses. On the other hand, some invertebrates show immune priming, i.e. improved survival after secondary exposure to a previously encounteRed pathogen. Until now, specificity of priming has only been demonstrated via the septic infection route or when live pathogens were used for priming. Therefore, we tested for specificity in the oral priming route in the Red Flour Beetle, Tribolium castaneum . For priming, we used pathogen-free supernatants derived from three different strains of the entomopathogen, Bacillus thuringiensis , which express different Cry toxin variants known for their toxicity against this Beetle. Subsequent exposure to the infective spores showed that oral priming was specific for two naturally occurring strains, while a third engineeRed strain did not induce any priming effect. Our data demonstrate that oral immune priming with a non-infectious bacterial agent can be specific, but the priming effect is not universal across all bacterial strains.
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Immune priming in arthropods: an update focusing on the Red Flour Beetle.
Zoology (Jena Germany), 2016Co-Authors: Barbara Milutinović, Robert Peuß, Kevin Ferro, Joachim KurtzAbstract:Abstract Immune priming has now been demonstrated in a wide range of invertebrate species. Studies testing this phenomenon largely differ in terms of experimental design, host–parasite combinations, agents used for priming, and in particular the degree of demonstrated specificity of the primed response. This review provides an overview of known and putative mechanisms underlying broad-spectrum and specific immune priming in arthropods. We focus on insects and particularly the Red Flour Beetle Tribolium castaneum, where priming has been demonstrated within and across generations. We will also draw attention to the relevance of routes of priming and infection, which can occur septically and orally, with largely differing physiology. For oral priming, an involvement of gut microbiota was demonstrated in mosquitoes and Flour Beetles. Generally, a primed state could result from long-lasting immune activation or a form of memory that does not entail lingering immune components. Moreover, the primed state could also be of a qualitatively different kind than the challenge response. Finally, we will consider that there should be natural variation in priming capability, and therefore a possibility to study this trait with experimental evolution approaches.
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Infection routes matter in population-specific responses of the Red Flour Beetle to the entomopathogen Bacillus thuringiensis
BMC genomics, 2014Co-Authors: Sarah Behrens, Robert Peuß, Barbara Milutinović, Hendrik Eggert, Daniela Esser, Philip Rosenstiel, Hinrich Schulenburg, Erich Bornberg-bauer, Joachim KurtzAbstract:Background Pathogens can infect their hosts through different routes. For studying the consequences for host resistance, we here used the entomopathogen Bacillus thuringiensis and the Red Flour Beetle Tribolium castaneum for oral and systemic (i. e. pricking the cuticle) experimental infection. In order to characterize the molecular mechanisms underpinning the two different infection routes, the transcriptomes of Beetles of two different T. castaneum populations – one recently collected population (Cro1) and a commonly used laboratory strain (SB) – were analyzed using a next generation RNA sequencing approach.
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Experimental evolution of external immune defences in the Red Flour Beetle
Journal of evolutionary biology, 2014Co-Authors: Gerrit Joop, Olivia Roth, Paul Schmid-hempel, Joachim KurtzAbstract:The Red Flour Beetle, Tribolium castaneum, secretes quinones that control the microbial flora in the surrounding environment. These secretions act as an external immune defence that provides protection against pathogens. At high concentrations, however, these secretions are harmful to the host itself, and selection may thus have optimized the level of expression under natural conditions. Here, we show that the expression of external immunity responded to selection during experimental evolution within a few generations. At the same time, one component of internal immune defence (phenoloxidase activity) was compromised in Beetles selected for either high or low external defences. Intriguingly, offspring protection against a natural pathogen was Reduced in Flour obtained from Beetle lines selected for low amounts of secretions. Altogether, this suggests that external and internal immune defences work together efficiently under natural conditions, whereas every manipulation on the side of external immune defence comes with costs to the internal immune defence.
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increased survival in the Red Flour Beetle after oral priming with bacteria conditioned media
Journal of Innate Immunity, 2014Co-Authors: Barbara Milutinovic, Svenja Fritzlar, Joachim KurtzAbstract:Immune priming is defined as enhanced protection upon secondary exposure to a pathogen. Such enhanced resistance after prior exposure has been demonstrated for a number of insect species including the Red Flour Beetle, Tribolium castaneum. In testing this phenomenon, the majority of studies have focused on introducing the pathogen into the insect's hemocoel via septic wounding through the cuticle. Although such septic injury can occur in nature, many pathogens enter their hosts via the oral route, i.e. by ingestion. Bacillus thuringiensis bacteria are well-known insect pathogens that infect their host orally. We found that T. castaneum larvae showed increased survival after oral exposure to B. thuringiensis, when they had been orally primed with filter-sterilized media in which spores of B. thuringiensis had been raised. Such priming was achieved only with a naturally pathogenic strain of B. thuringiensis and a strain that was made pathogenic by transfer of plasmids. Moreover, primed larvae were smaller in size 24 h after priming and had a longer developmental time, indicating that investment in such a response comes at a cost. However, the increased survival in primed larvae was not caused by larval size differences upon challenge.
Uwe Wenzel - One of the best experts on this subject based on the ideXlab platform.
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Hormesis is induced in the Red Flour Beetle Tribolium castaneum through ingestion of charRed toast
European Journal of Nutrition, 2015Co-Authors: Stefanie Grünwald, Janine Niedermeier, Uwe WenzelAbstract:Purpose CharRed foods are generally suspected to exert health threats by providing toxicants, such as acrylamide or polycyclic aromatic hydrocarbons. Using the Red Flour Beetle Tribolium castaneum as a model organism, we tested its survival under heat stress in response to feeding charRed toast. Methods Survival of Beetles was measuRed at 42 °C after a pre-feeding phase with Flour enriched with increasing concentrations of charRed toast. In order to assess the influence of key transcription factors for phase-I and phase-II xenobiotic metabolism, gene homologs for ahr and nrf - 2 , respectively, were knocked down by the use of RNA interference (RNAi). Results Beetles fed only charRed toast died off much earlier than control Beetles fed on Flour, whereas Beetles fed Flour enriched with 5 % charRed toast survived significantly longer than the control. Both, ahr and nrf - 2 proved essential in order to enable the increase in survival by the feeding of 5 % charRed toast. Moreover, functional loss of ahr and nrf - 2 made the Beetles hypersensitive versus the feeding of 100 % charRed toast. Finally, at the transcriptional level, it was shown that RNAi for ahr blocked the inducing activities of charRed toast on nrf - 2 . Conclusions Our studies suggest a hormetic response of the Red Flour Beetle to feeding of charRed toast that causes an increased stress resistance through the activation of ahr and nrf - 2. Those adaptations, however, are saturable and accordingly the hormetic effects at increasing concentrations of the toxicants become expended.
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Hormesis is induced in the Red Flour Beetle Tribolium castaneum through ingestion of charRed toast
European journal of nutrition, 2014Co-Authors: Stefanie Grünwald, Janine Niedermeier, Uwe WenzelAbstract:Purpose CharRed foods are generally suspected to exert health threats by providing toxicants, such as acrylamide or polycyclic aromatic hydrocarbons. Using the Red Flour Beetle Tribolium castaneum as a model organism, we tested its survival under heat stress in response to feeding charRed toast.
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the Red Flour Beetle tribolium castaneum as a model to monitor food safety and functionality
Advances in Biochemical Engineering \ Biotechnology, 2013Co-Authors: Stefanie Grünwald, Iris V Adam, Anamaria Gurmai, Ludmila Bauer, Michael Boll, Uwe WenzelAbstract:: Food quality is a fundamental issue all over the world. There are two major requirements to provide the highest quality of food: having the lowest reachable concentrations of health-threatening ingRedients or contaminants and having the optimal concentrations of health-improving functional ingRedients. Often, the boundaries of both requirements are blurRed, as might be best exemplified by nutraceuticals (enriched food products invented to prevent or even treat diseases), for which undesirable side effects have been reported sometimes. Accordingly, there is an increasing need for reliable methods to screen for health effects of wanted or unwanted ingRedients in a complex food matrix before more complex model organisms or human probands become involved. In this chapter, we present the Red Flour Beetle Tribolium castaneum as a model organism to screen for effects of complex foods on healthspan or lifespan by assessing the survival of the Beetles under heat stress at 42 °C after feeding different diets. There is a higher genetic homology between T. castaneum and humans when compaRed to other invertebrate models, such as Drosophila melanogaster or Caenorhabditis elegans. Therefore, the Red Flour Beetle appears as an interesting model to study interactions between genes and food ingRedients, with relevance for stress resistance and lifespan. In that context, we provide data showing Reduced lifespans of the Beetles when the food-relevant contaminant benz(a)pyrene is added to the Flour they were fed on, whereas a lifespan extension was observed in Beetles fed on Flour enriched with an extract of Red wine.
Subba Reddy Palli - One of the best experts on this subject based on the ideXlab platform.
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Identification of G Protein-Coupled Receptors RequiRed for Vitellogenin Uptake into the Oocytes of the Red Flour Beetle, Tribolium castaneum
Scientific Reports, 2016Co-Authors: Subba Reddy PalliAbstract:Previous studies suggested that a membrane receptor might be involved in mediating vitellogenin (Vg) uptake and juvenile hormone (JH)-regulated remodeling of follicular epithelium (also called ‘patency’). G protein-coupled receptor (GPCR) family is one of the largest membrane receptor protein families and controls many key physiological processes. To investigate the role of GPCRs in insect reproduction and juvenile hormone-regulated Vg uptake, we performed a comprehensive RNA interference (RNAi) screen targeting GPCRs in the Red Flour Beetle, Tribolium castaneum. Out of 112 GPCRs tested, knockdown of 41 GPCRs resulted in a Reduction in fecundity. Interestingly, RNAi against two GPCRs (a Rhodopsin-like receptor and a Dopamine D2-like receptor) led to a significant Reduction in Vg accumulation in developing oocytes. Functional assays of these two GPCRs showed that JH triggers a dose-dependent inhibition of intracellular cAMP levels in HEK293 cells expressing Tribolium Dopamine D2-like receptor. These data suggest that Dopamine D2-like receptor plays crucial roles in regulating Vg uptake and is a promising candidate membrane receptor mediating JH regulation of patency in the Red Flour Beetle.
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Large-scale RNAi screen of G protein-coupled receptors involved in larval growth, molting and metamorphosis in the Red Flour Beetle.
BMC genomics, 2011Co-Authors: Hua Bai, Fang Zhu, Kapil Shah, Subba Reddy PalliAbstract:The G protein-coupled receptors (GPCRs) belong to the largest superfamily of integral cell membrane proteins and play crucial roles in physiological processes including behavior, development and reproduction. Because of their broad and diverse roles in cellular signaling, GPCRs are the therapeutic targets for many prescription drugs. However, there is no commercial pesticide targeting insect GPCRs. In this study, we employed functional genomics methods and used the Red Flour Beetle, Tribolium castaneum, as a model system to study the physiological roles of GPCRs during the larval growth, molting and metamorphosis.
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juvenile hormone regulation of vitellogenin synthesis in the Red Flour Beetle tribolium castaneum
Insect Biochemistry and Molecular Biology, 2010Co-Authors: R Parthasarathy, Hua Bai, Zhiyuan Sun, Subba Reddy PalliAbstract:To elucidate the endocrine regulation of vitellogenin (Vg) synthesis in the Red Flour Beetle, Tribolium castaneum, the titers of juvenile hormone (JH) and ecdysteroids in the whole body of female Beetles were measuRed and compaRed with Vg mRNA levels. Juvenile hormone levels remained high while the ecdysteroid levels declined steadily during 1-5 days post adult emergence (PAE). The Vg mRNA levels began to increase by the end of 3rd day PAE and peaked by the 4th-5th day PAE. Gene expression profiling by microarray and quantitative real-time PCR analyses of RNA isolated from 1 to 5 days PAE Beetles revealed that the genes coding for proteins involved in JH biosynthesis and action, but not those involved in 20-hydroxyecdysone (20E) biosynthesis and action had similar expression patterns as the genes coding for Vg. RNA interference (RNAi)-aided knock-down in the expression of these genes showed that both JH and 20E were requiRed for Vg gene expression. However, Vg mRNA was induced by the application of JH III but not by the injection of 20E into the previtellogenic females. These data suggest that JH is requiRed for Vg synthesis in the fat body and 20E influences Vg synthesis through its action on oocyte maturation.
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proliferation and differentiation of intestinal stem cells during metamorphosis of the Red Flour Beetle tribolium castaneum
Developmental Dynamics, 2008Co-Authors: R Parthasarathy, Subba Reddy PalliAbstract:The insect midgut epithelium is remodeled during larval-pupal metamorphosis when larval polyploid cells (LPCs) are replaced by the daughters of intestinal stem cells (ISCs). We characterized the proliferation of ISCs during midgut remodeling in the Red Flour Beetle, Tribolium castaneum. Midgut remodeling is initiated at 96 hr after ecdysis into the final instar larval stage. Immunocytochemistry with bromodeoxyuridine and phospho-histone H3 antibodies showed that the ISCs are the progenitors of the pupal/adult midgut epithelium and they undergo proliferation and differentiation to form new midgut epithelium. In vitro midgut culture experiments revealed that 20-hydroxyecdysone (20E) in the absence of juvenile hormone induces proliferation of ISCs. RNA interference (RNAi) mediated silencing of ecdysone receptors (EcRA and EcRB) and ultraspiracle (USP) identified EcRA and USP but not EcRB as the proteins involved in 20E regulation of ISCs proliferation. These data show that the proliferation of ISCs is under both developmental and endocrine regulation. Developmental Dynamics 237:893–908, 2008. © 2008 Wiley-Liss, Inc.
Barbara Milutinović - One of the best experts on this subject based on the ideXlab platform.
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Immune priming in arthropods: an update focusing on the Red Flour Beetle.
Zoology (Jena Germany), 2016Co-Authors: Barbara Milutinović, Robert Peuß, Kevin Ferro, Joachim KurtzAbstract:Abstract Immune priming has now been demonstrated in a wide range of invertebrate species. Studies testing this phenomenon largely differ in terms of experimental design, host–parasite combinations, agents used for priming, and in particular the degree of demonstrated specificity of the primed response. This review provides an overview of known and putative mechanisms underlying broad-spectrum and specific immune priming in arthropods. We focus on insects and particularly the Red Flour Beetle Tribolium castaneum, where priming has been demonstrated within and across generations. We will also draw attention to the relevance of routes of priming and infection, which can occur septically and orally, with largely differing physiology. For oral priming, an involvement of gut microbiota was demonstrated in mosquitoes and Flour Beetles. Generally, a primed state could result from long-lasting immune activation or a form of memory that does not entail lingering immune components. Moreover, the primed state could also be of a qualitatively different kind than the challenge response. Finally, we will consider that there should be natural variation in priming capability, and therefore a possibility to study this trait with experimental evolution approaches.
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Infection routes matter in population-specific responses of the Red Flour Beetle to the entomopathogen Bacillus thuringiensis
BMC genomics, 2014Co-Authors: Sarah Behrens, Robert Peuß, Barbara Milutinović, Hendrik Eggert, Daniela Esser, Philip Rosenstiel, Hinrich Schulenburg, Erich Bornberg-bauer, Joachim KurtzAbstract:Background Pathogens can infect their hosts through different routes. For studying the consequences for host resistance, we here used the entomopathogen Bacillus thuringiensis and the Red Flour Beetle Tribolium castaneum for oral and systemic (i. e. pricking the cuticle) experimental infection. In order to characterize the molecular mechanisms underpinning the two different infection routes, the transcriptomes of Beetles of two different T. castaneum populations – one recently collected population (Cro1) and a commonly used laboratory strain (SB) – were analyzed using a next generation RNA sequencing approach.
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The Red Flour Beetle as a model for bacterial oral infections.
PloS one, 2013Co-Authors: Barbara Milutinović, Clemens Stolpe, Robert Peuβ, Sophie A. O. Armitage, Joachim KurtzAbstract:Experimental infection systems are important for studying antagonistic interactions and coevolution between hosts and their pathogens. The Red Flour Beetle Tribolium castaneum and the spore-forming bacterial insect pathogen Bacillus thuringiensis (Bt) are widely used and tractable model organisms. However, they have not been employed yet as an efficient experimental system to study host-pathogen interactions. We used a high throughput oral infection protocol to infect T. castaneum insects with coleopteran specific B. thuringiensis bv. tenebrionis (Btt) bacteria. We found that larval mortality depends on the dietary spore concentration and on the duration of exposure to the spores. Furthermore, differential susceptibility of larvae from different T. castaneum populations indicates that the host genetic background influences infection success. The recovery of high numbers of infectious spores from the cadavers indicates successful replication of bacteria in the host and suggests that Btt could establish infectious cycles in T. castaneum in nature. We were able to transfer plasmids from Btt to a non-pathogenic but genetically well-characterised Bt strain, which was thereafter able to successfully infect T. castaneum, suggesting that factors residing on the plasmids are important for the virulence of Btt. The availability of a genetically accessible strain will provide an ideal model for more in-depth analyses of pathogenicity factors during oral infections. Combined with the availability of the full genome sequence of T. castaneum, this system will enable analyses of host responses during infection, as well as addressing basic questions concerning host-parasite coevolution.
Stefanie Grünwald - One of the best experts on this subject based on the ideXlab platform.
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Hormesis is induced in the Red Flour Beetle Tribolium castaneum through ingestion of charRed toast
European Journal of Nutrition, 2015Co-Authors: Stefanie Grünwald, Janine Niedermeier, Uwe WenzelAbstract:Purpose CharRed foods are generally suspected to exert health threats by providing toxicants, such as acrylamide or polycyclic aromatic hydrocarbons. Using the Red Flour Beetle Tribolium castaneum as a model organism, we tested its survival under heat stress in response to feeding charRed toast. Methods Survival of Beetles was measuRed at 42 °C after a pre-feeding phase with Flour enriched with increasing concentrations of charRed toast. In order to assess the influence of key transcription factors for phase-I and phase-II xenobiotic metabolism, gene homologs for ahr and nrf - 2 , respectively, were knocked down by the use of RNA interference (RNAi). Results Beetles fed only charRed toast died off much earlier than control Beetles fed on Flour, whereas Beetles fed Flour enriched with 5 % charRed toast survived significantly longer than the control. Both, ahr and nrf - 2 proved essential in order to enable the increase in survival by the feeding of 5 % charRed toast. Moreover, functional loss of ahr and nrf - 2 made the Beetles hypersensitive versus the feeding of 100 % charRed toast. Finally, at the transcriptional level, it was shown that RNAi for ahr blocked the inducing activities of charRed toast on nrf - 2 . Conclusions Our studies suggest a hormetic response of the Red Flour Beetle to feeding of charRed toast that causes an increased stress resistance through the activation of ahr and nrf - 2. Those adaptations, however, are saturable and accordingly the hormetic effects at increasing concentrations of the toxicants become expended.
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Hormesis is induced in the Red Flour Beetle Tribolium castaneum through ingestion of charRed toast
European journal of nutrition, 2014Co-Authors: Stefanie Grünwald, Janine Niedermeier, Uwe WenzelAbstract:Purpose CharRed foods are generally suspected to exert health threats by providing toxicants, such as acrylamide or polycyclic aromatic hydrocarbons. Using the Red Flour Beetle Tribolium castaneum as a model organism, we tested its survival under heat stress in response to feeding charRed toast.
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the Red Flour Beetle tribolium castaneum as a model to monitor food safety and functionality
Advances in Biochemical Engineering \ Biotechnology, 2013Co-Authors: Stefanie Grünwald, Iris V Adam, Anamaria Gurmai, Ludmila Bauer, Michael Boll, Uwe WenzelAbstract:: Food quality is a fundamental issue all over the world. There are two major requirements to provide the highest quality of food: having the lowest reachable concentrations of health-threatening ingRedients or contaminants and having the optimal concentrations of health-improving functional ingRedients. Often, the boundaries of both requirements are blurRed, as might be best exemplified by nutraceuticals (enriched food products invented to prevent or even treat diseases), for which undesirable side effects have been reported sometimes. Accordingly, there is an increasing need for reliable methods to screen for health effects of wanted or unwanted ingRedients in a complex food matrix before more complex model organisms or human probands become involved. In this chapter, we present the Red Flour Beetle Tribolium castaneum as a model organism to screen for effects of complex foods on healthspan or lifespan by assessing the survival of the Beetles under heat stress at 42 °C after feeding different diets. There is a higher genetic homology between T. castaneum and humans when compaRed to other invertebrate models, such as Drosophila melanogaster or Caenorhabditis elegans. Therefore, the Red Flour Beetle appears as an interesting model to study interactions between genes and food ingRedients, with relevance for stress resistance and lifespan. In that context, we provide data showing Reduced lifespans of the Beetles when the food-relevant contaminant benz(a)pyrene is added to the Flour they were fed on, whereas a lifespan extension was observed in Beetles fed on Flour enriched with an extract of Red wine.