Determining the Functional Importance of Sialic Acid Residues in Sperm-Binding to the Oviduct
After insemination in mammals, sperm move to a storage reservoir in the oviduct and bind to the epithelial cells. This appears to be critical for sperm maturation to achieve fertilization. The adhesion of sperm to these cells may be mediated by sialic acid-containing sugars on proteins (glycoproteins). These experiments determine whether or not the sialic acid that binds sperm, found in the lower oviduct, has functional importance in sperm adhesion and in forming the reservoir. To accomplish this aim, oviducts from slaughtered female pigs were extracted. In these experiments, neuraminidase was used to remove the sialic acid residues from the oviductal epithelial cells to see if sperm still bind to the oviduct. The results have shown lower sperm-binding, after removal of sialic acid. Cells incubated with neuraminidase reduced sperm binding by 52% of sperm bound compared to the control without neuraminidase. After studying this component of sperm storage we found that sialic acid has a role in the sperm binding to the oviduct. These findings will contribute to increased knowledge about how this sugar can bind cells and will help to explain how the oviduct can store sperm to promote fertilization.