三株鸭肝炎病毒1型全基因序列分析

【研究目的】为分析三株1型鸭肝炎病毒（DHV）的遗传变异和进化关系；【方法】采用RT-PCR和5'-/3'-RACE.方法测定三株1型鸭肝炎病毒全基因序列；【结果】研究结果表明，不含poly（A）尾巴的3株病毒的基因组全长为7691~7700 nt，基因组均仅含一个长度为6750 nt的ORF，625~627 nt 5'端非翻译区和325~328 nt 3'端非翻译区(UTR)。将3株病毒株与GeneBank公布的其他DHV-1全基因序列及小RNA病毒科的其它属代表病毒株进行序列分析表明，聚蛋白均被分割成为12个蛋白，其中VP1的变异性最大，180~187位为高变区。3株病毒与DHV-1参考毒株核苷酸序列同源性在93.7%~98.8%，氨基酸序列同源性在96.9%~98.8%，DHV-1各株在小RNA科病毒多聚蛋白氨基酸序列进化树上形成一个独立的进化分支；【结论】DHVs-1病毒间核苷酸和氨基酸仍较保守，它们在进化中可将其归为小RNA病毒科的一个新属。

Genomic sequence analysis of three strains of duck hepatitis virus type 1

This experiment was conducted to study the genetic variations and phylogenetic analysis of three strains of duck hepatitis virus type 1（DHV-1）;The complete sequences of three DHVs-1（FZ86,FZ99 and FZ05） were acquired by RT-PCR and 5＇-/3＇-RACE;The results showed that the full genomic length of three strains virus were 7691-7700 nt without poly（A） tail,including 625-627 nt 5 ’ UTR,followed by a long open reading frame（ORF） of 6750 nt and 325-328nt 3 ’ UTR.The nucleotide sequences analysis of three DHV-1 strains and the cited DHV-1 isolates showed that their polyproteins can be cleaved into 12 proteins.In the 12 polyproteins,the VP1 polyprotein had large variation of aa180-187.The homologies of three DHVs-1 and other DHVs-1 were within 93.7%-98.8%,while the amino acid homology were 96.9%-98.8%.The DHV-1 strains clustered together and formed a separated sublinge with other numbers of the family Picornaviridae;DHVs-1 are conserved on nucleotide and amimo acid,and belong to a new genus in the family Picornaviridae.