【摘要】 为了解江西地区禽圆环病毒2型（AGV2）的流行情况及基因组的遗传进化关系，本研究利用PCR方法对2015年～2020年间采自江西各地区的1 372份地方鸡血清、粪便及内脏组织样品进行AGV2检测。结果显示，江西地区AGV2的阳性率为13.99%(192/1 372)，其中育成鸡阳性率最高，为17.16%(98/571)，且各生长阶段鸡AGV2阳性率均有逐年升高的趋势。从中选取12份AGV2阳性样品进行全基因组扩增，并对其全基因组序列和VP1蛋白序列进行同源性及遗传进化关系分析，同时对VP1蛋白线性抗原表位进行预测分析。结果显示：选取的12个AGV2全基因组之间的同源性为96.8%～99.8%，其中VP1基因序列的同源性在96.5%～99.9%，氨基酸序列同源性在99.4%～100%；遗传进化分析显示，12个AGV2全基因组分布于进化树的各分支，具有遗传多样性的特征；进一步分析发现AGV2 VP1蛋白氨基酸序列的突变并未导致VP1蛋白疏水性的改变，仅JX201601 VP1出现G36S突变，JX201802 VP1出现Q222R突变，致使VP1蛋白抗原性改变。本研究首次明确了江西地方鸡种中AGV2的流行状况和遗传演化特点，为江西地区AGV2感染的防控提供了重要数据支撑。更多还原

【Abstract】 To investigate the epidemiology and genetic variation of avian gyrovirus 2(AGV2) in local chicken breeds in Jiangxi province during 2015 to 2020, we collected 1 372 serum, faecal and visceral tissue samples for PCR testing. The results showed that the total positive rate of AGV2 of the local chicken breeds was 13.99%(192/1372) in Jiangxi province, which tended to increase slightly from the 2015 to the year 2020, and the positive rate of breeding chickens was the highest at 17.16%(98/571).Twelve AGV2 positive samples were amplified and sequenced, the resulting whole-genome and VP1 sequences were performed homology and genetic evolutionary analysis against the other AGV2 reference sequences, as well as the prediction analysis for the linear antigenic epitopes of VP1 protein. Sequence analysis showed that the homologies of 12 AGV2 whole genome sequences ranged from 96.8%-99.8%, among which the nucleotide sequence homology of VP1 ranged from 96.5%-99.9% and the amino acid sequence homology ranged from 99.4%-100%. Phylogenic analysis showed that the 12 AGV2 whole genome sequences were distributed in the different branches and were characterized by genetic diversity. Further analysis revealed that the mutation of amino acids in the sequence of VP1 protein did not result in the changes of the hydrophobicity of VP1 protein, only two unique mutations were observed at the position G36S in JX201601, Q222R in JX201802 causing antigenic changes in VP1 protein. This study is the first to clarify the prevalence and the genetic evolution of AGV2 for the local chicken breeds in Jiangxi province and provides important data support for the prevention and control of AGV2 in Jiangxi area.更多还原