Scinderin immunoreactivity in epididymal cells also coincides with the presence of the cortical perijunctional actin filament network reported along the principal cells’ lateral plasma membranes. Whether scinderin accompanies the cell junctions in the epididymal cells or in the Sertoli cells, the protein may conceivably have similar effects on cellular contacts.
Scinderin in Spermatozoa
Our immunoblot analyses revealed a decrease in the expression of scinderin in the ejaculated compared to the ep-ididymal spermatozoa. In addition, the protein was located principally in the anterior acrosome and in the equatorial segment in the epididymal spermatozoa, but in the ejaculated spermatozoa, scinderin was no longer detectable in the equatorial segment; it was detected chiefly in the ac-rosome and in the postacrosomal region. In the head of epididymal spermatozoa, most of the actin detected was nonfilamentous or G-actin except where membrane specialization occurs. F-actin, which was apparently not observed in noncapacitated spermatozoa, was reported to develop in most regions of the gamete during capacita-tion.