Diversity and evolution of a newly emerged North American Type 1 porcine arterivirus: analysis of isolates collected between 1999 and 2004
Diversity and evolution of a newly emerged North American Type 1 porcine arterivirus: analysis of isolates collected between 1999 and 2004
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DOI：
10.1007/s00705-007-0936-y
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发表时间：
2007-05-01
影响因子：
2.7
通讯作者：
Rowland, R. R. R.
中科院分区：
文献类型：
--
作者：
Fang, Y.;Schneider, P.;Rowland, R. R. R.
欧洲样1型猪繁殖与呼吸综合征病毒（PRRSV）分离株，称为北美（NA）1型PRRSV，出现在美国（U.S.）1999年的猪。他们的多样性和进化进行了研究，在五年的时间内，通过构建系统发育树使用nsp 2和ORF 5序列的20 NA 1型菌株，包括唯一已知的分离夏威夷。除两个菌株外，所有菌株在nsp 2中具有相同的51-nt缺失，表明克隆起源。简约性和距离分析表明，病毒可以被放置到两个不同的亚支，这是相似的nsp 2和ORF 5。两个树之间的不一致性确定了一个分离物04-41为重组产物。使用SimPlot的分解分析确定了位于nsp 2/3结下游的断裂点。这项研究的结果表明，NA 1型PRRSV在美国是一个成熟和快速发展的群体。然而，驱动遗传多样性和分离的力量是复杂的，仍有待阐明。
European-like Type 1 porcine reproductive and respiratory syndrome virus (PRRSV) isolates, known as North American (NA) Type 1 PRRSV, appeared in United States (U.S.) swine herds in 1999. Their diversity and evolution were studied over a five-year period by constructing phylogenetic trees using nsp2 and ORF5 sequences of 20 NA Type 1 isolates, including the only known isolate from Hawaii. All but two of the isolates possessed the same 51-nt deletion in nsp2, suggesting a clonal origin. Parsimony and distance analysis showed that viruses could be placed into two distinct sub-clades, which were similar for both nsp2 and ORF5. An incongruity between the two trees identified one isolate, 04-41, as the product of recombination. Recombination analysis using SimPlot identified a break point located downstream of the nsp2/3 junction. Results from this study suggest that NA Type 1 PRRSV in the U.S. is a well-established and rapidly evolving group. However, the forces driving genetic diversity and separation are complex and remain to be elucidated.