The mechanisms and aetiology underlying the development of premature ovarian insufficiency (POI) are poorly understood. However, oocyte clearly has a role as demonstrated by Double Mutant (DM) mouse model where dysfunction (6 weeks) is followed POI (3 months) due to oocyte-specific deletion complex hybrid N- O-glycans. ovaries DM mice contain more primary follicles (3a stage) accompanied fewer ...

In mammalian ovaries, a fixed population of primordial follicles forms during the perinatal stage and the oocytes contained within are arrested at the dictyate stage of meiotic prophase I. In the current study, we provide evidence that the level of cyclic AMP (cAMP) in oocytes regulates oocyte meiotic prophase I and primordial folliculogenesis in the perinatal mouse ovary. Our results show that...

Txndc9 (thioredoxin domain containing protein 9) has been shown to be involved in mammalian mitosis; however, its function in mammalian oocyte meiosis remains unclear. In this study, we initially found that Txndc9 is expressed during meiotic maturation of mouse oocytes and higher expression of Txndc9 mRNA and protein occurred in germinal vesicle (GV) stage. By using confocal scanning, we observ...

The signaling pathway by which luteinizing hormone (LH) acts on the somatic cells of vertebrate ovarian follicles to stimulate meiotic resumption in the oocyte requires a decrease in cAMP in the oocyte, but how cAMP is decreased is unknown. Activation of Gi family G proteins can lower cAMP by inhibiting adenylate cyclase or stimulating a cyclic nucleotide phosphodiesterase, but we show here tha...

Background: Cryobiology and in vitro maturation of oocytes are very important tools of reproductive technology. Oocyte plays an important role in fertility. The objective of this research is comparison study the effect of invitro maturation and IVF fertilization of cryopreserved oocyte with fresh oocyte in mice. Materials and Methods: For this purpose, after superovulation was performed oocytes...

Background When gonadal sex reversal occurs in mammalian species, the resultant XX males and XY females become infertile or subfertile, suggesting critical roles of sex chromosomes in germ cell differentiation. The objective of our study is to clarify the mechanism of infertility in the B6.YTIR (XY) sex-reversed female mouse, which can be attributed to a failure in the second meiotic division i...

Background:Differentiation of Embryonic Stem Cells into Oocyte-like cells in vitro is challenging. Successful derivation of oocyte from stem cells can provide an alternative source for curing ovogenesis problems. The current study aims to demonstrate a new protocol with two different types of media for differentiating embryonic stem cells (ESCs) into oocyte-like cells ...

background: mammalian oocytes are exposed to a mixture of many different growth factors and cytokines which provides an optimized microenvironment for oocyte maturation. in the lack of this natural microenvironment in vitro the quality of oocyte and embryos appears to be suboptimal. objective: this study was undertaken to investigate the effects of egf and lif on in vitro maturation fertilizati...

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. objective: effect of melatonin during in vitro oocyte maturation, fertilization and embryo development of mouse oocytes was evaluated. materials and methods: oocytes from supper-ovulated mouse were divided to two groups: cumulus ...