Sequence variation in the gp135 gene of Maedi visna virus strain EV1

We have used the PCR and HIRT DNA obtained from MVV-infected tissue culture cells as a template to generate a number of independently derived clones representing overlapping fragments of the gp135 region (env) of Maedi visna virus (MVV) strain EV1. Sequencing these clones revealed that homology between selected regions of gp135 ranged from 93.2% to 99.8%. Four hypervariable regions and one large highly conserved region have been identified. These data provide information on the variability of EV1 env, which extends and complements the data previously available on env variability between geographically distinct isolates of MVV.