The larvae of the moth Hyalophora cecropia spin silk cocoons with morphologically distinct layers. We investigated the expression of the individual silk protein components of these cocoons in relation to the morphology of the silk gland and its affiliation to the different layers of the cocoon. The study used transcriptomic and proteomic analyses to identify 91 proteins associated with the silk cocoons, 63 of which have a signal peptide indicating their secretory nature. We checked the specificity of their expression in different parts of the SG and the presence of the corresponding protein products in each cocoon layer. Differences were observed among less abundant proteins with unclear functions. The representation of proteins in the inner envelope and intermediate space was similar, except for a higher proportion of probable contaminating proteins, mostly originating from the gut. On the other hand, the outer envelope contains a number of putative enzymes with unclear function. However, the protein most specific to the outer layer has sequence homology to putative serine/threonine kinase-like proteins and some adhesive proteins, and its closest homolog in Bombyx mori was found in the scaffold silk. This research provides valuable insights into the silk production of the cecropia moth, highlighting both similarities and differences to other moth species.

• Klíčová slova
• Fibrohexamerin-like protein, Lepidoptera, Silk, Silk antibacterial proteins, Silk kinase, Silk laccase,
• MeSH
• hedvábí * metabolismus   genetika   MeSH
• hmyzí proteiny * metabolismus   genetika   MeSH
• larva metabolismus   genetika   růst a vývoj   MeSH
• můry * genetika   metabolismus   MeSH
• proteomika MeSH
• stanovení celkové genové exprese MeSH
• transkriptom MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hedvábí * MeSH
• hmyzí proteiny * MeSH

Ticks are blood-feeding arachnids that are known to transmit various pathogenic microorganisms to their hosts. During blood feeding, ticks activate their metabolism and immune system to efficiently utilise nutrients from the host's blood and complete the feeding process. In contrast to insects, in which the fat body is known to be a central organ that controls essential metabolic processes and immune defense mechanisms, the function of the fat body in tick physiology is still relatively unexplored. To fill this gap, we sought to uncover the repertoire of genes expressed in the fat body associated with trachea (FB/Tr) by analyzing the transcriptome of individual, partially fed (previtellogenic) Ixodes ricinus females. The resulting catalog of individual mRNA sequences reveals a broad repertoire of transcripts encoding proteins involved in nutrient storage and distribution, as well as components of the tick immune system. To gain a detailed insight into the secretory products of FB/Tr specifically involved in inter-tissue transport and humoral immunity, the transcriptomic data were complemented with the proteome of soluble proteins in the hemolymph of partially fed female ticks. Among these proteins, the hemolipoglyco-carrier proteins were predominant. When comparing immune peptides and proteins from the fat body with those produced by hemocytes, we found that the fat body serves as a unique producer of certain immune components. Finally, time-resolved transcriptional regulation of selected immune transcripts from the FB/Tr was examined in response to experimental challenges with model microbes and analyzed by RT-qPCR. Overall, our data show that the fat body of ticks, similar to insects, is an important metabolic tissue that also plays a remarkable role in immune defense against invading microbes. These findings improve our understanding of tick biology and its impact on the transmission of tick-borne pathogens.

• MeSH
• hemolymfa * MeSH
• klíště * genetika   metabolismus   MeSH
• proteiny členovců genetika   metabolismus   MeSH
• proteomika MeSH
• stanovení celkové genové exprese MeSH
• tukové těleso metabolismus   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• proteiny členovců MeSH

Host shift is ecologically advantageous and a crucial driver for herbivore insect speciation. Insects on the non-native host obtain enemy-free space and confront reduced competition, but they must adapt to survive. Such signatures of adaptations can often be detected at the gene expression level. It is astonishing how bark beetles cope with distinct chemical environments while feeding on various conifers. Hence, we aim to disentangle the six-toothed bark beetle (Ips sexdentatus) response against two different conifer defences upon host shift (Scots pine to Norway spruce). We conducted bioassay and metabolomic analysis followed by RNA-seq experiments to comprehend the beetle's ability to surpass two different terpene-based conifer defence systems. Beetle growth rate and fecundity were increased when reared exclusively on spruce logs (alternative host) compared to pine logs (native host). Comparative gene expression analysis identified differentially expressed genes (DEGs) related to digestion, detoxification, transporter activity, growth, signalling, and stress response in the spruce-feeding beetle gut. Transporter genes were highly abundant during spruce feeding, suggesting they could play a role in pumping a wide variety of endogenous and xenobiotic compounds or allelochemicals out. Trehalose transporter (TRET) is also up-regulated in the spruce-fed beetle gut to maintain homeostasis and stress tolerance. RT-qPCR and enzymatic assays further corroborated some of our findings. Taken together, the transcriptional plasticity of key physiological genes plays a crucial role after the host shift and provides vital clues for the adaptive potential of bark beetles on different conifer hosts.

• Klíčová slova
• Bark beetles, Chitin metabolism, Detoxification, Differential gene expression (DGE), Enzyme assay, Host adaptation, Host switch, Ips sexdentatus, Metabolomics, RT-qPCR,
• MeSH
• brouci * metabolismus   MeSH
• exprese genu MeSH
• nosatcovití * metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• terpeny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• terpeny MeSH

The molecular mechanisms of sex determination in moths and butterflies (Lepidoptera) with female heterogamety (WZ/ZZ) are poorly understood, except in the silkworm Bombyx mori. However, the Masculinizer (Masc) gene that controls male development and dosage compensation in B. mori, appears to be conserved in Lepidoptera, as its masculinizing function was recently confirmed in several moth species. In this work, we investigated the role of the Masc gene in sex determination of the codling moth Cydia pomonella (Tortricidae), a globally important pest of pome fruits and walnuts. The gene structure of the C. pomonella Masc ortholog, CpMasc, is similar to B. mori Masc. However, unlike B. mori, we identified 14 splice variants of CpMasc in the available transcriptomes. Subsequent screening for sex specificity and genetic variation using publicly available data and RT-PCR revealed three male-specific splice variants. Then qPCR analysis of these variants revealed sex-biased expression showing a peak only in early male embryos. Knockdown of CpMasc by RNAi during early embryogenesis resulted in a shift from male-to female-specific splicing of the C. pomonella doublesex (Cpdsx) gene, its downstream effector, in ZZ embryos, leading to a strongly female-biased sex ratio. These data clearly demonstrate that CpMasc functions as a masculinizing gene in the sex-determining cascade of C. pomonella. Our study also showed that CpMasc transcripts are provided maternally, as they were detected in unfertilized eggs after oviposition and in mature eggs dissected from virgin females. This finding is unique, as maternal provision of mRNA has rarely been studied in Lepidoptera.

• Klíčová slova
• Alternative splicing, Cydia pomonella, Lepidoptera, Masculinizer, Maternal provision of mRNA, Quantitative real-time PCR, RNA interference, Sex determination,
• MeSH
• bourec * genetika   MeSH
• kompenzace dávky (genetika) MeSH
• messenger RNA genetika   MeSH
• motýli * genetika   MeSH
• můry * genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• messenger RNA MeSH

Salivary glands are vital to tick feeding success and also play a crucial role in tick-borne pathogen transmission. In previous studies of Ixodes scapularis salivary glands, we demonstrated that saliva-producing type II and III acini are innervated by neuropeptidergic axons which release different classes of neuropeptides via their terminals (Šimo et al., 2009b, 2013). Among these, the neuropeptide SIFamide-along with its cognate receptor-were postulated to control the basally located acinar valve via basal epithelial and myoepithelial cells (Vancová et al., 2019). Here, we functionally characterized a second SIFamide receptor (SIFa_R2) from the I. scapularis genome and proved that it senses a low nanomolar level of its corresponding ligand. Insect SIFamide paralogs, SMYamides, also activated the receptor but less effectively compared to SIFamide. Bioinformatic and molecular dynamic analyses suggested that I. scapularis SIFamide receptors are class A GPCRs where the peptide amidated carboxy-terminus is oriented within the receptor binding cavity. The receptor was found to be expressed in Ixodes ricinus salivary glands, synganglia, midguts, trachea, and ovaries, but not in Malpighian tubules. Investigation of the temporal expression patterns suggests that the receptor transcript is highly expressed in unfed I. ricinus female salivary glands and then decreases during feeding. In synganglia, a significant transcript increase was detected in replete ticks. In salivary gland acini, an antibody targeting the SIFa_R2 recognized basal epithelial cells, myoepithelial cells, and basal granular cells in close proximity to the SIFamide-releasing axon terminals. Immunoreactivity was also detected in specific neurons distributed throughout various I. ricinus synganglion locations. The current findings, alongside previous reports from our group, indicate that the neuropeptide SIFamide acts via two different receptors that regulate distinct or common cell types in the basal region of type II and III acini in I. ricinus salivary glands. Our study investigates the peptidergic regulation of the I. ricinus salivary gland in detail, emphasizing the complexity of this system.

• Klíčová slova
• SIFamide, SIFamide receptors, Salivary gland acini, Synganglion, Ticks,
• MeSH
• klíště * genetika   metabolismus   MeSH
• neurony metabolismus   MeSH
• neuropeptidy * genetika   metabolismus   MeSH
• slinné žlázy metabolismus   MeSH
• sliny MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• neuropeptidy * MeSH

The extensive annual loss of honey bees (Apis mellifera L.) represents a global problem affecting agriculture and biodiversity. The parasitic mite Varroa destructor, associated with viral co-infections, plays a key role in this loss. Despite years of intensive research, the complex mechanisms of Varroa - honey bee interaction are still not fully defined. Therefore, this study employed a unique combination of transcriptomic, proteomic, metabolomic, and functional analyses to reveal new details about the effect of Varroa mites and naturally associated factors, including viruses, on honey bees. We focused on the differences between Varroa parasitised and unparasitised ten-day-old worker bees collected before overwintering from the same set of colonies reared without anti-mite treatment. Supplementary comparison to honey bees collected from colonies with standard anti-Varroa treatment can provide further insights into the effect of a pyrethroid flumethrin. Analysis of the honey bees exposed to mite parasitisation revealed alterations in the transcriptome and proteome related to immunity, oxidative stress, olfactory recognition, metabolism of sphingolipids, and RNA regulatory mechanisms. The immune response and sphingolipid metabolism were strongly activated, whereas olfactory recognition and oxidative stress pathways were inhibited in Varroa parasitised honey bees compared to unparasitised ones. Moreover, metabolomic analysis confirmed the depletion of nutrients and energy stores, resulting in a generally disrupted metabolism in the parasitised workers. The combined omics-based analysis conducted on strictly parasitised bees revealed the key molecular components and mechanisms underlying the detrimental effects of Varroa sp. and its associated pathogens. This study provides the theoretical basis and interlinked datasets for further research on honey bee response to biological threats and the development of efficient control strategies against Varroa mites.

• Klíčová slova
• Honey bee, Infestation, Metabolomic, Proteomic, Transcriptomic, Varroa destructor,
• MeSH
• čich MeSH
• proteomika MeSH
• stanovení celkové genové exprese MeSH
• transkriptom MeSH
• Varroidae * fyziologie   MeSH
• včely genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Diapause is one of the major strategies for insects to prepare for and survive harsh seasons. In females, the absence of juvenile hormone (JH) is a hallmark of adult reproductive diapause, a developmental arrest, which is much less characterized in males. Here we show that juvenile hormone III skipped bisepoxide (JHSB3) titers in hemolymph remarkably differ between reproductive males and females of the linden bug Pyrrhocoris apterus, whereas no JH was detected in diapausing adults of both sexes. Like in females, ectopic application of JH mimic effectively terminated male diapause through the canonical JH receptor components, Methoprene-tolerant and Taiman. In contrast to females, long photoperiod induced reproduction even in males with silenced JH reception or in males with removed corpus allatum (CA), the JH-producing gland. JHSB3 was detected in the accessory glands (MAG) of reproductive males, unexpectedly, even in males without CA. If there is a source of JHSB3 outside CA or a long-term storage of JHSB3 in MAGs remains to be elucidated. These sex-related idiosyncrasies are further manifested in different dynamics of diapause termination in P. apterus by low temperature. We would like to propose that this sexual dimorphism of diapause regulation might be explained by the different reproductive costs for each sex.

• Klíčová slova
• Allatectomy, Corpus allatum, Juvenile hormone, Mating, Methoprene-tolerant, Photoperiod, Reproductive diapause, Seasonality, Taiman,
• MeSH
• corpora allata MeSH
• diapauza hmyzu * MeSH
• diapauza * MeSH
• Heteroptera * fyziologie   MeSH
• juvenilní hormony MeSH
• methopren MeSH
• pohlavní dimorfismus MeSH
• rozmnožování MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• juvenilní hormony MeSH
• methopren MeSH

Eurasian spruce bark beetle, Ips typographus, is a destructive pest in spruce forests. The ability of I. typographus to colonise host trees depends on its massive aggregation behaviour mediated by aggregation pheromones, consisting of 2-methyl-3-buten-2-ol and cis-verbenol. Other biologically active compounds such as ipsdienol and verbenone have also been detected in the beetle. Biosynthesis of 2-methyl-3-buten-2-ol and ipsdienol de novo from mevalonate and that of cis-verbenol from α-pinene sequestrated from the host have been reported in preliminary studies. However, knowledge on the molecular mechanisms underlying pheromone biosynthesis in this pest is currently limited. In this study, we performed metabolomic and differential gene expression (DGE) analysis for the pheromone-producing life stages of I. typographus. The highest amounts of 2-methyl-3-buten-2-ol (238 ng/gut) and cis-verbenol (23 ng/gut) were found in the fed male gut (colonisation stage) and the immature male gut (early stage), respectively. We also determined the amount of verbenyl oleate (the possible storage form of cis-verbenol), a monoterpenyl fatty acid ester, to be approximately 1604 ng/mg in the immature stage in the beetle body. DGE analysis revealed possible candidate genes involved in the biosynthesis of the quantified pheromones and related compounds. A novel hemiterpene-synthesising candidate isoprenyl-di-phosphate synthase Ityp09271 gene proposed for 2-methyl-3-buten-2-ol synthesis was found to be highly expressed only in the fed male beetle gut. Putative cytochrome P450 genes involved in cis/trans-verbenol synthesis and an esterase gene Ityp11977, which could regulate verbenyl oleate synthesis, were identified in the immature male gut. Our findings from the molecular analysis of pheromone-producing gene families are the first such results reported for I. typographus. With further characterisation of the identified genes, we can develop novel strategies to disrupt the aggregation behaviour of I. typographus and thereby prevent vegetation loss.

• Klíčová slova
• Bark beetle, Gut tissue, Omics, Pheromone biosynthesis, Spruce, de novo,
• MeSH
• bicyklické monoterpeny chemie   MeSH
• esterasy genetika   MeSH
• feromony * biosyntéza   chemie   genetika   MeSH
• gastrointestinální trakt metabolismus   MeSH
• hmyzí geny MeSH
• kontrola škůdců MeSH
• lesy MeSH
• metabolomika MeSH
• nosatcovití * genetika   metabolismus   fyziologie   MeSH
• sekundární metabolismus genetika   MeSH
• smrk MeSH
• stanovení celkové genové exprese MeSH
• stravovací zvyklosti MeSH
• systém (enzymů) cytochromů P-450 genetika   MeSH
• transkriptom MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bicyklické monoterpeny MeSH
• esterasy MeSH
• feromony * MeSH
• systém (enzymů) cytochromů P-450 MeSH
• verbenol MeSH Prohlížeč
• verbenone MeSH Prohlížeč

Triatomine bugs are the blood feeding insect vectors transmitting Chagas disease to humans, a neglected tropical disease that affects over 8 million people, mainly in Latin America. The behavioral responses to host cues and bug signals in Rhodnius prolixus are state dependent, i.e., they vary as a function of post-ecdysis age. At the molecular level, these changes in behavior are probably due to a modulation of peripheral and central processes. In the present study, we report a significant modulation of the expression of a large set of sensory-related genes. Results were generated by means of antennal transcriptomes of 5th instar larvae along the first week (days 0, 2, 4, 6 and 8) after ecdysis sequenced using the Illumina HiSeq platform. Significant age-induced changes in transcript abundance were established for more than 6120 genes (54,7% of 11,186 genes expressed) in the antenna of R. prolixus. This was especially true between the first two days after ecdysis when more than 2500 genes had their expression significantly altered. In contrast, expression profiles were almost identical between day 6 and 8, with only a few genes showing significant modulation of their expression. A total of 86 sensory receptors, odorant carriers and odorant degrading enzymes were significantly modulated across age points and clustered into three distinct expression profiles. The set of sensory genes whose expression increased with age (profile 3) may include candidates underlying the increased responsiveness to host cues shown by R. prolixus during the first days after molting. For the first time, we describe the maturation process undergone at the molecular level by the peripheral sensory system of a hemimetabolous insect.

• Klíčová slova
• Age, Antennae, Rhodnius prolixus, Sensory genes, Transcriptome,
• MeSH
• Chagasova nemoc přenos   MeSH
• čich genetika   MeSH
• hmyz - vektory genetika   metabolismus   MeSH
• hmyzí geny * MeSH
• larva genetika   metabolismus   MeSH
• odoranty MeSH
• receptory pachové genetika   metabolismus   MeSH
• Rhodnius * genetika   metabolismus   MeSH
• smyslové orgány * embryologie   fyziologie   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom MeSH
• tykadla členovců * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• receptory pachové MeSH

We previously described the most highly expressed enzymes from the gut of the red flour beetle, Tribolium castaneum, as cathepsins L. In the present study, two C1 family-specific cysteine cathepsin L enzymes from the larval midgut were isolated and identified using MALDI-TOF MS analysis. The isolated T. castaneum cathepsins were characterized according to their specificity against chromogenic and fluorogenic peptide substrates, and the most efficiently hydrolyzed substrate was Z-FR-pNA with Arg in the P1 subsite. The specificity of insect digestive cathepsins was compared with human lysosomal cathepsin L, the well-studied peptidase of the C1 family cathepsins. T. castaneum digestive cathepsins efficiently hydrolyzed substrates with small and uncharged amino acid residues at P1 (Ala, Gln) more than human cathepsin L. In particular, these insect digestive cathepsins cleaved with higher efficiency the analogs of immunogenic peptides of gliadins, which contribute to autoimmune celiac disease in susceptible people, and thus insect enzymes may be useful in enzymatic treatments for this disease. A bioinformatic study supported by the proteomic analysis of the primary structures of the isolated cathepsins was used to compare tertiary models. The phylogenetic analysis of coleopteran and human cathepsins from the L subfamily indicated that insect digestive cathepsins grouped separately from lysosomal cathepsins.

• Klíčová slova
• Celiac disease, Cysteine cathepsins, Digestive cathepsin L, Digestive enzymes, Hydrolysis of gliadin peptides, Lysosomal cathepsin L, Tribolium castaneum,
• MeSH
• brouci MeSH
• celiakie farmakoterapie   MeSH
• fylogeneze MeSH
• hmyzí proteiny chemie   metabolismus   MeSH
• kathepsin L * chemie   metabolismus   MeSH
• kathepsiny chemie   metabolismus   MeSH
• larva metabolismus   MeSH
• lidé MeSH
• lyzozomy metabolismus   MeSH
• proteasy chemie   metabolismus   MeSH
• proteomika MeSH
• trávení fyziologie   MeSH
• trávicí systém metabolismus   MeSH
• Tribolium metabolismus   MeSH
• výpočetní biologie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hmyzí proteiny MeSH
• kathepsin L * MeSH
• kathepsiny MeSH
• proteasy MeSH