Abstract
In the study, a 122 bp fragment of gag gene encoding immunodominant epitope on capsid protein of small ruminant lentiviruses (SRLVs) found in sheep was amplified by PCR and analysed by SSCP and sequencing. Out of 30 DNA samples, five showed different migration patterns, demonstrating the individual variations within gag sequences, which were confirmed afterwards by sequence analysis. In two samples nucleotide changes yielded amino acid substitutions highlighting the conservative nature of gag encoded immunoreactive epitope but also potencial insensitivity of a single-strain-based immunoassay.