Oocyte Quality and DNA Damage Repair Mechanisms

Oocyte quality is defined by the capacity of a female gamete to complete meiosis, support fertilisation and sustain early embryonic development. Throughout the prolonged arrest in prophase of meiosis I, oocytes accumulate molecular damage that can compromise genomic integrity, most notably DNA lesions arising from oxidative stress, environmental insults or replication errors. To preserve fertility and prevent transmission of mutations, oocytes deploy specialised DNA damage response (DDR) pathways that detect lesions, signal to cell-cycle machinery and recruit repair factors. Key to this safeguarding is the spindle assembly checkpoint (SAC), which monitors chromosomal attachments and can enforce metaphase arrest in response to irreparable double-strand breaks (DSBs). Ageing further undermines these processes: repair efficiency declines, checkpoint stringency wanes and mitochondrial dysfunction exacerbates reactive oxygen species, collectively reducing developmental competence. Understanding the interplay between DNA repair mechanisms and oocyte quality has profound implications for reproductive medicine, from improving in vitro fertilisation protocols to devising interventions that mitigate age-related fertility loss.

Research from Nature Portfolio

Recent single-cell dual-omics studies have integrated transcriptome and translatome profiling to map gene expression dynamics during oocyte maturation in mouse and human. These analyses revealed species-specific translational programmes and identified factors such as OOSP2 that, when applied exogenously, can promote in vitro maturation by modulating small GTPase signalling pathways. Experimental work in mouse oocytes has demonstrated that DNA damage incurred before or after nuclear envelope breakdown activates the SAC, blocking anaphase-promoting complex activity and imposing a metaphase I arrest. This SAC-mediated response differs markedly from somatic cells and highlights a second essential function of the meiotic checkpoint in genome protection. Further investigations have shown that in aged oocytes this checkpoint is compromised, allowing progression despite DSBs and thereby contributing to the high incidence of aneuploidy observed in older females.

Oocyte Quality and DNA Damage Repair Mechanisms publication trend

The graph below shows the total number of articles in oocyte quality and dna damage repair mechanisms across all publications each year (not limited to Nature Index journals).

Technical terms

Oocyte quality: The developmental competence of an oocyte to undergo meiosis, fertilisation and early embryogenesis.

DNA damage response (DDR): A network of pathways that sense DNA lesions, halt cell-cycle progression and orchestrate repair.

Spindle assembly checkpoint (SAC): A surveillance mechanism that prevents chromosome segregation until all kinetochores are correctly attached to the spindle.

Double-strand break (DSB): A severe form of DNA damage in which both strands of the double helix are severed.

Transcriptome: The complete set of RNA transcripts present in a cell at a given time.

Translatome: The subset of the transcriptome actively engaged with ribosomes for protein synthesis.

References

1. Distinct characteristics of the DNA damage response in mammalian oocytes. Experimental & Molecular Medicine (2024).
2. Multi‐Omics Analysis Reveals Translational Landscapes and Regulations in Mouse and Human Oocyte Aging. Advanced Science (2023).
3. DNA damage-induced metaphase I arrest is mediated by the spindle assembly checkpoint and maternal age. Nature Communications (2015).
4. DNA damage induces a meiotic arrest in mouse oocytes mediated by the spindle assembly checkpoint. Nature Communications (2015).
5. Single-cell transcriptome and translatome dual-omics reveals potential mechanisms of human oocyte maturation. Nature Communications (2022).
6. The DNA damage response in mammalian oocytes. Frontiers in Genetics (2013).
7. Mechanisms of ovarian aging in women: a review. Journal of Ovarian Research (2023).