河北省塞内卡病毒A VP2基因克隆和序列分析

Cloning and sequence analysis of VP2 gene of Senecavirus A in Hebei Province

为了解河北省塞内卡病毒A(SVA)VP2基因的变异及分子进化情况,试验设计了一对VP2基因扩增引物,通过RT-PCR方法扩增和克隆测序,利用MEGA 7.0软件对测序获得的VP2基因序列和GenBank上的参考序列进行遗传进化分析,运用MegAlign 5.0软件进行核苷酸和氨基酸同源性分析。结果表明:成功扩增并测序得到VP2基因序列,将该序列上传至GenBank,获得基因登录号为MZ031967,命名为SVA HB-BD株。该毒株与中国毒株核苷酸序列相似性为95.9%~99.6%;与原型毒株SVV-001(DQ64125-7核苷酸)相似性较低,为94.6%;与其他美国毒株(MN812946、MN812947、KC667560、MH704432、MN812938、MN812937、KU954086、NC011349)核苷酸相似性为93.0%~94.6%。SVA HB-BD株与2015—2016年分离毒株亲缘关系较近,处于同一分支,而与2017—2018年分离毒株亲缘关系较远。SVA HB-BD株与广东省分离毒株氨基酸序列相似性较高,并且在VP2蛋白中和表位位点高度保守。说明HB-BD株与中国毒株具有相同起源,并且在不断演变。

In order to understand the mutation and molecular evolution of VP2 gene of Senecavirus A(SVA) in Hebei Province, a pair of amplification primers were designed based on VP2 gene, RT-PCR was used to amplity and cloned for sequencing;the genetic evolution analysis of the VP2 gene sequence obtained by sequencing and the reference sequences from GenBank was performed by MEGA 7.0 software, and the nucleotide and amino acid homology analysis was performed by MegAlign 5.0 software. The results showed that the VP2 gene sequence was successfully amplified and sequenced, and the sequence was uploaded to GenBank, and the gene accession number was MZ031967, which was named SVA HB-BD strain. The nucleotide sequence similarity between the strain and the Chinese strains was 95.9%-99.6%, and its nucleotide similarity with the prototype strain SVV-001(DQ 64125) was 94.6%, which was at a low level, and the nucleotide similarity with other American strains(MN812946, MN812947, KC667560, MH704432, MN812938, MN812937, KU954086, NC011349) was 93.0%-94.6%. The SVA HB-BD strain was closely related to the isolates from 2015—2016, and they belonged to the same branch, while it was far from the isolates from 2017—2018. The amino acid sequence analysis showed that the SVA HB-BD strain had higher similarity with the isolated strains in Guangdong Province, and the neutralization epitope of VP2 protein was highly conserved. The results suggested that the HB-BD strain had the same origin as the Chinese strains and was constantly evolving.