Toyama Yoshiro, Suzuki-Toyota Fumie, Maekawa Mamiko, Ito Chizuru, Toshimori Kiyotaka
Department of Anatomy and Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Asian J Androl. 2008 Jul;10(4):577-84. doi: 10.1111/j.1745-7262.2008.00357.x. Epub 2007 Dec 20.
To understand the biological functions of the ectoplasmic specializations between Sertoli cells and maturing spermatids in seminiferous epithelia.
In order to disrupt the function of the ectoplasmic specializations, nectin-2, which is expressed at the specialization, was neutralized with anti-nectin-2 antibody micro-injected into the lumen of the mouse seminiferous tubule. Anti-nectin-3 antibody was also micro-injected into the lumen in order to neutralize nectin-3, which is expressed at the specialization.
The actin filaments at the specialization disappeared, and exfoliation of maturing spermatids was observed by electron microscopy.
Nectin-2 was neutralized by anti-nectin-2 antibody and nectin-3 was neutralized by anti-nectin-3 antibody, respectively. Inactivated nectin-2 and nectin-3 disrupted the nectin-afadin-actin system, and finally the actin filaments disappeared. As a result, the specialization lost the holding function and detachment of spermatids was observed. One of the functions of the specialization seems to be to hold maturing spermatids until spermiation.
了解生精上皮中支持细胞与成熟精子细胞之间的外质特化结构的生物学功能。
为破坏外质特化结构的功能，将抗nectin-2抗体显微注射到小鼠生精小管管腔中，以中和在该特化结构处表达的nectin-2。还将抗nectin-3抗体显微注射到管腔中，以中和在该特化结构处表达的nectin-3。
电子显微镜观察发现，该特化结构处的肌动蛋白丝消失，且出现了成熟精子细胞的脱落。
抗nectin-2抗体分别中和了nectin-2，抗nectin-3抗体中和了nectin-3。失活的nectin-2和nectin-3破坏了nectin-afadin-肌动蛋白系统，最终肌动蛋白丝消失。结果，该特化结构失去了固定功能，观察到精子细胞发生脱落。该特化结构的功能之一似乎是在精子成熟释放前固定成熟精子细胞。
