title: Genetic diversity of equine gammaherpesviruses (γ-EHV) and isolation of a syncytium forming EHV-2 strain from a horse in Iceland.
abstract: The horse population in Iceland is a special breed, isolated from other equines for at least one thousand years. This provides an exceptional opportunity to investigate old and new pathogens in a genetically closed herd. Both types of equine gammaherpesviruses, EHV-2 and EHV-5, are common in Iceland. Genetic variation was examined by sequencing four genes, glycoprotein B (gB), glycoprotein H (gH), DNA polymerase and DNA terminase for 12 Icelandic and seven foreign EHV-2 strains. One Icelandic virus isolate, gEHV-Dv, induced syncytium formation, an uncharacteristic cytopathy for EHV-2 in equine kidney cells. When sequenced, the glycoprotein genes were different from both EHV-2 and EHV-5, but the polymerase and terminase genes had 98-99% identity to EHV-2. Therefore the gEHV-Dv strain can be considered a variant of EHV-2. Substantial genetic variability was seen within the EHV-2 glycoprotein genes but limited in the polymerase and terminase genes. The Icelandic EHV-2 strains do not seem to differ phylogenetically from the foreign viruses, despite isolation for over a thousand years.
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, Iceland.
authors.forename: Lilja
authors.initials: L
authors.lastname: Thorsteinsdóttir
authors.forename: Einar G
authors.initials: EG
authors.lastname: Torfason
authors.forename: Sigurbjörg
authors.initials: S
authors.lastname: Torsteinsdóttir
authors.forename: Vilhjálmur
authors.initials: V
authors.lastname: Svansson
mesh_terms: D000818:Animals; D001483:Base Sequence; D004279:DNA, Viral / Q000235:genetics; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D018142:Gammaherpesvirinae / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics; D015726:Giant Cells / Q000821:virology*; D006566:Herpesviridae Infections / Q000662:veterinary* / Q000821:virology; D006734:Horse Diseases / Q000821:virology*; D006736:Horses / Q000821:virology; D007055:Iceland; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000662:veterinary; D018144:Rhadinovirus / Q000235:genetics* / Q000302:isolation & purification; D014412:Tumor Virus Infections / Q000662:veterinary* / Q000821:virology
chemical_list: D004279:DNA, Viral