The effect of ovine oocyte vitrification on expression of subset of genes involved in epigenetic modifications during oocyte maturation and early embryo development

Apart from ultrastructural damages in oocytes subjected to cryopreservation procedures, little is known about the status of epigenetic modification and chromatin remodeling in vitrified oocytes. In present study, the expression patterns of eight genes involved in epigenetic modification (HAT1, HDAC1, SUV39H1, DNMT1, and DNMT3b), chromatin remodeling (HMGN3a and SMARCAL1), and transcription (STAT3), were investigated in fresh and vitrified germinal vesicle and metaphase II oocytes and their resulting embryos at 2 to 7 cells, 8 to 16 cells, morula, and blastocyst stages. The mRNA relative abundance was quantified by reverse transcriptase real-time polymerase chain reaction, as fold change relative to the value obtained for fresh germinal vesicle oocytes. Vitrified oocytes showed lower cleavage (38.1% vs. 95.5%, P