Laboratory of Veterinary Anatomy, Department of Veterinary Medicine, Okayama University of Science, Imabari, Japan.
Department of Veterinary Anatomy, The University of Tokyo, Tokyo, Japan.
Anat Histol Embryol. 2021 Mar;50(2):417-421. doi: 10.1111/ahe.12628. Epub 2020 Oct 26.
The postnatal testicular development and actin distribution in the seminiferous epithelium were examined by light microscopy, using the testes of the Habu (Trimeresurus flavoviridis; snake) from 0-year-old to 3-year-old. At 0-year-old (about 1 month after birth), the testis was quite small in size, and the seminiferous epithelium was composed of only Sertoli cells and large spermatogonia. Actin immunoreactivity was observed in the peritubular myoid cells, but could not be detected in the seminiferous epithelium. At 1-year-old (about 10 months after birth), the testicular size increased to a great degree. In the seminiferous epithelium, spermatocytes newly appeared. Actin could still not be detected in the seminiferous epithelium. At 2-year-old (about 1 year and 10 months after birth), the testes continued to develop in size. In the seminiferous epithelium, elongate spermatids and round spermatids were frequently seen, in addition to Sertoli cells, spermatogonia and spermatocytes. Thus, active spermatogenesis was clearly recognized at this age. Moreover, the actin distribution in the seminiferous epithelium was observed at the site between Sertoli cells and spermatids, as well as that at adult stage. The immunoreactivity of actin in the peritubular myoid cells gradually increased from 0-year-old to 2-year-old. Conclusively, it seems likely that spermatogenesis in the Habu initiates at 2-year-old, accompanying with the appearance of actin in the seminiferous epithelium.
通过光镜检查了来自 0 岁至 3 岁的哈布（Trimeresurus flavoviridis；蛇）睾丸的产后睾丸发育和生精上皮中的肌动蛋白分布。在 0 岁（出生后约 1 个月）时，睾丸体积很小，生精上皮仅由支持细胞和大精原细胞组成。肌动蛋白免疫反应性存在于小管周肌样细胞中，但在生精上皮中无法检测到。在 1 岁（出生后约 10 个月）时，睾丸大小显著增加。在生精上皮中，精母细胞新出现。生精上皮中仍然无法检测到肌动蛋白。在 2 岁（出生后约 1 年 10 个月）时，睾丸继续发育。在生精上皮中，除了支持细胞、精原细胞和精母细胞外，还经常看到长形精子和圆形精子。因此，在这个年龄段可以清楚地识别活跃的精子发生。此外，还观察到生精上皮中肌动蛋白的分布位于支持细胞和精子之间的部位，以及成年阶段的分布。小管周肌样细胞中的肌动蛋白免疫反应性从 0 岁到 2 岁逐渐增加。总之，哈布的精子发生似乎在 2 岁开始，伴随着生精上皮中肌动蛋白的出现。
