ABSTRACT
The vaccine L-IVP strain of vaccinia virus (VV) was used to construct the recombinant viral clones containing the influenza A hemagglutinin gene. The recombinant T plasmid was obtained with HA gene inserted in the vector pGS-20 (B. Moss) under the 7.5 K promoter of VV. A homologous recombination technique was used to insert the gene with the flanking TK sequences into vaccinia virus genome. The recombinant clones were selected by dot-hybridization with [32P]-labeled HA-probe. These recombinants were analysed for HA gene expression by the indirect immunoperoxidase method in situ using the peroxidase conjugate of the staphylococcal A-protein. This technique allows to obtain stable stained preparation and analyse the protein behavior at the ultrastructural level.
Subject(s)
Gene Expression , Genes, Viral , Hemagglutinins, Viral/genetics , Influenza A virus/genetics , Vaccinia virus/genetics , Clone Cells , DNA, Viral/genetics , Immunoenzyme Techniques , Nucleic Acid Hybridization , Plasmids , Promoter Regions, Genetic , Recombination, Genetic , Staphylococcal Protein AABSTRACT
The method allowing the detection of BLV proviral DNA in the peripheral blood leukocytes of cattle is reported. Cell DNA from leukocytes used without preliminary cultivation was dot-hydridized with 32P-labeled plasmid that included a fragment of BLV proviral DNA. In parallel, sera from the cattle under study were tested by immunodiffusion assay (ID). The results indicate that dot-hybridization assay is more sensitive as a diagnostic test than ID because it detects BLV infection in apparently normal cattle which was seronegative by ID.