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1.
农杆菌介导GNA基因对水稻的遗传转化   总被引:3,自引:0,他引:3  
在pCAMBIA3300质粒中插入带有RSs-1启动子的GNA基因,并利用农杆菌介导的遗传转化将其导入水稻的微不定芽受体,得到了再生植株。PCR,Southern blot和Western blot的检测结果初步证明GNA基因已经整合到水稻的基因组中并得到表达。  相似文献   

2.
含多种抗真菌病基因植物表达载体的构建   总被引:9,自引:2,他引:7  
含有大麦核糖体失活蛋白(BRIP) 编码序列的质粒pRC24/BRIP改造后, 依次与含有水稻碱性几丁质酶基因RCH10 和水稻酸性几丁质酶基因RAC22 编码序列的质粒pABC2 以及含有苜蓿β1 , 3葡聚糖酶编码序列的质粒pAAG89 连接, 得到了中间载体pRAS10 .pRAS10再与根癌农杆菌双元载体pCAMBIA1300 连接, 得到了适合水稻转化的双元载体pRAS1300 . 利用冻融法将此表达载体导入根癌农杆菌LBA4404 中, 并准备将pRAS1300 转入水稻, 以期获得对真菌病有广泛且较强抗性的水稻品种  相似文献   

3.
OA能诱发人神经母细胞瘤SK细胞进行编程死亡.死亡细胞缩小变圆,细胞质凝聚,DNA有控降解成约200bp左右的片段,且这一过程可由蛋白质合成抑制剂亚胺环己酮(CHX)抑制.将编码Bc1-2全长蛋白质的cDNA植入pXJ41neo载体中,使其表达由HCMV病毒启动子控制.形成的顺义(pBcl-2-S)及反义(pBcl-2-AS)表达质粒经转染导入SK细胞中获得稳定转染子,West-ern印迹表明顺义转染子表达较大量的26kdBc1-2蛋白,而反义转染子则不表达.增强表达的Bc1-2基因产物对OA引SK细胞编程死亡无抑制效应.  相似文献   

4.
从蓝藻Calothrixsp.PCC7601染色体DNA中分离出含藻蓝蛋白基因cpcB2A2的略3.8KbDNA片段,与质粒pUC18重组,构建成一种重组质粒,pPC218-PCZ,转化E.codiJM109,获得了一系列克隆子,经斑点分子杂交和限制性内切核酸酶分析,筛选出了初步认为含有cpcB2A2基因的克隆子。  相似文献   

5.
证明了d2k=δ2k=d2k≥b2k,其中d2k、δ2k、b2k分别表示A(BMp)在lNg中的kolmogrov、线性、Bernstein型2k-宽度,d2k表示AT(BlNq′)在lMp′中Gel′fand型2k-宽度,这里A(BMp)={Ax:x∈AlMp,‖x‖p≤1},其中A是一个N×M的CVD矩陈(N>M=rankA,M是奇数),1p+1p′=1,1q+1q′=1(1≤q≤p<+∞,p≠1).  相似文献   

6.
嗜碱芽孢杆菌NTT33β-甘露聚糖酶的特性研究   总被引:5,自引:0,他引:5  
本文研究了嗜碱芽孢杆菌( Bacillus alkalophilic) N T T33β- 甘露聚糖酶的产生条件和酶学性质.其产酶的最佳碳源为 1% 槐豆角,最佳氮源为 1% 蛋白胨+ 0.2% 酵母膏,发酵培养36h 产酶量最高(达 61.3u/m l).甘油、葡萄糖、甘露醇等对产酶有强的阻遏作用.经分离纯化后测得纯酶的分子量为38.9 K D,等电点 p I为3.0,酶反应最适 p H 为 9.0~10.0,最适温度为80℃,稳定 p H 为6.0~9.0,稳定温度为60℃以下,金属离子中 Cu2+ , Ba2+ , M g2+ , Al3+ , Co2+ 对该酶有一定的激活作用,而 Ag+ , Hg2+ , Mn2+ 对该酶有明显抑制作用  相似文献   

7.
利用启动子探针型质粒pKK232-8从卡介苗染色体DAN的BamHI酶切片段中克隆到4个具启动功能的DNA片段,测定各重组子对氯霉素(Cm)的抗性,其中含3.3Kb外源片段的重组质粒pBCG2大肠杆菌转化子在LM培养基上对Cm抗性可达170×10-6g/mL,作了该片段的限制性酶切图谱.对pBCG2利用SalⅠ位点,亚克隆出4种部分重叠的具启动功能的DNA片段,这4种重组质粒分别命名为pBCG2-1,pBCG2-2,pBCG2-6和pBCG2-8,并分析了其中插入片段的大小及其转化子对Cm的抗性.将pBCG2-2的SalⅠ外源片段插入到分枝杆菌启动子探针型穿梭质粒pEQ3,获得一个可在卡介苗中表达lacZ基因的重组子pEB22.斑点杂交实验证明,具有启动功能的DNA片段来源于卡介苗的染色体DNA.结果表明克隆到一个对大肠杆菌和卡介苗均具启动子活性的DNA片段  相似文献   

8.
Themonitoringobservationsoftheshort-timevariationofthewatermasertowardthesupergiantstarofVYCMawerecarriedoutfromAugust26throughSeptember241993,usingthe13.7mtelescopeattheQinghaistationofthePurplemountainObservatory.ThisantennapresentsaHPBWof4.2a…  相似文献   

9.
表高油菜素内酯在满天星组培中的应用   总被引:3,自引:0,他引:3  
表高油菜素内酯(Epihomobrassiolide,简称云大-120 ,或BR- 120) 能增加满天星组培苗的节数,并缩短节间距,使苗健壮,最适浓度为1.0 mg/L,BR- 120 对组培苗的生根也有显著促进作用,最适培养基为MS+BR- 120 1 mg/L,在相同浓度(0.2 mg/L)时,促进生根的效果是NAA> BR- 120 > IAA.BR- 120 对满天星组培苗的增殖无作用.在促进生根方面,BR- 120 与NAA,BR- 120 与IAA 均无明显的加成作用.  相似文献   

10.
AcNPV增强子hr5增强HBsAg基因表达的研究   总被引:3,自引:0,他引:3  
用形成包涵体(OOC+)并能利用人工合成启动序列和多角体XIV启动子表达外源基因的转移载体质粒pSXIVVI+X3将多角体基因、乙型肝炎病毒表面抗原(HBSAg)基因和苜蓿丫纹夜蛾核型多角体病毒(AcNPV)的增强子hr5部分序列同时插入无包涵体的粉纹夜蛾核型多角体病毒TnNPV-SVI-G基因组中,得到两株高效表达HBsAg基因又形成包涵体的重组病毒TnNPV-shr35-OCC+和TnNPV-shr26-OCC+.对重组病毒的酶切鉴定、DNA斑点杂交和Southernblot分析证实,外源基因及其相应的启动子和增强子序列已正确插入病毒基因组中.插入顺序中,hr5增强子是插入HBsAg基因下游,多角体基因与HBsAg基因方向相反.125Ⅰ-固相放射免疫检测和Westernblot结果表明,HBsAg基因在昆虫离体细胞中得到高效表达并保留了抗原活性.TnNPV-shr26-OCC+和TnNPV-shr35-OCC+表达的HBsA吕蛋白与没有插入增强子序列的重组病毒TnNPV—HBs85-OCC+的比较,分别提高了40%和46%.  相似文献   

11.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

12.
13.
Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications (up to 574.8 km/ h test speeds or 380 km/h commercial speeds) in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.  相似文献   

14.
Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to  相似文献   

15.
Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.  相似文献   

16.
为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。  相似文献   

17.
Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.  相似文献   

18.
The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.  相似文献   

19.
正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme  相似文献   

20.
介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。  相似文献   

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