Background Polycystic ovarian syndrome (PCOs) is one of the most common causes of infertility in women of reproductive age. Currently, one of the best therapeutic options for PCOs patients is ICSI. Moreover, IVM can be a useful technique for women with PCOs who are at the risk of ovarian hyperstimulation syndrome (OHSS). On the other hand, the oocyte quality can be a determining factor for outc...

Actin microfilaments and mitochondria distribution are considered useful markers of cytoplasmic maturation, but no information is available regarding their distribution in cat oocytes and embryos. Thus, the purpose of this study was to (i) assess cytoplasmic characteristics of the oocyte by mitochondria and actin staining in immature and in vitro/in vivo matured cat oocytes and (ii) characteriz...

MicroRNAs can promote translation of specific mRNAs in quiescent (G0) mammalian cells and immature Xenopus laevis oocytes. We report that microRNA-mediated upregulation of target mRNAs in oocytes is dependent on nuclear entry of the microRNA; cytoplasmically-injected microRNA repress target mRNAs. Components of the activation microRNP, AGO, FXR1 (FXR1-iso-a) and miR16 are present in the nucleus...

The objective of the research was to evaluate effect vitrification temperatures (VTs) and concentration cryoprotective agents (CPAs) on cytoskeleton bovine immature oocytes (BIOs). Bovine cumulus oocyte complexes (COCs) were collected divided randomly into five groups: (a) fresh control group, (b) vitrified in liquid helium (LHe; −269◦C with 5.6 M CPAs, (c) LHe (−269◦C 6.6 (d) nitrogen (LN; −19...

The oocyte is a remarkable haploid cell that carries all the information needed to undergo a complex maturation process to become a fertilizable egg and possesses the ability to initiate the early stages of development after fertilization. During the period of oocyte growth, mRNAs are synthesized and stored, and these mRNAs are very stable at this time, with a half-life of approximately 12 days...

BACKGROUND Approximately 20% of recovered oocytes are immature and discarded in intracytoplasmic sperm injection (ICSI) procedures. These oocytes represent a potential resource for both clinical and basic science application. OBJECTIVE The aim of this study was to evaluate the ultrastructure architecture of in vitro matured human oocytes using transmission electron microscopy (TEM). MATERIA...

In vitro fertilization, one of assisted reproduction`s technique is, for some couples, the only possibility to conceive a child. One of the main condition that must be fulfield in order to reach this goal is the quality of human oocytes. The ovarian stimulation protocols used have as an important goal the oocytes quality. The maturity grade of the oocytes is a good indicator of their quality.Th...

Protein kinase C (PKC) is involved in gonadotrophin-induced oocyte maturation. In the present study, we investigated the role of specific PKC isoforms in the process of follicle-stimulating hormone (FSH)-induced oocyte meiotic resumption. Small antral follicles (200-300 µm in diameter) were isolated from immature mice and cultured in vitro. FSH significantly induced follicle-enclosed oocytes (F...

An option for fertility preservation for women facing a cancer diagnosis involves the cryopreservation of ovarian tissue for later re-transplantation or in vitro culture, with in vitro culture preferred to avoid reintroduction of the cancer. Small, immature follicles survive the freeze-thaw process, and can be matured through in follicle maturation (IFM) that involves an initial growth of the f...

background: in vitro maturation (ivm) of immature oocytes collected from ovary has been proposed for fertility preservation. in addition, quality of oocytes post ivm is one of the factors determining its developmental competence. by using the non-invasive polscope system, both meiotic spindle (ms) and zona pellucida (zp) can be assessed in living oocytes. objective: the aim was to investigate t...