Electron microscope examination of thin sections of bullfrog (Rana catesbeiana) ovarian oocytes has shown the presence of mitochondria containing yolk-crystal inclusions in oocytes of all sizes, from 160 to 1500 μ mean diameter . The hexagonally shaped yolk-crystals have major periodicities of 73 .8 f 10.7 A (n = 100) . Several forms of modified mitochondria, observed in the smaller oocytes, ma...

A protein responsible for enhanced transcription by RNA polymerase III was identified in extracts from Xenopus oocytes. This protein, called EP3, interacts with a specific DNA sequence adjacent to the 3'-end of a Xenopus somatic 5S RNA gene and forms a distinct band shift complex with a unique DNase I footprint. Enhanced transcription was observed from both 5S RNA and tRNA reporter genes when E...

OBJECTIVE Lower pregnancy rates of in vitro matured oocytes compared to those of in vivo stimulated cycles indicate that optimization of in vitro maturation (IVM) remains a challenge. Reduced developmental competence of in vitro matured oocytes shows that current culture systems for oocyte maturation do not adequately support nuclear and/or cytoplasmic maturation. Therefore this study evaluates...

The par genes, identified by their role in the establishment of anterior-posterior polarity in the Caenorhabditis elegans zygote, subsequently have been shown to regulate cellular polarity in diverse cell types by means of an evolutionarily conserved protein complex including PAR-3, PAR-6, and atypical protein kinase C (aPKC). The Drosophila homologs of par-1, par-3 (bazooka, baz), par-6 (DmPar...

Many studies have shown that cyclic adenosine-5'-monophosphate (cAMP)-dependent protein kinase A (PKA) and G-protein-coupled receptor 3 (GPR3) are crucial for controlling meiotic arrest in oocytes. However, it is unclear how gonadotropins modulate these factors to regulate oocyte maturation, especially by gap junctional communication (GJC). Using an in vitro meiosis-arrested mouse cumulus-oocyt...

The molecular and structural changes in the follicle triggered by the gonadotropin luteinizing hormone (LH) at ovulation require complex interactions between somatic cells and the oocytes. It is well established that the signals originating from the oocytes play an essential role in orchestrating the growth and development of the follicle. Conversely, the exact contribution of local signals in ...

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...