ijms-logo

Journal Browser

Journal Browser

Molecular Ecology, Physiology and Biochemistry of Insects, 4th Edition

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Biochemistry".

Deadline for manuscript submissions: closed (30 August 2024) | Viewed by 22838

Special Issue Editor

Special Issue Information

Dear Colleagues,

Of all the zoological classes, insects are the most numerous in species and the most varied in structure. Estimates of the number of species vary from 1 to 10 million, and 1018 individuals are estimated to be alive at any given moment. Insects are relatively ancient and have survived more or less unchanged in their basic winged form for the last 300 million years. Due to their adaptability in behavior, physiology, and biochemistry to changing environmental conditions, insects have successfully colonized habitats stretching from arid deserts to the Arctic and Antarctic and from freshwater brooks to hot springs and saline marine environments.

Knowledge of the physiology and biochemistry of insects developed extensively at the end of the 20th century. The reasons for this increased interest in insect physiology and biochemistry were that insects can be useful as model systems for experimental studies of principles, but also as economic models. Mechanisms of environmental adaptation in growth and development, energy metabolism, or respiration to temperature, oxygen tension, food supply, or salt concentrations were the focus of interest. It was the time of “Physiological Ecology”.

About 30 years later, the omics era gives us the opportunity to gain deeper insight into the different aspects of insect physiology and environmental adaptation, for example, by silencing or overexpressing candidate genes of interest. A major challenge in current entomology is to integrate different levels of organization, from cellular mechanisms to functions in ecosystems. The rapid development of molecular techniques for studying the physiological functions of genes will revolutionize the entomology not only of so-called model organisms like Drosophila, but in general. When we understand how physiological processes are regulated and at what time, we will be able to manipulate them, thereby providing new attractive opportunities for practical applications, for example, in an ecologically friendly insect pest control.

We invite you to contribute original research articles and critical reviews on both basic and applied approaches in insect molecular biology. Articles on the molecular mechanisms of insect–plant interactions, and systems of insect communication in general, are also welcome.

Prof. Dr. Klaus H. Hoffmann
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. International Journal of Molecular Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. There is an Article Processing Charge (APC) for publication in this open access journal. For details about the APC please see here. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • insect development and reproduction
  • molecular endocrinology/neuropeptides
  • insect immunity
  • photoperiodism
  • cold hardiness
  • global climate change
  • insect aging
  • insect–plant interactions
  • molecular interactions of insects with microorganisms
  • chemical communication
  • biochemistry of insect venoms
  • insect genomics and proteomics
  • genetic engineering molecular
  • volution/population genetics
  • insect biotechnology

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (15 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

21 pages, 6447 KiB  
Article
Effect of Benzyl Alcohol on Main Defense System Components of Galleria mellonella (Lepidoptera)
by Michalina Kazek, Agata Kaczmarek, Anna K. Wrońska and Mieczysława I. Boguś
Int. J. Mol. Sci. 2024, 25(20), 11209; https://doi.org/10.3390/ijms252011209 - 18 Oct 2024
Viewed by 579
Abstract
Benzyl alcohol (E1519) is an aromatic alcohol used in the pharmaceutical and food industry. It is used to protect food products against microorganisms during storage, as a flavoring in the production of chocolate and confectionery products, as an important ingredient in fragrance, and [...] Read more.
Benzyl alcohol (E1519) is an aromatic alcohol used in the pharmaceutical and food industry. It is used to protect food products against microorganisms during storage, as a flavoring in the production of chocolate and confectionery products, as an important ingredient in fragrance, and as a preservative in medical products. However, little is known of its effect on insects. The main aim of this study was to determine the influence of benzyl alcohol on the defense systems of the wax moth Galleria mellonella, i.e., its cuticular lipid composition and critical elements of its immune system. A gas chromatography/mass spectrometry (GC/MS) analysis found benzyl alcohol treatment to elicit significant quantitative and qualitative differences in cuticular free fatty acid (FFA) profiles. Our findings indicate that benzyl alcohol treatment increased the levels of HSP70 and HSP90 and decreased those of HSF1, histamine, and cysteinyl leukotriene. Benzyl alcohol application also increased dismutase level in the hemolymph and lowered those of catalase and 8-OHdG. The treatment also had negative effects on G. mellonella hemocytes and a Sf9 cell line in vitro: 48-h treatment resulted in morphological changes, with the remaining cells being clearly spindle-shaped with numerous granules. The high insecticidal activity of compound and its lack of toxicity towards vertebrates suggest it could be an effective insecticide. Full article
Show Figures

Figure 1

23 pages, 4971 KiB  
Article
Satellitome Analysis of Adalia bipunctata (Coleoptera): Revealing Centromeric Turnover and Potential Chromosome Rearrangements in a Comparative Interspecific Study
by Pablo Mora, José M. Rico-Porras, Teresa Palomeque, Eugenia E. Montiel, Sebastián Pita, Diogo C. Cabral-de-Mello and Pedro Lorite
Int. J. Mol. Sci. 2024, 25(17), 9214; https://doi.org/10.3390/ijms25179214 - 25 Aug 2024
Viewed by 977
Abstract
Eukaryotic genomes exhibit a dynamic interplay between single-copy sequences and repetitive DNA elements, with satellite DNA (satDNA) representing a substantial portion, mainly situated at telomeric and centromeric chromosomal regions. We utilized Illumina next-generation sequencing data from Adalia bipunctata to investigate its satellitome. Cytogenetic [...] Read more.
Eukaryotic genomes exhibit a dynamic interplay between single-copy sequences and repetitive DNA elements, with satellite DNA (satDNA) representing a substantial portion, mainly situated at telomeric and centromeric chromosomal regions. We utilized Illumina next-generation sequencing data from Adalia bipunctata to investigate its satellitome. Cytogenetic mapping via fluorescence in situ hybridization was performed for the most abundant satDNA families. In silico localization of satDNAs was carried out using the CHRISMAPP (Chromosome In Silico Mapping) pipeline on the high-fidelity chromosome-level assembly already available for this species, enabling a meticulous characterization and localization of multiple satDNA families. Additionally, we analyzed the conservation of the satellitome at an interspecific scale. Specifically, we employed the CHRISMAPP pipeline to map the satDNAs of A. bipunctata onto the genome of Adalia decempunctata, which has also been sequenced and assembled at the chromosome level. This analysis, along with the creation of a synteny map between the two species, suggests a rapid turnover of centromeric satDNA between these species and the potential occurrence of chromosomal rearrangements, despite the considerable conservation of their satellitomes. Specific satDNA families in the sex chromosomes of both species suggest a role in sex chromosome differentiation. Our interspecific comparative study can provide a significant advance in the understanding of the repeat genome organization and evolution in beetles. Full article
Show Figures

Figure 1

14 pages, 2371 KiB  
Article
Transcription Factor CcFoxO Mediated the Transition from Summer Form to Winter Form in Cacopsylla chinensis
by Chuchu Wei and Songdou Zhang
Int. J. Mol. Sci. 2024, 25(15), 8545; https://doi.org/10.3390/ijms25158545 - 5 Aug 2024
Viewed by 819
Abstract
Amid global climate change featuring erratic temperature fluctuations, insects adapt via seasonal polyphenism, essential for population sustainability and reproductive success. Cacopsylla chinensis, influenced by environment variations, displays a distinct summer form and winter form distinguished by significant morphological variations. Previous studies have [...] Read more.
Amid global climate change featuring erratic temperature fluctuations, insects adapt via seasonal polyphenism, essential for population sustainability and reproductive success. Cacopsylla chinensis, influenced by environment variations, displays a distinct summer form and winter form distinguished by significant morphological variations. Previous studies have highlighted the role of temperature receptor CcTPRM in orchestrating the transition in response to 10 °C temperature. Nevertheless, the contribution of the transcription factor FoxO in this process has remained ambiguous. Here, we aimed to explore the correlation between C. chinensis FoxO (CcFoxO) and cold stress responses, while identifying potential energetic substances for monitoring physiological shifts during this transition from summer to winter form under cold stress by using RNAi. Initially, CcFoxO emerges as responsive to low temperatures (10 °C) and is regulated by CcTRPM. Subsequent investigations reveal that CcFoxO facilitates the accumulation of triglycerides and glycogen, thereby influencing the transition from summer form to winter form by affecting cuticle pigment content, cuticle chitin levels, and cuticle thickness. Thus, the knockdown of CcFoxO led to high mortality and failed transition. Overall, our findings demonstrate that CcFoxO governs seasonal polyphenism by regulating energy storage. These insights not only enhance our comprehension of FoxO functionality but also offer avenues for environmentally friendly management strategies for C. chinensis. Full article
Show Figures

Figure 1

29 pages, 3798 KiB  
Article
Challenges of Robust RNAi-Mediated Gene Silencing in Aedes Mosquitoes
by Lucas Henrique Figueiredo Prates, Jakob Fiebig, Henrik Schlosser, Eleni Liapi, Tanja Rehling, Célia Lutrat, Jeremy Bouyer, Qiang Sun, Han Wen, Zhiyong Xi, Marc F. Schetelig and Irina Häcker
Int. J. Mol. Sci. 2024, 25(10), 5218; https://doi.org/10.3390/ijms25105218 - 10 May 2024
Cited by 1 | Viewed by 1751
Abstract
In this study, we report the complexities and challenges associated with achieving robust RNA interference (RNAi)-mediated gene knockdown in the mosquitoes Aedes aegypti and Aedes albopictus, a pivotal approach for genetic analysis and vector control. Despite RNAi’s potential for species-specific gene targeting, our [...] Read more.
In this study, we report the complexities and challenges associated with achieving robust RNA interference (RNAi)-mediated gene knockdown in the mosquitoes Aedes aegypti and Aedes albopictus, a pivotal approach for genetic analysis and vector control. Despite RNAi’s potential for species-specific gene targeting, our independent efforts to establish oral delivery of RNAi for identifying genes critical for mosquito development and fitness encountered significant challenges, failing to reproduce previously reported potent RNAi effects. We independently evaluated a range of RNAi-inducing molecules (siRNAs, shRNAs, and dsRNAs) and administration methods (oral delivery, immersion, and microinjection) in three different laboratories. We also tested various mosquito strains and utilized microorganisms for RNA delivery. Our results reveal a pronounced inconsistency in RNAi efficacy, characterized by minimal effects on larval survival and gene expression levels in most instances despite strong published effects for the tested targets. One or multiple factors, including RNase activity in the gut, the cellular internalization and processing of RNA molecules, and the systemic dissemination of the RNAi signal, could be involved in this variability, all of which are barely understood in mosquitoes. The challenges identified in this study highlight the necessity for additional research into the underlying mechanisms of mosquito RNAi to develop more robust RNAi-based methodologies. Our findings emphasize the intricacies of RNAi application in mosquitoes, which present a substantial barrier to its utilization in genetic control strategies. Full article
Show Figures

Figure 1

28 pages, 4222 KiB  
Article
Immune Gene Repertoire of Soft Scale Insects (Hemiptera: Coccidae)
by Andrea Becchimanzi, Rosario Nicoletti, Ilaria Di Lelio and Elia Russo
Int. J. Mol. Sci. 2024, 25(9), 4922; https://doi.org/10.3390/ijms25094922 - 30 Apr 2024
Viewed by 1196
Abstract
Insects possess an effective immune system, which has been extensively characterized in several model species, revealing a plethora of conserved genes involved in recognition, signaling, and responses to pathogens and parasites. However, some taxonomic groups, characterized by peculiar trophic niches, such as plant-sap [...] Read more.
Insects possess an effective immune system, which has been extensively characterized in several model species, revealing a plethora of conserved genes involved in recognition, signaling, and responses to pathogens and parasites. However, some taxonomic groups, characterized by peculiar trophic niches, such as plant-sap feeders, which are often important pests of crops and forestry ecosystems, have been largely overlooked regarding their immune gene repertoire. Here we annotated the immune genes of soft scale insects (Hemiptera: Coccidae) for which omics data are publicly available. By using immune genes of aphids and Drosophila to query the genome of Ericerus pela, as well as the transcriptomes of Ceroplastes cirripediformis and Coccus sp., we highlight the lack of peptidoglycan recognition proteins, galectins, thaumatins, and antimicrobial peptides in Coccidae. This work contributes to expanding our knowledge about the evolutionary trajectories of immune genes and offers a list of promising candidates for developing new control strategies based on the suppression of pests’ immunity through RNAi technologies. Full article
Show Figures

Figure 1

18 pages, 3232 KiB  
Article
Physiological Measurements and Transcriptomics Reveal the Fitness Costs of Monochamus saltuarius to Bursaphelenchus xylophilus
by Jiaxing Li, Ningning Fu, Sixun Ge, Lili Ren and Youqing Luo
Int. J. Mol. Sci. 2024, 25(9), 4906; https://doi.org/10.3390/ijms25094906 - 30 Apr 2024
Cited by 1 | Viewed by 895
Abstract
The pine wood nematode (PWN) uses several Monochamus species as vehicles, through a temporary hitchhiking process known as phoresy, enabling it to access new host plant resources. Monochamus saltuarius acts as a new and major vector of the PWN in Northeastern China, showing [...] Read more.
The pine wood nematode (PWN) uses several Monochamus species as vehicles, through a temporary hitchhiking process known as phoresy, enabling it to access new host plant resources. Monochamus saltuarius acts as a new and major vector of the PWN in Northeastern China, showing lower PWN carrying capacity and a shorter transmission cycle compared to established vectors. The apparently altered symbiotic relationship offers an interesting area for researching the costs and adaptions involved in nematode–beetle, a specialized phoresy. We analyzed the response and fitness costs of M. saltuarius through physiological measurements and transcriptomics. The PWN exerted adverse repercussions on the growth and development of M. saltuarius. The PWN accelerated larval development into pupae, while beetle adults carrying the PWN exhibited an elevated abnormality rate and mortality, and reduced starvation resistance. During the pupal stage, the expression of growth-related genes, including ecdysone-inducible genes (E74EA), cuticle proteins, and chitin genes (CHTs), markedly increased. Meanwhile, the induced immune response, mainly by the IMD and Toll signaling pathways, could be a contributing factor to adult abnormality and mortality. Adult gonads and trachea exhibited enrichment in pathways related to fatty acid elongation, biosynthesis, and metabolism. FASN, ELOVL, and SCD possibly contributed to resistance against PWN. Our research indicated that phoretic interactions between vector beetles and PWN vary throughout the vector’s lifespan, particularly before and after entry into the trachea. This study highlighted the fitness costs of immunity and metabolism on the vector beetle, indicating the adaptation mechanisms and evolutionary trade-offs to PWN. Full article
Show Figures

Figure 1

15 pages, 3035 KiB  
Article
Antenna-Biased Odorant Receptor PstrOR17 Mediates Attraction of Phyllotreta striolata to (S)-Cis-Verbenol and (−)-Verbenone
by Zhanyi Xu, Peitong Chen, Ru Yan, Guoxing Chen, Jiali Qian, Guonian Zhu, Mengli Chen and Yirong Guo
Int. J. Mol. Sci. 2024, 25(8), 4362; https://doi.org/10.3390/ijms25084362 - 15 Apr 2024
Cited by 1 | Viewed by 1029
Abstract
Phyllotreta striolata, the striped flea beetle, is one of the most destructive pests in Brassicaceae plants worldwide. Given the drawbacks associated with long-term use of chemical insecticides, green strategies based on chemical ecology are an effective alternative for beetle control. However, the [...] Read more.
Phyllotreta striolata, the striped flea beetle, is one of the most destructive pests in Brassicaceae plants worldwide. Given the drawbacks associated with long-term use of chemical insecticides, green strategies based on chemical ecology are an effective alternative for beetle control. However, the lack of information on beetle ecology has hindered the development of effective biocontrol strategies. In this report, we identified two odorants, (S)-cis-verbenol and (−)-verbenone, which displayed significant attraction for P. striolata (p < 0.05), indicating their great potential for P. striolata management. Using the Drosophila “empty neuron” system, an antenna-biased odorant receptor, PstrOR17, was identified as responsible for the detection of (−)-verbenone and (S)-cis-verbenol. Furthermore, the interactions between PstrOR17 and (−)-verbenone or (S)-cis-verbenol were predicted via modeling and molecular docking. Finally, we used RNAi to confirm that PstrOR17 is essential for the detection of (−)-verbenone and (S)-cis-verbenol to elicit an attraction effect. Our results not only lay a foundation for the development of new and effective nonchemical insecticide strategies based on (S)-cis-verbenol and (−)-verbenone, but also provide new insight into the molecular basis of odorant recognition in P. striolata. Full article
Show Figures

Figure 1

11 pages, 2845 KiB  
Article
Microbial Community Changes in Silkworms Suspected of Septicemia and Identification of Serratia sp.
by Jong Woo Park, Seul Ki Park, Chan Young Jeong, Hyeok Gyu Kwon, Ji Hae Lee, Sang Kuk Kang, Seong-Wan Kim and Seong-Ryul Kim
Int. J. Mol. Sci. 2024, 25(7), 3957; https://doi.org/10.3390/ijms25073957 - 2 Apr 2024
Cited by 1 | Viewed by 1249
Abstract
Diseases that occur in silkworms include soft rot, hardening disease, digestive diseases, and sepsis. However, research on the causes of bacterial diseases occurring in silkworms and the resulting changes in the microbial community is lacking. Therefore, we examined the morphological characteristics of sepsis [...] Read more.
Diseases that occur in silkworms include soft rot, hardening disease, digestive diseases, and sepsis. However, research on the causes of bacterial diseases occurring in silkworms and the resulting changes in the microbial community is lacking. Therefore, we examined the morphological characteristics of sepsis and changes in the microbial community between silkworms that exhibit a unique odor and healthy silkworms; thus, we established a relationship between disease-causing microorganisms and sepsis. After producing a 16S rRNA amplicon library for samples showing sepsis, we obtained information on the microbial community present in silkworms using next-generation sequencing. Compared to that in healthy silkworms, in silkworms with sepsis, the abundance of the Firmicutes phylum was significantly reduced, while that of Proteobacteria was increased. Serratia sp. was dominant in silkworms with sepsis. After bacterial isolation, identification, and reinfection through the oral cavity, we confirmed this organism as the disease-causing agent; its mortality rate was 1.8 times higher than that caused by Serratia marcescens. In summary, we identified a new causative bacterium of silkworm sepsis through microbial community analysis and confirmed that the microbial community balance was disrupted by the aberrant proliferation of certain bacteria. Full article
Show Figures

Figure 1

14 pages, 2414 KiB  
Article
Roles of DNA Methylation in Color Alternation of Eastern Honey Bees (Apis cerana) Induced by the Royal Jelly of Western Honey Bees (Apis mellifera)
by Amal Abdelmawla, Xin Li, Wenkai Shi, Yunlin Zheng, Zhijiang Zeng and Xujiang He
Int. J. Mol. Sci. 2024, 25(6), 3368; https://doi.org/10.3390/ijms25063368 - 16 Mar 2024
Cited by 1 | Viewed by 1538
Abstract
Honey bees have a very interesting phenomenon where the larval diets of two different honey bee species are exchanged, resulting in altered phenotypes, namely, a honey bee nutritional crossbreed. This is a classical epigenetic process, but its underlying mechanisms remain unclear. This study [...] Read more.
Honey bees have a very interesting phenomenon where the larval diets of two different honey bee species are exchanged, resulting in altered phenotypes, namely, a honey bee nutritional crossbreed. This is a classical epigenetic process, but its underlying mechanisms remain unclear. This study aims to investigate the contribution of DNA methylation to the phenotypic alternation of a Apis mellifera–Apis cerana nutritional crossbreed. We used a full nutritional crossbreed technique to rear A. cerana queens by feeding their larvae with A. mellifera royal-jelly-based diets in an incubator. Subsequently, we compared genome-wide methylation sequencing, body color, GC ratio, and the DMRs between the nutritional crossbreed, A. cerana queens (NQs), and control, A. cerana queens (CQs). Our results showed that the NQ’s body color shifted to yellow compared to the black control queens. Genome methylation sequencing revealed that NQs had a much higher ratio of mCG than that of CQs. A total of 1020 DMGs were identified, of which 20 DMGs were enriched into key pathways for melanin synthesis, including tryptophan, tyrosine, dopamine, and phenylalanine KEGG pathways. Three key differentially methylated genes [OGDH, ALDH(NAD+) and ALDH7] showed a clear, altered DNA methylation in multiple CpG islands in NQs compared to CQs. Consequently, these findings revealed that DNA methylation participates in A. cerana–A. mellifera nutritional crossbreeding as an important epigenetic modification. This study serves as a model of cross-kingdom epigenetic mechanisms in insect body color induced by environmental factors. Full article
Show Figures

Figure 1

24 pages, 5281 KiB  
Article
Prolonged Heat Stress during Winter Diapause Alters the Expression of Stress-Response Genes in Ostrinia nubilalis (Hbn.)
by Iva Uzelac, Miloš Avramov, Teodora Knežić, Vanja Tatić, Snežana Gošić-Dondo and Željko D. Popović
Int. J. Mol. Sci. 2024, 25(6), 3100; https://doi.org/10.3390/ijms25063100 - 7 Mar 2024
Cited by 1 | Viewed by 1249
Abstract
During diapause, a state of temporarily arrested development, insects require low winter temperatures to suppress their metabolism, conserve energy stores and acquire cold hardiness. A warmer winter could, thus, reduce diapause incidence and duration in many species, prematurely deplete their energy reserves and [...] Read more.
During diapause, a state of temporarily arrested development, insects require low winter temperatures to suppress their metabolism, conserve energy stores and acquire cold hardiness. A warmer winter could, thus, reduce diapause incidence and duration in many species, prematurely deplete their energy reserves and compromise post-diapause fitness. In this study, we investigated the combined effects of thermal stress and the diapause program on the expression of selected genes involved in antioxidant defense and heat shock response in the European corn borer Ostrinia nubilalis. By using qRT-PCR, it has been shown that response to chronic heat stress is characterized by raised mRNA levels of grx and trx, two important genes of the antioxidant defense system, as well as of hsp70 and, somewhat, of hsp90, two major heat shock response proteins. On the other hand, the expression of hsc70, hsp20.4 and hsp20.1 was discontinuous in the latter part of diapause, or was strongly controlled by the diapause program and refractory to heat stress, as was the case for mtn and fer, genes encoding two metal storage proteins crucial for metal ion homeostasis. This is the first time that the effects of high winter temperatures have been assessed on cold-hardy diapausing larvae and pupae of this important corn pest. Full article
Show Figures

Graphical abstract

19 pages, 21492 KiB  
Article
Developmental and Nutritional Dynamics of Malpighian Tubule Autofluorescence in the Asian Tiger Mosquito Aedes albopictus
by Anna Cleta Croce, Anna Garbelli, Andrea Moyano, Sara Soldano, Carlos Tejeda-Guzmán, Fanis Missirlis and Francesca Scolari
Int. J. Mol. Sci. 2024, 25(1), 245; https://doi.org/10.3390/ijms25010245 - 23 Dec 2023
Viewed by 1432
Abstract
Malpighian tubules (MTs) are arthropod excretory organs crucial for the osmoregulation, detoxification and excretion of xenobiotics and metabolic wastes, which include tryptophan degradation products along the kynurenine (KYN) pathway. Specifically, the toxic intermediate 3-hydroxy kynurenine (3-HK) is metabolized through transamination to xanthurenic acid [...] Read more.
Malpighian tubules (MTs) are arthropod excretory organs crucial for the osmoregulation, detoxification and excretion of xenobiotics and metabolic wastes, which include tryptophan degradation products along the kynurenine (KYN) pathway. Specifically, the toxic intermediate 3-hydroxy kynurenine (3-HK) is metabolized through transamination to xanthurenic acid or in the synthesis of ommochrome pigments. Early investigations in Drosophila larval fat bodies revealed an intracellular autofluorescence (AF) that depended on tryptophan administration. Subsequent observations documented AF changes in the MTs of Drosophila eye-color mutants genetically affecting the conversion of tryptophan to KYN or 3-HK and the intracellular availability of zinc ions. In the present study, the AF properties of the MTs in the Asian tiger mosquito, Aedes albopictus, were characterized in different stages of the insect’s life cycle, tryptophan-administered larvae and blood-fed adult females. Confocal imaging and microspectroscopy showed AF changes in the distribution of intracellular, brilliant granules and in the emission spectral shape and amplitude between the proximal and distal segments of MTs across the different samples. The findings suggest AF can serve as a promising marker for investigating the functional status of MTs in response to metabolic alterations, contributing to the use of MTs as a potential research model in biomedicine. Full article
Show Figures

Figure 1

14 pages, 3496 KiB  
Article
Identification and Functional Analysis of an Epsilon Class Glutathione S-Transferase Gene Associated with α-Pinene Adaptation in Monochamus alternatus
by Mingyu Xue, Xiaohong Xia, Yadi Deng, Fei Teng, Shiyue Zhao, Hui Li, Dejun Hao and Wei-Yi Chen
Int. J. Mol. Sci. 2023, 24(24), 17376; https://doi.org/10.3390/ijms242417376 - 12 Dec 2023
Viewed by 1028
Abstract
Alpha-pinene is one of the main defensive components in conifers. Monochamus alternatus (Coleoptera: Cerambycidae), a wood borer feeding on Pinaceae plants, relies on its detoxifying enzymes to resist the defensive terpenoids. Here, we assayed the peroxide level and GST activity of M. alternatus [...] Read more.
Alpha-pinene is one of the main defensive components in conifers. Monochamus alternatus (Coleoptera: Cerambycidae), a wood borer feeding on Pinaceae plants, relies on its detoxifying enzymes to resist the defensive terpenoids. Here, we assayed the peroxide level and GST activity of M. alternatus larvae treated with different concentrations of α-pinene. Meanwhile, a gst gene (MaGSTe3) was isolated and analyzed. We determined its expression level and verified its function. The results showed that α-pinene treatment led to membrane lipid peroxidation and thus increased the GST activity. Expression of MaGSTe3 was significantly upregulated in guts following exposure to α-pinene, which has a similar pattern with the malonaldehyde level. In vitro expression and disk diffusion assay showed that the MaGSTe3 protein had high antioxidant capacity. However, RNAi treatment of MaGSTe3 did not reduce the hydrogen peroxide and malonaldehyde levels, while GST activity was significantly reduced. These results suggested MaGSTe3 takes part in α-pinene adaptation, but it does not play a great role in the resistance of M. alternatus larvae to α-pinene. Full article
Show Figures

Figure 1

16 pages, 8962 KiB  
Article
Untargeted Lipidomics Analysis Unravels the Different Metabolites in the Fat Body of Mated Bumblebee (Bombus terrestris) Queens
by Yueqin Guo, Fugang Liu, Yulong Guo, Yingping Qu, Zhengyi Zhang, Jun Yao, Jin Xu and Jilian Li
Int. J. Mol. Sci. 2023, 24(20), 15408; https://doi.org/10.3390/ijms242015408 - 21 Oct 2023
Viewed by 1384
Abstract
The fat body has important functions in energy, fertility, and immunity. In female insects, mating stimulates physiological, behavioral, and gene expression changes. However, it remains unclear whether the metabolites in the fat body are affected after the bumblebee (Bombus terrestris) queen [...] Read more.
The fat body has important functions in energy, fertility, and immunity. In female insects, mating stimulates physiological, behavioral, and gene expression changes. However, it remains unclear whether the metabolites in the fat body are affected after the bumblebee (Bombus terrestris) queen mates. Here, the ultrastructure and lipid metabolites in fat body of mated queens were compared with those of virgins. The fat body weight of mated bumblebee queens was significantly increased, and the adipocytes were filled with lipid droplets. Using LC-MS/MS-based untargeted lipidomics, 949 and 748 differential metabolites were identified in the fat body of virgin and mated bumblebee queens, respectively, in positive and negative ion modes. Most lipid metabolites were decreased, especially some biomembrane components. In order to explore the relationship between the structures of lipid droplets and metabolite accumulation, transmission electron microscopy and fluorescence microscopy were used to observe the fat body ultrastructure. The size/area of lipid droplets was larger, and the fusion of lipid droplets was increased in the mated queen’s fat body. These enlarged lipid droplets may store more energy and nutrients. The observed differences in lipid metabolites in the fat body of queens contribute to understanding the regulatory network of bumblebees post mating. Full article
Show Figures

Figure 1

Review

Jump to: Research

18 pages, 2489 KiB  
Review
Current Insights into Sublethal Effects of Pesticides on Insects
by Merle-Theresa Bartling, Annely Brandt, Henner Hollert and Andreas Vilcinskas
Int. J. Mol. Sci. 2024, 25(11), 6007; https://doi.org/10.3390/ijms25116007 - 30 May 2024
Cited by 5 | Viewed by 3095
Abstract
The effect of pesticides on insects is often discussed in terms of acute and chronic toxicity, but an important and often overlooked aspect is the impact of sublethal doses on insect physiology and behavior. Pesticides can influence various physiological parameters of insects, including [...] Read more.
The effect of pesticides on insects is often discussed in terms of acute and chronic toxicity, but an important and often overlooked aspect is the impact of sublethal doses on insect physiology and behavior. Pesticides can influence various physiological parameters of insects, including the innate immune system, development, and reproduction, through a combination of direct effects on specific exposed tissues and the modification of behaviors that contribute to health and reproductive success. Such behaviors include mobility, feeding, oviposition, navigation, and the ability to detect pheromones. Pesticides also have a profound effect on insect learning and memory. The precise effects depend on many different factors, including the insect species, age, sex, caste, physiological condition, as well as the type and concentration of the active ingredients and the exposure route. More studies are needed to assess the effects of different active ingredients (and combinations thereof) on a wider range of species to understand how sublethal doses of pesticides can contribute to insect decline. This review reflects our current knowledge about sublethal effects of pesticides on insects and advancements in the development of innovative methods to detect them. Full article
Show Figures

Figure 1

27 pages, 976 KiB  
Review
Notch Signaling in Insect Development: A Simple Pathway with Diverse Functions
by Yao Chen, Haomiao Li, Tian-Ci Yi, Jie Shen and Junzheng Zhang
Int. J. Mol. Sci. 2023, 24(18), 14028; https://doi.org/10.3390/ijms241814028 - 13 Sep 2023
Cited by 6 | Viewed by 2843
Abstract
Notch signaling is an evolutionarily conserved pathway which functions between adjacent cells to establish their distinct identities. Despite operating in a simple mechanism, Notch signaling plays remarkably diverse roles in development to regulate cell fate determination, organ growth and tissue patterning. While initially [...] Read more.
Notch signaling is an evolutionarily conserved pathway which functions between adjacent cells to establish their distinct identities. Despite operating in a simple mechanism, Notch signaling plays remarkably diverse roles in development to regulate cell fate determination, organ growth and tissue patterning. While initially discovered and characterized in the model insect Drosophila melanogaster, recent studies across various insect species have revealed the broad involvement of Notch signaling in shaping insect tissues. This review focuses on providing a comprehensive picture regarding the roles of the Notch pathway in insect development. The roles of Notch in the formation and patterning of the insect embryo, wing, leg, ovary and several specific structures, as well as in physiological responses, are summarized. These results are discussed within the developmental context, aiming to deepen our understanding of the diversified functions of the Notch signaling pathway in different insect species. Full article
Show Figures

Figure 1

Back to TopTop