Background: Leptin, the product of the obesity (ob) gene, acts as a signaling adipokine for modulating food intake, energy metabolism and reproductive functions in mammals. Leptin’s effects on the reproductive system at various levels of the hypothalamic-pituitary-gonadal axis have been established. Moreover, the direct and local effect of leptin on bovine oocyte maturation and corpus luteum fu...

background: ammonium is produced in culture medium due to amino acids degradation and has adverse effect on in vitro culture of embryo. in the current study, the purpose was to evaluate the effects of ammuniom chloride (ac) on in vitro oocyte maturation rate and early embryo development in the sheep and its effect on the expression of bcl-2. methods: in vitro maturation (ivm) was performed in t...

BACKGROUND Ammonium is produced in culture medium due to amino acids degradation and has adverse effect on in vitro culture of embryo. In the current study, the purpose was to evaluate the effects of ammuniom chloride (AC) on in vitro oocyte maturation rate and early embryo development in the sheep and its effect on the expression of Bcl-2. METHODS In vitro maturation (IVM) was performed in t...

The present study investigated whether supplementation with different doses of cerium dioxide nanoparticles (CeO2 NPs) during in vitro maturation (IVM) of prepubertal ovine oocytes influenced their embryonic development in vitro. Cumulus-oocyte complexes derived from the ovaries of slaughtered prepubertal sheep underwent IVM with CeO2NPs (0, 44, 88 or 220µg mL-1). Matured oocytes were fertilise...

Oocyte cryopreservation has encompassed various technical difficulties and thus remained a challenge to many cryobiologists. The effect of three widely used cryoprotectants and two cryopreservation techniques on the post thaw recovery rate of morphologically normal sheep oocyte, their fertilizability and developmental competence were analyzed. Ethylene glycol, propylene glycol and Dimethyl Sulf...

Mitochondrial DNA is an extranuclear genome normally maternally inherited through the oocyte. However, the use of nuclear transfer can result in both donor cell and recipient oocyte mitochondrial DNA persisting through to blastocyst and being transmitted to the offspring. The degree of donor mitochondrial DNA transmission appears to be random and currently no evidence exists to explain this phe...

This paper reviews two recent developments in the field of assisted reproduction: in-vitro culture (IVC) of follicles and in-vitro maturation (IVM) of oocytes. Both in-vitro procedures for oocytes and immature follicles were developed so as to enable storage of ovarian cortical tissue and oocyte-cumulus complexes (OCC) from small follicles. Until now, complete in-vitro development from a primor...

OBJECTIVE To evaluate DNA fragmentation in the oocyte of primordial and primary follicles and morphology of these follicles after freezing and thawing of ovarian cortex in sheep using two freezing protocols. DESIGN Fragmentation of DNA was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) technique. SETTING Fertility clinic in a large univ...

Nuclear transfer that involves the transfer of the nucleus from a donor cell into an oocyte or early embryo from which the chromosomes have been removed was considered first as a means of assessing changes during development in the ability of the nucleus to control development. In mammals, development of embryos produced by nuclear transfer depends upon coordination of the cell cycles of donor ...

The cross-talk between oocyte and somatic cells plays a crucial role in the regulation of follicular development and oocyte maturation. As a result, granulosa cell apoptosis causes follicular atresia. In this study, sheep granulosa cells were cultured under thermal stress to induce apoptosis, and melatonin (MT) was examined to evaluate its potential effects on heat-induced granulosa cell injury...