|References||Animal model||Materials||Number of oocytes||Number of embryos||Technology of assessment||Studied sequences||Conclusions|
|Chen et al. ||Bovine||Fresh MII, vitrified MII or embryos (D2-D8) from fresh or vitrified MII after IVM||10–15 oocytes or embryos per group||Immunofluorescence||5mC, H3K9ac, H3K9me3||Decrease in the global DNA methylation and H3K9me3 levels and increase in H3K9ac for vitrified MII oocytes. No difference observed specifically in the ICM. Decrease in the level of DNA methylation and H3K9ac in trophectoderm after oocyte vitrification.|
|Cheng et al. ||Murine||Blastocysts (D4) from fresh or vitrified MII||30–45 blastocysts per condition||Bisulfite treatment + sequencing||H19, Peg3, Snrpn||No significant differences in oocytes. Decrease in DNA methylation levels for H19, Peg3, and Snrpn in blastocysts after oocyte vitrification.|
|Zhao et al. ||Murine||Fresh MII, vitrified MII||100 oocytes per group||Bisulfite treatment + sequencing||Dnmt1o, Hat1, promoteur de Hdac1||No significant differences.|
|Hu et al. ||Bovine||Fresh MII after IVM, vitrified MII after IVM||150 oocytes per group||Immunofluorescence||Global analysis||
Decrease in methylation levels after oocytes slow freezing or after use of DMSO.|
Increase in methylation levels after using PROH.
|Spinaci et al. ||Porcine||Fresh MII after IVM, vitrified MII after IVM||H4K5ac 282 fresh oocytes, 192 vitrified oocytes; H3K9me 98 fresh oocytes, 121 vitrified oocytes||Immunofluorescence||H3K9 methylation and H4K5 acetylation||Increase in H4ac level and significant modifications of H3K9me2 levels (decrease or increase) after oocyte vitrification.|
|Milroy et al. ||Murine||Fresh MII, fresh MII after IVM, MII after IVM from vitrified GV||200 oocytes per group||Bisulfite treatment + sequencing||Pluripotency promotors Oct4, Nanog, Foxd3, Sox2||Increase in the methylation levels of Oct4 (25%) and Sox2 (4.5%) promoters after vitrification of in vitro matured oocytes compared to in vivo matured and fresh MII.|
|Yan et al. ||Murine||Fresh MII, vitrified MII||66 fresh, 70 vitrified||Immunofluorescence||H3K9me, H4K5ac||Increase in the H3K9me and H4K5ac levels after oocyte vitrification.|
|Suo et al. ||Murine||Fresh MII, vitrified MII||At least 78 oocytes per group||Immunofluorescence||H4K12ac||
Increase in the H4K12ac levels after oocyte vitrification.|
Zygotes from vitrified MII have disturbed levels before and after appearance of pronuclei.