I. M. Donnik1 , M. V. Petropavlovskiy1, A. G. Isaeva1 , A. S. Krivonogova2 , N. A. Martynov1
1 Ural Federal Agrarian Research Centre of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
2 Ural State Agrarian University, Ekaterinburg, Russia E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Volume 25 No. 11
Date of paper submission: 06.09.2025, date of review: 09.09.2025, date of acceptance: 12.09.2025.
Published: 11/30/2025
Abstract. Bovine leukosis remains one of the most widespread infectious pathologies in animal husbandry. The purpose of this study was to assess the proviral load in animals infected with the leukemia virus with a known molecular genetic characteristic. Biological samples were collected in three regions of the Russian Federation with varying degrees of epizootic concern. Materials and methods. The study employed hematological, serological (ELISA), and molecular genetic (PCR) methods. For the quantitative determination of the proviral load, an original technique developed at the Ural Scientific Research Veterinary Institute was used. This method involved DNA extraction, selection of specific primers and probes, optimization of real-time PCR with the construction of a calibration curve, and subsequent statistical data processing. A total of 88 biological samples from animals of different age groups were analyzed. Scientific novelty. For the first time, data have been obtained demonstrating a complex relationship between the molecular genetic characteristics (genetic type) of the Bovine Leukemia Virus (BLV), hematological parameters, and proviral load in animals, depending on the epizootic status of an administrative region of the Russian Federation regarding leukemia. Results. It was found that the level of proviral load correlates with the epizootic situation in the regions. The highest values (26 101.05 copies / 100 ng) were recorded in Krasnodar region, which had the maximum number of affected localities and animals with hematological signs of leukosis. In Tyumen region, with a moderate level of concern, the load was significantly lower (1544.73–2463.28 copies / 100 ng), while in Sverdlovsk regon, with a favorable situation, it was minimal (1401.59 copies / 100 ng). The study showed that proviral load is a key diagnostic and pathogenetic indicator, the level of which significantly depends on the virus genotype: for genotype G4, it was 10.6 times higher than for genotype G7 and positively correlated with the intensity of leukocytosis. Conclusion. The obtained data indicate a relationship between the virulence of different bovine leukemia virus genotypes (particularly G4) and the intensity of infection spread. The results underscore the importance of continuous monitoring of the genetic diversity of the bovine leukemia virus for developing effective disease control measures.
Keywords: Bovine Leukemia Virus (BLV), PCR diagnostics, ELISA, genotype G4, genotype G7, proviral load
Acknowledgements. The study was supported by a grant from the Russian Science Foundation, project No. 23-16- 00103, https://rscf.ru/project/23-16-00103/
For citation: Donnik I. M., Petropavlovskiy M. V., Isaeva A. G., Krivonogova A. S., Martynov N. A. Dynamics of proviral load in animals with different genotypes of bovine leukemia virus. Agrarian Bulletin of the Urals. 2025; 25 (11): 1855‒1864. https://doi.org/10.32417/1997-4868-2025-25-11-1855-1864 (In Russ.)
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