【作者】 马勋； 陆承平；

【Author】 MA Xun LU Cheng-ping(Key Laboratory of Animal Disease Diagnostic and Immunology,Ministry of Agriculture,Nanjing Agricultural University,Nanjing,Jiangsu 210095,China)

【机构】 南京农业大学农业部动物疫病诊断与免疫重点开放实验室；

【摘要】 设计18对 PCR 引物分片段扩增猪戊型肝炎病毒新疆分离株 swCH25全基因,对两末端采用末端快速扩增方法(RACE)进行扩增,扩增产物克隆到 pMD18-T 载体并测序。用 DNASTAR 软件进行序列同源性分析,PHYLIP 软件绘制基因进化树,在全基因序列的基础上比较猪 HEV 与其他 HEV 基因型的差异和人源 HEV 的关系。结果显示 swCH25全序列除去3’poly(A)尾,由7243个核苷酸组成,ORF 1～3分别编码含1707、674和114个氨基酸的蛋白质。全基因序列与 HEV Ⅰ、Ⅱ和Ⅲ型同源性73．5％～75．7％,与Ⅳ型的同源性为83．5％～89．8％,其中与Ⅳ型中国人源 T1株最高,达B9．8％。ORF1与Ⅰ～Ⅲ和Ⅳ型的核苷酸同源性分别为71．6％～74％和82．3％～89．4％,氨基酸同源性为80．7％～86．1％和94．3％～96．0％；ORF2与Ⅰ～Ⅲ和Ⅳ型的核苷酸同源性分别为78．4％～81．3％和87．1％～ 90．9％,氨基酸同源性为89．7％～93．8％和97．2％～98．2％；ORF3与Ⅰ～Ⅲ和Ⅳ型的核苷酸同源性分别为84．4％～87．3％和95．4％～96．8％,氟基酸同源性为74．8％～83．2％和93．8％～97．4％,基因进化树显示 swCH25与基因Ⅳ型人源 T1株最接近,在同一分支上。swCH25株是国内第一个测出全基因序列的猪戊型肝炎病毒。更多还原

【Abstract】 To analyze the full length sequence of swCH25,isolated from a pig fecal sample in Xinjiang in 2001,eight overlapping fragments of swCH25 genomes were amplified with reverse transcription nested polymerase chain reaction (RT-nPCR)and the 5’and 3’ends were amplified with RACE.The PCR products were cloned into pMD18-T vector and sequenced.The result showed that its genomeis consisted of 7243nt excluding the poly(A)tail,and contained three ORFs (ORFs1～3)that eneeded proteins of 1707,674 and 114aa.Sequence analysis revealed that the overall nucleotide se- quence identity of swCH25 was 73.5%～75.7 % and 83.5 %～89.8 % with HEV genotype Ⅰ～Ⅲ and Ⅳ,respective- ly.Compared with HEV genotypes Ⅰ～Ⅲ and Ⅳ,the OBF1 of swCH25 shared 71.6%～74% and 82.3%～89.4% sequence identity at nucleotide level and 80.7 %～86.1% and 94.3 %～96 % identity at amino acid level,the ORF2 shared 78.4%～81.3% and 87.1%～90.9% sequence identity at nucleotide level and 89.7%～93.8% and 97.2% ～98.2 % identity at amino acid level and the ORF3 shared 84.4 %～87.3 % and 95.4～96.8 % sequence identity at nucleotide level and 74.8 %～83.2 % and 93.8 %～97.4 % identity at amino acid level.The phylogenetic tree con- structed based on the full genomic sequence confirmed that swCH25 belong to genotype Ⅳ and were most closely related to T1,a prototype human HEV strain of genotype Ⅳ isolated from patients with acute hepatitis in China.This finding fur- ther supports the notion that the hepatitis E is a zoonosis.更多还原