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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EooRI和PstI切点之间,所得重组体pSN线性化后由T_7RNA多聚酶及SP6RNA多聚酶引导体外转录反应,产物经凝胶电泳及特异引物RT-PCR,证实SP6引导的是正义RNA,T7合成的是反义RNA,其大小分别力429bp和362bp。并证实所得RNA力HCV5'NCRcDNA转录而来。获得的HCV5'NCRcDNA和RNA在常规逆转录和PCR步骤中用于设立有效的模板对照,对消除假用性及评估试剂有重要意义。同时,HCV5'NCR体外转录载体的构建可用于制各RNA探针和反义RNA,改进后还可作为定量PCR的竞争性模板。  相似文献   

2.
人端粒酶RNA基因的克隆与鉴定   总被引:2,自引:0,他引:2  
以人血基因组DNA为模板,合成两段20个寡聚核苷酸为引物,经过PCR扩增,得到480bp的片段,克隆到pMD18-T载体中,经电泳、酶切、PCR鉴定后测定序列。序列分析表明氙克隆的人端粒酶RNA(human telomease RNA,hTR)基因含有480bp,包括约450bp的编码模板区主序列和约30bp的上游调控区序列,其中模板区的11个核苷酸(5’-CUAACCCUAAC-3’)合成端粒亚  相似文献   

3.
以人粒巨噬细胞集落刺激因子(hGM-CSF)、人α8干扰素(hIFN-α8)和分裂细胞核抗原(PCNA)的cDNA定点突变为例,建立了一种新的大区域非连续多核苷酸同步定点突变的方法。经碱变性后的质粒DNA,先用突变引物延伸单链,然后通过PCR扩增得到突变双链DNA。用该方法成功地改造了hGM-CSF基因5′端36个核苷酸中的9个位点、IFN-α8基因5′端39个核苷酸中的9个位点和PCNA基因SD顺序两侧6个和7个核苷酸。与经典的含U单链寡核苷酸定点突变方法相比,本方法突变效率高,并省去了对突变克隆杂交筛选的操作  相似文献   

4.
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   

5.
用富集文库克隆人胰岛素基因组基因   总被引:1,自引:0,他引:1  
通过构建可富集人胰岛素基因的λ噬菌体文库,克隆了人胰岛素基因组基因.首先从中国人血液白细胞中提取到人基因组DNA,用EcoRⅠ和BglⅡ对基因组DNA进行全酶切,经0.4%琼脂糖凝胶电泳,特异回收9.5kb左右的DNA片段.将该片段与λEMBL3/BamHⅠ臂连接,构建成一个特殊的人基因组λ噬菌体文库(富集文库),效价为2×104.同时采用PCR方法及用引物Ⅰ:5′GGACAGGCTACATCAGGAAGAGG3′,引物Ⅱ:5′CTGCGTCTAATTGCAGTAGTTC3′,从人基因组DNA中扩增出一段含胰岛素基因的1.36kbDNA片段,做为放射性标记探针,对文库进行了噬菌斑原位杂交筛选,从1×104个噬菌斑中筛选到一个含人胰岛素基因组基因的阳性克隆,并进一步完成了亚克隆和该基因1732bpDNA序列的测定.结果该基因的1732bpDNA序列包括部分5′端和3′端与国外发表的人胰岛素α型等位基因的序列相同  相似文献   

6.
以含有虹鳟鱼金属硫蛋白基因的质粒DNA为模板,以合成的两段32个寡聚核苷酸为引物,经过PCR扩增,合成了433bp的片段,把其克隆到pBL-CAT载体中,序列分析和限制酶切图谱表明所克隆的虹鳟鱼金属硫蛋白启动子含有433bp,含有TATA和CAAT序列,与Hong报导的鳟鱼金属硫蛋白启动子的序列比较,其核苷酸泊同源率为100%。  相似文献   

7.
诱生型一氧化氮合酶基因启动子的结构及其调控   总被引:3,自引:0,他引:3  
鼠类NOS2基因5′端1.7kb序列几乎包含了所有的顺式作用元件,其中NFκB结合位点,IRF-RE,CAATbox和GAS4等元件对该在的诱导性转录调控至关重要,人NOS2基因5′端3.7kb范围与鼠类有相似的调控元件,但该区域仅有基础启动子活性,其诱导性调控元件在-3.7kb的上游,其中NFκB结合位点着关键的作用。  相似文献   

8.
葡萄叶绿体rbcL基因的结构分析   总被引:2,自引:0,他引:2  
以玫瑰香葡萄(Vitisvinifera L.)为材料,克隆了含有叶绿体rbc L基因的3.1 kb Bam HⅠ片段,构建了该基因的限制性酶切图谱,测定了该基因的核苷酸序列。所测的核苷酸序列总长度为2004 bp,其中基因的编码区为1428 bp,编码一个含475 个氨基酸的蛋白质,其分子量约为53 kD;测定基因的5上游含启动子的部分共358 bp,包括- 10 区(TAAAAT)、- 35区(TTGCGC)和SD 序列(GGAGG);基因的3下游区共218 bp,含有3 个转录茎环终止结构。玫瑰香葡萄rbc L基因编码区的核苷酸序列与烟草、矮牵牛、菠菜、苜蓿、水稻和玉米之间的同源性分别为91.5% 、91.4% 、90.2% 、89.8% 、86.3% 和84.5% ;推导出的氨基酸序列的同源性分别为92.2% 、91.6% 、92.2% 、93.7% 、93.5% 和90.1% 。  相似文献   

9.
CS3纤毛抗原表达调控机理的研究   总被引:2,自引:0,他引:2  
CS3是某些肠毒素大肠杆菌菌体表面上的多聚物,它能使病原菌粘附于宿主的小肠上皮细胞上,是致病的重要因素.为了探索CS3菌毛抗原基因的表达调控机制,根据CS3亚基结构基因的核苷酸序列分析表明,在其翻译起始位点的上游存在着rbs位点及原核启动子的-10区和-35区DNA序列.采用基因重组技术将CS3结构基因上游120bp的DNA片段亚克隆进缺乏启动子而只含报告基因lacZ的质粒pCB267中.凝胶滞留和启动报告基因表达的实验证明了CS3亚基结构基因具有自身的启动子(Ps).将该启动子上游区域不同长度的核苷酸片段克隆进pCB267中,报告基因表达结果表明CS3结构基因的表达受其上游区域的抑制.核苷酸序列分析发现,在Ps-35区上游550bp和840bp处各存在一个富A-T簇.结合原核启动子的一般作用规律推知,CS3的表达可能受DNA结合蛋白型的正向调节因子的作用.用CFA/1菌毛抗原基因的正向调节基因cfaD对CS3基因进行的互补表达试验表明cfaD基因不仅可消除上游区对Ps的抑制,而且可大幅度地提高Ps的启动能力.在分析表达调控的基础上获得CS3重组高效表达.同时提出了其表达调控模型.  相似文献   

10.
《生命科学研究》1999,3(1):52-52
用RT-PCR方法从北京株丙型肝炎病毒中扩增出NS3区基因片段,该片段经pGEX-T载体克隆到大肠杆菌DH5α菌株中.经自动序列分析仪测出NS3基因的728bp长的核酸序列.发现在该片段中第31位核苷酸发生A→T突变,产生一个终止突变.这表明,丙型肝炎病毒北京株存在一定的变异,产生缺陷型病毒,这类缺陷型病毒的出现可能是丙型肝炎病毒持续性感染的原因之一.  相似文献   

11.
The systematic position ofthe Ebenaceae, Sapotaceae, Styracaceae, Ochnaceae, Stachyuraceae, Dipterocarpaceae, Clusiaceae and Hypericaceae has been investigated using serological comparisons of sets of antigenic determinants. The results show that the Sytracaceae and Sapotaceae are undoubtedly more closely associated with the Actinidiaeceae and Theaceae, respectively, than with each other. We found no corresponding determinants betnween antigen systems from the Ebenaceae and systems from any other family whose relations to this family have been proposed. As discovered previously, investigations of antigen systems from the Ochnaceae, Dipterocarpaceae, Stachyuraceae, Clusiaceae and Hypericaceae are against the idea of a natural order “Theales” in which these families, or at least some of them, are combined with the Theaceae and Actinidiaceae. This paper completes our previous investigations which largely support a superorder Ericanae sensu Ehrendorfer and Takhtajan. We propose to include the Actinidiaceae and Theaceae in this superorder, assigning them a central position laong with the Sapotaceae and Sytracaeae on one side and the Primulales and Ericales on the other. Another most interesting finding is that there are corresponding determinants between antigen systems from the members of the Ericanae and representatives of the Polemoniaceae and Loasaceae.  相似文献   

12.
The electrophoretical polymorphisms of some blood proteins were studied in the Talysh population of Pirasora situated in South-East Azerbaidjan. We calculated the gene frequencies of these polymorphisms and determined the genetic distances between the Talyshes and some Iranian populations of North, Central and South Iran, Afghans, and three populations of Azerbaijan. The Talyshes are very close to Iranians of Shiraz, whereas they are distant from the Azerbaijanians. Anthropological investigations showed that the Caucasoids and Mongoloids lived in the Aragvi Basin since the Eneolithic period. This was stated by Alexeev (1974), who emphasized the mixture of the Caucasus populations from ancient times on. We calculated the genetic distances between the Caucasus populations and numerous populations of other geographic regions, considering 28 alleles of 12 loci of blood group, serum protein and red cell enzyme polymorphisms and constructed the dendrogram of these populations. The position of the Caucasus populations in the dendrogram corresponds on principle to the earlier anthropological observations. The clustering of the Caucasoid populations corresponds completely with anthropological and historical data, and supports our earlier hypothesis (Nazarova 1999) concerning the differentiation of Caucasoids, Northern Mongoloids and Amerinds from the populations, which inhabitated Asia in palaeolithic times.  相似文献   

13.
Several different models of the linker histone (LH)–nucleosome complex have been proposed, but none of them has unambiguously revealed the position and binding sites of the LH on the nucleosome. Using Brownian dynamics-based docking together with normal mode analysis of the nucleosome to account for the flexibility of two flanking 10 bp long linker DNAs (L-DNA), we identified binding modes of the H5-LH globular domain (GH5) to the nucleosome. For a wide range of nucleosomal conformations with the L-DNA ends less than 65 Å apart, one dominant binding mode was identified for GH5 and found to be consistent with fluorescence recovery after photobleaching (FRAP) experiments. GH5 binds asymmetrically with respect to the nucleosomal dyad axis, fitting between the nucleosomal DNA and one of the L-DNAs. For greater distances between L-DNA ends, docking of GH5 to the L-DNA that is more restrained and less open becomes favored. These results suggest a selection mechanism by which GH5 preferentially binds one of the L-DNAs and thereby affects DNA dynamics and accessibility and contributes to formation of a particular chromatin fiber structure. The two binding modes identified would, respectively, favor a tight zigzag chromatin structure or a loose solenoid chromatin fiber.  相似文献   

14.
人类基因组及后基因组研究进展及其应用与开发研究现状   总被引:9,自引:0,他引:9  
人类对自身基因组的研究,随着人类基因组工作草图的绘制完成和对基因功能研究的深入已加快进入了实质性、关键性的开发利用阶段。本文概述了人类基因组及后基因组的研究进展及依此开展基因治疗及基因(组)药物研制等应用开发研究的现状。  相似文献   

15.
In order to analyze the complicated movements of the mandible as the open-closing movement and the protrusio are, it is useful to evaluate the basic kinematic principles and reduce them to simple technical constructions. Both the open-closing movement and the protrusio could be reduced to 4-bar links, which were used to simulate the movements with help of a computer. Besides, the polodes and the curves of points in the muscular attachments could be constructed. The 2 entirely different 4-bar links have 3 things in common: The resting system - cranium, the moving system - mandibula, and 1 of the 2 arms connecting these 2 systems - the ligamentum laterale. As this ligament is taut during movements it can be considered a "guiding ligament" representing 1 of the 3 determining components of the mandibular movements. The other of the 2 arms has no anatomical equivalent; this arm, however, is "replaced" by the 2 other determining components of the mandibular movements: the joint and the muscles. The curves, which the Caput mandibulae describes, are practically identical for the open-closing movement and the protrusio despite of the different 4-bar links and these curves exactly correspond to the Discus articularis, taut by the upper part of the M. pterygoideus lateralis. The muscles do not only just move the mandibula, but they are also the component, which can choose between the different mandibular movements. By means of the curves, which points in the muscular attachments describe, the function of the masticatory muscles could be analyzed exactly.  相似文献   

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Interpreting channel behavior in patches requires an understanding of patch structure and dynamics, especially in studies of mechanosensitive channels. High resolution optical studies show that patch formation occurs via blebbing that disrupts normal membrane structure and redistributes in situ components including ion channels. There is a 1-2 μm region of the seal below the patch where proteins are excluded and this may consist of extracted lipids that form the gigaseal. Patch domes often have complex geometries with inhomogeneous stresses due to the membrane-glass adhesion energy (Ea), cytoskeletal forces, and possible lipid subdomains. The resting tension in the patch dome ranges from 1-4 mN/m, a significant fraction of the lytic tension of a bilayer (∼10 mN/m). Thus, all patch experiments are conducted under substantial, and uneven, resting tension that may alter the kinetics of many channels. Ea seems dominated by van der Waals attraction overlaid with a normally repulsive Coulombic force. High ionic strength pipette saline increased Ea and, surprisingly, increased cytoskeletal rigidity in cell-attached patches. Low pH pipette saline also increased Ea and reduced the seal selectivity for cations, presumably by neutralizing the membrane surface charge. The seal is a negatively charged, cation selective, space with a resistance of ∼7 gigohm/μm in 100 mM KCl, and the high resistivity of the space may result from the presence of high viscosity glycoproteins. Patches creep up the pipette over time with voltage independent and voltage dependent components. Voltage-independent creep is expected from the capillary attraction of Ea and the flow of fresh lipids from the cell. Voltage-dependent creep seems to arise from electroosmosis in the seal. Neutralization of negative charges on the seal membrane with low pH decreased the creep rate and reversed the direction of creep at positive pipette potentials.  相似文献   

20.
ObjectiveTo investigate the efficacy of ropivacaine and bupivacaine in caesarean section and vital signs and the hemodynamics of the lying-in women.MethodsA total of 480 lying-in women who were admitted to this hospital for treatment between December 2017 and June 2018 were enrolled into this study as the subjects, which were divided into the experiment group and the control group, with 240 subjects in each group. In the experiment group, subjects received the local anesthesia by infusion of 1.5 mL ropivacaine (0.75%), while those in the control group also took the local anesthesia by infusion of 1.5 mL bupivacaine (0.75%). Thereafter, we observed the differences in the anesthetic efficiency, vital signs and hemodynamics of the lying-in women between two groups.ResultsThe excellent and good rates of the anesthesia in two groups were 92.1% and 87.9%, showing no obvious difference; in the experiment group, the average arterial pressures and systolic pressures at 5 min and 10 min after combined spinal and epidural analgesia (CSEA) were all elevated when comparing to the control group (all P < 0.05); in the experiment group, the onset time was obviously extended, while duration of sensory and motor block and the duration of motor block were all shorter than those in the control group (all P < 0.05). During anesthesia, the incidence rate of the adverse reactions in the control group was 2.50%, significantly higher than 0.83% in the experiment group (P < 0.05).ConclusionDespite that ropivacaine and bupivacaine are efficient in anesthesia in the CSEA in the caesarean section, ropivacaine is more recommended for little influence on the hemodynamics, shorter duration of sensory block and motor block and low incidence rate of adverse reactions, which are conducive to the recovery and also safe to the patients.  相似文献   

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