All mammalian eggs are surrounded by a relatively thick extracellular coat, the zona
pellucida, that plays vital roles during oogenesis, fertilization, and preimplantation
development. The mouse zona pellucida consists of three glycoproteins that are synthesized
solely by growing oocytes and assemble into long fibrils that constitute a matrix. Zona
pellucida glycoproteins are responsible for species-restricted binding of sperm to unfertilized
eggs, inducing sperm to undergo acrosomal exocytosis, and preventing sperm from binding …