1猪圆环病毒2型（PCV2）是引起猪圆环病毒相关疾病（PCVAD）的主要病因，自2002年以来，对中国猪业造成严重的经济损失。我们对2015-2016年我国华东地区的12个分离株进行了全基因组测序，并与2010-2013本实验室分离的毒株以及2013-2014收集的华东地区的毒株进行分析。结果显示，2015-2016年间，华东地区PCV2总阳性率为36.91%（110/298），安徽PCV2阳性率为52.70%（39/74），江苏为33.33%（70/210）。进化树分析显示，62个PCV2分离株中的5株（8.06％）分离株属于基因型PCV2a，11株（17.74%）分离株属于PCV2b，46株（74.19％）属于基因型PCV2d。说明我国华东地区PCV2有由PCV2b向PCV2d漂移的趋势。另外，本研究分离的PCV2序列ORF2区域有其特异的氨基酸变异位点，且PCV2d分离株在该区域末端有1个赖氨酸。以上结果表明，我国华东地区2010-2016年间PCV2分离株可能因疫苗和抗病毒试剂的双重压力而发生了遗传变异。
目 录
Abstract1
Key words1
引言（或绪论）2
1材料与方法2
1.1材料 2
1.1.1病料来源2
1.1.2 主要试剂3
1.1.3主要仪器3
1.2方法 3
1.2.1样品采集和处理 3
1.2.2病料DNA的提取 3
1.2.3引物设计与合成 4
1.2.4样品中PCV2的检测4
1.2.5 阳性样品PCV2全序列的扩增与PCR产物回收4
1.2.6目的基因连接4
1.2.7感受态制备5
1.2.8 PCV2全长序列的克隆与鉴定5
1.2.9序列测定与分析 5
1.1.10 PCV2的ORF2基因编码氨基酸序列分析7
2结果与分析 7
2.1样品检测7
2.1.1多个省份PCV2组织样品阳性率7
2.1.2不同年份PCV2组织样品检测结果8
2.2.PCV2基因组序列进化分析8< *景先生毕设|www.jxszl.com +Q: ￥351916072$ 
br /> 2.3 ORF2基因编码的氨基酸序列分析13
3讨论17
致谢19
参考文献20
近期我国华东地区猪圆环病毒2型分子流行病学调查
动物医学专业学生 丁铭
指导教师 周斌
Molecular epidemiological investigation of porcine circovirus type 2 in east China in recent years
Student majoring in veterinary medicine Ming Ding
Tutor Bin Zhou
Abstract： Porcine circovirus type 2 (PCV2) is the main cause of porcine circovirus associated diseases (PCVAD),which result in serious economic losses to pig industry Since 2002. In order to study the genetic variation of PCV2 under the dual pressures of vaccine and antiviral reagents, 12 isolates in East China were sequenced from 2015 to 2016 and analyzed with the isolates collected from 20102014 in East China. The results showed that the total positive rate of PCV2 was 36.91% (110/298) in 2005 ~ 2016, the positive rate of PCV2 was 52.70% (39/74) in Anhui and 33.33% (70/210) in Jiangsu. Phylogenetic tree analysis showed that 46 (74.19%) of the 62 PCV2 isolates belonged to genotype PCV2d, 5 strains (8.06%) were PCV2a and 11 (17.74%) were PCV2b. It shows that PCV2 in East China has the tendency to drift from PCV2b to PCV2d. The ORF2 region of PCV2 sequence isolated from this study has its specific amino acid mutation site, and PCV2d isolate has 1 lysine at the end of this region. The results showed that the PCV2 isolates in East China from 2010 to 2016 may have genetic variation due to the double pressure of vaccine and antiviral reagents.
Key words: Porcine circovirus type 2；Capsid protein ；Molecular epidemiology；Genetic variation
引言
猪圆环病毒(porcine circovirus，PCV)属圆环病毒科(circoviridae)圆环病毒属成员，是哺乳细胞中迄今已知最小的无囊膜的单股环状负链DNA病毒。病毒粒子直径约17~20nm[1]。PCV2具有很强的环境耐受性，70℃高温条件下仍能存活15min，对酸和氯仿耐受，可被强碱和季铵化合物灭活[2]。

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