Scaffold protein Lin7 family in membrane skeletal protein complex in mouse seminiferous tubules

In this study, we investigated the Lin7 family of scaffolding proteins, which interact with MPP6. By immunohistochemistry, Lin7a and Lin7c were localized in germ cells, an d Lin7c had especially strong staining in spermatogonia and early spermatocytes, characterized by staging of seminiferous tubules. By immunoelectron microscopy, Lin7 localization appeared under cell membranes in germ cells. The Lin7 staining pattern in seminiferous tubules was partially similar to t hat of 4.1G, cell adhesion molecule 1 (CADM1), and melanoma cell adhesion molecule (MCAM). Lin7-positive cells included type A spermatogonia, as revealed by double staining for Lin28a. Lin7 staining became weaker in MPP6-deficient mice by immunohistochemistry and western blotting, indicating that MP P6 transports and maintains Lin7 in germ cells. The histology of seminiferous tubules was unchanged in MPP6-deficient mice compared to that of wild-type mice. In cultured spermatogonial stem cells maintained with glial cell line-derived neurotropic factor (GDNF), Lin7 was clearly expressed and immun olocalized along cell membranes, especially at cell–cell junctions. Thus, Lin7 protein is expressed in germ cells, and Lin7, particularly Lin7c, is a useful marker for early spermatogenesis.
Source: Histochemistry and Cell Biology - Category: Biomedical Science Source Type: research