Submitted to: International Symposium on Double Stranded RNA Viruses
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/1997
Publication Date: N/A
Technical Abstract: The inner core protein VP7 of bluetongue virus (BTV) has been identified as the virus attachment protein for insect cells. Previously, phylogenetic analysis based on gene segment 3 (S3) from bluetongue viruses indicated a geographical topotyping. We hypothesize that certain VP7 protein sequences are preferred by the insect vector species present in a geographic location. This study compares the gene segment 7 (S7) from thirty-two BTV strains and eighteen strains of the related epizootic hemorrhagic disease viruses isolated from the Central American region, United States, South Africa and Australia. This gene was found to be very highly conserved. Phylogenetic analysis reveals that the S7 and to a lesser extent the deduced VP7 from BTV also display geographic topotypes but with several exceptions. There was evidence of naturally-occurring reassortment between BTV-17 and BTV-3. These findings suggest that the BTV receptor binding site in the insect is conserved but some variation between species may exist.