The uptake of insecticidal Cry1Ab from genetically engineered (GE) maize, via herbivore Rhopalosiphum padi, to a predator Harmonia axyridis and its potential intergenerational transfer were investigated. Cry1Ab concentration was found to be 400-fold lower in R. padi compared to GE maize, and more than two-fold lower in H. axyridis. For 62% of H. axyridis samples, Cry1Ab was under the limit of detection (LOD), for another 13% were under the limit of quantification (LOQ). The concentration of Cry1Ab was similar between H. axyridis exposed short-term and long-term with the exception of adults after long-term. There was no correlation between Cry1Ab in females and eggs and neonates. The performance of H. axyridis was comparable between Cry1Ab and control. Histological investigation did not show any pathological changes in the digestive and reproductive systems. The detected route of exposure is unlikely to be important for functional biological control by H. axyridis in agroecosystem.
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- brouci * metabolismus MeSH
- endotoxiny * MeSH
- geneticky modifikované rostliny metabolismus MeSH
- hemolyziny genetika metabolismus MeSH
- kukuřice setá genetika metabolismus MeSH
- larva metabolismus MeSH
- lidé MeSH
- novorozenec MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The ectoparasitic fungus Hesperomyces virescens was studied on its invasive host, the harlequin ladybird Harmonia axyridis, in the Czech Republic. A primary aim was to examine the relationship between fungal infection and elytral coloration of the ladybird. Furthermore, the role of host sex and mating status of females were analyzed. Beetles (n = 1,102) were sampled during autumn migration, and then sexed, weighed, and screened for infection. Females were dissected for detection of sperm in their spermathecae. Ladybirds were sorted according to color form and absorbance spectrophotometry was used to quantify carotenoid contents in their elytra. In individuals of the nonmelanic succinea form, the degree of melanization was measured using digital photographs and putative age groups were estimated based on background color of elytra. Sexual differences in infection patterns indicated transmission during copulation: males were infected mostly on elytra and venter, and females had infection almost exclusively on elytra. Mated females had higher infection rate than virgins. There was no influence of genetic color form on the fungal infection. Putative age groups (visual sorting to yellow, orange, and red) correlated with fungal infection. Infected individuals had elevated elytral carotenoid levels in comparison to uninfected individuals, which could be explained by host age. Infection-free succinea beetles were extensively melanized because they emerged later in the season at lower temperatures which induced melanization. Overall, we highlight that H. axyridis is a multivoltine species whose age, if not taken into account in ecophysiological studies, might present a considerable confounding factor.
- MeSH
- Ascomycota fyziologie MeSH
- biologické modely MeSH
- brouci metabolismus mikrobiologie MeSH
- interakce hostitele a patogenu * MeSH
- karotenoidy metabolismus MeSH
- melaniny metabolismus MeSH
- pigmentace * MeSH
- sexuální chování zvířat * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The Colorado potato beetle (CPB), Leptinotarsa decemlineata developed resistance to imidacloprid after exposure to this insecticide for multiple generations. Our previous studies showed that xenobiotic transcription factor, cap 'n' collar isoform C (CncC) regulates the expression of multiple cytochrome P450 genes, which play essential roles in resistance to plant allelochemicals and insecticides. In this study, we sought to obtain a comprehensive picture of the genes regulated by CncC in imidacloprid-resistant CPB. We performed sequencing of RNA isolated from imidacloprid-resistant CPB treated with dsRNA targeting CncC or gene coding for green fluorescent protein (control). Comparative transcriptome analysis showed that CncC regulated the expression of 1798 genes, out of which 1499 genes were downregulated in CncC knockdown beetles. Interestingly, expression of 79% of imidacloprid induced P450 genes requires CncC. We performed quantitative real-time PCR to verify the reduction in the expression of 20 genes including those coding for detoxification enzymes (P450s, glutathione S-transferases, and esterases) and ABC transporters. The genes coding for ABC transporters are induced in insecticide resistant CPB and require CncC for their expression. Knockdown of genes coding for ABC transporters simultaneously or individually caused an increase in imidacloprid-induced mortality in resistant beetles confirming their contribution to insecticide resistance. These studies identified CncC as a transcription factor involved in regulation of genes responsible for imidacloprid resistance. Small molecule inhibitors of CncC or suppression of CncC by RNAi could provide effective synergists for pest control or management of insecticide resistance.
- MeSH
- brouci * genetika metabolismus MeSH
- dusíkaté sloučeniny farmakologie MeSH
- hmyzí geny fyziologie MeSH
- hmyzí proteiny * genetika metabolismus MeSH
- léková rezistence * účinky léků genetika MeSH
- neonikotinoidy farmakologie MeSH
- transkripční faktory * genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Insecticide resistance is an increasingly global problem that hampers pest control. We sought the mechanism responsible for survival following pyrethroid treatment and the factors connected to paralysis/death of the pollen beetle Meligethes aeneus through a proteome-level analysis using nanoLC coupled with Orbitrap Fusion™ Tribrid™ mass spectrometry. A tolerant field population of beetles was treated with deltamethrin, and the ensuing proteome changes were observed in the survivors (resistant), dead (paralyzed) and control-treated beetles. The protein database consisted of the translated transcriptome, and the resulting changes were manually annotated via BLASTP. We identified a number of high-abundance changes in which there were several dominant proteins, e.g., the electron carrier cytochrome b5, ribosomal proteins 60S RPL28, 40S RPS23 and RPS26, eIF4E-transporter, anoxia up-regulated protein, 2 isoforms of vitellogenin and pathogenesis-related protein 5. Deltamethrin detoxification was influenced by different cytochromes P450, which were likely boosted by increased cytochrome b5, but glutathione-S-transferase ε and UDP-glucuronosyltransferases also contributed. Moreover, we observed changes in proteins related to RNA interference, RNA binding and epigenetic modifications. The high changes in ribosomal proteins and associated factors suggest specific control of translation. Overall, we showed modulation of expression processes by epigenetic markers, alternative splicing and translation. Future functional studies will benefit. BIOLOGICAL SIGNIFICANCE: Insects develop pesticide resistance, which has become one of the key issues in plant protection. This growing resistance increases the demand for pesticide applications and the development of new substances. Knowledge in the field regarding the resistance mechanism and its responses to pesticide treatment provides us the opportunity to propose a solution for this issue. Although the pollen beetle Meligethes aeneus was effectively controlled with pyrethroids for many years, there have been reports of increasing resistance. We show protein changes including production of isoforms in response to deltamethrin at the protein level. These results illustrate the insect's survival state as a resistant beetle and in its paralyzed state (evaluated as dead) relative to resistant individuals.
- MeSH
- brouci účinky léků genetika metabolismus MeSH
- databáze genetické * MeSH
- hmyzí proteiny genetika metabolismus MeSH
- insekticidy toxicita MeSH
- nitrily toxicita MeSH
- proteomika metody MeSH
- pyl metabolismus MeSH
- pyrethriny toxicita MeSH
- rezistence k insekticidům genetika MeSH
- transkriptom * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Several recent studies have demonstrated the great potential for exploiting semiochemicals in ecology and conservation studies. The cerambycid beetle Rosalia alpina represents one of the flagship species of saproxylic insect biodiversity in Europe. In recent years its populations appear to have declined substantially, and its range has shrunk considerably as a result of forest management and urbanization. Here, we collected volatile chemicals released by males and females of R. alpina. Analyses of the resulting extracts revealed the presence of a single male-specific compound, identified as a novel alkylated pyrone structure. In field bioassays in Slovenia, traps baited with the synthesized pyrone captured both sexes of R. alpina, indicating that the pyrone functions as an aggregation pheromone. Our results represent the first example of a new structural class of pheromones within the Cerambycidae, and demonstrate that pheromone-baited traps can provide a useful tool for sampling R. alpina. This tool could be particularly useful in the ongoing development of conservation strategies for the iconic but endangered Alpine longicorn.
- MeSH
- biotest MeSH
- brouci metabolismus MeSH
- feromony biosyntéza metabolismus MeSH
- hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
- magnetická rezonanční spektroskopie s uhlíkem 13C MeSH
- protonová magnetická rezonanční spektroskopie MeSH
- zachování přírodních zdrojů * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
The Colorado potato beetle (CPB), Leptinotarsa decemlineata, is a major pest of potato plants, and its digestive system is a promising target for development of pest control strategies. This work focuses on functional proteomic analysis of the digestive proteolytic enzymes expressed in the CPB gut. We identified a set of peptidases using imaging with specific activity-based probes and activity profiling with selective substrates and inhibitors. The secreted luminal peptidases were classified as: (i) endopeptidases of cathepsin D, cathepsin L, and trypsin types and (ii) exopeptidases with aminopeptidase (cathepsin H), carboxypeptidase (serine carboxypeptidase, prolyl carboxypeptidase), and carboxydipeptidase (cathepsin B) activities. The proteolytic arsenal also includes non-luminal peptidases with prolyl oligopeptidase and metalloaminopeptidase activities. Our results indicate that the CPB gut employs a multienzyme network of peptidases with complementary specificities to efficiently degrade ingested proteins. This proteolytic system functions in both CPB larvae and adults and is controlled mainly by cysteine and aspartic peptidases and supported by serine and metallopeptidases. The component enzymes identified here are potential targets for inhibitors with tailored specificities that could be engineered into potato plants to confer resistance to CPB.
- MeSH
- brouci enzymologie genetika růst a vývoj metabolismus MeSH
- fyziologie výživy zvířat MeSH
- gastrointestinální trakt enzymologie MeSH
- hmyzí proteiny genetika metabolismus MeSH
- larva genetika růst a vývoj metabolismus MeSH
- proteasy genetika metabolismus MeSH
- proteolýza MeSH
- proteomika MeSH
- rostlinné proteiny metabolismus MeSH
- trávení MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- brouci fyziologie metabolismus MeSH
- celulosa MeSH
- doškolování MeSH
- lidé MeSH
- mikrobiologické jevy MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Geografické názvy
- Nový Zéland MeSH
In insect larvae, optimising food utilisation with respect to available meals and time is essential for achieving maximum adult body size, which is a relevant proxy of fitness. We studied the efficiency of food conversion, body size, mortality, and development time in a solitary idiobiont ectoparasitoid, Brachinus explodens (Coleoptera: Carabidae), reared in the laboratory on the pupae of another carabid genus, Amara. The efficiency of conversion index (ECI - ratio of ingested to assimilated food) was, on average, 54.1±1.1% (n=76), with a minimum of 26.9% and a maximum of 81.6%. The rate of increase in biomass gained (W(gained)) with biomass of the host was constant in females, but it decreased in males over the range of host body mass. Females, therefore, grew heavier from hosts of the same mass compared to males. Body length increased with the host mass and was correlated with W(gained) identically for both sexes. Mortality was unaffected by the host mass, but it significantly increased below 20°C. In contrast, the development time of the feeding phase of the larva increased with the host mass at 20.3 and 23.7°C, but it remained unaffected at 26.9°C and in all three temperatures considering pupal development. W(gained) increased with development time up to ca. 8 days of larval feeding at 23.7°C. To our knowledge, our data are the first on food utilisation in solitary idiobiont coleopteran ectoparasitoids, and they present the highest values of ECI in insects.
- MeSH
- brouci růst a vývoj metabolismus parazitologie MeSH
- interakce hostitele a parazita MeSH
- larva růst a vývoj metabolismus parazitologie MeSH
- velikost těla MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
