Mammalian oocytes are deficient in their ability to carry out glycolysis. Therefore, the products of glycolysis that are necessary for oocyte development are provided to oocytes by companion cumulus cells. Mouse oocytes secrete paracrine factors that promote glycolysis in cumulus cells. The objective of this study was to identify paracrine factors secreted by oocytes that promote glycolysis and...

objective: this study examines the effects of hydrostatic pressure on in vitro maturation (ivm) of oocytes derived from in vitro grown follicles. materials and methods: in this experimental study, preantral follicles were isolated from 12-day-old female nmri mice. each follicle was cultured individually in alpha minimal essential medium (α-mem) under mineral oil for 12 days. then, follicles wer...

BACKGROUND The production of competent oocytes depends on a bi-directional communication between the oocyte and cumulus cells. The goal of this study was to determine whether simple parameters monitored in cumulus cells from individual human oocytes have any predictive value, and thus correlate with clinically relevant parameters. METHODS 97 cumulus-oocyte complexes were recovered from 31 pat...

Vitrifying oocytes is a potentially valuable means of preserving the female germ line, but significantly compromises oocyte developmental competence. This study examined the hypothesis that the cumulus complex protects the oocyte during vitrification. Vitrified-warmed immature cumulus oocyte complexes (COCs) were labelled with a plasma membrane impermeant DNA marker (ethidium homodimer-1) to ex...

Background: The study was carried out to investigate the relationship between the development potential and the diameter of ovine oocytes. Materials and Methods: Ovaries collected from a local abattoir were transported to the laboratory within 1-3 h of slaughter. The oocytes from follicles (2-6 mm in diameter) were recovered by aspiration and stored in a preincubated (at 38.6 C, 5% CO2 and maxi...

OBJECTIVE To evaluate the effect of the use of cumulus-aided embryo transfer on pregnancy rates. To study the proximity of expanded cumulus cells to the developing embryo. To document by light microscopy the anchoring of day 3 to day 4 embryos by the expanded cumulus cells. To demonstrate by transmission electron microscopy the cellular activity of the expanded cumulus cells. To evaluate the ex...

cAMP and intracellular Ca2+ are important second messengers involved in mammalian follicular growth and oocyte meiotic maturation. We investigated the capacity of the neurohormone serotonin (5-hydroxytryptamine, 5-HT) to regulate intracellular cAMP and Ca2+ in mouse oocytes and surrounding cumulus cells. On the basis of a reverse transcription-polymerase chain reaction study, 5-HT7 receptor mRN...

The morphology of canine cumulus-oocyte complexes (COCs) before puberty is still unknown. Therefore, the aim of our study was to elucidate the morphological characteristics of pre-pubertal oocytes and cumulus cells by light microscopy, scanning electron microscopy and transmission electron microscopy. The pre-pubertal oocyte was characterized by accumulation of lipid yolk droplets in the cytopl...

(1) Background: The binding sites of melatonin, as a multifunctional molecule, have been identified in human, porcine, and bovine samples. However, the binding sites and mechanisms of melatonin have not been reported in sheep; (2) Methods: Cumulus-oocyte complexes (COCs) were cultured in TCM-199 supplemented with melatonin at concentrations of 0, 10-3, 10-5, 10-7, 10-9, and 10-11 M. Melatonin r...