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1.
用RT-PCR扩增我国蓝舌病毒Z1株的VP7基因,直接将其克隆至pGEM-T载体中,用限制性内切酶EcoRI分析经蓝/白斑筛选和PCR鉴定的重组质粒,用DIG标记克隆片段制成探针与病毒基因组进行Northern blot杂交,证明插入片段为BTV VP7基因特异性片段。采用Sanger双脱氧终止法测定cDNA片段的核苷酸序列,将这一序列与国外已发表的9株蓝舌病毒及相关的环状病毒的VP7基因进行了比  相似文献   

2.
采用异硫氰酸胍(GuSCN)和硅藻从B95-8细胞中快速抽摸板DNA。根据EB病毒(EBV)B95-8株DNA全序列及编码EBV胸苷激酶(TK)的开放读框BXLF1的结构,设计合成一对引物,并在引物的5′一端分别引入EcoRI和PstI切点,用PCR技术扩增出一含完整的EBVTK基因的1.843KbDNA片段,NcoI酶切分析鉴定,EcoRI/PstI双酶切PCR产物和载体,使目的基因定向克隆至选  相似文献   

3.
根据已发表的序列,分别在鸡贫血病毒(CAV)环形基因组DNA(全长2.3kb)的EcoRI位点和BamHI位点的两侧选择适当序列合成两对引物,用PCR技术,从斑点杂交检测到病毒核酸的CAV感染的MDCCRP1细胞基因组DNA中,分别扩增出包含EcoRI和BamHI分割开的病毒基因组两部分(1.5kb和0.8kb)约1.5kb和约1.25kb的两个片段。再将其中相应序列拼接克隆进pUC18载体,获得包含CAV全基因组序列DNA片段的克隆质粒pCAV2.4。酶切分析表明,该质粒具有预期的BamHI位点、PstI位点、HindⅢ位点,而预期的EcoRI位点消失。重组质粒插入DNA片段的两端序列分析表明,质粒pCAV2.4是包含CAV全基因组序列的重组质粒,插入DNA片段序列中的EcoRI位点序列发生了一个碱基突变。  相似文献   

4.
L—山梨酮脱氢酶基因在大肠杆菌中的克隆和表达   总被引:10,自引:3,他引:7  
参照已知的L-山梨酮脱氢酶基因序列,合成了两个引物序列,以AcetobacterliqueficiensIF012258的染色体DNA为模板进行PCR反应,克隆得到了L-山梨酮脱氢酶基因,经酶切验证与预期结果相同,序列测定结果也与已知序列一致,采用PCR方法在此基因的两端加上了E.coRI和HindII两个酶切位点,经E.coRI和HindII酶切后去掉了两端的多余序列后,将此片段连接到pKKHh  相似文献   

5.
用PCR扩增和克隆马立克氏病病毒糖蛋白D基因   总被引:2,自引:0,他引:2  
用PCR技术,从GA株马立克氏病病毒(MDV)感染的成纤维细胞(GEF)基因组DNA中扩增出MDV糖蛋白D(gD)抗原基因片段的约1300bp编码序列,将该pcR扩增的产物于EcoRI和Kpnl位点克隆到pUC18质粒载体中,在以digoxigenin(dig)标记的gDPCR产物作为探针,进行原位杂交初步筛选到阳性重组质粒克隆,再根据酶切分析筛选到含MDVgD基因的重组质粒p18MgD。将p18MgD质粒DNA用dig标记后,在Southernblot中,该探针能识别MDV基因组DNA的BamHI-A克隆中的A片段DNA。酶切位点分析表明,该gD克隆也和已发表的MDV的RBIB株gD一样,不含有EcoRⅠ、HindⅢ、PstⅠ、SmaⅠ、pvuⅡ等酶切位点。证明该重组质粒是MDVgD克隆。  相似文献   

6.
采用加端聚合酶链反应技术,从湖北地区一宫颈癌患者癌组织DNA中分离出人乳头瘤病毒16型(HPV16)E7基因,并在pUC18载体中克隆。经限制性核酸内切酶分析和DNA序列分析,确认了含HPV16E7重组克隆质粒,命名pHPV16E7─HB。DNA序列分析表明,HPV16E7─HB基因全长294bp(与报道的标准株基因长度相同),但其核苷酸顺序中有两处发生了C→T突变,即第43位密码子CAA变为TAA,第76位CGT变为TGT;前者使谷氨酰胺密码子变为终止密码,即无义奕变(nonsensemutation)。这种突变发生在294个碱基的DNA扩增产物之中,不像是PCR本身的错配,而很可能是湖北株与标准株之间的结构差异。  相似文献   

7.
从我国内蒙古地区流行的犬细小病毒病病犬的肠溶物中分离提纯犬细小病毒(CPV)。提取病毒基因组DNA,并以此DNA为模板,采用人工合成的引物进行PCR扩增,PCR产物经BamHI、SacI双酶切后,克隆于pUC19质粒的BamHI/SacI位点。重组质粒pUCVP2经PCR鉴定、限制酶切分析和序列分析,结果表明:获得了犬细小病毒内蒙株(CPV-IM)VP2基因的全长克隆,VP2基因全长1755nt,  相似文献   

8.
近几年,有关幽门螺杆菌(HP)基因分型方法及其应用的研究取得了很大进展。基因分型方法包括:质粒分型、限制性内切酶分型(REA)、核糖分型、染色体DNA脉冲场凝胶电泳(PFGE)分型、多聚酶链反应限制性内切酶消化(PCR-RFLP)分型、任意引物PCR(AP-PCR)分型、PCR单链构型多态性(PCR-SSCP)分型和核苷酸序列分析等。基因分型方法广泛用于HP的研究,如基因图的构建、感染复发、耐药机  相似文献   

9.
采用加端聚合链反应技术,从湖北地区一宫颈癌患者癌组织DNA中分离出人乳头瘤病毒16型(HPV16)E7基因,并在pUC18载体中克隆,经限生核酸内切酶分析和DNA序列分析,确认了含HPV16E7重组克隆质粒,命名pfHPV16E7-HB。DNA序列分析表明,HPV16E7-HB基因全长294bp(与报道的标准基因长度相同)但其核苷酸顺序中的两处发生了C-(T)突变,即第43位密码子CAA变为TAA  相似文献   

10.
金顺钱  杨晓 《病毒学报》1998,14(1):38-44
采用PCR方法,从HPV16型质粒中分离出HPV16E7基因片段,用EcoRI和Sall双酶解后,定向插入到表达质粒pYA3332(asd+)的Ptrc启动子下游,构建成pYA3332-HPV16-E7重组表达质粒。在大肠杆菌X6212上筛选出重组质粒后,通过中间菌株X3730的转化过渡,将重组质粒导入鼠伤寒沙门氏减毒疫苗菌株X4072(asd-),构建成宿主和载体之间具有平衡致死结构的HPV16  相似文献   

11.
通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.  相似文献   

12.
Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m−2 s−1. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to Pfr.  相似文献   

13.
The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.  相似文献   

14.
A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.  相似文献   

15.
龙胆科药用植物化学成分的研究现状   总被引:16,自引:0,他引:16  
龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。  相似文献   

16.
17.
Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H2-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H2 with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD+, FMN+, and NAD(P)+ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H2OCO2+2H++2e- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation  相似文献   

18.
Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)8 barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)8 structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive ET and active ER. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive ET and active ER represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.  相似文献   

19.
20.
(鱼句)亚科花(鱼骨)型鱼类骨骼系统的比较   总被引:2,自引:0,他引:2  
对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。  相似文献   

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