Aphids are major insect pests in agriculture and forestry worldwide.Following attacks by natural enemies,many aphids release an alarm pheromone to protect their population.In most aphids,the main component of the aphi...Aphids are major insect pests in agriculture and forestry worldwide.Following attacks by natural enemies,many aphids release an alarm pheromone to protect their population.In most aphids,the main component of the aphid alarm pheromone(AAP)is the sesquiterpene hydrocarbon(E)-β-farnesene(EβF).However,the mechanisms behind its biosynthesis and regulation remain poorly understood.In this study,we used the bird cherry–oat aphid Rhopalosiphum padi,which is an important wheat aphid,to investigate the regulatory mechanisms of EβF biosynthesis.Our results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st-and 2nd-instar nymphs.Triglycerides provide the prerequisite material for EβF production and release.Based on transcriptome sequencing,RNAi analysis,hormone treatments,and quantitative measurements,we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation,which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid metabolism.This is the first systemic study on the modulation of EβF production in aphids.The results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis,as well as valuable information for designing potential aphid control strategies.展开更多
The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 valu...The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 values of fenvalerate to the 3rd instar larvae of DBM varied with host plants, however, there wasn＇t any significant difference among them （P〉 0.05）. Similarly, DBM fed on three host plants had same pupal weight, pupal period, pupation rate, adult emergence rate, female ratio, and fecundity. The activity of juvenile hormone esterase （JHE, EC 3.1.1.1） in the 3rd instar larvae of DMB did not significantly vary with host plants, either. These suggested that DBM had similar fitness on the three host plant species. When fed on the host plants pretreated with fenvalerate at the concentrations equivalent to LC20, LC50 and LC50, the pupation rate, pupal weight, adult emergence rate, female ratio, fecundity, and JHE activity of the tested insects were declined as compared with insects in control treatments fed on the same host plant species. Furthermore, the pupal period of the tested insects was extended after fenvalerate treatment. The decrease in JHE activity after fenvalerate treatment in the tested insects could partly explain the changes in the mentioned growth parameters. Whether the role of fenvalerate in the inhibition of JHE activity could serve as a new way to control DBM needs further investigation.展开更多
Juvenile hormone esterase(JHE) is a key enzyme for insects,playing an important role in the regulation of insect growth,development,diapause and reproduction.We identified a complete putative JHE of Cydia pomonella(Cp...Juvenile hormone esterase(JHE) is a key enzyme for insects,playing an important role in the regulation of insect growth,development,diapause and reproduction.We identified a complete putative JHE of Cydia pomonella(CpJHE-like) which is comprised of a 1 761 bp coding sequence(CDS) encoding 587 amino acid residues from the transcriptome data.The deduced protein sequence of CpJHE-like showed the highest identity of 60.44% with the Adoxophyes honmai JHE(AhJHE) and the minimal identity of 25.81% with Aedes aegypti JHE(AaJHE).CpJHE-like exhibited all the seven typical motifs of the functional JHEs and had the highly consistent tertiary structure with Manduca sexta JHE(MsJHE).Phylogenetic analysis showed that the CpJHE-like was close to two JHEs from the family Tortricidae.The CpJHE-like transcript level take a leap in the 3-day-old fifth instar larva,increased about 300-fold compared to the basal level.Tissue-specific expression profile showed that the CpJHE-like transcript was expressed mainly in the fat body.This study indicates that the CpJHE-like is the functional JHE,which may play vital roles in the development and reproduction of C.pomonella.展开更多
In insects, juvenile hormone (JH) decreases or has any effect upon the phenoloxidase (PO) activity, and favors or decreases the Antimicrobial Peptides (AMPs) expression. Although there is no information about the diff...In insects, juvenile hormone (JH) decreases or has any effect upon the phenoloxidase (PO) activity, and favors or decreases the Antimicrobial Peptides (AMPs) expression. Although there is no information about the differential effect of such hormone, two possibilities are that it depends on (a) the immune marker recorded and (b) sexual differences. Here, three commonly used immune markers, Phenoloxidase (PO), hydrogen peroxide (H2O2), and lytic activity, were measured 3, 6 and 24 hours after administration of methoprene (JHa, an analog of juvenile hormone) in male and female monarch butterflies (Danaus plexippus). At 3 and 6 h post-JHa administration, the PO activity increased in females but it only increased at 3 h in males, whereas H2O2 levels increased only in females at 3 h. For the remaining times the JHa had a null effect on POand H2O2. On the other hand, the JHa had a null effect for lytic activity in both sexes at 3, 6 and 24 h. To our knowledge, this is the first report of a positive effect of a JHa onPOand H2O2 and suggests that this effect is sex dependent.展开更多
Juvenile hormone(JH)acts in the regulation of caste differentiation between queens and workers(i.e.,with or without reproductive capacity)during vitellin synthesis and oogenesis in social insects.However,the regulator...Juvenile hormone(JH)acts in the regulation of caste differentiation between queens and workers(i.e.,with or without reproductive capacity)during vitellin synthesis and oogenesis in social insects.However,the regulatory mechanisms have not yet been elucidated.Here,we identified a highly expressed microRNA(miRNA),miR-1175-3p,in the red imported fire ant,Solenopsis invicta.We found that miR-1175-3p is prominently present in the fat bodies and ovaries of workers.Furthermore,miR-1175-3p interacts with its target gene,broad-complex core(Br-C),in the fat bodies.By utilizing miR-1175-3p agomir,we successfully suppressed the expression of the Br-C protein in queens,resulting in reduced vitellogenin expression,fewer eggs,and poorly developed ovaries.Conversely,decreasing miR-1175-3p levels led to the increased expression of Br-C and vitellogenin in workers,triggering the“re-development”of the ovaries.Moreover,when queens were fed with JH,the expression of miR-1175-3p decreased,whereas the expression of vitellogenin-2 and vitellogenin-3 increased.Notably,the suppression of fertility in queens caused by treatment with agomir miR-1175-3p was completely rescued by the increased vitellogenin expression induced by being fed with JH.These results suggest the critical role of miR-1175-3p in JH-regulated reproduction,shedding light on the molecular mechanism underlying miRNA-mediated fecundity in social insects and providing a novel strategy for managing S.invicta.展开更多
Hormones control the reproductive development of Aedes aegypti mosquitoes.The adult male reproductive process and mating behavior require adequate nutrients and energy.Understanding the molecular mechanism linking hor...Hormones control the reproductive development of Aedes aegypti mosquitoes.The adult male reproductive process and mating behavior require adequate nutrients and energy.Understanding the molecular mechanism linking hormones,energy metabolism,and reproduction in male mosquitoes is important.In this study,we found that the size of the male accessory gland,an essential part of the male reproductive system,gradually increased after eclosion.However,it was significantly reduced in male mosquitoes deficient in methoprene-tolerant(Met),the receptor of juvenile hormone.Likewise,egg hatchability of females that mated with Met-depleted males showed the same downward trend.The mRNA level of the gene encoding accessory gland protein,l-asparaginase(ASNase),was reduced in Met dsRNA-treated males.Electrophoretic mobility shift assay and quantitative reverse transcription-PCR results revealed that Met was capable of binding directly to the promoter of ASNase and activated its transcription.RNA interference of ASNase in males resulted in the reduction of egg hatchability of the females with which they mated.These results showed that Met influenced the fecundity of male mosquitoes by directly upregulating the expression of the ASNase gene.Moreover,the levels of triacylglycerol and the sizes of lipid droplets were decreased by 72-78 h after eclosion in the fat body cells,whereas both of them increased in Met-depleted male mosquitoes,indicating that Met knockdown reduced lipid catabolism.These data demonstrate that Met might influence the egg hatchability of females by regulating lipid metabolism and the development of the male accessory gland in male mosquitoes.展开更多
基金supported by the National Natural Science Foundation of China(31972267 and 3227253)the Chinese Universities Scientific Fund(2023TC109)。
文摘Aphids are major insect pests in agriculture and forestry worldwide.Following attacks by natural enemies,many aphids release an alarm pheromone to protect their population.In most aphids,the main component of the aphid alarm pheromone(AAP)is the sesquiterpene hydrocarbon(E)-β-farnesene(EβF).However,the mechanisms behind its biosynthesis and regulation remain poorly understood.In this study,we used the bird cherry–oat aphid Rhopalosiphum padi,which is an important wheat aphid,to investigate the regulatory mechanisms of EβF biosynthesis.Our results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st-and 2nd-instar nymphs.Triglycerides provide the prerequisite material for EβF production and release.Based on transcriptome sequencing,RNAi analysis,hormone treatments,and quantitative measurements,we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation,which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid metabolism.This is the first systemic study on the modulation of EβF production in aphids.The results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis,as well as valuable information for designing potential aphid control strategies.
基金support for this work was provided by the National Natural Science Foundation of China(30971922)the Natural Science Foundation of Fujian Province, China (B0320003, B0410015, 2004J010, and2007F5021)+1 种基金the Science and Technology Innovation Foundation of Fujian Academy of Agricultural Science,China (STIF-Y07)the Program for New Century Excellent Talents in University of Fujian Province, China,to Associate Professor Gu Xiaojun
文摘The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 values of fenvalerate to the 3rd instar larvae of DBM varied with host plants, however, there wasn＇t any significant difference among them （P〉 0.05）. Similarly, DBM fed on three host plants had same pupal weight, pupal period, pupation rate, adult emergence rate, female ratio, and fecundity. The activity of juvenile hormone esterase （JHE, EC 3.1.1.1） in the 3rd instar larvae of DMB did not significantly vary with host plants, either. These suggested that DBM had similar fitness on the three host plant species. When fed on the host plants pretreated with fenvalerate at the concentrations equivalent to LC20, LC50 and LC50, the pupation rate, pupal weight, adult emergence rate, female ratio, fecundity, and JHE activity of the tested insects were declined as compared with insects in control treatments fed on the same host plant species. Furthermore, the pupal period of the tested insects was extended after fenvalerate treatment. The decrease in JHE activity after fenvalerate treatment in the tested insects could partly explain the changes in the mentioned growth parameters. Whether the role of fenvalerate in the inhibition of JHE activity could serve as a new way to control DBM needs further investigation.
基金supported by the National Key Research and Development Program of China(2016YFC1201200,2017YFC1200600 and 2016YFC1200602)the Basic Research on Science and Technology Project of Shenzhen,China(JCYJ20160530191934833)the Dapeng New District Industrial Development Special Fund of Shenzhen,China(KY20180215)
文摘Juvenile hormone esterase(JHE) is a key enzyme for insects,playing an important role in the regulation of insect growth,development,diapause and reproduction.We identified a complete putative JHE of Cydia pomonella(CpJHE-like) which is comprised of a 1 761 bp coding sequence(CDS) encoding 587 amino acid residues from the transcriptome data.The deduced protein sequence of CpJHE-like showed the highest identity of 60.44% with the Adoxophyes honmai JHE(AhJHE) and the minimal identity of 25.81% with Aedes aegypti JHE(AaJHE).CpJHE-like exhibited all the seven typical motifs of the functional JHEs and had the highly consistent tertiary structure with Manduca sexta JHE(MsJHE).Phylogenetic analysis showed that the CpJHE-like was close to two JHEs from the family Tortricidae.The CpJHE-like transcript level take a leap in the 3-day-old fifth instar larva,increased about 300-fold compared to the basal level.Tissue-specific expression profile showed that the CpJHE-like transcript was expressed mainly in the fat body.This study indicates that the CpJHE-like is the functional JHE,which may play vital roles in the development and reproduction of C.pomonella.
基金Lidia Ruth Ordones Espinosa provided help to collect the animals A Grant from CONACyT(152666)was provided to JCG.
文摘In insects, juvenile hormone (JH) decreases or has any effect upon the phenoloxidase (PO) activity, and favors or decreases the Antimicrobial Peptides (AMPs) expression. Although there is no information about the differential effect of such hormone, two possibilities are that it depends on (a) the immune marker recorded and (b) sexual differences. Here, three commonly used immune markers, Phenoloxidase (PO), hydrogen peroxide (H2O2), and lytic activity, were measured 3, 6 and 24 hours after administration of methoprene (JHa, an analog of juvenile hormone) in male and female monarch butterflies (Danaus plexippus). At 3 and 6 h post-JHa administration, the PO activity increased in females but it only increased at 3 h in males, whereas H2O2 levels increased only in females at 3 h. For the remaining times the JHa had a null effect on POand H2O2. On the other hand, the JHa had a null effect for lytic activity in both sexes at 3, 6 and 24 h. To our knowledge, this is the first report of a positive effect of a JHa onPOand H2O2 and suggests that this effect is sex dependent.
基金National Key R&D Program of China(2021YFD1000500)the Natural Science Foundation of Guangdong Province(2023A1515012108)the Foundation of Guangdong Academy of Agricultural Sciences(R2023PY-JX010).
文摘Juvenile hormone(JH)acts in the regulation of caste differentiation between queens and workers(i.e.,with or without reproductive capacity)during vitellin synthesis and oogenesis in social insects.However,the regulatory mechanisms have not yet been elucidated.Here,we identified a highly expressed microRNA(miRNA),miR-1175-3p,in the red imported fire ant,Solenopsis invicta.We found that miR-1175-3p is prominently present in the fat bodies and ovaries of workers.Furthermore,miR-1175-3p interacts with its target gene,broad-complex core(Br-C),in the fat bodies.By utilizing miR-1175-3p agomir,we successfully suppressed the expression of the Br-C protein in queens,resulting in reduced vitellogenin expression,fewer eggs,and poorly developed ovaries.Conversely,decreasing miR-1175-3p levels led to the increased expression of Br-C and vitellogenin in workers,triggering the“re-development”of the ovaries.Moreover,when queens were fed with JH,the expression of miR-1175-3p decreased,whereas the expression of vitellogenin-2 and vitellogenin-3 increased.Notably,the suppression of fertility in queens caused by treatment with agomir miR-1175-3p was completely rescued by the increased vitellogenin expression induced by being fed with JH.These results suggest the critical role of miR-1175-3p in JH-regulated reproduction,shedding light on the molecular mechanism underlying miRNA-mediated fecundity in social insects and providing a novel strategy for managing S.invicta.
基金supported by the National Key Plan for Scientific Research and Development of China(2021YFC2600100)the Strategic Priority Research Program of Chinese Academy of Sciences(XDPB16)+1 种基金the key program of the Chinese Academy of Sciences(KJZD-SW-L11)the National Natural ScienceFoundation of China Grant 31802013.
文摘Hormones control the reproductive development of Aedes aegypti mosquitoes.The adult male reproductive process and mating behavior require adequate nutrients and energy.Understanding the molecular mechanism linking hormones,energy metabolism,and reproduction in male mosquitoes is important.In this study,we found that the size of the male accessory gland,an essential part of the male reproductive system,gradually increased after eclosion.However,it was significantly reduced in male mosquitoes deficient in methoprene-tolerant(Met),the receptor of juvenile hormone.Likewise,egg hatchability of females that mated with Met-depleted males showed the same downward trend.The mRNA level of the gene encoding accessory gland protein,l-asparaginase(ASNase),was reduced in Met dsRNA-treated males.Electrophoretic mobility shift assay and quantitative reverse transcription-PCR results revealed that Met was capable of binding directly to the promoter of ASNase and activated its transcription.RNA interference of ASNase in males resulted in the reduction of egg hatchability of the females with which they mated.These results showed that Met influenced the fecundity of male mosquitoes by directly upregulating the expression of the ASNase gene.Moreover,the levels of triacylglycerol and the sizes of lipid droplets were decreased by 72-78 h after eclosion in the fat body cells,whereas both of them increased in Met-depleted male mosquitoes,indicating that Met knockdown reduced lipid catabolism.These data demonstrate that Met might influence the egg hatchability of females by regulating lipid metabolism and the development of the male accessory gland in male mosquitoes.
