查看更多>>摘要：The brown planthopper(BPH,Nilaparvata lugens)is a notorious sap-sucking insect pest that damages rice(Oryza sativa)plants throughout Asia.During BPH feed-ing,saliva enters rice plant tissues,whereas during oviposition egg-associated secretions(EAS)are deposited in damaged plant tissue.Dynamic changes in rice to planthopper sali-vary effectors have been widely reported.However,the effects of E AS from planthopper on rice immunity remains largely unexplored.In this study,we found that both infesta-tion of rice by gravid BPH female adults and treatment with the EAS elicited a strong and rapid accumulation of jasmonic acid(JA),JA-isoleucine,and hydrogen peroxide in rice.EAS enhanced plant defenses not only in rice but also in tobacco,and these impaired the performance of BPH on rice,as well as the performance of aphids and whiteflies on tobacco.High-throughput proteome sequencing of EAS led to 110 proteins being identi-fied and 53 proteins with 2 or more unique peptides being detected.Some proteins from BPH EAS were also found in the salivary proteome from herbivores,suggesting potential evolutionary conservation of effector functions across feeding and oviposition;however,others were only identified in EAS,and these are likely specifically related to oviposition.These findings point to novel proteins affecting interactions between planthoppers and rice during oviposition,providing an additional source of information for effector studies.
查看更多>>摘要：Extracellular superoxide dismutase(EcSOD)protects tissues from oxidative stress,and thus is considered as a therapeutic agent for many diseases such as atheroscle-rosis,hypertension,and cancer.However,cost-effective production of bioactive recombi-nant human EcSOD(rhEcSOD)remains a challenge.Herein,we developed an efficient strategy for producing active rhEcSOD by transgenic silkworms.rhEcSOD was success-fully synthesized as homodimers and homotetramers in the middle silk gland and spun into the cocoons with a concentration of 9.48±0.21 mg/g.Purification of rhEcSOD from the cocoons could be conveniently achieved with a purity of 99.50％and a yield of 3.5±0.5 mg/g.Additionally,N-glycosylation at the only site of N89 in rhEcSOD with 10 types were identified.The purified rhEcSOD gained the potent enzymatic activity of 4 162±293 U/mg after Cu/Zn ions incorporation.More importantly,rhEcSOD was ca-pable of penetrating and accumulating in the nuclei of cells to maintain cell morphology and attenuate ultraviolet B-induced cell apoptosis by eliminating reactive oxygen species and inhibiting the C-Jun N-terminal kinase signaling pathway.These results demonstrated that the transgenic silkworm could successfully produce rhEcSOD with enzymatic and biological activities for biomedical applications.
查看更多>>摘要：Culex tarsalis Coquillett(Diptera:Culicidae)mosquitoes are capable of vec-toring numerous pathogens affecting public and animal health.Unfortunately,the prob-ing behaviors of mosquitoes are poorly understood because they occur in opaque tissues.Electropenetrography(EPG)has the potential to elucidate these behaviors by recording the electrical signals generated during probing.We used an AC-DC EPG with variable input resistors(Ri levels)to construct a waveform library for Cx.tarsalis feeding on hu-man hands.Biological events associated with mosquito probing were used to characterize waveforms at four Ri levels and with two electrical current types.The optimal settings for EPG recordings of Cx.tarsalis probing on human hands was an Ri level of 107 Ohms using an applied signal of 150 millivolts alternating current.Waveforms for Cx.tarsalis in-cluded those previously observed and associated with probing behaviors in Aedes aegypti L.(Diptera:Culicidae):waveform families J(surface salivation),K(stylet penetration through the skin),L(types 1 and 2,search for a blood vessel/ingestion site),M(types 1 and 2,ingestion),N(type 1,an unknown behavior which may be a resting and digestion phase),and W(withdrawal).However,we also observed variations in the waveforms not described in Ae.aegypti,which we named types L3,M3,M4,and N2.This investigation enhances our understanding of mosquito probing behaviors.It also provides a new tool for the automated calculation of peak frequency.This work will facilitate future pathogen acquisition and transmission studies and help identify new pest and disease management targets.
查看更多>>摘要：Our understanding of the nervous tissues that affect the wing flapping of in-sects mainly focuses on the brain,but wing flapping is a rhythmic movement related to the central pattern generator in the ventral nerve cord.To verify whether the neural activity of the abdominal ganglion of the honeybee(Apis mellifera)affects the flapping-wing flight,we profiled the response characteristics of indirect flight muscles to abdominal ganglion excitation.Strikingly,a change in the neural activity of ganglion 3 or ganglion 4 has a stronger effect on the electrophysiological activity of indirect flight muscles than that of ganglion 5.The electrophysiological activity of vertical indirect flight muscles is affected more by the change in neural activity of the abdominal ganglion than that of lateral in-direct flight muscles.Moreover,the change in neural activity of the abdominal ganglion mainly causes the change in the muscular activity of indirect wing muscles,but the activity patterns change relatively little and there is little change in the complicated details.This work improves our understanding of the neuroregulatory mechanisms associated with the flapping-wing flight of honeybees.
查看更多>>摘要：Sex pheromones are considered to play critical roles in partner communication of most parasitic Hymenoptera.However,the identification of sex pheromone components remains limited to a few families of parasitoid wasps.In this study,we functionally char-acterized a candidate sex pheromone component in Microplitis mediator(Hymenoptera:Braconidae),a solitary parasitoid of Noctuidae insects.We found that the body surface extract from female wasps could significantly stimulate courtship behavior of males.Gas chromatography-electroantennographic detection(GC-EAD)analysis revealed that a can-didate semiochemical from extract triggered significant electrophysiological response of antennae of males.By performing gas chromatography-mass spectrometer(GC-MS)mea-surement,GC-EAD active compound was identified as n-octyl acrylate,a candidate sex pheromone component in female M.mediator.In electroantennogram(EAG)tests,anten-nae of male wasps showed significantly higher electrophysiological responses to n-octyl acrylate than those of females.Y-tube olfactometer assays indicated that male wasps sig-nificantly chose n-octyl acrylate compared with the control.Furthermore,male wasps showed a remarkable preference for n-octyl acrylate in a simulated field condition behav-ioral trial;simultaneously,n-octyl acrylate standard could also trigger significant courtship behavior in males.We propose that n-octyl acrylate,as a candidate vital sex pheromone component,could be utilized to design behavioral regulators of M.mediator to implement the protection and utilization of natural enemies.
查看更多>>摘要：Imidacloprid is a neonicotinoid insecticide used for managing the Asian citrus psyllid,Diaphorina citri Kuwayama,which serves as vector of phytopathogens causing citrus greening.However,development of resistance to neonicotinoids among populations of D.citri has coincided with occasional control failures in the field.The objectives of this research were to(1)survey current levels of imidacloprid resistance in Florida citrus;(2)compare feeding behavior between imidacloprid-resistant and susceptible D.citri us-ing electrical penetration graph recordings,and(3)investigate the possible amplification of insecticide hormoligosis associated with resistance.Field surveys confirmed that the susceptibility of D.citri populations to imidacloprid has decreased in commercial Florida citrus groves compared with a laboratory-susceptible population.Following 12 genera-tions of selection,resistance to imidacloprid increased by 438 fold compared with the sus-ceptible strain.Imidacloprid-susceptible D.citri feeding on citrus exhibited significantly more bouts associated with intercellular pathway(C),phloem penetration(D),phloem salivation(E1),and nonprobing(Np)activities than imidacloprid-resistant counterparts.However,there were no differences observed in the frequency or duration of phloem in-gestion or xylem feeding between susceptible and resistant D.citri.There was no statis-tical difference in fecundity between resistant and susceptible strains.However,the fe-cundity of imidacloprid-susceptible female D.citri treated with a sublethal concentration of imidacloprid(LC25)increased significantly compared with controls,while such hor-moligosis was less pronounced among imidacloprid-resistant psyllids.Our results suggest that imidacloprid-resistant psyllids may cease feeding sooner than susceptible counter-parts following sublethal exposure to this insecticide,indicative of a behavioral resistance mechanism.
查看更多>>摘要：With climate change,the spotted-wing Drosophila(SWD,Drosophila suzukii)invades a great number of fruit production regions worldwide.A plethora of insecticides are being applied for management of this pest.As expected,SWD develops resistance against some potent insecticides or is rather insensitive to some others.Therefore,there is an urgent need to identify and characterize alternative insecticides to control SWD popu-lations.Here,we have studied the effects of the orally applied inhibitor of the fatty acid synthesis pathway spirotetramat on SWD fitness with respect to fecundity and surface bar-rier function at different stages.In our experiments,we applied spirotetramat mixed with baker's yeast and showed that females and males were not repelled by effective concentra-tions of this insecticide.We found that spirotetramat,by trend,lowers egg numbers laid by fed females.These eggs rapidly desiccate,and only a few larvae hatch.Spirotetramat is lethal to larvae and reduces survival of adult flies under low-humidity conditions.Taken together,based on our data,we propose to use yeast supplemented with spirotetramat and additional SWD-specific attractants in traps in non-crop areas in order to eradicate SWD populations before they infest crop production sites.
Patrick KlüberEmna ArousJeanny JerschowMarco Fraatz...
1231-1248页
查看更多>>摘要：The black soldier fly,Hermetia illucens,comes with big promises for indus-trial purposes since its larvae feed polyphagously on a broad spectrum of organic sub-strates.However,research focusing on adult flies is scarce,which is inconsistent with their reproductive relevance within the rearing cycle.In particular,directed oviposition is a challenge in artificial systems.Currently,decomposing organic matter is commonly used as oviposition substrate,which has extensive potential for improvement in view of the lack of standardization and the risk of microbial contamination.Here,we identified three fatty acids and one fatty acid methyl ester derived from the surface of old ovipo-sition sites and targeted to elucidate their effect on preference behavior and oviposition site selection using Y-olfactometry and prepared oviposition sites,respectively.Exposure to tetradecanoic acid attracted gravid females and stimulated oviposition most strongly,while decanoic acid demonstrated a repulsive effect.Females kept in mixed-sex popula-tions were attracted by tetradecanoic acid,resulting in a higher egg mass found in the compound box(3.0-11.4 fold),a ≥ 2.3 fold reduction of nonspecifically deposited eggs,and the highest total egg mass.Conversely,decanoic and dodecanoic acid caused females to lay a greater proportion of eggs nonspecifically outside both boxes.Our data suggest that fatty acids,especially tetradecanoic acid,are important cues for oviposition site selec-tion in black soldier flies.In order to achieve a directed oviposition behavior,the role of further short-and long-chain fatty acids as attractants should be examined.
查看更多>>摘要：Phenylacetaldehyde(PAH),an aromatic compound,is present in a diverse range of fruits including overripe bananas and prickly pear cactus,the two major host fruits for Drosophila melanogaster.PAH acts as a potent ligand for the ionotropic receptor 84a(IR84a)in the adult fruit fly and it is detected by the IR84a/IR8a heterotetrameric complex.Its role in the male courtship behavior through IR84a as an environmental aphrodisiac is of additional importance.In D.melanogaster,two distinct kinds of olfactory receptors,that is,odorant receptors(ORs)and ionotropic receptors(IRs),perceive the odorant stimuli.They display unique structural,molecular,and functional characteristics in addition to hav-ing different evolutionary origins.Traditionally,olfactory cues detected by the ORs such as ethyl acetate,1-butanol,isoamyl acetate,1-octanol,4-methylcyclohexanol,etc.classi-fied as aliphatic esters and alcohols have been employed in olfactory classical conditioning using fruit flies.This underlines the participation of OR-activated olfactory pathways in learning and memory formation.Our study elucidates that likewise ethyl acetate(EA)(an OR-responsive odorant),PAH(an IR-responsive aromatic compound)too can form learn-ing and memory when associated with an appetitive gustatory reinforcer.The association of PAH with sucrose(PAH/SUC)led to learning and formation of the long-term memory(LTM).Additionally,the Orco1,Ir84aMI00501,and Ir8al mutant flies were used to confirm the exclusive participation of the IR84a/IR8a complex in PAH/SUC olfactory associative conditioning.These results highlight the involvement of IRs via an IR-activated pathway in facilitating robust olfactory behavior.
查看更多>>摘要：Genes on the Y chromosome play important roles in male sex determination and development.The identification of Y-chromosome-specific genes not only provides a theoretical basis for the study of male reproductive development,but also offers genetic control targets for agricultural pests.However,Y-chromosome genes are rarely charac-terized due to their high repeatability and high heterochromatinization,especially in the oriental fruit fly.In this study,1 011 Y-chromosome-specific candidate sequences were screened from 2 to 4 h Bactrocera dorsalis embryo datasets with the chromosome quotient method,6 of which were identified as Y-chromosome-specific sequences by polymerase chain reaction,including typo-gyf,a 19 126-bp DNA sequence containing a 575-amino acid open reading frame.Testicular deformation and a significant reduction in sperm num-ber were observed after typo-gyf knockdown with RNA interference in embryos.After typo-gyfknockout with clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9 in the embryonic stage,the sex ratio of the emergent adults was unbalanced,with far more females than males.A genotype analysis of these females with the Y-chromosome gene MoY revealed no sex reversal.Typo-gyf knockout led to the death of XY individuals in the embryonic stage.We conclude that typo-gyf is an essential gene for male survival,and is also involved in testicular development and spermatogen-esis.The identification of typo-gyf and its functional verification provide insight into the roles of Y-chromosome genes in male development.
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