The in vitro developmental competence of equine oocytes is still low in comparison with other domestic mammals. A major factor affecting the viability of cells during in vitro culture is the increased oxidative stress. Oxidative modifications could be responsible for oocyte incompetence for in vitro maturation (IVM). Cysteamine, a glutathione (GSH) synthesis enhancer, has been shown to increase...

Background: Process of oocyte freezing, seriously damages the molecular structure of the oocyte into the life and impair its ability to develop. It seems Oocytes can partially recompense those damages. The pentose phosphate pathway (PPP) constitutes the major source of NADPH required for the neutralization of reactive oxygen species (ROS). Glucose-6-phosphate dehydrogenase (G6PDH) is the first ...

BACKGROUND Our aim was to evaluate whether extending the interval between human chorionic gonadotrophin (hCG) priming and immature oocyte retrieval increases the oocyte maturation rate following in vitro maturation (IVM). METHODS This study was performed retrospectively. IVM was performed on 113 polycystic ovary syndrome patients (n = 120 cycles). Oocyte collection was performed either 35 h (...

CONTENTS In vitro embryo production is possible in the horse both clinically and for research applications. Oocytes may be collected from excised ovaries post-mortem, or from either immature follicles or stimulated pre-ovulatory follicles in the live mare. In vitro maturation of immature oocytes typically yields approximately 60% mature oocytes. As standard in vitro fertilization is not yet rep...

abstract: introduction & objective: the infertility treatment by using in vitro matured oocyte has many potential applications. it minimizes the risk of ovarian hyper stimulation and is an alternative treatment for women with polycystic ovarian syndrome who may have problems regarding stimulation for ivf. this method may prove important for subjects in need of fertility preservation and also pr...

BACKGROUND Approximately 20% of oocytes are classified as immature and discarded following intracytoplasmic sperm injection (ICSI) procedures. These oocytes are obtained from gonadotropin-stimulated patients, and are routinely removed from the cumulus cells which normally would mature the oocytes. Given the ready access to these human oocytes, they represent a potential resource for both clinic...

Mitofusin-2 (Mfn2), one of the mitochondrial dynamic proteins plays a key role in maintaining the integrity of mitochondrial morphology and function. However, it is unknown if Mfn2 influences the quality of oocytes in the process of development by modulating mitochondrial function in vitro. In this study, immature oocytes were transfected with Mfn2-siRNA for 16 h. We found that the expression l...

Effective protocols are introduced for parthenogenesis activation in oocytes. Hydrostatic pressure can act as a mechanical stimulator that rearranges egg contents, leading to new structural or molecular combination. Alternatively, mechanical stimulation could stimulate a mechanically-gated process, such as opening or closing of stretch activated ion channels. This study, investigated the use of...

Background: Polycystic ovary syndrome (PCOS) is a frustrating experience for women, considered as a complex challenge for researchers and clinicians. Despite the enormous effort to define the cause of PCOS, the etiology and pathogenesis still remain unclear. Oocyte quality is reflected in the oocyte’s intrinsic developmental potential. Studies have shown that the follicular development is disru...

The relationship between onset of the early cytoplasmic stages of oocyte activation (vitelline membrane separation and elevation) and nuclear meiotic maturation was investigated in starfish oocytes after their exposure to divalent ionophore (A-23187) or sperm. Meiotically mature oocytes, isolated in calcium-free seawater, underwent activation in response to sperm or ionophore as previously repo...