Enables protein homodimerization activity. Predicted to be involved in fusion of sperm to egg plasma membrane involved in single fertilization; heterotypic cell-cell adhesion; and sperm-egg recognition. Predicted to be located in acrosomal vesicle. Predicted to be active in acrosomal membrane and plasma membrane. Predicted to be integral component of membrane. Orthologous to human IZUMO1 (izumo sperm-egg fusion 1). [provided by Alliance of Genome Resources, Apr 2022]