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病原真菌和细菌毒性基因的分离和鉴定 总被引:1,自引:0,他引:1
本文讨论最新发展起来的病原真菌和细菌毒性基因的分离和鉴别原理和方法,涉及到基因表达分析法、基因转移方法、基因组比较法、诱变方法及其诱变子的筛选鉴定。着重讨论了这些方法的优点和局限性,评估了标记诱变法(STM)和限制酶介导的整合法(REMI)两者相互结合在病原真菌毒性基因克隆中的应用潜力。 相似文献
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植物病原真菌的MAPK基因及其功能 总被引:10,自引:0,他引:10
叙述在植物病原真菌中促分裂原活化蛋白激酶 (Mitogenactivatedproteinkinase,MAPK)基因的种类和特征 ,概括了MAPK基因在植物病原真菌生长发育、胁迫反应和侵染、致病过程中的作用及其研究现状 ,讨论了进行植物病原真菌MAPK基因研究的意义及重点研究的课题 ,并根据最新研究进展 ,提出了植物病原真菌MAPK基因研究的发展前景。 相似文献
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昆虫病原真菌是一类重要的害虫自然控制因子,但由于病原真菌对寄主昆虫的慢击倒性,使得病原真菌的应用受到极大的限制。八十年代,人们的研究目标集中在昆虫病原真菌的酶学研究上;到了九十年代则全面进入了分子生物学的研究阶段。包括昆虫病原真菌毒力基因在内的许多基因得到了研究,使得对病原真菌的人工定向改造成为可能。1 蛋白酶基因昆虫的体壁主要是由蛋白基质和分布其中的几丁质组成,是防止大多数微生物入侵的有效途径。蛋白质的类型和数量在不同种类的昆虫、组织和生长阶段中是不断变化的(Andersen,1974)。为了能穿透这样一… 相似文献
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曾报道经化学诱变剂MMC、9-AA和EMS诱变的家蚕核型多角体病毒(BmNPV)多角体形态出现异常,继代分离的诱变BmNPV基因组对EcoRI、BglII和BamHI的酶切谱发生变化。研究进一步揭示,诱变BmNPV的多角体外层蛋白晶格排列呈现紊乱;多角体蛋白的SDS-PAGE电泳谱与对照组比较有显著差异;对多角体蛋白基因polh的测序结果显示,3组诱变BmNPV的polh基因发生了多处碱基(氨基酸 相似文献
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转几丁质酶基因防植物病害研究:进展、问题与展望 总被引:2,自引:0,他引:2
高必达 《中国生物工程杂志》1999,19(2):21-28
综合评述了近几年转几丁质酶基因防植物病害研究中的发现与进展:(1)至少31种病原真菌(含变种和专化型)可诱导植物几丁质酶,(2)据称已提纯的植物几丁质酶对立枯丝核菌等真菌呈现了体外抑菌活性;(3)一些生防细菌的防病作用依赖于其几丁质酶基因的存在;(4)数种植物几丁质酶基因和一种细菌几丁质酶基因已被转入水稻、烟草、番茄等植物,一些转基因株系抗病性显著增强;(5)粘质沙雷氏菌的一种几丁质酶基因已被转入荧光假单胞菌和根瘤菌中,转基因细菌对立枯丝核菌有显著抑制作用。就几丁质酶抑菌谱、转基因的策略和研究中存在的疑点进行了分析讨论。建议今后的研究方向应集中在以下几方面:(1)加速转几丁质酶基因或几丁质酶基因与其它基因组合的植物实用化;(2)进一步研究不同基因组合的增效作用及增效机理;(3)查明个别几丁质酶基因的抑菌谱及选择性抑菌机制;(4)转几丁质酶基因或与其它基因的组合于植物内生细菌。 相似文献
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高秆突变体Mh—1的株高遗传研究 总被引:9,自引:0,他引:9
Mh-1是从矮秆品种桂朝2号辐射诱变后代中产生的高秆突变体。用Mh-1与sd-1矮秆、非sd-1矮秆和普通高秆材料杂交,通过对F1、F2、F3等世代以及测交后代的株高进行遗传分析,结果表明,Mh-1的高秆特性是由1对隐性抑制基因控制的,该抑制基因能调节sd-1基因的表达,而对由非sd-1基因控制的矮秆没有抑制作用,这一隐性抑制基因暂时被定名为i-sd-1(t)。还讨论了该基因的遗传学意义和可能的育 相似文献
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转几丁质酶基因防植物病害研究:进展,问题与展望 总被引:34,自引:0,他引:34
综合评述了近几年转几丁质酶基因防植物研究中的发现与进展:(1)至少31种病原真菌可诱导植物几丁质酶(2)据称已提纯的植物几丁质酶对立枯丝核菌等真菌呈现了体外抑菌活; 相似文献
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[目的] 木霉属真菌是应用最为广泛和潜力最大的生防真菌,其产生的典型化合物哌珀霉素(peptaibols)类抗生素在生物防治中发挥重要作用。本研究采用基因组挖掘技术(genome mining)发现炭团木霉(Trichoderma hypoxylon)的潜在哌珀霉素生物合成基因簇及对病原菌的防治作用。[方法] 生物信息学分析预测合成哌珀霉素的基因簇,利用Quick-change技术构建基因骨架敲除盒,通过PEG介导的原生质体转化方法获得敲除突变株,通过平板对峙法和菌丝生长毒力实验验证该基因簇对炭团木霉生物活性的影响。[结果] 基因挖掘鉴定一个非核糖体多肽合成酶(nonribosomal peptide synthetases,NRPS)可能合成哌珀霉素类抗生素,命名为NRPS1,对该基因进行部分敲除,成功获得3株NRPS1缺失突变株。对峙实验表明,突变株对寄生曲霉(Aspergillus parasiticus)、尖孢镰刀菌(Fusarium oxysporum)、黑白轮枝菌(Verticillium alboatrum)等9株植物病原真菌的抑制作用与野生株相比显著下降,且突变株的粗提物的抑菌活性明显弱于野生型。[结论] NRPS1是一个潜在的哌珀霉素合成基因,该基因在宿主与病原真菌对抗过程中起关键作用,该研究为炭团木霉哌珀霉素结构解析及生物防治机理研究奠定了基础。 相似文献
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Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献