Region-specific localization of IMDS-60 protein in mouse epididymis and its relationship with sperm maturation.

Spermatozoa acquire forward motility and fertilizing capacity during their transit through the epididymis. This maturation process involves modifications of the sperm surface by different proteins secreted by a series of specialized regions in the epididymal epithelium. Previously, our lab has reported IMDS-60 gene, which is highly expressed in mouse corpus and cauda epididymidis. Here, to perform further characterization of IMDS-60 protein, the specific polyclonal antisera were raised to the C-terminal peptide of the IMDS-60 protein. Western blot and immunohistochemistry assay revealed that IMDS-60 protein was specifically localized in the corpus and cauda regions of epididymidis. IMDS-60 could be transported from epididymal epithelium to the surface of epididymal spermatozoa. Finally, the results of the antibody block experiments suggested that IMDS-60 might play important roles in sperm maturation in the epididymis.