Graduate Program in Zoology, Institute of Biological Sciences, Federal University of Amazonas, Av. General Rodrigo Octávio 6200, Coroado I, Manaus, Amazonas 69080-900, Brazil.
Department of Fisheries and Aquaculture, Federal Rural University of Pernambuco, Rua Dom Manoel de Medeiros - s/n, Dois Irmãos, Recife, Pernambuco 52171-900, Brazil.
Gen Comp Endocrinol. 2023 Dec 1;344:114375. doi: 10.1016/j.ygcen.2023.114375. Epub 2023 Sep 9.
In cururu stingray (Potamotrygon wallacei Carvalho, Rosa and Araújo 2016) males, plasma progesterone (P) levels appear to be associated with spermiation events. However, the specific contribution of P in sperm maturation via extratesticular ducts in this stingray species is unknown. With the aim of filling this knowledge gap, this study examined the morphology and the presence of progesterone receptors (PR) in the ducts, and analyzed the relationship of progesterone (P) with sperm maturation and formation of aggregates. Morphological analysis showed that a columnar pseudostratified epithelium with stereocilia lined all the attached ducts. In active males, the secretory cells of the epididymis and the Leydig glands presented PR; however, these receptors were not found in the distal region of the epididymis (essential for nurturing and capacitation events) of regressing males. In the seminal vesicles of active males, the spermatozoa are parallelly aligned and embedded in a matrix to form the spermatozeugmata. The matrixes are formed by proteins secreted by the ducts and Sertoli cell cytoplasts. These structures presented PR, which suggests that P engages in sperm metabolism during storage. Our findings allude to the potential role of P in regulating the development and function of the attached ducts in different reproductive phases. Furthermore, P seems to be an essential component for regulating sperm progress, protein secretion, aggregate formation, and maintenance of sperm during storage in this freshwater stingray.
在(cururu 黄貂鱼（Potamotrygon wallacei Carvalho, Rosa 和 Araújo 2016）雄性中，血浆孕酮（P）水平似乎与精子发生事件有关。然而，在这种黄貂鱼物种中，P 通过外分泌管对精子成熟的具体贡献尚不清楚。为了填补这一知识空白，本研究检查了管的形态和孕酮受体（PR）的存在，并分析了孕酮（P）与精子成熟和聚集形成的关系。形态分析表明，附着的管内衬有纤毛的柱状假复层上皮。在活跃的雄性中，附睾和睾丸间质细胞的分泌细胞呈现 PR；然而，在退化雄性的附睾远端（对营养和获能事件至关重要）未发现这些受体。在活跃雄性的精囊，精子平行排列并嵌入基质中形成精子簇。基质由管和支持细胞胞质体分泌的蛋白质形成。这些结构呈现 PR，这表明 P 在储存期间参与精子代谢。我们的发现暗示了 P 在调节附着管在不同生殖阶段的发育和功能中的潜在作用。此外，P 似乎是调节淡水黄貂鱼精子运动、蛋白质分泌、聚集形成和储存过程中精子维持的重要组成部分。
