BibSonomy publications for /user/ifzappliedentomol/IFZWed Jun 04 15:57:40 CEST 2008Nature7190949-955The genome of the model beetle and pest Tribolium castaneum4522008/04/24/printIFZ imported Wed Jun 04 15:33:28 CEST 2008BULLETIN OF INSECTOLOGY2209-210Chemo-ecologically mediated interactions among Candidatus Phytoplasma mah, its vector Cacopsylla picta, and their host plant Malus domestica602007Cacopsylla_picta Candidatus_Phytoplasma_mali IFZ Malus_domestica apple_proliferation head_space olfactory_orientation plant plant_odours psyllidae volatiles Apple proliferation caused by the apple proliferation phytoplasma, �Candidatus Phytoplasma mali�, causes major economic losses in European apple production. The apple proliferation phytoplasma is naturally spread by the two leaf sucker species Cacopsylla melanoneura and C picta (Hemiptera: Sternorrhyncha: Psyllidae) It was investigated in a previous study that both psyllid species use chemical cues for orientation. In this study investigation were: carried out on the behavioural reactions of C. picta on volatiles from healthy plants and those infected with apple proliferation in respect to the infection status of the psyllids themselves and to their previous host experience. The influence of the apple proliferation phytoplasma on the volatile emission of apple trees was investigated by head space collection followed by gas chromatography coupled with mass spectrometry. The differences in the behavioural responses to the volatiles of infected versus non-infected plants as well as the respective differences detected among the volatile compounds will be presented and ecological interactions between the association of C picta and �Ca. P. mali� will be discussed.Wed Jun 04 15:31:00 CEST 2008JOURNAL OF CHEMICAL ECOLOGY2179-188Protected by fumigants: Beetle perfumes in antimicrobial defense342008Bacillus_thuringiensis Beauveria_bassiana IFZ Metarhizium_anisopliae Phratora_vitellinae antimicrobial_activity fumigants glandular salicylaldehyde secretion Beetles share with other eukaryotes an innate immune system that mediates endogenous defense against pathogens. In addition, larvae of some taxa produce fluid exocrine secretions that contain antimicrobial compounds. In this paper, we provide evidence that larvae of the brassy willow leaf beetle Phratora vitellinae constitutively release volatile glandular secretions that combat pathogens in their microenvironment. We identified salicylaldehyde as the major component of their enveloping perfume cloud, which is emitted by furrow-shaped openings of larval glandular reservoirs and which inhibits in vitro the growth of the bacterial entomopathogen Bacillus thuringiensis. The suggested role of salicylaldehyde as a fumigant in exogenous antimicrobial defense was confirmed in vivo by its removal from glandular reservoirs. This resulted in an enhanced susceptibility of the larvae to infection with the fungal entomopathogens Beauveria bassiana and Metarhizium anisopliae. Consequently, we established the hypothesis that antimicrobial defense in beetles can be expanded beyond innate immunity to include external disinfection of their microenvironment, and we report for the first time the contribution of fumigants to antimicrobial defense in animals.Wed Jun 04 15:31:00 CEST 2008INFECTION AND IMMUNITY1175-183Microbial metalloproteinases mediate sensing of invading pathogens and activate innate immune responses in the lepidopteran model host Galleria mellonella752007IFZ imported Thermolysin-like metalloproteinases such as aureolysin, pseudolysin, and bacillolysin represent virulence factors of diverse bacterial pathogens. Recently, we discovered that injection of thermolysin into larvae of the greater wax moth, Galleria mellonella, mediated strong immune responses. Thermolysin-mediated proteolysis of hemolymph proteins yielded a variety of small-sized (< 3 kDa) protein fragments (protfrags) that are potent elicitors of innate immune responses. In this study, we report the activation of a serine proteinase cascade by thermolysin, as described for bacterial lipopolysaccharides (LPS), that results in subsequent prophenoloxidase activation leading to melanization, an elementary immune defense reaction of insects. Quantitative real-time reverse transcription-PCR analyses of the expression of immune-related genes encoding the inducible metalloproteinase inhibitor, gallerimycin, and lysozyme demonstrated increased transcriptional rates after challenge with purified protfrags similar to rates after challenge with LPS. Additionally, we determined the induction of a similar spectrum of immune-responsive proteins that were secreted into the hemolymph by using comparative proteomic analyses of hemolymph proteins from untreated larvae and from larvae that were challenged with either protfrags or LPS. Since G. mellonella was recently established as a valuable pathogenicity model for Cryptococcus neoformans infection, the present results add to our understanding of the mechanisms of immune responses in G. mellonella. The obtained results support the proposed danger model, which suggests that the immune system senses endogenous alarm signals during infection besides recognition of microbial pattern molecules.Wed Jun 04 15:31:00 CEST 2008DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY5585-595Beetle immunity: Identification of immune-inducible genes from the model insect Tribolium castaneum322008IFZ Tribolium_castaneum defensin innate_immunity model_organism response stress thaumatin The red flour beetle, Tribolium castaneum, is an established genetically tractable model insect for evolutionary and developmental studies. Therefore, it may also represent a valuable model for comparative analysis of insect immunity. Here, we used the suppression subtractive hybridization method to identify Tribolium genes that are transcriptionally induced in response to injection of crude lipopolysaccharide (LPS). Determined genes encode proteins that share sequence similarities with counterparts from other insects known to mediate sensing of infection (e.g. Toll and PGRP) or to represent potential antimicrobial effectors (e.g. ferritin, c-type lysozyme, serine proteinase inhibitors, and defensins). Especially significant is the identification of thaumatin-like peptides, representing ancient antifungal peptides originally reported from plants, that are absent from the genomes of many other insects such as Drosophila, Anopheles, and Apis. We produced recombinant thaumatin-1 in bacteria and we found that it represents an antimicrobial peptide against filamentous fungi in Tribolium. Additionally, septic injury induces expression of genes involved in stress adaptation (e.g. heat-shock proteins) or insecticide resistance (e.g. cytochrome P450s) in Tribolium, suggesting that there may be crosstalk between the immune and stress responses. (c) 2007 Elsevier Ltd. All rights reserved.Wed Jun 04 15:31:00 CEST 2008DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY4400-409Identification of a lepidopteran matrix metalloproteinase with dual roles in metamorphosis and innate immunity322008Galleria IFZ danger_model innate_immunity insects matrix_metalloproteinase mellonella metamorphosis Matrix metalloproteinases (MMPs) are key enzymes in mammalian tissue remodeling and inflammation. Recently, we postulated that an endogenous MMP expressed in the lepidopteran model Galleria mellonella during metamorphosis causes degradation of collagen-IV, which in turn results in activation of innate immunity. Here, we report that degradation of collagen-IV by hemocytes is enhanced upon injection of bacterial lipopolysaccharide (LPS), and that this activity is sensitive to the MMP-inhibitor GM6001. Therefore, we screened for enzymes behind this activity and identified the first MMP from Lepidoptera (Gm1-MMP), and the third from insects. Gm1-MMP shares homology with the first MMP from Drosophila (Dm1-MMP) known to be essential for tissue remodeling during metamorphosis. Using quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) analysis, we confirmed up-regulation of Gm1-MMP expression after pupation, when extracellular matrix breakdown of larval tissues occurs. In addition, we determined that LPS challenge induces Gm1-MMP expression in hemocytes, implicating its participation in collagen-IV degradation upon septic injury. These results suggest dual roles of Gm1-MMP in innate immunity and metamorphosis. Interestingly, our phylogenetic analysis elucidates that Gm1-MMP share highest similarity with human MMP-19 and MMP-28, whose functions in mammalian wounding and inflammatory response have recently been demonstrated; hence, the present findings may provide insights into the evolutionarily conserved features of MMPs. (c) 2007 Elsevier Ltd. All rights reserved.Wed Jun 04 15:31:00 CEST 2008BMC GENOMICSAnalysis of the immune-inducible transcriptome from microbial stress resistant, rat-tailed maggots of the drone fly Eristalis tenax82007IFZ imported Background: The saprophagous and coprophagous maggots of the drone fly Eristalis tenax (Insecta, Diptera) have evolved the unique ability to survive in aquatic habitats with extreme microbial stress such as drains, sewage pools, and farmyard liquid manure storage pits. Therefore, they represent suitable models for the investigation of trade-offs between the benefits resulting from colonization of habitats lacking predators, parasitoids, or competitors and the investment in immunity against microbial stress. In this study, we screened for genes in E. tenax that are induced upon septic injury. Suppression subtractive hybridization was performed to selectively amplify and identify cDNAs that are differentially expressed in response to injected crude bacterial endotoxin (LPS). Results: Untreated E. tenax maggots exhibit significant antibacterial activity in the hemolymph which strongly increases upon challenge with LPS. In order to identify effector molecules contributing to this microbial defense we constructed a subtractive cDNA library using RNA samples from untreated and LPS injected maggots. Analysis of 288 cDNAs revealed induced expression of 117 cDNAs corresponding to 30 novel gene clusters in E. tenax. Among these immune-inducible transcripts we found homologues of known genes from other Diptera such as Drosophila and Anopheles that mediate pathogen recognition (e. g. peptidoglycan recognition protein) or immune-related signaling (e. g. relish). As predicted, we determined a high diversity of novel putative antimicrobial peptides including one E. tenax defensin. Conclusion: We identified 30 novel genes of E. tenax that were induced in response to septic injury including novel putative antimicrobial peptides. Further analysis of these immune- related effector molecules from Eristalis may help to elucidate the interdependency of ecological adaptation and molecular evolution of the innate immunity in Diptera.Wed Jun 04 15:31:00 CEST 2008JOURNAL OF INSECT SCIENCEGenomic and proteomic analysis of innate immunity in the greater wax moth Galleria melonella72007IFZ imported Wed Jun 04 15:31:00 CEST 2008BIOLOGICAL CHEMISTRY1119-127The insect metalloproteinase inhibitor gene of the lepidopteran Galleria mellonella encodes two distinct inhibitors3882007Galleria_mellonella IFZ innate_immunity insects matrix metalloproteinases microbial_metalloproteinases protein_glycosylation The insect metalloproteinase inhibitor (IMPI) from the greater wax moth, Galleria mellonella, represents the first and to date only specific inhibitor of microbial metalloproteinases reported from animals. Here, we report on the characterization including carbohydrate analysis of two recombinant constructs encoded by impi cDNA either upstream or downstream of the furin cleavage site identified. rIMPI-1, corresponding to native IMPI purified from hemolymph, is encoded by the N-terminal part of the impi sequence, whereas rIMPI-2 is encoded by its C-terminal part. rIMPI-1 is glycosylated at N48 with GIcNAc2Man3, showing fucosylation to different extents. Similarly, rIMPI-2 is glycosylated at N149 with GIcNAc2Man3, but is fully fucosylated. rIMPI-1 represents a promising template for the design of second-generation antibiotics owing to its specific activity against thermolysin-like metalloproteinases produced by human pathogenic bacteria such as Vibrio vulnificus. In contrast, rIMPI-2 does not inhibit bacterial metalloproteinases, but is moderately active against recombinant human matrix metalloproteinases (MMPs). Both microbial metalloproteinases and MMPs induce expression of the impi gene when injected into G. mellonella larvae. These findings provide evidence that the impi gene encodes two distinct inhibitors, one inhibiting microbial metalloproteinases and contributing to innate immunity, the other putatively mediating regulation of endogenous MMPs during metamorphosis.Wed Jun 04 15:31:00 CEST 2008INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY7726-731Identification of immune-related genes from an apterygote insect, the firebrat Thermobia domestica372007IFZ Thermobia_domestica apterygote_insects defensin innate_immunity In this study, we report the analysis of the immune-related transcriptome from an apterygote insect, the firebrat Thermobia domestica (Zygentoma, Lepismatidae), which currently emerges as a suitable model insect for evolutionary and developmental studies. The suppression subtractive hybridization method was used for targeted screening of genes that are up-regulated in response to injected bacterial lipopolysaccharide (LPS). A subtracted cDNA library enriched in immune-inducible genes was constructed and analysis of 288 cDNAs resulted in identification of 26 novel genes in T. domestica. Among these immune-related transcripts we found homologues of genes from other insects which are involved in the regulation of signaling cascades and six novel putative antimicrobial peptides. The identified genes implicate the presence of sophisticated regulatory mechanisms in insect immune signaling and give insight into evolutionarily conserved features of insect innate immunity. (c) 2007 Elsevier Ltd. All rights reserved.