CP gene cloning and sequence analysis of Liu'an isolates of Leek yellow stripe virus, Onion yellow dwarf virus and Shallot yellow stripe virus

设计特异性引物PCR扩增了六安大蒜病样中的韭葱黄条病毒(Leek yellow stripe virus,LYSV)、洋葱黄矮病毒(Onion yellow dwarf virus,OYDV)和胡葱黄条病毒(Shallot yellow stripe virus,SYSV)的全长CP基因,插入到pGEM-T载体并测序.分别比较3种病毒CP基因种内变异性和种间亲缘关系.结果表明LYSV六安分离物CP基因由864个碱基组成,与Genbank上已报道的68个LYSV不同分离物CP基因的核苷酸序列同源性为76.12%～84.31%;OYDV的CP基因由771个碱基组成,与Genbank上已报道的86个OYDV不同分离物同源性为81.06%～90.40%;SYSV的CP基因由774个碱基组成,与Genbank上已报道的11个SYSV不同分离物CP基因同源性为88.63%～94.32%;从分析结果来看,LYSV的CP基因不同分离物之间变异性较大,OYDV CP变异性不大,SYSV变异性很小;3种病毒都有1个以上的宿主,病毒种内不同宿主分离物之间CP序列差异很小.进化分析显示OYDV和SYSV的CP基因亲缘性较近并成簇,LYSV的CP基因与OYDV和LYSV的CP基因亲缘性较远.     

韭葱黄条病毒、洋葱黄矮病毒和胡葱黄条病毒六安分离物CP基因克隆及同源性分析

设计特异性引物PCR扩增了六安大蒜病样中的韭葱黄条病毒(Leek yellow stripe virus,LYSV)、洋葱黄矮病毒(Onion yellow dwarf virus,OYDV)和胡葱黄条病毒(Shallot yellow stripe virus,SYSV)的全长CP基因,插入到pGEM-T载体并测序。分别比较3种病毒CP基因种内变异性和种间亲缘关系。结果表明LYSV六安分离物CP基因由864个碱基组成,与Genbank上已报道的68个LYSV不同分离物CP基因的核苷酸序列同源性为76.12%～84.31%;OYDV的CP基因由771个碱基组成,与Genbank上已报道的86个OYDV不同分离物同源性为81.06%～90.40%;SYSV的CP基因由774个碱基组成,与Genbank上已报道的11个SYSV不同分离物CP基因同源性为88.63%～94.32%;从分析结果来看,LYSV的CP基因不同分离物之间变异性较大,OYDV CP变异性不大,SYSV变异性很小;3种病毒都有1个以上的宿主,病毒种内不同宿主分离物之间CP序列差异很小。进化分析显示OYDV和SYSV的CP基因亲缘性较近并成簇,LYSV的CP基因与OYDV和LYSV的CP基因亲缘性较远。     

大豆花叶病毒CP基因原核表达与抗血清制备

根据已报道的大豆花叶病毒(SMV)序列设计引物,扩增SMV的外壳蛋白(CP)基因,序列同源性分析结果表明,与目前已报道的SMV不同分离物CP基因核苷酸序列同源性为85.0%～96.8%,相应推测的氨基酸序列同源性为87.9%～98.9%.将CP基因插入原核表达载体pSBET后在大肠杆菌BL21(DE3)Plys S中诱导表达.通过12%SDS-PAGE和5%～20%梯度SDS-PAGE两次制备电泳纯化诱导产物,免疫家兔获得抗CP血清,Western blot分析对CP具有高度特异性.硫酸铵沉淀法与Protein A-Red Sepharose 亲和层析相结合提取IgG,获得效价达1∶ 3 800的一抗,可用于田间SMV病样检测.     

大蒜A病毒CP基因的原核表达及抗血清制备

根据GenBank报道的大蒜A病毒(GarV-A)序列设计引物、扩增其外壳蛋白基因并进行序列分析.结果表明,GarV-A的CP基因与目前已报道的两种GarV-A不同分离物CP基因的核苷酸序列同源性为98％-99％;氨基酸序列同源性均为98％.将GarV-A CP基因插入表达载体pSBET,在大肠杆菌BL21(DE3)Plys E菌株中诱导表达.CP经12％SDS-PAGE和5％-20％SDS-PAGE两次纯化,免疫小鼠获得抗CP血清,Western blotting分析表明确定制备的抗体对CP具有高度特异性,ELISA检测表明制备的抗体能够与天然病毒离子结合,因此可以作为该病毒的检测.     

薯蓣褪绿坏死花叶病毒CP基因的原核表达及抗血清的制备

薯蓣褪绿坏死花叶病毒(yam chlorotic necrotic mosaic virus,YCNMV)是马铃薯Y病毒科柘橙病毒属暂定成员。采用RT-PCR方法,以Sprimer/M4简并引物对扩增获得的YCNMV分离物3'端基因组序列为参考序列,根据该序列设计CP基因特异引物获得YCNMV CP基因并插入p ET-30a表达载体中,在BL21(DE3)菌株中诱导表达。获得的融合蛋白经Ni+-NTA柱纯化后免疫新西兰大白兔,制备抗血清。结果表明,连接在表达载体中的CP基因序列及表达的蛋白氨基酸序列与预期的CP基因核苷酸和氨基酸序列同源性均为99.65%。聚丙烯酰胺凝胶电泳结果表明,获得的融合蛋白大小约为44 k D,与预期蛋白大小相符。制备的抗血清经Western blotting和ID-ELISA检测表明,获得的多克隆抗体效价较高,能可靠、灵敏、特异地与YCNMV病毒颗粒结合,可应用到该病毒的检测中。     

大麦黄矮病毒GAV基因组全序列测定及其结构分析

测定了在中国分离得到由麦二叉蚜和麦长管蚜传播的大麦黄矮病毒GAV的基因组核苷酸全序列, 该病毒分离物的RNA由5685个核苷酸组成, 内含6个开放阅读框架(ORF)和4个非编码区(UTR), 基因组大小和结构与黄症病毒属(Luteovirus)的大麦黄矮病毒PAV(BYDV-PAV)和MAV(BYDV-MAV)相似. 序列分析表明, 它与BYDV-MAV的PS1分离物基因组序列的同源性最高. 在6个开放阅读框架中, 除ORF6核苷酸序列同源性为72.0%外, 其他ORF的核苷酸序列同源性均大于90%. 两者全基因组的同源性为90.4%. 推导的编码产物氨基酸序列同源性除P6和通读蛋白(RTP)分别为67.4%和87.4%外, 其他均大于90%, 其中外壳蛋白(CP)为95.5%. 根据与BYDV-MAV的相似性, BYDV-GAV应是一种与BYDV-MAV类似的病毒.     

3种大蒜中洋葱黄矮病毒的RT-PCR分子鉴定

洋葱黄矮病毒(Onion yellow dwarf virus,OYDV)是危害大蒜产量和品质的主要病毒之一.快速有效的病毒检测方法可为大蒜病毒病的研究和有效防御提供理论与技术资料.本研究利用反转录-聚合酶链式反应(RT-PCR)技术对甘肃"成县迟蒜"和山东"鲁蒜王2号"中OYDV外壳蛋白基因进行特异性扩增,并克隆到载体PMD18-TEasy Vector上进行核苷酸序列测定及分析.成功分离得到OYDV的两个DNA片段--GSCCS和SDLSW2,与GenBank中已报道的AB000837.1、AB000838.1和AJ409311.1等22个OYDV DNA片段的核苷酸相似性分别为81%～98%和81%～84%,氨基酸相似性分别为85%～99%和89%～94%,二者之间核苷酸相似性为84%,氨基酸相似性为89%.系统进化树显示不同DNA片段可聚为3个组群,GSCCS与中国山东金乡OYDV DNA片段同属一组,SDLSW2与其它16个OYDV DNA片段同属一组,表明OYDV在甘肃"成县迟蒜"和山东"鲁蒜王2号"中均存在,但具有一定差异.本实验确定了OYDV的基因变异程度,为进一步研究病毒进化和变异提供了有利条件.     

小西葫芦黄花叶病毒外壳蛋白抗体制备

根据已报道的小西葫芦黄花叶病毒（ZYMV）序列设计特异引物,扩增ZYMV的全长外壳蛋白（CP）基因,插入原核表达载体pSBET后在大肠杆菌B121（DE3）plysS中诱导表达。通过12％SDS—PAGE和5％～20％梯度SDS—PAGE二次制备电泳纯化诱导产物,免疫小鼠,获得经过Western blot分析为特异的抗CP血清。硫酸铵沉淀法与ProteinA—Red Sepharose亲和层析相结合提取IgG,获得效价达1：4800的一抗,对西瓜和甜瓜田间样品的间接ELISA检测表明,ZYMV在田间普遍发生,研究制备的IgG可用于ZYMV检测。     

芜菁花叶病毒的3’末端序列克隆与CP基因序列分析

目的:克隆芜菁花叶病毒(Turnip mosaic virus,TuMV)的3'末端序列,并进行CP基因序列分析.方法:以TuMV杭州榨菜分离物(TuMv-HZZC)接种病叶为材料,利用病毒粒子吸附法制备病毒RNA模板,经RT-PCR扩增获得了TuMV-HZZC 3'末端序列,将其克隆到PMD 18-T质粒上进行序列分析.结果:TuMV-HZZC分离物3'末端序列包括部分的Nib基因、完整的TuMVCP基因和3'-UTR,CP基因为864bp,分别编码288个氨基酸,3'-UTR序列(不包括PolyA尾巴)为213bp.经过与其他TuMV分离物的CP基因核苷酸和氨基酸比较,同源性分别达到88.0%～97.6%和91.0%-96.5%.结论:TuMV的系统进化具有典型的地域和寄主关联性.     

侵染辣椒的黄瓜花叶病毒CP基因的序列分析、原核表达及抗血清制备

从吉林长春感病辣椒上获得一黄瓜花叶病毒(Cucumber mosaic virus,CMV)分离物(CMV-CC),根据GenBank中已登录的CMV外壳蛋白(coat protein,CP)基因核苷酸序列设计简并引物,通过RT-PCR的方法克隆到了长度为657 bp的目的片段。序列分析表明,CMV-CC与CMVI组各分离物核苷酸同源性为93.2%-97.9%。根据完整CP基因核苷酸序列构建的系统进化树显示:38个CMV分离物可分为3个组,CMV-CC属于CMV的IB亚组。将CMV-CC CP基因与原核表达载体pET-22b(+)连接,在大肠杆菌BL21(DE3)诱导表达出分子量约27 kD的融合蛋白。表达的融合蛋白经树脂纯化后免疫家兔制备了抗血清。用间接ELISA测定抗血清效价为1/4 096。Western blotting分析表明制备的抗血清对CP有高度特异性,为准确、快速地检测CMV奠定了基础。     

X病毒属6个成员中国分离物CP基因的克隆及同源性分析

根据Genbank报道的大蒜A病毒(GarVA)、大蒜B病毒(GarVB)、大蒜C病毒(GarVC)、大蒜D病毒(GarVD)、大蒜E病毒(GarVE)和大蒜X病毒(GarVX)的序列设计引物,克隆外壳蛋白(CP)基因、测序并进行同源性分析。结果表明,6种病毒CP基因分别由756、735、780、753、759和732核苷酸组成。氨基酸序列多重对齐比对结果表明,GarVC与GarVD同源性最低(57.69%),GarVB与GarVX同源性最高(87.70%);同属6种病毒CP基因在C端变异性大,N端保守。进化树显示Gar-VA、GarVE和GarVD成簇,GarVB和GarVX成簇,GarVC与其他5种病毒亲缘关系较远。本研究结果为预测6种病毒之间是否存在血清学交叉反应,在进行ELISA检测是否会相互干扰提供指导意义。     

侵染浙贝母3种病毒CP基因的原核表达、抗血清制备及其病毒检测

根据GenBank报道的浙贝母花叶病毒(Thunberg fritillary mosaic virus,TFMV)、浙贝母Y病毒(Fritillary virus Y,FVY)和百合斑驳病毒(Lily mottle virus,LMoV)序列设计引物,扩增其CP基因。将CP基因插入表达载体pSBET,转化大肠杆菌BL21(DE3)Plys E菌株,IPTG诱导表达。经12% SDS-PAGE和5%~20%梯度SDS-PAGE两次纯化CP,分别免疫小鼠获得抗CP血清。采用Western blot分析确定抗体的特异性及其之间的血亲学关系;采用ELISA分析确定抗体是否能与天然病毒粒子结合。采用Western blot、间接ELISA法和Dot-ELISA 法检测侵染浙贝母的3种病毒。结果表明,制备的抗体对CP有高度特异性,相互之间无交叉反应,且能与天然病毒离子结合。制备的抗血清可以用于检测3种病毒,其中间接ELISA法和Dot-ELISA法检测效果较好。     

An antibody and anti-idiotypic antibody against the extra signal peptide of pre-aspartate aminotransferase

A peptide (extra signal peptide) comprising amino acids 1-29 of pig liver pre-mitochondrial aspartate aminotransferase (p-mAAT) was synthesized chemically. The peptide was found to block the import of rat liver p-mAAT into rat liver mitochondria. An antibody raised against the peptide immunoprecipitated rat liver p-mAAT synthesized in a rabbit reticulocyte cell-free translation system. These results suggested that the extra signal peptide sequence of p-mAAT is essential for import of p-mAAT into the mitochondria and that there is structural homology between the extra signal peptides of pig and rat liver p-mAAT. An anti-idiotypic antibody against the peptide was also prepared and purified by affinity chromatography on an Affi-Gel 10 anti-peptide IgG column and was then characterized.     

Expression of Coat Protein of an Ordinary Strain of Potato virus Y in Escherichia coli and Production of Polyclonal Antibodies for Diagnosis

The coat protein gene (CP) of an ordinary strain of Potato virus Y (PVY^O) was cloned into the expression vector, pET‐28a(+). The insert was sequenced and analysis showed that the CP gene was in frame with intact N‐terminal 6X histidine tags. An approximately 35 kDa recombinant fusion protein was observed in inclusion bodies of induced Escherichia coli BL21 cells. This fusion protein was purified and used as antigen to raise polyclonal antibodies in rabbits. In Western blot and dot blot immuno‐binding assay (DIBA), both PVY^O‐CP IgG and PVY^O IgG strongly reacted with the recombinant CP. The PVY^O‐CP IgG could detect PVY^O in infected samples up to 1 : 3200 dilutions. A PVY^O‐CP ELISA kit was prepared and compared with conventional ELISA kit based on purified virus particles (PVY^O ELISA kit). The PVY^O‐CP ELISA kit consistently detected the PVY^O in DAS‐ELISA of field samples and was as effective as PVY^O ELISA kit.     

Immunochemical studies with a specific antiserum to rabbit fibroblast collagenase.

1. Antisera were raised against the collagenase from rabbit synovial fibroblasts and characterized by immunoprecipitation and immunoinhibition reactions. 2. Immunoglobulins from the antisera were potent inhibitors of the action of rabbit collagenase on both reconstituted collagen fibrils and collagen in solution. 3. The antibody-binding fragment, Fab', produced by digesting the IgG (immunoglobulin G) with pepsin, inhibited collagenase activity just as well as whole IgG. 4. A specific antiserum to the rabbit collagenase was raised by a multi-step procedure. An initial antiserum was made by injecting partially purified collagenase as a complex with sheep alpha2-macroglobulin into a sheep. The non-specific antiserum so obtained was used to produce precipitin lines with the purified enzyme, and these lines were used as antigen for the production of the specific antiserum. 5. An IgG preparation from the specific antiserum was a specific and potent inhibitor of the rabbit synovial fibroblast collagenase. Neutral metallo-proteinase activity secreted by the rabbit fibroblasts was not inhibited by the antibody to the rabbit collagenase. 6. Criteria for determination of the specificity of antisera are discussed.     

黑线毛足鼠和金仓鼠血清IgG的纯化及抗血清的制备

目的 纯化黑线毛足鼠和金仓鼠血清IgG,制备兔抗金仓鼠和黑线毛足鼠血清IgG的抗血清。方法 用Hitrap Protein G亲和层析纯化黑线毛足鼠和金仓鼠血清IgG,经SDS-PAGE电泳鉴定纯度,标准免疫方法免疫兔子制备抗血清。结果 黑线毛足鼠和金仓鼠血清IgG对protein G有很高的亲合性,用Hitrap Protein G亲和层析纯化,得到高纯度黑线毛足鼠和金仓鼠IgG,利用纯化的IgG作抗原制备了高效价的抗血清,免疫双扩散测定效价达1∶32和1∶16。结论 证实黑线毛足鼠和金仓鼠IgG和Protein G具有很高的亲和性,Protein G亲和层析是纯化黑线毛足鼠和金仓鼠IgG有效的方法之一,制备了黑线毛足鼠和金仓鼠IgG的抗血清。     

Role of cell-associated N-acetyl-d-glucosamine specific haemagglutinin in the adhesion of Vibrio cholerae O1 to rabbit intestinal epithelial cells in vitro

Abstract Previously a N -acetyl- d -glucosamine specific cell-associated haemagglutinin (HA) had been purified from a Vibrio cholerae O1 strain. This study documents the role of this purified HA as an adhesin of V. cholerae O1. A significant inhibition in the adhesion of V. cholerae O1 bacterial cells to isolated rabbit intestinal brush borders (RIBB) was observed when the latter were pretreated with purified HA in ELISA. Antibody raised against purified HA and Fab (IgG) fragment of this serum inhibited adhesion of the bacteria to isolated rabbit intestinal epithelial cells (RIEC). V. cholerae O1 (both Ogawa and Inaba serovars) showed less adherence to isolated RIEC of animals immunised with the purified HA. Patients convalescing from V. cholerae O1 infection showed high ELISA titres against the purified HA indicating that it is expressed in the host during the disease process.