昆虫毒蕈碱型乙酰胆碱受体的研究进展

毒蕈碱型乙酰胆碱受体(Muscarinic Acetylcholine Receptors,mAChRs)是昆虫神经系统中一类重要的G蛋白偶联受体.昆虫mAChRs可以分为A、B、C型三大类,它们通过偶联不同的G蛋白激活不同的第二信使,完成信号转导过程,从而发挥其功能.mAChRs参与调控昆虫多种生理反应和行为过程,如...     

气调(CA)对储藏物害虫的作用机制

本文系统地介绍了气调措施对储藏物害虫的作用机制。在气调环境中 ,高CO2 和低O2 迫使昆虫的气门开启 ,导致体内水分过多散失和神经麻痹 ;吸入昆虫体内的CO2 能抑制昆虫的有氧代谢 ,导致昆虫体内能源物质的耗尽和有毒物质的积累。此外 ,气调还可导致储藏物害虫一些行为习性上的改变。     

昆虫多巴胺及其受体的研究进展

多巴胺（dopamine, DA）是脊椎动物和无脊椎动物体内一种重要的生物胺, 其参与调控了昆虫的多种生理反应和行为过程, 如学习与记忆、 认知、 性取向、 抉择、 运动以及型变等。多巴胺主要通过结合特异性的G蛋白偶联受体, 即多巴胺受体（dopamine receptors, DARs）来发挥生理作用。本文综述了多巴胺在昆虫中的调控、 分布及所参与的生理功能, 如多巴胺调控昆虫的交配、 发育、 嗅觉以及运动行为等, 特别对DARs的信号转导、 生理功能以及药理学等方面进行了详细评述。昆虫的DARs大致可分为两大类： D1-like DARs和D2-like DARs。D1-like DARs包含有2种亚型, 分别为DOP1和DOP2。DOP1仅能偶联胞内cAMP的上升, 而DOP2不仅可以起胞内cAMP的上升, 还可偶联胞内Ca²⁺的释放。 D2-like DARs仅包含有1种亚型DOP3, 其被激活后引起胞内cAMP的降低。DA通过激活不同的DARs可偶联不同的第二信使系统, 所产生的下游细胞反应则与昆虫的各种行为相关, 而对昆虫DARs的药理学研究将有助于我们开发特异性的杀虫剂用于害虫防治。     

昆虫嗅觉相关蛋白及嗅觉识别机理研究概述

嗅觉是昆虫产生行为的基础之一,在长期进化的过程中昆虫形成了复杂的嗅觉系统,完成这一过程,需要有多种与嗅觉相关的蛋白参与,包括气味结合蛋白、化学感受蛋白、气味受体和感觉神经元膜蛋白等。了解昆虫感受外界信息的嗅觉机制可以帮助我们更好地理解昆虫识别配偶、天敌及寻找食物来源、产卵场地等行为特征,为进一步调控昆虫的行为、防控害虫侵袭、保护和利用有益昆虫奠定基础。本文综述了昆虫嗅觉相关的几类重要蛋白的生化特性和生理功能,并对昆虫气味分子的识别机制、气味分子在昆虫体内运输机制的最新研究进展进行了概述。     

植物挥发物对蛾类昆虫性信息素的影响

在植物与昆虫的协同进化过程中,植物挥发物与昆虫性信息素的相互关系一直以来被认为是物种间的重要通信系统。这种相互关系表现为植物挥发物对昆虫生理和行为的影响上,影响昆虫性信息素的合成和昆虫对性信息素的行为反应。本文针对植物挥发物对蛾类昆虫性信息素的影响进行了综述。评述了寄主植物挥发物对蛾类昆虫性信息素或前体的合成及性信息素的产生与释放的影响,总结了寄主植物和非寄主植物挥发物对蛾类昆虫的求偶行为的调控作用及对蛾类昆虫性信息素的增效或抑制作用阐述了植物挥发物影响蛾类昆虫对性信息素行为反应的机理,并且讨论了目前存在的问题。     

慈竹叶蝉类害虫DNA条形码分析

叶蝉类昆虫形态结构多样,在农林生态系统的物种多样性和植物保护工作中扮演着重要角色,但其物种的准确鉴定一直是农林植保工作中的难点。DNA条形码技术极大促进了农林生态系统物种的快速、准确鉴定。本研究经过连续2年的野外调查采集慈竹Bambusa emeiensis主要叶蝉种类,扩增了广泛分布于中国慈竹的12种主要叶蝉类害虫的线粒体基因COⅠ和16S rRNA序列片段,并进行了遗传距离、系统发育及矢量Klee-diagram图分析。结果显示:慈竹叶蝉昆虫COⅠ基因序列片段(590 bp)种内遗传距离为0.004,种间遗传距离为0.283;16S rRNA基因序列片段(463 bp)种内遗传距离为0.003,种间遗传距离为0.257;不同种间存在明显的条形码间隔。2个基因序列片段的分子系统发育分析结果与形态学研究谱系关系一致。Klee-diagram图分析结果和分子系统发育结果一致。上述结果表明,COⅠ和16S rRNA基因适用于慈竹叶蝉类昆虫的物种鉴定,可为竹林叶蝉类昆虫的准确快速鉴定提供参考方法。     

虫粪中信息化学物质的研究进展

排便是昆虫的一个重要生理过程,排便行为不仅可以清除食物残渣,而且可以释放某些化学信息,进而影响昆虫同种或异种之间的相互作用.昆虫粪便中的信息化学物质不仅影响同种昆虫的聚集、求偶行为,而且可以影响同种和异种昆虫的产卵行为.此外,虫粪还能为其天敌昆虫的寄主定位和识别提供信息,并能通过诱导植物的防御反应抑制植食性昆虫的取食行为.本文根据国内外的相关研究,对虫粪中存在的信息化学物质进行了分类总结,并介绍了虫粪信息化合物在害虫防治中的应用,还讨论了目前存在的问题和研究前景.     

昆虫对气味分子的感受机制

昆虫对外界气味的感受作用是一个庞大而复杂的体系,多种蛋白参与了这一过程。其中包括气味结合蛋白,气味结合蛋白受体,气味降解酶等多种蛋白。昆虫不仅可以通过外界气味分子携带的信息来识别配偶,天敌,还可以通过对外界环境特征的识别来寻找食物来源,产卵等。明确昆虫的化学感受机制不仅可以帮助我们理解昆虫的行为,还有助于深入了解动物的行为机制。文章综述昆虫对气味分子的识别、气味分子在昆虫体内的运输以及电化学信号传导机制等方面的进展。     

实蝇类昆虫生殖行为的研究进展

实蝇是全世界重要的农业害虫,其生殖行为规律对其防治方法的研究具有重要指导意义。本文在文献调研的基础上,对实蝇类昆虫求偶、交配和产卵等行为的最新研究进展进行综述。实蝇类昆虫具有非资源型交配系统,性内、性间选择共同驱动实蝇的性特征进化;同时,实蝇生殖行为受到性信息素、翅信号、物理、化学以及环境等因素的影响。此外,雌虫在交配后会为理想产卵位置发生竞争,而产卵标记信息素起着调节作用。实蝇类昆虫的诸多生殖行为研究结果已成功应用于田间防治,取得了较好的效果。     

大气CO2浓度增加对昆虫的影响

大气CO2浓度增加已经受到国内外的极大关注.CO2浓度升高不但影响植物的生长发育,而且还改变植物体内的化学成分的组成与含量,从而间接地影响到植食性昆虫,并进而通过食物链影响到以之为食的天敌.根据国内外研究进展,结合多年的研究,系统介绍了CO2浓度变化对植物-昆虫系统影响的研究方法,论述了CO2浓度变化对植食性昆虫、天敌的作用规律及作用机理,探讨了CO2浓度变化对植物-植食性昆虫系统影响的特征,分析了未来研究发展的趋势及其存在的问题.     

昆虫气味认知的嗅觉神经结构及分子机制

大多数昆虫主要通过气味认知感知外界环境的变化,维持生命活动。探究昆虫气味认知的嗅觉系统神经结构及分子机制,对于完善气味认知神经生物学理论及利用其原理进行仿生学研究等有重要的科学意义。近年,关于昆虫气味认知科学研究有了很大的进展。本文从昆虫神经生物学的视角详细综述了近年关于昆虫气味认知的嗅觉神经结构、分子机制及气味信号的神经传导途径等方面的基本理论及最新研究成果。综述结果显示:昆虫对气味的认知是通过嗅觉神经系统的触角感器、触角叶(AL)、蕈形体(MB)等脑内多层信号处理神经结构来实现的。当外界气味分子进入触角感器内后,由感器内特定的气味识别蛋白(OBP)将气味分子运载到达嗅觉感受神经元(ORN)树突膜上的受体位点,气味分子与表达特定气味的受体(OR)结合产生电信号,并以动作电位的形式通过ORN的轴突传到脑内的触角叶。在触角叶经过嗅觉纤维球对气味信息选择性加工处理,再由投射神经元(PNs)将初步的识别和分类的气味信息传到蕈形体和外侧角(LH)等神经中枢,实现对气味的识别和认知。虽然,近年昆虫气味认知神经生物学的研究有了很大的进步,但是,我们认为目前的研究成果还不能完全阐明昆虫气味认知的神经机制,还有很多问题,例如,触角叶上众多的嗅觉纤维球是如何对嗅觉感受神经元传入的气味信息进行编码处理的?等有待进一步深入研究。为了搞清这些疑难问题,我们认为需要提高现有的实验技术水平,加强电生理学和分子神经生物学相结合的实验研究,从分子水平探究气味认知的神经机制可能是未来研究的热点。     

CO2加富对UV-B辐射胁迫下亚心形扁藻光合作用和膜脂过氧化以及抗氧化酶活性的影响

在CO2浓度分别为当今CO2浓度(360 μL/L)和加富浓度(5 000 μL/L)条件下,研究了UV-B胁迫对亚心形扁藻(Platymonas subcordiformis(Wille)Hazen)的光合作用、膜脂过氧化和抗氧化酶活性的影响.实验结果表明:(1)UV-B单独作用下,亚心形扁藻的干重、光合速率、叶绿素a(Chl a)和类胡萝卜素(Car.)含量显著降低,CO2加富单独作用下,亚心形扁藻的干重和光合速率显著升高,叶绿素a和类胡萝卜素含量与对照相比没有显著变化,而UV-B与CO2共同作用则使亚心形扁藻的干重和光合速率与对照相比没有显著变化,叶绿素a和类胡萝卜素含量显著降低.(2)UV-B单独作用和CO2加富单独作用都使可溶性蛋白含量显著降低,UV-B与CO2共同作用下的可溶性蛋白含量比UV-B单独作用的要高.高CO2对藻的可溶性蛋白含量的变化在很大程度上归因于Rubisco蛋白的降低.(3)UV-B单独作用下,O-.2产生速率、H2O2含量和MDA含量显著升高,而CO2加富单独作用下,O-.2产生速率、H2O2含量和MDA含量显著降低,与UV-B单独作用相比,UV-B与CO2共同作用使O-.2产生速率、H2O2含量和MDA含量显著降低.说明CO2加富可以减少活性氧对亚心形扁藻的氧化胁迫,同时减少UV-B对亚心形扁藻的膜脂过氧化伤害.(4)UV-B单独作用下,SOD、POD、CAT、GR和GPx活性显著升高,高CO2单独作用使SOD、POD和GR活性显著降低,而CAT和GPx活性与对照相比稍有所降低,但降低不明显,而UV-B与CO2共同作用则使SOD、POD、CAT、GR和GPx活性比UV-B单独作用少得多.结果表明,高CO2对UV-B胁迫所造成的氧化胁迫具有一定的改善作用,因此CO2浓度升高可能对增强海洋微藻的抗逆能力有利.     

毒蕈碱Ⅱ型乙酰胆碱受体类似物在拟黑多刺蚁三个品级脑中的表达（英文）

昆虫脑内胆碱能系统在中枢神经系统中起着重要作用,其与昆虫的复杂行为密切相关.本文选取有复杂行为的膜翅目社会性昆虫拟黑多刺蚁为研究材料,用免疫组织化学方法,对毒蕈碱Ⅱ型乙酰胆碱受体类似物在拟黑多刺蚁工蚁、雌蚁和雄蚁脑中进行定位检测.结果表明,毒蕈碱Ⅱ型乙酰胆碱受体类似物在拟黑多刺蚁前脑蕈形体、中央体和中腩嗅叶中普遍存在,但不同品级表达区域和强弱存在差异.这意味着毒蕈碱Ⅱ型乙酰胆碱受体类似物在拟黑多刺蚁视觉信息、嗅觉信息的整合输出中起着重要作用.     

Basic proteins of rodent peripheral nerve myelin: immunochemical identification of the 21.5K, 18.5K, 17K, 14K, and P2 proteins

Abstract: Proteins in peripheral nervous system and central nervous system myelin and homogenates of sciatic nerve and brain from young and adult mice and rats were characterized with affinity-purified anti-P₂ and anti-myelin basic protein sera after electrophoretic transfer from sodium dodecyl sulfate-polyacrylamide gels to nitrocellulose sheets. Using this method we have identified a component of rodent peripheral nervous system myelin as P₂ protein. Peripheral nervous system myelin also showed the presence of four basic proteins in addition to P₂ protein. These were found to be analogous to the 14, 17, 18.5, and 21.5K species found in the central nervous system myelin. A number of high-molecular-weight proteins were also detected with anti-myelin basic protein serum in peripheral nervous system, as well as central nervous system myelin. In addition, we report the presence of a high-molecular-weight P₂ cross-reactive protein in rodent brain stem homogenates, but not in central nervous system myelin.     

利用单感器记录与神经元示踪结合对棉铃虫主要性信息素感器内神经元投射的鉴定

【目的】鉴定雄性棉铃虫Helicoverpa armigera成虫触角性信息素感器嗅觉受体神经元的功能、形态及中枢投射路径。【方法】利用单感器记录技术记录棉铃虫嗅觉受体神经元对性信息素的反应,同时采用荧光染料作为示踪剂染色标记嗅觉受体神经元;使用免疫组织化学方法处理相应的脑组织,标记脑内触角叶的神经纤维球结构;用激光扫描共聚焦显微镜获取图像数据,使用图形软件ZEN和Amira 4.1.1进行三维结构重建。【结果】记录到雄性棉铃虫成虫触角上长毛形感器对主要性信息素成分Z11-16∶Ald产生明显的电生理反应,并成功染色标记了该感器内的嗅觉受体神经元。染色标记显示该感器内具有两个嗅觉受体神经元,其轴突通过触角神经分别投射触角叶内的云状体神经纤维球和普通神经纤维球。【结论】单感器记录与神经元示踪两技术结合能够用于鉴定昆虫触角嗅觉受体神经元的功能、形态和投射至神经纤维球的路径。与赖氨酸钴方法比较,使用荧光染料法进行神经元示踪,操作更简便,且易于进行三维空间分析,为调查棉铃虫其他嗅觉神经元的投射路径以明确外周气味受体感受与中枢系统的联系提供了有力技术支持。     

Effect of carbon dioxide on antioxidant enzymes and ginsenoside production in root suspension cultures of Panax ginseng

The aim of this study was to investigate the effect of CO₂ at various concentrations (1, 2.5 and 5%) on antioxidant enzymes and ginsenoside accumulation in Panax ginseng roots in 5 l airlift bioreactors (working volume 4 l). One and 2.5% CO₂ was beneficial for root biomass accumulation, but 5% CO₂ decreased the biomass. Ginsenoside concentration decreased with increasing concentration of CO₂. No significant difference was observed in the malondialdehyde (MDA) content and lipoxygenase (LOX) activity between respective controls and CO₂ treated roots. Antioxidant enzymes such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), glutathione reductase (GR), catalase (CAT), guaiacol peroxidase (G-POD) including reduced ascorbate and total glutathione were induced in CO₂ exposed roots which emphasized the protective role of antioxidants against CO₂ induced stress. Superoxide dismutase activity (SOD) which was induced after 15 days was significantly inhibited after 45 days. Glutathione-S-transferase (GST) and glutathione peroxidase (GPX) activities also increased when the roots were subjected to 1 and 2.5% CO₂ compared to the respective controls but not at 5%. A higher reduced ascorbate to oxidized (ASC/DHA) ratio in CO₂ treated root indicates the plant's ability to tolerate CO₂ stress. These observations suggest that an increase in antioxidant enzymes may affect a defense response to the cellular damage induced by CO₂. Probably, this increase could not stop the deleterious effects of CO₂ concentration on ginsenoside concentration, but reduced stress severity and thereby allowing root growth to occur.     

A comparison of the anatomical distribution of substance P and substance P receptors in the rat central nervous system

A comparison of anatomical distributions of substance P (SP) and substance P receptors in the rat central nervous system was performed. SP was localized by microdissection and radioimmunoassay and SP fibers and cell bodies by immunohistochemistry. Receptors for ¹²⁵I-Bolton Hunter labelled SP (¹²⁵I-BH-SP) were characterized pharmacologically by a slice binding technique in sections that contained primarily striatum. The receptor was saturable and had an equilibrium dissociation constant (K_D) of 0.30 nM and maximum number of binding sites (B_max) of 37.8 fmol/mg protein. Pharmacological characterization using C terminal fragments and naturally occurring analogues of SP reflected characteristics of the receptor which had been shown previously in bioassays and biochemical assays. Comparison of distribution of SP fibers and cell bodies and SP receptors indicated that there is no consistent relationship between the amount of SP receptor and density of SP fibers or cell bodies in a given region of the brain.     

Structural Organization of the Murine D3 Dopamine Receptor Gene

Abstract: We have cloned the gene encoding the murine D₃ dopamine receptor and have analyzed its intron-exon structural organization, to gain a better understanding of the detailed architecture of the D₂ dopamine receptor genes. Restriction and sequence analysis reveal the presence of six introns, in contrast to the five introns previously reported for the rat D₃ receptor. The extra intron is located in the receptor's putative third cytoplasmic loop and generates an intron-exon organization directly analogous to that found in the D₂ receptor gene. In addition, we have sequenced the 5' and 3' nontranslated sequences flanking the coding region and have identified a putative poly(A) adenylation signal. These sequences are found to have a far lower homology with the corresponding rat nontranslated sequences than is found for the D₂ receptor, suggesting that the control of D₃ receptor expression may vary more between species than the control of D₂ receptor expression.     

Transcellular biosynthesis of cysteinyl leukotrienes in rat neuronal and glial cells

Leukotrienes are mediators of inflammation that belong to a family of lipids derived from arachidonic acid by the action of 5-lipoxygenase. Leukotrienes have been detected in the central nervous system in association with different pathological events, but little is known about their biosynthesis or function in the brain. When rat neurons and glial cells in primary culture were stimulated with the calcium ionophore, no significant biosynthesis of leukotrienes was detected using liquid chromatography/mass spectrometry (LC/MS) techniques. However, when exogenous LTA₄ was added to these cultured cells, both neurons and glia were able to synthesize LTC₄. Activated neutrophils are known to supply LTA₄ to other cells for transcellular biosynthesis of cysteinyl-leukotrienes. Since neutrophils can infiltrate brain tissue after stroke or traumatic brain injury, we examined whether neutrophils play a similar role in the central nervous system. When peripheral blood neutrophils were co-cultured with rat neurons, glia cells, and then stimulated with calcium ionophore, a robust production of LTC₄, LTD₄, and LTE₄ was observed, revealing that neurons and glia can participate in the transcellular mechanism of leukotriene biosynthesis. The formation of LTC₄ through this mechanism may be relevant in the genesis and progression of the inflammatory response as a result of brain injury.