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<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" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" article-type="research-article" dtd-version="1.2" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">Biology Bulletin</journal-id><journal-title-group><journal-title xml:lang="en">Biology Bulletin</journal-title><trans-title-group xml:lang="ru"><trans-title>Известия Российской академии наук. Серия биологическая</trans-title></trans-title-group></journal-title-group><issn publication-format="print">1026-3470</issn><issn publication-format="electronic">3034-5367</issn><publisher><publisher-name xml:lang="en">The Russian Academy of Sciences</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">687613</article-id><article-id pub-id-type="doi">10.31857/S1026347025040013</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>ZOOLOGY</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>ЗООЛОГИЯ</subject></subj-group><subj-group subj-group-type="article-type"><subject>Research Article</subject></subj-group></article-categories><title-group><article-title xml:lang="en">Fluke worm <italic>Azygia lucii </italic> and pike <italic>Esox lucius</italic>: features of the relationship</article-title><trans-title-group xml:lang="ru"><trans-title>Трематода <italic>Azygia lucii</italic> и щука <italic>Esox lucius</italic>: особенности взаимоотношений</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Frolova</surname><given-names>T. V.</given-names></name><name xml:lang="ru"><surname>Фролова</surname><given-names>Т. В.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>bianka28061981@gmail.com</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Sokolova</surname><given-names>A. S.</given-names></name><name xml:lang="ru"><surname>Соколова</surname><given-names>А. С.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>bianka28061981@gmail.com</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Izvekova</surname><given-names>G. I.</given-names></name><name xml:lang="ru"><surname>Извекова</surname><given-names>Г. И.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>bianka28061981@gmail.com</email><xref ref-type="aff" rid="aff1"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">Papanin Institute for Biology of Inland Waters</institution></aff><aff><institution xml:lang="ru">Институт биологии внутренних вод им. И.Д. Папанина РАН</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2025-08-04" publication-format="electronic"><day>04</day><month>08</month><year>2025</year></pub-date><issue>4</issue><issue-title xml:lang="en"/><issue-title xml:lang="ru"/><fpage>365</fpage><lpage>374</lpage><history><date date-type="received" iso-8601-date="2025-07-15"><day>15</day><month>07</month><year>2025</year></date><date date-type="accepted" iso-8601-date="2025-07-15"><day>15</day><month>07</month><year>2025</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2025, Russian Academy of Sciences</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2025, Российская академия наук</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="en">Russian Academy of Sciences</copyright-holder><copyright-holder xml:lang="ru">Российская академия наук</copyright-holder></permissions><self-uri xlink:href="https://medjrf.com/1026-3470/article/view/687613">https://medjrf.com/1026-3470/article/view/687613</self-uri><abstract xml:lang="en"><p>The effect of <italic>Azygia lucii</italic> fluke infection on the activity of proteolytic enzymes functioning in the stomach of the host pike and the ability of worms to suppress this activity was studied. The activity of a wide range of proteases was detected in the pike’s stomach. In extracts of marita <italic>A. lucii</italic>, both pepsin-like activity and activity of alkaline proteases, a significant part of which are metal-dependent proteases, were determined. Even with a low intensity of invasion, trematodes cause an increase in the activity of pepsin-like proteases in the host’s stomach. Worm extract suppresses the activity of commercial pepsin, but neither the incubation medium nor the trematode extract have a statistically significant inhibitory effect on the activity of pepsin-like proteases of the gastric mucosa of pike.</p></abstract><trans-abstract xml:lang="ru"><p>Исследовано влияние заражения трематодами <italic>Azygia</italic><italic> </italic><italic>lucii</italic> на активность протеолитических ферментов, функционирующих в желудке хозяина–щуки, и способность червей ингибировать эту активность. В желудке щуки обнаружена активность широкого спектра протеаз. В экстрактах марит <italic>A. lucii</italic> определена как пепсиноподобная активность, так и активность щелочных протеаз, большая доля которых приходится на металл-зависимые протеазы. Даже при невысокой интенсивности инвазии трематоды вызывают повышение активности пепсиноподобных протеаз в желудке хозяина. Экстракт червей ингибирует активность коммерческого пепсина, но ни среда инкубации, ни экстракт трематод не оказывают статистически значимого ингибирующего эффекта на активность пепсиноподобных протеаз слизистой оболочки желудка щуки.</p></trans-abstract><kwd-group xml:lang="en"><kwd>fluke worm</kwd><kwd>parasite</kwd><kwd>host</kwd><kwd>pepsin-like and alkaline proteases</kwd><kwd>protease inhibitors</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>трематоды</kwd><kwd>паразит</kwd><kwd>хозяин</kwd><kwd>пепсиноподобные и щелочные протеазы</kwd><kwd>ингибиторы протеаз</kwd></kwd-group><funding-group><award-group><funding-source><institution-wrap><institution xml:lang="ru">Правительство РФ</institution></institution-wrap><institution-wrap><institution xml:lang="en">Gobierno de la Federación de Rusia</institution></institution-wrap></funding-source><award-id>124032500018-8</award-id></award-group></funding-group></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Высоцкая Р. У., Немова Н. Н. Лизосомы и лизосомальные ферменты рыб. М.: Наука, 2008. 284 с.</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Добровольский А. А., Евланов И. А., Шульман С. С. Паразитарные системы: анализ структуры и стратегии, определяющих их устойчивость / Экологическая паразитология [Ред. С. С. Шульман]. Петрозаводск: КНЦ РАН, 1994. 198 с.</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Жохов А. Е., Пугачева М. Н. Факторы, влияющие на распределение Azygia lucii в популяции дефинитивного хозяина // Биология внутренних вод. 2023. № 1. С. 115–124. https://doi.org/10.31857/S0320965223010205</mixed-citation></ref><ref id="B4"><label>4.</label><mixed-citation>Номенклатура ферментов / Под ред. Браунштейна А. Е. М.: ВИНИТИ, 1979. 324 с.</mixed-citation></ref><ref id="B5"><label>5.</label><mixed-citation>Сопрунов Ф. Ф. Молекулярные основы паразитизма. М.: Наука, 1987. 224 с.</mixed-citation></ref><ref id="B6"><label>6.</label><mixed-citation>Alarcon F. J., Martínez T. F., Barranco P., Cabello T., Díaz M., Moyano F. J. Digestive proteases during development of larvae of red palm weevil, Rhynchophorus errugineus (Olivier, 1790) (Coleoptera: Curculionidae) // Insect Biochem. Mol. Biol. 2002. V. 32. P. 265–274. https://doi.org/10.1016/S0965-1748(01)00087-X</mixed-citation></ref><ref id="B7"><label>7.</label><mixed-citation>Bos D. H., Mayfield C., Minchella D. J. Analysis of regulatory protease sequences identified through bioinformatic data mining of the Schistosoma mansoni genome // BMC Genomics. 2009. № 10:488. https://doi.org/10.1186/1471-2164-10-488</mixed-citation></ref><ref id="B8"><label>8.</label><mixed-citation>Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding // Anal. Biochem. 1976. V. 72. P. 248–254. https://doi.org/10.1016/0003-2697(76)90527-3</mixed-citation></ref><ref id="B9"><label>9.</label><mixed-citation>Caffrey C. R., Goupil L., Rebello K. M., Dalton J. P., Smith D. Cysteine proteases as digestive enzymes in parasitic helminthes // PLoS Negl. Trop. Dis. 2018. V. 12(8):e0005840. https://doi.org/10.1371/journal.pntd.0005840</mixed-citation></ref><ref id="B10"><label>10.</label><mixed-citation>Cwiklinski K., Dalton J. P. Advances in Fasciola hepatica research using ‘omics’ technologies // Int. J. Parasitol. 2018. V. 48. P. 321–331. https://doi.org/10.1016/j.ijpara.2017.12.001</mixed-citation></ref><ref id="B11"><label>11.</label><mixed-citation>Dalton J. P., Skelly P., Halton D. W. Role of the tegument and gut in nutrient uptake by parasitic platyhelminths1 // Can. J. Zool. 2004. V. 82. P. 211–232. https://doi.org/10.1139/z03-213</mixed-citation></ref><ref id="B12"><label>12.</label><mixed-citation>Delcroix M., Sajid M., Caffrey C. R., Lim K.-C., Dvorak J., Hsieh I., Bahgat M., Dissous C., McKerrow J.H. A Multienzyme Network Functions in Intestinal Protein Digestion by a Platyhelminth Parasite // J. Biol. Chem. 2006. V. 281. № 51. P. 39316–39329. https://doi.org/10.1074/jbc.M607128200</mixed-citation></ref><ref id="B13"><label>13.</label><mixed-citation>Dvorak J., Horn M. Serine proteases in schistosomes and other trematodes // Int. J. Parasitol. 2018. V. 48. P. 333–344. https://doi.org/10.1016/j.ijpara.2018.01.001</mixed-citation></ref><ref id="B14"><label>14.</label><mixed-citation>Izvekova G. I., Solovyev M. M. Activity of Digestive Hydrolases in Fish Infected with Cestodes // Biol. Bull. Rev. 2013. V. 3. № 2. P. 167–175. https://doi.org/10.1134/S2079086413020047</mixed-citation></ref><ref id="B15"><label>15.</label><mixed-citation>Izvekova G. I., Solovyev M. M. The activity of digestive enzymes of the pike Esox lucius L. infected with the cestode Triaenophorus nodulosus (Pallas) // Inland Water Biol. 2012. V. 5. № 1. P. 113–118. https://doi.org/10.1134/S1995082911040080</mixed-citation></ref><ref id="B16"><label>16.</label><mixed-citation>Izvekova G. I., Solovyov M. M., Izvekov E. I. Effect of Caryophyllaeus laticeps (Cestoda, Caryophyllidea) upon Activity of Digestive Enzymes in Bream // Biol. Bull. 2011. V. 38, № 1. P. 50–56. https://doi.org/10.1134/S1062359011010055</mixed-citation></ref><ref id="B17"><label>17.</label><mixed-citation>Fernández-Delgado M., Cortez J., Sulbarán G., Matos C., Incani R. N., Ballén D. E., Cesari I. M. Differential distribution and biochemical characteristics of hydrolases among developmental stages of Schistosoma mansoni may offer new anti-parasite targets // Parasitol. Int. 2017. V. 66. P. 816–820. https://doi.org/10.1016/j.parint.2016.09.015</mixed-citation></ref><ref id="B18"><label>18.</label><mixed-citation>Kashinskaya E. N., Simonov E. P., Izvekova G. I., Baturina O. A., Solovyev M. M. Variability of Composition of Microbiota of Gastrointestinal Tract of Perch Perca fluviatilis and Prussian Carp Carassius gibelio During the Vegetative Season // J. Ichthyology. 2021. V. 61. № 6. P. 955–971. https://doi.org/10.1134/s0032945221060060</mixed-citation></ref><ref id="B19"><label>19.</label><mixed-citation>Kashinskaya E. N., Simonov E. P., Poddubnaya L. G., Vlasenko P. G., Shokurova A. V., Parshukov A. N., Andree K. B., Solovyev M. M. Trophic diversification and parasitic invasion as ecological niche modulators for gut microbiota of whitefish // Front. Microbiol. 2023. V. 14:1090899. https://doi.org/10.3389/fmicb.2023.1090899</mixed-citation></ref><ref id="B20"><label>20.</label><mixed-citation>Kolyaskin L. Yu., Shibeko A. M. The Role of Metalloproteinases in the Development of Ischemia-Induced Pathologies of the Blood–Brain Barrier // J. Evol. Biochem. Physiol. 2024. V. 60. № 1. P. 228–246. https://doi.org/10.31857/S0869813924010021</mixed-citation></ref><ref id="B21"><label>21.</label><mixed-citation>Michaud D. Gel electrophoresis of proteolytic enzymes // Anal. Chim. Acta. 1998. № 372. P. 173–185.https://doi.org/10.1016/s0003-2670(98)00349-3</mixed-citation></ref><ref id="B22"><label>22.</label><mixed-citation>Nolasco-Soria H. Improving and standardizing protocols for alkaline protease quantification in fish // Reviews in Aquaculture. 2021. V. 13. P. 43–65.https://doi.org/10.1111/raq.12463</mixed-citation></ref><ref id="B23"><label>23.</label><mixed-citation>Pearson M. S., Ranjit N., Loukas A. Blunting the knife: development of vaccines targeting digestive proteases of blood-feeding helminth parasites // Biol. Chem. 2010. V. 391. P. 901–911.https://doi.org/10.1515/BC.2010.074</mixed-citation></ref><ref id="B24"><label>24.</label><mixed-citation>Ranasinghe S. L., McManus D. P. Protease Inhibitors of Parasitic Flukes: Emerging Roles in Parasite Survival and Immune Defence // Trends in Parasitol. 2017. V. 33. № 5. P. 400–413. https://doi.org/10.1016/j.pt.2016.12.013</mixed-citation></ref><ref id="B25"><label>25.</label><mixed-citation>Rawlings N. D., Barrett A. J. Evolutionary families of peptidases // Biochem. J. 1993. V. 290. P. 205–218. https://doi.org/10.1042/bj2900205</mixed-citation></ref><ref id="B26"><label>26.</label><mixed-citation>Smith D., Cwiklinski K., Jewhurst H., Tikhonova I. G., Dalton J. P. An atypical and functionally diverse family of Kunitz-type cysteine/serine proteinase inhibitors secreted by the helminth parasite Fasciola hepatica // Sci. Rep. 2020. № 10. P. 20657. https://doi.org/10.1038/s41598-020-77687-7</mixed-citation></ref><ref id="B27"><label>27.</label><mixed-citation>Vainutis K. S., Voronova A. N., Mironovsky A. N., Zhigileva O. N., Zhokhov A. E. The Species Diversity Assessment of Azygia Looss, 1899 (Digenea: Azygiidae) from the Volga, Ob, and Artyomovka Rivers Basins (Russia), with Description of A. sibirica n. sp. // Diversity. 2023. V. 15. № 1. P. 119. https://doi.org/10.3390/d15010119</mixed-citation></ref><ref id="B28"><label>28.</label><mixed-citation>Worthington Biochemical Corporation. Worthington enzyme manual: Enzymes. Enzyme Reagents. 1991. 346 p.</mixed-citation></ref></ref-list></back></article>
