The aim of this study was to determine the influence of hamster oviductal
glycoprotein (
oviductin) on in vitro gamete interaction.
Oviductin was purified from the oviducts using
lithium 3,5-diiodosalicylate, followed by
phenol extraction. Immunocytochemistry using indirect fluorescence staining revealed that
oviductin binds to the sperm anterior acrosomal region. The specific binding of
oviductin resulted in inhibition of in vitro fertilization in studies using cumulus-free oocytes. The inhibitory effect was dependent on the concentration of
oviductin and occurred in both ovarian and oviductal oocytes but not
zona-free oocytes, indicating that sperm-
zona interaction was interferred by oviduction. However, the inhibitory effect of
oviductin in sperm-
zona interaction was reduced when cumulus-enclosed oocytes from ovaries and oviducts were used, indicating that the egg investment including cumulus oophorus has some effect on
oviductin-sperm complex and maintaining the fertilizing ability.