Genetic diversity of small-ruminant lentiviruses: characterization of Norwegian isolates of Caprine arthritis encephalitis virus.
Small-ruminant lentiviruses (SRLVs), including Caprine arthritis encephalitis virus (CAEV) in goats and maedi-visna virus (MVV) in sheep, are lentiviruses that, despite overall similarities, show considerable genetic variation in regions of the SRLV genome. To gain further knowledge about the genetic diversity and phylogenetic relationships among field isolates of SRLVs occurring in geographically distinct areas, the full-length genomic sequence of a CAEV isolate (CAEV-1GA) and partial env sequences obtained from Norwegian CAEV-infected goats were determined. The genome of CAEV-1GA consisted of 8,919 bp. Alignment studies indicated significant diversity from published SRLV sequences. Deletions and hypervariability in the 5' part of the env gene have implications for the size of the proposed CAEV-1GA Rev protein and the encoded surface glycoprotein (SU). The variable regions in the C-terminal part of SU obtained from Norwegian CAEV isolates demonstrate higher sequence divergence than has been described previously for SRLVs. Phylogenetic analysis based on SU sequences gives further support for a unique group designation. The results described here reveal a distant genetic relationship between Norwegian CAEV and other SRLVs and demonstrate that there is more geographical heterogeneity among SRLVs than reported previously.
Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Box 8146 Dep, N-0033 Oslo, Norway.
Britt
B
Gjerset
Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Box 8146 Dep, N-0033 Oslo, Norway.
Anne K
AK
Storset
Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Box 8146 Dep, N-0033 Oslo, Norway.
Espen
E
Rimstad
D000595:Amino Acid Sequence; D000818:Animals; D016088:Arthritis-Encephalitis Virus, Caprine / Q000235:genetics*; D015686:Gene Products, env / Q000235:genetics; D014644:Genetic Variation; D006023:Glycoproteins / Q000235:genetics; D006041:Goats / Q000821:virology; D008969:Molecular Sequence Data; D009664:Norway; D016415:Sequence Alignment; D013045:Species Specificity
D015686:Gene Products, env; D006023:Glycoproteins