The pollen beetle is a major pest of oilseed rape. Although various resistance mechanisms have been identified, such as kdr (mutation in the sodium channel) and metabolic resistance (CYP overexpression), other "hidden" factors also exist. Some studies have stressed the importance of epistasis as a genetic background. The combination of kdr and metabolic resistance appears to be unfavorable under field conditions in the absence of pesticide selection. The regulation of detoxification enzymes can play an important role, but we highlight different detoxification markers compared to those emphasized in other studies. We also stress the importance of studying the role of markers identified as pathogenesis-related protein 5-like (PR5; upregulated by insecticides) and highlight the role of RNA (DEAD-box) helicases (downregulated by insecticides). Thus, we suggest the importance of epigenetic drivers of resistance/tolerance to pesticides. The key results are similar to those of our previous study, in which deltamethrin treatment of the pollen beetle was also investigated by a proteogenomic approach. Indeed, the mechanism leading to resistance of the pollen beetle may be an innate mechanism that the pollen beetle can also employ in natural habitats, but under field conditions (pesticide exposure), this mechanism is used to survive in response to insecticides. SIGNIFICANCE: Pesticide resistance is a serious problem that hampers the successful production of crops. Understanding the mechanisms of insecticide resistance is highly important for successful pest control, especially when considering integrated pest management. Here, using a proteogenomic approach, we identified novel markers for understanding pollen beetle resistance to pesticides. In addition, future studies will reveal the role of these markers in the multiresistance of pollen beetle populations. We highlight that the proteins identified as PR5, which are known to occur in beetles and are similar to those in plants, may be responsible for tolerance to multiple stresses. In addition, our results indicate that the RNA helicases that exhibited changes in expression may be the epigenetic drivers of multiresistance. The nature of these changes remains an open question, and their relevance in different situations (responses to different stresses) in natural habitats in the absence of pesticides can be proposed.
- MeSH
- brouci * genetika MeSH
- insekticidy * farmakologie MeSH
- proteogenomika * MeSH
- pyl MeSH
- pyrethriny * farmakologie MeSH
- rezistence k insekticidům genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Beetles are the most species-rich animal radiation and are among the historically most intensively studied insect groups. Consequently, the vast majority of their higher-level taxa had already been described about a century ago. In the 21st century, thus far, only three beetle families have been described de novo based on newly collected material. Here, we report the discovery of a completely new lineage of soft-bodied neotenic beetles from the Brazilian Atlantic rainforest, which is one of the most diverse and also most endangered biomes on the planet. We identified three species in two genera, which differ in morphology of all life stages and exhibit different degrees of neoteny in females. We provide a formal description of this lineage for which we propose the new family Jurasaidae. Molecular phylogeny recovered Jurasaidae within the basal grade in Elateroidea, sister to the well-sclerotized rare click beetles, Cerophytidae. This placement is supported by several larval characters including the modified mouthparts. The discovery of a new beetle family, which is due to the limited dispersal capability and cryptic lifestyle of its wingless females bound to long-term stable habitats, highlights the importance of the Brazilian Atlantic rainforest as a top priority area for nature conservation.
- MeSH
- brouci genetika MeSH
- deštný prales MeSH
- ekosystém MeSH
- fylogeneze MeSH
- genetická variace MeSH
- sekvenční analýza DNA MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Brazílie MeSH
All more than 3000 species of Agrilus beetles are phytophagous and some cause economically significant damage to trees and shrubs. Facilitated by international trade, Agrilus species regularly invade new countries and continents. This necessitates a rapid identification of Agrilus species, as the first step for subsequent protective measures. This study provides the first DNA reference library for ~100 Agrilus species from the Northern Hemisphere based on three mitochondrial markers: cox1-5' (DNA barcode fragment), cox1-3', and rrnL. All 329 Agrilus records available in the Barcode of Life Database format, including specimen images and geo data, are released through a public dataset 'Agrilus1 329' available at: dx.doi.org/10.5883/DS-AGRILUS1. All Agrilus species were identified using adult morphology and by using molecular phylogenetic trees, as well as distance- and tree-based algorithms. Most DNA-based species limits agree well with the morphology-based identification. Our results include cases of high intraspecific variability and multiple species para- and polyphyly. DNA barcoding is a powerful species identification tool in Agrilus, although it frequently fails to recover morphologically-delimited Agrilus species-group. Even though the current three-gene database covers only ~3% of the known Agrilus diversity, it contains representatives of all principal lineages from the Northern Hemisphere and represents the most extensive dataset built for DNA-delimited species identification within this genus so far. Molecular data analyses can rapidly and cost-effectively identify an unknown sample, including immature stages and/or non-native taxa, or species not yet formally named.
- MeSH
- brouci genetika MeSH
- fylogeneze * MeSH
- lesnictví MeSH
- mitochondriální DNA MeSH
- taxonomické DNA čárové kódování * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Plastoceridae Crowson, 1972, Drilidae Blanchard, 1845 and Omalisidae Lacordaire, 1857 (Elateroidea) are families of the Coleoptera with obscure phylogenetic relationships and modified morphology showing neotenic traits such as soft bodies, reduced wing cases and larviform females. We shotgun sequenced genomes of Plastocerus, Drilus and Omalisus and incorporated them into data matrices of 66 and 4202 single-copy nuclear genes representing Elateroidea. Phylogenetic analyses indicate their terminal positions within the broadly defined well-sclerotized and fully metamorphosed Elateridae and thus Omalisidae should now be considered as Omalisinae stat. nov. in Elateridae Leach, 1815. The results support multiple independent origins of incomplete metamorphosis in Elateridae and indicate the parallel evolution of morphological and ecological traits. Unlike other neotenic elateroids derived from the supposedly pre-adapted aposematically coloured and unpalatable soft-bodied elateroids, such as fireflies (Lampyridae) and net-winged beetles (Lycidae), omalisids and drilids evolved from well-sclerotized click beetles. These findings suggest sudden morphological shifts through incomplete metamorphosis, with important implications for macroevolution, including reduced speciation rate and high extinction risk in unstable habitats. Precise phylogenetic placement is necessary for studies of the molecular mechanisms of ontogenetic shifts leading to profoundly changed morphology.
- MeSH
- anotace sekvence MeSH
- brouci klasifikace genetika MeSH
- fylogeneze MeSH
- genom hmyzu * MeSH
- hmyzí proteiny genetika MeSH
- křídla zvířecí anatomie a histologie metabolismus MeSH
- regulace genové exprese * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A phylogenetic tree at the species level is still far off for highly diverse insect orders, including the Coleoptera, but the taxonomic breadth of public sequence databases is growing. In addition, new types of data may contribute to increasing taxon coverage, such as metagenomic shotgun sequencing for assembly of mitogenomes from bulk specimen samples. The current study explores the application of these techniques for large-scale efforts to build the tree of Coleoptera. We used shotgun data from 17 different ecological and taxonomic datasets (5 unpublished) to assemble a total of 1942 mitogenome contigs of >3000 bp. These sequences were combined into a single dataset together with all mitochondrial data available at GenBank, in addition to nuclear markers widely used in molecular phylogenetics. The resulting matrix of nearly 16,000 species with two or more loci produced trees (RAxML) showing overall congruence with the Linnaean taxonomy at hierarchical levels from suborders to genera. We tested the role of full-length mitogenomes in stabilizing the tree from GenBank data, as mitogenomes might link terminals with non-overlapping gene representation. However, the mitogenome data were only partly useful in this respect, presumably because of the purely automated approach to assembly and gene delimitation, but improvements in future may be possible by using multiple assemblers and manual curation. In conclusion, the combination of data mining and metagenomic sequencing of bulk samples provided the largest phylogenetic tree of Coleoptera to date, which represents a summary of existing phylogenetic knowledge and a defensible tree of great utility, in particular for studies at the intra-familial level, despite some shortcomings for resolving basal nodes.
- MeSH
- algoritmy MeSH
- brouci klasifikace genetika MeSH
- databáze genetické MeSH
- fylogeneze * MeSH
- metagenomika * MeSH
- mitochondrie genetika MeSH
- sekvence nukleotidů MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem 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
The relationships of the monogeneric family Plastoceridae Crowson, 1972 (Coleoptera: Elateroidea) have remained contentious due to its modified morphology, incorrect information on incomplete metamorphosis of females and the absence of molecular data. We produced the sequences for P. angulosus (Germar, 1844) (the type-species of Plastocerus Schaum, 1852) and performed molecular phylogenetic analyses to estimate its position. The analyses of Elateroidea (186 spp.) and Elateridae (110 spp.) molecular datasets of two mitochondrial and two nuclear gene fragments repeatedly placed Plastocerus Schaum, 1852 in relationships with the elaterid genera Oxynopterus Hope, 1842 and Pectocera Hope, 1842. Alternative topologies were rejected by likelihood tests. Therefore, Plastoceridae Crowson, 1972 are down-ranked to the subfamily Plastocerinae in Elateridae Leach, 1815. We suggest that the morphology-based placement and high rank for some elateroid lineages were inferred from the presence of homoplasies which evolved due to incomplete sclerotization. Distantly related soft-bodied elateroids share freely movable and transverse coxae, a shortened prosternum, and a weakly sclerotized abdomen with free ventrites. Importantly, the apomorphic structures characteristic for their closest relatives, such as the prosternal process, mesoventral cavity, and intercoxal keel in the first abdominal ventrite are regularly absent. Consequently, morphology-based phylogenetic analyses suggest deeply rooted positions for lineages without expressed apomorphic character states. Molecular data represent an independent character system that is not affected by the convergent morphological evolution, and therefore molecular phylogenies can elucidate the relationships of incompletely sclerotized lineages.
The development of modern methods of species delimitation, unified under the "integrated taxonomy" approach, allows a critical examination and re-evaluation of complex taxonomic groups. The rose chafer Protaetia (Potosia) cuprea is a highly polymorphic species group with a large distribution range. Despite its overall commonness, its taxonomy is unclear and subject to conflicting hypotheses, most of which largely fail to account for its evolutionary history. Based on the sequences of two mitochondrial markers from 65 individuals collected across the species range, and a detailed analysis of morphological characters including a geometric morphometry approach, we infer the evolutionary history and phylogeography of the P. cuprea species complex. Our results demonstrate the existence of three separate lineages in the Western Palearctic region, presumably with a species status. However, these lineages are in conflict with current taxonomic concepts. None of the 29 analyzed morphological characters commonly used in the taxonomy of this group proved to be unambiguously species- or subspecies- specific. The geometric morphometry analysis reveals a large overlap in the shape of the analyzed structures (pronotum, meso-metaventral projection, elytra and aedeagus), failing to identify either the genetically detected clades or the classical species entities. Our results question the monophyly of P. cuprea in regard to P. cuprina, as well as the species status of P. metallica. On the other hand, we found support for the species status of the Sicilian P. hypocrita. Collectively, our findings provide a new and original insight into the taxonomy and phylogeny of the P. cuprea species complex. At the same time, the results represent the first attempt to elucidate the phylogeography of these polymorphic beetles.
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
BACKGROUND: The tribe Coccinellini is a group of relatively large ladybird beetles that exhibits remarkable morphological and biological diversity. Many species are aphidophagous, feeding as larvae and adults on aphids, but some species also feed on other hemipterous insects (i.e., heteropterans, psyllids, whiteflies), beetle and moth larvae, pollen, fungal spores, and even plant tissue. Several species are biological control agents or widespread invasive species (e.g., Harmonia axyridis (Pallas)). Despite the ecological importance of this tribe, relatively little is known about the phylogenetic relationships within it. The generic concepts within the tribe Coccinellini are unstable and do not reflect a natural classification, being largely based on regional revisions. This impedes the phylogenetic study of important traits of Coccinellidae at a global scale (e.g. the evolution of food preferences and biogeography). RESULTS: We present the most comprehensive phylogenetic analysis of Coccinellini to date, based on three nuclear and one mitochondrial gene sequences of 38 taxa, which represent all major Coccinellini lineages. The phylogenetic reconstruction supports the monophyly of Coccinellini and its sister group relationship to Chilocorini. Within Coccinellini, three major clades were recovered that do not correspond to any previously recognised divisions, questioning the traditional differentiation between Halyziini, Discotomini, Tytthaspidini, and Singhikaliini. Ancestral state reconstructions of food preferences and morphological characters support the idea of aphidophagy being the ancestral state in Coccinellini. This indicates a transition from putative obligate scale feeders, as seen in the closely related Chilocorini, to more agile general predators. CONCLUSIONS: Our results suggest that the classification of Coccinellini has been misled by convergence in morphological traits. The evolutionary history of Coccinellini has been very dynamic in respect to changes in host preferences, involving multiple independent host switches from different insect orders to fungal spores and plants tissues. General predation on ephemeral aphids might have created an opportunity to easily adapt to mixed or specialised diets (e.g. obligate mycophagy, herbivory, predation on various hemipteroids or larvae of leaf beetles (Chrysomelidae)). The generally long-lived adults of Coccinellini can consume pollen and floral nectars, thereby surviving periods of low prey frequency. This capacity might have played a central role in the diversification history of Coccinellini.
- MeSH
- biologická evoluce MeSH
- brouci klasifikace genetika růst a vývoj fyziologie MeSH
- fylogeneze MeSH
- larva fyziologie MeSH
- molekulární evoluce MeSH
- predátorské chování MeSH
- preference v jídle MeSH
- zavlečené druhy MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
