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1.
人丙型肝炎病毒 (HCV)感染可引起丙型肝炎、肝硬化和肝细胞癌[1] 。丙型肝炎病毒是单股正链RNA病毒 ,基因组约长 9.5kb ,仅有一个开放阅读框 ,编码一个大的聚蛋白前体 ,由宿主蛋白酶和病毒编码的蛋白酶加工成多个成熟蛋白。非结构蛋白NS5A分子量为 56kD/ 58kD。目前对NS5A蛋白的功能尚不清楚 ,NS5A蛋白可降低干扰素治疗效果[2 ] ;NS5A蛋白含核定位序列 ,因此人们推测它在HCVRNA复制过程中可能起一定的作用[3~ 4 ] 。本研究在大肠杆菌中表达全长NS5A蛋白 ,提纯后NS5A蛋白能与大多数丙肝阳性血清起强烈…  相似文献   

2.
丙型肝炎病毒基因组的翻译及其产物的加工   总被引:22,自引:0,他引:22  
成军  斯崇文 《微生物与感染》1995,18(4):14-16,22
丙型肝炎病毒(HCV)是一种单正链RNA病毒,其5’非编码区(5’NCR)是决定病毒蛋白表达的关键区。基因突变与报道基因表达技术研究表明5’NCR有一内部核糖体进入位点(IRES)。类似于微小RNA病毒属。HCVRNA翻译成为一条多蛋白分子,对蛋白酶的裂解加工后形成10余种结构和非结构蛋白。研究HCVRNA的翻译及产物加工,对HCV及其抗原表达载体有重要意义。  相似文献   

3.
牛奶子的组织培养及植株再生   总被引:1,自引:0,他引:1  
1 植物名称 牛奶子 (Elaeagnusumbellata) ,又称甜枣、羊奶子。2 材料类别 幼苗的下胚轴。3 培养条件  ( 1 )MS 6 BA 1mg·L- 1 (单位下同 ) 2 ,4 D 3 IAA 0 .5 CH 30 0 ;( 2 )MS 6 BA2 2 ,4 D 2 NAA 0 .5 CH 30 0 ;( 3)MS 6 BA3 2 .4 D 1 IBA 0 .5 CH 30 0 ;( 4 )MS 6 BA1 .5 IAA 0 .5;( 5)MS 6 BA 1 .5 NAA 0 .5;( 6)MS 6 BA 1 .5 IBA 0 .5;( 7)MS 6 BA 0 .2 IAA 0 .5 GA 0 .5;( 8)MS 6 BA 0 .2 IAA 0 .1 GA…  相似文献   

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不同株的熊蜂短膜虫与宿主生存的关系   总被引:1,自引:0,他引:1  
武文杰 《动物学报》1998,44(2):235-236
THERELATIONSHIPBETWEENDIFFERENTSTRAINSOFCRITHIDIABOMBIANDTHESURVIVALOFTHEIRHOSTBUMBLEBEES不同株的熊蜂短膜虫与宿主生存的关系KeywordsCrithidiabo...  相似文献   

5.
水母雪莲的幼根培养及植株再生   总被引:6,自引:0,他引:6  
1 植物名称 水母雪莲 (Saussureamedusa) ,藏药中称为恰羔素巴。2 材料类别 无菌苗的根。3 培养条件 诱导愈伤组织培养基以MS、C1 7或W 1 4为基本培养基 ,附加 2 ,4 D 1~ 2mg·L- 1 (单位下同 ) 肌醇 2 0 0 蔗糖 3% 琼脂 0 .5%。继代培养基为MS 2 ,4 D 1 肌醇 2 0 0 CH 30 0 蔗糖 3%~ 5% 琼脂 0 .5%。分化培养基配方为 1 /2MS KT 1 CH 30 0 肌醇 2 0 0 蔗糖 3% 琼脂0 .5% ,再附加 ( 1 )NAA 0 .5 6 BA 1或 ( 2 )NAA1 6 BA 2。所用培养基的 pH均调为 5.8。培养温度为…  相似文献   

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水稻草状矮化病于70年代曾在南亚、东南亚大面积发生,给当地的水稻生产造成严重损失,在我国也有分布[1]。其病原是水稻草矮病毒(Ricegrassystuntvirus,RGSV),为纤细病毒属(Tenuivirus)的一个成员,病毒粒体丝状,由核衣壳蛋白和基因组RNA组成[2]。基因组含六个ssRNA片段,均为双义编码[3,4],其中RNA5的毒义互补链编码核衣壳蛋白(nucleocapsidprotein,NCP)[3]。本文报道应用RTPCR技术获得RGSV沙县分离株(RGSVSX)NCP基因的cDNA克隆,并得到其在大肠杆…  相似文献   

7.
董辉 《微生物与感染》2000,23(4):7-9,38
丙型肝炎病毒(HCV)非结构3区(NS3)编码的丝氨酸蛋白酶是HCV复制过程中的重要蛋白酶,负责对NS3、NS4及NS5进行加工。NS4a是HCV丝氨酸蛋白酶作用的辅因子,并具有多种活性。HCV丝氨酸蛋白酶有相对特异的底物,其活性不能被一般的丝氨酸蛋白抑制剂所抑制。丝氨酸蛋白酶是HCV药物设计的靶目标之一。对其结构与功能的研究有着重要意义。  相似文献   

8.
金由辛 《生命的化学》2000,20(4):145-146
Sasaki等在ProcNatlAcadSciUSA 2 0 0 0年第 4期上报道了一种不依赖甲硫氨酸的翻译起始方式[1] 。PSIV (Plautiastaliintestinevirus)是一种昆虫RNA病毒 ,属蟋蟀麻痹样病毒组 (Cricketparalysis likeviruses) ,为正链RNA病毒。属于该组的还有DCV、RhPV、HiPV等。该组病毒的理化性质与哺乳动物的小RNA病毒 (picornavirus)相似 ,但基因图 1  (A)PSIV基因组结构 ;(B)预测的外壳蛋白编码区上游的茎环结构组织不同。…  相似文献   

9.
AuthorsNo . PageANLi Jia 1 10AOShi Zhou 2 192AOShi Zhou 4 43 8BAIChen 5 618BAIChen 6 685B¨OINGSebastian 3 2 73CAIChun 2 14 3CAIJin 4 45 6CAIShao Xi 6 75 2CAIWei Min 1 98CAIWei Min 2 2 3 0CAIYou Min 3 3 17CAOFang 3 3 0 4CAOJie 3 3 46CAOKai Ming 1 87CAOYa 1 16CHAIMin Qiang 3 3 10CHEWen Liang 2 2 0 3CHEYan Ke 4 5 0 5…  相似文献   

10.
张伟  明镇寰 《生命的化学》2000,20(5):208-211
转录因子Yin Yang 1 (YY1 ,又称NF E1、δ、UCRBP、CF1 )是锌指类转录因子GL1 Kr櫣ppl家族中的一员 ,广泛地存在于人、鼠、非洲爪蟾中[1、2 ] 。YY1蛋白含有 41 4个氨基酸残基 ,分子量为 6 5kD。在靠近N 末端处有一个酸性区域 ,紧接着是连续 1 2个组氨酸的序列和一段富含Gly和Ala的区域 ,在C 末端含有与REX 1蛋白相似序列的C2 H2 锌指结构。YY1因子最初是作为腺伴随病毒(AAV)的P5 启动子和免疫球蛋白 (Ig)k3′增强子的阻抑因子分离到的 ,后来又相继证实c fos、c myc、sur…  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

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For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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