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1.
河套蜜瓜ACC氧化酶基因cDNA部分片段的克隆和序列分析   总被引:1,自引:1,他引:1  
以河套蜜瓜(Cucumis melo L.ev Hetao)成熟果实为材料,用硫氰酸胍法提取总RNA,以oligo(dT)15为引物,反转录合成cDNA,利用一对甜瓜ACC氧化酶(1-aminocyclopropane-1-earboxylate oxidase,ACO)基因cDNA的特异性引物进行聚合酶链式反应(PCR)扩增。获得了预期大小的cDNA片段.将此片段克隆于pUCl9质粒中,进行DNA序列分析.序列分析结果表明该片段为545bp,编码甜瓜ACO的第126至第306个氨基酸.该河套蜜瓜ACO基因cDNA序列与Andes甜瓜、Cantaloup charentais甜瓜和哈密瓜的相应序列进行比较,其核苷酸序列与Andes甜瓜的同源性为99.4%;与Cantaloup charentais甜瓜和哈密瓜的同源性均为99.6%。与其对应的氨基酸序列的同源性均为99.4%.  相似文献   

2.
草鱼生长激素基因的克隆及原核表达研究   总被引:3,自引:2,他引:3  
应用RT-PCR技术从草鱼脑垂体总RNA中克隆草鱼生长激素cDNA(cGH),全长669bp,含开放阅读框633bp,编码210个氨基酸,分子量为23.6kDa,等电点为6.28;与已报道的草鱼GH有12个碱基、3个氨基酸残基的差异,同源性为98%.将草鱼cDNA定向插入原核表达载体pGEX-4T-1,构建了重组草鱼GH基因质粒pGEX-GcGH,经IPTG诱导,pGEX-GcGH在大肠杆菌中可表达49.6kDa的融合蛋白.  相似文献   

3.
以侵染苜蓿的苜蓿花叶病毒中国分离株(Alfalfa mosaic virus Chinese isolate,A1MV—Ch)RNA2为模板,利用人工合成的特异性引物,进行反转录及PCR扩增,分两段分别扩增了复制酶基因的5′端1.32kb和3′端及其非编码区的1.23kb cDNA序列.用限制性内切酶切割PCR产物后,与pUCl9重组,转化大肠杆菌DH5α,筛选重组质粒,用限制性内切酶分析及PCR鉴定,得到分别含有5′端序列和3′端序列的重组质粒。已由上述两种重组质粒构建了含有完整复制酶基因的重组质粒.进行了全序列测定,并与国外报道的A1MV-425株系的相应序列相比较,其复制酶基因编码区核苷酸序列同源性达97.8%,推测的氨基酸序列的同源性达97.6%,3′端非编码区核苷酸序列同源性为98.2%.并将全长复制酶基因与植物表达载体pROKⅡ重组,得植物转化载体pAlMV—FL.  相似文献   

4.
扩增出牦牛催乳素受体(尸碰尺)基因部分保守序列,为研究牦牛乳腺组织中朋三尺基因表达水平奠定基础.提取牦牛乳腺组织总RNA,根据NCB1的奶牛Jp月£只基因cDNA序列的保守区设计特异性引物,采用RT-PCR技术扩增牦牛尸胜尺基N,结果获得577bp的片段,将该片段连接于pMD18-Simple质粒中,转化大肠杆菌,菌液PCR鉴定阳性克隆子,测序并分析氨基酸序列.分析序列与氨基酸与其他物种同源性,结果表明该序列与水牛、奶牛、绵羊、人、小鼠的尸RLR基因mRNA的对应序列的同源性分别为97.40%、99.13%、93.41%、71.07%、60.20%,编码的氨基酸同源性分别为97.40%、100%、95.83%、82-38%、72-22%.  相似文献   

5.
利用RT-PCR,获得苹果褪绿叶斑病毒库尔勒香梨分离物外壳蛋白基因的cDNA克隆。序列分析结果表明,库尔勒香梨分离物外壳蛋白基因由582个核苷酸组成,编码一个由193个氨基酸组成的蛋白质。与已报道的P863、P205、A-Ball分离物序列比较,核苷酸序列同源性为80.0%~86.1%,推导的氨基酸序列同源性为84.9%~89.6%。  相似文献   

6.
小拟南芥几丁质酶基因cDNA的克隆与序列分析   总被引:1,自引:0,他引:1  
通过合成1对特异引物,应用RT-PCR技术从小拟南芥总RNA中经反转录克隆出几丁质酶基因,该cDNA基因全长985bp,含有1个963bp的开放阅读框(ORF),编码321个氨基酸,推测分子量为35.53kD,序列同源性分析表明,该基因与拟南芥几丁质酶基因有93%的同源性。  相似文献   

7.
诸葛菜EPSPS基因5’端的克隆和序列分析   总被引:1,自引:0,他引:1  
烯醇式丙酮基莽草酸—3—磷酸合成酶(5—enolpyruvylshikimate-3-phosphate synthase,EPSPS)是植物和微生物莽草酸途径中的一个必需合成酶,植物中该基因的超量表达或该基因中某些氨基酸突变可以产生对除草剂草甘膦(g1yphosate)的耐性.采用5’—RACE技术从诸葛菜(0rychophragmus violaceus)叶中克隆出一条长743bp的cDNA片段.序列分析结果表明:该cDNA与其它植物的EPSPS基因具有相当高的核苷酸序列同源性。其所编码的氨基酸序列与欧洲油菜(Brassica napus)同源性最高为90%,与拟南芥(Arabidopsis thaliana)、玉米(Zeamays)、西红柿(Lycopersicon esculentum)、烟草(Nicotiana tabacum)和水稻(Oryza sativa)的同源性分别为88%,81%,64%,62%和71%.  相似文献   

8.
青岛文昌鱼DAD1样蛋白基因的克隆和同源性分析   总被引:1,自引:0,他引:1  
dud1基因为一种内源性细胞凋亡抑制子基因,在发育中可能执行着重要功能.我们通过对青岛文昌鱼18小时神经胚cDNA文库进行测序,获得文昌鱼dud1样基因的2个cDNA片断,经拼接首次得到含有完整读框的文昌鱼dud1样基因的cDNA序列,其演绎的氨基酸序列与人、鼠、鸡、非洲爪蟾、果蝇、线虫、扁豆、番茄的DAD1蛋白的同源性分别为73.5%、73.5%、67.5%、70.9%、67.5%、55.5%、41.9%、41.8%.结果证实青岛文昌鱼dud1样基因在进化上具有高度的保守性,并且在进化上更接近于脊椎动物.  相似文献   

9.
通过对文昌鱼神经胚cDNA文库进行测序,获得编码文昌鱼AmphiCKS1样蛋白基因的cDNA序列,将演绎的氨基酸序列与多种脊椎动物和无脊椎动物的同源物进行比较。其同源性与人或家鼠的为77%,非洲爪蟾的为73.4%,果蝇的为77%,帽贝的为75%,线虫的为47.9%,酵母的为31.1%。结果证实在进化上介于脊椎动物和无脊椎动物之间的文昌鱼,由Amphicks 1基因所编码的AmphiCKS 1样蛋白更接近于脊椎动物;同时说明青岛文昌鱼Amphicks 1基因在进化上具有较高保守性。  相似文献   

10.
11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
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。  相似文献   

15.
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.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
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-  相似文献   

20.
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-  相似文献   

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