The bi-directional communication between the oocyte and the surrounding cumulus cells (CCs) is crucial for the acquisition of oocyte competence. We investigated the transcriptomic profile of human CCs isolated from mature and immature oocytes under stimulated cycle. We used human Genome U133 Plus 2.0 microarrays to perform an extensive analysis of the genes expressed in human CCs obtained from ...

BACKGROUND The negative impact of rising progesterone levels on pregnancy rates is well known, but data on mature oocyte yield are conflicting. We examined whether delaying the oocyte maturation trigger in IVF/ICSI affected the number of mature oocytes and investigated the potential influence of serum progesterone levels in this process. METHODS Between January 31, 2011, and December 31, 2011...

Cortical granule exocytosis (CGE), also known as cortical reaction, is a calcium- regulated secretion that represents a membrane fusion process during meiotic cell division of oocytes. The molecular mechanism of membrane fusion during CGE is still poorly understood and is thought to be mediated by the SNARE pathway; nevertheless, it is unkown if SNAP (acronym for soluble NSF attachment protein)...

Glutathione (GSH) is thought to play critical roles in oocyte function including spindle maintenance and provision of reducing power needed to initiate sperm chromatin decondensation. Previous observations that GSH concentrations are higher in mature than immature oocytes and decline after fertilization, suggest that GSH synthesis may be associated with cell cycle events. To explore this possib...

Both microRNAs (miRNAs) and endogenous small interfering RNAs (endo-siRNAs) play key regulatory roles in gene expression. Some studies have demonstrated that the function of miRNA is suppressed in mouse oocytes, suggesting that endo-siRNA, not miRNA, is essential for female meiosis. This finding has yet to be confirmed in other species. In this study, by knockdown of DICER1, DROSHA and its cofa...

Porcine immature oocyte quality (i.e., that of live oocytes at the germinal vesicle stage) was evaluated according to features of the surrounding cumulus, aiming to establish maturational competence of different subpopulations of such cumulus-oocyte complexes. Six subpopulations were identified: A1 (with a dense cumulus), A2 (with a translucent cumulus), B1 (with the corona radiata), B2 (partly...

We report on a binuclear human oocyte that underwent maturation in vitro from germinal vesicle stage to metaphase II. Following extrusion of two polar bodies, the oocyte was processed for cytogenetic analysis which revealed two separate haploid chromosome sets accompanied by the corresponding polar body chromatin. Tentatively established karyotypes were 23,X and 23,X,ace, respectively. This con...

Objective The objective of this study was to evaluate LH/FSH and demographic variables on maturation stage of oocytes in patients with polycystic ovary syndrome (PCOS) with or without insulin resistance. MaterialsAndMethods Sixty patients with IVF/ICSI indication were subdivided into 3 groups as follow: 20 subjects were assigned to control (fertile women with male infertility history) group, 20...

Background: The aim of the current study was to assess the mRNA levels of two mitochondria-related genes, including nuclear-encoded NRF1 (nuclear respiratory factor 1), mitochondrial transcription factor A (TFAM), and mitochondrial-encoded cytochrome c oxidase subunit 1 (MT-CO1) genes in various stages of the human oocyte maturation. Methods: Oocytes were obtained from nine infertile women wit...

Although securin/separase/cohesion pathway was reported to regulate chromosome segregation during meiotic metaphase-to-anaphase transition, little biochemical evidence was provided. We recently found that oocytes could not progress beyond meiotic metaphase when ubiquitin-proteasome pathway was inhibited, but the mechanisms remain unclear. In the present study, we investigated the quantity of se...