摘要：

旨在对猪细小病毒1型(PPV1)突变株生物学特性进行分析。对采自山东不同地区养猪场的67份流产胎儿组织样品进行PPV的分离和培养,经电镜观察和IFA试验进行鉴定,通过Overlap PCR对分离株进行全基因序列扩增,SnapGene V4进行序列拼接和比对,利用DNAMAN V6对基因组末端5'UTR和3'UTR二级结构进行展示和比较,应用MEGA V7进行遗传进化分析,最后利用多步生长曲线绘制对分离株在易感细胞内的增殖能力进行比较。共分离得到3株病毒,均鉴定为PPV1型毒株,分别命名为SDPV1、SDPV2和SDPV3,GenBank登录号分别为ON924737、ON924738和ON924739;3个分离株全基因序列长度基本一致,其中5'-UTR序列高度保守,呈Y型结构;而3'-UTR呈U型结构,个别碱基有所差异;VP2氨基酸序列中有5个非同义突变位点,分别为T20A、R82K、Q226E、D366N和K407N,为国内毒株首次发现。生长曲线显示,突变株生长趋势相对较快,与PPV-QN株相比,最高滴度相差10倍。报道了包含新型变异位点的PPV毒株的基因组特征。

关键词: 猪细小病毒1型, 突变株, 全基因组, 遗传变异

Abstract:

It conducted to analyze the biological characteristics of Porcine parvovirus type 1 (PPV1) mutant strains.The PPV was isolated and cultured from 67 aborted fetal tissue samples collected from pig farms in different regions of Shandong Province,and identified by electron microscopy and IFA test.DNAMAN V6 was used to demonstrate and compare the secondary structures of 5'UTR and 3'UTR,MEGA V7 was used for genetic evolutionary analysis,and finally the multi-step growth curve was used to compare the proliferation ability of the isolates in susceptible cells.Three strains were isolated and identified as PPV type 1 strains,named SDPV1,SDPV2 and SDPV3,with GenBank accession numbers ON924737,ON924738 and ON924739,respectively;the whole gene sequence lengths of the three isolates were basically the same,among which the 5'-UTR sequence was highly conserved and had a Y-shaped structure,while the 3' UTR had a U-shaped structure with some differences in individual bases;there were five non-synonymous mutation sites in the amino acid sequence of VP2,namely T20A,R82K,Q226E,D366N and K407N,which were found for the first time in domestic strains.The growth curve showed that the mutant strain had a relatively fast growth trend,with a 10-fold difference in the highest titer compared with the PPV-QN strain.It reported the genomic characteristics of PPV strains containing novel mutant loci.

Key words: Porcine parvovirus type 1, Mutant strain, Whole genome, Genetic variation