Current Research in Insect Science最新文献

{"title":"Spatial repellency and vapour toxicity of transfluthrin against the biting midges Culicoides nubeculosus and C. sonorensis (Ceratopogonidae)","authors":"Niels O. Verhulst,&nbsp;Jannis Ceril Cavegn,&nbsp;Alexander Mathis","doi":"10.1016/j.cris.2020.100002","DOIUrl":"10.1016/j.cris.2020.100002","url":null,"abstract":"<div><p>Biting midges (Diptera; Ceratopogonidae; <em>Culicoides</em> spp.) are biological vectors of disease agents, and they cause nuisance and insect bite hypersensitivity. Currently there are no effective means to control biting midges as screening is impractical and the application of insecticides or repellents is of limited efficacy. Spatial repellents have the advantage over contact repellents that they can create a vector-free environment. Studies have shown the efficacy of spatial repellents to protect humans against mosquitoes, also outdoors, but no data are available for biting midges. We tested the spatial repellency and toxicity (knockdown effect) of the volatile pyrethroid transfluthrin against the laboratory-reared biting midges <em>Culicoides nubeculosus</em> (Meigen) and <em>Culicoides sonorensis</em> (Wirth and Jones) and the mosquito <em>Aedes aegypti</em> (Linnaeus) in a high-throughput tube setup. Observations were made 15, 30 and 60 min. after application of the repellent. In addition to transfluthrin, the non-volatile pyrethroid permethrin and DEET, the gold standard of repellents, were included. Spatial repellency by transfluthrin was observed against both biting midge species and <em>Ae. aegypti</em>, already at the first observation after 15 min. and at much lower concentrations than DEET. Permethrin was spatially repellent only to <em>C. sonorensis</em> at the highest concentration tested (10 μg/cm²). Knockdown of biting midges and mosquitoes by transfluthrin, both by vapour or contact toxicity, was observed even at low concentrations. DEET had little to no effect on the knockdown of the insects, neither by direct contact nor vapour toxicity, while permethrin caused a high proportion of knockdown when direct contact was possible. In case these results can be confirmed in field experiments, spatial repellents could become a novel tool in integrated control programmes to reduce biting by Culicoides spp.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100002"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2020.100002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40424928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of neuropeptide precursors and differential expression of adipokinetic hormone/corazonin-related peptide, hugin and corazonin in the brain of malaria vector Nyssorhynchus albimanus during a Plasmodium berghei infection","authors":"Alejandro Alvarado-Delgado,&nbsp;Jesús Martínez-Barnetche,&nbsp;Juan Téllez-Sosa,&nbsp;Mario H. Rodríguez,&nbsp;Everardo Gutiérrez-Millán,&nbsp;Federico A. Zumaya-Estrada,&nbsp;Vianey Saldaña-Navor,&nbsp;María Carmen Rodríguez,&nbsp;Ángel Tello-López,&nbsp;Humberto Lanz-Mendoza","doi":"10.1016/j.cris.2021.100014","DOIUrl":"10.1016/j.cris.2021.100014","url":null,"abstract":"<div><p>Insect neuropeptides, play a central role in the control of many physiological processes. Based on an analysis of <em>Nyssorhynchus albimanus</em> brain transcriptome a neuropeptide precursor database of the mosquito was described. Also, we observed that adipokinetic hormone/corazonin-related peptide (ACP), hugin and corazonin encoding genes were differentially expressed during <em>Plasmodium</em> infection. Transcriptomic data from <em>Ny. albimanus</em> brain identified 29 pre-propeptides deduced from the sequences that allowed the prediction of at least 60 neuropeptides. The predicted peptides include isoforms of allatostatin C, orcokinin, corazonin, adipokinetic hormone (AKH), SIFamide, capa, hugin, pigment-dispersing factor, adipokinetic hormone/corazonin-related peptide (ACP), tachykinin-related peptide, trissin, neuropeptide F, diuretic hormone 31, bursicon, crustacean cardioactive peptide (CCAP), allatotropin, allatostatin A, ecdysis triggering hormone (ETH), diuretic hormone 44 (Dh44), insulin-like peptides (ILPs) and eclosion hormone (EH). The analysis of the genome of <em>An. albimanus</em> and the generated transcriptome, provided evidence for the identification of myosuppressin neuropeptide precursor. A quantitative analysis documented increased expression of precursors encoding ACP peptide, hugin and corazonin in the mosquito brain after <em>Plasmodium berghei</em> infection. This work represents an initial effort to characterize the neuropeptide precursors repertoire of <em>Ny. albimanus</em> and provides information for understanding neuroregulation of the mosquito response during <em>Plasmodium</em> infection.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100014"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2021.100014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40653136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dietary macronutrient balance and fungal infection as drivers of spermatophore quality in the mealworm beetle","authors":"Alicia Reyes-Ramírez,&nbsp;Maya Rocha-Ortega,&nbsp;Alex Córdoba-Aguilar","doi":"10.1016/j.cris.2021.100009","DOIUrl":"10.1016/j.cris.2021.100009","url":null,"abstract":"<div><p>Males of many insects deliver ejaculates with nutritious substances to females in the form of a spermatophore. Different factors can affect spermatophore quality. We manipulated males’ diet and health to determine the balance of macronutrients deposited in the spermatophores of <em>Tenebrio molitor</em> beetles. For diet, we varied the concentration of proteins and carbohydrates, while for health status we used a fungal infection. Males with different condition copulated with unmanipulated females, and spermatophores were extracted to measure the amount of proteins, lipids and carbohydrates. Diet and infection had an effect on the quality of the spermatophore. Diets with high protein and low carbohydrate contents produced spermatophores with higher protein, carbohydrate, and lipid contents. In contrast, diets with little protein and high in carbohydrates led to low quality spermatophores. Infected males produced spermatophores with the highest amount of all three macronutrients. In general, spermatophore content was carbohydrates&gt;proteins&gt;=lipids. The fact that sick males produced richer spermatophores can be explained as a terminal investment strategy. The large investment of carbohydrates may be related to the preparation of spermatozoa in males, and eggs in females.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100009"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2021.100009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40424929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potential mechanical transmission of Lumpy skin disease virus (LSDV) by the stable fly (Stomoxys calcitrans) through regurgitation and defecation","authors":"Anca I. Paslaru ,&nbsp;Niels O. Verhulst ,&nbsp;Lena M. Maurer ,&nbsp;Alexsandra Brendle ,&nbsp;Nicole Pauli ,&nbsp;Andrea Vögtlin ,&nbsp;Sandra Renzullo ,&nbsp;Yelena Ruedin ,&nbsp;Bernd Hoffmann ,&nbsp;Paul R. Torgerson ,&nbsp;Alexander Mathis ,&nbsp;Eva Veronesi","doi":"10.1016/j.cris.2020.100007","DOIUrl":"10.1016/j.cris.2020.100007","url":null,"abstract":"<div><p>Lumpy skin disease (LSD) is a viral disorder of cattle caused by the lumpy skin disease virus (LSDV) which can induce severe infections leading to high economic losses. Being of African origin, the first LSD outbreaks in Europe occurred in Greece and later in the Balkan region. Little is known about the mode of transmission, especially in relation to the potential role of arthropods vectors. The purpose of our study was to investigate the role of <em>Stomoxys calcitrans</em> in the transmission of LSDV and their presence at different farms in Switzerland. Laboratory-reared flies were exposed to LSDV spiked-blood and incubated under a realistic fluctuating temperature regime. Body parts, regurgitated blood, and faecal samples were analysed by qPCR for the presence of viral DNA and infectious virus at different time points post-feeding (p.f.). LSDV DNA was detected in heads, bodies, and regurgitated blood up to three days p.f. and up to two days p.f. in the faeces. Infectious virus was isolated from bodies and faeces up to two days and in the regurgitated blood up to 12 h p.f. There was no increase in viral load, consolidating the role of <em>S. calcitrans</em> as mechanical vectors for LSDV<em>. Stomoxys</em> flies were present at all eight farms investigated, including a farm located at 2128 m asl. The persistence of LSDV in <em>S. calcitrans</em> in combination with the long flight ranges of this abundant and widespread fly might have implications on LSD epidemiology and on implementing control measures during disease outbreaks.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100007"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2020.100007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40636723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aedes albopictus and Aedes flavopictus (Diptera: Culicidae) pre-imaginal abundance patterns are associated with different environmental factors along an altitudinal gradient","authors":"Luis Fernando Chaves ,&nbsp;Mariel D. Friberg","doi":"10.1016/j.cris.2020.100001","DOIUrl":"10.1016/j.cris.2020.100001","url":null,"abstract":"<div><p><em>Aedes (Stegomyia) albopictus</em> (Skuse) is a major global invasive mosquito species that, in Japan, co-occurs with <em>Aedes (Stegomyia) flavopictus</em> Yamada, a closely related species recently intercepted in Europe. Here, we present results of a detailed 25-month long study where we biweekly sampled pupae and fourth instar larvae of these two species from ovitraps set along Mt. Konpira, Nagasaki, Japan. This setting allowed us to ask whether these species had different responses to changes in environmental variables along the altitudinal gradient of an urban hill. We found that spatially <em>Ae. albopictus</em> abundance decreased, while <em>Ae. flavopictus</em> abundance increased, the further away from urban land. <em>Ae. flavopictus</em> also was more abundant than <em>Ae. albopictus</em> in locations with homogenous vegetation growth with a high mean Enhanced Vegetation Index (EVI), platykurtic EVI, and low SD in canopy cover, while <em>Ae. albopictus</em> was more abundant than <em>Ae. flavopictus</em> in areas with more variable (high SD) canopy cover. Moreover, <em>Ae. flavopictus</em> abundance negatively impacted the spatial abundance of <em>Ae. albopictus</em>. Temporally we found that <em>Ae. flavopictus</em> was more likely to be present in Mt. Konpira at lower temperatures than <em>Ae. albopictus</em>. Our results suggest that spatial and temporal abundance patterns of these two mosquito species are partially driven by their different response to environmental factors.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100001"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2020.100001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40653138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Capturing the transcription factor interactome in response to sub-lethal insecticide exposure","authors":"Victoria A Ingham ,&nbsp;Sara Elg ,&nbsp;Sanjay C Nagi ,&nbsp;Frank Dondelinger","doi":"10.1016/j.cris.2021.100018","DOIUrl":"10.1016/j.cris.2021.100018","url":null,"abstract":"<div><p>The increasing levels of pesticide resistance in agricultural pests and disease vectors represents a threat to both food security and global health. As insecticide resistance intensity strengthens and spreads, the likelihood of a pest encountering a sub-lethal dose of pesticide dramatically increases. Here, we apply dynamic Bayesian networks to a transcriptome time-course generated using sub-lethal pyrethroid exposure on a highly resistant <em>Anopheles coluzzii</em> population. The model accounts for circadian rhythm and ageing effects allowing high confidence identification of transcription factors with key roles in pesticide response. The associations generated by this model show high concordance with lab-based validation and identifies 44 transcription factors putatively regulating insecticide-responsive transcripts. We identify six key regulators, with each displaying differing enrichment terms, demonstrating the complexity of pesticide response. The considerable overlap of resistance mechanisms in agricultural pests and disease vectors strongly suggests that these findings are relevant in a wide variety of pest species.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100018"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2021.100018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39780168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shrubs as magnets for pollination: A test of facilitation and reciprocity in a shrub-annual facilitation system","authors":"Ally Ruttan,&nbsp;Christopher J. Lortie,&nbsp;Stephanie M. Haas","doi":"10.1016/j.cris.2021.100008","DOIUrl":"10.1016/j.cris.2021.100008","url":null,"abstract":"<div><p>The magnet species hypothesis proposes that flowering plants that are attractive to pollinators can increase the relative pollination rates of neighbouring plants by acting as ‘magnets.’ Here, we test the hypothesis that insect-pollinated shrub species <em>Larrea tridentata</em> and wind-pollinated shrub species <em>Ambrosia dumosa</em> act as magnets for the pollinator visitation of understory annual plant species in an arid ecosystem. As an extension to the magnet species hypothesis, we propose the double magnet species hypothesis in which we further test for reciprocity by the floral island created in the understory of the benefactor shrubs as an additional pollinator magnet for the shrub itself. We used an annual plant placed near each shrub and the open to measure the effect of shrubs on annuals. The double magnet species hypothesis was tested using L. <em>tridentata</em> with and without surrounding annuals. We measured pollinator visitation and visit duration using video and <em>in-situ</em> observation techniques to test whether shrubs increase pollinator visitation to understory annual plants, if insect-pollinated shrubs act as better pollinator magnets than wind-pollinated shrubs (to determine the effects of the floral resource itself), and whether shrubs with annuals in their understory have higher pollinator visitation rates relative to shrubs without annuals. We found that insect-pollinated shrubs increased the visitation rate and duration of visits by pollinators to their understory plants and that wind-pollinated shrubs decreased the duration of visits of some insect visitors, but these relationships varied between years. While the presence of annuals did not change the visitation rate of all possible pollinators to L. <em>tridentata</em> flowers, they did decrease the visitation duration of specifically bees, indicating a negative reciprocal effect of the understory on pollination. Thus, the concentrated floral resources of flowers on insect-pollinated shrubs can act as a magnet that attract pollinators but that in turn provide a cost to pollination of the shrub. However, while wind-pollinated shrubs may provide other benefits, they may provide a cost to the pollination of their understory. These findings support the magnet species hypothesis as an additional mechanism of facilitation by insect-pollinated shrubs to other plant species within arid ecosystems.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100008"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2021.100008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40653132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regional and seasonal activity predictions for fall armyworm in Australia","authors":"James L. Maino ,&nbsp;Rafael Schouten ,&nbsp;Kathy Overton ,&nbsp;Roger Day ,&nbsp;Sunday Ekesi ,&nbsp;Bosibori Bett ,&nbsp;Madeleine Barton ,&nbsp;Peter C. Gregg ,&nbsp;Paul A. Umina ,&nbsp;Olivia L. Reynolds","doi":"10.1016/j.cris.2021.100010","DOIUrl":"10.1016/j.cris.2021.100010","url":null,"abstract":"<div><p>Since 2016, the fall armyworm (FAW), <em>Spodoptera frugiperda</em>, has undergone a significant range expansion from its native range in the Americas, to continental Africa, Asia, and in February 2020, mainland Australia. The large dispersal potential of FAW adults, wide host range of immature feeding stages, and unique environmental conditions in its invasive range creates large uncertainties in the expected impact on Australian plant production industries. Here, using a spatial model of population growth and spread potential informed by existing biological and climatic data, we simulate seasonal population activity potential of FAW, with a focus on Australia's grain production regions. Our results show that, in Australia, the large spread potential of FAW will allow it to exploit temporarily favourable conditions for population growth across highly variable climatic conditions. It is estimated that FAW populations would be present in a wide range of grain growing regions at certain times of year, but importantly, the expected seasonal activity will vary markedly between regions and years depending on climatic conditions. The window of activity for FAW will be longer for growing regions further north, with some regions possessing conditions conducive to year-round population survival. Seasonal migrations from this permanent range into southern regions, where large areas of annual grain crops are grown annually, are predicted to commence from October, i.e. spring, with populations subsequently building up into summer. The early stage of the FAW incursion into Australia means our predictions of seasonal activity potential will need to be refined as more Australian-specific information is accumulated. This study has contributed to our early understanding of FAW movement and population dynamics in Australia. Importantly, the models established here provide a useful framework that will be available to other countries should FAW invade in the future. To increase the robustness of our model, field sampling to identify conditions under which population growth occurs, and the location of source populations for migration events is required. This will enable accurate forecasting and early warning to farmers, which should improve pest monitoring and control programs of FAW.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100010"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2021.100010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40653133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The critical thermal maximum of diving beetles (Coleoptera: Dytiscidae): a comparison of subterranean and surface-dwelling species","authors":"Karl K. Jones ,&nbsp;William F. Humphreys ,&nbsp;Mattia Saccò ,&nbsp;Terry Bertozzi ,&nbsp;Andy D. Austin ,&nbsp;Steven J.B. Cooper","doi":"10.1016/j.cris.2021.100019","DOIUrl":"10.1016/j.cris.2021.100019","url":null,"abstract":"<div><p>Thermal tolerance limits in animals are often thought to be related to temperature and thermal variation in their environment. Recently, there has been a focus on studying upper thermal limits due to the likelihood for climate change to expose more animals to higher temperatures and potentially extinction. Organisms living in underground environments experience reduced temperatures and thermal variation in comparison to species living in surface habitats, but how these impact their thermal tolerance limits are unclear. In this study, we compare the thermal critical maximum (CTmax) of two subterranean diving beetles (Dytiscidae) to that of three related surface-dwelling species. Our results show that subterranean species have a lower CTmax (38.3-39.0°C) than surface species (42.0-44.5°C). The CTmax of subterranean species is ∼10°C higher than the highest temperature recorded within the aquifer. Groundwater temperature varied between 18.4°C and 28.8°C, and changes with time, depth and distance across the aquifer. Seasonal temperature fluctuations were 0.5°C at a single point, with the maximum heating rate being ∼1000x lower (0.008°C/hour) than that recorded in surface habitats (7.98°C/hour). For surface species, CTmax was 7-10°C higher than the maximum temperature in their habitats, with daily fluctuations from ∼1°C to 16°C and extremes of 6.9°C and 34.9°C. These findings suggest that subterranean dytiscid beetles are unlikely to reach their CTmax with a predicted warming of 1.3-5.1°C in the region by 2090. However, the impacts of long-term elevated temperatures on fitness, different life stages and other species in the beetle's trophic food web are unknown.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100019"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/c5/82/main.PMC9387432.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40653135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhodnius prolixus uses the peptidoglycan recognition receptor rpPGRP-LC/LA to detect Gram-negative bacteria and activate the IMD pathway","authors":"Nicolas Salcedo-Porras ,&nbsp;Shireen Noor ,&nbsp;Charley Cai ,&nbsp;Pedro L. Oliveira ,&nbsp;Carl Lowenberger","doi":"10.1016/j.cris.2020.100006","DOIUrl":"https://doi.org/10.1016/j.cris.2020.100006","url":null,"abstract":"<div><p>Insects rely on an innate immune system to recognize and eliminate pathogens. Key components of this system are highly conserved across all invertebrates. To detect pathogens, insects use Pattern recognition receptors (PRRs) that bind to signature motifs on the surface of pathogens called Pathogen Associated Molecular Patterns (PAMPs). In general, insects use peptidoglycan recognition proteins (PGRPs) in the Immune Deficiency (IMD) pathway to detect Gram-negative bacteria, and other PGRPs and Gram-negative binding proteins (GNBPs) in the Toll pathway to detect Gram-positive bacteria and fungi, although there is crosstalk and cooperation between these and other pathways. Once pathogens are recognized, these pathways activate the production of potent antimicrobial peptides (AMPs). Most PRRs in insects have been reported from genome sequencing initiatives but few have been characterized functionally. The initial studies on insect PRRs were done using established dipteran model organisms such as <em>Drosophila melanogaster</em>, but there are differences in the numbers and functional role of PRRs in different insects. Here we describe the genomic repertoire of PGRPs in <em>Rhodnius prolixus</em>, a hemimetabolous hemipteran vector of the parasite <em>Trypanosoma cruzi</em> that causes Chagas disease in humans. Using a <em>de novo</em> transcriptome from the fat body of immune activated insects, we found 5 genes encoding PGRPs. Phylogenetic analysis groups <em>R. prolixus</em> PGRPs with <em>D. melanogaster</em> PGRP-LA, which is involved in the IMD pathway in the respiratory tract. A single <em>R. prolixus</em> PGRP gene encodes isoforms that contain an intracellular region or motif (cryptic RIP Homotypic Interaction Motif-cRHIM) that is involved in the IMD signaling pathway in <em>D. melanogaster</em>. We characterized and silenced this gene using RNAi and show that the PGRPs that contain cRHIMs are involved in the recognition of Gram-negative bacteria, and activation of the IMD pathway in the fat body of <em>R. prolixus</em>, similar to the PGRP-LC of <em>D. melanogaster</em>. This is the first functional characterization of a PGRP containing a cRHIM motif that serves to activate the IMD pathway in a hemimetabolous insect.</p></div>","PeriodicalId":34629,"journal":{"name":"Current Research in Insect Science","volume":"1 ","pages":"Article 100006"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.cris.2020.100006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91729677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}