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Updated: Jan 5, 2026
08:51
Human Egg Maturity Assessment and Its Clinical Application
Published on: August 19, 2019
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In vitro postovulatory oocyte aging affects H3K9 trimethylation in two-cell embryos after IVF
Theresa Petri1, Debora Dankert1, Hannah Demond2
1Institute of Anatomy, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
Summary
Postovulatory oocyte aging up to eight hours did not affect embryo development rates. However, epigenetic modifications, specifically H3K9 trimethylation (H3K9me3), were observed in two-cell embryos, suggesting potential impacts on later developmental stages.
Area of Science:
- Reproductive biology
- Epigenetics
- Developmental biology
Background:
- Oocyte maturation involves sensitive processes affected by the timing of fertilization.
- Prolonged intervals between ovulation and fertilization can impair oocyte and embryo development, potentially via epigenetic changes.
- Histone modifications, such as H3K9 trimethylation (H3K9me3), influence chromatin activity and have been noted to increase during murine oocyte maturation.
Purpose of the Study:
- To investigate the impact of postovulatory oocyte aging on H3K9me3 levels.
- To assess the developmental competence of oocytes aged in vitro after retrieval.
Main Methods:
- Murine oocytes were aged in vitro for 2, 4, 6, and 8 hours post-retrieval.
- Oocyte developmental competence to the two-cell and blastocyst stages was evaluated after in vitro fertilization (IVF).
- H3K9me3 levels were analyzed in aged oocytes and resulting two-cell embryos.
Main Results:
- Postovulatory oocyte aging up to 8 hours did not significantly affect the rates of two-cell embryo and blastocyst formation.
- Despite no impact on developmental rates, alterations in H3K9me3 were detected in two-cell embryos derived from aged oocytes.
Conclusions:
- Extended postovulatory oocyte aging induces epigenetic modifications in H3K9.
- These epigenetic changes may influence embryo developmental capacity during post-implantation stages.
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