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昆虫的RNA干扰 总被引:2,自引:0,他引:2
RNA干扰(RNAi)是一种强有力的分子生物学技术, 在昆虫研究中得到了较多的应用。目前, RNAi技术主要应用于昆虫功能基因和功能基因组研究, 已在多个目的19种昆虫上实现了RNAi。在昆虫上实现RNAi的方法主要有注射、浸泡、喂食、转基因和病毒介导等方法, 这些方法各有特点, 其中喂食法因其简单而最有应用前景。昆虫RNAi的系统性较为复杂, 只有部分昆虫具有RNAi的系统性。昆虫中RNAi信号传导的基因可能是sid-1, 但昆虫RNAi的系统性机理还不是很清楚。转基因植物产生的dsRNA实现了对作物的保护, 证实了RNAi技术可用于害虫控制, 为害虫控制开辟了新领域。昆虫的RNAi研究处在起步阶段, 研究昆虫RNAi的机理, 特别是RNAi在昆虫体内的系统性扩散机理, 改进实现RNAi的方法, 提高RNAi技术在昆虫研究中的应用, 有利于昆虫基因功能鉴定和害虫控制, 促进昆虫学科的发展。 相似文献
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昆虫迁飞的调控基础及展望 总被引:6,自引:0,他引:6
昆虫迁飞是在长期适应多变的环境过程中进化形成的一种行为对策,也是昆虫的种类和数量繁多,以及迁飞害虫经常暴发成灾的主要原因.昆虫迁飞行为的发生不仅受到外界环境因素的影响,而且受到本身生理因素的调控.目前,国内外对此类研究主要集中在生态环境、生理因素、行为学以及种群遗传学方面的调控机制.随着分子生物学技术的发展,昆虫迁飞行为发生的分子调控机制也越来越受到重视.在对国内外主要昆虫迁飞调控机制概述的基础上,对新的分子生物学技术在昆虫迁飞调控中的应用进行了探讨与展望. 相似文献
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昆虫数学形态学研究及其应用展望 总被引:1,自引:0,他引:1
数学形态学是用数学方法描述或分析一个物体图象的形状的理论和方法,是图象处理和图象识别技术的发展,但在生物学当中的应用还很有限。本文介绍了一个新的分支学科——昆虫数学形态学,包括三方面的内容:①昆虫数学形态学技术研究,涉及昆虫图象数字化技术和昆虫图象处理与识别技术;②昆虫数学形态学理论研究,主要以昆虫图象的解释和理解研究及昆虫数学形态学与分类学等学科的关系研究为主;③昆虫和昆虫数学形态学应用基础研究,涉及昆虫数学形态学数据库及其分析软件开发,昆虫图象的机器学习和计算机视觉等内容。昆虫数学形态学理论和方法与计算机视觉技术相结合,在害虫虫情监测、昆虫多媒体专家系统的构建等方面具有广阔的应用前景。 相似文献
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Fungal pathogens of plants and insects infect their hosts by direct penetration of the cuticle. Plant and insect cuticles are covered by a hydrocarbon-rich waxy outer layer that represents the first barrier against infection. However, the fungal genes that underlie insect waxy layer degradation have received little attention. Here we characterize the single cytochrome P450 monoxygenase family 52 (MrCYP52) gene of the insect pathogen Metarhizium robertsii, and demonstrate that it encodes an enzyme required for efficient utilization of host hydrocarbons. Expressing a green florescent protein gene under control of the MrCYP52 promoter confirmed that MrCYP52 is up regulated on insect cuticle as well as by artificial media containing decane (C10), extracted cuticle hydrocarbons, and to a lesser extent long chain alkanes. Disrupting MrCYP52 resulted in reduced growth on epicuticular hydrocarbons and delayed developmental processes on insect cuticle, including germination and production of appressoria (infection structures). Extraction of alkanes from cuticle prevented induction of MrCYP52 and reduced growth. Insect bioassays against caterpillars (Galleria mellonella) confirmed that disruption of MrCYP52 significantly reduces virulence. However, MrCYP52 was dispensable for normal germination and appressorial formation in vitro when the fungus was supplied with nitrogenous nutrients. We conclude therefore that MrCYP52 mediates degradation of epicuticular hydrocarbons and these are an important nutrient source, but not a source of chemical signals that trigger infection processes. 相似文献
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STEPHEN J. MARTIN WEIHAO ZHONG FALKO P. DRIJFHOUT 《Biological journal of the Linnean Society. Linnean Society of London》2009,96(4):732-737
Cuticular hydrocarbons are key compounds used for insect chemical communication and their species-specificity makes them of great utility to chemotaxonomists. However, very little is known about their long-term stability in relation to their use as reliable taxonomic tools. We compared the cuticular hydrocarbon profiles of fresh extracts from four hornet ( Vespa ) species with extracts from specimens that were frozen for 1 year and of those stored in insect display boxes for 20 years. Cuticular hydrocarbon profiles were qualitatively very stable, maintaining their species-specific profiles even after 20 years. The long-term stability of cuticular hydrocarbons in hymenopterans opens up the possibility of using museum collections for chemotaxonomy studies and helping with the delineation of species in difficult groups. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 732–737. 相似文献
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Roles of Hydrocarbons in the Recognition Systems of Insects 总被引:8,自引:0,他引:8
SYNOPSIS. Many bioassays have shown that cuticular hydrocarbonsare used in the recognition systems of both solitary and socialinsects. The function of insect recognition systems is to enablean insect to recognize, and possibly discriminate, its own species,sex, or kin from that of other insects. The primary functionof cuticular hydrocarbons is to protect the insects from desiccation.Hydrocarbons can be removed from insect cuticles and characterizedwith gas chromatography/mass spectrometry. Studies using suchanalytical techniques have revealed that insect hydrocarboncompositions are species-specific, sex-specific and, in socialinsects, colony- and caste-specific. Furthermore, recognitionbioassays have confirmed that certain components of the cuticleof some insect species are sex attractants as well as aphrodisiacsor sex inhibitors. Other bioassays have shown that hydrocarbonsare important in facilitating colony structure in social insects.In addition, the hydrocarbons of some parasitic insects appearto mimic those of their host species. Thus, hydrocarbons areproving to be very important in the everyday activities of manyinsect species. 相似文献
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Methyl-branched fatty acids present in the integument of the German cockroach, Blattella germanica, were identified by gas chromatography-mass spectrometry of their methyl esters and reduction products (alkanes) as n-3-, n-4-, n-5-, n-7-, n-8-, and n-9-monomethyl fatty acids and as n-5,9-, n-3,9-, and n-3,11-dimethyl fatty acids with 16 to 20 total carbons. These fatty acids have the same branching patterns as do the major hydrocarbons of this insect, including 3,11-dimethylnonacosane, the precursor to the major contact sex pheromone, and are presumed to be intermediates in hydrocarbon formation. A novel microsomal fatty acid synthetase (FAS) located in the integument of this insect incorporated [methyl-14C]methylmalonyl-CoA into methyl-branched fatty acids as demonstrated by radio-high-performance liquid chromatography. A cytosolic FAS is also present in the integument. Both the microsomal and the soluble FAS incorporated [methyl-14C]methylmalonyl-CoA into fatty acids, but only the microsomal FAS was able to efficiently use methylmalonyl-CoA as the sole elongating agent. This is the first report of the characterization of methyl-branched fatty acids from the integument of an insect and of an integumental microsomal FAS that incorporates methylmalonyl-CoA into branched fatty acids. 相似文献
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Wax,sex and the origin of species: Dual roles of insect cuticular hydrocarbons in adaptation and mating 下载免费PDF全文
Henry Chung Sean B. Carroll 《BioEssays : news and reviews in molecular, cellular and developmental biology》2015,37(7):822-830
Evolutionary changes in traits that affect both ecological divergence and mating signals could lead to reproductive isolation and the formation of new species. Insect cuticular hydrocarbons (CHCs) are potential examples of such dual traits. They form a waxy layer on the cuticle of the insect to maintain water balance and prevent desiccation, while also acting as signaling molecules in mate recognition and chemical communication. Because the synthesis of these hydrocarbons in insect oenocytes occurs through a common biochemical pathway, natural or sexual selection on one role may affect the other. In this review, we explore how ecological divergence in insect CHCs can lead to divergence in mating signals and reproductive isolation. We suggest that the evolution of insect CHCs may be ripe models for understanding ecological speciation. 相似文献
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David Baracchi Leonardo Dapporto Serafino Teseo Rosli Hashim Stefano Turillazzi 《Journal of Zoological Systematics and Evolutionary Research》2010,48(2):109-114
The Stenogastrinae wasps have been proposed as a key group for an understanding of social evolution in insects, but the phylogeny of the group is still under discussion. The use of chemical characters, in particular cuticular hydrocarbons, for insect taxonomy is relatively recent and only a few studies have been conducted on the cuticular polar substances. In this work, we ascertain, by the matrix‐assisted laser desorption ionization‐time of flight mass spectrometry technique, that different species of primitively eusocial hover wasps have different compositions of the epicuticular polar compounds ranging from 900 to 3600 Da. General linear model analysis and discriminant analysis showed that the average spectral profiles of this fraction can be diagnostic for identification of the species. Moreover, for the first time we show population diversification in the medium MW polar cuticular mixtures in insects. In conclusion, the results demonstrate that the chemical characters are consistent with the physical characters and the study support the importance of medium MW polar substances as powerful tools for systematics (chemosystematics) and chemical ecology (fertility signal and population characterization) in a primitively social insect taxon. 相似文献
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Patricia Jurez 《Archives of insect biochemistry and physiology》1994,25(3):193-206
Triatoma infestans eggs are shown to synthesize hydrocarbons. Radio-gas chromatography was used to demonstrate metabolism of [1-14C]propionate into precursor methyl-branched fatty acids and into methyl-branched hydrocarbons in T. infestans eggs. These reactions have not been demonstrated previously in insect eggs. An in vivo study showed that hydrocarbons are also transported to eggs by the hemolymph. Inhibition of hydrocarbon synthesis by sodium trichloroacetate (NaTCA) was correlated with reduced oviposition, reduced hatchability, and reduced insect survival. Scanning electron microscopy showed impoverishment of the eggs' epicuticular waxes following NaTCA treatment. © 1994 Wiley-Liss, Inc. 相似文献
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Karl E. Espelie Elizabeth A. Bernays John J. Brown 《Archives of insect biochemistry and physiology》1991,17(4):223-233
The roles of plant and insect cuticular lipids in insect and plant interactions are reviewed. Emphasis is given to the influence that the host plant and the surface lipids of the host plant have upon insect herbivores and the predators and parasitoids of these herbivores. Variations in cuticular lipids of herbivorous insects are dependent upon the host plant, and these variations may affect the behavior of predators and parasitoids. The cuticular lipids of species which interact on multiple trophic levels are compared. Similarities were found between the hydrocarbons of herbivorous insects, their host plants, and their predators or parasitoids. 相似文献
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Outi Ala-Honkola Hannele Kauranen Venera Tyukmaeva Fabian A.Boetzl Anneli Hoikkala Thomas Schmitt 《Insect Science》2020,27(2):304-316
Envipnmental cues,mainly photoperiod and temperature,are known to control female adult reproductive diapause in several insect species.Diapause enhances female survival during adverse conditions and postpones progeny production to the favorable season.Male diapause(a reversible inability to inseminate receptive females)has been studied much less than female diapause.However,if the males maximized their chances to fertilize females while minimizing their energy expenditure,they would be expected to be in diapause at the same time as females.We investigated Drosophila montana male mating bchavior under short-day conditions that induce diapause in females and found the males to be reproductively inactive.We also found that males reared under long-day conditions(reproducing individuals)court reproducing postdiapause fermales,but not diapausing ones.The diapausing fies of both sexes had more long-chain and less short-chain hydrocarbons on their cuticle than the reproducing ones,which presumably increase their survival under stressful conditions,but at the same time decrease their attractiveness.Our study shows that the mating behavior of females and males is well coordinated during and afier overwintering and it also gives support to the dual role of insect cuticular hydrocarbons in adaptation and mate choice. 相似文献
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Juárez MP Fernández GC 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,147(3):711-730
Triatomine insects (Hemiptera) are the vectors of Chagas disease. Their cuticular surface is covered by a thin layer of lipids, mainly hydrocarbons, wax esters, fatty alcohols, and free or esterified fatty acids. These lipids play a major role in preventing a lethal desiccation, altering the absorption of chemicals and microorganism penetration, they also participate in chemical communication events. Lipid components are biosynthetically related, the synthesis of long chain and very long chain fatty acids was first shown in the integument of Triatoma infestans through the concerted action of fatty acid synthases (FAS's) and fatty acyl-CoA elongases. A final decarboxylation step produces the corresponding hydrocarbon. Capillary gas chromatography coupled to mass spectrometry analyses showed that cuticular hydrocarbons of Triatominae comprise saturated straight and methyl-branched chains, from 18 to more than 43 carbon atoms. Odd-chain hydrocarbons, mostly from 27 to 33 carbons, are the major straight chains. Different isomers of mono, di, tri, and tetramethylcomponents, mostly from 29 to 39 atoms in the carbon skeleton, account for the major methyl-branched hydrocarbons. The presence, absence, and relative quantities of these hydrocarbons represent characters for their chemical phenotype, and are useful for differentiating genera, species and populations. In this review, we will discuss the metabolic pathways involved in hydrocarbon formation, and their structure, together with their role in insect survival. We will also review the utility of cuticular hydrocarbon fingerprints in chemotaxonomy. 相似文献