Immature oocytes become fertilisable eggs through a process called meiotic maturation, which is often induced by specific hormones. Oocyte maturation involves the activation of various signal transduction pathways that converge to activate maturation-promoting factor (MPF); this is a key activity that catalyses entry into M-phase of meiosis I and meiosis II. Whereas the function of MPF in promo...

Objectives: To find out occurrence of ovarian hyperstimulation in patients who were hyper responders vitro fertilization cycles. Secondary outcome was to assess number metaphase II oocyte and rate, cleavage rate pregnancy when GnRHa is used for final maturation triggering ovulation. STUDY DESIGN, SIZE, DURATION: This retrospective descriptive analysis cases managed at single center from June 20...

conclusions the present study showed that vitrification using cryotop and freezing medium can damage oocytes by reducing the maturation and fertilization rates in both developmental stages. results vitrification caused a significant reduction in the maturation rate of oocytes. of those that matured, the fertilization rate of vitrified ivm-mii (44.1%) and ov-mii oocytes (50%) was not significant...

Maturation (M-phase) promoting factor (MPF) plays a pivotal role in oocytes during their maturation. This review concentrates on its function at three important time-points. First, its activation during meiotic progression from prophase I arrest at germinal vesicle breakdown. Second, its role during the transition from meiosis I to meiosis II, a defining feature of meiosis involving segregation...

Background In vitro maturation (IVM) of human oocytes has acquired increasing attention in infertility treatment with great promise. This technique is an alternative conventional in vitro fertilization-embryo transfer (IVF-ET), and can be reduced the side effects of gonadotropin stimulation such as ovarian hyperstimulation (OHSS). Oocyte maturation is a complex process including cytoplasmic and...

In the ovary, the paracrine interactions between the oocyte and surrounded granulosa cells are critical for optimal oocyte quality and embryonic development. Mice lacking the androgen receptor (AR⁻/⁻) were noted to have reduced fertility with abnormal ovarian function that might involve the promotion of preantral follicle growth and prevention of follicular atresia. However, the detailed mechan...

In mitosis, the spindle assembly checkpoint (SAC) prevents anaphase onset until all chromosomes have been attached to the spindle microtubules and aligned correctly at the equatorial metaphase plate. The major checkpoint proteins in mitosis consist of mitotic arrest-deficient (Mad)1-3, budding uninhibited by benzimidazole (Bub)1, Bub3, and monopolar spindle 1(Mps1). During meiosis, for the form...

Improved oncological treatments permit increased survival rates, although cancer patients remain at risk of losing ovarian function. An attractive option for fertility preservation includes the use of immature oocytes, a strategy which can occur on a rapid timeline and without hormonal stimulation. As a result, cancer therapy can proceed promptly even in patients with hormone-sensitive tumors. ...