INTRODUCTION Today, oocyte donation has become well established, giving rise to thousands of children born worldwide annually. The introduction of oocyte cryopreservation through vitrification allows the introduction of egg banking, improving the efficiency and comfort of oocyte donation. Moreover, the vitrification technique can now enable autologous donation of oocytes to prevent future infer...

Oocyte quality in pigs is defined as the potential of that oocyte to develop into a viable offspring. There is increasing evidence that the programming of the oocyte must be completed before leaving the ovarian follicle, including both nuclear and cytoplasmic maturation. Pig oocytes matured in vitro under basic conditions are deficient in some, as yet unidentified, cytoplasmic factors and thus ...

The aim of this study was to investigate 2 quantification criteria to evaluate the developmental condition of follicles cohort and clarify their impacts upon the determining of human chorionic gonadotropin trigger timing and the reproductive outcome: the proportion of mature follicles in growing follicles cohort on the day of human chorionic gonadotropin trigger and the peak estradiol level per...

The maturation of an oocyte into an egg is a key step in preparation for fertilization. In Xenopus, oocyte maturation is independent of transcription, being regulated at the level of translation and post-translational modifications of proteins. To identify factors involved in the maturation process we used two-dimensional differential gel electrophoresis to compare the proteome of oocytes and e...

BACKGROUND An inverse relationship between oocyte efficiency and ovarian response was reported in conventional IVF. The purpose of this study was to report metaphase II (MII) oocyte efficiency according to oocyte yield in minimal/mild stimulation IVF (mIVF) and to assess whether oocyte yield affects live birth rate (LBR). METHODS Infertile women (n = 264) aged < 39 years old with normal ovari...

The oocyte is the largest cell found in multicellular organisms. Mitochondria, as the energy factories for cells, are found in high numbers in oocytes, as they provide the energy for oocyte maturation, fertilization, and embryo formation via oxidative phosphorylation. Failure of assisted reproduction is mainly attributed to oocyte aging and increased aneuploidy. As the most numerous organelle i...

Oocytes grow within ovarian follicles in which the oocyte is coupled to the surrounding granulosa cells by gap junctions. It was previously found that small growing oocytes isolated from juvenile mice and freed of their surrounding granulosa cells (denuded) lacked the ability to regulate their intracellular pH (pH(i)), did not exhibit the pH(i)-regulatory HCO(3)(-)/Cl(-) and Na(+)/H(+) exchange...

Development of animal germ cells depends critically on continuous contact and communication with the somatic compartment of the gonad. In females, each oocyte is enclosed within a follicle, whose somatic cells supply nutrients that sustain basal metabolic activity of the oocyte and send signals that regulate its differentiation. This maternal microenvironment thus plays an indispensable role in...

BACKGROUND Failed fertilization occurs in 2-3% of ICSI cycles and is mainly due to lack of oocyte activation. Heterologous ICSI of patient's sperm in mouse oocytes allows discrimination between sperm- and oocyte-related aetiologies of activation failure. Assisted oocyte activation (AOA) by Ca-ionophore treatment can initiate fertilization in subsequent therapeutic ICSI. We report on diagnosis a...

Fertilization involves an initial, highly localized signal delivered by the sperm, which becomes amplified by a signal transduction cascade to impact the entire oocyte cytoplasm. The zebrafish oocyte presents a unique opportunity to study this process since fertilization always occurs at the micropyle, allowing the investigator to image the earliest steps in the oocyte activation process. The o...