Sperm Membrane and Zona Pellucida Interactions during Fertilization

In most species, fertilization is a necessary and essential step for the passage of one generation to the next. The genome is passed via spermatozoon and ovum into the zygote, and development begins anew. The spermatozoon’s passage through the female reproductive tract and its capacitation, which is necessary for successful egg penetration, encompass the fertilization process. Successful fertilization and therefore the survival of the species depends upon a series of steps which has been described as a hierarchy of specificities (O’Rand, 1985): from geographic isolation to the egg plasma membrane. The meeting of the sperm’s plasma membrane and the egg’s zona pellucida is almost the last step in this hierarchy and is the subject of the present discourse.