Implication of Amphiphysin 1 and Dynamin 2 in Tubulobulbar Complex Formation and Spermatid Release

Cell Structure and Function

Atsushi Nagai³  Shun-Ai Li¹  Yuji Kashiwakura²  Hiromi Kumon³  Hiroshi Yamada¹  Yasutomo Nasu³  Norihiro Kusumi³  Kohji Takei¹  Takashi Matsukawa⁴  Masami Watanabe³ 

[1] Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University;Center for Gene and Cell Therapy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University;Department of Urology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University;Department of Anesthesia, University of Yamanashi, Faculty of Medicine

关键词: amphiphysin 1;    dynamin 2;    tubulobulbar complex;    spermatogenesis;    testis;    endocytosis;   

DOI  :  10.1247/csf.07024

学科分类：分子生物学，细胞生物学和基因

来源: Japan Society for Cell Biology

【 摘 要 】

References(43)Cited-By(13)Tubulobulbar complexes (TBCs) are composed of several tubular invaginations formed at the plasma membrane of testicular Sertoli cells. TBCs are transiently formed at the contact region with spermatids at spermatogenic stage VII in rat and mouse, and such TBC formation is prerequisite for spermatid release. Since the characteristic structure of TBCs suggests that the molecules implicated in endocytosis could be involved in TBC formation, we here investigated the localization and physiological roles of endocytic proteins, amphiphysin 1 and dynamin 2, at TBCs. We demonstrated by immunofluorescence that the endocytic proteins were concentrated at TBCs, where they colocalized with cytoskeletal proteins, such as actin and vinculin. Immunoelectron microscopy disclosed that both amphiphysin 1 and dynamin 2 were localized on TBC membrane. Next, we histologically examined the testis from amphiphysin 1 deficient {Amph–/–} mice. Morphometric analysis revealed that the number of TBCs was significantly reduced in Amph–/–. The ratio of stage VIII seminiferous tubules was increased, and the ratio of stage IX was conversely decreased in Amph–/–. Moreover, unreleased spermatids in stage VIII seminiferous tubules were increased in Amph–/–, indicating that spermatid release and the following transition from stage VIII to IX was prolonged in Amph–/– mice. These results suggest that amphiphysin 1 and dynamin 2 are involved in TBC formation and spermatid release at Sertoli cells.

【 授权许可】

Unknown