Genetic characterization of a new insect flavivirus isolated from Culex pipiens mosquito in Japan

• DOI: 10.1016/j.virol.2006.09.039
• Publication Date: 2006-11-01T01:25:28Z
• Authors: Keita Hoshino; Haruhiko Isawa; Yoshio Tsuda; Kazuhiko Yano; Toshinori Sasaki; Masao Yuda; Tomohiko Takasaki; Mutsuo Kobayashi; Kyoko Sawabe
• Keywords: 0301 basic medicine; 0303 health sciences; Phylogenetic analysis; Base Sequence; Flavivirus; Molecular Sequence Data; Complete nucleotide sequence; Cell Line; 3. Good health; Insect flavivirus; Culex; Viral Proteins; 03 medical and health sciences; Japan; Aedes; Virology; Cricetinae; Culex pipiens; Chlorocebus aethiops; Animals; Vero Cells; Phylogeny

We found a new flavivirus that is widespread in Culex pipiens and other Culex mosquitoes in Japan. The virus isolate, named Culex flavivirus (CxFV), multiplied only in mosquito cell lines producing a moderate cytopathic effect, but did not grow in mammalian cells. The CxFV genome is single-stranded RNA, 10,834 nt in length and containing a single open reading frame encoding a polyprotein of 3362 aa with 5' and 3' untranslated regions (UTRs) of 91 and 657 nt, respectively. Phylogenetic analyses revealed that CxFV is closely related to the insect flaviviruses associated with Aedes mosquitoes, Cell fusing agent (CFA) and Kamiti River virus (KRV). The 3' UTR of CxFV contains four tandem repeats, which have sequence similarities to the two direct repeats in the CFA and KRV 3' UTRs. These results suggest that CxFV may be a new group of insect flaviviruses.