The aim of the present study was to investigate the effect of follicle stimulating hormone (FSH) on survival, activation and growth of ovine primordial follicles using histological studies. Pieces of ovine ovarian cortex were obtained and cultured for 6 days in Minimum Essential Medium supplemented with or without FSH (50 ng/mL). These fragments were then process to be used for histology compar...

Background: The developmental competence of oocytes matured in vitro (IVM) is yet far below than in vivo counterparts. Recent studies suggest that the asynchrony between nuclear/cytoplasmic maturation and the initial low/heterogeneous quality of oocytes are the most important factors affecting IVM success. We investigated whether selection of growing oocytes (based on their glucose 6- phosphate...

Heat shock may affect different aspects of oocyte maturation and its subsequent development to the blastocyst stage. A series of in vitro experiments was performed to determine whether physiologically heat shock (41°C) disrupts the progression of the ovine oocytes through meiosis, activation and blastocyst formation. Cumulus-oocyte complexes (COCs) were aspirated from 2-6-mm follicles and cultu...

Background: Different culture media are used for in vitro maturation of ovine oocyte. The Weymouth medium are used for in vitro maturation of rat and mice oocytes with very low levels of supplementation (Just FBS, while to acquire the good results in TCM hormone, and serum supplementation and in some cases growth factor are necessary to gain the optimized results. The aim of the present study w...

BACKGROUND Leptin, as a 16 kDa adipokine, is a pleiotropic cytokine-like hormone that primarily secreted from adipose tissue. It also involves in the regulation of energy homeostasis, neuroendocrine function, immunity, lipid and glucose homeostasis, fatty acid oxidation, angiogenesis, puberty and reproduction. The aim of this study was to investigate the effects of in vitro addition of leptin t...

Background: This study was designed to respond to the controversy regarding the necessity of oocyte activation after the ICSI procedure for normal embryo development in sheep. Materials and Methods: The effect of chemical stimulation with either 5mM ionomycin (I) for 5 minutes or ionomycin + 2 mM 6-dimethylaminopurine (6-DMAP) for 3 hours on the efficiency of ICSI, was compared in six experimen...

Oocyte polarity and embryonic patterning are well-established features of development in lower species. Whether a similar form of pre-patterning exists in mammals is currently under hot debate in mice. This study investigated this issue for the first time in ovine as a large mammal model. Microsurgical trisection of unfertilized MII-oocytes revealed that cortical cytoplasm around spindle (S) co...

Background: Recent studies have revealed that oocyte competence can be assessed through the presence of the glucose-6-phosphate dehydrogenase (G6PDH) enzyme, as indicated by brilliant cresyl blue (BCB), a dye that can be degraded by G6PDH. In the present study, we aimed to examine the validity of BCB test to select developmentally competent oocyte in ovine and its association with stage-specifi...

Background: In vitro maturation is a good method to decrease cancer risk of superovulation by gonadotropin hormones. A paracrine effect of oocyte secretions on oocyte developmental competence is under investigation. Apart from oocyte maturation, ovulation in vivo requires a precise control of extracellular matrix modification. Cumulus cells secrete hyaluronan to form a muco-elastic extracellula...