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...

Backgroud: Oocyte cryopreservation is critical in assisted reproduction techniques. However, the effect of cryopreservation on the oocyte has not been widely explored yet. Currently a thorough understanding of oocyte cryobiology is urgently required due to its far lag behind the forces propelling the clinical application of oocyte cryopreservation. Methods: In this study, we used two different ...

31 32 In the growing follicle, communication between the oocyte and its surrounding follicular 33 cells is essential for normal oocyte and follicular development. Maturation of the fully34 grown oocyte in vivo is associated with the loss of cumulus cell-oocyte gap junctional 35 communication, preventing entry of meiotic-modulating factors such as cAMP into the 36 oocyte. We have previously show...

In the four decades since the Xenopus oocyte was first demonstrated to have the capacity to translate exogenous mRNAs, this system has been exploited for many different experimental purposes. Typically, the oocyte is used either as a "biological test tube" for heterologous expression of proteins without any particular cell biological insight or, alternatively, it is used for applications where ...

OBJECTIVE To assess whether there is an increased risk of infertility in women that have previously undergone ovarian stimulation and oocyte retrieval for oocyte donation. DESIGN Cross-sectional survey. SETTING Tertiary referral center. PATIENT(S) A total of 194 past oocyte donors. INTERVENTION(S) Telephone questionnaire. MAIN OUTCOME MEASURE(S) Incidence of infertility after oocyte d...

Vertebrate female reproduction is limited by the oocyte stockpiles acquired during embryonic development. These are gradually depleted over the organism's lifetime through the process of apoptosis. The timer that triggers this cell death is yet to be identified. We used the Xenopus egg/oocyte system to examine the hypothesis that nutrient stores can regulate oocyte viability. We show that pento...

Genetic experiments suggest that polarization of the oocyte is linked directly to the initial cell fate determination that singles out the oocyte from its 15 sister cells. Specification of oocyte cell fate as well as establishment and maintenance of a polarized microtubule network within the Drosophila oocyte require the activity of the egalitarian (egl) and BicaudalD (BicD) genes. We have isol...