ANALYTICAL REVIEW OF THE CURRENT STATE THE GENETIC STUDIES OF BOVINE LEUKEMIA VIRUS (BLV)

International trade in breeding and productive livestock has led to the spread of the BLV leukosis virus in all continents. BLV eradication programs and control measures have been developed in European Union member countries since the second half of the twentieth century, and eradication programs have been very successful in most countries in Western Europe. The bovine leukemia virus (BLV) causes lymphosarcoma and persistent lymphocytosis (PL). Phylogenetic analysis of the entire genome and the env gp51 strain of BLV showed that BLV can be classified into ten genotypes. Three BLV genotypes, namely genotype-1, genotype-4 and genotype-6, were mainly found throughout the world. Thus, these results clearly demonstrate that the BLV strain should be determined by complete sequencing of the genome. However, although BLV is present throughout the world, BLV genotyping studies are limited to certain areas, as shown. The accumulation of complete genomic sequencing of BLV strains assigned to different genotypes around the world can determine genotype-dependent pathogenesis and the association between genetic variation in each genotype and its infectivity, and differences in its functions in the future.