1株圆环病毒3型美国毒株全基因组克隆与遗传演化分析

Complete Genome Cloning and Genetic Evolution Analysis of an American Strain of Porcine Circovirus Type 3

为了解进口美国种猪中获取的猪圆环病毒3型(PCV3)毒株全基因组序列及遗传变异情况,根据GenBank中收录的PCV3基因组序列,设计2对特异性引物,对确诊感染PCV3的病死猪组织进行全基因组序列扩增、拼接、测序和序列分析。结果显示,获得的PCV3美国毒株(命名为PCV3_USA2021,GenBank登录号OL799306)全基因组序列长度约为2000 bp,与国内外不同地区的38个PCV3参考毒株同源性为98.7%~99.8%。其中,PCV3_USA2021株开放阅读框ORF1和ORF2与国内外38个参考毒株同源性分别为99.1%~99.9%和98.0%~100%。构建的全基因组系统进化树显示,该毒株为PCV3a亚型,与美国毒株(PCV3-US_SD2016)亲缘关系最近。本研究为PCV3的遗传变异、流行病学分析提供了参考,也为相关疫苗的研制打下了基础。

In order to identify the complete genome sequence and genetic variation of porcine circovirus type 3(PCV3)derived from the breeding pigs imported from America,two pairs of specifi c primers were designed according to the PCV3 genome sequence registered in GenBank.For the tissues from dead pigs infected with PCV3,the complete genome sequence amplification,splicing,sequencing and sequence analysis were conducted.The results showed that the complete genome sequence of the obtained strain(named as PCV3_USA2021,GenBank accession number OL799306)was about 2000 bp in length,and its complete genome nucleotide sequence homology was 98.7%to 99.8%with 38 reference strains from different regions both at home and abroad,in which,those of its open reading frames,ORF1 and ORF2,were 99.1%to 99.9%and 98.0%to 100%,respectively.It was showed that,by the constructed complete genome phylogenetic tree,the strain belonged to PCV3 subtype a,and was closest to the American strain(PCV3-US_SD2016).A reference was thus provided for future epidemiological analysis on genetic variation of PCV3,and a foundation was also laid for the development of relevant vaccines.