Troyer R M, LaPatra S E, Kurath G
Department of Pathobiology, University of Washington, Seattle, WA 98195, USA.
J Gen Virol. 2000 Dec;81(Pt 12):2823-32. doi: 10.1099/0022-1317-81-12-2823.
Infectious haematopoietic necrosis virus (IHNV) is the most significant virus pathogen of salmon and trout in North America. Previous studies have shown relatively low genetic diversity of IHNV within large geographical regions. In this study, the genetic heterogeneity of 84 IHNV isolates sampled from rainbow trout (Oncorhynchus mykiss) over a 20 year period at four aquaculture facilities within a 12 mile stretch of the Snake River in Idaho, USA was investigated. The virus isolates were characterized using an RNase protection assay (RPA) and nucleotide sequence analyses. Among the 84 isolates analysed, 46 RPA haplotypes were found and analyses revealed a high level of genetic heterogeneity relative to that detected in other regions. Sequence analyses revealed up to 7.6% nucleotide divergence, which is the highest level of diversity reported for IHNV to date. Phylogenetic analyses identified four distinct monophyletic clades representing four virus lineages. These lineages were distributed across facilities, and individual facilities contained multiple lineages. These results suggest that co-circulating IHNV lineages of relatively high genetic diversity are present in the IHNV populations in this rainbow trout culture study site. Three of the four lineages exhibited temporal trends consistent with rapid evolution.
传染性造血器官坏死病毒（IHNV）是北美鲑鱼和鳟鱼最重要的病毒病原体。先前的研究表明，在较大的地理区域内，IHNV的遗传多样性相对较低。在本研究中，对美国爱达荷州斯内克河12英里河段内四个水产养殖设施在20年期间从虹鳟（Oncorhynchus mykiss）中采集的84株IHNV分离株的遗传异质性进行了调查。使用核糖核酸酶保护分析（RPA）和核苷酸序列分析对病毒分离株进行了表征。在分析的84株分离株中，发现了46种RPA单倍型，分析显示相对于其他地区检测到的遗传异质性水平较高。序列分析显示核苷酸差异高达7.6%，这是迄今为止报道的IHNV最高的多样性水平。系统发育分析确定了代表四个病毒谱系的四个不同的单系分支。这些谱系分布在各个养殖设施中，每个设施都包含多个谱系。这些结果表明，在这个虹鳟养殖研究地点的IHNV种群中存在遗传多样性相对较高的共同传播的IHNV谱系。四个谱系中的三个呈现出与快速进化一致的时间趋势。
