Genetic diversity of the long terminal repeat of bovine leukaemia virus field isolates

In this study the sequences of the long terminal repeat (LTR) of field isolates of the bovine leukaemia virus (BLV) were analysed. These isolates came from emerging cases of BLV infection in cattle from herds having BLV-free status. We found several sequence variations within regulatory motifs in the LTRs like GRE, DAS and interferon binding site. These mutations can possibly affect transcriptional activity of the virus, leading to its silencing.