改良一步法提取植物RNA、DNA和蛋白质的研究

[目的]利用改良的一步法提取植物RNA、DNA和蛋白质。[方法]采用CTAB试剂对Biozol抽提法进行改良,用一步法分别对玉米（Zea maysL.）、大豆（Glycine maxL.）、苜蓿（Medicago sativaL.）和黄瓜（Cucumis sativusL.）4种作物根的RNA、DNA和蛋白质进行共提取,并对其HO-1和CDPK1基因及HO-1蛋白进行鉴定。[结果]经紫外分光光度计测定和琼脂糖凝胶电泳分析证明获得的RNA和DNA样品纯度较高;HO-1基因和CDPK1基因的RT-PCR结果呈阳性;所提取的蛋白质也可用于Western blot分析;整个提取过程只需3h。[结论]该方法实用性较强,具有广泛的应用价值。     

猪蛔虫感染相关基因07E12的RNAi研究

为寻找猪蛔虫免疫防治的“关键”靶分子,从已构建的猪蛔虫感染期幼虫消减cDNA文库中筛选了一感染相关基因（EST编号为07E12）,采用RNA干扰（RNAi）技术对该基因的功能进行了初步探讨。针对其EST序列设计了1对特异引物,体外转录合成双链RNA (dsRNA)后,通过浸泡的方式将dsRNA导入猪蛔虫感染期幼虫中,在浸泡后的4个不同时间点采用RT-PCR方法检测虫体浸泡后靶基因被干扰的效果。试验结果表明,在浸泡后24、48、72 h都检测到了相对应基因表达的存在,但表达量随时间依次减少,96 h之后试验组没有检测到07E12的相应RNA的表达,提示dsRNA进入虫体并逐渐发挥了干扰作用,说明该基因在猪蛔虫幼虫感染宿主的过程中可能扮演重要角色。     

改良Trizol法快速高效提取香石竹总RNA

因为多糖等大分子的污染,传统Trizol法难以从香石竹的叶片中获得完整RNA。本研究以香石竹为材料,对传统的Trizol法进行改良,成功地从香石竹花瓣和叶片中提取了总RNA,经琼脂糖电泳,紫外分光光度计测定总RNA完整性好,纯度大,花瓣的OD260/OD280=1.96,每0.1g花瓣可获得RNA61μg,叶片RNA的OD260/OD280=1.94,每0.1g幼叶可获得RNA33μg,花瓣的RNA产量普遍高于叶片。经改良Trizol法提取的被香石竹斑驳病毒侵染的植株的花瓣和叶片的总RNA,经RT-PCR获得了特异性条带,说明用改良Trizol法从香石竹花瓣和叶片中提取的RNA质量好、产率高、完整性强,完全适合于香石竹进一步的分子生物学研究。     

上西早生柿ETR5基因RNAi植物表达载体构建及遗传转化研究

据已测序的上西早生柿ETR5基因序列,设计了2对带限制性内切酶位点的特异性引物,以测序质粒为模板,PCR扩增到2个ETR5-Uenishiwase基因片段。2个片段经单酶切消化后连接成反向互补的大片断。连接片断经双酶切消化后,定向连接到植物表达载体pSMAK321的35S启动子和NOS终止子之间,构建成Uenishiwase-ETR5基因的RNA干扰植物表达载体。载体质粒经酶切鉴定正确后通过冻融法转入根癌农杆菌EHA101中。以上西柿组培苗叶片为外植体,优化遗传转化体系,结果表明:农杆菌重悬液和共培养基中均添加200μmol/L的AS及Spc梯度筛选能有效提高转化率。转化植株经PCR检测得到7株阳性植株。     

RNA干扰及其在水稻抗病毒基因工程中的应用

RNA干扰(RNA interference,RNAi)是一种基因沉默机制。RNAi作为新兴的基因阻断技术具有明显的优势,已被广泛应用到动植物功能基因组和植物抗病研究中。在抗病毒研究中,人为地将与病毒或宿主基因同源的双链RNA分子导入转基因植株,引起与其同源的基因发生沉默,达到抗病毒的作用。本文主要综述了RNA干扰的相关知识以及在水稻抗病毒基因工程研究中的应用进展。     

Reduced expression of voltage-gated chloride channel genes in Caenorhabditis elegans: Implications for the mode of action of chloride channel-directed nematicides

Caenorhabditis elegans nematodes (fourth-stage larvae) were exposed for 24 h to long (4 μg/μl) or short (5 μg/μl) double-stranded RNA (dsRNA) of two voltage-gated chloride channel (VGCC) genes, ceclc-1 and ceclc-2, coding for two VGCC proteins, CeClC-1 and CeClC-2. The treatments reduced expression of these genes in F₁ progeny in a time- and concentration-dependent manner. Progeny with reduced expression of ceclc-2 (but not ceclc-1) showed significant phenotypic effects, such as increased pharyngeal contractions and decreased locomotion, which were maximal in 48 h old worms. Generally, there was little effect on the worms when expression of ceclc-1 alone was reduced. F₁ progeny with reduced expression of both ceclc-1 and ceclc-2 had a higher percentage showing affected locomotion than were present with reduced expression of ceclc-2 alone, whereas the increase in frequency of pharyngeal contractions was not different from that obtained with reduced expression of ceclc-2 alone. These phenotypic effects were consistent with the known expression patterns of ceclc-1 and ceclc-2 in C. elegans tissues. A strong negative correlation was observed between in vitro concentration of long dsRNA and ceclc-2 expression level, as well as between ceclc-2 expression level and corresponding phenotypic effects. The effects of dsRNA exposure are similar to previous studies in which 24-h incubation in 50 ppm of anion transporter (AT) blockers DIDS, 9-AC, IAA-94, or NPPB increased pharyngeal contractions and the proportion of nematodes exhibiting impaired locomotion. These findings confirm that the principal mechanism of nematicidal activity of AT blockers may arise from the inhibition of CeClC-2.     

花生油酸脱氢酶基因RNAi表达载体的构建

根据克隆的花生油酸脱氢酶基因序列,选取高度保守的260 bp片段,插入植物双元表达栽体pFGC1008中,构建完成具有反向重复序列的pFGC/2nd表达栽体,利用RNAi以抑制内源目的基因表达,为获得高油酸亚油酸比值的花生种质奠定基础.     

一种木本植物RNA和DNA的简捷提取方法

将尾叶桉(Eucalyptus urophylla)叶片在液氮中研磨成粉,先用含山梨醇、聚乙烯吡咯烷酮(PVP)、牛血清白蛋白、聚乙二醇和亚精胺的提取缓冲液使总核酸沉淀,同时去除了大部分次生代谢物质。然后用山梨醇、月桂酰肌氨酸钠进一步裂解细胞,释放核酸。再用CTAB与核酸结合成复合物溶于高盐溶液。用氯仿/异戊醇除蛋白质后,离心得含总核酸的上清液。运用钙盐分步沉淀法,先在上清液中加入1/10体积的10%氯化钙溶液,使DNA与Ca2+结合成DNA钙盐。向溶液中加入1/5体积的乙醇,使DNA钙盐形成沉淀析出,离心得DNA后,再增大乙醇浓度使RNA钙盐沉淀。得到的DNA和RNA用非变性琼脂糖凝胶进行质量检测,可得完整的RNA和DNA条带。此法经济、快捷,可同时得到DNA和RNA。