Genetic diversity of the S10 RNA segment of field and vaccine strains of bluetongue virus from the P. R. China

Full-Genome Sequence of Bluetongue Virus Serotype 1 (BTV-1) Strain Y863, the First BTV-1 Isolate of Eastern Origin Found in China

The full-genome sequence of the bluetongue virus serotype 1 (BTV-1) strain Y863, the first BTV-1 isolate of Eastern origin found in China, was determined. The virus was isolated from sheep during a severe outbreak of bluetongue in Shizhong County, Yunnan Province, southwest China, in 1979. The total size of the BTV-1 strain Y863 genome is 19,170 bp. Phylogenetic analyses demonstrate that it belongs to the major “Eastern” BTV topotype. The sequence information provided here will help in understanding the geographical origin and spread of this Chinese isolate of BTV-1, as well as aid in its comparison with global isolates of BTV-1 from sheep, cattle, and other host species origins.

Full genome sequence of bluetongue virus serotype 4 from China

The complete genomic sequence of a bluetongue virus serotype 4 (BTV-4) strain (strain YTS-4), isolated from sentinel cattle in Yunnan Province, China, is reported here. This work is the first to document the complete genomic sequence of a BTV-4 strain from China. The sequence information will help determine the geographic origin of Chinese BTV-4 and provide data to facilitate future analyses of the genetic diversity and phylogenetic relationships of BTV strains.

Genetic and phylogenetic characterization of genome segments 2 and 6 of bluetongue virus isolates in Japan from 1985 to 2008

This study conducted genetic and phylogenetic analyses of genome segments 2 and 6 (Seg-2 and Seg-6), which encode serotype-specific structural proteins of the outer capsid, of bluetongue virus (BTV) isolated in Japan from 1985 to 2008. The Japanese strains of BTV were clearly sorted into six groups by several genetic characteristics of Seg-2, including segment length, ORF length and 5′- and 3′-terminal sequences, and were identified as serotypes 2, 3, 9, 12, 16 and 21 by phylogenetic comparisons with Seg-2 of reference and field strains of serotypes 1–24. In contrast, phylogenetic comparisons of Seg-6 also revealed some variations among the Japanese strains and partial correlations of the serotypes between the Japanese strains and the reference or field strains. Thus, the results revealed that at least six serotypes of BTV were isolated in Japan and that there were some variations in the genetic and phylogenetic characteristics of Seg-2 and Seg-6 among the Japanese strains, suggesting that BTV of several different origins has appeared sporadically in Japan. These data will be beneficial for understanding BTV epidemiology and taking better control measures against bluetongue in Japan and its neighbouring countries in the Asia-Pacific region.