Cortical granules are secretory vesicles formed in the eggs of most animals and are essential for the prevention of polyspermy in these organisms. We have studied the biogenesis of cortical granules in sea urchin oocytes by identifying cDNA clones that encode proteins targeted selectively to the cortical granules. These cDNA clones were identified by an immunoscreen of a cDNA library using anti...

OBJECTIVE Retinoids are recognized as important regulators of cell differention and tissue function. Previous studies, performed both in vivo and in vitro, indicate that retinoids influence several reproductive events. In this study, we investigated the effect of all-trans retinoic acid (t-RA) on maturation and fertilization rate of immature oocytes (germinal vesicle). MATERIALS AND METHODS G...

RGS2 is a negative regulator of G protein signaling that contains a GTPase-activating domain and a β-tubulin binding region. This study aimed to determine the localization and function of RGS2 during mouse oocyte maturation in vitro. Immunofluorescent staining revealed that RGS2 was widely expressed in the cytoplasm with a greater abundance on both meiotic spindles and first/second polar bodies...

Improved oncological treatments permit increased survival rates, although cancer patients remain at risk of losing ovarian function. An attractive option for fertility preservation includes the use of immature oocytes, a strategy which can occur on a rapid timeline and without hormonal stimulation. As a result, cancer therapy can proceed promptly even in patients with hormone-sensitive tumors. ...

In order to achieve developmental competence, porcine oocytes must undergo both nuclear and cytoplasmic maturation. Nuclear maturation results from breakdown of the germinal vesicle (GV) and progression of meiosis to metaphase II (MII). Cytoplasmic maturation is the accumulation, within the oocyte’s cytoplasm, of products necessary for fertilization, cleavage and development, prior to activatio...

To improve controlled reproduction of Eurasian perch Perca fluviatilis, the criteria for the evaluation of final oocyte maturation stages were revised. The new classification covers six preovulatory maturational stages (I -VI) from the end of vitellogenesis to germinal vesicle breakdown (GVBD) and was based on macroscopic changes of preovulatory oocytes (position of the germinal vesicle, GVBD, ...

OBJECTIVE Previously, we found that oocyte specific homeobox (Obox) 4 plays significant role in completion of meiosis specifically at meiosis I-meiosis II (MI-MII) transition. The purpose of this study was to determine the mechanism of action of Obox4 in oocyte maturation by evaluating downstream signal networking. METHODS The Obox4 dsRNA was prepared by in vitro transcription and microinject...