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Amino acid homeostasis is interconnected with the immune network of plants. During plant-pathogen interaction, amino acid transporters (AATs) have been shown to be involved in plant immune responses. However, the molecular mechanism by which how AATs function in this process remains elusive. In this study, we identify OsMP1 that acts as a quantitative trait locus against blast fungus from a joint analysis of GWAS and QTL mapping in rice. Heterogeneous expression of OsMP1 in yeast supports its function in transporting a wide range of amino acids, including Thr, Ser, Phe, His and Glu. OsMP1 could also mediate 15N-Glu efflux and influx in Xenopus oocyte cells. The expression of OsMP1 is dramatically induced by Magnaporthe oryzae in the resistant landrace Heikezijing, while remaining unresponsive in the susceptible landrace Suyunuo. Overexpressing OsMP1 in Suyunuo enhances disease resistance to blast fungus and leaf-blight bacterium without yield penalty. Furthermore, the overexpression of OsMP1 leads to increased accumulation of Thr, Ser, Phe and His in the leaves. And the heightened levels of these amino acids contribute to reduced disease susceptibility, which is associated with upregulated jasmonic acid pathway. Thus, our results elucidate the pivotal role of OsMP1 in disease resistance and provide a potential target for breeding more resistant rice cultivars without compromising yield.
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Yersinia pestis, the causative agent of plague, is endemic in certain regions due to a stable transmission cycle between rodents and their associated fleas. In addition, fleas are believed to serve as reservoirs that can occasionally cause enzootic plague cycles and explosive epizootic outbreaks that increase human exposure. However, transmission by fleas is inefficient and associated with a shortened lifespan of the flea and rodent hosts, indicating that there remain significant gaps in our understanding of the vector-animal cycle of Y. pestis. Here, we show that laboratory-reared, infected fleas (Xenopsylla cheopis) can transmit viable Y. pestis from adults to eggs, and the bacteria can be passed through all subsequent life stages of the flea. Thus, our data raise the possibility that transovarial transmission in fleas might contribute to the persistence of Y. pestis in the environment without detectable plague activity in mammals.
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Insectos Vectores , Peste , Xenopsylla , Yersinia pestis , Animales , Yersinia pestis/fisiología , Yersinia pestis/patogenicidad , Peste/transmisión , Peste/microbiología , Xenopsylla/microbiología , Insectos Vectores/microbiología , Femenino , Siphonaptera/microbiología , Humanos , Ratones , MasculinoRESUMEN
This study aimed to investigate the protective effects of glucose selenol on cadmium (Cd)-induced testicular toxicity. Twenty-four male Sprague-Dawley (SD) rats were randomly divided into four groups. Cd was administered orally at a dose of 40â¯mg/L or in combination with orally administered glucose selenol at doses of 0.15â¯mg/L and 0.4â¯mg/L for 30 days. The results showed that sperm quality decreased and testicular tissue was damaged in the Cd group; Glucose selenol significantly attenuated the negative effects by improving sperm quality and reducing testicular damage. Transcriptome sequencing analysis showed that Cd stress affected spermatogenesis, sperm motility, oxidative stress, blood-testis barrier and protein metabolism. Four clusters were obtained using the R Mfuzz package, which clustered highly expressed genes under different administrations, and 36 items were enriched. Notably, protein phosphorylation was enriched in the Cd group and is considered to play a key role in the response to Cd stress. We identified fifty-six target selenium (Se) and Cd co-conversion differentially expressed genes (DEGs), including three genes relating to spermatogenesis (Dnah8, Spata31d1b, Spata31d1c). In addition, the obtained DEGs were used to construct a protein-protein interaction network, co-processed with Se and Cd, and 5 modules were constructed. Overall, the analyses of rat testicular physiology and gene expression levels offer new insights into the reproductive toxicity of Cd in rats, and provide potential application prospects for glucose selenol in alleviating the impact of Cd-induced testicular damage.
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The vascular system in plants facilitates long-distance transportation of water and nutrients through the xylem and phloem, while also providing mechanical support for vertical growth. Although many genes that regulate vascular development in rice have been identified, the mechanism by which epigenetic regulators control vascular development remains unclear. This study found that Rolled Fine Striped (RFS), a Chromodomain Helicase DNA-binding 3 (CHD3)/Mi-2 subfamily protein, regulates vascular development in rice by affecting the initiation and development of primordia. The rfs mutant was found to affect auxin-related genes, as revealed by RNA sequencing and reverse transcription-quantitative PCR analysis. The transcript levels of OsPIN1 and NAL1 genes were downregulated in rfs mutant, compared to the wild-type plant. The chromatin immunoprecipitation assays showed lower levels of H3K4me3 in the OsPIN1a and NAL1 genes in rfs mutant. Furthermore, exogenous auxin treatment partially rescued the reduced adventitious root vascular development in rfs mutant. Subsequently, exogenous treatments with auxin or an auxin-transport inhibitor revealed that the expression of OsPIN1a and NAL1 is mainly affected by auxin. These results provide strong evidence that RFS plays an important role in vascular development and root formation through the auxin signaling pathway in rice.
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Terrestrial organisms are likely to face hypoxic stress during natural disasters such as floods or landslides, which can lead to inevitable hypoxic conditions for those commonly residing within soil. Pardosa pseudoannulata often inhabits soil crevices and has been extensively studied, yet research on its response to hypoxic stress remains unclear. Therefore, we investigated the adaptive strategies of Pardosa pseudoannulata under hypoxic stress using metabolomics and transcriptomics approaches. The results indicated that under hypoxic stress, metabolites related to energy and antioxidants such as ATP, D-glucose 6-phosphate, flavin adenine dinucleotide (FAD), and reduced L-glutathione were significantly differentially expressed. Pathways such as the citric acid (TCA) cycle and oxidative phosphorylation were significantly enriched. Transcriptome analysis and related assessments also revealed a significant enrichment of pathways associated with energy metabolism, suggesting that Pardosa pseudoannulata primarily copes with hypoxic environments by modulating energy metabolism and antioxidant-related substances.
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Viruses are encapsidated mobile genetic elements that rely on host cells for replication. Several cytoplasmic RNA viruses synthesize proteins and/or RNAs that translocate to infected cell nuclei. However, the underlying mechanisms and role(s) of cytoplasmic-nuclear trafficking are unclear. We demonstrate that infection of small brown planthoppers with rice stripe virus (RSV), a negarnaviricot RNA virus, results in K63-linked polyubiquitylation of RSV's nonstructural protein 3 (NS3) at residue K127 by the RING ubiquitin ligase (E3) LsRING. In turn, ubiquitylation leads to NS3 trafficking from the cytoplasm to the nucleus, where NS3 regulates primary miRNA pri-miR-92 processing through manipulation of the microprocessor complex, resulting in accumulation of upregulated miRNA lst-miR-92. We show that lst-miR-92 regulates the expression of fibrillin 2, an extracellular matrix protein, thereby increasing RSV loads. Our results highlight the manipulation of intranuclear, cytoplasmic, and extracellular components by an RNA virus to promote its own replication in an insect vector.
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Hemípteros , MicroARNs , Oryza , Tenuivirus , Animales , MicroARNs/genética , MicroARNs/metabolismo , Tenuivirus/metabolismo , Regulación hacia Arriba , Fibrilina-2/genética , Fibrilina-2/metabolismo , Replicación Viral , Oryza/genética , Enfermedades de las PlantasRESUMEN
Advanced DNA structures, such as the G-quadruplex (G4) and the i-motif, are widely but not randomly present in the genomes of many organisms. A G4 structure was identified in the promoter of the silk gland factor-1 gene (SGF1), which is the main regulatory gene for silk production in Bombyx mori. In this study, a BmSGF1 G4-/- homozygous mutant was generated with the G4 sequence knocked out. The promoter activity of BmSGF1 was lowered in the BmSGF1 G4-/- mutant. Pyridostatin (PDS) stabilized the G4 structure and increased the promoter activity of BmSGF1, whereas anti-sense oligonucleotide (ASO) complementary to the G4 sequence suppressed the promoter activity of BmSGF1. Compared with wild-type larvae, the deletion of the BmSGF1 G4 structure decreased both the expression of BmSGF1 and the fibroin heavy chain gene BmFib-H in the posterior silk gland and the weight of the cocoons. Overall, these results suggest that the promoter G4 structure of BmSGF1 participates in the transcription regulation of the BmSGF1 gene in the silkworm.
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The dynamic interplay between guanine-quadruplex (G4) structures and pathogenicity islands (PAIs) represents a captivating area of research with implications for understanding the molecular mechanisms underlying pathogenicity. This study conducted a comprehensive analysis of a large-scale dataset from reported 89 pathogenic strains of bacteria to investigate the potential interactions between G4 structures and PAIs. G4 structures exhibited an uneven and non-random distribution within the PAIs and were consistently conserved within the same pathogenic strains. Additionally, this investigation identified positive correlations between the number and frequency of G4 structures and the GC content across different genomic features, including the genome, promoters, genes, tRNA, and rRNA regions, indicating a potential relationship between G4 structures and the GC-associated regions of the genome. The observed differences in GC content between PAIs and the core genome further highlight the unique nature of PAIs and underlying factors, such as DNA topology. High-confidence G4 structures within regulatory regions of Escherichia coli were identified, modulating the efficiency or specificity of DNA integration events within PAIs. Collectively, these findings pave the way for future research to unravel the intricate molecular mechanisms and functional implications of G4-PAI interactions, thereby advancing our understanding of bacterial pathogenicity and the role of G4 structures in pathogenic diseases.
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G-Cuádruplex , Islas Genómicas , Islas Genómicas/genética , Bacterias/genética , ADN , Virulencia/genética , Escherichia coli/genética , Genoma BacterianoRESUMEN
Insects are susceptible to elevated temperatures, resulting in impaired fertility, and shortened lifespan. This study investigated the genetic mechanisms underlying heat stress effects. We conducted RNA sequencing on Pteromalus puparum exposed to 25°C and 35°C, revealing transcriptional signatures. Weighted Gene Co-expression Network Analysis uncovered heat stress-associated modules, forming a regulatory network of 113 genes. The network is naturally divided into two subgroups, one linked to acute heat stress, including heat shock proteins (HSPs), and the other to chronic heat stress, involving lipogenesis genes. We identified an Xap5 Heat Shock Regulator (XHSR) gene as a crucial network component, validated through RNA interference and quantitative PCR assays. XHSR knockdown reduced wasps' lifespan while directly inducing HSPs and mediating lipogenesis gene induction. CRISPR/Cas9-mediated knockout of the Drosophila XHSR homolog reduced mutants' survival, highlighting its conserved role. This research sheds light on thermal tolerance mechanisms, offering potential applications in pest control amid global warming.
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BACKGROUND: The ectoparasitic wasp Habrobracon hebetor (Hymenoptera, Braconidae) can parasitize various species of lepidopteran pests. To maximize its potential for biological control, it is necessary to investigate its gene function through genome engineering. RESULTS: To test the effectiveness of genome engineering system in H. hebetor, we injected the mixture of clustered regularly interspaced short palindromic repeats (CRISPR) -associated (Cas) 9 protein and single guide RNA(s) targeting gene white into embryos. The resulting mutants display a phenotype of eye pigment loss. The phenotype was caused by small indel and is heritable. Then, we compared some biological parameters between wildtype and mutant, and found there were no significant differences in other parameters except for the offspring female rate and adult longevity. In addition, cocoons could be used to extract genomic DNA for genotype during the gene editing process without causing unnecessary harm to H. hebetor. CONCLUSION: Our results demonstrate that the CRISPR/Cas9 system can be used for H. hebetor genome editing and it does not adversely affect biological parameters of the parasitoid wasps. We also provide a feasible non-invasive genotype detection method using genomic DNA extracted from cocoons. Our study introduces a novel tool and method for studying gene function in H. hebetor, and may contribute to better application of H. hebetor in biocontrol. © 2023 Society of Chemical Industry.
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Avispas , Animales , Femenino , Avispas/metabolismo , Sistemas CRISPR-Cas , ARN Guía de Sistemas CRISPR-Cas , Mutagénesis , ADNRESUMEN
Amblyomma americanum, also known as the lone star tick, is a small arachnid that feeds on blood and can spread disease to humans and other animals. Despite the overlapped ecological niche, geographic distribution, and host selection, there is no proof that A. americanum transmits the pathogen Borrelia burgdorferi that causes Lyme disease. Studies have shown that phospholipase A2 (PLA2) may act as a tool to eliminate B. burgdorferi, but particular PLA2 genes in A. americanum have not been identified and functionally characterized. Using the de novo sequencing method, we identified 42 putative A. americanum PLA2 (pAaPLA2) homologs in the present study, of which three pAaPLA2 had calcium binding sites and canonical histidine catalytic sites. Then, we determined phylogenetic relationships, sequence alignments, and conserved protein motifs of these pAaPLA2s. Protein structural analysis demonstrated that pAaPLA2s primarily consisted of α-helices, ß-sheets, and random coils. These genes were predicted to be engaged in the phospholipid metabolic process, arachidonic acid secretion, and PLA2 activity by functional annotation analysis. A transcriptional factor (Bgb) was discovered that interacted with pAaPLA2 proteins that may have unrecognized roles in regulating neuronal development. Based on the RNA-seq data, we surveyed expression profiles of key pAaPLA2-related genes to reveal putative modulatory networks of these genes. RNAi knockdown of pAaPLA2_1, a dominant isoform in A. americanum, led to decreased bacterial inhibition ability, suggesting pAaPLA2 may play an important role in mediating immune responses. Collectively, this study provides essential evidence of the identification, gene structure, phylogeny, and expression analysis of pAaPLA2 genes in A. americanum, and offers a deeper understanding of the putative borreliacidal roles in the lone star tick.
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Amblyomma , Ixodidae , Humanos , Animales , Amblyomma/genética , Ixodidae/microbiología , Interferencia de ARN , Filogenia , Fosfolipasas A2/genética , Perfilación de la Expresión GénicaRESUMEN
Yersinia pestis is the causative agent of bubonic plague, a deadly flea-borne disease responsible for three historic pandemics. Today annual cases of human disease occur worldwide following exposure to Y. pestis infected fleas that can be found within the rodent population where plague activity cycles between epizootic outbreaks and extended periods of apparent quiescence. Flea transmission of Y. pestis is most efficient in "blocked" fleas that are unable to feed, whereas mammalian transmission to fleas requires a susceptible host with end-stage high titer bacteremia. These facts suggest alternative mechanisms of transmission must exist to support the persistence of Y. pestis between epizootic outbreaks. In this work, we addressed whether vertical transmission could be a mechanism for persistent low-infection across generations of fleas. We demonstrate that Y. pestis infection of the Oriental rat flea, Xenopyslla cheopis, spreads to the reproductive tissues and is found in eggs produced by infected adult fleas. We further show that vertical transmission of Y. pestis from eggs to adults results in midgut colonization indicating a strong probability that it can reenter the sylvatic plague cycle.
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Bursicon, a neuropeptide hormone comprising two subunits-bursicon (burs) and partner of burs (pburs), belongs to the cystine-knot protein family. Bursicon heterodimers and homodimers bind to the lucine-rich G-protein coupled receptor (LGR) encoded by rickets to regulate multiple physiological processes in arthropods. Notably, these processes encompass the regulation of female reproduction, a recent revelation in Tribolium castaneum. In this study we investigated the role of burs/pburs/rickets in mediating female vitellogenesis and reproduction in a hemipteran insect, the whitefly, Bemisia tabaci. Our investigation unveiled a synchronized expression of burs, pburs and rickets, with their transcripts persisting detectable in the days following eclosion. RNAi-mediated knockdown of burs, pburs or rickets significantly suppressed the transcript levels of vitellogenin (Vg) and Vg receptor in the female whiteflies. These effects also impaired ovarian maturation and female fecundity, as evidenced by a reduction in the number of eggs laid per female, a decrease in egg size and a decline in egg hatching rate. Furthermore, knockdown of burs, pburs or rickets led to diminished juvenile hormone (JH) titers and reduced transcript level of Kruppel homolog-1. However, this impact did not extend to genes in the insulin pathway or target of rapamycin pathway, deviating from the results observed in T. castaneum. Taken together, we conclude that burs/pburs/rickets regulates the vitellogenesis and reproduction in the whiteflies by coordinating with the JH signaling pathway.
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Hemípteros , Hormonas de Invertebrados , Neuropéptidos , Raquitismo , Animales , Femenino , Hemípteros/genética , Hemípteros/metabolismo , Hormonas de Invertebrados/genética , Hormonas de Invertebrados/metabolismo , Hormonas Juveniles , VitelogénesisRESUMEN
Introduction: The lone star tick, Amblyomma americanum, is an important ectoparasite known for transmitting diseases to humans and animals. Ecdysis-related neuropeptides (ERNs) control behaviors crucial for arthropods to shed exoskeletons. However, ERN identification and characterization in A. americanum remain incomplete. Methods: We investigated ERNs in A. americanum, assessing their evolutionary relationships, protein properties, and functions. Phylogeny, sequence alignment, and domain structures of ERNs were analyzed. ERN functionality was explored using enrichment analysis, and developmental and tissue-specific ERN expression profiles were examined using qPCR and RNAi experiments. Results and discussion: The study shows that ERN catalogs (i.e., eclosion hormone, corazonin, and bursicon) are found in most arachnids, and these ERNs in A. americanum have high evolutionary relatedness with other tick species. Protein modeling analysis indicates that ERNs primarily consist of secondary structures and protein stabilizing forces (i.e., hydrophobic clusters, hydrogen bond networks, and salt bridges). Gene functional analysis shows that ENRs are involved in many ecdysis-related functions, including ecdysis-triggering hormone activity, neuropeptide signaling pathway, and corazonin receptor binding. Bursicon proteins have functions in chitin binding and G protein-coupled receptor activity and strong interactions with leucine-rich repeat-containing G-protein coupled receptor 5. ERNs were expressed in higher levels in newly molted adults and synganglia. RNAi-mediated knockdown of burs α and burs ß expression led to a significant decrease in the expression of an antimicrobial peptide, defensin, suggesting they might act in signaling or regulatory pathways that control the expression of immune-related genes. Arthropods are vulnerable immediately after molting because new cuticles are soft and susceptible to injury and pathogen infections. Bursicon homodimers act in prophylactic immunity during this vulnerable period by increasing the synthesis of transcripts encoding antimicrobial peptides to protect them from microbial invasion. Collectively, the expression pattern and characterization of ERNs in this study contribute to a deeper understanding of the physiological processes in A. americanum.
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Amblyomma , Artrópodos , Adulto , Animales , Humanos , Muda/genética , Transducción de Señal , Péptidos AntimicrobianosRESUMEN
Niemann-Pick C (NPC) disease is a neurodegenerative disorder related to cellular sterol trafficking and mutation of NPC1 gene is the main cause for this disease. The function of NPC1 have been reported in a few insects but rarely studied in hemipterans. In the present study, we investigate the function of NPC1 in a hemipteran pest, the whitefly Bemisia tabaci. It was found that B. tabaci had only one NPC1 homolog (BtNPC1), in contrast to two homologs in many other insects. BtNPC1 was ubiquitously expressed at all developmental stages and body parts of whiteflies, with the highest level in adult abdomen, and the expression of BtNPC1 was induced by cholesterol feeding. To further investigate the function of BtNPC1, leaf-mediated RNA interference experiments were carried out. Results showed that knockdown of BtNPC1 led to reduced survival of whiteflies, as well as reduced fecundity. Moreover, knockdown of BtNPC1 affected the development and metamorphosis of whitefly nymphs. Taken these together, we conclude that BtNPC1 played a crucial role in sterol-related biological processes of B. tabaci and might be used as an insecticide target for development of novel pest management approaches.
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Ticks are ectoparasites that can transmit various pathogens capable of causing life-threatening illnesses in people and animals, making them a severe public health threat. Understanding how ticks respond to bacterial infection is crucial for deciphering their immune defense mechanisms and identifying potential targets for controlling tick-borne diseases. In this study, an in-depth transcriptome analysis was used to investigate the molecular and immune responses of Amblyomma americanum to infection caused by the microinjection of Escherichia coli. With an abundance of differentially expressed genes discovered at different times, the analysis demonstrated significant changes in gene expression profiles in response to E. coli challenge. Notably, we found alterations in crucial immune markers, including the antimicrobial peptides defensin and microplusin, suggesting they may play an essential role in the innate immune response. Furthermore, KEGG analysis showed that following E. coli exposure, a number of key enzymes, including lysosomal alpha-glucosidase, fibroblast growth factor, legumain, apoptotic protease-activating factor, etc., were altered, impacting the activity of the lysosome, mitogen-activated protein kinase, antigen processing and presentation, bacterial invasion, apoptosis, and the Toll and immune deficiency pathways. In addition to the transcriptome analysis, we constructed protein interaction networks to elucidate the molecular interactions underlying the tick's response to E. coli challenge. Hub genes were identified, and their functional enrichment provided insights into the regulation of cytoskeleton rearrangement, apoptotic processes, and kinase activity that may occur in infected cells. Collectively, the findings shed light on the potential immune responses in A. americanum that control E. coli infection.
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Ixodidae , Garrapatas , Animales , Amblyomma , Ixodidae/microbiología , Escherichia coli/genética , Inmunidad InnataRESUMEN
Bursicon is a cystine knot family neuropeptide, composed of two subunits, bursicon (burs) and partner of burs (pburs). The subunits can form heterodimers to regulate cuticle tanning and wing maturation and homodimers to signal different biological functions in innate immunity, midgut stem cell proliferation and energy homeostasis, and reproductive physiology in the model insects Drosophila melanogaster or Tribolium castaneum. Here, we report on the role of the pburs homodimer in signaling innate immunity in T. castaneum larvae. Through transcriptome analysis we identified a set of immune-related genes that respond to pburs RNAi. Treating larvae with recombinant-pburs protein led to up-regulation of antimicrobial peptide (AMP) genes in vivo and in vitro. The upregulation of most AMP genes was dependent on the NF-κB transcription factor Relish. Most importantly, we identified a novel AMP, Tenecin 3-like peptide (Ten3LP), regulated by pburs via NF-κB transcription factor Dorsal-related immunity factor (Dif)/Dorsal2, but not Relish. We conducted Ten3LP RNAi, synthesized recombinant Ten3LP protein for microbial inhibition assays and functionally characterized Ten3LP as an AMP specific for fungi and Gram-positive bacteria. We demonstrate that expression of Ten3LP is activated by pburs via the Toll pathway. These findings identify new molecular targets for development of potential antibiotics for treating microbial infections and perhaps for RNAi based pest management technology.
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Proteínas de Drosophila , Neuropéptidos , Tribolium , Animales , Drosophila melanogaster/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Tribolium/genética , Tribolium/metabolismo , Neuropéptidos/genética , Péptidos Antimicrobianos , Inmunidad Innata/genética , Proteínas de Unión al ADN , Factores de Transcripción/genética , Proteínas de Drosophila/metabolismoRESUMEN
C-type lectins (CTLs) are a class of proteins containing carbohydrate recognition domains (CRDs), which are characteristic modules that recognize various glycoconjugates and function primarily in immunity. CTLs have been reported to affect growth and development and positively regulate innate immunity in Tribolium castaneum. However, the regulatory mechanisms of TcCTL16 proteins are still unclear. Here, spatiotemporal analyses displayed that TcCTL16 was highly expressed in late pupae and early adults. TcCTL16 RNA interference in early larvae shortened their body length and narrowed their body width, leading to the death of 98% of the larvae in the pupal stage. Further analysis found that the expression level of muscle-regulation-related genes, including cut, vestigial, erect wing, apterous, and spalt major, and muscle-composition-related genes, including Myosin heavy chain and Myosin light chain, were obviously down-regulated after TcCTL16 silencing in T. castaneum. In addition, the transcription of TcCTL16 was mainly distributed in the hemolymph. TcCTL16 was significantly upregulated after challenges with lipopolysaccharides, peptidoglycans, Escherichia coli, and Staphylococcus aureus. Recombinant CRDs of TcCTL16 bind directly to the tested bacteria (except Bacillus subtilis); they also induce extensive bacterial agglutination in the presence of Ca2+. On the contrary, after TcCTL16 silencing in the late larval stage, T. castaneum were able to develop normally. Moreover, the transcript levels of seven antimicrobial peptide genes (attacin2, defensins1, defensins2, coleoptericin1, coleoptericin2, cecropins2, and cecropins3) and one transcription factor gene (relish) were significantly increased under E. coli challenge and led to an increased survival rate of T. castaneum when infected with S. aureus or E. coli, suggesting that TcCTL16 deficiency could be compensated for by increasing AMP expression via the IMD pathways in T. castaneum. In conclusion, this study found that TcCTL16 could be involved in developmental regulation in early larvae and compensate for the loss of CTL function by regulating the expression of AMPs in late larvae, thus laying a solid foundation for further studies on T. castaneum CTLs.
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Tribolium , Animales , Tribolium/genética , Escherichia coli/metabolismo , Staphylococcus aureus/metabolismo , Inmunidad Innata/genética , Bacterias/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Larva/metabolismoRESUMEN
The transforming growth factor-ß (TGF-ß) superfamily in insects regulated various physiological events, including immune response, growth and development, and metamorphosis. This complex network of signaling pathways involves conserved cell-surface receptors and signaling co-receptors that allow for precisely coordinated cellular events. However, the roles of TGF-ß receptors, particularly the type II receptor Punt, in mediating the innate immunity in insects remains unclear. In this study, we used the red flour beetle, Tribolium castaneum, as a model species to investigate the role of TGF-ß type II receptor Punt in mediating antimicrobial peptide (AMP) expression. Developmental and tissue-specific transcript profiles revealed Punt was constitutively expressed throughout development, with the highest transcript level in 1-day female pupae and the lowest transcript level in 18-day larvae. Tissue specific expression profiles showed the highest transcript level of Punt was observed in the Malpighian tubule and ovary in 18-day larvae and 1-day female adults, respectively, suggesting Punt might have distinct functions in larvae and adults. Further results indicated that Punt RNAi in the 18-day larvae led to increased transcript level of AMP genes through transcription factor Relish, leading to inhibition of Escherichia coli proliferation. Knockdown of Punt in larvae also led to splitting of adult elytra and abnormal compound eyes. Furthermore, knockdown of Punt during the female pupal stage resulted in increased transcript levels of AMP genes, as well as abnormal ovary, reduced fecundity, and failure of eggs to hatch. This study deepens our understanding of the biological significance of Punt in insect TGF-ß signaling and lays the groundwork for further research of its role in insect immune response, development, and reproduction.