MicroRNAs (miRNAs) have been improved to regulate oocyte development in a cell- or stage-specific manner. In this study, we aimed to clarify microRNA-224's (miR-224) role in cumulus cells (CCs), to find out whether a change level of miR-224 in CCs could influence the maturation of oocyte. We found that overexpression of miR-224 of CCs led to the impairment of cell expansion, along with a decrea...

The authors sought to determine whether developmental differences in the magnitude of embryonic mortality caused by heat stress in vivo are caused by changes in resistance of embryos to elevated temperature. In this regard, responses of oocytes, two-cell embryos, four-to eight-cell embryos, and compacted morulae to heat shock were compared. An additional goal was to define further the role of c...

The efficacy of various culture systems was studied for the development of in-vitro produced Caprine embryos . For this purpose, 2 to 4 cell stage caprine embryos matured and fertilized under in vitro conditions were cultured with four culture systems (cumulus cell monolayers, oviductal cell monolayers, chick embryo and rabbit peritoneal fluid) and a control system (TCM-199 + FCS) for about 5 d...

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 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...

Intracellular communication between the cumulus cell complex and the oocyte is essential for numerous processes during oocyte maturation. The aim of this study was to determine the interaction between oocyte-secreted factors and the metabolic activity of bovine cumulus cell complexes during in vitro maturation (IVM). Cumulus-oocyte complexes (COCs) were aspirated from ovaries derived from an ab...

Background: Fertilization is a multistep process requiring spermatozoa with unique cellular structures and numerous germ cell-specific molecules that function in the various steps. In the highly coordinated process of male germ cell development, RNA splicing and polyadenylation help regulate gene expression to ensure formation of functional spermatozoa. Male germ cells express tauCstF-64 (Cstf2...

Background: It is important to protect oocytes and embryos from oxidative stress in the culture medium. Melatonin has been shown to be a direct free radical scavenger. Therefore, effect of melatonin during in vitro oocyte maturation (IVM), fertilization and embryo development of mouse oocytes was evaluated. Materials and Methods: Oocytes from supper-ovulated mouse were divided to two groups: cu...

The serpin peptidase inhibitor, clade E, member 2 (SERPINE2) inhibits urokinase-type plasminogen activator (PLAU) and tissue-type plasminogen activator. Higher SERPINE2 expression levels were detected in cumulus cells of human immature oocytes than in those of mature oocytes. The objective of this study was to evaluate whether high SERPINE2 levels in cumulus cells are associated with oocyte imm...