Boy meets girl. Sperm meets egg. Now, scientists are a step closer to understanding the climax of this eternal love story: how sperm and egg merge to create a brand new individual. “It’s really the defining moment in an organism,” says William Snell, a biologist at the University of Texas Southwestern Medical Center in Dallas, Texas, who headed one of the teams that made the find.
Snell, along with a group in Britain, discovered that a protein called HAP2 is involved with the fusion of egg and sperm, and found it in a wide range of species. As well as shedding new light on fertilization, the discovery opens up a possible new avenue to tackling parasite-carried diseases such as malaria: targeting HAP2 with drugs or vaccines could perhaps stop a parasite’s sex cells from consummating their union, preventing them from replicating.