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1.
海藻糖合酶基因的克隆及其植物表达载体的构建   总被引:1,自引:0,他引:1  
以担子菌灰树花的菌丝体中提取总RNA,并纯化出mRNA,mRNA经反转录合成cDNA第一链,以cDNA第一链为模板经PCR扩增海藻糖合酶(Tsase)基因,获得一长约2.2kb的片段,把该片段连接一pGEM-T-easy vector上进行测序,其全长共2199bp。随后将此片段以正向插入植物表达载体pBI121的HindⅢ+Xbal位点构建pUB,再把海藻糖合酶基因以正向插入载体pUB的BamH  相似文献   

2.
链霉菌质粒pSGL1最小复制子序列测定及分析   总被引:1,自引:1,他引:0  
张华  洪斌  李元 《微生物学报》1999,39(4):327-332
质粒pSGL1(7.4kb)是从球孢链霉菌(Streptomycesglobisporus)中分离得到的一个高拷贝质粒,已证明其最小复制子位于Sau3AI酶切的20kb片段上。对该片段进行亚克隆,测序后数据表明该片段是一个新序列。仅有一个开放阅读框架(ORFR)位于最小复制子中,推测其编码的蛋白质含有滚环复制质粒复制酶的特定序列。  相似文献   

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利用合成的寡聚核苷酸片段,从质粒pOS1000中分离出具有适合克隆位点的苏云金芽孢杆菌(Bacilusthuringiensis)δ内毒素cryIA(c)全长基因。将该基因与大肠杆菌表达载体pKK2233重组,并引入大肠杆菌JM109中,经IPTG诱导,获得了超量表达的CryIA(c)蛋白。将cryIA(c)全长基因插入链霉菌表达载体pHZ1272中,得到重组质粒pHZ1256,将该质粒引入变铅青链霉菌(Streptomyceslividans)JT46中,经硫链丝菌素诱导,通过Westernbloting测定表明,重组变铅青链霉菌JT46(pHZ1256)已表达出相应的CryIA(c)蛋白。杀虫试验表明,大肠杆菌和链霉菌所表达出的δ内毒素CryIA(c)对小菜蛾均有毒杀作用,其致死率分别为93%和57%。  相似文献   

4.
透明颤菌血红蛋白基因在阿维链霉菌中的表达   总被引:7,自引:0,他引:7  
将含有自身启动子的透明颤菌血红蛋白基因( vhb) 克隆至大肠杆菌—链霉菌穿梭质粒载体pIJ653 中构建成表达载体p WY101 和p WY102 ,用它们转化阿维菌素(avermectins) 产生菌———阿维链霉菌( Streptomyces avermitilis) ,经Western blotting 分析并未检测到vhb 基因表达,但用穿梭载体pHZ1252( 其中的vhb 基因位于受硫链丝菌素诱导的链霉菌强启动子PtipA之下) 转化阿维链霉菌并经硫链丝菌素诱导,则在该菌中表达出了有活性的VHb 蛋白。pHZ1252 在阿维链霉菌中发生了重组缺失,但缺失的pHZ1252 上仍含有完整的vhb 基因及诱导型强启动子,且可在阿维链霉菌中稳定遗传,却不能再转化大肠杆菌。  相似文献   

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信号肽疏水性的提高促进青霉素G酰化酶分泌   总被引:9,自引:0,他引:9  
设计和合成了一段具有连续10仆亮氨酸强疏水核心的信号肽(artificial signal peptide,ASP),由EcoRI-KpnI位点融合到青霉素G酰化酶(penicillin Gacylase,PAC)信号肽(wild typesignal peptide,WTSP)的-4Pro位点,分别构建了PAC表达质粒:pKKpac△SP,pKKpacWTSP,pKKpacASP,pETpac  相似文献   

6.
点状产气单胞菌脯氨酰内肽酶基因克隆与序列测定   总被引:2,自引:0,他引:2  
点状产气单胞菌点状亚种(Aeromonas puncata subsp.punctata)具有脯氨酰内肽酶(prolyl endopeptidase PEP)活性。将其染色体DNA有Eco RⅠ部分酶切后回收8-16kb的DNA片段,与EcoRⅠ消化载体pUC18连接后转化E.coil DH5α,用该酶的专一性底物Benzyloxycarbonyl-Gly-β-naphthylamide从质粒库中  相似文献   

7.
HCV5′端非编码区cDNA的体外转录   总被引:1,自引:0,他引:1  
采用逆转录聚合酶链反应(RT-PCR)从广东省一例慢性丙型肝炎病人血清中获得丙型肝炎病毒(HCV)5′端非编码区(5′NCR)302bp的cDNA片段,经补齐和提纯后插入pUC19质粒,获得的重组体pUN进行序列测定,将pUN的目的基因亚克隆进体外转录载体pSPORTI多克隆位点的EcoRffI和PstI切点之间,所得重组体pSN线性化后由T7RNA多聚酶及SP6RNA多聚酶引导体外转录反应,产物  相似文献   

8.
本文研究了中国奥姬小蜂属(Aulogymnus  Forster),该属在中国是首次发现。本文描述了 4个新种,A. elevatus sp. nov, A. hyalopterus  sp. nov, A 、insculptus sp. nov, A. longicalcar  sp. nov。所有模式标本保存于中国科学院动物研究所动物标本馆。  相似文献   

9.
斜纹夜蛾核多角体病毒几丁质酶基因的克隆及序列分析   总被引:3,自引:2,他引:3  
以苜蓿丫纹夜蛾核多角体病毒(Autographa calitirnica multinucleocapsid nuclear polyhedrosis virus,AcMN-PV)基因组含几丁质酶基因(chiA)的pstI M片段为探针,通过Southern杂交将斜纹夜蛾核多角体病毒(Spodoptera litura nuclear polyhedrosis virus,SpltNPV)的chi  相似文献   

10.
从农药厂废水中分离到6株能以除草剂阿特拉津为唯一氮源生长的细菌,即假单胞菌(Pseu-domonas spp.)AD1、AD2和 AD6,土壤杆菌(Agrobacterium sp.)AD4,黄单胞菌(Xanthomonas sp.)ADS,欧文氏菌(Erwinia sp.)AD7。AD1菌株能使无机盐培养基中的 0.3g/L阿特拉津在72h内降解99,9%。当以AD1、AD2、AD4、AD5、AD6和AD7菌株的总DNA为模板进行PCR扩增时,除A  相似文献   

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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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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   

17.
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   

18.
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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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   

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