Oocyte Maturation and Developmental Competence in Mammalian Systems

Oocyte maturation encompasses the coordinated progression of nuclear and cytoplasmic events that transform a quiescent germ cell into a fertilisable egg poised at metaphase II. This process relies on bidirectional communication between the oocyte and its surrounding granulosa and cumulus cells, dynamic reorganisation of organelles—particularly mitochondria and cortical granules—and precise hormonal cues that drive meiosis resumption. Developmental competence refers to the capacity of a mature oocyte to undergo successful fertilisation and sustain embryo development to the blastocyst stage and beyond. Competence is shaped by the quality of cytoplasmic maturation, maternal RNA and protein stores, metabolic resilience, and epigenetic programming. Insights into these processes underpin advances in assisted reproductive technologies, fertility preservation and livestock breeding, offering routes to improve oocyte selection, enhance in vitro protocols and mitigate age- or cryopreservation-related decline in female gamete quality.

Research from Nature Portfolio

Recent studies have demonstrated that the composition of maturation media can profoundly influence lipid metabolism in oocytes and subsequent embryo development. In porcine models, replacing maturation fluid with that from cyclic animals altered fatty acid profiles around the oocyte, upregulated transcripts governing lipid storage and synthesis, and increased the surface area occupied by lipid droplets. These changes were accompanied by improved blastocyst yield and morphological quality, indicating that extrinsic lipid cues in the follicular environment can modulate oocyte competence. Gene expression analyses highlighted key regulators of lipid homeostasis, suggesting new targets for media optimisation in vitro.

Oocyte Maturation and Developmental Competence in Mammalian Systems publication trend

The graph below shows the total number of articles in oocyte maturation and developmental competence in mammalian systems across all publications each year (not limited to Nature Index journals).

Technical terms

Oocyte maturation: progressive nuclear and cytoplasmic changes leading to a fertilisable egg.

Developmental competence: the ability of a mature oocyte to be fertilised and support embryo development.

Cumulus expansion: the enlargement of cumulus cell layers surrounding an oocyte indicative of maturation.

In vitro maturation (IVM): laboratory culture procedures enabling oocyte maturation outside the organism.

Vitrification: ultra-rapid freezing technique used to cryopreserve oocytes with minimal ice crystal formation.

Transcriptomic profiling: analysis of global gene expression patterns in cells or tissues.

References

1. Advances in Oocyte Maturation In Vivo and In Vitro in Mammals. International Journal of Molecular Sciences (2023).
2. The Role of Oocyte Organelles in Determining Developmental Competence. Biology (2017).
3. Functional signaling and gene regulatory networks between the oocyte and the surrounding cumulus cells. BMC Genomics (2018).
4. The consequences of porcine IVM medium supplementation with follicular fluid become reflected in embryo quality, yield and gene expression patterns. Scientific Reports (2018).
5. Astaxanthin Added during Post-Warm Recovery Mitigated Oxidative Stress in Bovine Vitrified Oocytes and Improved Quality of Resulting Blastocysts. Antioxidants (2024).
6. Transcriptomic Profile of Early Antral Follicles: Predictive Somatic Gene Markers of Oocyte Maturation Outcome. Cells (2025).