Megabase-scale mapping of the HLA gene complex by pulsed field gel electrophoresis

In the study of the genetic structure of mammalian chromosomes, there exists a "resolution gap" between molecular cloning experiments and meiotic linkage analyses. This gap has discouraged attempts to construct full-scale genetic maps of mammalian chromosomes. The organization of the human major histocompatibility complex was examined within this range by pulsed field gel electrophoresis. The data obtained indicate that the complex spans over 3000 kilobases and enable the construction of a megabase-scale molecular map. These results indicate that the techniques employed in DNA extraction, enzymatic digestion, electrophoresis, and hybridization are suitable for the efficient analysis of megabase regions of mammalian chromosomes and effectively bridge the resolution gap between molecular cloning and classical genetics.     

Mammalian ribosomal protein: analysis by electrophoresis on polyacrylamide gel

Ribosomal protein from five mammalian tissues when analyzed by discontinuous electrophoresis on polyacrylamide gel at pH 4.5 yielded 24 bands. Densitometric tracings indicated that the patterns of the basic ribosomal proteins from the several tissues were qualitatively similar. Protein from Escherichia coli ribosomes analyzed at pH 4.5 gave 29 bands, and the pattern was different from that of mammalian ribosomal protein. No distinct band was found when mammalian ribosomal protein was analyzed at pH 8.3 (acidic proteins). Ribosomal protein from Escherichia coli gave eight bands at pH 8.3. Thus, the structure of the genes responsible for synthesis of ribosomal protein in several mammalian tissues is the same, and different genes direct synthesis of ribosomal protein in bacteria.     

Theoretical studies of DNA during gel electrophoresis

A numerical study of the motion of a long-chain macromolecule in a gel has shown unexpected features. The application of a field appears to induce the chain to contract on itself. This is followed by its "unwinding" into an extended configuration. For long chains, the mobility tends toward a constant, in accord with experiments. For the parameter range used, the observed molecular motion differs strongly from assumptions made in the present theory of electrophoresis.     

几个黑杨新无性系的田间溃疡病抗性研究

【目的】从5年生69杨(从美洲黑杨中选育的优良无性系)天然杂种初选优良无性系对比试验林中选出抗溃疡病的杨树新品种。【方法】在杨树溃疡病高发期的7月中旬和9月下旬,调查每株无性系距地面0.3~1.8m枝干上的病斑数及胸径,计算各个杨树无性系的感病率和感病指数。【结果】高度抗病的杨树无性系有03-南-2-21、03-北-27-1和03-北-3-1;抗病的无性系有03-南-5-11、03-南-1-13和03-南-4-24,高度感病的无性系有03-南-4-1、03-北-1-7、03-南-3-2和03-北-1-15。【结论】03-南-2-21可以成为速生抗病性好的杨树新品种。     

利用双向电泳技术分离桃不同生长型差异蛋白

采用双向电泳技术(2-DE)对桃4种生长型的叶片蛋白质进行了分离,通过TCA/丙酮沉淀法,以180 μg上样量进行双向电泳,成功获得桃不同生长型的2-DE图谱.经Image Master 2D软件分析,发现大多数蛋白点分布于pI 4～7,分子量在14.3～66.4 kD 范围内;普通型(毛桃、大久保)2-DE图谱间蛋白点匹配率为64.86%,垂枝型(红垂枝、朱粉垂枝)为71.62%,矮化型(红寿星、粉红寿星)为70.28%,紧凑型(豫矮砧1号、紧凑罗曼)为53.92%;初步鉴定出9个差异蛋白点,其中包括1个普通型特异蛋白,3个垂枝型特异蛋白,1个矮化型特异蛋白,1个豫矮砧1号特异蛋白.     

小麦新品系的种子贮藏蛋白凝胶电泳鉴定

利用 SDS-聚丙烯酰胺凝胶电泳和酸性聚丙烯酰胺凝胶电泳对近年参加陕西省小麦区域试验的 2 6个新品系进行了高分子量谷蛋白亚基和醇溶蛋白鉴定 ,结果表明 :1 5个品系为 1 BL/1 RS易位系 ;HMW-CS表现 :Glu-A1 位点 ,1 9个品系编码一个亚基 1 ,7个品系不编码亚基 ;Glu-B1 位点 ,6个品系编码 7 8亚基 ,1 1个品系编码 7 9亚基 ,9个品系编码 1 4 1 5亚基 ;Glu-D1 位点 ,2 3个品系编码 2 1 2亚基 ,3个品系编码 5 1 0亚基。同时 ,对小麦种子贮藏蛋白聚丙烯酰胺凝胶电泳在鉴定小麦新品系中的应用进行了讨论。     

Observation of individual DNA molecules undergoing gel electrophoresis

Individual DNA molecules undergoing agarose gel electrophoresis were viewed with the aid of a fluorescence microscope. Molecular shape and orientation were studied in both steady and pulsed electric fields. It was observed that (i) DNA macromolecules advanced lengthwise through the gel in an extended configuration, (ii) the molecules alternately contracted and lengthened as they moved, (iii) the molecules often became hooked around obstacles in a U-shape for extended periods, and (iv) the molecules displayed elasticity as they extended from both ends at once. A computer model has been developed that simulates the migration of the molecules in a rotating-field gel electrophoresis experiment.     

双孢蘑菇培养料发酵过程中细菌群落结构分析

为探明双孢蘑菇培养料发酵过程中细菌群落多样性和组成的演变,获得相关优势菌落的信息,本研究利用变性梯度凝胶电泳(Denaturing gradient gel electrophoresis,DGGE)对不同季节不同发酵阶段样品的的细菌进行特异性扩增,并选取主要DNA条带进行克隆、测序和生物信息学分析。结果显示,不同发酵时期带谱差异明显。发酵过程中,培养料中主要有芽孢杆菌属、黄杆菌属、杆菌属、假单胞菌属、Solibacillus、嗜热裂孢菌属、高温双歧菌属和未知分类地位的不可培养细菌。不同季节(春季、冬季)的培养料一次发酵过程中细菌多样性变化趋势相似,且发酵结束时细菌菌落结构相似。双孢蘑菇培养料在发酵过程中细菌群落结构至少经历了3个阶段的演替,即建堆初期、一次发酵阶段和二次发酵阶段。双孢蘑菇培养料发酵过程中细菌种群丰富,并随着发酵的不同阶段发生演替,种群多样性受环境温度的影响。双孢蘑菇培养料发酵过程中一直存在的细菌群落与具有木质纤维素降解特性细菌的序列相似度较高,有利于培养料转化为双孢蘑菇栽培基质。     

水稻胚乳双向电泳技术体系的优化分析

为比较同一杂交组合不同直链淀粉含量后代在灌浆期胚乳内蛋白表达差异,文章建立了一套适合灌浆期水稻胚乳蛋白的双向电泳技术,探讨了胚乳蛋白的提取、等电聚焦上样量的选择、胶条转移等双向电泳的一些关键技术。结果表明,一次溶解蛋白样品,TCA-丙酮法优于酚法蛋白提取,300μg上样量为最适上样量,能得到清晰、分离效果好、蛋白点数较多的图像。     

牛精子蛋白质组的双向电泳和质谱鉴定初步研究

通过建立牛精子双向电泳-质谱鉴定研究平台,为从蛋白质水平研究精子生理机能奠定技术基础;采用改进的热TRIzol法裂解精子细胞制备蛋白,应用双向凝胶电泳(2-DE)分离牛精子蛋白,通过基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)鉴定蛋白质点.得到了重复性较好的牛精子2-DE图谱,质谱鉴定16个蛋白质点.建立牛精子双向电泳-质谱鉴定研究平台,为后续牛精子X、Y差异蛋白点的检测和分析奠定了理论和技术基础.     

油茶种仁蛋白双向电泳体系的建立

以普通油茶优良无性系‘闽43’成熟种仁为材料,从样品制备、IEF聚焦程序参数设定、SDS-PAGE凝胶浓度3个方面优化油茶种仁双向电泳体系。结果表明:采用TCA丙酮+SDS酚抽法提取油茶种仁蛋白能够得到更多较为清晰的蛋白点;采用62 000 V·h的高压进行等电聚焦更适合油茶种仁蛋白的第一向分离;10%SDS凝胶浓度更适合油茶种仁蛋白的双向分离,试验结果为深入开展油茶种仁蛋白质组学的研究奠定基础。     

应用DGGE技术分析自然免耕土与普通耕作土细菌群落的多样性

为探明免耕土壤与普通耕作土壤环境中细菌群落的多样性,获取相关优势菌落信息,该研究利用宏基因组学方法获得免耕土和普通耕作土样品总DNA,利用PCR获得16SrDNAV3片段,并进行变性梯度凝胶电泳(Denaturation gradient gel electrophoresis),通过微生物种群丰富度比较两样品中群落的丰富性,同时选取相关DNA条带进行克隆、测序和生物信息学分析.结果显示:免耕土壤中细菌群落多样性更加丰富;两类型土壤样品间细菌群落组成具有显著差异,证明耕作制度影响了土壤细菌群落结构.BLAST分析与系统发生分析结果表明,免耕土壤中特异存在的细菌群落与具有生物固氮、降解甲苯和倍硫磷等特性的细菌序列相似性较高或进化关系较近,推测其在免耕土壤肥力、有毒物质降解及有机质转变等过程中起作用.     

利用双向电泳构建并优化超数排卵犊牛卵泡液蛋白质图谱

以2～5月龄超数排卵犊牛卵泡液为研究对象,比较不同pH值的IPG胶条和4种上样量(150、250、350、450 μg)对卵泡液蛋白图谱构建的影响.结果表明,在pH 4～7的IPG胶条、上样量为350 μg时,获得较好质量的卵泡液蛋白图谱,并获得约319个蛋白点.成功构建的卵泡液蛋白双向电泳技术,为进一步研究犊牛与成年牛卵泡液中差异蛋白质组学分析奠定基础.     

Electrophoretic separations of large DNA molecules by periodic inversion of the electric field

In gel electrophoresis, nucleic acids and protein-detergent complexes larger than a threshold size all migrate at the same rate. For DNA molecules, this effect can be overcome by the simple procedure of periodically inverting the electric field. Tuning the frequency of the field inversions from 10 to 0.01 hertz, makes it possible to resolve selectively DNA's in the size range 15 to greater than 700 kilobase pairs.     

牛支原体蛋白质组学双向电泳技术的建立及初步分析

为了建立M.bovis蛋白质组学技术,试验采用M.bovis湖北分离株为实验材料,对样品处理、固相pH梯度胶条、上样量及染色等影响双向电泳图谱质量的关键因素与环节进行一系列的探索,2D Clean-up试剂盒处理的样品400μg在13 cm干胶条(pH 4~7)中进行双向凝胶电泳,考马斯亮蓝R350染色的方法,结果获得了能较好展示大部分蛋白点,分辨率及重复性均很好的双向电泳图谱,应用Image Master 2D Platinum version 6.0软件对图谱进行初步分析,不同重复图谱之间的平均匹配率达80.95%,随机取重复性好的20个蛋白点进行质谱分析,获得19蛋白质点的肽质量指纹图谱,鉴定成功率为95%。质谱鉴定结果与自建M.bovis蛋白库对比,蛋白点匹配率高于82分值限值(P<0.05)的不同蛋白有12个,初步分析这些蛋白多为酶类。说明该技术平台能有效用于M.bovis蛋白质组学的后续研究之中。     

龙眼种子蛋白质组双向电泳技术的优化

为建立适用于龙眼(Dimdcarpus longanaLour.)种子蛋白质组研究的双向电泳技术,对龙眼种子蛋白质的IEF、平衡时间及染色方法等关键步骤进行了优化。结果显示,龙眼种子蛋白质主要分布在pH4-7范围内,采用酚抽法,在聚焦达到50000 W.h的情况下能充分地聚焦,等电聚焦后经平衡缓冲液Ⅰ还原15 min,再经平衡缓冲液Ⅱ二次平衡20 min,考马斯亮蓝染色,24 cm IPG胶条上样量为1.2 mg时,在龙眼种子双向电泳图谱上检测到1000个多个蛋白点,蛋白点清晰,分辨率较好。本研究所建立的一套适用于龙眼种子蛋白质组分析的双向电泳方法分辨率和重复性较高,重复样品图谱间的相关系数在0.88-0.945之间。     

临床型乳房炎奶牛乳清差异蛋白质的双向电泳图谱分析

采用双向凝胶电泳技术和计算机辅助图象分析方法,对临床型乳房炎奶牛和健康奶牛的乳清蛋白质进行分析和比较,结果表明:在等电点为4~8,相对分子量为15 000-75 000 kD的区域内,临床型乳房炎奶牛乳清中有(128±8)个蛋白斑点,而健康奶牛乳清中有(122±4)个蛋白斑点.对临床型乳房炎奶牛与健康奶牛乳清蛋白质图谱匹配比较发现,有31个蛋白质点表达存在明显差异,其中乳房炎乳清中有7个蛋白点表达发生明显上调,6个蛋白点表达发生明显下调,4个蛋白点没有表达,并且乳房炎乳清新出现了10个蛋白点.     

Influence of solid friction on polymer relaxation in gel electrophoresis

Solid friction between a charged polymer and fixed gel points can dramatically affect polymer mobility in gel electrophoresis. The effect is present when a polymer chain is entangled over many gel points along a portion of its length, leading to significantly different behavior than predicted by conventional theory: the mobility of the chain decreases and exhibits a stronger length dependence, which separates long linear charged polymers of different molecular weights.