Background: The efficiency of in vitro maturation (IVM) has remained low despite extensive effort to understand the culture conditions. This study investigated the effect of cumulus cells and meiotic inhibitors on oocyte developmental competence in the presence of Alpha Lipoic acid (ALA) Materials and Methods: Mouse germinal vesicle oocytes were considered in cumulus-denuded oocytes (CDOs) and ...

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) ...

Reproductive biotechnology such as in vitro fertilization, the creation of transgenic animals or cloning by nuclear transfer depends on the use of fully grown, meiotically competent oocytes capable of completing meiotic maturation by reaching the stage of metaphase II. However, there exists only a limited quantity of these oocytes in the ovaries of females. In view of their limited number, grow...

In mouse oocytes, meiotic induction by pharmacological activation of PRKA (adenosine monophosphate-activated protein kinase; formerly known as AMPK) or by hormones depends on stimulation of fatty acid oxidation (FAO). PRKA stimulates FAO by phosphorylating and inactivating acetyl CoA carboxylase (ACAC; formerly ACC), leading to decreased malonyl CoA levels and augmenting fatty-acid transport in...

Pesticides can significantly harm reproduction in animals and people. Pyrethroids are often used as insecticides, and their toxicity for mammals is considered to be low. However, cypermethrin, deltamethrin and fenvalerate - as potent specific inhibitors of protein phosphatase calcineurin - can influence the meiosis of mammalian oocytes. The objective of this study was to evaluate the effects of...

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

a cytogenetical study on 13 alfalfa (medicago sativa) cultivars available in iranian forest and rangelands genebank was performed in order to obtain basic information on the variability in chiasma frequency/distribution, chromosome association and segregation. such cytogenetic information is useful for planning hybridization programs. cluster analysis of meiotic data and ordination of cultivars...

During meiosis, the formation of crossovers (COs) generates genetic variation and provides physical links that are essential for accurate chromosome segregation. COs occur in the context of a proteinaceous chromosome axis. The transcriptomes and proteomes of anthers and meiocytes comprise several thousand genes and proteins, but because of the level of complexity relatively few have been functi...

Meiotic cohesin serves in sister chromatid linkage and DNA repair until its subunit Rec8 is cleaved by separase. Separase is activated when its inhibitor, securin, is polyubiquitinated by the Cdc20 regulated anaphase-promoting complex (APC(Cdc20)) and consequently degraded. Differently regulated APCs (APC(Cdh1), APC(Ama1)) have not been implicated in securin degradation at meiosis I. We show th...