褐飞虱谷胱苷肽转移酶基因cDNA片段的克隆、测序及表达分析

谷胱苷肽转移酶是昆虫体内重要的解毒酶系之一，研究水稻害虫褐飞虱的谷胱苷肽转移酶基因在褐飞虱与水稻互作中的表达变化，可为有效防治褐飞虱提供新的理论依据。利用反转录多聚酶链式反应（RTPCR）技术克隆了褐飞虱谷胱苷肽转移酶基因编码区的eDNA片段，并使用Northern杂交技术检测了该基因对两种不同抗性水稻的分子反应。结果表明，所克隆到的eDNA片段长度为201bp，该片段所编码的氨基酸序列与来自大劣按蚊、细小按蚊、冈比亚按蚊、果蝇和木瓜果实蝇的谷胱苷肽转移酶的片段存在高度同源性。Northern杂交显示，在褐飞虱取食抗性水稻后，谷胱苷肽转移酶基因表达水平明显升高，但褐飞虱取食感虫水稻TN1后，该基因的表达水平没有明显变化。     

褐飞虱NADH泛醌氧化还原酶51kDa亚基cDNA片段的克隆及表达分析

NADH泛醌氧化还原酶是动物体内呼吸链电子传递系统的第一个酶，克隆水稻害虫褐飞虱的NADH泛醌氧化还原酶基因，及研究其在褐飞虱与水稻互作中的表达变化，将为科学防治褐飞虱提供新的线索。利用反转录多聚酶链式反应（RT-PCR）技术克隆了褐飞虱NADH泛醌氧化还原酶51kDa亚基基因的cDNA片段，并进行了序列测定；使用NoRhem杂交技术检测了该基因对两种不同抗性水稻的分子反应。分子杂交结果表明，在取食抗性水稻品种B5后，褐飞虱的NADH泛醌氧化还原酶51kDa亚基基因表达水平明显升高，而取食感虫水稻TN1后，该基因的表达水平没有明显变化。     

褐飞虱细胞色素P450基因cDNA片段的克隆、测序及表达分析

利用反转录多聚酶链式反应(RT-PCR)技术克隆了褐飞虱细胞色素P450基因编码区的cDNA片段,并进行了序列测定.结果表明,所克隆到的cDNA片段长度为237bp,经BLAST查找比对发现,该片段所编码的氨基酸序列与来自烟草天蛾、棉铃虫、埃及伊蚊、家蝇、黑腹果蝇和线虫的CYP6家族的P450的氨基酸序列存在同源性.Northern杂交分析显示,在褐飞虱取食抗性水稻后,P450基因的表达水平明显升高.以上结果表明,P450基因的表达受抗性水稻的诱导,该基因在褐飞虱对抗性水稻的耐受性和解毒方面可能起着重要作用.     

褐飞虱羧酸酯酶基因cDNA片段的克隆及表达分析

利用反转录多聚酶链式反应(RT-PCR)技术克隆了褐飞虱羧酸酯酶基因编码区的cDNA片段,并进行了序列测定.结果表明,所克隆到的cDNA片段长度为396 bp,经BLAST查找比对发现,该片段所编码的氨基酸序列与来自铜绿蝇、家蝇、沟鼠、黑腹果蝇、线虫和埃及伊蚊的羧酸酯酶的片段存在高度同源性.Northern杂交分析显示,在褐飞虱取食抗性水稻后,羧酸酯酶基因表达水平明显升高.以上结果表明,羧酸酯酶基因的表达受抗性水稻的诱导,该基因在有毒化学物质解毒及增强褐飞虱对抗性水稻的耐受性方面可能起着重要作用.     

凡纳滨对虾T7噬菌体cDNA展示文库的构建

以来源于多种组织的mRNA为模板,构建了一个凡纳滨对虾混合组织的T7噬菌体c DNA展示文库。结果表明:噬菌体文库容量大,达9.3×10~7pfu;文库重组率高,为97%;大于250 bp的片段占70%以上;利用液体扩增法对文库进行扩增,扩增后文库的滴度为2.1×10~(12)pfu/m L。     

褐飞虱在不同水稻品系上繁殖能力及相关解毒酶系基因表达变化分析

采用水稻敏感品系TN1和抗性品系中浙优、IR56饲养褐飞虱,研究褐飞虱产卵量等繁殖情况,测定解毒酶系中酯酶、细胞色素P450和谷胱甘肽转移酶(GST)及卵黄原蛋白(Vg)等基因在mRNA上的表达变化.结果显示褐飞虱在抗性水稻上产卵量减少,Vg2的表达量极显著下降,表明水稻抗性对褐飞虱的产卵量有抑制作用且Vg2调控产卵.酯酶和P450中的部分基因均在取食抗性水稻的褐飞虱体内表达量较高,存在极显著差异.     

水稻抗性品种对褐飞虱和白背飞虱 羧酸酯酶活力影响的比较研究

比较了ASD7、IR36、JX89、Mudgo四个抗褐飞虱水稻品种及感性品种TN1对褐飞虱和白背飞虱羧酸酯酶活力的影响.两种稻飞虱在各供试的抗性水稻品种上的羧酸酯酶活力均低于在感性品种TN1上的羧酸酯酶活力.在抗性水稻品种上,白背飞虱的羧酸酯酶活力只在Mudgo上低于褐飞虱,而在其余3个抗性品种上均较褐飞虱高.结果表明,抗褐飞虱水稻品种对褐飞虱和白背飞虱的羧酸酸酶活力均有不同程度的抑制作用,但对褐飞虱的抑制作用显然要大于对白背飞虱的抑制作用.供试水稻品种的这种低抑制作用,可能会导致白背飞虱持续取食抗褐飞虱的水稻品种,从而致使其在这类品种种区植内种群数量上升.     

水稻胰蛋白酶抑制剂对褐飞虱产卵刺激的响应

 昆虫产卵过程对寄主植物的直接刺激包括产卵器的机械损伤和卵表面物质带来影响,这些刺激是启动植物诱导抗虫性的重要途径。通过对褐飞虱产卵处理后水稻植株内胰蛋白酶抑制剂（BBPI）合成酶基因的表达量及物质含量的测定,对比褐飞虱取食和机械损伤处理,发现褐飞虱产卵能够诱导水稻BBPI合成酶基因的表达和BBPI物质的生成。处理后6 h,12 h,水稻 BBPI 表达量显著高于取食和机械损伤处理;产卵诱导的BBPI物质含量显著高于正常水稻。褐飞虱产卵诱导水稻启动〖WTBX〗BBPI〖WTBZ〗表达和物质合成表明,与取食危害类似,水稻同样会对褐飞虱产卵刺激产生响应,启动相应的植物防御体系,进而达到阻滞褐飞虱危害的目的。     

旋毛虫新生幼虫cDNA文库的构建与鉴定

利用λZAPExpress载体成功地构建了中国猪株旋毛虫分离株Trichinellaspiralis新生幼虫的cDNA文库 ,并对其重组噬菌体质粒pBK—CMV进行酶切鉴定 .结果表明 :所构建的cDNA文库容量为 1 92× 10 6,重组效率为 98 6 % ,所有的克隆片段都在 0 5— 2 0Kb之间 ,说明此cDNA文库几乎覆盖了全部mRNA .     

褐飞虱乙酰胆碱酯酶启动子的克隆及表观遗传分析

褐飞虱Nilaparvata lugens是水稻的重要害虫之一.本研究旨在扩增褐飞虱乙酰胆碱酯酶(acetylcholinesterase,AChE)基因的启动子,并从表观遗传学的角度探讨DNA甲基化与褐飞虱生物型进化间的关系.采用染色体步移(genome walking)方法扩增AChE启动子,根据所得启动子序列设计甲基化特异性PCR(MS-PCR)引物和重亚硫酸盐测序法BSP引物,分析褐飞虱生物型Ⅰ和生物型Ⅱ中AChE启动子的甲基化程度,然后利用荧光定量PCR技术检测AChE的表达水平差异.结果表明,扩增得到褐飞虱AChE上游侧翼DNA序列长度为1 919 bp,启动子元件分析显示,AChE启动子区域中有若干与MYB、WRKY、ARE等抗性相关转录因子的结合位点(元件),表明该启动子可能与逆境胁迫相关.基于甲基化水平的限制酶酶切位点分析发现,AChE启动子区域含有多个~(5m)CG甲基化位点,表明该区域DNA甲基化主要发生在胞嘧啶的C-5位.MS-PCR分析表明,生物型Ⅰ褐飞虱AChE启动子区域的甲基化程度高于生物型Ⅱ; BSP结果显示生物型Ⅰ启动子区域总体平均甲基化频率(24. 09%)高于生物型Ⅱ(7. 27%);实时定量PCR结果显示,AChE在生物型Ⅱ中的表达量高于生物型Ⅰ.本研究克隆得到AChE启动子序列,并证实褐飞虱生物型间AChE的表达存在差异,且启动子区域高甲基化水平可能是导致AChE低表达的原因之一.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that