Advances in Oocyte Maturation In Vivo and In Vitro in Mammals

Abstract

The quality and maturation of an oocyte not only play decisive roles in fertilization and embryo success, but also have long-term impacts on the later growth and development of the fetus. Female fertility declines with age, reflecting a decline in oocyte quantity. However, the meiosis of oocytes involves a complex and orderly regulatory process whose mechanisms have not yet been fully elucidated. This review therefore mainly focuses on the regulation mechanism of oocyte maturation, including folliculogenesis, oogenesis, and the interactions between granulosa cells and oocytes, plus in vitro technology and nuclear/cytoplasm maturation in oocytes. Additionally, we have reviewed advances made in the single-cell mRNA sequencing technology related to oocyte maturation in order to improve our understanding of the mechanism of oocyte maturation and to provide a theoretical basis for subsequent research into oocyte maturation.

In Vitro Growth of Human Follicles: Current and Future Perspectives

“…Follicle development involves a series of precisely regulated biological events (illustrated in Figure 2): activation of primordial follicles (35-40 µm) with GCs becoming cuboidal (called primary follicles; 50-60 µm diameter), growth of the primary follicles with an increase in the proliferation rate of GCs yielding a multilaminar granulosa layer (called secondary follicles; 115-125 µm diameter), creation of a theca layer that will produce steroid hormones through a complex interaction with the GCs, development of an antral cavity, and rupture of the ovulatory follicle releasing a cumulus-oocyte complex (COC) after antral follicles reach 20 mm in diameter [11][12][13]. Currently, it is estimated that more than 10,000 girls and women worldwide have undergone OTC [6], and more than 200 children have been conceived from OTT [7].…”

“…Early folliculogenesis is under paracrine control and is gonadotrophin-independent, whereas late folliculogenesis is under endocrine control and is gonadotrophin-dependent. Follicle and oocyte promedium sizes for human and mouse are mentioned, as well as time of appearance [13]. Created with BioRender.com.…”

Comparison of Steroidogenic and Ovulation-Inducing Effects of Orthosteric and Allosteric Agonists of Luteinizing Hormone/Chorionic Gonadotropin Receptor in Immature Female Rats

“…The main function of the metalloproteinase ADAMTS-1 is the degradation of the extracellular matrix, which is critical for normal terminal folliculogenesis and determines the ability of the oocyte to be fertilized by sperm [35][36][37][38]. Based on this, the distribution of ADAMTS-1 in the ovaries of female rats at various time points after treatment with TP4/2 and hCG was studied using an immunohistochemical approach with polyclonal anti-ADAMTS-1 antibody.…”

Enhancing antioxidant levels and mitochondrial function in porcine oocyte maturation and embryonic development through notoginsenoside R1 supplementation

“…Yet, the efficacy of IVP can be influenced by factors such as oocyte quality and culture conditions can impact the efficiency of IVP (Herrick, 2019). The quality and maturity of oocytes are vital for successful fertilization and have profound implications on subsequent embryonic growth and development (Jiang et al, 2023;Schultz & Heyner, 1992).…”