Immune response against the purified serotype specific antigen of bluetongue virus and initial attempts to clone the gene that codes for the synthesis of this protein.

: Sheep were injected with different amounts of purified protein P2 of bluetongue (BT) virus (BTV). About 3 X 50 mcg was required for the induction of neutralizing antibodies. Sheep injected with 3 X 10 mcg were, however, still largely protected when challenged with virulent virus. This has suggested the possibility of using P2 as a subunit vaccine and initiated an investigation of the possibility of synthesizing P2 by DNA-recombinant technology. In order to clone the gene that codes for the synthesis of P2 both the "shotgun" approach with unfractionated dsRNA and cloning of isolated segment 2 were investigated. The basic approach was to convert the dsRNA to DNA which was cloned into the Pst 1 site of E. coli plasmid pBR322. The largest BTV-specific insert that was obtained in the initial experiments was just more than 2,000 base pairs long. The largest insert obtained when isolated segment 2 dsRNA was cloned was about 1,200 base pairs which represents about 1/3 of the P2 gene.