Background: Leukemia inhibitory factor (LIF) is a 45-56 kDa glycoprotein that has an important role in proliferation and embryo implantation. Its effect on oocyte maturation and how to exert the function remained to be elucidated. Methods: Immature mice superovulated with human menopausal gonadotropin and germinal vesicle (GV) oocytes were obtained from ovary 48 hours after. GV oocytes were cul...

Background: The aim of this study was to assess effects of cysteamine as an anti-oxidant on rate of in vitro maturation of oocyte and determination of its effects on spindle size and shape. Methods: Pre-mature mice were primed with pregnant mare stimulating gonadotrophin (PMSG) and germinal vesicle (GV) stage oocytes were obtained 48 h after. The oocytes were cultured in tissue culture medium (...

background: the aim of this study was to assess effects of cysteamine as an anti-oxidant on rate of in vitro maturation of oocyte and determination of its effects on spindle size and shape. methods: pre-mature mice were primed with pregnant mare stimulating gonadotrophin (pmsg) and germinal vesicle (gv) stage oocytes were obtained 48 h after. the oocytes were cultured in tissue culture medium (...

NIMA is essential for entry into mitosis in Aspergillus nidulans. To examine whether there is a NIMA-like pathway in other eukaryotic cell cycles, we expressed NIMA and its dominant negative mutants in two different eukaryotic systems. In Xenopus oocytes, NIMA induced germinal vesicle breakdown without activating Mos, CDC2, or MAP kinase. In HeLa cells, NIMA induced premature mitotic events wit...

Total inhibition of germinal vesicle breakdown (GVBD) was observed in growing pig oocytes (internal diameter 80, 90 and 100 microns) when they were cultured in a medium conditioned by cumulus oocyte complexes (COCs) of fully grown oocytes. In denuded growing oocytes, only partial inhibition was observed. The inhibitory effect was fully reversible. The addition of heparin (300 IU/ml) could overc...

Hydrogen sulfide (H2S) has been revealed to be a signal molecule with second messenger action in the somatic cells of many tissues, including the reproductive tract. The aim of this study was to address how exogenous H2S acts on the meiotic maturation of porcine oocytes, including key maturation factors such as MPF and MAPK, and cumulus expansion intensity of cumulus-oocyte complexes. We observ...

Taxol, a drug which promotes microtubule assembly, was used to assess the microtubule nucleating activity of pericentriolar material (PCM) in mouse oocytes prevented from undergoing germinal vesicle breakdown (GVBD), compared with oocytes allowed to proceed normally through GVBD and also in nucleate and anucleate oocyte fragments. Both immunofluorescence staining and ultrastructural analysis re...

OBJECTIVE This study was aimed to determine the effects of n-hexane on the maturation of mouse oocytes. METHODS Cell culture was used to observe the maturation of mouse oocytes and CLSM was employed to determine their apoptosis. RESULTS Germinal vesicle breakdown (GVBD) and extrusion of the first polar body in mouse oocytes were significantly inhibited by n-hexane. After fertilization, the ...

During the winter season the full grown Bufo arenarum oocyte shows the metabolic behaviour characteristic of differentiated tissues of the same species. Due to seasonal variations, during the amplexus period, it acquires the metabolic behaviour of the segmenting egg. Short-time-induced ovulations (5-6 h) determine germinal vesicle breakdown immediately before the expulsion of the oocyte, withou...