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1.
Cell ; 184(7): 1693-1705.e17, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33770502

RESUMO

Plants protect themselves with a vast array of toxic secondary metabolites, yet most plants serve as food for insects. The evolutionary processes that allow herbivorous insects to resist plant defenses remain largely unknown. The whitefly Bemisia tabaci is a cosmopolitan, highly polyphagous agricultural pest that vectors several serious plant pathogenic viruses and is an excellent model to probe the molecular mechanisms involved in overcoming plant defenses. Here, we show that, through an exceptional horizontal gene transfer event, the whitefly has acquired the plant-derived phenolic glucoside malonyltransferase gene BtPMaT1. This gene enables whiteflies to neutralize phenolic glucosides. This was confirmed by genetically transforming tomato plants to produce small interfering RNAs that silence BtPMaT1, thus impairing the whiteflies' detoxification ability. These findings reveal an evolutionary scenario whereby herbivores harness the genetic toolkit of their host plants to develop resistance to plant defenses and how this can be exploited for crop protection.


Assuntos
Hemípteros/genética , Proteínas de Insetos/metabolismo , Solanum lycopersicum/genética , Toxinas Biológicas/metabolismo , Animais , Transferência Genética Horizontal , Genes de Plantas , Glucosídeos/química , Glucosídeos/metabolismo , Hemípteros/fisiologia , Herbivoria , Proteínas de Insetos/antagonistas & inibidores , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Mucosa Intestinal/metabolismo , Solanum lycopersicum/metabolismo , Malonil Coenzima A/metabolismo , Filogenia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Interferência de RNA , RNA de Cadeia Dupla/metabolismo , Toxinas Biológicas/química
2.
Mol Phylogenet Evol ; 150: 106859, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32497831

RESUMO

Parapanteles Ashmead (Braconidae: Microgastrinae) is a medium-sized genus of microgastrine wasps that was erected over a century ago and lacks a unique synapomorphic character, and its monophyly has not been tested by any means. Parapanteles usually are parasitoids of large, unconcealed caterpillars (macrolepidoptera) and have been reared from an unusually large diversity of hosts for a relatively small microgastrine genus. We used Cytochrome Oxidase I sequences ("DNA barcodes") available for Parapanteles and other microgastrines to sample the generic diversity of described and undescribed species currently placed in Parapanteles, and then sequenced four additional genes for this subsample (wingless, elongation factor 1-alpha, ribosomal subunit 28s, and NADH dehydrogenase subunit 1). We constructed individual gene trees and concatenated Bayesian and maximum-likelihood phylogenies for this 5-gene subsample. In these phylogenies, most Parapanteles species formed a monophyletic clade within another genus, Dolichogenidea, while the remaining Parapanteles species were recovered polyphyletically within several other genera. The latter likely represent misidentified members of other morphologically similar genera. Species in the monophyletic clade containing most Parapanteles parasitized caterpillars from only five families - Erebidae (Arctiinae), Geometridae, Saturniidae, Notodontidae, and Crambidae. We do not make any formal taxonomic decisions here because we were not able to include representatives of type species for Parapanteles or other relevant genera, and because we feel such decisions should be reserved until a comprehensive morphological analysis of the boundaries of these genera is accomplished.


Assuntos
Himenópteros/classificação , Animais , Teorema de Bayes , Complexo IV da Cadeia de Transporte de Elétrons/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Himenópteros/genética , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , NADH Desidrogenase/classificação , NADH Desidrogenase/genética , Filogenia , RNA Ribossômico 28S/classificação , RNA Ribossômico 28S/genética
3.
Gene ; 691: 45-55, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30611842

RESUMO

Myosins are a large family of actin filament-based motor proteins with a broad range of functions such as intracellular membrane trafficking, endocytosis, exocytosis, organellar transport, growth cone motility, cytokinesis, and cell locomotion. They are found in many organisms from fungi to humans. The myosin gene family in Bombyx mori is poorly studied, even though the molecular functions of these genes in vertebrates and insects, such as Drosophila, are well known. We identified 16 myosin genes from B. mori and identified the myosin genes in 12 vertebrates, eight insects, three nematodes, and seven protozoa. The number of myosin genes in vertebrates is double the number in invertebrates. The number of myosin isoforms in classes I and II is larger in vertebrates compared to invertebrates. B. mori myosin genes can be classified into 11 classes. Compared to B. mori, some myosin classes are not present in other insects. Classes I, II, XVIII, and XXI appear to be important for insect survival because they are conserved among nine insects. The relatively large sizes of B. mori myosin genes are due to their longer introns. Reverse transcription PCR (RT-PCR) and quantitative real-time PCR (qRT-PCR) analysis demonstrated that many B. mori myosin genes have tissue-specific expression and exhibit temporal-specific activity during metamorphosis. These data provide insights into evolutionary and functional aspects of B. mori myosin genes that could be useful for the study of homologous myosins in other Lepidoptera species.


Assuntos
Bombyx/crescimento & desenvolvimento , Bombyx/genética , Miosinas/genética , Sequenciamento Completo do Genoma/métodos , Animais , Mapeamento Cromossômico , Sequência Conservada , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Família Multigênica , Miosinas/classificação , Especificidade de Órgãos , Filogenia , Vertebrados/genética
4.
PLoS One ; 13(12): e0208639, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30576327

RESUMO

Butterfly monitoring and Red List programs in Switzerland rely on a combination of observations and collection records to document changes in species distributions through time. While most butterflies can be identified using morphology, some taxa remain challenging, making it difficult to accurately map their distributions and develop appropriate conservation measures. In this paper, we explore the use of the DNA barcode (a fragment of the mitochondrial gene COI) as a tool for the identification of Swiss butterflies and forester moths (Rhopalocera and Zygaenidae). We present a national DNA barcode reference library including 868 sequences representing 217 out of 224 resident species, or 96.9% of Swiss fauna. DNA barcodes were diagnostic for nearly 90% of Swiss species. The remaining 10% represent cases of para- and polyphyly likely involving introgression or incomplete lineage sorting among closely related taxa. We demonstrate that integrative taxonomic methods incorporating a combination of morphological and genetic techniques result in a rate of species identification of over 96% in females and over 98% in males, higher than either morphology or DNA barcodes alone. We explore the use of the DNA barcode for exploring boundaries among taxa, understanding the geographical distribution of cryptic diversity and evaluating the status of purportedly endemic taxa. Finally, we discuss how DNA barcodes may be used to improve field practices and ultimately enhance conservation strategies.


Assuntos
Borboletas/genética , Código de Barras de DNA Taxonômico , Mariposas/genética , Animais , Borboletas/classificação , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Biblioteca Gênica , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Masculino , Mariposas/classificação , Suíça
5.
J Proteome Res ; 17(11): 3889-3903, 2018 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-30298734

RESUMO

Adenosine-to-inosine RNA editing is one of the most common types of RNA editing, a posttranscriptional modification made by special enzymes. We present a proteomic study on this phenomenon for Drosophila melanogaster. Three proteome data sets were used in the study: two taken from public repository and the third one obtained here. A customized protein sequence database was generated using results of genome-wide adenosine-to-inosine RNA studies and applied for identifying the edited proteins. The total number of 68 edited peptides belonging to 59 proteins was identified in all data sets. Eight of them being shared between the whole insect, head, and brain proteomes. Seven edited sites belonging to synaptic vesicle and membrane trafficking proteins were selected for validation by orthogonal analysis by Multiple Reaction Monitoring. Five editing events in cpx, Syx1A, Cadps, CG4587, and EndoA were validated in fruit fly brain tissue at the proteome level using isotopically labeled standards. Ratios of unedited-to-edited proteoforms varied from 35:1 ( Syx1A) to 1:2 ( EndoA). Lys-137 to Glu editing of endophilin A may have functional consequences for its interaction to membrane. The work demonstrates the feasibility to identify the RNA editing event at the proteome level using shotgun proteomics and customized edited protein database.


Assuntos
Adenosina/metabolismo , Drosophila melanogaster/genética , Inosina/metabolismo , Proteínas de Insetos/genética , Proteogenômica/métodos , Edição de RNA , Aciltransferases/química , Aciltransferases/genética , Aciltransferases/metabolismo , Adenosina Desaminase/genética , Adenosina Desaminase/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/metabolismo , Bases de Dados de Proteínas , Conjuntos de Dados como Assunto , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/química , Drosophila melanogaster/metabolismo , Proteínas de Insetos/classificação , Proteínas de Insetos/metabolismo , Modelos Moleculares , Anotação de Sequência Molecular , Proteoma/genética , Proteoma/metabolismo , Proteínas Qa-SNARE/genética , Proteínas Qa-SNARE/metabolismo , Vesículas Sinápticas/química , Vesículas Sinápticas/metabolismo
6.
J Proteome Res ; 17(10): 3503-3516, 2018 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-30149710

RESUMO

The peptide toxins in the venoms of small invertebrates such as stinging ants have rarely been studied due to the limited amount of venom available per individual. We used a venomics strategy to identify the molecular diversity of the venom peptidome for the myrmicine ant Tetramorium bicarinatum. The methodology included (i) peptidomics, in which the venom peptides are sequenced through a de novo mass spectrometry approach or Edman degradation; (ii) transcriptomics, based on RT-PCR-cloning and DNA sequencing; and (iii) the data mining of the RNA-seq in the available transcriptome. Mass spectrometry analysis revealed about 2800 peptides in the venom. However, the de novo sequencing suggested that most of these peptides arose from processing or the artifactual fragmentations of full-length mature peptides. These peptides, called "myrmicitoxins", are produced by a limited number of genes. Thirty-seven peptide precursors were identified and classified into three superfamilies. These precursors are related to pilosulin, secapin or are new ant venom prepro-peptides. The mature myrmicitoxins display sequence homologies with antimicrobial, cytolytic and neurotoxic peptides. The venomics strategy enabled several post-translational modifications in some peptides such as O-glycosylation to be identified. This study provides novel insights into the molecular diversity and evolution of ant venoms.


Assuntos
Venenos de Formiga/metabolismo , Perfilação da Expressão Gênica/métodos , Proteínas de Insetos/metabolismo , Peptídeos/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Sequência de Aminoácidos , Animais , Venenos de Formiga/classificação , Venenos de Formiga/genética , Formigas/química , Formigas/genética , Formigas/metabolismo , Linhagem Celular , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Espectrometria de Massas , Camundongos , Peptídeos/química , Peptídeos/genética , Filogenia , Proteoma/genética , Análise de Sequência de Proteína/métodos , Homologia de Sequência de Aminoácidos
7.
Dev Comp Immunol ; 87: 204-215, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30017863

RESUMO

The prophenoloxidase (PPO) activating system in insects plays an important role in defense against microbial invasion. In this paper, we identified a PPO activating protease (designated OfPAP) containing a 1203 bp open reading frame encoding a 400-residue protein composed of two clip domains and a C-terminal serine protease domain from Ostrinia furnacalis. SignalP analysis revealed a putative signal peptide of 18 residues. The mature OfPAP was predicted to be 382 residues long with a calculated Mr of 44.8 kDa and pI of 6.66. Multiple sequence alignment and phylogenetic analysis indicated that OfPAP was orthologous to the PAPs in the other lepidopterans. A large increase of the transcript levels was observed in hemocytes at 4 h post injection (hpi) of killed Bacillus subtilis, whereas its level in integument increased continuously from 4 to 12 hpi in the challenged larvae and began to decline at 24 hpi. After OfPAP expression had been silenced, the median lethal time (LT50) of Escherichia coli-infected larvae (1.0 day) became significantly lower than that of E. coli-infected wild-type (3.0 days, p < 0.01). A 3.5-fold increase in E. coli colony forming units occurred in larval hemolymph of the OfPAP knockdown larvae, as compared with that of the control larvae not injected with dsRNA. There were notable decreases in PO and IEARase activities in hemolymph of the OfPAP knockdown larvae. In summary, we have demonstrated that OfPAP is a component of the PPO activation system, likely by functioning as a PPO activating protease in O. furnacalis larvae.


Assuntos
Catecol Oxidase/imunologia , Precursores Enzimáticos/imunologia , Escherichia coli/imunologia , Proteínas de Insetos/imunologia , Mariposas/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação/genética , Catecol Oxidase/classificação , Catecol Oxidase/genética , Resistência à Doença/genética , Resistência à Doença/imunologia , Ativação Enzimática/genética , Ativação Enzimática/imunologia , Precursores Enzimáticos/classificação , Precursores Enzimáticos/genética , Escherichia coli/fisiologia , Regulação Enzimológica da Expressão Gênica/imunologia , Hemócitos/enzimologia , Hemócitos/imunologia , Hemócitos/microbiologia , Hemolinfa/enzimologia , Hemolinfa/imunologia , Hemolinfa/microbiologia , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Larva/genética , Larva/imunologia , Larva/microbiologia , Mariposas/genética , Mariposas/microbiologia , Filogenia , Interferência de RNA , Homologia de Sequência de Aminoácidos
8.
Dev Comp Immunol ; 87: 137-146, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29935286

RESUMO

Antimicrobial peptides (AMPs) are produced by the stimulated humoral immune system. Most mature AMPs contain less than 50 amino acid residues. Some of them are generated from proproteins upon microbial challenges. Here, we report the antimicrobial activities of a proline-rich proprotein, named SlLebocin1 (SlLeb1), from the tobacco cutworm Spodoptera litura. SlLebocin1 cDNA contains a 477-bp open reading frame (ORF). It is mainly expressed in hemocytes and the midgut in naïve larvae. The transcript level was significantly induced in hemocytes but repressed in the midgut and fat body by bacterial challenges. The proprotein contains 158 amino acids with 3 RXXR motifs that are characteristic of some Lepidopteral lebocin proproteins. Four peptides corresponding to the predicted processed fragments were synthesized chemically, and their antimicrobial activities against two Gram-negative and two Gram-positive bacterial strains were analyzed. The peptides showed differential antimicrobial activities. For Escherichia coli and Bacillus subtilis, only the C-terminal fragment (124-158) showed strong inhibitory effects. For Staphylococcus aureus, all peptides showed partial inhibitions. None of them inhibited Serratia marcescens. Bacterial morphologies were examined by the scanning electron microscopy and confocal laser scanning microscopy. The antimicrobial peptides either disrupted cellular membrane or inhibited cell division and caused elongated/enlarged morphologies. The results may provide ideas for designing novel antibiotics.


Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Proteínas de Insetos/genética , Domínios Proteicos Ricos em Prolina/genética , Precursores de Proteínas/genética , Spodoptera/genética , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/classificação , Peptídeos Catiônicos Antimicrobianos/farmacologia , Sequência de Bases , Sistema Digestório/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/ultraestrutura , Perfilação da Expressão Gênica , Hemócitos/metabolismo , Proteínas de Insetos/classificação , Proteínas de Insetos/farmacologia , Larva/genética , Microscopia Eletrônica de Varredura , Filogenia , Precursores de Proteínas/classificação , Precursores de Proteínas/farmacologia , Homologia de Sequência de Aminoácidos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura
9.
Biochem Biophys Res Commun ; 502(3): 345-350, 2018 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-29803675

RESUMO

Among the various glutathione transferase (GST) isozymes in insects, the delta- and epsilon-class GSTs fulfill critical functions during the detoxification of insecticides. We crystalized MdGSTD1, the major delta-class GST isozyme in the housefly (Musca domestica), in complex with glutathione (GSH) and solved its structure at a resolution of 1.4 Å. The overall folding of MdGSTD1 resembled other known delta-class GSTs. Its substrate binding pocket was exposed to solvent and considerably more open than in the epsilon-class GST from M. domestica (MdGSTE2). However, their C-terminal structures differed the most because of the different lengths of the C-terminal regions. Although this region does not seem to directly interact with substrates, its deletion reduced the enzymatic activity by more than 70%, indicating a function in maintaining the proper conformation of the binding pocket. Binding of GSH to the GSH-binding region of MdGSTD1 results in a rigid conformation of this region. Although MdGSTD1 has a higher affinity for GSH than the epsilon class enzymes, the thiol group of the GSH molecule was not close enough to serine residue 9 to form a hydrogen-bond with this residue, which is predicted to act as the catalytic center for thiol group deprotonation in GSH.


Assuntos
Glutationa Transferase/química , Moscas Domésticas/enzimologia , Proteínas de Insetos/química , Sequência de Aminoácidos , Animais , Domínio Catalítico , Cristalografia por Raios X , Glutationa/metabolismo , Glutationa Transferase/classificação , Glutationa Transferase/genética , Moscas Domésticas/genética , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Isoenzimas/química , Isoenzimas/classificação , Isoenzimas/genética , Cinética , Modelos Moleculares , Proteínas Mutantes/química , Proteínas Mutantes/genética , Conformação Proteica , Deleção de Sequência , Homologia de Sequência de Aminoácidos
10.
Nat Commun ; 9(1): 205, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29335414

RESUMO

Beetles (Coleoptera) are the most diverse and species-rich group of insects, and a robust, time-calibrated phylogeny is fundamental to understanding macroevolutionary processes that underlie their diversity. Here we infer the phylogeny and divergence times of all major lineages of Coleoptera by analyzing 95 protein-coding genes in 373 beetle species, including ~67% of the currently recognized families. The subordinal relationships are strongly supported as Polyphaga (Adephaga (Archostemata, Myxophaga)). The series and superfamilies of Polyphaga are mostly monophyletic. The species-poor Nosodendridae is robustly recovered in a novel position sister to Staphyliniformia, Bostrichiformia, and Cucujiformia. Our divergence time analyses suggest that the crown group of extant beetles occurred ~297 million years ago (Mya) and that ~64% of families originated in the Cretaceous. Most of the herbivorous families experienced a significant increase in diversification rate during the Cretaceous, thus suggesting that the rise of angiosperms in the Cretaceous may have been an 'evolutionary impetus' driving the hyperdiversity of herbivorous beetles.


Assuntos
Besouros/genética , Evolução Molecular , Variação Genética , Proteínas de Insetos/genética , Animais , Besouros/classificação , Proteínas de Insetos/classificação , Filogenia , Especificidade da Espécie , Fatores de Tempo
11.
Sci Rep ; 5: 18124, 2015 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-26657797

RESUMO

A Leptinotarsa decemlineata SLC6 NAT gene (LdNAT1) was cloned. LdNAT1 was highly expressed in the larval alimentary canal especially midgut. LdNAT1 mRNA levels were high right after the molt and low just before the molt. JH and a JH analog pyriproxyfen activated LdNAT1 expression. RNAi of an allatostatin gene LdAS-C increased JH and upregulated LdNAT1 transcription. Conversely, silencing of a JH biosynthesis gene LdJHAMT decreased JH and reduced LdNAT1 expression. Moreover, 20E and an ecdysteroid agonist halofenozide repressed LdNAT1 expression, whereas a decrease in 20E by RNAi of an ecdysteroidogenesis gene LdSHD and disruption of 20E signaling by knockdown of LdE75 and LdFTZ-F1 activated LdNAT1 expression. Thus, LdNAT1 responded to both 20E and JH. Moreover, knockdown of LdNAT1 reduced the contents of cysteine, histidine, isoleucine, leucine, methionine, phenylalanine and serine in the larval bodies and increased the contents of these amino acids in the larval feces. Furthermore, RNAi of LdNAT1 inhibited insulin/target of rapamycin pathway, lowered 20E and JH titers, reduced 20E and JH signaling, retarded larval growth and impaired pupation. These data showed that LdNAT1 was involved in the absorption of several neutral amino acids critical for larval growth and metamorphosis.


Assuntos
Sistemas de Transporte de Aminoácidos/genética , Besouros/genética , Proteínas de Insetos/genética , Interferência de RNA , Sequência de Aminoácidos , Sistemas de Transporte de Aminoácidos/classificação , Aminoácidos Neutros/genética , Aminoácidos Neutros/metabolismo , Animais , Besouros/crescimento & desenvolvimento , Besouros/metabolismo , Ecdisterona/farmacologia , Fezes/química , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Proteínas de Insetos/classificação , Hormônios Juvenis/farmacologia , Dados de Sequência Molecular , Filogenia , Pupa/genética , Pupa/crescimento & desenvolvimento , Pupa/metabolismo , Piridinas/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
12.
Cell Mol Life Sci ; 72(22): 4429-43, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26265180

RESUMO

Locusts represent the excellent model of insect olfaction because the animals are equipped with an unusual olfactory system and display remarkable density-dependent olfactory plasticity. However, information regarding receptor molecules involved in the olfactory perception of locusts is very limited. On the basis of genome sequence and antennal transcriptome of the migratory locust, we conduct the identification and functional analysis of two olfactory receptor families: odorant receptors (ORs) and ionotropic receptors (IRs). In the migratory locust, there is an expansion of OR family (142 ORs) while distinctly lower number of IR genes (32 IRs) compared to the repertoires of other insects. The number of the locust OR genes is much less than that of glomeruli in antennal lobe, challenging the general principle of the "one glomerulus-one receptor" observed in other insects. Most OR genes are found in tandem arrays, forming two large lineage-specific subfamilies in the phylogenetic tree. The "divergent IR" subfamily displays a significant contraction, and most of the IRs belong to the "antennal IR" subfamily in the locust. Most ORs/IRs have olfactory-specific expression while some broadly- or internal-expressed members are also found. Differing from holometabolous insects, the migratory locust contains very similar expression profiles of ORs/IRs between nymph and adult stages. RNA interference and behavioral assays indicate that an OR-based signaling pathway, not IR-based, mediates the attraction of locusts to aggregation pheromones. These discoveries provide insights into the unusual olfactory system of locusts and enhance our understanding of the evolution of insect olfaction.


Assuntos
Proteínas de Insetos/genética , Locusta migratoria/genética , Bulbo Olfatório/metabolismo , Receptores Odorantes/genética , Sequência de Aminoácidos , Animais , Antenas de Artrópodes/metabolismo , Antenas de Artrópodes/fisiologia , Feminino , Perfilação da Expressão Gênica , Proteínas de Insetos/classificação , Proteínas de Insetos/fisiologia , Locusta migratoria/fisiologia , Masculino , Dados de Sequência Molecular , Família Multigênica/genética , Bulbo Olfatório/fisiologia , Filogenia , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiologia , Receptores Ionotrópicos de Glutamato/genética , Receptores Ionotrópicos de Glutamato/fisiologia , Receptores Odorantes/classificação , Receptores Odorantes/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Olfato/genética , Olfato/fisiologia , Transcriptoma/genética
13.
Int J Biol Sci ; 11(9): 1036-48, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26221071

RESUMO

Insect chemosensory genes have been considered as potential molecular targets to develop alternative strategies for pest control. However, in Spodoptera exigua, a seriously polyphagous agricultural pest, only a small part of such genes have been identified and characterized to date. Here, using a bioinformatics screen a total of 79 chemosensory genes were identified from a public transcriptomic data of different developmental stages (eggs, 1st to 5th instar larvae, pupae, female and male adults), including 34 odorant binding proteins (OBPs), 20 chemosensory proteins (CSPs), 22 chemosensory receptors (10 odorant receptors (ORs), six gustatory receptors (GRs) and six ionotropic receptors (IRs)) and three sensory neuron membrane proteins (SNMPs). Notably, a new group of lepidopteran SNMPs (SNMP3 group) was found for the first time in S. exigua, and confirmed in four other moth species. Further, reverse transcription PCR (RT-PCR) and quantitative real time PCR (qPCR) were employed respectively to validate the sequences and determine the expression patterns of 69 identified chemosensory genes regarding to sexes, tissues and stages. Results showed that 67 of these genes could be detected and reconstructed in at least one tissue tested. Further, 60 chemosensory genes were expressed in adult antennae and 52 in larval heads with the antennae, whereas over half of the genes were also detected in non-olfactory tissues like egg and thorax. Particularly, S. exigua OBP2 showed a predominantly larval head-biased expression, and functional studies further indicated its potentially olfactory roles in guiding food searching of larvae. This work suggests functional diversities of S. exigua chemosensory genes and could greatly facilitate the understanding of olfactory system in S. exigua and other lepidopteran species.


Assuntos
Proteínas de Insetos/genética , Receptores Odorantes/genética , Spodoptera/genética , Transcriptoma/genética , Animais , Biologia Computacional , Perfilação da Expressão Gênica , Proteínas de Insetos/classificação , Proteínas de Insetos/metabolismo , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Receptores Odorantes/classificação , Receptores Odorantes/metabolismo
14.
Appl Microbiol Biotechnol ; 98(13): 5807-22, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24811407

RESUMO

Insects are one of the major sources of antimicrobial peptides/proteins (AMPs). Since observation of antimicrobial activity in the hemolymph of pupae from the giant silk moths Samia Cynthia and Hyalophora cecropia in 1974 and purification of first insect AMP (cecropin) from H. cecropia pupae in 1980, over 150 insect AMPs have been purified or identified. Most insect AMPs are small and cationic, and they show activities against bacteria and/or fungi, as well as some parasites and viruses. Insect AMPs can be classified into four families based on their structures or unique sequences: the α-helical peptides (cecropin and moricin), cysteine-rich peptides (insect defensin and drosomycin), proline-rich peptides (apidaecin, drosocin, and lebocin), and glycine-rich peptides/proteins (attacin and gloverin). Among insect AMPs, defensins, cecropins, proline-rich peptides, and attacins are common, while gloverins and moricins have been identified only in Lepidoptera. Most active AMPs are small peptides of 20-50 residues, which are generated from larger inactive precursor proteins or pro-proteins, but gloverins (~14 kDa) and attacins (~20 kDa) are large antimicrobial proteins. In this mini-review, we will discuss current knowledge and recent progress in several classes of insect AMPs, including insect defensins, cecropins, attacins, lebocins and other proline-rich peptides, gloverins, and moricins, with a focus on structural-functional relationships and their potential applications.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Proteínas de Insetos/farmacologia , Insetos/química , Vírus/efeitos dos fármacos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/classificação , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Proteínas de Insetos/química , Proteínas de Insetos/classificação , Proteínas de Insetos/isolamento & purificação , Conformação Proteica
15.
Biochem Biophys Res Commun ; 442(1-2): 105-11, 2013 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-24246678

RESUMO

Medium- and long-chain polyprenyl diphosphate synthases (PDDSs) catalyze the synthesis of the side-chain prenyl tails of ubiquinones, which play critical physiological roles in all organisms. This class of enzymes has been extensively studied in bacteria, yeast, plants and mammals, but very little information about such enzymes is available in insects. Here we cloned the cDNAs encoding the two subunits of an aphid long-chain PDDS (designated as AgDPPS1 and AgDPPS2). AgDPPS1 and AgDPPS2 had an open reading frame of 1230 bp and 1275 bp, with a calculated isoelectric point of 8.13 and 6.28, respectively. Sequence alignment and phylogenetic analysis showed that the enzyme was a candidate decaprenyl diphosphate (DPP) synthase with two heterologous subunits. Recombinant expression and in vitro enzymatic assay revealed that the two subunits were essential for the activity of the enzyme that catalyzed the formation of a major intermediate product geranylgeranyl diphosphate. In vivo analysis of ubiquinone (UQ) by expressing the insect enzyme in Escherichia coli identified UQ-10. Our data suggested that the insect enzyme is a novel DPP synthase with a two-major step catalytic mechanism, which catalyzes the formation of DPP as the final product, with geranylgeranyl diphosphate as the major intermediate product. This is the first characterization of an insect long-chain DPPS that synthesizes the side-chain of coenzyme Q-10.


Assuntos
Alquil e Aril Transferases/química , Afídeos/enzimologia , Proteínas de Insetos/química , Alquil e Aril Transferases/classificação , Alquil e Aril Transferases/genética , Animais , Afídeos/genética , Catálise , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Cromatografia Gasosa-Espectrometria de Massas , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Filogenia , Subunidades Proteicas/química , Subunidades Proteicas/classificação , Subunidades Proteicas/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Ubiquinona/análise
16.
Gen Comp Endocrinol ; 193: 193-200, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23968772

RESUMO

Allatotropins (ATs) are multifunctional neuropeptides initially isolated from the tobacco hornworm, Manduca sexta, where they were found to stimulate juvenile hormone synthesis and release from the corpora allata. ATs have been found in a wide range of insects, but appear to be absent in Drosophila. The first AT receptor (ATR) was characterised in 2008 in the lepidopteran Bombyx mori. Since then ATRs have been characterised in Coleoptera and Diptera and in 2012, an AT precursor gene was identified in hymenopteran species. ATRs show large sequence and structural similarity to vertebrate orexin receptors (OXR). Also, AT in insects and orexin in vertebrates show some overlap in functions, including modulation of feeding behaviour and reproduction. The goal of this study was to identify a functional ATR in a hymenopteran species. We used ATRs (insect sequences) and OXRs (vertebrate sequences) to search the genome of the bumblebee, Bombus terrestris. Two receptors (XP_003402490 and XP_003394933) with resemblance to ATRs and OXRs were found. Phylogenetic analysis provided the first indication that XP_003402490 was more closely related to ATRs than XP_003394933. We investigated the transcript level distribution of both receptors and the AT precursor gene by means of quantitative real-time reverse transcriptase PCR. XP_003402490 displayed a tissue distribution comparable with ATRs in other species, with high transcript levels in the male accessory glands. After pharmacological characterisation, it appeared that XP_003402490 is indeed a functional ATR. Activation of the receptor causes an increase in intracellular calcium and cyclic AMP levels with an EC50 value in the low nanomolar to picomolar range. XP_003394933 remains an orphan receptor.


Assuntos
Abelhas/metabolismo , Proteínas de Insetos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Células CHO , Cricetulus , Hormônios de Inseto/metabolismo , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Neuropeptídeos/metabolismo , Orexinas , Filogenia , Receptores Acoplados a Proteínas G/classificação , Receptores Acoplados a Proteínas G/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
PLoS One ; 8(2): e54063, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23390494

RESUMO

Specimens of neotropical Anopheles (Nyssorhynchus) were collected and identified morphologically. We amplified three genes for phylogenetic analysis-the single copy nuclear white and CAD genes, and the COI barcode region. Since we had multiple specimens for most species we were able to test how well the single or combined genes were able to corroborate morphologically defined species by placing the species into exclusive groups. We found that single genes, including the COI barcode region, were poor at confirming species, but that the three genes combined were able to do so much better. This has implications for species identification, species delimitation, and species discovery, and we caution that single genes are not enough. Higher level groupings were partially resolved with some well-supported groupings, whereas others were found to be either polyphyletic or paraphyletic. There were examples of known groups, such as the Myzorhynchella Section, which were poorly supported with single genes but were well supported with combined genes. From this we can infer that more sequence data will be needed in order to show more higher-level groupings with good support. We got unambiguously good support (0.94-1.0 Bayesian posterior probability) from all DNA-based analyses for a grouping of An. dunhami with An. nuneztovari and An. goeldii, and because of this and because of morphological similarities we propose that An. dunhami be included in the Nuneztovari Complex. We obtained phylogenetic corroboration for new species which had been recognised by morphological differences; these will need to be formally described and named.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Anopheles/genética , DNA/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Proteínas de Insetos/genética , Filogenia , Fatores de Transcrição/genética , Transportadores de Cassetes de Ligação de ATP/classificação , Animais , Anopheles/classificação , Teorema de Bayes , DNA/classificação , Complexo IV da Cadeia de Transporte de Elétrons/classificação , Feminino , Proteínas de Insetos/classificação , Masculino , Filogeografia , América do Sul , Especificidade da Espécie , Fatores de Transcrição/classificação
18.
J Chem Ecol ; 38(12): 1513-20, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23224441

RESUMO

Helicoverpa armigera (Hübner) is one of the most polyphagous and cosmopolitan pest species, the larvae of which feed on numerous important crops. The gustatory system is critical in guiding insect feeding behavior. Here, we identified a gustatory receptor from H. armigera, HaGR9, which shows high levels of identity to DmGR43a from Drosophila melanogaster and BmGR9 from Bombyx mori. Reverse transcriptase PCR (RT-PCR) revealed HaGR9 is highly expressed in larval foregut, with little or no expression in other chemosensory tissues. Membrane topology studies indicated that, like two previously studied B. mori GRs, BmGR8 and BmGR53, HaGR9 has an inverted topology relative to G protein-coupled receptors (GPCRs), an intracellular N-terminus and an extracellular C-terminus. Calcium imaging studies confirmed HaGR9 is a sugar receptor showing dose-dependent responses to D-galactose, D-maltose, and D-fructose. This highly-expressed foregut-specific gustatory receptor may contribute to the regulation of larval feeding behavior.


Assuntos
Sistema Digestório/metabolismo , Proteínas de Insetos/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Bombyx/genética , Bombyx/metabolismo , Clonagem Molecular , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Larva/metabolismo , Mariposas/genética , Mariposas/crescimento & desenvolvimento , Mariposas/metabolismo , Filogenia , Receptores de Superfície Celular/classificação , Receptores de Superfície Celular/genética
19.
PLoS One ; 7(10): e46812, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23071645

RESUMO

BACKGROUND: Insect seminal fluid is a complex mixture of proteins, carbohydrates and lipids, produced in the male reproductive tract. This seminal fluid is transferred together with the spermatozoa during mating and induces post-mating changes in the female. Molecular characterization of seminal fluid proteins in the Mediterranean fruit fly, Ceratitis capitata, is limited, although studies suggest that some of these proteins are biologically active. METHODOLOGY/PRINCIPAL FINDINGS: We report on the functional annotation of 5914 high quality expressed sequence tags (ESTs) from the testes and male accessory glands, to identify transcripts encoding putative secreted peptides that might elicit post-mating responses in females. The ESTs were assembled into 3344 contigs, of which over 33% produced no hits against the nr database, and thus may represent novel or rapidly evolving sequences. Extraction of the coding sequences resulted in a total of 3371 putative peptides. The annotated dataset is available as a hyperlinked spreadsheet. Four hundred peptides were identified with putative secretory activity, including odorant binding proteins, protease inhibitor domain-containing peptides, antigen 5 proteins, mucins, and immunity-related sequences. Quantitative RT-PCR-based analyses of a subset of putative secretory protein-encoding transcripts from accessory glands indicated changes in their abundance after one or more copulations when compared to virgin males of the same age. These changes in abundance, particularly evident after the third mating, may be related to the requirement to replenish proteins to be transferred to the female. CONCLUSIONS/SIGNIFICANCE: We have developed the first large-scale dataset for novel studies on functions and processes associated with the reproductive biology of Ceratitis capitata. The identified genes may help study genome evolution, in light of the high adaptive potential of the medfly. In addition, studies of male recovery dynamics in terms of accessory gland gene expression profiles and correlated remating inhibition mechanisms may permit the improvement of pest management approaches.


Assuntos
Ceratitis capitata/genética , Genitália Masculina/metabolismo , Testículo/metabolismo , Transcriptoma , Animais , Etiquetas de Sequências Expressas , Feminino , Biblioteca Gênica , Genes de Insetos/genética , Genitália Masculina/anatomia & histologia , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Modelos Lineares , Masculino , Dados de Sequência Molecular , Análise Multivariada , Peptídeos/classificação , Peptídeos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Comportamento Sexual Animal , Testículo/anatomia & histologia
20.
J Proteome Res ; 11(9): 4526-40, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-22809620

RESUMO

The honeybees Apis mellifera ligustica (Aml) and Apis cerana cerana (Acc) are two different western and eastern bee species that evolved in distinct ecologies and developed specific antennal olfactory systems for their survival. Knowledge of how their antennal olfactory systems function in regards to the success of each respective bee species is scarce. We compared the antennal morphology and proteome between respective sexually mature drones and foraging workers of both species using a scanning electron microscope, two-dimensional electrophoresis, mass spectrometry, bioinformatics, and quantitative real-time polymerase chain reaction. Despite the general similarities in antennal morphology of the drone and worker bees between the two species, a total of 106 and 100 proteins altered their expression in the drones' and the workers' antennae, respectively. This suggests that the differences in the olfactory function of each respective bee are supported by the change of their proteome. Of the 106 proteins that altered their expression in the drones, 72 (68%) and 34 (32%) were overexpressed in the drones of Aml and Acc, respectively. The antennae of the Aml drones were built up by the highly expressed proteins that were involved in carbohydrate metabolism and energy production, molecular transporters, antioxidation, and fatty acid metabolism in contrast to the Acc drones. This is believed to enhance the antennal olfactory functions of the Aml drones as compared to the Acc drones during their mating flight. Likewise, of the 100 proteins with expression changes between the worker bees of the two species, 67% were expressed in higher levels in the antennae of Aml worker contrasting to 33% in the Acc worker. The overall higher expressions of proteins related to carbohydrate metabolism and energy production, molecular transporters, and antioxidation in the Aml workers compared with the Acc workers indicate the Aml workers require more antennal proteins for their olfactory mechanisms to perform efficient foraging activities than do the Acc worker bees. These data decipher the mechanisms of the western and eastern drone and worker bees acting in response to their different olfactory system in their distinct ecosystem.


Assuntos
Antenas de Artrópodes/química , Abelhas/química , Abelhas/fisiologia , Proteínas de Insetos/análise , Proteoma/análise , Animais , Antenas de Artrópodes/anatomia & histologia , Abelhas/anatomia & histologia , Comportamento Animal , Biologia Computacional , Eletroforese em Gel Bidimensional , Proteínas de Insetos/química , Proteínas de Insetos/classificação , Reação em Cadeia da Polimerase , Mapas de Interação de Proteínas/fisiologia , Proteoma/química , Reprodutibilidade dos Testes , Olfato/fisiologia
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