{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T09:41:03Z","timestamp":1772271663903,"version":"3.50.1"},"reference-count":34,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T00:00:00Z","timestamp":1772064000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"\u201cInstituto de Salud Carlos III\u201d, Madrid, Spain","award":["ISCIII; PI20CIII-00037"],"award-info":[{"award-number":["ISCIII; PI20CIII-00037"]}]},{"DOI":"10.13039\/501100006541","name":"\u201cComunidad Aut\u00f3noma de Madrid\u201d, Madrid, Spain","doi-asserted-by":"publisher","award":["CAM; TEC-2024\/BIO-66\/SALAINDEC-CM"],"award-info":[{"award-number":["CAM; TEC-2024\/BIO-66\/SALAINDEC-CM"]}],"id":[{"id":"10.13039\/501100006541","id-type":"DOI","asserted-by":"publisher"}]},{"name":"\u201cMinisterio de Universidades de Espa\u00f1a\u201d","award":["PRX22\/00660"],"award-info":[{"award-number":["PRX22\/00660"]}]},{"name":"\u201cMinisterio de Universidades de Espa\u00f1a\u201d","award":["PRX22\/00563"],"award-info":[{"award-number":["PRX22\/00563"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Babesia divergens, a zoonotic tick-borne pathogen, causes bovine and human babesiosis in Europe. The Elongation Factor 1 alpha (EF-1\u03b1) protein is important in many cellular processes and has emerged as a possible target for subunit vaccine development against parasitic infections, and its intergenic region (IG) is an important tool for genetic manipulation of Babesia parasites. While the EF-1\u03b1 locus of B. divergens has been described, structural variation between isolates was poorly defined. In order to fill this gap, we performed a comparative analysis of the EF-1\u03b1-IG in B. divergens human (Rouen 87 and Spanish sample) and bovine (T\u00fcrkiye) host isolates. Our findings revealed both conserved and variable elements, particularly in TA nucleotide repeat numbers and IG sequence length. The Spanish isolate exhibited the highest TA repeat expansion, whereas the Rouen 87 strain had the shortest IG. Given the known role of repeat-rich promoter elements in gene regulation, these differences may influence EF-1\u03b1 transcription. Additionally, these findings provide insights into the evolutionary divergence of B. divergens and its host adaptation mechanisms. This study establishes a foundation for future gene editing and transfection strategies, where selecting intergenic sequences with varying TA repeats could optimize transfection efficiency and explain phenotypic differences between isolates from different hosts or regions.<\/jats:p>","DOI":"10.3390\/ijms27052222","type":"journal-article","created":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T16:57:13Z","timestamp":1772125033000},"page":"2222","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparative Analysis of the EF-1\u03b1 Intergenic Region in Babesia divergens Isolates: Insights into TA Repeat Variation and Potential Regulatory Implications"],"prefix":"10.3390","volume":"27","author":[{"given":"Sezayi","family":"Ozubek","sequence":"first","affiliation":[{"name":"Department of Parasitology, Faculty of Veterinary Medicine, University of Firat, 23119 Elazig, T\u00fcrkiye"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alejandro","family":"Sanchez-Flores","sequence":"additional","affiliation":[{"name":"Unidad Universitaria de Secuenciaci\u00f3n Masiva y Bioinformatica, Institute of Biotechnology, Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM), Cuernavaca CP 62210, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3852-960X","authenticated-orcid":false,"given":"Estrella","family":"Montero","sequence":"additional","affiliation":[{"name":"Laboratorio de Referencia e Investigacion en Parasitolog\u0131a, Centro Nacional de Microbiolog\u00eda, ISCIII Majadahonda, 28220 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0260-7813","authenticated-orcid":false,"given":"Heba","family":"Alzan","sequence":"additional","affiliation":[{"name":"Parasitology and Animal Diseases Department, National Research Center, Dokki, Giza 12622, Egypt"},{"name":"Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, P.O. Box 647040, Pullman, WA 99164, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6112-2931","authenticated-orcid":false,"given":"Carlos E.","family":"Suarez","sequence":"additional","affiliation":[{"name":"Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, P.O. Box 647040, Pullman, WA 99164, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ricardo","family":"Grande","sequence":"additional","affiliation":[{"name":"Unidad Universitaria de Secuenciaci\u00f3n Masiva y Bioinformatica, Institute of Biotechnology, Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM), Cuernavaca CP 62210, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-4525-1086","authenticated-orcid":false,"given":"Aitor","family":"Gil","sequence":"additional","affiliation":[{"name":"Laboratorio de Referencia e Investigacion en Parasitolog\u0131a, Centro Nacional de Microbiolog\u00eda, ISCIII Majadahonda, 28220 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3188-8757","authenticated-orcid":false,"given":"Munir","family":"Aktas","sequence":"additional","affiliation":[{"name":"Department of Parasitology, Faculty of Veterinary Medicine, University of Firat, 23119 Elazig, T\u00fcrkiye"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9107-2450","authenticated-orcid":false,"given":"Luis Miguel","family":"Gonz\u00e1lez","sequence":"additional","affiliation":[{"name":"Laboratorio de Referencia e Investigacion en Parasitolog\u0131a, Centro Nacional de Microbiolog\u00eda, ISCIII Majadahonda, 28220 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1111\/j.1432-1033.1980.tb04898.x","article-title":"The Role of Eucaryotic Elongation Factor Tu in Protein Synthesis: The Measurement of the Elongation Factor Tu Content of Rabbit Reticulocytes and Other Mammalian Cells by a Sensitive Radioimmunoassay","volume":"110","author":"Slobin","year":"1980","journal-title":"Eur. 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