<!DOCTYPE article
PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.4 20190208//EN"
       "JATS-journalpublishing1.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" article-type="research-article" dtd-version="1.4" xml:lang="en">
 <front>
  <journal-meta>
   <journal-id journal-id-type="publisher-id">Agrarian Bulletin of the</journal-id>
   <journal-title-group>
    <journal-title xml:lang="en">Agrarian Bulletin of the</journal-title>
    <trans-title-group xml:lang="ru">
     <trans-title>Аграрный вестник Урала</trans-title>
    </trans-title-group>
   </journal-title-group>
   <issn publication-format="print">1997-4868</issn>
   <issn publication-format="online">2307-0005</issn>
  </journal-meta>
  <article-meta>
   <article-id pub-id-type="publisher-id">56739</article-id>
   <article-id pub-id-type="doi">10.32417/1997-4868-2022-229-14-33-42</article-id>
   <article-categories>
    <subj-group subj-group-type="toc-heading" xml:lang="ru">
     <subject>Биология</subject>
    </subj-group>
    <subj-group subj-group-type="toc-heading" xml:lang="en">
     <subject>Biology</subject>
    </subj-group>
    <subj-group>
     <subject>Биология</subject>
    </subj-group>
   </article-categories>
   <title-group>
    <article-title xml:lang="en">Study of genetic diversity of bovine leukemia virus isolates obtained in the Belgorod region</article-title>
    <trans-title-group xml:lang="ru">
     <trans-title>Изучение генетической вариабельности выделенных изолятов вируса лейкоза крупного рогатого скота в Белгородской области</trans-title>
    </trans-title-group>
   </title-group>
   <contrib-group content-type="authors">
    <contrib contrib-type="author">
     <contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-9892-6092</contrib-id>
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Петропавловский</surname>
       <given-names>Максим Валерьевич</given-names>
      </name>
      <name xml:lang="en">
       <surname>Petropavlovskiy</surname>
       <given-names>Maxim V.</given-names>
      </name>
     </name-alternatives>
     <xref ref-type="aff" rid="aff-1"/>
    </contrib>
    <contrib contrib-type="author">
     <contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-8349-3004</contrib-id>
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Донник</surname>
       <given-names>Ирина Михайловна</given-names>
      </name>
      <name xml:lang="en">
       <surname>Donnik</surname>
       <given-names>Irina M.</given-names>
      </name>
     </name-alternatives>
     <bio xml:lang="ru">
      <p>доктор биологических наук;</p>
     </bio>
     <bio xml:lang="en">
      <p>doctor of sciences in biology;</p>
     </bio>
     <xref ref-type="aff" rid="aff-2"/>
    </contrib>
    <contrib contrib-type="author">
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Безбородова</surname>
       <given-names>Наталья Александровна</given-names>
      </name>
      <name xml:lang="en">
       <surname>Bezborodova</surname>
       <given-names>Natalia Aleksandrovna</given-names>
      </name>
     </name-alternatives>
    </contrib>
    <contrib contrib-type="author">
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Коваленко</surname>
       <given-names>Анатолий Михайлович</given-names>
      </name>
      <name xml:lang="en">
       <surname>Kovalenko</surname>
       <given-names>Anatoliy Mihaylovich</given-names>
      </name>
     </name-alternatives>
     <xref ref-type="aff" rid="aff-3"/>
    </contrib>
    <contrib contrib-type="author">
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Беляева</surname>
       <given-names>Светлана Николаевна</given-names>
      </name>
      <name xml:lang="en">
       <surname>Belyaeva</surname>
       <given-names>Svetlana Nikolaevna</given-names>
      </name>
     </name-alternatives>
     <xref ref-type="aff" rid="aff-4"/>
    </contrib>
   </contrib-group>
   <aff-alternatives id="aff-1">
    <aff>
     <institution xml:lang="ru">Уральский государственный аграрный университет</institution>
     <city>Екатеринбург</city>
     <country>Россия</country>
    </aff>
    <aff>
     <institution xml:lang="en">Ural State Agrarian University</institution>
     <city>Yekaterinburg</city>
     <country>Russian Federation</country>
    </aff>
   </aff-alternatives>
   <aff-alternatives id="aff-2">
    <aff>
     <institution xml:lang="ru">Уральский государственный аграрный университет</institution>
     <city>Екатеринбург</city>
     <country>Россия</country>
    </aff>
    <aff>
     <institution xml:lang="en">Ural State Agrarian University</institution>
     <city>Yekaterinburg</city>
     <country>Russian Federation</country>
    </aff>
   </aff-alternatives>
   <aff-alternatives id="aff-3">
    <aff>
     <institution xml:lang="ru">Белгородский государственный аграрный университет имени В. Я. Горина</institution>
     <country>Россия</country>
    </aff>
    <aff>
     <institution xml:lang="en">Белгородский государственный аграрный университет имени В. Я. Горина</institution>
     <country>Russian Federation</country>
    </aff>
   </aff-alternatives>
   <aff-alternatives id="aff-4">
    <aff>
     <institution xml:lang="ru">Белгородский государственный аграрный университет имени В. Я. Горина</institution>
     <country>Россия</country>
    </aff>
    <aff>
     <institution xml:lang="en">Белгородский государственный аграрный университет имени В. Я. Горина</institution>
     <country>Russian Federation</country>
    </aff>
   </aff-alternatives>
   <pub-date publication-format="print" date-type="pub" iso-8601-date="2023-01-18T00:00:00+03:00">
    <day>18</day>
    <month>01</month>
    <year>2023</year>
   </pub-date>
   <pub-date publication-format="electronic" date-type="pub" iso-8601-date="2023-01-18T00:00:00+03:00">
    <day>18</day>
    <month>01</month>
    <year>2023</year>
   </pub-date>
   <volume>229</volume>
   <issue>14</issue>
   <fpage>33</fpage>
   <lpage>42</lpage>
   <history>
    <date date-type="received" iso-8601-date="2023-01-18T00:00:00+03:00">
     <day>18</day>
     <month>01</month>
     <year>2023</year>
    </date>
   </history>
   <self-uri xlink:href="https://usau.editorum.ru/en/nauka/article/56739/view">https://usau.editorum.ru/en/nauka/article/56739/view</self-uri>
   <abstract xml:lang="ru">
    <p>Аннотация. Цель исследования – изучение генетической вариабельности выделенных в Белгородской области изолятов вируса лейкоза с применением метода полиморфизма длин рестрикционных фрагментов (RFLP). Методы. Объектом исследований служили инфицированные вирусом лейкоза коровы 3–4-летнего возраста (n = 10), выявленные серологическими методами в неблагополучных молочно-товарных сельскохозяйственных предприятиях. Проводили РИД-диагностику, гематологические исследования, ПЦР, генотипирование, статистическую обработку полученных данных. Научная новизна. Лейкоз является одним из наиболее распространенных хронических инфекционных заболеваний крупного рогатого скота во многих странах мира и служит причиной существенных экономических потерь в отрасли животноводства. Типизация вируса лейкоза (BLV), изучение его генетической структуры, оценка мутаций и более подробное раскрытие биологических свойств патогена имеет большое фундаментальное и прикладное значение. Результаты. В результате проведенных гематологических исследований определена стадия лейкозного процесса у каждого животного. Методом двухэтапной гнездовой (nested) ПЦР был амплифицирован целевой участок env (gp51) гена BLV (444 п. н.) и осуществлено его генотипирование для всех изучаемых изолятов вируса лейкоза с применением метода полиморфизма длин рестрикционных фрагментов (RFLP). Нами дана первичная оценка генетической вариабельности BLV с установлением генетической группы (бельгийский генотип по RFLP). Мониторинговые исследования генотипов BLV и изучение антигенных изменений патогена позволят своевременно разрабатывать новейшие средства контроля и борьбы с распространением лейкоза, совершенствовать диагностические серологические и ПЦР тест-системы. Полученные специфические участки гена env (gp51) BLV будут использованы для дальнейшего проведения ДНК-секвенирования с последующим филогенетическим анализом и установлением аминокислотных изменений в структуре поверхностного гликопротеина (gp51) вируса лейкоза крупного рогатого скота.</p>
   </abstract>
   <trans-abstract xml:lang="en">
    <p>Abstract. The purpose of the research Was to study genetic diversity of bovine leukemia virus isolates obtained in the Belgorod Region using restriction fragment length polymorphism method (RFLP). Scientific novelty. Bovine leukosis is one of the most common chronic infectious diseases of cattle in many countries of the world, which causes significant economic losses in the livestock industry. The typing of bovine leukemia virus (BLV), the study of its genetic structure, the evaluation of the mutation vector and a more detailed disclosure of the biological properties of the pathogen represent fundamental and applied value. Methods. The object of the research was 3-4-year-old cows infected with leukemia virus (n = 10), identified by serological methods in disadvantaged dairy farms. The immunodiffusion (ID) test, hematologic studies, PCR, genotyping, statistical processing of obtained data were conducted. Results. Conducted hematological studies determined the stage of the leukemic process in each animal. The target env fragment of the BLV gene (444 bp) was amplificated by 2-stage nested PCR, and this region was genotyped for all studied leukemia virus isolates using the restriction fragment length polymorphism (RFLP) method. In the course of the work, specific regions of the BLV env (gp51) gene, 970 bp long, were also obtained. We have given a primary assessment of the genetic diversity of BLV with the establishment of a genetic group (Belgian genotype according to RFLP). In the course of the work, specific regions of the env gp51 BLV gene, 444 bp long, were obtained. These fragments will be used for further DNA sequencing followed by phylogenetic analysis and determination of amino acid changes in the structure of the surface glycoprotein (gp51) of the bovine leukemia virus. Monitoring studies of BLV genotypes and the study of antigenic changes in the pathogen will allow timely development of the latest means of controlling and restricting the spread of bovine leukosis and improvement of diagnostic serological and PCR test systems.</p>
   </trans-abstract>
   <kwd-group xml:lang="ru">
    <kwd>вирус лейкоза</kwd>
    <kwd>молекулярно-генетическая характеристика</kwd>
    <kwd>филогенетика</kwd>
    <kwd>гематология</kwd>
    <kwd>крупный рогатый скот</kwd>
    <kwd>генотипирование</kwd>
    <kwd>днк-секвенирование</kwd>
    <kwd>реакция энзимного полиморфизма</kwd>
   </kwd-group>
   <kwd-group xml:lang="en">
    <kwd>bovine leukemia virus</kwd>
    <kwd>molecular genetic characteristics</kwd>
    <kwd>phylogenetics</kwd>
    <kwd>hematology</kwd>
    <kwd>cattle</kwd>
    <kwd>genotyping</kwd>
    <kwd>DNA sequencing</kwd>
    <kwd>enzyme polymorphism reaction</kwd>
   </kwd-group>
  </article-meta>
 </front>
 <body>
  <p></p>
 </body>
 <back>
  <ref-list>
   <ref id="B1">
    <label>1.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Донник И. М., Гулюкин М. И., Бусол В. А., Коваленко Л. В., Коваленко А. М. Лейкоз крупного рогатого скота - диагностика, оздоровление, антропозоонозный потенциал (история вопроса) (обзор) // Сельскохозяйственная биология. 2021. Т. 56. № 2. С. 230-244.</mixed-citation>
     <mixed-citation xml:lang="en">Donnik I. M., Gulyukin M. I., Busol V. A., Kovalenko L. V., Kovalenko A. M. Leykoz krupnogo rogatogo skota - diagnostika, ozdorovlenie, antropozoonoznyy potencial (istoriya voprosa) (obzor) // Sel'skohozyaystvennaya biologiya. 2021. T. 56. № 2. S. 230-244.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B2">
    <label>2.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Гулюкин М. И., Капустина О. В., Ездакова И. Ю., Вальциферова С. В., Степанова Т. В., Аноятбеков М. Выявление специфических антител классов G и M к вирусу лейкоза крупного рогатого скота в сыворотках крови // Вопросы вирусологии. 2019. № 64 (4). С. 173-177. DOI: 10.36233/0507-4088-2019-64-4-173-177.</mixed-citation>
     <mixed-citation xml:lang="en">Gulyukin M. I., Kapustina O. V., Ezdakova I. Yu., Val'ciferova S. V., Stepanova T. V., Anoyatbekov M. Vyyavlenie specificheskih antitel klassov G i M k virusu leykoza krupnogo rogatogo skota v syvorotkah krovi // Voprosy virusologii. 2019. № 64 (4). S. 173-177. DOI: 10.36233/0507-4088-2019-64-4-173-177.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B3">
    <label>3.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Asfaw Y., Tsuduku S., Konishi M., Murakami K., Tsuboi T., Wu D. et al. Distribution and superinfection of bovine leukemia virus genotypes in Japan // Archives of Virology. 2005. No.150. Pp. 493-505.</mixed-citation>
     <mixed-citation xml:lang="en">Asfaw Y., Tsuduku S., Konishi M., Murakami K., Tsuboi T., Wu D. et al. Distribution and superinfection of bovine leukemia virus genotypes in Japan // Archives of Virology. 2005. No.150. Pp. 493-505.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B4">
    <label>4.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Bartlett P. C., Ladronka R. M., Ruggiero V. J., Hutchinson H. What dairy veterinarians should know about bovine leukemia virus // Bovine Practitioner. 2018. No. 52 (1). Pp. 1-7.</mixed-citation>
     <mixed-citation xml:lang="en">Bartlett P. C., Ladronka R. M., Ruggiero V. J., Hutchinson H. What dairy veterinarians should know about bovine leukemia virus // Bovine Practitioner. 2018. No. 52 (1). Pp. 1-7.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B5">
    <label>5.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Beier D., Blankenstein P., Marquardt O., Kuzmak J. Identification of different BLV provirus isolates by PCR, RFLPA and DNA sequencing // Berl Munch Tierarztl Wochenschr. 2001. Vol. 114. No. 7-8. Pp. 252-256.</mixed-citation>
     <mixed-citation xml:lang="en">Beier D., Blankenstein P., Marquardt O., Kuzmak J. Identification of different BLV provirus isolates by PCR, RFLPA and DNA sequencing // Berl Munch Tierarztl Wochenschr. 2001. Vol. 114. No. 7-8. Pp. 252-256.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B6">
    <label>6.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Chen Y. C., Chin W. Y., Chang C. C., Chuang S. T., Hsu W. L. Potential Risk Factors Associated with Infection with Bovine Leukaemia Virus in Dairy and Beef Cattle in Taiwan // Pathogens. 2021. No. 10 (12). Article number 1553. DOI: 10.3390/pathogens10121553.</mixed-citation>
     <mixed-citation xml:lang="en">Chen Y. C., Chin W. Y., Chang C. C., Chuang S. T., Hsu W. L. Potential Risk Factors Associated with Infection with Bovine Leukaemia Virus in Dairy and Beef Cattle in Taiwan // Pathogens. 2021. No. 10 (12). Article number 1553. DOI: 10.3390/pathogens10121553.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B7">
    <label>7.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Fechner H., Blankenstein P., Looman A. C., Elwert J., Geue L., Albrecht C. et al. Provirus variants of the bovine leukemia virus and their relation to the serological status of naturally infected cattle // Virology. 1997. Vol. 237. No. 2. Pp. 261-269.</mixed-citation>
     <mixed-citation xml:lang="en">Fechner H., Blankenstein P., Looman A. C., Elwert J., Geue L., Albrecht C. et al. Provirus variants of the bovine leukemia virus and their relation to the serological status of naturally infected cattle // Virology. 1997. Vol. 237. No. 2. Pp. 261-269.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B8">
    <label>8.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Frie M. C., Coussens P. M. Bovine leukemia virus: a major silent threat to proper immune responses in cattle // Veterinary Immunology and Immunopathology. 2015. Vol. 163 (3-4). Pp. 103-114. DOI: 10.1016/j.vetimm.2014.11.014.</mixed-citation>
     <mixed-citation xml:lang="en">Frie M. C., Coussens P. M. Bovine leukemia virus: a major silent threat to proper immune responses in cattle // Veterinary Immunology and Immunopathology. 2015. Vol. 163 (3-4). Pp. 103-114. DOI: 10.1016/j.vetimm.2014.11.014.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B9">
    <label>9.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Kuczewski A., Adams C., Lashewicz B., van der Meer F. Alberta dairy farmers’ and veterinarians’ opinion about bovine leukemia virus control measures // Preventive Veterinary Medicine. 2022. Vol. 200. Article number 105590. DOI: 10.1016/j.prevetmed.2022.105590.</mixed-citation>
     <mixed-citation xml:lang="en">Kuczewski A., Adams C., Lashewicz B., van der Meer F. Alberta dairy farmers’ and veterinarians’ opinion about bovine leukemia virus control measures // Preventive Veterinary Medicine. 2022. Vol. 200. Article number 105590. DOI: 10.1016/j.prevetmed.2022.105590.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B10">
    <label>10.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">LaDronka R. M., Ainsworth S., Wilkins M. J., Norby B., Byrem T. M., Bartlett P. C. Prevalence of bovine leukemia virus antibodies in US dairy cattle // Veterinary Medicine International. 2018. Vol. 2018. DOI: 10.1155/2018/5831278.</mixed-citation>
     <mixed-citation xml:lang="en">LaDronka R. M., Ainsworth S., Wilkins M. J., Norby B., Byrem T. M., Bartlett P. C. Prevalence of bovine leukemia virus antibodies in US dairy cattle // Veterinary Medicine International. 2018. Vol. 2018. DOI: 10.1155/2018/5831278.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B11">
    <label>11.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Enzootic Bovine Leukosis Disease situation [e-resource] URL: https://wahis.woah.org/#/dashboards/country-or-disease-dashboard (date of reference: 13.06.2022).</mixed-citation>
     <mixed-citation xml:lang="en">Enzootic Bovine Leukosis Disease situation [e-resource] URL: https://wahis.woah.org/#/dashboards/country-or-disease-dashboard (date of reference: 13.06.2022).</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B12">
    <label>12.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Pavliscak L. A., Nirmala J., Singh V. K., Sporer K. R. B., Taxis T M., Kumar P., Goyal S. M., Mor S. K., Schroeder D. C., Wells S.J., Droscha C. J. Tracing Viral Transmission and Evolution of Bovine Leukemia Virus through Long Read Oxford Nanopore Sequencing of the Proviral Genome // Pathogens. 2021. Vol. 10 (9). Article number 1191. DOI: 10.3390/pathogens10091191.</mixed-citation>
     <mixed-citation xml:lang="en">Pavliscak L. A., Nirmala J., Singh V. K., Sporer K. R. B., Taxis T M., Kumar P., Goyal S. M., Mor S. K., Schroeder D. C., Wells S.J., Droscha C. J. Tracing Viral Transmission and Evolution of Bovine Leukemia Virus through Long Read Oxford Nanopore Sequencing of the Proviral Genome // Pathogens. 2021. Vol. 10 (9). Article number 1191. DOI: 10.3390/pathogens10091191.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B13">
    <label>13.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Petropavlovskiy M. et al. Epizootiological and genetic characterization of the bovine leukemia virus in the Russian Federation - evaluation of bovine leukemia virus in Russia // Veterinary Archives. 2019; 89: 785-798.</mixed-citation>
     <mixed-citation xml:lang="en">Petropavlovskiy M. et al. Epizootiological and genetic characterization of the bovine leukemia virus in the Russian Federation - evaluation of bovine leukemia virus in Russia // Veterinary Archives. 2019; 89: 785-798.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B14">
    <label>14.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Petropavlovsky M. V., Vereshchak N. A., Bezborodova N. A., Oparina O. Yu. Immuno-biological evaluation of individual genetic variants of bovine leukemia virus in the conditions of the Ural region // Digital agriculture - development strategy: proceedings of the International Scientific and Practical Conference (ISPC 2019). Advances in Intelligent Systems Research. Ekaterinburg, 2019. Pp. 372-377.</mixed-citation>
     <mixed-citation xml:lang="en">Petropavlovsky M. V., Vereshchak N. A., Bezborodova N. A., Oparina O. Yu. Immuno-biological evaluation of individual genetic variants of bovine leukemia virus in the conditions of the Ural region // Digital agriculture - development strategy: proceedings of the International Scientific and Practical Conference (ISPC 2019). Advances in Intelligent Systems Research. Ekaterinburg, 2019. Pp. 372-377.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B15">
    <label>15.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Pluta A., Rola-Łuszczak M., Kubis´ P., Balov S., Moskalik R., Choudhury B., Kuzmak J.. Molecular characterization of bovine leukemia virus from Moldovan dairy cattle. Archives of Virology. 2018. Vol. 162. No. 6. Pp. 1563-1576.</mixed-citation>
     <mixed-citation xml:lang="en">Pluta A., Rola-Łuszczak M., Kubis´ P., Balov S., Moskalik R., Choudhury B., Kuzmak J.. Molecular characterization of bovine leukemia virus from Moldovan dairy cattle. Archives of Virology. 2018. Vol. 162. No. 6. Pp. 1563-1576.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B16">
    <label>16.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Polat M., Takeshima S., Aida Y. Epidemiology and genetic diversity of bovine leukemia virus // Virology Journal. 2017. Vol. 14. Article number 209. DOI: 10.1186/s12985-017-0876-4.</mixed-citation>
     <mixed-citation xml:lang="en">Polat M., Takeshima S., Aida Y. Epidemiology and genetic diversity of bovine leukemia virus // Virology Journal. 2017. Vol. 14. Article number 209. DOI: 10.1186/s12985-017-0876-4.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B17">
    <label>17.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Rice N. R., Stephens R. M., Couez D., Deschamps J., Keltmann R., Burny A. et al. The nucleotide sequence of the env gene and the post-env region of bovine leukemia virus // Virology. 1984.Vol. 138. Pp. 82-93.</mixed-citation>
     <mixed-citation xml:lang="en">Rice N. R., Stephens R. M., Couez D., Deschamps J., Keltmann R., Burny A. et al. The nucleotide sequence of the env gene and the post-env region of bovine leukemia virus // Virology. 1984.Vol. 138. Pp. 82-93.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B18">
    <label>18.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Rola-Łuszczak M., Pluta A., Olech M., Donnik I., Petropavlovskiy M., Gerilovych A. et al. The molecular characterization of bovine leukemia virus isolates from Eastern Europe and Siberia and its impact on phylogeny // PLoS One. 2013. Vol. 8. No. 3. Article number e58705. DOI: 10.1371/journal.pone.0058705.</mixed-citation>
     <mixed-citation xml:lang="en">Rola-Łuszczak M., Pluta A., Olech M., Donnik I., Petropavlovskiy M., Gerilovych A. et al. The molecular characterization of bovine leukemia virus isolates from Eastern Europe and Siberia and its impact on phylogeny // PLoS One. 2013. Vol. 8. No. 3. Article number e58705. DOI: 10.1371/journal.pone.0058705.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B19">
    <label>19.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Ruggiero V. J., Bartlett P. C. Control of Bovine Leukemia Virus in Three US Dairy Herds by Culling ELISA-Positive Cows // Veterinary Medicine International. 2019. Article number 3202184. DOI: 10.1155/2019/3202184.</mixed-citation>
     <mixed-citation xml:lang="en">Ruggiero V. J., Bartlett P. C. Control of Bovine Leukemia Virus in Three US Dairy Herds by Culling ELISA-Positive Cows // Veterinary Medicine International. 2019. Article number 3202184. DOI: 10.1155/2019/3202184.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B20">
    <label>20.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Sultanov A., Rola-Łuszczak M., Mamanova S., Ryło A., Osiński Z., Saduakassova M. A., Bashenova E., Kuźmak J. Molecular Characterization of Bovine Leukemia Virus with the Evidence of a New Genotype Circulating in Cattle from Kazakhstan // Pathogens. 2022. Vol. 11 (2). Article number 180. DOI: 10.3390/pathogens11020180.</mixed-citation>
     <mixed-citation xml:lang="en">Sultanov A., Rola-Łuszczak M., Mamanova S., Ryło A., Osiński Z., Saduakassova M. A., Bashenova E., Kuźmak J. Molecular Characterization of Bovine Leukemia Virus with the Evidence of a New Genotype Circulating in Cattle from Kazakhstan // Pathogens. 2022. Vol. 11 (2). Article number 180. DOI: 10.3390/pathogens11020180.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B21">
    <label>21.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Suzuki A., Chapman R., Douglass N., Carulei O., van Rensburg J., Williamson A. L. Phylogenetic Analysis of South African Bovine Leukaemia Virus (BLV) Isolates. Viruses. 2020. Vol. 12. No. 8. Article number 898. DOI: 10.3390/v12080898.</mixed-citation>
     <mixed-citation xml:lang="en">Suzuki A., Chapman R., Douglass N., Carulei O., van Rensburg J., Williamson A. L. Phylogenetic Analysis of South African Bovine Leukaemia Virus (BLV) Isolates. Viruses. 2020. Vol. 12. No. 8. Article number 898. DOI: 10.3390/v12080898.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B22">
    <label>22.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Enzootic bovine leucosis // In: OIE Terrestrial Manual 2018. Chap 3.4.9. Pp. 1113-1124. [e-resource] URL: https://www.woah.org/fileadmin/Home/eng/Health_standards/tahm/3.04.09_EBL.pdf (date of reference: 13.06.2022).</mixed-citation>
     <mixed-citation xml:lang="en">Enzootic bovine leucosis // In: OIE Terrestrial Manual 2018. Chap 3.4.9. Pp. 1113-1124. [e-resource] URL: https://www.woah.org/fileadmin/Home/eng/Health_standards/tahm/3.04.09_EBL.pdf (date of reference: 13.06.2022).</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B23">
    <label>23.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Yang, Y., Chen, L., Dong, M. et al. Molecular characterization of bovine leukemia virus reveals existence of genotype 4 in Chinese dairy cattle. Virology Journal. 2019. Vol. 16. Article number 108. DOI: 10.1186/s12985-019-1207-8.</mixed-citation>
     <mixed-citation xml:lang="en">Yang, Y., Chen, L., Dong, M. et al. Molecular characterization of bovine leukemia virus reveals existence of genotype 4 in Chinese dairy cattle. Virology Journal. 2019. Vol. 16. Article number 108. DOI: 10.1186/s12985-019-1207-8.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B24">
    <label>24.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Zhao X., Buehring G. Natural genetic variations in bovine leukemia virus envelope gene: possible effects of selection and escape // Virology. 2007. Vol. 366. Pp. 150-165.</mixed-citation>
     <mixed-citation xml:lang="en">Zhao X., Buehring G. Natural genetic variations in bovine leukemia virus envelope gene: possible effects of selection and escape // Virology. 2007. Vol. 366. Pp. 150-165.</mixed-citation>
    </citation-alternatives>
   </ref>
  </ref-list>
 </back>
</article>
