BLV Env

Bovine leukemia virus (BLV) is a retrovirus which causes enzootic bovine leukosis in cattle. It is closely related to the human T‑lymphotropic virus type 1 (HTLV-I). BLV integrates into the genomic DNA of B‑lymphocytes as a DNA intermediate (the provirus). Besides structural and enzymatic genes required for virion production, BLV contains an oncogene coding for a protein called Tax and expresses microRNAs of unknown function. In cattle, leukemia is rare (about 5% of infected animals), but lymphoproliferation is more frequent (30%).