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1.
Arch Insect Biochem Physiol ; 103(2): e21632, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31621105

RESUMO

Biogenic amines (BAs), such as octopamine, tyramine, dopamine, serotonin, and acetylcholine regulate various behaviors and physiological functions in insects. Here, we identified seven genes encoding BA biosynthetic enzymes and 16 genes encoding BA G protein-coupled receptors in the genome of the endoparasitoid wasp, Pteromalus puparum. We compared the genes with their orthologs in its host Pieris rapae and the related ectoparasitic wasp Nasonia vitripennis. All the genes show high (>90%) identity to orthologs in N. vitripennis. P. puparum and N. vitripennis have the smallest number of BA receptor genes among the insect species we investigated. We then analyzed the expression profiles of the genes, finding those acting in BA biosynthesis were highly expressed in adults and larvae and those encoding BA receptors are highly expressed in adults than immatures. Octα1R and 5-HT7 genes were highly expressed in salivary glands, and a high messenger RNA level of 5-HT1A was found in venom apparatuses. We infer that BA signaling is a fundamental component of the organismal organization, homeostasis and operation in parasitoids, some of the smallest insects.


Assuntos
Aminas Biogênicas/metabolismo , Borboletas/genética , Proteínas de Insetos/genética , Vespas/genética , Sequência de Aminoácidos , Animais , Borboletas/química , Borboletas/metabolismo , Borboletas/parasitologia , Embrião não Mamífero/química , Embrião não Mamífero/metabolismo , Feminino , Perfilação da Expressão Gênica , Interações Hospedeiro-Parasita , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Larva/genética , Larva/metabolismo , Masculino , Filogenia , Pupa/genética , Pupa/metabolismo , Alinhamento de Sequência , Vespas/enzimologia , Vespas/crescimento & desenvolvimento , Vespas/metabolismo
2.
Arch Insect Biochem Physiol ; 103(2): e21625, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31565815

RESUMO

In insects, neuropeptides constitute a group of signaling molecules that act in regulation of multiple physiological and behavioral processes by binding to their corresponding receptors. On the basis of the bioinformatic approaches, we screened the genomic and transcriptomic data of the parasitoid wasp, Pteromalus puparum, and annotated 36 neuropeptide precursor genes and 33 neuropeptide receptor genes. Compared to the number of precursor genes in Bombyx mori (Lepidoptera), Chilo suppressalis (Lepidoptera), Drosophila melanogaster (Diptera), Nilaparvata lugens (Hemiptera), Apis mellifera (Hymenoptera), and Tribolium castaneum (Coleoptera), P. puparum (Hymenoptera) has the lowest number of neuropeptide precursor genes. This lower number may relate to its parasitic life cycle. Transcriptomic data of embryos, larvae, pupae, adults, venom glands, salivary glands, ovaries, and the remaining carcass revealed stage-, sex-, and tissue-specific expression patterns of the neuropeptides, and their receptors. These data provided basic information about the identity and expression profiles of neuropeptides and their receptors that are required to functionally address their biological significance in an endoparasitoid wasp.


Assuntos
Proteínas de Insetos/genética , Neuropeptídeos/genética , Receptores de Neuropeptídeos/genética , Vespas/genética , Sequência de Aminoácidos , Animais , Embrião não Mamífero/química , Embrião não Mamífero/metabolismo , Feminino , Perfilação da Expressão Gênica , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Larva/genética , Larva/metabolismo , Masculino , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Filogenia , Pupa/genética , Pupa/metabolismo , Receptores de Neuropeptídeos/química , Receptores de Neuropeptídeos/metabolismo , Alinhamento de Sequência , Vespas/crescimento & desenvolvimento , Vespas/metabolismo
3.
Arch Insect Biochem Physiol ; 103(2): e21634, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31587360

RESUMO

Pteromalus puparum is a gregarious pupal endoparasitoid with a wide host range. It deposits eggs into pierid and papilionid butterfly pupae. Glutathione S-transferases (GSTs) are a family of multifunctional detoxification enzymes that act in xenobiotic metabolism in insects. Insect genome projects have facilitated identification and characterization of GST family members. We identified 20 putative GSTs in the P. puparum genome, including 19 cytosolic and one microsomal. Phylogenetic analysis showed that P. puparum GSTs are clustered into Hymenoptera-specific branches. Transcriptomic data of embryos, larvae, female pupae, male pupae, female adults, male adults, venom glands, carcass, salivary glands, and ovaries revealed stage-, sex-, and tissue-specific expression patterns of GSTs in P. puparum. This is the most comprehensive study of genome-wide identification, characterization, and expression profiling of GST family in hymenopterans. Our results provide valuable information for understanding the metabolic adaptation of this wasp.


Assuntos
Glutationa Transferase/genética , Proteínas de Insetos/genética , Vespas/genética , Sequência de Aminoácidos , Animais , Embrião não Mamífero/química , Embrião não Mamífero/metabolismo , Feminino , Perfilação da Expressão Gênica , Glutationa Transferase/química , Glutationa Transferase/metabolismo , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Larva/genética , Larva/metabolismo , Masculino , Filogenia , Pupa/genética , Pupa/metabolismo , Alinhamento de Sequência , Vespas/crescimento & desenvolvimento , Vespas/metabolismo
4.
Front Physiol ; 10: 1282, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31680999

RESUMO

The immunological interaction between Drosophila melanogaster and its larval parasitoids has been thoroughly investigated, however, little is known about the interaction between the host and its pupal parasitoids. Pachycrepoideus vindemmiae, a pupal ectoparasitoid of D. melanogaster, injects venom into its host while laying eggs on the puparium, which regulates host immunity and interrupts host development. To resist the invasion of parasitic wasps, various immune defense strategies have been developed in their hosts as a consequence of co-evolution. In this study, we mainly focused on the host immunomodulation by P. vindemmiae and thoroughly investigated cellular and humoral immune response, including cell adherence, cell viability, hemolymph melanization and the Toll, Imd, and JAK/STAT immune pathways. Our results indicated that venom had a significant inhibitory effect on lamellocyte adherence and induced plasmatocyte cell death. Venom injection and in vitro incubation strongly inhibited hemolymph melanization. More in-depth investigation revealed that the Toll and Imd immune pathways were immediately activated upon parasitization, followed by the JAK/STAT pathway, which was activated within the first 24 h post-parasitism. These regulatory effects were further validated by qPCR. Our present study manifested that P. vindemmiae regulated the cellular and humoral immune system of host D. melanogaster in many aspects. These findings lay the groundwork for studying the immunological interaction between D. melanogaster and its pupal parasitoid.

5.
Pest Manag Sci ; 75(5): 1361-1369, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30370997

RESUMO

BACKGROUD: Insect TRPV is a subfamily of transient receptor potential (TRP) ion channels, including two genes, nanchung and inactive. It has recently been found that two commercial insecticides, pymetrozine and pyrifluquinazon, target the heteromeric TRPV ion channel complex which is specifically expressed in the chordotonal organ neurons in Drosophila. However, information on the TRPV genes in agricultural insects is still limited. RESULTS: In this study, we cloned and characterized two TRPV genes from Nilaparvata lugens (NlNan and NLIav) and Nephotettix cincticeps (NcNan and NcIav), two serious rice pests throughout Asia. The deduced amino acid sequences share highly identity with other insect homologues (58-85%) and have the characteristic TRPV domain architecture: five ankyrin repeats and six transmembrane domains. These TRPV transcripts were expressed in all developmental stages and expression levels in male adults were significantly higher than in female adults. Moreover, expression levels in antennae were much higher than in heads and legs. CONCLUSION: NlNan, NlIav, NcNan and NcIav may have roles in male-specific behaviors, and the sequence information lays the foundation for further study on the structural and functional characterization of TRPVs in agricultural pests. © 2018 Society of Chemical Industry.


Assuntos
Hemípteros/genética , Proteínas de Insetos/genética , Oryza , Canais de Cátion TRPV/genética , Sequência de Aminoácidos , Animais , Clonagem Molecular , Regulação da Expressão Gênica no Desenvolvimento , Hemípteros/crescimento & desenvolvimento , Proteínas de Insetos/química , Modelos Moleculares , Especificidade de Órgãos , Conformação Proteica , Canais de Cátion TRPV/química
6.
Nat Plants ; 4(6): 338-344, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29735983

RESUMO

Rice is one of the world's most important foods, but its production suffers from insect pests, causing losses of billions of dollars, and extensive use of environmentally damaging pesticides for their control1,2. However, the molecular mechanisms of insect resistance remain elusive. Although a few resistance genes for planthopper have been cloned, no rice germplasm is resistant to stem borers. Here, we report that biosynthesis of serotonin, a neurotransmitter in mammals3, is induced by insect infestation in rice, and its suppression confers resistance to planthoppers and stem borers, the two most destructive pests of rice2. Serotonin and salicylic acid derive from chorismate4. In rice, the cytochrome P450 gene CYP71A1 encodes tryptamine 5-hydroxylase, which catalyses conversion of tryptamine to serotonin5. In susceptible wild-type rice, planthopper feeding induces biosynthesis of serotonin and salicylic acid, whereas in mutants with an inactivated CYP71A1 gene, no serotonin is produced, salicylic acid levels are higher and plants are more insect resistant. The addition of serotonin to the resistant rice mutant and other brown planthopper-resistant genotypes results in a loss of insect resistance. Similarly, serotonin supplementation in artificial diet enhances the performance of both insects. These insights demonstrate that regulation of serotonin biosynthesis plays an important role in defence, and may prove valuable for breeding insect-resistant cultivars of rice and other cereal crops.


Assuntos
Oryza/metabolismo , Serotonina/metabolismo , Animais , Regulação da Expressão Gênica de Plantas , Hemípteros , Herbivoria , Mariposas , Oryza/fisiologia , Reguladores de Crescimento de Planta/metabolismo , Ácido Salicílico/metabolismo
7.
Pest Manag Sci ; 74(8): 1854-1860, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29427309

RESUMO

BACKGROUND: Honeydew is a sugar-rich excretion produced by sap-feeding Sternorrhyncha and is an important source of carbohydrates for natural enemies, especially for parasitoids. Honeydew derived from genetically modified (GM) crops can contain amounts of the transgene product. Thus, it is a possible route of exposure for natural enemies feeding on honeydew. In the present study, the potential effects of Nilaparvata lugens honeydew derived from Cry1C and Cry2A rice on different life-table parameters and parasitism dynamics of the egg parasitoid Anagrus nilaparvatae were evaluated under laboratory and field conditions. Furthermore, the Bacillus thuringiensis (Bt) levels and the sugar and amino acid composition of honeydew were analyzed. RESULTS: Results indicated that A. nilaparvatae was exposed to Bt proteins by feeding on N. lugens honeydew produced from Bt rice. However, honeydew derived from the tested Cry1C and Cry2A rice lines did not affect the development, longevity, emergence rate and fecundity of A. nilaparvatae. Also, the parasitism dynamics in the field remained unaffected. In addition, the sugar and amino acid composition of N. lugens honeydew was not significantly altered for the tested Bt rice lines compared with the parental non-Bt plant. CONCLUSION: The quality of honeydew derived from the tested Bt rice lines as a food resource for natural enemies was maintained. © 2018 Society of Chemical Industry.


Assuntos
Proteínas de Bactérias/efeitos adversos , Endotoxinas/efeitos adversos , Hemípteros/parasitologia , Proteínas Hemolisinas/efeitos adversos , Interações Hospedeiro-Parasita , Inseticidas/efeitos adversos , Oryza/química , Vespas/fisiologia , Aminoácidos/química , Animais , Dieta , Tábuas de Vida , Plantas Geneticamente Modificadas/química , Açúcares/química
8.
Insect Biochem Mol Biol ; 90: 61-70, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28942992

RESUMO

As the counterparts of the vertebrate adrenergic transmitters, octopamine and tyramine are important physiological regulators in invertebrates. They control and modulate many physiological and behavioral functions in insects. In this study, we reported the pharmacological properties of a new α2-adrenergic-like octopamine receptor (CG18208) from Drosophila melanogaster, named DmOctα2R. This new receptor gene encodes two transcripts by alternative splicing. The long isoform DmOctα2R-L differs from the short isoform DmOctα2R-S by the presence of an additional 29 amino acids within the third intracellular loop. When heterologously expressed in mammalian cell lines, both receptors were activated by octopamine, tyramine, epinephrine and norepinephrine, resulting in the inhibition of cAMP production in a dose-dependent manner. The long form is more sensitive to the above ligands than the short form. The adrenergic agonists naphazoline, tolazoline and clonidine can stimulate DmOctα2R as full agonists. Surprisingly, serotonin and serotoninergic agonists can also activate DmOctα2R. Several tested adrenergic antagonists and serotonin antagonists blocked the action of octopamine or serotonin on DmOctα2R. The data presented here reported an adrenergic-like G protein-coupled receptor activated by serotonin, suggesting that the neurotransmission and neuromodulation in the nervous system could be more complex than previously thought.


Assuntos
Drosophila melanogaster/metabolismo , Receptores de Amina Biogênica/metabolismo , Serotonina/metabolismo , Processamento Alternativo , Sequência de Aminoácidos , Animais , Células CHO , Cricetulus , AMP Cíclico/metabolismo , Feminino , Células HEK293 , Humanos , Proteínas de Insetos/agonistas , Proteínas de Insetos/antagonistas & inibidores , Proteínas de Insetos/metabolismo , Masculino , Receptores de Amina Biogênica/agonistas , Receptores de Amina Biogênica/antagonistas & inibidores , Análise de Sequência de DNA
9.
Insect Biochem Mol Biol ; 87: 107-116, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28663125

RESUMO

Serotonin (5-hydroxytryptamine, 5-HT) plays a key role in modulating diverse physiological processes and behaviors in both protostomes and deuterostomes. These functions are mediated through the binding of serotonin to its receptors, which are recognized as potential insecticide targets. We investigated the sequence, pharmacology and tissue distribution of three 5-HT receptors (Piera5-HT1A, Piera5-HT1B, Piera5-HT7) from the small white butterfly Pieris rapae, an important pest of cultivated cabbages and other mustard family crops. Activation of Piera5-HT1A or Piera5-HT1B by 5-HT inhibited the production of cAMP in a dose-dependent manner. Stimulation of Piera5-HT7 with 5-HT increased cAMP level significantly. Surprisingly, with the exception of 5-methoxytryptamine, agonists including α-methylserotonin, 8-Hydroxy-DPAT and 5-carboxamidotryptamine activated these receptors poorly. The results are consistent with previous findings in Manduca sexta. All three receptors were blocked by methiothepin, but ketanserin and yohimbine were not effective. The selective mammalian 5-HT receptor antagonists SB 216641 and SB 269970 displayed potent inhibition effects on Piera5-HT1B and Piera5-HT7 respectively. The results we achieved here indicate that the pharmacological properties of Lepidoptera 5-HT receptors are quite different from those in other insects and vertebrates and may contribute to development of new selective pesticides. This study offers important information on three 5-HT receptors from P. rapae that will facilitate further analysis of the functions of 5-HT receptors in insects.


Assuntos
Borboletas/metabolismo , Proteínas de Insetos/fisiologia , Receptores de Serotonina/fisiologia , Animais , Borboletas/efeitos dos fármacos , AMP Cíclico/biossíntese , Especificidade de Órgãos , Serotonina/farmacologia , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia
10.
Toxins (Basel) ; 9(4)2017 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-28417942

RESUMO

Many species of endoparasitoid wasps provide biological control services in agroecosystems. Although there is a great deal of information on the ecology and physiology of host/parasitoid interactions, relatively little is known about the protein composition of venom and how specific venom proteins influence physiological systems within host insects. This is a crucial gap in our knowledge because venom proteins act in modulating host physiology in ways that favor parasitoid development. Here, we identified 37 possible venom proteins from the polydnavirus-carrying endoparasitoid Cotesia chilonis by combining transcriptomic and proteomic analyses. The most abundant proteins were hydrolases, such as proteases, peptidases, esterases, glycosyl hydrolase, and endonucleases. Some components are classical parasitoid venom proteins with known functions, including extracellular superoxide dismutase 3, serine protease inhibitor and calreticulin. The venom contains novel proteins, not recorded from any other parasitoid species, including tolloid-like proteins, chitooligosaccharidolytic ß-N-acetylglucosaminidase, FK506-binding protein 14, corticotropin-releasing factor-binding protein and vascular endothelial growth factor receptor 2. These new data generate hypotheses and provide a platform for functional analysis of venom components.


Assuntos
Proteínas de Insetos/genética , Venenos de Vespas/genética , Animais , Feminino , Filogenia , Proteômica , RNA Mensageiro/metabolismo , Transcriptoma , Vespas/genética
11.
Insect Biochem Mol Biol ; 83: 80-93, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28302436

RESUMO

Dopamine is an important neurotransmitter and neuromodulator in both vertebrates and invertebrates and is the most abundant monoamine present in the central nervous system of insects. A complement of functionally distinct dopamine receptors mediate the signal transduction of dopamine by modifying intracellular Ca2+ and cAMP levels. In the present study, we pharmacologically characterized three types of dopamine receptors, CsDOP1, CsDOP2 and CsDOP3, from the rice striped stem borer, Chilo suppressalis. All three receptors show considerable sequence identity with orthologous dopamine receptors. The phylogenetic analysis also clusters the receptors within their respective groups. Transcript levels of CsDOP1, CsDOP2 and CsDOP3 were all expressed at high levels in the central nervous system, indicating their important roles in neural processes. After heterologous expression in HEK 293 cells, CsDOP1, CsDOP2 and CsDOP3 were dose-dependently activated by dopamine and synthetic dopamine receptor agonists. They can also be blocked by different series of antagonists. This study offers important information on three dopamine receptors from C. suppressalis that will provide the basis for forthcoming studies investigating their roles in behaviors and physiology, and facilitate the development of new insecticides for pest control.


Assuntos
Mariposas/química , Receptores Dopaminérgicos/química , Sequência de Aminoácidos , Animais , Agonistas de Dopamina/química , Antagonistas de Dopamina/química , Células HEK293 , Humanos , Dados de Sequência Molecular , Análise de Sequência de DNA
12.
Insect Sci ; 24(3): 371-384, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26847606

RESUMO

Nicotinic acetylcholine receptors (nAChRs) are members of the cys-loop ligand-gated ion channel (cysLGIC) superfamily, mediating fast synaptic cholinergic transmission in the central nervous system in insects. Insect nAChRs are the molecular targets of economically important insecticides, such as neonicotinoids and spinosad. Identification and characterization of the nAChR gene family in the rice striped stem borer, Chilo suppressalis, could provide beneficial information about this important receptor gene family and contribute to the investigation of the molecular modes of insecticide action and resistance for current and future chemical control strategies. We searched our C. suppressalis transcriptome database using Bombyx mori nAChR sequences in local BLAST searches and obtained the putative nAChR subunit complementary DNAs (cDNAs) via reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends methods. Similar to B. mori, C. suppressalis possesses 12 nAChR subunits, including nine α-type and three ß-type subunits. Quantitative RT-PCR analysis revealed the expression profiles of the nAChR subunits in various tissues, including the brain, subesophageal ganglion, thoracic ganglion, abdominal ganglion, hemocytes, fat body, foregut, midgut, hindgut and Malpighian tubules. Developmental expression analyses showed clear differential expression of nAChR subunits throughout the C. suppressalis life cycle. The identification of nAChR subunits in this study will provide a foundation for investigating the diverse roles played by nAChRs in C. suppressalis and for exploring specific target sites for chemicals that control agricultural pests while sparing beneficial species.


Assuntos
Mariposas/metabolismo , Receptores Nicotínicos/metabolismo , Sequência de Aminoácidos , Animais , Sistema Nervoso Central/metabolismo , Expressão Gênica , Dados de Sequência Molecular , Mariposas/genética , Mariposas/crescimento & desenvolvimento , Subunidades Proteicas/metabolismo , Receptores Nicotínicos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Environ Entomol ; 45(4): 1090-6, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27389683

RESUMO

The effects of three transgenic Bacillus thuringiensis (Bt) rice lines, KMD1, KMD2, and G8-7, on biological parameters and population dynamics of nontarget insect, Rhopalosiphum maidis (Fitch) (Homoptera: Aphididae), were investigated in the laboratory and field. No significant differences were found between Bt and non-Bt rice lines for aphid survival. The developmental time of R. maidis that fed on KMD1 and KMD2 did not differ significantly from those of the individuals feeding on the parental variety Xiushui11, but significantly prolonged developmental time was observed on G8-7 as compared with its parental variety Xiushui110. Aphid fecundity was significantly higher on Bt than on parental rice. A 2-yr field survey indicated that Bt rice did not significantly affect the population dynamics of R. maidis in comparison with non-Bt rice. Additionally, guttation droplets of Bt rice and aphids feeding on Bt rice were analyzed for presence of Cry1Ab using ELISA. No Cry1Ab protein was found in aphid adults feeding on Bt rice lines both in the laboratory and field. By using the guttation droplets from the top of rice seedlings, we designed a novel method to collect phloem sap, and found that relatively low concentrations were detected in the guttation droplets from Bt rice lines. In conclusion, although the Bt rice lines tested in this study stimulate the fecundity of R. maidis, the aphid population density did not increase in Bt rice fields.


Assuntos
Afídeos/fisiologia , Oryza/genética , Plantas Geneticamente Modificadas , Animais , Afídeos/efeitos dos fármacos , Afídeos/crescimento & desenvolvimento , Proteínas de Bactérias/farmacologia , Endotoxinas/farmacologia , Ensaio de Imunoadsorção Enzimática , Fertilidade/efeitos dos fármacos , Proteínas Hemolisinas/farmacologia , Longevidade/efeitos dos fármacos , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Dinâmica Populacional
14.
Sci Rep ; 6: 28976, 2016 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-27353701

RESUMO

In insects, neuropeptides play important roles in the regulation of multiple physiological processes by binding to their corresponding receptors, which are primarily G protein-coupled receptors (GPCRs). The genes encoding neuropeptides and their associated GPCRs in the rice stem borer Chilo suppressalis were identified by a transcriptomic analysis and were used to identify potential targets for the disruption of physiological processes and the protection of crops. Forty-three candidate genes were found to encode the neuropeptide precursors for all known insect neuropeptides except for arginine-vasopressin-like peptide (AVLP), CNMamide, neuropeptide-like precursors 2-4 (NPLP2-4), and proctolin. In addition, novel alternative splicing variants of three neuropeptide genes (allatostatin CC, CCHamide 1, and short neuropeptide F) are reported for the first time, and 51 putative neuropeptide GPCRs were identified. Phylogenetic analyses demonstrated that 44 of these GPCRs belong to the A-family (or rhodopsin-like), 5 belong to the B-family (or secretin-like), and 2 are leucine-rich repeat-containing GPCRs. These GPCRs and their likely ligands were also described. qRT-PCR analyses revealed the expression profiles of the neuropeptide precursors and GPCR genes in various tissues of C. suppressalis. Our study provides fundamental information that may further our understanding of neuropeptidergic signaling systems in Lepidoptera and aid in the design of peptidomimetics, pseudopeptides or small molecules capable of disrupting the physiological processes regulated by these signaling molecules and their receptors.


Assuntos
Perfilação da Expressão Gênica/métodos , Lepidópteros/metabolismo , Neuropeptídeos/genética , Oryza/parasitologia , Receptores Acoplados a Proteínas-G/genética , Processamento Alternativo , Animais , Regulação da Expressão Gênica , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Lepidópteros/genética , Neuropeptídeos/metabolismo , Filogenia , Receptores Acoplados a Proteínas-G/metabolismo , Análise de Sequência de RNA/métodos , Distribuição Tecidual
15.
Arch Insect Biochem Physiol ; 92(1): 3-5, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27110951
16.
Elife ; 52016 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-26974346

RESUMO

Serotonin (5-HT) modulates both neural and immune responses in vertebrates, but its role in insect immunity remains uncertain. We report that hemocytes in the caterpillar, Pieris rapae are able to synthesize 5-HT following activation by lipopolysaccharide. The inhibition of a serotonin-generating enzyme with either pharmacological blockade or RNAi knock-down impaired hemocyte phagocytosis. Biochemical and functional experiments showed that naive hemocytes primarily express 5-HT1B and 5-HT2B receptors. The blockade of 5-HT1B significantly reduced phagocytic ability; however, the blockade of 5-HT2B increased hemocyte phagocytosis. The 5-HT1B-null Drosophila melanogaster mutants showed higher mortality than controls when infected with bacteria, due to their decreased phagocytotic ability. Flies expressing 5-HT1B or 5-HT2B RNAi in hemocytes also showed similar sensitivity to infection. Combined, these data demonstrate that 5-HT mediates hemocyte phagocytosis through 5-HT1B and 5-HT2B receptors and serotonergic signaling performs critical modulatory functions in immune systems of animals separated by 500 million years of evolution.


Assuntos
Hemócitos/efeitos dos fármacos , Hemócitos/fisiologia , Fagocitose/efeitos dos fármacos , Receptores de Serotonina/metabolismo , Serotonina/metabolismo , Animais , Borboletas , Drosophila melanogaster
17.
Micron ; 83: 1-10, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26826802

RESUMO

The whitefly Bemisia tabaci MEAM1 species complex has invaded several parts of the world in the past 30 years and replaced native whitefly populations in the invaded regions, including certain areas of China. One of the possible reasons for the invasion is that MEAM1 whiteflies are more fecund than native species. However, the factors that affect the reproduction of the B. tabaci cryptic species are not clearly known. The regulation of oogenesis is thought to be one of the essential processes for egg formation and ovary development and could affect its population dynamics. In this study, the ovariole structure and oogenesis of the MEAM1 species complex was examined using light and transmission electron microscopy. Telotrophic ovarioles were observed in the MEAM1 species complex. Each ovariole had two well defined regions: the tropharium and the vitellarium. The tropharium always had more than ten trophocytes. The development of a single oocyte in the vitellarium has four phases: oocyte formation, previtellogenesis, vitellogenesis and choriogenesis. Two arrested oocytes, follicular cells and uncompleted oocytes were separated from the tropharium by microtubule and microfilaments. Early previtellogenesis oocytes absorbed nutrients and endosymbiont bacteria through a nutritive cord. However, the vitellogenesis of oocytes transmitted Vg through both the nutritive cord and the space between follicular cells. Each mature oocyte with deposited yolk proteins had only one bacteriocyte and was surrounded by a single layer of follicular cells. The oogenesis in the B. tabaci MEAM1 species complex concluded with the differentiation of oocytes, the transport of yolk and endosymbionts as well as the development and maturation of oocytes. This result provides important information that further defines the regulation of oogenesis in the B. tabaci complex.


Assuntos
Hemípteros , Oogênese , Animais , Diferenciação Celular , Hemípteros/citologia , Hemípteros/ultraestrutura , Oócitos/citologia , Oócitos/ultraestrutura
18.
Toxins (Basel) ; 8(2): 52, 2016 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-26907346

RESUMO

Insect host/parasitoid interactions are co-evolved systems in which host defenses are balanced by parasitoid mechanisms to disable or hide from host immune effectors. Here, we report that Pteromalus puparum venom impairs the antimicrobial activity of its host Pieris rapae. Inhibition zone results showed that bead injection induced the antimicrobial activity of the host hemolymph but that venom inhibited it. The cDNAs encoding cecropin and lysozyme were screened. Relative quantitative PCR results indicated that all of the microorganisms and bead injections up-regulated the transcript levels of the two genes but that venom down-regulated them. At 8 h post bead challenge, there was a peak in the transcript level of the cecropin gene, whereas the peak of lysozyme gene occurred at 24 h. The transcripts levels of the two genes were higher in the granulocytes and fat body than in other tissues. RNA interference decreased the transcript levels of the two genes and the antimicrobial activity of the pupal hemolymph. Venom injections similarly silenced the expression of the two genes during the first 8 h post-treatment in time- and dose-dependent manners, after which the silence effects abated. Additionally, recombinant cecropin and lysozyme had no significant effect on the emergence rate of pupae that were parasitized by P. puparum females. These findings suggest one mechanism of impairing host antimicrobial activity by parasitoid venom.


Assuntos
Borboletas/efeitos dos fármacos , Borboletas/parasitologia , Regulação da Expressão Gênica/efeitos dos fármacos , Interações Hospedeiro-Parasita , Venenos de Vespas/toxicidade , Vespas/fisiologia , Animais , Borboletas/genética , Borboletas/imunologia , Hemolinfa/imunologia , Imunidade Humoral/efeitos dos fármacos , Proteínas de Insetos/genética , Muramidase/genética , Pupa/efeitos dos fármacos , Pupa/genética , Pupa/imunologia , Pupa/parasitologia
19.
J Insect Physiol ; 85: 46-56, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26685058

RESUMO

The larval endoparasitoid Cotesia chilonis injects venom and bracoviruses into its host Chilo suppressalis during oviposition. Here we study the effects of the polydnavirus (PDV)-carrying endoparasitoid C. chilonis (Hymenoptera: Braconidae) parasitism, venom and calyx fluid on host cellular and humoral immunity, specifically hemocyte composition, cellular spreading, encapsulation and melanization. Total hemocyte counts (THCs) were higher in parasitized larvae than in unparasitized larvae in the late stages following parasitization. While both plasmatocyte and granulocyte fractions and hemocyte mortality did not differ between parasitized and unparasitized hosts, in vitro spreading behavior of hemocytes was inhibited significantly by parasitism throughout the course of parasitoid development. C. chilonis parasitism suppressed the encapsulation response and melanization in the early stages. Venom alone did not alter cellular immune responses, including effects on THCs, mortality, hemocyte composition, cell spreading and encapsulation, but venom did inhibit humoral immunity by reducing melanization within 6h after injection. In contrast to venom, calyx fluid had a significant effect on cell spreading, encapsulation and melanization from 6h after injection. Dose-response injection studies indicated the effects of venom and calyx fluid synergized, showing a stronger and more persistent reduction in immune system responses than the effect of either injected alone.


Assuntos
Larva/imunologia , Lepidópteros/parasitologia , Peçonhas/toxicidade , Vespas/fisiologia , Animais , Feminino , Hemócitos/efeitos dos fármacos , Hemócitos/imunologia , Interações Hospedeiro-Parasita , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/parasitologia , Lepidópteros/efeitos dos fármacos , Lepidópteros/imunologia , Masculino
20.
Toxins (Basel) ; 7(12): 5098-113, 2015 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-26633500

RESUMO

Chitin-binding proteins (CBPs) are present in many species and they act in a variety of biological processes. We analyzed a Pteromalus puparum venom apparatus proteome and transcriptome and identified a partial gene encoding a possible CBP. Here, we report cloning a full-length cDNA of a sequence encoding a chitin-binding-like protein (PpCBP) from P. puparum, a pupal endoparasitoid of Pieris rapae. The cDNA encoded a 96-amino-acid protein, including a secretory signal peptide and a chitin-binding peritrophin-A domain. Phylogenetic analysis of chitin binding domains (CBDs) of cuticle proteins and peritrophic matrix proteins in selected insects revealed that the CBD of PpCBP clustered with the CBD of Nasonia vitripennis. The PpCBP is specifically expressed in the venom apparatus of P. puparum, mostly in the venom gland. PpCBP expression was highest at day one after adult eclosion and much lower for the following five days. We produced a recombinant PpCBP and binding assays showed the recombinant protein selectively binds chitin but not cellulose in vitro. We infer that PpCBP serves a structural role in the venom reservoir, or may be injected into the host to help wound healing of the host exoskeleton.


Assuntos
Proteínas de Transporte/metabolismo , Quitina/metabolismo , Proteínas de Insetos/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteínas de Transporte/química , Proteínas de Transporte/genética , Celulose/metabolismo , Clonagem Molecular , DNA Complementar/genética , Glândulas Exócrinas , Proteínas de Insetos/química , Proteínas de Insetos/genética , Dados de Sequência Molecular , Pupa , Análise de Sequência de DNA , Venenos de Vespas , Vespas
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