Oocyte activation is an important process triggered by fertilization that initiates embryonic development. However, parthenogenetic activation can occur either spontaneously or with chemical treatments. The LT/Sv mouse strain is genetically predisposed to spontaneous activation. LT oocytes have a cell cycle defect and are ovulated at the metaphase I stage instead of metaphase II. A thorough und...

INTRODUCTION This study investigated association of Asn680Ser FSHR polymorphism with the ovarian response in 104 women of Albanian ethnic population enrolled in ICSI program. The reason of infertility in all cases has been identified as male factor. METHODS Analysis of the Asn680Ser polymorphism was performed using TaqMan® SNP Genotyping Assay. Clinical and endocrinologic parameters were anal...

For successful fertilization by the male gamete, oocyte cytoplasmic organelles such as the Golgi apparatus have to undergo specific changes: the entire process is known as cytoplasmic maturation. The goal of this study was to unravel the dynamics of the Golgi apparatus in bovine oocytes at critical stages of in vitro maturation, i.e. germinal vesicle (GV), GV breakdown (GVBD), metaphase I (MI) ...

Abstract With the development of society, there has been a significant delay in female fertility and an increasing desire for childbearing among females advanced maternal age recent decades. Nevertheless, women over 35 years old have more risk infertility miscarriage compared to young women, due decreased oocyte quality. These changes are mainly caused by meiotic defects, especially aneuploidy....

Triggering final oocyte maturation with GnRH agonist during ovarian stimulation is feasible when inhibition of premature LH surge is performed with GnRH antagonists, and we aimed to systematically collate evidence on the clinical efficacy of GnRH agonist triggering in patients undergoing assisted reproduction in GnRH antagonist protocols. Twenty-three publications were identified by a comprehen...

The spindle assembly checkpoint (SAC) ensures correct separation of sister chromatids in somatic cells and provokes a cell cycle arrest in metaphase if one chromatid is not correctly attached to the bipolar spindle. Prolonged metaphase arrest due to overexpression of Mad2 has been shown to be deleterious to the ensuing anaphase, leading to the generation of aneuploidies and tumorigenesis. Addit...

KIF20A (Kinesin-like family member 20A), also called mitotic kinesin-like proteins 2 (MKLP2), is a mammalian mitotic kinesin-like motor protein of the Kinesin superfamily proteins (KIFs), which was originally involved in Golgi apparatus dynamics and thought to essential for cell cycle regulation during successful cytokinesis. In the present study, we investigated whether KIF20A has roles on por...

Mature oocytes of Drosophila are arrested in metaphase of meiosis I. Upon activation by ovulation or fertilization, oocytes undergo a series of rapid changes that have not been directly visualized previously. We report here the use of the Nonclaret disjunctional (Ncd) microtubule motor protein fused to the green fluorescent protein (GFP) to monitor changes in the meiotic spindle of live oocytes...

Butyrolactone I (BL I), a potent and specific inhibitor of cyclin-dependent kinases, was shown to block germinal vesicle breakdown (GVBD) in porcine oocytes in a concentration-dependent manner. GVBD was almost totally inhibited over the course of 44 h of culture when 100 pM BL I was included in TCM 199 containing either 3 mg/ml BSA or 5 % fetal calf serum (FCS). In contrast, 50 pM BL 1 was full...

In the final stages of ovarian follicular development, the mouse oocyte remains arrested in the first meiotic prophase, and cAMP-stimulated PKA plays an essential role in this arrest. After the LH surge, a decrease in cAMP and PKA activity in the oocyte initiates an irreversible maturation process that culminates in a second arrest at metaphase II prior to fertilization. A-kinase anchoring prot...