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1.
Broad bean wilt virus 2 (BBWV2) isolate P158 was characterized and the complete nucleotide sequence of viral genomic RNA2 was determined. P158 has 30 nm diameter isometric particles. Double immunodiffusion test suggested that P158 has high antigenicity homology with BBWV2 isolate B935. SDS-PAGE result showed that the coat protein of P158 was comprised of two types of polypeptide with molecular weight of 44.7 kD and 21.9 kD, respectively. The genome of P158 was made up of two RNA molecules with the length of 6.0 kb and 3.6 kb, respectively. cDNA of RNA2 was cloned by RT-PCR and sequenced. RNA2 was composed of 3597 nucleotide (nt) residues excluding the poly(A) tail and contained single long open reading frame extending from nt 230 to nt 3424 in the viral sense RNA, and encoded a polyprotein ofMr 119002 (119K). Comparison of the polyprotein and the counterpart of isolate B935 indicated that the polyprotein was cleaved at Q/G (465/466) and Q/A (867/868), to release three mature proteins: a protein of unknown function, large and small subunit. Sequence comparisons of P158 with fabaviruses showed P158 had very high sequence homology with BBWV2 isolates and patchouli mild mosaic virus, but to a less extent with BBWV1 isolates. Project supported by NSFC (No 39770035; 39900005). The GenBank accession number of the sequence reported in this paper is AF228423.  相似文献   

2.
Genome segments S8 of two Chinese isolates of rice black-streaked dwarf virus (RBSDV), one from Zhejiang Province and another from Hebei Province, were amplified by RT-PCR and sequenced. Both segments consisted of 1936 nts in full length (EMBL accession numbers were AJ297431 and AJ297432, respectively) and contained only one big open reading frame which encoded a polypeptide with molecular weight of 68kD. The two Chinese isolates shared 94.0% and 96.5% identity at nucleotide and amino acid level, respectively. They shared 94.5-94.9% and 92.5-92.9% homology with S8 of RBSDV Japanese isolate at nucleotide and amino acid level, respectively; shared 85.1-87.6% and 91.7-91.9% homology with S7 of Italian MRDV (maize rough dwarf virus).  相似文献   

3.
Emergence of a new satellite RNA from cucumber mosaic virus isolate P1   总被引:1,自引:0,他引:1  
INTRODUCTIONCucumbermosaicvirus (CMV) ,thetypespeciesofthegenusCucumovirusoffamilyBro moviridae,isanisometricviruswithatripartitesingle strandedRNAgenomeofpositivepolari ty.CMVhasaparticularlywidehostrange ,in fectingmorethan 80 0speciesinover 70familieso…  相似文献   

4.
The cucumber mosaic virus (CMV) isolate P1 caused very mild symptoms on many plant species After serial passages by mechanical inoculation over five years, CMV P1 caused severe symptoms on several tobacco cultivars and tomato. A specific band of approximately 0.3 kb in length was amplified by RT-PCR with primers synthesized based on reported CMV satellite RNA (satRNA) sequences. Sequence analysis showed there were two satRNAs (Sat-P1-1 and Sat-P1-2). Sat-P1-1 contained 335 nucleotides, and Sat-P1-2 contained 394 nucleotides. These two satRNAs shared 64% overall nucleotide sequence homology, and differences between the two satRNAs included mutations as well as deletions. Sat-P1-1 was identical to a satRNA (Z96099) reported in 1995 in CMV P1. Based on differences in the sequence and secondary structure between these two satRNAs, we conclude that Sat-P1-2 represents the emergence of a new satellite (necrotic satellite) from attenuated satRNA populations. The possible effect of the emergence of this new satRNA is discussed. Project supported by research grants from the Teaching and Research Award Program for Outstanding Teachers in Higher Education Institutes of the Ministry of Education of China and by the National Outstanding Youth Foundations of National Natural Science Foundation of China (No. 30125032). PhD student in Zhejiang University, from Agrarian University of Havana, Cuba.  相似文献   

5.
家蚕核型多角体病毒p35基因的核苷酸序列分析   总被引:1,自引:0,他引:1  
对家蚕核型多角体病毒苏州株(BmNPVsu)p35基因的序列分析表明:BmNPVsu p35编码序列为897mt,编码298aa。同源性分析表明:BmNPVsu p35与BmNPVT3、AcNPV 、SINPV在核苷酸水平上同源性分别为99.5%、95.1%、89.3%,在氨基酸水平上的 性分别为98.7%、89.4%、76.4%,显示了杆状病毒p35基因在进化上的保守性。BmNPVT3中位的N1  相似文献   

6.
用RT?PCR方法从云南省寻甸、嵩明、通海、芒市、沾益和陆良6个地区的水稻样品中扩增到水稻矮缩病毒S10片段部分序列,核苷酸测定及序列分析表明,6个地区水稻矮缩病毒分离物S10片段部分序列长度均为1 071个核苷酸,含1个1 059个核苷酸的ORF,编码352个氨基酸.云南分离物S10片段之间的核苷酸同源性约为97.9%~99.9%,其编码的氨基酸同源性为97.7%~100%;云南分离物与日本分离物的S10片段核苷酸同源性和氨基酸相似性分别为94.1%~95.4%和96.3%~99.2%,与中国分离物的S10片段核苷酸同源性和氨基酸相似性分别为94.8%~96.6%和95.2%~96.6%.云南分离物在亲缘关系上与日本分离物较中国分离物近.  相似文献   

7.
INTRODUCTIONOverthepast 1 0years,thesemiconductorTiO2 asapromisingphotocatalysthasbecomethefocusofnumerousstudiesowingtoitsstabilityinvarioussolventsunderphotoirradiation ,suitableredoxpotentialandmanyenvironmentalapplica tions,suchassolarenergyconversion…  相似文献   

8.
INTRODUCTIONInsectpostembryonicdevelopmentconsistsofgrowthpunctuatedbyaseriesofmoltsfollowedbymetamorphosis.Thesemoltsandmetamor phosisareinitiatedandcoordinatedbyhormones(Riddiford ,1 994 ) .Itisgenerallyacceptedthattheinterplayofecdysteriods,agroupofstero…  相似文献   

9.
For a long time, classification of Demodex mites has been based mainly on their hosts and phenotypic characteristics. A new subspecies of Demodex folliculorum has been proposed, but not confirmed. Here, cox1 partial sequences of nine isolates of three Demodex species from two geographical sources (China and Spain) were studied to conduct molecular identification of D. folliculorum. Sequencing showed that the mitochondrial cox1 fragments of five D. folliculorum isolates from the facial skin of Chinese individuals were 429 bp long and that their sequence identity was 97.4%. The average sequence divergence was 1.24% among the five Chinese isolates, 0.94% between the two geographical isolate groups (China (5) and Spain (1)), and 2.15% between the two facial tissue sources (facial skin (6) and eyelids (1)). The genetic distance and rate of third-position nucleotide transition/transversion were 0.0125, 2.7 (3/1) among the five Chinese isolates, 0.0094, 3.1 (3/1) between the two geographical isolate groups, and 0.0217, 4.4 (3/1) between the two facial tissue sources. Phylogenetic trees showed that D. folliculorum from the two geographical isolate groups did not form sister clades, while those from different facial tissue sources did. According to the molecular characteristics, it appears that subspecies differentiation might not have occurred and that D. folliculorum isolates from the two geographical sources are of the same population. However, population differentiation might be occurring between isolates from facial skin and eyelids.  相似文献   

10.
Rice stripe virus (RSV) is the type member of the genus Tenuivirus. RSV is known to have four segmented, single-stranded RNA molecules and causes rice stripe disease in the rice fields of China, Japan, and Korea. Based on the complete genomic sequences of the determined 6 RSV isolates (from Yunnan, Jiangsu, Zhejiang, and Liaoning Provinces, China) and 27 other RSV isolates (from Yunnan, Jiangsu, Anhui, Henan, and Shandong Provinces of China, also Japan and Korea) downloaded from GenBank, we provided a genotyping profile of RSV field isolates and described the population structure of RSV. All RSV isolates, except isolate CX, could be divided into two subtypes, one including 6 isolates from Yunnan Province, and the other including 26 isolates from different parts of China, Japan, and Korea, which were referred to as subtype II and subtype I, respectively. The amino acid distances between subtypes range from 0.053 to 0.085. RSV isolates in Yunnan Province were genetically differentiated from other parts of China, Japan, and Korea and showed infrequent gene flow. The RSV populations collected from other parts of China, Japan, and Korea were only composed of subtype I and showed very low genetic diversity. We speculated that isolate CX may be the result of recombination of isolates from two subtypes. Two potential recombination events were detected in RNA4 of isolate CX.  相似文献   

11.
Papaya leaf curl China virus (PaLCuCNV) was previously reported as a distinct begomovirus infecting papaya in southern China. Based on molecular diagnostic survey, 13 PaLCuCNV isolates were obtained from tomato plants showing leaf curl symptoms in Henan and Guangxi Provinces of China. Complete nucleotide sequences of 5 representative isolates (AJ558116, AJ558117, AJ704604, FN256260, and FN297834) were determined to be 2738–2751 nucleotides, which share 91.7%–97.9% sequence identities with PaLCuCNV isolate G2 (AJ558123). DNA-β was not found to be associated with PaLCuCNV isolates. To investigate the infectivity of PaLCuCNV, an in-fectious clone of PaLCuCNV-[CN:HeNZM1] was constructed and agro-inoculated into Nicotiana benthamiana, N. tabacum Samsun, N. glutinosa, Solanum lycopersicum and Petunia hybrida plants, which induced severe leaf curling and crinkling symptoms in these plants. Southern blot analysis and polymerase chain reaction (PCR) indicated a systemic infection of test plants by the agro-infectious clone.  相似文献   

12.
INTRODUCTIONC2 chiral 1 ,1’ bi 2 naphthol 1occupiesapositionofprimeimportanceinawiderangeofenantioselectivereactions.Itplaysanimportantroleinasymmetricsyntheseswithveryhighen antiomericpurity.Relevantliteraturereportsseveralmethodsforthepreparationofoptical…  相似文献   

13.
INTRODUCTIONTypeIIsuperconductorsinasufficientlystrongmagneticfieldchangetoamixedstateandavortexlattice (VL)forms .Theinfluenceofquenchedrandompinningsonthevortexlatticeisasubjectoflongstandinginterest.Inapplica tionofhigh Tcsuperconductorsinstrongmag ne…  相似文献   

14.
INTRODUCTION Chronic hepatitis B virus (HBV) infection is aserious clinical problem because of its wide distribu-tion and possible adverse consequences, such as he-patic decompensation, cirrhosis and/or primary livercancer (PLC). The natural course of chronic HBVinfection is characterized by a series of hepatitic flaresor exacerbations and remissions (Ganem and Prince,2004). The severity, extent, duration and frequency ofhepatic histopathological changes in hepatitic flaresare d…  相似文献   

15.
高浓度渗碳及其应用   总被引:1,自引:0,他引:1  
论述了高浓度渗碳的基本原理及方法。采用20CrMo钢代替Q235和10钢制作耐火砖成型模板,并适当降低渗碳温度,可实现高浓度渗碳。生产试验表明,20CrMo钢制模板的使用寿命是Q235钢和10钢制模板的3至4倍。  相似文献   

16.
Abstract : IncinerationasamethodofreducingMunicipalSolidWaste (MSW)volumeandrecoveryofener gyhasbeendevelopedgraduallyinChina .Moreattentionispaidonpolychlorinateddibenzo p dioxinsandpolychlorinateddibenzofurans (PCDD Fs)formedinMSWincinerationprocess .Thisp…  相似文献   

17.
针对一种新型的基于社区多角色的结构化P2P网络模型特点,提出了一种新的查询算法,即迭代扩展查询算法。该算法利用反馈机制,将已经返回的结果统计信息反馈到前端查询Q,指导查询Q向外路由的策略。将该算法与Chord网络查询算法进行了分析比较,使用P2Psim进行模拟验证。仿真结果表明,该网络模型性能稳定,资源查询速度快,通信量小,结果优良。  相似文献   

18.
根据GenBank发表的鸡γ-干扰素核苷酸序列,使用primer 5设计一对特异性引物,通过RT-PCR技术从ConA诱导培养的鸡脾脏淋巴细胞中克隆出鸡γ-干扰素基因并对其进行测序,测序结果表明,鸡γ-干扰素基因全长495bp,具有一个完整的开放阅读框,编码164个氨基酸,与国外发表的序列比较,两序列间同源性为100%.计算机软件对鸡γ-干扰素编码的氨基酸序列进行了抗原性分析,结果表明鸡γ-干扰素具有良好的免疫原性.  相似文献   

19.
叔本华将康德的“自在之物”原创性地置换为他自己的“意志” ,这在西方哲学史上不啻又一次哥白尼革命 ,德国哲学由此而走上了一条非理性主义的道路。不过 ,这一革命的完成并非轻而易举 :叔本华必须证明不可知的“自在之物”在被说成是“意志”之后如何是可知的。本文梳理和评论了叔本华研究者对“意志”之可知性的怀疑、批评和修正 ,并展示了叔本华自己在解决这一问题时的武断和犹豫 ,最后试图说明 ,问题之关键不是学术性的 ,而是在学术性之后所隐藏的思想动机和历史意图。本文所涉及的论争可能对认识中国哲学史上理学与心学之争有一定参考作用。  相似文献   

20.
用紫外线以不同时间处理小麦条锈菌水源致病类型1-4、条中29-3、条中23-2,当夏孢子致死率达90%左右时,确定为最适诱变时间分别为12、8、5min.以紫外线12min处理水源致病类型1时,经6批次筛选未获得突变体.以8 min处理条中29-3,得到在Hybrid46上表现3型的菌系,在尤皮Ⅱ号上表现4型的菌系和在阿夫上表现2型的菌系,分别命名Hybrid46菌系、尤Ⅱ菌系和阿夫菌系,三菌系经4代转接该品种,最后获得2个稳定的突变菌系,包括毒性突变产生的尤Ⅱ菌系和非毒性突变产生的阿夫菌系.以5 min处理条中23-2得到两个突变菌系:在尤皮Ⅱ号上表现3型的菌系和在水源11上表现2型的菌系,分别命名为尤Ⅱ-23菌系和水源11菌系,其中尤Ⅱ-23菌系经4次转接仍保持毒性.  相似文献   

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