Abstract
PURPOSE: to determine the effect of cryopreservation on acH4K12 in oocytes and their respective zygotes. METHODS: AcH4K12 in fresh or vitrified-warmed oocytes and their respective zygotes at 70 min-12 h post-fertilization were assessed using fluorescent staining. RESULTS: 1. AcH4K12 levels increased significantly in vitrified oocytes compared to controls. 2. Respective zygotes derived from vitrified oocytes had abnormal chromatin distribution or acH4K12 patterns before and after pronuclear formation. CONCLUSION: Cryopreservation alters AcH4K12 patterns in oocytes, which subsequently affect the chromatin distribution and acH4K12 in fertilized oocytes.