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谷氨酸门控氯离子通道(GluCls)介导快速抑制性神经传导,目前只发现于无脊椎动物中,是开发新型杀虫剂的理想作用靶标。GluCls属于半胱氨酸环超家族的配体门控离子通道,在昆虫中只发现有1个α亚基,但可以通过选择性剪接生成多种亚基剪接变体并且能够形成功能性受体。除了典型的神经传导功能外,GluCls还参与调控昆虫保幼激素合成及生长发育等生理功能。GluCls的氨基酸突变和表达量变化是导致昆虫对杀虫剂产生抗药性的部分原因。本文主要从GluCls的分子特征、选择性剪接、药理学性质、生理功能和昆虫的抗药性5个方面对昆虫GluCls的研究进展作一综述,为新型杀虫剂的研发提供理论基础。 相似文献
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抑制性谷氨酸受体(IGluRs)通道及其相关杀虫剂的作用 总被引：4，自引：1，他引：3
抑制性谷氨酸受体(IGluRs)属于半胱氨酸环配体门控离子通道超家族,主要介导神经和肌肉细胞中抑制性的神经传递,目前仅在无脊椎动物中发现,在脊椎动物中尚未发现,因此是高选择性杀虫剂的理想靶标。IGluRs主要分布在无脊椎动物的神经和肌肉组织中,对控制吞咽、运动、感知和保幼激素的生物合成等可能起关键作用。人们对IGluRs的了解大多来自于对线虫和模式昆虫的研究,目前在线虫中共发现了4种α亚基和1种β亚基,是否有一种新的亚基类型如γ亚基尚不确定,从昆虫体内仅克隆了α亚基。就生理功能和药理特性而言,IGluRs与γ-氨基丁酸(GABA)受体最为类似,但其氨基酸序列却与甘氨酸受体相似性最高。作用于IGluRs的杀虫剂包括阿维菌素/美倍霉素类、苯基吡唑类杀虫剂氟虫腈以及吲哚二萜类化合物Nodulisporic acid等。对IGluRs的生理功能、分子特性、药理性质及相关杀虫剂的作用机理等的研究进展进行了综述。 相似文献
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昆虫鱼尼丁受体及以其为靶标的杀虫剂的研究进展 总被引：9，自引：3，他引：6
植物保护领域以昆虫鱼尼丁受体(ryanodine receptor,RyR)为靶标的杀虫剂的研发取得了突破性进展。对近年来RyR在分子结构、功能调节,以及对以RyR为靶标的杀虫剂的作用机制方面的研究进展进行了综述。昆虫RyR与哺乳动物RyR仅有约47%的同源性,因而是一个有效的杀虫剂靶标。昆虫RyR克隆与表达技术的成熟为新型杀虫剂的开发和作用机制的研究提供了有力的工具。昆虫RyR单通道、配体结合和免疫学特性的研究补充了RyR的电生理学数据。近年来开发的新型RyR杀虫剂通过激活害虫鱼尼丁敏感的细胞内钙离子释放通道来达到杀虫的效果。 相似文献
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Cheryl A. Leichter Nathan Thompson Bruce R. Johnson Jeffrey G. Scott 《Pesticide biochemistry and physiology》2013
ME-5343 (afidopyropen) is a new and promising insecticide with an unknown mechanism of action that is effective against sucking insects. ME-5343 was highly toxic to pea aphids (Acyrthosiphon pisum), being more toxic than six other widely used insecticides. In contrast, ME-5343 was practically non-toxic to eight other species of insects we tested. ME-5343 was not toxic to German cockroaches (topical application) or American cockroaches (injection), suggesting that lack of toxicity in these species is not due to lack of cuticular penetration. House flies are insensitive to ME-5343 by topical, residual and feeding exposure. Addition of synergists did not change this result, suggesting that insensitivity to ME-5343 in house flies is not due to rapid detoxification nor is it dependent on the method of bioassay used. ME-5343 did not cause firefly lanterns to glow, nor did it prevent the octopamine stimulated lantern glow. Extracellular recordings of action potentials from a tonically active motor nerve of crayfish in situ showed no effects of ME-5343 at concentrations up to 10−5 M. These results suggest that the target site of ME-5343 is not the voltage gated sodium channel, voltage gated potassium channel, GABA gated chloride channel, nicotinic acetylcholine receptor, acetylcholinesterase, octopamine receptor or glutamate receptor. ME-5343 injected into crayfish caused flextion of the legs and tail, similar to the symptoms induced by 5-HT (serotonin). We evaluated the effect of ME-5343 on 5-HT2-like receptors with intracellular recordings of excitatory post-synaptic potentials from the peripheral neuromuscular junction of the crayfish and found no effect of ME-5343. Thus, ME-5343 was neither an agonist nor antagonist of 5-HT2 receptors, did not affect neurotransmitter release and did not affect glutamate receptors. We conclude that ME-5343 is highly toxic to aphids and that this is due to a unique, and currently undefined mechanism of action. 相似文献
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David M. Soderlund Jeffrey R. Bloomquist Fulton Wong Lori L. Payne Douglas C. Knipple 《Pest management science》1989,26(4):359-374
Recent advances in molecular neurobiology have provided an unprecedented insight into the structure and function of the three principal target sites for neurotoxic insecticides: acetylcholinesterase, the 4-aminobutyric acid (GABA) receptor–chloride ionophore complex, and the voltage-sensitive sodium channel. This paper reviews some of these advances and their current or potential application to problems in insecticide resistance. It particularly emphasizes studies of the molecular biology of voltage-dependent sodium channels in the context of resistance to DDT and pyrethroids resulting from reduced neuronal sensitivity. 相似文献
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Glutamate-activated chloride channels: Unique fipronil targets present in insects but not in mammals 总被引：1，自引：0，他引：1
Selectivity to insects over mammals is one of the important characteristics for a chemical to become a useful insecticide. Fipronil was found to block cockroach GABA receptors more potently than rat GABAA receptors. Furthermore, glutamate-activated chloride channels (GluCls), which are present in cockroaches but not in mammals, were very sensitive to the blocking action of fipronil. The IC50s of fipronil block were 30 nM in cockroach GABA receptors and 1600 nM in rat GABAA receptors. Moreover, GluCls of cockroach neurons had low IC50s for fipronil. Two types of glutamate-induced chloride current were observed: desensitizing and non-desensitizing, with fipronil IC50s of 800 and 10 nM, respectively. We have developed methods to separately record these two types of GluCls. The non-desensitizing and desensitizing currents were selectively inhibited by trypsin and polyvinylpyrrolidone, respectively. In conclusion, in addition to GABA receptors, GluCls play a crucial role in selectivity of fipronil to insects over mammals. GluCls form the basis for development of selective and safe insecticides. 相似文献
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Ibotenic acid [2-(3-hydroxyisoxazol-5-yl)glycine] induced a dose-dependent increase in chloride ion conductance in locust muscle fibres which was not sensitive to 4-aminobutyric acid (GABA). This ibotenate response became rapidly desensitised and appeared to be due to activation of extrasynaptic glutamate H receptors. 22-23-Dihydroavermectin B1a (DHAVM) (500 pg to 1 μg ml?1) induced irreversible increases in permeability to the chloride ion and abolished ibotenate responses. DHAVM responses were not altered when glutamate H receptors were desensitised by glutamate (1 mM) or ibotenate (100 μM). Irreversible changes in input conductance caused by DHAVM were not affected by penicillin G (1 mM) or bicuculline (1 mM), but picrotoxin (1 mM) and zinc chloride reduced DHAVM responses by 23.7 and 52.6%, respectively. It is concluded that DHAVM has a number of sites of action on locust muscle that include effects on the glutamate H receptor–chloride ion channel complex, in addition to effects on the GABA receptor–chloride ion channel previously described. 相似文献
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The role of GABA and glutamate receptors in susceptibility and resistance to chloride channel blocker insecticides 总被引：1，自引：0，他引：1
Xilong Zhao 《Pesticide biochemistry and physiology》2010,97(2):153-160
Despite a point mutation in the pore-forming segment of the Rdl GABA receptor subunit that is widespread and persistent in insect populations and confers high levels of resistance to dieldrin and other polychlorocycloalkane (PCCA) insecticides, the phenylpyrazole insecticide fipronil, which binds at same site, has proven to be effective in controlling many insects, including dieldrin-resistant populations. Fipronil and its major sulfone metabolite are unique among chloride channel blocking insecticides in that they also potently block GluCls. We present here a patch clamp study of the action of fipronil sulfone on native GABA receptors and GluCl receptors from susceptible and dieldrin-resistant German cockroaches, to provide a better understanding of the effect of the Rdl mutation on the function and insecticide sensitivity of these two targets, and its role in resistance. Dieldrin blocked GABA currents with an IC50 of 3 nM in wild-type cockroaches, and 383 nM in resistant insects, yielding a resistance ratio of 128. Fipronil sulfone blocked GABA currents with an IC50 of 0.8 nM in susceptible insects and 12.1 nM, or 15-fold higher, in resistant insects. While both GluClD (desensitizing) and GluClN (non-desensitizing) receptors were found in German cockroach neurons, GluClN receptors were rare and could not be included in this study. GluClD receptors from resistant insects had reduced sensitivity to glutamate and a lower rate of desensitization than those from susceptible insects, but their sensitivity to block by fipronil sulfone was not significantly changed, with an IC50 of 38.5 ± 2.4 nM (n = 8) in the susceptible strain and 40.3 ± 1.0 nM (n = 7) in the resistant strain. Fipronil sulfone also slowed the decay time course of GluClD currents. These results suggest that GluClD receptors contain the Rdl subunit, but their sensitivity to fipronil sulfone is not altered in resistant insects. 相似文献
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棉叶螨也称为棉红蜘蛛,属蛛形纲叶螨科,其种类繁多,分布范围广,世代周期短,是为害棉花的一类重要害螨。目前,用于防治棉叶螨的化学药剂主要是神经毒剂及呼吸抑制剂2大类,且棉叶螨对多数药剂产生了不同程度的抗性,以二斑叶螨Tetranychus urticae为首的植食性害螨已成为世界上抗药性最严重的节肢动物之一。美国路易斯安那州棉田二斑叶螨种群对阿维菌素产生了1 415倍抗性,而国内棉花上棉叶螨主要对有机磷类药剂产生了较强抗性,最高为467倍。棉叶螨产生抗药性的机制主要涉及靶标突变及解毒代谢增强,其中靶标突变主要涉及乙酰胆碱酯酶、电压门控钠离子通道和谷氨酸门控氯离子通道等;细胞色素P450单加氧酶、羧酸酯酶和谷胱甘肽S-转移酶等一种或多种解毒酶共同参与害螨对化学药剂的解毒代谢。该文主要从棉叶螨的种类及分布、用于防治棉叶螨的化学药剂、棉叶螨的抗药性现状、抗药性机制解析和抗药性治理策略5个方面进行阐述,提出因地制宜的抗药性治理策略,旨在为棉叶螨的田间防治提供指导。 相似文献
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Jian-Rong Gao Cheryl A. Leichter Toshio Shono 《Pesticide biochemistry and physiology》2007,88(1):66-70
Fipronil is a relatively new insecticide with great potential for insect control, however widespread use of cyclodiene insecticides has selected for an A302S mutation in the Rdl (GABA gated chloride channel) allele. This mutation gives resistance to cyclodienes and limited cross-resistance to fipronil. Given the concern over the possible reduction in efficacy and/or lifetime that fipronil might be used for pest control (given the extensive use of cyclodienes in the past), it is important to know the frequency of the A302S Rdl mutation in field populations. To ascertain the relative frequency of the A302S Rdl mutation in house fly populations we used three experimental approaches. First, we attempted to select for fipronil resistance by initially treating 33,100 field collected flies and selecting 14 additional generations. We were unable to produce a highly resistant strain. Second, we directly sequenced field collected flies. Third, we tested field collected house flies with a diagnostic dose of dieldrin and then genotyped the survivors. Out of the 4750 flies tested, there were no Rdl resistance alleles detected. We conclude that the resistant Rdl allele is rare in house flies in the US due to decades without cyclodiene use and a fitness disadvantage (in the absence of cyclodienes) of the 302S Rdl allele. The limited cross-resistance provided by the cyclodiene resistant Rdl allele, combined with the very low frequency of this allele in field populations, suggests that fipronil could be a promising insecticide for house fly control. 相似文献
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Among insect GABA receptors, the GABA-gated chloride channel subtype is insensitive to bicuculline and has been thought to be composed of two populations because of differences in chloride conductance increase, GABA and picrotoxin (PTX) sensitivity. To characterize this possible diversity in GABA-gated chloride channels, electropharmacological experiments were performed on giant interneuron synaptic GABA receptors and on somatic GABA receptors of dorsal unpaired median (DUM) neuron and fast coxal depressor (Df) motoneuron of the cockroach Periplaneta americana (L). Electrophysiological assays performed at cercal-afferent giant interneuron synapses demonstrated that a biphasic increase in membrane conductance, in response to long-lasting (30 s) neuropilar microapplication of GABA, could be explained by the existence of two GABA-operated chloride channel receptor subtypes. The low stable membrane conductance increase, representing less than 30% of the maximum reached during the early transient phase, was not desensitized quickly. It was reproduced by neuropilar microapplication of cis-4-aminocrotonic acid (CACA) and, in contrast to the fast phase, was not antagonized by bath application of 10−5 M PTX. Long-lasting (3 min) pneumatic pressure application of GABA on the cell body of motoneuron Df evoked a fast transient hyperpolarization followed by a slower phase of further hyperpolarization. PTX (10−5 M ) blocked the fast transient phase and revealed a slow stable hyperpolarization. PTX (10−4 M ) blocked the major part of the remaining GABA response. The slow hyperpolarization was reproduced by application of CACA. Similar effects of GABA and CACA were recorded on DUM neuron cell bodies. All of these observations are consistent with the possible existence of two GABA-gated chloride channel subtypes in the insect CNS. © 1999 Society of Chemical Industry 相似文献
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The action of avermectin was studied in the leg muscle and the central nervous system of the American cockroach, Periplanata americana L. Avermectin at a low concentration (10?7M) causes a failure of the leg muscles to respond to external stimuli within 30 min without affecting the magnitude of contraction. Avermectin was found to stimulate Cl? uptake by the leg muscles within 4 min at 10?7M. The threshold concentration to cause such stimulation was on the order of 10?8M. This stimulatory action could be antagonized by picrotoxinin (10?4M) and to a lesser extent by bicuculline methiodide (10?4M). The phenomenon is observable under both Na+-free and K+-free conditions. It was concluded that the action of avermectin is to open the chloride channel on the plasma membrane. This action of avermectin does not seem to be mediated through GABA, GABA receptors, diazepine receptors, or picrotoxinin receptor in this insect species, and therefore suggests that avermectin directly attacks the chloride channel proper both in the central nervous and the neuromuscular systems. 相似文献