title: Genetic characterization of maedi-visna virus (MVV) detected in Finland.
abstract: The aim of the study was to characterize the small-ruminant lentiviruses (SRLVs) detected in Finland by defining their phylogenetic relationships and by studying the evolution of the virus based on a well-known epidemiology. The study material comprised lung tissue samples of 20 sheep from 5 different farms, a cell-cultured virus from one of the original sheep lung samples, and a blood sample of a goat. The sheep were identified as positive during seroepidemiologic screenings in 1994-1996 and the goat in 2001. Initial classification of a 251 nucleotide sequence within gag gene amplified from the uncultured samples as well as from the cell-cultured virus showed that the SRLVs were genetically close and that they were more closely related to the prototype ovine maedi-visna viruses (MVVs) than to the caprine arthritis-encephalitis virus (CAEV). The lentivirus detected from the goat aligned within the cluster of the Finnish ovine viruses, demonstrating a natural sheep-to-goat transmission. Further phylogenetic analysis of the proviral gag, pol and env sequences confirmed the initial classification and showed that they constituted a new subtype within the diverse MVV group. The sequence analyses also showed that the virus had remained genetically relatively stable, in spite of the time given for virus evolution, an estimated 20 years, and in spite of the virus crossing the host species barrier.
authors.affiliation: Finnish Food Safety Authority Evira, Animal Disease and Food Research Department, Virology, Mustialankatu 3, Helsinki, Finland. ilona.laamanen@evira.fi
authors.forename: Ilona
authors.initials: I
authors.lastname: Laamanen
authors.forename: Miia
authors.initials: M
authors.lastname: Jakava-Viljanen
authors.forename: Liisa
authors.initials: L
authors.lastname: Sihvonen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004279:DNA, Viral / Q000737:chemistry*; D005387:Finland; D005784:Gene Amplification; D015750:Genes, gag / Q000235:genetics; D015511:Goat Diseases / Q000453:epidemiology / Q000821:virology*; D006041:Goats; D008969:Molecular Sequence Data; D010802:Phylogeny; D011021:Pneumonia, Progressive Interstitial, of Sheep / Q000453:epidemiology / Q000821:virology*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000821:virology*; D014790:Visna-maedi virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004279:DNA, Viral