Cuticle Protein Research Articles

Nuclear Receptor FTZ-F1 Controls Locust Molt by Regulating the Molting Process of Locusta migratoria.

Fushi-tarazu factor 1 (FTZ-F1) is a class of transcription factors belonging to the nuclear receptor superfamily and an important molting regulator in insects; however, its detailed function in the molting process of Locusta migratoria is still unclear. This study identified two FTZ-F1 transcripts (LmFTZ-F1-X1 and LmFTZ-F1-X2) in L. migratoria. The classical domains of FTZ-F1 were present in their protein sequences and distinguished based on their variable N-terminal domains. Reverse-transcription quantitative polymerase chain reaction analysis revealed that LmFTZ-F1-X1 and LmFTZ-F1-X2 were highly expressed in the integument. RNA interference (RNAi) was used to explore the function of LmFTZ-F1s in the molting of the third-instar nymph. Separate LmFTZ-F1-X1 or LmFTZ-F1-X2 silencing did not affect the normal development of third-instar nymphs; however, the simultaneous RNAi of LmFTZ-F1-X1 and LmFTZ-F1-X2 caused the nymphs to be trapped in the third instar stage and finally die. Furthermore, the hematoxylin-eosin and chitin staining of the cuticle showed that the new cuticles were thickened after silencing the LmFTZ-F1s compared to the controls. RNA-seq analysis showed that genes encoding four cuticle proteins, two chitin synthesis enzymes, and cytochrome P450 303a1 were differentially expressed between dsGFP- and dsLmFTZ-F1s-injected groups. Taken together, LmFTZ-F1-X1 and LmFTZ-F1-X2 are involved in the ecdysis of locusts, possibly by regulating the expression of genes involved in cuticle formation, chitin synthesis, and other key molting processes.

Spatio-temporal distribution and genetic background of elastic proteins inside the chitin/chitosan matrix of insects including their functional significance for locomotion

In insects, cuticle proteins interact with chitin and chitosan of the exoskeleton forming crystalline, amorphic or composite material structures. The biochemical and mechanical composition of the structure defines the cuticle's physical properties and thus how the insect cuticle behaves under mechanical stress. The tissue-specific ratio between chitin and chitosan and its pattern of deacetylation are recognized and interpreted by cuticle proteins depending on their local position in the body. Despite previous research, the assembly of the cuticle composites in time and space including its functional impact is widely unexplored. This review is devoted to the genetics underlying the temporal and spatial distribution of elastic proteins and the potential function of elastic proteins in insects with a focus on Resilin in the fruit fly Drosophila. The potential impact and function of localized patches of elastic proteins is discussed for movements in leg joints, locomotion and damage resistance of the cuticle. We conclude that an interdisciplinary research approach serves as an integral example for the molecular mechanisms of generation and interpretation of the chitin/chitosan matrix, not only in Drosophila but also in other arthropod species, and might help to synthesize artificial material composites.

Genome-wide identification of cuticle protein superfamily in Frankliniella occidentalis provide insight into the control of both insect vectors and plant virus.

The structural cuticle proteins (CPs) play important roles in the development and fitness of insects. However, knowledge about CP gene superfamily is limited in virus-transmitting insect vectors, although its importance on transmission of plant virus has been gradually emphasized. In this study, the genome-wide identification of CP superfamily was conducted in western flower thrips Frankliniella occidentalis that is the globally invasive pest and plant virus vector pest. The pest transmits notorious tomato spotted wilt virus (TSWV) around the world, causing large damage to a wide array of plants. One hundred and twenty-eightF. occidentalis CP genes (FoCPs) were annotated in this study and they were classified into 10 distinct families, including 68 CPRs, 16 CPAP1s, 6 CPAP3s, 2 CPCFCs, 10 Tweedles, 4 CPFs, 16 CPLCPs, and 6 CPGs. The comprehensive analysis was performed including phylogenetic relationship, gene location and gene expression profiles during different development stages of F. occidentalis. Transcriptome analysis revealed more than 30% FoCPs were upregulated at least 1.5-fold when F. occidentalis was infected by TSWV, indicating their potential involvement in TSWV interactions. Our study provided an overview of F. occidentalis CP superfamily. The study gave a better understand of CP's role in development and virus transmission, which provided clues for reducing viral damages through silencing CP genes in insect vectors.

Population-specific responses to developmental temperature in the arboviral vector Aedes albopictus: Implications for climate change.

The increase of environmental temperature due to current global warming is not only favouring the expansion of the distribution range of many insect species, but it is also changing their phenology. Insect phenology is tightly linked to developmental timing, which is regulated by environmental temperatures. However, the degree to which the effects of developmental temperatures extend across developmental stages and their inter-stage relationships have not been thoroughly quantified in mosquitoes. Here, we used the mosquito Aedes albopictus, which is an aggressive invasive species and an arboviral vector, to study how developmental temperature influences fitness across developmental stages, thermal traits, energy reserves, transcriptome and Wolbachia prevalence in laboratory-reared populations originally collected from either temperate or tropical regions. We show that hatchability, larval and pupal viability and developmental speed are strongly influenced by temperature, and these effects extend to wing length, body mass, longevity and content of water, protein and lipids in adults in a population-specific manner. On the contrary, neither adult thermal preference nor heat resistance significantly change with temperature. Wolbachia density was generally lower in adult mosquitoes reared at 18°C than at other tested temperatures, and transcriptome analysis showed enrichment for functions linked to stress responses (i.e. cuticle proteins and chitin, cytochrome p450 and heat shock proteins) in mosquitoes reared at both 18 and 32°C. Our data showed an overall reduced vector fitness performance when mosquitoes were reared at 32°C, and the absence of isomorphy in the relationship between developmental stages and temperature in the laboratory population deriving from larvae collected in northern Italy. Altogether, these results have important implications for reliable model projections of the invasion potentials of Ae. albopictus and its epidemiological impact.

Genome-Wide Exploration of Long Non-Coding RNAs of Helicoverpa armigera in Response to Pyrethroid Insecticide Resistance.

Genome-wide long non-coding RNAs (lncRNAs) in low, moderate, and high pyrethroid insecticide-resistant and -susceptible strains of Helicoverpa armigera were identified in this study. Using 45 illumina-based RNA-sequencing datasets, 8394 lncRNAs were identified. In addition, a sublethal dose of deltamethrin was administered to a Korean-resistant strain (Kor-T). The average length of lncRNAs was approximately 531 bp, and the expression ratio of lncRNAs was 28% of the total RNA. The identified lncRNAs were divided into six categories-intronic, intergenic, sense, antisense, cis-RNA, and trans-RNA-based on their location and mechanism of action. Intergenic and intronic lncRNA transcripts were the most abundant (38% and 33%, respectively). Further, 828 detoxification-related lncRNAs were selected using the Gene Ontology analysis. The cytochrome P450-related lncRNA expression levels were significantly higher in susceptible strains than in resistant strains. In contrast, cuticle protein-related lncRNA expression levels were significantly higher in all resistant strains than in susceptible strains. Our findings suggest that certain lncRNAs contribute to the downregulation of insecticide resistance-related P450 genes in susceptible strains, whereas other lncRNAs may be involved in the overexpression of cuticle protein genes, potentially affecting the pyrethroid resistance mechanism.

Transcriptomic profiling of different developmental stages reveals parasitic strategies of Wohlfahrtia magnifica, a myiasis-causing flesh fly

BackgroundWohlfahrtia magnifica is an obligatory parasite that causes myiasis in several warm-blooded vertebrates. Adult females deposit the first-stage larvae directly onto wounds or natural body orifices (e.g., genitalia) of the host, from where they quickly colonize the host tissue and feed on it for development. The infestation of W. magnifica can lead to health issues, welfare concerns, and substantial economic losses. To date, little is known about the molecular mechanisms of the W. magnifica-causing myiasis.ResultsIn this study, we collected parasitic-stage larvae of W. magnifica from wounds of naturally infested Bactrian camels, as well as pupae and adult flies reared in vitro from the wound-collected larvae, for investigating the gene expression profiles of the different developmental stages of W. magnifica, with a particular focus on examining gene families closely related to the parasitism of the wound-collected larvae. As key proteins related to the parasite-host interaction, 2049 excretory/secretory (ES) proteins were identified in W. magnifica through the integration of multiple bioinformatics approaches. Functional analysis indicates that these ES proteins are primarily involved in cuticle development, peptidase activity, immune response, and metabolic processes. The global investigation of gene expression at different developmental stages using pairwise comparisons and weighted correlation network analysis (WGCNA) showed that the upregulated genes during second-stage larvae were related to cuticle development, peptidase activity, and RNA transcription and translation; during third-stage larvae to peptidase inhibitor activity and nutrient reservoir activity; during pupae to cell and tissue morphogenesis and cell and tissue development; and during adult flies to signal perception, many of them involved in light perception, and adult behavior, e.g., feeding, mating, and locomotion. Specifically, the expression level analysis of the likely parasitism-related genes in parasitic wound-collected larvae revealed a significant upregulation of 88 peptidase genes (including 47 serine peptidase genes), 110 cuticle protein genes, and 21 heat shock protein (hsp) genes. Interestingly, the expression of 2 antimicrobial peptide (AMP) genes, including 1 defensin and 1 diptericin, was also upregulated in the parasitic larvae.ConclusionsWe identified ES proteins in W. magnifica and investigated their functional distribution. In addition, gene expression profiles at different developmental stages of W. magnifica were examined. Specifically, we focused on gene families closely related to parasitism of wound-collected larvae. These findings shed light on the molecular mechanisms underlying the life cycle of the myiasis-causing fly, especially during the parasitic larval stages, and provide guidance for the development of control measures against W. magnifica.

Chromosome-level genome of spider Pardosa pseudoannulata and cuticle protein genes in environmental stresses

Spiders are representative arthropods of adaptive radiation. The high-quality genomes have only been reported in several web weaver spider species, leaving the wandering spiders’ genomic information scarce. The pond wolf spider, Pardosa pseudoannulata, is a representative species in the retrolateral titial apophysis (RTA) clade. We present a chromosome-level P. pseusoannulata genome assembly of 2.42 Gb in size with a scaffold N50 of 169.99 Mb. Hi-C scaffolding assigns 94.83% of the bases to 15 pseudo-chromosomes. The repeats account for 52.79% of the assembly. The assembly includes 96.2% of the complete arthropod universal single-copy orthologs. Gene annotation predicted 24,530 protein-coding genes with a BUSCO score of 95.8% complete. We identified duplicate clusters of Hox genes and an expanded cuticle protein gene family with 243 genes. The expression patterns of CPR genes change in response to environmental stresses such as coldness and insecticide exposure. The high-quality P. pseudoannulata genome provides valuable information for functional and comparative studies in spiders.

Insights into the differences related to the resistance mechanisms to the highly toxic fruit Hippomane mancinella (Malpighiales: Euphorbiaceae) between the larvae of the sister species Anastrepha acris and Anastrepha ludens (Diptera: Tephritidae) through comparative transcriptomics.

The Manchineel, Hippomane mancinella ("Death Apple Tree") is one of the most toxic fruits worldwide and nevertheless is the host plant of the monophagous fruit fly species Anastrepha acris (Diptera: Tephritidae). Here we aimed at elucidating the detoxification mechanisms in larvae of A. acris reared on a diet enriched with the toxic fruit (6% lyophilizate) through comparative transcriptomics. We compared the performance of A. acris larvae with that of the sister species A. ludens, a highly polyphagous pest species that is unable to infest H. mancinella in nature. The transcriptional alterations in A. ludens were significantly greater than in A. acris. We mainly found two resistance mechanisms in both species: structural, activating cuticle protein biosynthesis (chitin-binding proteins likely reducing permeability to toxic compounds in the intestine), and metabolic, triggering biosynthesis of serine proteases and xenobiotic metabolism activation by glutathione-S-transferases and cytochrome P450 oxidoreductase. Some cuticle proteins and serine proteases were not orthologous between both species, suggesting that in A. acris, a structural resistance mechanism has been selected allowing specialization to the highly toxic host plant. Our results represent a nice example of how two phylogenetically close species diverged over recent evolutionary time related to resistance mechanisms to plant secondary metabolites.

TMT proteomics establishes correlations between solar drying and quality modifications in Penaeus vannamei

This study investigated proteomic changes in Penaeus vannamei in half-dried and dried shrimp using tandem mass-tag technology. After performing the drying treatment, the tandem mass-tag results revealed 1,162,306 spectra, 2997 quantifiable proteins, and 72 differentially expressed proteins (DEPs) compared with that in the untreated group. A total of 29 DEPs were found in the half-dried shrimp, while 49 DEPs were found in the dried shrimp. Bioinformatic analyses based on Gene Ontology term enrichment, Kyoto Encyclopedia of Genes and Genomes pathway enrichment, and protein–protein interactions showed that the DEPs were primarily involved in protein structure and fat metabolism. A correlation analysis between the DEPs and quality indicators showed that 45 DEPs were significantly associated with shrimp quality traits, with certain proteins potentially representing markers of color and texture. Of these, arthrodial cuticle protein AMP16.3 might be a protein marker for color, while heat shock protein 21, WH2 domain-containing protein, and myosin heavy chain 1 might be markers of shrimp muscle textural properties. These results provide a systematic understanding of the quality difference between half-dried and dried P. vannamei from the perspective of proteomics and have potential scientific significance and practical value for improving the quality of dried products.

Evolutionary genomics of three agricultural pest moths reveals rapid evolution of host adaptation and immune-related genes.

Understanding the genotype of pest species provides an important baseline for designing integrated pest management (IPM) strategies. Recently developed long-read sequence technologies make it possible to compare genomic features of nonmodel pest species to disclose the evolutionary path underlying the pest species profiles. Here we sequenced and assembled genomes for 3 agricultural pest gelechiid moths: Phthorimaea absoluta (tomato leafminer), Keiferia lycopersicella (tomato pinworm), and Scrobipalpa atriplicella (goosefoot groundling moth). We also compared genomes of tomato leafminer and tomato pinworm with published genomes of Phthorimaea operculella and Pectinophora gossypiella to investigate the gene family evolution related to the pest species profiles. We found that the 3 solanaceous feeding species, P. absoluta, K. lycopersicella, and P. operculella, are clustered together. Gene family evolution analyses with the 4 species show clear gene family expansions on host plant-associated genes for the 3 solanaceous feeding species. These genes are involved in host compound sensing (e.g., gustatory receptors), detoxification (e.g., ABC transporter C family, cytochrome P450, glucose-methanol-choline oxidoreductase, insect cuticle proteins, and UDP-glucuronosyl), and digestion (e.g., serine proteases and peptidase family S1). A gene ontology enrichment analysis of rapid evolving genes also suggests enriched functions in host sensing and immunity. Our results of family evolution analyses indicate that host plant adaptation and pathogen defense could be important drivers in species diversification among gelechiid moths.

Knockdown of Thitarodes host genes influences dimorphic transition of Ophiocordyceps sinensis in the host hemolymph.

The Chinese cordyceps, a unique parasitic complex of Thitarodes/Hepialus ghost moths and Ophiocordyceps sinensis fungus in the Tibetan Plateau, is a highly valuable biological resource for medicine and health foods in Asian countries. Efficient system for artificial cultivation of Chinese cordyceps relies on understanding the gene functions involved in the induction of growing blastospores into hyphae in the larval hemolymph of insect host, during O. sinensis infection. Transcriptome analysis and ribonucleic acid interference (RNA interference) method were employed to identify the key differentially expressed genes and to demonstrate their functions in Thitarodes xiaojinensis. Key larval genes critical for O. sinensis blastospore development or filamentation were identified. Nine of the 20 top upregulated genes encoded cuticles proteins, indicating that these proteins highly activated when the larval hemolymph was full of blastospores. Small interfering RNA (siRNA) knockdown of five larval genes such as Flightin, larval cuticle protein LCP-30, 26-hydroxylase (CYP18A1), cuticle protein 18.6, isoform B, and probable chitinase 3 significantly stimulated the dimorphic transition from blastospores to prehyphae in O. sinensis in the larval hemolymph after 120 h after injection. The expressions of these genes determined by quantitative real-time PCR were suppressed in various levels from 38.64% to 91.54%, compared to the controls. These results demonstrated that injection of the siRNAs of key upregulated genes into the larval hemolymph containing high load of blastospores caused the gene silence in T. xiaojinensis larvae and induced the fungal transition from blastospores to prehyphae, providing novel knowledge on the regulation of O. sinensis fungal dimorphism by Thitarodes host and cues for further study of Thitarodes biology and commercial cultivation of Chinese cordyceps.

Insecticidal activity and underlying molecular mechanisms of a phytochemical plumbagin against Spodoptera frugiperda.

Plumbagin is an important phytochemical and has been reported to exhibit potent larvicidal activity against several insect pests, However, the insecticidal mechanism of plumbagin against pests is still poorly understood. This study aimed to investigate the insecticidal activities of plumbagin and the underlying molecular mechanisms against a devastating agricultural pest, the fall armyworm Spodoptera frugiperda. The effects of plumbagin on S. frugiperda larval development and the activities of two detoxification enzymes were initially examined. Next, transcriptomic changes in S. frugiperda after plumbagin treatment were investigated. Furthermore, RNA-seq results were validated by qPCR. Plumbagin exhibited a high larvicidal activity against the second and third instar larvae of S. frugiperda with 72h LC50 of 0.573 and 2.676mg/g, respectively. The activities of the two detoxification enzymes carboxylesterase and P450 were significantly increased after 1.5mg/g plumbagin treatment. Furthermore, RNA-seq analysis provided a comprehensive overview of complex transcriptomic changes in S. frugiperda larvae in response to 1.5mg/g plumbagin exposure, and revealed that plumbagin treatment led to aberrant expression of a large number of genes related to nutrient and energy metabolism, humoral immune response, insect cuticle protein, chitin-binding proteins, chitin synthesis and degradation, insect hormone, and xenobiotic detoxification. The qPCR results further validated the reproducibility and reliability of the transcriptomic data. Our findings provide a valuable insight into understanding the insecticidal mechanism of the phytochemical plumbagin.

Identification of key genes and molecular pathways associated with claw regeneration in mud crab (Scylla paramamosain)

The mud crab (Scylla paramamosain) possesses extensive regenerative abilities, enabling it to replace missing body parts, including claws, legs, and even eyes. Studying the genetic and molecular mechanisms underlying regenerative ability in diverse animal phyla has the potential to provide new insights into regenerative medicine in humans. In the present study, we performed mRNA sequencing to reveal the genetic mechanisms underlying the claw regeneration in mud crab. Several differentially expressed genes (DEGs) were expressed in biological pathways associated with cuticle synthase, collagen synthase, tissue regeneration, blastema formation, wound healing, cell cycle, cell division, and cell migration. The top GO enrichment terms were microtubule-based process, collagen trimer, cell cycle process, and extracellular matrix structural constituent. The most enriched KEGG pathways were ECM-receptor interaction and focal adhesion. The genes encoding key functional proteins, such as collagen alpha, cuticle protein, early cuticle protein, arthrodial cuticle protein, dentin sialophosphoprotein (DSPP), epidermal growth factor receptor (EGFR), kinesin family member C1 (KIFC1), and DNA replication licensing factor mcm2-like (MCM2) were the most significant and important DEGs suspected to participate in claw regeneration. The findings of this research offer a comprehensive and insightful understanding of the genetic and molecular mechanisms underlying claw regeneration in S. paramamosain. By elucidating the specific genes and molecular pathways implicated in this process, our study contributes significantly to the broader field of regenerative biology and offers potential avenues for further exploration in crustacean limb regeneration.

High and Low Temperatures Differentially Affect Survival, Reproduction, and Gene Transcription in Male and Female Moths of Spodoptera frugiperda.

In this study, we found that both heat and cold stresses significantly affected the survival and reproduction of both sexes in Spodoptera frugiperda adults, with larvae showing relatively higher extreme temperature tolerance. Further transcriptomic analysis in adults found remarkable differences and similarities between sexes in terms of temperature stress responses. Metabolism-related processes were suppressed in heat stressed females, which did not occur to the same extend in males. Moreover, both heat and cold stress reduced immune activities in both sexes. Heat stress induced the upregulation of many heat shock proteins in both sexes, whereas the response to cold stress was insignificant. More cold tolerance-related genes, such as cuticle proteins, UDP-glucuronosyltransferase, and facilitated trehalose transporter Tret1, were found upregulated in males, whereas most of these genes were downregulated in females. Moreover, a large number of fatty acid-related genes, such as fatty acid synthases and desaturases, were differentially expressed under heat and cold stresses in both sexes. Heat stress in females induced the upregulation of a large number of zinc finger proteins and reproduction-related genes; whereas cold stress induced downregulation in genes linked to reproduction. In addition, TRPA1-like encoding genes (which have functions involved in detecting temperature changes) and sex peptide receptor-like genes were found to be differentially expressed in stressed moths. These results indicate sex-specific heat and cold stress responses and adaptive mechanisms and suggest sex-specific trade-offs between stress-resistant progresses and fundamental metabolic processes as well as between survival and reproduction.

Identifying the genes involved in the egg-carrying ovigerous hair development of the female blue crab Callinectes sapidus: transcriptomic and genomic expression analyses

BackgroundCrustacean female sex hormone (CFSH) controls gradually developing adult female-specific morphological features essential for mating and brood care. Specifically, ovigerous hairs are developed during the prepuberty molt cycle of the blue crab Callinectes sapidus that are essential for carrying the eggs until they finish development. Reduced CFSH transcripts by CFSH-dsRNA injections result in fewer and shorter ovigerous hairs than the control. This study aimed to identify the specific genes responsible for ovigerous hair formation using transcriptomic, genomic and expression analyses of the ovigerous setae at three stages: prepuberty at early (OE) and late premolt (OL), and adult (AO) stages.ResultsThe de novo Trinity assembly on filtered sequence reads produced 96,684 Trinity genes and 124,128 transcripts with an N50 of 1,615 bp. About 27.3% of the assembled Trinity genes are annotated to the public protein sequence databases (i.e., NR, Swiss-Prot, COG, KEGG, and GO databases). The OE vs. OL, OL vs. AO, and OE vs. AO comparisons resulted in 6,547, 7,793, and 7,481 differentially expressed genes, respectively, at a log2-fold difference. Specifically, the genes involved in the Wnt signaling and cell cycle pathways are positively associated with ovigerous hair development. Moreover, the transcripts of ten cuticle protein genes containing chitin-binding domains are most significantly changed by transcriptomic analysis and RT-qPCR assays, which shows a molt-stage specific, down-up-down mode across the OE-OL-AO stages. Furthermore, the expression of the cuticle genes with the chitin-binding domain, Rebers and Riddiford domain (RR)-1 appears at early premolt, followed by RR-2 at late premolt stage. Mapping these 10 cuticle protein sequences to the C. sapidus genome reveals that two scaffolds with a 549.5Kb region and 35 with a 1.19 Mb region harbor 21 RR1 and 20 RR2 cuticle protein genes, respectively. With these findings, a putative mode of CFSH action in decapod crustaceans is proposed.ConclusionsThe present study describes a first step in understanding the mechanism underlying ovigerous hair formation in C. sapidus at the molecular level. Overall, demonstrating the first transcriptome analysis of crustacean ovigerous setae, our results may facilitate future studies into the decapod female reproduction belonging to the suborder Pleocyemata.

Controllably Self-Assembled Antibacterial Nanofibrils Based on Insect Cuticle Protein for Infectious Wound Healing.

Developing self-assembled biomedical materials based on insect proteins is highly desirable due to their advantages of green, rich, and sustainable characters as well as excellent biocompatibility, which has been rarely explored. Herein, salt-induced controllable self-assembly, antibacterial performance, and infectious wound healing performance of an insect cuticle protein (OfCPH-2) originating from the Ostrinia furnacalis larva head capsule are investigated. Interestingly, the addition of salts could trigger the formation of beaded nanofibrils with uniform diameter, whose length highly depends on the salt concentration. Surprisingly, the OfCPH-2 nanofibrils not only could form functional films with broad-spectrum antibacterial abilities but also could promote infectious wound healing. More importantly, a possible wound healing mechanism was proposed, and it is the strong abilities of OfCPH-2 nanofibrils in promoting vascular formation and antibacterial activity that facilitate the process of infectious wound healing. Our exciting findings put forward instructive thoughts for developing innovative bioinspired materials based on insect proteins for wound healing and related biomedical fields.

Odor-evoked transcriptomics of Aedes aegypti mosquitoes.

Modulation of odorant receptors mRNA induced by prolonged odor exposure is highly correlated with ligand-receptor interactions in Drosophila as well as mammals of the Muridae family. If this response feature is conserved in other organisms, this presents an intriguing initial screening tool when searching for novel receptor-ligand interactions in species with predominantly orphan olfactory receptors. We demonstrate that mRNA modulation in response to 1-octen-3-ol odor exposure occurs in a time- and concentration-dependent manner in Aedes aegypti mosquitoes. To investigate gene expression patterns at a global level, we generated an odor-evoked transcriptome associated with 1-octen-3-ol odor exposure. Transcriptomic data revealed that ORs and OBPs were transcriptionally responsive whereas other chemosensory gene families showed little to no differential expression. Alongside chemosensory gene expression changes, transcriptomic analysis found that prolonged exposure to 1-octen-3-ol modulated xenobiotic response genes, primarily members of the cytochrome P450, insect cuticle proteins, and glucuronosyltransferases families. Together, these findings suggest that mRNA transcriptional modulation of olfactory receptors caused by prolonged odor exposure is pervasive across taxa and can be accompanied by the activation of xenobiotic responses.

The effects of Beauveria bassiana infection on the gene expression profiles of Diaphorina citri adults

The Asian citrus psyllid, Diaphorina citri Kuwayama, is a citrus pest worldwide. This pest transmits the pathogens of Huanglongbing, Candidatus Liberibacter asiaticus (CLas), and has led to huge economic losses. The use of chemical pesticides is the first choice for field pest control, while resistance, resurgence, and residue (3R) problems have received widespread attention. Biological control is an optional and effective method for D. citri management and needs to be developed. In this study, eleven entomopathogenic fungi strains were collected, and their morphologies were recorded. After blasting with the ITS sequences, eight strains were identified as Beauveria bassiana, and three strains were Metarhizium anisopliae. The pathogenicity of these fungi on D. citri adults at 1.0 × 107 conidia/mL was tested, with the LT50 ranging from 4.764 to 8.551. The virulence of B. bassiana strain XM-D1 was further evaluated, and the LC50 was 4.93 × 105 conidia/mL. A total of 155 and 894 differentially expressed genes (DEGs) were identified in the samples after 24 and 48 h of XM-D1 infection, respectively. Further analyses found that the pathways of apoptosis, cholesterol metabolism, fatty acid biosynthesis, and vitamin digestion and absorption could be involved in the response of D. citri adults to 48 h of infection, and DEGs encoding chaperone proteins, cuticle protein 12.5, P450s, and lysozymes may play important roles in immune defense. Our preliminary findings enrich the entomopathogenic fungi repository and shed light on the defense mechanism of D. citri in response to B. bassiana infection at the molecular level.

Transcriptome analysis of Litopenaeus vannamei during the early stage of limb regeneration process

Regeneration is a process in which organisms regrow new tissues or organs at the injury site, which has attracted the attention of many scientists and nonscientists. However, the underlying molecular mechanisms of regeneration after autotomy are largely unknown. In this study, we conducted RNA-seq sequencing on regenerated limb bud tissues of Litopenaeus vannamei at 0 hours post autotomy (0 hpa), 12 hours post autotomy (12 hpa), and 24 hours post autotomy (24 hpa). A total of 2,192 differentially expressed genes related to energy metabolism, transcription and translation, and epidermis development were identified between 0 hpa and 12 hpa, such as triosephosphate isomerase A, triosephosphate isomerase B, and zinc finger protein 367 that is upregulated in 12 hpa. Between 12 hpa and 24 hpa, 1,447 differentially expressed genes were identified that were related to cuticle development and energy metabolism, such as cuticle protein 6, which is upregulated in 24 hpa, and triosephosphate isomerase is downregulated in 24 hpa. The results indicated that energy metabolism, transcription and translation, epidermal formation, and chitin metabolism processes are involved during the early stage of limb regeneration. This study provides basic knowledge for investigating the molecular mechanisms associated with limb regeneration in crustaceans at the early regeneration stage.

Structural and functional characterization of Aedes aegypti pupal cuticle protein that controls dengue virus infection.

The pupal cuticle protein from Aedes aegypti (AaPC) inhibits dengue virus (DENV) infection; however, the underlying mechanism of this inhibition remains unknown. Here, we report that AaPC is an intrinsically disordered protein and interacts with domain I/II of the DENV envelope protein via residues Asp59, Asp61, Glu71, Asp73, Ser75, and Asp80. AaPC can directly bind to and cause the aggregation of DENV, which in turn blocks virus infection during the virus-cell fusion stage. AaPC may also influence viral recognition and attachment by interacting with human immune receptors DC-SIGN and CD4. These findings enhance our understanding of the role of AaPC in mitigating viral infection and suggest that AaPC is a potential target for developing inhibitors or antibodies to control dengue virus infection.