The general aim of our in vitro experiments was to study the role of the metabolic hormones leptin, ghrelin, obestatin and IGF-I and mitogen-activated protein kinase (MAPK)-dependent intracellular mechanisms in the control of nuclear maturation of porcine oocytes. For this purpose, porcine oocytes were isolated from the ovary and cultured in the presence of leptin, ghrelin, obestatin, IGF-I, MA...

Background: Polycystic ovary syndrome (PCOS) is a frustrating experience for women, considered as a complex challenge for researchers and clinicians. Despite the enormous effort to define the cause of PCOS, the etiology and pathogenesis still remain unclear. Oocyte quality is reflected in the oocyte’s intrinsic developmental potential. Studies have shown that the follicular development is disru...

The cryopreservation of female gametes is still an open problem because of their structural sensitivity to the cooling-and-freezing process and to the exposure to cryoprotectants. The present work was aimed to study the effect of vitrification on immature bovine oocytes freed of cumulus cell investment before freezing. To verify the feasibility and efficiency of denuded oocyte (DO) cryopreserva...

A morphological classification of the immature cumulus-oocyte complex (COC), which grossly resembled the atresia grade of its follicle source, was used in bovine oocytes to determine 1) the developmental potential by either in vitro fertilization or parthenogenetic activation, 2) the calcium current activity by whole-cell voltage clamp technique, and 3) the intracytoplasmic calcium stores by mi...

OBJECTIVE We found previously that interferon regulatory factor (Irf)-1 is a germinal vesicle (GV)-selective gene that highly expressed in GV as compared to metaphase II oocytes. To our knowledge, the function of Irf-1 in oocytes has yet to be examined. The present study was conducted to determine the relationship between retinoic acid (RA) and RA-mediated expression of Irf-1 and the mouse oocy...

This report describes a live birth produced from repeat vitrification and thawing of blastocysts derived from in-vitro matured (IVM) oocytes in a woman with polycystic ovarian syndrome. Immature oocyte retrieval was performed on day 12 of her induced menstrual cycle. The patient was administered 10,000 IU of human chorionic gonadotrophin s. c. 36 h before immature oocyte retrieval. A total of 4...

background: in vitro maturation (ivm) is a promising treatment option for certain infertile women. nowadays, with the aid of polscope, it has become possible to evaluate zona pellucida (zp) characteristics as a parameter of oocyte quality. moreover, quality of oocytes can be influenced by many factors, such as patient’s age. the polscope system is a non-invasive technique to assess birefringent...

The CD44 family belongs to a larger group of hyaluronic acid-binding proteins and plays important roles in oocyte maturation, fertilization and preimplantational embryo development. We analyzed the CD44 receptor in sheep oocytes and embryos. Immature oocytes (N = 66) were obtained from a local abattoir; mature oocytes (N = 35) and embryos (N = 41) were obtained by laparotomy from adult hai...

Background: Oocyte in vitro maturation success rate is still low in compareision to oocyte in vivo maturation. Thus prediction and improvement of oocyte competency are two critical issues in assisted reproductive technology. New insights into oocyte-cumulus cell regulatory loop may assist our optimization of in vitro maturation technique. Maturation and developmental competency of cumulus oocyt...