Zona Pellucida sperm-binding protein 3 receptor distribution during Gopc(-/-) globozoospermic spermatogenesis

Globozoospermia is a type of teratozoospermia characterized by round morphology of the sperm head. Gopc(-/-) infertile globozoospermic murine model has failures during spermiogenesis, such as the incorrect biogenesis of the acrosome, disorganized acroplaxome and manchette, round nuclei and spiral flagella. In this study, Western blot, RT-PCR, immunohistochemistry and immunogold were done for the localization of the acrosome protein Zona Pellucida sperm-binding protein 3 receptor (ZP3R), also called sp56, in wild type and Gopc(-/-) mice testis. The ZP3R protein was located in the acrosome and pseudo-acrosome vesicles of wild type and Gopc(-/-) mice, respectively. Also, it is distributed through the cytoplasm of the haploid spermatids only. The incorrect spermiogenesis of Gopc(-/-) mice causes a deregulation in the expression of ZP3R in the globozoospermic spermatids. Our results suggest that although the lack of GOPC causes a failure during the transport of the pre-acrosomal vesicles, the acrosome protein ZP3R is localized in the acrosome and is distributed through the cytoplasm only during spermiogenesis. Furthermore, the failure in spermiogenesis does not impair the synthesis of ZP3R and its localization in the pre-acrosomal vesicles.