Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/9/1994
Publication Date: N/A
Technical Abstract: The genetic variation of Epizootic Hemorrhagic Disease Viruses (EHDV) was examined. Previously we have reported the sequences of the genes which encode the three non-structural proteins & the outer capsid protein (VP2) for the two US serotypes (prototype strains). In addition, the inner capsid protein VP3 gene sequence of the US-EHDV serotype 1 has also been reported. Recently we have cloned and sequenced two laboratory strains originating from the prototype US-EHDV serotype 2 and compared their nucleic acid and deduced amino acid sequences to other known Orbivirus sequences. The two serotype 2 laboratory strains had quite different cell culture passage histories, yet their VP3 genes only differed by 0.1% indicating that this protein is very stable during passaging. Interestingly, the VP3 genes from the US serotype 2 strains had a 98% nucleic acid identity with US serotype 1, but only an 80% nucleic acid identity with the Australian serotype 2. This is consistent with the geographical variation observed among the related bluetongue Orbiviruses. To get an indication of the natural genetic variation, the gene which encodes VP2 from six field strains was sequenced. These strains had a nucleic acid identity of 97% or greater indicating that EHDV is genetically very stable. The results of these comparisons will be discussed in greater detail.