Oocyte Maturation Techniques in Mammalian Species

Oocyte maturation encompasses a series of coordinated nuclear and cytoplasmic events that prepare the female gamete for successful fertilisation and early embryonic development. In mammals, the transition from prophase arrest through germinal vesicle breakdown to metaphase II involves tightly regulated signalling cascades mediated by cyclic nucleotides and maturation-promoting factor. In vitro maturation (IVM) techniques have evolved from simple single-step culture systems to sophisticated biphasic or multiphasic approaches that mimic the ovarian microenvironment and preserve intercellular communication with cumulus cells. Advances in prematuration culture, the use of natriuretic peptides to maintain meiotic arrest, and pharmacological modulation of phosphodiesterases have significantly enhanced oocyte developmental competence across a range of species. These refinements hold promise for improving assisted reproductive technologies, preserving fertility and optimising livestock breeding programmes.

Research from Nature Portfolio

Recent studies have demonstrated that follicle-stimulating hormone induces rapid mitochondrial remodelling in porcine cumulus-oocyte complexes, revealing a transient shift from oxidative phosphorylation to glycolysis during early in vitro maturation. A novel system employing C-type natriuretic peptide preincubation followed by prostaglandin E₂ and amphiregulin stimulation has been shown to synchronise nuclear and cytoplasmic maturation in goat oocytes, improving blastocyst quality in both in vitro fertilisation and somatic cell nuclear transfer. Furthermore, bovine oocytes derived from medium-sized follicles exhibit enhanced meiotic arrest and subsequent developmental potential when subjected to a two-step maturation protocol based on natriuretic peptide pretreatment, underscoring the conserved role of cGMP-mediated signalling in meiotic regulation.

Oocyte Maturation Techniques in Mammalian Species publication trend

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

Technical terms

Cumulus-oocyte complex (COC): An oocyte surrounded by cumulus cells that support maturation and nutrient exchange.

Germinal vesicle (GV) stage: The phase in which the oocyte nucleus remains intact and meiosis is arrested.

Metaphase II (MII): The stage at which the oocyte completes the first meiotic division and is competent for fertilisation.

Meiotic arrest: The reversible suspension of oocyte meiosis regulated by cAMP and cGMP pathways.

Cyclic adenosine monophosphate (cAMP): A second messenger that maintains meiotic arrest when elevated in the oocyte.

Cyclic guanosine monophosphate (cGMP): A cyclic nucleotide produced in cumulus cells that diffuses into the oocyte to prevent cAMP degradation.

In vitro maturation (IVM): The process of maturing oocytes outside the ovarian environment under controlled laboratory conditions.

References

1. The follicle-stimulating hormone triggers rapid changes in mitochondrial structure and function in porcine cumulus cells. Scientific Reports (2024).
2. Live births after oocyte in vitro maturation with a prematuration step in women with polycystic ovary syndrome. Journal of Assisted Reproduction and Genetics (2020).
3. Signaling mechanisms and their regulation during in vivo or in vitro maturation of mammalian oocytes. Reproductive Biology and Endocrinology (2022).
4. Enhancing Oocyte Competence With Milrinone as a Phosphodiesterase 3A Inhibitor to Improve the Development of Porcine Cloned Embryos. Frontiers in Cell and Developmental Biology (2021).
5. Sequential IVM by CNP preincubation and cooperating of PGE2 with AREG enhances developmental competence of SCNT reconstructs in goat. Scientific Reports (2022).
6. Effects of C-type natriuretic peptide on meiotic arrest and developmental competence of bovine oocyte derived from small and medium follicles. Scientific Reports (2020).