Charlottesville, Va. – New reproductive research from the UVA School of Medicine has identified key molecular events that may play a critical role as human sperm and egg fuse to create new life. The findings could one day lead to the creation of a male contraceptive.
The discovery was made by members of John Herr’s lab at UVA’s Center for Research in Contraceptive and Reproductive Health. It has been featured on the cover of the scientific journal Biology of Reproduction. “This report expands our fundamental understanding of the molecular architecture at the site of sperm-egg fusion,” Herr explains. “Understanding at the molecular level exactly how the sperm is able to bind with and enter the egg opens opportunities to identify molecules that can disrupt or block the fertilization event.”
Sperm contains enzymes that help it penetrate the egg and fuse with its target. The release of these enzymes is known as the acrosomal reaction. The head of the sperm is completely transformed by this reaction. Herr’s research found that a particular protein within the sperm stays intact at the site of fusion. This protein remains in place while many other proteins are lost. This indicates that the protein, ESP1, is stabilizing the area where the sperm-egg fusion takes place.
Through this research, Herr could eventually find a way to block the protein’s interaction and possibly prevent pregnancy. Herr explains, “We don’t know enough yet about the protein-protein interactions here to be able to come up with a defined male contraceptive strategy so it’s pretty early in the process of seeing where a small molecule drug might interdict these interactions.”