Tolf Conny, Gullberg Maria, Johansson E Susanne, Tesh Robert B, Andersson Björn, Lindberg A Michael
School of Pure and Applied Natural Sciences, University of Kalmar, SE-39182 Kalmar, Sweden.
Discipline of Immunology and Microbiology, Faculty of Health, The University of Newcastle, David Maddison Clinical Sciences Building, Royal Newcastle Hospital, Newcastle, NSW 2300, Australia.
J Gen Virol. 2009 Apr;90(Pt 4):843-853. doi: 10.1099/vir.0.007948-0. Epub 2009 Mar 4.
Ljungan virus (LV) was discovered 20 years ago in Swedish bank voles (Myodes glareolus, previously referred to as Clethrionomys glareolus) during the search for an infectious agent causing lethal myocarditis in young athletes. To date, the genomes of four LV isolates, including the prototype 87-012 strain, have been characterized. Three of these LV strains were isolated from bank voles trapped in Sweden. Sequence analysis of an American virus (M1146), isolated from a montane vole (Microtus montanus) in western USA, indicates that this strain represents a genotype that is different from the Swedish strains. Here, we present genomic analyses of a fifth LV strain (64-7855) isolated from a southern red-backed vole (Myodes gapperi) trapped during arbovirus studies in New York state in the north-eastern USA in the 1960s. Sequence analysis of the 64-7855 genome showed an LV-like genome organization and sequence similarity to other LV strains. Genetic and phylogenetic analyses of the evolutionary relationship between the 64-7855 strain and other viruses within the family Picornaviridae, including previously published LV strains, demonstrated that the 64-7855 strain constitutes a new genotype within the LV species. Analyses also showed that different regions of the 64-7855 genome have different phylogenetic relationships with other LV strains, indicating that previous recombination events have been involved in the evolution of this virus.
吕宋病毒（LV）于20年前在瑞典田鼠（Myodes glareolus，以前称为Clethrionomys glareolus）中被发现，当时正在寻找一种导致年轻运动员致命心肌炎的传染原。迄今为止，包括原型87 - 012株在内的4株LV分离株的基因组已被鉴定。其中3株LV菌株是从在瑞典捕获的田鼠中分离出来的。对一株从美国西部山地田鼠（Microtus montanus）分离出的美国病毒（M1146）进行的序列分析表明，该菌株代表一种与瑞典菌株不同的基因型。在这里，我们展示了对第五株LV菌株（64 - 7855）的基因组分析，该菌株于20世纪60年代在美国东北部纽约州进行虫媒病毒研究期间，从捕获的一只南部红背田鼠（Myodes gapperi）中分离得到。64 - 7855基因组的序列分析显示出与其他LV菌株相似的LV样基因组结构和序列相似性。对64 - 7855菌株与微小核糖核酸病毒科内其他病毒（包括先前发表的LV菌株）之间进化关系的遗传和系统发育分析表明，64 - 7855菌株构成了LV物种内的一个新基因型。分析还表明，64 - 7855基因组的不同区域与其他LV菌株具有不同的系统发育关系，这表明先前的重组事件参与了该病毒的进化。
