Molecular cloning and hybridization studies on bluetongue virus serotype 17

The dsRNA of bluetongue virus (BTV) serotype 17 has been reverse transcribed and dsDNA copies of the viral RNA have been cloned into the plasmid vector pBR-322. Segments ranging from 3 kilobases to less than 500 bases have been cloned and at present 1 of the clones has been identified by hybridization to the genome segment of its origin (genome segment 7). Identification of further clones is proceeding. The techniques for northern blotting BTV dsRNA onto 2-aminophenylthioether (APT) paper and the detection of the transferred RNA by 32P labelled dsRNA or cDNA probes have been standardized. Cross-hybridization studies can be used to detect genetic relationships of different serotypes and isolates of BTV.