Sexual differentiation and steroidogenic mechanisms have an important impact on postnatal gonadal phenotypic development. Thus, establishing the activities that lead to male phenotypic development can provide a better understanding of this process. This study examined the prenatal development of cavies to establish morphological and histometric development patterns and protein and enzyme immunolocalization processes that are responsible for androgen synthesis in the testes and epididymis. Histological and histometric analyses of the diameter of the seminiferous cords and epididymal ducts of male fetuses on Days 25, 30, 40, and 50 were performed, as well as immunohistochemistry of the steroidogenic enzymes 5α-reductase and 17β-HSD, the androgen receptor, and the anti-Müllerian hormone (AMH). Our findings showed a cellular grouping of gonocytes from Day 30 onward that was characteristic of the seminiferous cord, which was not present in the lumen at any of the studied dates. From Day 50 onward, the differentiation of the three anatomical regions of the epididymis was evident, the head (caput), body (corpus), and tail (cauda), with tissue distinctions. Furthermore, the diameters of the seminiferous cords and epididymal ducts significantly increased with age. On Day 50, the tail showed the greatest diameter of the three regions. The Sertoli and Leydig cells exhibited AMH immunoreactivity at all dates. In addition, the Leydig cells and epididymal epithelial tissue were immunopositive for 5α-reductase, 17β-HSD, and the androgen receptor; therefore, these factors influenced the development and maintenance of the testis and epididymis during cavy prenatal development.

中文翻译：

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豚鼠（Galea spixii）胎儿睾丸和附睾分化过程中的形态组织学和类固醇生成参数

性别分化和类固醇生成机制对出生后性腺表型发育具有重要影响。因此，建立导致雄性表型发育的活动可以更好地理解这一过程。这项研究检查了豚鼠的产前发育，以建立形态学和组织学发育模式以及负责睾丸和附睾雄激素合成的蛋白质和酶免疫定位过程。对第 25、30、40 和 50 天的男性胎儿生精索和附睾管的直径进行组织学和组织计量分析，并对类固醇生成酶 5α-还原酶和 17β-HSD（雄激素受体）进行免疫组织化学分析。和抗苗勒氏管激素（AMH）。我们的研究结果显示，从第 30 天开始，生殖母细胞就出现了细胞群，这是生精索的特征，而在任何研究日期的管腔中都不存在生精索的特征。从第 50 天起，附睾的三个解剖区域的分化很明显，即头部（头部）、身体（体部）和尾部（尾部），并具有组织区别。此外，生精索和附睾管的直径随着年龄的增长而显着增加。第 50 天，尾部显示出三个区域中最大的直径。 Sertoli 和 Leydig 细胞在所有日期都表现出 AMH 免疫反应性。此外，Leydig细胞和附睾上皮组织的5α-还原酶、17β-HSD和雄激素受体免疫阳性；因此，这些因素影响了豚鼠产前发育过程中睾丸和附睾的发育和维持。