绿色荧光蛋白及其应用

许多海洋无脊椎动物体内都含有绿色荧光蛋白,这种蛋白质结构很特殊,在受到激发时可以发射绿色或蓝色荧光。本文将就绿色荧光蛋白的结构,性质及其应用前景作一综述。     

绿色荧光蛋白及其应用

许多海洋无脊椎动物体内都含有绿色荧光蛋白,这种蛋白质结构很特殊,在受到激发时可以发射绿色或蓝色荧光。虽然对它的研究从本世纪六十年代才开始,但是它独特的性质逐渐引起了生物学界的广泛关注。本文将就绿色荧光蛋白的结构、性质及其应用前景作一综述。     

GFP在植物分子生物学研究中的应用

许多海洋无脊椎动物体内都含有绿色荧光蛋白,这种蛋白质结构很特殊,在受到刺激时可以发射绿色或蓝色荧光.虽然对它的研究从20世纪60年代才开始,但是它独特的性质逐渐引起了生物学家的广泛关注.就绿色荧光蛋白的特性及其应用等进行简要综述.     

绿色荧光蛋白——照亮生命科学的一盏明灯

绿色荧光蛋白的发现及应用具有划时代的重要意义,它不仅为当代生物学研究提供了极为实用的基本研究手段,并且在此基础上改造发展和发现了一系列荧光蛋白,拓展了应用范围。这使得对微观生物学的研究也可以进入一个时空结合,研究鲜活动态过程的新时代。本文主要回顾总结了绿色荧光蛋白的发现、优化改造及其应用。     

珊瑚和海葵来源红荧光蛋白的研究和应用

绿色荧光蛋白作为标记蛋白和报告蛋白在生物学研究中应用越来越广。但在荧光共振能量转移(fluorescenceresonanceenergytransfer,FRET)等技术中存在一些缺陷,需要更大波长范围的荧光蛋白。最近研究发现了多种来源于珊瑚和海葵的红荧光蛋白,这些长波长的荧光蛋白对绿色荧光蛋白是一种很好的代替和补充,可以实现细胞内多荧光标记,提供更理想的FRET荧光对。经随机突变和定点突变等方法改建获得的红荧光蛋白变种显示出更高的荧光强度,成熟时间也更短。目前应用较多的是来源于香菇珊瑚(Discosomasp.)的红荧光蛋白DsRed。     

绿色荧光蛋白在转基因研究中的应用

绿色荧光蛋白(green fluorescent prote in,GFP)是一种能够自身催化形成生色团并在蓝光或紫外光激发下发出绿色荧光的蛋白。有现代生物学北斗星之美誉的它,在生物学的很多领域都有广泛应用。GFP具有荧光稳定、易于检测、表达调控简单、生物安全性好等优点,在转基因研究中的各个方面均应用颇多。就GFP在转基因研究中的应用特点及应用进展做一综述。     

绿色荧光蛋白及其在植物分子生物学研究中的应用

绿色荧光蛋白(GFP)是海洋生物水母(Aequoria victoria)体内的一种发光蛋白,近十年来成为在生物化学和细胞生物学研究和应用中用得最广泛的蛋白质之一。文章就绿色荧光蛋白的特性及其在植物分子生物学中应用的研究进展作了概述。     

绿色荧光蛋白在蛋白质研究中的应用

绿色荧光蛋白（green fluorescent protein,GFP）自发现以来,由于具有自发荧光等特性,在分子生物学和细胞生物学领域得到广泛应用。GFP作为一种报道分子,在研究蛋白质相互作用和构象变化、检测蛋白质表达、蛋白质和细胞荧光示踪中,起到了重要的作用。该文通过对绿色荧光蛋白特性的分析．介绍其作为荧光标记在蛋白质研究中的应用,并展望进一步的研究前景。     

红色荧光和绿色荧光转基因小鼠模型的建立

目的建立红色荧光和绿色荧光转基因小鼠,为活体荧光影像系统建立重要的实验动物模型。方法把DsRed-Express和EGFP基因插入chicken-βactin强启动子下游构建转基因载体,建立红色荧光和绿色荧光转基因C57BL/6J小鼠。PCR鉴定红色荧光和绿色荧光转基因小鼠的基因表型,活体荧光影像系统分析红色荧光和绿色荧光转基因小鼠,荧光显微镜检测红色荧光和绿色荧光转基因小鼠全身组织器官的组织形态。结果分别建立了3个系的红色荧光和3个系的绿色荧光转基因小鼠。活体荧光影像系统分析转基因小鼠分别呈现红色荧光和绿色荧光。经荧光显微镜观察,DsRed-Express转基因小鼠的红色荧光蛋白在多个组织器官中表达,尤其在胰腺、肝脏、肾脏和脾脏等器官表达量较高。EGFP转基因小鼠绿色荧光蛋白在全身各个组织器官中表达,尤其在胰腺、心脏、小肠、外周血细胞和脑组织等器官组织中表达量较高。结论DsRed-Express和EGFP基因在转基因小鼠中系统性高表达,成功建立了红色荧光和绿色荧光转基因小鼠。DsRed-Express和EGFP转基因小鼠将成为活体荧光影像系统的重要实验动物模型。     

一种原位示踪外源目的基因表达载体的构建

应用分子克隆技术 ,分别将增强型绿色荧光蛋白 (enhancedgreenfluorescentprotein ,EGFP)、内部核糖体进入位点 (internalribosomeentrysite,IRES)和编码H-ras基因C端 2 0个氨基酸的DNA(rasc2 0 )片段插入真核表达载体pcDNA3,构建真核重组表达载体并将其命名为pZX。通过脂质体介导将该载体转染人宫颈癌细胞系HeLa ,培养过夜后在荧光显微镜下观察绿色荧光蛋白在细胞内的分布 ,并与pEGFP-C3质粒DNA转染该细胞系进行比较。结果表明 ,转染pZX载体的实验组细胞膜发出绿色荧光 ,而对照组绿色荧光则均匀弥散于整个细胞中 ,工具性载体pZX已构建成功     

In Planta visual monitoring of green fluorescent protein in transgenic rice plants

The green fluorescent protein (GFP) from the jellyfish Aequorea victoria is a widely used reporter that can be directly visualized in the living cells in both animals and plants. We inserted a synthetic gene (sgfp) encoding a modified form of the GFP into expression vector, Act1-sgfp for the direct expression of GFP which is easily detectable in rice plants. Green fluorescence emitted from GFP could be visualized in calli, dry seeds, roots and seedlings with green shoots of transgenic rice plants. In our visualization system with a charge-coupled device camera, band-pass filters and a light source, the presence of red chlorophyll autofluorescence from chloroplasts did not alter the green fluorescence of GFP. These results demonstrate that GFP could be used as a non-destructive visual selection marker for examining gene expression in transformed calli, dry seeds and young plants.     

基于GFP观察的花粉介导植物转基因方法的细胞学研究

花粉介导的植物转基因方法不需要组织培养过程,且操作简便易行。为明确该方法的细胞学基础,以离体下米（Zeamays）郑单958花粉为材料,在超声波作用下将含有绿色荧光蛋白（GFP）基因的质粒与花粉共处理,对处理过的仡粉进行体外培养及人工授粉,并利用荧光显微镜对GFP基因在玉米花粉粒、花粉管及胚中的表达进行示踪观察。结果表明：处珲绀和对照组均有部分花粉粒呈强烈的绿色荧光,因此通过观察花粉粒荧光来确定GFP基因是否表达不可靠;处理组化粉管较对照旱现强烈的绿色荧光：GFP基因在玉米胚中表达可以作为鉴定转化体的证据。该实验首次利用荧光观察为花粉介导植物转基因方法提供了可视的细胞学证据。     

Measurement of green fluorescent protein concentration in single cells by image analysis

The gene encoding the green fluorescent protein (GFP) has been widely used in studies of gene expression. The GFP can be detected nondestructively in living cells or tissues by the green fluorescence of the protein under blue light. Solutions of enhanced GFP (EGFP) of known concentration were filled in glass capillaries and used to calibrate a method for quantitative determination of EGFP or GFP-S65T in plant cells. Images captured by a digital camera were analyzed to determine the linear range for measurement of EGFP expression. The value of the method was illustrated by analysis of the relative levels of GFP expression under control of different promoters in aleurone cells of barley.     

绿色荧光蛋白基因导入胡萝卜愈伤组织并获得表达

目的:将绿色荧光蛋白基因(green fluorescent protein,GFP)重组到胡萝卜愈伤组织细胞中,使其获得表达,为今后利用GFP基因作为植物报告基因提供条件。方法:通过冻融法将含有GFP基因的重组表达载体PBI1121转入到根癌农杆菌EHA105中,再利用根癌农杆菌介导的方法将GFP基因导入到胡萝卜愈伤组织细胞中,经过除菌和抗性筛选后观测转化结果。结果:荧光显微镜观测到被转化的愈伤组织在受蓝光激发后发出绿色荧光,利用PCR法扩增出约740bp的目的基因片断。结论:GFP基因在胡萝卜愈伤组织细胞中获得了表达。     

绿色荧光蛋白在草鱼肾细胞中的表达

应用阳离子脂质体介导法,将含绿色荧光蛋白（GFP）基因的质粒pEGFP-N1转染到培养成单层的草鱼肾细胞（CIK）中,通过荧光倒置显微镜和特异性RT-PCR方法检测GFP的表达.在荧光倒置显微镜下可见CIK细胞的胞质和胞核均呈现绿色荧光,且细胞核的绿色荧光强度强于细胞质.转染细胞中的转录产物经RT-PCR扩增后,凝胶电泳鉴定出与GFP基因片段分子量大小一致的条带,经测序证明其为GFP基因序列.结果表明,GFP基因可以在草鱼CIK细胞内高效率成功表达,为构建以GFP为报告基因的真核重组质粒及研究草鱼出血病DNA疫苗奠定了重要的基础.     

Differential rates of gene expression monitored by green fluorescent protein

The use of green fluorescent protein (GFP) as a reporter gene has made a broad impact in several areas, especially in studies of protein trafficking, localization, and expression analysis. GFP's many advantages are that it is small, autocatalytic, and does not require fixation, cell disruption, or the addition of cofactors or substrates. Two characteristics of GFP, extreme stability and chromophore cyclization lag time, pose a hindrance to the application of GFP as a real-time gene expression reporter in bioprocess applications. In this report, we present analytical methods that overcome these problems and enable the temporal visualization of discrete gene regulatory events. The approach we present measures the rate of change in GFP fluorescence, which in turn reflects the rate of gene expression. We conducted fermentation and microplate experiments using a protein synthesis inhibitor to illustrate the feasibility of this system. Additional experiments using the classic gene regulation of the araBAD operon show the utility of GFP as a near real-time indicator of gene regulation. With repetitive induction and repression of the arabinose promoter, the differential rate of GFP fluorescence emission shows corresponding cyclical changes during the culture.     

A versatile transreplication-based system to identify cellular proteins involved in geminivirus replication

A versatile green fluorescent protein (GFP) expression cassette containing the replication origins of the monopartite begomovirus Tomato yellow leaf curl Sardinia virus (TYLCSV) is described. Transgenic Nicotiana benthamiana plants containing one copy of the cassette stably integrated into their genome were superinfected with TYLCSV, which mobilized and replicated the cassette as an episomal replicon. The expression of the reporter gene (the GFP gene) was thereby modified. Whereas GFP fluorescence was dimmed in the intercostal areas, an increase of green fluorescence in veins of all leaves placed above the inoculation site, as well as in transport tissues of roots and stems, was observed. The release of episomal trans replicons from the transgene and the increase in GFP expression were dependent on the cognate geminiviral replication-associated protein (Rep) and required interaction between Rep and the intergenic region of TYLCSV. This expression system is able to monitor the replication status of TYLCSV in plants, as induction of GFP expression is only produced in those tissues where Rep is present. To further confirm this notion, the expression of a host factor required for geminivirus replication, the proliferating cellular nuclear antigen (PCNA) was transiently silenced. Inhibition of PCNA prevented GFP induction in veins and reduced viral DNA. We propose that these plants could be widely used to easily identify host factors required for geminivirus replication by virus-induced gene silencing.     

GFP在绿色荧光裸鼠不同组织中的表达及分析

目的研究外源绿色荧光蛋白（green fluorescent protein,简称GFP）基因在BALB/c绿色荧光裸鼠主要器官组织中的表达及其差异。方法小动物成像系统和RT-PCR方法检测GFP的组织分布以及荧光表达水平情况。结果经活体荧光影像系统观察及PCR方法检测发现GFP可以在裸鼠多个器官组织中表达,其中在胰腺、心脏、全脑、皮肤、睾丸中表达量较高。结论外源绿色荧光蛋白可以在模型动物体内成功表达且稳定遗传,其中在胰腺组织中高表达。     

Jellyfish green fluorescent protein as a reporter for virus infections

The gene encoding green fluorescent protein (GFP) of Aequorea victoria was introduced into the expression cassette of a virus vector based on potato virus X (PVX). Host plants of PVX inoculated with PVX.GFP became systemically infected. Production of GFP in these plants was detected initially between 1 and 2 days postinoculation by the presence of regions on the inoculated leaf that fluoresced bright green under UV light. Subsequently, this green fluorescence was evident in systemically infected tissue. The fluorescence could be detected by several methods. The simplest of these was by looking at the UV-illuminated plants in a darkened room. The PVX.GFP-infected tissue has been analysed either by epifluorescence or confocal laser scanning microscopy. These microscopical methods allow the presence of the virus to be localized to individual infected cells. It was also possible to detect the green fluorescence by spectroscopy or by electrophoresis of extracts from infected plants. To illustrate the potential application of this reporter gene in virological studies a derivative of PVX.GFP was constructed in which the coat protein gene of PVX was replaced by GFP. Confocal laser scanning microscopy of the inoculated tissue showed that the virus was restricted to the inoculated cells thereby confirming earlier speculation that the PVX coat protein is essential for cell-to-cell movement. It is likely that GFP will be useful as a reporter gene in transgenic plants as well as in virus-infected tissue.     

Engineering of a Sagiyama alphavirus RNA-based transient expression vector

Sagiyama virus (SAGV), a strain of Getah virus in the genus Alphavirus in the family Togaviridae, has a broad host range in vertebrates and invertebrates but is not pathogenic for humans. We engineered the SAGV genome as an efficient transient expression vector using the full-length infectious cDNA clone pSAG2 as the background. A green fluorescent protein (GFP) gene was used as a reporter gene and expressed from a subgenomic mRNA. When the GFP gene was placed downstream of the intact capsid protein gene or an internally deleted capsid protein gene encoding the N-terminal 9 amino acids and C-terminal 149 amino acids, autoproteolysis occurred efficiently at the boundary site to release GFP from the N-terminally-fused capsid-protease domain. GFP was also expressed efficiently without the 5'-terminal region of the capsid protein gene, suggesting that SAGV capsid protein gene does not have a translation enhancer sequence. To provide structural proteins for pseudovirion formation, a nonviable mutant construct, pSAG2.3L, which contains a Gly-to-Leu substitution at the - 2 position of the nsP3/4 cleavage site, was used as a helper. GFP was expressed up to 50 pg from 1 X 10(6) BHK21 cells after inoculation of pseudovirions. The C6/36 mosquito cell was also a suitable host for a large scale expression of GFP using pseudovirions. In addition to high-level transient expression, safeness of SAGV should give an advantage over other alphavirus expression vectors.