Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 10.300
Filtrar
1.
Zool Res ; 42(5): 637-649, 2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34472225

RESUMO

The insect brain is the central part of the neurosecretory system, which controls morphology, physiology, and behavior during the insect's lifecycle. Lepidoptera are holometabolous insects, and their brains develop during the larval period and metamorphosis into the adult form. As the only fully domesticated insect, the Lepidoptera silkworm Bombyx mori experienced changes in larval brain morphology and certain behaviors during the domestication process. Hormonal regulation in insects is a key factor in multiple processes. However, how juvenile hormone (JH) signals regulate brain development in Lepidoptera species, especially in the larval stage, remains elusive. We recently identified the JH receptor Methoprene tolerant 1 ( Met1) as a putative domestication gene. How artificial selection on Met1 impacts brain and behavioral domestication is another important issue addressing Darwin's theory on domestication. Here, CRISPR/Cas9-mediated knockout of Bombyx Met1 caused developmental retardation in the brain, unlike precocious pupation of the cuticle. At the whole transcriptome level, the ecdysteroid (20-hydroxyecdysone, 20E) signaling and downstream pathways were overactivated in the mutant cuticle but not in the brain. Pathways related to cell proliferation and specialization processes, such as extracellular matrix (ECM)-receptor interaction and tyrosine metabolism pathways, were suppressed in the brain. Molecular evolutionary analysis and in vitro assay identified an amino acid replacement located in a novel motif under positive selection in B. mori, which decreased transcriptional binding activity. The B. mori MET1 protein showed a changed structure and dynamic features, as well as a weakened co-expression gene network, compared with B. mandarina. Based on comparative transcriptomic analyses, we proposed a pathway downstream of JH signaling (i.e., tyrosine metabolism pathway) that likely contributed to silkworm larval brain development and domestication and highlighted the importance of the biogenic amine system in larval evolution during silkworm domestication.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Bombyx/metabolismo , Proteínas de Insetos/metabolismo , Hormônios Juvenis/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Bombyx/crescimento & desenvolvimento , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Sistemas CRISPR-Cas , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento , Genótipo , Proteínas de Insetos/genética , Tegumento Comum/fisiologia , Larva/crescimento & desenvolvimento , Larva/metabolismo , Filogenia , Conformação Proteica
2.
Pestic Biochem Physiol ; 178: 104923, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34446199

RESUMO

Cell division cycle protein 37 (Cdc37) is a molecular chaperone that actively participates in many intracellular physiological and biochemical processes as well as pathogen infection. However, the function of Cdc37 in silkworm cells under Bombyx mori nucleopolyhedrovirus (BmNPV) infection is unknown. We cloned and identified BmCdc37, a Cdc37 gene from B. mori, which is highly conserved among other species. After BmNPV infection, the expression level of the BmCdc37 gene was up-regulated and showed an expression pattern similar to the BmHsp90 gene, which relies on Cdc37 to stabilize and activate specific protein kinases. The immunofluorescence, bimolecular fluorescence complementation (BiFC), and co-immunoprecipitation (Co-IP) assays all indicated that BmCdc37 interacts with BmHsp90 in silkworm cells. Both BmCdc37 and BmHsp90 promote the reproduction of BmNPV. Co-expression of BmCdc37 and BmHsp90 was better at promoting virus proliferation than overexpression alone. These findings all indicate that BmCdc37 plays an active role in the proliferation of BmNPV.


Assuntos
Bombyx , Animais , Bombyx/genética , Proteínas de Ciclo Celular/genética , Proliferação de Células , Interações Hospedeiro-Patógeno , Proteínas de Insetos/genética , Nucleopoliedrovírus
3.
Pestic Biochem Physiol ; 178: 104934, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34446203

RESUMO

Chitin synthase (CHS) plays a critical role in chitin synthesis and excretion. In most insects, CHSs have been segregated into 1 and 2 classes. CHS1 is responsible for chitin production in the ectodermally-derived epidermal cells. CHS2 is dedicated to chitin biosynthesis in the midgut peritrophic matrix (PM). Henosepilachna vigintioctopunctata is a serious pest of Solanaceae and Cucurbitaceae plants. In this study, we identified HvCHS1 and HvCHS2. We found that HvCHS1 was abundantly transcribed in the larval tracheae and epidermis, whereas HvCHS2 was mainly expressed in the guts. Escherichia coli HT115 expressed double stranded RNAs targeting HvCHS1 and HvCHS2 (dsCHS1 and dsCHS2) were used to immerse potato foliage and the treated leaves were provided to the newly-molted fourth- and third-instar larvae. Ingestion of dsCHS1 by the fourth-instar larvae significantly diminished the target mRNA level and had slight influence on the expression of HvCHS2. In contrast, consumption of dsCHS2 significantly lowered the target mRNA level but triggered the transcription of HvCHS1. Knockdown of HvCHS1, rather than HvCHS2, arrested larval development and impaired larva-pupa-adult transition. A large proportion of HvCHS1 hypomorphs became stunting prepupae, deformed pupae or misshapen adults. Moreover, knockdown of HvCHS1 damaged gut integrity, decreased cuticle thickness, and delayed the formation of newly-generated cuticle layer during ecdysis. Furthermore, depletion of HvCHS1 inhibited the development of trachea system and thinned tracheal taenidia. Ingestion of dsCHS1 at the third-instar stage caused similar but severe negative effects. Our results demonstrated that HvCHS1 is responsible for chitin biosynthesis during ecdysis. Moreover, HvCHS1 is a potential amenable target gene and young larvae are more susceptible to dsRNA.


Assuntos
Quitina Sintase , Besouros , Animais , Quitina/metabolismo , Quitina Sintase/genética , Quitina Sintase/metabolismo , Besouros/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/genética , Larva/metabolismo , Muda/genética , Pupa/metabolismo , Interferência de RNA
4.
Pestic Biochem Physiol ; 178: 104943, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34446209

RESUMO

Structural cuticular proteins (CPs) are major components of the insect cuticle, and they play critical roles in insect development and insecticide resistance. Here, a total of 196 CP genes were successfully annotated in the Plutella xylostella genome. On the basis of motif analysis, these CPs were classified into 10 different families, including 122 CPR, 12 CPAP1, 8 CPAP3, 9 CPLCP, 2 Tweedle, 1 CPF, 1 CPFL, 1 CPCFC, 17 CPG and 2 18 aa proteins, and the remaining 21 unclassified CPs were classed as cuticular proteins hypothetical (CPH). A phylogenetic analysis of CPs from different insects revealed species-specific clades of RR-1 and RR-2 genes, suggesting that CP gene duplication might occur independently among insect taxa, while we also found that some other CPs (such as CPAP1 and CPAP3) had a closer relationship based on their conserved domain architecture. Using available RNAseq libraries, the expression profiles of the CPs were analyzed over the four developmental stages of the insect (i.e., egg, larva, pupa, and adult), revealing stage-specific expression patterns for the CPs. In a chlorpyrifos resistant strain, 18 CP genes were found to be more than two-fold upregulated compared to the susceptible control strain, and qRT-PCR analysis showed that these CP genes were overexpressed after exposure to chlorpyrifos, suggesting a potential role in the molecular mechanism of insecticide resistance in P. xylostella. This study provides the tools and molecular basis to study the role of CPs in the post-embryonal development and the mechanisms of insecticide resistance of P. xylostella.


Assuntos
Mariposas , Animais , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Larva/genética , Mariposas/genética , Filogenia
5.
Pestic Biochem Physiol ; 178: 104945, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34446211

RESUMO

The small GTPase Ran is a member of the Ras superfamily of small GTP-binding proteins, which plays a key role in the translocation of RNA and proteins through the nuclear pore complex. In this study, the full-length cDNA sequence of LmRan gene was obtained, which consists of 648-nucleotides open reading frame (ORF) and encodes 215 amino acids. RT-qPCR results revealed that LmRan was expressed in all developmental days and tissues investigated. Injection of dsLmRan into 4th and 5th instar nymphs, resulted in a significant down-regulation of LmRan transcripts, respectively. All dsLmRan-injected nymphs died before molting. Further hematoxylin and eosin staining of the integument showed that there was no apolysis occurred after silencing LmRan. In addition, the weight of dsLmRan-injected nymphs was significantly lower than that of the control group, and the gastric caecum and midgut was severely smaller. Especiallly, the mRNA level of LmCYP302a1, LmCYP315a1 and LmCYP314a1 responsible for 20E synthesis, LmE75 and LmE74 genes involved in the 20E signaling pathway, LmGfat, LmUAP1 and LmCHT10 genes involved in chitin metabolism pathway were dramatically decreased in the dsLmRan-injected nymphs. Together, the results indicated that LmRan participate in the 20E signaling pathway, which is essential for the growth and development of locusts.


Assuntos
Locusta migratoria , Animais , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Locusta migratoria/genética , Locusta migratoria/metabolismo , Muda/genética , Filogenia , Interferência de RNA , Transdução de Sinais , Proteína ran de Ligação ao GTP
6.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360963

RESUMO

The insect immune response is initiated by the recognition of invading microorganisms. Peptidoglycan recognition proteins (PGRPs) function primarily as pattern recognition receptors by specifically binding to peptidoglycans expressed on microbial surfaces. We cloned a full-length cDNA for a PGRP from the Asian corn borer Ostrinia furnacalis (Guenée) and designated it as PGRP1. PGRP1 mRNA was mainly detected in the fat bodies and hemocytes. Its transcript levels increased significantly upon bacterial and fungal challenges. Purified recombinant PGRP1 exhibited binding activity to the gram-positive Micrococcus luteus, gram-negative Escherichia coli, entomopathogenic fungi Beauveria bassiana, and yeast Pichia pastoris. The binding further induced their agglutination. Additionally, PGRP1 preferred to bind to Lys-type peptidoglycans rather than DAP-type peptidoglycans. The addition of recombinant PGRP1 to O. furnacalis plasma resulted in a significant increase in phenoloxidase activity. The injection of recombinant PGRP1 into larvae led to a significantly increased expression of several antimicrobial peptide genes. Taken together, our results suggest that O. furnacalis PGRP1 potentially recognizes the invading microbes and is involved in the immune response in O. furnacalis.


Assuntos
Imunidade Inata , Proteínas de Insetos/metabolismo , Lepidópteros/genética , Peptidoglicano/metabolismo , Animais , Beauveria/patogenicidade , Corpo Adiposo/metabolismo , Hemócitos/metabolismo , Proteínas de Insetos/genética , Lepidópteros/imunologia , Lepidópteros/microbiologia , Micrococcus luteus/patogenicidade , Monofenol Mono-Oxigenase/metabolismo , Peptidoglicano/genética , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Saccharomycetales/patogenicidade
7.
Zoolog Sci ; 38(4): 305-310, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34342950

RESUMO

To clarify the molecular mechanism of prevention of entry into diapause in Bombyx mori by HCl treatment, we biochemically analyzed calcineurin regulatory B subunit (CNB) in diapause eggs treated with HCl solution. Our previous studies revealed that HCl treatment causes Ca2+ to efflux from diapause eggs. Therefore, we attempted to analyze CNB, which is known to associate with Ca2+. The gene expression level of CNB was increased by HCl treatment and the changes of the gene expression were almost the same as that in the non-diapause eggs. As for diapause eggs, almost no gene expression of CNB was confirmed except just after oviposition. In the assay for phosphorylation by protein kinase CK2, recombinant CNB (rCNB) was phosphorylated in vitro. Additionally, a Ca2+ binding assay indicated that rCNB shows affinity for Ca2+. The distribution of CNB was investigated with an immunohistochemical technique using antiserum against rCNB in diapause eggs and HCl-treated diapause eggs. CNB was localized in serosa cells and yolk cells in both eggs. These data may suggest that CNB is activated by intracellular Ca2+ or efflux Ca2+ resulting from HCl treatment, and that it plays a role in the molecular mechanisms of artificial diapause prevention or the breaking of diapause in the silkworm.


Assuntos
Bombyx/fisiologia , Calcineurina/metabolismo , Diapausa , Proteínas de Insetos/metabolismo , Subunidades Proteicas/metabolismo , Animais , Bombyx/efeitos dos fármacos , Bombyx/genética , Calcineurina/química , Calcineurina/genética , Cálcio/metabolismo , Diapausa/efeitos dos fármacos , Regulação da Expressão Gênica , Ácido Clorídrico/farmacologia , Imuno-Histoquímica , Proteínas de Insetos/química , Proteínas de Insetos/genética , Óvulo/metabolismo , Fosforilação , Análise Serial de Proteínas , Subunidades Proteicas/química , Subunidades Proteicas/genética , Distribuição Tecidual
8.
Zoolog Sci ; 38(4): 332-342, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34342954

RESUMO

Animals survive nutrient deficiency by controlling their physiology, such as sugar metabolism and energy-consuming developmental events. Although research on the insect neural mechanisms of the starvation-induced modulation has progressed, the mechanisms have not been fully understood due to their complexity. Myoinhibitory peptides are known to be neuropeptides involved in various physiological activities, development, and behavior. Here, we analyzed the responsiveness of Plautia stali myoinhibitory peptides (Plast-MIPs) to starvation and their physiological role in the brown-winged green bug, P. stali. First, we performed immunohistochemical analyses to investigate the response of Plast-MIP neurons in the cephalic ganglion to fasting under long day conditions. Fasting significantly enhanced the immunoreactivity to Plast-MIPs in the pars intercerebralis (PI), which is known to be a brain region related to various endocrine regulations. Next, to analyze the physiological role of Plast-MIPs, we performed RNA interference-mediated knockdown of Plast-Mip and injection of synthetic Plast-MIP in normally fed and fasted females. The knockdown of Plast-Mip did not have significant effects on the body weight or proportions of ovarian development in each feeding condition. On the other hand, the knockdown of Plast-Mip increased the gonadosomatic index of normally fed females whereas it did not have a significant effect on food intake. Notably, the knockdown of Plast-Mip diminished the fasting-induced reduction of hemolymph reducing sugar levels. Additionally, injection of synthetic Plast-MIP acutely decreased the hemolymph reducing sugar level. Our results suggested responsiveness of Plast-MIPs in the PI to fasting and their functional role in reduction of the hemolymph reducing sugar level.


Assuntos
Carboidratos/química , Hemolinfa/química , Heterópteros/fisiologia , Proteínas de Insetos/metabolismo , Animais , Metabolismo dos Carboidratos , Feminino , Hemolinfa/metabolismo , Proteínas de Insetos/genética , Interferência de RNA
9.
J Insect Sci ; 21(4)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34333649

RESUMO

Chitin deacetylases (CDAs) are chitin-degrading enzymes that play a key role in insect molting. In this study, we identified and characterized four full-length cDNAs of CDAs from Sogatella furcifera (Horváth). Developmental expression showed that SfCDA1 and SfCDA2 were expressed at all nymph developmental stages, SfCDA3 and SfCDA4 were mainly expressed in the third-instar to fifth-instar nymph stages, whereas tissue-specific analyses indicated that four CDA genes were mainly high expressed in the integument and head during the fifth-instar nymph. RNA interference (RNAi) results revealed that SfCDA1, SfCDA2, and SfCDA4 are associated with molting defect and high mortality with nymph-adult molting. Furthermore, transcripts of chitin synthase 1 variants (SfCHS1, SfCHS1a, and SfCHS1b) were significantly downregulated and causing significant changes in the expression levels of trehalases (TRE1 and TRE2) in the SfCDA1, SfCDA2, and SfCDA4 dsRNA treatment groups. By contrast, no significant phenotypic characteristics were observed after dsSfCDA3 injection. Taken together, our results suggest that SfCDA1, SfCDA2, and SfCDA4 play a vital role in nymph-adult transition, and these genes could regulate chitin biosynthesis expression levels.


Assuntos
Amidoidrolases/genética , Hemípteros , Animais , Quitina/biossíntese , Quitina/genética , DNA Complementar , Genes de Insetos , Hemípteros/genética , Proteínas de Insetos/genética , Muda/genética , Ninfa/genética , Filogenia , Interferência de RNA , Asas de Animais/crescimento & desenvolvimento
10.
Science ; 373(6554): 535-541, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34326235

RESUMO

Interkingdom competition occurs between hymenopteran parasitoids and insect viruses sharing the same insect hosts. It has been assumed that parasitoid larvae die with the death of the infected host or as result of competition for host resources. Here we describe a gene family, parasitoid killing factor (pkf), that encodes proteins toxic to parasitoids of the Microgastrinae group and determines parasitism success. Pkfs are found in several entomopathogenic DNA virus families and in some lepidopteran genomes. We provide evidence of equivalent and specific toxicity against endoparasites for PKFs found in entomopoxvirus, ascovirus, baculovirus, and Lepidoptera through a mechanism that elicits apoptosis in the cells of susceptible parasitoids. This highlights the evolutionary arms race between parasitoids, viruses, and their insect hosts.


Assuntos
Entomopoxvirinae/fisiologia , Proteínas de Insetos/toxicidade , Lepidópteros/parasitologia , Lepidópteros/virologia , Proteínas Virais/toxicidade , Vespas/fisiologia , Animais , Apoptose , Evolução Biológica , Transferência Genética Horizontal , Genoma de Inseto , Interações Hospedeiro-Parasita , Proteínas de Insetos/química , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Vírus de Insetos/fisiologia , Larva/genética , Larva/parasitologia , Larva/virologia , Lepidópteros/genética , Lepidópteros/metabolismo , Nucleopoliedrovírus/fisiologia , Spodoptera/genética , Spodoptera/metabolismo , Spodoptera/parasitologia , Spodoptera/virologia , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo , Vespas/crescimento & desenvolvimento
11.
Arch Insect Biochem Physiol ; 108(1): e21824, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34272758

RESUMO

Insect gonads develop under endocrine signals. In this study, we assessed the characters of partial complementary DNAs encoding the Teleogryllus emma orthologs of 20-hydroxyecdysone (20E)-related genes (RXR, E75, HR3, Hsc70, and Hsp90) and analyzed their expression patterns in both nymph and adult crickets. 20E treatment suppressed expression of TeEcR, TeRXR, TeE75, TeHR3, TeHsc70, and TeHsp90. Temporal expression analysis demonstrated that TeERR and 20E-related genes were expressed in four stages of gonadal development from the fourth-instar nymph stage to the adult stage. The expression pattern of these genes differed in testicular and ovarian development. TeRXR, HR3, TeHsc70, and TeHsp90 were irregularly expressed in gonads of the same developmental stages, while mRNAs encoding TeERR, TeEcR, and TeE75 accumulated in higher levels in ovaries than in testes. RNA interference (RNAi) of TeEcR expression led to decrease of the expression levels of TeEcR, TeRXR, TeHR3, and TeHsc70, while it enhanced TeE75 and TeHsp90 expressions. These results demonstrate that the TeERR and 20E-related genes help regulate gonadal development, while TeEcR appears to inhibit TeE75 expression, TeE75 inhibits HR3 expression. Hsc70 indirectly regulated the expression of the primary and secondary response genes E74A, E75B, and HR3. Hsp90 regulated Usp expression with no direct regulatory relationship with EcR.


Assuntos
Ecdisterona , Gônadas , Gryllidae/metabolismo , Animais , Ecdisterona/genética , Ecdisterona/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genes de Insetos , Gônadas/crescimento & desenvolvimento , Gônadas/metabolismo , Gryllidae/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Masculino , Ovário/crescimento & desenvolvimento , Ovário/metabolismo , Testículo/crescimento & desenvolvimento , Testículo/metabolismo
12.
Arch Insect Biochem Physiol ; 108(1): e21830, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34288081

RESUMO

Zinc finger proteins (ZFPs) are a class of transcription factors that contain zinc finger domains and play important roles in growth, aging, and responses to abiotic and biotic stresses. These proteins activate or inhibit gene transcription by binding to single-stranded DNA or RNA and through RNA/DNA bidirectional binding and protein-protein interactions. However, few studies have focused on the oxidation resistance functions of ZFPs in insects, particularly Apis cerana. In the current study, we identified a ZFP41 gene from A. cerana, AcZFP41, and verified its function in oxidative stress responses. Real-time quantitative polymerase chain reaction showed that the transcription level of AcZFP41 was upregulated to different degrees during exposure to oxidative stress, including that induced by extreme temperature, UV radiation, or pesticides. In addition, the silencing of AcZFP41 led to changes in the expression patterns of some known antioxidant genes. Moreover, the activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and glutathione S-transferase (GST) in AcZFP41-silenced honeybees were higher than those in a control group. In summary, the data indicate that AcZFP41 is involved in the oxidative stress response. The results provide a theoretical basis for further studies of zinc finger proteins and improve our understanding of the antioxidant mechanisms of honeybees.


Assuntos
Abelhas , Estresse Oxidativo/genética , Estresse Fisiológico/genética , Dedos de Zinco/genética , Animais , Antioxidantes/metabolismo , Abelhas/genética , Abelhas/metabolismo , Abelhas/fisiologia , Glutationa Transferase/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Peroxidase/metabolismo , Interferência de RNA , Superóxido Dismutase/metabolismo , Dedos de Zinco/fisiologia
13.
Arch Insect Biochem Physiol ; 108(1): e21833, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34288091

RESUMO

The homeobox family is a large and diverse superclass of genes, many of which act as transcription factors that play important roles in tissue differentiation and embryogenesis in animals. The brown planthopper (BPH), Nilaparvata lugens, is the most destructive pest of rice in Asia, and high fecundity contributes significantly to its ecological success in natural and agricultural habits. Here, we identified 94 homeobox genes in BPH, which could be divided into 75 gene families and 9 classes. This number is comparable to the number of homeobox genes found in the honeybee Apis mellifera, but is slightly less than in Drosophila or the red flour beetle Tribolium castaneum. A spatio-temporal analysis indicated that most BPH homeobox genes were expressed in a development and tissue-specific manner, of which 21 genes were highly expressed in ovaries. RNA interference (RNAi)-mediated functional assay showed that 22 homeobox genes were important for nymph development and the nymph to adult transition, whereas 67 genes were dispensable during this process. Fecundity assay showed that knockdown of 13 ovary-biased genes (zfh1, schlank, abd-A, Lim3_2, Lmxb, Prop, ap_1, Not, lab, Hmx, vis, Pknox, and C15) led to the reproductive defect. This is the first comprehensive investigation into homeobox genes in a hemipteran insect and thus helps us to understand the functional significance of homeobox genes in insect reproduction.


Assuntos
Fertilidade/genética , Genes Homeobox , Hemípteros/genética , Animais , Perfilação da Expressão Gênica/métodos , Genes de Insetos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Ninfa/genética , Controle de Pragas , Interferência de RNA , Reprodução/genética
14.
Pestic Biochem Physiol ; 177: 104899, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34301361

RESUMO

The silkworm, Bombyx mori (B. mori) is an important economic insect which ingests mulberry leaves and products the silk in industry. Chlorfenapyr is a new halogenated pyrrole insecticide which has been promoted for the control of mulberry insect pests in China. However, the detoxification mechanism of the silkworm to chlorfenapyr has not been investigated yet. In the present study, we first estimated the LC30 dose of chlorfenapyr for 3rd instar B. mori larvae, and then, in order to characterise the chlorfenapyr detoxification mechanism, the transcriptomes of chlorfenapyr-treated and untreated 3rd instar B. mori larvae were compared using RNA-sequencing. In total, 146, 533, 126 and 148, 957, 676 clean reads were obtained from insecticide-treated and control silkworm larvae, respectively, and these reads generated 10, 954 genes. The transcriptional profile of silkworm larvae was significantly influenced by chlorfenapyr treatment. A total of 1196 differentially expressed genes (DEGs) were identified in insecticide-treated and control B. mori larvae, in which 644 genes were upregulated and 552 genes were downregulated. Results showed that multiple DEGs were enriched in detoxication-related gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Eleven detoxifying enzyme genes which differentially expressed were screened, and their expression patterns were validated by qRT-PCR. Furthermore, we successfully knocked down all differentially upregulated detoxifying enzyme genes, and a bioassay showed that the mortality of chlorfenapyr-treated silkworm larvae was significantly higher after silencing these genes than in groups injected with dsGFP. The present study reveals the molecular basis of silkworm detoxification to chlorfenapyr exposure, and provides new insights into the management of insecticide damage in the silkworm.


Assuntos
Bombyx , Animais , Bombyx/genética , Bombyx/metabolismo , China , Perfilação da Expressão Gênica , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Piretrinas , Transcriptoma
15.
Pestic Biochem Physiol ; 177: 104905, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34301366

RESUMO

The sulfuryl transfer reaction catalyzed by cytosolic sulfotransferase (SULT) is one of the major conjugating pathways responsible for the detoxification and subsequent elimination of xenobiotics, however, functional characterization of insect SULTs is still limited. In this study, cDNA encoding a cytosolic sulfotransferase, named TcSULT1, was cloned from the red flour beetle, Tribolium castaneum. Sequence analysis revealed that TcSULT1 had the conserved signature sequences of SULTs, and shared moderate amino acid identities with Bombyx mori and Drosophila SULTs. Analysis of the transcription level showed that TcSULT1 was highly expressed in head, epidermis and malpighian tube, and upregulated at 4 h after exposure to deltamethrin. Knockdown of TcSULT1 significantly increased the susceptibility of beetles to deltamethrin. Both RNAi and dual-luciferase assay revealed that the transcription factor TcCncC regulates the expression of TcSULT1. These data provides insights into the function and regulatory mechanism of insect SULTs.


Assuntos
Piretrinas , Tribolium , Animais , Proteínas de Insetos/genética , Nitrilas/toxicidade , Piretrinas/toxicidade , Sulfotransferases/genética , Tribolium/genética
16.
Gene ; 800: 145833, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34274477

RESUMO

As one of the most common benthic invertebrates in freshwater, mayflies are very sensitive to changes in water quality and have high requirements for the water environment to allow their nymphs to successfully live and grow. Neonicotinoids, such as imidacloprid, can enter fresh water and pollute the aquatic environment. The present study had two goals: (1) investigate imidacloprid effects on mayfly larvae Choroterpes (Euthralus) yixingensis, and (2) contribute to the phylogenetic status of Ephemeroptera that has always been controversial. Nymphs were collected from Jinhua, China and exposed to different concentrations imidacloprid (5, 10, 20, and 40 µg/L) in the laboratory. Survival of C. yixingensis nymphs decreased as a function of time and imidacloprid concentration with only ~ 55% survival after 72 h exposure to 40 µg/L imidacloprid. After culture under 40 µg/L imidacloprid for 24 h, the steady state transcript levels of mitochondrial COX3, ND4 and ND4L genes were reduced to just 0.07 ± 0.11, 0.30 ± 0.16, and 0.28 ± 0.13 as compared with respective control values (P < 0.01). Steady state transcript levels of ND4 and ND4L were also significantly reduced in a dose-dependent manner (P < 0.05), suggesting that the steady state transcript pattern of these genes in mayfly nymphs can change in response to different levels of environmental contamination. Hence, the mitochondrial protein-coding genes of mayflies could potentially be developed as biomarkers for water ecotoxicity monitoring in the future. In addition, we used the mitochondrial genome sequence of C. yixingensis for an assessment of the phylogenetic tree of Ephemeroptera. The monophyly of Leptophlebiidae was supported and showed that Leptophlebiidae was a sister group to the clade (Baetidae + Caenidae).


Assuntos
Ephemeroptera/genética , Expressão Gênica/efeitos dos fármacos , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Animais , Ephemeroptera/efeitos dos fármacos , Genoma de Inseto , Genoma Mitocondrial , Proteínas de Insetos/genética , Inseticidas/farmacologia , Ninfa/efeitos dos fármacos , Ninfa/genética , Filogenia
17.
Nat Commun ; 12(1): 4498, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301931

RESUMO

In animal germlines, PIWI proteins and the associated PIWI-interacting RNAs (piRNAs) protect genome integrity by silencing transposons. Here we report the extensive sequence and quantitative correlations between 2',3'-cyclic phosphate-containing RNAs (cP-RNAs), identified using cP-RNA-seq, and piRNAs in the Bombyx germ cell line and mouse testes. The cP-RNAs containing 5'-phosphate (P-cP-RNAs) identified by P-cP-RNA-seq harbor highly consistent 5'-end positions as the piRNAs and are loaded onto PIWI protein, suggesting their direct utilization as piRNA precursors. We identified Bombyx RNase Kappa (BmRNase κ) as a mitochondria-associated endoribonuclease which produces cP-RNAs during piRNA biogenesis. BmRNase κ-depletion elevated transposon levels and disrupted a piRNA-mediated sex determination in Bombyx embryos, indicating the crucial roles of BmRNase κ in piRNA biogenesis and embryonic development. Our results reveal a BmRNase κ-engaged piRNA biogenesis pathway, in which the generation of cP-RNAs promotes robust piRNA production.


Assuntos
Endorribonucleases/genética , Perfilação da Expressão Gênica/métodos , Proteínas de Insetos/genética , RNA Interferente Pequeno/genética , RNA/genética , Animais , Sequência de Bases , Bombyx , Linhagem Celular , Endorribonucleases/metabolismo , Feminino , Proteínas de Insetos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Mutação , Ácidos Fosfatídicos/química , RNA/química , RNA/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , RNA-Seq/métodos , Testículo/metabolismo
18.
Int J Mol Sci ; 22(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34298876

RESUMO

The neurohormone octopamine regulates many crucial physiological processes in insects and exerts its activity via typical G-protein coupled receptors. The roles of octopamine receptors in regulating behavior and physiology in Coleoptera (beetles) need better understanding. We used the red flour beetle, Tribolium castaneum, as a model species to study the contribution of the octopamine receptor to behavior and physiology. We cloned the cDNA of a ß-adrenergic-like octopamine receptor (TcOctß2R). This was heterologously expressed in human embryonic kidney (HEK) 293 cells and was demonstrated to be functional using an in vitro cyclic AMP assay. In an RNAi assay, injection of dsRNA demonstrated that TcOctß2R modulates beetle locomotion, mating duration, and fertility. These data present some roles of the octopaminergic signaling system in T. castaneum. Our findings will also help to elucidate the potential functions of individual octopamine receptors in other insects.


Assuntos
Locomoção/genética , Octopamina/genética , Receptores de Amina Biogênica/genética , Reprodução/genética , Tribolium/genética , Adrenérgicos/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Besouros/genética , AMP Cíclico/genética , Feminino , Células HEK293 , Humanos , Proteínas de Insetos/genética , Masculino , Interferência de RNA/fisiologia , RNA de Cadeia Dupla/genética , Receptores Acoplados a Proteínas G/genética , Alinhamento de Sequência
19.
Int J Mol Sci ; 22(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198929

RESUMO

The molecular mechanisms of insect resistance to Cry toxins generated from the bacterium Bacillus thuringiensis (Bt) urgently need to be elucidated to enable the improvement and sustainability of Bt-based products. Although downregulation of the expression of midgut receptor genes is a pivotal mechanism of insect resistance to Bt Cry toxins, the underlying transcriptional regulation of these genes remains elusive. Herein, we unraveled the regulatory mechanism of the downregulation of the ABC transporter gene PxABCG1 (also called Pxwhite), a functional midgut receptor of the Bt Cry1Ac toxin in Plutella xylostella. The PxABCG1 promoters of Cry1Ac-susceptible and Cry1Ac-resistant strains were cloned and analyzed, and they showed clear differences in activity. Subsequently, a dual-luciferase reporter assay, a yeast one-hybrid (Y1H) assay, and RNA interference (RNAi) experiments demonstrated that a cis-mutation in a binding site of the Hox transcription factor Antennapedia (Antp) decreased the promoter activity of the resistant strain and eliminated the binding and regulation of Antp, thereby enhancing the resistance of P. xylostella to the Cry1Ac toxin. These results advance our knowledge of the roles of cis- and trans-regulatory variations in the regulation of midgut Cry receptor genes and the evolution of Bt resistance, contributing to a more complete understanding of the Bt resistance mechanism.


Assuntos
Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Toxinas de Bacillus thuringiensis/genética , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Receptores de Superfície Celular/genética , Animais , Bacillus thuringiensis/genética , Endotoxinas/genética , Lepidópteros/efeitos dos fármacos , Lepidópteros/genética , Mutação/genética , Regiões Promotoras Genéticas/genética
20.
Pest Manag Sci ; 77(10): 4593-4606, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34092019

RESUMO

BACKGROUND: Broad use of insecticidal Cry proteins from Bacillus thuringiensis in biopesticides and transgenic crops has resulted in cases of practical field resistance, highlighting the need for novel approaches to insect control. Previously we described an anti-Cry1Ab idiotypic-antibody (B12-scFv) displaying toxicity against rice leafroller (Cnaphalocrocis medinalis) larvae, supporting the potential of antibodies for pest control. The goal of the present study was to generate insecticidal antibodies against diamondback moth (Plutella xylostella) larvae. RESULTS: Four genetically engineered antibodies (GEAbs) were designed in silico from B12-scFv using three-dimensional (3D) structure and docking predictions to alkaline phosphatase (ALP) as a Cry1Ac receptor in P. xylostella. Among these GEAbs, the GEAb-dVL antibody consisting of two light chains had overlapping binding sites with Cry1A and Cry1B proteins and displayed high binding affinity to P. xylostella midgut brush border membrane (BBM) proteins. Proteins in BBM identified by pull-down assays as binding to GEAb-dVL included an ABC transporter and V-ATPase subunit A protein. Despite lacking the α-helical structures in Cry1A that are responsible for pore formation, ingestion of GEAb-dVL disrupted the P. xylostella larval midgut epithelium and resulted in toxicity. Apoptotic genes were activated in gut cells upon treatment with GEAb-dVL . CONCLUSION: This study describes the first insecticidal GEAb targeting P. xylostella by mimicking Cry proteins. Data support that GEAb-dVL toxicity is associated to activation of intracellular cell death pathways, in contrast to pore-formation associated toxicity of Cry proteins. This work provides a foundation for the design of novel insecticidal antibodies for insect control. © 2021 Society of Chemical Industry.


Assuntos
Bacillus thuringiensis , Inseticidas , Mariposas , Animais , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Inseticidas/farmacologia , Larva/metabolismo , Mariposas/metabolismo , Ligação Proteica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...