The origin and evolution of porcine reproductive and respiratory syndrome viruses
The origin and evolution of porcine reproductive and respiratory syndrome viruses
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DOI：
10.1093/molbev/msi089
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发表时间：
2005-04-01
影响因子：
10.7
通讯作者：
Gojobori, T
中科院分区：
文献类型：
--
作者：
Hanada, K;Suzuki, Y;Gojobori, T
猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus，PRRSV）分为北美型和欧洲型，两者在氨基酸序列上存在40%左右的差异。根据流行病学资料，估计这两种类型的分歧时间约为1980年。这表明，与其他RNA病毒10（-3）至10（-5）/位点/年相比，PRRSV以更高的进化速率（10（-2）/位点/年的数量级）进化。为了验证根据流行病学背景推测的PRRSV进化历史，我们利用分子进化分析方法估算了PRRSV的分化时间和进化速率。估计的分离时间（1972-1988年）与流行病学资料估计的分离时间相吻合，PRRSV的进化速率（4.71-9.8）× 10 ~（-2）确实是迄今报道的RNA病毒中最高的。此外，我们推断的重要网站的适应，以检查如何PRRSV适应猪，因为他们出现。适应性位点不仅位于与免疫相关的表位上，还位于包括信号肽在内的跨膜区。特别地，跨膜区中的适应性位点被认为影响与宿主细胞膜的相容性。我们的结论是，猪繁殖与呼吸综合征病毒从另一个宿主物种传播到猪在1980年左右，并适应了猪通过改变跨膜区。
Porcine reproductive and respiratory syndrome viruses (PRRSV) are divided into North American and European types, which show about 40% difference in their amino acid sequences. The divergence time of these two types has been estimated to be about 1980 from epidemiological data. This suggested that PRRSV have evolved at a higher evolutionary rate (order of 10(-2)/site/year) compared with other RNA viruses of 10(-3) to 10(-5)/site/year. Here, to test the evolutionary history of PRRSV speculated by the epidemiological background, we estimated the divergence time and evolutionary rate of PRRSV with molecular evolutionary analysis. Estimated divergence time (1972-1988) corresponded well to that estimated by the epidemiological data, and the evolutionary rate (4.71-9.8) x 10(-2) of PRRSV was indeed the highest among RNA viruses so far reported. Furthermore, we inferred important sites for the adaptation in order to examine how PRRSV have adapted to swine since they emerged. The adaptive sites were located not only in the epitopes related to immunity but also in the transmembrane regions including a signal peptide. In particular, the adaptive sites in the transmembrane regions were considered to affect compatibility to the host cell membrane. We conclude that PRRSV were transmitted from another host species to swine in about 1980 and have adapted to swine by altering the transmembrane regions.