骨形态发生蛋白-7真核表达载体的构建及鉴定

从转录水平上对原有载体进行改造,以期提高外源蛋白的表达量,为进一步研究改建载体后蛋白表达量奠定基础。将pBI—EGFP载体上的反应元件Pbi-1切下,连在pTet-On载体上PCMV的下游;然后将外源基因BMP-7重组到原有的pBI—EGFP载体内,进行酶切和序列鉴定。成功地构建了pTet—0n—Pbi-1载体和其核表达载体pBI／BMP—7。     

Reduced mobilization of Rev-responsive element-deficient lentiviral vectors

Infection of cells transduced with a lentiviral vector by human immunodeficiency virus (HIV) could lead to packaging of the lentiviral vector RNA into HIV particles and unintended transfer of the vector. To prevent this, the Rev-responsive element (RRE) of an HIV-1 vector was functionally replaced by a heterologous RNA element (MS2). Providing Rev fused to an MS2 binding protein allowed efficient vector production. Mobilization of the vector from infected target cells was below the level of detection and at least 10(3)- to 10(4)-fold lower than for the RRE-containing vector. Thus, RRE-deficient lentiviral vectors provide a novel approach to reduce the risk of vector mobilization.     

Changes in the T-wave vector loop of the three-dimensional vectorcardiogram during exposure to cold pressor stress

Three-dimensional vectorcardiography was used to characterize changes in the T-wave vector loop during exposure to cold pressor stress. Data were collected from 8 subjects during baseline, cold pressor, and recovery periods. Maximum vector length, polar angle of the longest vector, azimuth angle of the longest vector, sum of all vectors, polar angle of the vector sum, azimuth angle of the vector sum, surface area of the loop, and maximum distance between adjacent vectors were computed from the T-wave vector loop. The amplitude of the one-dimensional T-wave (TWA) was also computed. Interbeat interval and TWA decreased during hand immersion and increased during recovery. Of the vectorcardiographic measures, only maximum vector length and vector sum showed statistically significant change; both decreased during the task and returned to baseline during recovery. TWA accounted for 46% of the task related variance compared to 53% and 47% respectively, for vector sum and maximum vector length. Changes in TWA probably reflect a true change in cardiac electrical potential rather than a change in T-wave vector loop shape or orientation.     

CBF4基因植物表达双元载体的构建

目的:对拟南芥CBF4基因序列进行克隆.方法:用限制性内切酶将CBF4基因从pMD18-T CBF4载体上切下,定向连接到含超强启动子的pC2301-35S-OCS表达载体上,成功构建了CBF4基因植物表达载体pC2301-35S-OCS-CBF4.利用冻融法将此表达载体导入只含辅助质粒的根癌农杆菌中,提取转化质粒,经PCR扩增和酶切验证鉴定表明.结果:CBF4基因植物表达双元载体构建成功.结论:转CBF4基因烟草的抗寒性比野生型烟草要高.     

Efficiency of insertion versus replacement vector targeting varies at different chromosomal loci.

We have analyzed the targeting frequencies and recombination products generated with isogenic vectors at the fah and fgr loci in embryonic stem cells. A single vector which could be linearized at different sites to generate either a replacement or an insertion vector was constructed for each locus. A replacement event predominated when the vectors were linearized at the edge of the homologous sequences, while an insertion event predominated when the vectors were linearized within the homologous sequences. However, the ratio of the targeting frequencies exhibited by the different vector configurations differed for the two loci. When the fgr vector was linearized as an insertion vector, the ratio of targeted to random integrations was four- to eightfold greater than when the vector was linearized as a replacement vector. By contrast, the ratio of targeted to random integrations at the fah locus did not vary with the linearization site of the vector. The different relationships between the targeting frequency and the vector configuration at the fgr and fah loci may indicate a DNA sequence or chromatin structure preference for different targeting pathways.     

A new versatile and compact lentiviral vector

During the past decade, lentiviral vectors based on the HIV-1 genome have been developed to become highly useful tools for efficient and stable delivery of transgenes to dividing and nondividing cells in a variety of experimental protocols. The vector system has been progressively and substantially improved, mainly to meet growing concerns over safety issues. However, the actual design and size of the lentiviral transfer vector often makes transgene cloning and DNA preparation a troublesome task. In this study, the pHR transfer vector used for lentivirus production in many laboratories was modified to contain a more versatile polylinker than the one present in the original pHR vector. In addition, the vector was significantly reduced in size from 12 to 7 kb, by replacing the original vector backbone with sequence from the multipurpose pUC18 vector. These modifications allowed for easier cloning and higher DNA yields without compromising the fundamental ability of this vector system to transduce cells in vitro and in vivo. Finally, the trimmed vector sequence was fully characterized by sequencing the vector in its entirety. In both cultured cells and directly into the rat striatum, transduction with this lentivirus, based on the modified pHsCXW vector, was as efficient and durable as with the pHR vector-based virus. In conclusion, the modified lentiviral transfer vector pHsCXW holds promise as a new valuable tool for the research community in the field of gene transfer.     

In-Fusion 技术构建Ⅰ型钠通道与绿色荧光蛋白融合表达及其突变载体

目的：构建Ⅰ型钠通道(Nav1.1)与绿色荧光蛋白（GFP）融合表达载体及其突变载体。方法：利用In-Fusion 技术将SCN1A 基 因亚克隆到绿色荧光蛋白真核细胞融合表达载体（pAcGFP1-C In-Fusion Ready Linear Vector）。PCR 扩增SCN1A 基因（与线性载 体对应两端有15 个相同碱基）,In-Fusion 技术进行融合即得到pCMV-GFP-C-SCN1A。将其转染HEK293T 细胞,Western blot 检 测Nav1.1 的表达。定点诱变试剂盒对其进行定点诱变。结果：1.成功构建Nav1.1 与GFP 融合表达载体pCMV-GFP-C-SCN1A;2. DNA 测序表明：在预期位点已经发生突变,SCN1A 基因第190 位色氨酸密码子(TGG)突变为终止密码子(TGA)。结论：Nav1.1 与 GFP 融合表达载体及其突变载体的构建成功,为进一步研究该突变位点导致Nav1.1 功能的改变奠定了基础。     

一种高效低背景T载体的构建

介绍一种构建高效低背景T载体的通用方法。使用含有ccdB致死基因的gateway cassette 片段作为插入DNA片段以降低背景干扰,连接到pGEM-T easy 载体骨架上,通过内切酶XcmI酶切重组质粒即得到T 载体。对重组质粒进行了酶切,PCR 和测序验证,并且利用连接效率实验证实了T 载体具有100% 的阳性克隆率。构建的T载体不仅继承了pGEM-T easy的众多优点,而且具有高效、低背景的卓越特点;另外,引入的常用限制性内切酶和 LR重组反应介导的gateway 技术为亚克隆提供了便利。     

微小RNA miR-125b真核表达载体的构建及其对细胞增殖的影响

目的:构建微小RNA125b(miR-125b)真核表达载体,研究其过表达后对细胞增殖的影响。方法:以pcDNA3.1(-)-myc-his载体为模板,PCR扩增CMV启动子,克隆入pHRS-1cla-EGFP慢病毒载体,构建pHRS-1cla-CMV-EGFP载体;以从人全血中提取的基因组DNA为模板,PCR扩增pri-miR-125b序列,将其克隆到pHRS-1cla-CMV-EGFP载体中,构建pHRS-1cla-miR125b-CMV-EGFP慢病毒表达载体;将pHRS-1cla-miR125b-CMV-EGFP表达载体瞬时转染入293FT细胞,用实时定量PCR技术对miR-125b在转录水平的表达进行检测,用MTT及Brdu法检测miR-125b过表达后对293FT细胞增殖的影响。结果:构建的pHRS-1cla-miR125b-CMV-EGFP真核表达载体经质粒酶切和测序鉴定正确,转染细胞后72h经实时定量PCR检测,成熟miR-125b表达上调约750倍(P0.01),说明其能有效高表达,MTT及Brdu法检测显示细胞增殖受到明显抑制(P0.01)。结论:构建了pHRS-1cla-miR-125b-CMV-EGFP慢病毒真核表达载体,转染293FT细胞后能高效表达成熟miR-125b,同时证明过表达miR-125b能使细胞的增殖受到非常明显的抑制。     

用于植物基因研究的mCherry表达载体构建及定位表达

荧光蛋白在生物学研究中具有广泛的应用和重要的作用,其中红色荧光蛋白mCherry因其颜色和良好的特性,对于植物基因研究具有重要的使用价值,本研究将mCherry基因构建到pBI121植物表达载体系统中,构建了pBI121MCS-mCherry载体。利用基因枪转化法转入洋葱表皮进行表达验证,显微镜观察结果显示整个洋葱细胞具有红色荧光,证明该载体能够在植物细胞中表达红色荧光蛋白。利用双酶切连接法将转录因子BpMYB4基因构建到该载体上,得到融合表达载体pBI121MCS-mCherry-BpMYB4,在洋葱表皮中表达,结果显示细胞核具有红色荧光,证明该载体能够准确表达融合蛋白,进行亚细胞定位。同时融合基因时不再需要中间载体,构建简便,引入的KpnⅠ酶切位点,增加了可选择性。因此该载体可用于植物基因表达定位及转基因植株筛选研究中,为今后的白桦基因组学研究提供了材料。     

PPARγ基因真核表达载体的构建及其在乳腺癌MDA—MB-231细胞中的表达

目的：构建以绿色荧光蛋白（GFP）为报告基因的重组表达质粒pEGFP—C1—PPARγ,观察小鼠PPARγ基因在MDA-MB-231细胞中的表达及定位。方法：采用克隆和亚克隆技术构建小鼠PPARγ基因真核表达载体,脂质体Lip2000介导转染MDA—MB-231细胞,real—time PCR和western—blot验证其mRNA和蛋白的表达,荧光显微镜观察该基因亚细胞定位。结果：酶切和测序结果证实重组质粒含有PPAIh编码区序列且插入方向正确,转染后观察该基因亚细胞定位于胞核,胞质有弥散分布。结论：成功构建了小鼠PPARγ基因真核表达载体,该基因在MDA—MB-231细胞中成功表达,PPARγ基因主要集中表达于胞核。     

双报告基因真核表达载体的构建及其功能鉴定

目的:构建绿色荧光蛋白和海肾荧光素酶共同高效表达的双报告基因真核表达载体。方法:将增强型绿色荧光蛋白基因和海肾荧光素酶基因以昆虫病毒T2A序列相连接而后克隆进入pcDNA3.1(-)质粒,构建双报告基因真核表达载体。将该载体转染至COS-7细胞,通过荧光显微镜观察、照度计定量分析检测绿色荧光蛋白和海肾荧光素酶生物活性,Western Bolt检测T2A序列自剪切效率。结果:双报告基因真核表达载体能够同时表达非融合的绿色荧光蛋白和海肾荧光素酶,与单独表达载体产物具有相似的生物活性和表达效率。结论:双报告基因真核表达载体建立成功,为基因表达调控等相关领域研究提供辅助工具。     

Highly efficient and sustained gene transfer in adult neurons with a lentivirus vector.

The identification of monogenic and complex genes responsible for neurological disorders requires new approaches for delivering therapeutic protein genes to significant numbers of cells in the central nervous system. A lentivirus-based vector capable of infecting dividing and quiescent cells was investigated in vivo by injecting highly concentrated viral vector stock into the striatum and hippocampus of adult rats. Control brains were injected with a Moloney murine leukemia virus, adenovirus, or adeno-associated virus vector. The volumes of the areas containing transduced cells and the transduced-cell densities were stereologically determined to provide a basis for comparison among different viral vectors and variants of the viral vector stocks. The efficiency of infection by the lentivirus vector was improved by deoxynucleoside triphosphate pretreatment of the vector and was reduced following mutation of integrase and the Vpr-matrix protein complex involved in the nuclear translocation of the preintegration complex. The lentivirus vector system was able to efficiently and stably infect quiescent cells in the primary injection site with transgene expression for over 6 months. Triple labeling showed that 88.7% of striatal cells transduced by the lentivirus vector were terminally differentiated neurons.     

An autonomously propagating luciferase-encoding vector for Dictyostelium discoideum

We have constructed a luc reporter vector for Dictyostelium discoideum using a 626-bp fragment from the nuclear-associated plasmid Ddp2. The ori from Ddp2 is localized within this fragment and was used to provide an autonomous replication sequence for the reporter vector. This reporter vector was stably retained in D. discoideum AX3K cells without alteration. The vector molecule was also found to exist in relatively low copy number compared to other Dictyostelium vectors in the transformed cells. We demonstrated the utility of this vector as a reporter vector with glycogen synthase promoter/luc fusions of varying sizes.     

小伞山羊草中新型avenin-like基因的克隆及真核表达载体的构建

目的：克隆小伞山羊草中新型avenin-like（类燕麦储藏蛋白）基因,揭示avenin-like基因的表达模式,并构建avenin-like基因真核胚乳特异性表达载体。方法：利用RT-PCR方法揭示avenin-like基因的表达模式,并用PCR方法从小伞山羊草中克隆新型avenin-like基因;将克隆的avenin-like基因插入表达载体pLRPT构建真核表达载体pLRPT-avel,并经酶切和测序鉴定。结果：avenin-like基因在胚乳中特异性表达;克隆得到新型avenin-like基因,并构建了其真核胚乳特异性表达载体。结论：新型avenin-like基因的克隆及其真核表达载体的构建,为小麦品质改良提供了研究基础。     

Changes in theT-wave vector loop of the three-dimensional vectorcardiogram during exposure to cold pressor stress

Three-dimensional vectorcardiography was used to characterize changes in the T-wave vector loop during exposure to cold pressor stress. Data were collected from 8 subjects during baseline, cold pressor, and recovery periods. Maximum vector length, polar angle of the longest vector, azimuth angle of the longest vector, sum of all vectors, polar angle of the vector sum, azimuth angle of the vector sum, surface area of the loop, and maximum distance between adjacent vectors were computed from the T-wave vector loop. The amplitude of the one-dimensional T-wave (TWA) was also computed. Interbeat interval and TWA decreased during hand immersion and increased during recovery. Of the vectorcardiographic measures, only maximum vector length and vector sum showed statistically significant change; both decreased during the task and returned to baseline during recovery. TWA accounted for 46% of the task related variance compared to 53% and 47% respectively, for vector sum and maximum vector length. Changes in TWA probably reflect a true change in cardiac electrical potential rather than a change in T-wave vector loop shape or orientation.This material was presented in part at the annual meeting of the Association for Applied Psychophysiology and Biofeedback, Washington, D.C., March 1990.We are indebted to Lawrence E. Widman, M.D., Ph.D. for his invaluable advice throughout this study.     

重组人粒细胞集落刺激因子(rhG-CSF)基因在鱼腥藻中的克隆

为了将rhG-CSF基因在鱼腥藻PCC 7120中克隆,用于制备口服制剂,利用DNA重组技术,在不改变阅读杠的前提下,将hG-CSF基因进行突变,并插入到pUC-19载体上,构建中间载体pUC=G-CSF;将pUC-G-CSF插入到pRL-489的启动子PpsbA的下游,构建穿梭表达载体pRL-G-CSF;通过三亲接合转移方法,将pRL-G-CSF转入丝状体蓝藻鱼腥藻PCC 7120内。本试验得到了有抗生素性的鱼腥藻,并用PCR技术检测到rhG-CSF基因在转基因鱼腥藻中存在。     

Report on construction of gene-targeting vector for homologous recombination and transformation in silkworm, Bombyx mori L.

Abstract:  This paper reports the methods of construction of gene-targeting vector for transformation of silkworm, Bombyx mori L. The genomic DNA was isolated from the posterior silk gland of the fifth-instar silkworm larvae. The short fragment (0.5 kb) and long fragment (5 kb) of the fibroin light-chain gene were obtained by polymerase chain reaction (PCR) analysis with special primers and genome DNA as templates and then recombined with pBlueselect vector into pBs-FS-FL. The target green flourescent protein (GFP) gene, was derived from pGEP-1 vector and recombined with pUC19 vector into pUCG vector. GFP was recovered after cutting with restriction endonucleases, Pst I and Bam HI. Finally, GFP was recombined with pBs-FS-FL into gene-targeting vector, pBs-FS-GFP-FL.     

禽痘病毒通用转移载体的构建及鉴定

禽痘病毒作为活载体已经得到广泛的应用。转移载体的构建是重组禽痘病毒构建的重要环节。在分析禽痘病毒基因组的基础上 ,以FL1 1基因为插入位点 ,设计引物分别扩增 1kb的同源臂 ,将PCR扩增后的同源臂在体外连接后 ,插入到pUC1 1 9中 ,构建转移载体 ,并且以此为基础 ,构建表达绿色荧光蛋白的转移载体。含有eGFP的转移载体转染禽痘病毒感染的鸡胚成纤维细胞后 ,报告基因获得表达 ,这将为禽痘病毒载体系统的进一步开发奠定基础。