Genotypic identity of bovine leukemia virus isolates, circulating in livestock populations of the Republic of Tatarstan

The bovine leukemia virus (BLV) is the etiological agent of bovine leukosis, which causes significant economic damage to the livestock sector. Molecular genetic methods of investigation are the most informative tools for its genotype identification, while the modern phylogenetic classification of BLV provides for the presence of ten genotypes of the pathogen. The aim of the study was to establish the genotypic identity of BLV isolates circulating in livestock populations of the Republic of Tatarstan, using a phylogenetic analysis of the envgene provirus sequences and PCR-RFLP-analysis, consistent with the phylogenetic classification of the studied viral pathogen. As a result of the study, it was found that the isolates of the 1st, 4th, 7th and 8th genotypes of BLV circulate in livestock populations of the Republic of Tatarstan. The strategy of PCR-RFLP-genotyping of BLV, proposed in accordance with the phylogenetic classification, was updated taking into account new knowledge of the genetic diversity of the pathogen, and allows identification of all ten known BLV genotypes