A good understanding of the mechanism oocyte development and maturation, regulatory factors involved therein are important for success a breeding program especially species used in aquaculture. It is crucial females to supply high quality mature oocytes, which generally achieved by fine-tuning meiotic arrest resumption progression. Therefore, knowledge maturation process fundamental methodologi...

Ovary is a dynamic organ and generates excess amount of reactive oxygen species (ROS) during follicular growth, development, maturation and ovulation [1]. The increased level of ROS is scavenged by antioxidant systems [2]. A moderate increase of ROS could be beneficial for oocyte meiotic maturation and reproductive outcome [3-5]. Overproduction of ROS or depletion of enzymatic antioxidant syste...

BACKGROUND Previous studies have reported that follicle-stimulating hormone (FSH) is often added to culture media to induce oocyte meiotic resumption and maturation and to improve subsequent embryonic development during in vitro maturation (IVM). However, the underlying mechanisms remain unclear. METHODS Cumulus-oocyte complexes (COCs) were collected from ovaries 46-48 h after the female mice...

ZFP36L2 protein destabilizes AU-rich element-containing transcripts and has been implicated in female fertility. In the C57BL/6NTac mouse, a mutation in Zfp36l2 that results in the decreased expression of a form of ZFP36L2 in which the 29 N-terminal amino acid residues have been deleted, ΔN-ZFP36L2, leads to fertilized eggs that arrest at the two-cell stage. Interestingly, homozygous ΔN-Zfp36l2...

Although it is established that cAMP accumulation plays a pivotal role in preventing meiotic resumption in mammalian oocytes, the mechanisms controlling cAMP levels in the female gamete have remained elusive. Both production of cAMP via GPCRs/Gs/adenylyl cyclases endogenous to the oocyte as well as diffusion from the somatic compartment through gap junctions have been implicated in maintaining ...

The mechanisms underlying the hormonal stimulation of meiotic maturation are not understood. The most prevalent hypothesis is that hormone-induced maturation is stimulated by an increase in the intracellular messengers, cAMP or Ca2+. This study investigated whether Ca2+ transients in somatic cells can lead to Ca2+ transients in the oocyte, and whether hormones that stimulate meiotic maturation ...

In mammals, oocytes are arrested at the diplotene stage of meiosis I until the pre-ovulatory luteinizing hormone (LH) surge triggers meiotic resumption through the signals in follicular granulosa cells. In this study, we show that the estradiol (E2)-estrogen receptors (ERs) system in follicular granulosa cells has a dominant role in controlling oocyte meiotic resumption in mammals. We found tha...

In vitro maturation (IVM) is being increasingly used to treat human infertility, especially as rescue therapy for patients of polycystic ovarian syndrome and ovarian hyperstimulation syndrome. Quality control and the determination of optimal fertilization conditions—important to increase the use of IVM oocytes for embryo production and improve pregnancy success rates—require a detailed understa...

Between 1989 and 1992 meiotic chromosome studies and synaptonemal complex analyses were evaluated using light and, in part, electron microscopy in 46 infertile males with highly abnormal spermiograms. This examination focused on whether the breakdown of spermatogenesis could be attributed to pairing anomalies of bivalents. The study of meiotic chromosomes and synaptonemal complexes indicated no...

Regulation of maturation in meiotically competent mammalian oocytes is a complex process involving the carefully coordinated exchange of signals between the somatic and germ cell compartments of the ovarian follicle via paracrine and cell-cell coupling pathways. This review highlights recent advances in our understanding of how such signaling controls both meiotic arrest and gonadotropin-trigge...