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Updated: Aug 12, 2025
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Chromatin Spread Preparations for the Analysis of Mouse Oocyte Progression from Prophase to Metaphase II
Published on: February 26, 2018
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Pre-pubertal oocytes harbor altered histone modifications and chromatin configuration
Pe'era Wasserzug Pash1, Gilad Karavani2, Eli Reich1
1Institute of Biomedical and Oral research, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
Frontiers in Cell and Developmental Biology
|January 27, 2023
Summary
Pubertal transition reorganizes oocyte chromatin, increasing histone methylation and advancing developmental potential. This finding aids in developing in vitro maturation for fertility preservation in young cancer survivors.
Area of Science:
- Reproductive Biology
- Epigenetics
- Developmental Biology
Background:
- Pre-pubertal oocytes are dormant, arrested in the germinal vesicle (GV) stage.
- Pubertal transition triggers molecular changes, but epigenetic events in oocytes remain unclear.
Purpose of the Study:
- To evaluate epigenetic marker levels in mouse and human oocytes across pubertal transition.
- To investigate the role of hormones in oocyte chromatin regulation during puberty.
Main Methods:
- Epigenetic marker analysis in pre-pubertal and post-pubertal mouse oocytes.
- H3K9me2 level assessment in human oocytes from fertility preservation patients.
- Hormonal (FSH) and pharmacological treatments on pre-pubertal oocytes.
Main Results:
- Post-pubertal mouse oocytes show fewer chromocenters and elevated heterochromatin markers (H3K9me2, H3K27me3, H4K20me1).
- Euchromatin markers H3K4me3 increased, while H3K27Ac decreased with pubertal transition.
- Follicle-stimulating hormone (FSH) treatment induced a post-pubertal chromatin configuration in pre-pubertal oocytes.
Conclusions:
- Pubertal transition significantly reorganizes oocyte chromatin structure and histone methylation.
- Hormones, particularly FSH, play a crucial role in regulating oocyte chromatin during pubertal transition.
- Findings support developing in vitro maturation protocols for pre-pubertal oocytes for fertility preservation.
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