Race法扩增4株鸭肝炎病毒3′末端序列及其克隆分析

Molecular cloning and analysis of the 3′ end sequence of four strains of duck hepatitis virus by 3′ RACE

利用3’RACE方法扩增并克隆了4株鸭肝炎病毒（DHV）（ZYM株、Z05株、Z07株和Z10株）的基因组的3’末端真实序列，包括部分非结构蛋白（3D）基因以及紧接着3D基因下游的3’端非编码区（untranslated region，UTR）和poly（A）尾巴。测序结果表明，扩增的特异性片段长度为597nt（不包括polyA尾巴）。各毒株3’UTR均为315nt，位于终止密码子TGA之后，比对分析结果表明各毒株间的同源性较高；4株DHV 3’末端核苷酸序列（不包括polyA尾巴）之间的同源性为96．3％～100％，而与参考毒株之间的同源性为93．5％～99．7％。在系统发生进化树上，各毒株亲缘关系较近。

The authentic 3＇end sequences of duck hepatitis virus （DHV） with four strains （ZYM, Z05, Z07 and Z10） were obtained by RACE. The sequence analysis showed that 3＇end sequences of the four DHV strains contained 3D region, 3＇untranslated region （3＇UTR） and a poly（A） tail. The sequencing results showed that the amplified specific sequence was 597 nt in length （not including polyA tail）, and the sequences of 3＇UTR were all 314 nt in length after the terminator codon TGA. The aligning analysis showed that the 3＇end sequences of DHV shared high nucleotide acid identity among the four DHV strains ranging from 96.3% to 100% while the homology with referenced strain ranged from 93.5% to 99.7%. Phylogenetic analysis of 3＇end sequences indicated that these strains shared high nucleotide acid identity.