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1.
《Insect Science》2007,14(2):171-171
We are building on the success of the Sixth Chinese Insect Physiology, Biochemistry and Molecular Biology Symposium, Beijing, held in 2005. The 2005 symposium saw many Chinese and international authorities share their expertise in a broad range of insect science, including analyses of insect genomes and proteomes, functional gene expression and regulation during development, insect immunity, insect neurobiology, insect-host interactions and insect chemical communication. The coming symposium, which will be held in Shandong University, Jinan, Shandong province, September 19-22, 2007, will offer material along similar lines.[第一段]  相似文献   

2.
Plants can accumulate, constitutively and/or after induction, a wide variety of defense compounds in their tissues that confer resistance to herbivorous insects. The naturally occurring plant resistance gene pool can serve as an arsenal in pest management via transgenic approaches. As insect-plant interaction research rapidly advances, it has gradually become clear that the effects of plant defense compounds are determined not only by their toxicity toward target sites, but also by how insects respond to the challenge. Insect digestive tracts are not passive targets of plant defense, but often can adapt to dietary challenge and successfully deal with various plant toxins and anti-metabolites. This adaptive response has posed an obstacle to biotechnology-based pest control approaches, which underscores the importance of understanding insect adaptive mechanisms. Molecular studies on the impact of protease inhibitors on insect digestion have contributed significantly to our understanding of insect adaptation to plant defense. This review will focus on exposing how the insect responds to protease inhibitors by both qualitative and quantitative remodeling of their digestive proteases using the cowpea bruchid-soybean cysteine protease inhibitor N system.  相似文献   

3.
Iron is essential to life,but surprisingly little is known about how iron is managed in nonvertebrate animals.In mammals,the well-characterized transferrins bind iron and are involved in iron transport or immunity,whereas other members of the transferrin family do not have a role in iron homeostasis.In insects,the functions of transferrins are still poorly understood.The goals of this project were to identify the transferrin genes in a diverse set of insect species,resolve the evolutionary relationships among these genes,and predict which of the transferrins are likely to have a role in iron homeostasis.Our phylogenetic analysis of transferrins from 16 orders of insects and two orders of noninsect hexapods demonstrated that there are four orthologous groups of insect transferrins.Our analysis suggests that transferrin 2 arose prior to the origin of insects,and transferrins/,i,and 4 arose early in insect evolution.Primary sequence analysis of each of the insect transferrins was used to predict signal peptides,carboxyl-terminal transmembrane regions,GPI-anchors,and iron binding.Based on this analysis,we suggest that transferrins 2,and 4 are unlikely to play a major role in iron homeostasis.In contrast,the transferrin 1 orthologs are predicted to be secreted,soluble,iron-binding proteins.We conclude that transferrin 1 orthologs are the most likely to play an important role in iron homeostasis.Interestingly,it appears that the louse,aphid,and thrips lineages have lost the transferrin 1 gene and,thus,have evolved to manage iron without transferrins.  相似文献   

4.
Insect viruses are attractive as biological control agents and could be a feasible alternative to chemical insecticides in the management of insect infestations. This review describes recent advances in the development of wild-type and genetically modified viruses as insecticides. A new strategy of application of insect viruses in China is reviewed. Also, the assessment of biosafety of genetically modified Helicoverpa armigera Nucleopolyhedovirus (HearNPV) is emphasized as a case-study.  相似文献   

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6.
Gamma glutamyl transferases (GGT) are highly conserved enzymes that occur from bacteria to humans. They remove terminal y-glutamyl residue from peptides and amides. GGTs play an important role in the homeostasis of glutathione (a major cellular antioxidant) and in the detoxification of xenobiotics in mammals. They are implicated in diseases like diabetes, inflammation, neurodegenerative diseases and cardiovascular diseases. The physiological role of GGTs in bacteria is still unclear. Nothing is known about the basis for the strong conservation of the enzyme across the living system. The review focuses on the enzyme's physiology, chemistry and structural properties of the enzyme with emphasis on the evolutionary relationships. The available data indicate that the members of the GGT family share common structural features but are functionally heterogenous.  相似文献   

7.
Some chalcidoids were collected by the author in the midddle of November,1933 on the campus of the College, in which 4 species of Pteromalidae werefound after studying. There species are new to China and one new to science.The holotype specimen is deposited in the Insect Collection of the NorthwesternCollege of Forestry, and the paratype in the Insect Collection of Institute ofZoology, Academia Sinica.  相似文献   

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9.
The cry gene family, produced during the late exponential phase of growth in Bacillus thuringiensis, is a large, still-growing family of homologous genes, in which each gene encodes a protein with strong specific activity against only one or a few insect species. Extensive studies are mostly focusing on the structural and functional relationships of Cry proteins, and have revealed several residues or domains that are important for the target recognition and receptor attachment. In this study, we have employed a maximum likelihood method to detect evidence of adaptive evolution in Cry proteins, and have identified 24 positively selected residues, which are all located in Domain Ⅱ or Ⅲ. Combined with known data from mutagenesis studies, the majority of these residues, at the molecular level, contribute much to the insect specificity determination. We postulate that the potential pressures driving the diversification of Cry proteins may be in an attempt to adapt for the "arm race" between δ-endotoxins and the targeted insects, or to enlarge their target spectra, hence result in the functional divergence. The sites identified to be under positive selection would provide targets for further structural and functional analyses on Cry proteins.  相似文献   

10.
Insects are a group of arthropods and the largest group of animals on Earth,with over one million species described to date.Like other life forms,insects suffer from viruses that cause disease and death.Viruses that are pathogenic to beneficial insects cause dramatic economic losses on agriculture.In contrast,viruses that are pathogenic to insect pests can be exploited as attractive biological control agents.All of these factors have led to an explosion in the amount of research into insect viruses in recent years,generating impressive quantities of information on the molecular and cellular biology of these viruses.Due to the wide variety of insect viruses,a better understanding of these viruses will expand our overall knowledge of their virology.Here,we review studies of several newly discovered RNA insect viruses in China.  相似文献   

11.
牛乳酪蛋白源抗菌肽的研究进展   总被引:1,自引:0,他引:1  
抗菌肽是具有抗菌活性的肽类物质的总称。除了广泛存在于生物体内的内源性抗菌肽外,已从酪蛋白的酶解产物中获得了多种外源性抗菌肽。抗菌肽的抗菌机理独特,有望成为新一代抗菌剂。简要综述了牛乳酪蛋白源抗菌肽的种类、抗菌机理及其研究展望。  相似文献   

12.
抗菌肽及抗菌肽转基因植物研究进展   总被引:1,自引:0,他引:1  
抗菌肽是一类小分子多肽,在生物体内分布广泛,具有广谱的抗菌性,是生物体内天然防御系统的一部分。主要介绍了抗菌肽的性质,类型,作用机制及抗菌肽转基因植物的研究进展。  相似文献   

13.
家蝇幼虫抗菌肽的抗菌谱及其与抗生素的协同作用研究   总被引:9,自引:0,他引:9  
研究3种家蝇幼虫抗菌肽的抗菌谱以及每种抗菌肽的最小抑菌浓度(MIC),初步探讨3种抗菌肽分别与青霉素、链霉素相结合后对抗菌活性的影响,并采用分级抑制浓度指数(Fractionalinhibitoryconcentrationindex,FIC)来定量检测抗菌肽与抗生素之间的抗菌作用关系。结果表明3种抗菌肽的抗菌谱不同,不同的抗菌肽对不同病原菌的抗菌活性不同。3种抗菌肽与链霉素、青霉素之间的抗菌协同关系因细菌种类不同。抗菌肽与抗生素之间并不是都存在协同关系,有些不相关,甚至表现为对抗关系,表明抗菌肽、抗生素与细菌三者的相互作用关系非常复杂。  相似文献   

14.
昆虫是地球上种类最为繁多的生物,其抗菌肽的种类和应用范围也远多于其他生物产生的抗菌肽。随着越来越多昆虫抗菌肽的发现及对其深入的研究,昆虫抗菌肽的结构和作用机制也被逐一阐明,并广泛应用于畜牧、食品工业及医药等领域。然而,由于某些限制因素,昆虫抗菌肽还未应用于临床。为了加快昆虫抗菌肽在临床中的应用,本文将从昆虫抗菌肽的结构分类、潜在的医学应用以及昆虫抗菌肽的生产研究现状等方面作一综述,以期为昆虫抗菌肽在抗细菌、抗病毒、抗肿瘤及抗寄生虫药物等方面的医用研发提供文献支持。  相似文献   

15.
家蝇蛆抗菌肽提取工艺研究   总被引:4,自引:0,他引:4  
陆婕  钟雅  柳林  付康  陈正望 《昆虫学报》2007,50(2):106-112
蝇蛆抗菌肽多有广谱抗菌、抗癌等功能,是很好的天然抗菌药物来源,但由于得率较低,目 前对其产品开发的研究较少。以家蝇Musca domestica干蝇蛆为原料,利用加热-层析法和海藻酸吸附法2种工艺提取蝇蛆抗菌肽。结果表明:加热-层析法快速、简便,抗菌肽提取得率达0.26%,是海藻酸吸附法提取抗菌肽得率的5.2倍。提取的家蝇抗菌肽主要是分子量6.2~17.2 kD、等电点5.59~5.91的弱酸性小分子多肽,其热稳定性高,能杀灭枯草杆菌Bacillus subtilis等多种革兰氏阳性菌。加热-层析法能有效去除外源性蛋白酶,保证肽类产品的稳定性,同时还能提取出非蛋白类的抗菌成分,提示其对开发具有高附加值的抗菌产品将会有良好的应用前景。  相似文献   

16.
宫霞  乐国伟  施用晖 《昆虫知识》2004,41(2):110-115
昆虫抗菌肽是昆虫免疫后存在于血淋巴中的一类活性肽.根据分子的结构可分为5类天蚕素类、昆虫防御素、富含脯氨酸或精氨酸的抗菌肽、富含甘氨酸的抗菌肽、抗真菌肽.且具有广谱的抗菌、抗病毒、抑制肿瘤的生物活性.概述了昆虫抗菌肽的基因的克隆与表达及转基因研究方面的进展,并展望了抗菌肽在基因工程中的应用前景.  相似文献   

17.
昆虫抗菌肽的生理活性及其转基因应用前景   总被引:3,自引:2,他引:1  
昆虫抗菌肽是昆虫免疫后存在于血淋巴中的一类活性肽。根据分子的结构可分为 5类 :天蚕素类、昆虫防御素、富含脯氨酸或精氨酸的抗菌肽、富含甘氨酸的抗菌肽、抗真菌肽。且具有广谱的抗菌、抗病毒、抑制肿瘤的生物活性。概述了昆虫抗菌肽的基因的克隆与表达及转基因研究方面的进展 ,并展望了抗菌肽在基因工程中的应用前景  相似文献   

18.
抗菌肽是一类小分子肽,具有广谱的抗菌活性。以往对抗菌肽抗菌机制的研究主要集中在细菌细胞膜的作用上,包含"桶板"模型、"毯式"模型,"环形孔"模型和"凝聚"模型。近年来相继发现某些抗菌肽可以作用于细菌细胞内部,与核酸物质结合,阻断DNA复制、RNA合成;影响蛋白质合成;抑制隔膜、细胞壁合成,阻碍细胞分裂;抑制胞内酶的活性。本文从胞内机制和胞外机制两个角度对抗菌肽的抗菌机制进行综述,以期阐明各类抗菌肽的作用机制,为进一步研究菌株耐药性、杀菌效果及其杀菌机制提供科学根据。  相似文献   

19.
抗菌肽及其应用研究进展   总被引:8,自引:0,他引:8  
抗菌肽是生物防御系统产生的一类对抗外源性病原体的肽类物质,具有抗细菌、真菌、霉菌、病毒、原虫、癌细胞等多种活性,具有广阔的应用前景。本文就抗菌肽的分类、理化特征、结构、作用机制、基因工程、应用前景及存在问题等方面进行了简要综述。  相似文献   

20.
家蝇抗菌肽的抑菌动力学研究及其机理初探   总被引:6,自引:0,他引:6  
利用鼠伤寒沙门氏菌针刺诱导家蝇幼虫表达抗菌肽,对抗菌肽的抑菌动力学进行研究,并通过抗菌肽样品对不同细菌动力学特性的研究出发对抗菌肽抑菌作用机制进行探讨。研究发现抗菌肽样品的活性与作用时间有关,24h内出现一到两个活性峰,同一抗菌肽样品对不同细菌的抑菌动力学有差异,抗菌肽的抑菌动力学机制应该与它的的抑菌作用机制有关。通过电镜观测、细胞磷代谢、紫外吸收物测定以及抗菌肽与细菌DNA相互作用结果可知,微生物诱导家蝇表达的抗菌肽样品不仅能够造成细菌细胞的快速坍塌破裂而且能够破坏细胞核心,与DNA结合作用。抗菌肽抑菌动力学的解释:微生物诱导产物中含有两类抗菌肽,一类抗菌肽能造成细胞膜的快速坍塌破裂形成第一个活性峰;另一类抗菌肽可进入细胞,破坏细胞核心,造成紫外吸收物大量外泄形成第二个活性峰。  相似文献   

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