Porcine reproductive and respiratory syndrome virus comparison: Divergent evolution on two continents
Porcine reproductive and respiratory syndrome virus comparison: Divergent evolution on two continents
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DOI：
10.1128/jvi.73.1.270-280.1999
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发表时间：
1999-01-01
影响因子：
5.4
通讯作者：
Faaberg, KS
中科院分区：
文献类型：
--
作者：
Nelsen, CJ;Murtaugh, MP;Faaberg, KS
猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus，PRRSV）是近年来发现的一种引起猪繁殖与呼吸综合征的动脉炎病毒。单链RNA病毒基因组的3 '末端结构基因的比较序列分析揭示了PRRSV的两种基因型类别的存在，分别以原型北美和欧洲毒株VR-2332和莱利斯塔病毒（LV）为代表。为了更好地了解PRRSV的进化和致病性，我们获得了VR-2332的12，066个碱基的5 '端核苷酸序列，编码病毒的复制活性，并将其与LV和其他动脉炎病毒进行了比较。VR-2332和LV在5'前导区和开放阅读框（ORF）1a区的区段上存在显著差异。ORF 1b序列几乎是共线性的，但不同的蛋白质编码的相似性在确定的区域。此外，亚基因组mRNA（sgmRNA）加工的分子和生物化学分析揭示了在感染期间可能产生的sgmRNA的数量以及前导体连接点和终止起始密码子AUC之间的非编码序列的长度的广泛变化。此外，VR-2332和LV从相似候选位点的库中选择不同的前导体连接位点以产生sgmRNA 7，编码病毒核衣壳蛋白。在整个基因组和sgmRNA加工中存在实质性变化表明PRRSV在不同的大陆上独立进化。全球几乎同时出现了一种由不同进化的病毒引起的新的猪病，这表明养猪业和管理的变化可能导致了PRRS的出现。
Porcine reproductive and respiratory syndrome virus (PRRSV) is a recently described arterivirus responsible for disease in swine worldwide. Comparative sequence analysis of 3'-terminal structural genes of the single-stranded RNA viral genome revealed the presence of two genotypic classes of PRRSV, represented by the prototype North American and European strains, VR-2332 and Lelystad virus (LV), respectively. To better understand the evolution and pathogenicity of PRRSV, we obtained the 12,066-base 5'-terminal nucleotide sequence of VR-2332, encoding the viral replication activities, and compared it to those of LV and other arteriviruses. VR-2332 and LV differ markedly in the 5' leader and sections of the open reading frame (ORF) 1a region. The ORF 1b sequence was nearly colinear but varied in similarity of proteins encoded in identified regions. Furthermore, molecular and biochemical analysis of subgenomic mRNA (sgmRNA) processing revealed extensive variation in the number of sgmRNAs which may be generated during infection and in the lengths of noncoding sequence between leader-body junctions and the translation-initiating codon AUG. In addition, VR-2332 and LV select different leader-body junction sites from a pool of similar candidate sites to produce sgmRNA 7, encoding the viral nucleocapsid protein. The presence of substantial variations across the entire genome and in sgmRNA processing indicates that PRRSV has evolved independently on separate continents. The near-simultaneous global emergence of a new swine disease caused by divergently evolved viruses suggests that changes in swine husbandry and management may have contributed to the emergence of PRRS.