Geography and host species shape the evolutionary dynamics of U genogroup infectious hematopoietic necrosis virus
Geography and host species shape the evolutionary dynamics of U genogroup infectious hematopoietic necrosis virus
复制标题
DOI：
10.1093/ve/vew034
复制
发表时间：
2016-07-01
期刊：
影响因子：
5.3
通讯作者：
Kurath, Gael
中科院分区：
文献类型：
--
作者：
Black, Allison;Breyta, Rachel;Kurath, Gael
传染性造血细胞坏死病毒（IHNV）是一种负义RNA病毒，感染美国和加拿大太平洋沿岸从加州到阿拉斯加的野生和养殖鲑鱼。虽然成鱼的感染通常是无症状的，但幼鱼感染可导致高死亡率事件，影响鲑鱼孵化计划和商业水产养殖。我们使用流行病学病例数据和病毒糖蛋白基因303 nt部分的遗传序列数据，研究了1971年至2013年美国西北太平洋地区U基因组IHNV的进化动态。我们在代表619起病毒检测事件的1，219 U基因组IHNV分离株中鉴定出114种独特基因型。我们发现了U基因组中两个先前未识别的广泛亚组的证据，我们将其命名为“UC”和“UP”。流行病学记录表明，UP病毒在红鲑（Oncorhynchus nerka）以及华盛顿和俄勒冈州的沿海沃茨中检出的频率更高，而UC病毒主要在哥伦比亚河流域的奇努克鲑鱼（Oncorhynchus tshawytscha）和虹鳟（Oncorhynchus mykiss）中检出，哥伦比亚河流域是一个大型复杂的分水岭，延伸至华盛顿、俄勒冈州和爱达荷州的大部分地区。这些研究结果支持系统发育分析和F-ST。祖先状态重建表明，早期UC病毒在哥伦比亚河流域最初感染红鲑鱼，但随后出现通过主机转移到奇努克鲑鱼和虹鳟鱼在20世纪80年代的某个时候。我们推测，U基因组内的这些亚组的发展是由选择压力驱动的病毒适应奇努克鲑鱼和虹鳟在哥伦比亚河流域。
Infectious hematopoietic necrosis virus (IHNV) is a negative-sense RNA virus that infects wild and cultured salmonids throughout the Pacific Coastal United States and Canada, from California to Alaska. Although infection of adult fish is usually asymptomatic, juvenile infections can result in high mortality events that impact salmon hatchery programs and commercial aquaculture. We used epidemiological case data and genetic sequence data from a 303 nt portion of the viral glycoprotein gene to study the evolutionary dynamics of U genogroup IHNV in the Pacific Northwestern United States from 1971 to 2013. We identified 114 unique genotypes among 1,219U genogroup IHNV isolates representing 619 virus detection events. We found evidence for two previously unidentified, broad subgroups within the U genogroup, which we designated 'UC' and 'UP'. Epidemiologic records indicated that UP viruses were detected more frequently in sockeye salmon (Oncorhynchus nerka) and in coastal waters of Washington and Oregon, whereas UC viruses were detected primarily in Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) in the Columbia River Basin, which is a large, complex watershed extending throughout much of interior Washington, Oregon, and Idaho. These findings were supported by phylogenetic analysis and by F-ST. Ancestral state reconstruction indicated that early UC viruses in the Columbia River Basin initially infected sockeye salmon but then emerged via host shifts into Chinook salmon and steelhead trout sometime during the 1980s. We postulate that the development of these subgroups within U genogroup was driven by selection pressure for viral adaptation to Chinook salmon and steelhead trout within the Columbia River Basin.