title: Sequence analysis of ORFs 5, 6 and 7 of equine arteritis virus during persistent infection of the stallion--a 7-year study.
abstract: Nucleotide and amino acid sequences of ORFs 5, 6 and 7 of EAV during persistent infection in the stallion of the Malopolska breed were analysed in the study. A total of 11 blood and semen samples were collected between 2004 and 2011. The titre of specific EAV antibodies in this carrier stallion was maintained at a high level throughout the study and was equal approximately 1:128. The sequence analysis of ORF5 showed 16 variable sites including 12 with synonymous substitutions and 4 with non-synonymous substitutions. The degree of nucleotide sequence identity among the strains ranged from 98.92% to 100%, whereas amino acid homology ranged from 98.06% to 100%. Ten substitutions were identified including 7 with synonymous mutations and 3 with non-synonymous mutations in ORF6. The degree of similarities among the strains ranged from 94.55 to 100% and from 98.41% to 100% at the level of nucleotide and amino acid sequence, respectively. Only a single point mutation at position 255 of ORF7 (99.6% identity) was found in nucleotide sequences of these strains. Phylogenetic analysis showed that all strains present in the semen of this carrier stallion created a separate cluster of "quasi-species" within the second European subgroup of EAV.
authors.affiliation: Department of Virology, National Veterinary Research Institute, Pulawy, Poland. jrola@piwet.pulawy.pl
authors.forename: Jerzy
authors.initials: J
authors.lastname: Rola
authors.forename: Wojciech
authors.initials: W
authors.lastname: Socha
authors.forename: Jan F
authors.initials: JF
authors.lastname: Zmudzinski
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018174:Arterivirus Infections / Q000662:veterinary* / Q000821:virology; D001947:Breeding; D002353:Carrier State / Q000662:veterinary / Q000821:virology; D007240:Equartevirus / Q000145:classification / Q000235:genetics*; D006734:Horse Diseases / Q000821:virology*; D006736:Horses; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames / Q000235:genetics*; D010802:Phylogeny; D017421:Sequence Analysis; D013995:Time