致胰腺泛黄鸭1型甲肝病毒全基因组分子特征

Molecular characteristic of duck hepatitis A virus type 1 causing pancreatitis

【目的】揭示致胰腺泛黄鸭1型甲肝病毒(duck hepatitis A virus 1,DHAV-1)全基因组的分子特征。【方法】运用RT-PCR技术,扩增出致胰腺泛黄DHAV-1 MPZJ1206株全基因组序列,并与鸭甲肝病毒参考毒株基因组序列进行比对分析。【结果】致胰腺泛黄DHAV-1 MPZJ1206株基因组全长为7703 nt,(G+C)%为43.05%,包含一个大的开放阅读框,编码2249个氨基酸残基的多聚蛋白,基因组结构与其他DHAV-1参考毒株一致。序列比对结果显示,MPZJ1206株全基因组序列与GenBank数据库中DHAV-1参考毒株核苷酸序列同源性在93.5%-99.6%之间,氨基酸同源性在97.9%-99.6%之间,遗传距离均低于7%;分子系统进化分析显示与2011年分离的2株DHAV-1(Du/CH/LGD/111238和Du/CH/LGD/111239)亲缘关系最近。【结论】尽管MPZJ1206毒株感染雏番鸭引起的临床病变与传统DHAV-1差异明显,但其基因组分子特征与传统的DHAV-1毒株相似,病毒致病型的改变可能与其组织嗜性改变相关。

[ Objective ] We studied the molecular characteristics of the full-length genome of duck hepatitis A virus type 1 causing pancreatitis in Muscovy ducklings. [ Methods] We determined the entire genomie sequence of duck hepatitis A virus type 1 strain MPZJ1206 using reverse transcription polymerase chain reaction assay and analyzed the bioinformatics of the viral genome sequence. [ Results] The genome length of strain MPZJ1206 comprised 7703 bases, with a G ＋ C content of 43.05%. The genome of MPZJI206 contains a single, long open reading frame encoding a polypeptide of 2249 amino acids, with a genomic organization similar to those of other isolates of duck hepatitis A virus type 1. MPZJ1206 is identical with previously isolates by 93.5% -99.6% in nucleotide sequence and 97.9% -99.6% in amino acid sequence and shares genetic distance no more than 7%. Phylogenetic analysis based on genome sequence indicates that MPZJ1206 shares a close genetic relationship with two strains isolated in 2011. [ Conclusion] Although pathotype caused by MPZJ1206 strain is significantly distinct from those induced by classical isolates of duck hepatitis A virus type 1, the genome of MPZJ1206 shares high homology with those of previous isolates. The change of pathotype may result from an alteration in viral tissue tropism of MPZJ1206.