OVGP1 (oviductal glycoprotein 1) is a chitinase-like glycoprotein secreted by non-ciliated epithelial cells of the mammalian oviduct that plays crucial roles in reproduction 12. The protein belongs to the GH18 family and contains substituted catalytic residues (Asp to Phe118, Glu to Leu120) that eliminate chitinase activity while retaining carbohydrate-binding properties 1. OVGP1's primary function involves modulating sperm capacitation by increasing intracellular calcium concentrations through CatSper channels and enhancing tyrosine phosphorylation of sperm proteins, particularly AKAP3 in the fibrous sheath 34. The protein binds specifically to the zona pellucida and significantly enhances sperm-zona binding, facilitating fertilization 4. Critically, OVGP1 determines species-specificity of fertilization by covering zona pellucida pores, with its glycosylation pattern controlling which sperm can penetrate 5. Knockout studies in golden hamsters demonstrate OVGP1's essential role, as females lacking this protein fail to produce viable offspring due to abnormal embryonic development and implantation failures 6. These findings establish OVGP1 as a fundamental component of the oviductal microenvironment that governs multiple aspects of mammalian reproduction from fertilization through early embryogenesis 26.