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1.
本研究对我国华东地区猪生殖和呼吸综合征病毒分离株S1主要结构蛋白基因进行了PCR扩增和DNA测序分析。结果表明,长度为1520bp DNA序列含有3个阅读框ORFs,即ORF5,ORF6和ORF7,ORF5和ORF6及ORF6和ORF7间有部分碱基重叠,且与欧洲一美洲型PRRSV相似。  相似文献   

2.
猪生殖—呼吸道综合征病毒CH—1al株ORF2~7序列测定   总被引:2,自引:0,他引:2  
新近发现的猪生殖-呼吸道综合征病毒(PRRSV)是单股RNA病毒,属不久前成立的动脉炎病毒科。为了比较从国内分离的PRRSV与欧美PRRSV毒株的分子遗传学关系,本文扩增并克隆了PRRSV CH-1a株ORF2 ̄7,测定了其核苷酸序列。与北美洲型代表株VR-2332遗传距离最近,可能来自同一祖先。  相似文献   

3.
猪生殖-呼吸道综合征病毒CH-1a株ORF2~7序列测定   总被引:2,自引:0,他引:2  
新近发现的猪生殖-呼吸道综合征病毒(PRRSV)是单股RNA病毒,属于不久前成立的动脉炎病毒科。为了比较从国内分离的PRRSV与欧美PRRSV毒株的分子遗传学关系,本文扩增并克隆了PRRSVCH-1a株ORF2~7,测定了其核苷酸序列。用序列分析软件进行核苷酸和氨基酸序列比较分析,结果表明CH-1a株与欧洲型代表株LV的遗传关系较远,与北美洲型代表株VR-2332遗传距离最近,可能来自同一祖先。  相似文献   

4.
将北京地区猪系列与呼吸综合征病毒(PRRSV)分离BJ-2和BJ04的ORF7及部分3端编码区(UTR)的RT_PCR扩增产物克隆连接于pGEM-Teasy质粒载体上,重组质粒经EcoRⅠ酶切鉴定后进行了双链测序。测定垢基因序列与欧已知序列比较发现,BJ-2和BJ-4株与美洲VR-2332株非常接近,在其长度为555bp的cDNA序列中,仅与VR-2332株分别相差1和2个核苷酸,其中ORF7的核  相似文献   

5.
根据猪繁殖与呼吸综合征病毒美洲型标准毒株的ORF6及部分ORF7的序列,设计合成了一对引物26374 PS/26375PR,用反转录-聚合酶链反应技术对6株PRRSV北京分离株进行了检测。结果该引物对6株病毒均能扩增出与预期大小相符的RT-PCR产物,并与ATCC VR-2332株扩增产物的大小相当,而欧洲型标准毒株未获扩增片段。  相似文献   

6.
测定了猪生殖--呼吸道综合征病毒(PRRSV)魁北克IAF-exp91株基因组3我的c-DNA序列,并与欧洲(Lelystad病毒LV)和美国(ATCCVR2385,MN-16)参考株序列进行了比较,魁北克株与Lely-stad病毒之间,包含ORF37序列(2834个核苷酸)出现广泛的基因组变异,迪是由于大量碱基置换和增删引起的。ORF5、3和7似乎最不稳定,魁北克株与Lelystad病毒的推测编  相似文献   

7.
本研究对猪生殖-呼吸道综合征病毒(PRRSV)的非结构基因,包括ORF1基因、5’端非编码区基因(Non-CodingRigon,NCR)和3’端非编码区基因(NCR)分别进行了分子克隆和测序,并对其基因特征作了研究分析。结果表明,PRRSV-CH-1a株ORF1a起始密码子上游是由保守序列5’UUAACC3’连接的5’NCR,在该区附近的约43个碱基有较高的保守性,其余核苷酸的变异较大。ORF1a编码的多聚蛋白又可切割生成六个非结构蛋白(Nsp1a、Nsp1β、Nsp2-5),其中Nsp2可能具有型特异性,在不同基因型的PRRSV分离株之间表现出较大的变异,和VR2332株的NsP2的编码基因相比有86%的同源性,同LV株只有45%的同源性;ORF1b所编码的聚合蛋白经切割后形成四个非结构蛋白(RdRp、CP2-4),同 ORF1a所编码的蛋白相比较为保守,但是,在CP4的C端仍有较大的变异,其编码区和VR2332株相比有88.7%的同源性,而和LV株只有53.4%的同源性。CH-1a株的ORF1a-ORF1b的衔接区为核糖体移码区,在所有的PRRSV分离株中高度保守,具有保守的5’UUUAAAC3’序列和  相似文献   

8.
我国猪繁殖和呼吸综合征病毒基因型鉴定   总被引:13,自引:0,他引:13  
应用RT-PCR技术,从我国东北和华北地区分离的2个猪繁殖和呼吸综合征病毒(PRRSV)毒株中扩增获得部分核衣壳蛋白基因。该基因片段长度与美洲型野毒株VR2332RT-PCR扩增片段相同,均为433bp,长于欧洲型Lelystad毒株扩增片段长度(395bp)。此外,用另1对引物,从这2个分离毒株及VR2332毒株扩增获得部分GP5蛋白基因,其限制性酶切片段长度多态性分析结果相同或相似。该结果表明,我国不同地区流行的PRRSV可能属于同一毒株,并且来源于美洲。  相似文献   

9.
猪生殖与呼吸综合征病毒ORF6片段的cDNA克隆及鉴定   总被引:1,自引:0,他引:1  
根据已发表的PRRSV基因组序列,设计并合成了1对特异扩增ATCC VR-2332株的ORF6的基因的引物,以ATCC VR-2332基因组为模板,通过RT-PCR扩增出586bp的cDNA产物。将该cDNA片段经T-A连接插入pGEM-Teasy载体中,用重组质粒转化大肠埃希氏菌JM109,获得重组质粒转化菌。对重南粒DNA进行PCR及酶切鉴定,证明插入的DNA片段与PCR扩增的DNA片段大小相  相似文献   

10.
在我国吉林省某地猪生殖-呼吸道综合征病毒(PRRSV)抗体阳性猪群的4头2日龄弱仔猪实质脏器中分离到2株PRRSV。间接荧光抗体试验(IFA)结果表明,PRRSV(LV.VR-2332)抗血清与2个分离株呈阳性反应;分离到病毒的弱仔猪血清与参考株(LV.VR-2332)也呈阳性反应;而分离株与HCV、PrV、PPV、TGEV、PEDV和HEV无交叉抗原。以上试验证明,我们已成功地分离到2株地方性PRRSV。进一步用六种PRRSV单抗(A~F)进行IFA试验,结果2个分离株与VR-2332的荧光反应谱相同。说明它们之间在抗原结构上具有同源性。  相似文献   

11.
A cold-adapted porcine reproductive and respiratory syndrome virus (CA-VR2332) was generated from the modified live virus strain VR2332. CA-VR2332 showed impaired growth when cultured at 37°C with numerous mutations (S731F, E819D, G975E, and D1014N) in the hypervariable region of the NSP2, in which the mutation S731F might play a vital role in viral replication at 30°C. Conserved amino acid sequences of the GP5 protein suggests that CA-VR2332 is a promising candidate for producing an effective vaccine against PRRSV infection. Further studies on replication and immunogenicity in vivo are required to evaluate the properties of CA-VR2332.  相似文献   

12.
根据GenBank中登录的美洲株ATCC VR-2332的MN蛋白基因序列,利用Oligo6.0设计一对特异性引物,以抽提的PRRSV-SCMS病毒感染细胞总RNA为模板,RT-PCR扩增出长约1.0 kb的基因片段,将其克隆入pMD 18-T载体,测序结果显示SCMS MN基因全长886 bp,包含完整的MN基因的开放阅读框,共编码297个氨基酸。PRRSV-SCMS MN基因序列与VR2332和LV株进行同源性分析结果显示,PRRSV-SCMS与VR2332和LV株之间的核苷酸序列同源性分别为99.7%和61.6%,根据M基因推导的氨基酸序列同源性分别为98.9%和78.7%,根据N基因推导的氨基酸序列同源性分别为100%和52.8%。结果表明,SCMS地方分离株与VR2332株在基因型上具有更近的亲缘关系,推测本次分离的PRRSV属于美洲型。  相似文献   

13.
应用RT PCR方法从实验室分离的两株高致病性PRRSV SX、ZQ株中扩增出ORF6和ORF7,将其分别克隆、测序。用DNAStar 软件分析所测序列,并与VR 2332株、LV株、周边国家及国内分离株进行核苷酸和推导氨基酸同源性比较,并绘制系统进化树,结果ORF6、ORF7核苷酸与北美洲型的同源性为91.1%~100%,与欧洲型的同源性为66.2%~70.7%,推导氨基酸与北美洲型的同源性为91.2%~100%,与欧洲型的同源性为62.3%~82.3%。证明新分离到的PRRSV SX株、ZQ株仍属北美洲型。SX株ORF6、ORF7核苷酸与国内新分离到的高致病性PRRSV JXA1株同源性分别为99.8%、100%;ZQ株ORF6、ORF7核苷酸与国内新分离到的高致病性PRRSV JXA1株同源性分别为99.6%、99.7%。  相似文献   

14.
近来,广西一些养殖场频繁发生以母猪流产、死胎、木乃伊、仔猪呼吸道症状等为特征的流行性传染病,怀疑为猪繁殖与呼吸综合征病毒(PRRSV)感染所致。本研究从病猪中采集材料,经RT-PCR检测为阳性后,接种于Marc-145细胞,经过6代盲传,发现典型的细胞病理变化(CPE),经鉴定为PRRSV,命名为GXA株,其毒价为105.33TCID50/mL。参考VR-2332和CH-1a株基因序列,设计了3对特异性引物,分别对GXA株的E、M、N基因同时进行了RT-PCR扩增、克隆和测序。应用DNAstar生物学软件拼接得到GXA株的E、M和N3个基因片段共长为1473bp。同源性分析表明,GXA株与VR-2332、MLV和BJ-4的同源性为99.7%~100%,而与欧洲型代表株LV的同源性只有66.4%。表明GXA与VR-2332、MLV及BJ-4株亲缘关系比较密切,与欧洲型代表株LV亲缘关系最远,属于美洲型毒株,有可能来源于疫苗株。  相似文献   

15.
广西一些养殖场频繁发生以母猪流产、死胎、木乃伊等为特征的流行性传染病,怀疑为猪繁殖与呼吸综合征病毒(PRRSV)所致.利用针对PRRSV的N基因的特异性引物P1和P2,通过RT-PCR技术对分别从广西贵港市(GXGG)和南宁市(GXNN)收集到的可疑病料进行检测,结果两份为阳性.合成针对M基因的引物M1和M2,分别扩增了GXGG和GXNN两株PRRSV的M基因,并进行克隆和测序,得到长582个核苷酸的目的基因片段.应用DNAStar序列分析软件对所测的两个广西毒株与国内外已发表的ATCC VR-2332、LV和CH-la毒株进行同源性比较.分析表明,GXGG与ATCC VR-2332、LV、CH-la的核苷酸同源性分别为95.6%、69.5%、97.7%;GXNN与ATCC VR-2332、LV、CH-la的核酸同源性分别为94.9%、69.5%、97.3%.对推定的氨基酸序列进行了比较,GXGG与ATCC VR-2332、LV、CH-la的氨基酸同源性分别为97.7%、80.5%、97.7%;GXNN与ATCC VR-2332、LV、CH-la的氨基酸同源性分别为98.3%、79.9%、97.1%.说明广西流行毒株与ATCC VR-2332和CH-la的同源性很高,而与LV毒株的同源性很低.从本研究构建的系统发育树分析,广西流行的PRRSV与ATCC VR-2332株的亲缘关系比较密切.  相似文献   

16.
I have used indirect ELISA with overlapping synthetic peptides representing the GP5 ectodomain to study the generation and specificity of peptide-binding Abs in pigs that were infected in utero with porcine reproductive and respiratory syndrome virus (PRRSV) strain VR2332 and in North American field sera submitted for PRRSV infection diagnosis. Peptide-binding Abs appeared in sera of the VR2332-infected pigs within about 30 days post-farrowing (dpf), reaching maximum titers 100-200 dpf and then decreasing slowly to about half of maximum titer by about 400 dpf. The formation of peptide-binding Abs and of virus neutralizing Abs correlated and their initial appearance coincided with disappearance of virus from the circulation. The Abs were specific for VR2332-specific peptides. In contrast, anti-N-protein Abs as measured by HerdCheck ELISA appeared within 7 dpf, reached maximum levels at about 100 dpf and had decreased below detectable levels by about 200 dpf. Twenty-seven field serum samples with virus neutralizing activity all possessed high levels of peptide binding Abs, but the Abs bound about equally to VR2332 and strain Lelystad virus (LV)-specific peptides. The indirect ELISA results using various large peptides and competition ELISA using small peptides (8 or 9 amino acids long) confirmed that the epitope recognized by the Abs is located in the GP5 ectodomain sequence 37SHLQLIYNL of VR2332. Use of mutated peptides in the competition ELISA showed that 42I to T and 38HL to TY substitutions blocked Ab recognition, whereas deletion of 41L had no effect. In addition, 26 serum samples submitted by two farms for diagnostic tests were found to possess low levels of Abs that bound to GP5 ectodomain peptides, even though the sera were sero-negative in the HerdChek ELISA and lacked neutralizing activity. Competition ELISA showed that the Abs recognized one or more epitopes located downstream of the PRRSV neutralization epitope. An epitope(s) located in the same area was recognized by Abs generated in mice by immunization with a GP5 ectodomain peptide conjugated to BSA. These Abs also lacked neutralizing activity.  相似文献   

17.
根据GenBank发表的猪繁殖与呼吸综合征病毒(PRRSV)ATCC VR-2332全基因序列,设计并合成2对引物,采用RT-PCR技术,对辽宁省站送检的病料进行分离扩增,分别获得相应的目的片段,将其分别克隆入pMD18-T载体中,并送上海生工测序。应用DNAStar软件分析所测序列,并与ATCC VR-2332、CH-1a、BJ-4、LV-M96262及疫苗株的ORF567基因进行序列比较,通过核苷酸序列分析表明这5株流行株与VR-2332、CH-1a、BJ-4等代表株的同源性为89.5%~95%,与LV-M96262的同源性为54%~58.3%.氨基酸序列分析表明这5株流行株与VR-2332、CH-1a、BJ-4等代表株的同源性为82.8%~94.7%.  相似文献   

18.
参考Genbank发表的猪繁殖与呼吸综合征病毒(PKRSV)ATCC VR-2332的ORF5基因序列,设计并合成了一对引物.对来自福建、浙江、山东等地的PRRSV分离毒株进行RT-PCR扩增.获得约748bp的DNA片断,将其分别克隆入pMD18-T载体中,并进行测序。应用DNAStar软件分析所测序列,并与ATCCVR-2332、CH-1a、MLV、Lv等毒株的ORF5序列进行比较,结果表明:SHDl与F114、MLV、ATCCVR-2332同源性高达98.5%,与CH-1a同源性为91.0%,与其它毒株同源性为86.6%~88.4%;F114与MLV、ATCCVR-2332同源性为99.3%~99.7%.其余分离毒株在遗传关系上和CH-1a又分为明显的两个群.显示近年来各地PRRSV分离毒株与cH-1a株的遗传差异越来越大。  相似文献   

19.
Sera were collected from convalescent sows and sick piglets from six pig farms in southern Quebec that have experienced outbreaks of the so-called porcine reproductive and respiratory syndrome. By indirect immunoperoxidase, a few of these sera (4 of 14) (28.6%) were found to be positive for antibody to the Lelystad virus, whereas by indirect immunofluorescence 30 of 36 (83.3%) were positive for antibody to the antigenically-related American isolate ATCC-VR2332. Pregnant sows inoculated intranasally with filtered homogenates prepared from the lungs of necropsied piglets obtained from a seropositive farm developed fever, inappetence, and reproductive failure characterized by stillbirths and various stages of mummification. Lesions of interstitial pneumonia were induced in experimentally-infected specific pathogen-free piglets. A virus, having morphological and biological characteristics of viruses assigned to the family Togaviridae, was isolated from lung tissues of experimentally-infected animals; it could only be propagated in primary cultures of porcine alveolar macrophages. Identification of the virus was confirmed by indirect immunofluorescence using a monoclonal antibody directed against the nucleocapsid protein of the ATCC-VR2332 isolate and porcine sera that were found positive for antibody to both the Lelystad and ATCC-VR2332 isolates.  相似文献   

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