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为扩大黑肩绿盲蝽Cyrtorhinus lividipennis的人工繁殖规模,利用RNA-seq技术对饥饿胁迫2 d的黑肩绿盲蝽雌成虫进行转录组测序分析,筛选参与生殖调控的相关信号通路,挖掘直接或者间接影响生殖的相关基因,采用实时荧光定量PCR（real-time fluorescence quantification PCR,qRT-PCR）对筛选的相关基因进行验证,并通过试验分析沉默S6K基因和饥饿处理对黑肩绿盲蝽生殖的影响。结果显示,与取食褐飞虱Nilaparvata lugens卵（CK）的黑肩绿盲蝽相比,饥饿处理2 d的黑肩绿盲蝽雌成虫有11 675个基因差异表达,其中有4 264个基因表达量上调,7 411个基因表达量下调。共筛选到7条与生殖调控相关的信号通路和6个与生殖调控相关的基因,除TSC2基因表达量上调外,其他S6K、INSR、Akt、HSP70-1、HSP70-2五个与生殖相关基因的表达量在7条生殖相关信号通路中均下调。qRT-PCR检测结果与转录组测序结果一致,说明转录组分析结果可靠。沉默S6K基因后,黑肩绿盲蝽雌成虫脂肪体和卵巢蛋白质含量、Vg基因表达量、雌成虫产卵量和Vg含量较对照显著降低。此外,饥饿处理2 d后黑肩绿盲蝽雌成虫产卵量也较对照显著减少。表明饥饿胁迫后黑肩绿盲蝽雌成虫的生殖相关通路可能受多个信号通路调控,S6K表达量下降显著影响黑肩绿盲蝽的生殖。 相似文献
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保幼激素(juvenile hormone, JH)是由咽侧体分泌的倍半萜类化合物,可以调控昆虫的很多生理过程,如发育、变态、生殖等。作为bHLH-PAS(helix-loop-helix-Per-ARNT-Sim)转录因子家族成员之一的methoprene-tolerant (Met)是JH的受体,在JH的信号传导过程中有非常重要的作用。本研究通过实时荧光定量PCR结合RNAi技术测定了沉默Met基因后黏虫Mythimna separata的Vg基因表达、卵巢发育和生殖行为,旨在探究Met基因在黏虫生殖过程中的功能。结果表明当Met基因沉默后,与卵巢发育密切相关的卵黄原蛋白(vitellogenin, Vg)基因表达量下调了50%,从而显著抑制了卵巢发育,并导致产卵显著延迟、产卵历期显著缩短,产卵量显著下降。结果表明Met基因是黏虫生殖发育过程中的关键受体基因,它通过调节后续Vg的表达和沉积,来达到控制卵巢发育,从而调控生殖作用。 相似文献
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Imidazole derivative KK-42 reduces ecdysteroid titers and interferes with reproductive processes in adult females of Tenebrio molitor 总被引：2，自引：0，他引：2
L. Amrani K. Zerguine J.-P. Farine G. Smagghe N. Soltani-Mazouni 《Pesticide biochemistry and physiology》2004,80(3):163-172
KK-42, an imidazole derivative considered as potent inhibitor of ecdysteroid biosynthesis, was tested on adult females of Tenebrio molitor. The compound was applied topically (0.1, 1, 5, and 10 μg/insect) on 0- or 2-day-old adult females or added to the culture medium (1 and 10 μM) of ovaries. To test the effect of KK-42 on the reproduction capacity, ovaries were explanted from 2- and 4-day-old females corresponding, respectively, to follicles at the beginning and the end of vitellogenesis. KK-42 treatment reduced the fecundity and the longevity of females, and in addition, it delayed oviposition and affected growth and development of oocytes as evidenced by measurements of the ovarian weight, the number of oocytes per ovaries, and the size of the basal follicle. Hence, the effects were stronger in newly emerged females compared to 2-day-old females. Interestingly, RH-0345, an ecdysteroid agonist, could partly restore the effects on reproductive events induced by KK-42. In a second series of experiments using an enzyme immunoassay to measure ecdysteroid titers, KK-42 reduced the amounts of ecdysteroids in ovaries after application on newly emerged adult females. In 2-day-old females, it caused a significant effect with the highest doses. In addition, the compound significantly reduced the amounts of ecdysteroid released into the culture medium by ovaries explanted from 2- or 4-day-old females. The results are discussed in relation to the mode of action of KK-42 on reproduction. 相似文献
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Effects of pyriproxyfen, a juvenile hormone analog, on development of the mealworm, Tenebrio molitor
Pyriproxyfen, an analog of the juvenile hormone (JH) in insects, has been evaluated in vivo and in vitro on an important stored product pest, the mealworm Tenebrio molitor. On newly ecdysed pupae, this insect growth regulator (IGR) was applied topically (at 0.10 and 0.20 μg/insect). Enzyme immunoassay measurements showed a decrease of the ecdysteroid titer in the hemolymph of treated specimens. In addition, the treatment induced an increase of the protein concentration in the hemolymph, however, there was no significant effect on the protein band pattern. Using in vitro pupal integument explant cultures, pyriproxyfen (at 1 and 10 μM in the medium) caused a significant inhibition of ecdysteroid amounts and of the thickness of new cuticle secreted. These new results are discussed in relation to the physiology of this IGR with a JH action. 相似文献
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BACKGROUND: Tribolium castaneum (red flour beetle) is a serious insect pest of stored products around the world. Current control measures for this species have several limitations: loss of registration of insecticides, insecticide resistance and consumer concerns about chemical residues in food. The objective of this study was to determine whether methoprene affects progeny production of T. castaneum. Late‐instar larvae or young adults were exposed to methoprene‐treated wheat, and progeny production was determined. The pairing of male and female adults was performed as untreated × untreated, treated × untreated or treated × treated, to study sex‐based effects. RESULTS: There were three outcomes to late‐instar larvae held on methoprene‐treated wheat kernels (0.001 and 0.0165 ppm): (1) failure to emerge as an adult; (2) emergence as an adult, and almost no offspring produced; (3) emergence as an adult and normal production of offspring. Male larvae were more susceptible to methoprene than female larvae. In contrast, young adults exposed to methoprene (1.67–66.6 ppm) showed no reduction in offspring production. CONCLUSION: Methoprene concentrations will decline with time following its application. However, this research indicates that methoprene can still reduce populations of T. castaneum by reducing their progeny production, even if adults emerge. Copyright © 2011 Society of Chemical Industry 相似文献
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Bengochea P Christiaens O Amor F Viñuela E Rougé P Medina P Smagghe G 《Pest management science》2012,68(7):976-985
BACKGROUND: The moulting accelerating compounds (MACs) or ecdysteroid agonists represent a selective group of insecticides acting upon binding to the ecdysteroid receptor (EcR) and leading to lethal premature moulting in larval stages and aborted reproduction in adults. Psyttalia concolor Szèpl. is a useful parasitic wasp attacking important tephritid pests such as the medfly and olive fruit fly. RESULTS: Contact and oral exposure in the laboratory of female parasitic wasps to the dibenzoylhydrazine‐based methoxyfenozide, tebufenozide and RH‐5849 did not provoke negative effects. No mortality and no reduction in beneficial capacity were observed. The ligand‐binding domain (LBD) of the EcR of P. concolor was sequenced, and a homology protein model was constructed which confirmed a cavity structure with 12 α‐helices, harbouring the natural insect moulting hormone 20‐hydroxyecdysone. However, a steric clash occurred for the MAC insecticides owing to a restricted extent of the ligand‐binding cavity of the PcLBD‐EcR, while they did dock well in that of susceptible insects. CONCLUSIONS: The insect toxicity assays demonstrated that MACs are selective for P. concolor. The modelling/docking experiments are indications that these insecticides do not bind with the LBD‐EcR of P. concolor and support the theory that they show no biological effects in the parasitic wasp. These data may help in explaining the compatible use of MACs together with parasitic wasps in IPM programmes. Copyright © 2012 Society of Chemical Industry 相似文献
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Tohidi-Esfahani D Lawrence MC Graham LD Hannan GN Simpson AM Hill RJ 《Pest management science》2011,67(11):1457-1467
BACKGROUND: Certain bisacylhydrazine compounds such as tebufenozide (RH5992) have been shown to act as order‐specific insecticides. Their compatibility with predatory Heteroptera, which are used as biological control agents, has also been demonstrated. However, the molecular mode of action of these ecdysone agonists has not been explored in a heteropteran, much less one that is a significant agricultural pest, such as Nezara viridula. RESULTS: Alternatively spliced ligand‐binding regions of the N. viridula ecdysone receptor were expressed, purified and characterised by 2D gel analysis, mass spectrometry, homology modelling and competitive binding of a bisacylhydrazine insecticidal compound (RH5992) and various ecdysteroids. Ligand binding by the two splice isoforms was indistinguishable, and relative affinities were found to occur in the order muristerone A > ponasterone A > 20‐hydroxyecdysone > inokosterone > RH5992 > α‐ecdysone. CONCLUSION: The predicted difference in amino acid sequence between the ligand‐binding domains of the N. viridula ecdysone receptor splice variants was verified by mass spectrometry. Both splice variant isoforms exhibit a greater affinity for the bisacylhydrazine insecticide RH5992 than do the other hemipteran ecdysone receptors characterised to date. Their affinities for a range of ecdysteroids also distinguish them from the ecdysone receptors of other Hemiptera characterised thus far. Homology models of both N. viridula receptor isoforms provide further insight into the bisacylhydrazine‐ and ecdysteroid‐binding properties of these receptors, including their similar affinity for 20‐hydroxyecdysone and the postulated pentatomomorphan moulting hormone makisterone A. Copyright © 2011 Society of Chemical Industry 相似文献
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Eiichi Kuwano Motohisa Shimizu Kenshi Shimazu Satoshi Nakazawa Koichi Suzuki 《Pest management science》1998,52(3):251-257
A new series of 5-(substituted phenoxy)pentyl 3-pyridyl ethers induced precocious metamorphosis in larvae of the silkworm, Bombyx mori. Both 2- and 4-pyridyl ethers were inactive, indicating that the 3-pyridine moiety was essential for the activity. Octyl, dodecyl and farnesyl 3-pyridyl ethers had no activity. Among the compounds tested so far, 5-(4-propylphenoxy)pentyl 3-pyridyl ether showed the highest activity. The activity fell off with increasing or decreasing length of the carbon chain between two oxygen atoms. Introduction of a methyl group at the 6 position of the pyridine ring completely eliminated the activity. Precocious metamorphosis induced by 3-pyridyl ethers was fully reversible by a simultaneous application of a small amount of tebufenozide, an ecdysteroid agonist, or methoprene, a JH agonist. © 1998 SCI. 相似文献
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BACKGROUND: Bed bugs (Cimex lectularius L.) have become a common insect pest in urban areas and are often difficult to manage. Eradication is made more problematic by widespread insecticide resistance, raising interest in alternative control products. Juvenile hormone analogs (JHAs) such as methoprene and hydroprene are relatively harmless to non‐arthropods and have proved to be effective against other urban insect pests. Two JHA products (Gentrol® and Precor®, Central Life Sciences, Schaumburg, IL) were tested for efficacy against various bed bug stages as direct spray and as dry residue using three bed bug strains. RESULTS: At 1× and 2× the label rate, Precor® [active ingredient (S)‐methoprene] had no significant effect on the development or fecundity of bed bugs. At 2× the label rate, confinement to residues of Gentrol® [active ingredient (S)‐hydroprene] had no significant effect, but residues at 3× and 10× the label rate caused a reduction in fecundity and impaired development. Field strains were more susceptible to the reproductive effects of (S)‐hydroprene than a long‐maintained laboratory strain. CONCLUSIONS: While JHAs are attractive alternatives for pest management because of their inherent safety and distinct mode of action, these JHA formulations would have little impact on bed bug populations without relabeling to allow for higher application rates. Copyright © 2012 Society of Chemical Industry 相似文献
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Thomas Soin Ellen De Geyter Hadi Mosallanejad Masatoshi Iga David Martín Shunsuke Ozaki Shigeki Kitsuda Toshiyuki Harada Hisashi Miyagawa Dimitra Stefanou Georgia Kotzia Rodica Efrose Vassiliki Labropoulou Danny Geelen Kostas Iatrou Yoshiaki Nakagawa Colin R Janssen Guy Smagghe Luc Swevers 《Pest management science》2010,66(5):526-535
BACKGROUND: Dibenzoylhydrazine analogues have been developed successfully as a new group of insect growth regulators, called ecdysone agonists or moulting accelerating compounds. A notable feature is their high activity against lepidopteran insects, raising the question as to whether species‐specific analogues can be isolated. In this study, the specificity of ecdysone agonists was addressed through a comparative analysis in two important lepidopterans, the silkworm Bombyx mori L. and the cotton leafworm Spodoptera littoralis (Boisd.). RESULTS: When collections of non‐steroidal ecdysone agonists containing different mother structures (dibenzoylhydrazine, acylaminoketone, tetrahydroquinoline) were tested, in vitro reporter assays showed minor differences using cell lines derived from both species. However, when compounds with high ecdysone agonist activity were examined in toxicity assays, larvicidal activity differed considerably. Of note was the identification of three dibenzoylhydrazine analogues with > 100‐fold higher activity against Bombyx than against Spodoptera larvae. CONCLUSION: The present study demonstrated that species‐specific ecdysone‐agonist‐based insecticides can be developed, but their species specificity is not based on differences in the activation of the ecdysone receptor but rather on unidentified in vivo parameters such as permeability of the cuticle, uptake/excretion by the gut or metabolic detoxification. Copyright © 2010 Society of Chemical Industry 相似文献
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Thomas Soin Luc Swevers Georgia Kotzia Kostas Iatrou Colin R Janssen Pierre Rougé Toshiyuki Harada Yoshiaki Nakagawa Guy Smagghe 《Pest management science》2010,66(11):1215-1229
BACKGROUND: Diacylhydrazine (DAH) analogues have been developed successfully as a new group of insect growth regulators, called ecdysone agonists or moulting accelerating compounds. These DAHs have been shown to manifest their toxicity via interaction with the ecdysone receptor (EcR) in susceptible insects, as does the natural insect moulting hormone 20‐hydroxyecdysone (20E). A notable feature is their high activity and specificity, particularly against lepidopteran insects, raising the question as to whether non‐lepidopteran‐specific analogues can be isolated. However, for the discovery of ecdysone agonists that target other important insect groups such as Diptera, efficient screening systems that are based on the activation of the EcR are needed. RESULTS: In this study, a dipteran‐specific reporter‐based screening system with transfected S2 cells of Drosophila melanogaster Meig. was developed in order to discover and evaluate compounds that have ecdysone agonistic or antagonistic activity. A library of non‐steroidal ecdysone agonists containing different mother structures with DAH and other related analogues such as acylaminoketone (AAK) and tetrahydroquinoline (THQ) was tested. None of the compounds tested was as active as 20E. This is in contrast to the very high activity of several DAH and AAK congeners in lepidopteran cells (Bombyx mori L.‐derived Bm5 cells). The latter agrees with a successful docking of a DAH, tebufenozide, in the binding pocket of the lepidopteran EcR (B. mori), while this was not the case with the dipteran EcR (D. melanogaster). Of note was the identification of two THQ compounds with activity in S2 but not in Bm5 cells. Although marked differences in activity exist with respect to the activation of EcR between dipterans and lepidopterans, there exists a positive correlation (R = 0.724) between the pLC50 values in S2 and Bm5 cells. In addition, it was found through protein modelling that a second lobe was present in the ligand‐binding pocket of lepidopteran BmEcR but was lacking in the dipteran DmEcR protein, suggesting that this difference in structure of the binding pocket is a major factor for preferential activation of the lepidopteran over the dipteran receptors by DAH ligands. CONCLUSIONS: The present study confirmed the marked specificity of DAH and AAK analogues towards EcRs from lepidopteran insects. THQ compounds did not show this specificity, indicating that dipteran‐specific ecdysone‐agonist‐based insecticides based on the THQ mother structure can be developed. The differences in activity of ecdysone agonists in dipteran and lepidopteran ecdysone‐reporter‐based screening systems are discussed. Copyright © 2010 Society of Chemical Industry 相似文献
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The development of insects is under the control of a steroid hormone, ecdysone. This paper reviews suicide substrate type inactivators designed to inhibit the biosynthesis of ecdysone. Several series of acetylenic derivatives of cholesterol were synthesized and their biological effects on the prothoracic glands of the locust were investigated in vitro, enabling structure-activity relationships to be studied. Information on the ability of brassinosteroids, a series of plant growth regulators, to inhibit ecdysteroid activities of insects is discussed as a precursor to a study of brassinosteroid ecdysone mimics. 相似文献
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Fermín Amor Olivier Christiaens Paloma Bengochea Pilar Medina Pierre Rougé Elisa Viñuela Guy Smagghe 《Pest management science》2012,68(12):1586-1594
BACKGROUND: Knowledge of pesticide selectivity to natural enemies is necessary for a successful implementation of biological and chemical control methods in integrated pest management (IPM) programmes. Diacylhydrazine (DAH)‐based ecdysone agonists, also known as moulting‐accelerating compounds (MACs), are considered to be a selective group of insecticides, and their compatibility with predatory Heteroptera, which are used as biological control agents, is known. However, their molecular mode of action has not been explored in beneficial insects such as Orius laevigatus (Fieber) (Hemiptera: Anthocoridae). RESULTS: In this project, in vivo toxicity assays demonstrated that the DAH‐based RH‐5849, tebufenozide and methoxyfenozide have no toxic effect against O. laevigatus. The ligand‐binding domain (LBD) of the ecdysone receptor (EcR) of O. laevigatus was sequenced, and a homology protein model was constructed that confirmed a cavity structure with 12 α‐helices, harbouring the natural insect moulting hormone 20‐hydroxyecdysone. However, docking studies showed that a steric clash occurred for the DAH‐based insecticides owing to a restricted extent of the ligand‐binding cavity of the EcR of O. laevigatus. CONCLUSIONS: The insect toxicity assays demonstrated that MACs are selective for O. laevigatus. The modelling/docking experiments are indications that these pesticides do not bind with the LBD‐EcR of O. laevigatus and support the supposition that they show no biological effects in the predatory bug. These data help in explaining the compatible use of MACs together with predatory bugs in IPM programmes. Copyright © 2012 Society of Chemical Industry 相似文献
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R.E. Redfern T.J. Kelly A.B. Bořkovec D.K. Hayes 《Pesticide biochemistry and physiology》1982,18(3):351-356
The ecdysteroid titers of insect growth regulator (IGR)-treated and untreated large milkweed bug nymphs, Oncopeltus fasciatus (Dallas) (Heteroptera: Lygaeidae), were determined by radioimmunoassay. All of the IGRs tested affected the ecdysteroid levels and the ecdysis of both sexes in some way. AI3-63604, a juvenile hormone mimic, accelerated ecdysteroid production and its subsequent decline, shortened the stadium, and induced a supernumerary nymphal molt. Diflubenzuron had no effect on the onset of ecdysteroid production but slightly retarded the decline in ecdysteroid titers before adult ecdysis, and the ecdysis was incomplete. Ecdysteroid production was delayed and erratic in nymphs treated with azadirachtin and AI3-63967, but the effect on ecdysis was different for each compound. Azadirachtin caused incomplete adult ecdysis, whereas AI3-63967 completely prevented any attempts at ecdysis. The large peak of exdysteroid activity associated with apolysis was absent in starved insects, and they made no attempt to ecdyse. 相似文献
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中黑盲蝽Adelphocoris suturalis是一种重要的农业害虫,主要为害棉花、果树和牧草等作物。昆虫保幼激素(juvenile hormone, JH)与蜕皮激素(molting hormone, 20E)是调控昆虫生殖的主要因素。本研究运用基因克隆、基因沉默(RNAi)、实时荧光定量PCR(qPCR)等技术研究蜕皮激素受体(ecdysone receptor, EcR)、超气门蛋白(ultraspiracle protein, USP)在中黑盲蝽生殖调控中的作用。结果表明,中黑盲蝽EcR基因的ORF全长1 413 bp,编码470个氨基酸。预测蛋白质分子量为53.65 kD,pI值为7.79。中黑盲蝽USP基因ORF全长1 209 bp,编码402个氨基酸。预测蛋白质分子量为44.99 kD, pI值为7.94。与对照相比,注射dsEcR、dsUSP后6～18 d的中黑盲蝽体内EcR基因、USP基因在转录水平分别被显著抑制;卵巢的挂卵量分别仅有对照组的31.5%、86.6%;单雌产卵量减少36.0%～80.4%,显著低于对照。EcR和USP基因沉默后,产卵前期与对照相比无显... 相似文献
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蜕皮激素受体(ecdysone receptor,Ec R)是调控昆虫蜕皮、变态和生殖等过程中基因表达的重要调控因子。为研究Ec R在烟粉虱Bemisia tabaci生长发育中的作用,利用RT-PCR和RACE等技术扩增了烟粉虱MED隐种Ec R基因的c DNA全长序列,并利用实时荧光定量PCR技术检测其在烟粉虱不同发育时期相对表达量的变化。Bt Ec R c DNA序列全长2 844 bp,含有一个1 518 bp的开放阅读框,共编码505个氨基酸,预测蛋白分子量为56 k D,等电点为6.43,含有特殊结构功能域:DNA结合域(DBD_Ec R)和配体结合域(LBD_Ec R),该序列编码的蛋白质序列与其它已报道的昆虫Ec R蛋白序列具有很高的相似性,命名为Bt Ec R(Gen Bank登录号:KR534774)。Bt Ec R在MED隐种若虫、雌成虫各发育时期均有表达,若虫期在伪蛹前期达到最高值,成虫期呈现先升高后降低的趋势,且在羽化后第7天达到最高值,约为羽化第1天的23倍。研究结果为揭示Bt Ec R在烟粉虱整个生长发育过程中的作用提供了重要依据。 相似文献
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In the summer of 1998, failures of methoprene field applications to control the mosquito Ochlerotatus nigromaculis (Ludlow) were noticed in several pastures in the outskirts of Fresno, California, USA. Effective control with methoprene had been achieved for over 20 years prior to this discovery. Susceptibility tests indicated that the Fresno Oc nigromaculis populations had developed several thousand‐fold higher LC50 and LC90 tolerance levels to methoprene compared with methoprene‐naïve populations. The synergists piperonyl butoxide (PBO), S,S,S‐tributyl phosphorotrithioate and 3‐octylthio‐1,1,1‐trifluoro‐2‐propanone had little synergistic effect, suggesting that the mechanism of methoprene tolerance was not mediated by P450 monooxygenase or carboxylesterase enzyme degradation. As part of initiating a resistance management strategy, partial reversion back to methoprene susceptibility was achieved in a resistant population after six consecutive applications of Bacillus thuringiensis israelensis Goldberg & Marga coupled with two oil and two pyrethrum + PBO applications. © 2002 Society of Chemical Industry 相似文献