Abstract :
Compelling evidence suggests that acetylation at histone H4 lysine 12 and 16 (acH4K12 and
acH4K16) influence oocyte competence. The current study was conducted to determine the
effect of vitrification on acH4K12 and acH4K16 patterns in sheep oocytes. Vitrified/warmed
oocytes or fresh oocytes were collected at GV, GVBD, MI and MII, and acH4K12 and
acH4k16 were assessed using fluorescent staining. Confocal microscopy analyses revealed
that acH4K12 and acH4K16 at GV, MI and MII were significantly higher in vitrified/warmed
oocytes than in fresh oocytes (P < 0.05). Vitrification failed to change acH4K12 and acH4K16
levels in sheep oocytes at the GVBD stage (P > 0.05). In summary, vitrification alters the
acH4K12 and acH4K16 levels in mature and immature sheep oocytes, which likely contributes
to the impaired development of vitrified oocytes after fertilization
