Abstract:
Spermadhesin AWN is a major protein of boar seminal plasma and a spermsurface-associated lectin. AWN binds to β-galactosides and to porcinezona pellucida glycoproteins, suggesting a role for this protein in primarygamete interaction. However, because capacitation induces remodelling of thesperm surface and AWN is peripherally bound to the plasma membrane, thepresent study sought to investigate whether AWN is present or absent in thesubpopulation of spermatozoa that reaches the ovulated oocyte at the period offertilization in vivo. Therefore, tubal tissues andoocytes from sows mated with a fertile boar were collected 6-8 h afterovulation. Tissues and oocyte-sperm complexes were fixed, immunolabelledwith anti-AWN monoclonal antibodies, and examined by means of light andscanning electron microscopy. The results show that spermadhesin AWN ispresent in spermatozoa seen along the genital tract of the natural mated sowas well as on plasmalemmal remnants of spermatozoa bound to the zona pellucidain vivo.