GENOMIC HETEROGENEITY OF SMALL RUMINANT LENTIVIRUSES - EXISTENCE OF HETEROGENEOUS POPULATIONS IN SHEEP AND OF THE SAME LENTIVIRAL GENOTYPESIN SHEEP AND GOATS

We have recently shown that French small ruminant lentiviruses (SRLV) from sheep are more similar to Caprine Arthritis Encephalitis Virus (C AEV) than to visna maedi virus (VMV) in a conserved region of the pol gene. To extend these results, we have examined sequences from a varia ble region of the env gene in French SRLV. We found that they were nea rly equally distant from both CAEV and VMV strains, suggesting a consi derable divergence since the initial introduction of the virus. Analys is of separate clones from individual animals showed that some carry a population of variant viruses. The study of further pol gene sequence s from both goats and sheep suggests that viral variants show little o r no host species specificity. A phylogenetic tree of pol gene sequenc es confirmed the presence of a novel genotype of SRLV in France.