Organizers play important roles during the embryonic development of many animals. The most famous example is the Spemann organizer that sets up embryonic axes in amphibian embryos. In spiders, a group of BMP secreting mesenchymal cells (the cumulus) functions as an organizer of the dorsoventral axis. Similar to experiments performed with the Spemann organizer, transplantation of the cumulus is ...

New protein synthesis is essential in sheep oocytes for the progression of the meiotic cycle to metaphase. Inhibition of transcription by alpha-amanitin, a specific inhibitor of RNA polymerase II, arrests meiosis in the G2 phase in cumulus enclosed oocytes but denuded oocytes progress to M-phase. Denuded oocytes injected with alpha-amanitin also undergo maturation. Cumulus-enclosed and denuded ...

Background: The effects of cumulus cells and the effectiveness of a PDE3 specific inhibitor (Cilostamide) in comparison with an adenylate cyclase activator (Forskolin) on the maturation rate and developmental competence of mouse germinal vesicle (GV) oocytes were evaluated Materials and Methods: Germinal vesicles (GV) oocytes of PMSG-primed mice were divided into cumulus denuded oocytes (CDOs) ...

UCP2 plays a physiological role by regulating mitochondrial biogenesis, maintaining energy balance, ROS elimination, and regulating cellular autophagy in numerous tissues. But the exact roles of UCP2 in cumulus cells are still not clear. Genipin, a special UCP2 inhibitor, was added into the cultural medium to explore the roles of UCP2 in human cumulus cells. There were no significant difference...

The extracellular matrix (ECM) of porcine mature oocytes was revealed by transmission electron microscopy (TEM) after treatment with tannic acid and ruthenium red. Present in the perivitelline space (PVS) and on the surface of the zona pellucida (ZP), it appeared to be composed of thin filaments and granules at the interconnections of the filaments, which were interpreted respectively as hyalur...

Normal oocyte maturation depends on signal transmission between granulosa cells and the oocyte. We have analysed the effects of inhibiting (I) cyclic AMP-dependent protein kinase (protein kinase A, PK-A), (II) Ca2+/phospholipid-dependent protein kinase (protein kinase C, PK-C) and (III) calmodulin (CaM) on pig oocyte maturation in vitro, protein synthesis and phosphorylation. The inhibition of ...

BACKGROUND The understanding of the mechanisms regulating human oocyte maturation is still rudimentary. We have identified transcripts differentially expressed between immature and mature oocytes and cumulus cells. METHODS Using oligonucleotide microarrays, genome-wide gene expression was studied in pooled immature and mature oocytes or cumulus cells from patients who underwent IVF. RESULTS...

15 Fatty acid oxidation (FAO) is essential for oocyte maturation in mice. The objective of this 16 experiment was to determine the effect of etomoxir (a FAO inhibitor; 100 μM), carnitine (1 17 mM), and palmitic acid (1 or 100 μM) during maturation on metabolism and gene expression of 18 the oocyte and cumulus cells, and subsequent embryo development in the mouse. Carnitine 19 significantly incr...

BACKGROUND Cryopreservation has limited successes and in-vitro maturation is used to improve its results. Hydrostatic pressure (HP) plays an important role in follicular development. OBJECTIVE This study was designed to examine the effects of HP on in-vitro maturation of oocytes and cell death in cumulus cells derived from vitrified-warmed mouse ovaries. MATERIALS AND METHODS Preovulatory f...

Ca(2+)-dependent mechanisms are critical for successful completion of fertilization. Here, we demonstrate that CRISP1, a sperm protein involved in mammalian fertilization, is also present in the female gamete and capable of modulating key sperm Ca(2+) channels. Specifically, we show that CRISP1 is expressed by the cumulus cells that surround the egg and that fertilization of cumulus-oocyte comp...