查看更多>>摘要：Due to the absence of acquired immunity,insects primarily rely on their innate immune system to resist pathogenic microorganisms and parasitoids in natural habitats.This innate immune system can be classified into cellular immunity and humoral immu-nity.Cellular immunity is mediated by hemocytes,which perform phagocytosis,aggrega-tion,and encapsulation to fight against invaders,whereas the humoral immunity primarily activates the immune signaling pathways and induces the generation of immune effectors.Existing studies have revealed that the hemipteran aphids lack some crucial immune genes compared to other insect species,indicating the different immune mechanisms in aphids.The current review summarizes the adverse impacts of pathogenic microorganisms and parasitoids on aphids,introduces the cellular and humoral immune systems in insects,and analyzes the differences between aphids and other insect species.Furthermore,our re-view also discussed the existing prospects and challenges in aphid immunity research,and proposed the potential application of immune genes in green pest management.
查看更多>>摘要：The fall armyworm(Spodoptera frugiperda)is one of the major pest insects damaging diverse crops including cotton,corn,rice,and sorghum.Fall armyworms have been identified as two morphologically indistinguishable strains,the corn strain,and the rice strain,named after their preferred host-plants.Although initially recognized as host-plant strains,there has been an ongoing debate regarding whether the corn and rice strains should be considered as such.In this article,we present arguments based on recent pop-ulation genomics studies supporting that these two strains should be considered to be host-plant strains.Furthermore,host-plant adaptation appears to be a driving evolutionary force responsible for incipient speciation in the fall armyworm.
查看更多>>摘要：The tanning hormone,Bursicon,is a neuropeptide secreted by the insect ner-vous system that functions as a heterodimer composed of Burs-α and Burs-β subunits.It plays a critical role in the processes of cuticle tanning and wing expansion in insects.In this study,we successfully identified the AcBurs-α and AcBurs-β genes in Aphis citri-cidus.The open reading frames of AcBurs-α and Ac Burs-β were 480 and 417 bp in length,respectively.Both AcBurs-α and AcBurs-β exhibited 11 conserved cysteine residues.AcBurs-α and AcBurs-β were expressed during all developmental stages of A.citricidus and showed high expression levels in the winged aphids.To investigate the potential role of AcBurs-α and AcBurs-β in wing development,we employed RNA interference(RNAi)techniques.With the efficient silencing of AcBurs-α(44.90％)and AcBurs-β(52.31％),malformed wings were induced in aphids.The proportions of malformed wings were 22.50％,25.84％,and 38.34％in dsAcBurs-α-,dsAcBur-β-,and dsAcBurs-α+dsAcBur-β-treated groups,respectively.Moreover,feeding protein kinase A inhibitors(H-89)also increased the proportion of malformed wings to 30.00％.Feeding both double-stranded RNA and inhibitors(H-89)significantly downregulated the wing development-related genes nubbin,vestigial,notch and spalt major.Silence of vestigial through RNAi also led to malformed wings.Meanwhile,the exogenous application of 3 hormones that in-fluence wing development did not affect the expression level of AcBursicon genes.These findings indicate that AcBursicon genes plays a crucial role in wing development in A.citricidus;therefore,it represents a potential molecular target for the control of this pest through RNAi-based approaches.
查看更多>>摘要：Earth's rotation shapes a 24-h cycle,governing circadian rhythms in organ-isms.In mammals,the core clock genes,CLOCK and BMAL1,are regulated by PERIODs(PERs)and CRYPTOCHROMEs(CRYs),but their roles remain unclear in the diamond-back moth,Plutella xylostella.To explore this,we studied P xylostella,which possesses a simplified circadian system compared to mammals.In P xylostella,we observed rhyth-mic expressions of the Pxper and Pxcry2 genes in their heads,with differing phases.In vitro experiments revealed that PxCRY2 repressed monarch butterfly CLK:BMAL1 tran-scriptional activation,while PxPER and other CRY-like proteins did not.However,PxPER showed an inhibitory effect on PxCLK/PxCYCLE.Using CRISPR/Cas9,we individually and in combination knocked out Pxper and Pxcry2,then conducted gene function studies and circadian transcriptome sequencing.Loss of either Pxper or Pxcry2 eliminated the activity peak after lights-off in light-dark cycles,and Pxcry2 loss reduced overall activ-ity.Pxcry2 was crucial for maintaining endogenous rhythms in constant darkness.Under light-dark conditions,1 098 genes exhibited rhythmic expression in wild-type P xylostella heads,with 749 relying on Pxper and Pxcry2 for their rhythms.Most core clock genes lost their rhythmicity in Pxper and Pxcry2 mutants,while Pxcry2 sustained rhythmic expres-sion,albeit with reduced amplitude and altered phase.Additionally,rhythmic genes were linked to biological processes like the spliceosome and Toll signaling pathway,with these rhythms depending on Pxper or Pxcry2 function.In summary,our study unveils differ-ences in circadian rhythm regulation by Pxper and Pxcry2 in P xylostella.This provides a valuable model for understanding circadian clock regulation in nocturnal animals.
查看更多>>摘要：The tobacco cutworm Spodoptera litura is one of the most destructive polyphagous crop pests.Olfaction and taste play a crucial role in its host plant selection and sexual communication,but the expression profile of chemosensory genes remains un-clear.In this study,we identified 185 chemosensory genes from 7 organs in S.litura by transcriptome sequencing,of which 72 genes were published for the first time,includ-ing 27 odorant receptors(ORs),26 gustatory receptors(GRs),1 ionotropic receptor(IR),16 odorant-binding proteins(OBPs),and 2 chemosensory proteins(CSPs).Phylogenetic analyses revealed that ORs,IRs,OBPs,and sensory neuron membrane proteins(SNMPs)were mainly expressed in antennae and sequence-conserved among Noctuidae species.The most differentially expressed genes(DEGs)between sexes were ORs and OBPs,and no DEGs were found in GRs.GR transcripts were enriched in proboscis,and the expres-sion of sugar receptors was the highest.Carbon dioxide receptors,sugar receptor-SliuGR6,and bitter GRs-SlituGR43 and SlituGR66 had higher sequence identities between Noctu-idae species.CSPs were broadly expressed in various organs,and SlituCSP13 was a DEG in adult antennae.The functional analysis in the Drosophila OR67d expression system found that SlituOR50,a receptor highly expressed in female antennae,is selectively tuned to farnesyl acetate.The results provide a solid foundation for understanding the molec-ular mechanisms by which chemosensory genes operate to elicit behavioral responses in polyphagous insects.
查看更多>>摘要：Mosquitoes(Anopheles sinensis),widely geographically distributed in Asia in-cluding China,are the primary vector of the malaria parasite Plasmodium vivax and other parasitic diseases such as Malayan filariasis.An.sinensis can survive through low winter temperatures.Aquaporin channels are found in all life forms,where they facilitate envi-ronmental adaptation by allowing rapid trans-cellular movement of water(classical aqua-porins)or water and solutes such as glycerol(aquaglyceroporins).Here,we identified and characterized 2 aquaporin(AQP)homologs in An.sinensis:AsAQP2(An.sinensis aquaglyceroporin)and AsAQP4(An.sinensis aquaporin).When expressed in frog(Xeno-pus laevis)oocytes,AsAQP2 transported water,glycerol,and urea;AsAQP4 transported only water.Water permeation through AsAQP2 and AsAQP4 was inhibited by mercuric chloride.AsAQP2 expression was slightly higher in adult female mosquitoes than in males,and AsAQP4 expression was significantly higher in adult males.The 2 AsAQPs were highly expressed in Malpighian tubules and midgut.AsAQP2 and AsAQP4 expression was up-regulated by blood feeding compared with sugar feeding.At freezing point(0 ℃),the AsAQP4 expression level increased and An.sinensis survival time reduced compared with those at normal temperature(26 ℃).At low temperature(8 ℃),the AsAQP2 and AsAQP4 expression levels decreased and survival time was significantly longer compared with those at 26 ℃.These results suggest that AsAQP2 and AsAQP4 have roles in water homeostasis during blood digestion and in low temperature adaptation of A.sinensis.To-gether,our results show that the 2 AQPs are important for mosquito diuresis after blood feeding and when exposed to low temperatures.
查看更多>>摘要：Apparently,the genomes of many organisms are pervasively transcribed,and long noncoding RNAs(lncRNAs)make up the majority of cellular transcripts.LncRNAs have been reported to play important roles in many biological processes;however,their effects on locomotion are poorly understood.Here,we presented a novel lncRNA,Loco-motion Regulatory Gene(LRG),which participates in locomotion by sequestering Synap-totagmin 1(SYT1).LRG deficiency resulted in higher locomotion speed which could be rescued by pan-neuronal overexpression but not by limited ellipsoid body,motoneuron or muscle-expression of LRG.At the molecular level,the synaptic vesicles(SVs)release and movement-related SYT1 protein was recognized as LRG-interacting protein candidate.Furthermore,LRG had no effects on SYT1 expression.Genetically,the behavioral defects in LRG mutant could be rescued by pan-neuronal knock-down of Syt1.Taken together,all the results suggested LRG exerts regulatory effects on locomotion via sequestering SYT1 thereby blocking its function without affecting its expression.Our work displays a new function of lncRNA and provides insights for revealing the pathogenesis of neurological diseases with motor disorders.
查看更多>>摘要：Changes in diet type and nutrient availability can impose significant environ-mental stress on organisms,potentially compromising physiological functions and repro-ductive success.In nature,dramatic fluctuations in dietary resources are often observed and adjustments to restore cellular homeostasis are crucial to survive this type of stress.In this study,we exposed male Drosophila melanogaster to two modulated dietary treat-ments:one without a fasting period before exposure to a high-fat diet and the other with a 24-h fasting period.We then investigated mitochondrial metabolism and molecular re-sponses to these treatments.Exposure to a high-fat diet without a preceding fasting pe-riod resulted in disrupted mitochondrial respiration,notably at the level of complex I.On the other hand,a short fasting period before the high-fat diet maintained mitochondrial respiration.Generally,transcript abundance of genes associated with mitophagy,heat-shock proteins,mitochondrial biogenesis,and nutrient sensing pathways increased either slightly or significantly following a fasting period and remained stable when flies were subsequently put on a high-fat diet,whereas a drastic decrease of almost all transcript abundances was observed for all these pathways when flies were exposed directly to a high-fat diet.Moreover,mitochondrial enzymatic activities showed less variation after the fasting period than the treatment without a fasting period.Overall,our study sheds light on the mechanistic protective effects of fasting prior to a high-fat diet and highlights the metabolic flexibility of Drosophila mitochondria in response to abrupt dietary changes and have implication for adaptation of species to their changing environment.
查看更多>>摘要：Symbiotic microorganisms are essential for the physiological processes of her-bivorous pests,including the pear lace bug Stephanitis nashi,which is known for causing extensive damage to garden plants and fruit trees due to its exceptional adaptability to diverse host plants.However,the specific functional effects of the microbiome on the adaptation of S.nashi to its host plants remains unclear.Here,we identified significant microbial changes in S.nashi on 2 different host plants,crabapple and cherry blossom,characterized by the differences in fungal diversity as well as bacterial and fungal com-munity structures,with abundant correlations between bacteria or fungi.Consistent with the microbiome changes,S.nashi that fed on cherry blossom demonstrated decreased metabolites and downregulated key metabolic pathways,such as the arginine and mitogen-activated protein kinase signaling pathway,which were crucial for host plant adaptation.Furthermore,correlation analysis unveiled numerous correlations between differential mi-croorganisms and differential metabolites,which were influenced by the interactions be-tween bacteria or fungi.These differential bacteria,fungi,and associated metabolites may modify the key metabolic pathways in S.nashi,aiding its adaptation to different host plants.These results provide valuable insights into the alteration in microbiome and func-tion of S.nashi adapted to different host plants,contributing to a better understanding of pest invasion and dispersal from a microbial perspective.
Perry G.Beasley-HallYukihiro KinjoHarley A.RoseJames Walker...
1810-1821页
查看更多>>摘要：Microbial symbioses have had profound impacts on the evolution of animals.Conversely,changes in host biology may impact the evolutionary trajectory of symbionts themselves.Blattabacterium cuenoti is present in almost all cockroach species and en-ables hosts to subsist on a nutrient-poor diet.To investigate if host biology has impacted Blattabacterium at the genomic level,we sequenced and analyzed 25 genomes from Aus-tralian soil-burrowing cockroaches(Blaberidae:Panesthiinae),which have undergone at least seven separate subterranean,subsocial transitions from above-ground,wood-feeding ancestors.We find at least three independent instances of genome erosion have occurred in Blattabacterium strains exclusive to Australian soil-burrowing cockroaches.These shrink-ages have involved the repeated inactivation of genes involved in amino acid biosynthesis and nitrogen recycling,the core role of Blattabacterium in the host-symbiont relationship.The most drastic of these erosions have occurred in hosts thought to have transitioned un-derground the earliest relative to other lineages,further suggestive of a link between gene loss in Blattabacterium and the burrowing behavior of hosts.As Blattabacterium is unable to fulfill its core function in certain host lineages,these findings suggest soil-burrowing cockroaches must acquire these nutrients from novel sources.Our study represents one of the first cases,to our knowledge,of parallel host adaptations leading to concomitant parallelism in their mutualistic symbionts,further underscoring the intimate relationship between these two partners.
万方数据
维普