Effect of cryopreservation on acetylation patterns of lysine 12 of histone H4 (acH4K12) in mouse oocytes and zygotes

Purpose To determine the effect of cryopreservation on acH4K12 in oocytes and their respective zygotes. Methods A cH4K12 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.