{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,10]],"date-time":"2026-11-10T15:31:10Z","timestamp":1794324670471,"version":"4.9.0"},"reference-count":0,"publisher":"ScopeMed","issue":"3","license":[{"start":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T00:00:00Z","timestamp":1775001600000},"content-version":"vor","delay-in-days":90,"URL":"https:\/\/www.openveterinaryjournal.com\/?sec=licenseinfo"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Open Vet. J."],"published-print":{"date-parts":[[2026]]},"abstract":"<jats:p>Background:\nAlthough the epididymal duct (ED) supports sperm maturation and storage, its ultrastructural and immunohistochemical adaptations in seasonal breeders, such as the Meriz buck, remain unclear.\n\nAim: \nThis study aimed to investigate seasonal adaptations in the ultrastructure and immunohistochemical profile of the ED in Meriz buck during mating and non-mating seasons.\n\nMethods: \nTwenty-four Meriz bucks from Duhok Province, Iraq, at the College of Veterinary Medicine were restudied. Epididymal tissues were examined using Transmission Electron Microscopy and immunohistochemistry \u03b1-smooth muscle actin (\u03b1-SMA), S-100, and von Willebrand factor (VWF) to characterize cellular localization during the mating and non-mating seasons.\n\nResults: \nThe epithelium of the ED comprised principal cells (PCs), basal cells, apical cells, narrow cells (NCs), and clear cells. Ultrastructurally, PCs displayed Abundant microvilli, apical blebs, and well-developed endocytotic apparatuses (vesicles and multivesicular bodies), which were more prominent in autumn (October) than in other seasons. Adjacent PCs were joined by occluding junctions, forming the Blood-Epididymal Barrier. During autumn, the supranuclear region of PCs exhibited a larger Golgi apparatus, extensive rough endoplasmic reticulum, and numerous mitochondria, whereas other epithelial cells exhibited notable seasonal variations. Immunohistochemical, \u03b1-SMA expression intensified in the peritubular and vascular smooth muscle layers during autumn (9.3 \u00b1 0.01, p &lt; 0.01), suggesting enhanced contractile activity or smooth muscle remodeling associated with reproductive seasonality. S-100 immunoreactivity was strongest in the PCs and NCs (7.5 \u00b1 0.002, p &lt; 0.01), whereas VWF expression in vascular endothelial cells increased significantly in autumn compared to other seasons (0.99 \u00b1 0.01, p &lt; 0.01).\n\nConclusion: \nThe study concludes that in October, increased ultrastructural activity and elevated expression of \u03b1- SMA, S-100, and VWF in the ED indicate increased reproductive function. Suggesting that this period corresponds to the Meriz bucks\\' mating season.<\/jats:p>","DOI":"10.5455\/ovj.2026.v16.i3.32","type":"journal-article","created":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T21:30:31Z","timestamp":1775079031000},"page":"1743","source":"Crossref","is-referenced-by-count":0,"title":["&lt;b&gt;Seasonal adaptations in the ultrastructural and immunohistochemical characterization of the epididymal duct in Meriz bucks&lt;\/b&gt;"],"prefix":"10.5455","volume":"16","author":[{"given":"Bayan","family":"Saadi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yahya","family":"Mohammed","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zeravan","family":"Mohammed","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"3407","container-title":["Open Veterinary Journal"],"original-title":[],"link":[{"URL":"https:\/\/www.bibliomed.org\/fulltextpdf.php?mno=282926","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T18:19:53Z","timestamp":1791483593000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.openveterinaryjournal.com\/?mno=282926"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2026]]}},"URL":"https:\/\/doi.org\/10.5455\/ovj.2026.v16.i3.32","relation":{},"ISSN":["2226-4485"],"issn-type":[{"value":"2226-4485","type":"print"}],"subject":[],"published":{"date-parts":[[2026]]}}}