狂犬病病毒糖蛋白在大肠埃希菌中的表达及鉴定

目的表达狂犬病病毒糖蛋白（GP）,用于狂犬病疫苗免疫抗体评估和狂犬病病毒糖蛋白功能的研究。方法采用分析软件,分析其可能的抗原表位,利用PCR方法扩增狂犬病病毒SRV9疫苗株G蛋白抗原位点区域基因,PCR产物经EcoRI和SalI双酶切后,插入大肠埃希菌表达载体pGEX-6P-1,构建重组表达质粒pGEX-6P-1/G87a和pGEX-6P-1/G100a。将重组质粒转化大肠埃希菌BL21感受态细胞中,在IPTG诱导下表达目的蛋白,进行SDS-PAGE分析。表达蛋白进行电洗脱纯化和Western blot鉴定分析。结果成功构建了pGEX-6P-1/G87a和pGEX-6P-1/G100a表达质粒,序列分析表明,插入片段大小分别为1314 bp和1275 bp。SDS-PAGE分析结果证明,在大肠埃希菌系统中成功表达了狂犬病病毒部分糖蛋白,表达的融合蛋白含有GST标签,大小分别约为74×103和73×103。Western blot鉴定结果表明,表达产物有抗原特异性并能与狂犬病病毒抗血清反应。结论利用大肠埃希菌表达系统成功表达了狂犬病病毒部分糖蛋白,表达产物有良好的反应原性。     

猪盖他病毒衣壳蛋白的原核表达、纯化和多克隆抗体的制备

原核表达猪盖他病毒(Getah virus)衣壳蛋白(Cap)并制备多克隆抗体。设计一对特异性引物,从含有Cap基因的pT-Cap质粒中扩增全长Cap基因,克隆至携带有His标签的原核表达载体pColdⅠ中,通过PCR、酶切鉴定和序列测定后,重组质粒pCold-Cap转化大肠杆菌Rosetta 2,IPTG诱导后SDS-PAGE和Western blot鉴定融合蛋白;蛋白经镍柱纯化后切胶免疫Balb/c小鼠,制备多克隆抗体。实验表明:经终浓度0.1mmol/L IPTG 15℃诱导24h后,Cap基因在Rosetta 2中获得高效表达,表达量占菌体蛋白的40.2%,SDS-PAGE显示融合蛋白相对分子质量为32.3kD。Western blot显示制备的鼠源抗血清可以与融合蛋白发生反应,有明显的特异性条带。猪盖他病毒衣壳蛋白原核表达成功,制备的多抗可以识别Cap蛋白。     

鸡传染性支气管炎病毒核蛋白基因在大肠杆菌中的表达及抗原性初步研究

为了研究重组鸡传染性支气管炎病毒核蛋白能否作为群特异性诊断抗原加以应用,将鸡传染性支气管炎病毒国内分离株IBV—LX4核蛋白基因亚克隆于大肠杆菌原核表达载体pPROEX^TM HT中。构建拟表达重组鸡传染性支气管炎病毒核蛋白的重组质粒pPROEX^TM HT—N。经核苷酸序列测定后,阳性质粒转化大肠杆菌DH5α,并进行诱导表达。表达产物经SDS-PAGE、Western blot鉴定,表明核蛋白在大肠杆菌中获得了表达,表达产物是分子量分别为约56kD和45kD的蛋白,其中分子量为56kD的蛋白表达量约为菌体总蛋白的13％。包涵体被6mol盐酸胍裂解后。通过镍离子亲和树脂进行了纯化,并用纯化的分子量为56kD的重组蛋白免疫新西兰白兔,所获得的兔抗鸡传染性支气管炎病毒核蛋白多克隆抗体,分别与不同致病型的鸡传染性支气管炎病毒进行琼脂扩散反应,结果表明。该多克隆抗体可与各不同致病型毒株发生反应。这初步表明重组鸡传染性支气管炎病毒核蛋白。可作为群特异性诊断抗原用于该病毒的诊断中。     

狂犬病病毒aG株糖蛋白膜外区的原核表达及纯化

旨在有效检测狂犬病毒抗原及抗体。以狂犬病病毒aG株为模板,反转录扩增糖蛋白膜外区基因,并进行序列测定。将目的片段与表达载体pET-32a(+)分别双酶切、胶回收后相连并转化至Rosseta(DE3)菌株。选取阳性克隆经IPTG诱导表达后,进行SDS-PAGE和Western blotting及质谱鉴定。结果显示,在大肠杆菌中成功表达了糖蛋白膜外区。本研究为建立检测狂犬病毒抗原及抗体的ELISA诊断方法奠定了基础。     

HCV核心蛋白在大肠杆菌中的表达及免疫学特性分析

目的:表达HCV核心蛋白,为检测丙肝病毒提供合适抗原。方法:以含HCV核心全长cDNA克隆的pMD18T/core质粒为模板,PCR扩增全长的HCV核心抗原基因,插入表达载体pQEN1构建重组质粒pQEN1/Core,转化BL-21(DE3)大肠杆菌,IPTG诱导表达6×His融合蛋白,表达产物经SDS-PAGE及Western blot检测和鉴定。结果:经SDS-PAGE及Western blot显示HCV核心蛋白在大肠杆菌中正确表达,融合蛋白分子量约为22 kD,表达量约占菌体蛋白总量的30%。纯化后的C蛋白能与慢性丙型肝炎患者有血清反应。结论:HCV核心蛋白在大肠杆菌中成功表达并具有较强的抗原性。     

金黄色葡萄球菌甲氧西林耐药辅助基因femB的克隆和原核表达

金黄色葡萄球菌femB基因与甲氧西林高水平耐药密切相关,可能成为开发抗MRSA药物的新靶位.以金葡菌基因组DNA为模板,PCR扩增femB全长基因,所得片段与pGM-T载体连接并转化感受态大肠杆菌DH5α,阳性克隆以PCR、双酶切及测序鉴定.将鉴定正确的目的片段定向克隆到pGEX-4T-1表达载体中,转化至大肠杆菌BL21后经IPTG诱导表达GST/FemB融合蛋白;采用SDS-PAGE及Western blot对融合蛋白进行鉴定.结果显示,重组质粒在宿主菌中获得了高效表达,融合蛋白相对分子质量为75 kD,该融合蛋白可与抗GST-tag抗体特异结合;表明femB基因的原核表达系统构建成功,为进一步研究其生物学功能奠定了基础.     

重组大肠杆菌表达水稻白叶枯病菌FtsZ蛋白

旨在通过现代分子生物学技术制备水稻白叶枯病菌FtsZ蛋白。以水稻白叶枯病菌总DNA为模板,采用巢式PCR方法扩增获得水稻白叶枯病菌fts Z基因,构建fts Z基因的表达载体p ET-22b-ftsZ,转化表达宿主E.coli BL21后,经PCR、Nde I/Xho I双酶切及测序鉴定、阳性克隆子经IPTG诱导表达,融合蛋白经镍柱纯化后,通过SDS-PAGE和Western blotting分析鉴定。结果显示,水稻白叶枯病菌ftsZ基因的重组表达载体构建成功,且阳性克隆子在IPTG的诱导下表达了Fts Z-6×His融合蛋白,并通过镍柱纯化获得了电泳纯的Fts Z-6×His融合蛋白。     

狐源犬瘟热病毒CDV-FOX-TA株核蛋白基因的原核表达及鉴定

应用RT-PCR技术扩增出犬瘟热病毒(CDV) 核衣壳(N)蛋白基因抗原性好的高保守基因片段,将其TA克隆至pMD18-T载体中,再利用酶切、连接的方法将测序正确的N基因目的片段亚克隆到原核表达载体pET24b中6×His Tag编码基因的上游,并将该重组质粒转化大肠杆菌Rosetta 2 (DE3)株,经IPTG诱导,N基因融合蛋白获得了高效表达。SDS-PAGE 分析和Western blot 分析的结果显示,表达产物的分子质量为15 kD,与CDV标准阳性血清呈阳性反应,间接ELISA结果也表明重组表达产物具有良好的抗原性,能够有效区分CDV标准阳性与阴性血清,表明大肠杆菌表达的CDV N 蛋白在免疫原性上具有与天然N蛋白同样的特性,可作为检测CDV的间接ELISA包被抗原。     

猪细小病毒vp2基因的表达和类病毒颗粒的构建

利用PCR方法从病毒基因组中获得了vp2完整的编码区并经测序后克隆到原核表达载体pET-32(a)上.在大肠杆菌中诱导表达了VP2与Trx-His-S Tag的融合蛋白,通过免疫家兔获得了高特异性的兔抗血清.另外,将vp2克隆到pFastBacDUAL载体上,利用昆虫表达系统,即AcMNPV的Bac-to-Bac系统对vp2进行了表达,经SDS-PAGE和Western blot分析,表达产物为64kD,并且该蛋白能在昆虫细胞中形成类病毒颗粒.     

猪水泡病病毒VPl基因抗原区的原核表达

利用RT-PCR和nested PCR(nPCR)技术扩增出猪水泡病病毒VPl基因的抗原区,将其克隆到表达载体pProEX-HTb中,获得重组质粒,经PCR、酶切和序列分析鉴定表明,目的基因插入的位置、大小和读码框均正确。将重组质粒导入BL21(DE3),经IPTG诱导表达后SDS-PAGE检测表明,重组菌能表达猪水泡病病毒VPl抗原区蛋白;Western blot检测表明,诱导表达的抗原区蛋白能与猪水泡病阳性血清发生特异性反应。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

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     

Selection with two alleles and complete dominance

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.