Graduate School of Science and Technology, Niigata University, Niigata, 959-2181, Japan.
Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-0054, Japan.
Anim Reprod Sci. 2020 Mar;214:106288. doi: 10.1016/j.anireprosci.2020.106288. Epub 2020 Jan 17.
The aim of this study was to investigate the proliferation and apoptosis of male germ cells during the seasonal reproductive cycle of the large Japanese field mice (Apodemus speciosus). Male mice residing in their natural habitat were captured in Niigata, Japan. Testis sections were stained with haematoxylin and eosin, and mitotic male germ cells were identified using immunofluorescence staining for proliferating cell nuclear antigen (PCNA). Apoptosis was analysed using terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labelling (TUNEL) assay. The phases of spermatogenesis during the seasonal reproductive cycle were classified as active, transitional, and inactive based on the diameter of the seminiferous tubules. The number of PCNA-positive germ cells was less during the inactive than other phases. The percentage of TUNEL-positive germ cells per seminiferous tubule was greater during the inactive than active and transitional phases. Spermatogenesis during the seasonal reproductive cycle is controlled by proliferation and apoptosis in male germ cells. This species of undomesticated mice could be used as an animal model to study spermatogenesis as a valuable indicator of the effects of ecological and anthropogenic factors on animal reproduction.
本研究旨在探讨季节生殖周期中雄性生殖细胞的增殖和凋亡。在日本新潟县捕获了居住在自然栖息地的雄性小鼠。使用苏木精和曙红染色对睾丸切片进行染色，并使用增殖细胞核抗原（PCNA）的免疫荧光染色来鉴定有丝分裂的雄性生殖细胞。使用末端脱氧核苷酸转移酶（TdT）介导的脱氧尿苷三磷酸（dUTP）缺口末端标记（TUNEL）分析来分析凋亡。根据精小管的直径将季节性生殖周期中的精子发生阶段分类为活跃期、过渡期和不活跃期。不活跃期的 PCNA 阳性生殖细胞数量少于其他阶段。不活跃期的 TUNEL 阳性生殖细胞占精小管的百分比大于活跃期和过渡期。季节性生殖周期中的精子发生受到雄性生殖细胞增殖和凋亡的控制。这种非驯化的小鼠可作为研究精子发生的动物模型，因为它是评估生态和人为因素对动物繁殖影响的有价值指标。
