A comparison of six different bluetongue virus isolates by cross-hybridization of the dsRNA genome segments.
The relationship between six different isolates of BTV was analyzed by cross-hybridization of genomic dsRNA using blotting and probe techniques (using an alkali fragmented probe made from BTV dsRNA). The viruses compared in this way included BTV serotype 1 from South Africa, serotypes 3 and 4 from Cyprus, serotype 10 from North America, and serotypes 1 and 20 from Australia. Under the hybridization and washing conditions used, which were calculated to allow stable duplex formation between RNA molecules containing greater than 90% sequence homology, two of the genome segments (segments 2 and either 5 or 6, which encode the two major outer capsid proteins VP2 and VP5) appeared to contain serotype-specific RNA sequences. Significant cross-hybridization between these segments from different serotypes was detected only with serotypes 4 and 20, which are known to have a particularly close antigenic relationship. The amounts of homologous sequence that were detected in segments other than 2 and 5 between different viruses indicated some correlation between their geographical origins and a degree of relatedness, which is independent of the virus serotype. High levels of sequence homology were detected between the isolates from Cyprus and Africa and to a slightly lesser extent from North America, suggesting a common ancestry. These results also indicated that within the limited number of viruses studied, the Australian isolates form a separate interrelated group of bluetongue viruses.
Mertens
P P
PP
Institute for Animal Disease Research, Pirbright Laboratory, Woking, Surrey, England, United Kingdom.
Pedley
S
S
Cowley
J
J
Burroughs
J N
JN
D001820:Bluetongue virus / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D009693:Nucleic Acid Hybridization; D012330:RNA, Double-Stranded / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics*; D012087:Reoviridae / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D012330:RNA, Double-Stranded; D012367:RNA, Viral