Genetic and biological characterization of Muko virus, a new distinct member of the species Great Island virus (genus Orbivirus, family Reoviridae), isolated from ixodid ticks in Japan

• Published in: Archives of virology Vol. 160; no. 12; pp. 2965 - 2977
• Main Authors: Ejiri, Hiroko, Lim, Chang-Kweng, Isawa, Haruhiko, Kuwata, Ryusei, Kobayashi, Daisuke, Yamaguchi, Yukie, Takayama-Ito, Mutsuyo, Kinoshita, Hitomi, Kakiuchi, Satsuki, Horiya, Madoka, Kotaki, Akira, Takasaki, Tomohiko, Maeda, Ken, Hayashi, Toshihiko, Sasaki, Toshinori, Kobayashi, Mutsuo, Saijo, Masayuki, Sawabe, Kyoko
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.12.2015; Springer Nature B.V
• Subjects: amino acid sequences; Animals; Antibodies; Arachnid Vectors - virology; Arachnids; Biomedical and Life Sciences; Biomedicine; Cell Line; coat proteins; cytopathogenicity; Genetic diversity; genetic variation; Genome, Viral; Genomes; geographical distribution; Great Island virus; Humans; Infectious Diseases; Ixodes; Ixodes - virology; Ixodidae; Japan; Medical Microbiology; Mice; Molecular Sequence Data; mortality; Open Reading Frames; Orbivirus; Orbivirus - classification; Orbivirus - genetics; Orbivirus - isolation & purification; Original Article; Phylogenetics; Phylogeny; Proteins; Reoviridae; Reoviridae Infections - virology; RNA polymerase; sequence analysis; serotypes; suckling; ticks; Turdus; Viral Proteins - genetics; Virology; Viruses; Japan; Genome Segment; Viral dsRNA; Intracerebral Inoculation; Suckling Mouse; Migratory Bird
• DOI: 10.1007/s00705-015-2588-7
• ISSN: 0304-8608

Among the tick-borne orbiviruses (genus Orbivirus, family Reoviridae), 36 serotypes are currently classified within a single virus species, Great Island virus. In this study, we report the first characterization of a tick-borne orbivirus isolated from the tick Ixodes turdus in Japan, which we identified as a new member of the species Great Island virus. The virus isolate, designated Muko virus (MUV), replicated and induced cytopathic effects in BHK-21, Vero E6, and CCL-141 cells and caused high mortality in suckling mice after intracerebral inoculation. Full genome sequence analysis showed that MUV shared the greatest phylogenetic similarity with Tribeč virus in terms of the amino acid sequences of all viral proteins except for outer capsid protein 1 (OC1; VP4 of MUV). Analysis of genome segment 9 in MUV detected an uninterrupted open reading frame that overlaps with VP6 (Hel), which putatively encodes a molecular and functional equivalent of NS4 from Great Island virus. Our study provides new insights into the geographic distribution, genetic diversity, and evolutionary history of the members of the species Great Island virus.