富含多酚类植物RNA提取的研究进展

植物体内广泛存在多糖、多酚等次生代谢物,由于其易被氧化,且难以与核酸分离,导致了RNA提取困难。针对植物多酚类化合物的结构及生物学特性进行分析,将现有的RNA提取方法进行分类,并对它们的原理及优劣进行了论述与评价。     

人体大肠癌细胞内RNA病毒对NiH小鼠的感染实验

用人大肠癌细胞内分离提取的一种ＲＮＡ病毒颗粒，对３７４只ＮｉＨ小鼠进行了４代感染和遗传研究。实验结果均未出现明显的感染和遗传症状，表明这种ＲＮＡ病毒颗粒对ＮｉＨ小鼠的感染是无效的。     

HSP27和Annexin A2蛋白对PRRSV感染的影响

猪繁殖与呼吸综合征病毒（PRRSV）侵染Marc145过程中HSP27和Annexin A2蛋白可参与病毒粒子的组装过程,且HSP27可起到抑制侵染早期细胞凋亡,增加病毒复制时间的作用。本研究分别构建HSP27和Annexin A2下调的Marc145细胞系,经PRRSV感染后发现,与空白对照相比,两者子代病毒TCID50值有明显下降。这一结果为研究PRRSV侵染过程及HSP27和Annexin A2调控机制奠定了基础,也为疫苗的研制提供了新的思路。     

A comparison of two colorimetric assays,based upon Lowry and Bradford techniques,to estimate total protein in soil extracts

Soil extracts usually contain large quantities of dissolved humified organic material, typically reflected by high polyphenolic content. Since polyphenols seriously confound quantification of extracted protein, minimising this interference is important to ensure measurements are representative. Although the Bradford colorimetric assay is used routinely in soil science for rapid quantification protein in soil-extracts, it has several limitations. We therefore investigated an alternative colorimetric technique based on the Lowry assay (frequently used to measure protein and humic substances as distinct pools in microbial biofilms). The accuracies of both the Bradford assay and a modified Lowry microplate method were compared in factorial combination. Protein was quantified in soil-extracts (extracted with citrate), including standard additions of model protein (BSA) and polyphenol (Sigma H1675-2). Using the Lowry microplate assay described, no interfering effects of citrate were detected even with concentrations up to 5 times greater than are typically used to extract soil protein. Moreover, the Bradford assay was found to be highly susceptible to two simultaneous and confounding artefacts: 1) the colour development due to added protein was greatly inhibited by polyphenol concentration, and 2) substantial colour development was caused directly by the polyphenol addition. In contrast, the Lowry method enabled distinction between colour development from protein and non-protein origin, providing a more accurate quantitative analysis. These results suggest that the modified-Lowry method is a more suitable measure of extract protein (defined by standard equivalents) because it is less confounded by the high polyphenolic content which is so typical of soil extracts.     

不同保存方法对牛卵母细胞总RNA和cDNA品质的影响

实时荧光定量RT-PCR是检测低丰度mRNA的敏感方法,也是精确定量RNA拷贝数的有效方法,它的出现使得在少量细胞中定量基因的表达量,在小量基因组中分析基因突变和等位基因缺失成为可能。为了使这种检测技术更加稳定可靠,就必须在检测步骤的每一环节做到精确无误,而总mRNA的提取质量就显得十分重要。研究选择了牛MⅡ期的卵母细胞作为研究对象,对不同保存方法进行了检测和比较,结果显示,-196℃液氮和-80℃冰箱保存24 h的卵母细胞,总RNA品质并未明显下降;在-20℃或-80℃环境中长时间保存cDNA模板都会造成模板品质的下降。     

周边建筑对体育馆屋盖和幕墙风荷载的干扰

分析张家界体育中心体育馆的风洞测压数据，分别考虑无周边建筑和有周边建筑2种情况，以屋盖和幕墙的风压为研究对象，研究周边场馆对屋盖和幕墙风荷载的干扰影响；采用干扰因子分析法和多阶模态力法分析屋盖等效风荷载.分析表明：在干扰影响下，屋盖峰值负压的干扰因子达到1.5，峰值正压的干扰因子达到5；干扰影响下的幕墙最不利风压集中位置为干扰体周边的幕墙凹陷处和干扰体周边的幕墙拐角处.     

一种有效提取无核荔枝幼胚总RNA的方法

笔者采用改良CTAB法从富含多酚的无核荔枝幼胚中提取总RNA,并用甲醛变性琼脂糖凝胶电泳和紫外分光光度计对所提RNA质量进行检测,旨在为多糖、多酚含量较高的植物材料RNA的提取提供一种有效方法。     

RNA干涉水稻端粒酶再生植株的初步研究

依据水稻端粒酶基因的相关生物学信息,构建了含有水稻端粒酶序列RNA干扰结构的植物表达载体pC am 23A-1-2,并利用农杆菌介导法将目的基因导入到粳稻品种日本晴中,获得了78个独立转化子,共165棵转基因植株。通过PCR和Southern杂交分析,证明RNA干扰结构已整合进水稻基因组中;应用染色体末端限制性片段分析法,显示在转基因水稻中端粒DNA序列长度有逐代缩短的趋势,初步证明这些转基因水稻中端粒酶亚基已失活,但是T0和T1代转基因水稻植株的主要农艺性状没有发生明显变化。     

提高RNA稳定性的操作技巧与探讨

随着生物技术的进步和发展,人们对RNA的研究越来越广泛和深入。本文讨论了严格RNA的实验条件是保证实验研究成功的关键。     

反义CCoAOMT基因调控烟草木质素的生物合成

[目的]研究木质素的生物合成及调控,降低木质素的含量或改变其组分。[方法]用农杆菌介导法将苎麻反义CCoAOMT基因导入烟草,采用PCR及Southern印迹对获得的转基因植株进行分子检测,并测定移栽3个月转基因植株Klason木质素及纤维素含量。[结果]转基因烟草与野生型对照相比木质素平均含量降低了16.8%,纤维素平均含量升高了15.2%,并且植株生长正常。[结论]抑制植物CCoAOMT表达是反向调控转基因植物木质素生物合成的有效途径。