Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, Pretoria 0110, South Africa.
Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private bag X04, Onderstepoort, Pretoria 0110, South Africa; Department of Basic Science, University of West Kordofan, West Kordofan State, Sudan.
Acta Histochem. 2022 Oct;124(7):151929. doi: 10.1016/j.acthis.2022.151929. Epub 2022 Aug 7.
This study investigated the developmental changes in the adherens junctions, gap junctions, as well as tight junctions forming the blood-testis barrier (BTB) in Japanese quail (Coturnix Coturnix japonica) testis. Testicular tissue from pre-pubertal, pubertal, adult, and aged Japanese quail were examined by immunohistochemistry and transmission electron microscopy (TEM). The tight junction proteins claudin-3, claudin-11, occludin and zonula occludens-1 (ZO-1), were generally localised in the cytoplasm of Sertoli cells, spermatogonia, and spermatocytes of pre-pubertal, pubertal, some adult birds. The adherens junction protein E-cadherin had a similar distribution pattern. During pre-pubertal development, the gap junction protein connexin-43 (Cx43) was only localised between Leydig cells in the testicular interstitium. However, TEM revealed the presence of gap junctions between cells of the seminiferous epithelium as early as the pre-pubertal stage. Furthermore, TEM confirmed the presence of tight and adherens junctions in the seminiferous epithelia of all age groups. The findings of this study document age-related differences in the immunolocalisation and intensity of the junctional proteins and the ultrastructure of the junctional complexes forming the BTB in quail testes. Additionally, the junctional complexes forming the BTB in the Japanese quail are well established prior to puberty. This study provides baseline information for the future evaluation of pathological changes in the BTB of avian species at different developmental stages.
本研究调查了日本鹌鹑（Coturnix Coturnix japonica）睾丸中形成血睾屏障（BTB）的黏附连接、缝隙连接以及紧密连接的发育变化。通过免疫组织化学和透射电子显微镜（TEM）检查了来自未成熟、青春期、成年和老年日本鹌鹑的睾丸组织。紧密连接蛋白 Claudin-3、Claudin-11、Occludin 和 Zonula Occludens-1（ZO-1）通常定位于未成熟、青春期、一些成年鸟类的支持细胞、精原细胞和精母细胞的细胞质中。黏附连接蛋白 E-钙黏蛋白具有相似的分布模式。在未成熟发育期间，间隙连接蛋白 Connexin-43（Cx43）仅定位于睾丸间质中的 Leydig 细胞之间。然而，TEM 早在未成熟阶段就显示出精上皮细胞之间存在缝隙连接。此外，TEM 证实了所有年龄组的生精上皮中均存在紧密连接和黏附连接。本研究记录了鹌鹑睾丸中与年龄相关的连接蛋白免疫定位和强度以及形成 BTB 的连接复合体的超微结构的差异。此外，日本鹌鹑中形成 BTB 的连接复合体在青春期前就已建立。本研究为未来评估不同发育阶段禽类 BTB 的病理变化提供了基线信息。
