ABSTRACT
The HindIII-HincII fragment of the 5.5 kbp H11 HindIII clone of ovine herpesvirus 1 (OvHV-1) was cloned and its primary structure was determined by preparation of nested deletion subclones and their sequencing. Sequence analysis of the overlapping clones revealed that 3239 bp OvHV-1 fragment contains complete thymidine kinase (TK) gene, a partial open reading frame of ORF20 and that encoding glycoprotein H (gH). The conserved OvHV-1 TK displayed the highest similarity to homologous TK proteins encoded by members of the Macavirus genus of the Gammaherpesvirinae subfamily. These data including our previous analysis of the partial sequence of VP23 homologue might serve as further evidence that OvHV-1 should be categorized within the genus Macavirus of the Herpesviridae family.
Subject(s)
Herpesviridae/enzymology , Thymidine Kinase/genetics , Viral Proteins/genetics , Amino Acid Sequence , Gammaherpesvirinae/chemistry , Gammaherpesvirinae/classification , Gammaherpesvirinae/genetics , Herpesviridae/chemistry , Herpesviridae/classification , Herpesviridae/genetics , Molecular Sequence Data , Open Reading Frames , Phylogeny , Sequence Analysis, Protein , Thymidine Kinase/chemistry , Viral Proteins/chemistryABSTRACT
Cytopathic effect (CPE) characterized mainly by foci of rounded cells was observed in cultures of primary plexus choroideus cells from healthy lamb following cryopreservation. It was possible to transmit the infectious agent to other primary cells of ovine origin by co-cultivation with infected cells. By indirect immunofluorescence microscopy it was found that high percentage of sheep (65-80% in 3 different herds from Slovakia) are infected with this infectious agent. Electron microscopy of cells with CPE revealed the presence of herpesvirus particles. Viral DNA was isolated from infected cells using pulse-field gel electrophoresis and further used as probe in Southern blot analysis. The probe reacted specifically only with DNA from cells infected with Ovine herpesvirus 1 (OvHV-1) but not with DNA of other ruminant herpesviruses. Some of the HindIII restriction fragments of DNA of the obtained OvHV-1 isolate denominated RKZ were cloned. Part of the H9 clone was sequenced identifying a gene that encoded a polypeptide homologous to conserved herpesvirus VP23 structural protein. From comparison of the sequence of this clone with VP23 sequences of other herpesviruses it was deduced that OvHV-1 might be classified within the Rhadinovirus genus of the Gammaherpesvirinae subfamily. The sequencing of the H9 clone of DNA of RKZ isolate enabled establishment of sensitive and highly specific polymerase chain reaction (PCR) assay for detection of OvHV-1.
Subject(s)
Herpesviridae Infections/veterinary , Herpesviridae/classification , Rhadinovirus/classification , Sheep Diseases/virology , Tumor Virus Infections/veterinary , Amino Acid Sequence , Animals , Antibodies, Viral/blood , Capsid/genetics , Coculture Techniques , Culture Techniques , Cytopathogenic Effect, Viral , DNA Primers , Deoxyribonuclease HindIII , Herpesviridae/genetics , Herpesviridae/isolation & purification , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , Rhadinovirus/genetics , Rhadinovirus/isolation & purification , Sensitivity and Specificity , Sequence Homology, Amino Acid , Sheep , Sheep Diseases/blood , Sheep Diseases/epidemiology , Slovakia/epidemiologyABSTRACT
Expression of the immediate-early genes of alpha-herpesviruses is stimulated by a family of trans-inducing factors represented by VP16 of HSV-1 and ORF10 gene product of VZV. We have identified and determined the nucleotide sequence of the UL48 gene encoding the herpesvirus of turkeys (HVT) homologue of HSV VP16. The gene maps to the BamHI-J fragment and appears to be expressed in a form of bicistronic transcript together with UL49. The deduced amino acid sequence of the protein encoded by HVT UL48 gene shows 55% identity with MDV UL48 gene product. Like the majority of related proteins in other alpha-herpesviruses, the protein encoded by HVT UL48 gene lacks the acidic C-terminal tail, known to possess the transactivation capacity of HSV VP16. Hydrophobic cluster analysis has revealed that its predicted domain composition is closely related to the transactivator protein encoded by ORF10 of VZV. However, the putative amino-terminal activation domain of the HVT homologue of HSV VP16 does not contain a typical horseshoe-like hydrophobic cluster found in other alpha-herpesvirus homologues, suggesting either that it acts as a transactivator via a different activation domain or that its transactivation potential is diminished.
