Morphological and molecular analyses on testiculture tissuer at hibernation period

首先，通过光学显微镜检查日本小马蹄蝠（冬眠期）精子发生的季节性变化。 3月份，生精小管几乎没有管腔。生精上皮由支持细胞和精原细胞组成。 6月，生精小管直径逐渐增大。流明清晰可见。偶尔会识别出精母细胞。八月和十月，可以清楚地观察到活跃的精子发生。 12月（冬眠期），精子发生完全消失。小管直径大大减小。在大多数情况下，生精上皮仅含有支持细胞和精原细胞。其次，作为冬眠实验的初步步骤，我们研究了长光周期和短光周期对叙利亚仓鼠睾丸的影响。在长光周期下，观察到活跃的精子发生，而在短光周期下，精子发生完全停止。免疫组织化学在活跃睾丸精母细胞的细胞质中检测到 Smad2 和 Smad 3。在退化的睾丸中，精母细胞核中检测到了两种 Smad。第三，研究了暴露于短光周期和低环境温度的叙利亚仓鼠精子发生的形态动力学。将雄性叙利亚仓鼠置于长光周期条件下，转入短光周期条件下（6L18D），持续13周，诱导睾丸退化。然后将部分仓鼠从23℃房间转移至5℃房间（5℃组）。其余仓鼠继续保持在23℃（23℃组）。结果，23℃组观察到快速复发。 2周（共15周）出现粗线期精母细胞，4周时检测到圆形精子细胞，8周时精子发生终于恢复。而5℃组在最初几周内几乎没有观察到复发。第13周（共26周）出现粗线期精母细胞，第16周观察到圆形精子细胞。直到20周时才发现活跃的精子发生。然后检测5℃和23℃组生精上皮增殖和凋亡活性的变化。虽然5℃和23℃组之间的精原细胞增殖活性没有显着差异，但与23℃组相比，5℃组的细胞凋亡率显着增加。此外，这种增加在冬眠期间更为明显。这些结果表明，寒冷的环境温度导致睾丸复活的延迟，这种延迟是由5℃组精原细胞凋亡活性的增加引起的，而不是由精原细胞增殖活性的变化引起的。与低温环境相比，5℃组睾丸复生延迟，这种延迟是由于精原细胞凋亡活性增加所致，而不是由于精原细胞增殖活性变化所致。与寒冷的环境温度相比，冬眠可能是刺激细胞凋亡活性以诱导复发延迟的更主导因素。较少的

First, seasonal changes in spermatogenesis of Japanese lesser horseshoe bats (a hibernating) were examined by light microscopy. In march, the seminiferous tubules revealed almost no lumen. The seminiferous epithelium consisted of Sertoli ells and spermatogonia. In june, the seminiferous tubule gradually increased in diameter. Lumen was clearly seen. Spermatocytes were occasionally recognized. In August and October, active spermatogenesis was clearly observed. In December (hibernation period), spermatogenesis completely disappeard. The diameter of tuvules greatly decreased. In most cases, the seminiferous epithelium contained only Sertoli cells and spermatogonia. Second, as the preliminary step for hibernation experiments, we examined the influence of long and short photoperiods in testes of Syrian hamsters. Under a long photoperiod, active spermatogenesis was observed, whereas under a short photoperiod, spermatogenesis completely ceased. Immunohistochemistry detected Smad2 and Smad 3 i … More n the cytoplasm of spermatocytes in the active testes. In the regressed testes, both Smads were detected in the nucleus of spermatocytes. Third, morphological dynamics on spermatogenesis in Syrian hamsters exposed to both short photoperiod and low ambient temperature were examined. Male Syrian hamsters, kept in a long photoperiod, were transferred to a short fff (6L18D) and kept there for 13weeks to induce testicular regression Some hamsters were then transferred from the room at 23℃ to that at 5℃(5℃ group). Remaining hamsters were continuously kept at 23℃ (23℃group). As a result, a rapid recrudescence was observed in 23℃ group. At 2 weeks (total 15 weeks), pachytene spermatocytes appeared, at 4 weeks round spermatids were detected, and at 8 weeks spermatogenesis finally recomvered. While littl recrudescence was observed in 5℃group during the first several weeks. At 13 weeks (total 26 weeks), pachytene spermatocytes appeared and at 16weeks round spermatids were observed. It was not until 20 weeks that active spermatogenesis was recognized. Then, the changes in the proliferative and apoptotic activities in the seminiferous epithelium of 5℃ and 23℃ groups were examined. Although no significant difference in spermatogonia proliferative activity between 5℃ and 23℃ groups was confirmed, a notable increase in the rate of apoptosis was observed in 5℃ group compared with 23℃ group. Furthermore, this increase was more salient during the hibernation period. These findings suggest that cold ambient temperature causes the delay of testicular recrudescence and this delay arises from the increase of apoptotic activity but not the change in proliferative activity in spermatogonia in 5℃ group. Compared to cold ambient temperature causes the delya of testicular recrudescence and this delay arises from the increase of apoptotic activity but not the change in proliferative activity in spermatogonia in 5℃ group. Compared to cold ambient temperature, hibernation may be more dominant factor that stimulates the apoptotic activity to induce a recrudescent delay. Less