The study of canine herpesvirus biology and pathogenesis, and the search for novel canine viruses, using recently developed molecular biology techniques
Canine herpesvirus 1 (CHV-1) is as yet the only described canine herpesvirus. Only limited information on this virus, in terms of both its molecular biology and pathogenesis, was available at the start of this project. Degenerate primer polymerase chain reaction was used to amplify a small part of the glycoprotein B (gB) gene of CHV-1. This product was cloned and sequenced in order to provide some initial sequence information on the virus, thus assisting in its definitive classification and permitting further study using molecular biology techniques. Conventional primers were then designed from the known gB sequence and used to test a variety of canine tissues for the presence of viral genome. Viral sequences were found in a number of tissues, and it would appear that on the basis of these experiments, the prevalence of CHV-1 is much higher than previously reported. The molecular biology techniques used in the first part of this project were then applied to the study of canine lymphoma, one of the most common neoplasms affecting the dog. Following the success of the degenerate primer system in amplifying a portion of the gB gene of the known canine herpesvirus, a degenerate primary system was designed that was capable of amplifying part of the gB gene of any known gammaherpesvirus. This system was used to test tissues from a number of cases of canine lymphoma for the presence of gammaherpesvirus sequences. Representation difference analysis was also used to analyse cases of canine lymphoma for genetic differences from normal tissue. A number of differences were identified using this technique; their significance, and avenues of further study, are discussed.