Glucosamine enhanced sperm-egg binding but inhibited sperm-egg fusion in mouse

In order to study the sperm-egg recognition mechanism of the surface of the plasma membrane, zonae were removed from mouse eggs by exposure to acidic conditions. Sperm binding to denuded eggs was then observed in the presence of various sugars. Among several carbohydrates tested, only glucosamine (GlcN) was found to increase the number of sperm bound to eggs while inhibiting sperm-egg fusion. The inhibition was reversible; when denuded eggs were transferred to a GlcN free medium, a high rate of polyspermy was observed.