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1.
Chicken anaemia virus (CAV) was detected in the bursa of Fabricius of a 4‐week‐old chicken obtained from an outbreak of acute infectious bursal disease in Bangladesh. Repeated attempts to grow this virus in MDCC‐MSB1 cells were not successful. A full‐length PCR amplicon of the genome of this strain, designated as BD‐3 CAV, was cloned and sequenced. The complete nucleotide sequence and the deduced amino acid sequence were compared with those of 12 other CAV strains. The genetic analysis of the amino acid sequences of VP1 indicated the possible existence of genetic groups among CAV strains, as BD‐3 CAV along with four other strains (CIA‐1, L‐028, Isolate 704 and TR‐20) formed a distinct lineage. These strains have four signatory amino acids in VP1, such as 75I/T, 97L, 139Q and 144Q, out of which the latter two are located in a small hydrophilic peak.  相似文献   

2.
The presence of chicken anemia virus (CAV) in Slovenia was confirmed by inoculation of 1-day-old chickens without antibodies against CAV and isolation of the virus on the Marek's disease chicken cell-MSB1 line and by polymerase chain reaction (PCR). Experimental inoculation of 1-day-old chickens resulted in lower hematocrit values, atrophy of the thymus, and atrophy of bone marrow. CAV was confirmed by PCR in the thymus, bone marrow, bursa of Fabricius, liver, spleen, ileocecal tonsils, duodenum, and proventriculus. The nucleotide sequence of the whole viral protein (VP)1 gene was determined by direct sequencing. Alignment of VP1 nucleotide sequences of Slovenian CAV isolates (CAV-69/00, CAV-469/01, and CAV-130/03) showed 99.4% to 99.9% homology. The VP1 nucleotide sequence alignment of Slovenian isolates with 19 other CAV strains demonstrated 94.4% to 99.4% homology. Slovenian isolates shared highest homology with the BD-3 isolate from Bangladesh. Alignment of the deduced VP1 amino acids showed that the Slovenian isolates shared 100% homology and had an amino acid sequence most similar to the BD-3 strain from Bangladesh (99.6%) and were 99.1% similar to the G6 strain from Japan and the L-028 strain from the United States. The Slovenian isolates were least similar (96.6%) to the 82-2 strain from Japan. A phylogeneric analysis on the basis of the alignment of the VP1 amino acids showed that CAV isolates used in the study formed three groups that indicated the possible existence of genetic groups among CAV strains. The CAV isolates were grouped together independent of their geographic origin and pathogenicity.  相似文献   

3.
鸡贫血病毒vp3突变体的构建   总被引:1,自引:0,他引:1  
以本实验室克隆保存的含野生型鸡贫血病毒 ( CAV)全基因序列的 p UC18-CAV为模板 ,通过双向聚合酶链式反应 ( PCR)的方法在CAV的 DNA序列中制造定点突变并新增特定限制性酶切位点 ,得到载有 CAV突变体的p UC18-CAVm。突变体中致病基因 vp3的起始密码子 ATG(在 m RNA是 AUG)突变为 ACG而失去翻译起始位点的功能 ,虽然 vp3基因完全重叠于 vp2基因内部 ,但由于读码框的不同和密码子的简并性 ,突变位点的碱基变化并未引起VP2蛋白的氨基酸残基序列发生变化 ,从而保证了突变体和原始病毒抗原性的一致 ,为开发鸡贫血病毒的 DNA疫苗奠定了坚实的基础  相似文献   

4.
Between January 2004 and December 2005, cloacal swabs from essentially healthy chickens and silky chickens from live birds markets in Guangdong and Hunan provinces in southeastern China were screened for chicken anemia virus (CAV) by polymerase chain reaction. Phylogenetic analysis of the major structural protein VP1 sequences showed no clear genotype cluster and no correlation with the geographic origin of CAV strains. Virus evolution at the amino acid level was very slow, which corresponds to a strong negative selection of the VP1 gene in China and worldwide. A high proportion (87%) of birds was CAV positive, suggesting that many farms in the region were infected. Further investigations are necessary to evaluate the economic losses caused by CAV and the cost-benefit of vaccination.  相似文献   

5.
Chicken anemia virus (CAV) isolates show extremely limited genetic variability worldwide. We determined the nucleotide sequence of an 823-nucleotide portion of the 2.3-kb CAV genome found in 10 liver and/or spleen specimens of Alabama 29-to-49-day-old commercial broiler chickens exhibiting lymphocyte depletion of the thymus submitted to the state diagnostic laboratory because of problems unrelated to anemia. We determined the nucleotide sequence directly from DNA isolated from tissues, without isolation of virus in culture. This procedure enabled us to characterize CAV that might not have replicated in culture and avoided the potential for changes during passage. Results confirmed the limited genetic variability of CAV. All sequences were identical in 93% of nucleotide positions. The sequences encoded only two distinct VP1 hypervariable regions, and both had been found previously in other CAV isolates. A novel amino acid, glutamine, was found at VP1 position 22 in half the sequences, replacing the histidine residue encoded by most previously characterized CAV genomes. We were able to distinguish among CAV genomes with different codons at VP1 amino acid 22 and different hypervariable regions by restriction endonuclease analysis of polymerase chain reaction products.  相似文献   

6.
鸡贫血病毒vp3基因克隆、序列分析和比较   总被引:2,自引:0,他引:2  
克隆了从我国哈尔滨分离的一株鸡贫血病毒(CAV)的vp3基因,并对之进行了测序。该基因的开放读码枢由366bp组成,编码121个氨基酸,氨基酸组成具有已报道VP3的典型特点。本次克隆的基因与GenBank收录的CAV的vp3基因进行序列比较,同源性至少为98%。与国内报道的山东株SJ1的vp3基因有3个核苷酸的差异,表明国内的CAV毒株已经产生了一些分化。在EMBL中比较本次克隆的VP3蛋白一级结构,与之差异最大的是马来西亚分离株的VP3,有5个氨基酸残基不同,同源性为96%。同时收集EMBL中的CAV的VP3蛋白绘制进化树,我国哈尔滨分离的CAV毒株与CIA进化关系最近,而与Cux-1的2个衍生株QDWX1、QDWX3进化关系最远。这些结果进一步证明了CAV在遗传方面是较保守的病毒,来自哈尔滨的CAV不是CAV的一个独立分支。  相似文献   

7.
Specific amino acid (aa) substitutions in VP1, VP2 and VP3 genes were reported as a distinctive feature of the American CIA-1 strain, characterized as having a variable rate of growth and tropism for different MSB-1 cell sublines [Renshaw RW, Soiné C, Weinkle T, O'Connell PH, Ohashi K, Watson S, et al. A hypervariable region in VP1 of chicken anemia virus mediates rate of spread and cell tropism in tissue culture. J Virol 1996;70(12):8872-8]. DNA sequencing of 878 nucleotides from twelve Brazilian CAV, eight of which tested for in vitro isolation in three different sources of MDCC-MSB1 cell line and identified as lacking capacity to propagate in any of these cells, were compared to sequence data available for CAV strains propagated or not in cell culture. Alignment of the deduced aa resulted in a lack of singled out amino acid substitutions in the partial genomic sequences of Brazilian isolates that would entirely contrast them to viruses propagated in MSB-1 cells, indicating that the combined VP1, VP2 and VP3 substitutions observed may not entirely account as sole determinants of CAV isolation and propagation in MDCC-MSB-1 cells.  相似文献   

8.
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10.
从法氏囊组织分离IBDV超强毒株HK46并提取基因组RNA。以RNA为模板进行反转录合成cDNA第一链。采用长PCR扩增技术获得VP2-4-3 cDNA全长片段。将PCR产物克隆到pcDNA3.1( )载体,得到重组质粒pPP1。对pPP1插入片段全长序列进行了测序并对其序列进行了分析。结果表明,VP2-4-3 cDNA阅读框架由3039bp组成,可编码1012个氨基酸组成的前体多聚蛋白。经比较得知,HK46超强毒株VP2-4-3氨基酸序列与经典毒株间存在19-28个氨基酸的差异;与Harbin强毒株相差32个氨基酸;而与超强毒株OKYM和UK661分别相差2和6个氨基酸,且它们的VP2序列完全相同。在HK46超强毒株所特有的9个氨基酸中,3个位于VP2可变区,显示超强毒株其抗原性存在着变异。  相似文献   

11.
In this study, a total of nine chicken samples obtained from two broiler flocks in Oita and Tottori prefectures in 2020 were examined for Chicken anemia virus (CAV) infection. The samples were collected from clinically suspected flocks and diseased chickens. The CAV genome was detected in all nine samples tested by real-time PCR. Phylogenetic analyses and sequence comparisons of the full-length VP1 gene sequences indicated that all the Japanese CAV strains obtained in this study formed a similar cluster of genotype III and shared high nucleotide (99.62–100%) identity. The current Japanese CAV strains were closely related to Chinese CAV strains but not related to vaccine strains. One positive selection site of VP1 was detected among the Japanese CAV strains.  相似文献   

12.
根据GenBank中CAV哈尔滨分离株基因序列,设计出针对CAV VP1大片段(608 bp)的引物,利用PCR方法从CAV基因组序列中扩增出VP1基因的大片段(608 bp),按照正确的读码框克隆到原核表达载体pET32a( )上,得到含VP1大片段的pET32a( )重组子,转化大肠埃希菌BL21(DE3)感受态细胞,IPTG诱导重组蛋白表达,经SDS-PAGE和Western blotting检测发现有分子质量约42 ku的融合蛋白表达,与预期分子质量大小一致,通过Ni亲和层析柱纯化出融合蛋白,经Western blotting鉴定,融合蛋白与His单抗能够结合.CAV VP1基因的克隆表达及其融合蛋白的纯化为后续制备多克隆抗体和单克隆抗体提供了良好的抗原来源,也为研究VP1与其他CAV蛋白之间的相互关系奠定了基础.  相似文献   

13.
根据GenBank中已发表的CAV纤突基因序列,设计合成4对8条引物,用已建立的PCR方法,对犬2型腺病毒沈阳分离株第5代强毒经蚀斑克隆驯化的第60代毒弱毒(SY-V60)和犬1型腺病毒长春犬株(CCC-V6)的纤突基因进行了扩增,PCR产物经纯化后进行基因序列测定,测定结果经拼接后得到一个由1632和1629个核苷酸组成的纤突蛋白全基因序列,分别编码543和542个氨基酸。犬2型腺病毒(SY-V60)与犬1型腺病毒(CCC-V6)的纤突基因的同源性达到80.48%。犬2型腺病毒(SY-V60)与犬1型腺病毒(CCC-V6)纤突基因的同源性达到80.48%;根据犬的腺病毒与人2型腺病毒纤突蛋白的序列同源性比较结果,推测了犬腺病毒纤突蛋白的尾(tail)、轴(shaft),结(knob)三个功能区的氨基酸序列,2个型之间的尾区同源性为76.9%;轴区同源性为78.59%;其结区同源性为83.24%,而同型毒株之间结和尾区同源性较高,轴区同源性较低。  相似文献   

14.
CAV基因T程亚单位苗与IBDV二联灭活疫苗的研究   总被引:2,自引:0,他引:2  
IBDV为自行分离的VVIBDV COB-C1组织毒,毒价为CELD5010^5.0/0.2mL,CAV为VP1和VP2基因克隆进家蚕杆状病毒转基因载体质粒中,后经重组,筛选后获得的重组VP1和VP2基因产物,IBDV经甲醛灭活后与CAV按适当比例混合。1:4与白油佐剂研制成油包水型乳化剂二联疫苗,经安全试验、免疫保护试验证明该二联灭活疫苗安全有效,免疫种鸡群后可使其后代产生IBDV和CAV抗体,雏鸡得到较好的保护。  相似文献   

15.
In the present study, we describe the development of a DNA vaccine against chicken anemia virus. The VP1 and VP2 genes of CAV were amplified and cloned into pBudCE4.1 to construct two DNA vaccines, namely, pBudVP1 and pBudVP2-VP1. In vitro and in vivo studies showed that co-expression of VP1 with VP2 are required to induce significant levels of antibody against CAV. Subsequently, the vaccines were tested in 2-week-old SPF chickens. Chickens immunized with the DNA-plasmid pBudVP2-VP1 showed positive neutralizing antibody titer against CAV. Furthermore, VP1-specific proliferation induction of splenocytes and also high serum levels of Th1 cytokines, IL-2 and IFN-γ were detected in the pBudVP2-VP1-vaccinated chickens. These results suggest that the recombinant DNA plasmid co-expressing VP1 and VP2 can be used as a potential DNA vaccine against CAV.  相似文献   

16.
Gao HL  Wang XM  Gao YL  Fu CY 《Avian diseases》2007,51(4):893-899
The complete genomic sequence of very virulent infectious bursal disease virus (vvIBDV) Gx strain was determined, including the sequences of segment A, encoding the precursor polyprotein, and segment B, encoding the viral RNA polymerase (VP1) and 5'- and 3'-untranslating regions. Alignment of segment A of Gx with the sequences of 12 other vvIBDV strains showed 97.5% to 99.0% amino acid identity, whereas alignment of segment B of Gx with nine other vvIBDV strains revealed high sequence divergence, ranging from 10.3% to 11%. Phylogenetic analysis of segments A and B showed that they were in different branches, indicating that the reassortment occurred in this strain and that segment A and segment B derived from different pathotype strains. The mutant spectrum analysis of quasispecies virus demonstrated that the mean minimum mutation frequency in VP1 was 8.78-fold higher than in the polyprotein. The most frequent mutations were in the first 1986 nucleotides (nonsynonymous mutations) and the last 660 nucleotides (synonymous mutations), indicating that the 219 amino acid residues in the C-terminal of the VP1 form a functional region.  相似文献   

17.
18.
Chicken anemia virus (CAV) is an important viral pathogen that causes anemia and severe immunodeficiency syndrome in chickens worldwide. In this study, a potential diagnostic monoclonal antibody against the CAV VP1 protein was developed which can precisely recognize the CAV antigen for diagnostic and virus recovery purposes. The VP1 gene of CAV encoding the N-terminus-deleted VP1 protein, VP1Nd129, was cloned into an Escherichia (E.) coli expression vector. After isopropyl-β-D-thiogalactopyronoside induction, VP1Nd129 protein was shown to be successfully expressed in the E. coli. By performing an enzyme-linked immunoabsorbent assay using two coating antigens, purified VP1Nd129 and CAV-infected liver tissue lysate, E3 monoclonal antibody (mAb) was found to have higher reactivity against VP1 protein than the other positive clones according to the result of limiting dilution method from 64 clones. Using immunohistochemistry, the presence of the VP1-specific mAb, E3, was confirmed using CAV-infected liver and thymus tissues as positive-infected samples. Additionally, CAV particle purification was also performed using an immunoaffinity column containing E3 mAb. The monoclonal E3 mAb developed in this study will not only be very useful for detecting CAV infection and performing histopathology studies of infected chickens, but may also be used to purify CAV particles in the future.  相似文献   

19.
通过PCR方法克隆了从我国哈尔滨分离的一株鸡贫血病毒(CAV)的VP2基因,并对之进行了测序,该基因的开放读码框由65bp组成,编码216个氨基酸。通过将本次克隆的基因与GenBank收录的CAV的VP2基因比较,同源性至少为99%,未发现与本次克隆的VP2蛋白完全一致的CAV分离株,与之同源性最好的是CIA-1的VP2蛋白,相差1个氨基酸,与Cux-1也仅相差2个氨基酸,因此从该蛋白看CAV哈尔滨分离株的变异程度不很高。比较这27株病毒的VP2及其基因序列,发现共有31处核苷酸发生变异,这些变异将导致VP2的12个氨基酸变化,尽管他们散布于整个VP2,但在186到191号氨基酸区域存在一个没有报道过的变异程度相对较高的区域,CAV的VP2是相对较保守的蛋白。  相似文献   

20.
为了解吉林地区小鹅瘟病毒(Gosling plague virus,GPV)的基因特征,及其与黑龙江及中国其他省份和国外流行毒株的相关性,本研究采用PCR方法鉴定2018年吉林某养鹅场送检的病死雏鹅的肠组织,同时对GPV的非结构蛋白NS1基因及结构蛋白VP1基因进行了克隆和测序,并与国内外16株GPV参考毒株的相应序列进行分析。结果表明,病死雏鹅为GPV与减蛋综合征病毒(Egg drop syndrome virus,EDSV)混合感染;吉林地区GPV的NS1基因长为1 884 bp,编码627个氨基酸,与参考毒株核苷酸序列同源性为93.8%~99.8%,氨基酸序列同源性为97.1%~99.7%;VP1基因长为2 199 bp,编码732个氨基酸,与参考毒株核苷酸序列同源性为93.4%~99.9%,氨基酸序列同源性为96.4%~99.9%。NS1及VP1基因的系统进化树分析均表明,吉林地区GPV与哈尔滨分离株98E属于同一进化分支,亲缘关系最近,与国外分离株、中国台湾和安徽分离株亲缘关系均较远。吉林地区GPV与鹅源GPV具有较近的亲源关系,同源性明显高于其他水禽来源的GPV。该研究为明确中国东北地区GPV空间的流行规律提供基础数据,为东北地区GPV的诊断与治疗提供参考依据。  相似文献   

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